@article {699,
	title = {Thermal activation of hydrocarbon C-H bonds initiated by a tungsten allyl complex},
	journal = {Journal of the American Chemical Society},
	volume = {125},
	number = {49},
	year = {2003},
	note = {ISI Document Delivery No.: 750QETimes Cited: 12Cited Reference Count: 62},
	month = {Dec},
	pages = {15210-15223},
	type = {Article},
	abstract = {Gentle thermolysis of the allyl complex, (CpW)-W-*(NO)(CH2CMe3)(eta(3)-H2CCHCMe2) (1), at 50 degreesC in neat hydrocarbon solutions results in the loss of neopentane and the generation of transient intermediates that subsequently activate solvent C-H bonds. Thus, thermal reactions of 1 with tetramethylsilane, mesitylene, and benzene effect single C-H activations and lead to the exclusive formation of (CpW)-W-*(NO)(CH2SiMe3)(eta(3)-H2CCHCMe2) (2), (CpW)-W-*(NO)(CH2C6H3-3,5-Me-2)(eta(3)-H2CCHCMe2) (3), and (CpW)-W-*(NO)(C6H5)(eta(3)-H2CCHCMe2) (4), respectively. The products of reactions of 1 with other methyl-substituted arenes indicate an inherent preference of the system for the activation of stronger arene sp(2) C-H bonds. For example, C-H bond activation of p-xylene leads to the formation of (CpW)-W-*(NO)(CH2C6H4-4-Me)(eta(3)-H2CCHCMe2) (5) (26\%) and (CpW)-W-*(NO)(C6H3-2,5-Me-2)(eta(3)-H2CCHCMe2) (6) (74\%). Mechanistic and labeling studies indicate that the transient C-H-activating intermediates are the allene complex, (CpW)-W-*(NO)(eta(2)-H2C=C=CMe2) (A), and the eta(2)-diene complex, (CpW)-W-*(NO)(eta(2)-H2C=CHC(Me)=CH2) (B). Intermediates A and B react with cyclohexene to form (CpW)-W-*(NO)(eta(3)-CH2C(2-cyclohexenyl)CMe2)(H) (18) and (CpW)-W-*(NO)(eta(3)-CH2CHC)(Me)CH2CbetaH(C4H8)CalphaH (19), respectively, and intermediate A can be isolated as its PMe3 adduct, (CpW)-W-*(NO)(PMe3)(eta(2)-H2C=C=CMe2) (20). Interestingly, thermal reaction of 1 with 2,3-dimethylbut-2-ene results in the formation of a species that undergoes eta(3) {\textendash}> eta(1) isomerization of the dimethylallyl ligand following the initial C-H bond-activating step to yield (CpW)-W-*(NO)(eta(3)-CMe2CMeCH2)(eta(1)-CH2CHCMe2) (21). Thermolyses of 1 in alkane solvents afford allyl hydride complexes resulting from three successive C-H bond-activation reactions. For instance, 1 in cyclohexane converts to (CpW)-W-*(NO)(eta(3)-C6H9)(H) (22) with dimethylpropylcyclohexane being formed as a byproduct, and in methylcyclohexane it forms the two isomeric complexes, (CpW)-W-*(NO)(eta(3)-C7H11)(H) (23a,b). All new complexes have been characterized by conventional spectroscopic methods, and the solid-state molecular structures of 2, 3, 4, 18, 19, 20, and 21 have been established by X-ray crystallographic analyses.},
	keywords = {ALKYLIDENE COMPLEXES, ALLENE, CHEMICAL-PROPERTIES, COMPLEXES, CRYSTAL-STRUCTURE, ETA-3-ALLYL COMPLEXES, MOLECULAR-STRUCTURE, ORGANOMETALLIC NITROSYL CHEMISTRY, SOLID-STATE, STRUCTURAL CHARACTERIZATION, TRANSITION-METAL COMPLEXES},
	isbn = {0002-7863},
	url = {<Go to ISI>://000187007400050},
	author = {Ng, S. H. K. and Adams, C. S. and Hayton, T. W. and Legzdins,Peter and Patrick, B. O.}
}
@article {3295,
	title = {GENERATION AND REACTIVITY OF CP-ASTERISK-W(NO)(CH(2)SIME(3))H, A 16-VALENCE-ELECTRON ALKYL HYDRIDE COMPLEX},
	journal = {Organometallics},
	volume = {14},
	number = {5},
	year = {1995},
	note = {ISI Document Delivery No.: QX798Times Cited: 23Cited Reference Count: 48},
	month = {May},
	pages = {2543-2555},
	type = {Article},
