STUDY ON THE MECHANISM OF PHOTOOXIDATION OF NEAR-INFRARED ABSORBING CYANINE DYES

In this paper,spectrum characteristic and stability of three near-infrared cyanine dyes against photooxidation have been studied. Results showed that the stability of dyes with three kinds typical structure of heterocyclic stem against photooxidation was in such order:benzoxazolebenzothiazolebenselenazole. It was indicated through the quenching experiments that both of singlet oxygen mechanism and superoxide anion mechanism might be present in the auto-sensitized photooxidation of cyanine dyes, and photooxidation merely occurred in single oxygen mechanism.