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X-ray Crystallography and Electron Paramagnetic Resonance Spectroscopy Reveal Active Site Rearrangement of Cold-Adapted Inorganic Pyrophosphatase. Sci Rep 2020; 10:4368. [PMID: 32152422 PMCID: PMC7062746 DOI: 10.1038/s41598-020-61217-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Accepted: 02/24/2020] [Indexed: 11/08/2022] Open
Abstract
Inorganic pyrophosphatase (PPase) catalyses the hydrolysis reaction of inorganic pyrophosphate to phosphates. Our previous studies showed that manganese (Mn) activated PPase from the psychrophilic bacterium Shewanella sp. AS-11 (Mn-Sh-PPase) has a characteristic temperature dependence of the activity with an optimum at 5 °C. Here we report the X-ray crystallography and electron paramagnetic resonance (EPR) spectroscopy structural analyses of Sh-PPase in the absence and presence of substrate analogues. We successfully determined the crystal structure of Mn-Sh-PPase without substrate and Mg-activated Sh-PPase (Mg-Sh-PPase) complexed with substrate analogue (imidodiphosphate; PNP). Crystallographic studies revealed a bridged water placed at a distance from the di-Mn centre in Mn-Sh-PPase without substrate. The water came closer to the metal centre when PNP bound. EPR analysis of Mn-Sh-PPase without substrate revealed considerably weak exchange coupling, whose magnitude was increased by binding of substrate analogues. The data indicate that the bridged molecule has weak bonds with the di-Mn centre, which suggests a 'loose' structure, whereas it comes closer to di-Mn centre by substrate binding, which suggests a 'well-tuned' structure for catalysis. Thus, we propose that Sh-PPase can rearrange the active site and that the 'loose' structure plays an important role in the cold adaptation mechanism.
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Wu HL, Gao YC. Synthesis, crystal structure and properties of manganese(II) complexes with the tripod ligand tris(2-benzimidazylmethyl)amine and α,β-unsaturated carboxylates. J COORD CHEM 2007. [DOI: 10.1080/00958970500266156] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Hui-Lu Wu
- a College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou 730000, P.R. China
| | - Yi-Ci Gao
- a College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou 730000, P.R. China
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Lyon JM, Gunther E. KINETICS OF DISSOCIATION OF NICKEL COMPLEXES WITH PENTADENTATE LIGANDS. J COORD CHEM 2006. [DOI: 10.1080/00958979508024299] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Wu AJ, Penner-Hahn JE, Pecoraro VL. Structural, spectroscopic, and reactivity models for the manganese catalases. Chem Rev 2004; 104:903-38. [PMID: 14871145 DOI: 10.1021/cr020627v] [Citation(s) in RCA: 404] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Amy J Wu
- Willard H Dow Laboratories, Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, USA
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Bazzicalupi C, Bencini A, Berni E, Bianchi A, Danesi A, Giorgi C, Valtancoli B, Lodeiro C, Lima JC, Pina F, Bernardo MA. New Terpyridine-Containing Macrocycle for the Assembly of Dimeric Zn(II) and Cu(II) Complexes Coupled by Bridging Hydroxide Anions and π-Stacking Interactions. Inorg Chem 2004; 43:5134-46. [PMID: 15285691 DOI: 10.1021/ic049660l] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis of the new terpyridine-containing macrocycle 2,5,8,11,14-pentaaza[15](6,6' ')cyclo(2,2':6',2' ')terpyridinophane (L) is reported. The ligand contains a pentaamine chain linking the 6,6' ' positions of a terpyridine unit. A potentiometric, (1)H NMR, UV-vis spectrophotometric and fluorescence emission study on the acid-base properties of L in aqueous solutions shows that the first four protonation steps occur on the polyamine chain, whereas the terpyridine nitrogens are involved in proton binding only at strongly acidic pH values. L can form both mono- and dinuclear Cu(II), Zn(II), Cd(II), and Pb(II) complexes in aqueous solution. The crystal structures of the Zn(II) and Cd(II) complexes ([ZnLH](2)(micro-OH))(ClO(4))(5) (6) and ([CdLH](2)(micro-Br))(ClO(4))(5).4H(2)O (7) show that two mononuclear [MLH](3+) units are coupled by a bridging anion (OH(-) in 6 and Br(-) in 7) and pi-stacking interactions between the terpyridine moieties. A potentiometric and spectrophotometric study shows that in the case of Cu(II) and Zn(II) the dimeric assemblies are also formed in aqueous solution containing the ligand and the metals in a 1:1 molar ratio. Protonation of the complexes or the addition of a second metal ion leads to the disruption of the dimers due to the increased electrostatic repulsions between the two monomeric units.
