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Kubo M, Nakane D, Funahashi Y, Ozawa T, Inomata T, Masuda H. Catalytic Oxidation of Methanol to Formaldehyde Catalyzed by Iron Complex with N 3S 3-type Tripodal Ligand. Chemistry 2024; 30:e202303955. [PMID: 38268122 DOI: 10.1002/chem.202303955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/19/2024] [Accepted: 01/24/2024] [Indexed: 01/26/2024]
Abstract
A Fe3+ complex with N3S3-type tripod ligand, 1, reacts with O2 in CH3OH to generate formaldehyde, which has been studied structurally, spectroscopically, and electrochemically. Complex 1 crystallizes as an octahedral structure with crystallographic C3 symmetry around the metal, with Fe-N=2.2917(17) Å and Fe-S=2.3574(6) Å. UV-vis spectrum of 1 in CH3OH under Ar shows an intense band at 572 nm (ϵ 4,100 M-1cm-1), which shifts to 590 nm (ϵ 2,860 M-1cm-1) by the addition of O2, and a new peak appeared at 781 nm (ϵ 790 M-1cm-1). Such a spectral change is not observed in CH2Cl2. Cyclic voltammogram (CV) of 1 in CH2Cl2 under Ar gives reversible redox waves assigned to Fe2+/Fe3+ and Fe3+/Fe4+ couples at -1.60 V (ΔE=69 mV) and -0.53 V (ΔE=71 mV) vs Fc/Fc+, respectively. In contrast, in CH3OH, the reversible redox waves, albeit accompanied by a positive shift of the Fe2+/Fe3+ couple, are observed at -1.20 V (ΔE=85 mV) and -0.53 V (ΔE=64 mV) vs Fc/Fc+ under Ar. Interestingly, a catalytic current was observed for the CV of 1 in CH3OH in the presence of CH3ONa under Ar, when the sweep rate was slowed down.
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Affiliation(s)
- Masaki Kubo
- Department of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa, Nagoya, 466-8555, Japan
| | - Daisuke Nakane
- Department of Chemistry, Faculty of Science Division II, Tokyo University of Science, 1-3 Kagurazaka Shinjuku, Tokyo, 162-0825, Japan
| | - Yasuhiro Funahashi
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
| | - Tomohiro Ozawa
- Department of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa, Nagoya, 466-8555, Japan
| | - Tomohiko Inomata
- Department of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa, Nagoya, 466-8555, Japan
| | - Hideki Masuda
- Department of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa, Nagoya, 466-8555, Japan
- Department of Applied Chemistry, Aichi Institute of Technology, 1247 Yachigusa, Yakusa-cho, Toyota, 470-0392, Japan
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Jeremies A, Lehmann U, Gruschinski S, Matulis V, Ivashkevich OA, Jäschke A, Kersting B. Synthesis, structure, electrochemistry, and magnetic properties of face-sharing bioctahedral nickel complexes containing a N 3 Ni( μ -S 2 )( μ -X)NiN 3 core (X = F − , Cl − , Br − , N 3 − , OH − ). J Organomet Chem 2016. [DOI: 10.1016/j.jorganchem.2016.04.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Fuchs MA, Zevaco TA, Ember E, Walter O, Held I, Dinjus E, Döring M. Synthesis of cyclic carbonates from epoxides and carbon dioxide catalyzed by an easy-to-handle ionic iron(III) complex. Dalton Trans 2013; 42:5322-9. [PMID: 23403909 DOI: 10.1039/c3dt32961e] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the successful utilization of monometallic, ionic iron(II)- and iron(III)-N2O2-ligand-systems as highly active homogeneous catalysts for the conversion of CO2 with different epoxides to cyclic carbonates. The catalytic tests were performed using propylene oxide (PO) and a range of nine substituted epoxides. Terminal monosubstituted oxides react quantitatively.
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Affiliation(s)
- M A Fuchs
- Institut für Katalyseforschung und -Technologie (IKFT), Karlsruher Institut für Technologie (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
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Ohki Y, Tatsumi K. Thiolate‐Bridged Iron–Nickel Models for the Active Site of [NiFe] Hydrogenase. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.201001087] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yasuhiro Ohki
- Department of Chemistry, Graduate School of Science, and Research Center for Materials Science, Nagoya University, Furo‐cho, Chikusa‐ku, 464–8602, Nagoya, Japan, Fax: +81‐52‐789‐2943
| | - Kazuyuki Tatsumi
- Department of Chemistry, Graduate School of Science, and Research Center for Materials Science, Nagoya University, Furo‐cho, Chikusa‐ku, 464–8602, Nagoya, Japan, Fax: +81‐52‐789‐2943
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Krupskaya Y, Alfonsov A, Parameswaran A, Kataev V, Klingeler R, Steinfeld G, Beyer N, Gressenbuch M, Kersting B, Büchner B. Interplay of magnetic exchange interactions and Ni-S-Ni bond angles in polynuclear nickel(II) complexes. Chemphyschem 2010; 11:1961-70. [PMID: 20408157 DOI: 10.1002/cphc.200900935] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The ability of bridging thiophenolate groups (RS(-)) to transmit magnetic exchange interactions between paramagnetic Ni(II) ions is examined. Specific attention is paid to complexes with large Ni-SR-Ni angles. For this purpose, dinuclear [Ni(2)L(1)(mu-OAc)I(2)][I(5)] (2) and trinuclear [Ni(3)L(2)(OAc)(2)][BPh(4)](2) (3), where H(2)L(1) and H(2)L(2) represent 24-membered macrocyclic amino-thiophenol ligands, are prepared and fully characterized by IR- and UV/Vis spectroscopy, X-ray crystallography, static magnetization M measurements and high-field electron spin resonance (HF-ESR). The dinuclear complex 2 has a central N(3)Ni(2)(mu-S)(2)(mu-OAc)Ni(2)N(3) core with a mean Ni-S-Ni angle of 92 degrees . The macrocycle L(2) supports a trinuclear complex 3, with distorted octahedral N(2)O(2)S(2) and N(2)O(3)S coordination environments for one central and two terminal Ni(II) ions, respectively. The Ni-S-Ni angles are at 132.8 degrees and 133.5 degrees . We find that the variation of the bond angles has a very strong impact on the magnetic properties of the Ni complexes. In the case of the Ni(2)-complex, temperature T and magnetic field B dependencies of M reveal a ferromagnetic coupling J=-29 cm(-1) between two Ni(II) ions (H=JS(1)S(2)). HF-ESR measurements yield a negative axial magnetic anisotropy (D<0) which implies a bistable (easy axis) magnetic ground state. In contrast, for the Ni(3)-complex we find an appreciable antiferromagnetic coupling J'=97 cm(-1) between the Ni(II) ions and a positive axial magnetic anisotropy (D>0) which implies an easy plane situation.
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Affiliation(s)
- Yulia Krupskaya
- Leibniz Institute for Solid State and Materials Research, IFW Dresden, 01171 Dresden, Germany.
