Spectroscopic study on the structural isomers of 7-azaindole(ethanol)(n) (n=1-3) and multiple-proton transfer reactions in the gas phase.
Spectroscopic study on the structural isomers of 7-azaindole(ethanol)(n) (n=1-3) and multiple-proton transfer reactions in the gas phase.
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DOI：
10.1063/1.3149772
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发表时间：
2009-06
期刊：
影响因子：
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通讯作者：
Kenji Sakota;Noriyuki Komure;W. Ishikawa;H. Sekiya
中科院分区：
文献类型：
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作者：
Kenji Sakota;Noriyuki Komure;W. Ishikawa;H. Sekiya
利用共振增强双光子电离（RE 2 PI）和激光诱导荧光激发光谱研究了7-氮杂吲哚（乙醇）（n）（n=1-3）[7Al（EtOH）（n）（n = 1 -3）]团簇的几何结构和多质子/氢原子转移反应动力学.分别鉴定了7Al（EtOH）（2）和7Al（EtOH）（3）的四种和两种结构异构体。在B3 LYP/6-31++G（* *）/6- 31 G（*）水平上的密度泛函理论计算预测了7 Al（EtOH）（2）的四种不同的乙基构象，与RE 2 PI光谱中四种结构异构体的观察结果一致。在7Al（EtOH）（2）的所有异构体的S（1）态中都观察到来自互变异构体形式的可见荧光，但在7Al（EtOH）（1）和7Al（EtOH）（3）的电子光谱中分别没有获得双质子/氢原子转移和四质子/氢原子转移的迹象。这些结果表明，多质子转移反应具有团簇尺寸选择性，并且三质子/氢原子转移势由7AI（EtOH）（2）中的环状氢键网络主导。同相分子间伸缩振动的激发显著增强了激发态三质子/氢原子转移反应。
The resonance-enhanced two-photon ionization (RE2PI) and laser-induced fluorescence excitation spectra were recorded for the S(1)-S(0)(pipi( *)) region of the 7-azaindole(ethanol)(n) (n=1-3) [7AI(EtOH)(n) (n=1-3)] clusters in the gas phase to investigate the geometrical structures and the multiple-proton/hydrogen atom transfer reaction dynamics. Four and two structural isomers were identified for 7AI(EtOH)(2) and 7AI(EtOH)(3), respectively. Density functional theory calculations at the B3LYP/6-31++G( * *)/6-31G( *) level predicted four different conformations of the ethyl group for 7AI(EtOH)(2), in good agreement with the observation of the four structural isomers in the RE2PI spectra. Visible fluorescence from the tautomeric forms was observed in the S(1) states for all isomers of 7AI(EtOH)(2), but no sign of double-proton/hydrogen atom transfer and quadruple-proton/hydrogen atom transfer has been obtained in the electronic spectra of 7AI(EtOH)(1) and 7AI(EtOH)(3), respectively. These results suggest that the multiple-proton transfer reaction is cluster-size selective, and the triple-proton/hydrogen atom transfer potential is dominated by the cyclic hydrogen-bonded network in 7AI(EtOH)(2). The excitation of the in-phase intermolecular stretching vibration prominently enhances the excited-state triple-proton/hydrogen atom transfer reaction.