Interpretation of c i s-hexatriene absorption spectrum. The Duschinsky effect

Abstract

The differences between the uv absorption spectra of trans- and cis-hexatriene are interpreted in terms of the coupling between the ground state normal modes in the electronic excited state, i.e., the Duschinsky effect. The model Hamiltonian is derived and its eigenvalues and eigenvectors are found by means of the standard perturbation theory. The spectra of both molecules are simulated at the computer. A good agreement with experiment is found. Some approximations involved are discussed and the possibilities of further experimental verification are pointed out.