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Zhang Z, Zhang L, Li Y, Hong L, Chen Z, Zhou X. Activation of Bis(guanidinate)lanthanide Alkyl and Aryl Complexes on Elemental Sulfur: Synthesis and Characterization of Bis(guanidinate)lanthanide Thiolates and Disulfides. Inorg Chem 2010; 49:5715-22. [DOI: 10.1021/ic100617n] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Zhengxing Zhang
- Molecular Catalysis and Innovative Material Laboratory, Department of Chemistry, Fudan University, Shanghai 200433, People's Republic of China
| | - Lixin Zhang
- Molecular Catalysis and Innovative Material Laboratory, Department of Chemistry, Fudan University, Shanghai 200433, People's Republic of China
| | - Yanrong Li
- Molecular Catalysis and Innovative Material Laboratory, Department of Chemistry, Fudan University, Shanghai 200433, People's Republic of China
| | - Longcheng Hong
- Molecular Catalysis and Innovative Material Laboratory, Department of Chemistry, Fudan University, Shanghai 200433, People's Republic of China
| | - Zhenxia Chen
- Molecular Catalysis and Innovative Material Laboratory, Department of Chemistry, Fudan University, Shanghai 200433, People's Republic of China
| | - Xigeng Zhou
- Molecular Catalysis and Innovative Material Laboratory, Department of Chemistry, Fudan University, Shanghai 200433, People's Republic of China
- State Key Laboratory of Organometallic Chemistry, Shanghai 200032, People's Republic of China
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Das P, Sarmah PP, Borah M, Phukan AK. Low-spin, mononuclear, Fe(III) complexes with P,N donor hemilabile ligands: A combined experimental and theoretical study. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2009.08.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kersting B, Lehmann U. Chemistry of metalated container molecules. ADVANCES IN INORGANIC CHEMISTRY 2009. [DOI: 10.1016/s0898-8838(09)00207-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Theisen RM, Shearer J, Kaminsky W, Kovacs JA. Steric and electronic control over the reactivity of a thiolate-ligated Fe(II) complex with dioxygen and superoxide: reversible mu-oxo dimer formation. Inorg Chem 2004; 43:7682-90. [PMID: 15554633 PMCID: PMC4485619 DOI: 10.1021/ic0491884] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The reactivity between a thiolate-ligated five-coordinate complex [FeII(SMe2N4(tren))]+ (1) and dioxygen is examined in order to determine if O2 activation, resembling that of the metalloenzyme cytochrome P450, can be promoted even when O2 binds cis, as opposed to trans, to a thiolate. Previous work in our group showed that [FeII(SMe2N4(tren))]+ (1) reacts readily with superoxide (O2-) in the presence of a proton source to afford H2O2 via an Fe(III)-OOH intermediate, thus providing a biomimetic model for the metalloenzyme superoxide reductase (SOR). Addition of O2 to 1 affords binuclear mu-oxo-bridged [FeIII(SMe2N4(tren))]2(mu2-O)(PF6)2.3MeCN (3). At low temperatures, in protic solvents, an intermediate is detected, the details of which will be the subject of a separate paper. Although the thiolate ligand does not appear to perturb the metrical parameters of the unsupported mu-oxo bridge (Fe-O= 1.807(8) A, and Fe-O-Fe= 155.3(5) degrees fall in the usual range), it decreases the magnetic coupling between the irons (J=-28 cm(-1)) and creates a rather basic oxo site. Protonation of this oxo using strong (HBF4, HCl) or weak (HOAc, NH4PF6, LutNHCl) acids results in bridge cleavage to cleanly afford the corresponding monomeric anion-ligated (OAc- (6), or Cl- (7)) or solvent-ligated (MeCN (4)) derivatives. Addition of OH- converts [FeIII(SMe2N4(tren))(MeCN2+ (4) back to mu-oxo 3. Thus, mu-oxo bridge cleavage is reversible. The protonated mu-hydroxo-bridged intermediate is not observed. In an attempt to prevent mu-oxo dimer formation, and facilitate the observation of O2-bound intermediates, a bulkier tertiary amine ligand, tren-Et4= N-(2-amino-ethyl)-N-(2-diethylamino-ethyl)-N',N'-diethyl-ethane-1,2-diamine, and the corresponding [FeII(SMe2N4(tren-Et4))]+ (5) complex was synthesized and structurally characterized. Steric repulsive interactions create unusually long FeII-N(3,4) amine bonds in 5 (mean distance=2.219(1) A). The [(tren-Et4)N4SMe2]1- ligand is unable to accommodate iron in the +3 oxidation state, and consequently, in contrast to most thiolate-ligated Fe(II) complexes, [FeII(SMe2N4(tren-Et4))]+ (5) does not readily react with O2. Oxidation of 5 is irreversible, and the potential (Epa=+410 mV (vs SCE)) is anodically shifted relative to 1 (E1/2=-100 mV (vs SCE)).
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Affiliation(s)
- Roslyn M. Theisen
- Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700
| | - Jason Shearer
- Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700
| | | | - Julie A. Kovacs
- Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700
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Sreekanth A, Kurup M. Synthesis, EPR and Mössbauer spectral studies of new iron(III) complexes with 2-benzoylpyridine-N(4), N(4)-(butane-1,4-diyl) thiosemicarbazone (HBpypTsc): X-ray structure of [Fe(BpypTsc)2]FeCl4·2H2O and the free ligand. Polyhedron 2004. [DOI: 10.1016/j.poly.2004.01.006] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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11
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Kovacs JA. Synthetic analogues of cysteinate-ligated non-heme iron and non-corrinoid cobalt enzymes. Chem Rev 2004; 104:825-48. [PMID: 14871143 PMCID: PMC4487544 DOI: 10.1021/cr020619e] [Citation(s) in RCA: 224] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Julie A Kovacs
- Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195, USA
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Chang CH, Boone AJ, Bartlett RJ, Richards NGJ. Toward a Computational Description of Nitrile Hydratase: Studies of the Ground State Bonding and Spin-Dependent Energetics of Mononuclear, Non-Heme Fe(III) Complexes. Inorg Chem 2003; 43:458-72. [PMID: 14731008 DOI: 10.1021/ic0350032] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The metal coordination and spin state of the Fe(III) center in nitrile hydratase (NHase) has stimulated the synthesis of model complexes in efforts to understand the reactivity and spectroscopic properties of the enzyme. We report density functional theory (DFT) calculations on a number of Fe(III) complexes that have been prepared as models of the NHase metal center, together with others having similar ligands but different ground state spin multiplicities. Our results suggest that a DFT description of specific spin configurations in these systems does not suffer from significant amounts of spin contamination. In particular, B3LYP calculations not only reproduce the observed spin state preferences of these Fe(III) complexes but also predict spin-dependent structural properties consistent with those expected on the basis of ligand field models. An analysis of the natural bond orbital (NBO) transformation of the Kohn-Sham wave functions has enabled quantitation of the overall contribution to covalency of ligand-to-metal sigma-donation and pi-donation, and metal-to-ligand pi-back-bonding in these Fe(III) complexes at their BLYP-optimized geometries. Although sulfur ligands are the primary source of covalency in the Fe(III) complexes, our quantitative analysis suggests that hyperbonding between metal-bound nitrogens and an Fe-S bond represents a mechanism by which Fe-N covalency may arise. These studies establish the computational methodology for future theoretical investigations of the NHase Fe(III) center.
