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

•New pyrylocyanine dyes with julolidinyl donor groups are synthesized and used as luminescent reagent for determination of aromatic amines on silica support.•Spectral and luminescent characteristics of dyes with julolidinyl and acyclic donors are compared.•Initially formed red luminescent pyridocyanines are unstable on silica and give oxidation and dehydration products having bright blue, green luminescence.•The structures of luminescent forms of the julolidinyl pyridocyanine were established by X-ray and NMR methods.