1
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Clausen KU, Schlimm A, Bedbur K, Näther C, Strunskus T, Fu L, Gruber M, Berndt R, Tuczek F. Molybdenum(0)-Tricarbonyl Complex Supported by an Azacalix-pyridine Ligand: Synthesis, Characterization, Surface Deposition and Conversion to a Molybdenum(VI)-Trioxo Complex with O 2. Chemistry 2024; 30:e202303912. [PMID: 38319524 DOI: 10.1002/chem.202303912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 02/07/2024]
Abstract
Adsorption of metal-organic complexes on metallic surfaces to produce well-defined single site catalysts is a novel approach combining the advantages of homogeneous and heterogeneous catalysis. To avoid the "surface trans-effect" a dome-shaped molybdenum(0) tricarbonyl complex supported by an tolylazacalix[3](2,6)pyridine ligand is synthesized. This vacuum-evaporable complex both activates CO and reacts with molecular oxygen (O2) to form a Mo(VI) trioxo complex which in turn is capable of catalytically mediating oxygen transfer. The molybdenum tricarbonyl- and trioxo complexes are investigated in the solid state, in homogeneous solution and on noble metal surfaces (Cu, Au) employing a range of spectroscopic and analytical methods.
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Affiliation(s)
- Kai Uwe Clausen
- Institute of Inorganic Chemistry, Christian-Albrechts-University of Kiel, Max-Eyth Straße 2, 24118, Kiel, Germany
| | - Alexander Schlimm
- Institute of Inorganic Chemistry, Christian-Albrechts-University of Kiel, Max-Eyth Straße 2, 24118, Kiel, Germany
| | - Katja Bedbur
- Institute of Inorganic Chemistry, Christian-Albrechts-University of Kiel, Max-Eyth Straße 2, 24118, Kiel, Germany
| | - Christian Näther
- Institute of Inorganic Chemistry, Christian-Albrechts-University of Kiel, Max-Eyth Straße 2, 24118, Kiel, Germany
| | - Thomas Strunskus
- Department of Material Science, Christian-Albrechts-University of Kiel, Kaiserstraße 1, 24143, Kiel, Germany
| | - Ling Fu
- Institute of Experimental and Applied Physics, Christian-Albrechts-University of Kiel, Leibnizstraße 11-19, 24118, Kiel, Germany
| | - Manuel Gruber
- Faculty of Physics, University of Duisburg-Essen, Lotharstr. 1, 47057, Duisburg, Germany
| | - Richard Berndt
- Institute of Experimental and Applied Physics, Christian-Albrechts-University of Kiel, Leibnizstraße 11-19, 24118, Kiel, Germany
| | - Felix Tuczek
- Institute of Inorganic Chemistry, Christian-Albrechts-University of Kiel, Max-Eyth Straße 2, 24118, Kiel, Germany
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2
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Karbalaei S, Knecht E, Franke A, Zahl A, Saunders AC, Pokkuluri PR, Beyers RJ, Ivanović-Burmazović I, Goldsmith CR. A Macrocyclic Ligand Framework That Improves Both the Stability and T1-Weighted MRI Response of Quinol-Containing H 2O 2 Sensors. Inorg Chem 2021; 60:8368-8379. [PMID: 34042423 DOI: 10.1021/acs.inorgchem.1c00896] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Previously prepared Mn(II)- and quinol-containing magnetic resonance imaging (MRI) contrast agent sensors for H2O2 relied on linear polydentate ligands to keep the redox-activatable quinols in close proximity to the manganese. Although these provide positive T1-weighted relaxivity responses to H2O2 that result from oxidation of the quinol groups to p-quinones, these reactions weaken the binding affinity of the ligands, promoting dissociation of Mn(II) from the contrast agent in aqueous solution. Here, we report a new ligand, 1,8-bis(2,5-dihydroxybenzyl)-1,4,8,11-tetraazacyclotetradecane, that consists of two quinols covalently tethered to a cyclam macrocycle. The macrocycle provides stronger thermodynamic and kinetic barriers for metal-ion dissociation in both the reduced and oxidized forms of the ligand. The Mn(II) complex reacts with H2O2 to produce a more highly aquated Mn(II) species that exhibits a 130% greater r1, quadrupling the percentile response of our next best sensor. With a large excess of H2O2, there is a noticeable induction period before quinol oxidation and r1 enhancement occurs. Further investigation reveals that, under such conditions, catalase activity initially outcompetes ligand oxidation, with the latter occurring only after most of the H2O2 has been depleted.
