@article {2528,
	title = {Synthesis and Characterization of a New Thiophene-Bridged Diamidophosphine [NPN] Donor Set and Its Coordination Chemistry with Zirconium(IV): Unexpected Deprotonation-Lithiation Sequence with a Mesitylaminothiophene Precursor},
	journal = {Organometallics},
	volume = {28},
	number = {17},
	year = {2009},
	note = {ISI Document Delivery No.: 489MMTimes Cited: 1Cited Reference Count: 43Menard, Gabriel Jong, Howard Fryzuk, Michael D.},
	month = {Sep},
	pages = {5253-5260},
	type = {Article},
	abstract = {The synthesis and characterization of the thiophene-bridged diamidophosphine proligand [NPN]H-S(2) (2) (where [NPN]H-S(2) = {[N-(2,4,6-Me3C6H2)(3-NH-SC4H2-2-)](2)PPh}) along with several [NPN](ZrX2)-Zr-S (X = NMe2, Cl, I) complexes are presented. The ligand precursor [NPN]H-S(2) was prepared from N-(2,4,6-Me3C6H2)(3-NH-4-Br-SC4H2) (1),(BuLi)-Bu-t, and PhPCl2 in Et2O in 50\% yield; the stereochemistry of the ligand precursor was unexpected and likely resulted from a competitive bromine-lithium exchange and deprotonation sequence with the thiophene starting material I and (BuLi)-Bu-t. A mechanism to rationalize the observed stercochemistry of the product is proposed following deuteration experiments. [NPN]Zr-S(NMe2)(2) (8) can be prepared in 80\% yield by the direct reaction of [NPN]H-S(2) and Zr(NMe2)(4) in toluene. Both [NPN](ZrCl2)-Zr-S (9) and [NPN](ZrI2)-Zr-S (10) are prepared in high yield by the reaction of 8 with excess Me3SiCl or Me3SiI, respectively.},
	keywords = {DIARYLAMIDO-PHOSPHINE-LIGANDS, DIRECTED ORTHO-LITHIATION, END-ON, hafnium, HALOGEN EXCHANGE, lithium, METAL-COMPLEXES, MOLECULAR NITROGEN, ON-BOUND DINITROGEN, PALLADIUM-CATALYZED AMINATION, SIDE-ON},
	isbn = {0276-7333},
	url = {<Go to ISI>://000269424200046},
	author = {Menard, G. and Jong, H. and Fryzuk,Michael D.}
}
@article {1573,
	title = {Inner-sphere two-electron reduction leads to cleavage and functionalization of coordinated dinitrogen},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {103},
	number = {46},
	year = {2006},
	note = {ISI Document Delivery No.: 108OPTimes Cited: 14Cited Reference Count: 55Spencer, Liam P. MacKay, Bruce A. Patrick, Brian O. Fryzuk, Michael D.},
	month = {Nov},
	pages = {17094-17098},
	type = {Article},
	abstract = {Activation of molecular nitrogen by transition metal complexes is an area of current interest as investigations using the inert N-2 molecule to produce higher-value organonitrogen compounds intensify. In an attempt to extend the addition of hydride reagents E-H (where E = BR2, AIR(2), and SiR3) to the dinitrogen complex ([NPN]Ta)(2)(mu-H)(2)(mu-eta(2):eta(2)-N-2) [1; where NPN = (PhNSiMe2CH2)(2)PPh], the reaction with zirconocene chlorohydride, [Cp2Zr(Cl)H](x), was examined. The crystalline product formed in 35\% yield was determined to be ([NP(N)N]Ta)(mu-H)(2)(mu-N)(Ta[NPN])(ZrCP2) (2) in which the coordinated N-2 has been cleaved to form a phosphinimide bridging between Ta and Zr and a triply bridging nitride. The mechanism of this reaction was examined to determine the fate of the chloride and hydricle ligands attached to Zr in the starting zirconocene reagent. Using the zirconocene dihydride dimer ([Cp2ZrH2](2)), a higher yield of 2 was obtained (76\%), and H-2 was also observed by H-1 NMR spectroscopy. To probe the origin of the eliminated H-2, the dideuterated dinitrogen complex ([NPN]Ta)(2)(tLID)(2)(mu-eta(1):n(2)-N-2) (d(2)-1) was allowed to react with ([CP2ZrH2](2)), which resulted in the formation of ([NP(N)N]Ta)(mu-D)(2)(mu-N)(Ta[NPN]) (ZrCP2), (d(2)-2), with no evidence of hydrogen for deuterium scrambling between the starting zirconocene dihydride and the ditantalum dinitrogen complex. Studies into the use of preformed Zr(II) and Ti(II) reagents were also performed. The proposed mechanism involves initial adduct formation that facilitates inner-sphere electron transfer to cleave the N-N bond to form a species with bridging nitrides, one of which is transformed by nucleophilic attack of a phosphine donor to generate the observed phosphinimide.},