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Affiliation(s)
- Christopher H Chang
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA
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Tsujimura M, Odaka M, Nakayama H, Dohmae N, Koshino H, Asami T, Hoshino M, Takio K, Yoshida S, Maeda M, Endo I. A novel inhibitor for Fe-type nitrile hydratase: 2-cyano-2-propyl hydroperoxide. J Am Chem Soc 2003; 125:11532-8. [PMID: 13129355 DOI: 10.1021/ja035018z] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nitrile hydratase (NHase) is a non-heme iron or non-corrin cobalt enzyme having two post-translationally modified ligand residues, cysteine-sulfinic acid (alphaCys112-SO(2)H) and -sulfenic acid (alphaCys114-SOH). We studied the interaction between Fe-type NHase and isobutyronitrile (iso-BN) which had been reported as a competitive inhibitor with a K(i) value of 5 microM. From detailed kinetic studies of the inhibitory effect of iso-BN on Fe-type NHase, we found that authentic iso-BN was hydrated normally and that the impurity present in commercially available iso-BN inhibited NHase activity strongly. The inhibitory compound induced significant changes in the UV-vis absorption spectrum of NHase, suggesting its interaction with the iron center. This compound was purified by using reversed-phase HPLC and identified as 2-cyano-2-propyl hydroperoxide (Cpx) by (1)H and PFG-HMBC NMR spectroscopy. Upon addition of a stoichiometric amount of Cpx, NHase was irreversibly inactivated, probably by the oxidation of alphaCys114-SOH to Cys-SO(2)H. This result suggests that the -SOH structure of alphaCys114 is essential for the catalytic activity. The oxygen atom in Cys-SO(2)H is confirmed to come from the solvent H(2)O. The oxidized NHase was found to induce the UV-vis absorption spectral changes by addition of Cpx, suggesting that Cpx strongly interacted with iron(III) in the oxidized NHase to form a stable complex. Thus, Cpx functions as a novel irreversible inhibitor for NHase.
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Affiliation(s)
- Masanari Tsujimura
- Biomolecular Characterization Division, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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Pavlishchuk V, Birkelbach F, Weyhermüller T, Wieghardt K, Chaudhuri P. Polynuclear complexes of the pendent-arm ligand 1,4,7-tris(acetophenoneoxime)-1,4,7-triazacyclononane. Inorg Chem 2002; 41:4405-16. [PMID: 12184757 DOI: 10.1021/ic011322m] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The ligand 1,4,7-tris(acetophenoneoxime)-1,4,7-triazacyclononane (H(3)L) has been synthesized and its coordination properties toward Cu(II), Ni(II), Co(II), and Mn(II) in the presence of air have been investigated. Copper(II) yields a mononuclear complex, [Cu(H(2)L)](ClO(4)) (1), cobalt(II) and manganese(II) ions yield mixed-valence Co(III)(2)Co(II) (2a) and Mn(II)(2)Mn(III) (4) complexes, whereas nickel(II) produces a tetranuclear [Ni(4)(HL)(3)](2+) (3) complex. The complexes have been structurally, magnetochemically, and spectroscopically characterized. Complex 3, a planar trigonal-shaped tetranuclear Ni(II) species, exhibits irregular spin-ladder. Variable-temperature (2-290 K) magnetic susceptibility analysis of 3 demonstrates antiferromagnetic exchange interactions (J = -13.4 cm(-1)) between the neighboring Ni(II) ions, which lead to the ground-state S(t) = 2.0 owing to the topology of the spin-carriers in 3. A bulk ferromaganetic interaction (J = +2 cm(-1)) is prevailing between the neighboring high-spin Mn(II) and high-spin Mn(III) ions leading to a ground state of S(t) = 7.0 for 4. The large ground-state spin value of S(t) = 7.0 has been confirmed by magnetization measurements at applied magnetic fields of 1, 4 and 7 T. A bridging monomethyl carbonato ligand formation occurs through an efficient CO(2) uptake from air in methanolic solutions containing a base in the case of complex 4.
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Affiliation(s)
- Vitaly Pavlishchuk
- Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
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Li M, Bonnet D, Bill E, Neese F, Weyhermüller T, Blum N, Sellmann D, Wieghardt K. Tuning the electronic structure of octahedral iron complexes [FeL(X)] (L = 1-alkyl-4,7-bis(4-tert-butyl-2-mercaptobenzyl)-1,4,7-triazacyclononane, X = Cl, CH(3)O, CN, NO). The S = 1/2 <==>3/2 Spin equilibrium of [FeL(Pr)(NO)]. Inorg Chem 2002; 41:3444-56. [PMID: 12079463 DOI: 10.1021/ic011243a] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two new pentadentate, pendent arm macrocyclic ligands of the type 1-alkyl-4,7-bis(4-tert-butyl-2-mercaptobenzyl)-1,4,7-triazacyclononane where alkyl represents an isopropyl, (L(Pr))(2-), or an ethyl group, (L(Et))(2-), have been synthesized. It is shown that they bind strongly to ferric ions generating six-coordinate species of the type [Fe(L(alk))X]. The ground state of these complexes is governed by the nature of the sixth ligand, X: [Fe(III)(L(Et))Cl] (2) possesses an S = 5/2 ground state as do [Fe(III)(L(Et))(OCH(3))] (3) and [Fe(III)(L(Pr))(OCH(3))] (4). In contrast, the cyano complexes [Fe(III)(L(Et))(CN)] (5) and [Fe(III)(L(Pr))(CN)] (6) are low spin ferric species (S = 1/2). The octahedral [FeNO](7) nitrosyl complex [Fe(L(Pr))(NO)] (7) displays spin equilibrium behavior S = 1/2<==>S = (3)/(2) in the solid state. Complexes [Zn(L(Pr))] (1), 4.CH(3)OH, 5.0.5toluene.CH(2)Cl(2), and 7.2.5CH(2)Cl(2) have been structurally characterized by low-temperature (100 K) X-ray crystallography. All iron complexes have been carefully studied by zero- and applied-field Mössbauer spectroscopy. In addition, Sellmann's complexes [Fe(pyS(4))(NO)](0/1+) and [Fe(pyS(4))X] (X = PR(3), CO, SR(2)) have been studied by EPR and Mössbauer spectroscopies and DFT calculations (pyS(4) = 2,6-bis(2-mercaptophenylthiomethyl)pyridine(2-)). It is concluded that the electronic structure of 7 with an S = 1/2 ground state is low spin ferrous (S(Fe) = 0) with a coordinated neutral NO radical (Fe(II)-NO) whereas the S = 3/2 state corresponds to a high spin ferric (S(Fe) = 5/2) antiferromagnetically coupled to an NO(-) anion (S = 1). The S = 1/2<==>S = 3/2 equilibrium is then that of valence tautomers rather than that of a simple high spin<==>low spin crossover.
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Affiliation(s)
- Ming Li
- Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
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Grapperhaus CA, Patra AK, Mashuta MS. First [Fe-NO](6) complex with an N(2)S(3)Fe-NO core as a model of NO-inactivated iron-containing nitrile hydratase. Are thiolates and thioethers equivalent donors in low-spin iron complexes? Inorg Chem 2002; 41:1039-41. [PMID: 11874334 DOI: 10.1021/ic015629x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The spectroscopic and structural properties of [(bmmp-TASN)FeNO]BPh(4) (1) (bmmp-TASN = 4,7-bis(2'-methyl-2'-mercaptopropyl)-1-thia-4,7-diazacyclononane) have been determined and are compared with the nitric oxide inactivated form of iron-containing nitrile hydratase, NHase(dark). [(bmmp-TASN)FeNO]BPh(4) is prepared from the addition of NO to (bmmp-TASN)FeCl followed by addition of sodium tetraphenylborate. [(bmmp-TASN)FeNO]BPh(4) crystallizes from acetonitrile-methanol solutions upon ether vapor diffusion as dark blue plates in the monoclinic space group P2(1)/c with a = 11.9521(14) A, b = 11.3238(13) A, c = 26.624(3) A, beta = 98.280(2), and Z = 4. The nu(NO) stretching frequency of 1856 cm(-)(1) and the Mössbauer parameters, delta = 0.06 mm/s and DeltaE(q) = 1.75 mm/s, compare favorably with those of NHase(dark). The similarities of the iron-sulfur bond distances to the thiolate, 2.284(2) A and 2.291(2) A, versus thioether, 2.285(2) A, are attributed to the low-spin configuration of the iron. The relationship between this structural observation and the spectroscopic properties of the complex are discussed.
