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Kejriwal A. Non-heme iron coordination complexes for alkane oxidation using hydrogen peroxide (H 2O 2) as powerful oxidant. J COORD CHEM 2022. [DOI: 10.1080/00958972.2022.2085567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Ambica Kejriwal
- Department of Chemistry, Raiganj University, Raiganj, West Bengal, India
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2
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Ghosh S, Tran PN, McElheny D, Perez JJ, Nguyen AI. Peptidic Scaffolds Enable Rapid and Multivariate Secondary Sphere Evolution for an Abiotic Metallocatalyst. Inorg Chem 2022; 61:6679-6687. [PMID: 35446044 DOI: 10.1021/acs.inorgchem.2c00901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Metalloenzymes have benefited from the iterative process of evolution to achieve the precise arrangements of secondary sphere non-covalent interactions that enhance metal-centered catalysis. Iterative synthesis of scaffolds that display complex secondary sphere elements in abiotic systems can be highly challenging and time-intensive. To overcome this synthetic bottleneck, we developed a highly modular and rapid synthetic strategy, leveraging the efficiency of solid-phase peptide synthesis and conformational control afforded by non-canonical residues to construct a ligand platform displaying up to four unique residues of varying electronics and sterics in the secondary coordination sphere. As a proof-of-concept that peptidic secondary sphere can cooperate with the metal complex, we applied this scaffold to a well-known, modestly active C-H oxidizing Fe catalyst to evolve specific non-covalent interactions that is more than double its catalytic activity. Solution-state NMR structures of several catalyst variants suggest that higher activity is correlated with a hydrophobic pocket above the Fe center that may enhance the formation of a catalyst-substrate complex. Above all, we show that peptides are a convenient, highly modular, and structurally defined ligand platform for creating secondary coordination spheres that comprise multiple, diverse functional groups.
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Affiliation(s)
- Sabari Ghosh
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Phuong Nguyen Tran
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Dan McElheny
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Juan J Perez
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Andy I Nguyen
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, United States
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3
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Keisers K, Hüppe HM, Iffland-Mühlhaus L, Hoffmann A, Göbel C, Apfel UP, Weber B, Herres-Pawlis S. Interplay of Spin Crossover and Coordination-Induced Spin State Switch for Iron Bis(pyrazolyl)methanes in Solution. Inorg Chem 2020; 59:15343-15354. [PMID: 33002361 DOI: 10.1021/acs.inorgchem.0c02306] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Bis(pyrazolyl)bipyridinylmethane iron(II) complexes show a versatile spin state switching behavior in different solvents. In the solid, the magnetic properties of the compounds have been characterized by X-ray diffraction, Mößbauer spectroscopy, and SQUID magnetometry and point toward a high spin state. For nitrilic solvents, the solvation of the complexes leads to a change of the coordination environment from {N5O} to {N6} and results in a temperature-dependent SCO behavior. Thermodynamic properties of this transformation are obtained via UV/vis spectroscopy, SQUID measurements, and the Evans NMR method. Moreover, a coordination-induced spin state switch (CISSS) to low spin is observed by using methanol as solvent, triggered through a rearrangement of the coordination sphere. The same behavior can be observed by changing the stoichiometry of the ligand-to-metal ratio in MeCN, where the process is reversible. This transformation is monitored via UV/vis spectroscopy, and the resulting new bis-meridional coordination motif, first described for bis(pyrazolyl)methanes, is characterized in the solid state via X-ray diffraction, Mößbauer spectroscopy, and SQUID measurements. The sophisticated correlation of these switchable properties in dependence on different types of solvents reveals that the influence of the solvent on the coordination environment and magnetic properties should not be underestimated. Furthermore, careful investigation is necessary to differentiate between a thermally-induced spin crossover and a coordination-induced spin state switch.
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Affiliation(s)
- Kristina Keisers
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany
| | - Henrika M Hüppe
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany
| | - Linda Iffland-Mühlhaus
- Inorganic Chemistry I, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany
| | - Alexander Hoffmann
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany
| | - Christoph Göbel
- Department of Chemistry, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Ulf-Peter Apfel
- Inorganic Chemistry I, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany.,Fraunhofer UMSICHT, Osterfelder Straße 3, 46047 Oberhausen, Germany
| | - Birgit Weber
- Department of Chemistry, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Sonja Herres-Pawlis
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany
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4
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Vicens L, Olivo G, Costas M. Rational Design of Bioinspired Catalysts for Selective Oxidations. ACS Catal 2020. [DOI: 10.1021/acscatal.0c02073] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Laia Vicens
- Institut de Quı́mica Computacional i Catàlisi (IQCC) and Departament de Quı́mica, Universitat de Girona, Campus de Montilivi, 17071 Girona, Spain
| | - Giorgio Olivo
- Institut de Quı́mica Computacional i Catàlisi (IQCC) and Departament de Quı́mica, Universitat de Girona, Campus de Montilivi, 17071 Girona, Spain
| | - Miquel Costas
- Institut de Quı́mica Computacional i Catàlisi (IQCC) and Departament de Quı́mica, Universitat de Girona, Campus de Montilivi, 17071 Girona, Spain
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5
