Synthesis and properties of 6,7-dihydroxybenzopyrylium perchlorate halogen derivatives: X-ray, spectroscopic and theoretical studies

This study describes the synthesis of 6,7-dihydroxy-4-methyl-2-phenylbenzopyrylium perchlorate halogen derivatives and its spectroscopic and theoretical studies. The compounds were characterized by NMR, XRD, IR-spectroscopy and mass-spectrometry methods. The acid-base properties of obtained compounds were investigated by UV VIS spectrophotometric and tristimulus colorimetric methods. The most probable protonation/deprotonation schemes were theoretically determined for studied unsubstituted and halogen derivatives of 6,7-dihydroxy-4-methyl-2-phenylbenzopyrylium perchlorate using DFT calculations. (C) 2020 Elsevier Ltd. All rights reserved.