A Study of Photofading Process of 1H-pyrazolo [5, 1-c]-1, 2, 4-triazole Azomethine Dye

Abstract

The photochemical behavior of 1H-pyrazolo [5, 1-c]-1, 2, 4-triazole azomethine dye (PT dye) was analyzed using semi-empirical PM3 method. It was found that the first excited triplet state became stable by twisting the azomethine double bond. The calculated singlet-triplet energy gap agreed well with the observed value already reported. Calculated heats of formation for the reaction of the PT dye with oxygen predicted the most reactive positions for an attack by singlet oxygen.