Department of Physics, College of Mathematics and Physics, Bohai University, Jinzhou 121013, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2013 Aug;112:257-62. doi: 10.1016/j.saa.2013.04.067. Epub 2013 Apr 23.
In this work, the dynamics of hydrogen bonds (as well as the hydrogen-bonded wire) in excited-state tautomerization of 7-hydroxyquinoline·(NH3)3 (7HQ·(NH3)3) cluster has been investigated by using time-dependent density functional theory (TDDFT). It shows that upon an excitation, the hydrogen bond between -OH group in 7-hydroxyquinoline (7HQ) and NH3 moiety would extremely strengthened in S1 state, which could effectively facilitate the releasing of the proton from the phenolic group of 7HQ moiety to the hydrogen-bonded wire and the forming an Eigen-like cationic wire (NH3···NH4(+)···NH3) in the cluster. To fulfill the different optimal angles of NH4(+) in the wire, a wagging motion of hydrogen-bonded wire would occur in excited state. Moreover, the wagging motion of the hydrogen-bonded wire would effectively promote excited-state proton transfer reaction. As the results, an excited-state multiple proton transfer (ESMPT) mechanism containing two concerted and asymmetrical processes has been proposed for the proton transfer dynamics of 7HQ·(NH3)3 cluster.
在这项工作中，通过使用含时密度泛函理论（TDDFT）研究了 7-羟基喹啉·（NH3）3（7HQ·（NH3）3）团簇在激发态互变异构过程中氢键（以及氢键键合线）的动力学。结果表明，在激发态下，7-羟基喹啉（7HQ）中-OH 基团与 NH3 部分之间的氢键在 S1 态下会被极大加强，这有效地促进了 7HQ 部分的酚基中的质子释放到氢键键合线上，并在团簇中形成了 Eigen 型阳离子线（NH3···NH4(+)···NH3）。为了满足线中 NH4(+)的不同最佳角度，键合线上会发生摇摆运动。此外，键合线的摇摆运动会有效地促进激发态质子转移反应。结果，提出了一种包含两个协同和不对称过程的激发态多重质子转移（ESMPT）机制，用于 7HQ·（NH3）3 团簇的质子转移动力学。
