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Extended‐Core Discotic Liquid Crystals Based on the Intramolecular H‐Bonding in N ‐Acylated 2,2′‐Bipyridine‐3,3′‐diamine Moieties
Author(s) -
Palmans Anja R. A.,
Vekemans Jozef A. J. M.,
Fischer Hartmut,
Hikmet Rifat A.,
Meijer E. W.
Publication year - 1997
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.19970030220
Subject(s) - intramolecular force , diamine , discotic liquid crystal , bipyridine , core (optical fiber) , 4,4' bipyridine , materials science , crystallography , chemistry , hydrogen bond , polymer chemistry , stereochemistry , molecule , crystal structure , organic chemistry , composite material
A new type of disc‐shaped molecule ( 1 a‐c ) has been synthesised and characterised. The molecules were built up by linking three lipophilic, N ‐monoacylated 2,2′‐bipyridine‐3,3′‐diamine wedges to a central 1,3,5–benzenetricarbonyl unit. They show liquid crystalline behaviour, as shown by DSC, polarisation microscopy and X‐ray diffraction. In all cases the mesophase was characterised as a D ho phase. From 1 H NMR results it was shown that the interior of compounds 1 a‐c preferentially adopts a C 3 symmetrical conformation owing to strong intramolecular H‐bonding, which gives rise to an extended core. This large core induces strong interactions between molecules, leading to mesophases of enhanced thermal stability.