	keywords = {BOND-CLEAVAGE, BRIDGING N-2 UNIT, CLEAVAGE, COMPLEXES, dinitrogen coordination, END-ON, METAL-COMPLEXES, MOLECULAR, MOLYBDENUM-IRON PROTEIN, NITROGEN, nitrogen fixation, nitrogen-nitrogen bond, PHOSPHINIMIDE COMPLEXES, SIDE-ON, TANTALUM COMPLEX, TUNGSTEN},
	isbn = {0027-8424},
	url = {<Go to ISI>://000242249400008},
	author = {Spencer, L. P. and MacKay, B. A. and Patrick, B. O. and Fryzuk,Michael D.}
}
@article {1579,
	title = {N-N splitting of a functionalized mu-eta(1):eta(2) coordinated N-2 ligand leading to a mu-nitrido mu-imido core: mechanistic insight from DFT},
	journal = {Dalton Transactions},
	number = {9},
	year = {2006},
	note = {ISI Document Delivery No.: 021NKTimes Cited: 5Cited Reference Count: 35},
	pages = {1137-1140},
	type = {Article},
	abstract = {Silylation of a dinuclear tantalum complex containing a side- on end-on coordinated dinitrogen ligand initiates a sequence of reactions ultimately leading to a bis(mu-imido) structure. DFT is employed to determine the energetics of the entire reaction cascade. Particular emphasis is put on the unprecedented N-N cleavage reaction of the functionalized, mu-eta(1):eta(2) coordinated dinitrogen ligand. A mechanism for this reaction is derived theoretically and the corresponding transition state is determined.},
	keywords = {ammonia, ATOMS, BOND-CLEAVAGE, END-ON, MOLECULAR CALCULATIONS, POTENTIALS, REACTIVITY, SIDE-ON, SPECTROSCOPIC PROPERTIES, TANTALUM DINITROGEN COMPLEX},
	isbn = {1477-9226},
	url = {<Go to ISI>://000235989700003},
	author = {Studt, F. and MacKay, B. A. and Fryzuk,Michael D. and Tuczek, F.}
}
@article {1475,
	title = {Substituent effects in the hydrosilylation of coordinated dinitrogen in a ditantalum complex: Cleavage and functionalization of N-2},
	journal = {Journal of the American Chemical Society},
	volume = {128},
	number = {29},
	year = {2006},
	note = {ISI Document Delivery No.: 064WLTimes Cited: 19Cited Reference Count: 44MacKay, Bruce A. Munha, Rui F. Fryzuk, Michael D.},
	month = {Jul},
	pages = {9472-9483},
	type = {Article},
	abstract = {{The dinitrogen complex ([NPN]Ta)(2)(mu(1)-eta(2):eta(2)-N-2)(mu-H)(2), 1, (where [NPN] = (PhNSiMe2CH2)(2)PPh) 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)(mu-N-N-SiHnR3-n)(mu-H)(2)(Ta[NPN]) (5},
	keywords = {CATALYTIC-REDUCTION, END-ON, LIGAND, METAL-COMPLEXES, MOLECULAR NITROGEN, MOLYBDENUM, N BOND-CLEAVAGE, SIDE-ON, TERMINAL ALKYNES, TRIAMIDOAMINE COMPLEXES},
	isbn = {0002-7863},
	url = {<Go to ISI>://000239120700063},
	author = {MacKay, B. A. and Munha, R. F. and Fryzuk,Michael D.}
}
@article {1476,
	title = {Synthesis and reactivity of side-on-bound dinitrogen metal complexes},
	journal = {Organometallics},
	volume = {25},
	number = {7},
	year = {2006},
	note = {ISI Document Delivery No.: 025SVTimes Cited: 59Cited Reference Count: 107},
	month = {Mar},
	pages = {1530-1543},
	type = {Review},
