Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2011-04-01

Journal: JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY

Included Journals: SCIE

Volume: 10

Issue: 2

Page Number: 121-132

ISSN: 0219-6336

Key Words: Charge transfer; protonated Schiff base retinal chromophores; one-photon absorption; two-photon absorption

Abstract: The S-1 and S-2 excited states of gas-phase protonated Schiff base retinal chromophores in the one-and two-photon absorptions (TPAs) are investigated with time-dependent density functional theory. In one-photon absorption, the two-dimensional (2D) site and three-dimensional (3D) cube representations reveal that S-1 and S-2 excited states of gas-phase protonated Schiff base retinal chromophores are all charge transfer excited states. To better study the weak S-2 excited states of gas-phase protonated Schiff base retinal chromophores, we investigated theoretically excited state properties of them in TPA. For 11-cis dimethyl retinal, it is found that the cross section of S-2 excited state is 51.04 GM in PTA, which is only slightly smaller than that of S-1 (77.04 GM) in TPA. Therefore, the S-2 excited state of 11-cis dimethyl retinal can be clearly observed in TPA experiment. The 2D site and 3D cube representations reveal that electronic transition from S-1 to S-2 excited state of gas-phase protonated Schiff base retinal chromophores in TPA are also of charge transfer character.