论文信息 - Nonexponential decay of fluorescence of jet‐cooled isoquinoline related to intermediate level structure of S2–S1 coupling

Nonexponential decay of fluorescence of jet‐cooled isoquinoline related to intermediate level structure of S2–S1 coupling

We report ’’fast’’ and ’’slow’’ components of fluorescence in jet‐cooled isoquinoline, which represents the first known observation of biexponential fluorescence that can be attributed to the intermediate level structure of S2–S1 coupling. The slowly decaying component of the emission appears only upon strong internal cooling of the molecule, while the rapidly decaying component appears under all nozzle conditions. The sensitivity of the slow component fluorescence to the internal cooling provides an important clue to the origin of the thermal quenching of fluorescence and triplet formation, which represents one of the most conspicuous photophysical characteristics of molecules with close‐lying, lowest energy, nπ* and ππ* singlet states.

E. C. Lim | A. Jameson | S. Okajima | H. Saigusa

[1] W. Siebrand,et al. Radiationless decay of vibronically coupled electronic states. III. Strong coupling and its effect on triplet decay in aromatic hydrocarbons , 1981 .

[2] E. C. Lim,et al. Rotational cooling and electronic relaxation in diazabenzenes , 1981 .

[3] J. Jortner,et al. Excited‐state dynamics of the isolated ultracold ovalene molecule , 1981 .

[4] E. C. Lim,et al. Temperature effects on S1 →S0/S1 →T1 branching ratio in radiationless transitions of N-heterocyclic compounds , 1979 .

[5] E. C. Lim,et al. Radiationless transitions in gaseous nitrogen heterocyclics: Energy dependence of internal conversion in quinoline and isoquinoline , 1978 .

[6] W. A. Wassam,et al. ’’Proximity effect’’ in radiationless transitions , 1978 .

[7] G. Fischer,et al. Narrow band laser excited fluorescence as a probe of the near-resonance vibronic coupling in isoquinoline vapor , 1976 .

[8] R. Naaman,et al. Near Resonance vibronic coupling. Isoquinoline , 1976 .

[9] F. Lahmani,et al. Nonexponential decays in single vibronic level fluorescence: A comparison between kinetics and quantum mechanical treatment , 1974 .

[10] A. Nitzan,et al. Intermediate level structure in highly excited electronic states of large molecules , 1972, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.