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11.
《Journal of Coordination Chemistry》2012,65(12):2066-2074
Two N-functionally substituted diiron azadithiolate complexes, [(µ-SCH2)2NCH2CH2OC(O)C6H4I-p]Fe2(CO)6 (1) and {[(µ-SCH2)2NCH2CH2OC(O)C6H4I-p]Fe2(CO)5Ph2PCH}2 (2) as models for the active site of [FeFe] hydrogenases, have been prepared and fully characterized. Complex 1 was prepared by the reaction of [(µ-SCH2)2NCH2CH2OH]Fe2(CO)6 with p-iodobenzoic acid in the presence of 4-dimethylaminopyridine (DMAP) and N,N′-dicyclohexylcarbodiimide (DCC) in 78% yield. Further treatment of 1 with 1 equiv. of Me3NO?·?2H2O followed by 0.5 equiv. of trans-1,2-bis(diphenylphosphino)ethylene (dppe) affords 2 in 60% yield. The new complexes 1 and 2 were characterized by IR and 1H (13C, 31P) NMR spectroscopic techniques and their molecular structures were confirmed by X-ray diffraction analysis. The molecular structure of 1 has two conformational isomers, in one isomer its N-functional substituent is axial to its bridged nitrogen and in the other isomer its N-functional substituent is equatorial. The crystal structure of 2 revealed that its N-functional substituents are equatorial to its nitrogens and dppe occupies the two apical positions of the square-pyramidal irons. 相似文献
12.
The diiron complex [Fe2{μ-к1(O):η1(C):η3(C)-C(N(Me)(Xyl))C(H)C(Me)C(O)OMe}(μ-CO)(Cp)2] (2) has been obtained from the diiron bridging vinyliminium [Fe2{μ-η1:η3-C(Me)C(H)CN(Me)(Xyl)}(μ-CO)(CO)(Cp)2][SO3CF3] (1; Xyl = 2,5-C6H3Me2) upon treatment with NaH in the presence of CH2CCMe2, followed by chromatography on alumina with MeOH as eluent. The reaction consists in the incorporation of a methylcarboxylate unit, assembled from CO and MeO−, into the bridging vinyliminium ligand. The resulting complex 2 exhibits a C4 fragment bridging the two iron centres through the carbonyl oxygen atom and the allylidene moiety.The X-ray molecular structure of 2 has been determined. 相似文献
13.
Xiao-Qin Chen Zhong-Qing Jiang Ying-Xin Zhang Xie Li Xiao-Ning Tian 《Journal of Coordination Chemistry》2016,69(9):1439-1446
Reactions of (μ-edt)Fe2(CO)6 (edt = SCH2CH2S) (1) with the monophosphine ligands Ph2PCH2Ph, Ph2PC6H11, Ph2PCH2CH2CH3, or P(2-C4H3O)3 in the presence of Me3NO?2H2O afforded (μ-edt)Fe2(CO)5L [L = Ph2PCH2Ph, 2; Ph2PC6H11, 3; Ph2PCH2CH2CH3, 4; P(2-C4H3O)3, 5] in 70–88% yields. Complexes 2–5 were characterized by spectroscopy and single crystal X-ray diffraction analysis. The phosphorus of 2–5 is in an apical position of the distorted octahedral geometry of iron. 相似文献
14.
Xu-Feng Liu 《Journal of Coordination Chemistry》2016,69(17):2620-2629
Four diiron toluenedithiolate complexes 2–5 with monophosphine ligands are reported. Treatment of [μ-SC6H3(CH3)S-μ]Fe2(CO)6 (1) with tris(3-chlorophenyl)phosphine, tris(4-chlorophenyl)phosphine, tris(4-methylphenyl)phosphine or 2-(diphenylphosphino)benzaldehyde, and Me3NO?2H2O in MeCN resulted in the formation of [μ-SC6H3(CH3)S-μ]Fe2(CO)5[P(3-C6H4Cl)3] (2), [μ-SC6H3(CH3)S-μ]Fe2(CO)5[P(4-C6H4Cl)3] (3), [μ-SC6H3(CH3)S-μ]Fe2(CO)5[P(4-C6H4CH3)3] (4), and [μ-SC6H3(CH3)S-μ]Fe2(CO)5[Ph2P(2-C6H4CHO)] (5) in 64–82% yields. Complexes 2–5 have been characterized by elemental analysis, IR, 1H NMR, 31P{1H} NMR, 13C{1H} NMR and further confirmed by single crystal X-ray diffraction analysis. The molecular structures show that 2–5 contain a butterfly diiron toluenedithiolate cluster coordinated by five terminal carbonyls and an apical monophosphine. 相似文献
15.
