Molecular dynamics and metadynamics simulations of [2 + 2] photocycloaddition

0500251 - ÚFCH JH 2019 RIV US eng J - Článek v odborném periodiku
Muchová, E. - Bezek, M. - Suchan, J. - Cibulka, R. - Slavíček, Petr
Molecular dynamics and metadynamics simulations of [2 + 2] photocycloaddition.
International Journal of Quantum Chemistry. Roč. 118, č. 10 (2018), č. článku e25534. ISSN 0020-7608. E-ISSN 1097-461X
Grant CEP: GA ČR(CZ) GA17-04068S
Institucionální podpora: RVO:61388955
Klíčová slova: ab initio dynamics * [2 + 2] cycloaddition * metadynamics
Obor OECD: Physical chemistry
Impakt faktor: 2.263, rok: 2018

Triplet state mechanism of [2 + 2] photocycloaddition forming a cyclobutane ring from two ethylenes is investigated in the context of photocatalysis. High‐level ab initio calculations are combined with ab initio adiabatic molecular dynamics and ab initio metadynamics for rare events modeling. In a photocatalytic scheme, a reactant reaches the triplet state either via intersystem crossing (ISC) or triplet sensitization. The model system adopts a biradical structure, which represents energy intersection with the ground state. The system either completes cyclization or undergoes fragmentation into two olefinic units. The potential and free energy surfaces of the cyclobutane/ethylenes system are mapped with multireference approaches describing possible reaction pathways. To obtain a full picture of a double bond photoreactivity, ab initio adiabatic dynamical calculations were used to estimate reaction yields and to model the effects of excess energy. The potential use of density functional theory based approaches for [2 + 2] photocycloaddition was investigated for future simulations and design of realistic photocatalytic systems. Dynamical aspects of [2 + 2] photocycloaddition via a triplet state manifold are investigated by combining ab initio multireference methods and ab initio molecular dynamics and metadynamics. The reaction pathways are studied for a model system of two ethylenes forming a cyclobutane ring to provide a basis for further studies on design of photocatalytic systems.

Trvalý link: http://hdl.handle.net/11104/0292352