Dr. Dmitri Kilin from North Dakota State University will present a seminar.

Light-to-matter interaction integrated with ab initio molecular dynamics

Abstract:

Several aspects of electromagnetic field to matter interaction are addressed by computational modeling of transitions between ground and excited state potential energy surfaces, driving molecular system away from the equilibrium. Photoinduced bond breaking events are enhanced for molecular systems placed in the center of resonant microcavity via formation of a bound matter-to-field polaritonic state. A description of matter-to-electromagnetic radiation interaction is is integrated with on-the-fly ab initio molecular dynamics and electronic structure methods. Validity and predictive power of several algorithms applicable for the IR and UV-vis range excitations are discussed. A vibrational polariton algorithm is tested by exploring an ensemble of hydrogen fluoride molecules in the IR cavity. A time-dependent excited state dynamics (TDESMD) algorithm is applied to a several UV-photoactivated reactions ranging from formation of luminescent defects at surface of carbon nanotubes [1] to photodegradation of polymers and plastics [2] to photopolymerization of molecular precursors for fabrication of silicon nanostructures. [3] Introduced TDESMD algorithm seems most useful in the limit of multiple reaction pathways and multiple products. Validation of TDESMD predictions is based on comparison of computed and measured distribution of products and mass spectra. Optical properties, such as lifetimes, and photoluminescence quantum yield of the molecular structures are computationally evaluated through implementation of nonequilibrium dynamics of excited electronic states.[4] Support of NSF-1944921 is gratefully acknowledged.

[1] Zheng, Y.; Han, Y.; Weight, B. M.; Lin, Z.; Gifford, B. J.; Zheng, M.; Kilin, D.; Kilina, S.; Doorn, S. K.; Htoon, H.; et al. Photochemical spin-state control of binding configuration for tailoring organic color center emission in carbon nanotubes. Nature Comm. 2022, 13 (1), 4439. DOI: 10.1038/s41467-022-31921-0.

[2] Erickson, M.; Han, Y.; Rasulev, B.; Kilin, D. Molecular Dynamics Study of the Photodegradation of Polymeric Chains. J. Phys. Chem. Lett. 2022, 13 (19), 4374-4380. DOI: 10.1021/acs.jpclett.2c00802.

[3] Han, Y.; Anderson, K.; Hobbie, E. K.; Boudjouk, P.; Kilin, D. S. Unraveling Photodimerization of Cyclohexasilane from Molecular Dynamics Studies. J. Phys. Chem. Lett. 2018, 9 (15), 4349-4354. DOI: 10.1021/acs.jpclett.8b01691.

[4] Forde, A.; Lystrom, L.; Sun, W.; Kilin, D.; Kilina, S. Improving Near-Infrared Emission of meso-Aryldipyrrin Indium(III) Complexes via Annulation Bridging: Excited-State Dynamics. J. Phys. Chem. Lett. 2022, 13 (39), 9210-9220. DOI: 10.1021/acs.jpclett.2c02115.

Host: Dr. Wenfang Sun