61091-28-9Relevant articles and documents
Electrochemical synthesis and structure of Sn[Co(CO)4]4 and its use as a stable precursor of [Co(CO)4]- for the catalysis of hydrolysis of propylene carbonate
Cabrera, Armando,Samain, Henri,Mortreux, André,Petit, Francis,Welch, Alan J.
, p. 959 - 964 (1990)
The complex Sn[Co(CO)4]4 (I) has been prepared in high yield by the controlled potential electrolysis of Co2(CO)8 in the presence of a tin anode. The major advantage afforded by this electrochemical synthesis is to produce I quickly and cleanly. Results of an X-ray diffraction study on I are reported. We have established that I and Co2(CO)8 are very active catalysts for the hydrolysis of cyclic organic carbonates. The 100% selectivity in mpnoglycol is in marked contrast to other catalytic systems that require an excess of water to inhibit production of polyglycols. Studies, under various CO pressures, of the catalytic activities of Co2(CO)8 and I during the hydrolysis of propylene carbonate have led us to suggest that (i) [Co(CO)4]- is the active moiety, (ii) I can eliminate Co2(CO)8, and (iii) I is more stable than Co2(CO)8 at low CO pressures. Isotopic analysis of the remaining substrate and products after the hydrolysis of propylene carbonate by H218O show that (iv) the attack of water occurs at the carbonyl site of the carbonate and (v) it is likely that hydration is activated by [Co(CO)4]-.
Octacarbonyl dicobalt-catalyzed selective transformation of ethyl diazoacetate into organic products containing the ethoxycarbonyl carbene building block
Tuba, Robert,Ungváry, Ferenc
, p. 59 - 67 (2008/10/08)
In the presence of 1 mol% octacarbonyl dicobalt ethyl diazoacetate can be transformed at room temperature and carbon monoxide pressure selectively into diethyl 2-diazo-3-oxo-pentanedicarboxylate or in the presence of an alcohol (methanol, ethanol, tert-bu
DECARBOXYLATION OF ALKOXYCARBONYLCOBALT CARBONYLS
Bartik, Tamas,Kruemmling, Thomas,Marko, Laszlo,Palyi, Gyula
, p. 307 - 308 (2007/10/02)
Alkoxycarbonylcobalt tetracarbonyls undergo thermal decarboxylation between 25 and 90 deg C yielding up to 67percent CO2/Co atom; the decarboxylation is favoured by ligand excess (CO, PR3, NEt3).
Steric and Electronic Factors That Control Two-Electron Processes between Metal Carbonyl Cations and Anions
Zhen, Yueqian,Feighery, William G.,Lai, Chung-Kung,Atwood, Jim D.
, p. 7832 - 7837 (2007/10/02)
Reactions of metal carbonyl cations (Mn(CO)6(+), Re(CO)6(+), Mn(CO)5PPh3(+), Mn(CO)4(PPh3)2(+), Mn(CO)5PEt3(+), Mn(CO)5PPh2Me(+), Re(CO)5PPh3(+), and CpFe(CO)3(+)) with metal carbonyl anions (Co(CO)3PPh3(-), Co(CO)4(-), Mn(CO)5(-), Mn(CO)4PPh3(-), Mn(CO)4PEt3(-), Mn(CO)4PPh2Me(-), Mn(CO)3(PPh3)2(-), CpFe(CO)2(-), Re(CO)5(-), and Re(CO)4PPh3(-)) are reported.Peak potentials are reported for all ions, and nucleophilicites (as measured by reaction with MeI) are reported for the anions.Reaction of any metal carbonyl cation with any metal carbonyl anion leads ultimately to binuclear products, which are the thermodynamic products.The binuclear products are formed by single-electron transfer.In over half of the reactions between metal carbonyl cations and anions, a two-electron change results in a new metal carbonyl cation and anion.The two-electron change may be considered mechanistically as a CO(2+) transfer with the more nucleophilic of the two anions retaining the CO(2+).The kinetic and thermodynamic driving forces and the suggested mechanism are examined.
