Electronic Properties of π-conjugated Materials II - Universität ...

Conference of the DFG Research Training School 1221
at the University of Würzburg
Electronic Properties
of π-conjugated
Materials II
September 27 to 30, 2011
Würzburg Residenz

π 2011
Welcome to the International Conference on
“Electronic Properties of π-conjugated Materials II”
Over the last twenty years π-conjugated molecules have received increasing a�ention owing to
their versatile functions that are demanded for breakthroughs in many interdisciplinary fields like
bio-imaging or plastic electronics. For the la�er field, organic light emi�ing diodes (OLEDs) have
spearheaded the entry of an entirely new class of semiconductors based on organic molecules into
industrial applications. Other devices, such as organic field effect transistors and organic photovoltaic
cells, have not yet reached the same marketability, thus motivating substantial research
programmes by academic and industrial groups. To achieve these aims, the understanding of
the underlying electronic processes for exciton and charge transport and charge separation in
organic materials are of fundamental importance. �is research, however, can only be carried
out successfully in close interdisciplinary interaction between chemists and physicists, encompassing
synthesis, spectroscopy and theory from small molecules via supermolecular aggregates
in solution or on surfaces to the bulk solid: Scientists who are mainly involved in the synthesis
of chromophores for such aggregates need to know how structural modification of the underlying
molecules will eventually affect the electronic material properties, as well as spectroscopy
researchers have to be aware of the synthetic accessibility of certain classes of compounds and
the theoretical basis of their technologically relevant properties. �is is the background of the
research training school GRK1221 Control of Electronic Properties of Aggregated π-conjugated
Molecules of German Science Foundation (DFG), founded in 2006 at the University of Würzburg.
In 2010, the DFG granted a second term of research funding which will last until 2014. Primarily
designed as an interdisciplinary training programme for participating PhD students, the GRK is
focused on basic research as well.
Tying in with the first convention, which took place in 2008, this second international conference
on π-conjugated materials brings together scientists from all over the world working on
various different aspects of the field. With invited talks from leading international experts and
further oral and poster contributions from within the GRK and beyond, we hope that this meeting
will strengthen the interactions between different groups and foster the broad understanding
of the complex issues involved in this research. �e World Heritage Site of Würzburg Residenz,
amidst the beautiful university town and wine growing center Würzburg, provides the se�ing
for this encounter between the different subdisciplines as well as between the experienced and
the younger generation of researchers. We hope that it will be a stimulating and memorable
event for all of us.
Speaker GRK1221
Dean of the Faculty of Bernd Engels Dean of the Faculty of
Chemistry and Pharmacy Physics and Astronomy
Ulrike Holzgrabe Organizing Committee �omas Trefzger
Volker Engel
Christoph Lambert
Bernd Engels
Alexander Schubert
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π 2011
Edited by Christoph Brüning, Alexander Schubert and Johannes Wehner for DFG research training
school 1221 at the University of Würzburg.
Photo on title page courtesy of Sebastian Piszczan, sebbo-media.de
Other photos by Organizing Commi�ee, University of Würzburg and Würzburg Tourist Information.
Printed by Popp & Seubert GmbH, Würzburg
All rights reserved.
V. i. S. d. P.: Bernd Engels
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer-Str. 42
97074 Würzburg
A PDF file of this document can be downloaded from the GRK website at
http://www.gk-1221.uni-wuerzburg.de/pi2011
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π 2011 Contents
Contents
General Information 7
Würzburg – History, Points of Interest, Art and Cultural Events . . . . . . . . . 7
Universtity of Würzburg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Conference Venue and Scientific Programme . . . . . . . . . . . . . . . . . . . . 14
Invited Lectures 21
Oral Presentations 43
Posters 69
First Session . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Second Session . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
List of Participants 199
Glossary 208
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π 2011
General Information
Würzburg – History, Points of Interest, Art and Cultural Events
General Information
Würzburg – a town for looking and browsing, a historical and arthistorical picture-book with
various views, but at the same time a jigsaw-puzzle of a joy of living, an art to live, cultural flair
and Franconian way of life.
Marienberg fortress. Foto: �omas Huth.
Würzburg started its history as a celtic shelter (around 1000 BC) and a Franconian duchy (650
AD) on the hill known today as Marienberg, which gave shelter to a se�lement of fishermen in
early times. In 689, the Irish missionaries Kilian, Kolonat and Totnan suffered a martyr’s death
here in Würzburg. Since the foundation on the bishopry in 742, Würzburg has been the clerical
center of the area, with Charlemagne taking part in the consecration of the cathedral in 788. �e
privilege of holding a market dates back to 1030 when the king’s town became the town of the
bishop. In 1156, Frederic Barbarossa was married to Beatrice of Burgundy here in Würzburg. He
also confirmed the duchy to the bishops of Würzburg in 1168. In 1397, King Wencelas promised
imperial immediacy, but was never able to keep this promise. During the Peasant’s Revolt in 1525,
the town sided with the peasants, who tried to storm the fortress, but failed. �is sealed the fate of
Würzburg’s famous woodcarver, alderman and mayor, Tilman Riemenschneider, who died here
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in 1531 a poor and broken man. In the following decades strong clerico-worldly sovereigns ruled
the town, among them prince-bishop Julius Echter of Mespelbrunn, who founded the Juliusspital
in 1576 and the second university of Würzburg in 1582. �ere, at the institute of physics, would
Wilhelm Conrad Röntgen discover the X-Rays in 1895. �e town reached its zenith under the
leadership of the artloving family of Schönborn. For them, the architect Balthasar Neumann built
the “castle of castles” – the Residenz – between 1719 and 1744 including the famous staircase,
where the Venetian artist Giovanni Ba�ista Tiepolo created the world’s largest ceiling fresco.
A�er various political quarrels, Würzburg finally became Bavarian in 1814. On March 16, 1945 the
town was almost completely destroyed within 17 minutes in an air raid. It owes its reconstruction
to the enormous commitment of the inhabitants.
Prince’s Garden at Marienberg fortress. Foto: Andreas Bestle.
Today, Würzburg has 134 000 inhabitants. �e town, not only in the center of Germany, but also
in the heart of Europe, has perfect traffic connections. Several highway exits close to the city
connect it to a variety of routes in any direction. About 300 trains, among them 112 intercity
high-speed trains stop over at Würzburg’s main station every day. �e airports of Nürnberg
and Frankfurt are within reach in less than 2 hours without switching trains. �e high-speed
railway line between Hannover and Würzburg adds a special treat to the possibilities of reaching
Würzburg by train. Flourishing river traffic on the river completes the picture.
Würzburg is a town of tourism and conventions, and it has acquired a unique profile within
German tourism. �e best way to learn about Würzburgs points of interest is to follow the route
that leads from the “Residenz”, Balthasar Neumann’s masterpiece (including Tiepolos famous
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Würzburg Residenz. Foto: CTW.
General Information
frescoes, the court chapel and the court garden) and the former home of the prince-bishops, to
the fortress Marienberg. �is path covers St. Kilian’s cathedral, the Neumünster church with the
grave site of medieval poet Walther von der Vogelweide, the market square with the splendid
ensemble of the chapel of St. Mary and the “House of the Falcon”, a combination of Rococo and
gothic style, and last but surely not least the city hall including the Grafeneckart, the Fountain
of the Four rivers and the Old Main Bridge. From here, one can see St. Burkard’s church and the
pilgrimage church Käppele; looking down the river there is the Old Crane, the convention center
and finally the vineyard “Würzburger Stein”. Up the fortress hill, accessible for a pedestrian from
the western side or – in summer – by bus, the “Mainfränkisches Museum” hosts, among other
interesting collections, a huge selection of Riemenschneider’s works. �e church of St. Mary,
the Renaissance well-temple and the fortress tower catch the eye of a visitor participating in a
convention at the “Hofstuben” (400 persons) inside the Marienberg fortress, thus offering a strong
contrast to the newly built “Congress Centrum” downtown.
As yet, not all interesting sights have been mentioned. Many profane and clerical buildings, such
as Sti� Haug with its Tintore�o, or the Old University church with its impressive Renaissance
tower, Augustiner- and Franciscan church, St. Peter, St. Stephan, St. Johannis and many more
buildings are within easy reach, and especially the a�ractive court yards and the famous “Bürgerspital
zum Hl. Geist”, founded in 1319, and the “Juliusspital”, founded in 1576, where many a
bo�le of franconian wine, mild or dry, have been sampled and will be sampled again over the
years. In addition, a lot of wine cellars, the most imposing being the cellar beneath the Residenz,
winehouses and restaurants with a lot of local flair proudly represent Franconian hospitality,
and about 60 lodging enterprises from simple guesthouses up to hotels of international standard
provide more than 4.000 beds all together. �e university and shopping town of Würzburg offers
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�e bridge “Alte Mainbrücke” was erected from 1473 to 1543 in place
of an old Romanesque bridge. Foto: CTW.
an interesting variety of cultural programmes althrough the year; museums and galleries cater
for various exhibitions and the theatre offers first class performances and concerts. Wine tasting
sessions, wine- and beer-festivals as well as short trips by boat or coach complete the agenda
for the tourist. Among the largest traditional events are the “Africa Festival” in May and the
“Mozartfest” in June with more than 35 000 visitors per year.
Further information
Congress – Tourismus – Wirtscha� (Tourist Office)
Am Congress Centrum, 97070 Würzburg
Phone: +49 931 37 23 35
Fax: +49 931 37 36 52
Internet: h�p//www.wuerzburg.de
E-Mail: tourismus@wuerzburg.de
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π 2011
Universtity of Würzburg
Past and Recent History
General Information
�e University of Würzburg was founded in 1402 by Prince Bishop Johann von Egloffstein, making
it the oldest university in today’s Bavaria and the sixth oldest in a German-speaking world.
Reconfirmed by papal and imperial decrees under Prince Bishop Julius Echter von Mespelbrunn
in 1582, it has since developed a long tradition of successful science and research. Numerous
famous scientists and scholars, including 14 Nobel prize laureates, have worked and taught here.
Among them are Rudolf Virchow, Carl Siebold, Franz Brentano, the physicists Wilhelm Conrad
Röntgen, who discovered the “X-rays” here in 1895, and Klaus von Klitzing, discoverer of the
quantised Hall effect and laureate in 1985. �e most recent one is Harald zur Hausen, who was
awarded the Nobel prize in Medicine in 2008.
In 1895, the physicist Wilhelm Conrad Röntgen discovered the X-rays in Würzburg.
Immediately a�er the end of World War II, the reconstruction of the University was embarked
upon, a�er it had been almost completely destroyed in the air raid on March 16. Since its completion
in the 1960s, there has been a continuous extension of university sites which is still being
carried out today. As a result, a modern campus, “Am Hubland”, has come into being. It is situated
on one of the hills at the outskirts of Würzburg and offers a magnificent view of the city and
its surrounding vineyards. �e University Library, a large refectory and brand-new university
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General Information π 2011
sports facilities are to be found here as well as a state-of-the-art microstructure laboratory and
the Biozentrum, equipped with the latest biological technology.
�e “Hubland”, however, is not the only place of the university’s expansion and development:
In the urban district of Grombühl, for example, where the university hospital is situated, an
extensive new surgical complex (ZOM) and a modern centre for internal medicine (ZIM) were
opened in 2008 and 2009. �ey are run by the Faculty of Medicine and are closely cooperating
with the 22 specialised clinics of the city’s teaching hospital, where approximately 50 000 people
receive inpatient treatment each year.
Campus Hubland, including sciences, philosophic faculty, main library and cafeteria. On the
bo�om right side, there is the center of chemistry with the pharmacy and food chemistry building;
on the top edge, there is the building of theoretical chemistry on the new “Campus Hubland
Nord”.
�e newest site is the “Campus Hubland Nord” which was established in April 2011. A�er US
Army had abandoned their “Leighton Barracks” facilities situated right next to the Hubland campus
and had handed over the area to German civil administration in 2008, a part of the site was
turned over to the University. Today, the new campus offers a student’s residential hall, office
space – especially for researchers in theoretical natural sciences – seminar rooms, computer pools
and libraries. Lots of new facilities for research and study, however, are about to emerge in the
next couple of years, making that area another vital place of university life.
Having been closely linked to the history of the city for centuries, the Julius-Maximilians Universität
has become an essential part of its cultural life and an important factor in the local economy.
A Service Centre for Research and Innovation at the University has therefore been set up in order
to ensure the legal protection and the application of inventions and the results of research.
Another important task of this office is to introduce local firms and companies to partners of the
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π 2011
General Information
University with whom they can enter into a cooperation, and to provide them with information
about the latest technology developed in the University’s laboratories, along with the achievements
and potential of the University in general. With its numerous special research projects,
research training schools, research groups and research centres focussing on various areas of the
natural sciences and the arts, the University of Würzburg is one of the most successful universities
in Germany today.
�e University regularly holds a series of public lectures and organises open days for prospective
students. It also stages concerts and organises exhibitions – most of them in its own university
museum. �roughout the year, these events and a large variety of cultural and recreational
activities such as theatre, music, open air concerts, and wine festivals offered by the city, turn
Würzburg and its university into a highly a�ractive place to live and work.
Facts and Figures
Some 22,000 students including 1,600 internationals are enrolled at ten faculties, which can be
classified into four main categories: Humanities, Law and Economics, LifeSciences and Science
and Technology. Of the 10,000 people employed by the University, 3,000 are academic staff, 400 of
whom are professors. �e University of Würzburg maintains partnerships with 37 universities
in many countries in western and eastern Europe as well as overseas.
�e university building at Sanderring in the city center.
�e University offers degree courses in all subjects leading to university and/or state examinations.
�e traditional State Examination is required for Medicine, Dentistry, Pharmacy, Law,
and Teacher Training for all categories of schools. New Bachelor and Master degrees have been
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General Information π 2011
introduced in nearly all other subjects of study, replacing the traditional Diploma or Magister degrees.
For postgraduates, it offers a number of special courses and degrees, e. g. MBA in Business
Integration, M. A. in German for non-native speakers, LL. M. Eur. in European Law, Licentiate in
Roman Catholic �eology, and, of course, PhD studies in any subject taught.
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Conference Venue and Scientific Programme
Free Wi-Fi
During the whole conference free Wi-Fi is provided in all conference rooms.
To connect to an access point open your browser and call up an arbitrary website.
You will be forwarded to a login screen. As a member of the University
of Würzburg please use your individual Novell username and password.
All guests are invited to connect via
A������
17:00 - 20:00 Registration
18:00 - Welcome event
Tuesday, September 27
username: pi2011
password: pi2011

π 2011
General Information
15
Schedule

General Information π 2011
16
Wednesday, September 28
08:30 - 09:00 Bernd Engels
Welcome and opening remarks by Prof. Dr. Alfred For�el, President of
the University of Würzburg, and Prof. Dr. Ulrike Holzgrabe, Dean of the
Faculty of Chemistry and Pharmacy
Chairman: Frank Würthner
09:00 - 09:45 I-1 Mi�ael R. Wasielewski
Self-Assembled Organic Nanostructures for Solar Energy Conversion
09:45 - 10:30 I-2 Karl Leo
Small-molecule organic devices: status and perspectives
10:30 - 11:00 ������ �����
Chairman: Anke Krueger
11:00 - 11:45 I-3 Eii�i Nakamura
Organic Photovoltaics Resear� Guided by New Reactions and New
Molecules
11:45 - 12:05 O-1 Jörg Tat�en
Optical Transitions and Excitonic Coupling in a Covalently linked Spiroindolone
Bi�romophore
12:05 - 12:25 O-2 Fabrizia Negri
Modeling electronic and �arge transport properties of ambipolar and ntype
organic semiconductors
12:25 - 15:00 L����
Chairman: Ingo Fischer
15:00 - 15:20 O-3 �omas Bas�é
Electronic coupling in molecular dimers: Single molecule studies and
quantum �emical calculations
15:20 - 15:40 O-4 Andreas Köhn
�antum-�emical contributions to the understanding of triplet excitons
15:40 - 16:00 O-5 Matthias Stolte
Ambient Stable Solution-processed n-Channel Organic �in Film Transistors
Based on Di�lorinated Naphthalene Diimides

π 2011
16:00 - 16:30 ������ �����
Chairman: Martin Kaupp
General Information
16:30 - 16:50 O-6 Daniela Gamon
Synthesis, Coordination and Reduction of novel Borole-Derivates
16:50 - 17:10 O-7 Tatjana �ast
Light-induced �arge transfer in two-dimensional and polymeric neutral
organic mixed-valence compounds
17:10 - 17:30 O-8 Manuel Renz
How to perform quantum �emical calculations on organic mixed-valence
systems
17:30 - 19:30 Poster session I
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Schedule

General Information π 2011
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Chairman: Achim Schöll
�ursday, September 29
09:00 - 09:45 I-4 Jean-Luc Brédas
Electronic and Optical Processes in Organic Semiconductors: �e Case of
Organic Solar Cells
09:45 - 10:30 I-5 Nobuo Ueno
Study of electrical conductivity of organic semiconductor by UPS: Charge
delocalization, hopping and impacts of invisible band-gap states
10:30 - 11:00 ������ �����
Chairman: Christoph Lambert
11:00 - 11:45 I-6 Frank C. Spano
J- and H-aggregate Behavior in Conjugated Polymers
11:45 - 12:05 O-9 Bernd Engels
New Insights into Exciton Trapping in Organic Photo Voltaics
12:05 - 12:25 O-10 Ingo Fis�er
Spectroscopy of Cyclophanes: Investigating model systems for π/πinteractions
12:25 - 15:00 L����
Chairman: Holger Braunschweig
15:00 - 15:45 I-7 Suning Wang
Photo�romic N,C-Chelate Organoboron Compounds
15:45 - 16:05 O-11 Liangfei Tian
A Reliable Supramolecular Method to Self-Assemble Conjugated
Molecules into Well-Defined Nanoscopic Fibrils
16:25 - 19:00 Poster session II
19:30 - Wine tasting

π 2011
Chairman: Tobias Brixner
Friday, September 30
General Information
09:00 - 09:45 I-8 Eric Vauthey
Ultrafast excited-state dynamics of multi�romophoric systems
09:45 - 10:30 I-9 Jennifer P. Ogilvie
Studies of Multi�romophoric Systems by Two-dimensional Electronic
Spectroscopy: Application to the Photosystem II Reaction Center
10:30 - 11:00 ������ �����
Chairman: Tobias Hertel
11:00 - 11:45 I-10 Stefan Grimme
Accurate Density Functionals for Large Molecules
11:45 - 12:05 O-12 Christoph Lambert
Donor-Acceptor Interactions in Multidimensional Boron-Chromophores
12:05 - 12:40 Bernd Engels
Concluding remarks
Departure
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Schedule

π 2011
Invited Lectures
Invited Lectures
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Lectures

Invited Lectures – 1 π 2011
Self-Assembled Organic Nanostructures for Solar Energy
Conversion
Michael R. Wasielewski
Solar Energy Research (ANSER) Center, Northwestern University, Evanston, USA
Natural photosynthesis is carried out by organized assemblies of photofunctional tetrapyrrole
chromophores and catalysts within proteins that provide specifically tailored environments to
optimize solar energy conversion. Artificial photosynthetic systems for practical solar fuels
production must collect light energy, separate charge, and transport charge to catalytic sites
where multi-electron redox processes will occur. While encouraging progress has been made
on each aspect of this complex problem, researchers have not yet developed self-ordering and
self-assembling components as well as the tailored environments necessary to realize a fullyfunctional
artificial system. �e primary goal of our research in this field is to understand the
fundamental principles needed to develop integrated artificial photosynthetic systems. �ese
principles include how to promote and control: 1) energy capture, charge separation, and longrange
directional energy and charge transport, 2) coupling of separated charges to multi-electron
catalysts for fuel formation, and 3) supramolecular self-assembly for scalable, low-cost processing
from the nanoscale to the macroscale. �e central scientific challenge is to develop small,
functional building blocks, having a minimum number of covalent linkages, which also have the
appropriate molecular recognition properties to facilitate self-assembly of complete, functional
artificial photosynthetic systems. �is lecture will describe our use of ultrafast optical spectroscopy
and time-resolved EPR spectroscopy to understand charge transport in self-assembled
structures for artificial photosynthesis.
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π 2011
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Invited Lectures – 1
23
Lectures

Invited Lectures – 2 π 2011
Small-molecule organic devices: status and perspectives
Karl Leo
Technische Universität Dresden and Fraunhofer-Institut für Photonische Mikrosysteme, Dresden
Organic semiconductors with conjugated electron system are currently intensively investigated
since they offer the possibility for novel flexible, low-cost ubiquitous electronics. Prime examples
are novel devices such as organic light-emi�ing diodes (OLED), and organic solar cells. In this talk
I will discuss recent progress in this field, with a focus on oligomer (small-molecule) devices. Although
organic semiconductors are characterized by mobilities many orders of magnitude below
silicon or GaAs, they allow in certain applications surprisingly efficient devices. For instance,
white OLED have recently achieved very high efficiencies of 90 lm/W [1], significantly higher
than fluorescent tubes, opening the path to a new form of high-efficiency area lighting devices.
For solar cells, efficiencies and lifetimes are still quite low, but have also improved significantly:
Recently, we have achieved solar cells with certified efficiency reaching over 8% on larger area.
I will discuss some of the remaining open issues to bring these devices to broad application.
References
[1] S. Reineke, F. Lindner, G. Schwartz, N. Seidler, K. Walzer, B. Lüssem, Nature 459, 234 (2009)
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π 2011
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Invited Lectures – 2
25
Lectures

Invited Lectures – 3 π 2011
Organic Photovoltaics Research Guided by New Reactions
and New Molecules
Eiichi Nakamura
University of Tokyo, Japan
Natural products have given so much inspirations to chemists, and served for the development of
drugs and biological science. An amazing diversity of molecules are being discovered in nature
and being utilized for drug discovery. Natural products however are not very useful in materials
science, except porphyrin - a crucial molecule in photosynthesis. Our strategy in the field of
organoelectronic research capitalizes on the new classes of organic molecules obtained by newly
invented reactions. �is strategy has proven to generate remarkable array of molecules that
have hitherto not been synthesized and examined in organic electronics research. Examples in
the OPV research will be presented. �e synthesis of new organofullerenes and polycondensed
aromatics and the new device structures based on the new compounds will be discussed.
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π 2011
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Invited Lectures – 3
27
Lectures

Invited Lectures – 4 π 2011
Electronic and Optical Processes in Organic
Semiconductors: The Case of Organic Solar Cells
Jean-Luc Brédas
Georgia Institute of Technology, Atlanta, USA
Our objective in this presentation is two-fold. First, we provide a general overview of the optical
and electronic processes that take place in a solid-state organic solar cell, which we define as a cell
in which the semiconducting materials between the electrodes are organic, be them polymers,
oligomers or small molecules.
We briefly turn our a�ention to: (i) optical absorption and exciton formation; (ii) exciton migration
to the donor-acceptor interface; (iii) exciton dissociation into charge carriers, resulting in
the appearance of holes in the donor and electrons in the acceptor; (iv) charge carrier mobility;
and (v) charge collection at the electrodes,[1-4] see Figure I4.1.
Secondly, we underline the complexity of the processes taking place at the nanoscale at the organic/organic
interface and highlight the balance that needs to be found for the optimization of
materials parameters in terms of photovoltaic performance.
Figure I4.1: Simplified sketch of the electronic and optical processes taking place in an organic
solar cell.
References
[1] B. Kippelen and J. L. Bredas, Energ & Enviromental Science 2, 251 (2009)
[2] J. L. Bredas, J. Norton, J. Cornil and V. Coropceanu, Acc. Chem. Res. 42, 1691 (2009)
[3] C. Risko, M. D. McGehee and J. L. Bredas, Chemical Science 2, 1200 (2011)
[4] D. Beljonne, J. Cornil, L. Muccioli, C. Zannoni, J. L. Bredas and F. Castet, Chem. Mat. 23, 591
(2011)
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π 2011
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Invited Lectures – 4
29
Lectures