	abstract = {An up-to-date account of the Synthesis of side-on-bound dinitrogen complexes of the lanthanides, the actinides, and the transition elements over the past 40 years is given. In addition, the reactivity of these derivatives is summarized. There have been many complicated multinuclear Cluster complexes with the N-2 imbedded in a fashion that corresponds to side-on N-2. There have been some suggestions, as early as 1960. that side-on dinitrogen complexes should exist. However, a key date in this area is 1988, which is when the disamarium Complex (CP*Sm-2)(2)(mu-eta(2):eta(2)-N-2) was reported. It is this date that is used in this account as the real starting point for the area of side-on dinitrogen coordination chemistry. After 1988, side-on dinitrogen complexes are reviewed from the point of view of Synthesis, structure (N-N bond lengths, where applicable), and reactivity. What becomes apparent is that while there have been many new side-on dinitrogen complexes discovered recently, investigations into their reactivity patterns are still at a primitive stage.},
	keywords = {BRIDGING N-2 UNIT, COORDINATED DINITROGEN, DINUCLEAR TANTALUM COMPLEX, ELECTRONIC-STRUCTURE, END-ON, MOLECULAR NITROGEN, NICKEL-LITHIUM COMPLEX, RAY CRYSTAL-STRUCTURE, REDUCTION SYSTEM, X-RAY},
	isbn = {0276-7333},
	url = {<Go to ISI>://000236288100002},
	author = {MacLachlan, E. A. and Fryzuk,Michael D.}
}
@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.}
}
@article {1252,
	title = {Cleavage of hydrazine and 1,1-dimethylhydrazine by dinuclear tantalum hydrides: Formation of imides, nitrides, and N,N-dimethylamine},
	journal = {Journal of the American Chemical Society},
	volume = {127},
	number = {2},
	year = {2005},
	note = {ISI Document Delivery No.: 887RZTimes Cited: 11Cited Reference Count: 21},
	month = {Jan},
	pages = {500-501},
	type = {Article},
	keywords = {BRIDGING N-2 UNIT, COORDINATION, DINITROGEN COMPLEX, END-ON, FUNCTIONALIZATION, LIGAND, METAL-COMPLEXES, N-N BOND, REDUCTIVE CLEAVAGE, SIDE-ON},
	isbn = {0002-7863},
	url = {<Go to ISI>://000226324500013},
	author = {Shaver, M. P. and Fryzuk,Michael D.}
}
@article {1185,
	title = {Functionalization and cleavage of coordinated dinitrogen via hydroboration using primary and secondary boranes},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {83},
	number = {4},
	year = {2005},
	note = {ISI Document Delivery No.: 921DLTimes Cited: 14Cited Reference Count: 30},
	month = {Apr},
	pages = {315-323},
	type = {Article},
	abstract = {The reaction of the side-on, end-on ditantalum dinitrogen complex ([NPN]Ta)(2)(mu-eta(1):eta(2)-N-2)(mu-H)(2) (where NPN = PhP(CH2SiMe2NPh)(2)) with a variety of secondary and primary boranes is reported. With 9-BBN, hydroboration of the Ta2N2 unit occurs via B-H addition, which in turn triggers a cascade of reactions that result in N-N bond cleavage, ancillary ligand rearrangement involving silicon group migration, and finally elimination of benzene from the N-Ph group and a B-H moiety to generate the imide-nitride derivative. In the presence of excess 9-BBN, the Lewis acid - base adduct of the imide-nitride ([NP mu-N]Ta(=NBC8H14)(mu-NB(H)C8H14)Ta[NPN]) is formed. A similar set of reactions is observed for dicyclohexylborane (Cy2BH), which hydroborates the dinitrogen complex to generate [NPN]Ta(H)(mu-eta(1):eta(2)-NNBCy2)(mu-H)(2)Ta[NPN], followed by loss of H-2 and silicon group migration to yield the imide-nitride [NP mu-N]Ta(=NBCy2)(mu-N)(Ta[NPN]. With thexyl borane (H2BCMe2CHMe2), a similar sequence of reactions is suggested starting with hydroboration to generate [NPN]Ta(H)(mu-eta(1):eta(2)-NNB(H)C6H13)(mu-H)(2)Ta[NPN], followed by loss of H-2 and ancillary ligand rearrangement. When bis(pentafluorophenyl)borane (HB(C6F5)(2)) is used, no hydroboration of coordinated N-2 is observed, rather simple adduct formation to give ([NPN]Ta)(2)(mu-eta(1):eta(2)-NN-B(H)(C6F5)(2))(mu-H)(2) occurs.},
