853021-54-2Relevant academic research and scientific papers
Phosphine-induced ancillary ligand orthometalation at a tantalum-tantalum double bond
Shaver, Michael P.,Fryzuk, Michael D.
, p. 2606 - 2611 (2005)
The dinuclear tantalum tetrahydride complexes (RPh[NPN]Ta) 2(μ-H)4 ([NPN] = (PhNSiMe2-CH 2)2PR; R = Ph, Cy) promote the asymmetric activation of molecular nitrogen to form (RPh[NPN]Ta)2(μ- η1:η2-N2)(μ-H)2. The coordinatively unsaturated dinuclear dihydride, (RPh[NPN]Ta) 2(μ-H)2, has been proposed as the reactive intermediate, with a tantalum-tantalum double bond storing four electrons with which to reduce N2. Efforts to trap (Cyph[NPN]Ta) 2(μ-H)2 with excess PMe3 at low temperatures promoted the formation of a green product, proposed to be (Cyph[NPN] Ta(PMe3))2(μ-H)2. Attempts to isolate this product promoted the orthometalation of an ancillary ligand N-Ph ring, forming CyPh[NPN]Ta(μ-H)2[μ-N(C6H 4)]Ta[PN](H)(PMe3). Addition of 1 equiv of PMe3 to (PhPh[NPN]-Ta)2(μ-H)4 immediately produced the analogous orthometalation derivative, PhPh[NPN]Ta(μ- H)2[μ-N(C6H4)]Ta[PN](H)(PMe3).
