COLOUR AND CONSTITUTION OF AZO COMPOUNDS DERIVED FROM DIAMINOAZINES

Article abstract of DOI:10.1016/S0040-4020(01)91257-8

Visible absorption spectra have been recorded for azo compounds derived from 2,5-dichlorosulphanilic acid azo-coupled with N,N-diethyl-m-phenylenediamine, and with azine analogues.The effects of the ring-aza substituents as well as cyano on the spectra indicate a surprising difference in sensitivity of the two ring positions meta to the azo group.M.O. calculations show that the amino group ortho to the azo linkage introduces asymmetry into the HOMO, and this is responsible for the differing effects of substitution.