	abstract = {Treatment of solutions of Cp*W(NO)(CH(2)SiMe(3))(2) with H-2 generates in situ the reactive 16-valence-electron alkyl hydride Cp*W(NO)(CH(2)SiMe(3))H, formed by hydrogenolysis of one of the W-C sigma-bonds of the dialkyl reactant. The Lewis-acidic hydride complex has not yet been isolated, but its existence has been inferred on the basis of the varied chemical reactions that it undergoes when generated in the presence of reactive substrates. PPh(3) affords the orthometalated complex Cp*W(NO)(H)(PPh(2)C(6)H(4)) as a yellow crystalline solid probably via the 18-electron adduct Cp*W(NO)(CH(2)SiMe(3))(PPh(3))H. Consistently, the same reaction effected with PPh(3)-d(15) results in complete deuteration of the hydride position in the product. Acyclic, conjugated dienes such as butadiene or 2,3-dimethyl-1,3-butadiene afford Cp*W(NO)(eta(4)-trans-diene) complexes. The characteristic chemistry of Cp*W(NO)(CH(2)SiMe(3))H is, however, dominated by the ability of its W-H link to insert unsaturated linkages, the regioselectivity of the insertions indicating that the hydride Ligand is hydridic in nature. For instance, insertion of acetonitrile affords the ethylideneamido complex Cp(*)W(NO)(CH(2)SiMe(3))(N=CHMe), which is isolable as a diastereomeric pair. Similarly, insertions of organic reagents containing carbonyl (O=C) or imine (HN=C) functional groups produce the corresponding alkyl alkoxide or alkyl amide products, respectively, in virtually quantitative yields. Phenylacetylene affords the novel alkyl alkenyl compound Cp*W(NO)(CH(2)SiMe(3))(CPh=CH2), which is thermally unstable and isolable in only low yields. Insertions into the W-H bond by other olefinic substrates are successful only if the unsaturated hydrocarbon also contains a Lewis-base functional group. Thus, propargylamine and allylamine produce the related metallacyclic complexes Cp*W(NO)(CH(2)SiMe(3))(NH2CH2CHCH) and Cp*W(NO)(CH(2)SiMe(3))(NH2CH2CH2CH2), respectively. Treatment of Cp*W(NO)(CH(2)SiMe(3))(2) with H-2 in the presence of allyl alcohol does not produce an oxometallacycle, but rather affords the allylalkoxo complex resulting from the alcohol simply functioning as a protonic acid toward the dialkyl reactant. The solid-state molecular structures of Cp*W(NO)(CH(2)SiMe(3))(N=CHMe) and Cp*W(NO)(CH(2)SiMe(3))(NH2CH2CH2CH2) have been established by single-crystal X-ray crystallographic analyses. Crystals of Cp*W(NO)(CH(2)SiMe(3))(N=CHMe) are monoclinic of space group P2(1)/n: a = 9.515(2) Angstrom; b = 21.946(3) Angstrom; c = 9.552(2) Angstrom; Z = 4; V = 1946.8 Angstrom(3); T = 200 K; R(f) = 0.029 for 2035 data (I-0 greater than or equal to 2.5 sigma(I-0)) and 106 variables. Crystals of Cp*W(NO)(CH(2)SiMe(3))(NH2CH2CH2CH2) are orthorhombic of sp ace group P2(1)2(1)2(1): a 11.417(4) Angstrom; b = 13.178(2) Angstrom; c 13.804(4) Angstrom; Z = 4; V = 2076.9 Angstrom(3); T = 200 K; R(f) = 0.020 for 2420 data (I-0 greater than or equal to 2.5 sigma(I-0)) and 208 variables.},
	keywords = {ACIDS, ALKENYL, CHEMICAL-PROPERTIES, {ACETYLENES},
	isbn = {0276-7333},
	url = {<Go to ISI>://A1995QX79800061},
	author = {Debad, J. D. and Legzdins,Peter and Lumb, S. A. and Batchelor, R. J. and Einstein, F. W. B.}
}
@article {7300,
	title = {ORGANOMETALLIC NITROSYL CHEMISTRY .54. REACTIONS OF 16-ELECTRON CP{\textquoteright}M(NO)R2 COMPLEXES OF MOLYBDENUM AND TUNGSTEN WITH WATER},
	journal = {Organometallics},
	volume = {11},
	number = {9},
	year = {1992},
	note = {ISI Document Delivery No.: JN066Times Cited: 29Cited Reference Count: 38},
	month = {Sep},
	pages = {2991-3003},
	type = {Article},
