12078-28-3Relevant articles and documents
A KINETIC STUDY OF THE CLEAVAGE OF THE IRON-CARBON ? BOND IN η5-C5H5Fe(CO)2R BY HALOGENATED ACETIC ACIDS
Luca, Nancy De,Wojcicki, Andrew
, p. 359 - 378 (1980)
The rates of the reaction of η5-C5H5Fe(CO)2R (R = alkyl and aryl) with CF3CO2H to give η5-C5H5Fe(CO)2OC(O)CF3 and RH were investigated in organic solvents, mostly at 25 deg C, by infrared spectroscopic, manometric and volumetric techniques.When R = alkyl, the cleavage in CH2Cl2 is first order in η5-C5H5Fe(CO)2R and first order in the CF3CO2H monomer at acid concentrations 0.1 M, but first order in η5-C5H5Fe(CO)2R and second order in the CF3CO2H monomer at lower acid concentrations.The dependence of the second-order rate constant on R follows the order C6H5 > CH2Si(CH3)3 (>110) > CH3 (32) > n-C4H9 (15) > C2H5 (11) > CH2C(CH3)3 (6.2) > CH2CH2C6H5 (5.3) > CH(CH3)C6H5 (ca. 1.2) CH2C6H5 (1.0) > CH(CH3)2.The isotope effect, kH/kD, for the cleavage of η5-C5H5Fe(CO)2CH3 by CF3CO2H and CF3CO2D is 4.7.Solvent influence on the rate of the Fe-CH3 bond scission in CH2Cl2, CH2ClCH2Cl and C6H6 is very small.A mechanism is proposed which involves the formation of an Fe-H-OC(O)CF3 hydrogen-bridged 1/1 adduct of the reactants in a reversible step.This adduct then affords 5-C5H5Fe(CO)2(R)H> with the assistance of a second molecule of CF3CO2H.Reductive elimination of RH and coordination to iron of CF3CO2- complete the reaction.The corresponding cleavage of a given Fe-R bond by CHCl2CO2H is substantially slower than that by CF3CO2H; for the aryl complexes it follows the order R = p-C6H4CH3 > p-C6H4F > C6H5 > p-C6H4Cl, with ρ ca. -5.4.
Fe:Co/TiO2 bimetallic catalysts for the Fischer-Tropsch reaction: Part 4: A study of nitrate and carbonyl derived FT catalysts
Duvenhage,Coville
, p. 230 - 239 (2005)
A series of Fe:Co bimetallic catalysts supported on TiO2 were prepared by precipitation from nitrate salts and by impregnation from metal carbonyl complexes. These Fe:Co materials were characterized by a range of techniques including BET, temperature programmed reduction (TPR) and CO chemisorption, and their Fischer-Tropsch (FT) activity was evaluated in a series of fixed bed reactors (220 °C, 10 bar, 2H2:1CO, 350 h -1, 200 h). Important observations from the study are (i) both preparation technique yield catalysts in which the Fe:Co/TiO2 has lower activity than the equivalent Co/TiO2 catalyst and (ii) selectivity patterns are similar to a Co/TiO2 catalyst but indicate the impact of Fe on the system. Methane levels produced with the precipitated catalysts are high (20 wt%) while levels for the most active carbonyl bimetallic catalysts are lower (10 wt%). The impregnated catalysts produced from metal carbonyl precursors proved to be the better long chain hydrocarbon producers and olefin producers than the precipitated catalysts produced from metal nitrate precursors.
The Carbalkoxymethyl Ligand on (η-C5H5)(CO)FeCH2CO2CH3 as a CO-Derived C2 Template for Generating C2 Organic Ligands and Molecules
Crawford, Edward J.,Lambert, Carol,Menard, Kevin P.,Cutler, Alan R.
, p. 3130 - 3139 (1985)
The carbalkoxymethyl ligand on Cp(CO)FeCH2CO2R (7) (R = CH3, CH2CH3) serves as a C2 template for generating other C2-coordinated ligands and organic molecules.In this study 7 is procured by acid isomerization of the alkoxyacetyl complexes Cp(CO)FeCOCH2OR (5), which are obtained by P(OCH3)3-induced CO-insertion on Cp(CO)2FeCH2OR. (Overall, the carbalkoxymethyl ligand on 7 derives from two CO groups on Cp(CO)3Fe(1+)).A mechanism for this alkoxyacetyl-carbalkoxymethyl ligand isomerization is advanced whereby protonation of 5 generates a ligated ketene intermediate that regioselectively adds alcohol and gives 7.In excess acid either 5 or 7 quantitatively releases acetic acid ester, a selective generation of this C2 organic from CO.The carbalkoxymethyl ligand on 7 is activated as a hydride acceptor by converting it to the (dialkoxycarbenio)methyl salt Cp(CO)FeCH2C(OR)2(1+) (8). (Interestingly, 8 cannot be generated from the alkoxycarbene system Cp(CO)FeC(OR)CH2OR(1+) (6).) BH4(1-) converts 8 into a mixture of η2-ethylene and η1-ethyl complexes of Cp(CO)Fe, whereas (sec-Bu)3BH(1-)Li(1+) generates the corresponding η2-ethyl vinyl ether and η1-formylethyl compounds.The conversion of these latter two into acetaldehyde is discussed.
