@article {2494,
	title = {N,O-Chelates of Group 4 Metals: Contrasting the Use of Amidates and Ureates in the Synthesis of Metal Dichlorides},
	journal = {European Journal of Inorganic Chemistry},
	number = {18},
	year = {2009},
	note = {ISI Document Delivery No.: 467LNTimes Cited: 5Cited Reference Count: 69Leitch, David C. Beard, J. David Thomson, Robert K. Wright, Vincent A. Patrick, Brian O. Schafer, Laurel L.},
	month = {Jun},
	pages = {2691-2701},
	type = {Article},
	abstract = {A series of dichloride complexes of titanium and zirconium with amidate and ureate ancillary ligands have been prepared, Three examples of bis(amidate)dichlorotitanium and zirconium complexes were effectively synthesized through salt metathesis with metal tetrachloride as starting materials. Optimum results were achieved using sodium amidate salts formed from sodium bis(trimethylsilyl)amide and neutral amide proligands, while other methods were ineffective. Use of electron-donating ureate ligands in lieu of amidates enables preparation through alternate routes. Protonolysis of Ti(NMe2)(2)Cl-2 and Zr(NMe2)(2)Cl-2(dme) with urea proligands leads to dichlorobis(ureate) complexes in good yield. Using a tethered bis(ureate) ligand eliminates the fluxional behaviour and coordination isomerism observed for both bis(amidate) and bis(ureate) zirconium complexes. ((C) Wiley-VCH Verlag GmbH \& Co. KGaA, 69451 Weinheim, Germany, 2009)},
	keywords = {amidate, BIS(AMIDATE) TITANIUM PRECATALYST, CATALYTIC, Chelates, COORDINATION CHEMISTRY, EARLY, GUANIDINATE LIGANDS, HYDROAMINATION, INTERMOLECULAR HYDROAMINATION, N, O ligands, OLEFIN POLYMERIZATION, SOLUTION DYNAMICS, STRUCTURAL-CHARACTERIZATION, TITANIUM, TRANSITION-METALS, Ureate, ZIEGLER-NATTA POLYMERIZATION, ZIRCONIUM},
	isbn = {1434-1948},
	url = {<Go to ISI>://000267740500015},
	author = {Leitch, D. C. and Beard, J. D. and Thomson, R. K. and Wright, V. A. and Patrick, B. O. and Schafer, L. L.}
}
@article {2197,
	title = {trans-Disubstituted diamido/diamine cyclam zirconium complexes},
	journal = {Inorganic Chemistry Communications},
	volume = {11},
	number = {10},
	year = {2008},
	note = {ISI Document Delivery No.: 367KCTimes Cited: 6Cited Reference Count: 24Munha, Rui F. Alves, Luis G. Maulide, Nuno Duarte, M. Teresa Marko, Istvan E. Fryzuk, Michael D. Martins, Ana M.},
	month = {Oct},
	pages = {1174-1176},
	type = {Article},
	abstract = {The reaction of H-2[1,8-dibenzyl-1,4,8,11-tetraazacyclotetradecanel (H(2)Bn(2)CYclam) with 2 equiv of LiBu gives Li(2)Bn(2)Cyclam(L)2 (L = Et2O or THF) that reacts with ZrCl4(THF)(2) to afford (Bn(2)Cyclam)ZrCl2 in 40\% yield. Alternatively (Bn(2)Cyclam)ZrCl2 may be obtained via ZrCl2(CH2SiMe3)(2)(Et2O)(2) in a significantly higher yield (87\%), avoiding the lithiation of H(2)Bn(2)Cyclam. The syntheses of other H-2*Bn(2)CYClaM ligand precursors (*Bn = 3,5-dimethylbenzyl and 3,5-di(tert-butyl)benzyl) and the corresponding Zr derivatives ({3,5-Me2Bn}(2)-Cyclam)ZrCl2 and ({3,5-(Bu2Bn)-Bu-t}(2)-Cyclam)ZrCl2 are also reported. Results on preliminary tests of E-caprolactone and ethylene polymerisation reactions are presented. (C) 2008 Elsevier B.V. All rights reserved.},
	keywords = {amido ligands, CATALYSTS, CHEMISTRY, CONTAIN, Cyclam, epsilon-Caprolactone polymerisation, ETHYLENE, HAFNIUM COMPLEXES, LIGANDS, macrocycles, OLEFIN POLYMERIZATION, polymerisation, Tetraazamacrocycles, TITANIUM COMPLEXES, ZIRCONIUM},
	isbn = {1387-7003},
	url = {<Go to ISI>://000260549900019},
