N,N-Disubstituted-4-aminophenylazostyrylformate derivatives: their synthesis, mesogenic behaviour and photostability

Abstract

A series of new azo dye liquid crystals was prepared by the reaction of the N,N-disubstituted-4-aminophenylazobenzaldehydes with butyl cyanoacetate in the presence of piperidine in refluxing ethanol. The new azo dye liquid crystals possess a SmA phase, and representative samples were found to be reasonably photostable.

Notes

Sample SI-426 was purified by chromatography before measuring its photo-stability. ¹H NMR (CDCl₃): 0.90 (s, 9H, 3CH₃), 1.00 (d, J=6.0, 3H, CH₃), 1.27 (t, 6H, 2CH₃), 1.54–1.90 (m, 5H, 2CH₂ +CH), 3.46 (quart, 4H, 2CH₂), 4.06 (t, 2H, CH₂), 6.73 (d, 2H, J=8.8, 2Ar–H), 7.00 (d, 2H, J=8.8, 2Ar–H), 7.87–8.094 (mix of 6d, 12H, 12Ar–H). M⁺ for C₃₇H₄₅N₇O: 604; found: 604.

The structure of SI-426.