RAMAN AND RESONANCE RAMAN-SPECTROSCOPY OF IODOPLATINATE(II), IODOPLATINATE(IV) AND MIXED-VALENCE IODOPLATINATE(II,IV) SALTS

The Raman and resonance Raman spectra of a number of new iodoplatinate(II), iodoplatinate(IV) and mixed valence iodoplatinate(II,IV) salts are presented. Previous X-ray structure determination showed that the building blocks of all these compounds consist of PtI6 octahedra and/or PtI4 squares, which can be isolated or connected to dimeric units or polymeric chains. The Raman spectra show that the different coordination polyhedra and oxidation states of the platinum atoms have only a small influence on the wavenumbers of bands attributable to the Pt-I stretching modes. Due to the presence of intervalence transitions in the region probed the mixed-valence compounds show stronger resonance effects then the single-valence parent compounds. The resonance Raman spectra are determined not only by A-term activity but also by B-term activity.