1
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Devkota L, SantaLucia DJ, Wheaton AM, Pienkos AJ, Lindeman SV, Krzystek J, Ozerov M, Berry JF, Telser J, Fiedler AT. Spectroscopic and Magnetic Studies of Co(II) Scorpionate Complexes: Is There a Halide Effect on Magnetic Anisotropy? Inorg Chem 2023; 62:5984-6002. [PMID: 37000941 DOI: 10.1021/acs.inorgchem.2c04468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Abstract
The observation of single-molecule magnetism in transition-metal complexes relies on the phenomenon of zero-field splitting (ZFS), which arises from the interplay of spin-orbit coupling (SOC) with ligand-field-induced symmetry lowering. Previous studies have demonstrated that the magnitude of ZFS in complexes with 3d metal ions is sometimes enhanced through coordination with heavy halide ligands (Br and I) that possess large free-atom SOC constants. In this study, we systematically probe this "heavy-atom effect" in high-spin cobalt(II)-halide complexes supported by substituted hydrotris(pyrazol-1-yl)borate ligands (TptBu,Me and TpPh,Me). Two series of complexes were prepared: [CoIIX(TptBu,Me)] (1-X; X = F, Cl, Br, and I) and [CoIIX(TpPh,Me)(HpzPh,Me)] (2-X; X = Cl, Br, and I), where HpzPh,Me is a monodentate pyrazole ligand. Examination with dc magnetometry, high-frequency and -field electron paramagnetic resonance, and far-infrared magnetic spectroscopy yielded axial (D) and rhombic (E) ZFS parameters for each complex. With the exception of 1-F, complexes in the four-coordinate 1-X series exhibit positive D-values between 10 and 13 cm-1, with no dependence on halide size. The five-coordinate 2-X series exhibit large and negative D-values between -60 and -90 cm-1. Interpretation of the magnetic parameters with the aid of ligand-field theory and ab initio calculations elucidated the roles of molecular geometry, ligand-field effects, and metal-ligand covalency in controlling the magnitude of ZFS in cobalt-halide complexes.
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2
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Ćwiertnia A, Kozłowski M, Cymbaluk-Płoska A. The Role of Iron and Cobalt in Gynecological Diseases. Cells 2022; 12:cells12010117. [PMID: 36611913 PMCID: PMC9818544 DOI: 10.3390/cells12010117] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 12/12/2022] [Accepted: 12/26/2022] [Indexed: 12/29/2022] Open
Abstract
Iron and cobalt are micronutrients that play an important role in the regulation of cellular processes, being part of the centre of catalases, peroxidases, cytochromes and metalloproteins such as hemoglobin and myoglobin (Fe). Cobalt primarily functions as a component of hydroxycobalamin, which is essential for regulating red blood cell production. Maintaining normal levels of cobalt and iron in the human body is important, as a deficiency can lead to anaemia. These elements are also involved in reactions during which oxidative stress occurs and are therefore considered to be a cause of tumor formation. This paper will discuss aspects of the influence of cobalt and iron on mechanisms that may contribute to the growth of gynecological tumors, as well as other obstetric-gynecological disease entities, by altering the conditions of the microenvironment. In addition, the following review also highlights the role of cobalt and iron in the treatment of gynecological tumors.
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3
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Jaworski A, Hedin N. Electron correlation and vibrational effects in predictions of paramagnetic NMR shifts. Phys Chem Chem Phys 2022; 24:15230-15244. [PMID: 35703010 DOI: 10.1039/d2cp01206e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electronic structure calculations are fundamentally important for the interpretation of nuclear magnetic resonance (NMR) spectra from paramagnetic systems that include organometallic and inorganic compounds, catalysts, or metal-binding sites in proteins. Prediction of induced paramagnetic NMR shifts requires knowledge of electron paramagnetic resonance (EPR) parameters: the electronic g tensor, zero-field splitting D tensor, and hyperfine A tensor. The isotropic part of A, called the hyperfine coupling constant (HFCC), is one of the most troublesome properties for quantum chemistry calculations. Yet, even relatively small errors in calculations of HFCC tend to propagate into large errors in the predicted NMR shifts. The poor quality of A tensors that are currently calculated using density functional theory (DFT) constitutes a bottleneck in improving the reliability of interpretation of the NMR spectra from paramagnetic systems. In this work, electron correlation effects in calculations of HFCCs with a hierarchy of ab initio methods were assessed, and the applicability of different levels of DFT approximations and the coupled cluster singles and doubles (CCSD) method was tested. These assessments were performed for the set of selected test systems comprising an organic radical, and complexes with transition metal and rare-earth ions, for which experimental data are available. Severe deficiencies of DFT were revealed but the CCSD method was able to deliver good agreement with experimental data for all systems considered, however, at substantial computational costs. We proposed a more computationally tractable alternative, where the A was computed with the coupled cluster theory exploiting locality of electron correlation. This alternative is based on the domain-based local pair natural orbital coupled cluster singles and doubles (DLPNO-CCSD) method. In this way the robustness and reliability of the coupled cluster theory were incorporated into the modern formalism for the prediction of induced paramagnetic NMR shifts, and became applicable to systems of chemical interest. This approach was verified for the bis(cyclopentadienyl)vanadium(II) complex (Cp2V; vanadocene), and the metal-binding site of the Zn2+ → Co2+ substituted superoxide dismutase (SOD) metalloprotein. Excellent agreement with experimental NMR shifts was achieved, which represented a substantial improvement over previous theoretical attempts. The effects of vibrational corrections to orbital shielding and hyperfine tensor were evaluated and discussed within the second-order vibrational perturbation theory (VPT2) framework.
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Affiliation(s)
- Aleksander Jaworski
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden.
| | - Niklas Hedin
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden.
