51
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Xiao-Ming L, Shun-Cheng L, Ling J, Xi-An M, Zhao-Hui Y. Synthesis, Crystal Structure of Cis-dioxo-catecholatotungsten(VI) Complex and Its NMR Studies on the Interaction with ATP. CHINESE J CHEM 2010. [DOI: 10.1002/cjoc.20030210614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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52
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Lu XM, Lu JF, Mao XA. Crystal Structure and EPR Spectra of cis-Dioxo-molybdenum(V) Complex with o-Aminophenol. CHINESE J CHEM 2010. [DOI: 10.1002/cjoc.20020200619] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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53
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Nguyen N, Harrison DJ, Lough AJ, De Crisci AG, Fekl U. Molybdenum Dithiolene Complexes as Structural Models for the Active Sites of Molybdenum(IV) Sulfide Hydrodesulfurization Catalysts. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.201000269] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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54
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Nomura M, Cauchy T, Fourmigué M. Radical CpNi(dithiolene) and CpNi(diselenolene) complexes: Synthetic routes and molecular properties. Coord Chem Rev 2010. [DOI: 10.1016/j.ccr.2009.11.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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55
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Sproules S, Benedito FL, Bill E, Weyhermüller T, DeBeer George S, Wieghardt K. Characterization and electronic structures of five members of the electron transfer series [Re(benzene-1,2-dithiolato)3](z) (z = 1+, 0, 1-, 2-, 3-): a spectroscopic and density functional theoretical study. Inorg Chem 2010; 48:10926-41. [PMID: 19831363 DOI: 10.1021/ic9010532] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of ReCl(5) with 3 equiv of a benzene-1,2-dithiolate derivative in CH(3)CN produced, after the addition of [C(8)H(16)N]Br ([C(8)H(16)N](+) is 5-azonia-spiro[4,4]nonane), brownish-green crystals of [C(8)H(16)N][Re(tms)(3)] (1c) and [C(8)H(16)N][Re(Cl(2)-bdt)(3)] (2c), where (tms)(2-) represents 3,6-bis(trimethylsilyl)benzene-1,2-dithiolate and (Cl(2)-bdt)(2-) is 3,6-dichlorobenzene-1,2-dithiolate. Chemical reduction of [Re(bdt)(3)] (3b) with n-butyllithium in the presence of PPh(4)Br yielded [PPh(4)][Re(bdt)(3)] (3c), where (bdt)(2-) is benzene-1,2-dithiolate. The three monoanionic complexes possess a diamagnetic ground state (Re(V), d(2), S = 0). The crystal structures of 1c x 2 CH(3)CN and 2c x C(3)H(6)O have been determined by X-ray crystallography. The electrochemistry establishes that the complexes are members of electron transfer series involving a monocation [Re(V)(L(*))(2)(L)](+) (S = 0(?)), a neutral [Re(V)(L(*))(L)(2)](0) (S = 1/2), a monoanion [Re(V)(L)(3)](1-) (S = 0), a dianion [Re(IV)(L)(3)](2-) (S = 1/2), and a trianion [Re(III)(L)(3)](3-) (S = 1(?)). The unique X-band EPR spectrum of the neutral species clearly describes a diamagnetic Re(V) d(2) central ion with the unpaired electron located in a purely ligand-centered molecular orbital, whereas it is metal-centered in the dianionic form: a Re(IV) d(3) ion with three dithiolate(2-) ligands. S K-edge and Re L-edge X-ray absorption spectroscopy confirms these assignments and furthermore shows that the monoanion has a Re(V) central ion with three dianionic ligands. The geometrical and electronic structures of all members of the electron transfer series have been calculated by density functional theoretical methods, and the S K-pre-edge spectra have been simulated and assigned using a time-dependent DFT protocol.
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Affiliation(s)
- Stephen Sproules
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany.
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56
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Ryde U, Schulzke C, Starke K. Which functional groups of the molybdopterin ligand should be considered when modeling the active sites of the molybdenum and tungsten cofactors? A density functional theory study. J Biol Inorg Chem 2009; 14:1053-64. [PMID: 19479286 PMCID: PMC3085732 DOI: 10.1007/s00775-009-0548-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2008] [Accepted: 05/01/2009] [Indexed: 11/29/2022]
Abstract
A density functional theory study of the influence of the various functional groups of the molybdopterin ligand on electronic and geometric properties of active-site models for the molybdenum and tungsten cofactors has been undertaken. We used analogous molybdenum and tungsten complexes with increasingly accurate representation of the molybdopterin ligands and compared bond lengths, angles, charge distribution, composition of the binding orbitals, as well as the redox potentials in relation to each other. On the basis of our findings, we suggest using ligand systems including the pyrane and the pyrazine rings, besides the dithiolene function, to obtain sufficiently reliable computational, but also synthetic, models for the molybdenum and tungsten cofactors, whereas the second ring of the pterin might be neglected for efficiency reasons.
