Tetrapotassium μ-carbonato-μ-oxo-bis[nitrilotriacetatoiron(III)] dimethanol dihydrate

Fujita, Takafumi; Ohba, Shigeru; Nishida, Yu.; Goto, Akito; Tokii, Tadashi

doi:10.1107/s0108270193009618

Cited by 12 publications

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“…For binuclear bidentate complexes the Fe−C distance is in the 2.40−3.01 Å range. This is the case for the different compounds analyzed from the CSD database: C 24 H 26 Fe 4 N 4 O 26 ·6(Na)·20(H 2 O) (Fe−C = 3.00 Å), Fe 2 N 2 O 16 K 4 ·2(CH 4 O)·2(H 2 O) (Fe−C = 2.91 Å), C 29 H 36 Fe 2 N 8 O 4 I 2 ·6(H 2 O) (Fe−C = 3.01 Å), C 20 H 42 Fe 2 N 6 O 7 ·4.25(H 2 O) (Fe−C = 2.97 Å), C 60 H 120 Fe 6 N 12 O 24 (Fe−C = 2.95 and 3.01 Å), C 11 H 4 FeN 2 O 9 ·5(H 2 O) (Fe−C = 2.47 Å), C 39 H 76 Fe 3 N 3 O 14 ·C 7 H 8 (Fe−C = 2.96 Å). No bidentate complex was found from the CSD database with an Fe−C distance higher than 3.01 Å.…”

Section: Resultsmentioning

confidence: 95%

Synthesis and Characterization of Carboxylate−FeOOH Nanoparticles (Ferroxanes) and Ferroxane-Derived Ceramics

et al. 2002

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A new environmentally benign process for producing Fe-based ceramics of variable properties is presented. We have demonstrated that the reaction between lepidocrocite and acetic acid (=AA) in water results in the formation of carboxylate−FeOOH nanoparticles called ferroxane−AA analogous to aluminum-based alumoxanes. The structure of the ferroxane particles consists of an FeOOH core part with the structure of the lepidocrocite (γ-FeOOH), coated with AA. FTIR and EXAFS at the Fe K edge indicates that AA is chemically adsorbed onto the FeOOH core part. The size of these ferroxanes is 0.3 μm composed of nanodomains of 20−30 Å with a γ-FeOOH structure. Thermolysis of the ferroxane−AA yields Fe oxide ceramics. The specific surface area of 134 m2/g does not increase from the initial mineral to the ferroxane while the pore size distribution becomes monodisperse and the diameter of the pore size decreases from 55 to 12 and 13 nm after the firing of the ferroxanes. Moreover, the ferroxane−AA has been successfully doped with metal to form a precursor for Fe mixed-metal oxides. Upon thermolysis the products evolve to homogeneous Fe−metal oxides. A low firing temperature for conversion to ceramic as well as the use of environmentally benign feedstock suggest that the process for creating ferroxane-derived ceramics should have minimal environmental impacts.

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Section: Resultsmentioning

confidence: 95%

Synthesis and Characterization of Carboxylate−FeOOH Nanoparticles (Ferroxanes) and Ferroxane-Derived Ceramics

et al. 2002

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“…The structure of the μ-oxodiiron(III) complex with bridging methyl carbonate, namely [Fe 2 (μ-O)(μ-CH 3 OCO 2 )( N -MeIm) 8 ] 3+ (the cation of 5 ), is shown in Figure . Although a large number of carbonato complexes (including bridging carbonate) are reported, examples of iron complexes with bound carbonate have been limited. − The rapid formation of oxo- and hydroxo-bridged polymeric species by iron salts in aqueous (or mixed) medium in the presence of carbonate or bicarbonate is responsible for this scarcity. No iron complex with bound methyl carbonate has been reported so far.…”

Section: Resultsmentioning

confidence: 99%

“…Thus, while the mono-µ-acetato µ-oxodiiron(III) complexes 6 and [Fe 2 (µ-O)(µ-CH 3 CO 2 )(TPA) 2 ](ClO 4 ) 3 exhibit an Fe-Fe distance of 3.29 and 3.24 Å, respectively, the di-µ-acetato µ-oxodiiron- 29 examples of iron complexes with bound carbonate have been limited. [30][31][32][33][34] The rapid formation of oxo-and hydroxo-bridged polymeric species by iron salts in aqueous (or mixed) medium in the 2). In addition, the O(2)-C(33)-O(3) angle is 126.7(6)°.…”

