学术报告
报告题目：Singlet Oxygen Photosensitization in Weakly Coupled Floppy Complexes
报告人：Prof. Mario Barbatti, Aix Marseille University
时间: 2020年10月15日（周四）15:00-17:00
地点: 曾呈奎楼B311（线上）
腾讯会议 ID：237 919 795
会议密码：201015
报告摘要：
Singlet oxygen (1O2) is a chemically reactive species of great importance for biological and medical research. It is usually synthesized through triplet fusion, following the general internal conversion formula
1[3A + 3B] → 1[1A + 1B] (1)
where A + B is a molecular complex.
Triplet fusion treatment in a weakly-coupled floppy complex like PS-O2, where PS is a photosensitizer, poses a tremendous challenge for computational chemistry due to the process’s long time scales, the lack of a unique transition state, and the open-shell character of the ground state.
In the last years, Shuming Bai and I have worked out a research program to address these challenges, combining conventional quantum-chemical methods, software implementation for calculating spin-orbit couplings,1 model development for calculating kinetic rates for reaction 1,2 and proposition of proxies for efficient calculation of nonadiabatic and diabatic couplings.3 All this program has been specially tailored to deal with reaction 1 in weakly-coupled floppy complexes.
Taking thionucleobases and thionucleosides as prototypical PS, we have characterized their spectra,4 intersystem crossing dynamics,5 and decay of their triplet state.6 We have tackled the physical chemistry of reaction 1, for which we have determined singlet oxygen rates as a function of the incidence direction of the O2 on PS.7 We could explain the main features of the reaction and even propose heuristic rules to maximize or minimize the 1O2 yield, according to the application.8
Finally, we generalized the theory underlying triplet fusion, showing that it is a particular case of a broader class, theSpin-Exchange Internal Conversion, which includes other important reactions like singlet fission.3
1. Gao, X.; Bai, S.; Fazzi, D.; Niehaus, T.; Barbatti, M.; Thiel, W., J. Chem. Theory Comput. 2017, 13, 515-524.
2. Bai, S.; Barbatti, M., J. Chem. Theory Comput. 2017, 13, 5528-5538.
3. Bai, S.; Barbatti, M., J. Chem. Theory Comput. 2019, 15, 1503-1513.
4. Bai, S.; Barbatti, M., J. Phys. Chem. A 2016, 120, 6342-6350.
5. Mohamadzade, A.; Bai, S.; Barbatti, M.; Ullrich, S., Chem. Phys. 2018, 515, 572-579.
6. Bai, S.; Barbatti, M., Phys. Chem. Chem. Phys. 2017, 19, 12674-12682.
7. Bai, S.; Barbatti, M., J. Phys. Chem. Lett. 2017, 8, 5456-5460.
8. Bai, S.; Barbatti, M., Phys. Chem. Chem. Phys. 2018, 20, 16428-16436.
报告人简介：
Mario Barbatti教授主要从事应用于分子光化学的理论计算化学研究、方法发展、软件开发、非绝热分子过程、混合量子-经典动力学模拟等方面的研究，是Newton-x程序的主要开发者。Mario Barbatti教授于1995年获里约热内卢联邦大学理学学士，1997年获里约热内卢联邦大学理学硕士学位，2001年获里约热内卢联邦大学博士学位，2008年到维也纳大学交流访问，2003-2010年任维也纳大学理论化学研究所资深科学家，2010-2015年任德国慕尔海姆普朗克科学研究所（Max-Planck-Institut für Kohlenforschung）课题组长，2015年至今任艾克斯马赛大学教授，在Chem. Rev.，J. Am. Chem. Soc.和WIREs: Comp. Mol. Sci.等刊物上发表高水平学术论文多篇。