Invited Lectures – 5 π 2011
Study of electrical conductivity of organic semiconductor
by UPS: Charge delocalization, hopping and impacts of
invisible band-gap states
Nobuo Ueno
Chiba University, Inage-ku, Japan
We discuss two topics, which are related to quantum mechanical/chemical studies of electrical
conductivity in organic devices by using UV photoelectron spectroscopy (UPS):
(i) Energy band dispersion [1, 2], charge-phonon coupling and polaron [3, 4] for understanding
the charge mobility (µ),
(ii) direct detection of very low density of electronic states in organic HOMO-LUMO gap [5-9].
As the electrical conductivity (σ) is given by σ = n e µ, where n is the carrier concentration and
e the charge, the topic (i) is a direct experimental study of µ in molecular aggregates and in a
molecule, and the topic (ii) is related to study n since n is related to the energy level alignment/the
Fermi level position that must be controlled by unknown and undetectable electronic states in
organic HOMO-LUMO gaps [5, 10]. �e topic (ii) is thus related to elucidation of a well-known
mystery; why the transport types appear depending on molecules without impurity doping, in
other words why the Fermi level undergoes a change between HOMO-LUMO gap. �is might
be originated from a primary deference between organic semiconductors and their inorganic
counter parts.
References
[1] N. Ueno and S. Kera, Prog. Surf. Sci. 83, 490 (2008), review
[2] S. Machida, Y. Nakayama, S. Duhm, Q. Xin, A. Funakoshi, N. Ogawa, S. Kera, N. Ueno and H.
Ishii, Phys. Rev. Le�. 104, 156401 (2010)
[3] S. Kera, H. Yamane and N. Ueno, Prog. Surf. Sci. 84, 135 (2009), Progress Highlight
[4] S. Duhm, Q. Xin, S. Hosoumi, H. Fukagawa, K. Sato, N Ueno and S. Kera, to be published
[5] H. Fukagawa , S. Kera, T. Kataoka, S. Hosoumi , Y. Watanabe, K. Kudo and N. Ueno, Adv.
Mater. 19, 665 (2007)
[6] T. Sueyoshi, H. Fukagawa, M. Ono, S. Kera and N. Ueno, Appl. Phys. Le�. 95, 183303 (2009)
[7] T. Sueyoshi, H. Kakuta, M. Ono, K. Sakamoto, S. Kera and N. Ueno, Appl. Phys. Le�. 96, 093303
(2010)
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π 2011
Invited Lectures – 5
[8] H. Y. Mao, F. Bussolo�i, D. C. Qi, R. Wang, S. Kera, N. Ueno, A. T. S. Wee and W. Chen, Org.
Electronics 12, 534 (2011)
[9] T. Hosokai, H. Machida, S. Kera, A. Gerlach, F. Schreiber and N. Ueno, Phys. Rev. B 83, 195310
(2011)
[10] S. Kera, Y. Yabuuchi, H. Yamane, H. Setoyama, K.K. Okudaira, A. Kahn and N. Ueno, Phys.
Rev. B. 70, 085304 (2004)
N����
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Lectures

Invited Lectures – 6 π 2011
J- and H-aggregate Behavior in Conjugated Polymers
Hajime Yamagata and Frank C. Spano
Temple University, Philadelphia, USA
Understanding how the photophysical properties of conjugated polymer films depend on film
morphology is essential in designing and optimizing devices such as organic solar cells, light
emi�ing diodes, and field-effect transistors. It has been previously shown [1] that poly(3-hexylthiopehene)
π-stacks, the dominant morphology in films spun from solution, can be modeled
as weakly-coupled H-aggregates, successfully accounting for the absorption and photoluminescence
spectral line shapes. Isolated chains of conjugated polymers can also be understood in
terms of ”aggregates” of coupled repeat units. An ideal example is the highly-ordered ”red”
form of the polydiaceteylene (PDA) derivative 3BMCU. Such chains are polymerized in situ from
a monomer crystal with 1B� exciton coherence lengths reaching several microns.[2, 3] �e red
form of 3BMCU is highly emissive, with the PL line shape dominated by the 0−0 transition with
much smaller satellite peaks due to the vinyl and acetyl stretching modes.
Using a Hamiltonian which includes electron-phonon, hole-phonon and exciton-phonon coupling,
and represented in a basis set consisting of Frenkel-like and charge-separated multi-particle
states, the absorption and emission spectra of PDA chains are calculated. �e ratio of the 0 − 0
and 0 − 1 line strengths in the photoluminescence spectrum, I 0−0 /I 0−1 , is shown to provide
direct measures of the 1¹B� exciton coherence length and effective mass. �e calculated temperature
dependence of I 0−0 /I 0−1 scales as T −1/2 , in excellent agreement with experiment.[2] �e
PDA chains are shown to behave remarkably like J-aggregates[4], displaying dominant absorption
and emission 0 − 0 transitions, as well as a T 1/2 scaling of the (superradiant) lifetime[2].
�e emission from interacting PDA chains is determined by a competition between inter-chain
H-like behavior due to Frenkel excitons and intra-chain J-like behavior due to Wannier excitons.
Applications to P3HT and PPV are also discussed.
References
[1] J. Clark, C. Silva, R. H. Friend, and F. C. Spano, Phys. Rev. Le�. 98, 206406 (2007)
[2] R. Lecuiller, J. Berrehar, J. D. Ganiere, C. Lapersonne-Meyer, P. Lavallard, and M. Scho�, Phys.
Rev. B 66, 125205 (2002)
[3] F. Dubin, R. Melet, T. Barisien, R. Grousson, L. Legrand, M. Scho�, and V. Voliotist, Nature
Physics 2, 32-35 (2006)
[4] H. Yamagata and F.C. Spano, J. Chem. Phys. 135, 054906 (2011)
32

π 2011
Invited Lectures – 6
Figure I6.1: �e PL line strength ratio I 0−0 /I 0−1 for a PDA chain with 100 repeat units as a function
of T −1/2 for several values of electron and hole transfer integral, te = th = t.
Also shown (triangles) is the data from Ref.[2], divided by a factor of 1.3 to eliminate
the cubic frequency dependence. Inset shows calculated and measured radiative
lifetimes from [2] as a function of T 1/2 .
N����
33
Lectures

Invited Lectures – 7 π 2011
Photochromic N,C-Chelate Organoboron Compounds
Suning Wang, Yingli Rao, Hazem Amarne, Leanne Chen and Nick Mosey
�een’s University, Kingston, Canada
N,C-chelate organoboron compounds based on phenylpyridyl and derivatives were found recently
to undergo an unusual photoisomerization with a distinctive color change.[1] �is isomerisation
is thermally reversible. To understand this unusual photochromic phenomenon, we
examined the effect of substituents of the phenylpyridyl chelate on the isomerisation process.[2]
We also examined the impact of extended π-conjugation, alternative isomerisation pathways[3]
and polyboryl chromophores[4, 5] on the kinetics and quantum efficiency of photoisomerization.
Furthermore, we investigated the influence of metal chelation. To establish the generality of
this photoisomerization phenomenon for N,C-chelate boron compounds, we extended our investigation
to N,C-chelate systems that contain heterocyclic rings such as thienyl,[2, 6] furyl and
thiazolyl. Our studies showed that the heterocyclic systems display a similar photoisomerization
phenomenon as the phenylpyridyl system does. Recently we have carried out computational
studies on possible photo- and thermal isomerisation pathways. �e details of our investigation
will be presented.
References
[1] Y. L. Rao, H. Amarne, S. B. Zhao, T. M. McCormick, S. Martić, Y. Sun, R. Y. Wang, S. Wang, J.
Am. Chem. Soc. 130, 12898 (2008)
[2] H. Amarne, C. Baik, S. K. Murphy, S. Wang, Chem. Eur. J. 16, 4750 (2010)
[3] C. Baik, Z. M. Hudson, H. Amarne, S. Wang, J. Am. Chem. Soc. 131, 14549 (2009)
[4] C. Baik, S. K. Murphy, S. Wang, Angew. Chem. Intl. Ed. 49, 8224 (2010)
[5] S. K. Murphy, C. Baik, J. S. Lu, S. Wang, Org. Le�. 12, 5266 (2010)
[6] H. Amarne, C. Baik, R. Wang, S. Wang, Organometallics 30, 665 (2011)
34

π 2011
N����
Invited Lectures – 7
35
Lectures

Invited Lectures – 8 π 2011
Ultrafast excited-state dynamics of multichromophoric
systems
Eric Vauthey
University of Geneva
Molecular systems containing several identical chromophoric units have found many types of
applications, from artificial photosynthesis to DNA detection and molecular electronics. We will
present some of our results obtained by ultrafast optical spectroscopy with various multichromophoric
systems going from molecules with two chromophoric units to more complex systems
with up to ten units. We will concentrate on two main processes that can take place in these
arrays: excitation energy hopping and charge transfer. �e first one is common to most systems
and takes place within a few picoseconds. We will show that the dynamics of energy hopping in
a bichromophoric system intercalated into DNA can yield interesting conformational information.[1]
Photoinduced charge separation (CS) between identical chromophoric units is less common and
we will discuss some of our efforts to understand the direction of the charges in such symmetrybreaking
process.[2]
Finally, the excited-state dynamics of multichromophoric systems consisting of eight to ten coresubstituted
naphtahlenediimide (NDI) chromophores covalently a�ached to a p-octiphenyl (POP)
or an oligophenylethynyl (OPE) scaffold will be discussed. It will be shown that in a lipid bilayer,
POP-NDI systems self-organise in a tetrameric architecture allowing photoinduced transmembrane
electron transport.[3] Both POP-NDI and OPE-NDI systems also self-assemble on gold surfaces
resulting to photocurrent generation.[4] All the CS pathways as well as the ensuing charge
recombination (CR) channels have been elucidated.[5, 6] Our investigations reveal that, depending
on the nature of the NDI core-substituents and on the scaffold, as well as on the excitation
wavelength, either symmetry breaking CS between two NDI moieties or CS between the scaffold
and a NDI unit take place. �ese processes result to charge-separated states with different
lifetimes and thus different efficiencies for photocurrent generation. Although very long-lived
charge separation (> ms) was not realised in these systems, this study opens several promising
new avenues for ultrafast CS and slow CR.
36

π 2011
References
Invited Lectures – 8
[1] A. Fürstenberg, M. D. Julliard, T. G. Deligeorgiev, N. I. Gadjev, A. A. Vassilev, E. Vauthey, J.
Am. Chem. Soc. 128, 7661 (2006)
[2] V. Markovic, D. Villamaina, I. Barabanov, L. M. Lawson Daku, E. Vauthey, Angew. Chem. Int.
Ed. 50, 7596 (2011)
[3] S. Bhosale, S. A. L., P. Talukdar, A. Fürstenberg, N. Banerji, E. Vauthey,G. Bollot, J. Mareda,
C. Röger, F. Würthner, N. Sakai, S. Matile, Science 313, 84 (2006)
[4] A. L. Sisson, N. Sakai, N. Banerji, A. Fürstenberg, E. Vauthey, S. Matile, Angew. Chem. Int.
Ed. 47, 3727 (2008)
[5] N. Banerji, A. Fürstenberg, S. Bhosale, A. L. Sisson, N. Sakai, S. Matile, E. Vauthey, J. Phys.
Chem. B 112, 8912 (2008)
[6] N. Banerji, G. Duvanel, A. Perez-Velasco, S. Maity, N. Sakai, S. Matile, E. Vauthey, J. Am.
Chem. Soc. 128, 7661 (2006)
N����
37
Lectures

Invited Lectures – 9 π 2011
Studies of Multichromophoric Systems by
Two-dimensional Electronic Spectroscopy: Application to
the Photosystem II Reaction Center
Jennifer P. Ogilvie
University of Michigan, Ann Arbor, USA
�e photosystem II (PSII) reaction center is the heart of oxygenic photosynthesis, taking absorbed
light from neighboring antenna complexes and creating a charge separation capable of
spli�ing water. Despite the wealth of spectroscopic studies of the PSII reaction center, the basic
energy transfer and charge separation dynamics remain poorly understood. With six chlorophyll
a pigments and two pheophytins, the reaction center has a complex multichromophoric structure;
similar pigment site energies and varying degrees of electronic coupling combine to create
a broad linear absorption spectrum, making spectral assignments particularly difficult.
In traditional nonlinear spectroscopy experiments, one must choose between temporal and spectral
resolution, complicating the interpretation of these experiments. In addition, the degree of
static disorder and electronic coupling in the system is difficult to discern. Two-dimensional electronic
spectroscopy (2DES) overcomes many of these challenges, providing a more direct view
of electronic coupling and femtosecond energy and charge dynamics.
We present low-temperature 2DES data of the D1-D2-Cyt b559 reaction center complex from
the femtosecond to the hundred picosecond timescale. We also present the decomposition of
2DES data into two-dimensional decay associated spectra (2D DAS), a method that characterizes
the spectral signatures of energy and charge separation. Within this framework, we discuss the
ultrafast energy and charge transfer dynamics of the PSII reaction center. A number of competing
excitonic models for the PSII reaction center have been proposed in the literature.
We present simulated 2D spectra based on these models for comparison with our 2DES data, and
suggest possible refinements. Finally, we discuss future multidimensional spectroscopy experiments
aimed at be�er separating signatures of energy and charge transfer.
38

π 2011
Invited Lectures – 9
Figure I9.1: 2DES spectra and simulations of the PSII RC at 77 K. Le�: at waiting time t2 = 28 fs,
cross-peaks indicate excitonic coupling in the system. Middle: 2DES spectrum at
waiting time t2 = 215 fs, showing growth of the cross-peak below the diagonal as energy
is transferred to lower-lying electronic states. Right: simulated 2DES spectrum
at waiting time t2 = 215 fs, based on a proposed exciton model for the PSII reaction
center, using modified Redfield theory.
N����
39
Lectures

Invited Lectures – 10 π 2011
Accurate Density Functionals for Large Molecules
Stefan Grimme
Universität Bonn
�e electronic correlation energy is a quantum-mechanically modulated many-particle effect. In
order to quantitatively describe chemical processes, its accurate computation is mandatory. �e
talk addresses the omnipresent long- (London) and medium-range dispersion (correlation) effects
on chemical energetics. In recent years it became clear that they not only have to be considered
for typical van der Waals systems, but also influence “normal” thermochemistry. �ey are very
imporant for many functional systems (that are typically rather large, >50-100 atoms) in which
structural or chemical transformations occur in the ‘dispersion-active’ 3-5 Å inter-atomic distance
range. Four main topics are discussed:
1. Effect of dispersion corrections on the performance of 45+ different density functional
approximations for a huge thermochemical benchmark (GMTKN30).[1]
2. Stability of hexaphenylethane derivatives: “steric crowding can stabilize a molecule”![2]
3. Adsorption unsaturated molecules on surfaces.
4. Performance of double-hybrid functionals for excited state problems of large π-systems.
[3, 4]
As quantum-chemical method, mainly dispersion corrected DFT in our most recent first-principles
version (DFT-D3[5] using Becke-Johnson damping[6, 7]) is employed. It has recently been
extended such that ionic surfaces and solids are treated accurately[8].
References
[1] L. Goerigk and S. Grimme, Phys. Chem. Chem. Phys. 13, 6670 (2011)
[2] S. Grimme and P. Schreiner, Angew. Chem., in press
[3] L. Goerigk and S. Grimme, J. Chem. �eor. Comput., DOI: 10.1021/ct200380v
[4] L. Goerigk and S. Grimme, J. Chem. Phys. 132, 184103 (2010)
[5] S. Grimme, J. Antony, S. Ehrlich and H. Krieg, J. Chem. Phys. 132, 154104 (2010)
[6] A. D. Becke and E. R. Johnson, J. Chem. Phys. 122, 154101 (2005)
[7] S. Grimme, S. Ehrlich and L. Goerigk, J. Comput. Chem. 32, 1456-1465 (2011)
[8] S. Ehrlich, J. Moellmann, W. Reckien, T. Bredow, and S. Grimme, Chem. Phys. Chem., DOI:
10.1002/cphc.201100521
40

π 2011
N����
Invited Lectures – 10
41
Lectures

π 2011
Oral Presentations
Oral Presentations
43
Talks

Oral Presentations – 1 π 2011
Optical Transitions and Excitonic Coupling in a Covalently
linked Spiroindolone Bichromophore
A. Wohlert and J. Tatchen
Universität Düsseldorf
We present a quantum chemical study of the electronic excitation spectrum of a novel luminescent
bichromophoric dye [1] which is made up of a diphenylbutadiene and a dihydroindolone
unit which is carrying a dansyl moiety. Experimentally, a broad fluorescence band with a maximum
at 511 nm has been observed [1] which could in principle result as emission from either one
of the chromophores or from both (dual fluorescence). In order to unravel the mechanism behind
the luminescence, we calculate absorption and emission spectra employing time-dependent density
functional theory. Minima on the excited state potential energy surfaces are identified which
correspond in good approximation to local excitations. Strictly local excitations are generated by
means of the fragment molecular orbital approach [2, 3]. Possibilities will be explored for obtaining
excitonic couplings within the covalently linked system from the strictly local excitations.
References
[1] D. M. D’Souza, A. Kiel, D.-P. Herten, F. Rominger, T. J. J. Müller, Chem. Eur. J. 14, 529 (2008),
J. Schönhaber, Dissertation, Düsseldorf (2010)
[2] K. Kitaura, E. Ikeo, T. Asada, T. Nakano, M. Uebayasi, Chem. Phys. Le�. 313, 701 (1999)
[3] M. Chiba, D. G. Fedorov, K. Kitaura, J. Chem. Phys. 127, 104108 (2007)
44

π 2011
N����
Oral Presentations – 1
45
Talks

Oral Presentations – 2 π 2011
Modeling electronic and charge transport properties of
ambipolar and n-type organic semiconductors
F. Negri and S. Di Mo�a
Università degli Studi di Bologna, Italy
Recently synthesized quinoidal oligothiophenes have been shown to be promising materials for
their proved amphoteric properties[1], and also for their near infrared (NIR) absorption features,
driven by the reduction of their HOMO-LUMO energy gap, that make them of potential use in the
field of organic photodetectors. Here we present evidence[2] for the biradicaloid and polyenic
character of quinoidal oligothiophenes by proving at CASSCF//CASPT2 computational level the
presence of a low lying double exciton state responsible for the weak features observed in the
NIR absorption region of the longest members of this class of molecules. �e identification of
the doubly exciton state offers a unified view of the low lying electronic states for quinoidal
oligothiophenes and polyenes.
Among n-type organic semiconductors perylene bisimide (PBI) have been shown to display
promising electron mobilities. �e solid state packing and functional properties of PBIs can be
tailored by the introduction of appropriate substituents in the imide position or by core substitution
in the bay region.[3] Here we discuss charge transport properties, modeled by propagating
the charge carrier in the crystals of planar-core and core-twisted PBIs (see Figure O2.2), with
a kinetic Monte Carlo scheme. �ermally induced dynamical effects are investigated by means
of molecular dynamics simulations coupled to quantum-chemical evaluation of electronic couplings
V ij. �e study reveals that the reduced π − π stacking induced by core-twisting influences
not only static properties of the molecular material but also dynamical effects that should be
considered in the design of future organic semiconductor architectures.
46
Figure O2.1 Figure O2.2

π 2011
References
Oral Presentations – 2
[1] Ortiz, R. P., Casado, J., Hernandez, V., Navarrete, J. T. L., Orti, E., Viruela, P. M., Milian, B.,
Ho�a, S., Zo�i, G., Zecchin, S.et al. Adv. Func. Mat. 2006, 16, 531-536.
[2] S. Di Mo�a, F. Negri, D. Fazzi, C. Castiglioni, E. V. Canesi J. Phys. Chem. Le�. 2010, 1, 3334.
[3] Schmidt, R.; Oh, J. H.; Sun, Y. S.; Deppisch, M.; Krause, A. M.; Radacki, K.; Braunschweig, H.;
Konemann, M.; Erk, P.; Bao, Z. A.; Würthner, F. J. Am. Chem. Soc. 2009, 131, 6215-6228.
N����
47
Talks

Oral Presentations – 3 π 2011
Electronic coupling in molecular dimers: Single molecule
studies and quantum chemical calculations
F. P. Diehl, C. Roos, A. Köhn and T. Basché
Universität Mainz
A series of molecular dimers (Dye-Dye) was prepared by increasing the intermolecular distance
by a growing number n (n = 0 − 3) of phenyl-rings. Individual dimers were investigated by
time and frequency resolved single molecule spectroscopy at T = 1.2 K. With increasing distance
between the two chromophores, a transition from the weak (incoherent energy transfer) to the
strong (coherent energy transfer) coupling regime is observed. �e signatures of the various
coupling limits are reflected in the number of zero-phonon lines and the fluorescence lifetimes of
the dimers. At intermediate distances the particular site energy difference for single dimers tips
the scale between the two coupling regimes; hence either weak or strong coupling is observed for
individual dimers. Electronic coupling strengths V as deduced from single molecule excitation
spectra are in good agreement with results from quantum chemistry.
48

π 2011
N����
Oral Presentations – 3
49
Talks

Oral Presentations – 4 π 2011
�antum-chemical contributions to the understanding of
triplet excitons
A. Köhn
Universität Mainz
Knowledge of the energy levels and properties of triplet excited states is vital for the atomistic
understanding of the processes in organic semiconductor devices [1]. Experimentally, direct
optical measurements of triplet states are difficult to conduct due to the spin-forbidden nature
of singlet-triplet transitions. Hence, reliable quantum-chemical calculations are an important
source of information.
In this contribution, we present results from a recent investigation of the triplet energies of
30 state-of-the-art organic semiconductor materials [2]. For this study we employed the ADC(2)
method which includes effects of electron-correlation at second-order perturbation theory [3-
5]. Structural changes in the excited state are fully taken into account. Particularly for multichromophoric
compounds, this effect is important to correctly describe the localization of the
exciton within the molecule. Furthermore, we discuss transient Tn ← T1 absorption spectra
of these compounds. �ese are of particular interest as Tn ← T1 transitions of accumulated
triplet excitons play the main role in inhibiting a continuous wave operation of organic solid
state laser devices [6]. Finally, we will show some initial results from our a�empts to model
exciton diffusion via kinetic Monte Carlo [7].
References
[1] see, e.g., Köhler, Bässler, Mater. Sci. Eng. R 66, 71 (2009)
[2] Pabst, Sundholm, Köhn, in preparation
[3] Schirmer, Phys. Rev. A 26, 2395 (1982)
[4] Hä�ig, Adv. �antum Chem. 50, 37 (2005)
[5] Hä�ig, J. Chem. Phys. 119, 5021 (2003)
[6] Lehnhardt, Riedl, Weimann, Kowalsky, Phys. Rev. B 81, 165206 (2010)
[7] Lunkenheimer, Köhn, Fuchs, Lennartz, May, Andrienko, in preparation
50

π 2011
N����
Oral Presentations – 4
51
Talks

Oral Presentations – 5 π 2011
Ambient Stable Solution-processed n-Channel Organic
Thin Film Transistors Based on Dichlorinated Naphthalene
Diimides
M. Stolte¹, M. Gsänger¹, S.-L. Suraru¹, J. H. Oh², W.-Y. Lee², Z. Bao², J. Brill³, N. Langer³, H.
Klauk⁴, U. Zschieschang⁴ and F. Würthner¹
¹Universität Würzburg, ²Stanford University, ³InnovationLab GmbH, Heidelberg, and BASF SE, Ludwigshafen, ⁴Max
Planck Institute for Solid State Research, Stu�gart
Naphthalene diimides (NDIs) with fluoroalkyl substituents are among the most promising semiconductors
for n-channel organic thin-film transistors (TFTs).[1] Recently, we reported vacuumprocessed
n-channel TFTs based on dichlorinated NDIs in the bo�om-gate, top-contact transistor
configuration with record electron mobilities of up to 1.3 cm² V⁻¹ s⁻¹ under ambient conditions.[2,
3]
Figure O5.1: Dichlorinated naphthalene diimides with fluoroalkyl substituents for vacuum- and
solution-processed n-channel organic thin-film transistors.
In this contribution we will present results achieved by solution shearing to deposit highly crystalline
and aligned thin films of NDIs from chlorinated solvents.[4] Surface treatment of the gate
dielectric by different self-assembled monolayers (SAM) as well as the optimization of the deposition
conditions were performed to obtain n-channel TFTs with electron mobilities greater
than 0.4 cm² V⁻¹ s⁻¹ measured in ambient air. �e influence of the fluorinated substituents at
the imide nitrogen of the NDI on the thin-film morphology, the field-effect mobilities, and the
ambient stability of the TFTs were investigated. �e synthetic simplicity and process versatility
combined with the high performance and good ambient stability make these semiconductors
highly promising for low-cost, large-area, and flexible electronics.
52

π 2011
References
Oral Presentations – 5
[1] F. Würthner, M. Stolte, Chem. Commun. 47, 5109-5115 (2011)
[2] J. H. Oh, S.-L. Suraru, W-Y. Lee, M. Könemann, H. W. Hö�en, C. Röger, R. Schmidt, Y. Chung,
W-C. Chen, F. Würthner, Z. Bao, Adv. Funct. Mater. 20, 2148 (2010)
[3] M. Stolte, S.-L. Suraru, F. Würthner, J. H. Oh, Z. Bao, J. Brill, M. Könemann, J, �, U. Zschieschang,
H. Klauk, Proc. of SPIE 7778, 777804-1 (2010)
[4] H. A. Becerril, M. E. Roberts, Z. Liu, J. Locklin, Z. Bao, Adv. Mater. 20, 2588 (2008)
N����
53
Talks

