Hydrosilation of alkynes by an osmium cluster complex. The isolation and structural characterization of an intermediate

Reactivity of Silylated Dinuclear Iron−Platinum Acyl Complexes: Formation of μ-Vinylidene Complexes and Crystal Structures of the Acyl Complex [(OC)3{(MeO)3Si}Fe(μ-dppm)Pt{C(O)Me}(t-BuNC)] and the μ-Vinylidene Complex [(OC)3Fe{μ-CC(H)Ph}(μ-dppm)Pt(PPh3)]

“…The silyl group may be lost as HSi(OMe) 3 or in the form of the hydrosilation product Ph(H)CdC(H)Si(OMe) 3 . 30 Future GC/MS studies will be necessary to characterize the cleavage products in order to gain a better insight into the various mechanistic steps of this complex transformation.…”

“…Calcd for C 37H41FeO6P3-Pt‚CH 2Cl2 (M ) 925.58 + 84.93): C, 45.17; H, 4.29). IR (KBr) ν(CO): 1991 m, 1924 vs, 1914 sh, ν(CdC): 1584 w cm -1 ; NMR: 1 H δ 1.33 (s, 9H, t-Bu), 3.45 (d, 9H, POMe, 3 J(P-H) ) 13.1), 4.16 (dt, 2H, PCH 2P, 2 J(P-H) ) 10.0, 4 J(P-H) ) 2.2, 3 J(Pt-H) ) 35.3), 7.15-7.85 (m, 21H, C6H5 and obscured vinylidene proton); 13 C{ 1 H} (295 K), R-C and FeCO not detected, 152.6 (s, β-C, 2 J(Pt-C) ) 122), 127.9-138.6 (m, phenyl), 51.2 (s, POCH 3, 2 J(P-C) ) 18), 51.0 (m, PCP, partially obscured), 34.7 (d, CCH 3, 4 J(P-C) ) 13 Hz), 30 […”

MOLECULAR STRUCTURE OF ORGANOSILICON COMPOUNDS WITH Si - Os, Si - Ir, and Si - Pt BONDS

“…The positions of three hydride atoms in complex 24 [28] were not located. Complex 26 [24,25] is the first example of a triply bridged r/ J -Si(OEt) 3 ligand coordinated to the face of the cluster through the silicon atom and the oxygen atoms of two ethoxy groups. The oxygen atom of one of the methoxy substituents is coordinated to the neighbour osmium atom.…”

Oxidative addition of silanes R3SiH to the unsaturated cluster [Os3(μ-H){μ3-Ph2PCH2PPh(C6H4)}(CO)8]: Evidence for reversible silane formation in the dynamic behaviour of [Os3(μ-H)(SiR3)(CO)9(μ-dppm)]

“…2 Agostic M-H-Si interactions are important in several clusters 2 and have been implicated in catalytic processes such as hydrosilation. [3][4][5] Since agostic bonds are readily formed, they have been studied as analogues of the agostic M-H-C bonds and C-H bond activation. In some cases agostic M-H-Si bonds have been found in ground-state structures and have been characterised by XRD.…”

“…2 In other cases they appear as intermediates in reactions. 6 Examples of the oxidative addition of silanes to triosmium clusters are the addition of (EtO) 3 SiH to [Os 3 (CO) 10 (MeCN) 2 ] 7,8 and of Et 3 SiH (and related Ge and Sn compounds) or Ph 2 SiH 2 to [Os 3 (l-H) 2 (CO) 10 ]. 6,9 Other examples of silyl osmium clusters 10,11 and silyl ruthenium clusters have been reported.…”