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4
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G Jafari M, Fehn D, Reinholdt A, Hernández-Prieto C, Patel P, Gau MR, Carroll PJ, Krzystek J, Liu C, Ozarowski A, Telser J, Delferro M, Meyer K, Mindiola DJ. Tale of Three Molecular Nitrides: Mononuclear Vanadium (V) and (IV) Nitrides As Well As a Mixed-Valence Trivanadium Nitride Having a V 3N 4 Double-Diamond Core. J Am Chem Soc 2022; 144:10201-10219. [PMID: 35652694 DOI: 10.1021/jacs.2c00276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Transmetallation of [VCl3(THF)3] and [TlTptBu,Me] afforded [(TptBu,Me)VCl2] (1, TptBu,Me = hydro-tris(3-tert-butyl-5-methylpyrazol-1-yl)borate), which was reduced with KC8 to form a C3v symmetric VII complex, [(TptBu,Me)VCl] (2). Complex 1 has a high-spin (S = 1) ground state and displays rhombic high-frequency and -field electron paramagnetic resonance (HFEPR) spectra, while complex 2 has an S = 3/2 4A2 ground state observable by conventional EPR spectroscopy. Complex 1 reacts with NaN3 to form the VV nitride-azide complex [(TptBu,Me)V≡N(N3)] (3). A likely VIII azide intermediate en route to 3, [(TptBu,Me)VCl(N3)] (4), was isolated by reacting 1 with N3SiMe3. Complex 4 is thermally stable but reacts with NaN3 to form 3, implying a bis-azide intermediate, [(TptBu,Me)V(N3)2] (A), leading to 3. Reduction of 3 with KC8 furnishes a trinuclear and mixed-valent nitride, [{(TptBu,Me)V}2(μ4-VN4)] (5), conforming to a Robin-Day class I description. Complex 5 features a central vanadium ion supported only by bridging nitride ligands. Contrary to 1, complex 2 reacts with NaN3 to produce an azide-bridged dimer, [{(TptBu,Me)V}2(1,3-μ2-N3)2] (6), with two antiferromagnetically coupled high-spin VII ions. Complex 5 could be independently produced along with [(κ2-TptBu,Me)2V] upon photolysis of 6 in arene solvents. The putative {VIV≡N} intermediate, [(TptBu,Me)V≡N] (B), was intercepted by photolyzing 6 in a coordinating solvent, such as tetrahydrofuran (THF), yielding [(TptBu,Me)V≡N(THF)] (B-THF). In arene solvents, B-THF expels THF to afford 5 and [(κ2-TptBu,Me)2V]. A more stable adduct (B-OPPh3) was prepared by reacting B-THF with OPPh3. These adducts of B are the first neutral and mononuclear VIV nitride complexes to be isolated.
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Affiliation(s)
- Mehrafshan G Jafari
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Dominik Fehn
- Inorganic Chemistry, Department of Chemistry and Pharmacy, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany
| | - Anders Reinholdt
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Cristina Hernández-Prieto
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Prajay Patel
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Michael R Gau
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Patrick J Carroll
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - J Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Cong Liu
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Andrew Ozarowski
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Joshua Telser
- Department of Biological, Physical and Health Sciences, Roosevelt University, Chicago, Illinois 60605, United States
| | - Massimiliano Delferro
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Karsten Meyer
- Inorganic Chemistry, Department of Chemistry and Pharmacy, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany
| | - Daniel J Mindiola
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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5
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Liu M, Yang Y, Jing R, Zheng S, Yuan A, Wang Z, Luo SC, Liu X, Cui HH, Ouyang ZW, Chen L. Slow magnetic relaxation in dinuclear Co(III)-Co(II) complexes containing a five-coordinated Co(II) centre with easy-axis anisotropy. Dalton Trans 2022; 51:8382-8389. [PMID: 35587605 DOI: 10.1039/d2dt00857b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Two air-stable Co(III)-Co(II) mixed-valence complexes of molecular formulas [CoIICoIII(L)(DMAP)3(CH3COO)]·H2O·CH3OH (1) and [CoIICoIII(L)(4-Pyrrol)3 (CH3COO)]·0.5CH2Cl2 (2) (H4L = 1,3-bis-(5-methyl pyrazole-3-carboxamide) propane; DMAP = 4-dimethylaminopyridine; and 4-Pyrrol = 4-pyrrolidinopyridine) were synthesized and characterized by single-crystal X-ray crystallography, high-field electron paramagnetic resonance (HFEPR) spectroscopy, and magnetic measurements. Both complexes possess one five-coordinated paramagnetic Co(II) ion and one six-coordinated Co(III) ion with octahedral geometry. Direct-current magnetic susceptibility and magnetization measurements show the easy-axis magnetic anisotropy that is also confirmed by low-temperature HFEPR measurements and theoretical calculations. Frequency- and temperature-dependent alternating-current magnetic susceptibility measurements reveal their field-assisted slow magnetic relaxation, which is a characteristic behavior of single-molecule magnets (SMMs), caused by the individual Co(II) ion. The effective energy barrier of complex 1 (49.2 cm-1) is significantly higher than those of the other dinuclear Co(III)-Co(II) SMMs. This work hence presents the first instance of the dinuclear Co(III)-Co(II) single-molecule magnets with a five-coordinated environment around the Co(II) ion.
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Affiliation(s)
- Mengyao Liu
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, P. R. China.
| | - Yimou Yang
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, P. R. China.
| | - Rong Jing
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, P. R. China.
| | - Shaojun Zheng
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, P. R. China.
| | - Aihua Yuan
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, P. R. China.
| | - Zhenxing Wang
- Wuhan National High Magnetic Field Center & School of Physics, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
| | - Shu-Chang Luo
- School of Chemical Engineering, Guizhou University of Engineering Science, Bijie 551700, P. R. China.
| | - Xiangyu Liu
- State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, National Demonstration Center for Experimental Chemistry Education, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, P. R. China.
| | - Hui-Hui Cui
- School of Chemistry and Chemical Engineering, Nantong University, Nantong 226019, P. R. China
| | - Zhong-Wen Ouyang
- Wuhan National High Magnetic Field Center & School of Physics, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
| | - Lei Chen
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, P. R. China.
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6
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Amrutha K, Kathirvelu V. Interpretation of EPR and optical spectra of Ni(II) ions in crystalline lattices at ambient temperature. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2022; 60:414-421. [PMID: 34859492 DOI: 10.1002/mrc.5237] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/24/2021] [Accepted: 11/25/2021] [Indexed: 06/13/2023]
Abstract
Many biologically important paramagnetic metal ions are characterized by electron paramagnetic resonance (EPR) spectroscopy to use as spin probes to investigate the structure and function of biomolecules. Though nickel(II) ions are an essential trace element and part of many biomolecules, the EPR properties are least understood. Herein, the EPR and optical absorption spectra measured at 300 K for Ni(II) ions diluted in two different diamagnetic hosts are investigated and reported. The EPR spectrum of a polycrystalline Ni/Mg(3-methylpyrazole)6 (ClO4 )2 [Ni/MMPC] shows two transitions at X-band frequency (~9.5 GHz), suggesting the zero-field splitting parameter (D) is larger than the resonance field of the free electron (Ho ). This incomplete and complex spectrum is successfully analyzed to obtain EPR parameters. The EPR spectrum of the polycrystalline Ni/Zn(pyrazole)6 (NO3 )2 [Ni/ZPN] shows a triplet spectrum indicating D < Ho . A detailed analysis of single-crystal EPR data yielded the spin Hamiltonian parameters. The optical absorption spectra are deconvoluted to understand the symmetry of the coordination environment in the complex.
