UV absorption spectra and the physical nature of the optical properties of pyridoxine hydrochloride

Abstract

A study of the nature of electronic transitions in different structural forms of pyridoxine hydrochloride molecule shows that the maxima in experimental absorption spectra at wavelengths 244 ± 1 nm, 310 ± 1 nm (pH 12.5), 291 ± 1 nm (pH 1.1, pH 4.1), 258 ± 1 nm, 291 ± 1 nm, and 324 ± 1 nm (pH 4.15) are, along with the corresponding lines in theoretical spectra, due to electron transitions from occupied molecular p-orbitals localized on the nitrogen atoms in the structure of pyridine rings to the vacant p-orbitals of double C=N bonds.