Li Hui, Shi Ying, Yin Hang, Wang Ye, Cong Lin, Jin Mingxing, Ding Dajun
Institute of Atomic and Molecular Physics, Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, Changchun 130012, China.
Institute of Atomic and Molecular Physics, Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, Changchun 130012, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2015 Apr 15;141:211-5. doi: 10.1016/j.saa.2015.01.060. Epub 2015 Jan 31.
Excited-state double proton transfer (ESDPT) in the hydrogen-bonded 2-(1H-pyrazol-5-yl)pyridine with propyl alcoholic partner (PPP) was theoretically investigated by time-dependent density functional theory (TDDFT) method. Great changes have taken place for the calculated geometric structures, the electron density features and vibrational spectrum of PPP system in S0 and S1 state. Our results have demonstrated that ESDPT reaction happens within the system upon photoexcitation. We also found that the ESDPT process is facilitated by the electronically excited state intermolecular hydrogen bond strengthening. Particularly, after the photoexcitation from HOMO(π) to the LUMO(π(∗)), the rearrangement of electronic density distribution of frontier molecular orbitals (MOs) on pyridine and the pyrazol moieties exhibits a very important positive factor for the ESDPT. Furthermore, by the investigation of the stretching vibrations of NH and OH groups, the infrared (IR) spectroscopic results provide us not only a theoretical evidence of ESDPT, but also a considerable clue to characterize the nature of intermolecular reaction. In addition, efforts have also been devoted towards calculating the absorption peak, which shows good consistency with the experimental result of the studied system.
采用含时密度泛函理论（TDDFT）方法对氢键连接的2-(1H-吡唑-5-基)吡啶与丙醇（PPP）体系中的激发态双质子转移（ESDPT）进行了理论研究。PPP体系在S0和S1态下的计算几何结构、电子密度特征和振动光谱发生了很大变化。我们的结果表明，光激发后体系内发生了ESDPT反应。我们还发现，电子激发态分子间氢键的加强促进了ESDPT过程。特别是，从最高占据分子轨道（HOMO(π)）到最低未占据分子轨道（LUMO(π(∗))）的光激发后，吡啶和吡唑部分前沿分子轨道（MOs）电子密度分布的重排对ESDPT表现出非常重要的积极作用。此外，通过对NH和OH基团伸缩振动的研究，红外（IR）光谱结果不仅为ESDPT提供了理论证据，也为表征分子间反应的性质提供了重要线索。此外，还致力于计算吸收峰，其与所研究体系的实验结果具有良好的一致性。
