title: Extended-Core Discotic Liquid Crystals Based on the Intramolecular H-Bonding in N-Acylated 2,2'-Bipyridine-3,3'-diamine Moieties.
abstract: 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 Dho phase. From (1) H NMR results it was shown that the interior of compounds 1 a-c preferentially adopts a C3 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.
authors.affiliation: Laboratory of Organic Chemistry, Eindhoven University of Technology POBox 513, 5600 MB Eindhoven (The Netherlands), Fax: Int. code +(40)245-1036, e-mail: tgtobm@chem.tue.nl.
authors.forename: A R
authors.initials: AR
authors.lastname: Palmans
authors.forename: J A
authors.initials: JA
authors.lastname: Vekemans
authors.forename: H
authors.initials: H
authors.lastname: Fischer
authors.forename: R A
authors.initials: RA
authors.lastname: Hikmet
authors.forename: E W
authors.initials: EW
authors.lastname: Meijer
keywords: bipyridines; discotic liquid crystals; hydrogen bonds; liquid crystals; mesophases