The spectral and luminescent properties of a new Schiff base obtained from 2,3-diaminopyridine with two different (benzo and naphtho) azomethine moieties have been studied. A comparison has been made with the properties of both a bisazomethine of similar benzene structure obtained from 1,2-phenylenediamine and azomethines with identical azomethine moieties. The absorption and luminescence spectra of the new pyridine compound indicate that the naphthoazomethine moiety is in the keto form, while solutions of benzene azomethine contain isomers with two tautomeric forms of the naphtho unit and, as such, determine the difference in luminescence between these compounds.
Mardaleishvili et al. (2026) studied this question.