14592-26-8Relevant academic research and scientific papers
Kinetics and Mechanism of CO Substitution of M2(CO)10 (M = Mn, Re) with an Entering Ligand (PPh3 or Py) in the Presence of an O-Atom Transfer Reagent (Me3NO or (CH3OC6H4)2TeO)
Gao, Yi-Ci,Shen, Jian-Kun,Peng, Li,Shi, Qi-Zhen,Basolo, Fred
, p. 464 - 469 (2007/10/02)
Detailed kinetic data are reported for the CO substitution of M2(CO)10 ( M = Mn, Re) with PPh3 or Py in the presence of Me3NO or (CH3OC6H4)TeO as an O atom transfer reagent in CHCl3 solvent.The rates of reactions are first order in concentrations of M2(CO
Ring-opening Hydroformylation of α-Cyclopropylstyrene by HMn(CO)5, and Structure of a Novel Mn2(CO)9(η1-Aldehyde) Complex
Bullock, R. Morris,Rappoli, Brian J.,Samsel, Edward G.,Rheingold, Arnold L.
, p. 261 - 263 (2007/10/02)
An η1-aldehyde complex, Mn2(CO)9, was isolated from the reaction of α-cyclopropylstyrene with wet HMn(CO)5; the crystal structure of this unusual compound confirmed the η1 (?) bonding of the aldehyde oxygen as an equatorial ligand on Mn2(CO)9.
Formation of metal-metal bonds by ion-pair annihilation. Dimanganese carbonyls from manganate(-I) anions and manganese(I) cations
Lee,Kuchynka,Kochi
, p. 1886 - 1897 (2008/10/08)
The coupling of the anionic Mn(CO)5- and the cationic Mn(CO)6+ occurs upon mixing to afford the dimeric Mn2(CO)10 in essentially quantitative yields. Dimanganese decacarbonyl is formed with equal facility from the coupling of Mn(CO)5- with Mn(CO)5(py)+ and Mn(CO)5(NCMe)+. By way of contrast, the annihilation of Mn(CO)4PPh3- with Mn(CO)6+ yields a pair of homo dimers Mn2(CO)10 and Mn2(CO)8(PPh3)2 together with the cross dimer Mn2(CO)9PPh3. Extensive scrambling of the carbonylmanganese moieties also obtains with Mn(CO)4P(OPh)3- and Mn(CO)5PPh3+, as indicated by the production of Mn2(CO)8[P(OPh)3]2, Mn2(CO)8[P(OPh)3](PPh3), and Mn2(CO)8(PPh3)2 in more or less statistical amounts. These diverse Mn-Mn couplings can be accounted for by a generalized formulation (Scheme VI), in which the carbonylmanganese anions Mn(CO)4P- and the cations Mn(CO)5L+ undergo an initial electron transfer to produce Mn(CO)4P? and Mn(CO)5L?, respectively. The behaviors of these 17- and 19-electron radicals coincide with those independently generated in a previous study of the anodic oxidation of Mn(CO)4P- and the cathodic reduction of Mn(CO)5L+, respectively. The facile associative ligand substitution of 17-electron carbonylmanganese radicals by added phosphines provides compelling evidence for the interception of Mn(CO)4P? and its interconversion with 19-electron species in the course of ion-pair annihilation. The reactivity trend for the various ion pairs qualitatively parallels the driving force for electron transfer based on the oxidation and reduction potentials of Mn(CO)4P- and Mn(CO)5L+, respectively, in accord with the radical-pair mechanism in Scheme VI.
Syntheses and dynamic stereochemistry of hydrido-carbonyl heterobinuclear metal-metal bonded complexes. Crystal structures of MoPt(H)(η-C5H5)(CO)3(PPh3) 2(Mo-Pt) and MnPt(μ-H)(μ-CO)(CO)4(PEt3)2(Mn-Pt)
Bars, Odile,Braunstein, Pierre,Geoffroy, Gregory L.,Metz, Bernard
, p. 2021 - 2030 (2008/10/08)
The hydrido-carbonyl heterobinuclear complexes MPt(H)(η-C5H5)(CO)3(PPh3) 2(M-Pt) (M = Mo, 1; M = W, 2) and MnPt(μ-H)(μ-CO)(CO)4(PR3)2(Mn-Pt) (R = Ph, 3; R = Et, 4) were prepared by the reaction of the corresponding carbonylmetalates with trans-PtH(Cl)(PR3)2. X-ray diffraction studies have been performed on complexes 1 and 4. Data for 1: monoclinic, P21/n, a = 15.42 (1) A?, b = 16.44 (1) A?, c = 16.50 (2) A?, β = 103.13 (5)°, V = 4076 A?3, Z = 4, R = 0.053, Rw = 0.080 for 4159 reflections with I ≥ 3σ(I). The molecule consists of a CpMo(CO)3 fragment bonded to a Pt atom (Mo-Pt = 2.839 (1) A?) which is further ligated by two mutually cis PPh3 ligands and a hydride ligand in a terminal position. Data for 4: monoclinic, P21/n, a = 11.142 (2) A?, b = 18.999 (4) A?, c = 11.661 (2) A?, β = 104.81 (1)°, V = 2387 A?3, Z = 4, R = 0.059, Rw = 0.075 for 2899 reflections with I ≥ 3σ(I). The environment about the Pt atom is planar and consists of the two mutually cis PEt3 ligands, the bridging carbonyl, and the bridging hydride (the latter not located by X-ray diffraction). The Mn atom, which is in the octahedral environment defined by the bridging ligands and the four terminal carbonyls, is at distance of 2.730 (2) A from the Pt atom. Spectroscopic, IR, and 1H, 31P{1H}, and 31P NMR data are discussed and are consistent with the structure of the complexes. These heterobinuclear complexes undergo a unique fluxional process, which is detailed for 1 and 4. The observed changes in the temperature-dependent 1H NMR spectra imply a mutual exchange process, equivalencing the phosphorus atoms, that maintains spin correlation and is thus strictly intramolecular and nondissociative, within the limits of the NMR experiment. The mechanism is discussed, and connections made with the chemical behavior of the complexes.
Substitution of Mn(CO)5 Is Associative
Herrinton, Thomas R.,Brown, Theodore L.
, p. 5700 - 5703 (2007/10/02)
The substitution of Mn(CO)5 radicals by triphenylphosphine (PPh3) or triphenylarsine (AsPh3) in hexane has been studied by observing the manner in which the competition between CCl4 and PPh3 or between CH2Br2 and AsPh3 is affected by changes in concentrations of the reactants.In both cases the substitution process shows kinetics behavior indicative of an associative process.The second-order rate constants are 1.7 (+/- 0.2) E7 and 6.5 (+/-0.8) E4 M-1 s-1 for PPh3 and AsPh3, respectively, in hexane at 24 deg C.Less extensive measurements provide analogous bimolecular rate constants for substitution by P(n-Bu)3, P(i-Pr)3, and P(O-i-Pr)3 of 1.0 (+/-0.1) E9, 6.7 (+/-0.7) E7, and 3.1 (+/-0.3) E7 M-1 s-1, respectively.There is no evidence in the results for a concurrent dissociative loss of CO from Mn(CO)5.On the basis of the data for AsPh3, which exhibits the smallest associative rate constant, the first-order dissociative rate constant must be less than about 90 s-1.
