Picosecond—nanosecond laser photolysis studies of a photoacid generator in solutions: Transient absorption spectroscopy and transient grating measurements
Picosecond—nanosecond laser photolysis studies of a photoacid generator in solutions: Transient absorption spectroscopy and transient grating measurements
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DOI：
10.1039/b411283k
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发表时间：
2005-01
影响因子：
3.1
通讯作者：
Mie Saotome;S. Takano;Asako Tokushima;S. Ito;S. Nakashima;Y. Nagasawa;T. Okada;H. Miyasaka
中科院分区：
文献类型：
--
作者：
Mie Saotome;S. Takano;Asako Tokushima;S. Ito;S. Nakashima;Y. Nagasawa;T. Okada;H. Miyasaka
采用皮秒、纳秒瞬态吸收光谱和瞬态光栅测量技术研究了光酸发生器N -三氟甲基磺酰氧基-1,8-萘酰亚胺（NI-Sf）在溶液中的光化学反应谱。皮秒瞬态吸收光谱直接揭示了随着溶剂极性的增加，S_1态的寿命和体系间交叉产率降低。另一方面，光化学反应产率随溶剂极性的增加而增加。这些结果表明，光化学反应开始于S_1态。瞬态光栅测量直接检测到质子的扩散过程，得到其扩散系数为3.9 × 10^−9 m^2 s^−1，比一般溶质分子的扩散系数大数倍。
Photochemical reaction profiles of a photoacid generator, N -trifluoromethylsulfonyloxy-1,8-naphthalimide (NI-Sf), in solution phase were investigated by means of picosecond and nanosecond transient absorption spectroscopy as well as transient grating measurements. Picosecond transient absorption spectroscopy directly revealed that the lifetime of the S_1 state and the intersystem-crossing yield decreased with increasing solvent polarity. On the other hand, photochemical reaction yield increased with an increase in the solvent polarity. These results indicated that the photochemical reaction started in the S_1 state. Transient grating measurement directly detected the diffusion process of the proton and its diffusion coefficient was obtained to be 3.9 × 10^−9 m^2 s^−1, which was several times larger than those of the usual solute molecules.