A Trimetal Carbene with Reactivity Reminiscent ofFischer–Tropsch Catalysis.

Metal-carbenesare common reaction intermediates in chemical catalysis;however, very few catalysts are known with a trimetal-carbene activecenter. In this work, we describea computational study into the chemical and catalytic properties ofa 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 individualorbital interactions are identified from a natural bond orbital analysis,and the reaction pathways for consecutive intramolecular CH3and H transfer (or vice versa) are investigated. The studies showthat CO binding has dramatic effects on the reaction mechanism andweakens the Ru–H bond strength. The reaction processes arerationalized by valence bond models and thermochemical bond strengthstudies. The work leads to suggestions on how to improve this chemicalsystem for enhanced alkane synthesis. [ABSTRACT FROM AUTHOR]