Solvent effects on the low-lying excited states of a model of retinal.
The low-lying excited states of a solution in alcohol of a five-double-bond model of the rhodopsin protein chromophore, the protonated 11-cis-retinal Schiff base (PSB11), are studied theoretically. We combine a multireference perturbational treatment in the description of the solute molecule with molecular dynamics calculations in the description of the solvent. The geometry, charge distribution, and electronic spectra are strongly influenced by the solvent. The solvent shift values show a marked dependence on the use of relaxed geometries in solution and on the nature of the states involved in the excitation process. The dynamic correlation has a strong effect on the order of the excited states. In solution, the first two excited states almost become degenerate.
Muñoz Losa
Aurora
A
Departamento de Química Física, Facultad de Ciencias, Universidad de Extremadura, Avda de Elvas s/n, 06071 Badajoz, Spain.
Fdez Galván
Ignacio
I
Martín
M Elena
ME
Aguilar
Manuel A
MA
D000438:Alcohols; D004583:Electrons; D008954:Models, Biological; D008958:Models, Molecular; D012172:Retinaldehyde / Q000737:chemistry*; D012243:Rhodopsin; D012545:Schiff Bases; D012997:Solvents
D000438:Alcohols; D012545:Schiff Bases; D012997:Solvents; D012243:Rhodopsin; D012172:Retinaldehyde