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Affiliation(s)
- Sana Karbalaei
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States
| | - Erik Knecht
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States
| | - Alicja Franke
- Department of Chemistry, Ludwig-Maximilians-Universität München. Butenandtstrasse 5-13, Haus D 81377 München, Germany
| | - Achim Zahl
- Department of Chemistry and Pharmacy, Friedrich-Alexander University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Alexander C Saunders
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States
| | - P Raj Pokkuluri
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States
| | - Ronald J Beyers
- Magnetic Resonance Imaging Research Center, Auburn University, Auburn, Alabama 36849, United States
| | - Ivana Ivanović-Burmazović
- Department of Chemistry, Ludwig-Maximilians-Universität München. Butenandtstrasse 5-13, Haus D 81377 München, Germany
| | - Christian R Goldsmith
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States
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3
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Li J, Lutz M, Klein Gebbink RJM. A Cp‐based Molybdenum Catalyst for the Deoxydehydration of Biomass‐derived Diols. ChemCatChem 2020. [DOI: 10.1002/cctc.202001115] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Jing Li
- Organic Chemistry and Catalysis Debye Institute for Nanomaterials Science Utrecht University Universiteitsweg 99 3584CG Utrecht The Netherlands
| | - Martin Lutz
- Crystal and Structural Chemistry Bijvoet Centre for Biomolecular Research Faculty of Science Utrecht University Padualaan 8 3584 CH Utrecht The Netherlands
| | - Robertus J. M. Klein Gebbink
- Organic Chemistry and Catalysis Debye Institute for Nanomaterials Science Utrecht University Universiteitsweg 99 3584CG Utrecht The Netherlands
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4
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Sugiarto, Kazakami S, Kawamoto K, Hayashi Y. Stabilization of titanium(IV) and indium(III) complexes by coordination of [MoO3(1,4,7-triazacyclononane)] metalloligand in aqueous solution. Inorganica Chim Acta 2020. [DOI: 10.1016/j.ica.2020.119691] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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5
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Wang J, Gondrand C, Touti F, Hasserodt J. A pair of highly biotolerated diamagnetic and paramagnetic iron(ii) complexes displaying electroneutrality. Dalton Trans 2015; 44:15391-5. [DOI: 10.1039/c5dt02192h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A pair of structurally analogous macrocyclic iron(ii) complexes with a magnetic off-on relationship is reported that exhibit electroneutrality at neutral pH and high stability in physiological media.
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Affiliation(s)
- J. Wang
- Laboratoire de Chimie
- Université de Lyon – ENS
- Lyon
- France
- School of Chemistry and Molecular Engineering
| | - C. Gondrand
- Laboratoire de Chimie
- Université de Lyon – ENS
- Lyon
- France
| | - F. Touti
- Laboratoire de Chimie
- Université de Lyon – ENS
- Lyon
- France
| | - J. Hasserodt
- Laboratoire de Chimie
- Université de Lyon – ENS
- Lyon
- France
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6
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Bjornsson R, Delgado-Jaime MU, Lima FA, Sippel D, Schlesier J, Weyhermüller T, Einsle O, Neese F, DeBeer S. Molybdenum L-Edge XAS Spectra of MoFe Nitrogenase. Z Anorg Allg Chem 2014. [PMID: 26213424 PMCID: PMC4510703 DOI: 10.1002/zaac.201400446] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A molybdenum L-edge X-ray absorption spectroscopy (XAS) study is presented for native and oxidized MoFe protein of nitrogenase as well as Mo-Fe model compounds. Recently collected data on MoFe protein (in oxidized and reduced forms) is compared to previously published Mo XAS data on the isolated FeMo cofactor in NMF solution and put in context of the recent Mo K-edge XAS study, which showed a MoIII assignment for the molybdenum atom in FeMoco. The L3-edge data are interpreted within a simple ligand-field model, from which a time-dependent density functional theory (TDDFT) approach is proposed as a way to provide further insights into the analysis of the molybdenum L3-edges. The calculated results reproduce well the relative spectral trends that are observed experimentally. Ultimately, these results give further support for the MoIII assignment in protein-bound FeMoco, as well as isolated FeMoco.
