@article {2366, title = {Calorimetric studies of the interaction between the insulin-enhancing drug candidate bis(maltolato)oxovanadium(IV) (BMOV) and human serum apo-transferrin}, journal = {Journal of Inorganic Biochemistry}, volume = {103}, number = {4}, year = {2009}, note = {ISI Document Delivery No.: 429EUTimes Cited: 8Cited Reference Count: 31Bordbar, Abdol-Khalegh Creagh, A. Louise Mohammadi, Fakhrossadat Haynes, Charles A. Orvig, Chris6th International Vanadium SymposiumJUL 17-19, 2008Lisbon, PORTUGALSp. Iss. SI}, month = {Apr}, pages = {643-647}, type = {Proceedings Paper}, abstract = {Bis(maltolato)oxovanadium(IV) (BMOV), and its ethylmaltol analog, bis(ethymaltolato)oxovanadium(IV) (BEOV), are candidate insulin-enhancing agents for the treatment of type 2 diabetes mellitus; in mid-2008, BEOV advanced to phase 11 clinical testing. The interactions of BMOV and its inorganic congener, vanadyl Sulfate (VOSO4), with human serum apo-transferrin (hTf) were investigated using differential scanning calorimetry (DSC). Addition of BMOV or VOSO4 to apo-hTf resulted in an increase in thermal stability of both the C- and N-lobes of transferrin as a result of binding to either vanadyl compound. A series of DSC thermograms of hTf Solutions containing different molar ratios of BMOV and VOSO4 were used to determine binding constants: at 25 degrees C the binding constants of BMOV to the C- and N-lobes of apo-hTf were found to be 3 (+/- 1) x 10(5) and 1.8 (+/- 0.7) x 10(5) M-1, respectively. The cot-responding values for VOSO4 were 1.7 (+/- 0.3) x 10(5) and 7 (+/- 2) x 10(4) M-1. The results show that the vanadium species initially presented as either BMOV or VOSO4 had similar affinities for human serum transferrin due to oxidation of solvated vanadyl(IV) prior to complexation to transferrin. Binding of metavanadate (VO3-) was confirmed by DSC and isothermal titration calorimetry (ITC) experiments of the interaction between sodium metavanadate (NaVO3) and hTf. (C) 2008 Elsevier Inc. All rights reserved.}, keywords = {Apo-transferrin, BINDING, BIS(MALTOLATO)OXOVANADIUM(IV), CHEMISTRY, COMPLEXES, Insulin-enhancing, iron, MALTOL, MOLYBDENUM, NICKEL, RATS, STABILITY, VANADIUM}, isbn = {0162-0134}, url = {://000264904400022}, author = {Bordbar, A. K. and Creagh, A. L. and Mohammadi, F. and Haynes, C. A. and Orvig, Chris} } @article {23411, title = {Side-on End-on Bound Dinitrogen: An Activated Bonding Mode That Facilitates Functionalizing Molecular Nitrogen}, journal = {Accounts of Chemical Research}, volume = {42}, year = {2009}, month = {Jan}, pages = {127-133}, type = {Review}, abstract = {

Molecular nitrogen is the source of all of the nitrogen necessary to sustain life on this planet. How it is incorporated into the biosphere is complicated by its intrinsic inertness. For example, biological nitrogen fixation takes N-2 and converts it into ammonia using various nitrogenase enzymes, whereas industrial nitrogen fixation converts N-2 and H-2 to NH3 using heterogeneous iron or ruthenium surfaces. In both cases, the processes are energy-intensive. Is it possible to discover a homogeneous catalyst that can convert molecular nitrogen into higher-value organonitrogen compounds using a less energy-intensive pathway? If this could be achieved, it would be considered a major breakthrough in this area. In contrast to carbon monoxide, which is reactive and an important feedstock in many homogeneous catalytic reactions, the ischelectronic but inert N-2 molecule is a very poor ligand and not a common industrial feedstock, except for the above-mentioned industrial production of NH3. Because N-2 is readily available from the atmosphere and because nitrogen is an essential element for the biosphere, attempts to discover new processes involving this simple small molecule have occupied chemists for over a century. Since the first discovery of a dinitrogen complex in 1965, inorganic chemists have been key players in this area and have contributed much fundamental knowledge on structures, binding modes, and reactivity patterns. For the most part, the synthesis of dinitrogen complexes relies on the use of reducing agents to generate an electron-rich intermediate that can interact with this rather inert molecule. In this Account, a facile reaction of dinitrogen with a ditantalum tetrahydride species to generate the unusual side-on end-on bound N-2 moiety is described. This particular process is one of a growing number of new, milder ways to generate dinitrogen complexes. Furthermore, the resulting dinitrogen complex undergoes a number of reactions that expand the known patterns of reactivity for coordinated N-2. This Account reviews the reactions of ([NPN]Ta)(2)(mu-H)(2)(mu-eta(1):eta(2)-N-2), 2 (where NPN = PhP(CH2SiMe2NPh)(2)), with a variety of simple hydride reagents, E-H (where E-H = R2BH, R2AlH, RSiH3, and Cp2ZrCl(H)), each of which results in the cleavage of the N-N bond to form various functionalized imide and nitride moieties. This work is described in the context of a possible catalytic cycle that in principle could generate higher-value nitrogen-containing materials and regenerate the starting ditantalum tetrahydride. How this fails for each particular reagent is discussed and evaluated.

}, keywords = {ammonia, CLEAVAGE, CONVERSION, COORDINATED N-2 LIGAND, H-2, HYDROSILYLATION, MOLYBDENUM, REACTIVITY, REDUCTION, TANTALUM COMPLEX}, isbn = {0001-4842}, author = {Fryzuk, MD} } @article {2592, title = {Toward Alkane Functionalization Effected with Cp*W(NO)(alkyl)(eta(3-)allyl) Complexes}, journal = {Organometallics}, volume = {28}, number = {15}, year = {2009}, note = {ISI Document Delivery No.: 476PYTimes Cited: 2Cited Reference Count: 32Semproni, Scott P. Graham, Peter M. Buschhaus, Miriam S. A. Patrick, Brian O. Legzdins, Peter}, month = {Aug}, pages = {4480-4490}, type = {Article}, abstract = {Cp*W(NO)(n-alkyl)(eta(3)-allyl) complexes result from the selective activations of the terminal C-H bonds of alkanes. Consequently, the reactions of prototypical members of this family of complexes with a range of electrophilers and nucleophiles have been explored with a view to developing methods for functionalizing the newly formed alkyl ligands. The two principal complexes investigated in this regard have been Cp*W(NO)CH2SiMe3)(eta(3)-CH2CHCHMe) (1) and Cp*W(NO)(CH2C6H5)-(eta(3)-CH2CHCHMe) (2). In has been found that treatment of 1 and 2 with the oxidant I-2 at - 60 degrees C produces Cp*W(NO)I-2 and terminallly functionalized ICH2SiMe3 and ICH2C6H5, respectively. Oxidation of 1 by H2O2 also results in the loss of the allyl ligand and production of known oxo peroxo complex Cp*W(O)(eta(2)-O-2)(CH2SiMe3). Treatment of 1 and 2 with electrophiles affords the products resulting from addition of the electrophile to the electron-rich terminus of the sigma(-)pi distorted allyl ligands in the reactants. Thus, reagents of the type E-X (E = triphenylcarbenium, H. catecholborane; X = Cl, BF4) liberate CH3CH = CHCH2E and form the organometallic products Cp*W(NO)(X)(CH2SiMe3) and cp*W(NO)(X)(CH2C6H5), respectively. Exposure of the tungsten alkyl allyl complexes to isocyanide reagents leads to the formation of complexes insertion of isocyanide into the tungsten-allyl linkages. For instance, reaction of 1 with 2,6-xylylisocyanide produces Cp*w-(NO)(CH2SiMe3)(eta(2)-CH3CH2CHCHC = NC6H3Me2) (4b). A similar reaction of 2 with 2.6-xylylisocyanide affords both unconjugated and conjugated isocyanide insertion products, while treatment of 2 with n-butylisocyanide produces primarily the conjugated product. Finally. exposure of these tungsten alkyl allyl complexes to 1000 psi of CO gas generally results in the desired migratory insertion of the CO into the metal-alkyl linkages to form acyl compounds. Hence, 1 is first converted into Cp*W(NO)-(C(O)CH2SiMe3)(eta 3-CH2CHCHMe), which then subsequently transforms into isolable Cp*W(NO)-(C(O)CH3)(eta 3-CH2CHCHMe) (7). Interestingly, 2 does not react with CO under these experimental conditions. Nevertheless, the generality of this mode of reactivity is established by the fact that similar treatment of four other Cp*(W)(NO)(CH2CMe3)(eta(3)-allyl) complexes with CO gas at elevated pressures does afford the corresponding acyl products (8-11). All new organometallic complexes have been characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of several compounds have been established by X-ray crystallographic analyses.