1
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Wu YY, Hong JC, Tsai RF, Pan HR, Huang BH, Chiang YW, Lee GH, Cheng MJ, Hsu HF. Ligand-Based Reactivity of Oxygenation and Alkylation in Cobalt Complexes Binding with (Thiolato)phosphine Derivatives. Inorg Chem 2020; 59:4650-4660. [PMID: 32186861 DOI: 10.1021/acs.inorgchem.9b03740] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In our efforts to understand the nature of metal thiolates, we have explored the chemistry of cobalt ion supported by (thiolato)phosphine ligand derivatives. Herein, we synthesized and characterized a square-planar CoII complex binding with a bidentate (thiolato)phosphine ligand, Co(PS1″)2 (1) ([PS1″]- = [P(Ph)2(C6H3-3-SiMe3-2-S)]-). The complex activates O2 to form a ligand-based oxygenation product, Co(OPS1″)2 (2) ([OPS1″]- = [PO(Ph)2(C6H3-3-SiMe3-2-S)]-). In addition, an octahedral CoIII complex with a tridentate bis(thiolato)phosphine ligand, [NEt4][Co(PS2*)2] (3) ([PS2*]2- = [P(Ph)(C6H3-3-Ph-2-S)2]2-), was obtained. Compound 3 cleaves the C-Cl bond in dichloromethane via an S-based nucleophilic attack to generate a chloromethyl thioether group. Two isomeric products, [Co(PS2*)(PSSCH2Cl*)] (4 and 4') ([PSSCH2Cl*]- = [P(Ph)(C6H3-3-Ph-2-S)(C6H3-3-Ph-2-SCH2Cl)]-), were isolated and fully characterized. Both transformations, oxygenation of a CoII-bound phosphine donor in 1 and alkylation of a CoIII-bound thiolate in 3, were monitored by spectroscopic methods. These reaction products were isolated and fully characterized. Density functional theory (DFT, the B3LYP functional) calculations were performed to understand the electronic structure of 1 as well as the pathway of its transformation to 2.
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Affiliation(s)
- Yi-Ying Wu
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
| | - Jia-Cheng Hong
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
| | - Ruei-Fong Tsai
- Department of Chemistry and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Hung-Ruei Pan
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
| | - Bo-Hua Huang
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
| | - Yun-Wei Chiang
- Department of Chemistry and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Gene-Hsiang Lee
- Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | - Mu-Jeng Cheng
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
| | - Hua-Fen Hsu
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
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2
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Ternes VA, Morgan HA, Lanquist AP, Murray MJ, Wile BM. Ruthenium (II) complexes bearing thioether‐appended α‐iminopyridine ligands: Arene precursors permit access to κ
2
‐N,N and κ
3
‐N,N,S complexes. Appl Organomet Chem 2020. [DOI: 10.1002/aoc.5459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Victoria A. Ternes
- Donald J. Bettinger Department of Chemistry and BiochemistryOhio Northern University 525 South Main Street Ada OH 45810 USA
| | - Hannah A. Morgan
- Donald J. Bettinger Department of Chemistry and BiochemistryOhio Northern University 525 South Main Street Ada OH 45810 USA
| | - Austin P. Lanquist
- Donald J. Bettinger Department of Chemistry and BiochemistryOhio Northern University 525 South Main Street Ada OH 45810 USA
| | - Michael J. Murray
- Donald J. Bettinger Department of Chemistry and BiochemistryOhio Northern University 525 South Main Street Ada OH 45810 USA
| | - Bradley M. Wile
- Donald J. Bettinger Department of Chemistry and BiochemistryOhio Northern University 525 South Main Street Ada OH 45810 USA
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3
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Yano T, Wasada-Tsutsui Y, Ikeda T, Shibayama T, Kajita Y, Inomata T, Funahashi Y, Ozawa T, Masuda H. Co(III) Complexes with N 2S 3-Type Ligands as Structural/Functional Models for the Isocyanide Hydrolysis Reaction Catalyzed by Nitrile Hydratase. Inorg Chem 2018; 57:4277-4290. [PMID: 29582997 DOI: 10.1021/acs.inorgchem.6b02324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
It has been before reported that, in addition to hydration of nitriles, the Fe-type nitrile hydratase (NHase) also catalyzes the hydrolysis of tert-butylisocyanide ( tBuNC). In order to investigate the unique isocyanide hydrolysis by NHase, we prepared three related Co(III) model complexes, PPh4[Co(L)] (1), PPh4[Co(L-O3)] (2), and PPh4[Co(L-O4)] (3), where L is bis( N-(2-mercapto-2-methylpropionyl)aminopropyl)sulfide. The suffixes L-O3 and L-O4 indicate ligands with a sulfenate and a sulfinate and with two sulfinates, respectively, instead of the two thiolates of L. The X-ray analyses of 1 and 3 reveal trigonal bipyramidal and square pyramidal structures, respectively. Complex 2, however, has five-coordinate trigonal-bipyramidal geometry with η2-type S-O coordination by a sulfenyl group. Addition of tBuNC to 1, 2, and 3 induces an absorption spectral change as a result of formation of an octahedral Co(III) complex. This interpretation is also supported by the crystal structures of PPh4[Co(L-O4)( tBuNC)] (4) and (PPh4)2[Co(L-O4)(CN)] (5). A water molecule interacts with 3 but cannot be activated as reported previously, as demonstrated by the lack of absorption spectral change in the pH range of 5.5-10.2. Interestingly, the coordinated tBuNC is hydrolyzed by 2 and 3 at pH 10.2 to produce tBuNH2 and CO molecule, but 1 does not react. These findings provide strong evidence that hydrolysis of tBuNC by NHase proceeds not by activation of the coordinated water molecule but by coordination of the substrate. The mechanism of the hydrolysis reaction of tBuNC is explained with support provided by DFT calculations; a positively polarized C atom of tBuNC on the Co(III) center is nucleophilically attacked by a hydroxide anion activated through an interaction of the sulfenyl/sulfinyl oxygen with the nucleophile.