	keywords = {ACTIVATION, ammonia, CHEMISTRY, DINITROGEN, END-ON, FIXATION, hydroboration, METAL-COMPLEXES, MOLECULAR NITROGEN, MOLYBDENUM, N-2, N-N bond cleavage, SIDE-ON, tantalum},
	isbn = {0008-4042},
	url = {<Go to ISI>://000228744300008},
	author = {MacKay, B. A. and Johnson, S. A. and Patrick, B. O. and Fryzuk,Michael D.}
}
@article {1186,
	title = {Hydroalumination of a dinuclear tantalum dinitrogen complex: N-N bond cleavage and ancillary ligand rearrangement},
	journal = {Organometallics},
	volume = {24},
	number = {16},
	year = {2005},
	note = {ISI Document Delivery No.: 949ZKTimes Cited: 15Cited Reference Count: 32},
	month = {Aug},
	pages = {3836-3841},
	type = {Article},
	abstract = {The addition of diisobutylaluminum hydride (DIBAL) to the side-on end-on dinitrogen complex ([NPN]Ta)(2)(mu-eta(1):eta(2)-N-2)(mu-H)(2), 1 (where [NPN] = (PhNSiMe2CH2)(2)PPh), is described. The two end products are diastereomeric rotational isomers in which N-N bond cleavage has occurred with an Al(Bu-i)H group attached to one of the nitride atoms. The reaction proceeds through addition of DIBAL to 1 to generate a thermally sensitive intermediate that has been characterized in solution as the result of Al-H addition across the TaN2 moiety, namely, ([NPN]TaH)(mu-eta(1):eta(2)-NNA1(i)Bu(2))(mu-H)(2)(Ta[NPN), 2. This material subsequently rearranges via a second thermally labile intermediate to ultimately generate two diastereomeric end products that show N-N bond cleavage, loss of H-2, loss of an aluminum isobutyl group, and NPN ligand migration from tantalum to aluminum. Both of these complexes have been isolated in crystalline form and analyzed by single-crystal X-ray diffraction. The second thermally sensitive intermediate has been characterized on the basis of multinuclear NMR spectroscopy as ([NPN]TaH)(mu-eta(1):eta(2)-(NNAlBu)-Bu-i(mu-H))(mu-H)(2)(Ta[NPN), 3.},
	keywords = {ACTIVATION, ATMOSPHERIC NITROGEN, CHEMISTRY, COORDINATED DINITROGEN, END-ON, FUNCTIONALIZATION, METAL-COMPLEXES, MOLECULAR NITROGEN, N-2, SIDE-ON},
	isbn = {0276-7333},
	url = {<Go to ISI>://000230827200007},
	author = {MacKay, B. A. and Patrick, B. O. and Fryzuk,Michael D.}
}
@article {1187,
	title = {A new arene-bridged diamidophosphine ligand and its coordination chemistry with zirconium(IV)},
	journal = {Organometallics},
	volume = {24},
	number = {6},
	year = {2005},
	note = {ISI Document Delivery No.: 904YFTimes Cited: 15Cited Reference Count: 48},
	month = {Mar},
	pages = {1112-1118},
	type = {Article},
	abstract = {The arene-bridged dilithium diamidophosphine ligand, [(2,4,6-Me3C6H2)NLi-2-(5-MeC6H3)](2)PPh, [NPN]*Li-2, was prepared from (2,4,6-Me3C6H2)(2-Br-4-MeC6H3)NH, (BuLi)-Bu-n, and PhPCl2 in Et2O and isolated as a dioxane adduct in similar to 85\% yield. The solid-state structure of [NPN]*Li-2(THF)2 as determined by X-ray diffraction shows both lithiums bridged by the amido nitrogens with one Li ion coordinated to the phosphine donor. The reaction of [NPN]*H-2 and Zr(NMe2)(4) in toluene produced [NPN]*Zr(NMe2)(2) in 90\% isolated yield. Addition of excess Me3SiCl to [NPN]*Zr(NMe2)(2) converts it to [NPN]*ZrCl2 in high yield. The solid-state structure of [NPN] *ZrCl2 as determined by X-ray diffraction shows the Zr center is a distorted trigonal bipyramid with the phosphine and the chloride apical. The ortho-Me{\textquoteright}s on the N-mesityl moiety are inequivalent in both the Li and Zr complexes of [NPN]* by NMR spectroscopy, while in [NPN]*H-2 MesN ortho-Me{\textquoteright}s appear as broad singlets. VT-NMR of [NPN]*H-2 indicated that Delta G(rot)(double dagger) of MesC(ipso)-N is approximately 15.5 +/- 0.3 kcal mol(-1). The thermally labile and light-sensitive zirconium dimethyl complex [NPN]*ZrMe2 was prepared from [NPN]*ZrCl2 and MeMgCl in Et2O in 80\% yield.},
