TY  - JOUR
A1  - Zhang, Fangyuan
A1  - Radacki, Krzysztof
A1  - Braunschweig, Holger
A1  - Lambert, Christoph
A1  - Ravat, Prince
T1  - Zinc-[7]helicenocyanine and its discrete π-stacked homochiral Dimer
JF  - Angewandte Chemie International Edition
N2  - In this communication, we demonstrate a novel approach to prepare a discrete dimer of chiral phthalocyanine (Pc) by exploiting the flexible molecular geometry of helicenes, which enables structural interlocking and strong aggregation tendency of Pcs. Synthesized [7]helicene-Pc hybrid molecular structure, zinc-[7]helicenocyanine (Zn-7HPc), exclusively forms a stable dimeric pair consisting of two homochiral molecules. The dimerization constants were estimated to be as high as 8.96×10\(^6\) M\(^{−1}\) and 3.42×107 M\(^{−1}\) in THF and DMSO, respectively, indicating remarkable stability of dimer. In addition, Zn\(^{-7}\)HPc exhibited chiral self-sorting behavior, which resulted in preferential formation of a homochiral dimer also in the racemic sample. Two phthalocyanine subunits in the dimeric form strongly communicate with each other as revealed by a large comproportionation constant and observation of an IV-CT band for the thermodynamically stable mixed-valence state.
KW  - organic chemistry
KW  - supramolecular assembly
KW  - chirality
KW  - helicenes
KW  - homochiral dimer
KW  - phthalocyanines
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256534
VL  - 60
ER  - 
TY  - JOUR
A1  - Zhang, Fangyuan
A1  - Michail, Evripidis
A1  - Saal, Fridolin
A1  - Krause, Ana-Maria
A1  - Ravat, Prince
T1  - Stereospecific Synthesis and Photophysical Properties of Propeller-Shaped C\(_{90}\)H\(_{48}\) PAH
JF  - Chemistry - A European Journal
N2  - Herein, we have synthesized an enantiomerically pure propeller‐shaped PAH, C\(_{90}\)H\(_{48}\), possessing three [7]helicene and three [5]helicene subunits. This compound can be obtained in gram quantities in a straightforward manner. The photophysical and chiroptical properties were investigated using UV/Vis absorption and emission, optical rotation and circular dichroism spectroscopy, supported by DFT calculations. The nonlinear optical properties were investigated by two‐photon absorption measurements using linearly and circularly polarized light. The extremely twisted structure and packing of the homochiral compound were investigated by single‐crystal X‐ray diffraction analysis.
KW  - chirality
KW  - enantiomers
KW  - helicenes
KW  - polycyclic aromatic hydrocarbons
KW  - stereospecific sythesis
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-208682
VL  - 25
IS  - 71
ER  -