INFLUENCE OF COLLECTIVE DECAY OF EXCITED ELECTRONIC STATES OF CHROMOPHORES ON DISPERSION CHARACTERISTICS OF RESONANCE RAMAN-SCATTERING BY CHROMOPHORE DIMERS WITH DYNAMIC COUPLING BETWEEN CHROMOPHORES

Expressions for the excitation profiles and dispersion curves of the d epolarization ratio of Raman lines and for the Raman optical activity signal were obtained for freely orienting rigid chromophore dimers, fo r which the interactions between identical chromophores are due to bot h 'collective decay' of the excited electronic states of the chromopho res (described by off-diagonal elements of the dimer damping matrix) a nd 'dynamic coupling' (described by a coupling operator with real matr ix elements), The frequency region near the frequency of the pure elec tronic transition of the chromophore is considered, It is shown that i n such chromophores the collective decay leads to suppression and wide ning one of two components of excitation profile of Raman line (separa ted by dynamic coupling) and to enhancement and narrowing the other, T here is the same influence on intensity and width of two components of dispersion curves of Raman optical activity signal. The collective de cay also causes shifting of the extremes of the dispersion curves of t he depolarization ratio of the Raman line towards the enhancing compon ents of the excitation profiles and a decrease in width, when the vect ors of the transition dipoles of the chromophores are not parallel or antiparallel. Calculated examples are presented.