The effects of cyclic terminal groups in 4-aminoazobenzene and related azo dyes: Part 4—Electronic absorption spectra of some Monoazo dyes derived from N-phenylaziridine and N-Phenylazetidine

Abstract

Monoazo dyes containing a terminal aziridinyl group absorb hypso-chromically when compared with their azetidinyl counterparts. Geometrical and hybridisation factors prevent the aziridinyl lone pair of electrons from efficient conjugation with the adjacent aromatic ring system. In acid solution, the aziridinyl ring opens as a result of solvolysis whereas the azetidinyl ring is stable.