}, keywords = {ALLYL LIGANDS, CHEMISTRY, H BOND ACTIVATION, MOLYBDENUM, REACTIVITY}, isbn = {0276-7333}, url = {://000268455900035}, author = {Semproni, S. P. and Graham, P. M. and Buschhaus, M. S. A. and Patrick, B. O. and Legzdins,Peter} } @article {2088, title = {Reactivity of Cp*Mo(NO)(= CHCMe3) with olefins and dienes: C-H activation reactions of molybdenacyclobutanes}, journal = {Organometallics}, volume = {27}, number = {12}, year = {2008}, note = {ISI Document Delivery No.: 312BHTimes Cited: 5Cited Reference Count: 30Graham, Peter A. Buschhaus, Miriam S. A. Pamplin, Craig B. Legzdins, Peter}, month = {Jun}, pages = {2840-2851}, type = {Article}, abstract = {Reactions of a variety of cyclic and acyclic olefins with the title alkylidene complex (formed spontaneously by loss of neopentane from Cp*Mo(NO)(CH2CMe3)(2) under ambient conditions) result in the initial formation of molybdenacyclobutane complexes (Cp* = C5Me5). These molybdenacyclobutane complexes do not react via olefin metathesis or cyclopropanation pathways, but instead via C-H activation. Thus, when cyclopentene is the olefinic substrate, the direct result of C-H activation at the beta-position of the metallacyclobutane affords a thermally stable allyl hydrido complex that can be isolated. Such an allyl hydride intermediate is not isolable for larger cyclic olefins (cyclohexene, cycloheptene, and cyclooctene) or acyclic olefins (allylbenzene and 1-hexene). Instead, those complexes react further, undergoing a second C-H activation at the allylic position to produce eta(4)-trans-diene complexes concomitant with the loss of dihydrogen. Upon heating, these eta(4)-trans-diene complexes liberate diene, thereby enabling the 14e Cp*Mo(NO) metal fragment to catalyze the oligomerization of cyclic olefins and dienes including cyclohexene and 1,4-cyclohexadiene. In the case of the acyclic olefin allylbenzene, the metal fragment catalyzes a dimerization to (E)-(4-methylpent-1-ene-1,5-diyl)dibenzene under ambient conditions.}, keywords = {ALPHA-HYDROGEN ABSTRACTION, BONDS, COMPLEXES, CRYSTAL-STRUCTURES, CYCLOHEXENE, METATHESIS, MOLYBDENUM, NEOPENTYLIDENE, OLIGOMERIZATION, TUNGSTEN}, isbn = {0276-7333}, url = {://000256643600023}, author = {Graham, P. A. and Buschhaus, M. S. A. and Pamplin, C. B. and Legzdins,Peter} } @article {2027, title = {Transformations of cyclic olefins mediated by tungsten nitrosyl complexes}, journal = {Organometallics}, volume = {27}, number = {18}, year = {2008}, note = {ISI Document Delivery No.: 348URTimes Cited: 3Cited Reference Count: 35Buschhaus, Miriam S. A. Pamplin, Craig B. Blackmore, Ian J. Legzdins, Peter}, month = {Sep}, pages = {4724-4738}, type = {Article}, abstract = {This report describes investigations that have elucidated the nature, extent, and mechanism of the cyclic-olefin oligomerization effected by a series of tungsten precatalysts, with particular focus on Cp*W(NO)(CH2CMe3)(2) (1) and Cp*W(NO)(CH2SiMe3)(eta(2)-CPhCH2) (2). Upon thermolysis, these precatalysts oligomerize simple cyclic olefins, from cyclopentene to cyclooctene, into ring-retaining oligomers as high as dodecamers (depending on the substrate) with remaining sites of unsaturation. Precatalyst initiation involves the coupling of one equivalent of the substrate with the reactive 16e intermediate thermally generated by the precatalyst (i.e., an alkylidene by 1 or an eta(2)-alkyne complex by 2), followed by rearrangement of the coupled ligand in the metal{\textquoteright}s coordination sphere either to an olefin or to a diene (with concomitant loss of two hydrogen atoms). The rearranged ligand is displaced from the metal center as two equivalents of substrate coordinate to form a putative bis-olefin complex, Cp*W(NO)(cyclic olefin)2, that represents the convergent entry point to the catalytic cycle for the precatalysts. The coordinated olefins undergo metal-mediated coupling to form a metallacyclopentane complex. The metallacycle then undergoes beta-hydrogen activation and reductive elimination to generate an eta(2)-cyclic-olefin dimer. Further incorporation of substrate leads to formation of trimers and higher oligomers. Alternatively, expulsion of any coordinated oligomer from the tungsten center regenerates the reactive bis-olefin complex. Finally, decomposition of the tungsten catalyst species is consistent with a bimetallic pathway. All new organometallic complexes have been characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of several compounds have been established by X-ray crystallographic analyses.}, keywords = {1, 3-CYCLOHEXADIENE, ALKYLIDENE COMPLEXES, C-H ACTIVATION, CATALYTIC-ACTIVITY, CRYSTAL-STRUCTURES, CYCLOHEXENE, METATHESIS, MOLYBDENACYCLOBUTANES, MOLYBDENUM, REACTIVITY}, isbn = {0276-7333}, url = {://000259236100022}, author = {Buschhaus, M. S. A. and Pamplin, C. B. and Blackmore, I. J. and Legzdins,Peter} } @article {1433, title = {Reaction of H2S with MoRu(CO)(6)(dppm)(2) to give H-2 and a bridged-sulfide product via hydrido-sulfhydryl intermediates (dppm = Ph2PCH2PPh2)}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {84}, number = {2}, year = {2006}, note = {ISI Document Delivery No.: 040YKTimes Cited: 2Cited Reference Count: 29}, month = {Feb}, pages = {330-336}, type = {Article}, abstract = {Oxidative addition of H2S to MoRu(CO)(6)(mu-dppm)(2) (1) at similar to 20 degrees C in toluene yields an isolable complex formulated as Mo(CO)(3)(mu-SH)(mu-CO)(mu-dppm)(2)RuH(CO) (2) via the possible intermediate Mo(CO)(3)(mu-H)(mu-CO)(mu-dppm)(2)Ru(SH)(CO) (4) (dppm = Ph2PCH2PPh2) that is detectable at lower temperatures. Over 2 days, species 2 in toluene loses H-2 (and CO) to yield the bridged-sulfide product, Mo(CO)(2)(mu-CO)(mu-S)(mu-dppm)(2)Ru(CO) (5) that is also formed directly from the reaction of 1 with elemental sulfur. The solid-state molecular structure of 5 is determined by X-ray crystallography. A further hydrido-sulfhydryl species, possibly Mo(CO)(3)(mu-SH)(mu-H)(mu-dppm)(2)Ru(CO)(2) (3), is in equilibrium with 2 at ambient temperature.}, keywords = {bis(diphenylphosphino) methane, bis(diphenylphosphino)methane, BOND ACTIVATION, bridged-sulfide complex, carbonyl complexes, CHEMISTRY, COMPLEXES, hydrido-sulfhydryl species, HYDROGEN, HYDROGEN-SULFIDE, MECHANISTIC ASPECTS, METAL, MO, MOLYBDENUM, RECOVERY, ruthenium, sulfide, SULFUR-DIOXIDE}, isbn = {0008-4042}, url = {://000237417600031}, author = {Khorasani-Motlagh, M. and Safari, N. and Pamplin, C. B. and Patrick, B. O. and James, Brian R.} } @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 = {://000239120700063}, author = {MacKay, B. A. and Munha, R. F. and Fryzuk,Michael D.} } @article {1062, title = {Distinctive properties of Cp {\textquoteright} M(NO)(alkyl)(2) (M = MO, W) complexes}, journal = {Organometallics}, volume = {24}, number = {17}, year = {2005}, note = {ISI Document Delivery No.: 953ZRTimes Cited: 16Cited Reference Count: 40}, month = {Aug}, pages = {4088-4098}, type = {Review}, abstract = {This account summarizes our work with the title complexes, which are rare examples of electronically and coordinatively unsaturated transition-metal alkyls that can be isolated under ambient conditions. It first outlines the synthetic methods employed for the preparation of these compounds and then presents their distinctive physical properties. It then classifies the characteristic chemical properties of these complexes in terms of the reactivity being either metal or ligand based, and specific examples of particular transformations are illustrated with reference to the most studied systems.}, keywords = {CARBON BONDS, CP{\textquoteright}M(NO)R2, INTERMOLECULAR ACTIVATION, MIGRATORY INSERTION, MOLYBDENUM, NITRIC-OXIDE, ORGANOMETALLIC NITROSYL CHEMISTRY, {C-H BONDS}, isbn = {0276-7333}, url = {://000231124400002}, author = {Blackmore, I. J. and Jin, X. and Legzdins,Peter} } @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 = {://000228744300008}, author = {MacKay, B. A. and Johnson, S. A. and Patrick, B. O. and Fryzuk,Michael D.