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Affiliation(s)
- Kamalon Amrutha
- Department of Applied Sciences, National Institute of Technology Goa, Ponda, India
| | - Velavan Kathirvelu
- Department of Applied Sciences, National Institute of Technology Goa, Ponda, India
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7
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Buchhorn M, Deeth RJ, Krewald V. Revisiting the Fundamental Nature of Metal‐Ligand Bonding: An Impartial and Automated Fitting Procedure for Angular Overlap Model Parameters. Chemistry 2022; 28:e202103775. [PMID: 34981589 PMCID: PMC9303604 DOI: 10.1002/chem.202103775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Indexed: 11/29/2022]
Abstract
The properties and reactivities of transition metal complexes are often discussed in terms of Ligand Field Theory (LFT), and with ab initio LFT a direct connection to quantum chemical wavefunctions was recently established. The Angular Overlap Model (AOM) is a widely used, ligand‐specific parameterization scheme of the ligand field splitting that has, however, been restricted by the availability and resolution of experimental data. Using ab initio LFT, we present here a generalised, symmetry‐independent and automated fitting procedure for AOM parameters that is even applicable to formally underdetermined or experimentally inaccessible systems. This method allows quantitative evaluations of assumptions commonly made in AOM applications, for example, transferability or the relative magnitudes of AOM parameters, and the response of the ligand field to structural or electronic changes. A two‐dimensional spectrochemical series of tetrahedral halido metalates ([MIIX4]2−, M=Mn−Cu) served as a case study. A previously unknown linear relationship between the halide ligands’ chemical hardness and their AOM parameters was found. The impartial and automated procedure for identifying AOM parameters introduced here can be used to systematically improve our understanding of ligand–metal interactions in coordination complexes.
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Affiliation(s)
- Moritz Buchhorn
- TU Darmstadt Department of Chemistry Theoretical Chemistry Alarich-Weiss-Straße 4 64287 Darmstadt Germany
| | - Robert J. Deeth
- University of Warwick Department of Chemistry University of Warwick Gibbet Hill Coventry CV4 7AL United Kingdom
| | - Vera Krewald
- TU Darmstadt Department of Chemistry Theoretical Chemistry Alarich-Weiss-Straße 4 64287 Darmstadt Germany
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8
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Chen SY, Lv W, Cui HH, Chen L, Zhang YQ, Chen XT, Wang Z, Ouyang ZW, Yan H, Xue ZL. Magnetic anisotropies and slow magnetic relaxation of three tetrahedral tetrakis(pseudohalido)–cobalt( ii) complexes. NEW J CHEM 2021. [DOI: 10.1039/d1nj01916c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Magnetic anisotropies and slow magnetic relaxation of three homoleptic cobalt(ii) complexes with different pseudohalide ligands were studied via magnetometry, HFEPR and theoretical calculations.
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Affiliation(s)
- Shu-Yang Chen
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Wei Lv
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Hui-Hui Cui
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Lei Chen
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China
| | - Yi-Quan Zhang
- Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, China
| | - Xue-Tai Chen
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Zhenxing Wang
- Wuhan National High Magnetic Field Center & School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zhong-Wen Ouyang
- Wuhan National High Magnetic Field Center & School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Hong Yan
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Zi-Ling Xue
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee, 37996, USA
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9
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Reinholdt A, Pividori D, Laughlin AL, DiMucci IM, MacMillan SN, Jafari MG, Gau MR, Carroll PJ, Krzystek J, Ozarowski A, Telser J, Lancaster KM, Meyer K, Mindiola DJ. A Mononuclear and High-Spin Tetrahedral Ti II Complex. Inorg Chem 2020; 59:17834-17850. [PMID: 33258366 PMCID: PMC7928263 DOI: 10.1021/acs.inorgchem.0c02586] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Indexed: 12/31/2022]
Abstract
A high-spin, mononuclear TiII complex, [(TptBu,Me)TiCl] [TptBu,Me- = hydridotris(3-tert-butyl-5-methylpyrazol-1-yl)borate], confined to a tetrahedral ligand-field environment, has been prepared by reduction of the precursor [(TptBu,Me)TiCl2] with KC8. Complex [(TptBu,Me)TiCl] has a 3A2 ground state (assuming C3v symmetry based on structural studies), established via a combination of high-frequency and -field electron paramagnetic resonance (HFEPR) spectroscopy, solution and solid-state magnetic studies, Ti K-edge X-ray absorption spectroscopy (XAS), and both density functional theory and ab initio (complete-active-space self-consistent-field, CASSCF) calculations. The formally and physically defined TiII complex readily binds tetrahydrofuran (THF) to form the paramagnetic adduct [(TptBu,Me)TiCl(THF)], which is impervious to N2 binding. However, in the absence of THF, the TiII complex captures N2 to produce the diamagnetic complex [(TptBu,Me)TiCl]2(η1,η1;μ2-N2), with a linear Ti═N═N═Ti topology, established by single-crystal X-ray diffraction. The N2 complex was characterized using XAS as well as IR and Raman spectroscopies, thus establishing this complex to possess two TiIII centers covalently bridged by an N22- unit. A π acid such as CNAd (Ad = 1-adamantyl) coordinates to [(TptBu,Me)TiCl] without inducing spin pairing of the d electrons, thereby forming a unique high-spin and five-coordinate TiII complex, namely, [(TptBu,Me)TiCl(CNAd)]. The reducing power of the coordinatively unsaturated TiII-containing [(ΤptBu,Me)TiCl] species, quantified by electrochemistry, provides access to a family of mononuclear TiIV complexes of the type [(TptBu,Me)Ti═E(Cl)] (with E2- = NSiMe3, N2CPh2, O, and NH) by virtue of atom- or group-transfer reactions using various small molecules such as N3SiMe3, N2CPh2, N2O, and the bicyclic amine 2,3:5,6-dibenzo-7-azabicyclo[2.2.1]hepta-2,5-diene.
