EMITTING STATE ENERGIES AND VIBRONIC STRUCTURE IN THE LUMINESCENCE SPECTRA OF TRANS-DIOXORHENIUM(V) COMPLEXES

The luminescence properties of a series of trans-dioxo complexes of rh enium(V) with nitrogen donor ligands are summarized and their luminesc ence spectra analyzed. New emissions in the visible to near infrared w avelength region are observed for dioxo complexes with imidazole and e thylenediamine ligands. The intensity distribution within the main pro gression of the resolved spectra is very similar for all compounds, de spite a variation of the luminescence band maxima by approximately 300 0 cm(-1) within the series of complexes. Molecular orbital and crystal field models are combined with time-dependent theory to analyze the e xperimental results. Unusual vibronic structure is shown to arise from coupling between the (1)A(1g) (D-4h point group) ground state and a ( 1)A(1g) excited state, an effect that is correlated with excited state energies. (C) 1998 Elsevier Science S.A.