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Affiliation(s)
- Ragnar Bjornsson
- Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany ; Present address: Science Institute University of Iceland, Dunhaga 3, 107 Reykjavik, Iceland
| | - Mario U Delgado-Jaime
- Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Frederico A Lima
- Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany ; Present address: Centro Nacional de Pesquisa,em Energia e Materiais, Brazilian Synchrotron Light Laboratory - LNLS, CP 6192 13084-971 Campinas, SP, Brazil
| | - Daniel Sippel
- Institute for Biochemistry Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany
| | - Julia Schlesier
- Institute for Biochemistry Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany
| | - Thomas Weyhermüller
- Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Oliver Einsle
- Institute for Biochemistry Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany
| | - Frank Neese
- Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Serena DeBeer
- Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany
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7
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Lima FA, Bjornsson R, Weyhermüller T, Chandrasekaran P, Glatzel P, Neese F, DeBeer S. High-resolution molybdenum K-edge X-ray absorption spectroscopy analyzed with time-dependent density functional theory. Phys Chem Chem Phys 2014; 15:20911-20. [PMID: 24197060 DOI: 10.1039/c3cp53133c] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
X-ray absorption spectroscopy (XAS) is a widely used experimental technique capable of selectively probing the local structure around an absorbing atomic species in molecules and materials. When applied to heavy elements, however, the quantitative interpretation can be challenging due to the intrinsic spectral broadening arising from the decrease in the core-hole lifetime. In this work we have used high-energy resolution fluorescence detected XAS (HERFD-XAS) to investigate a series of molybdenum complexes. The sharper spectral features obtained by HERFD-XAS measurements enable a clear assignment of the features present in the pre-edge region. Time-dependent density functional theory (TDDFT) has been previously shown to predict K-pre-edge XAS spectra of first row transition metal compounds with a reasonable degree of accuracy. Here we extend this approach to molybdenum K-edge HERFD-XAS and present the necessary calibration. Modern pure and hybrid functionals are utilized and relativistic effects are accounted for using either the Zeroth Order Regular Approximation (ZORA) or the second order Douglas-Kroll-Hess (DKH2) scalar relativistic approximations. We have found that both the predicted energies and intensities are in excellent agreement with experiment, independent of the functional used. The model chosen to account for relativistic effects also has little impact on the calculated spectra. This study provides an important calibration set for future applications of molybdenum HERFD-XAS to complex catalytic systems.
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Affiliation(s)
- Frederico A Lima
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, D- 45470, Mülheim an der Ruhr, Germany.