	author = {Munha, R. F. and Alves, L. G. and Maulide, N. and Duarte, M. T. and Marko, I. E. and Fryzuk,Michael D. and Martins, A. M.}
}
@article {1287,
	title = {Structure, bonding, and reactivity of Ti and Zr amidate complexes: DFT and X-ray crystallographic studies},
	journal = {Inorganic Chemistry},
	volume = {44},
	number = {24},
	year = {2005},
	note = {ISI Document Delivery No.: 986ZLTimes Cited: 21Cited Reference Count: 75},
	month = {Nov},
	pages = {8680-8689},
	type = {Article},
	abstract = {Easily prepared and highly modular organic amide proligands have been used to synthesize a series of new bis(amidate)-bis(amido) Ti and Zr complexes via protonolysis. These complexes have been structurally characterized by NMR spectroscopy and X-ray crystallography. The solid-state molecular structures of these complexes indicate that the amidate ligands bind to the metal centers in an exclusively bidentate fashion, resulting in discrete monomeric species. Geometric isomerism in these species is highly dependent upon the steric characteristics of the proligands utilized in the synthesis. In solution, these complexes are observed to isomerize on the NMR time scale, with one isomer being predominant. Bonding in the bis(amidate)-bis(amido) complexes was investigated by DFT calculations. The geometric isomers predicted by theory matched the experimentally observed results, within experimental error. The orbitals associated with amidate-metal bonding are energetically well below the frontier orbitals. The HOMO in these complexes is a pi orbital associated with amido ligand-to-metal bonding character, while the LUMO in all cases is a vacant d orbital on the metal center.},
	keywords = {ALKYNYL GROUPS, C-H BONDS, ENHANCED REACTIVITY, HYDROAMINATION, IMIDO COMPLEXES, INTERMOLECULAR, OLEFIN POLYMERIZATION, PROPYLENE POLYMERIZATION, SI-H, TITANIUM CATALYSTS, ZIRCONIUM(IV) COMPLEXES},
	isbn = {0020-1669},
	url = {<Go to ISI>://000233488100008},
	author = {Thomson, R. K. and Zahariev, F. E. and Zhang, Z. and Patrick, B. O. and Wang, Y. A. and Schafer, L. L.}
}
@article {1287,
	title = {Structure, bonding, and reactivity of Ti and Zr amidate complexes: DFT and X-ray crystallographic studies},
	journal = {Inorg. Chem.},
	volume = {44},
	number = {24},
	year = {2005},
	note = {ISI Document Delivery No.: 986ZLTimes Cited: 21Cited Reference Count: 75},
	month = {Nov},
	pages = {8680-8689},
	type = {Article},
	abstract = {<p>Easily prepared and highly modular organic amide proligands have been used to synthesize a series of new bis(amidate)-bis(amido) Ti and Zr complexes via protonolysis. These complexes have been structurally characterized by NMR spectroscopy and X-ray crystallography. The solid-state molecular structures of these complexes indicate that the amidate ligands bind to the metal centers in an exclusively bidentate fashion, resulting in discrete monomeric species. Geometric isomerism in these species is highly dependent upon the steric characteristics of the proligands utilized in the synthesis. In solution, these complexes are observed to isomerize on the NMR time scale, with one isomer being predominant. Bonding in the bis(amidate)-bis(amido) complexes was investigated by DFT calculations. The geometric isomers predicted by theory matched the experimentally observed results, within experimental error. The orbitals associated with amidate-metal bonding are energetically well below the frontier orbitals. The HOMO in these complexes is a pi orbital associated with amido ligand-to-metal bonding character, while the LUMO in all cases is a vacant d orbital on the metal center.</p>},