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Affiliation(s)
- Ulf Ryde
- Department of Theoretical Chemistry, Chemical Center, Lund University, 124, 221 00 Lund, Sweden
| | - Carola Schulzke
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstr. 4, 37077 Göttingen, Germany
| | - Kerstin Starke
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstr. 4, 37077 Göttingen, Germany
- Department of Chemical Physics, Chemical Center, Lund University, 124, 221 00 Lund, Sweden
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57
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Antony S, Bayse CA. Theoretical Studies of Models of the Active Site of the Tungstoenzyme Acetylene Hydratase. Organometallics 2009. [DOI: 10.1021/om900230x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sonia Antony
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia 23529
| | - Craig A. Bayse
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia 23529
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58
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Majumdar A, Sarkar S. Mixed-ligand tris chelated complexes of Mo(IV) and W(IV): A comparative study. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2009.03.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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59
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Banerjee P, Sproules S, Weyhermüller T, DeBeer George S, Wieghardt K. Electronic Structure of the [Tris(dithiolene)chromium]z (z = 0, 1−, 2−, 3−) Electron Transfer Series and Their Manganese(IV) Analogues. An X-ray Absorption Spectroscopic and Density Functional Theoretical Study. Inorg Chem 2009; 48:5829-47. [DOI: 10.1021/ic900154v] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Priyabrata Banerjee
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Stephen Sproules
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Thomas Weyhermüller
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Serena DeBeer George
- Stanford Synchroton Radiation Lightsource, SLAC, Stanford University, Stanford, California 94309
| | - Karl Wieghardt
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
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60
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Eierhoff D, Tung WC, Hammerschmidt A, Krebs B. Molybdenum complexes with O,N,S donor ligands as models for active sites in oxotransferases and hydroxylases. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2008.01.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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61
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Majumdar A, Pal K, Sarkar S. Necessity of fine tuning in Mo(iv) bis(dithiolene) complexes to warrant nitrate reduction. Dalton Trans 2009:1927-38. [DOI: 10.1039/b815436h] [Citation(s) in RCA: 14] [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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62
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Pal K, Sarkar S. The Role of Axial Ligation in Nitrate Reductase: A Model Study by DFT Calculations on the Mechanism of Nitrate Reduction. Eur J Inorg Chem 2008. [DOI: 10.1002/ejic.200800514] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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63
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Sugimoto H, Tsukube H. Chemical analogues relevant to molybdenum and tungsten enzyme reaction centres toward structural dynamics and reaction diversity. Chem Soc Rev 2008; 37:2609-19. [PMID: 19020675 DOI: 10.1039/b610235m] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recent characterisation of molybdenum and tungsten enzymes revealed novel structural types of reaction centres, as well as providing new subjects of interest as synthetic chemical analogues. This tutorial review highlights the structure/reactivity relationships of the enzyme reaction centres and chemical analogues. Chemical analogues for the oxygen atom transfer enzymes have been well expanded in structure and reactivity. Other types of chemical analogues that exhibit different coordination chemistry have recently been presented for reaction centres of the hydroxylation and dehydrogenation enzymes and others.
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Affiliation(s)
- Hideki Sugimoto
- Department of Chemistry, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka, 558-8585, Japan.
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64
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Tano H, Tajima R, Miyake H, Itoh S, Sugimoto H. Selenidobis(dithiolene)metal(IV) Complexes (Metal M = Mo, W) Potentially Related to the Nicotinic Acid Hydroxylase Reaction Center: Redox Aspects in Electrochemistry and Oxygen Atom Transfer from Me3NO to MIV Centers. Inorg Chem 2008; 47:7465-7. [DOI: 10.1021/ic8009942] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hiroyuki Tano
- Department of Chemistry, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Reiko Tajima
- Department of Chemistry, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Hiroyuki Miyake
- Department of Chemistry, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Shinobu Itoh
- Department of Chemistry, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Hideki Sugimoto
- Department of Chemistry, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan
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65
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Hofmann M. Electronic State of the Dimethyl Sulfoxide Reductase Active Site. Inorg Chem 2008; 47:5546-8. [DOI: 10.1021/ic800519d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Matthias Hofmann
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
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66
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Tenderholt AL, Szilagyi RK, Holm RH, Hodgson KO, Hedman B, Solomon EI. Electronic control of the "Bailar twist" in formally d0-d2 molybdenum tris(dithiolene) complexes: a sulfur K-edge X-ray absorption spectroscopy and density functional theory study. Inorg Chem 2008; 47:6382-92. [PMID: 18517189 DOI: 10.1021/ic800494h] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Sulfur K-edge X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations have been used to determine the electronic structures of a series of Mo tris(dithiolene) complexes, [Mo(mdt)3](z) (where mdt = 1,2-dimethylethene-1,2-dithiolate(2-) and z = 2-, 1-, 0), with near trigonal-prismatic geometries (D3h symmetry). These results show that the formally Mo(IV), Mo(V), and Mo(VI) complexes actually have a (dz(2))(2) configuration, that is, remain effectively Mo(IV) despite oxidation. Comparisons with the XAS data of another set of Mo tris(dithiolene) complexes, [Mo(tbbdt)3](z) (where tbbdt = 3,5-ditert-butylbenzene-1,2-dithiolate(2-) and z = 1-, 0), show that both neutral complexes, [Mo(mdt)3] and [Mo(tbbdt)3], have similar electronic structures while the monoanions do not. Calculations reveal that the "Bailar twist" present in the crystal structure of [Mo(tbbdt)3](1-) (D3 symmetry) but not [Mo(mdt)3](1-) (D3h symmetry) is controlled by electronic factors which arise from bonding differences between the mdt and tbbdt ligands. In the former, configuration interaction between the Mo d(z(2)) and a deeper energy, occupied ligand orbital, which occurs in D3 symmetry, destabilizes the Mo d(z(2)) to above another ligand orbital which is half-occupied in the D3h [Mo(mdt)3](1-) complex. This leads to a metal d(1) configuration with no ligand holes (i.e., d(1)[L3](0h)) for [Mo(tbbdt)3](1-) rather than the metal d(2) configuration with one ligand hole (i.e., d(2)[L3](1h)) for [Mo(mdt)3](1-). Thus, the Bailar twist observed in some metal tris(dithiolene) complexes is the result of configuration interaction between metal and ligand orbitals and can be probed experimentally by S K-edge XAS.
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Affiliation(s)
- Adam L Tenderholt
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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67
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McNaughton RL, Lim BS, Knottenbelt SZ, Holm RH, Kirk ML. Spectroscopic and electronic structure studies of symmetrized models for reduced members of the dimethylsulfoxide reductase enzyme family. J Am Chem Soc 2008; 130:4628-36. [PMID: 18341333 DOI: 10.1021/ja074691b] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Enzymes belonging to the dimethylsulfoxide reductase (DMSOR) family of pyranopterin Mo enzymes have a unique active-site geometry in the reduced form that lacks a terminal oxo ligand, unlike the reduced active sites of other pyranopterin Mo enzymes. Furthermore, the DMSOR family is characterized by the coordination of two pyranopterin-ene-1,2-dithiolate ligands in their active sites, which is distinctive among the other pyranopterin Mo enzymes but analogous to all of the currently known tungsten-containing enzymes. Electronic absorption, resonance Raman, and ground- and excited-state density functional calculations of symmetrized analogues of the reduced DMSOR active site ([NEt4][Mo(IV)(QAd)(S2C2Me2)2] where Ad = 2-adamantyl; Q = O, S, Se) have allowed for a detailed description of Mo-bisdithiolene electronic structure in the absence of a strong-field oxo ligand. The electronic absorption spectra are dominated by dithiolene S --> Mo charge-transfer transitions, and the totally symmetric Mo-S Raman stretch is observed at approximately 400 cm(-1) for all three complexes. These data indicate that the Mo-bisdithiolene bonding scheme in high-symmetry [Mo(QAd)(S2C2Me2)2]- complexes is not strongly perturbed by the apical QAd- ligands, but instead, the dithiolene ligands define the t(2g) ligand field splitting. The effects of conserved geometric distortions observed in DMSOR, relative to these high-symmetry models, were explored by spectroscopically calibrated bonding calculations, and the results are discussed within the context of electronic structure contributions to ground-state destabilization and transition-state stabilization. The specific electronic structure tuning of the endogenous amino acid ligation on the mechanism of DMSOR is also discussed.