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Affiliation(s)
- Anders Reinholdt
- Department
of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Daniel Pividori
- Inorganic
Chemistry, Department of Chemistry and Pharmacy, Friedrich-Alexander University (FAU) Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Alexander L. Laughlin
- Baker
Laboratory, Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Ida M. DiMucci
- Baker
Laboratory, Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Samantha N. MacMillan
- Baker
Laboratory, Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Mehrafshan G. Jafari
- Department
of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Michael R. Gau
- Department
of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Patrick J. Carroll
- Department
of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - J. Krzystek
- National
High Magnetic Field Laboratory, Florida
State University, Tallahassee, Florida 32310, United States
| | - Andrew Ozarowski
- National
High Magnetic Field Laboratory, Florida
State University, Tallahassee, Florida 32310, United States
| | - Joshua Telser
- Department
of Biological, Physical and Health Sciences, Roosevelt University, Chicago, Illinois 60605, United States
| | - Kyle M. Lancaster
- Baker
Laboratory, Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Karsten Meyer
- Inorganic
Chemistry, Department of Chemistry and Pharmacy, Friedrich-Alexander University (FAU) Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Daniel J. Mindiola
- Department
of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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10
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Müller L, Nadurata VL, Cula B, Hoof S, Herwig C, Limberg C. Versatile Coordination Behavior of the Asymmetric Bis(3‐mesityl‐pyrazol‐1‐yl)(5‐mesitylpyrazol‐1‐yl) Hydroborate Ligand towards Late 3 d M
2+
Ions. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Lars Müller
- Institut für Chemie Humboldt-Universität zu Berlin Brook-Taylor-Straße 2 12489 Berlin Germany
| | - Vincent L. Nadurata
- School of Chemistry University of Melbourne Parkville Victoria 3010 Australia
| | - Beatrice Cula
- Institut für Chemie Humboldt-Universität zu Berlin Brook-Taylor-Straße 2 12489 Berlin Germany
| | - Santina Hoof
- Institut für Chemie Humboldt-Universität zu Berlin Brook-Taylor-Straße 2 12489 Berlin Germany
| | - Christian Herwig
- Institut für Chemie Humboldt-Universität zu Berlin Brook-Taylor-Straße 2 12489 Berlin Germany
| | - Christian Limberg
- Institut für Chemie Humboldt-Universität zu Berlin Brook-Taylor-Straße 2 12489 Berlin Germany
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11
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Kumar P, SantaLucia DJ, Kaniewska-Laskowska K, Lindeman SV, Ozarowski A, Krzystek J, Ozerov M, Telser J, Berry JF, Fiedler AT. Probing the Magnetic Anisotropy of Co(II) Complexes Featuring Redox-Active Ligands. Inorg Chem 2020; 59:16178-16193. [DOI: 10.1021/acs.inorgchem.0c01812] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Praveen Kumar
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States
| | - Daniel J. SantaLucia
- Department of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Kinga Kaniewska-Laskowska
- Department of Inorganic Chemistry, Faculty of Chemistry, Gdańsk University of Technology, Gdańsk PL-80-233, Poland
| | - Sergey V. Lindeman
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States
| | - Andrew Ozarowski
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - J. Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Joshua Telser
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, Illinois 60605, United States
| | - John F. Berry
- Department of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Adam T. Fiedler
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States
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12
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Coste SC, Pearson TJ, Altman AB, Klein RA, Finney BA, Hu MY, Alp EE, Vlaisavljevich B, Freedman DE. Orbital energy mismatch engenders high-spin ground states in heterobimetallic complexes. Chem Sci 2020; 11:9971-9977. [PMID: 34094259 PMCID: PMC8162423 DOI: 10.1039/d0sc03777j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The spin state in heterobimetallic complexes heavily influences both reactivity and magnetism. Exerting control over spin states in main group-based heterobimetallics requires a different approach as the orbital interactions can differ substantially from that of classic coordination complexes. By deliberately engendering an energetic mismatch within the two metals in a bimetallic complex we can mimic the electronic structure of lanthanides. Towards this end, we report a new family of complexes, [Ph,MeTpMSnPh3] where M = Mn (3), Fe (4), Co (5), Ni (6), Zn (7), featuring unsupported bonding between a transition metal and Sn which represent an unusual high spin electronic structure. Analysis of the frontier orbitals reveal the desired orbital mismatch with Sn 5s/5p primarily interacting with 4s/4p M orbitals yielding localized, non-bonding d orbitals. This approach offers a mechanism to design and control spin states in bimetallic complexes. We report a series of high spin bimetallic transition metal–tin complexes. The unusual high spin configuration in a bimetallic complex is enabled by an energetic mismatch in the orbital energies, leading to lanthanide-like nonbonding interactions.![]()
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Affiliation(s)
- Scott C Coste
- Department of Chemistry, Northwestern University Evanston Illinois 60208 USA
| | - Tyler J Pearson
- Department of Chemistry, Northwestern University Evanston Illinois 60208 USA
| | - Alison B Altman
- Department of Chemistry, Northwestern University Evanston Illinois 60208 USA
| | - Ryan A Klein
- Department of Chemistry, Northwestern University Evanston Illinois 60208 USA
| | - Brian A Finney
- Department of Chemistry, University of South Dakota Vermillion South Dakota 57069 USA
| | - Michael Y Hu
- Advanced Photon Source, Argonne National Laboratory Lemont IL 60439 USA
| | - E Ercan Alp
- Advanced Photon Source, Argonne National Laboratory Lemont IL 60439 USA
| | - Bess Vlaisavljevich
- Department of Chemistry, University of South Dakota Vermillion South Dakota 57069 USA
| | - Danna E Freedman
- Department of Chemistry, Northwestern University Evanston Illinois 60208 USA
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13
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Plugis NM, Rudd ND, Krzystek J, Swenson DC, Telser J, Larrabee JA. Cobalt(II) "Scorpionate" complexes as electronic ground state models for cobalt-substituted zinc enzymes: Structure investigation by magnetic circular dichroism. J Inorg Biochem 2019; 203:110876. [PMID: 31756558 DOI: 10.1016/j.jinorgbio.2019.110876] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 09/19/2019] [Accepted: 10/01/2019] [Indexed: 12/15/2022]
Abstract
Zinc centers in pseudo-tetrahedral geometry are widely found in biology, often with three histidine ligands from protein. The trispyrazolylborate "scorpionate" ligand is used as a model for this tris(histidine) motif, and spectroscopically active CoII is often used as a substitute for spectroscopically silent ZnII. In this work, four pseudo-tetrahedral scorpionate complexes with the formula (Tpt-Bu,Tn)CoL, where Tpt-Bu,Tn = hydrotris(3-tert-butyl, 5-2'-thienyl-pyrazol-1-yl)borate anion and L = Cl-, N3-, NCO-, or NCS-, were studied using variable-temperature, variable-field magnetic circular dichroism (VTVH MCD) spectroscopy. The major goal was to determine the axial and rhombic zero field splitting (ZFS) parameters (D and E, respectively) of these S = 3/2 systems and compare these ZFS parameters to those determined previously by high-frequency and -field electron paramagnetic resonance (HFEPR) spectroscopy on the same (L = Cl- and NCS-) or closely related complexes. Additionally, HFEPR studies were undertaken here on the complexes with L = N3-, NCO-. Crystal structures for these two complexes are also first reported here. The values of D determined by VTVH MCD were + 12.8 and + 3.6 cm-1 for the L = Cl- and NCS- complexes, respectively. These values are in close agreement with those for the same complexes as previously determined by HFEPR. The values of D determined by VTVH MCD were + 3.0 and + 6.6 cm-1 for the L = N3- and NCO- complexes, respectively. These values were not as close to those determined by HFEPR in the present study, which are 4.2 cm-1 ≤ |D| ≤ 5.6 cm-1 in Tpt-Bu,TnCoN3, and 8.3 cm-1 ≤ |D| ≤ 11.0 cm-1 in Tpt-Bu,TnCoNCO. The bands in MCD spectra of these complexes were assigned in C3v symmetry and a complete ligand-field analysis of the MCD data was made using the Angular Overlap Model (AOM), which is compared to previous results.