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Affiliation(s)
- Takuma Yano
- Department of Frontier Materials, Graduate School of Engineering , Nagoya Institute of Technology , Gokiso-cho, Showa-ku, Nagoya 466-8555 , Japan
| | - Yuko Wasada-Tsutsui
- Department of Frontier Materials, Graduate School of Engineering , Nagoya Institute of Technology , Gokiso-cho, Showa-ku, Nagoya 466-8555 , Japan
| | - Tomohiro Ikeda
- Department of Frontier Materials, Graduate School of Engineering , Nagoya Institute of Technology , Gokiso-cho, Showa-ku, Nagoya 466-8555 , Japan
| | - Tomonori Shibayama
- Department of Frontier Materials, Graduate School of Engineering , Nagoya Institute of Technology , Gokiso-cho, Showa-ku, Nagoya 466-8555 , Japan
| | - Yuji Kajita
- Department of Applied Chemistry, Graduate School of Engineering , Aichi Institute of Technology , Yakusa, Toyota 470-0392 , Japan
| | - Tomohiko Inomata
- Department of Frontier Materials, Graduate School of Engineering , Nagoya Institute of Technology , Gokiso-cho, Showa-ku, Nagoya 466-8555 , Japan
| | - Yasuhiro Funahashi
- Department of Chemistry, Graduate School of Science , Osaka University , Machikaneyama , Toyonaka, Osaka 560-0043 , Japan
| | - Tomohiro Ozawa
- Department of Frontier Materials, Graduate School of Engineering , Nagoya Institute of Technology , Gokiso-cho, Showa-ku, Nagoya 466-8555 , Japan
| | - Hideki Masuda
- Department of Frontier Materials, Graduate School of Engineering , Nagoya Institute of Technology , Gokiso-cho, Showa-ku, Nagoya 466-8555 , Japan
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4
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Li FF, Chen HY, Jin Y, Zhao QH, Xie MJ. Synthesis, X-Ray Structure and In Vitro Cytotoxic Activity of a New Dinuclear Cobalt(III) Complex with Diazine Ligands. Pharm Chem J 2018. [DOI: 10.1007/s11094-018-1711-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Jana M, Majumdar A. C–S Bond Cleavage, Redox Reactions, and Dioxygen Activation by Nonheme Dicobalt(II) Complexes. Inorg Chem 2017; 57:617-632. [DOI: 10.1021/acs.inorgchem.7b02432] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Manish Jana
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Amit Majumdar
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
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6
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Villar-Acevedo G, Lugo-Mas P, Blakely MN, Rees JA, Ganas AS, Hanada EM, Kaminsky W, Kovacs JA. Metal-Assisted Oxo Atom Addition to an Fe(III) Thiolate. J Am Chem Soc 2016; 139:119-129. [PMID: 28033001 DOI: 10.1021/jacs.6b03512] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cysteinate oxygenation is intimately tied to the function of both cysteine dioxygenases (CDOs) and nitrile hydratases (NHases), and yet the mechanisms by which sulfurs are oxidized by these enzymes are unknown, in part because intermediates have yet to be observed. Herein, we report a five-coordinate bis-thiolate ligated Fe(III) complex, [FeIII(S2Me2N3(Pr,Pr))]+ (2), that reacts with oxo atom donors (PhIO, IBX-ester, and H2O2) to afford a rare example of a singly oxygenated sulfenate, [FeIII(η2-SMe2O)(SMe2)N3(Pr,Pr)]+ (5), resembling both a proposed intermediate in the CDO catalytic cycle and the essential NHase Fe-S(O)Cys114 proposed to be intimately involved in nitrile hydrolysis. Comparison of the reactivity of 2 with that of a more electron-rich, crystallographically characterized derivative, [FeIIIS2Me2NMeN2amide(Pr,Pr)]- (8), shows that oxo atom donor reactivity correlates with the metal ion's ability to bind exogenous ligands. Density functional theory calculations suggest that the mechanism of S-oxygenation does not proceed via direct attack at the thiolate sulfurs; the average spin-density on the thiolate sulfurs is approximately the same for 2 and 8, and Mulliken charges on the sulfurs of 8 are roughly twice those of 2, implying that 8 should be more susceptible to sulfur oxidation. Carboxamide-ligated 8 is shown to be unreactive towards oxo atom donors, in contrast to imine-ligated 2. Azide (N3-) is shown to inhibit sulfur oxidation with 2, and a green intermediate is observed, which then slowly converts to sulfenate-ligated 5. This suggests that the mechanism of sulfur oxidation involves initial coordination of the oxo atom donor to the metal ion. Whether the green intermediate is an oxo atom donor adduct, Fe-O═I-Ph, or an Fe(V)═O remains to be determined.