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Payard P, Zheng Y, Zhou W, Khrouz L, Bonneviot L, Wischert R, Grimaud L, Pera‐Titus M. Iron Triflate Salts as Highly Active Catalysts for the Solvent‐Free Oxidation of Cyclohexane. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000263] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Pierre‐Adrien Payard
- Eco‐Efficient Products and Processes Laboratory (E2P2L) UMI 3464 CNRS Solvay 3966 Jin Du Road, Xin Zhuang Ind Zone 201108 Shanghai China
- Laboratoire des Biomolécules LBM PSL University, Sorbonne Université 24 rue Lhomond 75005 Paris France
| | - Yu‐Ting Zheng
- Eco‐Efficient Products and Processes Laboratory (E2P2L) UMI 3464 CNRS Solvay 3966 Jin Du Road, Xin Zhuang Ind Zone 201108 Shanghai China
| | - Wen‐Juan Zhou
- Eco‐Efficient Products and Processes Laboratory (E2P2L) UMI 3464 CNRS Solvay 3966 Jin Du Road, Xin Zhuang Ind Zone 201108 Shanghai China
| | - Lhoussain Khrouz
- Université Claude Bernard Lyon 1, Laboratoire de Chimie LBM Univ Lyon, ENS de Lyon, CNRS UMR 5182 46 Allée d'Italie 69342 Lyon France
| | - Laurent Bonneviot
- Université Claude Bernard Lyon 1, Laboratoire de Chimie LBM Univ Lyon, ENS de Lyon, CNRS UMR 5182 46 Allée d'Italie 69342 Lyon France
| | - Raphael Wischert
- Eco‐Efficient Products and Processes Laboratory (E2P2L) UMI 3464 CNRS Solvay 3966 Jin Du Road, Xin Zhuang Ind Zone 201108 Shanghai China
| | - Laurence Grimaud
- Laboratoire des Biomolécules LBM PSL University, Sorbonne Université 24 rue Lhomond 75005 Paris France
| | - Marc Pera‐Titus
- Eco‐Efficient Products and Processes Laboratory (E2P2L) UMI 3464 CNRS Solvay 3966 Jin Du Road, Xin Zhuang Ind Zone 201108 Shanghai China
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6
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Chen L, Dulaney HA, Wilkins BO, Farmer S, Zhang Y, Fronczek FR, Jurss JW. High-spin enforcement in first-row metal complexes of a constrained polyaromatic ligand: synthesis, structure, and properties. NEW J CHEM 2018. [DOI: 10.1039/c8nj02072h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The coordination chemistry of a rigid tetradentate polypyridyl ligand has been developed with first-row transition metals Mn(ii), Fe(ii), Co(ii), Ni(ii), and Zn(ii).
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Affiliation(s)
- Lizhu Chen
- Department of Chemistry and Biochemistry
- University of Mississippi
- University
- USA
| | - Hunter A. Dulaney
- Department of Chemistry and Biochemistry
- University of Mississippi
- University
- USA
| | | | - Sarah Farmer
- Department of Chemistry and Biochemistry
- University of Mississippi
- University
- USA
| | - Yanbing Zhang
- Department of Chemistry and Biochemistry
- University of Mississippi
- University
- USA
| | | | - Jonah W. Jurss
- Department of Chemistry and Biochemistry
- University of Mississippi
- University
- USA
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7
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Speciation in iron epoxidation catalysis: A perspective on the discovery and role of non-heme iron(III)-hydroperoxo species in iron-catalyzed oxidation reactions. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.09.015] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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8
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Li J, Banerjee A, Hasse TA, Loloee R, Biros SM, Staples RJ, Chavez FA. Synthesis and reactivity of a 4His enzyme model complex. RSC Adv 2017; 7:50713-50719. [PMID: 29147561 PMCID: PMC5683714 DOI: 10.1039/c7ra09456f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A new iron(II) complex has been prepared and characterized. [Fe(TrIm)4(OTf)2] (1, TrIm = 1-Tritylimidazole). The solid state structure of 1 has been determined by X-ray crystallography. Compound 1 crystallizes in triclinic space group P1̄, with a = 13.342(7) Å, b = 13.5131(7) Å and c = 13.7025(7) Å. The iron center resides in distorted octahedral geometry coordinated to four equatorial imidazole groups and two axial triflate oxygens groups. The complex is high spin between 20 K and 300 K as indicated by variable field variable temperature magnetic measurements. A fit of the magnetic data yielded g = 2.24 and D = -0.80 cm-1. A large HOMO-LUMO gap energy (3.89 eV) exists for 1 indicating high stability. Addition of H2O2 or t BuOOH to 1 results in formation of an oxygenated intermediate which upon decomposition results in oxidation of the trityl substituent on the imidazole ligand.
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Affiliation(s)
- Jia Li
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA, , Ph: (248) 370-4092
| | - Atanu Banerjee
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA, , Ph: (248) 370-4092
| | - Timothy A Hasse
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA, , Ph: (248) 370-4092
| | - Reza Loloee
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA
| | - Shannon M Biros
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
| | - Richard J Staples
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
| | - Ferman A Chavez
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA, , Ph: (248) 370-4092
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9
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Li J, Molenda MA, Biros SM, Staples RJ, Chavez FA. Assembly of a mononuclear ferrous site using a bulky aldehyde-imidazole ligand. Inorganica Chim Acta 2017; 464:152-156. [PMID: 29238096 PMCID: PMC5724793 DOI: 10.1016/j.ica.2017.05.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A new iron(II) complex has been prepared and characterized. [Fe(TrImA)2(OTf)2] (1, TrImA = 1-Tritylimidazole-4-carboxaldehyde). The solid state structure of 1 has been determined by X-ray crystallography. Compound 1 crystallizes in monoclinic space group P21/c, with a = 10.8323(18) Å, b = 8.1606(13) Å and c = 24.818(4) Å. The iron center is coordinated to two imidazole groups, two pendant aldehyde-derived carbonyl oxygens and two triflate oxygens. The complex is high spin between 300 and 20 K as indicated by variable field variable temperature magnetic measurements. A fit of the magnetic data yielded g = 2.17 and D = 4.05 cm-1. A large HOMO-LUMO gap energy (4.49 eV) exists for 1 indicating high stability.
