APPLICATION OF TRANSIENT VIBRATIONAL SPECTROSCOPIES TO THE EXCITED-STATES OF METAL POLYPYRIDYL COMPLEXES

Time-resolved resonance Raman and infrared spectroscopies have been ap plied to a variety of problems arising in excited states and molecular assemblies based on polypyridyl complexes of Re(I), Ru(II) and Os(II) . Application of transient resonance Raman spectroscopy has been used to assign the acceptor ligand in heteroleptic Ru(II) complexes and to characterize molecular structure in acceptor ligands. It has been appl ied to intramolecular electron transfer in chromophore-quencher comple xes and molecular assemblies and to intramolecular energy transfer in polynuclear complexes. Time-resolved infrared spectroscopy has opened new avenues for the study of excited-state electronic structure and dy namics by the observation of v(CO) and v(CN) bands in transient absorp tion difference spectra. This technique has been applied to distinguis hing between metal-to-ligand charge transfer and ligand-based pi pi s tates in Re (I) complexes and to intramolecular energy transfer in cya no-bridged oligomers. (C) 1997 Elsevier Science S.A.