511522-50-2Relevant academic research and scientific papers
Hydrosilylation of a dinuclear tantalum dinitrogen complex: Cleavage of N2 and functionalization of both nitrogen atoms
Fryzuk, Michael D.,MacKay, Bruce A.,Patrick, Brian O.
, p. 3234 - 3235 (2003)
Hydrosilylation of the ditantalum dinitrogen complex ([NPN]Ta)2(μ-H)2(μ-η1:η2-N2) proceeds via an addition reaction to produce ([NPN]TaH)(μ-H)2(μ-η1:η2-N-NSiH2Bu)(Ta[NPN]), which contains a new N-Si bond and a terminal tantalum hydride; this species has been characterized by NMR spectroscopy and X-ray diffraction. This complex undergoes reductive elimination of H2 followed by N-N bond cleavage to generate a new intermediate with the formula ([NPN]TaH)(μ-N)(μ-NSiH2Bu)(Ta[NPN]); confirmation of N-N bond cleavage is evident from the 15N-labeled isotopomer that displays an absence of 15N-15N scalar coupling in the 15N NMR spectrum. In the presence of additional silane, a second hydrosilylation and reductive elimination results to give ([NPN]Ta)2(μ-NSiH2Bu)2, a species in which each dinitrogen-derived N atom has been converted to a bridging silylimide ligand. This latter complex displays C2h symmetry both in solution and in the solid state. Copyright
Substituent effects in the hydrosilylation of coordinated dinitrogen in a ditantalum complex: Cleavage and functionalization of N2
MacKay, Bruce A.,Munha, Rui F.,Fryzuk, Michael D.
, p. 9472 - 9483 (2006)
The dinitrogen complex ([NPN]Ta)2(μ-η1: η2-N2)(μ-H)2, 1, (where [NPN] = (PhNSiMe2CH2)2PPh) undergoes hydrosilylation with primary and secondary alkyl- and arylsilanes, giving a new N-Si bond and a new terminal tantalum hydride derived from one Si-H unit. Various primary silanes can be employed to give isolable complexes of the general formula ([NPN]TaH)(μ-N-N-SiHnR3-n)(μ-H)2(Ta[NPN]) (5, R=Bu, n = 2; 9, R=Ph, n = 2). Analogous complexes featuring secondary silanes are not isolable, because these products, and 5 and 9, are uniformly unstable toward reductive elimination of bridging hydrides as H2, followed by cleavage of the N-N bond to give ([NPN]TaH)(μ-N)(μ-N-SiH nR3-n)(Ta[NPN]) (6, R=Bu, n = 2; 10, R=Ph, n = 2; 15, R=Ph, n = 1; 16, R=Ph and Me, n = 1). The bridging nitrido ligand in these complexes is itself a substrate for a second hydrosilylation when n = 2, and schemes leading to Ta(IV) complexes of the general formula ([NPN]Ta) 2(μ-N-SiH2R)(μ-N-SiH2R') via elimination of H2 are reported (4, R=R′ = Bu; 12, R=Bu, R′ = Ph; 13, R=Bu, R′ = CH2CH2SiH3). At this point, the general reaction manifold for these compounds ramifies, with distinct outcomes occurring for different R groups-[NPN] ligand amide migration from Ta to RSi affords 11, ([NPN]Ta(μ-NSiH2Ph)(μ-NSiH 2Ph)Ta[NPN]), whereas stable complex 6 rearranges to give 7, ([NP(C6H4)N]Ta(BuSiH2N-μ-SiHBu-μ-N) Ta[NPN]) in the presence of excess silane. Ethanediylbissilane reacts with 1 to give 14, ([NP(C6H4)N]Ta(N-SiH2CH 2CH2Si(H)-μ-N)Ta[NPN]), isostructural to 7.