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Affiliation(s)
- Gloria Villar-Acevedo
- The Department of Chemistry, University of Washington , Box 351700, Seattle, Washington 98195-1700, United States
| | - Priscilla Lugo-Mas
- The Department of Chemistry, University of Washington , Box 351700, Seattle, Washington 98195-1700, United States
| | - Maike N Blakely
- The Department of Chemistry, University of Washington , Box 351700, Seattle, Washington 98195-1700, United States
| | - Julian A Rees
- The Department of Chemistry, University of Washington , Box 351700, Seattle, Washington 98195-1700, United States
| | - Abbie S Ganas
- The Department of Chemistry, University of Washington , Box 351700, Seattle, Washington 98195-1700, United States
| | - Erin M Hanada
- The Department of Chemistry, University of Washington , Box 351700, Seattle, Washington 98195-1700, United States
| | - Werner Kaminsky
- The Department of Chemistry, University of Washington , Box 351700, Seattle, Washington 98195-1700, United States
| | - Julie A Kovacs
- The Department of Chemistry, University of Washington , Box 351700, Seattle, Washington 98195-1700, United States
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7
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Functionalized mercaptoacetic and propionic acid amides: synthesis, cyclopalladation features, and catalytic activity of metal complexes. Russ Chem Bull 2016. [DOI: 10.1007/s11172-015-1207-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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8
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Electrochemical synthesis and crystal structure studies of defective dicubane tetranuclear hydroxo and carboxamide ligand bridged cobalt(II)–cobalt(III) complexes with carboxamides produced from unprotected hydroxyaromatic carboxylic acids. CR CHIM 2015. [DOI: 10.1016/j.crci.2014.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Börjesson K, Ćoso D, Gray V, Grossman JC, Guan J, Harris CB, Hertkorn N, Hou Z, Kanai Y, Lee D, Lomont JP, Majumdar A, Meier SK, Moth-Poulsen K, Myrabo RL, Nguyen SC, Segalman RA, Srinivasan V, Tolman WB, Vinokurov N, Vollhardt KPC, Weidman TW. Exploring the Potential of Fulvalene Dimetals as Platforms for Molecular Solar Thermal Energy Storage: Computations, Syntheses, Structures, Kinetics, and Catalysis. Chemistry 2014; 20:15587-604. [DOI: 10.1002/chem.201404170] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Indexed: 11/11/2022]
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10
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Aleksanyan DV, Nelyubina YV, Klemenkova ZS, Kozlov VA. Synthesis and Complexing Properties of Phosphorus-Substituted Pyridine-2-Carboxylic Acid Anilides. PHOSPHORUS SULFUR 2014. [DOI: 10.1080/10426507.2014.905571] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Diana V. Aleksanyan
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russia
| | - Yulia V. Nelyubina
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russia
| | - Zinaida S. Klemenkova
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russia
| | - Vladimir A. Kozlov
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russia
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11
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Lumb I, Hundal MS, Hundal G. Copper(II)-Catalyzed Disulfide Scission—Stepwise Aerobic Oxidative Cleavage to Sulfinate and Sulfonate and Reductive Anaerobic Cleavage to Thiols. Inorg Chem 2014; 53:7770-9. [DOI: 10.1021/ic501141m] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Isha Lumb
- Department of Chemistry,
Centre for Advanced Studies in Chemistry, Guru Nanak Dev University, Amritsar-143005, India
| | - Maninder Singh Hundal
- Department of Chemistry,
Centre for Advanced Studies in Chemistry, Guru Nanak Dev University, Amritsar-143005, India
| | - Geeta Hundal
- Department of Chemistry,
Centre for Advanced Studies in Chemistry, Guru Nanak Dev University, Amritsar-143005, India
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12
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Synthesis, crystal structure and electrochemistry of cobalt(III) carboxamide complexes with amine and azide ancillary ligands. Polyhedron 2014. [DOI: 10.1016/j.poly.2013.09.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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13
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Lozan V. Dinuclear Complexes as Building Blocks for Tetra-Nuclear Macrocyclic Complexes with Dithiolate Macrocyclic Ligand. CHEMISTRY JOURNAL OF MOLDOVA 2013. [DOI: 10.19261/cjm.2013.08(1).08] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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14
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Lehmann U, Lach J, Schleife F, Jeremies A, Kersting B. The Effects of Ring Expansion and
N
‐Methylation on the Complexation Behaviour of Macrodinucleating Hexaaza‐Dithiophenolate Macrocycles: Destabilization of the Co
III
Oxidation Level and Lowering of the Coordination Number. Eur J Inorg Chem 2013. [DOI: 10.1002/ejic.201201314] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Ulrike Lehmann
- Institut für Anorganische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany, Fax: +49‐341‐97‐36199, http://www.uni‐leipzig.de/~bkerst
| | - Jochen Lach
- Institut für Anorganische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany, Fax: +49‐341‐97‐36199, http://www.uni‐leipzig.de/~bkerst
| | - Frederik Schleife
- Institut für Anorganische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany, Fax: +49‐341‐97‐36199, http://www.uni‐leipzig.de/~bkerst
| | - Alexander Jeremies
- Institut für Anorganische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany, Fax: +49‐341‐97‐36199, http://www.uni‐leipzig.de/~bkerst
| | - Berthold Kersting
- Institut für Anorganische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany, Fax: +49‐341‐97‐36199, http://www.uni‐leipzig.de/~bkerst
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15
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New members of a class of dinitrosyliron complexes (DNICs): The characteristic EPR signal of the six-coordinate and five-coordinate {Fe(NO)2}9 DNICs. J Inorg Biochem 2012; 113:83-93. [DOI: 10.1016/j.jinorgbio.2012.03.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2012] [Revised: 03/16/2012] [Accepted: 03/21/2012] [Indexed: 11/22/2022]
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16
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Synthesis and characterization of an unsymmetrical cobalt(III) active site analogue of nitrile hydratase. J Biol Inorg Chem 2011; 16:937-47. [PMID: 21638158 DOI: 10.1007/s00775-011-0794-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 05/19/2011] [Indexed: 10/18/2022]
Abstract
The design, synthesis, and characterization of an unsymmetrical diamidato-dithiol ligand (H(4) 1, where the hydrogen atoms represent deprotonatable amide and thiol protons) and its cobalt(III) complex, a synthetic analogue of the cobalt-containing nitrile hydratase enzyme family, are reported. The ligand was prepared in 24% yield from an overall eight-step synthetic pathway following a modified protocol established in our laboratory that includes two peptide couples using O-(1H-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate as the coupling agent. The ligand and all precursors were characterized by NMR spectroscopy and elemental analysis. The cobalt nitrile hydratase synthetic analogue complex [NBu(4)][Co(1)] was prepared on deprotonating ligand H(4) 1 to [1](4-) on addition of 5 equiv of NaH in N,N-dimethylformamide and adding 1 equiv of CoCl(2) at -40 °C under a N(2) atmosphere followed by oxidizing the complex by stirring it overnight open to dry air. The complex [NBu(4)][Co(1)] was isolated after counterion exchange with 1 equiv of NBu(4)Cl followed by crystallization from MeCN/Et(2)O in 71% yield. The structure of the complex was confirmed by X-ray diffraction analysis. Cyclic voltammetry studies on [NBu(4)][Co(1)] in a 0.1 M [NBu(4)][PF(6)]/MeCN solution showed a quasi-reversible reduction potential at -1.1 V (vs. Ag/AgCl), and magnetic susceptibility investigations indicated the complex is paramagnetic in both the solid and the solution states as determined from inverse-Gouy and Evans NMR methods, respectively.
