Photophysics of organic photostabilizers: ab initio electronic-structure and quantum-dynamics calculations

这个项目的目的是利用计算化学的工具来研究解释有机光稳定剂功能的动力学过程。我们将用从头算电子结构理论来确定激发态和基态势能面的本质特征。一个主要的目标是识别和表征最低激发单重态(S1)和电子基态(S0)的能面的锥形相交。这些锥形交叉点充当了激发态超快失活的光化学漏斗。用含时量子波包方法研究了S_1-S_0锥形交叉口的S_1？S_0无辐射衰变过程的动力学。理论研究将集中在三个分子内氢键芳香族体系：邻羟基苯甲醛、水杨酸和2-(2-羟基苯基)苯并三唑(TINUVIN)。相互作用总结：从头算电子结构计算将在华沙的A.L.索博列夫斯基小组中进行。这包括探索激发态势能面，确定反应路径和锥形交点，以及在核坐标空间的大网格上计算从头算能量数据。利用华沙小组提供的从头计算数据，将在慕尼黑的W.Domcke小组中构造多维多页解析势能函数。依赖时间的量子反应动力学计算将使用慕尼黑小组提供的程序进行。大部分信息交换将通过电子邮件或文件传输进行。为了扩大对学生和/或博士后的教育，这些同事将每年访问各自的合作伙伴小组一次。

The aim of this project is the investigation of the dynamical processes which account for the functionality of organic photostabilizers, using the tools of computational chemistry. Ab initio electronic-structure theory will be employed to determine the essential features of the excited-state and ground-state potential-energy surfaces. A primary goal is the identification and characterization of conical intersections of the energy surfaces of the lowest exited singlet state (S1) and the electronic ground state (S0). These conical intersections serve as photochemical funnels for the ultrafast deactivation of the excited state. The dynamics of the S1¿S0 radiationless decay processes at the S1-S0 conical intersections will be investigated with time-dependent quantum wave-packet methods. The theoretical studies will be focused on three intramolecularly hydrogen-bonded aromatic systems for which an extensive set of experimental data is available: ohydroxybenzaldehyde, salicylic acid and 2-(2 -hydroxyphenyl)benzotriazole (TINUVIN). Summary of the interaction: The ab initio electronic-structure calculations will be performed in the group of A. L. Sobolewski in Warsaw. This includes the exploration of exited-state potential-energy surfaces, the determination of reaction paths and conical intersections, as well as the calculation of ab initio energy data on large grids in nuclear coordinate space. Multidimensional multi-sheeted analytic potential-energy functions will be constructed in the group of W. Domcke in Munich, using the ab initio-data provided by the Warsaw group. The time-dependent quantum reaction dynamics computations will be performed with the programs available in the Munich group. Much of the exchange of information will occur by email or file transfer. To broaden the education of the students and/or postdocs, these coworkers will visit the respective partner group once per year.