Element–Hydrogen Bond Activations at Cationic Platinum Centers To Produce Silylene, Germylene, Stannylene, and Stibido Complexes

Reactions of [(dippe)PtMe(Et2O)][BArf4] (4[BArf4], dippe = 1,2-bis(diisopropylphosphino)ethane; Arf = 3,5-(CF3)2C6H3) with Mes2EH2 (Mes = mesityl) liberate methane and produce silylene, germylene, or stannylene products [(dippe)Pt(H)═EMes2][BArf4] (E = Si, 1[BArf4]; Ge, 8; Sn, 9). In contrast, treatment of 4[BArf4] with tertiary silanes HSiR3 (R = Ph, Et, OEt) failed to give the expected cationic silyl complexes but instead produced the bridging hydride [(dippe)Pt(μ-H)]2[BArf4]2 (10) along with the corresponding disilane Si2R6. Complex 10 reacts with primary stibines RSbH2 (R = Mes, dmp) to afford dimeric stibido complexes [(dippe)Pt(μ-SbHR)]2[BArf4]2 (R = Mes, 11; dmp, 12) via Sb–H bond activation.