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Affiliation(s)
- Craig A Grapperhaus
- Department of Chemistry, University of Louisville, Louisville, KY 40292, USA.
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Kimura S, Bill E, Bothe E, Weyhermüller T, Wieghardt K. Phenylthiyl radical complexes of gallium(III), iron(III), and cobalt(III) and comparison with their phenoxyl analogues. J Am Chem Soc 2001; 123:6025-39. [PMID: 11414836 DOI: 10.1021/ja004305p] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Three hexadentate, asymmetric pendent arm macrocycles containing a 1,4,7-triazacyclononane-1,4-diacetate backbone and a third, N-bound phenolate or thiophenolate arm have been synthesized. In [L(1)](3)(-) the third arm is 3,5-di-tert-butyl-2-hydroxybenzyl, in [L(2)](3)(-) it is 2-mercaptobenzyl, and in [L(3)](3)(-) it is 3,5-di-tert-butyl-2-mercaptobenzyl. With trivalent metal ions these ligands form very stable neutral mononuclear complexes [M(III)L(1)] (M = Ga, Fe, Co), [M(III)L(2)] (M = Ga, Fe, Co), and [M(III)L(3)] (M = Ga, Co) where the gallium and cobalt complexes possess an S = 0 and the iron complexes an S = (5)/(2) ground state. Complexes [CoL(1)].CH(3)OH.1.5H(2)O, [CoL(3)].1.17H(2)O, [FeL(1)].H(2)O, and [FeL(2)] have been characterized by X-ray crystallography. Cyclic voltammetry shows that all three [M(III)L(1)] complexes undergo a reversible, ligand-based, one-electron oxidation generating the monocations [M(III)L(1)(*)](+) which contain a coordinated phenoxyl radical as was unambiguously established by their electronic absorption, EPR, and Mössbauer spectra. In contrast, [M(III)L(2)] complexes in CH(3)CN solution undergo an irreversible one-electron oxidation where the putative thiyl radical monocationic intermediates dimerize with S-S bond formation yielding dinuclear disulfide species [M(III)L(2)-L(2)M(III)](2+). [GaL(3)] behaves similarly despite the steric bulk of two tertiary butyl groups at the 3,5-positions of the thiophenolate, but [Co(III)L(3)] in CH(2)Cl(2) at -20 to -61 degrees C displays a reversible one-electron oxidation yielding a relatively stable monocation [Co(III)L(3)(*)](+). Its electronic spectrum displays intense transitions in the visible at 509 nm (epsilon = 2.6 x 10(3) M(-)(1) cm(-)(1)) and 670sh, 784 (1.03 x 10(3)) typical of a phenylthiyl radical. The EPR spectrum of this species at 90 K proves the thiyl radical to be coordinated to a diamagnetic cobalt(III) ion (g(iso) = 2.0226; A(iso)((59)Co) = 10.7 G).
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Affiliation(s)
- S Kimura
- Max-Planck-Institut für Strahlenchemie, D-45470 Mülheim an der Ruhr, Germany
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Noveron JC, Olmstead MM, Mascharak PK. A synthetic analogue of the active site of Fe-containing nitrile hydratase with carboxamido N and thiolato S as donors: synthesis, structure, and reactivities. J Am Chem Soc 2001; 123:3247-59. [PMID: 11457060 DOI: 10.1021/ja001253v] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
As part of our work on models of the iron(III) site of Fe-containing nitrile hydratase, a designed ligand PyPSH(4) with two carboxamide and two thiolate donor groups has been synthesized. Reaction of (Et(4)N)[FeCl(4)] with the deprotonated form of the ligand in DMF affords the mononuclear iron(III) complex (Et(4)N)[Fe(III)(PyPS)] (1) in high yield. The iron(III) center is in a trigonal bipyramidal geometry with two deprotonated carboxamido nitrogens, one pyridine nitrogen, and two thiolato sulfurs as donors. Complex 1 is stable in water and binds a variety of Lewis bases at the sixth site at low temperature to afford green solutions with a band around 700 nm. The iron(III) centers in these six-coordinate species are low-spin and exhibit EPR spectra much like the enzyme. The pK(a) of the water molecule in [Fe(III)(PyPS)(H(2)O)](-) is 6.3 +/- 0.4. The iron(III) site in 1 with ligated carboxamido nitrogens and thiolato sulfurs does not show any affinity toward nitriles. It thus appears that at physiological pH, a metal-bound hydroxide promotes hydration of nitriles nested in close proximity of the iron center in the enzyme. Redox measurements demonstrate that the carboxamido nitrogens prefer Fe(III) to Fe(II) centers. This fact explains the absence of any redox behavior at the iron site in nitrile hydratase. Upon exposure to limited amount of dioxygen, 1 is converted to the bis-sulfinic species. The structure of the more stable O-bonded sulfinato complex (Et(4)N)[Fe(III)(PyP[SO(2)](2))] (2) has been determined. Six-coordinated low-spin cyanide adducts of the S-bonded and the O-bonded sulfinato complexes, namely, Na(2)[Fe(III)(PyP[SO(2)](2))(CN)] (4) and (Et(4)N)(2)[Fe(III)(PyP[SO(2)](2))(CN)] (5), afford green solutions in water and other solvents. The iron(II) complex (Et(4)N)(2)[Fe(II)(PyPS)] (3) has also been isolated and structurally characterized.
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Affiliation(s)
- J C Noveron
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, USA
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Boone AJ, Cory MG, Scott MJ, Zerner MC, Richards NG. Investigating the structural and electronic properties of nitrile hydratase model iron(III) complexes using projected unrestricted Hartree-Fock (PUHF) calculations. Inorg Chem 2001; 40:1837-45. [PMID: 11312740 DOI: 10.1021/ic0009021] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Important structural and mechanistic details concerning the non-heme, low-spin Fe(III) center in nitrile hydratase (NHase) remain poorly understood. We now report projection unrestricted Hartree-Fock (PUHF) calculations on the spin preferences of a series of inorganic complexes in which Fe(III) is coordinated by a mixed set of N/S ligands. Given that many of these compounds have been prepared as models of the NHase metal center, this study has allowed us to evaluate this computational approach as a tool for future calculations on the electronic structure of the NHase Fe(III) center itself. When used in combination with the INDO/S semiempirical model, the PUHF method correctly predicts the experimentally observed spin state for 12 of the 13 Fe(III)-containing complexes studied here. The one compound for which there is disagreement between our theoretical calculations and experimental observation exhibits temperature-dependent spin behavior. In this case, the failure of the PUHF-INDO/S approach may be associated with differences between the structure of the Fe(III) complex present under the conditions used to measure the spin preference and that observed by X-ray crystallography. A preliminary analysis of the role of the N/S ligands and coordination geometry in defining the Fe(III) spin preferences in these complexes has also been undertaken by computing the electronic properties of the lowest energy Fe(III) spin states. While any detailed interpretation of our results is constrained both by the limited set of well-characterized Fe(III) complexes used in this study and by the complicated dependence of Fe(III) spin preference upon metal-ligand interactions and coordination geometry, these PUHF-INDO/S calculations support the hypothesis that the deprotonated amide nitrogens coordinating the metal stabilize the low-spin Fe(III) ground state seen in NHase. Strong evidence that the sulfur ligands exclusively define the Fe(III) spin state preference by forming metal-ligand bonds with significant covalent character is not provided by these computational studies. This might, however, reflect limitations in modeling these systems at the INDO/S level of theory.