Oral Presentations – 6 π 2011
Reduction- and Coordination-Chemistry of Boroles
D. Gamon, H. Braunschweig, F. Breher, D. Nied, B. Engels, K. Ansorg and M. Hügel
Universität Würzburg
Even though pentaphenylborole is known since 1969 examples for free boroles are rare because
their synthesis is nontrivial, which is due to the electron deficiency of the boron centre; yet we
developed novel free boroles [1, 2]. �e empty boron pz orbital promotes a delocalisation of the
4π electrons within the fivemembered ring, which results in an antiaromatic system and causes
the strong Lewis-acidity of the molecules.
While the two electron reduction of pentaarylboroles leads to well studied aromatic borole dianions
the reduction of the ferrocenylborole 1, previously published in our group, results in an
unexpected migration of the Cp−Fe unit from cyclopentadienyl to the borole ring to yield 2 [3, 4].
Coordination of Lewis-bases to the boron atom enlarges the HOMO-LUMO gap of boroles and
causes a significant colour change from blue to yellow. Photoexcitation of the 2,6-lutidine adduct
from pentaphenylborole 3 results in an intense green colour. NMR spectroscopic investigations
of the system suggests an unusual rearrangement under formation of a B−C double bound and
the shi�ing of 2,6-lutidine from boron to carbon [5].
54

π 2011
References
Oral Presentations – 6
[1] J. J. Eisch, J. E. Galle and S. Kozima, J. Am. Chem. Soc. 91, 4575 (1969).
[2] H. Braunschweig, I. Fernández, G. Frenking, T. Kupfer, Angew. Chem. Int. Ed. 47, 1951 (2008).
[3] H. Braunschweig, F. Breher, C.-W. Chiu, D. Gamon, D. Nied, K. Radacki, Angew. Chem. Int.
Ed. 49, 8975 (2010).
[4] H. Braunschweig, T. Kupfer, Chem. Comm., 4487 (2008).
[5] K. Ansorg, H. Braunschweig, C.-W. Chiu, B. Engels, D. Gamon, M. Hügel, T. Kupfer and K.
Radacki, Angew. Chem. Int. Ed. 50, 2833 (2011).
N����
55
Talks

Oral Presentations – 7 π 2011
Light-induced charge transfer in two-dimensional and
polymeric neutral organic mixed-valence compounds
T. �ast, F. Kanal, M. Kullmann, S. Rützel, D. Reitzenstein, J. Köhler, J. Buback, P. Nürnberger,
C. Lambert, I. Fischer and T. Brixner
Universität Würzburg
Upon absorption of a photon, charge transfer is the initial step in many photophysical and photochemical
reactions. A variety of subsequent reactions a�er charge transfer is possible, depending
upon the properties of the molecular system under investigation.
Neutral organic mixed-valence compounds represent an ideal class of model systems to study the
basic charge-transfer dynamics. �ey consist of two or more redox centers in different oxidation
states which are linked by spacer units. �e light-induced charge transfer between those redox
centers is associated with an absorption band in the visible or near-infrared spectral range, the
so-called inter-valence charge-transfer (IVCT) band. �erefore these compounds are ideal candidates
to study their charge-transfer dynamics by means of transient absorption spectroscopy.
A�er exciting the system with a laser pulse, the subsequent absorption changes are detected with
a second time-delayed laser pulse. �is allows to draw conclusions on which quantum states are
involved in the dynamics a�er an optically induced charge transfer.
�e first system presented here is a two-dimensional mixed-valence compound which is constituted
of a truxenone-based acceptor, substituted with three triarylamine-based donors via spacer
units of different length [1]. In this case, the experimental results suggest that two deactivation
channels have to be considered, associated with two rotational conformers which are initially
excited. We also find that the rate of back electron back transfer is determined by the steric
hindrance between the acceptor and the rotated donor, rather than by the length of the spacer
unit.
�e second example is the comparison of the charge transfer dynamics of a polymeric mixedvalence
compound and its reference monomer [2]. �e monomer unit is composed of a triarylamine
donor and a perchlorotriphenylmethyl radical acceptor. In average, the polymer is
constituted of 12 monomer units. By comparing the time-resolved spectroscopic data on the
monomer and the polymer, one can conclude that the excitation of the polymer is confined to
one monomeric unit. In contrast to the monomer, which exclusively reveals a direct pathway
from the excited state to the ground state, the polymer also forms an equilibrium with a fully
charge-separated state. In order to relax back to the ground state, the charges have to migrate
along the polymer until positive and negative charges are located on adjacent donor and acceptor
units, respectively. �is deactivation channel can therefore be associated with a longer-lived
excited state.
References
[1] C. Lambert et al., Chem. Eur. J. 4 No. 11, 2129-2135 (1998)
[2] D. Reitzenstein et al., Chem. Mater. 22, 6641-6655 (2010)
56

π 2011
N����
Oral Presentations – 7
57
Talks

Oral Presentations – 8 π 2011
How to perform quantum chemical calculations on organic
mixed-valence systems
M. Renz and M. Kaupp
Technische Universität Berlin
Organic mixed-valence (MV) compounds are the focus of recent research because they are simple
and suitable model systems for the investigation of electron-transfer (ET) processes. Usually
these MV systems consist of two redox centers in different redox states, linked by a saturated
or unsaturated bridge unit. �antum-chemical studies on the localization or delocalization
of the electron hole have been scarce, due to severe limitations of the available methods. Using
Hartree-Fock-�eory (HF), the systems are always too localized,[1] whereas with Density-
Functional-�eory (DFT) and common functionals they are too delocalized.[2] Accurate post-
HF ab initio methods currently tend to be too demanding for organic MV systems of realistic
size. We therefore developed a reliable quantitative quantum-chemical protocol for the treatment
of organic MV systems based on non-standard hybrid functionals.[3] �is protocol, which
was originally based on four radical cationic bis-triarylamine systems containing bridge units of
different length, has recently been extended to further bis-triarylamine systems as well as neutral
perchlorotriphenylmethyl-triarylamine radicals.[4] Simulation of dielectric solvent effects by a
conductor-like screening model (COSMO) allows the use of a realistic exact-exchange admixtures
near 35% to localize the class II systems. Calculations of the typical intervalence charge transfer
(IVCT) excitation energies by time-dependent DFT (TD-DFT) with 35% HF exchange provides a
further tool to classify the MV systems. Experimental ¹⁴N-hyperfine coupling constants can be
simulated as well using such DFT approaches.
In an extension to MV dinitroaromatic radical anions, the protocol has been refined further regarding
the details of the solvent model and other environmental effects (e.g. counterions), as
well as the basis set.
References
[1] S. F. Nelsen, F. Blomgren, J. Org. Chem. 2001, 66, 6551.
[2] V. Coropceanu, C. Lambert, G. Nöll, J. L. Brédas, Chem. Phys. Le�. 2003, 373, 153.
[3] M. Renz, K. �eilacker, C. Lambert, M. Kaupp, J. Am. Chem. Soc. 2009, 131, 16292.
[4] M. Kaupp M. Renz, M. Parthey, M. Stolte, F. Würthner, C. Lambert, Phys. Chem. Chem.
Phys., accepted.
58

π 2011
N����
Oral Presentations – 8
59
Talks

Oral Presentations – 9 π 2011
New Insights into Exciton Trapping in Organic Photo
Voltaics
V. Se�els, A. Schubert, M. Tafipolski, W. Liu, V. Stehr, V. Engel, R. F. Fink and B. Engels
Universität Würzburg
�e talk summarizes our work about possible exciton trapping processes in aggregates of perylene
derivatives. Experiments reveal that a�er excitation the excitons relax into stable and immobile
intermolecular states in a few picoseconds [1, 2]. However, a molecular picture which
may help to impede such trappings is still missing. To contribute to a be�er understanding we
investigated possible molecular models.
Our investigations are based on dimers. �ey start with high level ab-initio computations to
create the potential energy surfaces of all electronically excited states being potentially involved
in exciton transfer. �e influence of crystal environments is taken into account by mechanical
embedding approaches which use specially designed force fields while solvent effects were estimated
by continuum approaches. �e ansatz is completed by wave packet dynamics on the
computed PESs which accounts for dynamical effects.
In the talk we focus on new trapping mechanisms for PBI aggregates and for crystal structures of
α-PTCDA and DIP, respectively. �e trapping mechanism for PBI aggregates involves population
transfer between neutral as well as charge-transfer states and can nicely explain the data of
time-resolved experiments on a femtosecond timescale. �e involved conical intersections are
reached through induced stretch distortions in the monomers. In the case of α-PTCDA a different
mechanism comes into play. In this case shi� motions of two neighboured molecules leads to
the relaxation into an optically dark excited state through a conical intersection. �is trapping
mechanism can be generalized for a wide range of perylene based dyes, but our computations
indicate that it cannot take place in DIP crystals due to the molecular arrangement. �is may
explain why DIP possesses considerably larger exciton diffusion length than α-PTCDA.
References
[1] B. A. West, J.M. Womick, L. E. McNeil, K. J. Tan, A. M. Moran, J. Phys. Chem. B 115, 5157
(2011)
[2] I. A. Howard, F. Laquai, P. E. Keivanidis, R. H. Friend, N. C. Greenham, J. Phys. Chem. C 113,
21225 (2009)
60

π 2011
N����
Oral Presentations – 9
61
Talks

Oral Presentations – 10 π 2011
Spectroscopy of Cyclophanes: Investigating model systems
for π/π-interactions
I. Fischer
Universität Würzburg
Paracyclophanes are suitable models to study the interaction between π-systems because the
alkyl bridges enforce a well-defined distance between the benzene rings and give rise to a strained
ring system with strong π/π-interactions that are predefined by covalent bonds. Furthermore
gas-phase spectra of cyclophanes permit a comparsion with highly accurate ab initio computations.
We therefore investigated the electronic structure of various hydroxy-substituted [2.2]paracyclophanes
using multiphoton ionisation and spectral hole burning. Recent results will be summarized
and compared with high-level coupled cluster computations.
62

π 2011
N����
Oral Presentations – 10
63
Talks

Oral Presentations – 11 π 2011
A Reliable Supramolecular Method to Self-Assemble
Conjugated Molecules into Well-Defined Nanoscopic
Fibrils
L. Tian¹ ² and H. Frauenrath¹
¹École Polytechnique Fédérale de Lausanne, ²ETH Zürich, Switzerland
Supramolecular self-assembly has proven to be a versatile tool for the preparation of nanostructured
materials [1]. Various examples utilize the self-assembly of β-sheet forming oligopeptides
[2]. Recently, we have demonstrated that oligopeptide-polymer conjugates based on hydrogenated
poly(isoprene) and oligo(alanine) can be used for the formation of soluble nanostructures
in a “bo�om-up” approach [4]. In the present study, we prepared and investigated a series
of diacetylene macromonomers which comprised hydrogenated poly(isoprene) segments with
different degrees of polymerization as well as oligo(alanine)s of different lengths. �e resulting
nanostructures were visualized by AFM, and their stability as well as polymerizability was investigated
by solution phase IR and UV/vis spectra. Our investigations showed that the stability
of the nanostructures in solution and their polymerizability was strictly determined by both the
length of the a�ached polymers and the number of N−H···O−C hydrogen bonds.
�e lessons learned from the diacetylene conjungates were then transferred to oligopeptidepolymer-equipped
derivatives of other conjungated molecules such as quaterthiophene and perylene
bisimide. A systematic investigation of UV/vis, CD, and IR spectra as well as AFM images
revealed that oligopeptide-polymer conjugates based on hydrogenated poly(isoprene) and
oligo(alanine) were versatile scaffolds for the reproducible formation of one-dimensional aggregates
of conjugated molecules.
A�nowledgements: We thank Dr. L. Bertschi and Dr. X. Zhang at the Laboratory of Organic
Chemistry at ETH Zürich for the assistance with mass spectra, Dr. R. Szilluweit for the AFM
measurements, Dr. M. Yu and Prof. F. Stellacci from SUNMIL at EPFL for the STM mesurements,
and Dr. Andrzej Sienkiewicz from LPMC at EPFL for the ESR measurements. Funding from ETH
Züri� (Projekt ETH-05 08-2) is gratefully acknowledged.
References
[1] Lehn, Science 295, 2400-03 (2002)
[2] Sumner et al., J. Mol. Biol. 335, 1279-1288 (2004)
[3] Börner et al., J. Am. Chem. Soc. 128, 7722-23 (2006)
[4] Frauenrath et al., Chem. Eur. J. 15, 388-404 (2009)
[5] Frauenrath et al., Angew. Chem. Int. Ed. 45, 5383-86 (2006)
64

π 2011
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Oral Presentations – 11
65
Talks

Oral Presentations – 12 π 2011
Donor-Acceptor Interactions in Multidimensional
Boron-Chromophores
C. Lambert
Universität Würzburg
Triarylboranes have frequently been used as acceptor moieties in functional π-systems for e.g.
OLED or sensor applications. �e combination with triarylamine or carbazole donor moieties
yields donor-acceptor systems that are highly fluorescent. �ese donor and acceptor groups can
be used to construct molecular one-dimensional or two-dimensional chromophores [1, 2]. but
also polymers with benzidine (A) or para-phenylene (B) backbones.[3] Trimerisation of appropriately
functionalised tolans yield symmetric or asymmetric hexaarylbenzenes (C) that are twodimensional
in nature. All these chromophore systems show versatile redox chemistry as well
as static and time-dependent photophysical behavior which is presented in this contribution.
References
[1] R. Stahl, C. Lambert, C. Kaiser, R. Wortmann, R. Jakober, Chem.-Eur. J. 12, 2358-2370 (2006)
[2] U. Megerle, F. Selmaier, C. Lambert, E. Riedle, S. Lochbrunner, Phys. Chem. Chem. Phys. 10,
6245-6251 (2008)
[3] D. Reitzenstein, C. Lambert, Macromolecules 42, 773-782 (2009)
66

π 2011
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Oral Presentations – 12
67
Talks

π 2011
Posters
First Session
Posters
69
Posters I

Posters – 1 π 2011
On the way to preparative Stone-Wales rearrangements
J. Auerswald and A. Krueger
Universität Würzburg
New carbon allotropes like fullerenes, carbon nanotubes (CNT) or graphene spurred considerable
interest in the past two decades. However, their mechanisms of formation are still not fully
understood. One hypothesis for the fullerene formation process postulates the involvement of
Stone-Wales rearrangements which lead to the exchange of five- and six-membered rings as part
of larger PAHs (Fig. P1.1).[1]
Figure P1.1: �e postulated Stone-Wales rearrangement of pyracylen
�eoretical investigations show a high activation barrier for this transformation, caused by the
thermally forbidden reaction.[2] So it is not surprising that first a�empts to rearrange the parent
pyracylen 1a in a Stone-Wales type reaction have indeed failed.[3]
In this work we aim for the synthesis of sterically hindered pyracylenes like 1b-c to simulate the
steric stress of defect centers during formation of several carbon allotropes and to increase the
driving force for the Stone-Wales rearrangement.
References
[1] A. J. Stone, D. J. Wales, Chem. Phys. Le�. 128, 501-503 (1986)
[2] P. W. Fowler, J. Baker, J. Chem. Soc. Perkin. Trans. 2, 1665-1666 (1992)
[3] L. T. Sco�, Pure & Appl. Chem. 68, 291-300 (1996)
70

π 2011
N����
Posters – 1
71
Posters I: A

Posters – 2 π 2011
Towards Fluorescent Memories with Non-destructive
Read-out: Photoswitching of Fluorescence by
Intramolecular Electron Transfer in a
Diarylethene-Perylene Bisimide Photochromic System
M. Berberich¹, A.-M. Krause¹, M. Orlandi², F. Scandola² and F. Würthner¹
¹Universität Würzburg, ²Università di Ferrara, Italy
In the recent years, photoswitching of fluorescence in dyads composed of a photochromic diarylethene
and a fluorescent dye has been reported by several groups. In these systems, the
quenching of fluorescence originates from an intramolecular energy transfer (FRET) from excited
dye to the closed from of the diarylethene. A disadvantageous follow-up reaction of this
FRET process is the ring-opening during reading the fluorescence “o�” state that destroys the
memory a�er a couple of read-outs.
Such destructive read-out may be avoided by switching of fluorescence through intramolecular
electron transfer. For this purpose, we have designed a photochromic system based on a
diarylethene and a perylene bisimide fluorophore.
Based on the data of the cyclic voltammetry measurements and UV/vis absorption spectroscopy,
the driving force for the electron transfer was estimated by the Rehm-Weller equation.
�e emission studies show that the fluorescence is quenched only in the closed form of the
diarylethene-perylene bisimide photochromic system via an intramolecular electron transfer
from the excited perylene bisimide dye to the diarylethene. �is electron transfer intermediate
was detected by ultrafast transient absorption spectroscopy.
�e development of such photochromic systems is of interest for applications due to the possibility
of non-destructive read-out.
References
[1] M. Berberich, A.-M. Krause, M. Orlandi, F. Scandola, F. Würthner, Angew. Chem. 2008, 120,
6718–6721; Angew. Chem. Int. Ed. 2008, 47, 6616–6619.
72

π 2011
N����
Posters – 2
73
Posters I: B

Posters – 3 π 2011
Fluorescence correlation spectroscopy of SWNT-ssDNA
conjugates
F. Brunecker
Universität Würzburg
Dynamic interactions between nanoparticles and organic molecules play a key role in several
areas of nanotechnology. Despite of the significance of such interactions, only li�le is known
about kinetic and dynamical processes at nanoparticle-solvent interfaces. �is deficit can partly
be a�ributed to a lack of experimental methodology to investigate the questions associated with
nanoparticle-adsorbate interactions.
Here, we explore the potential of fluorescence correlation spectroscopy (FCS) for the investigation
of dynamical processes at the nanoparticle-solvent interface. FCS is a well-established
technique for the examination of the dynamics of biochemical reactions and processes. FCS allows
to determine concentrations and diffusion coefficients of small fluorophore ensembles.
More specifically, we present first experiments that show how FCS can be used to study conjugates
of single stranded DNA (ssDNA) and carbon nanotubes (CNTs), as a model system for the
investigation of nanoparticle-adsorbate interactions. To study the dynamics of adsorbed DNA
without interference from Brownian motion of the nanoparticle, CNTs were immobilized in an
agarose gel matrix. Diffusion coefficients of different adsorbed DNA-oligomers are then determined
in pure agarose gel as a reference and in agarose gel loaded with CNTs. We find that the
concentration of adsorbed DNA-oligomers on the tubes increases with oligomer length in agreement
with the behaviour expected for oligomers with increased binding energy. �e experiments
also suggest that DNA diffusion coefficients of adsorbed oligomers are similar to those of free
DNA, indicative of high mobility of adsorbed DNA on the CNT surface.
74

π 2011
N����
Posters – 3
75
Posters I: B

Posters – 4 π 2011
Electrochemical Properties of Donor Substituted Azulene
Squaraines
H. Ceymann and C. Lambert
Universität Würzburg
Due to their donor-acceptor-donor structure squaraines typically have sharp and intense lowenergy
absorption bands. �erefore they are used in many applications such as solar cells and
field-effect transistors. In order to obtain an even smaller band gab and hence a red-shi� of the
absorption into the infrared region we used azulene squaraine dyes as an electron rich bridge
between two electron donating redox centers like triarylamines, bisphenylamines or carbazols.
In solution the NMR-data of the dyes show additional signals. �ese strongly suggest that the
molecules do not only exist in the trans form shown below, but also in the cis form. At room
temperature the ratio of trans and cis isomers is about 2:1. Absorption spectra of oxidized dyes
indicate that the positive charge is symmetrically delocalized. �e dyes were investigated by
absorption, cyclic voltammetry and spectroelectrochemistry and shall act as model systems for
conjugated polymers.
76

π 2011
N����
Posters – 4
77
Posters I: C

Posters – 5 π 2011
Orbital reconstruction from photoemission - the power to
distinguish between quantum theories
M. Dauth¹, T. Körzdörfer¹, S. Kümmel¹, J. Ziroff², M. Wiessner², A. Schöll², F. Reinert², M.
Arita³ and K. Shimada³
¹Universität Bayreuth, ²Universität Würzburg, ³Hiroshima University, Japan
Visualization of molecular orbitals has become a powerful tool to gain detailed information about
the electronic structure of molecules and solids. Interpreting the data from angular resolved
photoemission spectroscopy (ARPES) as a visualization of molecular orbitals reveals the spatial
structure of single orbitals. We compare the orbitals obtained from first principle calculations to
ARPES experiments. Different theoretical approaches predict qualitatively different spatial orbital
structures. By comparison with experiment we are able to decide which quantum approach
yields the orbitals that are closest to those seen in experiment.
Our investigation focuses on organic semiconductors like PTCDA and NTCDA and shows that
the orbital interpretation even holds for these complex systems. However, we also discuss first
steps to go beyond the “ground-state orbital” interpretation to take into account the dynamical
nature of the photoemission process.
Figure P5.1: �e absolute value of the Fourier transform of the NTCDA HOMO from a Generalized
Gradient Approximation (PBE, le�) and a self-interaction corrected LDA calculation
(middle) evaluated for |k| = 2.75 Å −1 compared to the square root of the
measured ARPES intensity (right).
78

π 2011
N����
Posters – 5
79
Posters I: D

Posters – 6 π 2011
Synthesis and Photophysics of Redox Cascades Consisting
of Triarylamine Donors and a Perchlorinated
Triphenylmethyl Radical Acceptor
N. Dürrbeck and C. Lambert
Universität Würzburg
Photoinduced electron transfer processes play an important role in chemistry as well as in biology.
Artificial redox cascades are frequently used to mimic such processes. We synthesised
redox cascades based on triarylamines which serve as electron donor subunits and exhibit a
decreasing redox potential, which can easily be tuned by adequate substituents at the phenyl
rings. Furthermore, triarylamines show relatively low internal reorganisation energies and are
widely used as hole conducting materials in optoelectronic devices because of the stability of
their oxidised states.[1] As the acceptor subunit we chose a perchlorinated triphenylmethyl radical.
Such radicals are electroactive species and are known for their large persistency, high termal
and chemical stability.[2] �e redox cascades were investigated concerning their photophysical
and electrochemical properties in order to study directed photoinduced electron transfer along a
redox gradient.
References
[1] B. E. Koene, D. E. Loy, M. E. �ompson, Chem. Mater. 10(8), 2235-2250 (1998)
[2] M. Ballester, J. Riera, J. Castaner, A. Rodriguez, Tetrahedron Le�. , 2079-2082 (1971)
80

π 2011
N����
Posters – 6
81
Posters I: D

Posters – 7 π 2011
Electronic structure of novel and air stable n-type organic
semiconductors: A comparison of different bay-substituted
perylene-bisimide dyes
M. Scholz¹, R. Schmidt¹, S. Fiedler¹, A. Schöll¹, F. Würthner¹ and F. Reinert¹ ²
¹Universität Würzburg,² Karlsruhe Institute for Technology (KIT)
�e development of air stable n-conducting organic semiconductors is a bo�le neck in organic
electronics. We present a comparative analysis of the electronic structure of different baysubstituted
perylene-bisimide (PBI) dyes, which have already demonstrated very high mobilitiesin
thin film devices [1]. Occupied and unoccupied valence levels were measuredwith UPS
and IPES, which allows investigating the transport gap. Remarkable is, that the transport gap
does not vary remarkablybetween the compounds [2]. If the contact properties to a Ag(111) metal
substrate are investigated, work function measurements reveal strong interface dipoles. In case
of PBIs with fluoro alkyl chains, the interface dipole is about 0.7 eV, which can be related to the
C 4F 7- chains and their out-of-plane orientation. For PBI films with isopropylphenyl-groups, the
magnitude and the direction of the interface dipole depends strongly on thepreparationand thus
provide a possible route to modify the interfacial energy level alignment.
References
[1] R. Schmidt, J. Hak Oh, Y. Sun, M. Deppisch, A. Krause, K. Radacki, H. Braunschweig, M.
Könemann, P. Erk, Z. Bao, F. Würthner, J. Am. Chem. Soc. 131(17), 6215 (2009)
[2] M. Scholz, R. Schmidt, S. Krause, A. Schöll, F. Reinert, and F. Würthner, Applied Physics A
95, 285 (2009)
82

π 2011
N����
Posters – 7
83
Posters I: F

Posters – 8 π 2011
Foldamer with spiral perylene bisimide staircase aggregate
structure
V. Dehm, B. Fimmel, M. Büchner, J. Seibt, V. Engel and F. Würthner
Universität Würzburg
Although the precise control of dye-dye interactions is known to be of fundamental importance
to achieve desired functional properties in π-conjugated materials, there are only sporadic examples
where precise structural control of dye-dye interactions could be achieved by the a�achment
of the chromophores to an oligomeric or polymeric backbone. In this article, we introduce
an oligophenylene ethynylene / perylene bisimide (PBI) dye system which is conceived by the
foldamer concept. �e molecular design enables folding of the π-conjugated oligomer to give a
geometrically well-defined π-stack of intrastrand PBI molecules. �e synthesis of the foldamer
and its characterisation by MALDI-TOF mass spectrometry are described, and the average size
is estimated by gel permeation chromatography (GPC) and diffusion ordered NMR spectroscopy
(DOSY). �e folding dynamics are demonstrated by ultraviolet/visible absorption and fluorescence
emission spectroscopic studies as the folded and unfolded states possess distinct optical
properties. �antum dynamic considerations revealed a good agreement of the calculated aggregate
absorption spectrum with those obtained experimentally.
84

