A theoretical study of molecular structure in the excited state and molecular luminescence part II: An SCF—CI calculation of luminescence and molecular structure in equilibrium excited states of some compounds with strong bond alternation

Abstract

It is shown that the iterative procedure SCF—CI-SC previously suggested [1] can be successfully used for calculation of the Stokes shift, FC luminescent maxima and equilibrium molecular geometry in excited states of compounds which have strong bond alterna- tion in their ground state. The influence, in the excited state, of molecular geometry on the positions and intensities of the luminescent transitions is discussed. The calculated molecular geometries show that there is a strong conjugation effect in some excited states of compounds with strong, moderate and weak bond alternation; this latter factor probably determines the luminescent properties of these organic compounds.