The emission of α,ω-diphenylpolyenes: A model involving several molecular structures

It is shown that some polyenes may exist in more than one structure of Cs symmetry in the excited electronic state with lower energy than that of the 1Bu state, from which the Cs structures are produced. Hence, more than one electronic structure may be involved in the deactivation processes of the 1Bu state, which is initially populated upon photo-excitation of the polyene molecule in the ground electronic state.