	keywords = {ALKYNYL GROUPS, C-H BONDS, ENHANCED REACTIVITY, HYDROAMINATION, IMIDO COMPLEXES, INTERMOLECULAR, OLEFIN POLYMERIZATION, PROPYLENE POLYMERIZATION, SI-H, TITANIUM CATALYSTS, ZIRCONIUM(IV) COMPLEXES},
	isbn = {0020-1669},
	url = {<Go to ISI>://000233488100008},
	author = {Thomson, R. K. and Zahariev, F. E. and Zhang, Z. and Patrick, B. O. and Y. A. Wang* and L. L. Schafer*}
}
@article {5196,
	title = {The elusive 16-electron Cp*M(NO)Me-2 (M = Mo, W) complexes and their spontaneous conversions to Cp*M(NMe)(O)Me isomers},
	journal = {Journal of the American Chemical Society},
	volume = {123},
	number = {26},
	year = {2001},
	note = {ISI Document Delivery No.: 447QPTimes Cited: 17Cited Reference Count: 115},
	month = {Jul},
	pages = {6272-6282},
	type = {Review},
	abstract = {Treatment of [Cp*Mo(NO)Cl mu(-Cl)](2) with magnesium (Me2Mg.dioxane, MeMgCl) or aluminum (Me3Al) methylating reagents affords the known compound [Cp*Mo(NO)Me(mu 0Cl)](2) (1). Similar treatment of the dicbloro precursor with MeLi in ethereal solvents generates an equimolar mixture of 1 and the trimethyl "ate" complex, Cp*MoMe3(NO-Li(OEt2)(n)). (2-Et2O). Reaction of 2-Et2O with a source of [Me](+) forms Cp*MoMe3(dropN-OMe) (3), a rare terminal alkoxylimido complex. Metathesis of the chloro ligands of [Cp*Mo-(NO)Cl(mu -Cl)](2) by MeLi in toluene at low temperatures produces the target dimethyl complex. Cp*Mo(NO)-Me-2 (4). in 75\% isolated yield. In solution, 4 is predominantly a monomeric species, whereas in the solid state it adopts a dimeric or oligomeric structure containing isonitrosyl bridges as indicated by IR and N-15/C-13 NMR spectroscopies. Hydrolysis of 4 affords meso- and rac-[Cp*Mo(NO)Me](2)(mu -O)(5), and the reactions of 4 with a range of Lewis bases. L, to form the 18e adducts Cp*Mo(NO)(L)Me-2 (e.g., Cp*Mo(NO)(PMe3)Me-2 (7)), have established it to be the most electrophilic complex of its family. Acidolysis of the methyl groups of 4 is also facile. Most notably, 4 is thermally unstable in solution and undergoes isomerization via nitrosyl N-O bond cleavage to its oxo(imido) form, Cp*Mo(NMe)(O)Me (11), which is isolable from the final reaction mixture as the mu -oxo-bridged adduct formed by 4 and 11, i.e., Cp*Mo(NO)Me2(mu -O)Cp*Mo(NMe)Me (4 <{\textendash} 11). The rate of this isomerization is significantly faster for the tungsten dimethyl complex; hence, Cp*W(NO)- (NO)Me-2 (12) is not isolable free of a supporting donor interaction and can only be isolated as Cp*W(NO)-Me-2(mu -O)Cp*W(NMe)Me (12 <{\textendash} 13) or Cp*W(NO)Me-2(PMe3) (14) adducts.},
	keywords = {ALPHA-OLEFINS, COORDINATED NITRIC-OXIDE, CRYSTAL-STRUCTURE, EFFECTIVE CORE POTENTIALS, INSERTION, LIGAND REDISTRIBUTION REACTIONS, MIGRATORY, MOLECULAR CALCULATIONS, OLEFIN POLYMERIZATION, ORGANOMETALLIC NITROSYL CHEMISTRY, POLYMERIZATION CATALYSTS},
	isbn = {0002-7863},
	url = {<Go to ISI>://000169584200009},
	author = {Sharp, W. B. and Daff, P. J. and McNeil, W. S. and Legzdins,Peter}
}
@article {5078,
	title = {Synthesis, structure, and reactivity of diamidophosphine complexes of yttrium and the lanthanides},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {79},
	number = {7},
	year = {2001},
	note = {ISI Document Delivery No.: 473RETimes Cited: 10Cited Reference Count: 17},
	month = {Jul},
	pages = {1194-1200},
	type = {Article},
