Abstract

Here, the structural parameters of the enol and keto tautomers of the 4-(2-thiazolylazo)-resorcinol (TAR) were determinate. Also, tautomerization mechanism of the TAR was investigated, employing density functional theory and the polarizable continuum model (PCM). In addition to the gas phase calculations, the tautomerization mechanism of the TAR was investigated in the chloroform and dimethyl sulfoxide (DMSO) solutions for analysis of the solvent effects. More polar solvent results in higher activation energy for the keto-enol tautomerization, and larger amount of keto tautomer than the enol.

Key words: Density functional theory (DFT), 4-(2-thiazolylazo)-resorcinol, enol-keto tautomerism, polarizable continuum model (PCM), mechanism, solvent effects.