Conical Intersection Structure and Dynamics for a Model Protonated Schiff Base Photoisomerization in Solution.
Résumé
Here, we present some highlights of our recent study [Malhado et al. J. Phys. Chem. A 115 , 3729 (2011)] of the photoisomerization involving a conical intersection for a model protonated Schiff base (PSB) in modeled water and acetonitrile solvents, in which the inclusion of energy‐ and momentum‐transfer effects is described via a generalized Langevin equation (GLE) frictional approach and surface‐hopping dynamics. Short‐time GLE frictional effects on the model's three coordinates, the intramolecular bond length alternation, and torsional PSB coordinates and a solvent coordinate, have a number of important features. Among these are the general feature of accelerating nonadiabatic transitions to the ground electronic state and a predicted preferential higher proportion of ground‐state trans isomer, that is, a successful cis to trans photoreaction. This preference is solvent‐dependent and is enhanced in water solvent with its higher friction intensity and short time scales.