Initial process of proton transfer in salicylideneaniline studied by time-resolved photoelectron spectroscopy
Initial process of proton transfer in salicylideneaniline studied by time-resolved photoelectron spectroscopy
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时间分辨光电子能谱研究水杨基苯胺中质子转移的初始过程
DOI：
10.1007/978-3-642-28948-4_52
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
and A. Stolow
中科院分区：
文献类型：
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作者：
T. Sekikawa;O. Schalk;G. Wu;A. E. Boguslavskiy;and A. Stolow
利用飞秒时间分辨光电子能谱研究了亚水杨基苯胺（SA）分子在超音速气体射流中膨胀后的激发态分子内质子转移（ESIPT）。虽然在SA中的ESIPT被预测为发生在平面结构中，但分子从扭曲的Franck-Condon态的变胖过程从未被解决。在这里，我们确定了在光电子产额的衰减动力学的脂肪化过程中的苯胺基环的扭曲运动，考虑到的能量表面的烯醇形式的S1（π，π）状态和ESIPT的势能面计算的含时密度泛函理论（TDDFT）。扭转运动被发现是缓慢的溴化和甲基化的SA，而在硝化SA没有显着变化。这些取代的效果解释的取代基，也预测的TDDFT计算的势垒的修改，并支持分配的衰减动力学的苯胺环之前ESIPT的扭转运动。
Excited state intramolecular proton transfer (ESIPT) in salicylideneaniline (SA) molecules expanded in a supersonic gas jet has been investigated by femtosecond time-resolved photoelectron spectroscopy. Although ESIPT in SA was predicted to take place in a planar structure, the fattening process of a molecule from a twisted Franck–Condon state has never been resolved. Here, we identified the twisting motion of the anilino ring during the fattening process in the decay dynamics of the photoelectron yield, taking account of the energy surface of the S1(π, π∗) state of the enol form and the potential surface of ESIPT calculated by a time-dependent density functional theory (TDDFT). The twisting motion was found to be slower in the bromide and methylated SAs, while that in the nitrated SA did not change significantly. These substitution effects are explained by the modification of the potential barriers by the substituents, also predicted by the TDDFT calculation, and support the assignment of the decay dynamics to the twisting motion of the anilino ring prior ESIPT.