π 2011
N����
Posters – 8
85
Posters I: F

Posters – 9 π 2011
Investigation of a borylene with synchrotron radiation
K. H. Fischer, M. Schneider, A. Bödi, I. Fischer, B. Pfaffinger and H. Braunschweig
Universität Würzburg
With the help of synchrotron radiation the borylene complex [(OC) 5Cr−B−N(SiMe 3) 2] was ionized
and its dissociation studied. �e TEPEPICO method was employed and the experiments were
carried out at the Swiss Light Source (SLS). �e most important dissociation channels were analyzed
and die ionization energy (IE) as well as the appearance energies (AE) determined. Within
the fragments CO ligands dissociate sequentially. �e dissociation process was quantitatively
modeled within the framework of the SSACM theory.[1]
References
OC
OC Cr B N
OC
CO
CO
SiMe3
SiMe 3
[1] B. Sztáray, A. Bodi, T. Bear, J. Mass. Spectrom., 2010, 45, 1233 – 1245.
86

π 2011
N����
Posters – 9
87
Posters I: F

Posters – 10 π 2011
Self-assembly of Pt 4 Rings: From Small Molecules to
Nanotubes in One-pot
P. D. Frischmann¹, S. Guieu², B. Sahli² and M. J. MacLachlan²
¹Universität Würzburg, ²University of British Columbia
Self-assembly has emerged as a powerful technique to organize small molecules into functional
materials with minimal effort. Disk-shaped molecules composed primarily of aromatic units often
code for the assembly of one-dimensional fibers or noncovalent nanotubes and are being
pursued as materials for photovoltaic active layers, sensors, and molecular wires. Planar coordination
complexes such as Krogmann’s Salt[1] also assemble into one-dimensional wires where
anisotropic metal-metal interactions aid in assembly and impart unique conductivity properties,
o�en inaccessible with purely organic analogues. We have designed disk-shaped macrocycles
that self-assemble through Pt-pyridyl coordination chemistry (Figure P10.1).[2] �ese macrocycles
exhibit columnar organization forming non-covalent nanotubes in solution and columnar
lyotropic mesophases upon concentration. DFT calculations suggest reductive doping of the
nanotubes may impart anisotropic conductivity.
Figure P10.1: Hierarchical self-assembly of Pt 4 rings from molecular components to nanotubes
and lyotropic liquid crystals.
References
[1] Krogmann, K. Angew. Chem. Int. Ed. 1969, 8, 35.
[2] Frischmann, P. D.; Guieu, S.; Tabeshi, R. MacLachlan, M. J. J. Am. Chem. Soc. 2010 132, 7668.
88

π 2011
N����
Posters – 10
89
Posters I: F

Posters – 11 π 2011
Functional Liquid Crystals – Synthesis and
Structure-Property-Relationship of Six-Armed Star-Shaped
Mesogens
B. Fröhlich, P. Maier and M. Lehmann
University of Würzburg
�e current intense investigation of discotic mesogens forming columnar LCs is motivated by
their unique structures and electronic properties.[1] Manifold promising applications in optoelectronic
devices such as organic light emi�ing diodes (OLED), field-effect transistors (FET) and
organic photovoltaic cells make such materials very a�ractive.[2]
�is project focuses on the synthesis and structure–property relationship of six-armed starshaped
molecules based on oligo benzoate arms linked to a benzene core with ester- or amidfunctionalities
(see Figure P11.1). Such mesogens form nanostructured columns by nanosegregation
of incompatible peripheral chains and polar core with the assistance of intermolecular hydrogen
bonds. �e nanomorphology is controlled synthetically by the variation of the elements
of diversity such as core, repeating units and peripheral chains. In addition host-guest chemistry
of pyridyl-substituted cores like 1 and its effect on mesophase formation will be studied.[3]
�e structure-property-relationship will be elucidated by microscopic methods, differential scanning
calorimetry, UV-Vis-, CD- and fluorescence spectroscopy, X-ray diffraction and modeling.
Figure P11.1: Six-armed star-shaped molecules 1 with different repeating units, functionalities
and peripheral chains.
90

π 2011
References
Posters – 11
[1] S. Laschat, A. Baro, N. Steinke, F. Giesselmann, C. Hägele, G. Scalia, R. Judele, E. Kapatsina,
S. Sauer, A. Schreivogel, M. Tosoni, Angew. Chem. 2007, 119, 4916–4973; Angew. Chem. Int.
Ed. 2007, 46, 4832–4887.
[2] S. Sergeyev, W. Pisula, Y. H. Geerts, Chem. Soc. Rev. 2007, 36, 1902–1929.
[3] M. Lehmann, Chem. Eur. J. 2009, 15, 3638–3651.
N����
91
Posters I: F

Posters – 12 π 2011
Synthesis, Coordination and Reduction of novel
Borole-Derivates
D. Gamon, H. Braunschweig, F. Breher, C. Chiu, A. Damme, T. Kupfer, D. Nied and K. Radacki
Universität Würzburg
�e increasing number of recent publications reveals non annulated boroles as a highly interesting
research field.[1] �is is due to the unique properties of borole-derivates like the high
Lewis-acidity derived from the empty p z orbital at boron, which is able to support the delocalization
of the antiaromatic 4π electron system.[2] �e energetically low lying LUMO is responsible
for the facile reduction of boroles furnishing their 6π electron containing aromatic dianions.[3]
We studied the reduction chemistry of the ferrocenyl substituted boroles 1 and 2 and found an
unexpected reduction-induced rearrangement of 1 to the dianion 3.[4] A migration of the borole-moiety
towards the metal-center was observed, which arises from the be�er π-donating
effect of the borole dianion compared to the cyclo-pentadienyl anion. In contrast, no such rearrangement
was observed upon reduction of 2 to the corresponding tetraanion. Furthermore we
were able to study the monoanion 4 via ESR, UV-Vis and theoretical analysis.
Moreover we present the synthesis and coordination of 1-cymantrenyl-2,3,4,5-tetraphenyl borole
5 which is a system that nicely demonstrate the characteristic high Lewis-acidity of boroles and
displays them as strong chromophors.
92

π 2011
References
Posters – 12
[1] a) H. Braunschweig, C.-W. Chiu, K. Radacki, T. Kupfer, Angew. Chem. Int. Ed. 2010, 49, 2041
(VIP), b) H. Braunschweig, I. Fernández, G. Frenking, T. Kupfer, Angew. Chem. Int. Ed. 2008,
47, 1951, c) H. Braunschweig, T. Kupfer, Chem. Comm. 2008, 4487.
[2] J. J. Eisch, J. E. Galle, S. Kozima, J. Am. Chem. Soc. 1986, 108, 379.
[3] C.-W. So, D. Watanabe, A. Wakamiya, S. Yamaguchi, Organometallics 2008, 27, 3496.
[4] H. Braunschweig, F. Breher, C.-W. Chiu, D. Gamon, D. Nied, K. Radacki, Angew. Chem. Int.
Ed. 2010, 49, 8975.
N����
93
Posters I: G

Posters – 13 π 2011
Star-Shaped Mesogens Combining Donor- and
Acceptor-Units in one Compound as a Potential New
Design Concept for Photovoltaic Materials
S. Gloza¹, M. Jahr² and M. Lehmann¹,²
¹Universität Würzburg, ²Technische Universität Chemnitz
�e conversion of light to chemical or electrical energy is not only a long existing and fascinating
process used successfully by plants and bacteria for energy production, but will be of increasing
relevance for power generation in the modern society.[1] Besides silicon based solar cells, organic
photovoltaic materials will provide photovoltaic devices with cheaper production costs and high
flexibility. �erefore, they will become progressively the focus of scientific interest, although
currently the efficiency η is low, comprising cells with η = 5.8 %.
Figure P13.1: Donor-acceptor substituted mesogens 1 and 2.
Star-shaped Mesogens (Hekates) fold and pack into hexagonal columnar and helical, orthorhombic
columnar structures.[2] �e combination of donor and acceptor chromophores, e. g. anthracene
and anthraquinone in one compound may result in new organic photovoltaic active
materials. Of crucial importance, however, is the separation of the chromophores, which will be
achieved by nanosegregation of peripheral chains (see Figure P13.1), such as alkyl or semiperfluorinated
chains. In this contribution, we present the five step synthesis towards Hekates 1 and
2 with three different arms with incompatible peripheral chains, different chromophores and
discuss their mesomorphic behaviour. �e photophysical and thermotropic properties are investigated
by UV-Vis, fluorescence spectroscopy, optical microscopy, differential scanning calorimetry
and X-ray sca�ering.
A�nowledgement: �is work was supported by DFG and BMBF.
94

π 2011
References
Posters – 13
[1] A. W. Hains. Z. Liang, M. A. Woodhouse, B. A. Gregg, Chem. Rev. 110, 6689-6735 (2010)
[2] M. Lehmann, Chem. Eur. J. 15, 3638-3651 (2009)
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Posters – 14 π 2011
Functional, Water-soluble Vesicular Aggregates Based on
Perylene Bisimide Dyes
D. Görl, X. Zhang and F. Würthner
Universität Würzburg
Amphiphilic perylene bisimides (PBIs) containing hydrophilic oligoethyleneglycol (OEG) units
at the imide position form well-defined fluorescent nanostructures such as micelles and vesicles
upon self-assembly or co-assembly in water that are precisely controlled by changing molecular
curvatures [1]. pH-sensitive vesicular nanocapsules have been achieved in water by loading energy
donor molecules into the PBI vesicles. �ese water-soluble vesicular nanocapsules provide
ultrasensitive pH information by displaying pH-dependent fluorescence color changes covering
the whole visible light range [2]. Recently we have synthesized crown-ether-functionalized
PBIs which display high fluorescence sensitivity toward biologically relevant metal ions. Coassembly
of crown-ether-functionalized PBIs with OEG-containing PBIs in water leads to functional
PBI vesicles with crown ether receptors on the surface that display fluorescence sensitivity
and selective recognition for different metal cations. It could also be shown that such receptorfunctionalized
vesicles are able to distinguish between Cu(II) and Ni(II) ions. Our recent results
on water-soluble, functionlized PBI vesicles will be discussed in our poster.
References
[1] X. Zhang, Z. Chen, F. Würthner, J. Am. Chem. Soc. 2007, 129, 4886 – 4887.
[2] X. Zhang, S. Rehm, M. M. Safont-Sempere, F. Würthner, Nature Chem. 2009, 1, 623 – 629.
96

π 2011
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Posters – 14
97
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Posters – 15 π 2011
Solution-Processed Organic Transistors Based on
Core-Chlorinated Naphthalene Diimides
M. Gsänger¹, M. Stolte¹, S.-L. Suraru¹, J. H. Oh², W.-Y. Lee², Z. Bao², J. Brill³, N. Langer³, H.
Klauk⁴, U. Zschieschang⁴ and F. Würthner¹
¹Universität Würzburg, ²Stanford University, ³InnovationLab GmbH, Heidelberg and BASF SE, Ludwigshafen ⁴Max Planck
Institute for Solid State Research, Stu�gart
Naphthalene diimides (NDIs) are among the most promising semiconductors for n-channel organic
field effect transistors (OTFTs).[1] Recently, we reported vacuum-processed n-channel
OTFTs based on chlorinated NDIs in the bo�om-gate, top-contact transistor configuration with
record electron mobilities of up to 1.3 cm 2 V – 1 s – 1 under ambient conditions.[2, 3] In this contribution
we will present results achieved by different solution-processing techniques in comparison
to vacuum deposition to obtain highly crystalline thin films of NDIs from chlorinated
solvents. Surface treatment of the gate dielectric by different self-assembled monolayers (SAM)
as well as the optimization of the deposition conditions were performed to influence the thin
film morphology. Additionally, the influence of the substituents of the molecules on the thin-film
morphology, the field-effect mobilities, and the ambient stability of the OTFTs were investigated.
References
[1] F. Würthner, M. Stolte Chem. Commun. 2011, 47, 5109-5115.
[2] J. H. Oh, S.-L. Suraru, W-Y. Lee, M. Könemann, H. W. Hö�en, C. Röger, R. Schmidt, Y. Chung,
W-C. Chen, F. Würthner, Z. Bao Adv. Funct. Mater. 2010, 20, 2148.
[3] M. Stolte, S.-L. Suraru, F. Würthner, J. H. Oh, Z. Bao, J. Brill, M. Könemann, J, �, U. Zschieschang,
H. Klauk Proc. of SPIE 2010, 7778, 777804-1.
98

π 2011
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Posters – 15
99
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Posters – 16 π 2011
Self-assembly of Multichromophoric Systems: The
Interplay of Different Secondary Interactions of Benzene
Amide Derivatives Containing 1,8-Naphthalimides
A. T. Haedler, K. Kreger, D. Han� and H.-W. Schmidt
Universität Bayreuth
Self-assembled multichromophoric systems are envisioned to serve as materials for organic solar
cells with improved performance. Promising candidates to meet this task are supramolecular
π-functional materials. However, fundamental research is required on the interplay of multiple
secondary interactions to get a be�er insight into different self-assembly mechanisms. Here we
present a novel class of chromophore-containing benzene-amides featuring two secondary interactions,
i.e., H-bonding and π-π stacking. 1,8-Naphthalimides were a�ached as chromophores
via an amide linkage in different quantities and geometries adjusting the strength of the intermolecular
interactions (1a, 2a, 3a, 4a). Additionally, as reference compounds the corresponding
ester analogs (1b, 2b, 3b, 4b) were prepared to study π-π interactions only. Scanning Electron
Microscopy (SEM) was conducted on self-assembled samples of the amide compounds from solution
revealing nano-fibrilar structures as commonly observed for H-bonded systems. In contrast,
continuous π-stacking is evidenced for compound 1b by single crystal x-ray diffraction analysis.
Furthermore, amorphous thin films of all compounds were prepared and investigated. FT-IR and
fluorescence spectroscopy were used to study H-bonding and π-π interactions, respectively. We
demonstrate that the morphologies in thin film architectures depend on the diverse intermolecular
interactions revealing a competitive behavior between H-bonding and π-π stacking.
Figure P16.1: Synthesized and investigated chromophore-containing benzene-amid- and –ester
compounds.
100

π 2011
Posters – 16
Acknowledgement: �is work was supported by the DFG Research Training Group (GRK1640)
“Photophysics of Synthetic and Biological Multi�romophoric Systems”. ATH also acknowledges
the support by the Elite Study Program – Macromolecular Science (Elite Network of Bavaria) and
the “Universität Bayern e.V.” for the scholarship.
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Posters – 17 π 2011
Modeling cylindrical J-aggregates
of an amphiphilic cyanine dye
F. Haverkort, A. Stradomska, J. Knoester
University of Groningen, Netherlands
Cylindrical molecular aggregates are potential candidates for application in artificial light-harvesting
systems and as energy transport wires. In order to understand their optical and energy
transport properties, the electronic structure must be known, which in turn demands knowledge
of the structure at the molecular scale. We address this issue by performing molecular
dynamics simulations of the aggregate formation. We choose to model aggregates of the amphipseudoisocyanine
dye (amphi-PIC, see Fig. P17.1), which have been used in recent experiments
on exciton transport [1]. First, a molecular dynamics force field parametrisation is obtained for
the dihedral angle between the quinoline rings of the amphi-PIC monomer.
Knowing the aggregate structure, the couplings between the amphi-PIC monomers can be calculated.
Because of the close proximity of the monomers, calculating the couplings in the point
dipole or the extended dipole approximation gives an incorrect result. �erefore a more precise
scheme is needed. We calculate the atomic transition charges using the TrEsp method [2].
Having obtained the couplings, modeling the exciton transport will be within reach.
References
Figure P17.1: �e amphi-PIC monomer.
[1] A. Sorokin, I. Filimonova, R. Grynyov, G. Guralchuk, S. Yefimova, Y. Malyukin, J. Chem. Phys.
C 114, 1299 (2010)
[2] M. Madjet, A. Abdurahman, T. Renger, J. Phys. Chem. B 110, 17268 (2006)
102

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103
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Posters – 18 π 2011
Dispersion of carbon nanotubes by sonication and shear
mixing
T. Hefner, S. Stahl and T. Hertel
Universität Würzburg
Here we present a comparative study of the dispersion of single wall carbon nanotubes in aqueous
surfactant solution by sonication and shear mixing. Sonication is a widely-used technique to disperse
carbon nanotubes (CNTs) but it is also known to cause considerable damage to CNTs which
in turn can lead to a significant reduction of photoluminescence quantum yields. Shear mixing is
here studied as an alternative, less aggressive means for dispersing carbon nanotubes in aqueous
or organic solvents. We compare the efficiency of sonication and shear mixing techniques for disassembly
of nanotube aggregates and the effect that they have on photoluminescence quantum
yields of CNTs in dispersion.
104

π 2011
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Posters – 18
105
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Posters – 19 π 2011
Photoionization of hydroxyl-substituted
[2,2]paracyclophanes with VUV synchrotron radiation
P. Hemberger¹, C. Schon¹, M. Steinbauer², K. H. Fischer², I. Fischer², A. Bodi¹ and M.
Johnson¹
¹Paul Scherrer Institut, Switzerland, ²Universität Würzburg
π-conjugated molecules are widely applied in optoelectronic devices such as organic light emitting
diodes. Paracyclophanes are possible new candidates to expand the variety of these materials
because of their interesting physical properties, like high electronic conductivity, due to the
coupling between the two benzene rings.[1]
�e photoionization and dissociative photoionization of hydroxyl-substituted [2,2]paracyclophanes
were investigated at the VUV beamline of the Swiss Light Source, especially the substituent
effects on the ionization energies when the benzene frameworks are hydroxyl-substituted.
Additionally, photoionization data help interpret our previous UV measurements in the gas
phase.[1-3]
At a photon energy of around 10 eV, the sample starts to dissociatively photoionize. �e most
prominent channel is the dissociation of both C−C bonds of the −CH 2−CH 2− bridges in para
position between the two phenol rings leading to the molecule fragmenting in half. A few minor
dissociative photoionization channels were also identified, for example CO loss, H 2O loss and the
asymmetric fragmentation of the −CH 2−CH 2− bridges. �e data were subsequently modeled
taking into account the thermal energy distribution of the neutral sample and the experimentally
determined dissociation rate constants in order to obtain appearance energies, which then lead
to bond dissociation energies and other thermochemical data.
106

π 2011
References
Posters – 19
[1] C. Schon, W. Roth, I. Fischer, J. Pfister, C. Kaiser, R. F. Fink, B. Engels, Phys. Chem. Chem.
Phys., 2010, 12, 9339.
[2] C. Schon, W. Roth, I. Fischer, J. Pfister, R. F. Fink, B. Engels, Phys. Chem. Chem. Phys., 2011,
13, 11076.
[3] J. Pfister, C. Schon, W. Roth, C. Kaiser, C. Lambert, K. Gruss, H. Braunschweig, I. Fischer, R.
F. Fink, B. Engels, J. Phys. Chem. A, 2011, 115, 3583.
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Posters – 20 π 2011
FTIR- and Ramanspectroscopy of Substituted
Paracyclophane Molecules
J. Herterich, S. Zeißner and I. Fischer
Universität Würzburg
What is pu�ing paracyclophanes in our focus? It’s the interaction between π-systems combined
with an unusual three-dimensional structure. �e paracyclophanes also arouse interest because
of their character. Paracyclophanes are both: aromatics and aliphates with through-bond and
through-space interactions. (Para)cyclophanes are characterized by the specific geometric and
electronic properties of the aromatic rings. �erefore, a variety of two- and three-dimensional
structures can be built by connecting aromatic rings. �e extraordinary configuration of the
paracyclophanes is asking questions like:
• Which configurations and conformations are preferred?
• What influence has the change in the bridge length?
• What role do π-π interactions play?
In this work we investigated the ground state geometry of 4-Hydroxy-[2.2]Paracyclophane and
2,11-Dithia-[3.3]Paracyclophane via IR- and Raman spectroscopy. Comprehensive theoretical
studies were performed by using two unrestricted DFT methods, B3LYP and wB97xD. �e wB97xD
method, which is considering dispersion, yields best results for our systems.
108

π 2011
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Posters – 20
109
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Posters – 21 π 2011
Synthesis of new π-conjugated Boroles
C. Hörl, H. Braunschweig, A. Damme, L. Mailänder and K. Radacki
Universität Würzburg
During the last decades boron-containing π-conjugated systems have a�racted considerable attention
because of their remarkable nonlinear optical properties. For instance Shirota and coworkers
have demonstrated that Mes 2B-functionalized bithiophene derivatives act as electron
transport layer in organic light emi�ing devices (OLEDs).[1, 2]
�e key features of boron, such as the vacant p-orbital, high Lewis acidity, and trigonal geometry
are responsible for the interesting characteristics of boron-containing materials.
Boroles are unsaturated, extreme electron deficient, pentacyclic molecules featuring a 4π electron
system. Due to their photopysical properties and close relationship to the cyclopentadienyl
cation, boroles are of fundamental interest. �e empty p� orbital at the boron shows a strong
tendency for p-π interactions with extended organic systems. Based on this we present the synthesis
of the first boroles connected to different heterocycles (thiophene, pyrrole, furane) which
are substituents at boron.
Similar to the previously described pentaphenyl- and ferrocenyl-substituted derivatives, 1, 2, 3
and 4 can be obtained via tin-boron exchange reaction.[3-6]
110

π 2011
References
Posters – 21
[1] T. Noda, Y. Shirota, J. Am. Chem. Soc. 1998, 120, 9714.
[2] H. Li, A. Sundararaman, K. Venkatasubbaiah, F. Jäkle, J. Am. Chem. Soc. 2007, 129, 5792.
[3] J. J. Eisch, J. E. Galle, S. Kozima, J. Am. Chem. Soc. 1986, 108, 379.
[4] H. Braunschweig, T. Kupfer, Chem. Comm. 2008, 37, 4487.
[5] H. Braunschweig, I. Fernandez, G. Frenking, T. Kupfer, Angew. Chem. 2008, 120, 1977; Angew.
Chem. Int. Ed. 2008, 47, 1951.
[6] H. Braunschweig, T. Kupfer, Chem. Comm. 2011, DOI: 10.1039/c1cc13071d.
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Posters – 22 π 2011
Probing the wave-function of π-conjugated molecules
S. Huppmann¹, M. Wiessner¹, M. Scholz¹, J. Ziroff¹, P. Puschnig², A. Schöll¹ and F. Reinert¹ ³
¹Universität Würzburg, ²Universität Leoben, Austria, ³Karlsruher Institut für Technologie KIT
Wave-function tomography using angular resolved photoemission is a fascinating method to visualize
the highest occupied molecular orbitals and even their modification upon interaction with
substrates [1, 2]. �e combination with quantum-chemical calculations, like density functional
theory (DFT), can clearly explain the measured intensity distributions. However, this theory neglects
sca�ering of the emi�ed photoelectrons, which might possibly be enhanced in the presence
of metal atoms in the molecule [3].
�e experimental test on this influence can be done by comparing phthalocyanines (Pc) with
metal atoms (e. g. copper(II) phthalocyanine (CuPc)) with the metal free phthalocyanine (H 2Pc).
�e geometric arrangement of Pcs usually shows many domains, which smear out the detailed
angular information. By using the (1x2) reconstruction of the Au (110) surface one can induce
a quasi 1-dimensional chain-like growth mode of these molecules. By this approach, we can
compare the highest occupied orbital of the CuPc with the H 2Pc and determine the influence of
the central metal atom.
Another intriguing aspect of wave-function tomography is the application on highly ordered
monolayers of coronene. On the Ag (111) surface the coronene overlayer can be regarded as a
graphene quantum-well structure, each quantum-well separated by terminating hydrogen atoms.
�e electronic structure of this system can be explained by the formation of lateral graphene
quantum-well states: the k-dependent photoemission spectra exhibit discrete states whose position
in k-space follows the band structure of the 2D infinite graphene. From a quantum-chemical
point of view, each of these states can be seen as a molecular orbital, whose k-dependent photoemission
distribution is given by the Fourier transformation of the respective density. Here
we show that both explanations - the evolution of quantum-well states as well as the quantumchemical
approach - provide the same results.
References
[1] Puschnig et al., Science, 326, 702 (2009).
[2] Ziroff et al., Phys. Rev. Le�. 104, 233004 (2010)
[3] Kera et al., Chem. Phys. 325, (2006), 113–120.
[4] F. Evangelista et al., J. Chem. Phys. 131, 174710 (2009).
[5] M. Shang et al., J. Electon. Spectrosc. 184, 261 (2010).
112

