Reactivity of a Bis(N-heterocyclic carbene) with Ruthenium Carbonyl. Synthesis of Mono- and Trinuclear Derivatives and Ligand Modification via C–H Bond Activation

Abstract

The bis(N-heterocyclic carbene) 1,1′-dimethyl-3,3′-(o-xylylene)diimidazol-2,2′-diylidene (MeImCH2C6H4CH2ImMe) reacted with [Ru3(CO)12] at room temperature, in a 3/1 molar ratio, to give the mononuclear derivative [Ru(κ2C2-MeImCH2C6H4CH2ImMe)(CO)3] (1), which contains a chelating bis(NHC) ligand. However, the use of a 1/1 ratio of the reactants led to the trinuclear cluster [Ru3(μ-κ2C2-MeImCH2C6H4CH2ImMe)(CO)10] (2), which contains an edge-bridging bis(NHC) ligand and which, upon heating in refluxing THF, underwent a double C(sp3)–H bond activation process to give the dihydride derivative [Ru3(μ-H)2(μ3-κ3C3-MeImCC6H4CH2ImMe)(CO)8] (3).