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Affiliation(s)
- Rebecca L McNaughton
- Department of Chemistry, The University of New Mexico, MSC03 2060, Albuquerque, New Mexico 87131, USA
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68
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Majumdar A, Pal K, Sarkar S. Selectivity of Thiolate Ligand and Preference of Substrate in Model Reactions of Dissimilatory Nitrate Reductase. Inorg Chem 2008; 47:3393-401. [DOI: 10.1021/ic7024268] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Amit Majumdar
- Department of Chemistry, IIT Kanpur, Kanpur 208016, India
| | - Kuntal Pal
- Department of Chemistry, IIT Kanpur, Kanpur 208016, India
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69
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Pal K, Sarkar S. Synthesis, Structure and a DFT/TDDFT Study of a Diimido‐Bridged Asymmetric Dimolybdenum Complex. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200700628] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Kuntal Pal
- Department of Chemistry, Indian Institute of TechnologyKanpur, Kanpur 208016, India, Fax: +91‐512‐2597265
| | - Sabyasachi Sarkar
- Department of Chemistry, Indian Institute of TechnologyKanpur, Kanpur 208016, India, Fax: +91‐512‐2597265
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70
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Hofmann M. Density functional theory studies of model complexes for molybdenum-dependent nitrate reductase active sites. J Biol Inorg Chem 2007; 12:989-1001. [PMID: 17636351 DOI: 10.1007/s00775-007-0271-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Accepted: 06/11/2007] [Indexed: 11/25/2022]
Abstract
Molybdenum and tungsten complexes as models for the active sites of assimilatory or dissimilatory nitrate reductases (NR) were computed at the CPCM-B98/SDDp//B3LYP/Lanl2DZp* plus zero point energy level of density functional theory. The ligands were chosen on the basis of available experimental protein or small chemical model structures. A water molecule is found to bind to assimilatory NR models [(Me(2)C(2)S(2))MO(YMe)](-) (-11.5 kcal mol(-1) for M is Mo, Y is S) and may be replaced by nitrate (-4.5 kcal mol(-1)) (but a hydroxy group may not). Nature's choice of M is Mo and Y is S for NR has the largest activation energy for protein-free models (13.3 kcal mol(-1)) and the least exothermic reaction energy for the nitrate reduction (-14.9 kcal mol(-1)) compared with M is W and Y is O or Se alternatives. Water binding to dissimilatory NR model complexes [(Me(2)C(2)S(2))(2)M(YR)](-) is considerably endothermic (10.3 kcal mol(-1)); nitrate binding is only slightly so (1.5 kcal mol(-1) for RY(-) is MeS(-)). The exchange of an oxo ligand (assimilatory NR) for a dithiolato ligand (dissimilatory NR model) reduces the exothermicity (-8.6 kcal mol(-1) relative to the fivefold-coordinate reduced complex) and raises the barrier for oxygen atom transfer (OAT) in the nitrate complex (19.2 kcal mol(-1)). Not for the mono but only for the bisdithiolato complexes hydrogen bonding involving the coordinated substrate may significantly lower the OAT barrier as shown by explicitly adding water molecules. Substitution of tungsten for molybdenum generally lowers OAT activation energies and makes nitrate reduction reaction energies more negative. Bidentate carboxylato binding identified in Escherichia coli NarGHI is the preferred binding mode also for an acetato model. However, one dithiolato ligand folds when the Mo(VI) center is bare of a good pi-donor ligand, e.g., an oxo group. Computations on [(mnt)(2)Mo(IV)(YR)(PPh(3))](-) [mnt is (CN)(2)C(2)S(2) (2-)] gave a smaller nitrate reduction activation energy for RY(-) is Cl(-), compared with RY(-) is PhS(-), although experimentally only the phenyl thiolato complex and not the chloro complex was found to be a functional NR model.
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Affiliation(s)
- Matthias Hofmann
- Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
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71
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Ray K, Debeer George S, Solomon EI, Wieghardt K, Neese F. Description of the ground-state covalencies of the bis(dithiolato) transition-metal complexes from X-ray absorption spectroscopy and time-dependent density-functional calculations. Chemistry 2007; 13:2783-97. [PMID: 17290468 DOI: 10.1002/chem.200601425] [Citation(s) in RCA: 188] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The electronic structures of [M(L(Bu))(2)](-) (L(Bu)=3,5-di-tert-butyl-1,2-benzenedithiol; M=Ni, Pd, Pt, Cu, Co, Au) complexes and their electrochemically generated oxidized and reduced forms have been investigated by using sulfur K-edge as well as metal K- and L-edge X-ray absorption spectroscopy. The electronic structure content of the sulfur K-edge spectra was determined through detailed comparison of experimental and theoretically calculated spectra. The calculations were based on a new simplified scheme based on quasi-relativistic time-dependent density functional theory (TD-DFT) and proved to be successful in the interpretation of the experimental data. It is shown that dithiolene ligands act as noninnocent ligands that are readily oxidized to the dithiosemiquinonate(-) forms. The extent of electron transfer strongly depends on the effective nuclear charge of the central metal, which in turn is influenced by its formal oxidation state, its position in the periodic table, and scalar relativistic effects for the heavier metals. Thus, the complexes [M(L(Bu))(2)](-) (M=Ni, Pd, Pt) and [Au(L(Bu))(2)] are best described as delocalized class III mixed-valence ligand radicals bound to low-spin d(8) central metal ions while [M(L(Bu))(2)](-) (M=Cu, Au) and [M(L(Bu))(2)](2-) (M=Ni, Pd, Pt) contain completely reduced dithiolato(2-) ligands. The case of [Co(L(Bu))(2)](-) remains ambiguous. On the methodological side, the calculation led to the new result that the transition dipole moment integral is noticeably different for S(1s)-->valence-pi versus S(1s)-->valence-sigma transitions, which is explained on the basis of the differences in radial distortion that accompany chemical bond formation. This is of importance in determining experimental covalencies for complexes with highly covalent metal-sulfur bonds from ligand K-edge absorption spectroscopy.
