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

Abstract

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, MesF; trip = 2,4,6-iPr3-C6H2, dmp = 2,6-Mes2-C6H3, MesF = 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; MesF, 5]. Complexes 3−5 exhibit characteristic SiH 1H NMR resonances downfield of 8 ppm and very small 2JSiH 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).