ANALYSIS OF THE VIBRONIC INTENSITIES IN THE EMISSION-SPECTRUM OF ME2AU(HFAC) - ELECTRONIC-TRANSITIONS TO A 2-DIMENSIONAL COUPLED POTENTIAL SURFACE

(Hexafluoroacetylacetonato)dimethylgold(III), Me2Au(hfac), is luminescent at low temperature. The emission spectrum contains vibronic structure with an intensity distribution that is indicative of coupling between normal coordinates. A good fit to the spectrum is obtained when two totally symmetric coordinates, a low-frequency ring deformation mode and a high-frequency C-C ring stretching mode, are coupled. The effects of coordinate coupling on electronic emission spectra are calculated by using the split-operator technique for numerical integration of the time-dependent Schrodinger equation and the time-dependent theory of electronic spectroscopy. Spectra resulting from emission to a coupled ground state contain unusual intensity distributions in the vibronic structure. The spectra are calculated, and the trends in the intensity distributions are analyzed in terms of the sign and the magnitude of the distortion and the type and the magnitude of the coupling. The theory is applied to the luminescence spectrum of Me2Au(hfac).