	abstract = {{The hydrolytic instability of Cp{\textquoteright}Mo(NO)R2 complexes (Cp{\textquoteright} = Cp (eta-5-C5H5), Cp* (eta-5-C5Me5); R = alkyl, aryl) becomes evident during attempts to synthesize them by procedures which have previously afforded the congeneric tungsten species. Thus, treatment of Cp*Mo(NO)I2 with 2 equiv of Me3SiCH2MgCl in Et2O at room temperature results in the formation of three organometallic complexes which are separable by chromatography on alumina. These products are (a) the expected alkylation product, i.e. the 16-valence-electron dialkyl complex Cp*Mo(NO)(CH2SiMe3)2 (1), (b) a novel bimetallic bridging-oxo complex, [CP*Mo(NO)(CH2SiMe3)]2(eta-O) (2), formed by hydrolysis of 1 during workup, and (c) a dimeric reduction product of the starting material, namely [Cp*Mo(NO)I]2 (3). Each of the complexes 1-3 has been fully characterized by conventional spectroscopic methods, and a single-crystal X-ray crystallographic analysis of 2 has also been performed. Crystal data for 2: triclinic, space group P1BAR},
	keywords = {BR, CHEMICAL-PROPERTIES, CP-STAR ETA-5-C5ME5, DIMETHYLHAFNOCENE, I), MO, REDUCTION BEHAVIOR, {<CP{\textquoteright}MO(NO)X2> RADICAL-ANIONS},
	isbn = {0276-7333},
	url = {<Go to ISI>://A1992JN06600010},
	author = {Legzdins,Peter and Lundmark, P. J. and Phillips, E. C. and Rettig, S. J. and Veltheer, J. E.}
}
@article {7068,
	title = {ORGANOMETALLIC NITROSYL CHEMISTRY .43. SYNTHESIS, CHARACTERIZATION, AND PHYSICAL-PROPERTIES OF UNUSUAL CYCLOPENTADIENYL BIS(BENZYL) NITROSYL COMPLEXES OF MOLYBDENUM AND TUNGSTEN},
	journal = {Organometallics},
	volume = {10},
	number = {4},
	year = {1991},
	note = {ISI Document Delivery No.: FG976Times Cited: 44Cited Reference Count: 52},
	month = {Apr},
	pages = {986-1002},
	type = {Article},
	abstract = {{Treatment of either the dichloro or diiodo nitrosyl precursors Cp{\textquoteright}M(NO)X2 (Cp{\textquoteright} = Cp (eta-5-C5H5) or Cp* (eta-5-C5Me5); M = Mo or W; X = Cl or I) in THF/Et2O with 2 equiv of a benzyl Grignard reagent, Ph{\textquoteright}CH2MgCl (Ph{\textquoteright} = C6H5 or 2,4,6-Me3C6H2), at 0-degrees-C affords the corresponding bis(benzyl) nitrosyl complexes, Cp{\textquoteright}M(NO)(CH2Ph{\textquoteright})2, isolated yields typically being 50-65\%. All the bis(benzyl) nitrosyl complexes are relatively high melting (143-163-degrees-C), orange-red, diamagnetic solids that are soluble in most common organic solvents. They are all stable to air in the solid state for at least 2 months, and only solutions of the tungsten species react with O2 to produce moderate yields of the corresponding dioxo benzyl complexes, Cp{\textquoteright}W(O)2(CH2Ph{\textquoteright}). The spectroscopic properties of the bis(benzyl) complexes are consistent with their possessing 18-electron, monomeric Cp{\textquoteright}M(NO)(eta-1-CH2Ph{\textquoteright})(eta-2-CH2Ph{\textquoteright}) molecular structures. Variable-temperature H-1 and C-13{H-1} NMR spectra of all the compounds in CD2Cl2 establish that they are stereochemically nonrigid in solutions at ambient temperatures, the principal fluxionality involving the two benzyl ligands exchanging their modes of attachment to the metal centers. C-13 NMR spectroscopy also establishes that the low-temperature limiting structures of the complexes in solution are identical with their solid-state molecular structures. Interestingly, the tungsten bis(benzyl) complexes exhibit the more facile fluxional processes in solution, this increased nonrigidity apparently rendering the tungsten complexes more reactive to Lewis bases. Crystal structure analyses of the five bis(benzyl) nitrosyl complexes have been performed in order to establish their solid-state molecular structures. Crystals of CpMo(NO)(CH2Ph)2 (1a) are orthorhombic, Pbca, with a = 10.122 (1) angstrom},
	keywords = {CARBONYL-COMPLEXES, CHEMICAL-PROPERTIES, COMPLEXES, LIGAND, NICKEL, OXO, PENTAFULVENES, RAY CRYSTAL-STRUCTURE},
	isbn = {0276-7333},
	url = {<Go to ISI>://A1991FG97600034},