} } @article {1169, title = {Intermolecular activation of hydrocarbon C-H bonds initiated by the tungsten hydrocarbyl hydrido complexes Cp*W(NO)(R)(H)(PMe3) (R = alkyl, aryl)}, journal = {Organometallics}, volume = {24}, number = {4}, year = {2005}, note = {ISI Document Delivery No.: 896HITimes Cited: 5Cited Reference Count: 32}, month = {Feb}, pages = {638-649}, type = {Article}, abstract = {trans-CP*W(NO)(CH2EMe3)(H)(PMe3) (E = C, Si) complexes can be prepared by the hydrogenation at 1 atm of the appropriate Cp*W(NO)(CH2EMe3)(2) precursor in the presence of a slight excess of PMe3. (Our designation of a particular geometrical isomer as cis or trans in this family of complexes indicates the relative positions of the hydrocarbyl and the hydrido ligands in the base of a four-legged piano-stool molecular structure.) The use of D-2 in place of H-2 during these syntheses affords the corresponding trans-Cp*W(NO)(CH2EMe3)(D)(PMe3) (E = C, Si) complexes. The cis-Cp*W(NO)(CH2EMe3)(H)(PMe3) isomers are obtainable by C-H bond-activation reactions of the trans precursors. Thus, activation of SiMe4 by trans-Cp*W(NO)(CH2CMe3)(H)(PMe3) under ambient conditions produces cis-Cp*W(NO)(CH2SiMe3)(H)(PMe3). Similarly, activations of C6H6 and C6D6 at 20-27 degreesC by the trans-Cp*W(NO)(CH2EMe3)(H)(PMe3) complexes produce cis-Cp*W(NO)(C6H5)(H)(PMe3) and cisCp*W(NO)(C6D5)(D)(PMe3), respectively, and the solid-state molecular structure of the latter complex has been established by a single-crystal X-ray crystallographic analysis. Kinetic, mechanistic, and theoretical investigations of these benzene C-H activation processes are consistent with initial trans to cis isomerization of the reactants followed by intramolecular reductive elimination of EMe4 to form the 16-electron Cp*W(NO)(PMe3) intermediate. Subsequent oxidative addition of the incoming benzene substrate to this coordinatively unsaturated intermediate produces the final cis hydrido phenyl complex. These single C-H activation processes are the requisite first steps in the development of these organometallic complexes as catalysts for the selective functionalization of hydrocarbons. All new complexes have been characterized by conventional spectroscopic methods.}, keywords = {CALCULATIONS, density, EFFECTIVE CORE POTENTIALS, MOLECULAR, MOLYBDENUM, ORGANOMETALLIC NITROSYL CHEMISTRY, REACTIVITY}, isbn = {0276-7333}, url = {://000226924800024}, author = {Lee, K. and Legzdins,Peter and Pamplin, C. B. and Patrick, B. O. and Wada, K.} } @article {947, title = {Carbon-nitrogen bond formation via the reaction of terminal alkynes with a dinuclear side-on dinitrogen complex}, journal = {Journal of the American Chemical Society}, volume = {126}, number = {31}, year = {2004}, note = {ISI Document Delivery No.: 843TSTimes Cited: 27Cited Reference Count: 21}, month = {Aug}, pages = {9480-9481}, type = {Article}, keywords = {ACTIVATION, COORDINATION, FIXATION, FUNCTIONALIZATION, HETEROCYCLES, HYDROAMINATION, METAL-COMPLEXES, MOLECULAR NITROGEN, MOLYBDENUM, N-2}, isbn = {0002-7863}, url = {://000223110100007}, author = {Morello, L. and Love, J. B. and Patrick, B. O. and Fryzuk,Michael D.} } @article {1011, title = {Comparison of anti-hyperglycemic effect amongst vanadium, molybdenum and other metal maltol complexes}, journal = {Journal of Inorganic Biochemistry}, volume = {98}, number = {5}, year = {2004}, note = {ISI Document Delivery No.: 824HVTimes Cited: 37Cited Reference Count: 7411th International Conference on Biological Inorganic ChemistryJUL 19-23, 2003Cairns, AUSTRALIA}, month = {May}, pages = {683-690}, type = {Proceedings Paper}, abstract = {A wide variety of vanadium-containing complexes have been tested, both in vivo and in vitro, as possible therapeutic agents for the oral treatment of type 2 diabetes mellitus. None so far has surpassed bis(maltolato)oxovanadium(IV) (BMOV) for glucose- and lipid-lowering in an orally available formulation. Ligand choice is clearly an important factor in pharmacological efficacy of vanadium compounds as insulin enhancing agents. In this study, we kept the ligand and dose the same, varying instead the metal ion bound to the maltolato ligand in a series of binary complexes of neutral charge. A requirement for vanadyl ion as the metal ion of choice was apparent; no other metal ion tested served as a suitable substitute. Amongst [MoO2](2+), Co(II), Cu(II), Cr(III), and Zn(II), only [MoO2](2+) and Co(II) showed any hypoglycemic activity at the ED50 dose for bis(maltolato)oxovanadium(IV), 0.6 mmol kg(-1) by oral gavage in streptozotocin (STZ)-diabetic rats within 72 It of administration of compound. (C) 2004 Elsevier Inc. All rights reserved.}, keywords = {ABSORPTION, CHROMIUM, cobalt, COORDINATION MODE, copper, DEPENDENT DIABETES-MELLITUS, GLUCOSE-METABOLISM, IN-VIVO, INSULIN, LIPID-METABOLISM, MOLYBDENUM, RATS, VANADIUM, zinc, ZINC SUPPLEMENTATION}, isbn = {0162-0134}, url = {://000221678300004}, author = {Thompson, K. H. and Chiles, J. and Yuen, V. G. and Tse, J. and McNeill, J. H. and Orvig, Chris} } @article {879, title = {Reactivity of (trimpsi)V(NO)X-2 complexes (X = Cl, Br, I; trimpsi = (BuSi)-Bu-t(CH2PMe2)(3)). Synthesis of the first group 5 alkyl nitrosyls}, journal = {Organometallics}, volume = {23}, number = {4}, year = {2004}, note = {ISI Document Delivery No.: 772ZFTimes Cited: 4Cited Reference Count: 40}, month = {Feb}, pages = {657-664}, type = {Article}, abstract = {Treatment of (trimpsi)V(NO)Cl-2 (trimpsi = (BuSi)-Bu-t(CH2PMe2)(3)) in NEt3 with 2 equiv each of p-toluic acid and Proton Sponge affords lemon yellow (trimpsi)V(NO)(eta(1)-O2C-4-C6H4Me)(2) (1) in 47\% isolated yield. Similarly, reaction of (trimpsi)V(NO)Cl-2 with 2 equiv of AgOTf in CH2Cl2 provides lemon yellow (trimpsi)V(NO)(OTf)(2) (2) in a comparable yield. Alternatively, 2 can be obtained directly in 40\% yield by treating CH2Cl2 solutions of (trimpsi)V(CO)(2)(NO) at -60 degreesC with 2 equiv of AgOTf. Likewise, both benzoyl peroxide and diphenyl disulfide are capable of oxidizing (trimpsi)V(CO)(2)(NO) under similar conditions to form (trimpsi)V(NO)X-2-type complexes, namely (trimpsi)V(NO)(O2CPh)(2) (3) and (trimpsi)V(NO)(SPh)(2) (4), respectively. The reactions of (trimpsi)V(NO)X-2 (X = Cl, Br) with Mg(CH2SiMe3)(2)(.)x(dioxane) (either 0.5 equiv or an excess) in THF afford the orange-red alkyl complexes (trimpsi)V(NO)(CH2SiMe3)X (X = Cl (5), Br (6)) in reasonable yields. Other members of this family of complexes such as (trimpsi)V(NO)(CH2CMe3)Cl (7) and (trimpsi)V(NO)(Me)Cl (8) can also be obtained by employing similar metathetical methodology, but all attempts to synthesize (trimpsi)V(NO)(alkyl)2 complexes have to date been unsuccessful. All new complexes have been fully characterized by standard methods, and the solid-state molecular structures of 1(.)1.5C(6)H(5)Me and 5(.)2C(4)H(8)O have been established by single-crystal X-ray diffraction analyses.}, keywords = {CHEMISTRY, CP{\textquoteright}M(NO)R2, CRYSTAL-STRUCTURES, DERIVATIVES, H BOND ACTIVATION, MOLYBDENUM, THERMAL-ACTIVATION, TUNGSTEN, V METAL-CARBONYLS, VANADIUM}, isbn = {0276-7333}, url = {://000188872700007}, author = {Hayton, T. W. and Patrick, B. O. and Legzdins,Peter} } @article {880, title = {The solid-state molecular structure of W(NO)(3)Cl-3 and the nature of its W-NO bonding}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {82}, number = {2}, year = {2004}, note = {ISI Document Delivery No.: 802BHTimes Cited: 1Cited Reference Count: 46}, month = {Feb}, pages = {285-292}, type = {Article}, abstract = {{The monomeric trinitrosyl complex, W(NO)(3)Cl-3, can be prepared by the treatment of WCl6 in CH2Cl2 with NO gas, and its identity has been unambiguously confirmed by a single-crystal X-ray diffraction analysis. The complex crystallizes in the space group Pmn2(1) as a three-component twin (a = 10.4280(4) Angstrom}, keywords = {bonding, CARBONYL, CHEMISTRY, CRYSTAL-STRUCTURE, DERIVATIVES, DICHLORODINITROSYLTUNGSTEN, DICHLOROTRINITROSYLVANADIUM, MOLYBDENUM, MONONUCLEAR, NITROSYL, NITROSYL COMPLEXES, STRUCTURE, TUNGSTEN}, isbn = {0008-4042}, url = {://000220138500024}, author = {Hayton, T. W. and Patrick, B. O. and Legzdins,Peter and McNeil, W. S.