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Affiliation(s)
- Jia Li
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA
| | - Monika A Molenda
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA
| | - Shannon M Biros
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
| | - Richard J Staples
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
| | - Ferman A Chavez
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA
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10
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Song Y, Mayes HG, Queensen MJ, Bauer EB, Dupureur CM. Spectroscopic investigation and direct comparison of the reactivities of iron pyridyl oxidation catalysts. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2017; 174:130-137. [PMID: 27889672 DOI: 10.1016/j.saa.2016.11.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 11/06/2016] [Accepted: 11/16/2016] [Indexed: 06/06/2023]
Abstract
The growing interest in green chemistry has fueled attention to the development and characterization of effective iron complex oxidation catalysts. A number of iron complexes are known to catalyze the oxidation of organic substrates utilizing peroxides as the oxidant. Their development is complicated by a lack of direct comparison of the reactivities of the iron complexes. To begin to correlate reactivity with structural elements, we compare the reactivities of a series of iron pyridyl complexes toward a single dye substrate, malachite green (MG), for which colorless oxidation products are established. Complexes with tetradentate, nitrogen-based ligands with cis open coordination sites were found to be the most reactive. While some complexes reflect sensitivity to different peroxides, others are similarly reactive with either H2O2 or tBuOOH, which suggests some mechanistic distinctions. [Fe(S,S-PDP)(CH3CN)2](SbF6)2 and [Fe(OTf)2(tpa)] transition under the oxidative reaction conditions to a single intermediate at a rate that exceeds dye degradation (PDP=bis(pyridin-2-ylmethyl) bipyrrolidine; tpa=tris(2-pyridylmethyl)amine). For the less reactive [Fe(OTf)2(dpa)] (dpa=dipicolylamine), this reaction occurs on a timescale similar to that of MG oxidation. Thus, the spectroscopic method presented herein provides information about the efficiency and mechanism of iron catalyzed oxidation reactions as well as about potential oxidative catalyst decomposition and chemical changes of the catalyst before or during the oxidation reaction.
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Affiliation(s)
- Yang Song
- Department of Chemistry & Biochemistry, University of Missouri St. Louis, St. Louis, MO 63121, United States; Center for Nanoscience, University of Missouri St. Louis, St. Louis, MO 63121, United States
| | - Howard G Mayes
- Department of Chemistry & Biochemistry, University of Missouri St. Louis, St. Louis, MO 63121, United States; Center for Nanoscience, University of Missouri St. Louis, St. Louis, MO 63121, United States
| | - Matthew J Queensen
- Department of Chemistry & Biochemistry, University of Missouri St. Louis, St. Louis, MO 63121, United States
| | - Eike B Bauer
- Department of Chemistry & Biochemistry, University of Missouri St. Louis, St. Louis, MO 63121, United States.
| | - Cynthia M Dupureur
- Department of Chemistry & Biochemistry, University of Missouri St. Louis, St. Louis, MO 63121, United States; Center for Nanoscience, University of Missouri St. Louis, St. Louis, MO 63121, United States.
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11
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Oxidation of alkane and alkene moieties with biologically inspired nonheme iron catalysts and hydrogen peroxide: from free radicals to stereoselective transformations. J Biol Inorg Chem 2017; 22:425-452. [DOI: 10.1007/s00775-016-1434-z] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 12/27/2016] [Indexed: 11/26/2022]
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12
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Chakraborty B, Jana RD, Singh R, Paria S, Paine TK. Reductive Activation of O2 by Non-Heme Iron(II) Benzilate Complexes of N4 Ligands: Effect of Ligand Topology on the Reactivity of O2-Derived Oxidant. Inorg Chem 2016; 56:359-371. [DOI: 10.1021/acs.inorgchem.6b02282] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Biswarup Chakraborty
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Rahul Dev Jana
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Reena Singh
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Sayantan Paria
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Tapan Kanti Paine
- 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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13
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Petzold H, Djomgoue P, Hörner G, Speck JM, Rüffer T, Schaarschmidt D. (1)H NMR spectroscopic elucidation in solution of the kinetics and thermodynamics of spin crossover for an exceptionally robust Fe(2+) complex. Dalton Trans 2016; 45:13798-809. [PMID: 27506162 DOI: 10.1039/c6dt01895e] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of Fe(2+) spin crossover (SCO) complexes [Fe(5/6)](2+) employing hexadentate ligands (5/6) with cis/trans-1,2-diamino cyclohexanes (4) as central building blocks were synthesised. The ligands were obtained by reductive amination of 4 with 2,2'-bipyridyl-6-carbaldehyde or 1,10-phenanthroline-2-carbaldehyde 3. The chelating effect and the rigid structure of the ligands 5/6 lead to exceptionally robust Fe(2+) and Zn(2+) complexes conserving their structure even in coordinating solvents like dmso at high temperatures. Their solution behavior was investigated using variable temperature (VT) (1)H NMR spectroscopy and VT Vis spectroscopy. SCO behavior was found for all Fe(2+) complexes in this series centred around and far above room temperature. For the first time we have demonstrated that the thermodynamics as well as kinetics for SCO can be deduced by using VT (1)H NMR spectroscopy. An alternative scheme using a linear correction term C(1) to model chemical shifts for Fe(2+) SCO complexes is presented. The rate constant for the SCO of [Fe(rac-trans-5)](2+) obtained by VT (1)H NMR was validated by Laser Flash Photolysis (LFP), with excellent agreement (1/(kHL + kLH) = 33.7/35.8 ns for NMR/LFP). The solvent dependence of the transition temperature T1/2 and the solvatochromism of complex [Fe(rac-trans-5)](2+) were ascribed to hydrogen bond formation of the secondary amine to the solvent. Enantiomerically pure complexes can be prepared starting with R,R- or S,S-1,2-diaminocyclohexane (R,R-trans-4 or S,S-trans-4). The high robustness of the complexes reduces a possible ligand scrambling and allows preparation of quasiracemic crystals of [Zn(R,R-5)][Fe(S,S-5)](ClO4)4·(CH3CN) composed of a 1 : 1 mixture of the Zn and Fe complexes with inverse chirality.
