Activation of Dichloromethane by a Bis-NHC Cp*Ru Complex: Formation of a Pentamethyl(chloromethyl)cyclopentadiene Ligand

The dinitrogen complex [{Cp*Ru­(L)}2(μ-N2)]­[BPh4]2 (L = bis­(3-methylimidazol-2-ylidene) reacts with dichloromethane at room temperature, furnishing the diene derivative [Ru­(η4, κ1-Cl-C5Me5CH2Cl)­Cl­(L)]­[BPh4] as result of CH2Cl2 oxidative addition and subsequent migration of the chloromethyl group into the Cp* ring. Mechanistic insight provided by DFT computations indicate that while the cleavage of the C–Cl bond is not thermodynamically favored, the subsequent migration step is largely exergonic and thus provides the driving force for the formation of the observed product.