} } @article {994, title = {Spectroscopic properties and quantum chemistry-based normal coordinate analysis (QCB-NCA) of a dinuclear tantalum complex exhibiting the novel side-on end-on bridging geometry of N-2: Correlations to electronic structure and reactivity}, journal = {Journal of the American Chemical Society}, volume = {126}, number = {1}, year = {2004}, note = {ISI Document Delivery No.: 761ZMTimes Cited: 16Cited Reference Count: 40}, month = {Jan}, pages = {280-290}, type = {Article}, abstract = {The vibrational properties and the electronic structure of the side-on end-on N-2-bridged Ta complex ([NPN]Ta(mu-H))(2)(mu-eta(1):eta(2)-N-2) (1) (where [NPN] = (PhNSiMe2CH2)(2)PPh) are analyzed. Vibrational characterization of the Ta-2(mu-N-2)(mu-H)(2) core is based on resonance Raman and infrared spectroscopies evaluated with a novel quantum chemistry-based normal coordinate analysis (QCB-NCA). The N-N stretching frequency is found at 1165 cm(-1) exhibiting a N-15(2) isotope shift of -37 cm(-1). Four other modes of the Ta2N2H2 core are observed between 430 and 660 cm(-1). Two vibrations of the bridging hydrido ligands are also identified in the spectra. On the basis of experimental frequencies and the QCB-NCA procedure, the N-N force constant is determined to be 2.430 mdyn -Angstrom(-1). The Ta-N force constants are calculated to be 2.517 mdyn Angstrom(-1) for the Ta-eta(1)-N-2 bond and 1.291 and 0.917 mdyn Angstrom(-1) for the Ta-eta(2)-N-2 bonds, respectively. DFT calculations on 1 suggest that the bridging dinitrogen ligand carries a charge of -1.1, which is equally distributed over the two nitrogen atoms. However, orbital analysis reveals that the terminal nitrogen makes lower contributions to the pi orbitals and much higher contributions to the pi* orbitals of the N-2 ligand than the bridging nitrogen. This suggests that reactions of the dinitrogen ligand with electrophiles should preferentially occur at the terminal N atom, in agreement with experimental results.}, keywords = {ACTIVATION, CLEAVAGE, DINITROGEN FIXATION, EFFECTIVE CORE POTENTIALS, FUNCTIONALIZATION, LIGAND, MOLECULAR CALCULATIONS, MOLYBDENUM, NITROGEN-FIXATION, REDUCTION PATHWAY}, isbn = {0002-7863}, url = {://000187945400064}, author = {Studt, F. and MacKay, B. A. and Fryzuk,Michael D. and Tuczek, F.} } @article {328, title = {C-H activation of substituted arenes by tungsten alkylidene complexes: Products, selectivity, and mechanism}, journal = {Organometallics}, volume = {21}, number = {7}, year = {2002}, note = {ISI Document Delivery No.: 534QZTimes Cited: 18Cited Reference Count: 35}, month = {Apr}, pages = {1474-1486}, type = {Article}, abstract = {Thermolyses (70 degreesC, 40 h) of Cp*W(NO)(CH2CMe3)(2) (1) and Cp*W(NO)(CH2CMe3)(CH2C6H5) (2) in xylenes, mesitylene, and a,a,(x-trifluorotoluene generate mixtures of the corresponding aryl and/or benzyl products derived from aromatic sp(2) and benzylic sp(3) C-H bond activations of the solvent molecules by the intermediate alkylidene complexes Cp*W(NO)(=CHCMe3)(sigma-CMe4) (sigma-A) and Cp*W(NO)(=CHC6H5)(sigma-CMe4) (sigma-B), respectively. For instance, the thermolysis of 1 in p-xylene affords products resulting from the activation of one and two molecules of p-xylene. The two products derived from the activation of one solvent molecule are Cp*W(NO)(CH2CMe3)(C6H3-2,5-Me-2) (10) and CP*W(NO)(CH2CMe3)(CH2C6H4-4-Me)(2) (11). The other two complexes derived from the activation of two solvent molecules are Cp*W(NO)(CH2C6H4-4-Me)(C6H4-2,5-Me-2) (12) and Cp*W(NO)(CH2C6H4-4Me)(2) (13). The ratio of the four products in the final reaction mixture is 10:11:12:13 = 1.81 +/- 0.09:0.44 +/- 0.05:1.0:0.15 +/- 0.02. All new complexes prepared have been characterized as fully as possible by conventional spectroscopic methods, and the solid-state molecular structures of Cp*W(NO)(CH2C6H5)(C6H3-3,5-Me-2) (7) and Cp*W(NO)(CH2C6H5)(CH2C6H3-3,5-Me-2) (9) have been established by X-ray diffraction methods. Analyses of the product distributions resulting from the various thermolyses indicate that the benzyl products are increasingly favored over the aryl products as the number of methyl substituents on the solvent molecule increases. Likewise, the movement of the methyl groups from the ortho to meta to para position in the xylenes shifts the aryl vs benzyl product distribution toward the benzyl products. With respect to the aryl product regioselectivities, only the least sterically congested aryl regioisomers are formed in the activations of o- and m-xylene, while the meta and para aryl products are formed preferentially for (x,(x,(x-trifluorotoluene. Finally, the distributions obtained from sigma-B are more abundant in the aryl products than are those obtained from a-A. However, despite these general trends, it is also apparent that the origin of the observed product selectivities is highly dependent on the nature of the substrate, the nature of the C-H activation products, and the intermediate alkylidene complex.}, keywords = {1, 2-RH-ELIMINATION, ARYL, BOND ACTIVATION, CARBON-HYDROGEN, FUNCTIONALIZATION, HYDROCARBON ACTIVATION, METHANE, MOLYBDENUM, ORGANOMETALLIC NITROSYL CHEMISTRY, REVERSIBLE, THERMOLYSIS}, isbn = {0276-7333}, url = {://000174599400020}, author = {Adams, C. S. and Legzdins,Peter and Tran, E.} } @article {394, title = {Di-mu-methoxy-bis[(eta(5)-cyclopentadienyl)(nitrosyl-kappa N)(trimethylsilyl-methyl)molybdenum(II)]}, journal = {Acta Crystallographica Section C-Crystal Structure Communications}, volume = {58}, year = {2002}, note = {ISI Document Delivery No.: 568WFTimes Cited: 1Cited Reference Count: 11Part 7}, month = {Jul}, pages = {m377-m378}, type = {Article}, abstract = {The title complex, [Mo-2 (C5H5)(2) (CH3O)(2) (C4H11Si)(2)(NO)(2)], is formed in high yield by treating [CpMo(NO)(CH2SiMe3)(2)] (Cp is cyclopentadienyl) with methanol. The nitrosyl ligands are nearly linear [O-N-Mo 170.1 (4) and 170.1 (5)degrees], with short Mo-N bonds [1.769 (4) and 1.776 (4) Angstrom] and long N- O bonds [1.216 (5) and 1.201 (4) Angstrom]. The central four-membered Mo2O2 ring exhibits an average Mo-O bond length of 2.15 Angstrom.}, keywords = {CHEMISTRY, COMPLEXES, MOLYBDENUM, TUNGSTEN}, isbn = {0108-2701}, url = {://000176567300011}, author = {Hayton, T. W. and Legzdins,Peter and Rettig, S. J.} } @article {537, title = {Parallel modes of C-H bond activation initiated by Cp*Mo(NO)(CH2CMe3)(C6H5) at ambient temperatures}, journal = {Journal of the American Chemical Society}, volume = {124}, number = {33}, year = {2002}, note = {ISI Document Delivery No.: 584EVTimes Cited: 15Cited Reference Count: 32}, month = {Aug}, pages = {9680-9681}, type = {Article}, keywords = {ALKANES, ARYNE COMPLEXES, CHEMISTRY, HYDROCARBONS, INTERMEDIATE, METAL-COMPLEXES, MOLYBDENUM, REACTIVITY, THERMOLYSIS, TUNGSTEN ALKYLIDENE COMPLEXES}, isbn = {0002-7863}, url = {://000177455000012}, author = {Wada, K. and Pamplin, C. B. and Legzdins,Peter} } @article {5013, title = {alpha-agostic interactions in Cp*W(NO)(CH2CMe3)(2) and related nitrosyl complexes}, journal = {Organometallics}, volume = {20}, number = {22}, year = {2001}, note = {ISI Document Delivery No.: 488TLTimes Cited: 22Cited Reference Count: 59}, month = {Oct}, pages = {4492-4501}, type = {Article}, abstract = {The solid-state molecular structure of Cp*W(NO)(CH2CMe3)(2) (1) has been shown to contain one "strongly agostic" and one "weakly agostic" methylene hydrogen atom by a neutron diffraction analysis at 120 K and by an X-ray diffraction analysis at -100 degreesC. The X-ray diffraction analysis of Cp*W(NO)(CH2SiMe3)(2) (2) at -20 degreesC reveals that its solid-state molecular structure possesses a crystallographically imposed mirror plane. Consequently, only the average existence of a relatively strong C-(HM)-M-... interaction for each hydrocarbyl ligand in 2 in the solid state can be established. The H-1 and gated C-13{H-1} NMR spectra of representative Cp{\textquoteright}M(NO)(R)(R{\textquoteright}) (M = Mo, W; R = hydrocarbyl, R{\textquoteright} = hydrocarbyl, halide, amide) complexes exhibit spectral parameters for the alpha -H and alpha -C atoms (i.e., delta (H), delta (C), Delta delta (H), DeltaJ(HC), and J(HW)) that provide evidence for the presence of a-agostic interactions in the molecular structures of these complexes in solution. The picture that has emerged from these investigations is that these complexes do adopt an a-agostic structure both in solution and in the solid state when secondary interactions such as pi -electron donation are weak (as in Cp*W(NO)(CH2CMe3)Cl), competitive (as in Cp*W(NO)(CH2CMe3)(CH2Ph)), or not possible (as in Cp*W(NO)(hydrocarbyl)(2) complexes generally). The bis(hydrocarbyl) complexes are probably stereochemically nonrigid in solution, as they appear to interconvert between the two limiting structures having one strongly agostic and one weakly agostic hydrocarbyl ligand. The neopentyl ligand forms alpha -agostic linkages with the metal centers in all neopentyl complexes studied, and these agostic interactions appear to be independent of the nature of the metal or the ancillary cyclopentadienyl ligand. Interestingly, the presence of these groundstate agostic interactions does not correlate with the tendency of the various compounds to undergo intramolecular alpha -H abstraction reactions and form reactive alkylidene complexes.