《Journal of Coordination Chemistry》2012,65(9):1559-1570
Reaction of the diiron propanedithiolate complex [μ-(SCH2)2CHO2CC6H5]Fe2(CO)6 (A) with triphenylphosphine (PPh3) or cis-1,2-bis(diphenylphosphine)ethylene (cis-dppv) in the presence of one equivalent of Me3NO·2H2O yielded a mono-substituted complex [μ-(SCH2)2CHO2CC6H5]Fe2(CO)5(PPh3) (1) or an asymmetrically substituted complex [(μ-SCH2)2CHO2CC6H5]Fe2(CO)4(κ2-dppv) (2), respectively. The structures of both complexes were characterized by spectroscopic methods and X-ray crystallography. In the solid state, the PPh3 ligand in 1 occupies an apical position of the square pyramidal geometries of the Fe2, while the cis-dppv in 2 coordinates Fe2 in an apical-basal manner. The electrochemistry of both complexes was investigated. The electron-withdrawing benzoate functionality on the bridgehead carbon of the propanedithiolate bridge shifts the oxidation and reduction potentials of 1 or 2 slightly. Both complexes can catalyze the reduction of protons from CF3COOH but with a higher efficiency for 2. 相似文献
16.
《Journal of Coordination Chemistry》2012,65(23):4061-4067
The reaction of (μ-PDT)Fe2(CO)6 (PDT?=?SCH2CH2CH2S) with 1,1′-bis(diphenylphosphino)ferrocene in the presence of the decarbonylating agent Me3NO·2H2O afforded [(μ-PDT)Fe2(CO)5]2[(η 5-Ph2PC5H4)2Fe] (1) in 80% yield. The new complex 1 was characterized by elemental analysis, IR, and 1H-(31P-, 13C-) NMR spectroscopies. The structure of 1 was determined by single crystal X-ray diffraction analysis; the molecule is centrosymmetric and two cyclopentadienyl (Cp) rings reside in a staggered conformation. 相似文献
17.
《Journal of Coordination Chemistry》2012,65(6):1023-1031
A series of N-functionalized diiron azadithiolate complexes, [(µ-SCH2)2NCH2CO2Me]Fe2(CO)5?L [L?=?CO (1); PPh3 (2); Ph2PCH2PPh2 (3)], as active site models of [FeFe]-hydrogenases has been prepared and characterized. While 1 was prepared by a sequential reaction of (µ-HS)2Fe2(CO)6 with two equiv. of aqueous HCHO, followed by treatment of (µ-HOCH2S)2Fe2(CO)6 with one equiv. of H2NCH2CO2Me in 46% yield; 2 and 3 were prepared by a carbonyl substitution reaction of 1 with PPh3 or Ph2PCH2PPh2 in the presence of Me3NO?·?2H2O in 90% and 85% yields, respectively. The crystal structures of 1 and 2 revealed that the substituent attached to the bridgehead nitrogen occupies an equatorial position and the PPh3 ligand resides in an axial position of the square pyramid of Fe2. 相似文献
18.
