Cationic Imido Alkylidene Complexes of Molybdenum Supported by β-Diketonate and β-Diketiminate Ligands

Reaction of Mo(NAr)(CHCMe₂Ph)(OTf)₂(DME) (Ar = 2,6-i-Pr₂C₆H₃) with the lithium salt of various β-diketonates and β-diketiminates leads to complexes of the type Mo(NAr)(CHCMe₂Ph)(L)(OTf) (L = β-diketonate or β-diketiminate). Treatment of these compounds with NaB[3,5-(CF₃)₂C₆H₃]₄ in dichloromethane affords rare examples of cationic imido alkylidene complexes. The solid-state structures of two of these compounds, {Mo(NAr)(CHCMe₂Ph)(TMHD)(THF)}{B[3,5-(CF₃)₂C₆H₃]₄} and {Mo(NAr)(CHCMe₂Ph)(Ar^Cl-Nacnac)}{B[3,5-(CF₃)₂C₆H₃]₄} (TMHD = tetramethylheptanedionato, Ar^Cl-Nacnac = [2,6-Cl₂C₆H₃NC(Me)]₂CH), have been determined by X-ray diffraction, and their reactivity with ethylene and other simple olefins has been explored.