	abstract = {The reaction of the dilithiodiamidophosphine ligand precursor PhP(CH2SiMe2NPh)(2)Li-2(THF)(2)([NPN]Li-2(THF)(2)) with LnCl(3)(THF)(3) (Ln = Y, Sm, Ho. Yb. Lu; THF = tetrahydrofuran) in refluxing toluene generates the mononuclear complexes [NPN]LnCI(THF) in good yield. The molecular structures have been shown to be five-coordinate in the solid state and in solution. Attempts to prepare alkyl derivatives have only met with partial success; the reaction of MeMgCl with [NPN]YCl(THF) generates the partially characterized mixed-metal derivative [NPN]YMe2MgCl. The reaction with LiAlH4 results in complete ligand exchange and the formation of the tetranuclear lithium aluminum hydride derivative ([NPN]AlH2Li(THF))(2). Reduction of the lutetium derivative with KC8 and naphthalene generated the dinuclear naphthalene-bridged species {[NPN]Lu}(2)(mu-eta (4):eta (4)-C10H8) wherein each Lu centre engages in eta (4)-coordination to opposite sides of the arene moiety. X-ray crystallography was used to characterize the four complexes.},
	keywords = {aluminum, BRIDGING N-2 UNIT, CATALYSTS, CRYSTAL-STRUCTURE, DINITROGEN, F-BLOCK METALS, lanthanides, LIGAND, lithium, mixed-donor ligands, NAPHTHALENE, OLEFIN POLYMERIZATION, SIDE-ON, TERTIARY PHOSPHINE COMPLEXES, YTTRIUM},
	isbn = {0008-4042},
	url = {<Go to ISI>://000171061200016},
	author = {Fryzuk,Michael D. and Yu, P. H. and Patrick, B. O.}
}
@article {4326,
	title = {Density functional study of spin state in CpM(NO)X-2 (M=Mo, Cr; X=Cl, NH2, CH3): Spectrochemical and nephelauxetic effects in organometallic compounds},
	journal = {Organometallics},
	volume = {17},
	number = {4},
	year = {1998},
	note = {ISI Document Delivery No.: YY508Times Cited: 19Cited Reference Count: 83},
	month = {Feb},
	pages = {615-622},
	type = {Article},
	abstract = {The relationship between spin state and metal-ligand bonding interactions in CpM(NO)Xa species was investigated using density functional computational techniques. The geometries of CpM(NO)Cl-2 (M = Cr, Mo), CpCr(NO)(NH2)X, and CpCr(NO)(CH3)X (X = Cl, CH3) were optimized at the DFT-B3LYP level for both the diamagnetic (S = 0) and paramagnetic (S = 1) electronic configurations. While the geometric parameters of the singlet compounds matched well with structures determined experimentally, the Cr-NO bond lengths in the triplet Species exceeded the experimentally observed range by a significant margin, thereby indicating a propensity for nitrosyl-ligand dissociation from the high-spin complexes. The order of relative singlet vs triplet spin-state stability (expressed as Delta Es-t (kcal/mol)) was determined to be CpCr(NO)Cl-2 (8.20) > CpCr(NO)(CH3)Cl (1.52) approximate to CpCr(NO)(NH2)Cl (0.95), > CpCr(NO)(CH3)(2) (-2.37) > CpCr(NO)(NH2)CH3 (-9.55) > CpMQ(NO)Cl-2 (-17.62). The amide pi-donation increases the HOMO-LUMO energy splitting, thus favoring the diamagnetic configuration. The alkyl ligand reduces the electron-electron repulsion through orbital expansion, thereby lowering the relative energy of the singlet state. Extended Huckel molecular-orbital calculations were performed on the DFT-optimized structures to help rationalize the metal-ligand bonding interactions, and interelectron repulsions were quantified by evaluation of the Coulomb (S) and exchange (K) integrals based on the B3LYP-optimized triplet spin-state geometries.},
	keywords = {DINITROGEN CLEAVAGE, EFFECTIVE CORE POTENTIALS, GROUP-6 COMPLEXES, LIGANDS, MOLECULAR CALCULATIONS, NITROSYL CHEMISTRY, OLEFIN POLYMERIZATION, PI-ACCEPTOR, POLYMERIZATION CATALYSTS, TRANSITION-METAL COMPLEXES, X-RAY},
	isbn = {0276-7333},
	url = {<Go to ISI>://000072154500023},
	author = {Legzdins,Peter and McNeil, W. S. and Smith, K. M. and Poli, R.}
}