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8
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Thangavel A, Wieliczko M, Bacsa J, Scarborough CC. 1,4,7-Triazacyclononane Ligands Bearing Tertiary Alkyl Nitrogen Substituents. Inorg Chem 2013; 52:13282-7. [PMID: 24187908 DOI: 10.1021/ic402626p] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Arumugam Thangavel
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Marika Wieliczko
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - John Bacsa
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
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9
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Sobieściak TD, Zielenkiewicz P. Double Selective Synthetic Approach to the N-Functionalized 1,4,7-Triazacyclononane Derivatives: Chelating Compounds for Controllable Protein Orientation. J Org Chem 2010; 75:2069-72. [DOI: 10.1021/jo902504d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tomasz D. Sobieściak
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, Warsaw 02-106, Poland
| | - Piotr Zielenkiewicz
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, Warsaw 02-106, Poland
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10
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11
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Kostakis GE, Abbas G, Anson CE, Powell AK. Inclusion of a well resolved T4(2)6(2) water tape in a H-bonded, (4,7)-binodal 3D network. CrystEngComm 2009. [DOI: 10.1039/b811376a] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Gott AL, McGowan PC, Podesta TJ. Controlling the binding of dihydrogen using ruthenium complexes containing N-mono-functionalised 1,4,7-triazacyclononane ligand systems. Dalton Trans 2008:3729-38. [PMID: 18615220 DOI: 10.1039/b804572k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Pendant arm macrocycles derived from 1,4,7-triazacyclononane were reacted with RuHCl(CO)(PPh(3))(3) and RuHCl(PPh(3))(3) to yield air-stable cationic ruthenium hydrides that were characterised by a variety of techniques, including X-ray crystallography. Protonation of the metal hydride complexes with a proton source yielded eta(2)-dihydrogen complexes. The lifetime of the dihydrogen ligand was effected by a judicious choice of ancillary ligands.
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Affiliation(s)
- Andrew L Gott
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, UK LS2 9JT
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13
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Gott AL, McGowan PC, Temple CN. Controlling the Coordination Mode of 1,4,7-Triazacyclononane Complexes of Rhodium and Iridium and Evaluating Their Behavior as Phenylacetylene Polymerization Catalysts. Organometallics 2008. [DOI: 10.1021/om800180a] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andrew L. Gott
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
| | - Patrick C. McGowan
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
| | - Claire N. Temple
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
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14
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Suzuki K, Shimmura N, Thipyapong K, Uehara T, Akizawa H, Arano Y. Assessment of Macrocyclic Triamine Ligands As Synthons for Organometallic 99mTc Radiopharmaceuticals. Inorg Chem 2008; 47:2593-600. [DOI: 10.1021/ic7019654] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Keisuke Suzuki
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, 260-8675 Chiba, Japan, Research Center, Nihon Medi-Physics Co., Ltd., 3-1 Kitasode, Sodegaura-city, 299-0266 Chiba, Japan, and Faculty of Science, Burapha University, Chonburi, 20130, Thailand
| | - Naomi Shimmura
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, 260-8675 Chiba, Japan, Research Center, Nihon Medi-Physics Co., Ltd., 3-1 Kitasode, Sodegaura-city, 299-0266 Chiba, Japan, and Faculty of Science, Burapha University, Chonburi, 20130, Thailand
| | - Khajadpai Thipyapong
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, 260-8675 Chiba, Japan, Research Center, Nihon Medi-Physics Co., Ltd., 3-1 Kitasode, Sodegaura-city, 299-0266 Chiba, Japan, and Faculty of Science, Burapha University, Chonburi, 20130, Thailand
| | - Tomoya Uehara
