Electronic Communication and Photoinduced Intramolecular Electron Transfer in Hybrid Ru(II)-Re(I) Complexes Using Eigenstate-Based and Diabatic-State-Based Models

Photoinduced intramolecular electron transfer (PIET) plays a vital role in the efficiency of electronics communication in transition metal complexes catalysing oxidation-reduction reaction. In this work, we theoretically calculate the rate of electron transfer(ET) in Ru(II)-BL-Ru(I) hybrid complexes; where BL is bridging ligand. A brief concept of ET in the basis of Marcus theory, which is extended to address a variety of different type of ET, is provided. We show that, in the case of Ru(II)-BL-Ru(I) complex, ET involves a non-adiabatic state which thanks to a fast electronics communication between donor and acceptor connected by BL and becomes rigid complex. Single electron transferring in Ru(II)-BL-Ru(I) complex governed by PIET constructed by potential energy curve as change of structural transformation over time-evolution. We also investigate the mechanism of PIET involving a redox reaction in excited state, wherein the oxidation state of Ru(II) (donor) and Ru(I) (acceptor) changes. To access non-adiabatic state of Ru(II)-BL-Ru(I), we use constrained density functional theory to allow ground state calculation to be performed along with geometry constraints. We also systematically study the role of distance of donor-acceptor separation on kinetics of PIET