	keywords = {CLEAVAGE, COMPLEX, COUPLING REACTIONS, DINITROGEN LIGAND, END-ON, METAL-COMPLEXES, MOLECULAR NITROGEN, N-2 UNIT, palladium, SIDE-ON, tantalum},
	isbn = {0276-7333},
	url = {<Go to ISI>://000227533800014},
	author = {MacLachlan, E. A. 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.}
}
@article {933,
	title = {Dinitrogen coordination chemistry: On the biomimetic borderlands},
	journal = {Chemical Reviews},
	volume = {104},
	number = {2},
	year = {2004},
	note = {ISI Document Delivery No.: 773QMTimes Cited: 189Cited Reference Count: 177},
	month = {Feb},
	pages = {385-401},
	type = {Review},
	keywords = {BRIDGING N-2 UNIT, DIPORPHYRIN, ELECTRONIC-STRUCTURE, END-ON, IRON-MOLYBDENUM COFACTOR, NITROGENASE FEMO-COFACTOR, RAY CRYSTAL-STRUCTURES, REDUCTIVE CLEAVAGE, RUTHENIUM COFACIAL, TRANSITION-METAL-COMPLEXES, VANADIUM DIAMIDOAMINE COMPLEX},
	isbn = {0009-2665},
	url = {<Go to ISI>://000188934400003},
	author = {MacKay, B. A. and Fryzuk,Michael D.}
}
@article {615,
	title = {Activation and functionalization of molecular nitrogen by metal complexes},
	journal = {Chemical Record},
	volume = {3},
	number = {1},
	year = {2003},
	note = {ISI Document Delivery No.: 669WPTimes Cited: 48Cited Reference Count: 52},
	pages = {2-11},
	type = {Article},
	abstract = {Molecular nitrogen is intrinsically unreactive, so much so that it has confounded chemists for decades in attempts to functionalize this abundant diatomic molecule. While biological systems and industrial processes can fix nitrogen to form ammonia, the challenge is to discover a process that involves a homogeneous catalyst that can utilize N-2 as a feedstock to generate higher value organonitrogen materials. In this review, the activation of molecular nitrogen by transition metal complexes is reviewed with the view to present new kinds of transformations for coordinated dinitrogen. Moreover, some reaction types that are as yet unknown are outlined to try and stimulate further research in this area. (C) 2003 The Japan Chemical Journal Forum and Wiley Periodicals, Inc.},
	keywords = {BRIDGING N-2 UNIT, CHEMISTRY, COORDINATED, COORDINATION CHEMISTRY, CRYSTAL-STRUCTURE, DINITROGEN, DINITROGEN COMPLEXES, END-ON, FIXATION, nitrogen fixation, nitrogenase, REDUCTION, SIDE-ON, transition metal complexes, ZIRCONIUM},
	isbn = {1527-8999},
	url = {<Go to ISI>://000182373700001},
	author = {Fryzuk,Michael D.}
}
@article {617,
	title = {Dinuclear organometallic dinitrogen complexes of niobium},
	journal = {Inorganica Chimica Acta},
	volume = {345},
	year = {2003},
	note = {ISI Document Delivery No.: 653EUTimes Cited: 4Cited Reference Count: 30},
	month = {Mar},
	pages = {53-62},
	type = {Article},
	abstract = {{The niobium(III) chloride precursors (R)[P2N2]NbCl stabilized by the bis-(amidophosphine) macrocycle (where (R)[P2N2] RP(CH2SiMe2NSiMe2CH2)(2)PR},
	keywords = {ACTIVATION, amidophosphine ligands, AZOBENZENE, CLEAVAGE, CRYSTAL-STRUCTURE, CRYSTALLOGRAPHY, DINITROGEN COMPLEXES, END-ON, FIXATION, fluxionality, macrocycle, macrocycles, N-2, NIOBIUM, NITRIDE, SIDE-ON},
	isbn = {0020-1693},