Section: Structure Of [Fe 2 (µ-O)(µ-hco 2 )(N-meim) 8 ](Clo 4 ) 3 (4)mentioning

confidence: 99%

Reaction of (μ-Oxo)diiron(III) Core with CO₂ in N-Methylimidazole: Formation of Mono(μ-carboxylato)(μ-oxo)diiron(III) Complexes with N-Methylimidazole as Ligands

2003

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Several iron(III) complexes with N-methylimidazole (N-MeIm) as the ligand have been synthesized by using N-MeIm as the solvent. Under anaerobic conditions, [Fe(N-MeIm)(6)](ClO(4))(3) (1) reacts with stoichiometric amounts of water in N-MeIm to afford the (mu-oxo)diiron(III) complex, [Fe(2)(mu-O)(N-MeIm)(10)](ClO(4))(4) (3). Exposure of a solution of 3 in N-MeIm to stoichiometric and excess CO(2) gives rise to the (mu-oxo)(mu-carboxylato)diiron(III) species [Fe(2)(mu-O)(mu-HCO(2))(N-MeIm)(8)](ClO(4))(3) (4) and the methyl carbonate complex [Fe(2)(mu-O)(mu-CH(3)OCO(2))(N-MeIm)(8)](ClO(4))(3) (5), respectively. Formation of the formato-bridged complex 4 upon fixation of CO(2) by 3 in N-MeIm is unprecedentated. Methyl transfer from N-MeIm to a bicarbonato-bridged (mu-oxo)diiron(III) intermediate appears to give rise to 5. Complex 3 is a good starting material for the synthesis of (mu-oxo)mono(mu-carboxylato)diiron(III) species [Fe(2)(mu-O)(mu-RCO(2))(N-MeIm)(8)](ClO(4))(3) (where R = H (4), CH(3) (6), or C(6)H(5) (7)); addition of the respective carboxylate ligand in stoichiometric amount to a solution of 3 in N-MeIm affords these complexes in high yields. Attempts to add a third bridge to complexes 4, 6, and 7 to form the (mu-oxo)bis(mu-carboxylato)diiron(III) species result in the isolation of the previously known triiron(III) mu-eta(3)-oxo clusters [[Fe(mu-RCO(2))(2)(N-MeIm)](3)O](ClO(4)) (8). The structures of 3, 4, 6, and 7 allow one, for the first time, to inspect the various features of the [Fe(2)(mu-O)(mu-RCO(2))](3+) moiety with no strain from the ligand framework.

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“…Compound 8 belongs to a rather rare group of carbonato-bridged diiron complexes. [44][45][46][47][48][49][50] As with the synthesis of the carbonate complex 8, the carboxylato-bridged complex 7 could be prepared in a variety of ways in moderate yields, either in a reaction between the ligand H 2 BPG 2 DEV and 2 equiv of Fe(ClO 4 ) 3 • 9H 2 O in the presence of base and excess HO 2 CAr iPrO , or by addition of the carboxylic acid to a CH 3 CN solution of 6 in the presence of base. Scheme 3 summarizes the pathways for the synthesis of compounds 6, 7, and 8.…”

Section: Resultsmentioning

confidence: 99%

Modeling the Syn Disposition of Nitrogen Donors in Non-Heme Diiron Enzymes. Synthesis, Characterization, and Hydrogen Peroxide Reactivity of Diiron(III) Complexes with the Syn N-Donor Ligand H₂BPG₂DEV