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Affiliation(s)
- Holm Petzold
- TU Chemnitz, Institut für Chemie, Anorganische Chemie, Straße der Nationen 62, 09111 Chemnitz, Germany.
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14
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Kong DL, Cheng L, Yue T, Wu HR, Feng WC, Wang D, Liu L. Cobalt-Catalyzed Peroxidation of 2-Oxindoles with Hydroperoxides. J Org Chem 2016; 81:5337-44. [DOI: 10.1021/acs.joc.6b00622] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- De-Long Kong
- Beijing
National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory
of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Liang Cheng
- Beijing
National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory
of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Tao Yue
- Chemical Technology Academy of Shandong Province, Jinan 250014, China
| | - Hong-Ru Wu
- Beijing
National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory
of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Wei-Chun Feng
- Chemical Technology Academy of Shandong Province, Jinan 250014, China
| | - Dong Wang
- Beijing
National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory
of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Li Liu
- Beijing
National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory
of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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15
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Olivo G, Lanzalunga O, Di Stefano S. Non-Heme Imine-Based Iron Complexes as Catalysts for Oxidative Processes. Adv Synth Catal 2016. [DOI: 10.1002/adsc.201501024] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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16
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Sarkar T, Butcher RJ, Banerjee S, Mukherjee S, Hussain A. Visible light-induced cytotoxicity of a dinuclear iron(III) complex of curcumin with low-micromolar IC50 value in cancer cells. Inorganica Chim Acta 2016. [DOI: 10.1016/j.ica.2015.09.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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17
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Olivo G, Nardi M, Vìdal D, Barbieri A, Lapi A, Gómez L, Lanzalunga O, Costas M, Di Stefano S. C-H Bond Oxidation Catalyzed by an Imine-Based Iron Complex: A Mechanistic Insight. Inorg Chem 2015; 54:10141-52. [PMID: 26457760 DOI: 10.1021/acs.inorgchem.5b01500] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A family of imine-based nonheme iron(II) complexes (LX)2Fe(OTf)2 has been prepared, characterized, and employed as C-H oxidation catalysts. Ligands LX (X = 1, 2, 3, and 4) stand for tridentate imine ligands resulting from spontaneous condensation of 2-pycolyl-amine and 4-substituted-2-picolyl aldehydes. Fast and quantitative formation of the complex occurs just upon mixing aldehyde, amine, and Fe(OTf)2 in a 2:2:1 ratio in acetonitrile solution. The solid-state structures of (L1)2Fe(OTf)(ClO4) and (L3)2Fe(OTf)2 are reported, showing a low-spin octahedral iron center, with the ligands arranged in a meridional fashion. (1)H NMR analyses indicate that the solid-state structure and spin state is retained in solution. These analyses also show the presence of an amine-imine tautomeric equilibrium. (LX)2Fe(OTf)2 efficiently catalyze the oxidation of alkyl C-H bonds employing H2O2 as a terminal oxidant. Manipulation of the electronic properties of the imine ligand has only a minor impact on efficiency and selectivity of the oxidative process. A mechanistic study is presented, providing evidence that C-H oxidations are metal-based. Reactions occur with stereoretention at the hydroxylated carbon and selectively at tertiary over secondary C-H bonds. Isotopic labeling analyses show that H2O2 is the dominant origin of the oxygen atoms inserted in the oxygenated product. Experimental evidence is provided that reactions involve initial oxidation of the complexes to the ferric state, and it is proposed that a ligand arm dissociates to enable hydrogen peroxide binding and activation. Selectivity patterns and isotopic labeling studies strongly suggest that activation of hydrogen peroxide occurs by heterolytic O-O cleavage, without the assistance of a cis-binding water or alkyl carboxylic acid. The sum of these observations provides sound evidence that controlled activation of H2O2 at (LX)2Fe(OTf)2 differs from that occurring in biomimetic iron catalysts described to date.