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, 260-8675 Chiba, Japan, Research Center, Nihon Medi-Physics Co., Ltd., 3-1 Kitasode, Sodegaura-city, 299-0266 Chiba, Japan, and Faculty of Science, Burapha University, Chonburi, 20130, Thailand
| | - Hiromichi Akizawa
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, 260-8675 Chiba, Japan, Research Center, Nihon Medi-Physics Co., Ltd., 3-1 Kitasode, Sodegaura-city, 299-0266 Chiba, Japan, and Faculty of Science, Burapha University, Chonburi, 20130, Thailand
| | - Yasushi Arano
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, 260-8675 Chiba, Japan, Research Center, Nihon Medi-Physics Co., Ltd., 3-1 Kitasode, Sodegaura-city, 299-0266 Chiba, Japan, and Faculty of Science, Burapha University, Chonburi, 20130, Thailand
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15
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Affiliation(s)
- Bin Zhao
- a Department of Chemistry , Nankai University , Tianjin 300071, PR China
| | - Xiao-Yan Chen
- a Department of Chemistry , Nankai University , Tianjin 300071, PR China
| | - Peng Cheng
- a Department of Chemistry , Nankai University , Tianjin 300071, PR China
| | - Bin Ding
- a Department of Chemistry , Nankai University , Tianjin 300071, PR China
| | - Dai-Zheng Liao
- a Department of Chemistry , Nankai University , Tianjin 300071, PR China
| | - Shi-Ping Yan
- a Department of Chemistry , Nankai University , Tianjin 300071, PR China
| | - Zong-Hui Jiang
- a Department of Chemistry , Nankai University , Tianjin 300071, PR China
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16
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Romba J, Kuppert D, Morgenstern B, Neis C, Steinhauser S, Weyhermüller T, Hegetschweiler K. The Coordination Chemistry of 1,4-Diazepan-6-amine. Eur J Inorg Chem 2006. [DOI: 10.1002/ejic.200500690] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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17
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Del Piero S, Melchior A, Polese P, Portanova R, Tolazzi M. N-Methylation Effects on the Coordination Chemistry of Cyclic Triamines with Divalent Transition Metals and Their CoII Dioxygen Carriers. Eur J Inorg Chem 2006. [DOI: 10.1002/ejic.200500675] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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18
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Battle AR, Spiccia L. Molecular structure and hydrolytic stability amidinium salts derived from triazatricyclo[5.2.1.04,10]decane. Tetrahedron 2005. [DOI: 10.1016/j.tet.2005.05.049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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19
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Goldcamp M, Ashley K, Edison S, Pretty J, Shumaker J. A Bis-Oxime Derivative of Diaza-18-Crown-6 as an Ionophore for Silver Ion. ELECTROANAL 2005. [DOI: 10.1002/elan.200403196] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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20
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Anda C, Bencini A, Berni E, Ciattini S, Chuburu F, Danesi A, Giorgi C, Handel H, Le Baccon M, Paoletti P, Tripier R, Turcry V, Valtancoli B. Mono- and Dinuclear CuII and ZnII Complexes of Cyclen-Based Bis(macrocycles) Containing Two Aminoalkyl Pendant Arms of Different Lengths. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200400896] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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21
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Gott AL, McGowan PC, Temple CN. The formation, reactivity and interconversion of novel small eta(1)- and eta(3)-triazacyclononane complexes of rhodium(I) and rhodium(III). Dalton Trans 2004:1841-5. [PMID: 15381989 DOI: 10.1039/b401877j] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have successfully synthesised and characterised a number of eta(1)- and eta(3)-triazacyclononane Rh(I) and Rh(III) derivatives. By using different reaction conditions, we have been able to convert one of the eta(1)-triazacyclononane complexes to an eta(3)-derivative. Also, we have observed a rare example of an addition of an organic fragment to a metal bound ligand to form a quaternary carbon centre.
