Excitation energy transfer in chromophore aggregates within a dissipative medium

The Redfield theory-based model of excitation energy transfer in chromophore ensembles within dissipative environment is proposed. Application of the multipole expansion to an operator of interaction between the chromophore molecules and the environment together with some assumptions about the latter led to the closed-form expressions for the elements of the dissipation tensor. These expressions relate the rates of transition between eigenstates of a chromophore ensemble with the spectral and electronic properties of an environment and the chromophore molecules. For several model cases the exact solution of the Redfield equations was obtained. -- Highlights: ► A model for electronic relaxation dynamics in supramolecular ensembles is proposed. ► Closed-form expressions for relaxation rates are derived. ► Redfield equations are solved in closed form for several model systems. ► The effect of structural and electronic parameters on relaxation rates is discussed.