This online talk is part of Xiamen Theoretical Chemistry Lectures (XTCL)
"Xiamen Seminar Series" are held in the key labrotary during semester, including online presentation and one-on-one meeting. This will be the first presentation in the series. All are welcome.
Ttitle：Singlet Oxygen Photosensitization in Weakly Coupled Floppy Complexes
Speaker：Prof. Mario Barbatti, Aix Marseille University
Date & Time：15:00, Oct 15 2020
Venue：B311 Zengchegnkui Building
Abstract：
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, the Spin-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.
Introduction to the speaker：
Prof. Mario Barbatti (homepage: https://barbatti.org) focuses on the research work on molecular photochemistry, including methodology development and program implementation, nonadiabatic phenomena, mixed QM/MM simulation etc., and is the major developer of Newton-X.
Research field
Theoretical computational chemistry applied to molecular photochemistry. Method development, software implementation, and investigations of nonadiabatic molecular processes. Mixed quantum-classical dynamics simulations. Leading developer of the Newton-X program.
Professional Appointments
Since Sep 2015 Professor of Chemistry, Aix Marseille University, France
Sep 2010 - Aug 2015 Group Leader, Max-Planck-Institut für Kohlenforschung, Mülheim, Germany
Nov 2003 - Aug 2010 Senior scientist, Institute for Theoretical Chemistry, University of Vienna, Austria
Awards
• ERC Advanced Grant, 2019-2024
• Chair of excellence A*Midex, 2015-2019
Education and Titles
2008 Habilitation for teaching Theoretical Chemistry, University of Vienna
1997 - 2001 Doctor of Sciences (Physics). Institute of Physics, Federal University of Rio de Janeiro
1995 - 1997 Master of Sciences (Physics). Institute of Physics, Federal University of Rio de Janeiro
1991 - 1995 Bachelor of Sciences (Physics), Institute of Physics, Federal University of Rio de Janeiro
Bibliographic Indicators
• Peer-reviewed papers: 151
• Book chapters: 8
• Citations: 7723 – H-index: 49
• ORCID: orcid.org/0000-0001-933 6-6607
• Research ID: F-5647-2014
• Full publication list at www.barbatti.org/publications
Selected Papers
• Barbatti, M. Simulation of Excitation by Sunlight in Mixed Quantum-Classical Dynamics. J. Chem. Theory Comput. 2020, 16, 4849-4856.
• Crespo-Otero, R.; Barbatti, M. Recent Advances and Perspectives on Nonadiabatic Mixed Quantum-Classical Dynamics. Chem. Rev. 2018, 118, 7026-7068.
• Dral, P. O.; Barbatti, M.; Thiel, W. Nonadiabatic Excited-State Dynamics with Machine Learning. J. Phys. Chem. Lett. 2018, 9, 5660-5663.
• Barbatti, M.; Ruckenbauer, M.; Plasser, F.; Pittner, J.; Granucci, G.; Persico, M.; Lischka, H. Newton-X: a surface-hopping program for nonadiabatic molecular dynamics. WIREs: Comp. Mol. Sci. 2014, 4, 26-33.
• Barbatti, M. Photorelaxation Induced by Water-Chromophore Electron Transfer. J. Am. Chem. Soc. 2014, 136, 10246-10249.
Software Development
• M. Barbatti, G. Granucci, M. Ruckenbauer, F. Plasser, R. Crespo-Otero, J. Pittner, M. Persico, and H. Lischka, NEWTON-X: a package for Newtonian dynamics close to the crossing seam (2007-2020), www.newtonx.org