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Affiliation(s)
- Nicholas M Plugis
- Department of Chemistry & Biochemistry, 547 Bicentennial Way, Middlebury College, Middlebury, VT 05753, USA
| | - Nathan D Rudd
- Department of Chemistry & Biochemistry, 547 Bicentennial Way, Middlebury College, Middlebury, VT 05753, USA
| | - J Krzystek
- National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310, USA
| | - Dale C Swenson
- Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA
| | - Joshua Telser
- Department of Biological, Physical and Health Sciences, Roosevelt University, 430 South Michigan Avenue, Chicago, IL 60605, USA
| | - James A Larrabee
- Department of Chemistry & Biochemistry, 547 Bicentennial Way, Middlebury College, Middlebury, VT 05753, USA.
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14
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Coste SC, Pearson TJ, Freedman DE. Magnetic Anisotropy in Heterobimetallic Complexes. Inorg Chem 2019; 58:11893-11902. [DOI: 10.1021/acs.inorgchem.9b01459] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Scott C. Coste
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Tyler J. Pearson
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Danna E. Freedman
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
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15
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Switlicka A, Machura B, Kruszynski R, Cano J, Toma LM, Lloret F, Julve M. The influence of pseudohalide ligands on the SIM behaviour of four-coordinate benzylimidazole-containing cobalt(ii) complexes. Dalton Trans 2018; 47:5831-5842. [PMID: 29648565 DOI: 10.1039/c7dt04735e] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Three, mononuclear complexes of the formula [Co(bmim)2(SCN)2] (1), [Co(bmim)2(NCO)2] (2) and [Co(bmim)2(N3)2] (3) [bmim = 1-benzyl-2-methylimidazole] were prepared and structurally analyzed by single-crystal X-ray crystallography. The cobalt(ii) ions in 1-3 are tetrahedrally coordinated with two bmim molecules and two pseudohalide anions. The angular distortion parameter δ was calculated and the SHAPE program (based on the CShM concept) was used for 1-3 to estimate the angular distortion from an ideal tetrahedron. The molecules of 1-3 are effectively separated, and the values of the shortest distance of cobalt-cobalt are 8.442(6) and 6.774(8) Å for 1, 10.349(8) and 10.716(8) Å for 2 and 6.778(1) and 9.232(1) Å for 3. Direct current (dc) magnetic susceptibility measurements on the crushed crystals of 1-3 were carried out in the temperature range 1.9-295 K. The variable-temperature magnetic data of 1-3 mainly obey the zero-field splitting effect (D) of the 4A2 ground term of the tetrahedral cobalt(ii) complexes (2D being the energy gap between the |±1/2 and |±3/2 levels of the spin). The analysis of their magnetic data through the Hamiltonian H = D[S2z - S(S + 1)/3] + E(Sx2 - Sy2) + gβHS led to the following best-fit parameters: g = 2.29, D = -7.5 cm-1 and E/D = 0.106 (1), g = 2.28, D = + 6.3 cm-1 and E/D = 0.007 (2) and g = 2.36, D = + 6.7 cm-1 and E/D = 0.090 (3). The signs of D for 1-3 were confirmed by Q-band EPR spectra on powdered samples in the temperature range 4.0-20 K. Field-induced SIM behaviour was observed for 1-3 below 4.0 K, and the frequency-dependent maxima of χ''M were observed for 1 and only incipient signals of χ''M occurred for 2 and 3. The values of the exponential factor (τ0) and activation energy (Ea) for 1-3 which were obtained from the Arrhenius plot suggest a single relaxation process characteristic of an Orbach mechanism.
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Affiliation(s)
- A Switlicka
- Department of Crystallography, Institute of Chemistry, University of Silesia, 9th Szkolna St., 40-006 Katowice, Poland.
