Synthesis, Structure, and Reactivity of Neutral Hydrogen-Substituted Ruthenium Silylene and Germylene Complexes

Reaction of Cp*(ⁱPr₂MeP)RuCl (1) with 0.5 equiv of Mg(CH₂Ph)₂(THF)₂ afforded the benzyl complex Cp*(ⁱPr₂MeP)Ru(η³-CH₂Ph) (2). Complex 2 readily reacted with primary silanes H₃SiR (R = trip, dmp, Mes^F; trip = 2,4,6-ⁱPr₃-C₆H₂, dmp = 2,6-Mes₂-C₆H₃, Mes^F = 2,4,6-(CF₃)₃-C₆H₂) to liberate toluene and afford hydrogen-substituted silylene complexes Cp*(ⁱPr₂MeP)(H)RuSiH(R) [R = trip, 3; dmp, 4; Mes^F, 5]. Complexes 3−5 exhibit characteristic SiH ¹H NMR resonances downfield of 8 ppm and very small ²J_SiH coupling constants (8−10 Hz). The solid state structures of complexes 3 and 5 feature short Ru−Si distances of 2.205(1) and 2.1806(9) Å, respectively, and planar silicon centers. In addition, the silylene complex Cp*(ⁱPr₂MeP)(H)RuSiPh(trip) (6) and the unusual, chlorine-substituted species Cp*(ⁱPr₂MeP)(H)RuSiCl(R) [R = trip, 7; dmp, 8] were prepared. Hydrogen-substituted ruthenium germylene complex Cp*(ⁱPr₂MeP)(H)RuGeH(trip) (9) was prepared similarly by reaction of 2 with tripGeH₃. Complex 9 is the first structurally characterized ruthernium germylene complex and has a remarkably short Ru−Ge distance of 2.2821(6) Å. Complex 9 adds H₂O across its RuGe bond to give Cp*(ⁱPr₂MeP)(H)₂RuGeH(OH)(trip) (10).