	author = {Legzdins,Peter and Jones, R. H. and Phillips, E. C. and Yee, V. C. and Trotter, J. and Einstein, F. W. B.}
}
@article {7068,
	title = {ORGANOMETALLIC NITROSYL CHEMISTRY .43. SYNTHESIS, CHARACTERIZATION, AND PHYSICAL-PROPERTIES OF UNUSUAL CYCLOPENTADIENYL BIS(BENZYL) NITROSYL COMPLEXES OF MOLYBDENUM AND TUNGSTEN},
	journal = {Organometallics},
	volume = {10},
	number = {4},
	year = {1991},
	note = {ISI Document Delivery No.: FG976Times Cited: 44Cited Reference Count: 52},
	month = {Apr},
	pages = {986-1002},
	type = {Article},
	abstract = {{Treatment of either the dichloro or diiodo nitrosyl precursors Cp{\textquoteright}M(NO)X2 (Cp{\textquoteright} = Cp (eta-5-C5H5) or Cp* (eta-5-C5Me5); M = Mo or W; X = Cl or I) in THF/Et2O with 2 equiv of a benzyl Grignard reagent, Ph{\textquoteright}CH2MgCl (Ph{\textquoteright} = C6H5 or 2,4,6-Me3C6H2), at 0-degrees-C affords the corresponding bis(benzyl) nitrosyl complexes, Cp{\textquoteright}M(NO)(CH2Ph{\textquoteright})2, isolated yields typically being 50-65\%. All the bis(benzyl) nitrosyl complexes are relatively high melting (143-163-degrees-C), orange-red, diamagnetic solids that are soluble in most common organic solvents. They are all stable to air in the solid state for at least 2 months, and only solutions of the tungsten species react with O2 to produce moderate yields of the corresponding dioxo benzyl complexes, Cp{\textquoteright}W(O)2(CH2Ph{\textquoteright}). The spectroscopic properties of the bis(benzyl) complexes are consistent with their possessing 18-electron, monomeric Cp{\textquoteright}M(NO)(eta-1-CH2Ph{\textquoteright})(eta-2-CH2Ph{\textquoteright}) molecular structures. Variable-temperature H-1 and C-13{H-1} NMR spectra of all the compounds in CD2Cl2 establish that they are stereochemically nonrigid in solutions at ambient temperatures, the principal fluxionality involving the two benzyl ligands exchanging their modes of attachment to the metal centers. C-13 NMR spectroscopy also establishes that the low-temperature limiting structures of the complexes in solution are identical with their solid-state molecular structures. Interestingly, the tungsten bis(benzyl) complexes exhibit the more facile fluxional processes in solution, this increased nonrigidity apparently rendering the tungsten complexes more reactive to Lewis bases. Crystal structure analyses of the five bis(benzyl) nitrosyl complexes have been performed in order to establish their solid-state molecular structures. Crystals of CpMo(NO)(CH2Ph)2 (1a) are orthorhombic, Pbca, with a = 10.122 (1) angstrom},
	keywords = {CARBONYL-COMPLEXES, CHEMICAL-PROPERTIES, COMPLEXES, LIGAND, NICKEL, OXO, PENTAFULVENES, RAY CRYSTAL-STRUCTURE},
	isbn = {0276-7333},
	url = {<Go to ISI>://A1991FG97600034},
	author = {Legzdins,Peter and Jones, R. H. and Phillips, E. C. and Yee, V. C. and Trotter, J. and Einstein, F. W. B.}
}
@article {7004,
	title = {ORGANOMETALLIC NITROSYL CHEMISTRY .45. IMPROVED SYNTHESES OF CYCLOPENTADIENYL DICHLORO NITROSYL COMPLEXES OF MOLYBDENUM AND TUNGSTEN - UTILITY OF PHOSPHORUS-PENTACHLORIDE AS A CHLORINATING AGENT},
	journal = {Organometallics},
	volume = {10},
	number = {6},
	year = {1991},
	note = {ISI Document Delivery No.: FQ933Times Cited: 33Cited Reference Count: 30},
	month = {Jun},
	pages = {2077-2081},
	type = {Note},
	abstract = {Treatment of Cp{\textquoteright}M(NO)(CO)2 (Cp{\textquoteright} = Cp (eta-5-C5H5) or Cp* (eta-5-C5Me5); M = Mo or W) with an equimolar amount of PCl5 in Et2O at 20-degrees-C results in the efficient, high-yield (80-95 \%) syntheses of the corresponding [Cp{\textquoteright}M(NO)Cl2]2 complexes. The product complexes have been fully characterized by conventional analytical and spectroscopic methods, including a single-crystal X-ray crystallographic analysis of [Cp*Mo(NO)Cl2]2, which reveals a dimeric molecular configuration, the piano-stool monomers being linked through bridging chlorine atoms.},
