@article {1253,
	title = {Activation and cleavage of alkynes by the dinuclear tantalum complexes ([NPN]Ta)(2)(mu-H)(4) and ([NPN]Ta)(2)(mu-eta(1):eta(2)-N-2)(mu-H)(2) (where NPN = PhP(CH2SiMe2NPh)(2))},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {83},
	number = {6-7},
	year = {2005},
	note = {ISI Document Delivery No.: 963UVTimes Cited: 4Cited Reference Count: 29},
	month = {Jun},
	pages = {652-660},
	type = {Article},
	abstract = {Reaction of phenylacetylene with the dinuclear tetrahydride complex ([NPN]Ta)(2)(mu-H)(4) gives the product ([NPN]Ta)(2)(mu-PhCCH)(mu-H)(2) (where NPN is PhP(CH2SiMe2NPh)(2)). Activation of other terminal alkynes by ([NPN]Ta)(2)(mu-H)(4) accesses ([NPN]Ta)(2)(mu-RCCH)(mu-H)(2) (R = n-Pr, t-Bu). Crystallographic analysis of the R = Ph derivative showed it to be a bis(mu-alkylidene) bound asymmetrically to the two tantalum centres. Storage of solutions of ([NPN]Ta)(2)(mu-PhCCH)(mu-H)(2) under vacuum promotes the loss of H-2 and cleavage of the C-C bond to give a bis(mu-alkylidyne) complex, ([NPN]Ta)(2)(mu-CPh)(mu-CH). Addition of diphenylacetylene did not give the desired ([NPN]Ta)(2)(mu-CPh)(2), but rather promotes a complex decomposition of the supporting [NPN] ligands. Reaction of phenylacetylene with the dinitrogen complex ([NPN]Ta)(2)(mu-eta(1):eta(2)-N-2)(mu-H)(2) results in the dissociation of the bound dinitrogen and the formation of ([NPN]Ta)(2)(mu-PhCCH)(mu-H)(2), which is identical to that derived from the reaction with the dinuclear tetrahydride.},
	keywords = {activation of small molecules, alkylidene, alkylidyne, ALKYLIDYNE COMPLEXES, ALKYNE, amidodiphosphine, BONDS, DIAMIDOPHOSPHINE COMPLEXES, DINITROGEN CLEAVAGE, DINUCLEAR, END-ON, FUNCTIONALIZATION, hydride dinitrogen, LIGAND, N-2, NIOBIUM(III), SIDE-ON, tantalum},
	isbn = {0008-4042},
	url = {<Go to ISI>://000231832500020},
	author = {Shaver, M. P. and Johnson, S. A. and Fryzuk,Michael D.}
}
@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.}
}