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Affiliation(s)
- Giorgio Olivo
- Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza" and Istituto CNR di Metodologie Chimiche (IMC-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza", P.le A. Moro 5, I-00185 Rome, Italy.,Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona , Campus de Montilivi, 17071 Girona, Spain
| | - Martina Nardi
- Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza" and Istituto CNR di Metodologie Chimiche (IMC-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza", P.le A. Moro 5, I-00185 Rome, Italy
| | - Diego Vìdal
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona , Campus de Montilivi, 17071 Girona, Spain
| | - Alessia Barbieri
- Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza" and Istituto CNR di Metodologie Chimiche (IMC-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza", P.le A. Moro 5, I-00185 Rome, Italy
| | - Andrea Lapi
- Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza" and Istituto CNR di Metodologie Chimiche (IMC-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza", P.le A. Moro 5, I-00185 Rome, Italy.,Consortium of Chemical Catalysis and Reactivity, CIRCC Interuniversity , Via Celso Ulpiani 27, 70126 Bari, Italy
| | - Laura Gómez
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona , Campus de Montilivi, 17071 Girona, Spain.,Serveis Tècnics de Recerca (STR), Universitat de Girona , Parc Cientı́fic i Tecnològic, E-17003 Girona, Spain
| | - Osvaldo Lanzalunga
- Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza" and Istituto CNR di Metodologie Chimiche (IMC-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza", P.le A. Moro 5, I-00185 Rome, Italy.,Consortium of Chemical Catalysis and Reactivity, CIRCC Interuniversity , Via Celso Ulpiani 27, 70126 Bari, Italy
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona , Campus de Montilivi, 17071 Girona, Spain
| | - Stefano Di Stefano
- Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza" and Istituto CNR di Metodologie Chimiche (IMC-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza", P.le A. Moro 5, I-00185 Rome, Italy.,Consortium of Chemical Catalysis and Reactivity, CIRCC Interuniversity , Via Celso Ulpiani 27, 70126 Bari, Italy
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18
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Lindhorst AC, Haslinger S, Kühn FE. Molecular iron complexes as catalysts for selective C–H bond oxygenation reactions. Chem Commun (Camb) 2015; 51:17193-212. [DOI: 10.1039/c5cc07146a] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This feature article summarises recent developments in homogeneous C–H bond oxygenation catalysed by molecular iron complexes.
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Affiliation(s)
- A. C. Lindhorst
- Chair of Inorganic Chemistry/Molecular Catalysis
- Technische Universität München (TUM)
- Department of Chemistry/Catalysis Research Center
- D-85747 Garching bei München
- Germany
| | - S. Haslinger
- Chair of Inorganic Chemistry/Molecular Catalysis
- Technische Universität München (TUM)
- Department of Chemistry/Catalysis Research Center
- D-85747 Garching bei München
- Germany
| | - Fritz E. Kühn
- Chair of Inorganic Chemistry/Molecular Catalysis
- Technische Universität München (TUM)
- Department of Chemistry/Catalysis Research Center
- D-85747 Garching bei München
- Germany
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19
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Tang Z, Mandal S, Paul ND, Lutz M, Li P, van der Vlugt JI, de Bruin B. Rhodium catalysed conversion of carbenes into ketenes and ketene imines using PNN pincer complexes. Org Chem Front 2015. [DOI: 10.1039/c5qo00287g] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PNN pincer-type rhodium complexes catalyze ketene and ketene imine synthesis, using CO or an isocyanide and a carbene precursor.
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Affiliation(s)
- Z. Tang
- Supramolecular
- Homogeneous & Bio-inspired Catalysis
- van't Hoff Institute for Molecular Sciences
- University of Amsterdam
- The Netherlands
| | - S. Mandal
- Supramolecular
- Homogeneous & Bio-inspired Catalysis
- van't Hoff Institute for Molecular Sciences
- University of Amsterdam
- The Netherlands
| | - N. D. Paul
- Supramolecular
- Homogeneous & Bio-inspired Catalysis
- van't Hoff Institute for Molecular Sciences
- University of Amsterdam
- The Netherlands
| | - M. Lutz
- Crystal and Structural Chemistry
- Bijvoet Center for Biomolecular Research
- Utrecht University
- Utrecht
- The Netherlands
| | - P. Li
- Supramolecular
- Homogeneous & Bio-inspired Catalysis
- van't Hoff Institute for Molecular Sciences
- University of Amsterdam
- The Netherlands
| | - J. I. van der Vlugt
- Supramolecular
- Homogeneous & Bio-inspired Catalysis
- van't Hoff Institute for Molecular Sciences
- University of Amsterdam
- The Netherlands
| | - B. de Bruin
- Supramolecular
- Homogeneous & Bio-inspired Catalysis
- van't Hoff Institute for Molecular Sciences
- University of Amsterdam
- The Netherlands
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20
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21
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Ganeshpandian M, Ramakrishnan S, Palaniandavar M, Suresh E, Riyasdeen A, Akbarsha MA. Mixed ligand copper(II) complexes of 2,9-dimethyl-1,10-phenanthroline: Tridentate 3N primary ligands determine DNA binding and cleavage and cytotoxicity. J Inorg Biochem 2014; 140:202-12. [DOI: 10.1016/j.jinorgbio.2014.07.021] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 07/29/2014] [Accepted: 07/30/2014] [Indexed: 10/24/2022]
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22
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McArthur S, Baird MC. Oxyfunctionalization of polystyrene by hydrogen peroxide using non-heme iron catalysts. Eur Polym J 2014. [DOI: 10.1016/j.eurpolymj.2014.03.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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23
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Heider S, Petzold H, Speck JM, Rüffer T, Schaarschmidt D. Modification of a Hexadentate Amine based Ligand System byN-Methylation and Effects on Spin State and Redox Behavior of the Corresponding Transition Metal Complexes. Z Anorg Allg Chem 2014. [DOI: 10.1002/zaac.201300615] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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24
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Grau M, Kyriacou A, Cabedo Martinez F, de Wispelaere IM, White AJP, Britovsek GJP. Unraveling the origins of catalyst degradation in non-heme iron-based alkane oxidation. Dalton Trans 2014; 43:17108-19. [DOI: 10.1039/c4dt02067g] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of iron(ii) complexes with tetradentate and pentadentate pyridyl amine ligands has been used for the oxidation of cyclohexane with hydrogen peroxide. Ligand degradation is observed under oxidising conditions via oxidative N-dealkylation.