Photochemical Splitting of a Polar Metal-Metal Bond by Metal to Metal Charge Transfer Excitation of
Vogler, Arnd,Kunkely, Horst
, p. 132 - 134 (2007/10/02)
The polar metal-metal bond of I-Co-I(CO)4> was cleaved photochemically by metal to metall (Co-IAu+I) charge transfer excitation.Metallic gold, Ph3P and were formed as products. - Keywords: Photolysis, Metal-Metal Bond, Charge Transfer Excitation
Alkylcobalt carbonyls. 9. Alkoxy-, silyloxy-, and hydroxy-substituted methyl- and acetylcobalt carbonyls. Reduction of formaldehyde to methanol by hydridocobalt tetracarbonyl
Sisak, Attila,Sámpár-Szerencsés, Ella,Galamb, Vilmos,Németh, László,Ungváry, Ferenc,Pályi, Gyula
, p. 1096 - 1100 (2008/10/08)
(Alkoxymethyl)-, ((silyloxy)methyl)-, and (hydroxymethyl)cobalt and (alkoxyacetyl)-, ((silyloxy)acetyl)-, and (hydroxyacetyl)cobalt tetracarbonyls and phosphine-substituted derivatives were prepared. The interconversions of these compounds by carbonylatio
Benzyltitanium and -zirconium cobalt carbonyls. Preparation and spectroscopic characterization
Bartik, Tamás,Happ, Berit,Sorkau, Angela,Thiele, Karl-Heinz,Pályi, Gyula
, p. 558 - 560 (2008/10/08)
Tetrabenzyltitanium (1a) and -zirconium (1b) react with equimolar HCo(CO)4 (2) to give the corresponding tribenzylmetal-cobalt tetracarbonyl (M = Ti, 5a; M = Zr, 5b) derivatives. Compounds 5 also can be obtained from (PhCH2)3/s
Reactions of homo- and heterobinuclear cobalt carbonyls with metal carbonyl hydrides
Kovács, István,Sisak, Attila,Ungváry, Ferenc,Markó, László
, p. 1873 - 1877 (2008/10/08)
HMn(CO)5, HMo(CO)3Cp, and HFe(CO)2Cp (Cp = cyclopentadienyl) were found to react with Co2(CO)8 forming HCo(CO)4 and the corresponding mixed-metal carbonyl dimers. It was shown that HMo(CO)3Cp transferred the hydrogen atom to Co2(CO)8 and CoMn(CO)9 in reversible processes. The substituted hydride HMn(CO)4P-n-Bu3 and Co2(CO)8 afforded (CO)4CoMn(CO)4P-n-Bu3 which was characterized by elementary analysis and IR and mass spectroscopy. Its reaction with HMo(CO)3Cp gave HMn(CO)4P-n-Bu3 and CoMo(CO)7Cp. The attack of the hydrides took place in mixed-metal complexes exclusively on the cobalt atom. A mechanism in which the hydrides oxidatively add to a coordinatively unsaturated Co center formed by CO loss is proposed.
Photochemistry of (M = Zn, Cd, Hg) induced by metal to metal charge transfer excitation
Vogler, A.,Kunkely, H.
, p. 1 - 6 (2007/10/02)
The electronic absorption spectra of the complexes -1MIICo-1(CO)4> with M = Zn, Cd, and Hg display an intense long-wavelength band which is assignated to the allowed Σu+ -> Σg+ transition from a non-bonding ? to an antibonding ? orbital of the Co-M-Co moiety.This transition is shifted to higher energies and gains an increasing charge transfer (CT) contribution in changing M in the order M = Hg, Cd, and Zn.In a limiting description the ?n -> ?* transition can be regarded as a metal to metal (MM) CT transition from Co-1 to MII.MMCT excitation induced a photoredox reaction: -1-MII-Co-1(CO)4> -> M0 + 02(CO)8>.The quantum yields are Φ = 0.45 (λirr = 333 nm) for M = Hg and Φ = 0.03 (λirr = 313 nm) for Cd.
The mechanism of the formation of silyl enol ethers from hydrosilanes and organic carbonyl compounds in the presence of cobalt carbonyls. Kinetic investigation of some reaction steps
Kovács, István,Sisak, Attila,Ungváry, Ferenc,Markó, László
, p. 1025 - 1028 (2008/10/08)
The cleavage of isobutyrylcobalt tetracarbonyl with triethylsilane gives (triethylsilyl)cobalt tetracarbonyl, isobutyraldehyde, dicobalt octacarbonyl, and the corresponding unsaturated and saturated silyl ethers. Silyl enol ether was also formed, along wi