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113
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Posters – 23 π 2011
Single Molecule Studies of Calix[4]arene-linked Perylene
Bisimide Dimers with Spectral and Temporal Resolution
A. Issac¹, D. Ernst¹, C. Hippius², F. Würthner² and J. Köhler¹
¹Universität Bayreuth, ²Universität Würzburg
Initial studies of single calix[4]arene linked perylene bisimide dimers embedded in a polymer
matrix revealed changes of the fluorescence intensity between high, medium and the background
levels [1]. �e change from the highest level to the background is a�ributed to an efficient energy
transfer between a neutral bisimide monomer unit and its radical anion, whereas the medium
intensity level presumably reflects the photoreduction of one of the monomer units. According
to the chronological order of the intensity levels the studied dimers were grouped into three
categories.
Here we report about recent experiments where we recorded the different signal levels together
with either the emission spectra or the fluorescence lifetime. �is additional information allows
us to identify the involved intermediate states in the three categories.
References
[1] D.Ernst, R.Hildner, C. Hippius, F. Würthner, J. Köhler, Chem.Phys.Le�. 2009, 482 93-98.
114

π 2011
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Posters – 23
115
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Posters – 24 π 2011
Time Resolved Spectroscopy of Charge Separation and
Recombination in
Triarylamine-Naphtalinbisimide-Substituted
Paracyclophanes
C. Kaiser and C. Lambert
Universität Würzburg
Optically induced charge separation, recombination and associated processes can be understood
best by investigating simple donor-acceptor model systems. Focus of our work was the synthetically
challenging incorporation of tiny π-stacks mimicked by paracyclophane bridges into
such small systems. Upon investigation of these compounds by transient spectroscopy from the
microsecond down to the femtosecond timescale our compounds show high quantum yields of
charge separation upon excitation. �e charge separation is followed by a considerable amount of
intersystem-crossing resulting in the population of long living charge separated states. Spectroelectrochemical
studies in combination with a serendipitous proportion of the charge separated
state lifetimes in the upper nanosecond and lower microsecond regime allow new insights into
the charge recombination processes.
116

π 2011
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Posters – 24
117
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Posters – 25 π 2011
Time-resolved electron-transfer properties of a
low-band-gap neutral mixed-valence polymer
F. Kanal, T. �ast, M. Kullmann, S. Ruetzel, J. Buback, S. Keiber, D. Reitzenstein, C. Lambert
and T. Brixner
Universität Würzburg
�e formation, migration and separation of charges in polymers used for photovoltaic devices
are important processes a�er optical excitation. We present liquid-phase femtosecond pumpprobe
spectroscopy of the electron-transfer properties of a polyradical consisting of alternating
triarylamine donor and triarylmethyl radical acceptor moieties. �is first polymeric neutral
mixed-valence compound shows an intervalence charge transfer (IVCT) band in the near infrared.
�erefore it is a�ractive for photovoltaic applications as well as for model studies of the electron
transfer in polymeric donor-acceptor systems.
�e polyradical and a reference monomer [1] were investigated in two solvents of different polarity
[2]. Excited in the visible spectral range and probed with a whitelight supercontinuum,
the transient spectra of the polyradical feature three bands around 430 nm, 550 nm and 650 nm.
�ese bands are assigned to the ground state bleach and characteristic transitions of the anion and
the radical cation, respectively, which are formed upon optically induced electron transfer. �e
decay curves of the polymer exhibit a biexponential decay in the picosecond time regime. �e
short-living – solvent dependent – component refers to the direct decay from the IVCT state to
the ground state which is faster in the more polar solvent. �e long-living – solvent independent
– component is tentatively a�ributed to an equilibrium formation of the IVCT state and a completely
charge-separated state. Unable to achieve a complete charge separation, the monomer
shows just a monoexponential decay a�ributed to the direct decay of the IVCT state.
References
[1] S. Dümmler, W. Roth, I. Fischer, A. Heckmann, and C. Lambert, Chem. Phys. Le�. 408, 264
(2005).
[2] D. Reitzenstein, T. �ast, F. Kanal, M. Kullmann, S. Rützel, M. S. Hammer, C. Deibel, V.
Dyakonov, and T. Brixner, C. Lambert, Chem. Mater. 22, 6641 (2010).
118

π 2011
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Posters – 25
119
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Posters – 26 π 2011
Tailoring the optical gap in light harvesting molecules
A. Karolewski and S. Kümmel
Universität Bayreuth
�e reliable calculation of charge-transfer (CT) excitations from first principles is an a�ractive
task because it allows theory to provide guidance in the design of light harvesting molecules.
In the past Time-Dependent Density Functional �eory has become infamous for its inability
to predict CT excitations, in particular for molecules of practically relevant complexity. Here
we show by using a range-separated hybrid functional with a non-empirical tuning of the range
separation parameter that we are able to deal with practically relevant CT problems. We calculated
the photoabsorption spectra of donor-acceptor-donor systems with a variable number of
thiophene rings acting as the donors. In this way we systematically vary the optical gap that is
associated with CT excitations. Our calculated absorption energies agree with measured ones.
Other range separated hybrid functionals with globally fi�ed parameters do not describe these
excitations correctly. We predict the lowest absorption energy that is reached in the limit of an
infinitely extended donor system. �us TDDFT can assist in tailoring the gap of light harvesting
molecules that are used in the design of organic solar cells[1].
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π 2011
References
[1] A. Karolewski, T. Stein, R. Baer and S. Kümmel, J. Chem. Phys. 134, 151101 (2011)A
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121
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Posters – 27 π 2011
Synthesis of Complete and Partial Ortho-Methylated
Tribenzotriquinacenes
Y. Kirchwehm and A. Krueger
Universität Würzburg
Tribenzotriquinacene (TBTQ) 1 and its centro-substituted derivatives represent completely benzoannelated
congeners of the centropolyindane family.[1] Due to their three mutually fused indane
units, the molecular framework is characterized by its conformational rigidity: the bowlshaped
structure exhibits a C 3v-symmetry.
�e benzoannelation is associated with both a stabilization of the triquinacene core and an increased
reactivity of the three equivalent bridgehead positions.[2] Furthermore, substitution at
the aromatic periphery offers a great potential for expanding the molecular framework.[3]
�e synthetic approach to TBTQs usually proceeds via a three-step synthesis with a double cyclodehydration
as the final step. However, subsequent substitution at the baywards oriented
“ortho”-positions is not possible due to steric hindrance. We present a synthetic access to such
sterically crowded TBTQs based on the introduction of the substituents at the beginning of the
synthetic scheme.
References
[1] L. Zhou, T.-X. Zhang, B.-R. Li, X.-P. Cao, D. Kuck, J. Org. Chem. 2007, 72, 6382-6389.
[2] D. Kuck, T. Lindenthal, A. Schuster, Chem. Ber. 1992, 125, 1449-1460.
[3] D. Kuck, A. Schuster, R. A. Krause, J. Tellenbröker, C. P. Exner, M. Penk, H. Bögge, A. Müller,
Tetrahedron 2001, 57, 3587-3613.
122

π 2011
Posters – 27
Me 3-TBTQ 2a, Me 7-TBTQ 2b and Me 6-TBTQ 2c were isolated in multi-step syntheses and represent
the first TBTQ derivatives with substituents in “ortho”-position to the triquinacene core.
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Posters – 28 π 2011
Photoinduced charge transfer properties of donor and
acceptor substituted iridium(III)-complexes containing
dipyrromethane-ligands
J. H. Klein, T. L. Sunderland and C. Lambert
Universität Würzburg
Cyclometalated iridium(III)-complexes are widely used as triplet emi�ers in OLED devices, but
there are only few investigations in the field of photoinduced electron transfer. We chose donor
and acceptor substituted iridium(III)-complexes to achieve an efficient electron transfer across
long distances.[1] We used triarylamines (TAA) for the donor and naphthalinediimide (NDI) for
the acceptor unit. A new approach was to employ dipyrromethane ligands to synthesise neutral
iridium(III)-complexes. All compounds were electrochemically and photophysically characterised.
Transient absorption measurements in the fs to ns regime show the formation of the
charge separated state by the rise of the TAA cation and the NDI anion band.
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π 2011
References
[1] Geiß, B.; Lambert, C. Chem. Commun. 2009, 1670–1672.
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125
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Posters – 29 π 2011
Ultrafast dynamics of a new model bisporphyrin
M. Kullmann, A. Hipke, P. Nuernberger, D. C. G. Götz, G. Bringmann and T. Brixner
Universität Würzburg
Tetrapyrroles and their metallated derivatives are ubiquitous in nature. �e unique spectroscopic,
photophysical, and photochemical properties of this large family of compounds have resulted in
their use in applications as diverse as organic solar photovoltaic cells, photodynamic therapy,
oxygen sensors, and molecular electronics. �e studies described in the present contribution offer
insight into the photochemistry of an intrinsically axially chiral, directly β, β ′ -linked porphyrin
dimer, bis[tetraphenylporphyrinato-zinc(II)] (ZnTPP) 2.
Results from a comparative fs-resolved transient absorption study of (ZnTPP) 2 and its monomeric
subunit ZnTPP a�er excitation to their respective first and second excited electronic state are
presented.
Findings obtained from global analysis schemes, covering time scales ranging up to the nanosecond
regime, applied to both molecules will be discussed. �e monomer’s relaxation process,
which is in strong agreement with the literature, differs significantly from the dimer’s kinetics.
Preliminary interpretations based on this observation, the excitonic character of the dimer, and
on comparisons with similar literature-known compounds [1] will be discussed.
Figure P29.1: ZnTPP 2 (le�) and corresponding evolution-associated difference spectra (right)
showing the relaxation pathways a�er excitation into the energetically higher lying
excitonic S 2-state
References
[1] R. Kumble, S. Palese, V. S.-Y. Lin, M. J. �erien, and R. M. Hochstrasser, J. Am. Chem. Soc
120, 44 (1998).
126

π 2011
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127
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Posters – 30 π 2011
Assessment of the exciton transfer and charge transport
parameters for large π-conjugated aggregates through an
ab initio model Hamiltonian method
W. Liu¹ ², V. Se�els², A. Dreuw¹, B. Engels² and R. Fink² ³
¹Universität Heidelberg, ²Universität Würzburg, ³Universität Tübingen
A model Hamiltonian (MH) method, which was proposed by P. Petelenz,[1] gives direct information
of exciton coupling parameter and charge (hole/electron) transport parameters for dimer
systems. �is method introduces four energetically lowest excited states in a localized picture,
which are two neutral excited (NE) and two charge transfer (CT) states. By consider the coupling
of these four excited states one immediately gets a 4 × 4 matrix, and originally these matrix elements
are achieved by fi�ing with either experimental or theoretical data. In this following work,
we give implicitly clear definition for the four excited states that allow us to evaluate the matrix
elements in an ab initio manner. �e method has been tested on a symmetrized PBI dimer system
and shows surprisingly good agreement with the SCS-CC2 method (Fig. P30.1).[2] Furthermore,
this method can be extended for considering larger non-symmetry aggregates.
Figure P30.1: Potential energy of the ground state and the energetically lowest four excited states
of PBI dimer.
References
[1] Petelenz P., Chem. Phys. Le�. 47, 603 (1977)
[2] Liu, W., Ph.D. thesis, Julius-Maximilians Universität Würzburg, Würzburg, (2011)
128

π 2011
N����
Posters – 30
129
Posters I: L

Posters – 31 π 2011
Simulation of Exciton Diffusion in
Aluminium-tris-(8-hydroxy-quinoline)
B. Lunkenheimer and A. Köhn
Universität Mainz
Modern organic light emi�ing diodes (OLEDs) play an important role in research and industry
because of their promising optical properties. We are interested in ge�ing a basic atomistic
understanding of excitons in OLEDs. Our aim is to simulate exciton diffusion in layers of typical
OLED materials with the help of kinetic Monte Carlo (KMC)-methods [1]. For triplet excitons it
is assumed that Marcus theory delivers a reasonable rate approximation to describe the exciton
transfer from donor to acceptor molecule [2] with a minimal input: electronic transfer integral
V , reorganisation energy λ and site energy difference ∆ɛ.
�e transfer integral V can be estimated within the Förster or Dexter approach [3] but also via
Davydov spli�ing. In addition the consideration of charge transfer (CT) excitons is important for
a complete picture.
Figure P31.1: Exciton diffusion pathways in the β-crystal structure of Aluminium-tris-
(8-hydroxy-quinoline), Alq3. �e bright coloured path is prefered.
We will characterize the processes regarding excitons in the prototypical OLED material Alq3
by means of quantum chemistry. Furthermore we will present our results for the simulation of
triplet exciton diffusion in the crystalline β-phase of Alq3 (see fig. P31.1).
References
[1] A. F. Voter, in Radiation Effects in Solids edited by K. E. Sickafus and E. A. Kotomin (Springer,
NATO Publishing Unit, Dordrecht, �e Netherlands, 2005)
[2] A. Köhler and H. Bässler, J. Mater. Chem. 21 (2011), 4003
[3] G. D. Scholes, Annu. Rev. Phys. Chem. 54 (2003), 57
130

π 2011
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Posters – 31
131
Posters I: L

π 2011
Posters
Second Session
Posters
133
Posters II

Posters – 32 π 2011
�antum Chemical Investigations of OLED Emi�ers
M. Kleinschmidt and C. M. Marian
Universität Düsseldorf
In organic light emi�ing diodes (OLEDs), electric current is converted into visible light by means
of phosphorescent emi�ers. An electronically excited state is generated by charge recombination
preferrably at or close to the emi�er. Spin statistics leads to ¾ of the molecules generated in the
triplet state and ¼ as singlets.
Efficient intersystem crossing is necessary for the phosphorescence as well as for harvesting
the 25% of singlet molecules. To achieve the necessary large spin-orbit coupling, organic complexes
containing heavy metals like Ir, Ru, Rh or Os are used. �e challenge for a computational
treatment is to accurately calculate the emission wavelength as well as spin-orbit coupling and
phosphorescence rates.
�e DFT/MRCI method is capable of giving very reasonable energies for excited states in larger
molecules[1]. We use it in combination with the spin-orbit coupling kit SPOCK, developed in
our laboratory[2, 3]. All calculations are based on geometries obtained with the TURBOMOLE
package.
We present calculated phosphorescence wavelengths and lifetimes of different Ir–containing
OLED emi�ers, which show the good agreement with available experimental data.
References
[1] S. Grimme, M. Waletzke, J. Chem. Phys. 111, 5645-5655 (1999)
[2] M. Kleinschmidt, J. Tatchen, C. M. Marian, J. Comput. Chem. 23, 824-833 (2003)
[3] M. Kleinschmidt, C. M. Marian, Chem. Phys. 311, 71-79 (2005)
134

π 2011
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Posters – 32
135
Posters II: M

Posters – 33 π 2011
Hierarchically Structured Materials for Organic Electronics
R. Marty and H. Frauenrath
École Polytechnique Fédérale de Lausanne, Switzerland
Hierarchically structured synthetic polymers containing monodisperse π-conjugated segments
could offer intriguing perspectives for organic electronic devices and sensors. Previous investigations
in our group had revealed that a precise control of position, orientation, and reactivity
of π-conjugated molecular fragments was achieved by directional non-covalent interactions, i.e.
N−H · · · O−C hydrogen-bonding. �e investigated diacetylene macromonomers gave rise to
well-defined fibrillar features with a length of several micrometers and a uniform width of a
few nanometers.[1] Similar aggregates were found for symmetric oligopeptide-polymer conjugates
bearing quarter- and sexithiophene as well as perylene bisimide as organic semiconducting
segments. �e aggregation behavior was investigated by IR, CD, UV/VIS, and fluorescence
spectroscopy and the formation of fibrillar aggregates was proven by AFM. �e fibrillar arrangement
brings the π-conjugated segments in close contact so that nanowires with a well-defined
charge percolation path should be obtained. Dilute solutions (0.2 wt%) of these nanowires were
solution-cast into a non-solvent whereby microfibers were produced that had a length of several
centimeters and a width of 20 micrometer uniform throughout the length of the microfiber. Most
interestingly, SEM investigations showed that the threads were constituted from highly aligned
nanowires parallel to the microfiber axis, supposedly, resulting from the shear forces present at
the moment of dispensing.[2] �e details of the internal structure of these microfibers will be
investigated by means of SAXS/WAXS, fluorescence- and polarized optical microscopy, as well
as linearly polarized UV/VIS and IR-spectroscopy.
References
[1] H. Frauenrath et al. Adv. Mater. 2008, 20, 409.
[2] S. I. Stupp et al. Nature Mater. 2010, 9, 594.
136

π 2011
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Posters – 33
137
Posters II: M

Posters – 34 π 2011
Multiblock π-conjugated copolymer architectures as
charge-qubits
C. A. Mujica-Martinez and M. Thorwart
Universität Hamburg
Among the several possibilities to construct ‘quantum hardware’, solid-state based nanostructures
are highly promising candidates for the realization of quantum information processing
devices, exhibing a particularly high degree of scalability. Traditionally, inorganic semiconductor
heterostructures have been used to control the spatial degrees of freedom of charge carriers,
obtaining quantum dots, wells, and wires. Here, we suggest a different alternative in form of πconjugated
block copolymers. �ey can be considered as unimolecular organic heterostructures,
and allow to construct various different forms. �e advantage is that the interface between the
materials is a chemical carbon-carbon bond, in contrast to the inorganic devices which require
the materials to exhibit similar la�ice constants to avoid interfacial stress. We report the conceptual
design of charge-qubits based on poly-(p-phenylene) (PPP) and poly-diacetylene (PDA)
π-conjugated heterostructures. Initially, we design quantum dot structures with a single confined
state in the conduction band. �e charge qubit arises when two quantum dots are localized
in the same molecule, such that the electronic wave functions in each dot overlap. �e resulting
energy spli�ing can thus be controlled. For the single negatively doped heterostructure, the state
of the charge-qubit is specified when the electron is in the le�/right dot respectively. �e results
indicate a high versatility in the control of the confined states, as well as the possibility to control
the structured vibrational environment that influence the electronic coherence.
138

π 2011
N����
Posters – 34
139
Posters II: M

Posters – 35 π 2011
Modeling electronic and charge transport properties of
ambipolar and n-type organic semiconductors
F. Negri and S. Di Mo�a
Università degli Studi di Bologna, Italy
Recently synthesized quinoidal oligothiophenes have been shown to be promising materials for
their proved amphoteric properties[1], and also for their near infrared (NIR) absorption features,
driven by the reduction of their HOMO-LUMO energy gap, that make them of potential use in the
field of organic photodetectors. Here we present evidence[2] for the biradicaloid and polyenic
character of quinoidal oligothiophenes by proving at CASSCF//CASPT2 computational level the
presence of a low lying double exciton state responsible for the weak features observed in the
NIR absorption region of the longest members of this class of molecules. �e identification of
the doubly exciton state offers a unified view of the low lying electronic states for quinoidal
oligothiophenes and polyenes.
Among n-type organic semiconductors perylene bisimide (PBI) have been shown to display
promising electron mobilities. �e solid state packing and functional properties of PBIs can be
tailored by the introduction of appropriate substituents in the imide position or by core substitution
in the bay region.[3] Here we discuss charge transport properties, modeled by propagating
the charge carrier in the crystals of planar-core and core-twisted PBIs (see Figure P35.2), with
a kinetic Monte Carlo scheme. �ermally induced dynamical effects are investigated by means
of molecular dynamics simulations coupled to quantum-chemical evaluation of electronic couplings
V ij. �e study reveals that the reduced π − π stacking induced by core-twisting influences
not only static properties of the molecular material but also dynamical effects that should be
considered in the design of future organic semiconductor architectures.
140
Figure P35.1 Figure P35.2

π 2011
References
Posters – 35
[1] Ortiz, R. P., Casado, J., Hernandez, V., Navarrete, J. T. L., Orti, E., Viruela, P. M., Milian, B.,
Ho�a, S., Zo�i, G., Zecchin, S.et al. Adv. Func. Mat. 2006, 16, 531-536.
[2] S. Di Mo�a, F. Negri, D. Fazzi, C. Castiglioni, E. V. Canesi J. Phys. Chem. Le�. 2010, 1, 3334.
[3] Schmidt, R.; Oh, J. H.; Sun, Y. S.; Deppisch, M.; Krause, A. M.; Radacki, K.; Braunschweig, H.;
Konemann, M.; Erk, P.; Bao, Z. A.; Würthner, F. J. Am. Chem. Soc. 2009, 131, 6215-6228.
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Posters – 36 π 2011
Electronic structure of Copper phthalocyanine monolayer
on Graphene/Ru(0001) surface
T.-N. Nguyen¹, M. Scholz¹, S. Huppmann¹, M. Ernst¹, A. Schoell¹, D. Ehm² and F. Reinert¹
¹Universität Würzburg, ²Carl Zeiss SMT GmbH
We have studied the electronic structure of single layers of copper phthalocyanine (CuPc) on
graphene/Ru(0001). �e CuPc monolayers were prepared on graphene/Ru(0001) by using organic
molecular beam deposition (OMBD). �e surface structure of CuPc was measured by low energy
electron diffraction (LEED) and angle-resolved photoemission spectroscopy (ARPES) was used
to investigate the electronic structure of the CuPc monolayer. We show that there is a strong
coupling between the CuPc molecule and the gaphene/Ru(0001) surface. �is is reflected by the
ARPES data that shows a HOMO peak at a binding energy of 2.1 eV and an additional signal near
the Fermi edge at about 0.8 eV. �is can be assigned to the former LUMO (F-LUMO) state [1]
which is (partly) occupied due to the strong interaction between the graphene/Ru(0001) surface
and the CuPc and a subsequent charge transfer in to the molecule [2].
References
[1] Zou, Y., et al., Chemical bonding of PTCDA on Ag surfaces and the formation of interface
states. Surface Science, 2006. 600(6): p. 1240-1251.
[2] Stadtmuller, B., et al., Submonolayer growth of CuPc on noble metal surfaces. Physical Review
B, 2011. 83(8).
142

π 2011
N����
Posters – 36
143
Posters II: N

Posters – 37 π 2011
Ab initio Calculations on the Triplet Properties of Organic
Semiconductor Molecules
M. Pabst¹, D. Sundholm² and A. Köhn¹
¹Universität Mainz, ²University of Helsinki, Finland
�e majority of present day’s organic light emi�ing devices (OLEDs) are constructed of hostguest
systems on the basis of modern triplet emi�ers by reason of their high efficiency, i.e. nearly
100% internal quantum yield.[1] However, the efficiency decreases drastically at higher current
densities which is mainly caused by interactions between triplet excitons, in particular by triplettriplet
annihilation (TTA).[2]
Figure P37.1: Sketch of the desired triplet energies of emi�er (guest) molecules in fluorescent and
phosphorescent OLEDs compared to the triplet energy of the host material.
In order to understand the stabilization of triplet excitons and the process of TTA, the knowledge
of triplet energies E T and triplet absorption spectra is crucial. �e triplet energies are relevant
for a proper choice of the matrix material matching the properties of the emi�ing dye. For
phosphorescent OLEDs the matrix is required to stabilize the triplet excitons on the emi�er dyes
to prevent the exciton from diffusion through the matrix. For the design of fluorescent OLEDs
and organic lasers, on the other hand, a higher triplet energy on the dopant (fluorescent dye)
compared to the matrix is needed to prevent triplet quenching in the device (see Figure P37.1).
144

π 2011
Posters – 37
Here we present our results on the triplet energy and triplet absorption spectra of 30 state of the
art organic semiconductor compounds determined with accurate ab initio second order methods.[3,
4] In addition, we comment on the predictability of the molecular properties from the
properties of the chromophore fragments.
References
[1] M. A. Baldo et al., Nature 395, 151 (1998)
[2] M. A. Baldo, C. Adachi and S. R. Forrest, Phys. Rev. B 62, 10967 (2000)
[3] M. Pabst and A. Köhn, J. Chem. Phys. 129, 214101 (2008)
[4] M. Pabst, D. Sundholm and A. Köhn, in preparation.
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Posters – 38 π 2011
The signatures of vibrations in exciton dynamics and in
absorption of Perylene Bisimide molecular aggregates
S. Polyutov and O. Kühn
Universität Rostock
Molecular aggregates (MA) being a common structural motif in nature exhibit also highly promising
potentials in many applications, for example in optoelectronics, advanced composites, and
biomedics. �e theoretical framework for understanding the collective properties exist in MAs is
Frenkel exciton theory. Already in the early studies [1-3] the importance of the nuclear motions
in exciton theory was recognized. For instance, the coupling of the electronic and nuclear degrees
of freedom (DOF) results in the appearance of vibrational progressions in absorption spectra of
MAs [3] and causes dephasing and population relaxation among the exciton levels [4]. It was
also recently shown that vibrations result in vibronic enhancement of exciton size and energy
transport in photosynthetic complexes [5]. It was shown, in particular, that a pure electronic
system where all system vibrations are included into the thermal bath is not able to describe the
observed experiments [5], and explicitly accounting for a vibrational DOF is required.
In this presentation we, first, consider coupled exciton-vibrational dynamics in a dissipative environment
on the base of two generic dimer models each containing one dominating vibrational
mode. Specifically, the properties of an vibronic dimer [6] have been contrasted with those of
purely electronic dimer. Exciton dynamics were calculated using the Redfield approach where
exciton-phonon coupling is treated perturbatively up to the second order through Markovian
relaxation operators. Notable difference in the dissipative dynamics include the transient vibrational
population trapping which is unique to the exciton-vibrational dimer [6].
Secondly, we studied the electron-vibrational absorption spectra of Perylene Bisimide (PBI) molecular
aggregates, in particular, the spectra of PBI monomer and dimer in the region of 600nm.
�e spectrum, first,was calculated using exact multimode approach based on explicit treatment
of dominating vibrational modes with largest Huangh-Rhys factor [7]. �e calculated energy
positions and relative intensities of vibrational peaks well reproduce the experimental spectra.
However, our simulations show that non-uniform broadenings of different vibrational peaks of
experimental absorption spectra can not be explained only by interplaying of mostly pronounced
vibrational modes. To explain this difference we propose to account the contributions of different
conformations of PBI monomer exist in aggregate. To get the spectra related to different conformations
of PBI we utilize classical molecular dynamics simulations (to have different conformations
of PBI monomer) with subsequent quantum-chemical calculations. �e corresponding
spectra will be presented.
Finally we modify the generic vibronic dimer model considered in [7] to multimode case and
apply it to the real PBI dimer where mostly important modes are taken from the above results
related to the absorption spectra.
146