	keywords = {16-ELECTRON COMPLEX, CHEMICAL-PROPERTIES, CRYSTAL, ETA-5-C5H5, LIGANDS, MO},
	isbn = {0276-7333},
	url = {<Go to ISI>://A1991FQ93300067},
	author = {Dryden, N. H. and Legzdins,Peter and Batchelor, R. J. and Einstein, F. W. B.}
}
@article {6989,
	title = {ORGANOMETALLIC NITROSYL CHEMISTRY .47. CYCLOPENTADIENYL(ETA(4)-TRANS-DIENE)NITROSYLMOLYBDENUM COMPLEXES AND THEIR REACTIVITIES TOWARD ACETYLENES AND PROTONIC ACIDS},
	journal = {Organometallics},
	volume = {10},
	number = {9},
	year = {1991},
	note = {ISI Document Delivery No.: GF405Times Cited: 19Cited Reference Count: 25},
	month = {Sep},
	pages = {3070-3080},
	type = {Article},
	abstract = {{Reduction of [Cp*Mo(NO)I2]2 [CP* = eta-5-C5Me5] by sodium amalgam in THF at -30-degrees-C in the presence of an isomeric mixture of (E)- and (Z)-1,3-pentadiene affords two isolable isomers of Cp*Mo(NO)(eta-4-trans-1,3-pentadiene), one yellow (1A) and one red (1B). The most significant feature of the solid-state molecular structure of 1A is the fact that the transoidal (E)-1,3-pentadiene ligand is coordinated to the molybdenum with its methyl substituent pointing away from the cyclopentadienyl ring. The spectroscopic properties of 1B are consistent with it possessing a similar orientation of its (Z)-1,3-diene methyl substituent. This observation establishes that even though the Cp*Mo(NO) fragment in 1A and 1B exerts the electronic influence to bind the diene ligands in a twisted, transoidal fashion, steric interactions determine which face of the diene ligand can best accommodate this electronic requirement. Cyclic voltammetry studies have been carried out on two representative diene-containing compounds, namely CpMo(NO)(eta-4-trans-2,5-dimethyl-2,4-hexadiene) and CpMo(NO)(eta-4-cis-2,3-dimethylbutadiene) (Cp = eta-5-C5H5), in order to establish the redox properties of these types of complexes. The cyclic voltammograms indicate that both diene complexes are reasonably stable with respect to addition of electrons, since no reduction behavior is observed to the limit of the CH2Cl2 solvent (ca. -2 V). On the other hand, each of the complexes is quite readily oxidized and each exhibits three irreversible oxidations before the solvent limit of ca. +2 V. These redox properties are in accord with the results of Fenske-Hall molecular orbital calculations previously performed on the CpMo(NO)(eta-4-butadiene) model systems. Consistently, CpMo(NO)(eta-4-trans-2,5-dimethyl-2,4-hexadiene) does not undergo concomitant reduction when treated with acetylenes but rather effects a coupling between the diene ligand and the alkyne to produce a eta-4 (eta-3, eta-1) ligand in which the eta-3-allyl portion of the ligand is oriented endo with respect to the cyclopentadienyl ring. Thus, when the alkyne employed is 1-phenylpropyne, the resulting complex is CpMo(NO)[eta-4-C(Me)2CHCHC(Me)2C(Me)C(Ph)] (2), whose molecular structure has been established by specialized NMR spectroscopic techniques and by single-crystal X-ray crystallography. The reaction between CpMo(NO)(eta-4-trans-2,5-dimethyl-2,4-hexadiene) and 1,7-octadiyne affords two major isomers of a similar organometallic product. Finally, the isolable products of the reactions between CpMo(NO)(eta-4-trans-diene) and HX (diene = 2,5-dimethyl-2,4-hexadiene},
	keywords = {ALKYNES, CHEMICAL-PROPERTIES, CHROMIUM, DIENES, LIGANDS},
	isbn = {0276-7333},
	url = {<Go to ISI>://A1991GF40500020},
	author = {Christensen, N. J. and Legzdins,Peter and Einstein, F. W. B. and Jones, R. H.}
}
