A Trimetal Carbene with Reactivity Reminiscent of Fischer–Tropsch Catalysis

Metal-carbenes are common reaction intermediates in chemical catalysis; however, very few catalysts are known with a trimetal-carbene active center. In this work, we describe a computational study into the chemical and catalytic properties of a unique trimetal carbene containing a Ru2Pt-carbene core, [(CpRu)2(μ2-CH2)(μ3-NCH3)Pt(P(CH3)3)2], with and without bound CO. The chemical structure and individual orbital interactions are identified from a natural bond orbital analysis, and the reaction pathways for consecutive intramolecular CH3 and H transfer (or vice versa) are investigated. The studies show that CO binding has dramatic effects on the reaction mechanism and weakens the Ru–H bond strength. The reaction processes are rationalized by valence bond models and thermochemical bond strength studies. The work leads to suggestions on how to improve this chemical system for enhanced alkane synthesis.