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Affiliation(s)
- Kallol Ray
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
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72
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Ma X, Schulzke C, Schmidt HG, Noltemeyer M. Structural, electrochemical and oxygen atom transfer properties of a molybdenum selenoether complex [Mo2O4(OC3H6SeC3H6O)2] and its thioether analogue [Mo2O4(OC3H6SC3H6O)2]. Dalton Trans 2007:1773-80. [PMID: 17471372 DOI: 10.1039/b617652f] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The first crystallographically characterized molybdenum(vi) selenoether complex [Mo(2)O(4)(OC(3)H(6)SeC(3)H(6)O)(2)] and its thioether analogue [Mo(2)O(4)(OC(3)H(6)SC(3)H(6)O)(2)] were synthesised. Their structural, electrochemical and oxygen atom transfer properties are compared. This is relevant for the molybdenum cofactors of the DMSO reductase family where the coordination of the active site metal occurs through O (serine/aspartate), S (cysteine) or Se (selenocysteine). Both structures are almost identical except for those parameters that are directly derived from the different sizes of the varied ligand atoms (Se and S). No trans influence was observed. The metal centered redox process (Mo(V)<-->Mo(VI)) is at slightly lower voltage for the sulfur than for the selenium complex. The selenium compound catalyses the oxygen atom transfer from DMSO to PPh(3) by a different mechanism and at a higher rate than the sulfur compound, which is an indication that cysteine and selenocysteine might be used for a purpose in the different molybdenum and tungsten cofactors.
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73
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Adams H, Gardner HC, McRoy RA, Morris MJ, Motley JC, Torker S. Heterometallic Dithiolene Complexes Formed by Stepwise Displacement of Cyclopentadienyl Ligands from Nickelocene with CpMo(S2C2Ph2)2. Inorg Chem 2006; 45:10967-75. [PMID: 17173456 DOI: 10.1021/ic0606227] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The dithiolene ligand transfer reaction between Ni(S2C2Ph2)2 (1) and CpMo(CO)3Cl (2; Cp = eta-C5H5) affords the neutral paramagnetic molybdenum bis(dithiolene) complex CpM(S2C2Ph2)2 (3), which has been structurally characterized. As found in other d1 complexes of this type, one dithiolene ligand is planar while the other is significantly folded toward the Cp ligand. An unexpected second product of the reaction is the unusual trinuclear species Ni[Mo(S2C2Ph2)2Cp]2 (4), which in the solid state contains three different dithiolene bonding modes (terminal, bridging, and semi-bridging) in the same molecule. Complex 4 can also be synthesized by displacement of the diene ligands in Ni(cod)2 with 2 equiv of 3. In contrast, the reaction of nickelocene with 3 proceeds by displacement of the Cp ligands in a stepwise manner to give initially the dinuclear species NiMo(mu-S2C2Ph2)2Cp2 5, which then reacts further with 3 to produce 4.
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Affiliation(s)
- Harry Adams
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
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74
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Nomura M, Cauchy T, Geoffroy M, Adkine P, Fourmigué M. [CpNi(dithiolene)] (and Diselenolene) Neutral Radical Complexes. Inorg Chem 2006; 45:8194-204. [PMID: 16999418 DOI: 10.1021/ic0608546] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Various preparations of the neutral radical [CpNi(dddt)] complex (dddt = 5,6-dihydro-1,4-dithiin-2,3-dithiolate) were investigated with CpNi sources, [Cp2Ni], [Cp2Ni](BF4), [CpNi(CO)]2, and [CpNi(cod)](BF4), and dithiolene transfer sources, O=C(dddt), the naked dithiolate (dddt(2-)), the monoanion of square-planar Ni dithiolene complex (NBu4)[Ni(dddt)2], and the neutral complex [Ni(dddt)2]. The reaction of [CpNi(cod)](BF4) with (NBu4)[Ni(dddt)2] gave the highest yield for the preparation of [CpNi(dddt)] (86%). [CpNi(ddds)] (ddds = 5,6-dihydro-1,4-dithiin-2,3-diselenolate), [CpNi(dsdt)] (dsdt = 5,6-dihydro-1,4-diselenin-2,3-dithiolate), [CpNi(bdt)] (bdt = 1,2-benzenedithiolate), and [CpNi(bds)] (bds = 1,2-benzenediselenolate) were synthesized by the reactions of [Cp2Ni] with the corresponding neutral Ni dithiolene complexes [Ni(ddds)2]2, [Ni(dsdt)2], [Ni(bdt)2], and [Ni(bds)2], respectively. The five, formally Ni(III), radical complexes oxidize and reduce reversibly. They exhibit, in the neutral state, a strong absorption in the NIR region, from 1000 nm in the dddt/ddds/dsdt series to 720 nm in the bdt/bds series with epsilon values between 2500 and 5000 M(-1) cm(-1). The molecular and solid state structures of the five complexes were determined by X-ray structure analyses. [CpNi(dddt)] and [CpNi(ddds)] are isostructural, while [CpNi(dsdt)] exhibits a closely related structure. Similarly, [CpNi(bdt)] and [CpNi(bds)] are also isostructural. Correlations between structural data and magnetic measurements show the presence of alternated spin chains in [CpNi(dddt)], [CpNi(ddds)], and [CpNi(dsdt)], while a remarkably strong antiferromagnetic interaction in [CpNi(bdt)] and [CpNi(bds)] is attributed to a Cp...Cp face-to-face sigma overlap, an original feature in organometallic radical complexes.
