4th EucheMs chemistry congress

Poster Session 2
s1352
chem. Listy 106, s257–s1425 (2012)
Poster session 2 - organic chemistry
P - 0 9 7 9
unPreCedented MetA-SuBStitution of
CALixArenS: direCt wAy to inherentLy
ChirAL reCePtorS
P. SLAviK 1 , M. dudiC 2 , K. fLidrovA 1 , J. SyKorA 3 ,
i. CiSArovA 4 , S. BÖhM 1 , P. LhotAK 1
1 Institute of Chemical Technology Prague, Department of
Organic Chemistry, Praha 6, Czech Republic
2 Academy of Sciencies of Czech Republic, Institute of Organic
Chemistry and Biochemistry, Praha 6, Czech Republic
3 Academy of Sciencies of Czech Republic, Institute of Chemical
Process Fundamentals, Praha 6, Czech Republic
4 Charles University, Department of Inorganic Chemistry, Praha 2,
Czech Republic
The electrophilic aromatic substitution in calix[n]arene
series is a well-established procedure leading exclusively to the
para-substituted derivatives. Here, we describe an unprecedented
regioselectivity of mercuration reaction leading to the
meta-substituted calix[4]arenes. We have recently described
similar unexpected regioselectivity during the nitration and
formylation of thiacalix[4]arene [1] skeleton.
These compounds represent a new type of substitution
pattern in classical calixarene chemistry and open the door for the
straightforward synthesis of inherently chiral receptors based on
calixarenes.
Acknowledgement: This research was supported by the Czech
Science Foundation (P207/12/2027).
references:
1.. a) O. Kundrat, J. Kroupa, S. Böhm, J. Budka, V. Eigner,
P. Lhotak, J. Org. Chem. 2010, 75, 8372-8375.
b) O. Kundrat, I. Cisarova, S. Böhm, M. Pojarova,
P. Lhotak, J. Org. Chem. 2009, 74, 4592-4596.
c) O. Kundrat, H. Dvorakova, V. Eigner, P. Lhotak, J. Org.
Chem. 2010, 75, 407-411.
Keywords: Calix[4]arenes;
4 th EucheMs chemistry congress
P - 0 9 8 0
BuiLdinG BLoCKS for SuPrAMoLeCuLAr
PhotoCAtALySiS BASed on
2,2'-BiBenziMidAzoLe
d. SorSChe 1 , n. roCKStroh 2 , S. rAu 1
1 Inorganic Chemistry I, Materials and Catalysis, Ulm,
Germany
2 Leibniz Institut für Katalyse, Angewandte Homogenkatalyse,
Rostock, Germany
In natural photosynthesis, light driven electron transfer
processes between an oxygen evolving manganese cluster and
several reduction catalysts lead to efficient water splitting and
fixation of CO . In green leafs, the process is powered by
2
light absorption through the porphyrin-moieties of the
photosystems P680 and P700. In artificial photosynthesis,
tris(bipyridyl)ruthenium(II) complexes have proven their ability
to convert light as efficiently into electronic energy to drive
chemical conversions. One of the most challenging aspects here
is to establish the directional electron transfer between two
catalytically active systems. Looking at the electron transfer chain
of the z-scheme, guiding the intermolecular transport of an excited
electron through supramolecular pre-orientation is an interesting
route. [1] Several groups including ourselves have shown that
ruthenium(II) chromophors containing a bibenzimidazole ligand
establish defined supramolecular assemblies with anions as well
as cations through hydrogen bonds. [2–4] Since such aggregation
changes the luminescent properties of the complexes, the
corresponding complexes can also be considered as luminescent
sensors. Following the procedure presented by Siegel et al. [5] we
synthesized several substituted bibenzimidazoles and their
corresponding ruthenium(II) complexes and characterized them
with respect to their photochemistry, also in the presence of
several guest molecules.
references:
1. S. Rau, B. Schäfer, S. Schebesta, A. Grüßing, W. Poppitz,
D. Walther, M. Duati, W.R. Browne, J.G. Vos, Eur.
J. Inorg. Chem., 2003, 8, 1503–1506
2. S. Rau, T. Büttner, C. Temme, M. Ruben, H. Görls,
and D. Walther*, M. Duati, S. Fanni, and J.G. Vos*,
Inorganic Chemistry 2000 39 (7), 1621–1624
3. Y. Cui, Y-L. Niu, M-L. Cao, K. Wang, H-J. Mo, Y-R. Zhong,
and B-H. Ye, Inorganic Chemistry, 2008, 47 (13),
5616–562
4. N. Rockstroh, K. Peuntinger, H. Görls, D. M. Guldi,
F. W. Heinemann, B. Schäfer, and S. Rau*, Z. Naturforsch,
2010, 65b, 281
5. Y. Yasui, D.K. Frantz, and J.S. Siegel*, Organic Letters
2006 8 (22), 4989-4992
Keywords: Bibenzimidazole; Ruthenium; Photochemistry;
Supramolecular;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc