19537-79-2Relevant academic research and scientific papers
IN SITU RAMAN SPECTROSCOPY STUDIES OF THE HYDROFORMYLATION OF PROPYLENE.
Woo,Hill Jr.
, p. 231 - 258 (1985)
In situ Raman spectroscopy studies of the catalytic hydroformylation of propylene have been carried out over Co//2(CO)//6(PPh//3)//2 supported on alumina and on silica. A comparison in situ Raman spectroscopy study of the corresponding homogeneous liquid-phase reaction has also been carried out. The surface reaction intermediates identified spectroscopically in the heterogeneous reaction studies differed from one another for the two supported catalyst systems. The spectral data also indicated that these intermediates are not necessarily identical to those for the homogeneous liquid-phase hydroformylation reaction as catalyzed by Co//2(CO)//6(PPh//3)//2.
An NMR study of cobalt-catalyzed hydroformylation using para-hydrogen induced polarisation
Godard, Cyril,Duckett, Simon B.,Polas, Stacey,Tooze, Robert,Whitwood, Adrian C.
, p. 2496 - 2509 (2009/12/02)
The syntheses of Co(η3-C3H5)(CO) 2PR2R′ (R, R′ = Ph, Me; R, R′ = Me, Ph; R = R′ = Ph, Cy, CH2Ph) and Co(η3-C 3H5)(CO)(L) (L = dmpe and dppe) are described,
Heterodinuclear titanium-cobalt complexes: Syntheses and properties. X-ray structure of [(tC4H9O)3TiCo(CO)4] (Ti-Co)
Selent, Detlef,Beckhaus, Rüdiger,Pickardt, Joachim
, p. 2857 - 2860 (2008/10/08)
An X-ray structural investigation establishes an unbridged Ti-Co bond in [(tC4H9O)3Ti-Co(CO)4] (1a) and shows it to crystallize in the orthorhombic space group Pbn21, with a = 1192.5(7) pm, b = 1375.8(9) pm, c = 1405.0-(10) pm, and Z = 4. The variation of the alkoxide ligand leads to the more thermally unstable derivatives [(RO)3-TiCo(CO)4] (R = i-C3H7, CH(CF3)2, Ph), whereas trans-[(tC4H9O)3TiCo(CO) 3(PPh3)] is formed in a selective axial carbon monoxide ligand substitution reaction between 1a and triphenylphosphine.
Cobalt hydroformylation catalyst supported on a phosphinated polyphosphazene. Identification of phosphorus-carbon bond cleavage as mode of catalyst deactivation
Dubois, Robert A.,Garrou, Philip E.,Lavin, Karen D.,Allcock, Harry R.
, p. 460 - 466 (2008/10/08)
The interaction of Co2(CO)8 with [NP(OPh)1.7(OC6H4PPh2) 0.3]n (1), N3P3(OPh)5(OC6H4PPh 2) (2), PPh2-linked polystyrene (3), or triarylphosphine [PPh3, P(p-CH3C6H4)3] yielded species of the type Co2(CO)7PR3, [Co(CO)3PR3]2, and [Co(CO)3(PR3)2]+Co(CO) 4- as identified by infrared spectroscopy and 31P NMR. Catalysts derived from 1 were expected to have higher thermal stability based on the inherent thermal stability of 1 vs. 3. A study of the catalyst system 1/Co2(CO)8 for 1-hexene hydroformylation revealed an initial activity equal to its homogeneous analogue. This has been rationalized as due to cleavage of cross-linking P-Co-P sites during reaction with CO/H2 to give soluble hydride HCo(CO)3PR3 type species. All of the catalysts also revealed a time-dependent decrease in catalytic activity, due to a cobalt-mediated phosphorus-carbon bond cleavage. Benzene, toluene, benzyl alcohol, and P-MeC6H4CH2OH were detected as primary cleavage products. When olefin was omitted from these reactions, R2PH was observed.
Reaction of acetyl complexes with HMR3 (M = Si, Sn). Mechanism of acetaldehyde formation
Wegman
, p. 707 - 711 (2008/10/08)
The thermal reaction of the acyl complexes CH3C(O)M(CO)xL (M = Co, Mn; L = PPh3) with HM′R3 (M′ = Si, Sn; R = Bu, Ph) results in the formation of acetaldehyde and R3M′M(CO)xL. The rate law for the reaction is consistent with a pathway involving initial CO dissociation from CH3C(O)M(CO)xL, oxidative addition of the H-M′ bond, and reductive elimination of acetaldehyde. With HSnR3 the rate-determining step is CO dissociation from CH3C(O)M(CO)xL. In the case of HSiR3 the rate-determining step is oxidative addition of the H-Si bond.
Kinetic and Thermodynamic Acidity of Hydrido Transition-Metal Complexes. 3. Thermodynamic Acidity of Common Mononuclear Carbonyl Hydrides
Moore, Eric J.,Sullivan, Jeffrey M.,Norton, Jack R.
, p. 2257 - 2263 (2007/10/02)
The pKa values of the common mononuclear carbonyl hydrides have been determined in acetonitrile by IR measurement of the position of deprotonation equilibria with various nitrogen bases and potassium phenolate.The resulting values cover a range of about 20 pKa units, from 8.3 for HCo(CO)4 to 26.6 for CpW(CO)2(PMe3)H.Hydrides with η5-C5Me5 ligands are appreciably weaker acids than the corresponding hydrides with η5-C5H5 ligands (e.g., the pKa of (η5-C5Me5)Fe(CO)2H is 26.3, while that of (η5-C5H5)Fe(CO)2H is 19.4).The acidities of the group 8 carbonyl hydrides H2M(CO)4 decrease in the order Fe > Ru > Os.
Organosilicon Chemistry. Part 26. Silyl Derivatives of Substituted Cobalt Carbonyls, of the Type
Haszeldine, Robert N.,Mather, Adrian P.,Parish, R. V. (Dick)
, p. 923 - 927 (2007/10/02)
The series of cobalt(I) silyl complexes (R = F, n = 1-3; R = Ph or OEt, n = 2 or 3; L = tertiary phosphine or arsine) has been prepared, and the reaction of with PPh3 has been studied.For R = Ph, substitution of CO occu