π 2011
References
Posters – 38
[1] J. I. Frenkel, Phys. Rev., 37, 1276 (1931).
[2] A. S. Davydov, �eory of Molecular Excitons, Plenum, New York (1971).
[3] B. Kopainsky. J.K. Hallermeier and W. Kaiser, Chem. Phys le�., 83, 498 (1981); 87, 7 (1982).
[4] V. May, O. Kühn, Charge and energy transfer Dynamics in Molecular system, Wiley-VCH,
Weinheim (2011).
[5] J. M. Womick, A. M. Moran, J. Phys. Chem., B, 115, 1347 (2011).
[6] S. Polyutov, O. Kühn, T. Pullerits, Chem. Phys. (2011) (submi�ed to Chem. Phys.).
[7] S. Polyutov, I. Minkov, F. Gel’mukhanov, H. Ågren, J. Phys. Chem. A 109, 9507 (2005).
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Posters – 39 π 2011
Nanostructured Materials Containing Organic
Semiconductors
D. Rolland and H. Frauenrath
École polytechnique fédérale de Lausanne, Switzerland
Due to the specific energy conversion mechanisms taking place in organic photovoltaics, the
active part of organic solar cells, an interface between n- and p-type semiconductors, has to be
shaped at the nanometer scale.[1] In this context, the synthesis and self-assembly of block copolymers
comprising π-conjugated rod (opto-electronically active part) and flexible coil segments
(structuring part) is expected to provide well-ordered and electronically active thin films.[2] For
this reason, we investigated the preparation of multiblock copolymers containing semiconducting
rods and flexible poly(tetrahydrofurane) (PTHF) coils, their characterization and their processing
into nanostructured materials. �e PTHF coils can be selectively removed and then replaced
by another type of semiconductor, required for suitable photovoltaic properties.
References
Figure P39.1: Representative example of the multiblock copolymers investigated.
[1] A. C. Mayer, S. R. Scully, B. E. Hardin, M. W. Rowell, M. D. McGehee, Mater. Today. 2007, 10,
28.
[2] a) F. S. Bates, G. H. Fredrickson, Phys. Today. 1999, 52, 32; b) G. Hadziioannou, MRS Bull.
2002, 27, 456.
148

π 2011
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Posters – 39
149
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Posters – 40 π 2011
Theoretical and Experimental Investigation of Transition
between Weak and Strong Coupling in Bichromophoric
Systems
F. P. Diehl, C. Roos, B. Lunkenheimer, A. Köhn and T. Basché
Universität Mainz
One important factor that determines the photophysics of bichromophoric systems is the electronic
coupling of the constituent chromophores. Depending on the strength of the interaction
in comparison to external perturbations two limiting cases can be realized [1, 2]. In the strong
coupling regime the excitation is delocalized over many chromophore sites while in the weak coupling
regime it quickly localizes on a single site and migrates by a ’hopping’ mechanism between
neighboring sites. In recent time, experimental evidence was provided in favor of a significant
contribution from quantum coherence to energy transfer in photoactive proteins, even at ambient
conditions [3, 4]. Hence the investigation of systems that show a transition between the two
coupling regimes is expected to provide new insight into the phenomenon of energy transfer.
As model systems we investigated dimers of perylene diimide (PDI) linked by oligophen-ylenebridges.
We examined the excited state Born-Oppenheimer surfaces of the systems PDI-(Ph)n-
PDI (n = 0, 1, 2, 3), and found nearly perfect localization of the electronic excitation when allowing
the system to relax on the S1 surface. �e actual transition between coherent and incoherent
behavior takes place in the vibrational wavefunction, which was investigated by a simple vibronic
coupling model. Comparison is made to single-molecule experiments at low temperatures. Good
agreement to the calculated data is found which supports our interpretation of the nature of the
transition from weak to strong coupling [5].
References
[1] V. May and O. Kühn, Charge and Energy Transfer Dynamics in Molecular Systems, Wiley,
Berlin (2008)
[2] S. Speiser, Chem. Rev. 96 (1996) 1953
[3] H. Lee, Y. C. Cheng, G. R. Fleming, Science 316 (2010) 1462
[4] G. D. Scholes, J. Phys. Chem. Le�. 1 (2010) 2
[5] F. P. Diehl, C. Roos, B. Lunkenheimer, A. Köhn, T. Basché, (2011) in preparation.
150

π 2011
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Posters – 40
151
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Posters – 41 π 2011
Reaction Dynamics of a Molecular Switch Unveiled by
Coherent Two-Dimensional Electronic Spectroscopy
S. Ruetzel, M. Kullmann, J. Buback, P. Nuernberger and T. Brixner
Universität Würzburg
Coherent two-dimensional (2D) electronic spectroscopy is usually employed on molecular species
with fixed geometric configuration. Here we present two-dimensional Fourier-transform electronic
spectra of dissolved 6,8-dinitro-1’,3’,3’-trimethylspiro[2H-1-benzopyran-2,2’-indoline] (6,8dinitro
BIPS), a photochromic system present in two ring-open forms differing by a cis/trans
configuration of a double bond which both undergo a photo-induced ring closure [1, 2]. �e
two-dimensional spectra, recorded with 20 fs pump pulses centered at 605 nm and a supercontinuum
probe [3] covering the complete visible spectral range, allow for a detailed analysis of the
photophysics and photochemistry of the two isomers, and directly reveal that cis/trans isomerization
among them does not play a major role [4]. �is experiment demonstrates the potential
of two-dimensional electronic spectroscopy for reactive processes.
Figure P41.1: Le�: Normalized absorption spectrum (gray), excitation (green), and probe spectrum
(purple). Inset: the two 6,8-dinitro BIPS isomers (TTC, TTT) present in solution.
Right: Two-dimensional electronic spectrum for the waiting time T = 300
ps.
152

π 2011
References
Posters – 41
[1] J. Buback, M. Kullmann, F. Langhojer, P. Nuernberger, R. Schmidt, F. Würthner, and T. Brixner,
J. Am. Chem. Soc. 132, 16510 (2010).
[2] J. Buback, P. Nuernberger, M. Kullmann, F. Langhojer, R. Schmidt, F. Würthner, and T. Brixner,
J. Phys. Chem. A. 115, 3924-3935 (2011).
[3] P.F. Tekavec, J.A. Myers, K.L.M. Lewis, and J.P. Ogilvie, Opt. Le�. 34, 1390 (2009).
[4] M. Kullmann, S. Ruetzel, J. Buback, P. Nuernberger, and T. Brixner, J. Am. Chem. Soc. (In
Press, 2011).
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Posters – 42 π 2011
Control of Aggregates in Poly(3-hexylthiophene) Solutions
and Thin Films
C. Scharsich¹, A. Köhler¹, R. Lohwasser¹, M. Thelakkat¹, U. Asawapirom² and U. Scherf²
¹Universität Bayreuth, ²Universität Wuppertal
�e photophysical and electronic properties of regioregular poly(3-hexylthiophene) (P3HT) are
of great interest for many applications in the field of organic semiconducting materials such
as solar cells and field-effect transistors. Recent research has shown that the aggregation of
polymer chains plays an important role in the performance of organic field-effect transistors.
Properties such as conjugation length, intermolecular coupling within the aggregates as well
as the packing behavior of the polymer chains and disorder affect the applicable optical and
electronic properties of P3HT. In order to understand and control the nature of P3HT aggregates,
we measure absorption in solution and in thin films as well as the resulting field effect mobility
in thin film transistors. By a detailed analysis, we study the effect of molecular weight, solvent,
and synthetic approach to P3HT on the excitonic coupling within aggregates, the fraction of
aggregates, and the packing behavior of P3HT chains.
154

π 2011
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Posters – 42
155
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Posters – 43 π 2011
Perylene bisimide macrocycles and their self-assembly on
HOPG surfaces
F. Schlosser, V. Stepanenko and F. Würthner
Universität Würzburg
�e importance of the circular arrangement of chromophores, in particular chlorophylls, for the
photosynthesis is quite evident in natural light-harvesting systems of purple bacteria as these
cyclic dye arrays ensure highly efficient light absorption and excitation energy transport to the
photosynthetic reaction center. Such pivotal functions of natural cyclic dye assemblies have
inspired tremendous efforts in the past decades for the development of their artificial counterparts.
Previously, our group has reported on perylene bisimide-based metallosupramolecular
cyclic arrays and their self-assembly into honeycomb-structured two-dimensional nanopa�erns
on HOPG [1].
Here we report our recent results on covalently bound macrocycles based on perylene bisimide
(PBI) dyes [2]. Such covalent cyclic dye arrays are much more stable due to their rigid, shapepersistent
structure and thus should facilitate desired electronic coupling between monomeric
dye units. �e synthesis of covalently bound macrocycles of PBI dyes was achieved by oxidative
homo-coupling of acetylene functionalized PBI monomers (see Figure P43.1), and successfully
separated from oligomeric byproducts with recycling GPC. �e rigid, trimeric PBI macrocycle
(n = 3) self-assembles on HOPG into donut-like structures in hexagonal arrangements which are
further organized into bigger defined pa�erns (see Figure P43.2).
References
[1] Stepanenko, V.; Würthner, F. Small 2008, 4, 2158–2161.
[2] Schlosser, F.; Stepanenko, V.; Würthner, F. Chem. Commun. 2010, 46, 8350–8352.
156

π 2011
Figure P43.1: Covalent synthesis of cyclic
PBI arrays.
Posters – 43
Figure P43.2: Self-assembly of trimeric PBI
macrocycle into donut-like
structure on HOPG.
Our novel results will be presented in more detail in our poster and discussed during the poster
session.
N����
157
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Posters – 44 π 2011
Predicting Ionization Potentials with Density Functional
Theory: Chances and Challenges
T. Schmidt and S. Kümmel
Universität Bayreuth
Density-Functional �eory is one of the standard methods used in the theoretical investigation of
molecular semiconductors. In particular the prediction of photoemission spectra has been based
on density functional theory. In this context, Kohn-Sham eigenvalues are frequently interpreted
as approximations to ionization potentials. �e quality of this approximation depends very much
on the quality of the exchange-correlation potential approximation. We show that the influence
of the exchange-correlation potential is particularly large for certain organic semiconductors. We
discuss new density functional approaches that offer the hope to yield physically interpretable
eigenvalues and at the same time good binding properties. �e basic idea of this yet ongoing
development is to combine full exact exchange with a compatible correlation functional.
158

π 2011
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Posters – 44
159
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Posters – 45 π 2011
Time Resolved Spectroscopic Methods from the
Femtosecond- up to the Millisecond-Regime
A. Schmiedel and C. Lambert
Universität Würzburg
In our group different measurement systems are available to characterize photoinduced processes
in molecules that are synthesized in our group. �e most important characterization methods
are fluorescence lifetimes, quantum yields, transient absorption spectra, steady-state absorption,
fluorescence, excitation spectra and fluorescence anisotropy measurements.
Our LP920 from Edinburgh Instruments is applied to measure transient spectra, where decay
times from 3 ns to several seconds can be covered. �e excitation wavelengths are the first up to
the fourth harmonic of a Nd:YAG-laser and, in addition, 416 nm produced with a H 2 Ramancell.
�e detection range is from 185 nm to 2 µm. It is also possible to measure fluorescence lifetimes
with this apparatus.
We have also the Fluorescence System �antaMaster 2000-4 from PTI to measure quantum yields,
steady state anisotropy, plus fluorescence- and excitation-spectra. It is also possible to measure
fluorescence lifetimes in a range from 200 ps - 3 µs. �e detector has a band-width from 200
- 1600 nm and the excitation wavelengths are 340, 450, and 650 nm with pulsing LEDs with ns
durations.
Our newest system is a femtosecond-laser spectroscopy system. �e amplified Ti:sapphire laser
Solstice from Newport Spectra-Physics generates pulses with durations less than 100 fs and a
repetition rate with 1 kHz. To have a broad band of excitation wavelength the Solstice will be
equipped with an OPA (TOPAS-C) whose emission can be set from 285 nm 2.6 µm. One measurement
system is the Helios transient absorption spectrometer with a time window from 150 fs up
to 8 ns and a detection range from 350 nm - 1.6 µm. �e other is the Halcyone Fluorescence Life
Time Measurement System which is capable for fluorescence upconversion and Time Correlated
Single Photon Counting (TCSPC). �e Upconversion mode can detect from 320 - 1600 nm and the
TCSPC-mode has a spectral range from 160 - 900 nm.
�e measurement equipment shown above makes it possible to perform a time resolved characterization
of molecules from the femtosecond- up to the millisecond-regime without a gap.
160

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Posters – 46 π 2011
Ultrafast Exciton �enching upon Geometry Deformation
in Molecular Aggregates
A. Schubert¹, V. Se�els¹, W. Liu¹ ², F. Würthner¹, C. Meier³, R. F. Fink¹ ⁴, S. Schindlbeck⁵, S.
Lochbrunner⁶, B. Engels¹ and V. Engel¹
¹Universität Würzburg, ²Universität Heidelberg, ³Université de Toulouse, France, ⁴Universität Tübingen, ⁵LMU München,
⁶Universität Rostock
�e efficiency of energy transport in molecular π-aggregates is strongly a�enuated by de-excitation
mechanisms. In order to understand these quenching processes we exemplarily investigated experimentally
and theoretically dimer aggregates of 3,4,9,10-perylene tetracarboxylic bisimide acid
(PBI) [1].
�e measured absorption spectra could successfully be interpreted assuming a dipole-dipole coupling
in the excited states and a single effective vibrational mode for each monomer [2]. An additional
intermolecular torsional mode was required [3] to explain the fluorescence spectroscopic
measurements indicating a long radiative lifetime of 33 ns and a low fluorescence yield. Up to
this point, a consistent picture of the absorption and emission properties could be established.
Whereas a more fundamental insight into the decay dynamics of the optically excited state and
the reaction path which leads to the fluorescing state is missing up to date.
Femtosecond transient absorption measurements demonstrate that the excited state decays nonradiatively
on an ultrafast time-scale of 215 fs. Due to the large moment of inertia, the torsional
motion is too slow to reach the geometry where a curve crossing occurs. �us, there must exist a
different dimer geometry change which makes the non-adiabatic transition effective. We determine
potential energy curves along a reaction coordinate relating the Franck-Condon geometry
at which photon absorption occurs to a charge transfer configuration where the first monomer
exhibits the anion geometry and the second the geometry of the cation.
Including phenomenologically an energy dispersion into modes different from the reaction coordinate
(being inter-, intra-molecular or solvent modes), leads to results which are in excellent
agreement with the experimental findings. Furthermore, it is shown that a coherent superposition
of states in the reaction coordinate and other internal modes which are excited coherently
may lead to quantum beats with the same oscillation period as seen in the measured transient
absorption spectrum.[4]
References
[1] F. Würthner, Chem. Commun., 1564 (2004)
[2] Z. Chen, V. Stepanenko, V. Dehm, P. Prins, L. D. A. Siebbeles, J. Seibt, P. Marquetand, V. Engel,
F. Würthner, Chem. Eur. J. 13, 436 (2007)
[3] R. Fink, J. Seibt, V. Engel, M. Renz, M. Kaupp, S. Lochbrunner, H.-M. Zhao, J. Pfister, F. Würthner
and B. Engels, J. Am. Chem. Soc. 130, 12858 (2008)
[4] V. Se�els, A. Schubert, W. Liu, F. Würthner, C. Meier, R. F. Fink, S. Schindlbeck, S. Lochbrunner,
B. Engels and V. Engel, in preparation
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π 2011
Figure P46.1: Time-dependent absorption
change ∆OD at
520 nm (open circles),
signal of the pure solvent
(upper fine line) and
model function fi�ed to
the data (thick solid line).
�e three lower lines
show the contributions
to the model function.
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Figure P46.2: Le� upper panel: population dynamics
in the diabatic electronic states (nd).
Le� lower panel: damped quantum beat
signals. �e right hand panels exhibit
the time-dependent probability densities
|ψ d n d (q, t)| 2 in the diabatic states
(nd = 1; 2), as indicated.
163
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Posters – 47 π 2011
Theoretical investigations on 2D electronic spectra of a
π-aggregated dimer with intermolecular torsional motion
J. Seibt¹ and A. Eisfeld²
¹Max-Planck Institute for the Physics of Complex Systems, Dresden, ²Harvard University, Cambridge, USA
We investigate the influence of relaxation and dissipation effects on two-dimensional electronic
spectra of a π-aggregated dimer, where the employed model system contains an intermolecular
torsional degree of freedom. Even though absorption from the ground state mainly populates
the upper 1-exciton state, the system is affected by dissipation, which results in subsequent dynamics
at the lower singly excited state potential. During a sufficiently large relaxation time, the
respective transfer processes either arise in passing a conical intersection upon nuclear motion
or stem from interactions with the surrounding bath. In this context, characteristic changes in
the 2D-spectrum are discussed with specific a�ention to the signatures of torsional dynamics
and relaxation effects. �e total 2D-spectrum is itemized with respect to the different excitation
pathways, where also the impact of statistical orientation of the dimers and the respective averaging
is taken into account. �e studies rely on results from quantum chemical calculations and
are performed using a mixed quantum-classical approach for the nuclear dynamics.
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Posters – 48 π 2011
Towards Artificial Chlorosomes and Beyond
S. Sengupta, V. Huber, C. Röger, M. Ka�erle, S. Uemura, X. Zhang and F. Würthner
Universität Würzburg
Chlorosomes are light-harvesting organelles found in green sulfur bacteria (phylum Chlorobi),
filamentous anoxygenic phototrophs (phylum Chloroflexi), and the newly discovered aerobic
phototroph, Candidatus Chloracidobacterium thermophilum (phylum Acidobacteria). �ey are
one of the most fascinating examples of functional dye assemblies created by ∼250,000 bacteriochlorophylls
(BChls), stabilized solely through pigment-pigment interactions. Owing to
their high pigment density and fast exciton transport capabilities, they constitute ideal building
blocks towards artificial photosynthesis. However, their exact structural organization is still
a ma�er of great scientific debate.[1] Efforts in mimicking the chlorosomal self-assembly algorithm
with semisynthetic molecules, namely, zinc chlorin (ZnChl) pigments are presented in our
poster. Tailoring of ZnChls with hydroxy and methoxy groups at 3 1 -position and esterified hydrophobic
or hydrophilic substituents at 17 2 -position allowed to induce their self-assembly into
nanotubes[2-4] and stacks.[5, 6] �e structure of these well-defined and stable self-assemblies
in solution could be revealed by spectroscopy,[2-5] scanning probe microscopy[5] and electron
microscopy.[4] Furthermore, solid-state NMR and powder X-ray diffraction provided information
on precise short-range packing of these dyes in the solid state.[6] Functionalization of the
ZnChls at the 17 2 -position with second-generation dendron wedges facilitated tuning their twodimensional
surface organization from linear to cyclic arrangement as well as afforded novel
liquid crystalline functional materials.[7, 8] �us, our studies have unravelled important structural
and functional features of these assemblies, justifying their suitability as model systems to
imitate natural chlorosomal assemblies.
References
[1] F. Würthner, T. E. Kaiser, C. R. Saha-Möller Angew. Chem. Int. Ed. 2011, 50, 3376–3410.
[2] V. Huber, S. Sengupta, F. Würthner Chem.-Eur. J. 2008, 14, 7791–7807.
[3] V. Huber, M. Ka�erle, M. Lysetska, F. Würthner Angew. Chem., Int. Ed. 2005, 44, 3147–3151.
[4] S. Sengupta, X. Zhang, F. Würthner Unpublished results.
[5] V. Huber, M. Lysetska, F. Würthner Small 2007, 3, 1007–1014.
[6] S. Ganapathy, S. Sengupta, P. K. Wawrzyniak, V. Huber, F. Buda, U. Baumeister, F. Würthner,
H. J. M. de Groot Proc. Natl. Acad. Sci. U. S. A. 2009, 106, 11472–11477.
[7] S. Sengupta, S. Uemura, S. Patwardhan, V. Huber, F. C. Grozema, L. D. A. Siebbeles, U.
Baumeister, F. Würthner Chem.-Eur. J 2011, 17, 5300–5310.
[8] S. Uemura, S. Sengupta, F. Würthner Angew. Chem. Int. Ed. 2009, 48, 7825–7828.
166

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Posters – 49 π 2011
Can intermolecular motions explain exciton trapping in
organic photovoltaics using perylene derivatives?
V. Se�els, A. Schubert, M. Tafipolski, W. Liu, V. Stehr, V. Engel, R. F. Fink and B. Engels
Universität Würzburg
Exciton trapping was figured out to be one of the main sources for the small internal quantum efficiency
of organic solar cells using perylene based dyes. Experiments show that on a picoseconds
time scale excitons relax into stable and immobile intermolecular states a�er excitation [1, 2], but
a molecular picture of this process is still missing. Such an insight would help to understand how
such trapping effects can be impeded.
We present a molecular picture for an exciton trapping mechanism which explains many experimental
findings. Our investigations use a QM/MM hybrid approach which describes the
underlying potential energy surfaces (PES) of dimers by SCS-CC2 computations [3]. �e influence
of the crystal surroundings is taken into account by molecular mechanics which employs
specially designed force fields. Dynamical effects are considered via wave packet dynamics on
the computed PESs.
Our investigations indicate that for α-PTCDA crystals light absorption induces a relative motion
of two neighboured molecules. �is movement leads to a relaxation into a lower lying optically
dark excited state through a conical intersection. �e accompanied loss of energy and a low
transition dipole moment to the ground state yield a trap for Förster resonant energy transfer
[4], which should be dominant for exciton transport at room temperature. Wave packet dynamics
performed on the computed potential energy surfaces yield a low picoseconds timescale for
exciton trapping, which agrees with experimental findings [2]. �is trapping mechanism can be
generalized for a wide range of perylene based dyes, but our computations show that the corresponding
trapping mechanism cannot take place in DIP crystals. �is explains why DIP possesses
considerably larger exciton diffusion lengths than α-PTCDA.
References
[1] B. A. West, J. M. Womick, L. E. McNeil, K. J. Tan, A. M. Moran, J. Phys. Chem. B 115, 5157
(2011)
[2] I. A. Howard, F. Laquai, P. E. Keivanidis, R.H. Friend, N. C. Greenham, J. Phys. Chem. C 113,
21225 (2009)
[3] W. Liu, V. Se�els, P. H. P. Harbach, A. Dreuw, R. F. Fink, J. Comput. Chem. 32, 1971 (2011)
[4] R. F. Fink, J. Seibt, V. Engel, M. Renz, M. Kaupp, S. Lochbrunner, H. M. Zhao, J. Pfister, F.
Würthner, B. Engels, J. Am. Chem. Soc. 130, 12858 (2008)
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Posters – 50 π 2011
Spectroscopy of SWNT-polymer conjugates
F. Späth, T. Hefner, M. Iljina and T. Hertel
Universität Würzburg
Recent advances in sample preparation techniques have facilitated the fabrication of novel πconjugated
composites made of nearly monodisperse single-wall carbon nanotube (SWNT)-polymer
conjugates. �ese systems are currently explored for their potential use in new organic
compound based electronic devices. Here we are interested in fundamental electronic processes,
such as charge or energy transfer and excited state dynamics at the polymer-SWNT interface.
In this study, semiconducting (6,5)-SWNTs were solubilized in THF by functionalization with
poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(6,6’-{2,2’-bipyridine})] (PFO-BPy) or with
poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-bithiophene] (F8T2). Significant effort was directed towards
reducing the polymer-to-SWNT weight ratios from 500:1 in as-prepared samples to be
in the vicinity of 1:1 which is a prerequisite to testing these systems in device applications. We
will present preliminary results from continuous wave absorption and fluorescence spectroscopy,
time correlated single photon counting (TCSPC) and fs transient absorption measurements.
170
Figure P50.1: Absorption spectra of SWNT-polymer conjugates in THF.