}, keywords = {ALKYL, C-H ACTIVATION, CARBON, COMPLEXES, CRYSTAL-STRUCTURE, DIALKYL COMPLEXES, hydride, HYDROGEN, MOLYBDENUM, TRANSITION-METAL BONDS, TUNGSTEN}, isbn = {0276-7333}, url = {://000171951700012}, author = {Bau, R. and Mason, S. A. and Patrick, B. O. and Adams, C. S. and Sharp, W. B. and Legzdins,Peter} } @article {4995, title = {Intermolecular C-H activation of hydrocarbons by tungsten alkylidene complexes: An experimental and computational mechanistic study}, journal = {Organometallics}, volume = {20}, number = {23}, year = {2001}, note = {ISI Document Delivery No.: 493VBTimes Cited: 17Cited Reference Count: 65}, month = {Nov}, pages = {4939-4955}, type = {Article}, abstract = {Cp*W(NO)(CH2CMe3)(2) (1) and Cp*W(NO)(CH2CMe3)(CH2C6H5) (2) under moderate conditions (70 degreesC, 40 h) generate the reactive complexes Cp*W(NO)(=CHCMe3) (A) and Cp*W(NO)(=CHC6H5) (B), respectively, which activate hydrocarbon solvents via the addition of C-H across the M=C bond. The alpha -deuterated derivative Cp*W(NO)(CD2CMe3)(2) (1-d(4)) undergoes intramolecular H/D exchange within the neopentyl ligands, consistent with the formation of a-neopentane complexes prior to neopentane elimination. The thermolysis of 1 in a 1:1 molar mixture of tetramethylsilane-h(12) and tetramethylsilane-d(12) (70 degreesC, 40 h) yields an intermolecular KIE of 1.07(4):1. Thermolysis of I and 2 in 1:1 benzene/benzene-d(6) yields intermolecular KIEs of 1.03(5):1 and 1.17(19):1, respectively. The KIE values are inconsistent with rate-determining C-H bond addition to the M=C linkage and indicate that coordination of the substrate to the metal center is the discriminating factor in alkane and arene intermolecular competitions. The complexes Cp*W(NO)(CH2CMe3)(C6D5) (5-d(5)) and CP*W(NO)(CH2C6H5)(C6D5) (6-d(5)) convert to the respective H/D scrambled products Cp*W(NO)(CHDsynCMe3)(C6D4H1) (5{\textquoteright}-d(5)) and Cp*W(NO)(CHDsynC6H5)(C6D4H1) (6{\textquoteright}-d(5)) under thermolytic conditions, consistent with the occurrence of reversible aromatic sp(2) C-H bond cleavage. The results suggest that the previously reported discrimination between the aryl and benzyl products of toluene activation by A and B originates from coordination of toluene to the metal center in two distinct modes. Supporting DFT calculations on the activation of toluene by CpW(NO)(=CH2) (C) indicate that aromatic sp(2) C-H bond activation proceeds through a pi -arene complex, while benzylic sp(3) C-H bond activation proceeds through a eta (2)(C,H),sigma -phenylmethane complex. The principal factor behind the preferential formation of the aryl products appears to be the relative energies of formation of these intermediates.}, keywords = {BOND ACTIVATION, EFFECTIVE CORE POTENTIALS, EXCHANGE, METAL-ALKANE COMPLEXES, METHANE, METHYL-HYDRIDE, MOLECULAR CALCULATIONS, MOLYBDENUM, ORGANOMETALLIC NITROSYL CHEMISTRY, REDUCTIVE ELIMINATION}, isbn = {0276-7333}, url = {://000172243200026}, author = {Adams, C. S. and Legzdins,Peter and McNeil, W. S.} } @article {5197, title = {O-protonation of a terminal nitrosyl group to form an eta(1)-hydroxylimido ligand}, journal = {Journal of the American Chemical Society}, volume = {123}, number = {33}, year = {2001}, note = {ISI Document Delivery No.: 463TWTimes Cited: 9Cited Reference Count: 26}, month = {Aug}, pages = {8143-8144}, type = {Article}, keywords = {CHEMISTRY, COMPLEXES, CRYSTAL-STRUCTURE, METAL, MOLYBDENUM, NITRIC-OXIDE, REACTIVITY, REDUCTION, TUNGSTEN}, isbn = {0002-7863}, url = {://000170494200032}, author = {Sharp, W. B. and Legzdins,Peter and Patrick, B. O.} } @article {4733, title = {Organometallic oxides: preparation of the cluster [(eta-C5Me5)Mo](4)O-7 by reduction of [(eta-C5Me5)MoCl(O)](2)(mu-O) or (eta-C5Me5)MoCl2(O)}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {78}, number = {3}, year = {2000}, note = {ISI Document Delivery No.: 296TVTimes Cited: 5Cited Reference Count: 63}, month = {Mar}, pages = {383-394}, type = {Article}, abstract = {Reduction of [(eta-C5Me5)MoCl(O)](2)(mu-O) or (eta-C5Me5)MoCl2(O) with sodium or magnesium amalgam, magnesium turnings, or tributyltin hydride produced [(eta-C5Me5)Mo](4)O-7, with [(eta-C5Me5)Mo(O)(mu-O)](2) as a co-product. [(eta-C5Me5)Mo](4)O-7 was characterized by X-ray diffraction, mass spectrometry, H-1 NMR and IR spectroscopies, and magnetism. Crystals of [(eta-C5Me5)Mo](4)O-7 contained a tetrahedral [(eta-C5Me5)Mo](4) unit (Mo-Mo = 2.909 (3) Angstrom) with the Mo4O7 core having the structure Mo-4(mu(2)-O(b))(3)(mu(2)-O(c))(3)(mu(3)-O(a)) (3). Microcrystalline samples of [(eta-C5Me5)Mo](4)O-7 were paramagnetic over the temperature range 2-300 K, with an effective moment of 1.26 mu(B) at 300 K. [(eta-C5Me5)Mo](4)O-7 was also paramagnetic in chloroform solution, over the temperature range 223-298 K, with an effective moment of 1.43 mu(B) at 298 K. The H-1 NMR spectrum showed a broad resonance at 16.3 ppm (delta nu(1/2) = 113 Hz) and two narrow resonances at 1.89 ppm and 1.69 ppm (delta nu(1/2) = 5 Hz). The magnetism and NMR spectra showed that [(eta-C5Me5)Mo](4)O-7 existed in two forms which were in equilibrium in solution. One form was paramagnetic (S = 1), with the Mo4O7 core having the geometry 3, and the other was diamagnetic (S = 0), with the Mo4O7 core having the geometry 4.}, keywords = {CARBONYL-COMPLEXES, CHARGE-TRANSFER SALTS, CLUSTER, CRYSTAL-STRUCTURES, CYCLOPENTADIENYL, ELECTRONIC-STRUCTURE, MOLECULAR-STRUCTURE, MOLYBDENUM, OXIDATION, OXIDE, OXO, OXYGEN, paramagnetism, X-RAY}, isbn = {0008-4042}, url = {://000086043200009}, author = {Bottomley, F. and Sanchez, V. and Thompson, R. C. and Womiloju, O. O. and Xu, Z. Q.} } @article {4491, title = {Synthesis and structure of [{Mo(CO)(4)}(2)(cis-mu-F2SbF4)(3)](x)[Sb2F11](x): An ionic coordination polymer}, journal = {Inorganic Chemistry}, volume = {38}, number = {16}, year = {1999}, note = {ISI Document Delivery No.: 226JVTimes Cited: 16Cited Reference Count: 35}, month = {Aug}, pages = {3684-3687}, type = {Article}, abstract = {{The oxidation of molybdenum hexacarbonyl, Mo(CO)(6), by antimony(V) fluoride, SbF5, at 60 degrees C in an excess of liquid SbF5, produces polymeric [{Mo(CO)(4)}(2)(cis-mu-F2SbF4)(3)](x)[Sb2F11](x) as the main product. Recrystallization from HF-SbF5 produces orange prismatic crystals, suitable for a single-crystal X-ray diffraction study. Crystals of [{Mo(CO)(4)}(2)(cis-mu-F2SbF4)(3)](x)[Sb2F11](x) are monoclinic, space group P2(1)/c (No. 14)}, keywords = {ANIONS, COMPLEXES, CRYSTAL, FLUORIDE, FLUOROSULFATE, MOLYBDENUM, UNDECAFLUORODIANTIMONATE(V)}, isbn = {0020-1669}, url = {://000082017600016}, author = {Brochler, R. and Freidank, D. and Bodenbinder, M. and Sham, I. H. T. and Willner, H. and Rettig, S. J. and Trotter, J. and Aubke, F.} } @article {4491, title = {Synthesis and structure of [{Mo(CO)(4)}(2)(cis-mu-F2SbF4)(3)](x)[Sb2F11](x): An ionic coordination polymer}, journal = {Inorganic Chemistry}, volume = {38}, number = {16}, year = {1999}, note = {ISI Document Delivery No.: 226JVTimes Cited: 16Cited Reference Count: 35}, month = {Aug}, pages = {3684-3687}, type = {Article}, abstract = {{The oxidation of molybdenum hexacarbonyl, Mo(CO)(6), by antimony(V) fluoride, SbF5, at 60 degrees C in an excess of liquid SbF5, produces polymeric [{Mo(CO)(4)}(2)(cis-mu-F2SbF4)(3)](x)[Sb2F11](x) as the main product. Recrystallization from HF-SbF5 produces orange prismatic crystals, suitable for a single-crystal X-ray diffraction study. Crystals of [{Mo(CO)(4)}(2)(cis-mu-F2SbF4)(3)](x)[Sb2F11](x) are monoclinic, space group P2(1)/c (No. 14)}, keywords = {ANIONS, COMPLEXES, CRYSTAL, FLUORIDE, FLUOROSULFATE, MOLYBDENUM, UNDECAFLUORODIANTIMONATE(V)}, isbn = {0020-1669}, url = {://000082017600016}, author = {Brochler, R. and Freidank, D. and Bodenbinder, M. and Sham, I. H. T. and Willner, H. and Rettig, S. J. and Trotter, J. and Aubke, F.