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17
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Koo BK. Synthesis and Structural Studies of Mn(II), Co(III), and Ni(II) Complexes with Schiff Base Ligands Derived from 2-Acetylpyridine. B KOREAN CHEM SOC 2011. [DOI: 10.5012/bkcs.2011.32.5.1729] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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18
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Carlson LJ, Welby J, Zebrowski KA, Wilk MM, Giroux R, Ciancio N, Tanski JM, Bradley A, Tyler LA. Spectroscopic differences between heterocyclic benzothiazoline, -thiazole and imine containing ligands and comparison of the Co and Cu pyridine benzothiazole and imine complexes. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2010.09.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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19
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Pandey S, Das PP, Singh AK, Mukherjee R. Cobalt(ii), nickel(ii) and copper(ii) complexes of a hexadentate pyridine amide ligand. Effect of donor atom (ether vs. thioether) on coordination geometry, spin-state of cobalt and MIII–MII redox potential. Dalton Trans 2011; 40:10758-68. [DOI: 10.1039/c1dt10661a] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Baran Y, Comba P, Lawrance GA. Trends in Base Hydrolysis Rates of Chlorocobalt(III) Complexes of a Series of Related Pentaamine Ligands. ACTA ACUST UNITED AC 2010. [DOI: 10.1080/1028662021000062509] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Yakup Baran
- a Department of Chemistry, Art and Science Faculty , The University of Karaelmas , Zonguldak , 67100 , Turkey
| | - Peter Comba
- b Anorganisch-Chemisches Institut der Universität Heidelberg , Im Neuenheimer Feld 270, Heidelberg , D-69120 , Germany
| | - Geoffrey A. Lawrance
- c Discipline of Chemistry, School of Environmental and Life Sciences , The University of Newcastle , Callaghan , NSW , 2308 , Australia
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21
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Shearer J, Callan PE, Amie J. Use of metallopeptide based mimics demonstrates that the metalloprotein nitrile hydratase requires two oxidized cysteinates for catalytic activity. Inorg Chem 2010; 49:9064-77. [PMID: 20831172 PMCID: PMC3570060 DOI: 10.1021/ic101765h] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nitrile hydratases (NHases) are non-heme Fe(III) or non-corrin Co(III) containing metalloenzymes that possess an N(2)S(3) ligand environment with nitrogen donors derived from amidates and sulfur donors derived from cysteinates. A closely related enzyme is thiocyanate hydrolase (SCNase), which possesses a nearly identical active-site coordination environment as CoNHase. These enzymes are redox inactive and perform hydrolytic reactions; SCNase hydrolyzes thiocyanate anions while NHase converts nitriles into amides. Herein an active CoNHase metallopeptide mimic, [Co(III)NHase-m1] (NHase-m1 = AcNH-CCDLP-CGVYD-PA-COOH), that contains Co(III) in a similar N(2)S(3) coordination environment as CoNHase is reported. [Co(III)NHase-m1] was characterized by electrospray ionization-mass spectrometry (ESI-MS), gel-permeation chromatography (GPC), Co K-edge X-ray absorption spectroscopy (Co-S: 2.21 Å; Co-N: 1.93 Å), vibrational, and optical spectroscopies. We find that [Co(III)NHase-m1] will perform the catalytic conversion of acrylonitrile into acrylamide with up to 58 turnovers observed after 18 h at 25 °C (pH 8.0). FTIR data used in concert with calculated vibrational data (mPWPW91/aug-cc-TZVPP) demonstrates that the active form of [Co(III)NHase-m1] has a ligated SO(2) (ν = 1091 cm(-1)) moiety and a ligated protonated SO(H) (ν = 928 cm(-1)) moiety; when only one oxygenated cysteinate ligand (i.e., a mono-SO(2) coordination motif) or the bis-SO(2) coordination motif are found within [Co(III)NHase-m1] no catalytic activity is observed. Calculations of the thermodynamics of ligand exchange (B3LYP/aug-cc-TZVPP) suggest that the reason for this is that the SO(2)/SO(H) equatorial ligand motif promotes both water dissociation from the Co(III)-center and nitrile coordination to the Co(III)-center. In contrast, the under- or overoxidized motifs will either strongly favor a five coordinate Co(III)-center or strongly favor water binding to the Co(III)-center over nitrile binding.
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Affiliation(s)
- Jason Shearer
- Department of Chemistry, University of Nevada, Reno, Nevada 89557, USA.
