Synthesis and reactions of Cyanovinyl Substituted Benzenediazonium Salts for nonlinear optics.

A synthetic method for the preparation of azo dyes with strong electron acceptor groups has been developed. The dyes are prepared in one step, under moderate reaction conditions by the azo coupling of di- and tricyanovinylbenzenediazonium hexafluorophosphates to aniline moieties. The diazonium salts can be made in bulk and assayed for purity by nmr. This method is useful for making simple azo dyes as well as dyes which are otherwise inaccessible, such as polymeric azo dyes. These dyes may have difficulty as nonlinear optical materials.