Developments in laser selective spectroscopy and photophysics of d 6 metal-(di-imine) complexes

Abstract

A brief introduction to laser selective spectroscopy is presented. The power of these techniques in being able to clearly elucidate the nature of electronic excitations and photophysical processes in the title complexes is provided by a number of examples. Included in the discussion are the determination of g = 2, S = 1 nature and zero field splittings of 3π−π ∗ luminescent states, direct measurements of excitation localisation and intramolecular excitation transfer in 3MLCT states of ruthenium complexes and mini-excitation ton behaviour in osmium complexes. An important conclusion is that the intensities of sharp vibrational sideline patterns are variable and cannot be easily used to argue for or against excitation localisation. Far better is the study of electronic origins. The phenomenon termed nanoheterogeneity, where in addition to each chromophore having a distinct environment, each ligand or metal-ligand subunit experiences an independently distinct environment, has important consequences in amorphous environments.