On the Homolytic Cleavage of the N,O Bond in<i>N</i>-(Methoxy)pyridine-2(1<i>H</i>)-thione and<i>N</i>-(Methoxy)thiazole-2(3<i>H</i>)-thione in Thermally and Photochemically Induced Reactions: A Theoretical Study

Abstract

The accuracy of theoretical approaches to describe electronic absorption spectra of N-(hydroxy)- and N-(methoxy)- derivatives of pyridine-2(1H)-thione and thiazole-2(3H)-thione are examined with the aim to identify methods that are applicable for a rational design of new photochemically active oxyl radical precursors. In addition, the mechanism of the photochemically induced methoxyl radical formation from N-(methoxy)pyridine-2(1H)-thiones and of N-(methoxy)thiazole-2(3H)-thiones is investigated by means of theoretical methods. The results of the study are applied in order to explain differences in photoreactions of N-(alkoxy)pyridine-2(1H)-thiones and the corresponding thiazole-2(3H)-thiones.