Heavy metalla vinyl-cations show metal-Lewis acid cooperativity in reaction with small molecules (NH, NH, HO, H).

Halide abstraction from tetrylidene complexes [TbbE(Br)IrH(PMe)] [E = Ge (1), Sn (2)] and [Ar*E(Cl)IrH(PMe)] gives the salts [TbbEIrH(PMe)][BAr ] [E = Ge (3), Sn (4)] and [Ar*EIrH(PMe)][BAr ] [E = Ge (3'), E = Sn (4')] (Tbb = 2,6-[CH(SiMe)]-4-(-Bu)CH, Ar* = 2,6-TripCH, Trip = 2,4,6-triisopropylphenyl). Bonding analysis suggests their most suitable description as metalla-tetrela vinyl cations with an Ir[double bond, length as m-dash]E double bond and a near linear coordination at the Ge/Sn atoms. Cationic complexes 3 and 4 oxidatively add NH, NH, HO, HCl, and H selectively to give: [TbbGe(NH)IrH(PMe)][BAr ] (5), [TbbE(NHNH)IrH(PMe)][BAr ] [E = Ge (7), Sn (8)], [TbbE(OH)IrH(PMe)][BAr ] [E = Ge (9), Sn (10)], [TbbE(Cl)IrH(PMe)][BAr ] [E = Ge (11a), Sn (12a)], [TbbGe(H)IrH(PMe)][BAr ] (13), [TbbSn(μ-H)Ir(PMe)][BAr ] (14), and [TbbSn(H)IrH(PMe)][BAr ] (15). 14 isomerizes to give 15 an 1,2-H shift reaction. Hydride addition to cation 3 gives a mixture of products [TbbGeHIrH(PMe)] (16) and [TbbGeIrH(PMe)] (17) and a reversible 1,2-H shift between 16 and 17 was studied. In the tin case 4 the dihydride [TbbSnIrH(PMe)] (18) was isolated exclusively. The PMe and PEt derivatives, 18 and [TbbSnIrH(PEt)] (19), respectively, could also be synthesized in reaction of [TbbSnH] with the respective chloride [(RP) IrCl] (R = Me, = 4; R = Et, = 3). Reaction of complex 19 with CO gives the substitution product [TbbSnIrH(CO)(PEt)] (20). Further reaction with CO results in hydrogen transfer from the iridium to the tin atom to give [TbbSnHIr(CO)(PEt)] (21). The reversibility of this ligand induced reductive elimination transferring 20 to 21 is shown.