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22
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Sharma AK, Biswas S, Barman SK, Mukherjee R. Azo-containing pyridine amide ligand. A six-coordinate nickel(II) complex and its one-electron oxidized species: Structure and properties. Inorganica Chim Acta 2010. [DOI: 10.1016/j.ica.2010.03.056] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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23
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Lu TT, Chen CH, Liaw WF. Formation of the Distinct Redox-Interrelated Forms of Nitric Oxide from Reaction of Dinitrosyl Iron Complexes (DNICs) and Substitution Ligands. Chemistry 2010; 16:8088-95. [DOI: 10.1002/chem.201000524] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Tong LH, Wong YL, Pascu SI, Dilworth JR. An unprecedented iron(III) complex supported by an asymmetric N-capped tripodal ligand incorporating the NO2S donor set. Inorganica Chim Acta 2010. [DOI: 10.1016/j.ica.2009.09.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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25
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Rose MJ, Betterley NM, Oliver AG, Mascharak PK. Binding of Nitric Oxide to a Synthetic Model of Iron-Containing Nitrile Hydratase (Fe-NHase) and Its Photorelease: Relevance to Photoregulation of Fe-NHase by NO. Inorg Chem 2010; 49:1854-64. [DOI: 10.1021/ic902220a] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Michael J. Rose
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064
| | - Nolan M. Betterley
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064
| | - Allen G. Oliver
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064
| | - Pradip K. Mascharak
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064
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26
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Leigh DA, Lusby PJ, McBurney RT, Morelli A, Slawin AMZ, Thomson AR, Walker DB. Getting harder: cobalt(III)-template synthesis of catenanes and rotaxanes. J Am Chem Soc 2009; 131:3762-71. [PMID: 19275264 DOI: 10.1021/ja809627j] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis of catenanes and rotaxanes using the hard trivalent transition metal ion cobalt(III) as a template is reported. Tridentate dianionic pyridine-2,6-dicarboxamido ligands, each with two terminal alkene groups, coordinate Co(III) in a mutually orthogonal arrangement such that entwined or interlocked molecular architectures are produced by ring-closing olefin metathesis. Double macrocyclization of two such ligands bound to Co(III) afford a non-interlocked "figure-of-eight" complex in 42% yield, the structure determined by X-ray crystallography. Preforming one macrocycle and carrying out a single macrocyclization of the second bis-olefin with both ligands attached to the Co(III) template led to the isomeric [2]catenate in 69% yield. The mechanically interlocked structure was confirmed by X-ray crystallography of both the Co(III) catenate and the metal-free catenand. A Co(III)-template [2]rotaxane was assembled in 61% yield by macrocyclization of the bis-olefin ligand about an appropriate dianionic thread. For both catenanes and rotaxanes, removal of the metal ion via reduction under acidic conditions to the more labile Co(II) gave neutral interlocked molecules with well-defined co-conformations stabilized by intercomponent hydrogen bonding.
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Affiliation(s)
- David A Leigh
- School of Chemistry, University of Edinburgh, The King's Buildings, West Mains Road, Edinburgh EH9 3JJ, United Kingdom.
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Patra A, Sarkar S, Drew MG, Zangrando E, Chattopadhyay P. Synthesis and crystal structure characterization of iron(II), cobalt(II) and nickel(II) complexes with 1,3-bis(2-pyridylmethylthio)propane. Polyhedron 2009. [DOI: 10.1016/j.poly.2009.02.039] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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28
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Jacob W, Mishra H, Pandey S, Lloret F, Mukherjee R. Six-coordinate CoIII and four-coordinate MII (M = Co, Zn) mixed-valence dimers supported by a deprotonated pyridine amide ligand: magnetism of a CoIIICoII complex and C–H⋯O/Cl/Br interactions. NEW J CHEM 2009. [DOI: 10.1039/b814303j] [Citation(s) in RCA: 13] [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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29
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Singh AK, Jacob W, Boudalis AK, Tuchagues JP, Mukherjee R. A Tetragonal Core with Asymmetric Iron Environments Supported Solely by Bis(μ-OH){μ-(O–H···O)} Bridging and Terminal Pyridine Amide (N, O) Coordination: A New Member of the Tetrairon(III) Family. Eur J Inorg Chem 2008. [DOI: 10.1002/ejic.200800032] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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30
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Hopmann KH, Himo F. Theoretical Investigation of the Second-Shell Mechanism of Nitrile Hydratase. Eur J Inorg Chem 2008. [DOI: 10.1002/ejic.200701137] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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31
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Singh AK, Mukherjee R. Cobalt(ii) and cobalt(iii) complexes of thioether-containing hexadentate pyrazine amide ligands: C–S bond cleavage and cyclometallation reaction. Dalton Trans 2008:260-70. [DOI: 10.1039/b709901k] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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32
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Lozan V, Buchholz A, Plass W, Kersting B. Dinuclear Amine–Thiophenolate Complexes Coligated by Ferrocenemonocarboxylate and 1,1′-Ferrocenedicarboxylate Anions: Preparation, Characterization and Structures of Trinuclear [LMII2(O2CC5H4FeCp)]+ and Pentanuclear [(LMII2)2(O2CC5H4)2Fe]2+ Complexes (M=Co, Ni, Zn). Chemistry 2007; 13:7305-16. [PMID: 17577912 DOI: 10.1002/chem.200700107] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A series of novel tri- and pentanuclear complexes composed of dinuclear LM(2) units (M=Co, Ni, Zn; L=24-membered macrocyclic hexaazadithiophenolate ligand) and ferrocenecarboxylate ([CpFeC(5)H(4)CO(2)](-)) or 1,1'-ferrocenedicarboxylate ([Fe(C(5)H(4)CO(2))(2)](2-)) groups is reported. The complexes [LM(II) (2)(O(2)CC(5)H(4)FeCp)](+) (M=Co (6), Ni (7), Zn (8)) and [(LM(II) (2))(2)(O(2)CC(5)H(4))(2)Fe](2+) (M=Co (9), Ni (10)) have been prepared by substitution reactions from labile [LM(II) (2)L'](+) precursors (L'=Cl, OAc) and the respective ferrocenecarboxylate anions in methanol. Mixed-valent [(LCo(II)Co(III))(2)(O(2)CC(5)H(4))(2)Fe](4+) (11) was prepared by oxidation of 9 with bromine. Complexes 7[BPh(4)], 8[BPh(4)], 9[BPh(4)](2), 10[BPh(4)](2), and 11[ClO(4)](4) have been characterized by X-ray crystallography; showing that the ferrocenyl carboxylates act as bidentate (7, 8) or bis-bidentate (9-11) bridging ligands towards one or two bioctahedral LM(2) subunits, respectively. The structures are retained in solution as indicated by NMR spectroscopic studies on the diamagnetic Zn(2)Fe complex 8[ClO(4)]. Electrochemical studies reveal significant anodic potential shifts for the oxidation potential of the ferrocenyl moieties upon complexation and the magnitude of the potential shift appears to correlate with the charge of the LM(2) subunits. This is qualitatively explained in terms of destabilizing electrostatic (Coulomb) interactions between the M(2+) ions of the LM(2) unit and the proximate ferrocenium fragment. An analysis of the temperature-dependent magnetic susceptibility data for 10[BPh(4)](2) shows the presence of weak ferromagnetic magnetic exchange interactions between the Ni(II) ions in the LNi(2) units. The exchange coupling across the ferrocenedicarboxylate bridge is negligible.
