Silylation of Coordinated Dinitrogen by Silylcobalt Complexes. Preparation of a New Series of Silyldiazenido and Silylhydrazido(2−) Complexes of Molybdenum and Tungsten

Abstract

The silylcobalt complexes [R2R′SiCo(CO)4] (R, R′ = Ph, Me) reacted with dinitrogen complexes of the type [M(N2)2(P)4] (M = Mo, W; P = tertiary phosphine) to give new silyldiazenido complexes trans-[M(NNSiR2R′)(P)4][(μ-OC)Co(CO)3], which were further converted to silylhydrazido(2−) complexes such as trans-[WX(NNHSiR2R′)(dpe)2][Co(CO)4] by treatment with HX (dpe = Ph2PCH2CH2PPh2; X = OH, OMe, Br).

Manganese Carbonyl Complexes as Catalysts for the Hydrosilation of Ketones: Comparison with RhCl(PPh3)3

“…Samples of (CO) 5 MnBr,14a (PPh 3 )(CO) 4 MnBr, (CO) 5 MnCH 3 , (CO) 5 MnC(O)CH 3 , (PPh 3 )(CO) 4 MnC(O)CH 3 ( 1 ), (CO) 5 MnSiMe 2 Ph ( 2 ), , and (CO) 5 MnC(O)- p -C 6 H 4 CH 3 18 were prepared by literature procedures and judged pure by IR and 1 H NMR spectroscopy. (CO) 4 CoSiMe 2 Ph ( 11 ) was prepared by the procedure of Chalk and Harrod as a brown fluid: IR (hexane) ν(CO) 2090 m, 2026 s, 1993 s, br cm -1 ; 1 H NMR δ 0.72 (SiMe), 7.17 (m, 3 H, Ph), 7.61 (m, 2 H, Ph); 13 C NMR (C 6 D 6 ) δ 5.88 (SiMe), 199.58 (br s, CO), 141.45 (Ph, ipso-C), 133.22, 129.78, 128.20 (Ph).…”

Recent Advances in the Chemistry of Dinitrogen Complexes

“…As expected from the facile NH3 formation from the reactions with sulfuric acid, 2b reacts with acidic transition metal carbonyl hydrides to give NH3 in substantial yields after base distillation of the reaction mixture.830 155 156 Besides these acidic hydrides, the hydridic transition metal compound [Cp2ZrHCl] also reacts with 2 to give NH3 under the similar conditions.155 Although any intermediate stages are unknown for the whole reactions of 2 with metal hydrides, a series of hydrazido(2-) complexes, frans-[W(OR)(NNH2)(dppe)2][A] (A = Co-(CO)4, FeCo3(CO)i2), were isolated from the reactions of lb with [HCo(CO)4] or [HFeCo3(CO)i2] in various ROH.83c Related silylation reaction of 1 and 2b with [Ph2MeSiCo(CO)4] giving the silyldiazenido complexes has been cited already. 149 More recently, formation of 26b from the reaction of lb with 2 equiv of acidic Ru complex [CpRu(dtfpe)H2][BF4] (41) has been reported (Scheme 15).157 Complex 41 exists in solution as a slowly interconverting mixture of the dihydrogen and dihydride species [CpRu(dtfpe)(^2-H2)]+ and [CpRu(dtfpe)(H)2]+, the pK& values of which are estimated to be 4.3 and 4.4, respectively. In this reaction the heterolytic cleavage of the dihydrogen ligand within 41 into HBF4 and [CpRu(dtfpe)H] is taking place.…”