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Affiliation(s)
- Andrew L Gott
- Department of Chemistry, University of Leeds, Leeds, UK LS2 9JT
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22
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Gott AL, McGowan PC, Podesta TJ, Tate CW. Formation and structural studies of iron(III) and ruthenium(II) complexes of 1,4,7-triazacyclononane and N-monofunctionalised 1,4,7-triazacyclononane. Inorganica Chim Acta 2004. [DOI: 10.1016/j.ica.2003.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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23
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Tei L, Bencini A, Blake AJ, Lippolis V, Perra A, Valtancoli B, Wilson C, Schröder M. Co-ordination chemistry of amino pendant arm derivatives of 1,4,7-triazacyclononane. Dalton Trans 2004:1934-44. [PMID: 15252580 DOI: 10.1039/b404312j] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The binding properties of 1,4,7-triazacyclononane ([9]aneN3) to metal cations can be adapted through sequential functionalisation of the secondary amines with aminoethyl or aminopropyl pendant arms to generate ligands with increasing numbers of donor atoms. The new amino functionalised pendant arm derivative of 1,4,7-triazacyclononane ([9]aneN3), L1, has been synthesised and its salt [H2L1]Cl2 characterised by X-ray diffraction. The protonation constants of the ligands L1-L4 having one, two or three aminoethyl or three aminopropyl pendant arms, respectively, on the [9]aneN3 framework, and the thermodynamic stabilities of their mononuclear complexes with CuII and ZnII have been investigated by potentiometric measurements in aqueous solutions. In order to discern the protonation sites of ligands L1-L4, 1H NMR spectroscopic studies were performed in D2O as a function of pH. While the stability constants of the CuII complexes increase on going from L1 to L2 and then decrease on going from L2 to L3 and L4, those for ZnII complexes increase from L1 to L3 and then decrease for L4. The X-ray crystal structures of the complexes [Cu(L1)(Br)]Br, [Zn(L1)(NO3)]NO3, [Cu(L2)](ClO4)2, [Ni(L2)(MeCN)](BF4)2, [Zn(L4)](BF4)2.MeCN and [Mn(L4)](NO3)2.1/2H2O have been determined. In both [Cu(L1)(Br)]Br and [Zn(L1)(NO3)]NO3 the metal ion is five co-ordinate and bound by four N-donors of the macrocyclic ligand and by one of the two counter-anions. The crystal structures of [Cu(L2)](ClO4)2 and [Ni(L2)(MeCN)](BF4)2 show the metal centre in slightly distorted square-based pyramidal and octahedral geometry, respectively, with a MeCN molecule completing the co-ordination sphere around NiII in the latter. In both [Zn(L4)](BF4)2.MeCN and [Mn(L4)](NO3)2.1/2H2O the metal ion is bound by all six N-donors of the macrocyclic ligand in a distorted octahedral geometry. Interestingly, and in agreement with the solution studies and with the marked preference of CuII to assume a square-based pyramidal geometry with these types of ligands, the reaction of L4 with one equivalent of Cu(BF4)2.4H2O in MeOH at room temperature yields a square-based pyramidal five co-ordinate CuII complex [Cu(L6)](BF4)2 where one of the three propylamino pendant arms of the starting ligand has been cleaved to give L6.
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Affiliation(s)
- Lorenzo Tei
- Dipartimento di Chimica Inorganica ed analitica, University of Cagliari, Complesso Universitario di Monserrato, S. S. 554 Bivio per Sestu, 09042 (CA), Italy
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Partyka DV, Staples RJ, Holm RH. Nucleophilic Reactivity and Oxo/Sulfido Substitution Reactions of MVIO3 Groups (M = Mo, W). Inorg Chem 2003; 42:7877-86. [PMID: 14632504 DOI: 10.1021/ic030185l] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The nucleophilic reactivity of oxo ligands in the groups M(VI)O(3) in the trigonal complexes [(Me(3)tacn)MO(3)] (M = Mo (1), W (10)) and [(Bu(t)(3)tach)MO(3)] (M = Mo (5), W (14)) has been investigated. Complexes 1/10 can be alkylated with MeOTf to give [(Me(3)tacn)MO(2)(OMe)](1+) (2/11), silylated with Pr(i)(3)SiOTf to form [(Me(3)tacn)MO(2)(OSiPr(i)(3))](+) (3/12), and protonated with HOTf to yield [(Me(3)tacn)MoO(2)(OH)](+) (4). Similarly, complexes 5/14 can be silylated to [(Bu(t)(3)tach)MO(2)(OSiPr(i)(3))](+) (6/15) and protonated to [(Bu(t)(3)tach)MO(2)(OH)](+) (7/16). Products were isolated as triflate salts in yields exceeding 70%. When excess acid was used, the dinuclear mu-oxo species [(Bu(t)(3)tach)(2)M(2)O(5)](2+) (8/17) were obtained. X-ray structures are reported for 2-4, 6-8, 12, and 15-17. All mononuclear complexes have dominant trigonal symmetry with a rhombic distortion owing to a M[bond]OR bond (R = Me, SiPr(i)(3), H), which is longer than M[double bond]O oxo interactions; the latter exert a substantial trans influence on M[bond]N bond lengths. Oxo ligands in 5/14 undergo replacement with sulfide. Lawesson's reagent effects formation of [(Bu(t)(3)tach)MS(3)] (9/18), 14 with excess B(2)S(3) yields incompletely substituted [(Bu(t)(3)tach)WOS(2)] (20), and 5 with excess B(2)S(3) yields [(Bu(t)(3)tach)Mo(IV)O(S(4))] (19). The structures of 9, 19, and 20 are reported. Precedents for M(VI)S(3) groups in five- and six-coordinate molecules are limited. This investigation is the first detailed study of the behavior of M(VI)O(3) groups in nucleophilic and oxo/sulfido substitution reactions and should be useful in synthetic approaches to the active sites of the xanthine oxidase enzyme family and of certain tungstoenzymes. (Bu(t)(3)tach = 1,3,5-tri-tert-butyl-1,3,5-triazacyclohexane, Me(3)tacn = 1,4,7-trimethyl-1,4,7-triazacyclonane; OTf = triflate).