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Affiliation(s)
- Vasile Lozan
- Institut für Anorganische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany
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33
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Dey A, Jeffrey SP, Darensbourg M, Hodgson KO, Hedman B, Solomon EI. Sulfur K-edge XAS and DFT studies on NiII complexes with oxidized thiolate ligands: implications for the roles of oxidized thiolates in the active sites of Fe and Co nitrile hydratase. Inorg Chem 2007; 46:4989-96. [PMID: 17500514 PMCID: PMC2565589 DOI: 10.1021/ic070244l] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
S K-edge X-ray absorption spectroscopy data on a series of NiII complexes with thiolate (RS-) and oxidized thiolate (RSO2-) ligands are used to quantify Ni-S bond covalency and its change upon ligand oxidation. Analyses of these results using geometry-optimized density functional theory (DFT) calculations suggest that the Ni-S sigma bonds do not weaken on ligand oxidation. Molecular orbital analysis indicates that these oxidized thiolate ligands use filled high-lying S-O pi* orbitals for strong sigma donation. However, the RSO2- ligands are poor pi donors, as the orbital required for pi interaction is used in the S-O sigma-bond formation. The oxidation of the thiolate reduces the repulsion between electrons in the filled Ni t2 orbital and the thiolate out-of-plane pi-donor orbital leading to shorter Ni-S bond length relative to that of the thiolate donor. The insights obtained from these results are relevant to the active sites of Fe- and Co-type nitrile hydratases (Nhase) that also have oxidized thiolate ligands. DFT calculations on models of the active site indicate that whereas the oxidation of these thiolates has a major effect in the axial ligand-binding affinity of the Fe-type Nhase (where there is both sigma and pi donation from the S ligands), it has only a limited effect on the sixth-ligand-binding affinity of the Co-type Nhases (where there is only sigma donation). These oxidized residues may also play a role in substrate binding and proton shuttling at the active site.
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Affiliation(s)
- Abhishek Dey
- Department of Chemistry, Stanford University, Stanford, CA, 94305
| | - Stephen P. Jeffrey
- Department of Chemistry, Texas A&M University, College Station, TX, 77843
| | | | - Keith O. Hodgson
- Department of Chemistry, Stanford University, Stanford, CA, 94305
- Stanford Synchrotron Radiation Laboratory, SLAC, Stanford University, Menlo Park, California 94025
| | - Britt Hedman
- Stanford Synchrotron Radiation Laboratory, SLAC, Stanford University, Menlo Park, California 94025
| | - Edward I. Solomon
- Department of Chemistry, Stanford University, Stanford, CA, 94305
- Stanford Synchrotron Radiation Laboratory, SLAC, Stanford University, Menlo Park, California 94025
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34
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Syntheses, structures, and properties of Co(III) complexes derived from polypyridine ligands containing one carboxamido nitrogen donor. Inorganica Chim Acta 2006. [DOI: 10.1016/j.ica.2006.04.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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35
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Behrens A, Rehder D. An unusual Li-Na-β-octamolybdate(VI) sandwiched by dinuclear organomolybdenum(V) units. INORG CHEM COMMUN 2006. [DOI: 10.1016/j.inoche.2006.04.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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36
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Novel cobalt(II) complexes with pyridyl/ether or pyridyl/thioether ligands. The conversion of pyridyl/thioether cobalt(II) complex to pyridyl/sulfinato cobalt(III) compound. Inorganica Chim Acta 2006. [DOI: 10.1016/j.ica.2005.09.057] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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37
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Harrop TC, Olmstead MM, Mascharak PK. Modeling the Active Site of Nitrile Hydratase: Synthetic Strategies to Ensure Simultaneous Coordination of Carboxamido-N and Thiolato-S to Fe(III) Centers. Inorg Chem 2005; 44:9527-33. [PMID: 16323940 DOI: 10.1021/ic051183z] [Citation(s) in RCA: 19] [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
A general strategy for synthesizing Fe(III) complexes of ligands containing carboxamido-N and thiolato-S donors has been described. Reaction of the doubly deprotonated ligand PyPepS2- (where PyPepSH2=N-2-mercaptophenyl-2'-pyridinecarboxamide) with Fe(III) salts in DMF had previously afforded the Fe(III) complex (Et4N)[Fe(PyPepS)2] without any problem(s) associated with autoredox reactions of the thiolate functionality. In the present work, similar reactions with the doubly deprotonated ligand PiPepS2- (where PiPepSH2=2-mercapto-N-pyridin-2-yl-methylbenzamide) with Fe(III) salts, however, fail to afford any Fe(III) complex because of autoredox reactions. The break in the conjugation in the PiPepSH2 ligand frame is the key reason for this difference in behavior between these two very similar ligands. This is demonstrated by the fact that the same reaction with AqPepS2- (where AqPepSH2=2-mercapto-N-quinolin-8-yl-benzamide), another ligand with extended conjugation, affords the Fe(III) complex (Et4N)[Fe(AqPepS)2] without any synthetic complication. It is therefore evident that ligands in which the carboxamide and thiolate functionalities are kept in conjugation could be used to isolate Fe(III) complexes with carboxamido-N and thiolato-S coordination. This finding will be very helpful in future research work in the area of modeling the active site of Fe-containing nitrile hydratase.