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Affiliation(s)
- Michaela Grau
- Department of Chemistry
- Imperial College London
- London, UK
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25
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Lenze M, Sedinkin SL, Bauer EB. Polydentate pyridyl ligands and the catalytic activity of their iron(II) complexes in oxidation reactions utilizing peroxides as the oxidants. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.molcata.2013.03.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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26
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Non-heme iron catalysis in C C, C–H, and CH2 oxidation reactions. Oxidative transformations on terpenoids catalyzed by Fe(bpmen)(OTf)2. Tetrahedron 2013. [DOI: 10.1016/j.tet.2013.02.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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27
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Silva AR, Mourão T, Rocha J. Oxidation of cyclohexane by transition-metal complexes with biomimetic ligands. Catal Today 2013. [DOI: 10.1016/j.cattod.2012.07.043] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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28
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Heider S, Petzold H, Teucher G. A Bis(hexadentate) Biphenyl-Based N12Ligand and Its FeIIComplexes. Eur J Inorg Chem 2013. [DOI: 10.1002/ejic.201201443] [Citation(s) in RCA: 10] [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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29
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Heider S, Petzold H, Chastanet G, Schlamp S, Rüffer T, Weber B, Létard JF. Biphenyl bridged hexadentate N6-ligands – a rigid ligand backbone for Fe(ii) spin crossover complexes. Dalton Trans 2013; 42:8575-84. [DOI: 10.1039/c2dt32451b] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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30
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Shul'pin GB. C–H functionalization: thoroughly tuning ligands at a metal ion, a chemist can greatly enhance catalyst's activity and selectivity. Dalton Trans 2013; 42:12794-818. [DOI: 10.1039/c3dt51004b] [Citation(s) in RCA: 155] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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31
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Iron(II) α-Aminopyridine Complexes and Their Catalytic Activity in Oxidation Reactions: A Comparative Study of Activity and Ligand Decomposition. Chempluschem 2012. [DOI: 10.1002/cplu.201200244] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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32
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Dehghanpour S, Afshariazar F, Assoud J. Reduction of 2,2′-dinitrobiphenyl with hydrazine hydrate catalyzed by Pd/C: Cobalt(II), zinc(II) and mercury(II) complexes with benzo[c]cinnoline and N2,N2′-bis(3-phenylallylidene)biphenyl-2,2′-diamine. Polyhedron 2012. [DOI: 10.1016/j.poly.2011.12.041] [Citation(s) in RCA: 4] [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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33
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Company A, Lloret J, Gómez L, Costas M. Alkane C–H Oxygenation Catalyzed by Transition Metal Complexes. CATALYSIS BY METAL COMPLEXES 2012. [DOI: 10.1007/978-90-481-3698-8_5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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34
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Zhang Q, Gorden JD, Beyers RJ, Goldsmith CR. Manganese(II)-containing MRI contrast agent employing a neutral and non-macrocyclic ligand. Inorg Chem 2011; 50:9365-73. [PMID: 21888331 DOI: 10.1021/ic2009495] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The ligand N,N'-bis(2-pyridylmethyl)-bis(ethylacetate)-1,2-ethanediamine (debpn) coordinates divalent transition metal ions in either a pentadentate or hexadentate fashion. The coordination number correlates with the ionic radius of the metal ion, with larger cations being heptacoordinate as assessed by solid-state analysis. With Mn(II), the debpn ligand is hexadentate and remains bound to the oxophilic metal ion, even when dissolved in water. The ligand's incomplete coordination of the manganous ion allows water molecules to coordinate to the metal center. These two properties, coupled with the high paramagnetism associated with the S = 5/2 metal center, enable [Mn(debpn)(H(2)O)](ClO(4))(2) to serve as a stable and effective magnetic resonance imaging contrast agent despite the ligand's lack of both a macrocyclic component and an anionic charge.
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Affiliation(s)
- Qiao Zhang
- Department of Chemistry & Biochemistry, Auburn University, Auburn, Alabama 36849, United States
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35
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Marlier EE, Tereniak SJ, Ding K, Milliken JE, Mulliken JE, Lu CC. First-row transition-metal chloride complexes of the wide bite-angle diphosphine (iPr)DPDBFphos and reactivity studies of monovalent nickel. Inorg Chem 2011; 50:9290-9. [PMID: 21879709 DOI: 10.1021/ic200589e] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The diphosphine 4,6-bis(3-diisopropylphosphinophenyl)dibenzofuran (abbreviated as (iPr)DPDBFphos) has been metalated with transition metal dichlorides of zinc, cobalt, and nickel to yield ((iPr)DPDBFphos)MCl(2) complexes. Within these compounds, the diphosphine (iPr)DPDBFphos adapts a wide range of bite angles (115 to 180°) as determined by X-ray crystallography. A three-coordinate planar Ni(I) species was isolated from the reduction of ((iPr)DPDBFphos)NiCl(2) with KC(8). Low-temperature electron paramagnetic resonance (EPR) measurements of ((iPr)DPDBFphos)NiCl allow the determination of g values (2.09, 2.14, 2.37) and hyperfine coupling constants to two (31)P nuclei, A(iso) = 46 × 10(-4) cm(-1), and one (37)Cl/(35)Cl nucleus, A = (12, 0.7, 35) × 10(-4) cm(-1). Density functional theory (DFT) studies reveal the nature of the magnetic orbital to be d(xy), which has σ-antibonding and π(∥)-antibonding interactions with the phosphorus and chloride atoms, respectively. The monovalent nickel complex reacts with substrates containing C-X bonds; and in the case of vinyl chloride, a Ni(II) vinyl species ((iPr)DPDBFphos)Ni(CH═CH(2))Cl is generated along with the Ni(II) dichloride complex. The monovalent Ni(I) chloride is an active catalyst in the Kumada cross-coupling reaction of vinyl chloride and phenyl Grignard reagent.
