Observation of the set of the three sublevel phosphorescence spectra. III. External heavy atom effect on the phosphorescence spectra of quinoxaline and 2,3‐dichloroquinoxaline

摘要: The sublevel phosphorescence spectra of quinoxaline and 2,3‐dichloroquinoxaline are obtained in a light atom host such as naphthalene‐d8 1,2,4,5‐tetramethylbenzene heavy 1,2,4,5‐tetrabromobenzene. Only the radiative decays, but not nonradiative susceptible to external effect. For from in‐plane sublevels significant effect is observed for 0–0 some vibronic bands involving nontotally symmetric vibrations. out‐of‐plane sublevel, exists enhancement very slight. These features interpreted satisfactorily framework theory. 1,4‐dibromobenzene differs considerably, origin discrepancy discussed.