π 2011
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Posters – 51 π 2011
Electron and Energy Transfer in Donor and Acceptor
Substituted Hexaarylbenzenes
M. Steeger and C. Lambert
Universität Würzburg
Hexaarylbenzenes (HABs) can be readily synthesised by transition metal catalysed cyclotrimerisation
of the appropriate tolan derivatives. If asymmetric tolans are used the reaction yields a
symmetric and an asymmetric isomer with a statistical ratio of 1:3. �e therewith straightforwardly
synthesized HAB framework enables energy transfer as well as electronic communication
among up to six ring-like arranged chromophors and/or redox centres. �e former interaction
is based on the spatial proximity of the substituents and the la�er on electronic communication
through space. �e benzene rings a�ached to the central one are tilted out of the central plain
because of sterical reasons. As a result they are cofacially aligned and the π-orbitals can overlap
through space. �e conjugation via the central benzene ring should be hampered strongly by the
tilting.
By substituting the HABs framework with electron donor and acceptor centres we obtained compound
1 and 2, which show charge transfer (CT) from the amine to the borane moieties, varified
by UV/vis, fluorescence and transient absorption spectroscopy. By adding fluoride ions the acceptor
ability of the borane moiety vanishes due to complexation. Consequently, the CT absorption
and emission vanish, too.
As the transition moment direction of the charge transfer excitation is known, steady state fluorescence
anisotropy measurements were performed to investigate energy transfer between the
possible charge transfer states. By comparison with a model compound we conclude that the
energy of the excited state is readily redistributed within the fluorescence lifetime.
Furthermore, the electrochemical properties were studied by cyclovoltammetry as six redox centres
are combined in one molecule. �e influence of the conducting salt on the redoxpotential
spli�ing was considered in more detail.
172
MeO
B
N
MeO
MeO OMe
N
B
B
N
OMe
OMe
MeO
B
N
MeO
1 2
MeO OMe
OMe
N
B
N
B
OMe

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Posters – 52 π 2011
Exciton transport in organic semiconductor crystals
V. Stehr, J. Pfister, R. F. Fink, C. Deibel and B. Engels
Universität Würzburg
Organic solar cells become more and more interesting for applications due to their low production
costs and easy processability. In order to increase their efficiency, it is very important
to understand the basic principles of energy (exciton) transport in these materials. Besides the
charge carrier mobility, the exciton diffusion length is the crucial material property which decides
on the applicability for solar cells. �e exciton transport and its orientational dependency
have been studied theoretically by means of quantum chemical methods and a hopping approach
using Marcus theory along with the master equation. �e implementation of the approach presented
here is straightforward and is shown to provide exciton diffusion lengths which are in
excellent agreement with experimental data. Results for anthracene and other promising organic
semiconductors are presented.
c
30 40 50 60 70 80
diffusion length L [nm]
Figure P52.1: Crystal structure of anthracene and the orientational dependency of the exciton
diffusion length.
174
a
b

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Posters – 53 π 2011
Precise and rapid detection of optical activity for
femtosecond spectroscopy
A. Steinbacher , J. Buback, P. Nuernberger and T. Brixner
Universität Würzburg
We present polarimetry, i.e. the detection of optical rotation of light polarization, in a configuration
that is suitable for femtosecond spectroscopy. �e polarimeter is based on the common-path
optical heterodyne interferometry method [1] and provides fast and highly sensitive detection of
rotating power. Femtosecond pump and polarimeter probe beams are integrated into a recently
developed accumulative technique [2, 3] that further enhances sensitivity with respect to singlepulse
methods. By using a pair of pump pulses, a time-resolution on the femtosecond timescale
can be a�ained. �e sensitivity of rotary detection, i.e. the minimum rotation angle that can be
measured, is determined experimentally including all noise sources to be 0.10 milli-degrees for
a measurement time of one second and an interaction length of only 250 µm. We illustrate the
concept on the photodissociation of the chiral enantiomers of methyl p-tolyl sulfoxide [4] (see
Figure P53.1).
176
Figure P53.1

π 2011
References
[1] J. Lee and D. Su, Opt. Commun. 256, 337–341 (2005).
[2] F. Langhojer, F. Dimler, G. Jung, and T. Brixner, Opt. Le�. 32, 3346–3348 (2007).
[3] F. Langhojer, F. Dimler, G. Jung, and T. Brixner, Biophys. J. 96, 2763–2770 (2009).
[4] Y. Guo and W. S. Jenks, J. Org. Chem. 62, 857–864 (1997).
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Posters – 54 π 2011
High-Performance Organic Thin-Film Transistors Based on
Small Molecules
S.-L. Suraru¹, M. Stolte¹, J. H. Oh², Z. Bao², J. Brill³, M. Könemann³, J. �³, U. Zschieschang⁴, H.
Klauk⁴ and F. Würthner¹
¹Universität Würzburg, ²Stanford University, USA, ³InnovationLab GmbH, Heidelberg, and BASF SE, Ludwigshafen, ⁴Max
Planck Institute for Solid State Research, Stu�gart
�e development of organic thin film transistors (TFTs) has emerged to a great field of research,
strongly connected to the finding of new powerful organic semiconductor materials. Herein we
report the synthesis of new π-conjugated small molecules exhibiting excellent field effect mobilities
and high on/off ratios in air.
�us easily accessible dichlorinated naphthalene tetracarboxylic diimides (NDIs) were synthesized
and their optical and electrochemical properties were investigated. �ese compounds show
n-type behavior with outstanding field-effect mobilities of up to 1.3 cm² V⁻¹ s⁻¹ and on/off ratios
of 10⁷.[1, 2] Furthermore a new diketopyrrolopyrrole derivative exhibits excellent hole mobility
of 0.7 cm² V⁻¹ s⁻¹ and a current on/off ratio of 10⁶ under ambient conditions in bo�om-gate, topcontact
organic thin film transistors (OTFTs) fabricated by vacuum deposition.[3]
References
[1] J. H. Oh, S.-L. Suraru, W-Y. Lee, M. Könemann, H. W. Hö�en, C. Röger, R. Schmidt, Y. Chung,
W-C. Chen, F. Würthner, Z. Bao, Adv. Funct. Mater. 20, 2148-2156 (2010)
[2] M. Stolte, S.-L. Suraru, F. Würthner, J. H. Oh, Z. Bao, J. Brill, M. Könemann, J, �, U. Zschieschang,
H. Klauk, Proc. of SPIE 7778, 777804-1 (2010)
[3] S.-L. Suraru, U. Zschieschang, H. Klauk, F. Würthner, Chem. Commun. 47, 1767-1769 (2011)
178

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Posters – 55 π 2011
Plasmon-induced enhancement of nonlinear optical
rectification in organic materials
I. Thanopulos¹, E. Paspalakis² and V. Yannopapas²
¹National Hellenic Research Foundation, Athens, ²University of Patras, Greece
We show that nonlinear optical rectification (NOR) can be greatly enhanced in proximity of
plasmonic nanostructures. �e NOR enhancement in the visible frequency range near Cu-coated
SiO2 nanospheres is calculated by a rigorous first-principle electromagnetic Green’s tensor technique.
Exemplary compounds with absorption in the visible optical spectrum based on free- and
metallo-porphyrin molecules are discussed exhibiting enhancement factors typically larger than
10. �eir spectral properties in relation to NOR are obtained by first-principle electronic structure
calculations.
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Posters – 56 π 2011
A Reliable Supramolecular Method to Self-Assemble
Conjugated Molecules into Well-Defined Nanoscopic
Fibrils
L. Tian¹ ² and H. Frauenrath¹
¹École Polytechnique Fédérale de Lausanne, ²ETH Zürich, Switzerland
Supramolecular self-assembly has proven to be a versatile tool for the preparation of nanostructured
materials [1]. Various examples utilize the self-assembly of β-sheet forming oligopeptides
[2]. Recently, we have demonstrated that oligopeptide-polymer conjugates based on hydrogenated
poly(isoprene) and oligo(alanine) can be used for the formation of soluble nanostructures
in a “bo�om-up” approach [4]. In the present study, we prepared and investigated a series
of diacetylene macromonomers which comprised hydrogenated poly(isoprene) segments with
different degrees of polymerization as well as oligo(alanine)s of different lengths. �e resulting
nanostructures were visualized by AFM, and their stability as well as polymerizability was investigated
by solution phase IR and UV/vis spectra. Our investigations showed that the stability
of the nanostructures in solution and their polymerizability was strictly determined by both the
length of the a�ached polymers and the number of N−H···O−C hydrogen bonds.
�e lessons learned from the diacetylene conjungates were then transferred to oligopeptidepolymer-equipped
derivatives of other conjungated molecules such as quaterthiophene and perylene
bisimide. A systematic investigation of UV/vis, CD, and IR spectra as well as AFM images
revealed that oligopeptide-polymer conjugates based on hydrogenated poly(isoprene) and
oligo(alanine) were versatile scaffolds for the reproducible formation of one-dimensional aggregates
of conjugated molecules.
A�nowledgements: We thank Dr. L. Bertschi and Dr. X. Zhang at the Laboratory of Organic
Chemistry at ETH Zürich for the assistance with mass spectra, Dr. R. Szilluweit for the AFM
measurements, Dr. M. Yu and Prof. F. Stellacci from SUNMIL at EPFL for the STM mesurements,
and Dr. Andrzej Sienkiewicz from LPMC at EPFL for the ESR measurements. Funding from ETH
Züri� (Projekt ETH-05 08-2) is gratefully acknowledged.
References
[1] Lehn, Science 295, 2400-03 (2002)
[2] Sumner et al., J. Mol. Biol. 335, 1279-1288 (2004)
[3] Börner et al., J. Am. Chem. Soc. 128, 7722-23 (2006)
[4] Frauenrath et al., Chem. Eur. J. 15, 388-404 (2009)
[5] Frauenrath et al., Angew. Chem. Int. Ed. 45, 5383-86 (2006)
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Posters – 57 π 2011
Triarylamine/Bisphenylamine-functionalized Indolenine
Squaraines: Synthesis and Redox Properties
S. F. Völker¹, M. Renz², M. Kaupp² and C. Lambert¹
¹Universität Würzburg, ²Technische Universität Berlin
We synthesized various indolenine squaraine dyes with additional electron donating amine redox
centres like triarylamine or bisphenylamine and investigated their redox properties. To characterize
the electronic structure of the mono-, di- and in one case trications we used a combination
of cyclic voltammetry, spectroelectrochemistry and DFT calculations. We extended previous investigations
on organic mixed valence compounds by using squaraines as electron rich bridging
units to provoke a strong coupling between the redox centres. Because of the low redox potential
of the squaraine bridge, all monocations still retain the cyanine like delocalized character that is
typical for the neutral compounds. �us all monocations belong to the delocalized Robin-Day
class III even though the N,N-distance between the additional redox centres (up to 26 bonds for
TA3) is rather large. Additionally we show that the change of symmetry, due to substitution
of the squaric ring oxygen by a dicyanomethylene group, can have direct impact on the optical
properties of the monocations and we describe the electron density distribution of the di- and
trications. �e mulit-chromophore dyes serve as model compounds for future polymers.
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Posters – 58 π 2011
Synthesis and Reactivity of 1-Haloboroles: From
Antiaromaticity to non-classical Structures
J. Wahler, H. Braunschweig, K. Ferkinghoff, S. Ghosh, C. Lambert and J. Klein
Universität Würzburg
Examples of uncoordinated borole derivatives are rare and steric protection of the antiaromatic
borole ring is crucial to realize isolation of neutral, monomeric borole systems.[1] �e interest in
free boroles arises from their strong Lewis-acidity and photophysical properties, which can be
tuned by variation of the boron bound substituent.[2-4]
Synthesis of 1-haloboroles such as 1-chloro-2,3,4,5-tetraphenylborole (1) and 1-bromo-2,3,4,5tetraphenylborole
(2) provides a versatile basis for direct functionalization of the borole moiety
which extends the classical approach of synthesis via tin-boron exchange reaction. �e boronhalide
bond of 1-haloboroles exhibits a broad range of reactivity such as substitution reactions,
halide abstraction, oxidative addition and reduction.[2-5]
Our investigations showed that 1 and 2 are thermally less stable compared to pentaarylboroles
like PhBC 4Ph 4. Heating of 1 and 2 in solution gives unusual [1,6]-diboraspiro[4.5]deca-3,7,9triene
derivatives Cl 2B 2C 8Ph 8 (3) and Br 2B 2C 8Ph 8 (4), which feature a chiral spirobicyclic framework.[6,
7] Subsequent experiments revealed that 3 and 4 are redox-active. Reaction with mild
reducing agents yields a 2,3,4,5-tetracarba-1,6-nido-hexaborane(6) cluster with an exo-polyhedral
boracycle (5).[8] 5 shows a high thermal stability, whereas irradiation with UV-light results in
migration of the bridging butadiene unit to form the isomeric product 6 (see figure P58.1).
186
Figure P58.1

π 2011
References
Posters – 58
[1] J. J. Eisch, J. E. Galle, S. Kozima, J. Am. Chem. Soc. 1986, 108, 379.
[2] H. Braunschweig, T. Kupfer, Chem. Commun. 2008, 4487.
[3] H. Braunschweig, I. Fernandez, G. Frenking, T. Kupfer, Angew. Chem., Int. Ed. 2008, 47, 1951.
[4] C. Fan, W. E. Piers, M. Parvez, Angew. Chem., Int. Ed. 2009, 48, 2955.
[5] H. Braunschweig, C.-W. Chiu, K. Radacki, P. Brenner, Chem. Commun. 2010, 916.
[6] H. Braunschweig, C.-W. Chiu, J. Wahler, K. Radacki, T. Kupfer, Chem. Eur. J. 2010, 16, 12229.
[7] H. Braunschweig, C.-W. Chiu, A. Damme, K. Ferkinghoff, K. Kra�, K. Radacki, J. Wahler,
Organometallics 2011, 30, 3210.
[8] H. Braunschweig, S. Ghosh, T. Kupfer, K. Radacki, J. Wahler, Chem. Eur. J. 2011, 17, 4081.
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Posters – 59 π 2011
Allene or Not allene, is that a question?
C. Walter¹, B. Braïda², P. C. Hiberty³ and B. Engels¹
¹Universität Würzburg, ²Université Paris 06, ³Université de Paris-Sud, France
Since Bertrand and co-workers published the synthesis of a stable five-membered-ring allene [1]
(1), there has been a lot of discussion in the literature about the true electronic nature of this
compound.[2]
RO
N N
R' R'
OR
1
1'
R= 2,6-Me2C6H3
R'=Ph
R=R'=H
In this study we use DFT, multi-reference and valence bond methods to investigate the bending
and twisting mode of open-chain model systems in order to obtain a be�er understanding for
these interesting compounds.
R
R' R'
R
21
22
2 3
24
R=R'=H
R=H, R'=CH 2 -
R=H, R'=NH 2
R=OH, R'=NH2
In addition 1’ is analysed and its electronic structure is interpreted in terms of VB theory.
References
[1] Lavallo, V.; Dyker, C. A.; Donnadieu, B.; Bertrand, G. Angew. Chem. Int. Ed. 2008, 47, 5411-4
[2] e.g.: Christl, M.; Engels, B. Angew. Chem. Int. Ed. 2009, 48, 1538-9.
Lavallo, V.; Dyker, C. A.; Donnadieu, B.; Bertrand, G. Angew. Chem. Int. Ed. 2009, 48, 1540-2.
Hänninen, M.M.; Peuronen, A.; Tuononen, H.M. Chem. Eur. J. 2009, 15, 7287-91.
Klein, S; Tonner, R.; Frenking, G. Chem. Eur. J. 2010, 16, 10160-70.
188

π 2011
N����
Posters – 59
189
Posters II: W

Posters – 60 π 2011
STM investigations of NTCDA on Ag(111) substrate
H. Wetzstein¹, S. Fiedler¹, J. Weinrich¹, M. Winnerlein¹, A. Schöll¹ and F. T. Reinert¹ ²
¹Universität Würzburg, ²Karlsruher Institut für Technologie KIT
�e adsorption of organic molecules on single crystalline substrates generally results in a wealth
of structural arrangements. �is polymorphism is due to the complicated interplay between
lateral and vertical interactions and is strongly depending on coverage, temperature, and preparation
conditions.
We investigated the adsorption of 1,4,5,8-naphthalene-tetracarboxylic-dianhydride (NTCDA) on
Ag(111) substrates [1] at different temperatures with the help of variable temperature scanning
tunneling microscopy (VT-STM) and low energy electron diffraction (LEED) in order to analyse
the structural and electronic properties. �is systems shows a reversible order-disordering transition
upon cooling (so called inverse metling) [2]. While some thermodynamic parameters have
already been derived, the structural arrangement at low temperature as well as the the driving
force for this unusual ordering phenomenon have not been accessed, yet.
Our STM results show the existence of various phases with no long range order, which seem to
coexist at low temperature. Moreover, disordered regimes can already be found at room temperature
by STM, while LEED shows a dominating commensurate super structure [1]. By a further
systematic correlation of our new results with existing LEED data we intend to shed light on the
mechanisms involved in the ordering of planar organic molecules on metal substrates.
References
[1] U. Stahl et al., Surf. Sci. 414 423 (1998).
[2] A. Schöll et al., Science 329 303 (2010).
190

π 2011
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Posters – 60
191
Posters II: W

Posters – 61 π 2011
Helical Nanowires Based on asymmetric Perylene
Bisimides
Z. Xie and F. Würthner
Universität Würzburg
Perylene bisimides (PBIs) constitute one of the most useful classes of fluorophores whose potential
in organic field effect transistors, organic solar cells and light emi�ing devices has been well
recognized [1]. PBIs are also investigated intensively as supramolecular building blocks to form
nanostructures with ordered molecular stacking and J- or H-type coupling [2].
In our group, the core-twisted PBIs were used to construct highly fluorescent J-aggregates with
double-string-cable molecular packing, by using the multiple intermolecular H-bondings and also
using the bay-area substituents to suppress face-to-face π-π interactions [3]. �e bay phenoxy
substituents endow the perylene core with a twisted π-system that makes the PBIs have two
enantiomers (P- and M-enantiomers) and possess chiroptical properties. In this contribution, a
2,2’-biphenol bridge was used to impart a twisting of the perylene core structure and also to
ensure its rigidity [4]. �e remaining two reactive chlorine atoms facilitate further functionalization,
which was confirmed by nucleophilic substitution with different phenols. From this
platform functional chiral material including enantiopure J-aggregates could be developed.
192
Figure P61.1: Schematic of chiral nanorods with double molecular string structure.

π 2011
References
Posters – 61
[1] (a) Würthner, F.; Stolte, M. Chem. Commun. 2011, DOI: 10.1039/c1cc10321k. (b) Zhan, W.;
Facche�i, A.; Barlow, S.; Marks, T.J.; Ratner, M.A.; Wasielewski, M.R.; Marder, S.R. Adv.
Mater. 2011, 23, 268-284.
[2] Würthner, F. Chem. Commun. 2004, 1564-1579.
[3] (a) Kaiser, T.E.; Wang, H.; Stepanenko, V.; Würthner, F. Angew. Chem. Int. Ed. 2007, 46,
5541-5544. (b) Kaiser, T.E.; Stepanenko, V.; Würthner, F. J. Am. Chem. Soc. 2009, 131, 6719-
6732.
[4] Xie, Z.; Würthner, F. Org. Le�. 2010, 12, 3204-3206.
N����
193
Posters II: X

Posters – 62 π 2011
Dendritic Systems based on Triarylamine Building Blocks:
Optical and Electrochemical Properties
F. Zieschang and C. Lambert
Universität Würzburg
�e well-known copper(I) catalysed cyclisation between a terminal alkyne and an azide (CuAAC)
leades to 1,4-disubstituted 1,2,3-triazoles and provides a promising access to π-conjugated dendrimers.
Synthesis of a branch-unit, which contains both functional groups, is the key-step in a
modular synthetic route. �e use of different building blocks allows the variation of either the
core or the terminal units. �ereby, numerous different branched systems with triarylamines
as the redox-chromophore can be obtained. In this context the ability of the triazole to act as a
spacer modulating the interaction of the chromophores is also part of this study.
All systems were characterised by UV/Vis/NIR- and fluorescence spectroscopy in solvents of different
polarity and by electrochemical techniques such as cyclic voltammetry (CV) and Osteryoung
square wave voltammetry (OSWV). Radical cations were prepared by stepwise oxidation of
the neutral compounds and their UV/Vis/NIR-spectra were analysed by Mulliken-Hush theory.
194

π 2011
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Posters – 62
195
Posters II: Z

Posters – 63 π 2011
Bulk heterojunction organic solar cells based on
merocyanine dye supramolecular polymers
A. Zitzler¹, F. Würthner¹, M. Lenze² and K. Meerholz²
¹Universität Würzburg, ²Universität zu Köln
In recent years, bulk heterojunction (BHJ) organic solar cells based on organic semiconductors
gained more and more interest as a renewable energy source due to their tremendous potential
for large-area, low cost power generation and their compatibility with flexible substrates. By
the combination of soluble fullerenes [6,6]-phenyl-C71-butyric-acid methyl ester (PC71BM) as
electron acceptors and semiconducting polymers like PTB7 as electron donors power conversion
efficiencies (PCE) of up to 7.4 % and external quantum efficiencies (EQE) reaching 80 % were
achieved.
Beside conjugated polymers the search for new efficient electron donor components lead to the
observation that small organic molecules are a�ractive candidates for optoelectronic applications
as they do not suffer from polydispersity, low absorption coefficients and cumbersome
purification procedures. �erefore BHJ solar cells based on low-molecular weight organic semiconductors
with PCE’s up to 4.4 % have been developed.
In recent work we could introduce dipolar merocyanine (MC) dyes as suitable electron donor materials
for organic solar cells.[1] Owing to their high dipole moment MC dyes self-assemble into
antiparallel dimer aggregates in dilute solution.[2] �e utilization of this binding motif afforded
the assembly of supramolecular polymers based on a bis(MC) dye.[3]
�is concept of supramolecular polymerisation is now applied to new bis- and tris(MC) dyes, that
already showed good PCEs as mono(MC) dyes, namely the ATOP (Amino�ienyl-diOxoPyridone)
chromophore. �e synthesis and aggregation studies, as well as the first non-optimized results
based on these novel multichromophoric dyes are reported.
196

π 2011
References
Posters – 63
[1] N. M. Kronenberg, M. Deppisch, F. Würthner, H. W. A. Lademann, K. Deing, K. Meerholz,
Chem. Commun. 2008, 6489–6491.
[2] F. Würthner, S. Yao, T. Debaerdemaeker, R. Wortmann, J. Am. Chem. Soc. 2002, 124,
9431–9447.
[3] F. Würthner, S. Yao, U. Beginn, Angew. Chem. Int. Ed. 2003, 42, 3247–3250.
N����
197
Posters II: Z

π 2011
List of Participants
Anderl, Nicole
Technische Universität Darmstadt
Ernst-Berl-Institut �ür Makromolekulare Chemie
Petersenstr. 22, 64287 Darmstadt, Deutschland
nanderl@dki.tu-darmstadt.de
Ansorg, Kay
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer-Str. 42, 97074 Würzburg, Deutschland
kay.ansorg@uni-wuerzburg.de
Auerswald, Johannes
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
Johannes.Auerswald@uni-wuerzburg.de
Bas�é, �omas
Johannes Gutenberg-Universität Mainz
Institut �ür Physikalische Chemie
Welderweg 11, 55099 Mainz
�omas.Bas�e@uni-mainz.de
Be�er, Johannes
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer Straße 42, 97074 Würzburg, Deutschland
johannes.be�er@uni-wuerzburg.de
Bellinger, Daniel
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer Straße 42, 97074 Würzburg, Deutschland
daniel.b.bellinger@stud-mail.uni-wuerzburg.de
Berberi�, Martin
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
berberi�@�emie.uni-wuerzburg.de
Braatz, Carolin
Universität Marburg
Fachbereich Physik
Renthof 5, 35032 Marburg, Deutschland
Carolin.Braatz@physik.uni-marburg.de
List of Participants
Brauns�weig, Holger
Universität Würzburg
Institut �ür Anorganische Chemie
Am Hubland, 97074 Würzburg, Deutschland
h.brauns�weig@uni-wuerzburg.de
Brédas, Jean-Luc
Georgia Institute of Technology
Chemistry and Biology
901 Atlantic Drive, Atlanta, GA 30332-0400, USA
jean-luc.bredas@�emistry.gate�.edu
Brixner, Tobias
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Am Hubland, 97074 Würzburg, Deutschland
brixner@phys-�emie.uni-wuerzburg.de
Brune�er, Frank
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Am Hubland, 97074 Würzburg, Deutschland
Frank.Brune�er@uni-wuerzburg.de
Brüning, Christoph
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer-Str. 42, 97074 Würzburg, Deutschland
�ristoph.bruening@uni-wuerzburg.de
Büttner, Johannes
Universität Bayreuth
Experimentalphysik II
Universitätsstraße 30, 95447 Bayreuth, Deutschland
johannes.a.bue�ner@stmail.uni-bayreuth.de
199
Participants

