LIGAND-CENTERED (3)PI-PI-ASTERISK EMISSION AND RAMAN ACTIVITY OF [PT(BPY-H(8))(N)(BPY-D(8))(2-N)](2T) (N=O, 1, 2)

Highly resolved emission and excitation spectra as well as emission de cay data of [Pt(bpy-h(8))(n)(bpy-d(8))(2-n)](2+) (n = 0, 1, 2;bpy = 2, 2'-bipyridine) are presented. These compounds are investigated as trap s in neat [Pt(bpy)(2)](ClO4)(2) matrices. The traps, having their emit ting states several cm(-1) below those of the majority of complexes, l ead to spectral resolutions, which are by a factor of several hundreds better than hitherto published. The highest resolution of approximate to 4 cm(-1) is found for [Pt(bpy-h(8))(2)](2+) doped into [Pt(bpy-d(8 ))(2)](ClO4)(2). The low-lying electronic origins (0-0 lines), e.g. at 21 237 cm(-1) for [Pt(bpy-h(8))(2)](2+) in [Pt(bpy-h(8))(2)] (ClO4)(2 ), and the well-resolved vibrational satellite structures carry the in formation needed for a classification of the lowest electronic states. They are assigned as ligand centered of of (3) pi pi character with small metal admixtures. The partially deuterated [Pt(bpy-h(8)) (bpy-d( 8))](2+) emits only from the energetically lower lying (bpy-h(8))-liga nd due to an effective intra-molecular energy transfer, which quenches the emission from the (bpy-d(8))-ligand and prevents a dual emission. The spectra reveal further that a significant vibrational ligand-liga nd coupling of (high-energy) internal ligand modes does not take place . Raman spectra of the neat perchlorate materials are also presented. In particular, the Raman spectrum of [Pt(bpy-h(8)) (bpy-d(8))](2+) con sists of a superposition of (bpy-h(8))- and (bpy-d(8))-ligand modes. I nterestingly, the (bpy-d(8))-ligand exhibits much higher Raman scatter ing intensities than the (bpy-h(8))-ligand. An important message is fo und from the comparison of the emission with the Raman spectrum of [Pt (bpy-h(8)) (bpy-d(8))](2+). This comparison demonstrates the different kinds of information carried by the two types of spectra. Raman lines are observed for both ligands, while the emission spectrum is highly selective and displays just the information about the spatial region o f the complex, which is responsible for the electronic transition. (C) 1997 Elsevier Science S.A.