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Affiliation(s)
- A J Boone
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, USA
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Jackson HL, Shoner SC, Rittenberg D, Cowen JA, Lovell S, Barnhart D, Kovacs JA. Probing the influence of local coordination environment on the properties of Fe-type nitrile hydratase model complexes. Inorg Chem 2001; 40:1646-53. [PMID: 11261975 PMCID: PMC4485621 DOI: 10.1021/ic001271d] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of four structurally related cis-dithiolate-ligated Fe(III) complexes, [Fe(III)(DITpy)2]Cl (1), [Fe(III)(DITIm)2]Cl (2), [Fe(III)(ADIT)2]Cl (3), and [Fe(III)(AMIT)2]Cl (4), are described. The structural characterization of 3 as well as the spectroscopic properties of 3 and 4 has been previously reported. Crystal data for 1, 2, and 4 are as follows: 1.3H2O crystallizes in the orthorhombic space group Pca2(1) with a = 19.800(4) A, b = 18.450(4) A, c = 14.800(3) A, and Z = 8. 2.(1/2)EtOH.1/2H2O crystallizes in the monoclinic space group Cc with a = 24.792(4) A, b = 14.364(3) A, c = 17.527(3) A, beta = 124.91(2) degrees, and Z = 8. 4 crystallizes in the triclinic space group P1 with a = 8.0152(6) A, b = 10.0221(8) A, c = 11.8384(10) A, alpha = 73.460(3) degrees, beta = 71.451(5) degrees, gamma = 72.856(4) degrees, and Z = 2. Complexes 1-4 share a common S2N4 coordination environment that consists of two cis-thiolates, two trans-imines, and two cis-terminal nitrogen donors: Nterm = pyridine (1), imidazole (2), and primary amine (3 and 4). The crystallographically determined mean Fe-S bond distances in 1-4 range from 2.196 to 2.232 A and are characteristic of low-spin Fe(III)-thiolate complexes. The low-spin S = 1/2 ground state was confirmed by both EPR and magnetic susceptibility measurements. The electronic spectra of these complexes are characterized by broad absorption bands centered near approximately 700 nm that are consistent with ligand-to-metal charge-transfer (CT) bands. The complexes were further characterized by cyclic voltammetry measurements, and all possess highly negative Fe(III)/Fe(II) redox couples ( approximately -1 V vs SCE, saturated calomel electrode) indicating that alkyl thiolate donors are effective at stabilizing Fe(III) centers. Both the redox couple and the 700 nm band in the visible spectra show solvent-dependent shifts that are dependent upon the H-bonding ability of the solvent. The implications of these results with respect to the active site of the iron-containing nitrile hydratases are also discussed.
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Affiliation(s)
| | | | | | | | | | | | - Julie A. Kovacs
- Author to whom correspondence should be addressed: Dr. Julie A. Kovacs, Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195-1700. . Fax: 206-685-8665
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Albela B, Bill E, Brosch O, Weyhermüller T, Wieghardt K. Molecular and Electronic Structure of Two Linear Thiophenolate-Bridged Heterotrinuclear Complexes [LFeRuFeL]2+/3+ (L = 1,4,7-Tris(4-tert-butyl-2-mercaptobenzyl)-1,4,7-triazacyclononane). Eur J Inorg Chem 2000. [DOI: 10.1002/(sici)1099-0682(200001)2000:1<139::aid-ejic139>3.0.co;2-e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Albela B, Bothe E, Brosch O, Mochizuki K, Weyhermüller T, Wieghardt K. Redox Chemistry of (1,4,7-Tris(4-tert-butyl-2-mercaptobenzyl)-1,4,7- triazacyclononane)ruthenium(III), [Ru(III)L]: Synthesis and Characterization of [Ru(II)(2)(L-L)](BPh(4))(4).10CH(3)CN and [LRuRuRuL](PF(6))(2).H(2)O. Inorg Chem 1999; 38:5131-5138. [PMID: 11671260 DOI: 10.1021/ic9906297] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The mononuclear blue complex [Ru(III)L] (1) where L represents the trianion of 1,4,7-tris(4-tert-butyl-2-mercaptobenzyl)-1,4,7-triazacyclononane has been synthesized by the reaction of H(3)L.3HPF(6) with [Ru(II)Cl(2)(dmso)(4)] in refluxing CH(3)OH in the presence of air. Chemical or electrochemical oxidation of 1 generates [Ru(II)(2)(L-L)](PF(6))(4) (2), a dinuclear species containing two Ru(II) ions and a neutral tris(disulfide) ligand L-L. The reaction of 1 with 1 equiv of [Ru(II)Cl(2)(dmso)(4)] produces the trinuclear species [LRuRuRuL](PF(6))(2) (3) in low yield. Complexes 2 and 3 have been structurally characterized by X-ray crystallography: [Ru(II)(2)(L-L)](BPh(4))(4).10CH(3)CN, C(194)H(218)B(4)N(16)Ru(2)S(6), crystallizes in the monoclinic space group C2/c with a = 28.734(5) Å, b = 16.347(3) Å, c = 37.986(7) Å, beta = 102.35(2) degrees, and Z = 4 whereas [LRuRuRuL](PF(6))(2).H(2)O, C(78)H(110)F(12)N(6)OP(2)Ru(3)S(6), crystallizes in the monoclinic space group P2(1)/n with a = 18.755(4) Å, b = 22.278(4) Å, c = 21.920(4) Å, beta = 91.69(3) Å, and Z = 4. The electro- and spectroelectrochemistry of 1-3 have been studied in detail as have their electronic structures by (1)H NMR, EPR, UV-vis, IR, and Raman spectroscopy.
