Ab initio study on one-way photoisomerization of the maleic acid and fumaric acid anion radical system as a model system of their esters

Masato Sumita; Kazuya Saito

doi:10.1021/jp064377o

Ab initio study on one-way photoisomerization of the maleic acid and fumaric acid anion radical system as a model system of their esters

J Phys Chem A. 2006 Nov 9;110(44):12276-81. doi: 10.1021/jp064377o.

Authors

Masato Sumita¹, Kazuya Saito

Affiliation

¹ Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571, Japan.

PMID: 17078625
DOI: 10.1021/jp064377o

Abstract

Potential energy surfaces (PESs) of the maleic acid anion radical (MA-*: cis isomer)/fumaric acid anion radical (FA-*: trans isomer) system as a model system of their esters have been studied in detail using CASSCF method. The results suggest the following: The photoisomerization is initiated with the H-C-C-H dihedral angle distortion [hydrogen out of plain (HOOP) motion] on the D1 PES. The C-C-C-C dihedral angle distortion occurs on the D0 PES after the deactivation from D1 to D0. A large fraction of the net motion along the isomerization coordinate occurs on the D0 PES. The D0 state is responsible for the one-way nature of the photoisomerization.