4th EucheMs chemistry congress

Poster Session 2
s1266
chem. Listy 106, s257–s1425 (2012)
Poster session 2 - organic chemistry
P - 0 8 0 6
PerSPeCtiveS in the deSiGn, SyntheSiS And
ChArACterizAtion of PoLyMer MAteriALS
with APPLiCAtionS in oPtiCAL fieLd
A. M. ALBu 1 , i. GAvriLA 1 , L. trinCA 1
1 University Politehnica of Bucharest, Department of
Bioresources and Polymer Science, Bucharest, Romania
The organic macromolecules with extended electronic
sequences remain one of the most attractive points of start for
implementation of the specialized device. Why the polymer
systems? Because is relatively easy to process organic polymeric
materials into practical devices. They are certainly remarkable
materials through their flexibility, versatility and architectural
accessibility, which allow their optimization for the desired
applications.
Since the discovery of the photorefractive effect in organic
polymers, polymers containing carbazole have also attracted
much attention for their photoconductivity. In this context,
multicomponent polymers with structural units containing both
photoconductive and electrooptic functionalities in the side chain
can be regarded as potentially suitable materials for
photorefractive applications. Indeed, polymers with the carbazolyl
diazene side group prepared by polymerization of the
corresponding functionalized monomers, or by azocoupling postreaction
to carbazole containing polymers, proved to show
photorefractive and NLO properties as well as photoinduced
orientation and formation of surface relief gratings. Moreover, the
helical configurations, particularly the ‘stacking’ of the carbazole
pendant groups in the syndiotactic polymer, would allow for many
of the interesting electronic and photoconductive properties
associated with polyvinylcarbazole. The such materials can be
characterized, in solution, by chiral conformations related to the
combined effects of the strongly dipolar conjugated carbazole
system with the conformational stiffness of optically active rings,
favouring the instauration of a conformational arrangement with
a prevailing handedness, at least for chain sections of the
macromolecules.
In this idea, we propose the synthesis and characterization
of few new carbazole compounds, to foreshadowing, based theirs
physical properties, the potential applications of polymer
materials, with such sequences, in the nonlinear optical field.
Structured in three sections, the aims is to highlight the most
important peculiarities regarding the structural - constituent
relationship to the polymer materials, based on the consacrated
analytical techniques.
Keywords: Azo compounds; polymers;
4 th EucheMs chemistry congress
P - 0 8 0 7
Proton-CAtALyzed, SiLAne-fueLed
intrAMoLeCuLAr friedeL–CrAftS AryL
CouPLinG: fLuoroArene C–f ACtivAtion By
SiLyL CAtionS
o. ALLeMAnn 1 , K. BALdridGe 1 , J. SieGeL 1
1 University of Zurich, OCI, Zürich, Switzerland
Friedel–Crafts transformations are known for a long time
and still present a very important class of chemical reactions. In
terms of aryl-aryl couplings, the reaction is limited due to the
thermodynamic instability of the phenyl cation. This fact gave rise
to a large variety of coupling reactions using transition metal
catalysts and activated arenes. Combining our group’s knowledge
about silylium ions in general [1] and our findings on carbon
fluorine bond activation, [2] we developed a method for an
intramolecular Friedel–Crafts type coupling of an aryl fluoride
with an unactivated aryl nucleophile without using a transition
metal. [3] The transformation involves cleavage of the C–F bond
using the very reactive silylium ion and attack by an adjacent
arene moiety within the same molecule. In our example reaction,
we use an iPr Si carborane to abstract fluoride from
3
1-(2-Fluorophenyl)naphthalene, which is transformed to
fluoranthene by ring closure and subsequent elimination of a
proton. Since the proton can be used to generate a silyl cation from
a silane, only a catalytic amount of initiator (i.e. silylium ion) can
be used. We applied this method to more complex systems
towards larger polyaromatic hydrocarbons and are exploring the
possibilities concerning substrate scope and adaptabilities of the
reaction.
references:
1. a) S. Duttwyler, Q. Q. Do, A. Linden, K. Baldridge, J.
Siegel, Angewandte Chemie International Edition 2008,
47, 1719;
b) P. Romanato, S. Duttwyler, A. Linden, K. K. Baldridge,
J. S. Siegel, Journal of the American Chemical Society
2010, 132, 7828.
2. S. Duttwyler, C. Douvris, N. L. P. Fackler, F. S. Tham,
C. A. Reed, K. K. Baldridge, J. S. Siegel, Angewandte
Chemie International Edition 2010, 49, 7519.
3. O. Allemann, S. Duttwyler, P. Romanato, K. K. Baldridge,
J. S. Siegel, Science 2011, 332, 574.
Keywords: silyl cations; C-F activation; Friedel–Crafts;
polyaromatic hydrocarbons; proton-catalyzed;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc