Spectral Luminescent Properties and Nature of Electronically Excited States of Sulfaguanidine in Water

Abstract

The absorption and fluorescence spectra of sulfaguanidine, its complexes with hydrogen bonds, and doubly charged cationic forms have been studied experimentally and theoretically. The orbital nature of electronically excited states is established and a theoretical interpretation of the absorption and fluorescence spectra is given. It was shown that the main reason for the anomalously large Stokes shift of fluorescence is the rearrangement of the benzoid structure of the phenyl fragment of sulfaguanidine into a quasi-quinoid one. The influence of the formation of hydrogen bonds and the addition of a proton on the amount of charge transfer between weakly bound fragments of the molecule has been established Keywords: sulfaguanidine, sulgin, absorption spectra, fluorescence, quantum chemical calculation.

Nature of Luminescence and Pharmacological Activity of Sulfaguanidine

“…In particular, the exact structure of the first coordination sphere of a molecule in a proton-donor solvent is unknown. We believe that the closer the chosen geometry of the studied molecule and the location of the solvent molecules in the first coordination sphere of the real molecule, the better the agreement between the calculated spectral-luminescent properties and the experimental data [ 32 ].…”