Three-color luminescent transformation of the julolidine pyrylo/pyridocyanine dyes in the adsorbed state

Abstract Pyrylocyanine dyes with julolidinyl donor groups are used for determination of aromatic amines on silica gel. The formed julolidine pyridocyanines are unstable on silica support and give bright three-color luminescent products: initial red proceeds to green and blue. The latter appear due to oxidation and dehydration of the julolidine cycle in the pyridocyanine dye formed. The structures of pyridocyanine oxidized forms were established by X-ray and NMR methods. The luminescence spectra transformations of the pyridocyanines on silica support and the evidence of the chemical and photochemical oxidation by the air oxygen are represented.