Photoinduced Carbon Monoxide Release from Half-Sandwich Iron(II) Carbonyl Complexes by Visible Irradiation: Kinetic Analysis and Mechanistic Investigation
Jiang, Xiujuan,Chen, Limei,Wang, Xiu,Long, Li,Xiao, Zhiyin,Liu, Xiaoming
, p. 13065 - 13072 (2015)
Three half-sandwich iron(II) complexes, [Fe(η5-Cp)(cis-CO)2X] (X-=Cl-, Br-, I-), were synthesized and characterized. The kinetics of the CO-releasing behaviour of these complexes upon illumination by visible irradiation in various media was investigated. Our results indicated that the CO release was significantly affected by the auxiliary ligands. Of the three light sources used (blue, green, and red), blue light exhibited the highest efficiency. In the photoinduced CO release, the solvents and exogenous nucleophiles in the media were involved, which allowed their CO-releasing reaction to comply with pseudo first-order model rather than the characteristic zero-order model for a photochemical reaction. In aqueous media (D2O), an intermediate bearing the core of {FeII(cis-CO)2} involving cleavage of cyclopentadiene was detected. Despite the non-absorption of the red light, its illumination combined with nucleophilic substitution did cause considerable CO release. Assessment of the cytotoxicity of the three complexes indicated that they showed good biocompatibility.
Further reactions of (MLn=Fe(η-C5H5)(CO)2, Re(CO)5) with organic electrophiles
Busetto, L.,Bordoni, S.,Zanotti, V.
, p. 125 - 132 (1988)
Reaction of FpC(S)SMLn (Fp=Fe(η-C5H5)(CO)2; MLn=Fp (1a), Re(CO)5 (1b)) with MeC(O)Cl affords Cl and LnMSC(O)Me (3); 1a reacts with (CF3CO)2O to yield CF3CO2 and FpSC(O)CF3 (5).In both cases the reactions have been shown to occur via the unstable S-acylated intermediates SMLn>+ (R=CF3, Me).Alkylation of 1a with RBr (R=Me, Et, CH2Ph, CH2CHCH2) or CF3SO2OR (R=Me, Et) followed by treatment of the stable S-alkylated derivatives + with I- provides a useful alternative method for the synthesis of a variety of FpC(S)SR.
-
Crawford,E.J.,Bodnar,T.W.,Cutler,A.R.
, p. 6202 (1986)
-
Synthesis, characterization and reactions of the transition metal halogenoalkyl carbocation complexes [Cp(CO)2M{η2-CH2CH(CH2)nX}]PF6 (n = 1-8, 10, M = Fe; n = 3, 4 M = Ru; X = Br, I)
Changamu, Evans O.,Friedrich, Holger B.
, p. 3351 - 3356 (2008)
The halogenoalkyl complexes [Cp(CO)2M{(CH2)nX}] (n = 3-10, 12, M = Fe; n = 5, 6, M = Ru, X = Br, I) react with Ph3CPF6 in dry CH2Cl2 to give the corresponding carbocation complex
Electrochemical Reduction Mechanism of [(η5-C5H5)Fe(dppf)(CO)]+(dppf = 1,1′-Bis(diphenylphosphino)ferrocene)
Pan, Yixian,Schnierle, Marc,Auweiler, Daniel,Ringenberg, Mark R.
, p. 760 - 765 (2021)
The complex [CpFe(dppf)(CO)][B(ArF)4] [1][B(ArF)4] (Cp = cyclopentadienyl, dppf = 1,1′-bis(diphenylphosphino)ferrocene, and [B(ArF)4]- = tetrakis[3,5-bis(trifluoromethyl)phenyl]borate) was made by removal of one carbonyl ligand from the dicarbonyl complex
Reaction of Bidentate Isonitrile Ligands with Iron Carbonyls
Howell, James A. S.,Rowan, Anthony J.
, p. 297 - 301 (1981)
Reaction of the bidentate isonitriles CN(CH2)nNC ( n =2, 3, 4, or 6) with (cp = η-cyclopentadienyl) yields exclusively 2> derivatives which are fluxional in solution and exist in three isomeric forms (bridged-bridged, bridged-terminal, and terminal-terminal with respect to the bonding mode of the bidentate isonitrile).The proportion of the isomers containing terminally bound isonitrile increases with the length of the alkyl chain.The complexes may be protonated to yield 2>2 salts (n = 2 or 6) and may be cleaved with I2 to give and 2nNC>> (n = 2 or 6).Reaction ofCN(CH2)nNC (n = 2 or 6 with or yields exclusively 2nNC>>
Oxidation of Iron Complex with NHC Ligand with Molecular Iodine
Shapovalov,Tikhonova,Skabitskii,Kolos,Sakharov,Torubaev, Yu. V.
, p. 1418 - 1423 (2019/12/25)
Abstract: Complex (η5-C5H5)2Fe2(CO)4 (I) reacts with 1,3-dimethylimidazolium-2-carboxylate Me2ImCO2 to give asymmetric binuclear carbene iron complex (η5-C5H5)2Fe2(CO)3(Me2Im) (II) (Me2Im = 1,3-dimethylimidazol-2-ylidene). The oxidation of compound II with elemental iodine proceeds via two mechanisms, symmetrical and asymmetrical, to form four products: (η5-C5H5Fe(CO)2(Me2Im)I (III), (η5-C5H5)Fe(CO)2I (IV), (η5-C5H5Fe(CO)2(Me2Im)I3 (V), and ferrocene (VI). In each case, two pairs of reaction products have formed, two of which include NHC ligand: neutral iron(III) complex and ionic complex V. Optimal synthesis conditions to obtain preferably one of these complexes have been found. Geometry and transition state energy of supposed reaction mechanism have been calculated by quantum chemistry methods.