} } @article {4399, title = {Kinetic analysis and comparison of uptake, distribution, and excretion of V-48-labeled compounds in rats}, journal = {Journal of Applied Physiology}, volume = {84}, number = {2}, year = {1998}, note = {ISI Document Delivery No.: YU964Times Cited: 63Cited Reference Count: 43}, month = {Feb}, pages = {569-575}, type = {Article}, abstract = {Vanadium has been found to be orally active in lowering plasma glucose levels; thus it provides a potential treatment for diabetes mellitus. Bis(maltolato)oxovanadium(rv) (BMOV) is a well-characterized organovanadium compound that has been shown in preliminary studies to have a potentially useful absorption profile. Tissue distributions of BMOV compared with those of vanadyl sulfate (VS) were studied in Wistar rats by using V-48 as a tracer. In this study, the compounds were administered in carrier-added forms by either oral gavage or intraperitoneal injection. Data analyzed by a compartmental model, by using simulation, analysis, and modeling (i.e., SAAM II) software, showed a pattern of increased tissue uptake with use of V-48-BMOV compared with (VS)-V-48. The highest V-48 concentrations at 24 h after gavage were in bone, followed by kidney and liver. Most ingested V-48 was eliminated unabsorbed by fecal excretion. On average, V-48 concentrations in bone, kidney, and liver 24 h after oral administration of V-48-BMOV were two to three times higher than those of (VS)-V-48, which is consistent with the increased glucose-lowering potency of BMOV in acute glucose lowering compared with VS.}, keywords = {ADIPOCYTES, analysis, and modeling, BIS(MALTOLATO)OXOVANADIUM(IV), compartmental modeling, diabetes, DISSOCIATION, FERRIC MALTOL, GLUCOSE, INDUCED DIABETIC RATS, INSULIN, insulin mimetic, METABOLISM, MOLYBDENUM, SIMULATION, SMALL-INTESTINE, Software, VANADIUM, VANADYL SULFATE}, isbn = {8750-7587}, url = {://000071774300025}, author = {Setyawati, I. A. and Thompson, K. H. and Yuen, V. G. and Sun, Y. and Battell, M. and Lyster, D. M. and Vo, C. and Ruth, T. J. and Zeisler, S. and McNeill, J. H. and Orvig, Chris} } @article {4039, title = {Synthesis of novel diamagnetic chromium(II) alkyl complexes}, journal = {Organometallics}, volume = {16}, number = {16}, year = {1997}, note = {ISI Document Delivery No.: XP426Times Cited: 7Cited Reference Count: 38}, month = {Aug}, pages = {3569-3571}, type = {Article}, abstract = {Reaction of Cr(NO)((NPr2)-Pr-i)(3) with PhCO2H leads to Cr(NO)((NPr2)-Pr-i)(O2CPh)(2) (1). The benzoate ligands of 1 may be replaced to form the diamagnetic, structurally-characterized organometallic complexes CpCr(NO)-((NPr2)-Pr-i)(OC(O)Ph) (2), CpCr(NO)((NPr2)-Pr-i)(CH2SiMe3) (3),and Cr(NO)((NPr2)-Pr-i)(CH2SiMe3)(2) (4).}, keywords = {CLEAVAGE, LIGANDS, MOLYBDENUM, ORGANOMETALLIC CHEMISTRY, REACTIVITY, TUNGSTEN}, isbn = {0276-7333}, url = {://A1997XP42600001}, author = {Kuzelka, J. and Legzdins,Peter and Rettig, S. J. and Smith, K. M.} } @article {3419, title = {NITROSYL N-O BOND-CLEAVAGE DURING REACTIONS OF ORGANOMETALLIC NITROSYL COMPLEXES OF THE GROUP-6 ELEMENTS}, journal = {Comments on Inorganic Chemistry}, volume = {17}, number = {4}, year = {1995}, note = {ISI Document Delivery No.: RH843Times Cited: 11Cited Reference Count: 44Part A}, pages = {239-254}, type = {Article}, abstract = {The nitrosyl ligands in organotransition-metal nitrosyl complexes usually stay intact during chemical transformations of these complexes. However, our continuing study of the characteristic reactivity of Group 6 organometallic nitrosyl complexes has recently revealed a number of new product complexes which result from N-O bond cleavage of the nitrosyl groups in the reactants. The various reactions and reaction conditions during which these complexes undergo facile nitrosyl N-O bond dissociation are summarized, and mechanistic ideas as to why these bond cleavages occur are also presented.}, keywords = {(ETA-5-C5ME5)RU(NO), ACTIVATION, COORDINATED NITRIC-OXIDE, COORDINATIVELY UNSATURATED BRIDGING, GAS-PHASE, GROUP 6, LIGANDS, MIGRATORY INSERTION, MOLYBDENUM, NITROSYL, NITROSYL BOND CLEAVAGE, OXIDATIVE ADDITION-REACTIONS, OXO COMPLEXES, TUNGSTEN}, isbn = {0260-3594}, url = {://A1995RH84300003}, author = {Legzdins,Peter and Young, M. A.} } @article {3420, title = {SPONTANEOUS ISOMERIZATION OF SYMMETRICAL M(MU-NO)(2)M LINKAGES TO (ON)M=N=M=O GROUPINGS}, journal = {Journal of the American Chemical Society}, volume = {117}, number = {34}, year = {1995}, note = {ISI Document Delivery No.: RR735Times Cited: 13Cited Reference Count: 50}, month = {Aug}, pages = {8798-8806}, type = {Article}, abstract = {{Treatment of Cp*Mo(NO)R(2) complexes (Cp* = eta(5)-C(5)Me(5); R = CH(2)CMe(3), CH(2)CMe(2)Ph) in C6H6 at 5 degrees C with H-2 results in the formation of [Cp*MoR](2)(mu-NO)(2) products (R = CH(2)CMe(3) (1), CH(2)CMe(2)Ph (2)) which are isolable in 25-30\% yields. Similar treatment of an equimolar mixture of Cp*Mo(NO)(CH(2)SiMe(3))(2) and Cp*W(NO)(CH(2)SiMe(3))(2) with H-2 results in the formation of a heterobimetallic species, [Cp*Mo(CH(2)SiMe(3))](mu-NO)(2)[Cp*W(CH(2)SiMe(3))] (3). Complexes 1, 2, and 3 isomerize in solution at ambient temperatures To form [Cp*Mo-(NO)R](mu-N)[Cp*Mo(O)R] (R = CH(2)CMe(3) (4), CH(2)CMe(2)Ph (5)) and a 60:40 (M(1) = W:M(1) = Mo) mixture of [Cp*M(1)(NO)(CH(2)SiMe(3))](mu-N)[Cp*M(2)(O)(CH(2)SiM(3))] (6), respectively. The solid-state molecular structures of 1 and 6 have been established by single-crystal X-ray crystallographic analyses. Crystals of [Cp*Mo(CH(2)CMe(3))](2)-(mu-NO)(2) (1) are orthorhombic of space group Pbcn: a = 12.570(3) Angstrom}, keywords = {(ETA-5-C5ME5)RU(NO), BOND, COMPLEXES, GAS-PHASE, LIGANDS, MOLYBDENUM, NITRIC-OXIDE, ORGANOMETALLIC NITROSYL CHEMISTRY, OXIDATIVE ADDITION-REACTIONS, TUNGSTEN}, isbn = {0002-7863}, url = {://A1995RR73500013}, author = {Legzdins,Peter and Young, M. A. and Batchelor, R. J. and Einstein, F. W. B.} } @article {3102, title = {ALKYL-FOR-IODIDE METATHESIS INITIATED BY DISSOCIATION OF THE PHOSPHINE LIGAND FROM CPCR(NO)(PPH3)I}, journal = {Journal of the American Chemical Society}, volume = {116}, number = {17}, year = {1994}, note = {ISI Document Delivery No.: PD697Times Cited: 6Cited Reference Count: 20}, month = {Aug}, pages = {7700-7705}, type = {Article}, abstract = {{The alkyl-for-iodide metathesis reaction that occurs when CpCr(NO)(PPh(3))I (1) is treated with 2 equiv of Me(3)SiCH(2)MgCl in THF to form CpCr(NO)(PPh(3))(CH(2)SiMe(3)) (6) has been investigated in some detail. The conversion is initiated by loss of the phosphine ligand from the chromium atom{\textquoteright}s coordination sphere, the most compelling evidence for this step being that addition of excess phosphine (e.g. 4 equiv) to the initial reaction mixture completely inhibits the reaction. Four intermediate complexes which are formed sequentially on the reaction path from 1 to 6 have been detected by IR and ESR spectroscopy. These complexes have been identified as CpCr(NO)(THF)I (2), CpCr-(NO{\textendash}>Mg{CH(2)SiMe(3)})Cl)(THF)I (3), CpCr(NO{\textendash}>Mg{CH(2)SiMe(3)}Cl)(THF)(CH(2)SiMe(3)) (4), and CpCr(NO) (THF)(CH(2)SiMe(3)) (5). Complexes 3 and 4 have also been detected spectroscopically during the reaction of CpCr(NO)(THF)I (2) with Me(3)SiCH(2)MgCl which produces CpCr(NO)(THF)(CH(2)SiMe(3)) (5). This understanding of the mechanistic pathway has resulted in the development of a general synthetic route to previously inaccessible 17-valence-electron CpCr(NO)(L)R complexes (L = C5H11N Or NH(2)CMe(3)}, keywords = {COMPLEXES, MECHANISM, MO, MOLYBDENUM, ORGANOMETALLIC NITROSYL CHEMISTRY, TUNGSTEN}, isbn = {0002-7863}, url = {://A1994PD69700029}, author = {Legzdins,Peter and Shaw, M. J.} } @article {2976, title = {FACILE NITROSYL N-O BOND-CLEAVAGE UPON THERMOLYSIS OF CP-ASTERISK-W(NO)PH2}, journal = {Organometallics}, volume = {13}, number = {5}, year = {1994}, note = {ISI Document Delivery No.: NL713Times Cited: 20Cited Reference Count: 18}, month = {May}, pages = {2088-2091}, type = {Note}, abstract = {{Thermolysis of Cp*W(NO)Ph2 (1) in C6H6 at 60-degrees-C for 24 h affords the new nitrosyl N-0 bond cleavage products Cp*W(eta2-ONPh)(NPh)Ph (2) and [Cp*W(O)Ph](mu-N)[Cp*W(NO)Ph] (3), as well as the known Cp*W(O)2Ph (4), in isolated yields of 10, 9, and 30\%, respectively. Complex 2 has been subjected to a single-crystal X-ray crystallographic analysis. Crystals of 2 are orthorhombic, space group Pcab, with a = 16.538(2) angstrom}, keywords = {CHEMISTRY, COMPLEXES, CP{\textquoteright}M(NO)R2, MOLYBDENUM, TUNGSTEN}, isbn = {0276-7333}, url = {://A1994NL71300077}, author = {Brouwer, E. B. and Legzdins,Peter and Rettig, S. J. and Ross, K. J.