14971-27-8Relevant articles and documents
Reactivity of [ClCCo3(CO)9] with metal iron carbonyl clusters. Formation of carbide and dicarbide mixed metal clusters
Reina, Roser,Riba, Olga,Rossell, Oriol,Seco, Miquel,Font-Bardia, Mercè,Solans, Xavier
, p. 5307 - 5311 (2002)
The reaction of [ClCCo3(CO)9] with (PPh4)2[Fe3(CO)11] in CH2Cl2 at room temperature in the presence of thallium salt gives the brown cluster complex (PPh4)[Co5Fe(C2)(CO)17] (1), on which X-ray crystal structure determination has been carried out. The anion of 1 consists of two distorted Co3C and Co2FeC tetrahedra linked by a C-C bond (dicarbide unit) and by a Co-Co bond. The reactivity of [ClCCo3(CO)9] with the anions [Fe4C(CO)12]2- and [Fe5C(CO)14]2- was tested, giving [Fe4CoC(CO)14]2- and [Fe5CoC(CO)16]2-, respectively, as major products. Addition of [ClCCo3(CO)9] to a solution of [Fe3(CO)9(CCO)]2- in CH2Cl2, in the presence of thallium salt, generates the species [{Co3(CO)9}C{Fe3(CO)9(CCO)}]- (2). Subsequent addition of ethanol affords the hexametallic complex (PPh4)2[{Co3(CO)9}C{Fe3- (CO)9(CCO2C2H5)}] (3), which reacts with ClAuPPh3 in a 1:3 molar ratio, in the presence of thallium salt, to form the cluster [{AuPPh3}3Fe3(CO)9(CCO2C 2H5)] (4). According to its X-ray crystal determination, the anion of 4 can be described as a 48-electron Fe3 equilateral triangle capped on both sides by a μ3-CCO2C2H5 group and a AuPPh3 fragment. Additionally, two AuPPh3 units cap Fe2Au faces.
Paramagnetic Organometallic Molecules. 12. Electrochemical Studies of Reactions with Lewis Bases following Metal-Metal Bond Cleavage in R2C2Co2(CO)6 Radical Anions
Arewgoda, Malini,Rieger, Philip H.,Robinson, Brian H.,Simpson, Jim,Visco, Steven J.
, p. 5633 - 5640 (1982)
A detailed electrochemical study of the RC2R'Co2(CO)60/-. redox couple is presented utilizing DC polarography and cyclic voltammetry on Hg and Pt electrodes.All acetylene complexes of this type undergo an electrochemically reversible one-electron reduction to the radical anions at potentials ranging from -0.5 to -1.1 V vs.Ag/AgCl in acetone.However, with the exception of the R, R' = CF3 compound, the radical anions disintegrate into a variety of monocobalt species including Co(CO)4- and RC2R'Co(CO)3.These radical anions also undergo a series of complicated reactions with CO, phosphines, and phosphites that can be analyzed in terms of C and C mechanisms.Major products include Co(CO)4-, Co(CO)3L-, RC2R'Co(CO)2L, and RC2R'Co2(CO)5L .The electrochemistry of the R,R'= CF3 compound is much cleaner and does not involve fragmentation to monocobalt species.The different redox properties can be correlated with the lifetimes of the radical anions calculated from the electrochemical data.Detailed studies of the redox chemistry of the Lewis base derivatives, RC2R'Co(CO)6-nLn , are also presented.These derivatives also undergo one-electron reductions to radical anions, but the n = 3, 4 derivatives undergo reversible one-electron oxidations to radical cations as well.The redox chemistry of all compounds can be rationalized on the basis of reactions involving intermediate radical anions produced by the reversible homolytic cleavage of the metal-metal bond.The synthetic utility of enhanced receptiveness to nucleophilic attack on the metal-metal cleaved intermediate is emphasized.
COBALT(II)-TETRACARBONYLCOBALTATE ION PAIRS: ELECTRON TRANSFERS PHENOMENA
Fachinetti, G.,Cima, F. Del,Braca, G.,Funaioli, T.
