Excited state dynamics of a model asymmetric molecular rotor: A five-dimensional study on 2-cyclopentylidene-tetrahydrofuran
Excited state dynamics of a model asymmetric molecular rotor: A five-dimensional study on 2-cyclopentylidene-tetrahydrofuran
复制标题
DOI：
10.1016/j.chemphys.2010.08.019
复制
发表时间：
2010-11-25
期刊：
影响因子：
2.3
通讯作者：
Gonzalez, Leticia
中科院分区：
文献类型：
--
作者：
Assmann, Mariana;Sanz, Cristina Sanz;Gonzalez, Leticia
使用量子动力学研究了 2-亚环戊基-四氢呋喃 (CPTHF) 的激发态动力学。 CPTHF 可以被认为是不对称分子转子的模型，其中可以围绕双键触发单向旋转。激发后，扭曲角度的圆锥形交叉允许无理衰减到基态。使用 CASSCF 计算了基态和第一 (pi pi*) 激发态的二维势能面。它们包括双键周围的扭转和一个碳原子的金字塔化。然后使用多达五个自由度研究了光激发后 CPTHF 的弛豫。显式 PES 上的二维波包传播不允许系统在激励后耗散能量。使用 MCTDH 方法研究的更多模式的包含表明，内部转换率根据所包含的模式而显着改变。 (C) 2010 Elsevier B.V. 保留所有权利。
The excited state dynamics of 2-cyclopentylidene-tetrahydrofuran (CPTHF) is investigated using quantum dynamics. CPTHF can be considered a model for an asymmetric molecular rotor in which unidirectional rotation could be triggered around the double bond. After excitation, conical intersections at twisted angles allow for rationless decay to the ground state. Two-dimensional potential energy surfaces for the ground and first (pi pi*) excited state have been calculated using CASSCF. They include the torsion around the double bond and the pyramidalisation at one carbon atom. The relaxation of CPTHF after photo-excitation has been then studied using up to five degrees of freedom. 2D wavepacket propagations on the explicit PESs do not allow the dissipation of the energy of the system after excitation. The inclusion of further modes, studied using the MCTDH method, show that the internal conversion rate is significantly altered depending on the modes included. (C) 2010 Elsevier B.V. All rights reserved.