Nonadiabatic Excited-State Dynamics with Hybrid ab Initio Quantum-Mechanical/Molecular-Mechanical Methods: Solvation of the Pentadieniminium Cation in Apolar Media

0353649 - ÚOCHB 2011 RIV US eng J - Journal Article
Ruckenbauer, M. - Barbatti, M. - Müller, T. - Lischka, Hans
Nonadiabatic Excited-State Dynamics with Hybrid ab Initio Quantum-Mechanical/Molecular-Mechanical Methods: Solvation of the Pentadieniminium Cation in Apolar Media.
Journal of Physical Chemistry A. Roč. 114, č. 25 (2010), s. 6757-6765. ISSN 1089-5639. E-ISSN 1520-5215
Institutional research plan: CEZ:AV0Z40550506
Keywords : Nonadiabatic excited-state dynamics * hybrid methods * multireference methods * penta-2,4-dien-1-iminium cation (PSB3) * 4-methyl-penta-2,4-dien-1- iminium cation (MePSB3)
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 2.732, year: 2010

A new implementation of nonadiabatic excited-state dynamics using hybrid methods is presented. This approach is aimed at the simulation of photoexcited molecules in solution. The chromophore is treated at the ab initio level, and its interaction with the solvent is approximated by point charges within the electrostatic embedding approach and by a Lennard-Jones potential for the nonbonded interactions. Multireference configuration interaction (MRCI) and multiconfiguration self-consistent field (MCSCF) methods can be used. Dynamics of penta-2,4-dien-1-iminium (PSB3) and 4-methyl-penta-2,4-dien-1- iminium cations (MePSB3) was investigated in gas phase and in n-hexane solution. The excited-state (S1) lifetime and temporal evolution of geometrical parameters were computed. In the case of PSB3 the n-hexane results resemble closely the gas phase data. MePSB3 shows an extension of lifetime due to steric hindering of the torsion around the central bond because of solute-solvent interactions.
Permanent Link: http://hdl.handle.net/11104/0006231