Solvent effects for vertical absorption and emission processes in solution using a self-consistent state specific method based on constrained equilibrium thermodynamics
Solvent effects for vertical absorption and emission processes in solution using a self-consistent state specific method based on constrained equilibrium thermodynamics
复制标题
使用基于约束平衡热力学的自洽状态特定方法研究溶液中垂直吸收和发射过程的溶剂效应
DOI：
10.1039/c8cp00930a
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发表时间：
2018
影响因子：
3.3
通讯作者：
Li Xiang Yuan
中科院分区：
文献类型：
--
作者：
Bi Ting Jun;Xu Long Kun;Wang Fan;Li Xiang Yuan
在TDDFT框架下，提出了一种自洽状态特异性（SS）方法来解释溶剂对溶液中分子吸收和发射过程的影响。在这些过程中，初始态为平衡态，而溶剂的极化与最终态溶质的电子密度处于非平衡状态。基于约束平衡操作的非平衡溶剂化模型，计算了非平衡溶剂化自由能。使用极化连续统方法（PCM）来考虑体溶剂效应，其中溶剂-溶质相互作用用反应场来描述。分子轨道和激发态对应于反应场存在时的轨道能量被采用，溶剂的响应不包括在TDDFT计算中。设计了一种自洽程序来获得激发态反应场。在自洽SS-PCM/TDDFT方法框架下，提出了基于这种新的非平衡溶剂化模型的方程，用于计算垂直吸收和发射能量，并在Q-Chem软件包中实现。用新开发的程序计算了溶液中几种小分子的垂直吸收和发射能量，并与现有的实验数据和其他理论研究结果进行了比较。用这种方法可以合理地再现吸收和发射能量的溶剂位移。该模型是研究溶液中非平衡吸收和发射过程的一种很有前途的方法。
A self-consistent state specific (SS) method in the framework of TDDFT is presented to account for solvent effects on absorption and emission processes for molecules in solution. In these processes, the initial state is an equilibrium state, while the polarization of the solvent is in nonequilibrium with the electron density of the solute in the final state. Nonequilibrium solvation free energy is calculated based on a novel nonequilibrium solvation model with constrained equilibrium manipulation. The bulk solvent effects are considered using the polarizable continuum method (PCM), where the solvent–solute interaction is described with a reaction field. Molecular orbitals and orbital energies in the presence of the reaction field corresponding to the excited state are employed and the response of the solvent is not included in the TDDFT calculations. A self-consistent procedure is designed to obtain the excited state reaction field. The equations based on this new nonequilibrium solvation model in the framework of the self-consistent SS-PCM/TDDFT method for calculation of vertical absorption and emission energies are presented and implemented in the Q-Chem package. Vertical absorption and emission energies for several small molecules in solution using the newly developed code are calculated and compared with available experimental data and the results of other theoretical studies. Solvent shifts of absorption and emission energies are reasonably reproduced with this approach. The new model is a promising approach to study nonequilibrium absorption and emission processes in solution.