@article {1251,
	title = {Addition of primary and secondary phosphines to dinuclear tantalum hydrides: Synthesis of phosphides and phosphinidenes via P-H bond activation},
	journal = {Organometallics},
	volume = {24},
	number = {7},
	year = {2005},
	note = {ISI Document Delivery No.: 909LJTimes Cited: 11Cited Reference Count: 42},
	month = {Mar},
	pages = {1419-1427},
	type = {Article},
	abstract = {The dinuclear complex ((RPh)[NPN]Ta)(2)(mu-H)(4) (where (RPh)[NPN] = [RP(CH2SiMe2NPh)(2)] and R = Ph, Cy) shows remarkable reactivity with molecular nitrogen, producing the side-on end-on bound dinitrogen complex ((RPh)[NPN]Ta)(2)(mu-eta(1):eta(2)-N-2)(mu-H)(2.) This tantalum tetrahydride also promotes other small molecule activation. Addition of secondary phosphines HPR{\textquoteright}(2) (R{\textquoteright} = Ph, Cy) to ((RPh)[NPN]Ta)(2)(mu-H)(4) accesses trihydride phosphide systems ((RPh)[NPN]Ta)(2)(mu-H)(3)(mu-PR{\textquoteright}(2)). Addition of primary phosphines H2PR" (R" = Cy, Ad) gives bridging phosphinidene tantalum complexes ((RPh)[NPN]Ta)(2)(mu-H)(2)(mu-PR"). Molecular structures as determined by X-ray crystallography for the complexes ((PhPh) [NPN]Ta)(2)(mu-H)(3)(mu-PCy2) and ((CyPh)[NPN]Ta)(2)(mu-H)(2)(mu 1-PAd) are presented. Isotopic labeling studies offer mechanistic insights into the reactivity of this tetrahydride system. Reaction Of Cy2PH with ((CyPh)[NPN]Ta)(2)(mu-D)(4), for instance, gives solely the monchydride dideuteride complex ((CyPh)[NPN]Ta)(2)(Y-H)(mu-D)(2)(mu-PCy2). This labeling study indicates that D-2 loss forms the reactive species, ((CyPh) [NPN]Ta)(2)(mu-D)(2), which promotes small molecule activation. Addition of CyPH2 to ((CyPh)[NPN]Ta)(2)(AtD)(4) gives a series of isotopomers, with an average composition of 0.67 H and 1.33 D, supporting a 1,2-H-2 elimination step to form the tantalum phosphinidenes. These results are tied into the general reactivity of ((RPh)[NPN]Ta)(2)(mu-H)(4).},
	keywords = {BRIDGING N-2 UNIT, CP-ASTERISK, DIAMIDOPHOSPHINE COMPLEXES, DINITROGEN LIGAND, EARLY TRANSITION-METALS, END-ON, IMIDE FORMATION, MOLECULAR-STRUCTURES, RAY CRYSTAL-STRUCTURE, SIDE-ON},
	isbn = {0276-7333},
	url = {<Go to ISI>://000227861100010},
	author = {Shaver, M. P. and Fryzuk,Michael D.}
}
@article {1250,
	title = {Phosphine-induced ancillary ligand orthometalation at a tantalum-tantalum double bond},
	journal = {Organometallics},
	volume = {24},
	number = {11},
	year = {2005},
	note = {ISI Document Delivery No.: 927XMTimes Cited: 0Cited Reference Count: 32},
	month = {May},
	pages = {2606-2611},
	type = {Article},
	abstract = {The dinuclear tantalum tetrahydride complexes ((RPh)[NPN]Ta)(2)(mu-H)(4) ([NPN] = (PhNSiMe2CH2)(2)PR; R = Ph, Cy) promote the asymmetric activation of molecular nitrogen to form ((RPh)[NPN]Ta)(2)(mu-eta(1):eta(2)-N-2)(mu-H)(2). The coordinatively unsaturated dinuclear dihydride, ((RPh)[NPN]Ta)(2)(mu-H)(2), has been proposed as the reactive intermediate, with a tantalum-tantalum double bond storing four electrons with which to reduce N-2. Efforts to trap ((CyPh)[NPN]Ta)(2)(mu-H)(2) with excess PMe3 at low temperatures promoted the formation of a green product, proposed to be (CyPh [NPN]Ta(PMe3))(2)(mu-H)(2). Attempts to isolate this product promoted the orthometalation of an ancillary ligand N-Ph ring, forming (CyPh)[NPN]Ta(mu-H)(2)[mu-N(C6H4)]Ta[PN](H)(PMe3). Addition of 1 equiv of PMe3 to ((PhPh)[NPN] Ta)(2)(mu-H)(4) immediately produced the analogous orthometalation derivative, [NPN]Ta(mu-H)(2)[mu-N(C6H4)]Ta[PN](H)(PMe3).},
	keywords = {BRIDGING N-2 UNIT, C-H ACTIVATION, CLEAVAGE, CRYSTAL-STRUCTURE, DINITROGEN LIGAND, DINUCLEAR, EARLY TRANSITION-METALS, END-ON, ORGANODIMETALLIC COMPLEXES, SIDE-ON},
	isbn = {0276-7333},
	url = {<Go to ISI>://000229233800011},
	author = {Shaver, M. P. and Fryzuk,Michael D.}
}
