Synthesis, characterisation, electrochemical properties, photochemical properties, and reactivity of bis(2,2′-bipyridyl)hydridoruthenium complexes

Abstract

Complexes [Ru(bipy)₂H(L)]X (bipy = 2,2′-bipyridyl; L = CO or PPh₃, X = PF₆; L = AsPh₃, X = ClO₄) and [Ru(Me₂bipy)H(CO)]PF₆(Me₂bipy = 4,4′-dimethyl-2,2′-bipyridyl) have been synthesised by the reaction of the corresponding [Ru(bipy)₂Cl(L)]⁺ complex or [Ru(Me₂bipy)Cl(CO)]⁺ respectively with sodium tetrahydroborate in aqueous ethanol. In dilute acid [Ru(bipy)₂H(CO)]⁺ yields [Ru(bipy)₂(OH₂)(CO)]²⁺ and hydrogen gas. [Ru(bipy)₂H(CO)]⁺ is relatively photostable compared with [Ru(bipy)₂H(PPh₃)]⁺. The phosphine and arsine complexes show, in general, an increased reactivity compared to the carbonyl complexes.