Journal: Organometallics

Abbreviation

Organometallics

Publisher

American Chemical Society

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ISSN

1520-6041
0276-7333

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Publications1 - 10 of 132
  • Aqua and Diethyl Ether PNNP Complexes of Ruthenium(II)
    Item type: Journal Article
    Schotes, Christoph; Ranocchiari, Marco; Mezzetti, Antonio (2011)
    Organometallics
  • Cyclopentadienone Iron Complex-Catalyzed Hydrogenation of Ketones
    Item type: Journal Article
    Bütikofer, André; Chen, Peter (2022)
    Organometallics
    The sulfonate charge-tagged cyclopentadienone iron complexes [FeR(MeCN)(CO)2-SO3]Na (R = TMS, tBu) were prepared and used for mechanistic investigations using Pressurized-Sample-Infusion Electrospray-Ionization Mass Spectrometry (PSI-ESI-MS) in the hydrogenation of acetophenone. Reactions were conducted in mixed aqueous/alcoholic solvent. Based on kinetic and mass spectrometric experiments, information about the operating reaction mechanism was obtained. Furthermore, analysis of the kinetic profiles and mass spectra indicated catalyst decomposition. By analysis of the mass spectrometric results, the decomposition cascade was found to start by solvolysis of the TMS groups flanking the carbonyl group in the cyclopentadienone ligand of the catalyst. Subsequent dimerization, comproportionation to form Fe(I) radical species and formation of catalytically inactive iron tricarbonyl species was observed, limiting the catalyst life time. Replacement of the TMS groups by non-hydrolysable tert-butyl groups leads to a significant increase in observed turnover frequency (TOF) and catalyst longevity. The turnover number (TON), determined to be approximately 65 under standardized reaction conditions, could be increased to > 1000 by the mechanism-guided structural change in the catalyst. No compounds corresponding to Fe(I) species or dimerization products could be identified in this case. The present study suggests that for hydrogenations with cyclopentadienone iron complexes, the use of alkyl groups flanking the C=O double bond in the ligand is beneficial over the use of silyl groups when conducted in aqueous media.
  • Diorganostannide Dianions (R2Sn2-) as Reaction Intermediates Revisited
    Item type: Journal Article
    Trummer, Markus; Caseri, Walter (2010)
    Organometallics
  • Structural and 13C NMR Studies on Palladium MOP Compounds
    Item type: Journal Article
    Dotta, Pascal; Kumar, P.G. Anil; Pregosin, Paul S.; et al. (2004)
    Organometallics
  • PGSE NMR Diffusion, Overhauser, and DFT Studies on the Salts [Pd(η3-CH3CHCHCHPh)(dppe)](anion)
    Item type: Review Article
    Schott, Daniele; Pregosin, Paul S. (2005)
    Organometallics
  • Mechanistic Insights from the Gas-Phase Reactivity of Phosphorus-Ylid-Supported Benzylidene Gold Complexes
    Item type: Journal Article
    Fedorov, Alexey; Chen, Peter (2010)
    Organometallics
  • Structure, bonding, and dynamics of several palladium eta(3)-allyl carbene complexes
    Item type: Journal Article
    Filipuzzi, Serena; Pregosin, Paul S.; Albinati, Alberto; et al. (2008)
    Organometallics
  • CpCo-stabilized cyclopentadienones from cyclobutadiene complexes
    Item type: Journal Article
    Schaefer, Carsten; Werz, Daniel B.; Staeb, Tobias H.; et al. (2005)
    Organometallics
  • Pyridine(diimine) Chelate Hydrogenation in a Molybdenum Nitrido Ethylene Complex
    Item type: Journal Article
    Bezdek, Máté; Chirik, Paul J. (2019)
    Organometallics
    Addition of H2 gas to the aryl-substituted pyridine(diimine) molybdenum nitride (iPrPDI)Mo(N)(C2H4) ([1-(N)(η2-C2H4)]; iPrPDI = 2,6-(2,6-iPr2-C6H3N═CMe)2C5H3N) in the presence of the rhodium hydride precatalyst (η5-C5Me5)(py-Ph)Rh(H) ([Rh–H]; py-Ph = 2-phenylpyridine) resulted in partial hydrogenation of the central pyridine of the iPrPDI chelate to yield (iPrTHPDI)Mo(N)(C2H4) ([2-(N)(η2-C2H4)]; iPrTHPDI = 2,6-(2,6-iPr2-C6H3N═CMe)2C5H6N). The product, [2-(N)(η2-C2H4)], was structurally and spectroscopically characterized, and its electronic structure was examined by density functional theory (DFT). The stepwise addition of H atoms from [Rh–H] to [1-(N)(η2-C2H4)] was computed to be thermodynamically viable by DFT. Copyright © 2019 American Chemical Society
  • Synthesis and Reactivity of Reduced α-Diimine Nickel Complexes Relevant to Acrylic Acid Synthesis
    Item type: Journal Article
    Joannou, Matthew V.; Bezdek, Máté; Albahily, Khalid; et al. (2018)
    Organometallics
    The aryl-substituted α-diimine (DI) nickel vinyl complex (iPrDI)Ni(CH═CH2) (iPrDI = [2,6 (iPr)2C6H3N═C(CH3)]2) was synthesized and structurally characterized. The complex is dimeric in the solid state and has a distorted-square-planar geometry at nickel. A combination of single-crystal X-ray diffraction, EPR, magnetic susceptibility, and NMR analyses was used to elucidate the electronic structure of the compound, and it is best described as a low-spin Ni(II) derivative with a singly reduced α diimine chelate. Addition of CO2 to the nickel vinyl complex resulted in insertion into the nickel–carbon bond to yield the corresponding nickel acrylate (iPrDI)Ni(κ2-O2CCH═CH2). EPR spectroscopy coupled with DFT calculations established that the S = 1/2 product maintains the nickel(II) oxidation state with an α-diimine-centered radical. Addition of acrylic acid to (iPrDI)Ni(CH═CH2) induced rapid, net bimetallic reductive elimination to release butadiene and produced the metastable olefin-bound acrylic acid complex (iPrDI)Ni(η2-CH2═CHCO2H). Over the course of 2 h at 23 °C, this complex underwent a net oxidation to produce (iPrDI)Ni(κ2-O2CCH═CH2), with concomitant loss of H2. © 2018 American Chemical Society
Publications1 - 10 of 132