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Affiliation(s)
- Elodie E Marlier
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States
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36
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Hong S, Lee YM, Cho KB, Sundaravel K, Cho J, Kim MJ, Shin W, Nam W. Ligand Topology Effect on the Reactivity of a Mononuclear Nonheme Iron(IV)-Oxo Complex in Oxygenation Reactions. J Am Chem Soc 2011; 133:11876-9. [DOI: 10.1021/ja204008u] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Seungwoo Hong
- Department of Bioinspired Science, Ewha Womans University, Seoul 120-750, Korea
- Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul 121-742, Korea
| | - Yong-Min Lee
- Department of Bioinspired Science, Ewha Womans University, Seoul 120-750, Korea
| | - Kyung-Bin Cho
- Department of Bioinspired Science, Ewha Womans University, Seoul 120-750, Korea
| | | | - Jaeheung Cho
- Department of Bioinspired Science, Ewha Womans University, Seoul 120-750, Korea
| | - Myoung Jin Kim
- Department of Bioinspired Science, Ewha Womans University, Seoul 120-750, Korea
| | - Woonsup Shin
- Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul 121-742, Korea
| | - Wonwoo Nam
- Department of Bioinspired Science, Ewha Womans University, Seoul 120-750, Korea
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37
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Granum DM, Riedel PJ, Crawford JA, Mahle TK, Wyss CM, Begej AK, Arulsamy N, Pierce BS, Mehn MP. Synthesis and characterization of sterically encumbered β-ketoiminate complexes of iron(II) and zinc(II). Dalton Trans 2011; 40:5881-90. [PMID: 21541436 DOI: 10.1039/c1dt10024f] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The synthesis, structure, and spectroscopic signatures of a series of four-coordinate iron(II) complexes of β-ketoiminates and their zinc(II) analogues are presented. An unusual five-coordinate iron(II) triflate with three oxygen bound protonated β-ketoimines is also synthesized and structurally characterized. Single-crystal X-ray crystallographic analysis reveals that the deprotonated bis(chelate)metal complexes are four-coordinate with various degrees of distortion depending on the degree of steric bulk and the electronics of the metal center. Each of the high-spin iron(II) centers exhibits multiple electronic transitions including ligand π to π*, metal-to-ligand charge transfer, and spin-forbidden d-d bands. The (1)H NMR spectra of the paramagnetic high-spin iron(II) centers are assigned on the basis of chemical shifts, longitudinal relaxation times (T(1)), relative integrations, and substitution of the ligands. The electrochemical studies support variations in the ligand strength. Parallel mode EPR measurements for the isopropyl substituted ligand complex of iron(II) show low-field resonances (g > 9.5) indicative of complex aggregation or crystallite formation. No suitable solvent system or glassing mixture was found to remedy this phenomenon. However, the bulkier diisopropylphenyl substituted ligand exhibits an integer spin signal consistent with an isolated iron(ii) center [S = 2; D = -7.1 ± 0.8 cm(-1); E/D = 0.1]. A tentative molecular orbital diagram is assembled.
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Affiliation(s)
- David M Granum
- Department of Chemistry, University of Wyoming, Laramie, Wyoming 82071, USA
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38
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Abstract
Manganese(II) chloride reacts with trimethylsilyl triflate (TMS(OTf) where OTf = (-)OSO(2)CF(3)) in a 1:1 mixture of acetonitrile and tetrahydrofuran, and after recrystallization affords the linear coordination polymer [Mn(II)(CH(3)CN)(2)(OTf)(2)](n). Each distorted octahedral manganese(II) center in the polymeric chain has trans-acetonitriles and the remaining equatorial coordination positions are occupied by the bridging triflate anions. Dissolving [Mn(II)(CH(3)CN)(2)(OTf)(2)](n) in equal volumes of acetonitrile and pyridine followed by recrystallization with diethyl ether yields trans-[Mn(II)(C(5)H(5)N)(4)(OTf)(2)]. The distorted octahedral geometry of the manganese center features monodentate trans-triflate anions and four equatorial pyridines. Exposure of either [Mn(II)(CH(3)CN)(2)(OTf)(2)](n) or [Mn(II)(C(5)H(5)N)(4)(OTf)(2)] to water readily gives [Mn(II)(H(2)O)(6)](OTf)(2). XRD reveals hydrogen-bonding interactions between the [Mn(II)(H(2)O)(6)](2+) cation and the triflate anion. All three of these species are easily crystallized and provide convenient sources of manganese(II) for further synthetic elaboration.