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Affiliation(s)
- Carla Bazzicalupi
- Department of Chemistry, University of Florence, Via della Lastruccia 3, Sesto Fiorentino, Florence, Italy
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Pierce BS, Elgren TE, Hendrich MP. Mechanistic implications for the formation of the diiron cluster in ribonucleotide reductase provided by quantitative EPR spectroscopy. J Am Chem Soc 2003; 125:8748-59. [PMID: 12862469 DOI: 10.1021/ja021290h] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The small subunit of Escherichia coli ribonucleotide reductase (R2) is a homodimeric (betabeta) protein, in which each beta-peptide contains a diiron cluster composed of two inequivalent iron sites. R2 is capable of reductively activating O(2) to produce a stable tyrosine radical (Y122*), which is essential for production of deoxyribonucleotides on the larger R1 subunit. In this work, the paramagnetic Mn(II) ion is used as a spectroscopic probe to characterize the assembly of the R2 site with EPR spectroscopy. Upon titration of Mn(II) into samples of apoR2, we have been able to quantitatively follow three species (aquaMn(II), mononuclear Mn(II)R2, and dinuclear Mn(2)(II)R2) and fit each to a sequential two binding site model. As previously observed for Fe(II) binding within apoR2, one of the sites has a greater binding affinity relative to the other, K(1) = (5.5 +/- 1.1) x 10(5) M(-)(1) and K(2) = (3.9 +/- 0.6) x 10(4) M(-)(1), which are assigned to the B and A sites, respectively. In multiple titrations, only one dinuclear Mn(2)(II)R2 site was created per homodimer of R2, indicating that only one of the two beta-peptides of R2 is capable of binding Mn(II) following addition of Mn(II) to apoR2. Under anaerobic conditions, addition of only 2 equiv of Fe(II) to R2 (Fe(2)(II)R2) completely prevented the formation of any bound MnR2 species. Upon reaction of this sample with O(2) in the presence of Mn(II), both Y122* and Mn(2)(II)R2 were produced in equal amounts. Previous stopped-flow absorption spectroscopy studies have indicated that apoR2 undergoes a protein conformational change upon binding of metal (Tong et al. J. Am. Chem. Soc. 1996, 118, 2107-2108). On the basis of these observations, we propose a model for R2 metal incorporation that invokes an allosteric interaction between the two beta-peptides of R2. Upon binding the first equiv of metal to a beta-peptide (beta(I)), the aforementioned protein conformational change prevents metal binding in the adjacent beta-peptide (beta(II)) approximately 25 A away. Furthermore, we show that metal incorporation into beta(II) occurs only during the O(2) activation chemistry of the beta(I)-peptide. This is the first direct evidence of an allosteric interaction between the two beta-peptides of R2. Furthermore, this model can explain the generally observed low Fe occupancy of R2. We also demonstrate that metal uptake and this newly observed allosteric effect are buffer dependent. Higher levels of glycerol cause loss of the allosteric effect. Reductive cycling of samples in the presence of Mn(II) produced a novel mixed metal Fe(III)Mn(III)R2 species within the active site of R2. The magnitude of the exchange coupling (J) determined for both the Mn(2)(II)R2 and Fe(III)Mn(III)R2 species was determined to be -1.8 +/- 0.3 and -18 +/- 3 cm(-)(1), respectively. Quantitative spectral simulations for the Fe(III)Mn(III)R2 and mononuclear Mn(II)R2 species are provided. This work represents the first instance where both X- and Q-band simulations of perpendicular and parallel mode spectra were used to quantitatively predict the concentration of a protein bound mononuclear Mn(II) species.