} } @article {3098, title = {LIGAND CONTROL OF ELECTRONIC STABILITY - 17-VALENCE VS 18-VALENCE ELECTRON CONFIGURATIONS OF CPCR(NO)(LIGAND)(2) COMPLEXES}, journal = {Journal of the American Chemical Society}, volume = {116}, number = {13}, year = {1994}, note = {ISI Document Delivery No.: NV421Times Cited: 6Cited Reference Count: 24}, month = {Jun}, pages = {6021-6022}, type = {Note}, keywords = {MOLYBDENUM, SUBSTITUTION}, isbn = {0002-7863}, url = {://A1994NV42100084}, author = {Legzdins,Peter and McNeil, W. S. and Batchelor, R. J. and Einstein, F. W. B.} } @article {3101, title = {STEPWISE HYDROLYSIS OF A TERMINAL NITROSYL LIGAND}, journal = {Journal of the American Chemical Society}, volume = {116}, number = {26}, year = {1994}, note = {ISI Document Delivery No.: QA288Times Cited: 18Cited Reference Count: 19}, month = {Dec}, pages = {12105-12106}, type = {Note}, keywords = {CHEMISTRY, COMPLEXES, CONVERSION, ELECTROCATALYTIC REDUCTION, MOLYBDENUM, NITRIC-OXIDE, TUNGSTEN, WATER}, isbn = {0002-7863}, url = {://A1994QA28800082}, author = {Legzdins,Peter and Rettig, S. J. and Sayers, S. F.} } @article {2790, title = {OCTAMOLYBDENUM OXO-PYRAZOLATE CLUSTERS - SYNTHESES, CHARACTERIZATION, AND CRYSTAL AND MOLECULAR-STRUCTURES OF THE MO(V)/MO(VI) AND MO(VI) OCTAMOLYBDENUM CLUSTERS MO8(PZ)6O18(PZH)6 AND MO8(PZ)6O21(PZH)6}, journal = {Inorganic Chemistry}, volume = {32}, number = {23}, year = {1993}, note = {ISI Document Delivery No.: MG613Times Cited: 20Cited Reference Count: 36}, month = {Nov}, pages = {5176-5182}, type = {Article}, abstract = {{Two octamolybdenum compounds, containing both bridging pyrazolate and terminal pyrazole ligands, have been prepared by the reaction of molten pyrazole with molybdenum oxides, and their structures have been determined by single-crystal X-ray diffraction. Crystals of Mo8(pz)6O18(pzH)6.2pzH (1;pzH=pyrazole, C3H4N2; pz = pyrazolate anion, C3H3N2) are monoclinic, space group C2/c, with a = 23.026(3) angstrom}, keywords = {3, 5-DIMETHYLPYRAZOLATE, CATALYSIS, CHEMISTRY, COMPLEXES, HETEROPOLY, MAGNETIC-PROPERTIES, MOLYBDATES, MOLYBDENUM, OXYGEN, POLYMERS}, isbn = {0020-1669}, url = {://A1993MG61300039}, author = {Ehlert, M. K. and Rettig, S. J. and Storr, A. and Thompson, R. C. and Trotter, J.} } @article {2790, title = {OCTAMOLYBDENUM OXO-PYRAZOLATE CLUSTERS - SYNTHESES, CHARACTERIZATION, AND CRYSTAL AND MOLECULAR-STRUCTURES OF THE MO(V)/MO(VI) AND MO(VI) OCTAMOLYBDENUM CLUSTERS MO8(PZ)6O18(PZH)6 AND MO8(PZ)6O21(PZH)6}, journal = {Inorganic Chemistry}, volume = {32}, number = {23}, year = {1993}, note = {ISI Document Delivery No.: MG613Times Cited: 20Cited Reference Count: 36}, month = {Nov}, pages = {5176-5182}, type = {Article}, abstract = {{Two octamolybdenum compounds, containing both bridging pyrazolate and terminal pyrazole ligands, have been prepared by the reaction of molten pyrazole with molybdenum oxides, and their structures have been determined by single-crystal X-ray diffraction. Crystals of Mo8(pz)6O18(pzH)6.2pzH (1;pzH=pyrazole, C3H4N2; pz = pyrazolate anion, C3H3N2) are monoclinic, space group C2/c, with a = 23.026(3) angstrom}, keywords = {3, 5-DIMETHYLPYRAZOLATE, CATALYSIS, CHEMISTRY, COMPLEXES, HETEROPOLY, MAGNETIC-PROPERTIES, MOLYBDATES, MOLYBDENUM, OXYGEN, POLYMERS}, isbn = {0020-1669}, url = {://A1993MG61300039}, author = {Ehlert, M. K. and Rettig, S. J. and Storr, A. and Thompson, R. C. and Trotter, J.} } @article {2790, title = {OCTAMOLYBDENUM OXO-PYRAZOLATE CLUSTERS - SYNTHESES, CHARACTERIZATION, AND CRYSTAL AND MOLECULAR-STRUCTURES OF THE MO(V)/MO(VI) AND MO(VI) OCTAMOLYBDENUM CLUSTERS MO8(PZ)6O18(PZH)6 AND MO8(PZ)6O21(PZH)6}, journal = {Inorganic Chemistry}, volume = {32}, number = {23}, year = {1993}, note = {ISI Document Delivery No.: MG613Times Cited: 20Cited Reference Count: 36}, month = {Nov}, pages = {5176-5182}, type = {Article}, abstract = {{Two octamolybdenum compounds, containing both bridging pyrazolate and terminal pyrazole ligands, have been prepared by the reaction of molten pyrazole with molybdenum oxides, and their structures have been determined by single-crystal X-ray diffraction. Crystals of Mo8(pz)6O18(pzH)6.2pzH (1;pzH=pyrazole, C3H4N2; pz = pyrazolate anion, C3H3N2) are monoclinic, space group C2/c, with a = 23.026(3) angstrom}, keywords = {3, 5-DIMETHYLPYRAZOLATE, CATALYSIS, CHEMISTRY, COMPLEXES, HETEROPOLY, MAGNETIC-PROPERTIES, MOLYBDATES, MOLYBDENUM, OXYGEN, POLYMERS}, isbn = {0020-1669}, url = {://A1993MG61300039}, author = {Ehlert, M. K. and Rettig, S. J. and Storr, A. and Thompson, R. C. and Trotter, J.} } @article {2785, title = {REACTIONS OF 16-ELECTRON CP{\textquoteright}M(NO)R2 COMPOUNDS [M = MO, W R = ALKYL, ARYL] WITH CARBON-MONOXIDE}, journal = {Organometallics}, volume = {12}, number = {6}, year = {1993}, note = {ISI Document Delivery No.: LG158Times Cited: 14Cited Reference Count: 28}, month = {Jun}, pages = {2085-2093}, type = {Article}, abstract = {{This paper reports the reactions of 16-electron Cp{\textquoteright}M(NO)R2 complexes [Cp{\textquoteright} = CP (eta5-C5H5), Cp* (eta5-C5Me5); M = Mo, W; R = alkyl, aryl] with carbon monoxide. The reactions proceed in a stepwise fashion, and their outcomes are dependent on both the natures of Cp{\textquoteright} and R and the experimental conditions employed. Thus, treatment of solutions of Cp{\textquoteright}W(NO)R2 with CO under ambient conditions affords the corresponding 18-electron monoacyl species Cp{\textquoteright}W(NO)-(eta2-C{O}R) (R) (Cp{\textquoteright} = Cp*}, keywords = {COORDINATION, CRYSTAL, ETA-2-ACYL COMPLEXES, MOLYBDENUM, ORGANOMETALLIC NITROSYL CHEMISTRY, TUNGSTEN}, isbn = {0276-7333}, url = {://A1993LG15800019}, author = {Dryden, N. H. and Legzdins,Peter and Lundmark, P. J. and Riesen, A. and Einstein, F. W. B.} } @article {2778, title = {REACTIVITY OF THE LEWIS-ACIDS CP-ASTERISK-M(NO)(CH2CME3)CL [M = MO, W] AND RELATED COMPLEXES}, journal = {Organometallics}, volume = {12}, number = {7}, year = {1993}, note = {ISI Document Delivery No.: LU682Times Cited: 26Cited Reference Count: 43}, month = {Jul}, pages = {2714-2725}, type = {Article}, abstract = {{Treatments of Cp*M(NO)Cl2 [Cp* = eta5-C5Me5; M = Mo, W] with 0.5 equiv of (Me3CCH2)2Mg.X(dioxane) in THF at low temperatures affords the monoalkylated complexes, Cp*M(NO)(CH2CMe3)Cl (1, 1{\textquoteright}). Exposure to a second 0.5 equiv of (Me3CCH2)2Mg.X(dioxane) at higher temperatures produces the dialkyl complexes, Cp*M(NO)(CH2CMe3)2 (2,2{\textquoteright}). Utilizing the two series of Cp*M(NO)Cl2, Cp*M(NO)(CH2CMe3)Cl and Cp*M(NO)(CH2CMe3)2 complexes, the relative electron deficiencies in these 16-electron complexes can be assessed spectroscopically and electrochemically. Without exception, the Mo complexes are the stronger Lewis acids. Also, the mononeopentyl derivatives for both metals are more reactive toward a variety of substrates than are their bis(neopentyl) analogues. Complexes 1 and 1{\textquoteright} serve as precursors to mixed alkyl and alkyl aryl complexes (3, 3{\textquoteright}, 4, 4{\textquoteright}) and yield metal-centered adducts with PMe3 and pyridine (5, 5{\textquoteright}, 6, 6{\textquoteright}). CO and CNCMe3 readily insert into the M-C bonds of 1 and 1{\textquoteright}. The insertion products, Cp*M(NO)(C{E}CH2CMe3)Cl (7, 7{\textquoteright}}, keywords = {ALKYL, C-H, CARBONYLATION, CONVERSION, DERIVATIVES, H ACTIVATION REACTIONS, MIGRATORY INSERTION, MOLYBDENUM, ORGANOMETALLIC NITROSYL CHEMISTRY, TUNGSTEN}, isbn = {0276-7333}, url = {://A1993LU68200046}, author = {Debad, J. D. and Legzdins,Peter and Rettig, S. J. and Veltheer, J. E.