Exciton localization in a Pt-acetylide complex

J Phys Chem A. 2005 Nov 3;109(43):9856-9. doi: 10.1021/jp053139a.

Abstract

We present a theoretical study of the low-lying electronic excitations in the [Pt(P((n)Bu)(3))(2)(ethynylbenzene)(2)] molecule. Although the ground electronic state possesses D(2)(h) symmetry, with both ethynylbenzene ligands being equivalent, in the excited state the molecule breaks the symmetry deforming along a b(3u) direction and localizing the excitation on a single ligand. This localized exciton is of (3)pipi* nature with the unpaired electron and hole spread over one of the benzene rings and the ethyne linkage. The localization indicates an activated hopping mechanism for transport. Our estimate of the barrier is approximately 0.61 eV.