Two carboxy-functionalized diiron complexes [{(μ-SCH2)2X}{Fe(CO)3}{Fe(CO)2L}] (X = NC3H7, L = Ph2PCH2CH2COOH, 4; X = CH2, L = Ph2PCH2COOH, 5) were prepared, as biomimetic models of the [FeFe] hydrogenase active site, from the CO-replacement of [{(μ-SCH2)2NC3H7}Fe2(CO)6] (1) and (μ-pdt)Fe2(CO)6 (2) by phosphine ligands in CH3CN at 40 °C, respectively. In contrast, the reaction of 1 with Ph2PCH2COOH under the same condition afforded complex [{(μ-SCH2)2NC3H7}{Fe(CO)3}{Fe(CO)2(Ph2PCH3)}] (3) with a decarboxylated phosphine ligand. The molecular structures of complexes 3-5 were determined by X-ray crystallographic analyses, which show that they have similar frameworks with the phosphine ligand on the apical position. The interesting C-H···S contacts between the methylene hydrogen atoms of the PhCH2COOH ligand and the μ-S atoms of the pdt-bridge are found in the crystal of 5. According to the experimental evidence, a plausible mechanism, via sequential phosphine coordination, N-protonation, and decarboxylation steps, is proposed for the formation of 3 and for explanation of the contrastive reactivities of the adt- (2-aza-1,3-propanedithiolato) and the pdt- (1,3-propanedithiolato) bridged diiron complexes toward decarboxylation of the Ph2PCH2COOH ligand. 相似文献
19.
Luigi Busetto Mauro Salmi Valerio Zanotti 《Journal of organometallic chemistry》2007,692(11):2245-2252
The bridging diiron thiocarbyne complex [Fe2{μ-CS(Me)}(μ-CO)(CO)2(Cp)2][SO3CF3] (1) reacts with activated olefins (methyl acrylate, acrylonitrile, styrene, diethyl maleate), in the presence of Me3NO and NaH, to give the corresponding μ-allylidene complexes [Fe2{μ-η1:η3-Cα(SMe)Cβ(R′)Cγ(H)(R″)} (μ-CO)(CO)(Cp)2] (R″ = CO2Me, R′ = H, 3a; R″ = CN, R′ = H, 3b; R″ = C6H5, R′ = H, 3c; R″ = R′ = CO2Et, 3d). The coupling reaction of olefin with thiocarbyne is regio- and stereospecific, leading to the formation of only one isomer. C-C bond formation occurs between the less substituted alkene carbon and the thiocarbyne. Moreover, olefinic hydrogens of the bridging ligands are mutually trans.The reactions of 3a-b with MeSO3CF3 result, selectively, in the formation of the cationic μ-sulphonium allylidene complexes [Fe2{μ-η1:η3-Cα(SMe2)Cβ (H)Cγ(H)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R = CO2Me, 4a; R = CN, 4b). Compound 4a undergoes displacement of the SMe2 group by nucleophiles such as NaBH4, NBu4CN and NaOMe, affording the complexes [Fe2{μ-η1:η3-Cα(R)Cβ (H)Cγ(H)(CO2Me)}(μ-CO)(CO)(Cp)2] (R = H, 5a; R = CN, 5b; R = OMe, 5c), respectively. The molecular structures of 3a and 5a have been determined by X-ray diffraction studies. 相似文献
20.
Xu-Feng Liu 《Journal of Coordination Chemistry》2017,70(1):116-126
Four diiron dithiolate complexes with monophosphine ligands have been prepared and structurally characterized. Reactions of (μ-SCH2CH2S-μ)Fe2(CO)6 or [μ-SCH(CH3)CH(CH3)S-μ]Fe2(CO)6 with tris(4-chlorophenyl)phosphine or diphenyl-2-pyridylphosphine in the presence of Me3NO·2H2O afforded diiron pentacarbonyl complexes with monophosphine ligands (μ-SCH2CH2S-μ)Fe2(CO)5[P(4-C6H4Cl)3] (1), (μ-SCH2CH2S-μ)Fe2(CO)5[Ph2P(2-C5H4N)] (2), [μ-SCH(CH3)CH(CH3)S-μ]Fe2(CO)5[P(4-C6H4Cl)3] (3), and [μ-SCH(CH3)CH(CH3)S-μ]Fe2(CO)5[Ph2P(2-C5H4N)] (4) in good yields. Complexes 1–4 were characterized by elemental analysis, 1H NMR, 31P{1H} NMR and 13C{1H} NMR spectroscopy. Furthermore, the molecular structures of 1–4 were confirmed by X-ray crystallography. 相似文献