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Affiliation(s)
- Brad S Pierce
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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Synthesis, crystal structure and properties of the zinc complexes with unsymmetrical tridentate ligands. J Mol Struct 2003. [DOI: 10.1016/s0022-2860(03)00240-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Döring M, Ciesielski M, Walter O, Görls H. Salicylaldimine Dizinc Complexes: Activation of Water Molecules and Fixation of CO2 in the Coordination Sphere of Zinc. Eur J Inorg Chem 2002. [DOI: 10.1002/1099-0682(200207)2002:7<1615::aid-ejic1615>3.0.co;2-f] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Adams H, Bradshaw D, Fenton D. Dinuclear Zinc(II) Complexes of N,N′-Bis[2-(hydroxyphenyl)methyl]-N,N′-bis(2-pyridylmethyl)-1,n-alkanediamines. Eur J Inorg Chem 2001. [DOI: 10.1002/1099-0682(200103)2001:3<859::aid-ejic859>3.0.co;2-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Syntheses and structures of and catalysis of hydrolysis by Zn(II) complexes of chelating pyridyl donor ligands. J Inorg Biochem 1999. [DOI: 10.1016/s0162-0134(99)00025-2] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Ledoux I, Zyss J. From one- to two-dimensional complexes for quadratic nonlinear optics: the influence of ligand and complexing metal atoms. ACTA ACUST UNITED AC 1999. [DOI: 10.1088/0963-9659/5/5/014] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Khangulov SV, Sossong TM, Ash DE, Dismukes GC. L-arginine binding to liver arginase requires proton transfer to gateway residue His141 and coordination of the guanidinium group to the dimanganese(II,II) center. Biochemistry 1998; 37:8539-50. [PMID: 9622506 DOI: 10.1021/bi972874c] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Rat liver arginase contains a dimanganese(II,II) center per subunit that is required for catalytic hydrolysis of l-arginine to form urea and l-ornithine. A recent crystallographic study has shown that the Mn2 center consists of two coordinatively inequivalent manganese(II) ions, MnA and MnB, bridged by a water (hydroxide) molecule and two aspartate residues [Kanyo et al. (1996) Nature 383, 554-557]. A conserved residue, His141, is located near the proposed substrate binding region at 4.2 A from the bridging solvent molecule. The present EPR studies reveal that there is no essential alteration of the Mn2 site upon mutation of His141 to an Asn residue, which lacks a potential acid/base residue, while the catalytic activity of the mutant enzyme is 10 times lower vs wild-type enzyme. The binding affinity of l-lysine, l-arginine (substrate), and Nomega-OH-l-arginine (type 2 binders) increases inversely with the pKa of the side chain. Binding of l-lysine is more than 10 times weaker, and the substrate Michaelis constant (Km) is >6-fold greater (weaker binding) in the His141Asn mutant than in wild-type arginase. L-Lysine and Nomega-OH-L-arginine, type 2 binders, induce extensive loss of the EPR intensity, suggesting direct coordination to the Mn2 center. From these data and the pH dependence of type 2 binders, we conclude that His141 functions as the base for deprotonation of the side-chain amino group of L-lysine and the substrate guanidinium group, -NH-C(NH2)2+ and that the unprotonated side chain of these amino acids is responsible for binding to the active site. A different class of inhibitors (type 1), including L-isoleucine, L-ornithine, and L-citrulline, suppresses enzymatic activity, producing only minor change in the zero-field splitting of the Mn2 EPR signal and no change in the EPR intensity, suggestive of minimal conformational transformation. We propose that type 1 alpha-amino acid inhibitors do not bind directly to either Mn ion, but interact with the recognition site on arginase for the alpha-aminocarboxylate groups of the substrate. A new mechanism for the arginase-catalyzed hydrolysis of L-arginine is proposed which has general relevance to all binuclear hydrolases: (1) Deprotonation of substrate l-arginine(H+) by His141 permits entry of the neutral guanidinium group into the buried Mn2 region. Binding of the substrate imino group (>C=NH), most likely to MnB, is coupled to breaking of the MnB-(mu-H2O) bond, forming a terminal aquo ligand on MnA. (2) Proton transfer from the terminal MnA-aqua ligand to the substrate Ndelta-guanidino atom forms the nucleophilic hydroxide on MnA and the cationic NdeltaH2+-guanidino leaving group. Protonation of the substrate -NdeltaH2+-group is likely assisted by hydrogen bonding to the juxtaposed anionic carboxylate group of Glu277. (3) Attack of the MnA-bound hydroxide at the electrophilic guanidino C-atom forms a tetrahedral intermediate. (4) Formation of products is initiated by cleavage of the Cepsilon-NdeltaH2+ bond, yielding urea and L-ornithine(H+).