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16
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Plaul D, Böhme M, Ostrovsky S, Tomkowicz Z, Görls H, Haase W, Plass W. Modeling Spin Interactions in a Triangular Cobalt(II) Complex with Triaminoguanidine Ligand Framework: Synthesis, Structure, and Magnetic Properties. Inorg Chem 2017; 57:106-119. [DOI: 10.1021/acs.inorgchem.7b02229] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Daniel Plaul
- Institut für
Anorganische und Analytische Chemie, Friedrich-Schiller-Universität Jena, Humboldtstr. 8, 07743 Jena, Germany
| | - Michael Böhme
- Institut für
Anorganische und Analytische Chemie, Friedrich-Schiller-Universität Jena, Humboldtstr. 8, 07743 Jena, Germany
| | - Serghei Ostrovsky
- Institute of Applied Physics, Academy of Sciences of Moldova, Academiei str.5, MD-2028, Chisinau, Moldova
| | - Zbigniew Tomkowicz
- Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Krakow, Poland
| | - Helmar Görls
- Institut für
Anorganische und Analytische Chemie, Friedrich-Schiller-Universität Jena, Humboldtstr. 8, 07743 Jena, Germany
| | - Wolfgang Haase
- Eduard-Zintl-Institute
of Inorganic and Physical Chemistry, Darmstadt University of Technology, Alarich-Weiss-Str. 4, 64287 Darmstadt, Germany
| | - Winfried Plass
- Institut für
Anorganische und Analytische Chemie, Friedrich-Schiller-Universität Jena, Humboldtstr. 8, 07743 Jena, Germany
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17
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Xu S, Bucinsky L, Breza M, Krzystek J, Chen CH, Pink M, Telser J, Smith JM. Ligand Substituent Effects in Manganese Pyridinophane Complexes: Implications for Oxygen-Evolving Catalysis. Inorg Chem 2017; 56:14315-14325. [DOI: 10.1021/acs.inorgchem.7b02421] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Song Xu
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, United States
| | - Lukas Bucinsky
- Institute of Physical Chemistry and Chemical
Physics, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, SK-81237 Bratislava, Slovakia
| | - Martin Breza
- Institute of Physical Chemistry and Chemical
Physics, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, SK-81237 Bratislava, Slovakia
| | - J. Krzystek
- National
High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Chun-Hsing Chen
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, United States
| | - Maren Pink
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, United States
| | - Joshua Telser
- Department of Biological, Chemical and
Physical Sciences, Roosevelt University, Chicago, Illinois 60605, United States
| | - Jeremy M. Smith
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, United States
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18
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Schweinfurth D, Krzystek J, Atanasov M, Klein J, Hohloch S, Telser J, Demeshko S, Meyer F, Neese F, Sarkar B. Tuning Magnetic Anisotropy Through Ligand Substitution in Five-Coordinate Co(II) Complexes. Inorg Chem 2017; 56:5253-5265. [DOI: 10.1021/acs.inorgchem.7b00371] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- David Schweinfurth
- Institut für
Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße
34-36, D-14195 Berlin, Germany
| | - J. Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Mihail Atanasov
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, D-45470 Mülheim an der Ruhr, Germany
- Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Johannes Klein
- Institut für
Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße
34-36, D-14195 Berlin, Germany
| | - Stephan Hohloch
- Institut für
Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße
34-36, D-14195 Berlin, Germany
| | - Joshua Telser
- Department of Biological, Chemical, and Physical Sciences, Roosevelt University, Chicago, Illinois 60605, United States
| | - Serhiy Demeshko
- Universität Göttingen, Institut
für Anorganische Chemie, Tammanstraße 4, D-37077 Göttingen, Germany
| | - Franc Meyer
- Universität Göttingen, Institut
für Anorganische Chemie, Tammanstraße 4, D-37077 Göttingen, Germany
| | - Frank Neese
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Biprajit Sarkar
- Institut für
Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße
34-36, D-14195 Berlin, Germany
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19
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Fujisawa K, Soma S, Kurihara H, Dong HT, Bilodeau M, Lehnert N. A cobalt–nitrosyl complex with a hindered hydrotris(pyrazolyl)borate coligand: detailed electronic structure, and reactivity towards dioxygen. Dalton Trans 2017; 46:13273-13289. [DOI: 10.1039/c7dt01565h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The cobalt–nitrosyl complex [Co(NO)(L3)] is supported by a highly hindered tridentate nitrogen ligand, hydrotris(3-tertiary butyl-5-isopropyl-1-pyrazolyl)borate (denoted as L3−), and shows a linear Co–N–O unit.
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Affiliation(s)
| | - Shoko Soma
- Department of Chemistry
- Ibaraki University
- Mito 310-8512
- Japan
| | | | - Hai T. Dong
- Department of Chemistry and Department of Biophysics
- University of Michigan
- Ann Arbor
- USA
| | - Max Bilodeau
- Department of Chemistry and Department of Biophysics
- University of Michigan
- Ann Arbor
- USA
| | - Nicolai Lehnert
- Department of Chemistry and Department of Biophysics
- University of Michigan
- Ann Arbor
- USA
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20
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Marts AR, Kaine JC, Baum RR, Clayton VL, Bennett JR, Cordonnier LJ, McCarrick R, Hasheminasab A, Crandall LA, Ziegler CJ, Tierney DL. Paramagnetic Resonance of Cobalt(II) Trispyrazolylmethanes and Counterion Association. Inorg Chem 2016; 56:618-626. [PMID: 27977149 DOI: 10.1021/acs.inorgchem.6b02520] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Paramagnetic resonance studies (EPR, ESEEM, ENDOR, and NMR) of a series of cobalt(II) bis-trispyrazolylmethane tetrafluoroborates are presented. The complexes studied include the parent, unsubstituted ligand (Tpm), two pyrazole-substituted derivatives (4Me and 3,5-diMe), and tris(1-pyrazolyl)ethane (Tpe), which includes a methyl group on the apical carbon atom. NMR and ENDOR establish the magnitude of 1H hyperfine couplings, while ESEEM provides information on the coordinated 14N. The data show that the pyrazole 3-position is more electron rich in the Tpm analogues, that the geometry about the apical atom influences the magnetic resonance, and that apical atom geometry appears more fixed in Tpm than in Tp. NMR and ENDOR establish that the BF4- counterion remains associated in fluid solution. In the case of the Tpm3,5Me complex, it appears to associate in solution, in the same position it occupies in the X-ray structure.
