TY  - JOUR
A1  - Lehmann, Matthias
A1  - Baumann, Maximilian
A1  - Lambov, Martin
A1  - Eremin, Alexey
T1  - Parallel polar dimers in the columnar self‐assembly of umbrella‐shaped subphthalocyanine mesogens
JF  - Advanced Functional Materials
N2  - The self-assembly of umbrella-shaped mesogens is explored with subphthalocyanine cores and oligo(thienyl) arms with different lengths in the light of their application as light-harvesting and photoconducting materials. While the shortest arm derivatives self-assemble in a conventional columnar phase with a single mesogen as a repeating unit, the more extended derivatives generate dimers that pile up into liquid crystalline columns. 

In contrast to the antiparallel arrangement known from single crystals, the present mesogens align as parallel dimers in polar columnar phases as confirmed by X-ray scattering, experimental densities, dielectric spectroscopy, second harmonic generation, alignment, and conductivity studies. 

UV–vis and fluorescence spectroscopies reveal a broad absorption in the visible range and only weak emission of the Q-band. Thus, these light-collecting molecules forming strongly polar columnar mesophases are attractive for application in the area of photoconductive materials.
KW  - umbrella-shaped mesogens
KW  - parallel polar dimers
KW  - subphthalocyanine
KW  - columnar   phases
KW  - ferroelectrics
KW  - liquid   crystal   alignment
KW  - organic   semiconductors
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256343
VL  - 31
IS  - 38
ER  -