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Affiliation(s)
- David V Partyka
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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Iranzo O, Elmer T, Richard JP, Morrow JR. Cooperativity between Metal Ions in the Cleavage of Phosphate Diesters and RNA by Dinuclear Zn(II) Catalysts. Inorg Chem 2003; 42:7737-46. [PMID: 14632489 DOI: 10.1021/ic030131b] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of ligands containing linked 1,4,7-triazacyclononane macrocycles are studied for the preparation of dinuclear Zn(II) complexes including 1,3-bis(1,4,7-triazacyclonon-1-yl)-2-hydroxypropane (L2OH), 1,5-bis(1,4,7-triazacyclonon-1-yl)pentane (L3), 2,9-bis(1-methyl-1,4,7-triazacyclonon-1-yl)-1,10-phenanthroline (L4), and alpha,alpha'-bis(1,4,7-triazacyclonon-1-yl)-m-xylene (L5). The titration of these ligands with Zn(NO(3))(2) was monitored by (1)H NMR. Each ligand was found to bind two Zn(II) ions with a very high affinity at near neutral pH under conditions of millimolar ligand and 2 equiv of Zn(NO(3))(2). In contrast, a stable mononuclear complex was formed in solutions containing 5.0 mM L2OH and 1 equiv of Zn(NO(3))(2). (1)H and (13)C NMR spectral data are consistent with formation of a highly symmetric mononuclear complex Zn(L2OH) in which a Zn(II) ion is sandwiched between two triazacyclononane units. The second-order rate constant k(Zn) for the cleavage of 2-hydroxypropyl-4-nitrophenyl phosphate (HPNP) at pH 7.6 and 25 degrees C catalyzed by Zn(2)(L2O) is 120-fold larger than that for the reaction catalyzed by the closely related mononuclear complex Zn(L1) (L1 = 1,4,7-triazacyclononane). By comparison, the observation that the values of k(Zn) determined under similar reaction conditions for cleavage of HPNP catalyzed by the other Zn(II) dinuclear complexes are only 3-5-fold larger than values of k(Zn) for catalysis by Zn(L1) provides strong evidence that the two Zn(II) cations in Zn(2)(L2O) act cooperatively in the stabilization of the transition state for cleavage of HPNP. The extent of cleavage of an oligoribonucleotide by Zn(L1), Zn(2)(L5), and Zn(2)(L2O) at pH 7.5 and 37 degrees C after 24 h incubation is 4,10, and 90%. The rationale for the observed differences in catalytic activity of these dinuclear Zn(II) complexes is discussed in terms of the mechanism of RNA cleavage and the structure and speciation of these complexes in solution.
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Affiliation(s)
- Olga Iranzo
- Department of Chemistry, University at Buffalo, The State University of New York, Amherst, New York 14260, USA
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