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Affiliation(s)
- Belén Albela
- Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
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Glaser T, Bill E, Weyhermüller T, Meyer-Klaucke W, Wieghardt K. Sn(III) and Ge(III) in the Thiophenolato-Bridged Complexes [LFeSnFeL]n+ and [LFeGeFeL]n+ (n = 2, 3; L = 1,4,7-(4-tert-Butyl-2-mercaptobenzyl)-1,4,7-triazacyclononane). Inorg Chem 1999. [DOI: 10.1021/ic9902018] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Thorsten Glaser
- Contribution from the Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany, and the European Molecular Biology Laboratory, Outstation Hamburg, D-22603 Hamburg, Germany
| | - Eckhard Bill
- Contribution from the Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany, and the European Molecular Biology Laboratory, Outstation Hamburg, D-22603 Hamburg, Germany
| | - Thomas Weyhermüller
- Contribution from the Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany, and the European Molecular Biology Laboratory, Outstation Hamburg, D-22603 Hamburg, Germany
| | - Wolfram Meyer-Klaucke
- Contribution from the Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany, and the European Molecular Biology Laboratory, Outstation Hamburg, D-22603 Hamburg, Germany
| | - Karl Wieghardt
- Contribution from the Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany, and the European Molecular Biology Laboratory, Outstation Hamburg, D-22603 Hamburg, Germany
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Sun Y, Cutler CS, Martell AE, Welch MJ. New multidentate ligands containing mercaptobenzyl functional groups, and biodistribution of gallium-67-TACN-HSB. Tetrahedron 1999. [DOI: 10.1016/s0040-4020(99)00243-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Glaser T, Beissel T, Bill E, Weyhermüller T, Schünemann V, Meyer-Klaucke W, Trautwein AX, Wieghardt K. Electronic Structure of Linear Thiophenolate-Bridged Heterotrinuclear Complexes [LFeMFeL]n+ (M = Cr, Co, Fe; n = 1−3): Localized vs Delocalized Models. J Am Chem Soc 1999. [DOI: 10.1021/ja982898m] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Thorsten Glaser
- Contribution from the Max-Planck-Institut für Strahlenchemie, D-45470 Mülheim and der Ruhr, Germany, Institut für Physik, Medizinische Universität, D-23538 Lübeck, Germany, and European Molecular Biology Laboratory, Outstation Hamburg, D-22603 Hamburg, Germany
| | - Thomas Beissel
- Contribution from the Max-Planck-Institut für Strahlenchemie, D-45470 Mülheim and der Ruhr, Germany, Institut für Physik, Medizinische Universität, D-23538 Lübeck, Germany, and European Molecular Biology Laboratory, Outstation Hamburg, D-22603 Hamburg, Germany
| | - Eckhard Bill
- Contribution from the Max-Planck-Institut für Strahlenchemie, D-45470 Mülheim and der Ruhr, Germany, Institut für Physik, Medizinische Universität, D-23538 Lübeck, Germany, and European Molecular Biology Laboratory, Outstation Hamburg, D-22603 Hamburg, Germany
| | - Thomas Weyhermüller
- Contribution from the Max-Planck-Institut für Strahlenchemie, D-45470 Mülheim and der Ruhr, Germany, Institut für Physik, Medizinische Universität, D-23538 Lübeck, Germany, and European Molecular Biology Laboratory, Outstation Hamburg, D-22603 Hamburg, Germany
| | - Volker Schünemann
- Contribution from the Max-Planck-Institut für Strahlenchemie, D-45470 Mülheim and der Ruhr, Germany, Institut für Physik, Medizinische Universität, D-23538 Lübeck, Germany, and European Molecular Biology Laboratory, Outstation Hamburg, D-22603 Hamburg, Germany
| | - Wolfram Meyer-Klaucke
- Contribution from the Max-Planck-Institut für Strahlenchemie, D-45470 Mülheim and der Ruhr, Germany, Institut für Physik, Medizinische Universität, D-23538 Lübeck, Germany, and European Molecular Biology Laboratory, Outstation Hamburg, D-22603 Hamburg, Germany
| | - Alfred X. Trautwein
- Contribution from the Max-Planck-Institut für Strahlenchemie, D-45470 Mülheim and der Ruhr, Germany, Institut für Physik, Medizinische Universität, D-23538 Lübeck, Germany, and European Molecular Biology Laboratory, Outstation Hamburg, D-22603 Hamburg, Germany
| | - Karl Wieghardt
- Contribution from the Max-Planck-Institut für Strahlenchemie, D-45470 Mülheim and der Ruhr, Germany, Institut für Physik, Medizinische Universität, D-23538 Lübeck, Germany, and European Molecular Biology Laboratory, Outstation Hamburg, D-22603 Hamburg, Germany
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Glaser T, Kesting F, Beissel T, Bill E, Weyhermüller T, Meyer-Klaucke W, Wieghardt K. Spin-Dependent Delocalization in Three Isostructural Complexes [LFeNiFeL](2+/3+/4+) (L = 1,4,7-(4-tert-Butyl-2-mercaptobenzyl)-1,4,7-triazacyclononane). Inorg Chem 1999; 38:722-732. [PMID: 11670840 DOI: 10.1021/ic9811289] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reaction of mononuclear [LFe(III)] where L represents the trianionic ligand 1,4,7-tris(4-tert-butyl-2-mercaptobenzyl)-1,4,7-triazacyclononane with NiCl(2).6H(2)O and subsequent oxidations with [Ni(III)(tacn)(2)](ClO(4))(3) (tacn = 1,4,7-triazacyclononane) and PbO(2)/methanesulfonic acid produced an isostructural series of complexes [LFeNiFeL](n)()(+) (n = 2 (1), n = 3 (2), n = 4 (3)), which were isolated as PF(6)(-) (1, 3) or ClO(4)(-) salts (2). The molecular structures were established by X-ray crystallography for [LFeNiFeL](ClO(4))(2).5CH(3)CN (1), C(88)H(123)Cl(2)Fe(2)N(11)NiO(8)S(6), and [LFeNiFeL](ClO(4))(3).8acetone (2), C(102)H(156)Cl(3)Fe(2)N(6)NiO(20)S(6). Both compounds crystallize in the triclinic space group P&onemacr; with a = 13.065(2) Å (13.155(2) Å), b = 13.626(3) Å (13.747(3) Å), c = 14.043(3) Å (16.237(3) Å), alpha = 114.47(3) degrees (114.20(2) degrees ), beta = 97.67(3) degrees (96.57(2) degrees ), gamma = 90.34(3) degrees (98.86(2) degrees ), Z = 1(1) (values in parentheses refer to 2). The cations in 1, 2, and 3 have been determined to be isostructural by Fe and Ni K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy. All compounds contain linear trinuclear cations (face-sharing octahedral) with an N(3)Fe(&mgr;-SR)(3)Ni(&mgr;-SR)(3)FeN(3) core structure. The electronic structures of 1, 2, and 3 have been studied by Fe and Ni K-edge X-ray absorption near edge (XANES), UV-vis, EPR, and Mössbauer spectroscopy as well as by temperature-dependent magnetic susceptibility measurements. Complexes 1 and 3 possess an S(t)() = 0 whereas 2 has an S(t)() = (1)/(2) ground state. It is shown that the electronic structures cannot be described by using localized valences (oxidation states). Delocalized models invoking the double-exchange mechanism are appropriate; i.e., spin-dependent delocalization via a double-exchange mechanism yields the correct ground state in each case. 1, 2, and 3 represent the first examples where double exchange stabilizes a ground state of minimum spin multiplicity.
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Affiliation(s)
- Thorsten Glaser
- Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany, and the European Molecular Biology Laboratory, Outstation Hamburg, D-22603 Hamburg, Germany
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C. Noveron J, Herradora R, Olmstead MM, Mascharak PK. Low-spin iron(III) complexes with N,S coordination: syntheses, structures, and properties of bis(N-2-mercaptophenyl-2′-pyridylmethyleniminato)iron(III) tetraphenylborate and bis(N-2-mercapto-2-methylpropyl-2′-pyridylmethyleniminato)iron(III) tetraphenylborate. Inorganica Chim Acta 1999. [DOI: 10.1016/s0020-1693(98)00354-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Ellison JJ, Nienstedt A, Shoner SC, Barnhart D, Cowen JA, Kovacs JA. Reactivity of Five-Coordinate Models for the Thiolate-Ligated Fe Site of Nitrile Hydratase. J Am Chem Soc 1998. [DOI: 10.1021/ja973129q] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jeffrey J. Ellison
- Contribution from the Department of Chemistry, University of Washington, Seattle, Washington 98195
| | - Andrew Nienstedt
- Contribution from the Department of Chemistry, University of Washington, Seattle, Washington 98195
| | - Steven C. Shoner
- Contribution from the Department of Chemistry, University of Washington, Seattle, Washington 98195
| | - David Barnhart
- Contribution from the Department of Chemistry, University of Washington, Seattle, Washington 98195