	url = {<Go to ISI>://000181422900008},
	author = {Fryzuk,Michael D. and Kozak, C. M. and Patrick, B. O.}
}
@article {618,
	title = {Hydrosilylation of a dinuclear tantalum dinitrogen complex: Cleavage of N-2 and functionalization of both nitrogen atoms},
	journal = {Journal of the American Chemical Society},
	volume = {125},
	number = {11},
	year = {2003},
	note = {ISI Document Delivery No.: 655MFTimes Cited: 54Cited Reference Count: 20},
	month = {Mar},
	pages = {3234-3235},
	type = {Article},
	keywords = {BONDS, CHEMISTRY, COORDINATED DINITROGEN, END-ON, FIXATION, LIGAND, REACTIVITY, REDUCTION, SIDE-ON, SILANES},
	isbn = {0002-7863},
	url = {<Go to ISI>://000181555600022},
	author = {Fryzuk,Michael D. and MacKay, B. A. and Patrick, B. O.}
}
@article {745,
	title = {Side-on bridging coordination of N-2: Spectroscopic characterization of the planar Zr2N2 core and theoretical investigation of its butterfly distortion},
	journal = {Chemistry-a European Journal},
	volume = {9},
	number = {2},
	year = {2003},
	note = {ISI Document Delivery No.: 638VDTimes Cited: 14Cited Reference Count: 37},
	month = {Jan},
	pages = {520-530},
	type = {Article},
	abstract = {The vibrational and electronic structure of the side-on N-2-bridged Zr complex [{(P2N2)Zr}(2)(u-n(2):n(2)-N-2)] (P2N2=PhP(CH2SiMe2NSiMe2CH2)(2)PPh) were analyzed. The vibrational characterization of the planar Zr2N2 core was based on resonance Raman and infrared spectroscopy. In the Raman spectrum, the N-N stretching band is found at 775 cm(-1) with an isotope shift of 22 cm(-1). Due to its appearance in many overtones and combination modes, the metal-metal stretch is assigned to the peak at 295 cm(-1). The two ungerade modes of the Zr2N2 core were identified in the infrared spectrum. Based on these four vibrations of the Zr2N2 unit, a quantum chemical assisted normal coordinate analysis (OCA-NCA) was performed. The force constants for the N-N and Zr-N bonds were calculated to be 1.53 and 2.58 mdyn Angstrom(-1), respectively. The butterfly distortion of the Zr2N2 unit obtained in DFT geometry optimizations of planar side-on N-2-bridged Zr complexes was analyzed in more detail. It was found that on bending of the Zr2N2 core, the lone pairs of the axial amide ligands are rotated by 90degrees. The bent Zr2N2 unit is 11 kcal mol(-1) lower in energy than the planar core due to a more uniform distribution of electron density between the metal atoms and NZ and delocalization of electron density from the amide ligands to the Zr2N2 unit. The spectroscopic implications of this distortion are analyzed.},
	keywords = {<P2N2>ZR(MU-ETA(2)-N-2)ZR<P2N2>, coordination modes, CRYSTAL-STRUCTURE, DIHYDROGEN, DINITROGEN COMPLEX, DINITROGEN COMPLEXES, END-ON, EXCHANGE, METAL, MOLECULAR CALCULATIONS, NITROGEN, POTENTIALS, REDUCTION, SPECTROSCOPY, vibrational, ZIRCONIUM},
	isbn = {0947-6539},
	url = {<Go to ISI>://000180592000018},
	author = {Studt, F. and Morello, L. and Lehnert, N. and Fryzuk,Michael D. and Tuczek, F.}
}
@article {734,
	title = {Vanadium and niobium diamidophosphine complexes and their reactivity},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {81},
	number = {12},
	year = {2003},
	note = {ISI Document Delivery No.: 751CNTimes Cited: 7Cited Reference Count: 27},
	month = {Dec},
	pages = {1431-1437},
	type = {Article},