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Affiliation(s)
- Mitsushiro Nomura
- Laboratoire Chimie, Ingénierie Moléculaire et Matériaux d'Angers (CIMMA), UMR 6200 CNRS, Université d'Angers, UFR Sciences, Bât. K, 2 Bd. Lavoisier, 49045 Angers, France
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75
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Petrenko T, Ray K, Wieghardt KE, Neese F. Vibrational markers for the open-shell character of transition metal bis-dithiolenes: an infrared, resonance raman, and quantum chemical study. J Am Chem Soc 2006; 128:4422-36. [PMID: 16569020 DOI: 10.1021/ja0578451] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Transition metal complexes involving the benzene-1,2-dithiol (L(2-)) and Sellmann's 3,5-di-tert-butylbenzene-1,2-dithiol(L(Bu 2-)) ligands have been studied by UV-vis, infrared (IR), and resonance Raman (rR) spectroscopies. Raman spectra were obtained in resonance with the intervalence charge transfer (IVCT) bands in the near-infrared region and ligand-to-metal charge transfer (LMCT) bands in the near-UV region. Geometry optimization and frequency calculations using density functional theory (DFT) have been performed for [M(L)(2)](z) and [M(L(Bu))(2)](z) species (M = Ni, Pd, Pt, Co, Cu, Au, z = -1; M = Au, z = 0). On the basis of frequency calculations and normal-mode analysis, we have assigned the most important totally symmetric vibrations as well as corresponding overtone and combination bands that appear in rR spectra of compounds [Ni(L)(2)](1-), [M(L(Bu))(2)](1-) (M = Ni, Pt, Co, Cu). Experimental values of dimensionless normal coordinate displacements in excited states have been determined by fitting of rR spectra together with the absorption band shape, based on the time-dependent theory of Heller. Time-dependent density functional theory (TD-DFT) and multireference post-Hartree-Fock ab initio calculations, using the difference dedicated configuration interaction (MR-DDCI) method, were carried out to evaluate dimensionless normal coordinate displacements quantum chemically. The calculations show encouraging agreement with the experimental values. The large distortions along several normal modes led to significant vibronic broadening of IVCT and LMCT bands, and the broadening was accounted for in the deconvolution of the absorption spectra. The presence of an intense rR band around approximately 1100 cm(-1) was found to be a reliable marker for the presence of sulfur-based radicals.
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Affiliation(s)
- Taras Petrenko
- Max Planck Institut für Bioanorganische Chemie, Mülheim an der Ruhr, Germany
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76
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Friedle S, Partyka DV, Bennett MV, Holm R. Synthesis of metal dithiolene complexes by Si–S bond cleavage of a bis(silanylsulfanyl)alkene. Inorganica Chim Acta 2006. [DOI: 10.1016/j.ica.2005.09.067] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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77
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Sugimoto H, Tarumizu M, Tanaka K, Miyake H, Tsukube H. A new series of molybdenum-(IV), -(V), and -(VI) dithiolate compounds as active site models of molybdoenzymes: preparation, crystal structures, spectroscopic/electrochemical properties and reactivity in oxygen atom transfer. Dalton Trans 2005:3558-65. [PMID: 16234938 DOI: 10.1039/b503828f] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new set of molybdenum-(IV), -(V), and -(VI) compounds containing 3,6-dichloro-1,2-benzenedithiolate (bdtCl2) were isolated and characterised by crystallographic and other spectroscopic techniques as active site models of arsenite oxidase, one of the molybdoenzymes. MoO2 compounds were prepared in high yields by reaction of MoO2Cl2 with bdtCl2, related dithiolene and thiocatecholate in methanol at low temperature. The bdtCl2 ligand particularly stabilised the MoO compounds with oxidation numbers of +4 and +5 as well as the MoO2 compound with an oxidation number of +6. The compounds (Et4N)2[MoVIO2(bdtCl2)2], (Et4N)2[MoIVO(bdtCl2)2] and (Et4N)[MoVO(bdtCl2)2] were successfully isolated, whereas (Et3NH)2[MoO2(thiocatecholate)2] gradually decomposed in acetonitrile. A distorted octahedral structure similar to that of was suggested for the structure of the active site of the oxidised form of arsenite oxidase on the basis of a comparison of their bond distances and angles. The bond distances and angles around the molybdenum(IV) atom in were similar to those around the molybdenum(IV) centre in the reduced form of arsenite oxidase. The reversible / couple exhibited a more positive redox potential than common MoO dithiolene compounds. Underwent an irreversible proton-coupled reduction process to yield. An oxygen atom transfer reaction of with triphenylphosphine afforded and triphenylphosphine oxide, and proceeded in second order as v=-d/dt[MoO2]=k[MoO2][PPh3]. The structures and properties of the oxo-bridged dinuclear compound (Et4N)2[MoVIO2(bdtCl2)]2(micro-O), a dimer of bdtCl2 and were also characterised.
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Affiliation(s)
- Hideki Sugimoto
- Department of Chemistry, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka, 558-8585, Japan.
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78
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McNamara JP, Mohr M, Wang H, Hillier * IH. Oxygen atom transfer reactions in inorganic analogues of the active site of dimethyl sulfoxide reductase; a DFT and ONIOM (DFT:PM3) study. Mol Phys 2005. [DOI: 10.1080/00268970500179461] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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79
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Sugimoto H, Sakurai T, Miyake H, Tanaka K, Tsukube H. Mononuclear Five-Coordinate Molybdenum(IV) and -(V) Monosulfide Complexes Coordinated with Dithiolene Ligands: Reversible Redox of Mo(V)/Mo(IV) and Irreversible Dimerization of [MoVS]- Cores to a Dinuclear [MoV2(μ-S)2]2- Core. Inorg Chem 2005; 44:6927-9. [PMID: 16180851 DOI: 10.1021/ic0509128] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A mononuclear five-coordinate molybdenum(IV) monosulfide complex, (Et4N)2[MoS(L)2] (L = cyclohexene-1,2-dithiolate) (1), was obtained and characterized by IR, UV-vis spectroscopic methods, and X-ray crystallography. 1 was oxidized by an equivalent ferrocenium cation to give the corresponding mononuclear molybdenum(V) complex, (Et4N)[MoS(L)2] (2), which was stable for a few minutes under a lower concentration than 0.3 mM and then further dimerized to (Et4N)2[Mo(L)2]2(mu-S)2 (3).
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Affiliation(s)
- Hideki Sugimoto
- Department of Chemistry, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Japan.
