A decanuclear ruthenium(II)–polypyridine complex: synthesis, absorption spectrum, luminescence and electrochemical behaviour

Abstract

A novel oligonuclear Ru(II)–polypyridine complex, Ru{(µ-2,3-dpp)Ru[(µ-2,3-dpp)Ru(bpy)₂]₂}₃(PF₆)₂₀1, where dpp = bis(2-pyridyl)pyrazine and bpy = 2,2′ bipyridine, has been prepared from the reaction of a Ru(2,3-dpp)₃²⁺ core 2 with three Ru[(µ-2,3-dpp)Ru(bpy)₂]₂Cl₂⁴⁺ units; 1 shows a very intense absorption band at 541 nm (ε= 1.25 × 10⁵ dm³ mol^–1 cm^–1), room temperature luminescence (λ_max= 809 nm, τ= 55 ns, Φ= 10^–3), and independent one-electron oxidation of the six peripheral Ru²⁺ ions at +1.43 V vs. saturated calomel electrode (SCE).