Synthesis and study of N,N-disubstituted 4-aminophenylazobenzaldehydes

Abstract

A series of ^N , ^N -disubstituted 4-aminophenylazobenzaldehydes (azo dyes) were synthesized by the reaction of phenylpiperazine derivatives with 4-formylbenzenediazonium tetrafluoroborate. The salt was easily prepared by reacting poly(aminobenzaldehyde) with sodium nitrite in the presence of tetrafluoroboric acid. A representative sample was studied by crystallography, and the charge distribution of the molecule was calculated with the aim of understanding the form of molecular stacking on the basis of crystal data. The mesogenic behaviour of the azo dyes was also studied.