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80
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Nomura M, Okuyama R, Fujita-Takayama C, Kajitani M. New Synthetic Methods for η5-Cyclopentadienyl Nickel(III) Dithiolene Complexes Derived from Nickelocene. Organometallics 2005. [DOI: 10.1021/om050502r] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mitsushiro Nomura
- Department of Chemistry, Faculty of Science and Technology, Sophia University, 7-1, Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan
| | - Ryoko Okuyama
- Department of Chemistry, Faculty of Science and Technology, Sophia University, 7-1, Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan
| | - Chikako Fujita-Takayama
- Department of Chemistry, Faculty of Science and Technology, Sophia University, 7-1, Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan
| | - Masatsugu Kajitani
- Department of Chemistry, Faculty of Science and Technology, Sophia University, 7-1, Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan
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81
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Sugimoto H, Harihara M, Shiro M, Sugimoto K, Tanaka K, Miyake H, Tsukube H. Dioxo-Molybdenum(VI) and Mono-oxo-Molybdenum(IV) Complexes Supported by New Aliphatic Dithiolene Ligands: New Models with Weakened MoO Bond Characters for the Arsenite Oxidase Active Site. Inorg Chem 2005; 44:6386-92. [PMID: 16124818 DOI: 10.1021/ic050234p] [Citation(s) in RCA: 41] [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
The cis-dioxo-molybdenum(VI) complexes, [MoO2(L(H))2]2- (1b), [MoO2(L(S))(2)]2- (2b), and [MoO2(L(O))2]2- (3b) (L(H) = cyclohexene-1,2-dithiolate, L(S) = 2,3-dihydro-2H-thiopyran-4,5-dithiolate, and L(O) = 2,3-dihydro-2H-pyran-4,5-dithiolate), with new aliphatic dithiolene ligands were prepared and investigated by infrared (IR) and UV-vis spectroscopic and electrochemical methods. The mono-oxo-molybdenum(IV) complexes, [MoO(L(H))2]2- (1a), [MoO(L(S))2]2- (2a), and [MoO(L(O))2]2- (3a), were further characterized by X-ray crystal structural determinations. The IR and resonance Raman spectroscopic studies suggested that these cis-dioxo molybdenum(VI) complexes (1b-3b) had weaker Mo=O bonds than the common Mo(VI)O2 complexes. Complexes 1b-3b also exhibited strong absorption bands in the visible regions assigned as charge-transfer bands from the dithiolene ligands to the cis-MoO2 cores. Because the oxygen atoms of the cis-Mo(VI)O2 cores are relatively nucleophilic, these complexes were unstable in protic solvents and protonation might occur to produce Mo(VI)O(OH), as observed with the oxidized state of arsenite oxidase.
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Affiliation(s)
- Hideki Sugimoto
- Department of Chemistry, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka, 558-8585, Japan.
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82
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Sugimoto H, Furukawa Y, Tarumizu M, Miyake H, Tanaka K, Tsukube H. Synthesis and Crystal Structures of [W(3,6-dichloro-1,2-benzenedithiolate)3]n- (n = 1, 2) and [Mo(3,6-dichloro-1,2-benzenedithiolate)3]2-: Dependence of the Coordination Geometry on the Oxidation Number and Counter-Cation in Trigonal-Prismatic and Octahedral Structures. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200500074] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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83
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Takuma M, Ohki Y, Tatsumi K. Sulfido-Bridged Dinuclear Molybdenum−Copper Complexes Related to the Active Site of CO Dehydrogenase: [(dithiolate)Mo(O)S2Cu(SAr)]2- (dithiolate = 1,2-S2C6H4, 1,2-S2C6H2-3,6-Cl2, 1,2-S2C2H4). Inorg Chem 2005; 44:6034-43. [PMID: 16097823 DOI: 10.1021/ic050294v] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The [MoCu] carbon monoxide dehydrogenase (CODH) is a Cu-containing molybdo-flavoprotein, the active site of which contains a pterin-dithiolene cofactor bound to a sulfido-bridged dinuclear Mo-Cu complex. In this paper, the synthesis and characterization of dinuclear Mo-Cu complexes relevant to the active site of [MoCu]-CODH are described. Reaction of [MoO2S2]2- with CuCN affords the dinuclear complex [O2MoS2Cu(CN)]2- (1), in which the CN- ligand can be replaced with various aryl thiolates to give rise to a series of dinuclear complexes [O2MoS2Cu(SAr)]2- (Ar = Ph (2), o-Tol (3), and p-Tol (4)). An alternative synthesis of complex 2 is the reaction of [MoO2S2]2- with [Cu(SPh)3]2-. Similarly, [O2MoS2Cu(PPh3)]- (5), [O2MoS2Cu(dppe)]- (dppe = 1,2-bis(diphenylphosphino)ethane) (6), and [O2MoS2Cu(triphos)]- (triphos = 1,1,1-tris[(diphenylphosphino)methyl]ethane) (7) were prepared from the reactions of [MoO2S2]2- with the Cu(I) phosphine complexes. Treatment of 1, 2, 4, or 5 with dithiols (1,2-(SH)2C6H4, 1,2-(SH)2C6H2-3,6-Cl2, and 1,2-(SH)2C2H4), in acetonitrile, leads to the replacement of a molybdenum-bound oxo ligand to yield [(dithiolate)Mo(O)S2CuL]2- (L = CN, SAr; dithiolate = 1,2-S2C6H4, 1,2-S2C6H2-3,6-Cl2, or 1,2-S2C2H4) (8-13) or [(1,2-S2C6H4)Mo(O)S2Cu(PPh3)]- (14) complexes.
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Affiliation(s)
- Motoki Takuma
- Department of Chemistry, Graduate School of Science and Research Center for Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
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84
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Schulzke C. Temperature dependent electrochemical investigations of molybdenum and tungsten oxobisdithiolene complexes. Dalton Trans 2005:713-20. [PMID: 15702182 DOI: 10.1039/b414853c] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
To achieve a better understanding why thermophilic and hyperthermophilic organisms use tungsten instead of molybdenum within the active sites of their molybdopterin dependent oxidases, electrochemical investigations of model complexes for the active sites of enzymes belonging to the DMSO reductase (molybdenum) and the aldehyde oxidoreductase (tungsten) family have been undertaken. Cyclic voltammetry and differential pulse voltammetry of four pairs of molybdenum and tungsten oxobisdithiolene compounds show huge differences in the response of their redox potentials to rising or decreasing temperatures, depending on the substituents at the dithiolene group. The mnt2- compounds (1a, 1b) respond with decreasing redox potentials E(1/2) to rising temperatures whereas all other compounds show positive gradients deltaE/deltaT. In every case the values for the gradients for the tungsten compounds are greater than those for the molybdenum compounds. Six of the investigated compounds are known in the literature and two compounds were newly synthesized. These two new compounds include the pyrane subunit of the native molybdopterin ligand and should therefore be even better models for the active site of the molybdopterin containing enzymes. The molybdenum/tungsten pair with these new ligands shows a remarkably small difference for the redox potentials of the transition M(IV) <--> M(V) of only 30 mV at 25 degrees C and the reversion of the usual order with higher potentials for the molybdenum than the tungsten compound at a temperature of 70 degrees C; a temperature that is in the range where usually tungsten containing enzymes instead of molybdenum containing ones are found.