, p. C25 - C29 (1984)
The disproportionation of Co2(CO)8 in THF takes place only when water is present.Ion pairing interactions between Co and Co(CO)4 are observed.The disproportionation is reversible at room temperature and under low PCO as a consequence of electron transfers between Co-I and CoII.
PREPARATION AND STUDY OF CYCLIC POLYNUCLEAR FERROCENES DERIVED FROM (C6H5)2PCH2CH2Si(CH3)2C5H4Li AS A BRIDGING LIGAND
Iyer, Savithri R.,Tueting, David R.,Schore, Neil E.
, p. 339 - 348 (1987)
The synthesis of the potential bridging ligand (C6H5)2PCH2CH2Si(CH3)2C5H4 (3) is described.The ferrocene (6) derived from 3 has been found to form macrocyclic complexes with metal fragments NiCl2, NiBr2, and Co2(CO)6.Although monomeric, bimetallic products might have been expected based upon the reduced steric demands of ligand 3 relative to an analogous ligand, (C6H5)2PCH2Si(CH3)2C5H4 (1), it appears that the increased flexibility in 3 is the overriding factor leading to a preference for inter- rather than intramolecular coordination of the second phosphine function in 6.
Site selectivity and competitive CO attack in Co4(CO)10(μ4-PPh)2 using methanolic
Partin, John A.,Richmond, Michael G.
, p. 339 - 353 (1990)
The reaction between the tetracobalt cluster Co4(CO)10(μ4-PPh)2 (1) and (1.1 equivalents of a 1.3 M solution in MeOH) has been examined in THF at -78 deg C.Low temperature IR analysis reveals the presence of both the hydroxycarbonyl
An electron-transfer induced migratory insertion reaction originating from a 19-electron cobaltacyclic anion
Morneau, Andre,Donovan-Merkert, Bernadette T.,Geiger, William E.
, p. 96 - 101 (2008/10/08)
The cyclopentadienyl cobaltafluorenyl carbonyl complex Cp(CO)CoC12H8 (3) is reduced in THF in a one-electron irreversible process. The reduction products include the fluorenone radical anion, Fl-, which is proposed to arise through migratory insertion of the CO ligand into the metallacyclic Co-C bond of the 19-electron complex 3-. Electrochemical and IR analyses show that bulk electrolysis under N2 gives 1/3 equiv. each of Fl- and CpCo(CO)2 and 2/3 equiv. of a 17-electron anion [CpCoC12H8]- (2-) Under CO the yield of Fl- is quantitative. The insertion product is also formed when the reduction of the analogous phosphine complex Cp(PPh3)CoC12H8 is performed under CO. An equilibrium between 17- and 19-electron compounds is postulated to account for the synthetic and voltammetric observations. When the cobaltacycle Cp(PPh3)CoC4Ph4 (5) is reduced under carbon monoxide, the CO-insertion product is the π-cyclopentadienone complex CpCo(η4-C4Ph4O) (8). (C) 2000 Elsevier Science S.A.
Solid-state and solution structure of (bpy)CuCo(CO)4 (bpy = 2,2′-bipyridine)
Darensbourg, Donald J.,Chao, Chi-Shan,Bischoff, Christopher,Reibenspies, Joseph H.
, p. 4637 - 4640 (2008/10/08)
The heterobimetallic complex (bpy)CuCo(CO)4 has been prepared by the reaction of NaCo(CO)4 with 2,2′-bipyridine and CuCl in dichloromethane and has been characterized by X-ray crystallography at -80°C. The complex crystallizes in the monoclinic space group P21/a, with unit cell dimensions a = 7.210 (3) A?, b = 16.580 (6) A?, c = 11.912 (6) A?, β = 97.88 (4)°, V = 1410 (1) A?3, Z = 4, and RF = 3.34%. The Cu-Co bond distance was found to be 2.404 (1) A? and to be supported by an asymmetrically bridged carbonyl ligand. This bridging CO group persists in polar solvents as well, as indicated by a v(CO) band at 1850 cm-1 in the infrared spectra in both THF and Nujol mull. On the other hand, the Cu-Co bond is disrupted by a facile reaction at -78 °C with dppe (1,2-bis(diphenylphosphino)ethane) to provide the Co(CO)4- anion and Cu(bpy)(dppe)+.