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Affiliation(s)
- S V Khangulov
- Department of Chemistry, Henry H. Hoyt Laboratory, Princeton University, New Jersey 08544, USA
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Schultz BE, Ye BH, Li XY, Chan SI. Electronic Paramagnetic Resonance and Magnetic Properties of Model Complexes for Binuclear Active Sites in Hydrolase Enzymes. Inorg Chem 1997. [DOI: 10.1021/ic960988r] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Brian E. Schultz
- Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, and Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Bao-Hui Ye
- Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, and Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Xiao-yuan Li
- Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, and Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Sunney I. Chan
- Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, and Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
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Deroche A, Morgenstern-Badarau I, Cesario M, Guilhem J, Keita B, Nadjo L, Houée-Levin C. A Seven-Coordinate Manganese(II) Complex Formed with a Single Tripodal Heptadentate Ligand as a New Superoxide Scavenger. J Am Chem Soc 1996. [DOI: 10.1021/ja952508l] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alain Deroche
- Contribution from the Laboratoire de Chimie Bioorganique et Bioinorganique, Institut de Chimie Moléculaire d'Orsay, Université Paris-Sud, 91405 Orsay, France, Institut de Chimie des Substances Naturelles, CNRS, 91198 Gif-s/-Yvette, France, Laboratoire d'Electrochimie et de Photoélectrochimie, Institut de Chimie Moléculaire d'Orsay, Université Paris-Sud, 91405 Orsay, France, and Institut Curie, U350 INSERM, Université Paris-Sud, 91405 Orsay, France
| | - Irène Morgenstern-Badarau
- Contribution from the Laboratoire de Chimie Bioorganique et Bioinorganique, Institut de Chimie Moléculaire d'Orsay, Université Paris-Sud, 91405 Orsay, France, Institut de Chimie des Substances Naturelles, CNRS, 91198 Gif-s/-Yvette, France, Laboratoire d'Electrochimie et de Photoélectrochimie, Institut de Chimie Moléculaire d'Orsay, Université Paris-Sud, 91405 Orsay, France, and Institut Curie, U350 INSERM, Université Paris-Sud, 91405 Orsay, France
| | - Michèle Cesario
- Contribution from the Laboratoire de Chimie Bioorganique et Bioinorganique, Institut de Chimie Moléculaire d'Orsay, Université Paris-Sud, 91405 Orsay, France, Institut de Chimie des Substances Naturelles, CNRS, 91198 Gif-s/-Yvette, France, Laboratoire d'Electrochimie et de Photoélectrochimie, Institut de Chimie Moléculaire d'Orsay, Université Paris-Sud, 91405 Orsay, France, and Institut Curie, U350 INSERM, Université Paris-Sud, 91405 Orsay, France
| | - Jean Guilhem
- Contribution from the Laboratoire de Chimie Bioorganique et Bioinorganique, Institut de Chimie Moléculaire d'Orsay, Université Paris-Sud, 91405 Orsay, France, Institut de Chimie des Substances Naturelles, CNRS, 91198 Gif-s/-Yvette, France, Laboratoire d'Electrochimie et de Photoélectrochimie, Institut de Chimie Moléculaire d'Orsay, Université Paris-Sud, 91405 Orsay, France, and Institut Curie, U350 INSERM, Université Paris-Sud, 91405 Orsay, France
| | - Bineta Keita
- Contribution from the Laboratoire de Chimie Bioorganique et Bioinorganique, Institut de Chimie Moléculaire d'Orsay, Université Paris-Sud, 91405 Orsay, France, Institut de Chimie des Substances Naturelles, CNRS, 91198 Gif-s/-Yvette, France, Laboratoire d'Electrochimie et de Photoélectrochimie, Institut de Chimie Moléculaire d'Orsay, Université Paris-Sud, 91405 Orsay, France, and Institut Curie, U350 INSERM, Université Paris-Sud, 91405 Orsay, France
| | - Louis Nadjo
- Contribution from the Laboratoire de Chimie Bioorganique et Bioinorganique, Institut de Chimie Moléculaire d'Orsay, Université Paris-Sud, 91405 Orsay, France, Institut de Chimie des Substances Naturelles, CNRS, 91198 Gif-s/-Yvette, France, Laboratoire d'Electrochimie et de Photoélectrochimie, Institut de Chimie Moléculaire d'Orsay, Université Paris-Sud, 91405 Orsay, France, and Institut Curie, U350 INSERM, Université Paris-Sud, 91405 Orsay, France
| | - Chantal Houée-Levin