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Affiliation(s)
- Paul J Riedel
- Department of Chemistry, University of Wyoming, 1000 E. University Avenue, Laramie, Wyoming 82071, USA
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39
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Silva TF, Guedes da Silva MF, Mishra GS, Martins LM, Pombeiro AJ. Synthesis and structural characterization of iron complexes with 2,2,2-tris(1-pyrazolyl)ethanol ligands: Application in the peroxidative oxidation of cyclohexane under mild conditions. J Organomet Chem 2011. [DOI: 10.1016/j.jorganchem.2010.12.036] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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40
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Goldsmith CR, Coates CM, Hagan K, Mitchell CA. Hydrocarbon chlorination promoted by manganese and iron complexes with methylated derivatives of bis(2-pyridylmethyl)-1,2-ethanediamine. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.molcata.2010.11.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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41
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Coates CM, Hagan K, Mitchell CA, Gorden JD, Goldsmith CR. Structural characterization of manganese and iron complexes with methylated derivatives of bis(2-pyridylmethyl)-1,2-ethanediamine reveals unanticipated conformational flexibility. Dalton Trans 2011; 40:4048-58. [DOI: 10.1039/c0dt01556c] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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42
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Shejwalkar P, Rath NP, Bauer EB. New iron(ii) α-iminopyridine complexes and their catalytic activity in the oxidation of activated methylene groups and secondary alcohols to ketones. Dalton Trans 2011; 40:7617-31. [DOI: 10.1039/c1dt10387c] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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43
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Dengler JE, Lehenmeier MW, Klaus S, Anderson CE, Herdtweck E, Rieger B. A One-Component Iron Catalyst for Cyclic Propylene Carbonate Synthesis. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.201000861] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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44
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Das P, Que L. Iron Catalyzed Competitive Olefin Oxidation and ipso-Hydroxylation of Benzoic Acids: Further Evidence for an FeV═O Oxidant. Inorg Chem 2010; 49:9479-85. [DOI: 10.1021/ic101144s] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Parthapratim Das
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455
| | - Lawrence Que
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455
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45
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Cabrero-Antonino J, Leyva-Pérez A, Corma A. Iron-Catalysed Regio- and Stereoselective Head-to-Tail Dimerisation of Styrenes. Adv Synth Catal 2010. [DOI: 10.1002/adsc.201000096] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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46
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47
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Sabiah S, Varghese B, Murthy NN. Mononuclear [(BP)(2)MX](n+) (M = Cu(2+), Co(2+), Zn(2+); X = OH(2), Cl(-)) complexes with a new biphenyl appended N-bidentate ligand: structural, spectroscopic, solution equilibrium and ligand dynamic studies. Dalton Trans 2009:9770-80. [PMID: 19885522 DOI: 10.1039/b910519k] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new series of five-coordinate [(BP)2MX]n+ complexes, (where X = OH2, M = Zn(II) (1), Cu(II) (2); X = Cl-, M = Cu(II) (3), Co(II) (4)) with a new bidentate chelating ligand [{N,N(1,1'-biphenyl-2,2'-dimethylene)-N(2-pyridyl methyl)} amine] with a biphenyl group (BP), have been synthesized and characterized by X-ray crystal structure and combined spectroscopic methods. They display unique trigonal bipyramidal (TBP) geometry, influenced by the bidentate ligand. The Zn(II) complex 1 reveals ligand dynamics due to an atropisomeric biphenyl moiety as indicated by variable temperature (VT) proton NMR spectroscopy. The calculated free energy for the inversion of the bridged biphenyl is approximately 13.08 kcal mol-1 (Tc = 273 K, Delta(nu) = 82.8 Hz, J = 8.7 Hz). The absorption spectra of Cu(II) complexes 2 and 3, in CH2Cl2 display greatly enhanced d-d bands (800-950 nm, epsilon>500 M-1 cm-1). On the other hand, complex 2 in N,N-dimethylformamide (DMF) showed almost 50% reduction in absorption intensity as DMF, a coordinating solvent, displaces the weakly-coordinated tertiary amine-nitrogens of the ligand and this competitive binding was studied by electronic absorption spectroscopy. When the mononuclear copper aqua complex 2 was treated with a base, a dicopper dihydroxide complex, [{(BP)Cu}2(mu-OH)2]2+, (2a) was obtained. The same phenomenon was also observed with chloro complex 3 when treated with a base. This mono-dicopper equilibrium and conversion of 2 --> 2a was monitored by UV-vis spectroscopy. Copper(II) complexes 2 and 3 displayed reverse EPR spectra consistent with the TBP geometry. Cyclic voltammetry of 2 and 3 in DMF showed an irreversible redox wave owing to Cu(II)/Cu(I) of five and four-coordinate species. The solution magnetic moment values of 1.76, 1.81 and 4.47 microB for 2, 3 and 4, respectively, are in agreement with Cu(II) (S = 1/2) and Co(II) (S = 3/2) high-spin configurations. The 1H NMR of 4 displays sharp but hyperfine shifted signals for the ligand protons between -30 to +220 ppm. The ESI-mass data complement the data obtained from X-ray structure.
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48
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Hoshino N, Shiga T, Nihei M, Oshio H. Chiral dinuclear complexes with tetradentate ligands derived from (R)-(+)-1, 1′-binaphthyl-2,2′-diamine. Polyhedron 2009. [DOI: 10.1016/j.poly.2008.11.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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