Dynamical processes in the lowest-excited triplet metal-to-ligand charge transfer states of ruthenium and osmium diimine complexes in crystals

Abstract

This review presents a detailed description of the lowest-excited states in ruthenium(II) and osmium(II) diimine complexes, based on extensive studies of their optical spectra in crystalline environments. Deuteration, and Zeeman and Stark effects provide a wealth of incisive results. The transferred charge in the lowest-excited triplet metal-to-ligand charge transfer states is localized on a single ligand in ruthenium(II) diimine complexes and the excitation exchange interaction between equivalent metal-ligand subunits is 0 5 cm . Localization gives rise to subtle effects, such as small Stokes shifts, in spectra. The lowest-excited states of osmium(II) diimine complexes in crystals with low inhomogeneous broadening are well described as coherent intramolecular excitons with excitation exchange interactions in the range from 2 to 30 cm .