	abstract = {The tridentate ligand precursors R{\textquoteright}P(CH2SiMe2NR")(2) ((R{\textquoteright}R{\textquoteright}{\textquoteright})[NPN]: R{\textquoteright} = Cy, Ph; R" = Ph, Mes, Me) were prepared from metathesis reactions of a lithiated amine, chloro(chloromethyl)dimethylsilane, the appropriate 1degrees phosphine, and n-butyl lithium and were isolated as solvent adducts. Metathesis between (CyPh)[NPN]Li-2(OEt2), 2, and VCl3(THF)(3) afforded ((CyPh)[NPN]VCl)(2), 7, whose solid-state structure was established by X-ray crystallography. Reduction attempts of the ((R{\textquoteright}R{\textquoteright}{\textquoteright})[NPN]VCl)(2) species with KC8 incorporated molecular nitrogen but were complicated by imide formation and ligand decomposition. Metathesis of 2 with NbCl2Me3 afforded the highly unstable complex (CyPh)[NPN]NbMe3, 15. Attempts to hydrogenate this species were unsuccessful.},
	keywords = {3-COORDINATE MOLYBDENUM(III), BRIDGING N-2 UNIT, COORDINATION, COORDINATION CHEMISTRY, DINITROGEN COMPLEX, END-ON, FUNCTIONALIZATION, HYDROGENATION, LIGAND, METATHESIS, NIOBIUM, REDUCTION, REDUCTIVE CLEAVAGE, SIDE-ON, TANTALUM COMPLEX, VANADIUM},
	isbn = {0008-4042},
	url = {<Go to ISI>://000187035400001},
	author = {Shaver, M. P. and Thomson, R. K. and Patrick, B. O. and Fryzuk,Michael D.}
}
@article {380,
	title = {Hydroboration of coordinated dinitrogen: A new reaction for the N-2 ligand that results in its functionalization and cleavage},
	journal = {Angewandte Chemie-International Edition},
	volume = {41},
	number = {19},
	year = {2002},
	note = {ISI Document Delivery No.: 604GZTimes Cited: 48Cited Reference Count: 30},
	pages = {3709-3712},
	type = {Article},
	keywords = {ACTIVATION, COMPLEX, DINITROGEN, END-ON, EXCHANGE, hydroboration, iron, MILD CONDITIONS, nitrides, NITROGEN, nitrogen fixation, REDUCTION, SIDE-ON, tantalum, TUNGSTEN},
	isbn = {1433-7851},
	url = {<Go to ISI>://000178609900046},
	author = {Fryzuk,Michael D. and MacKay, B. A. and Johnson, S. A. and Patrick, B. O.}
}
@article {378,
	title = {Nitride formation by thermolysis of a kinetically stable niobium dinitrogen complex},
	journal = {Journal of the American Chemical Society},
	volume = {124},
	number = {28},
	year = {2002},
	note = {ISI Document Delivery No.: 573QWTimes Cited: 46Cited Reference Count: 58},
	month = {Jul},
	pages = {8389-8397},
	type = {Article},
	abstract = {The reduction of [P2N2]NbCl (where [P2N2] = PhP(CH2SiMe2NSiMe2CH2)(2)PPh) with KC8 under a dinitrogen atmosphere generates the paramagnetic dinuclear dinitrogen complex ([P2N2]Nb)(2)(mu-N-2) (2). Complex 2 has been characterized crystallographically and by EPR spectroscopy. Variable-temperature magnetic susceptibility measurements indicate that 2 displays antiferromagnetic coupling between two Nb(IV) (d(1)) centers. A density functional theory calculation on the model complex [(PH3)(2)(NH2)(2)Nb](2)(mu-N-2) was performed. Thermolysis of ([P2N2]Nb)(2)(mu-N-2) in toluene generates the paramagnetic bridging nitride species where one N atom of the dinitrogen ligand inserts into the macrocycle backbone to form [P2N2]Nb(mu-N)Nb[PN3] (3) (where [PN3] = PhPMe(CHSiMe2NSiMe2CH2P(Ph)CH2SiMe2NSiMe2N)). Complex 3 has been characterized in the solid state as well as by variable-temperature magnetic susceptibility measurements. The reaction of ([P2N2]Nb)(2)(mu-N-2) with phenylacetylene displaces the dinitrogen fragment to generate a paramagnetic eta(2)-alkyne complex, [P2N2]Nb(eta(2)-HCCPh) (4).},
	keywords = {BRIDGING DINITROGEN, COORDINATED, DINITROGEN, END-ON, METAL-METAL BOND, MOLECULAR-STRUCTURE, {3-COORDINATE MOLYBDENUM(III)},
	isbn = {0002-7863},
	url = {<Go to ISI>://000176843200034},
	author = {Fryzuk,Michael D. and Kozak, C. M. and Bowdridge, M. R. and Patrick, B. O. and Rettig, S. J.}
}