| | - Jerry A. Cowen
- Contribution from the Department of Chemistry, University of Washington, Seattle, Washington 98195
| | - Julie A. Kovacs
- Contribution from the Department of Chemistry, University of Washington, Seattle, Washington 98195
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Higgs TC, Ji D, Czernuszewicz RS, Matzanke BF, Schunemann V, Trautwein AX, Helliwell M, Ramirez W, Carrano CJ. The Fe(III), Co(III), and V(III) Complexes of the “Heteroscorpionate” Ligand (2-Thiophenyl)bis(pyrazolyl)methane. Inorg Chem 1998. [DOI: 10.1021/ic971151e] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Timothy C. Higgs
- Departments of Chemistry, Southwest Texas State University, San Marcos, Texas 78666, University of Houston, Houston, Texas, 77204, The University of Manchester, Oxford Road, Manchester, M13 9PL, England, and The Institute for Physics, Medical University of Lübeck, D-23538 Lübeck, Germany
| | - David Ji
- Departments of Chemistry, Southwest Texas State University, San Marcos, Texas 78666, University of Houston, Houston, Texas, 77204, The University of Manchester, Oxford Road, Manchester, M13 9PL, England, and The Institute for Physics, Medical University of Lübeck, D-23538 Lübeck, Germany
| | - Roman S. Czernuszewicz
- Departments of Chemistry, Southwest Texas State University, San Marcos, Texas 78666, University of Houston, Houston, Texas, 77204, The University of Manchester, Oxford Road, Manchester, M13 9PL, England, and The Institute for Physics, Medical University of Lübeck, D-23538 Lübeck, Germany
| | - Berthold F. Matzanke
- Departments of Chemistry, Southwest Texas State University, San Marcos, Texas 78666, University of Houston, Houston, Texas, 77204, The University of Manchester, Oxford Road, Manchester, M13 9PL, England, and The Institute for Physics, Medical University of Lübeck, D-23538 Lübeck, Germany
| | - Volker Schunemann
- Departments of Chemistry, Southwest Texas State University, San Marcos, Texas 78666, University of Houston, Houston, Texas, 77204, The University of Manchester, Oxford Road, Manchester, M13 9PL, England, and The Institute for Physics, Medical University of Lübeck, D-23538 Lübeck, Germany
| | - Alfred X. Trautwein
- Departments of Chemistry, Southwest Texas State University, San Marcos, Texas 78666, University of Houston, Houston, Texas, 77204, The University of Manchester, Oxford Road, Manchester, M13 9PL, England, and The Institute for Physics, Medical University of Lübeck, D-23538 Lübeck, Germany
| | - Madeleine Helliwell
- Departments of Chemistry, Southwest Texas State University, San Marcos, Texas 78666, University of Houston, Houston, Texas, 77204, The University of Manchester, Oxford Road, Manchester, M13 9PL, England, and The Institute for Physics, Medical University of Lübeck, D-23538 Lübeck, Germany
| | - Wilfredo Ramirez
- Departments of Chemistry, Southwest Texas State University, San Marcos, Texas 78666, University of Houston, Houston, Texas, 77204, The University of Manchester, Oxford Road, Manchester, M13 9PL, England, and The Institute for Physics, Medical University of Lübeck, D-23538 Lübeck, Germany
| | - Carl J. Carrano
- Departments of Chemistry, Southwest Texas State University, San Marcos, Texas 78666, University of Houston, Houston, Texas, 77204, The University of Manchester, Oxford Road, Manchester, M13 9PL, England, and The Institute for Physics, Medical University of Lübeck, D-23538 Lübeck, Germany
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Noveron JC, Olmstead MM, Mascharak PK. Effect of Carboxamido N Coordination to Iron on the Redox Potential of Low-Spin Non-Heme Iron Centers with N,S Coordination: Relevance to the Iron Site of Nitrile Hydratase. Inorg Chem 1998; 37:1138-1139. [PMID: 11670316 DOI: 10.1021/ic971388a] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Juan C. Noveron
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, and Department of Chemistry, University of California, Davis, California 95616
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Tsujimura M, Dohmae N, Odaka M, Chijimatsu M, Takio K, Yohda M, Hoshino M, Nagashima S, Endo I. Structure of the photoreactive iron center of the nitrile hydratase from Rhodococcus sp. N-771. Evidence of a novel post-translational modification in the cysteine ligand. J Biol Chem 1997; 272:29454-9. [PMID: 9368004 DOI: 10.1074/jbc.272.47.29454] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Nitrile hydratase (NHase) from Rhodococcus sp. N-771 is a photoreactive enzyme that is inactivated by nitrosylation of the non-heme iron center and activated by photodissociation of nitric oxide (NO). To obtain structural information on the iron center, we isolated peptide complexes containing the iron center by proteolysis. When the tryptic digest of the alpha subunit isolated from the inactive form was analyzed by reversed-phase high performance liquid chromatography, the absorbance characteristic of the nitrosylated iron center was observed in the peptide fragment, Asn105-Val-Ile-Val-Cys-Ser-Leu-Cys-Ser-Cys-Thr-Ala-Trp-Pro-Ile-Leu - Gly-Leu-Pro-Pro-Thr-Trp-Tyr-Lys128. The peptide contained 0.79 mol of iron/mol of molecule as well as endogenous NO. Subsequently, by digesting the peptide with thermolysin, carboxypeptidase Y, and leucine aminopeptidase M, we found that the minimum peptide segment required for the nitrosylated iron center is the 11 amino acid residues from alphaIle107 to alphaTrp117. Furthermore, by using mass spectrometry, protein sequence, and amino acid composition analyses, we have shown that the 112th Cys residue of the alpha subunit is post-translationally oxidized to a cysteine-sulfinic acid (Cys-SO2H) in the NHase. These results indicate that the NHase from Rhodococcus sp. N-771 has a novel non-heme iron enzyme containing a cysteine-sulfinic acid in the iron center. Possible ligand residues of the iron center are discussed.
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Affiliation(s)
- M Tsujimura
- Graduate School of Science and Engineering, Saitama University, Urawa, Saitama, Japan
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35
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Synthetic and structural aspects of the chemistry of saturated polyaza macrocyclic ligands bearing pendant coordinating groups attached to nitrogen. Coord Chem Rev 1997. [DOI: 10.1016/s0010-8545(97)00003-9] [Citation(s) in RCA: 238] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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36
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Odaka M, Fujii K, Hoshino M, Noguchi T, Tsujimura M, Nagashima S, Yohda M, Nagamune T, Inoue Y, Endo I. Activity Regulation of Photoreactive Nitrile Hydratase by Nitric Oxide. J Am Chem Soc 1997. [DOI: 10.1021/ja962179c] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Masafumi Odaka
- Contribution from the Biochemical Systems Laboratory, The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako, Saitama 351-01, Japan, Faculty of Engineering, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan, Chemical Dynamics Laboratory, RIKEN, Photosynthesis Research Laboratory, RIKEN, and Graduate School of Science and Engineering, Saitama University, Urawa, Saitama 338, Japan
| | - Kaoru Fujii
- Contribution from the Biochemical Systems Laboratory, The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako, Saitama 351-01, Japan, Faculty of Engineering, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan, Chemical Dynamics Laboratory, RIKEN, Photosynthesis Research Laboratory, RIKEN, and Graduate School of Science and Engineering, Saitama University, Urawa, Saitama 338, Japan
| | - Mikio Hoshino
- Contribution from the Biochemical Systems Laboratory, The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako, Saitama 351-01, Japan, Faculty of Engineering, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan, Chemical Dynamics Laboratory, RIKEN, Photosynthesis Research Laboratory, RIKEN, and Graduate School of Science and Engineering, Saitama University, Urawa, Saitama 338, Japan
| | - Takumi Noguchi
- Contribution from the Biochemical Systems Laboratory, The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako, Saitama 351-01, Japan, Faculty of Engineering, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan, Chemical Dynamics Laboratory, RIKEN, Photosynthesis Research Laboratory, RIKEN, and Graduate School of Science and Engineering, Saitama University, Urawa, Saitama 338, Japan
