Intervalence charge transfer in a "chain-like" ruthenium trinuclear assembly based on the bridging ligand 4,7-phenanthrolino-5,6:5',6'-pyrazine (ppz).
The IVCT characteristics of the mixed valence forms of the trinuclear complex [{Delta-Ru(bpy)2}2{Delta(t)-Ru(bpy)(mu-ppz)2}]n+ (n = 7, 8; t = trans), and the diastereoisomers (meso and rac) of the dinuclear complex [{Ru(bpy)2}2(mu-ppz)]5+, display a marked dependence on the nuclearity and extent of oxidation of the assemblies. The dinuclear species are classified as borderline localised-delocalised mixed valence species while the two mixed valence states of the trinuclear complex exhibit localised behaviour. One-electron oxidation of a terminal Ru centre in the trinuclear case gives rise to a broad, low intensity IVCT band for the +7 mixed valence species which is composed of two underlying Gaussian-shaped bands. The transitions are identified as adjacent and remote IVCT transitions, with the former dominating the intensity of the IVCT manifold. The +8 mixed valence species exhibits a single dominant IVCT band arising from the equivalent IVCT transitions from the central Ru(II) to peripheral Ru(III) centres.
D'Alessandro
Deanna M
DM
School of Pharmacy and Molecular Sciences, James Cook University, Townsville, Queensland 4811, Australia.
Keene
F Richard
FR
D002621:Chemistry / Q000379:methods; D004563:Electrochemistry; D004583:Electrons; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D010100:Oxygen / Q000737:chemistry; D011522:Protons; D011719:Pyrazines / Q000737:chemistry*; D012413:Rubidium / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry*; D013237:Stereoisomerism
D008024:Ligands; D011522:Protons; D011719:Pyrazines; D012428:Ruthenium; D012413:Rubidium; D010100:Oxygen