et al. 2009

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In order to model the syn disposition of histidine residues in carboxylate-bridged non-heme diiron enzymes, we prepared a new dinucleating ligand, H2BPG2DEV, that provides this geometric feature. The ligand incorporates biologically relevant carboxylate functionalities, which have not been explored as extensively as nitrogen-only analogs. Three novel oxo-bridged diiron(III) complexes [Fe2(μ-O)(H2O)2-(BPG2DEV)](ClO4)2 (6), [Fe2(μ-O)(μ-O CAriPrO)(BPG2DEV)](ClO4) (7), and [Fe2(μ-O)(μ-CO3)(BPG2DEV)] (8) were prepared. Single crystal X-ray structural characterization confirms that two pyridines are bound syn with respect to the Fe–Fe vector in these compounds. The carbonato-bridged complex 8 forms quantitatively from 6 in a rapid reaction with gaseous CO2 in organic solvents. A common maroon-colored intermediate (λmax = 490 nm; ε = 1500 M−1 cm−1) forms in reactions of 6, 7, or 8 with H2O2 and NEt3 in CH3CN/H2O solutions. Mass spectrometric analyses of this species, formed using 18O-labeled H2O2, indicate the presence of a peroxide ligand bound to the oxo-bridged diiron(III) center. The Mössbauer spectrum at 90 K of the EPR-silent intermediate exhibits a quadrupole doublet with trueδ. = 0.58 mm/s and ΔEQ = 0.58 mm/s. The isomer shift is typical for a peroxodiiron(III) species, but the quadrupole splitting parameter is unusually small compared to related complexes. These Mössbauer parameters are comparable to those observed for a peroxo intermediate formed in the reaction of reduced toluene/o-xylene monooxygenase hydroxylase (ToMOH) with dioxygen. Resonance Raman studies reveal an unusually low-energy O–O stretching mode in the peroxo intermediate that is consistent with a short diiron distance. Although peroxodiiron(III) intermediates generated from 6, 7, and 8 are poor O-atom transfer catalysts, they display highly efficient catalase activity, with turnover numbers up to 10,000. In contrast to hydrogen peroxide reactions of diiron(III) complexes that lack a dinucleating ligand, the intermediates generated here could be reformed in significant quantities after a second addition of H2O2, as observed spectroscopically and by mass spectrometry.

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Tetrapotassium μ-carbonato-μ-oxo-bis[nitrilotriacetatoiron(III)] dimethanol dihydrate

Cited by 12 publications

References 0 publications

Synthesis and Characterization of Carboxylate−FeOOH Nanoparticles (Ferroxanes) and Ferroxane-Derived Ceramics

Synthesis and Characterization of Carboxylate−FeOOH Nanoparticles (Ferroxanes) and Ferroxane-Derived Ceramics

Reaction of (μ-Oxo)diiron(III) Core with CO₂ in N-Methylimidazole: Formation of Mono(μ-carboxylato)(μ-oxo)diiron(III) Complexes with N-Methylimidazole as Ligands

Modeling the Syn Disposition of Nitrogen Donors in Non-Heme Diiron Enzymes. Synthesis, Characterization, and Hydrogen Peroxide Reactivity of Diiron(III) Complexes with the Syn N-Donor Ligand H₂BPG₂DEV

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Tetrapotassium μ-carbonato-μ-oxo-bis[nitrilotriacetatoiron(III)] dimethanol dihydrate

Cited by 12 publications

References 0 publications

Synthesis and Characterization of Carboxylate−FeOOH Nanoparticles (Ferroxanes) and Ferroxane-Derived Ceramics

Synthesis and Characterization of Carboxylate−FeOOH Nanoparticles (Ferroxanes) and Ferroxane-Derived Ceramics

Reaction of (μ-Oxo)diiron(III) Core with CO2 in N-Methylimidazole: Formation of Mono(μ-carboxylato)(μ-oxo)diiron(III) Complexes with N-Methylimidazole as Ligands

Modeling the Syn Disposition of Nitrogen Donors in Non-Heme Diiron Enzymes. Synthesis, Characterization, and Hydrogen Peroxide Reactivity of Diiron(III) Complexes with the Syn N-Donor Ligand H2BPG2DEV

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Reaction of (μ-Oxo)diiron(III) Core with CO₂ in N-Methylimidazole: Formation of Mono(μ-carboxylato)(μ-oxo)diiron(III) Complexes with N-Methylimidazole as Ligands

Modeling the Syn Disposition of Nitrogen Donors in Non-Heme Diiron Enzymes. Synthesis, Characterization, and Hydrogen Peroxide Reactivity of Diiron(III) Complexes with the Syn N-Donor Ligand H₂BPG₂DEV