| | - Masanari Tsujimura
- Contribution from the Biochemical Systems Laboratory, The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako, Saitama 351-01, Japan, Faculty of Engineering, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan, Chemical Dynamics Laboratory, RIKEN, Photosynthesis Research Laboratory, RIKEN, and Graduate School of Science and Engineering, Saitama University, Urawa, Saitama 338, Japan
| | - Shigehiro Nagashima
- Contribution from the Biochemical Systems Laboratory, The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako, Saitama 351-01, Japan, Faculty of Engineering, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan, Chemical Dynamics Laboratory, RIKEN, Photosynthesis Research Laboratory, RIKEN, and Graduate School of Science and Engineering, Saitama University, Urawa, Saitama 338, Japan
| | - Masafumi Yohda
- Contribution from the Biochemical Systems Laboratory, The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako, Saitama 351-01, Japan, Faculty of Engineering, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan, Chemical Dynamics Laboratory, RIKEN, Photosynthesis Research Laboratory, RIKEN, and Graduate School of Science and Engineering, Saitama University, Urawa, Saitama 338, Japan
| | - Teruyuki Nagamune
- Contribution from the Biochemical Systems Laboratory, The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako, Saitama 351-01, Japan, Faculty of Engineering, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan, Chemical Dynamics Laboratory, RIKEN, Photosynthesis Research Laboratory, RIKEN, and Graduate School of Science and Engineering, Saitama University, Urawa, Saitama 338, Japan
| | - Yorinao Inoue
- Contribution from the Biochemical Systems Laboratory, The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako, Saitama 351-01, Japan, Faculty of Engineering, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan, Chemical Dynamics Laboratory, RIKEN, Photosynthesis Research Laboratory, RIKEN, and Graduate School of Science and Engineering, Saitama University, Urawa, Saitama 338, Japan
| | - Isao Endo
- Contribution from the Biochemical Systems Laboratory, The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako, Saitama 351-01, Japan, Faculty of Engineering, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan, Chemical Dynamics Laboratory, RIKEN, Photosynthesis Research Laboratory, RIKEN, and Graduate School of Science and Engineering, Saitama University, Urawa, Saitama 338, Japan
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37
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Beissel T, Glaser T, Kesting F, Wieghardt K, Nuber B. Mono- and Dinuclear Transition Metal Complexes of the Hexadentate Ligand Tris(4-tert-butyl-2-mercaptobenzyl)-1,4,7-triazacyclononane (L). Inorg Chem 1996; 35:3936-3947. [PMID: 11666587 DOI: 10.1021/ic951623u] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The hexadentate, pendant arm macrocycle 1,4,7-tris(4-tert-butyl-2-mercaptobenzyl)-1,4,7-triazacyclononane (H(3)L) has been synthesized and isolated as its trihydrochloride, H(3)L.3HCl, or sodium salt, Na(3)L, and its coordination chemistry with first-row transition metals has been studied. Mononuclear complexes of the type [LM(III)] (M = Ga (1), In (2), V (3), Cr (4), Mn (5), Fe,Co (6)) have been isolated as have the one-electron-oxidized forms [LM]PF(6) (M = V(IV) (3a), Mn(IV) (5a)). The crystal structure of 6 has been determined by single-crystal X-ray crystallography. Complex 6 crystallizes in the orthorhombic space group Iba2, with cell constants a = 14.206(8) Å, b = 22.53(1) Å, c = 26.07(1) Å, V = 8344.0(3) Å(3), and Z = 8. The cobalt(III) ion is in a distorted octahedral fac-N(3)S(3) donor set. The reaction of L with divalent metal chlorides in a 1:2 ratio in methanol affords the homodinuclear complexes [LM(II)(2)Cl] (M = Mn (7), Co (8), Ni (9), Zn (10), Cd (11)) where one metal is six- (N(3)MS(3)) and the other is four-coordinate (S(3)MCl); the two polyhedra are linked by three &mgr;(2)-thiolato bridges. Heterodinuclear complexes of the type [LM(1)M(2)Cl] have been obtained from [LM(2)Cl] species by abstraction of the four-coordinate metal ion and replacement by a different metal ion. The complexes [LZn(II)M(II)Cl] (M = Fe (12), Co (13), Ni (14)), [LNi(II)M(II)Cl] (M = Co (15), Zn (16)), and [LMn(II)M(II)Cl] (M = Fe (17), Co (18), Ni (19), Zn (20), Cd (21), Hg (22)) have been isolated as solid materials. The crystal structure of 14 has been determined by X-ray crystallography. Complex 14 crystallizes in the orthorhombic space group P2(1)2(1)2(1), with cell constants a = 15.45(1) Å, b = 17.77(1) Å, c = 17.58(1) Å, V = 4826.5(4) Å(3), and Z = 4. The linkage isomers 14 and 16 show characteristic electronic spectra for octahedrally and tetrahedrally coordinated Ni(II), respectively. The electronic structures of new complexes have been investigated by UV-vis spectroscopy; their magnetochemistry and electrochemistry are reported.
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Affiliation(s)
- Thomas Beissel
- Max-Planck-Institut für Strahlenchemie, D-45470 Mülheim an der Ruhr, Germany, and Anorganisch-Chemisches Institut der Universität, D-69120 Heidelberg, Germany
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38
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Blake AJ, Fallis IA, Gould RO, Parsons S, Ross SA, Schröder M. Selective derivatisation of aza macrocycles. ACTA ACUST UNITED AC 1996. [DOI: 10.1039/dt9960004379] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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39
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Beissel T, Birkelbach F, Bill E, Glaser T, Kesting F, Krebs C, Weyhermüller T, Wieghardt K, Butzlaff C, Trautwein AX. Exchange and Double-Exchange Phenomena in Linear Homo- and Heterotrinuclear Nickel(II,III,IV) Complexes Containing Six μ2-Phenolato or μ2-Thiophenolato Bridging Ligands. J Am Chem Soc 1996. [DOI: 10.1021/ja961305+] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ma R, Welch MJ, Reibenspies J, Martell AE. Stability of metal ion complexes of 1,4,7-tris(2-mercaptoethyl)-1,4,7-triazacylclonane (TACN-TM) and molecular structure of In(C12H24N3S3). Inorganica Chim Acta 1995. [DOI: 10.1016/0020-1693(95)04617-i] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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42
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Blake AJ, Donlevy TM, England PA, Fallis IA, Parsons S, Ross SA, Schröder M. Synthesis of a new binucleating ligand LH4: synthesis and X-ray structures of anti-[Co2(LH4)(OH2)2](NO3)4·5H2O, anti-[Ni2(LH4)(NCMe)2](PF6)4·4H2O, anti-[Zn2(LH4)(NO3)2](NO3)2and syn-[Cu2(LH2)](BPh4)2. ACTA ACUST UNITED AC 1994. [DOI: 10.1039/c39940001981] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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43
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Blake AJ, Fallis IA, Gould RO, Parsons S, Ross SA, Schröder M. Stacked amido macrocyclic complexes: synthesis and single crystal X-ray structure of Na[Cu(L)(NCMe)](BF4)2(NO3)[L = 1-formyl-4,7-bis(2-hydroxy-2-methylpropyl)-1,4,7-triazacyclononane]. ACTA ACUST UNITED AC 1994. [DOI: 10.1039/c39940002467] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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44
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Mochizuki K, Kesting F, Weyhermüller T, Wieghardt K, Butzlaff C, Trautwein AX. Synthesis, molecular and electronic structure of complexes [LNaMIVNaL](MRu,Os; H3L = 1,4,7-tris(4-tert-butyl-2-mercaptobenzyl)-1,4,7-triazacyclononane). ACTA ACUST UNITED AC 1994. [DOI: 10.1039/c39940000909] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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45
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Shukla R, Bharadwaj PK. A convenient route to iron(III)-thiolates: Synthesis and characterization of low-spin (S = ) iron(III) complexes having the chromophore FeN2S*2S2 (S* = thioether). Polyhedron 1993. [DOI: 10.1016/s0277-5387(00)81470-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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