- Contribution from the Laboratoire de Chimie Bioorganique et Bioinorganique, Institut de Chimie Moléculaire d'Orsay, Université Paris-Sud, 91405 Orsay, France, Institut de Chimie des Substances Naturelles, CNRS, 91198 Gif-s/-Yvette, France, Laboratoire d'Electrochimie et de Photoélectrochimie, Institut de Chimie Moléculaire d'Orsay, Université Paris-Sud, 91405 Orsay, France, and Institut Curie, U350 INSERM, Université Paris-Sud, 91405 Orsay, France
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Gahan LR, Grillo VA, Hambley TW, Hanson GR, Hawkins CJ, Proudfoot EM, Moubaraki B, Murray KS, Wang D. Synthetic, X-ray Structure, Electron Paramagnetic Resonance, and Magnetic Studies of the Manganese(II) Complex of 1-Thia-4,7-diazacyclononane ([9]aneN(2)S). Inorg Chem 1996; 35:1039-1044. [PMID: 11666282 DOI: 10.1021/ic950549c] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Reaction of manganese(II) perchlorate hexahydrate with a methanol solution of 1-thia-4,7-diazacyclononane ([9]aneN(2)S) resulted in the isolation of the manganese(II) complex [Mn([9]aneN(2)S)(2)](ClO(4))(2). The X-ray structure of this complex is reported: crystal system orthorhombic, space group Pbam, No. 55, a = 7.937(2) Å,b = 8.811(2) Å, c = 15.531(3) Å, Z = 2, R = 0.0579. The complex is high spin (S = (5)/(2)) with an effective magnetic moment (&mgr;(eff)) 5.82 &mgr;(B) at 298 K and 5.65 &mgr;(B) at 4.2 K. Computer simulation of the Q-band EPR spectrum of [Mn([9]aneN(2)S)(2)](ClO(4))(2) yields g = 1.99 +/- 0.01, |D| = 0.19 +/- 0.005 cm(-)(1), and E/D = 0.04 +/- 0.02. For the analogous hexaamine complex [Mn([9]aneN(3))(2)](ClO(4))(2) ([9]aneN(3) = 1,4,7-triazacyclononane) analysis of the EPR spectra produced the following values: g = 1.98 +/- 0.01, |D| = 0.09 +/- 0.003 cm(-)(1), and E/D = 0.1 +/- 0.01. The spin Hamiltonian parameters for [Mn([9]aneN(2)S)(2)](ClO(4))(2) derived from the EPR spectra produced a good fit to the magnetic susceptibility data.
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Affiliation(s)
- Lawrence R. Gahan
- Department of Chemistry and Centre for Magnetic Resonance, The University of Queensland, Brisbane, QLD 4072, Australia, The School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia, and Chemistry Department, Monash University, Clayton, Victoria 3168, Australia
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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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Stockheim C, Hoster L, Weyhermüller T, Wieghardt K, Nuber B. First-row transition-metal complexes of mixed ‘pendant-arm’ derivatives of 1,4,7-triazacyclononane containing phenolate and carboxylate functional groups. ACTA ACUST UNITED AC 1996. [DOI: 10.1039/dt9960004409] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Gultneh Y, Allwar, Ahvazi B, Blaise D, Butcher RJ, Jasinski J, Jasinski J. Synthesis, reactions and structure of a hydroxo-bridged dinuclear Zn(II) complex: modeling the hydrolytic zinc enzymes. Inorganica Chim Acta 1996. [DOI: 10.1016/0020-1693(95)04791-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Melnik M, Györyová K, Skoršepa J, Holloway CE. REVIEW: ZINC(II) COMPOUNDS: CLASSIFICATION AND ANALYSIS OF CRYSTALLOGRAPHIC AND STRUCTURAL DATA. J COORD CHEM 1995. [DOI: 10.1080/00958979508024038] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Di Vaira M, Mani F, Stoppioni P. Co-ordination of 1,4,7-tris(pyrazol-3-ylmethyl)-1,4,7-triazacyclononane with iron(III), nickel(II) and zinc(II). Crystal and molecular structures of [ML][ClO4]2·nH2O (M = Ni, n= 0.5; M = Zn, n= 1). ACTA ACUST UNITED AC 1994. [DOI: 10.1039/dt9940003739] [Citation(s) in RCA: 13] [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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23
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Ikawa Y, Nagata T, Maruyama K. Synthesis and Electrochemical Properties of Dinuclear Manganese(II) Complexes with Octadentate Schiff-base Macrocycles. Fine Tuning of the Redox Behavior. CHEM LETT 1993. [DOI: 10.1246/cl.1993.1049] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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McKee V. Macrocyclic Complexes as Models for Nonporphine Metalloproteins. ADVANCES IN INORGANIC CHEMISTRY 1993. [DOI: 10.1016/s0898-8838(08)60186-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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