Synthesis and characterisation of cyanide-bridged heterobinuclear mixed-valence compounds based on cyclopentadienylorganophosphine-ruthenium(II) and -osmium(II) cyano and pentaammine-ruthenium(III) and -osmium(III) moieties

摘要: Six novel cyanide-bridged mixed-valence complexes. [(η5-C5H5)(PPh3)2M′(µ-CN)M(NH3)5][CF3SO3]3(M = Ru, M′= Ru or Os; M Os, Os) and [(η5-C5R5)(PPh3)2Ru(η-CN)Ru(NH3)5][CF3SO3]3(C5R5= C5H4Me C5Me5), have been synthesised using a simple coupling reaction characterised by electronic infrared absorption spectroscopy cyclic voltammetry. They exhibit moderately intense (Iµmax≈ 2000–4000 dm3 mol–1 cm–1), broad (Δν½≈ 5000 cm–1) intervalence charge-transfer transitions in the visible spectrum, analysis of which reveals Robin–Day Class II behaviour (α2≈ 0.8–2.0%, Hrp≈ 1700–2000 cm–1). Outer-sphere effects upon cyanide-bridge stretching frequency all band characteristics are reported interpreted linear correlations with respect to Gutmann solvent donicity, where appropriate, perturbation arguments. The weak dependence element, Hrp, indicates that mechanism proceeds primarily through an electron, rather than hole, transfer pathway. bands cyclopentadienylosmium complexes pronounced spin-orbit splitting, relative intensities components also showing dependence.