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Affiliation(s)
- Carola Schulzke
- Institut für Anorganische Chemie, Universität Göttingen, 37077 Göttingen, Germany.
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85
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Baba K, Okamura TA, Yamamoto H, Yamamoto T, Ohama M, Ueyama N. Monooxomolybdenum(IV) Complex with Extremely Bulky Dithiolate Ligands — Acceleration of O-atom Transfer by Distorted Square Pyramidal Conformation. CHEM LETT 2005. [DOI: 10.1246/cl.2005.44] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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86
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Aragoni M, Arca M, Demartin F, Devillanova F, Lelj F, Isaia F, Lippolis V, Mancini A, Pala L, Verani G. A Theoretical Investigation of the Donor Ability of [M(R,R′timdt)2] Dithiolene Complexes towards Molecular Diiodine (M = Ni, Pd, Pt; R,R′timdt = Formally Monoreduced Disubstituted Imidazolidine-2,4,5-trithione). Eur J Inorg Chem 2004. [DOI: 10.1002/ejic.200300953] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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87
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Adams H, Morris MJ, Morris SA, Motley JC. Dithiolene transfer from nickel to a dimolybdenum centre: the first dithiolene alkyne complex. J Organomet Chem 2004. [DOI: 10.1016/j.jorganchem.2003.10.041] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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88
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Enemark JH, Cooney JJA, Wang JJ, Holm RH. Synthetic Analogues and Reaction Systems Relevant to the Molybdenum and Tungsten Oxotransferases. Chem Rev 2003; 104:1175-200. [PMID: 14871153 DOI: 10.1021/cr020609d] [Citation(s) in RCA: 424] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- John H Enemark
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721, USA
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89
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Sugimoto H, Siren K, Tsukube H, Tanaka K. Mono-Dithiolene Molybdenum(IV) Complexes of cis-1,2-Dicyano-1,2-ethylenedithiolate (mnt2): New Models for Molybdenum Enzymes. Eur J Inorg Chem 2003. [DOI: 10.1002/ejic.200200638] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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90
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Spectroelectrochemical cell for the study of interactions between redox-activated species and moderate pressures of gaseous substrates. J Electroanal Chem (Lausanne) 2002. [DOI: 10.1016/s0022-0728(02)01176-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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91
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Miki Y, Takagi H, Ichimura A, Akashi H, Shibahara T. Redox Chemistry of Dinuclear Molybdenum Dithiolene Complexes. Interconversion of the Bridging Disulfide and Sulfides. CHEM LETT 2002. [DOI: 10.1246/cl.2002.482] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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92
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Shibahara T, Nishiura K, Tsuboi M, Akashi H, Sakane G. Photochromism of Dinuclear Tungsten Complexes with Disulfur and Ethylene-1,2-dithiolate Ligands. CHEM LETT 2001. [DOI: 10.1246/cl.2001.1002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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93
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Lu X, Liu S, Mao X, Bu X. Synthesis, crystal structure and EPR spectra of cis-dioxo-molybdenum(V) with catechol ligand. J Mol Struct 2001. [DOI: 10.1016/s0022-2860(00)00764-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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94
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Fomitchev DV, Lim BS, Holm RH. Electron distribution in the nonclassical bis(dithiolene) electron transfer series [M(CO)2(S2C2Me2)2]0/1-/2- (M = Mo, W): assessment by structural, spectroscopic, and density functional theory results. Inorg Chem 2001; 40:645-54. [PMID: 11225106 DOI: 10.1021/ic001046w] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The electron-transfer series [M(CO)2(S2C2Me2)2]0/1-/2- (series 2) have been established, and the previously reported series [M(S2C2Me2)3]0/1-/2- (series 3) confirmed, by voltammetry (M = Mo, W). Redox reactions are reversible with EMo > EW, and all members of each series have been isolated. Members of a given series have very similar distorted trigonal prismatic structures; isoelectronic complexes are isostructural. The existence of these series with structurally characterized members facilitates examination of geometric and electronic properties over three consecutive oxidation states. Upon traversing the series in the reducing direction, M-S, S-C, and C-O bond distances increase, and M-C, chelate ring C-C, and vCO values decrease. Density functional calculations identify the electroactive orbital, which is well separated in energy from other orbitals. Trends in bond lengths and vibrational frequencies in a given series are fully accountable in terms of increasing population of this orbital, whose composition is roughly constant across the series and is dominantly ligand (ca. 80%) in character. Consequently, redox reactions in the two series are essentially ligand-based. The noninnocent nature of dithiolene ligands in oxidized complexes has been long recognized. The results of DFT calculations provide a contemporary description of the delocalized ground states in the two series. The trends in parameters involving the carbonyl groups provide a particularly clear indication of the classical behavior of a pi-acceptor ligand in isostructural molecules subject to consecutive reductions over three oxidation states.