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Affiliation(s)
- Amy R Marts
- Department of Chemistry and Biochemistry, Miami University , Oxford, Ohio 45056, United States
| | - Joshua C Kaine
- Department of Chemistry and Biochemistry, Miami University , Oxford, Ohio 45056, United States
| | - Robert R Baum
- Department of Chemistry and Biochemistry, Miami University , Oxford, Ohio 45056, United States
| | - Vivien L Clayton
- Department of Chemistry and Biochemistry, Miami University , Oxford, Ohio 45056, United States
| | - Jami R Bennett
- Department of Chemistry and Biochemistry, Miami University , Oxford, Ohio 45056, United States
| | - Laura J Cordonnier
- Department of Chemistry and Biochemistry, Miami University , Oxford, Ohio 45056, United States
| | - Robert McCarrick
- Department of Chemistry and Biochemistry, Miami University , Oxford, Ohio 45056, United States
| | - Abed Hasheminasab
- Department of Chemistry, University of Akron , Akron, Ohio 44325, United States
| | - Laura A Crandall
- Department of Chemistry, University of Akron , Akron, Ohio 44325, United States
| | | | - David L Tierney
- Department of Chemistry and Biochemistry, Miami University , Oxford, Ohio 45056, United States
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21
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Reinig RR, Mukherjee D, Weinstein ZB, Xie W, Albright T, Baird B, Gray TS, Ellern A, Miller GJ, Winter AH, Bud'ko SL, Sadow AD. Synthesis and Oxidation Catalysis of [Tris(oxazolinyl)borato]cobalt(II) Scorpionates. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201600237] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Regina R. Reinig
- Department of ChemistryIowa State University1605 Gilman Hall50011AmesIAUSA
- US Department of Energy Ames Lab50011AmesIAUSA
| | | | - Zachary B. Weinstein
- Department of ChemistryIowa State University1605 Gilman Hall50011AmesIAUSA
- US Department of Energy Ames Lab50011AmesIAUSA
| | - Weiwei Xie
- Department of ChemistryIowa State University1605 Gilman Hall50011AmesIAUSA
- US Department of Energy Ames Lab50011AmesIAUSA
| | - Toshia Albright
- Department of ChemistryIowa State University1605 Gilman Hall50011AmesIAUSA
| | - Benjamin Baird
- Department of ChemistryIowa State University1605 Gilman Hall50011AmesIAUSA
| | - Tristan S. Gray
- Department of ChemistryIowa State University1605 Gilman Hall50011AmesIAUSA
| | - Arkady Ellern
- Department of ChemistryIowa State University1605 Gilman Hall50011AmesIAUSA
| | - Gordon J. Miller
- Department of ChemistryIowa State University1605 Gilman Hall50011AmesIAUSA
- US Department of Energy Ames Lab50011AmesIAUSA
| | - Arthur H. Winter
- Department of ChemistryIowa State University1605 Gilman Hall50011AmesIAUSA
| | | | - Aaron D. Sadow
- Department of ChemistryIowa State University1605 Gilman Hall50011AmesIAUSA
- US Department of Energy Ames Lab50011AmesIAUSA
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22
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Baum RR, Myers WK, Greer SM, Breece RM, Tierney DL. The Original CoII Heteroscorpionates Revisited: On the EPR of Pseudotetrahedral CoII. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201501356] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Robert R. Baum
- Department of Chemistry and BiochemistryMiami University45056OxfordOHUSA
| | - William K. Myers
- Department of Chemistry and BiochemistryMiami University45056OxfordOHUSA
| | - Samuel M. Greer
- Department of Chemistry and BiochemistryMiami University45056OxfordOHUSA
| | - Robert M. Breece
- Department of Chemistry and BiochemistryMiami University45056OxfordOHUSA
| | - David L. Tierney
- Department of Chemistry and BiochemistryMiami University45056OxfordOHUSA
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23
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Adach A, Daszkiewicz M, Tyszka-Czochara M. A family of complexes with N-scorpionate-type and other N-donor ligands obtained in situ from pyrazole derivative and zerovalent cobalt. Physicochemical and cytotoxicity studies. RSC Adv 2016. [DOI: 10.1039/c6ra06439f] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
In this paper we described one pot synthetic pathways which generated in situ three complexes which contain three different ligands: N,N,N-tris(3,5-dimethylpyrazolylmethyl)amine (L1), urotropine (L2) and 3,5-dimethylpyrazole (L3).
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Affiliation(s)
- A. Adach
- Institute of Chemistry
- Jan Kochanowski University of Kielce
- 25-406 Kielce
- Poland
| | - M. Daszkiewicz
- Institute of Low Temperature and Structure Research
- Polish Academy of Sciences
- 50-950 Wrocław
- Poland
| | - M. Tyszka-Czochara
- Department of Radioligands
- Faculty of Pharmacy
- Jagiellonian University Medical College
- 30-688 Kraków
- Poland
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24
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Wang GF, Zhang X, Sun SW, Sun H, Ma HX. Synthesis and structural characterization of two half-sandwich nickel(II) complexes with the scorpionate ligands. CRYSTALLOGR REP+ 2015. [DOI: 10.1134/s1063774515070299] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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25
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Schofield JA, Brennessel WW, Urnezius E, Rokhsana D, Boshart MD, Juers DH, Holland PL, Machonkin TE. Metal-Halogen Secondary Bonding in a 2,5-Dichlorohydroquinonate Cobalt(II) Complex: Insight into Substrate Coordination in the Chlorohydroquinone Dioxygenase PcpA. Eur J Inorg Chem 2015. [DOI: 10.1002/ejic.201500845] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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26
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Schweinfurth D, Sommer MG, Atanasov M, Demeshko S, Hohloch S, Meyer F, Neese F, Sarkar B. The ligand field of the azido ligand: insights into bonding parameters and magnetic anisotropy in a Co(II)-azido complex. J Am Chem Soc 2015; 137:1993-2005. [PMID: 25588991 DOI: 10.1021/ja512232f] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The azido ligand is one of the most investigated ligands in magnetochemistry. Despite its importance, not much is known about the ligand field of the azido ligand and its influence on magnetic anisotropy. Here we present the electronic structure of a novel five-coordinate Co(II)-azido complex (1), which has been characterized experimentally (magnetically and by electronic d-d absorption spectroscopy) and theoretically (by means of multireference electronic structure methods). Static and dynamic magnetic data on 1 have been collected, and the latter demonstrate slow relaxation of the magnetization in an applied external magnetic field of H = 3000 Oe. The zero-field splitting parameters deduced from static susceptibility and magnetizations (D = -10.7 cm(-1), E/D = 0.22) are in excellent agreement with the value of D inferred from an Arrhenius plot of the magnetic relaxation time versus the temperature. Application of the so-called N-electron valence second-order perturbation theory (NEVPT2) resulted in excellent agreement between experimental and computed energies of low-lying d-d transitions. Calculations were performed on 1 and a related four-coordinate Co(II)-azido complex lacking a fifth axial ligand (2). On the basis of these results and contrary to previous suggestions, the N3(-) ligand is shown to behave as a strong σ and π donor. Magnetostructural correlations show a strong increase in the negative D with increasing Lewis basicity (shortening of the Co-N bond distances) of the axial ligand on the N3(-) site. The effect on the change in sign of D in going from four-coordinate Co(II) (positive D) to five-coordinate Co(II) (negative D) is discussed in the light of the bonding scheme derived from ligand field analysis of the ab initio results.
