ONE-PHOTON AND 2-PHOTON SPECTROSCOPY OF THE HEXAFLUOROPLATINATE(IV) ION

One- and two-photon excitation spectra of Pt(IV) in Cs2MF6 (M = Si, Ge) were taken at high resolution and low temperatures using laser methods. The zero-phonon line of the first absorption and emission transition was found to be located at 19 490 +/- 15 cm-1, although it has not been directly observed. A zero-phonon line of the 1A1g --> 3T1g(A1g) multiplet component was identified at 27 030 cm-1, and it permitted us to reassign the one-photon spectrum of Patterson from 27 000 to 30000 cm-1. The nu-4t1u mode is active in promoting the 1A(g) --> 3T1g(A1g) transition as well as the fluorescence and absorption between 1A1g and 3T1g(E(g)). The nu-3 Mode is active only in the latter transition and nu-6 was not observable. Bond length changes upon excitation to several excited states were determined. A standard crystal field calculation gave an accurate account of the energy level positions determined in this work.