Observation of the set of the three sublevel phosphorescence spectra.II. Mechanisms of radiative and radiationless transitions of 2,3-dichloroquinoxaline

Publisher Website
Google Scholar
Abstract
The phosphorescence spectra of 2,3-dichloroquinoxaline in a single crystal of 1,2,4,5-tetramethylbenzene are observed for all the three spin sublevels with the aid of the time-resolved microwave induced delayed phosphorecence. The absolute values of radiative and radiationless decay rate constants are also obtained for the three sublevel phosphorescence. The results are compared with those of quinoxaline reported earlier. The heavy atom enhancement of radiative character is most significant in the Ty spectrum, somewhat less in the Tx spectrum whereas no heavy atom enhancement is obserrved in the Tz spectrum. For the radiationless decay rate constants heavy atom enhancement is observed only in the Ty spectrum. All of the observed features of radiative and radiationless transitions are satisfactorily interpreted.