Theoretical investigation on tautomerism and NBO analysis of 3-hydroxy-1,2,5-thiadiazole derivatives: Solvent and substituent effects

Abstract

Thiadiazole compounds including 3-hydroxy- 4-substituted-1,2,5-thiadiazole are known as non-nucleoside inhibitors of HIV-1. Density functional calculations at the B3LYP/6-311++G(d,p) level were employed to determine the stability, tautomerism, and substituent effects of 1,2,5-thiadiazole, a widely used skin-whitening, antibrowning, and antibacterial agent, and its derivatives (4-NO2 , 4-CN, 4-F, 4-H, 4-Me, 4-NH2 ), in the gas phase and solution using the polarizable continuum method model. Some selected IR frequencies, molecular parameters, charges on atoms, and dipole moment results were analyzed. © 2011-2012 by Walter de Gruyter GmbH.