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Affiliation(s)
- Todd C Harrop
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, USA
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38
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39
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Sellmann D, Hein K, Heinemann F. Ruthenium(II) and Ruthenium(III) Complexes Containing the [pyS4]2− Ligand [pyS42− = 2,6-Bis(2-mercaptophenylthio)dimethylpyridine(2−)]. Eur J Inorg Chem 2004. [DOI: 10.1002/ejic.200400066] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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40
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Bis-axial cyanide coordination induces high nucleophilicity of the in-plane thiolato ligands bound to a Co(III) center: model complexes related to the Co-containing nitrile hydratases. Inorganica Chim Acta 2004. [DOI: 10.1016/j.ica.2004.02.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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41
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Harrop TC, Mascharak PK. Fe(III) and Co(III) centers with carboxamido nitrogen and modified sulfur coordination: lessons learned from nitrile hydratase. Acc Chem Res 2004; 37:253-60. [PMID: 15096062 DOI: 10.1021/ar0301532] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nitrile hydratase (NHase) is a non-heme Fe(III) or non-corrinoid Co(III) metalloenzyme with an unprecedented coordination sphere comprising deprotonated carboxamido nitrogens and modified Cys-S (-SO(-) and -SO(2)(-)) sulfurs. We have synthesized model complexes derived from designed ligands that contain these donor groups. The model complexes mimic almost all the intrinsic properties of the unique M(III) (M = Fe, Co) active site of NHase. Even a functional Co(III) model has been synthesized that hydrolyzes nitriles catalytically at pH close to the optimum pH of the enzyme. Our studies have provided insight into how the unusual donor atoms dictate the overall properties of the biological M(III) sites.
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Affiliation(s)
- Todd C Harrop
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, USA
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42
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Grapperhaus CA, Mullins CS, Kozlowski PM, Mashuta MS. Synthesis and Oxygenation of a Nickel(II) and Zinc(II) Dithiolate: An Experimental and Theoretical Comparison. Inorg Chem 2004; 43:2859-66. [PMID: 15106973 DOI: 10.1021/ic035205y] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The diamino-dithiolato N2S2 ligand N,N'-bis-2-methyl-mercaptopropyl-N,N'-dimethylethylenediamine, H2bmmp-dmed), and its nickel (1) and zinc (2) complexes have been prepared and their reactivities with hydrogen peroxide investigated. Complex 1 yields a mixture of sulfenato (RSO-), 4, sulfinato (RSO2-), 3, and sulfonato (RSO3-), 5, products upon addition of H2O2. Products are separable by column chromatography. Stoichiometric addition of H2O2 to 2 yields an inseparable mixture. Excess peroxide addition results in oxygenation of the ligand to the disulfonate, 6, and decomplexation of zinc. Complexes 1, 2, and 3 and compound 6 have been investigated by X-ray crystallography, and their structures are reported. Density functional theory (DFT) calculations of 1 and 2 reveal significant sulfur p character in the HOMO of each complex. However, 1 also shows significant metal d character that is pi-antibonding with respect to the sulfur p orbitals. Complex 2 shows little metal character in the HOMO. Implications of the HOMO with respect to S-centered reactivity and metal ligand distances in S-oxygenated products are provided.
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Affiliation(s)
- Craig A Grapperhaus
- Department of Chemistry, University of Louisville, Louisville, Kentucky 40292, USA.
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43
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Maiti D, Paul H, Chanda N, Chakraborty S, Mondal B, Puranik VG, Kumar Lahiri G. Synthesis, structure, spectral and electron-transfer properties of octahedral-[CoIII(L)2]+/[ZnII(L)2] and square planar-[CuII(L){OC(O)CH3}] complexes incorporating anionic form of tridentate bis(8-quinolinyl)amine [N1C9H6–N2–C9H6N3, L−] ligand. Polyhedron 2004. [DOI: 10.1016/j.poly.2003.11.053] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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44
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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: 233] [Impact Index Per Article: 11.7] [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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45
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Tyler LA, Noveron JC, Olmstead MM, Mascharak PK. Modulation of the pK(a) of metal-bound water via oxidation of thiolato sulfur in model complexes of Co(III) containing nitrile hydratase: insight into possible effect of cysteine oxidation in Co-nitrile hydratase. Inorg Chem 2003; 42:5751-61. [PMID: 12950226 DOI: 10.1021/ic030088s] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The Co(III) complexes of N,N'-bis(2-mercaptophenyl)pyridine-2,6-dicarboxamide (PyPSH(4)), a designed pentadentate ligand with built-in carboxamide and thiolate groups, have been synthesized and studied to gain insight into the role of Cys-S oxidation in Co-containing nitrile hydratase (Co-NHase). Reaction of [Co(NH(3))(5)Cl]Cl(2) with PyPS(4)(-) in DMF affords the thiolato-bridged dimeric Co(III) complex (Et(4)N)(2)[Co(2)(PyPS)(2)] (1). Although the bridged structure is quite robust, reaction of (Et(4)N)(CN) with 1 in acetonitrile affords the monomeric species (Et(4)N)(2)[Co(PyPS)(CN)] (2). Oxidation of 2 with H(2)O(2) in acetonitrile gives rise to a mixture which, upon chromatographic purification, yields K(2)[Co(PyPSO(2)(OSO(2))(CN] (3), a species containing asymmetrically oxidized thiolates. The Co(III) metal center in 3 is coordinated to a S-bound sulfinate and an O-bound sulfonate (OSO(2)) group. Upon oxidation with H(2)O(2), 1 affords an asymmetrically oxidized dimer (Et(4)N)(2)[Co(2)(PyPS(SO(2)))(2)] (4) in which only the terminal thiolates are oxidized to form S-bound sulfinate groups while the bridging thiolates remain unchanged. The thiolato-bridge in 4 is also cleaved upon reaction with (Et(4)N)(CN) in acetonitrile, and one obtains (Et(4)N)(2)[Co(PyPS(SO(2)))(CN)] (5), a species that contains both coordinated thiolate and S-bound sulfinate around Co(III). The structures of 1-4 have been determined. The spectroscopic properties and reactivity of all the complexes have been studied to understand the behavior of the Co(III) site in Co-NHase. Unlike typical Co(III) complexes with bound CN(-) ligands, the Co(III) centers in 2 and 5 are labile and rapidly lose CN(-) in aqueous solutions. Since 3 does not show this lability, it appears that at least one thiolato sulfur donor is required in the first coordination sphere for the Co(III) center in such species to exhibit lability. Both 2 and 5 are converted to the aqua complexes [Co(PyPS)(H(2)O)](-) and [Co(PyPS(SO(2))(H(2)O)](-) in aqueous solutions. The pK(a) values of the bound water in these two species, determined by spectrophotometry, are 8.3 +/- 0.03 and 7.2 +/- 0.06, respectively. Oxidation of the thiolato sulfur (to sulfinate) therefore increases the acidity of the bound water. Since 2 and 5 promote hydrolysis of acetonitrile at pH values above their corresponding pK(a) values, it is also evident that a metal-bound hydroxide is a key player in the mechanism of hydrolysis by these model complexes of Co-NHase. The required presence of a Cys-sulfinic residue and one water molecule at the Co(III) site of Co-NHase as well as the optimal pH of the enzyme near 7 suggests that (i) modulation of the pK(a) of the bound water molecule at the active site of the enzyme could be one role of the oxidized Cys-S residue(s) and (ii) a cobalt-bound hydroxide could be responsible for the hydrolysis of nitriles by Co-NHase.