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Affiliation(s)
- D V Fomitchev
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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95
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Musgrave KB, Lim BS, Sung KM, Holm RH, Hedman B, Hodgson KO. X-ray spectroscopy of enzyme active site analogues and related molecules: bis(dithiolene)molybdenum(IV) and -tungsten(IV,VI) complexes with variant terminal ligands. Inorg Chem 2000; 39:5238-47. [PMID: 11154582 DOI: 10.1021/ic000601r] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The X-ray absorption spectra at the molybdenum and selenium K-edges and the tungsten L2,3-edges are acquired for a set of 14 Mo(IV) and W(IV,VI) bis(dithiolene) complexes related to the active sites of molybdo- and tungstoenzymes. The set includes square pyramidal [MoIVL(S2C2Me2)2]- (L = O2-, R3SiO-, RO-, RS-, RSe-) and [WIV(OR)(S2C2Me2)2]-, distorted trigonal prismatic [MoIV(CO)(SeR)(S2C2Me2)2]- and [WIV(CO)L(S2C2Me2)2]- (L = RS-, RSe-), and distorted octahedral [WVIO(OR)(S2C2Me2)2]-. The dithiolene simulates the pterin-dithiolene cofactor ligand, and L represents a protein ligand. Bond lengths are determined by EXAFS analysis using the GNXAS protocol. Normalized edge spectra, non-phase-shift-corrected Fourier transforms, and EXAFS data and fits are presented. Bond lengths determined by EXAFS and X-ray crystallography agree to < or = 0.02 A as do the M-Se distances determined by both metal and selenium EXAFS. The complexes [MoIV(QR)(S2C2Me2)2]- simulate protein ligation by the DMSO reductase family of enzymes, including DMSO reductase itself (Q = O), dissimilatory nitrate reductase (Q = S), and formate dehydrogenase (Q = Se). Edge shifts of these complexes correlate with the ligand electronegativities. Terminal ligand binding is clearly distinguished in the presence of four Mo-S(dithiolene) interactions. Similarly, five-coordinate [ML(S2C2Me2)2]- and six-coordinate [M(CO)L(S2C2Me2)2]- are distinguishable by edge and EXAFS spectra. This study expands a previous XAS investigation of bis(dithiolene)metal(IV,V,VI) complexes (Musgrave, K. B.; Donahue, J. P.; Lorber, C.; Holm, R. H.; Hedman, B.; Hodgson, K. O. J. Am. Chem. Soc. 1999, 121, 10297) by including a larger inventory of molecules with variant physiologically relevant terminal ligation. The previous and present XAS results should prove useful in characterizing and refining metric features and structures of enzyme sites.
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Affiliation(s)
- K B Musgrave
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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Umakoshi* K, Nishimoto E, Sokolov M, Kawano H, Sasaki Y, Onishi* M. Synthesis, structure, and properties of sulfido-bridged dinuclear tungsten(V) complex of dithiolene, (Pr4N)2[W2(μ-S)2{S2C2(CO2Et)2}4]. J Organomet Chem 2000. [DOI: 10.1016/s0022-328x(00)00409-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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97
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McNaughton RL, Helton ME, Rubie ND, Kirk ML. The Oxo-Gate Hypothesis and DMSO Reductase: Implications for a Psuedo-σ Bonding Interaction Involved in Enzymatic Electron Transfer. Inorg Chem 2000. [DOI: 10.1021/ic000474z] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Rebecca L. McNaughton
- Department of Chemistry, The University of New Mexico, Albuquerque, New Mexico 81731-1096
| | - Matthew E. Helton
- Department of Chemistry, The University of New Mexico, Albuquerque, New Mexico 81731-1096
| | - Nick D. Rubie
- Department of Chemistry, The University of New Mexico, Albuquerque, New Mexico 81731-1096
| | - Martin L. Kirk
- Department of Chemistry, The University of New Mexico, Albuquerque, New Mexico 81731-1096
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98
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Seino H, Mizobe Y, Hidai M. Preparation of Dinuclear Rhodium and Iridium Complexes with Two Bridging Hydroselenido Ligands and Their Conversion into Tri- and Tetranuclear Selenido Clusters. Organometallics 2000. [DOI: 10.1021/om0004040] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hidetake Seino
- Institute of Industrial Science, The University of Tokyo, Roppongi, Minato-ku, Tokyo 106-8558, Japan, and Department of Materials Science and Technology, Faculty of Industrial Science and Technology, Science University of Tokyo, Noda, Chiba 278-8510, Japan
| | - Yasushi Mizobe
- Institute of Industrial Science, The University of Tokyo, Roppongi, Minato-ku, Tokyo 106-8558, Japan, and Department of Materials Science and Technology, Faculty of Industrial Science and Technology, Science University of Tokyo, Noda, Chiba 278-8510, Japan
| | - Masanobu Hidai
- Institute of Industrial Science, The University of Tokyo, Roppongi, Minato-ku, Tokyo 106-8558, Japan, and Department of Materials Science and Technology, Faculty of Industrial Science and Technology, Science University of Tokyo, Noda, Chiba 278-8510, Japan
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99
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Sung KM, Holm RH. Synthesis and structures of bis(dithiolene)-tungsten(IV) complexes related to the active sites of tungstoenzymes. Inorg Chem 2000; 39:1275-81. [PMID: 12526419 DOI: 10.1021/ic991153u] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recent protein crystallographic results on tungsten enzymes and primary sequence relationships between certain molybdenum and tungsten enzymes provoke interest in the generalized bis(dithiolene) complexes [WIV(QR)(S2C2R'2)2]1- and [WVIO(QR)(S2C2R'2)2]1- (Q = O, S, Se) as minimal representations of enzyme sites. The existence and stability of W(IV) complexes have been explored by synthesis. Reaction of [W(CO)2(S2C2Me2)2] (1) with PhO- results in complete CO substitution to give [W(OPh)(S2C2Me2)2]1- (2). Reaction of 1 with PhQ- affords the monocarbonyls [W(CO)(QPh)(S2C2Me2)2]1- (Q = S (3), Se (5)). The use of sterically demanding 2,4,6-Pri3C6H2Q- also yields monocarbonyls, [W(CO)(QC6H2-2,4,6-Pri3)(S2C2Me2)2]1- (Q = S (4), Se (6)). The X-ray structures of square pyramidal 2 and trigonal prismatic 3-6 (with unidentate ligands cis) are described. The tendency to substitute one or both carbonyl ligands in 1 in the formation of [MIV(QAr)(S2C2Me2)2]1- and [MIV(CO)(QAr)(SeC2Me2)2]1- with M = Mo and W is related to the M-Q bond length and ligand steric demands. The results demonstrate a stronger binding of CO by W(IV) than Mo(IV), a behavior previously demonstrated by thermodynamic and kinetic features of zerovalent carbonyl complexes. Complexes 3-6 can be reversibly reduced to W(III) at approximately -1.5 V versus SCE. On the basis of the potential for 2(-2.07 V), monocarbonyl ligation stabilizes W(III) by approximately 500 mV. This work is part of a parallel investigation of the chemistry of bis(dithiolene)-molybdenum (Lim, B. S.; Donahue, J. P.; Holm, R. H. Inorg. Chem. 2000, 39, 263) and -tungsten complexes related to enzyme active sites.
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Affiliation(s)
- K M Sung
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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