} } @article {2853, title = {SYNTHESIS, CHARACTERIZATION, AND REACTIVITY OF ALKOXO COMPLEXES CONTAINING CP-ASTERISK-M(NO) GROUPS (M=MO, W)}, journal = {Organometallics}, volume = {12}, number = {9}, year = {1993}, note = {ISI Document Delivery No.: LX172Times Cited: 11Cited Reference Count: 29}, month = {Sep}, pages = {3545-3552}, type = {Article}, abstract = {{Stepwise treatment of Cp*M(NO)Cl2 [CP* = eta5-C5Me5;M = Mo,W] in THF at low temperatures with 2 equiv of alkoxide anion affords first Cp*M(NO)(OR)CI complexes and then the bis(alkoxo) compounds Cp*M(NO)(OR)2 [M = Mo}, keywords = {ALKYL, MOLYBDENUM, ORGANOMETALLIC NITROSYL CHEMISTRY, PI-DONATION, TUNGSTEN}, isbn = {0276-7333}, url = {://A1993LX17200029}, author = {Legzdins,Peter and Lundmark, P. J. and Rettig, S. J.} } @article {2856, title = {THERMAL CHEMISTRY OF CPMO(NO)(CH2CME3)2 - LEWIS BASE ADDUCTS OF CPMO(NO)(=CHCME3) AND A NEW BONDING MODE FOR NITRIC-OXIDE}, journal = {Organometallics}, volume = {12}, number = {9}, year = {1993}, note = {ISI Document Delivery No.: LX172Times Cited: 28Cited Reference Count: 55}, month = {Sep}, pages = {3575-3585}, type = {Article}, abstract = {{Treatment of CpMo(NO)Cl2 with (Me3CCX2)2Mg-X(dioxane) [X = H, D] in THF at low temperatures provides moderate yields of the bis(neopentyl) complexes, CpMo(NO)(CH2CMe3)2 (1) and CpMo(NO)(CD2CMe3)2 (1-d4). The solid-state molecular structure of 1-d4 has been determined at 170 K. Crystals of 1-d4 are monoclinic of space group P2(1)/n; a = 5.9781(6) angstrom}, keywords = {METAL MULTIPLE BONDS, METATHESIS, MOLYBDENUM, NEOPENTYLIDENE COMPLEXES, ORGANOMETALLIC NITROSYL CHEMISTRY, {LIGANDS}, isbn = {0276-7333}, url = {://A1993LX17200033}, author = {Legzdins,Peter and Rettig, S. J. and Veltheer, J. E. and Batchelor, R. J. and Einstein, F. W. B.} } @article {7196, title = {ORGANOMETALLIC NITROSYL CHEMISTRY .51. NEW ORGANOMETALLIC NITROSYL CATIONS CONTAINING THE GROUP-6 ELEMENTS}, journal = {Organometallics}, volume = {11}, number = {2}, year = {1992}, note = {ISI Document Delivery No.: HE298Times Cited: 14Cited Reference Count: 39}, month = {Feb}, pages = {913-922}, type = {Article}, abstract = {{Treatment of the dihalo nitrosyl complexes of molybdenum and tungsten, Cp{\textquoteright}M(NO)X2 (Cp{\textquoteright} = Cp (eta(5)-C5H5), Cp* (eta(5)-C5Me5); M = Mo, W;X = Cl, Br, I), in CH3CN with NO+ or Ag+ salts affords a series of new diamagnetic cationic nitrosyl complexes, [Cp*Mo(NO)(NCCH3)3]2+ and [Cp{\textquoteright}M(NO)X(NCCH3)2]+. Eight such complexes have been isolated analytically pure as either their PF6- or BF4- salts by crystallization from CH3CN/Et2O. The physical and spectroscopic properties of these organometallic cations are consistent with their possessing four-legged piano stool molecular structures. This conclusion has been confirmed by single-crystal X-ray crystallographic analyses of [Cp*Mo(NO)(NCCH3)3][PF6]2 and [CpMo(NO)Cl-(NCCH3)2]BF4 which also establish that the acetonitrile ligands are coordinated linearly through their N atoms to the metal centers. Crystal data for [Cp*Mo(NO)(NCCH3)3][PF6]2: monoclinic}, keywords = {COMPLEXES, HEXAFLUOROPHOSPHATE, MO, MOLYBDENUM, REDUCTION}, isbn = {0276-7333}, url = {://A1992HE29800062}, author = {Chin, T. T. and Legzdins,Peter and Trotter, J. and Yee, V. C.} } @article {7196, title = {ORGANOMETALLIC NITROSYL CHEMISTRY .51. NEW ORGANOMETALLIC NITROSYL CATIONS CONTAINING THE GROUP-6 ELEMENTS}, journal = {Organometallics}, volume = {11}, number = {2}, year = {1992}, note = {ISI Document Delivery No.: HE298Times Cited: 14Cited Reference Count: 39}, month = {Feb}, pages = {913-922}, type = {Article}, abstract = {{Treatment of the dihalo nitrosyl complexes of molybdenum and tungsten, Cp{\textquoteright}M(NO)X2 (Cp{\textquoteright} = Cp (eta(5)-C5H5), Cp* (eta(5)-C5Me5); M = Mo, W;X = Cl, Br, I), in CH3CN with NO+ or Ag+ salts affords a series of new diamagnetic cationic nitrosyl complexes, [Cp*Mo(NO)(NCCH3)3]2+ and [Cp{\textquoteright}M(NO)X(NCCH3)2]+. Eight such complexes have been isolated analytically pure as either their PF6- or BF4- salts by crystallization from CH3CN/Et2O. The physical and spectroscopic properties of these organometallic cations are consistent with their possessing four-legged piano stool molecular structures. This conclusion has been confirmed by single-crystal X-ray crystallographic analyses of [Cp*Mo(NO)(NCCH3)3][PF6]2 and [CpMo(NO)Cl-(NCCH3)2]BF4 which also establish that the acetonitrile ligands are coordinated linearly through their N atoms to the metal centers. Crystal data for [Cp*Mo(NO)(NCCH3)3][PF6]2: monoclinic}, keywords = {COMPLEXES, HEXAFLUOROPHOSPHATE, MO, MOLYBDENUM, REDUCTION}, isbn = {0276-7333}, url = {://A1992HE29800062}, author = {Chin, T. T. and Legzdins,Peter and Trotter, J. and Yee, V. C.} } @article {7218, title = {ORGANOMETALLIC NITROSYL CHEMISTRY .53. SYNTHESIS, CHARACTERIZATION, AND PROPERTIES OF 16-ELECTRON CP-ASTERISK-M(NO)(ARYL)2 (M = MO, W) COMPLEXES}, journal = {Organometallics}, volume = {11}, number = {7}, year = {1992}, note = {ISI Document Delivery No.: JD622Times Cited: 37Cited Reference Count: 28}, month = {Jul}, pages = {2583-2590}, type = {Article}, abstract = {{Treatment of Cp*M(NO)Cl2 (Cp* = eta-5-C5Me5; M = Mo, W) in THF at low temperatures with equimolar amounts of diarylmagnesium reagents, (aryl)2Mg.x(dioxane), affords the diaryl complexes Cp*M(NO)(aryl)2 (aryl = Ph, o-tolyl, or p-tolyl), which are isolable in moderate yields and have been fully characterized by conventional spectroscopic methods. In addition, single-crystal X-ray crystallographic analyses have been performed on both o-tolyl complexes. Crystal data for Cp*Mo(NO)(o-tolyl)2 (3): a = 11.570 (2) angstrom}, keywords = {MOLYBDENUM, TUNGSTEN}, isbn = {0276-7333}, url = {://A1992JD62200048}, author = {Dryden, N. H. and Legzdins,Peter and Rettig, S. J. and Veltheer, J. E.} } @article {7302, title = {ORGANOMETALLIC OXO CHEMISTRY .4. REACTIVITY OF CP-ASTERISK-W(O)2(CH2SIME3) TOWARD PARA-TOLYL ISOCYANATE - CYCLOADDITION REACTIONS OF TUNGSTEN-OXO AND TUNGSTEN-IMIDO LINKAGES}, journal = {Organometallics}, volume = {11}, number = {9}, year = {1992}, note = {ISI Document Delivery No.: JN066Times Cited: 50Cited Reference Count: 40}, month = {Sep}, pages = {3104-3110}, type = {Article}, abstract = {{Treatment of CP*W(O)2(CH2SiMe3) with p-tolyl isocyanate under appropriate experimental conditions leads to the formation of Cp*W(O)(NC6H4-p-Me)(CH2SiMe3) (1), Cp*W(NC6H4-p-Me)2(CH2SiMe3) (2), or Cp*W(NC6H4-P-Me)[N(C6H4-P-Me)C(O)N(C6H4-P-Me)](CH2SiMe3) (3). Each of the complexes 1-3 is derived in a sequential manner from its precursor by incorporation of an additional p-tolyl isocyanate fragment or molecule. The spectroscopic properties of these organometallic imido complexes are consistent with their possessing three-legged (1 and 2) and four-legged (3) piano-stool molecular structures. These conclusions have been confirmed by single-crystal X-ray crystallographic analyses of 2 and 3. Crystal data for 2: triclinic}, keywords = {ACTIVATION, AMIDO, AMMOXIDATION, COMPLEXES, LIGANDS, METAL, MOLYBDENUM, OXIDATION, propylene, SULFIDO}, isbn = {0276-7333}, url = {://A1992JN06600027}, author = {Legzdins,Peter and Phillips, E. C. and Rettig, S. J. and Trotter, J. and Veltheer, J. E. and Yee, V. C.} } @article {7302, title = {ORGANOMETALLIC OXO CHEMISTRY .4. REACTIVITY OF CP-ASTERISK-W(O)2(CH2SIME3) TOWARD PARA-TOLYL ISOCYANATE - CYCLOADDITION REACTIONS OF TUNGSTEN-OXO AND TUNGSTEN-IMIDO LINKAGES}, journal = {Organometallics}, volume = {11}, number = {9}, year = {1992}, note = {ISI Document Delivery No.: JN066Times Cited: 50Cited Reference Count: 40}, month = {Sep}, pages = {3104-3110}, type = {Article}, abstract = {{Treatment of CP*W(O)2(CH2SiMe3) with p-tolyl isocyanate under appropriate experimental conditions leads to the formation of Cp*W(O)(NC6H4-p-Me)(CH2SiMe3) (1), Cp*W(NC6H4-p-Me)2(CH2SiMe3) (2), or Cp*W(NC6H4-P-Me)[N(C6H4-P-Me)C(O)N(C6H4-P-Me)](CH2SiMe3) (3). Each of the complexes 1-3 is derived in a sequential manner from its precursor by incorporation of an additional p-tolyl isocyanate fragment or molecule. The spectroscopic properties of these organometallic imido complexes are consistent with their possessing three-legged (1 and 2) and four-legged (3) piano-stool molecular structures. These conclusions have been confirmed by single-crystal X-ray crystallographic analyses of 2 and 3. Crystal data for 2: triclinic}, keywords = {ACTIVATION, AMIDO, AMMOXIDATION, COMPLEXES, LIGANDS, METAL, MOLYBDENUM, OXIDATION, propylene, SULFIDO}, isbn = {0276-7333}, url = {://A1992JN06600027}, author = {Legzdins,Peter and Phillips, E. C. and Rettig, S. J. and Trotter, J. and Veltheer, J. E. and Yee, V. C.} }