List of Participants π 2011
Ceymann, Harald
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
harald.ceymann@uni-wuerzburg.de
Dauth, Matthias
Universität Bayreuth
�eoretical Physics IV
Richard Wagner Straße 30a, 95444 Bayreuth, Deutschland
Ma�hias.Dauth@uni-bayreuth.de
Dreuw, Andreas
Universität Heidelberg
Interdisciplinary Center for Scientific Computing
Im Neuenheimer Feld 368, 69120 Heidelberg, Deutschland
dreuw@uni-heidelberg.de
Dürrbe�, Nina
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
duerrbe�@�emie.uni-wuerzburg.de
Ehbets, Julia
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
julia.ehbets@uni-wuerzburg.de
Engel, Volker
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer-Straße 42, 97074 Würzburg, Deutschland
voen@phys-�emie.uni-wuerzburg.de
Engels, Bernd
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer-Str. 42, 97074 Würzburg, Deutschland
bernd@�emie.uni-wuerzburg.de
Falge, Mirjam
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer-Straße 42, 97074 Würzburg, Deutschland
mirjam.falge@physik.uni-wuerzburg.de
Fiedler, Sebastian
Universität Würzburg
Experimentalphysik VII
200
Am Hubland, 97074 Würzburg, Deutschland
Sebastian.Fiedler@physik.uni-wuerzburg.de
Fimmel, Benjamin
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
benjamin.fimmel@uni-wuerzburg.de
Fink, Reinhold
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer-Str. 42, 97074 Würzburg, Deutschland
reinhold.fink@uni-wuerzburg.de
Fis�er, Ingo
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Am Hubland, 97074 Würzburg, Deutschland
ingo.fis�er@uni-wuerzburg.de
Fis�er, Kathrin
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Am Hubland, 97074 Würzburg, Deutschland
kathrin.fis�er@uni-wuerzburg.de
Fris�mann, Peter
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
peter.fris�mann@uni-wuerzburg.de
Fröhli�, Benjamin
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
benjamin.froehli�@uni-wuerzburg.de
Gamon, Daniela
Universität Würzburg
Institut �ür Anorganische Chemie
Am Hubland, 97074 Würzburg, Deutschland
daniela.gamon@uni-wuerzburg.de
Gershberg, Jana
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
jana.gershberg@uni-wuerzburg.de

π 2011
Gloza, Steffi
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
steffi.gloza@uni-wuerzburg.de
Görl, Daniel
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
daniel.goerl@uni-wuerzburg.de
Grimme, Stefan
West�älische Wilhelms-Universität Münster
Organisch-Chemisches Institut
Abt. �eoretische Chemie
Corrensstraße 40, 48149 Münster, Deutschland
grimmes@uni-muenster.de
Gsänger, Marcel
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
gsaenger@�emie.uni-wuerzburg.de
Hader, Kilian
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer-Str. 42, 97074 Würzburg, Deutschland
kilian.hader@uni-wuerzburg.de
Haedler, Andreas
Universität Bayreuth
Macromoleculare Chemie I
Universitätsstr. 30, 95440 Bayreuth, Deutschland
andreas.haedler@uni-bayreuth.de
Haverkort, Frank
University of Groningen
Zernike Institute for Advanced Materials
Nijenborgh 4, 9747 AG Groningen, Niederlande
f.haverkort@rug.nl
Hefner, Timo
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Am Hubland, 97074 Würzburg, Deutschland
timo.hefner@uni-wuerzburg.de
Heilos, Anna
Universität Würzburg
List of Participants
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer-Str. 42, 97074 Würzburg, Deutschland
AnnaHeilos@web.de
Hemberger, Patri�
Paul Scherrer Institut
Swiss Light Source
WSLA 115, 5234 Villigen PSI, Schweiz
patri�.hemberger@psi.�
Hertel, Tobias
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Am Hubland, 97074 Würzburg, Deutschland
tobias.hertel@uni-wuerzburg.de
Herteri�, Jörg
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Am Hubland, 97074 Würzburg, Deutschland
joerg.herteri�@uni.wuerzburg.de
Hoerl, Christian
Universität Würzburg
Institut �ür Anorganische Chemie
Am Hubland, 97074 Würzburg, Deutschland
�ristian.hoerl@uni-wuerzburg.de
Huppmann, Sophia
Universität Würzburg
Experimentalphysik VII
Am Hubland, 97074 Würzburg, Deutschland
shuppmann@physik.uni-wuerzburg.de
Issac, Abey
Universität Bayreuth
Experimentalphysik IV
Universitätsstr. 30, 95447 Bayreuth, Deutschland
abey.issac@uni-bayreuth.de
Kaiser, Conrad
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
conradkaiser@gmx.de
Kanal, Florian
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Am Hubland, 97074 Würzburg, Deutschland
florian.kanal@phys-�emie.uni-wuerzburg.de
201
Participants

List of Participants π 2011
Karolewski, Andreas
Universität Bayreuth
�eoretical Physics IV
Bayreuth, 95440 Bayreuth, Deutschland
andreas.karolewski@uni-bayreuth.de
Kaupp, Martin
TU Berlin
Institut �ür Chemie, �eoretische Chemie, Sekr. C7
Strasse des 17. Juni 135, 10623 Berlin, Deutschland
martin.kaupp@tu-berlin.de
Kir�wehm, Yvonne
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
yvonne.kir�wehm@uni-wuerzburg.de
Klein, Johannes
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
klein@�emie.uni-wuerzburg.de
Köhler, Juliane
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Am Hubland, 97074 Würzburg, Deutschland
juliane@phys-�emie.uni-wuerzburg.de
Köhn, Andreas
Universitaet Mainz
Institut �ür Physikalische Chemie
Jakob Welder-Weg 11, 55099 Mainz, Deutschland
andreas.koehn@uni-mainz.de
Kritzer, Robert
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer-Str. 42, 97074 Würzburg, Deutschland
kritzer@uni-wuerzburg.de
Krueger, Anke
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
krueger@�emie.uni-wuerzburg.de
Kullmann, Martin
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
202
Am Hubland, 97074 Würzburg, Deutschland
martin.kullmann@phys-�emie.uni-wuerzburg.de
Lambert, Christoph
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, D-97074 Würzburg, Deutschland
�ristoph.lambert@uni-wuerzburg.de
Lee, Wook
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer-Straße 42, 97074 Würzburg, Deutschland
wlee@�emie.uni-wuerzburg.de
Lehmann, Matthias
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
Ma�hias.Lehmann@uni-wuerzburg.de
Lennartz, Christian
BASF SE
Organic Electronics
Carl Bosch Strasse 38, 67056 Ludwigshafen, Deutschland
�ristian.lennartz@basf.com
Leo, Karl
Technische Universität Dresden and
Fraunhofer-Institute for Photonic Microsystems
Institut �ür Angewandte Photophysik
01109 Dresden, Deutschland
leo@iapp.de
Liu, Linlin
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
linlin.liu@uni-wuerzburg.de
Liu, Wenlan
Ruprecht-Karls-Universität Heidelberg
Interdisciplinary Center for Scientific Computing
Im Neuenheimer Feld 368, 69120 Heidelberg, Deutschland
wenlan.liu@iwr.uni-heidelberg.de
Lu, Han
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
lvhanabc@hotmail.com

π 2011
Lunkenheimer, Bernd
Johannes Gutenberg-Universität Mainz
Institut �ür Physikalische Chemie
Jakob-Welder-Weg 11, 55128 Mainz, Deutschland
lunkenheimer@uni-mainz.de
Maier, Philipp
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
ph.maier@uni-wuerzburg.de
Marian, Christel M.
Heinrich-Heine-Universität Düsseldorf
�eoretical and Computational Chemistry
Universitätsstr. 1, 40476 Düsseldorf, Deutschland
Christel.Marian@hhu.de
Marty, Roman
Ecole Polytechnique Fédérale de Lausanne
EPFL – STI – IMX – LMOM
Station 12, 1015 Lausanne, Schweiz
rmarty@alumni.ethz.�
Moos, Mi�ael
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
mi�ael.moos@uni-wuerzburg.de
Mujica Martinez, Cesar Augusto
Universität Hamburg
I. Institut �ür �eoretische Physik
Jungiusstraße 9, 20355 Hamburg, Deutschland
cesar.mujica@physik.uni-hamburg.de
Nakamura, Eii�i
University of Tokyo
Department of Chemistry
7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
nakamura@�em.s.u-tokyo.ac.jp
Negri, Fabrizia
University of Bologna
Department of Chemistry ‘G. Ciamician’
Via F. Selmi, 2, 40126 Bologna, Italien
fabrizia.negri@unibo.it
Nguyen, �anh Nam
Universität Würzburg
Experimentalphysik VII
List of Participants
Am Hubland, 97074 Würzburg, Deutschland
thanh-nam.nguyen@physik.uni-wuerzburg.de
Ogilvie, Jennifer P.
University of Michigan
Department of Physics/Biophysics
450 Church St., Ann Arbor, MI 48109, USA
jogilvie@umi�.edu
Paas�e, Alexander
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer Straße 42, 97074 Würzburg, Deutschland
paas�e@�emie.uni-wuerzburg.de
Pabst, Mathias
Johannes Gutenberg-Universität Mainz
Institut �ür Physikalische Chemie
Jakob Welder-Weg 11, 55099 Mainz, Deutschland
pabst@uni-mainz.de
Polyutov, Sergey
Rostock University/Institute of Physics
Molecular �antum Dynamics
Wismarsche Str. 43-45, 18057 Rostock, Deutschland
sergey.polyutov@uni-rosto�.de
�ast, Tatjana
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Am Hubland, 97074 Würzburg, Deutschland
tatjana.quast@phys-�emie.uni-wuerzburg.de
Rei�enberger, Markus
Universität Bayreuth
Experimentalphysik II
Universitätsstraße 30, 95447 Bayreuth, Deutschland
markus.rei�enberger@gmx.de
Renz, Manuel
Technische Universität Berlin
Institut �ür Chemie, �antenchemie, Sekr. C7
Straße des 17. Juni 135, 10623 Berlin, Deutschland
manuel.renz@tu-berlin.de
Renziehausen, Klaus
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer-Straße 42, 97074 Würzburg, Deutschland
KsRenzie@phys-�emie.uni-wuerzburg.de
203
Participants

List of Participants π 2011
Rolland, Damien
Ecole Polytechnique Fédérale de Lausanne
EPFL – STI – IMX – LMOM
Station 12, 1015 Lausanne, Schweiz
damien.rolland@epfl.�
Roos, Claudia
Johannes Gutenberg-Universität Mainz
Institut �ür Physikalische Chemie
Jakob-Welder-Weg 11, 55128 Mainz, Deutschland
Claudia.Roos@uni-mainz.de
Rudni�, Alexander
Universität Bayreuth
Experimentalphysik II
Universitätsstraße 30, 95447 Bayreuth, Deutschland
alexander.rudni�@uni-bayreuth.de
Rudolf, Philipp
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Am Hubland, 97074 Würzburg, Deutschland
philipp.rudolf@phys-�emie.uni-wuerzburg.de
Ruetzel, Stefan
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Am Hubland, 97074 Würzburg, Deutschland
stefan.ruetzel@phys-�emie.uni-wuerzburg.de
Sander, Regina
Deutsches Kunststoff-Institut
Schlossgartenstr. 6, 64289 Darmstadt, Deutschland
rsander@dki.tu-darmstadt.de
Sauer, Christoph
Universität Würzburg
Physikalisches Institut
Am Hubland, 97074 Würzburg, Deutschland
cesauer@physik.uni-wuerzburg.de
S�arsi�, Christina
Universität Bayreuth
Experimentalphysik II
Universitätsstr. 30, 95440 Bayreuth, Deutschland
�ristina.s�arsi�@uni-bayreuth.de
S�losser, Felix
Universität Würzburg
Institut �ür Organische Chemie
204
Am Hubland, 97074 Würzburg, Deutschland
s�losser@�emie.uni-wuerzburg.de
S�midt, Regina
Universität Bayreuth
Experimentalphysik IV
Universitätsstr. 30, 95447 Bayreuth, Deutschland
regina.s�midt@uni-bayreuth.de
S�midt, �omas
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil Fischer Strasse 42, 97074 Würzburg, Deutschland
thomas.s�midt@uni-wuerzburg.de
S�midt, Tobias
Universität Bayreuth
�eoretical Physics IV
Universitätsstraße 30, 95440 Bayreuth, Deutschland
tobias.s�midt@uni-bayreuth.de
S�miedel, Alexander
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
alexander.s�miedel@uni-wuerzburg.de
S�öll, A�im
Universität Würzburg
Experimentalphysik VII
Am Hubland, 97074 Würzburg, Deutschland
a�im.s�oell@physik.uni-wuerzburg.de
S�olz, Markus
Universität Würzburg
Experimentalphysik VII
Am Hubland, 97074 Würzburg, Deutschland
markus.s�olz@physik.uni-wuerzburg.de
S�ubert, Alexander
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer-Str. 42, 97074 Würzburg, Deutschland
a.s�ubert@uni-wuerzburg.de
S�warz, Christian
Universität Bayreuth
Experimentalphysik II
Universitätsstraße 30, 95447 Bayreuth, Deutschland
�ristian.s�warz@uni-bayreuth.de

π 2011
Seibt, Joa�im
Max-Planck-Institut �ür Physik komplexer Systeme
Abteilung Endliche Systeme
Noethnitzer Strasse 38, 01187 Dresden, Deutschland
seibt@pks.mpg.de
Selig, Ulrike
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Am Hubland, 97074 Würzburg, Deutschland
ulrike.selig@phys-�emie.uni-wuerzburg.de
Sengupta, San�ita
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
sengupta@�emie.uni-wuerzburg.de
Settels, Volker
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer-Straße 42, 97074 Würzburg, Deutschland
se�els@�emie.uni-wuerzburg.de
Shao, Changzhun
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
�zh.shao@hotmail.com
Spano, Frank
Temple University
Department of Chemistry, Beury Hall 130
1901 N. 13th Street, Philadelphia, PA 19122, USA
spano@temple.edu
Späth, Florian
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Am Hubland, 97074 Würzburg, Deutschland
florian.spaeth@uni-wuerzburg.de
Steeger, Markus
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
steeger@�emie.uni-wuerzburg.de
Stehr, Vera
Universität Würzburg
Experimentalphysik VI
Am Hubland, 7074 Würzburg, Deutschland
Stehr@Physik.Uni-Wuerzburg.de
List of Participants
Steinba�er, Andreas
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Am Hubland, 97074 Würzburg, Deutschland
Andreas.Steinba�er@physik.uni-wuerzburg.de
Stolte, Matthias
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
ma�hias.stolte@uni-wuerzburg.de
Suraru, Sabin-Lucian
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
suraru@�emie.uni-wuerzburg.de
Tat�en, Jörg
Heinrich-Heine Universität Düsseldorf
Institute of �eoretical Chemistry
Universitätsstrasse 1, 40225 Düsseldorf, Deutschland
joerg@theo�em.uni-duesseldorf.de
�anopulos, Ionnanis
National Hellenic Research Foundation
�eoretical and Physical Chemistry Institute
48 Vassileos Constantinou Ave., 11635 Athens,
Griechenland
ithano@eie.gr
Tian, Liangfei
Ecole Polytechnique Fédérale de Lausanne
Institute of Materials
EPFL – STI – IMX – LMOM
Station 12, 1015 Lausanne, Schweiz
liangfei.tian@epfl.�
Ts�eus�ner, Steffen
Universität Bayreuth
Experimentalphysik II
Universitätsstraße 30, 95447 Bayreuth, Deutschland
steffen.ts�eus�ner@stmail.uni-bayreuth.de
205
Participants

List of Participants π 2011
Ueno, Nobuo
Chiba University
Graduate School of Advanced Integration Science
Inage-ku, Chiba, Japan
uenon@faculty.�iba-u.jp
Vauthey, Eric
University of Geneva
Physical Chemistry Department - Sciences II
30, �ai Ernest Ansermet, 1211 Geneva 4, Schweiz
Eric.Vauthey@unige.�
Vilbrandt, Nicole
Technische Universität Darmstadt
Ernst-Berl-Institut �ür Makromolekulare Chemie
Petersenstr. 22, 64287 Darmstadt, Deutschland
NVilbrandt@dki.tu-darmstadt.de
Völker, Sebastian
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
voelker@�emie.uni-wuerzburg.de
Wahler, Johannes
Universität Würzburg
Institut �ür Anorganische Chemie
Am Hubland, 97074 Würzburg, Deutschland
johannes.wahler@uni-wuerzburg.de
Walter, Christof
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer-Str. 42, 97074 Würzburg, Deutschland
�ristof.walter@uni-wuerzburg.de
Wang, Suning
�een’s University
Department of Chemistry
Kingston, Ontario, K7L 3N6, Kanada
wangs@�em.queensu.ca
Wasielewski, Mi�ael
Northwestern University
Department of Chemistry and
Argonne-Northwestern Solar Energy Research Center
2145 Sheridan Rd., Evanston, IL 60208-3113, USA
m-wasielewski@northwestern.edu
Weber, Daniel
Universität Würzburg
206
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer Straße 42, 97074 Würzburg, Deutschland
daniel.weber@uni-wuerzburg.de
Wehner, Johannes
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer-Str. 42, 97074 Würzburg, Deutschland
johannes.g.wehner@uni-wuerzburg.de
Wei�ert, Anastasia
Universität Würzburg
Institut �ür Physikalische und �eoretische Chemie
Emil-Fischer-Str. 42, 97074 Würzburg, Deutschland
anastasia.wei�ert@uni-wuerzburg.de
Wetzstein, Holger
Universität Würzburg
Experimentalphysik VII
Am Hubland, 97074 Würzburg, Deutschland
holger.wetzstein@physik.uni-wuerzburg.de
Wießner, Mi�ael
Universität Würzburg
Experimentalphysik VII
Am Hubland, 97074 Würzburg, Deutschland
mwiessner@physik.uni-wuerzburg.de
Würthner, Frank
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
wuerthner@�emie.uni-wuerzburg.de
Xie, Zengqi
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
zengqi.xie@uni-wuerzburg.de
Zhang, Xin
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
zhang@�emie.uni-wuerzburg.de
Zies�ang, Fabian
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
zies�ang@�emie.uni-wuerzburg.de

π 2011
Zitzler, André
Universität Würzburg
Institut �ür Organische Chemie
Am Hubland, 97074 Würzburg, Deutschland
andre.zitzler@uni-wuerzburg.de
List of Participants
207
Participants

Glossary π 2011
Glossary
Amarne, H. I7
Ansorg, K. O6
Arita, M. P5
Asawapirom, U. P42
Auerswald, J. P1
Bödi, A. P9, P19
Büchner, M. P8
Bao, Z. O5, P15, P54
Basché, T. O3, P40
Berberich, M. P2
Brédas, J.-L. I4
Braïda, B. P59
Braunschweig, H. O6, P9, P12, P21, P58
Breher, F. O6, P12
Brill, J. H. O5, P15, P54
Bringmann, G. P29
Brixner, T. O7, P25, P29, P41, P53
Brunecker, F. P3
Buback, J. O7, P25, P41, P53
Ceymann, H. P4
Chen, L. I7
Chiu, C. P12
Dürrbeck, N. P6
Damme, A. P12, P21
Dauth, M. P5
Dehm, V. P8
Deibel, C. P52
Di Mo�a, S. O2, P35
Diehl, F. P. O3, P40
Dreuw, A. P30
Ehm, D. P36
Eisfeld, A. P47
Engel, V. O9, P8, P46, P49
Engels, B. O6, O9, P30, P46, P49, P52, P59
Ernst, D. P23
Ernst, M. P36
Ferkinghoff, K. P58
Fiedler, S. P7, P60
Fimmel, B. P8
Fink, R. F. O9, P30, P46, P49, P52
Fischer, I. O7, O10, P9, P19, P20
Fischer, K. H. P9, P19
Fröhlich, B. P11
Frauenrath, H. O11, P33, P39, P56
Frischmann, P. D. P10
208
Görl, D. P14
Götz, D. C. G. P29
Gamon, D. O6, P12
Gloza, S. P13
Gosh, S. P58
Grimme, S. I10
Gsänger, M. O5, P15
Guieu, S. P10
Hörl, C. P21
Haedler, A. T. P16
Han�, D. P16
Haverkort, F. P17
Hefner, T. P18, P50
Hemberger, P. P19
Hertel, T. P18, P50
Herterich, J. P20
Hiberty, P. C. P59
Hipke, A. P29
Hippius, C. P23
Huber, V. P48
Hügel, M. O6
Huppmann, S. P22, P36
Iljina, M. P50
Isaac, A. P23
Jahr, M. P13
Johnson, M. P19
Köhler, Juliane O7
Köhler, Jürgen P23
Köhn, A. P31, P37, P40
Könemann, M. P54
Körzdörfer, T. P5
Kühn, O. P38
Kümmel, S. P5, P26, P44
Köhler, A. P42
Köhn, A. O3, O4
Kaiser, C. P24
Kanal, F. O7, P25
Karolewski, A. P26
Ka�erle, M. P48
Kaupp, M. O8, P57
Keiber, S. P25
Kirchwehm, Y. P27
Klauk, H. O5, P15, P54
Klein, J. H. P28, P58
Kleinschmidt, M. P32
Knoester, J. P17

π 2011
Krause, A.-M. P2
Kreger, K. P16
Krueger, A. P1, P27
Kullmann, M. O7, P25, P29, P41
Kupfer, T. P12
Lambert, C. O7, O12, P4, P6, P24, P25, P28,
P45, P51, P57, P58, P62
Langer, N. O5, P15
Lee, W.-Y. O5, P15
Lehmann, M. P11, P13
Lenze, M. P63
Leo, K. I2
Liu, W. O9, P30, P46, P49
Lochbrunner, S. P46
Lohwasser, R. P42
Lunkenheimer, B. P31, P40
MacLachlan, M. J. P10
Maier, P. P11
Mailänder, L. P21
Marian, C. M. P32
Marty, R. P33
Meerholz, K. P63
Meier, C. P46
Mosey, N. I7
Mujica-Martinez, C. A. P34
Nürnberger, P. O7
Nakamura, E. I3
Negri, F. O2, P35
Nguyen, T.-N. P36
Nied, D. O6, P12
Nuernberger, P. P29, P41, P53
Ogilvie, J. P. I9
Oh, J. H. O5, P15, P54
Orlandi, M. P2
Pabst, M. P37
Paspalakis, E. P55
Pfaffinger, B. P9
Pfister, J. P52
Polyutov, S. P38
Puschnig, P. P22
�, J. P54
�ast, T. O7, P25
Röger, C. P48
Rützel, S. O7
Radacki, K. P12, P21
Rao, Y. I7
Reinert, F. P5, P7, P22, P36, P60
Reitzenstein, D. O7, P25
Renz, M. O8, P57
Rolland, D. P39
Roos, C. O3, P40
Ruetzel, S. P25, P41
Sahli, B. P10
Glossary
Scandola, F. P2
Schöll, A. P5, P7, P22, P36, P60
Scharsich, C. P42
Scherf, U. P42
Schindlbeck, S. P46
Schlosser, F. P43
Schmidt, R. P7
Schmidt, H.-W. P16
Schmidt, T. P44
Schmiedel, A. P45
Schneider, M. P9
Scholz, M. P7, P22, P36
Schon, C. P19
Schubert, A. O9, P46, P49
Seibt, J. P8, P47
Sengupta, S. P48
Se�els, V. O9, P30, P46, P49
Shimada, K. P5
Späth, F. P50
Spano, F. C. I6
Stahl, S. P18
Steeger, M. P51
Stehr, V. O9, P49, P52
Steinbacher, A. P53
Steinbauer, M. P19
Stepanenko, V. P43
Stolte, M. O5, P15, P54
Stradomska, A. P17
Sunderland, T. L. P28
Sundholm, D. P37
Suraru, S.-L. O5, P15, P54
Tafipolski, M. O9, P49
Tatchen, J. O1
�anopulos, I. P55
�elakkat, M. P42
�ian, L. P56
�orwart, M. P34
Tian, L. O11
Uemura, S. P48
Ueno, N. I5
Völker, S. F. P57
Vauthey, E. I8
Würthner, F. O5, P2, P7, P8, P14, P15, P23, P43,
P46, P48, P54, P61, P63
Wahler, J. P58
Walter, C. P59
Wang, S. I7
Wasielewski, M. R. I1
Weinrich, J. P60
Wetzstein, H. P60
Wiessner, M. P5, P22
Winnerlein, M. P60
Wohlert, A. O1
209
Glossary

Glossary π 2011
Xie, Z. P61
Yamagata, H. I6
Yannopapas, V. P55
Zeißner, S. P20
Zhang, X. P14, P48
Zieschang, F. P62
Ziroff, J. P5, P22
Zitzler, A. P63
Zschieschang, U. O5, P15, P54
210