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Affiliation(s)
- Laurie A Tyler
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, USA
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46
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Harrop TC, Rodriguez K, Mascharak PK. Convenient One-Pot Synthesis ofN,N ′-bis(2-Mercaptophenyl)pyridine-2,6-dicarboxamide andN-2-Mercaptophenyl-2′-pyridinecarboxamide Without Protection of the Thiol Group(s). SYNTHETIC COMMUN 2003. [DOI: 10.1081/scc-120020209] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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47
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Kotera T, Fujita A, Mikuriya M, Tsutsumi H, Handa M. Cobalt complexes with 2-[(3-aminopropyl)amino]ethanethiol. INORG CHEM COMMUN 2003. [DOI: 10.1016/s1387-7003(02)00755-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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48
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Rat M, Sousa R, Tomas A, Frapart Y, Tuchagues JP, Artaud I. Synthesis, X-ray Structure and Properties of a Trinuclear Mixed-Valence CoIII-CoII-CoIII Complex with Carboxamido N and Sulfinato S Donors. Eur J Inorg Chem 2003. [DOI: 10.1002/ejic.200390105] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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49
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Karambelkar VV, Krishnamurthy D, Stern CL, Zakharov LN, Rheingold AL, Goldberg DP. A new bis(imidazolyl)(alkylthiolate) tripodal ligand and the spontaneous formation of a disulfide-linked, hydroxo-bridged dinuclear zinc complex. Chem Commun (Camb) 2002:2772-3. [PMID: 12478739 DOI: 10.1039/b207770a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The new sterically encumbered, tripodal N2S(alkylthiolate) ligand, LIm2SH, has been synthesized and used to prepare [(LIm2S)ZnCH3], which upon protonolysis under acidic conditions leads to the synthesis of a novel dinucleating ligand and a zinc dimer with an unusual structure.
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Affiliation(s)
- Vivek V Karambelkar
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, USA
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50
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Dutta SK, Samanta S, Ghosh D, Butcher RJ, Chaudhury M. Oxovanadium(V) and cobalt(III) complexes of dithiocarbazate-based Schiff base ligands: formation of a thiadiazole ring by vanadium-induced cyclization of the coordinated ligand. Inorg Chem 2002; 41:5555-60. [PMID: 12377053 DOI: 10.1021/ic0200895] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
S-Methyl 3-((2-hydroxyphenyl)methyl)dithiocarbazate (H(2)L(1)) and its bromo derivative (H(2)L(2)), which are traditionally biprotic tridentate (ONS) ligands, behave in an unprecedented manner when allowed to react with [VO(acac)(2)] under an oxidative environment in acetonitrile-water medium containing a catalytic amount of alkali metal ion. The products obtained are oxovanadium(V) compounds [VOL(L(cyclic))] (L = L(1), 1a, and L(2), 1b) that contain one molecule of ligand which undergoes metal-induced cyclization to form a thiadiazole ring. Compound 1a crystallizes in the triclinic space group P(-)1 with a = 9.1830(9) A, b = 9.4165(12) A, c = 12.700(2) A, alpha = 100.988(8)(o), beta = 100.195(7)(o), gamma = 78.774(8)(o), V = 1046.3(2) A(3), and Z = 2. With cobalt(III), however, the products [CoL(HL)].H(2)O (L = L(1), 2a, and L(2), 2b) have hydrogen-bonded dimeric structures with each ligand virtually carrying 1.5 units of negative charge as confirmed by X-ray crystal structure analysis of 2a. It also crystallizes in triclinic space group P(-)1 with a = 12.0842(8) A, b = 13.5251(9) A, c = 14.1960(10) A, alpha = 78.122(6)(o), beta = 73.888(6)(o), gamma = 78.255(6)(o), V = 2154.7(3) A(3), and Z = 4. In solution, 2a is a symmetric molecule as indicated by (1)H NMR, involving a characteristic hydrogen-bonded O-H-O broad feature in the downfield (at 14.5 ppm) connecting both monoprotonated (LH(-)) and deprotonated (L(2-)) forms of the ligand--a situation somewhat analogous to the classic H-F-H case as observed in bifluoride ion.
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Affiliation(s)
- Subodh Kanti Dutta
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700 032, India
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