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Affiliation(s)
- David Schweinfurth
- Institut für Chemie und Biochemie, Freie Universität Berlin , Fabeckstraße 34-36, D-14195 Berlin, Germany
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27
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Perić M, García-Fuente A, Zlatar M, Daul C, Stepanović S, García-Fernández P, Gruden-Pavlović M. Magnetic Anisotropy in “Scorpionate” First-Row Transition-Metal Complexes: A Theoretical Investigation. Chemistry 2015; 21:3716-26. [DOI: 10.1002/chem.201405480] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Indexed: 11/12/2022]
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28
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Phosphate ester hydrolysis catalyzed by a dinuclear cobalt(II) complex equipped with intramolecular β-cyclodextrins. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.molcata.2014.10.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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29
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Deng YF, Han T, Wang Z, Ouyang Z, Yin B, Zheng Z, Krzystek J, Zheng YZ. Uniaxial magnetic anisotropy of square-planar chromium(ii) complexes revealed by magnetic and HF-EPR studies. Chem Commun (Camb) 2015; 51:17688-91. [DOI: 10.1039/c5cc07025b] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two chromium(ii) complexes exhibit single-molecule-magnet behavior due to uniaxial magnetic anisotropy revealed by magnetic and HF-EPR studies.
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Affiliation(s)
- Yi-Fei Deng
- Centre for Applied Chemical Research
- Frontier Institute of Science and Technology
- and MOE Key Laboratory for Nonequilibrium Synthesis
- College of Science
- Xi'an Jiaotong University
| | - Tian Han
- Centre for Applied Chemical Research
- Frontier Institute of Science and Technology
- and MOE Key Laboratory for Nonequilibrium Synthesis
- College of Science
- Xi'an Jiaotong University
| | - Zhenxing Wang
- Wuhan National High Magnetic Field Centre
- Huazhong University of Science and Technology
- Wuhan 430074
- China
| | - Zhongwen Ouyang
- Wuhan National High Magnetic Field Centre
- Huazhong University of Science and Technology
- Wuhan 430074
- China
| | - Bing Yin
- MOE Key Laboratory of Synthetic and Natural Functional Molecule Chemistry
- College of Chemistry and Materials Science
- Northwest University
- Xi'an 710069
- China
| | - Zhiping Zheng
- Department of Chemistry and Biochemistry
- The University of Arizona
- Tucson Arizona 85721
- USA
| | - J. Krzystek
- National High Magnetic Field Laboratory
- Florida State University
- Tallahassee
- USA
| | - Yan-Zhen Zheng
- Centre for Applied Chemical Research
- Frontier Institute of Science and Technology
- and MOE Key Laboratory for Nonequilibrium Synthesis
- College of Science
- Xi'an Jiaotong University
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30
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Gupta SK, Kuppuswamy S, Walsh JPS, McInnes EJL, Murugavel R. Discrete and polymeric cobalt organophosphates: isolation of a 3-D cobalt phosphate framework exhibiting selective CO2 capture. Dalton Trans 2015; 44:5587-601. [DOI: 10.1039/c4dt03379e] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Auxiliary ligand assisted control over the structural diversity has been achieved in the case of cobalt(ii) organophosphates.
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Affiliation(s)
- Sandeep K. Gupta
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai 400 076
- India
| | | | - James P. S. Walsh
- School of Chemistry and Photon Science Institute
- The University of Manchester
- Manchester
- UK
| | - Eric J. L. McInnes
- School of Chemistry and Photon Science Institute
- The University of Manchester
- Manchester
- UK
| | - Ramaswamy Murugavel
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai 400 076
- India
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31
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Allyl molybdenum(II) and tungsten(II) compounds bearing bidentate and tridentate pyrazolylmethane ligands. Polyhedron 2014. [DOI: 10.1016/j.poly.2014.06.045] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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32
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Machonkin TE, Boshart MD, Schofield JA, Rodriguez MM, Grubel K, Rokhsana D, Brennessel WW, Holland PL. Structural and spectroscopic characterization of iron(II), cobalt(II), and nickel(II) ortho-dihalophenolate complexes: insights into metal-halogen secondary bonding. Inorg Chem 2014; 53:9837-48. [PMID: 25167329 DOI: 10.1021/ic501424e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Metal complexes incorporating the tris(3,5-diphenylpyrazolyl)borate ligand (Tp(Ph2)) and ortho-dihalophenolates were synthesized and characterized in order to explore metal-halogen secondary bonding in biorelevant model complexes. The complexes Tp(Ph2)ML were synthesized and structurally characterized, where M was Fe(II), Co(II), or Ni(II) and L was either 2,6-dichloro- or 2,6-dibromophenolate. All six complexes exhibited metal-halogen secondary bonds in the solid state, with distances ranging from 2.56 Å for the Tp(Ph2)Ni(2,6-dichlorophenolate) complex to 2.88 Å for the Tp(Ph2)Fe(2,6-dibromophenolate) complex. Variable temperature NMR spectra of the Tp(Ph2)Co(2,6-dichlorophenolate) and Tp(Ph2)Ni(2,6-dichlorophenolate) complexes showed that rotation of the phenolate, which requires loss of the secondary bond, has an activation barrier of ~30 and ~37 kJ/mol, respectively. Density functional theory calculations support the presence of a barrier for disruption of the metal-halogen interaction during rotation of the phenolate. On the other hand, calculations using the spectroscopically calibrated angular overlap method suggest essentially no contribution of the halogen to the ligand-field splitting. Overall, these results provide the first quantitative measure of the strength of a metal-halogen secondary bond and demonstrate that it is a weak noncovalent interaction comparable in strength to a hydrogen bond. These results provide insight into the origin of the specificity of the enzyme 2,6-dichlorohydroquinone 1,2-dioxygenase (PcpA), which is specific for ortho-dihalohydroquinone substrates and phenol inhibitors.
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Affiliation(s)
- Timothy E Machonkin
- Department of Chemistry, Whitman College , Walla Walla, Washington 99362, United States
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33
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Chen L, Wang J, Wei JM, Wernsdorfer W, Chen XT, Zhang YQ, Song Y, Xue ZL. Slow magnetic relaxation in a mononuclear eight-coordinate cobalt(II) complex. J Am Chem Soc 2014; 136:12213-6. [PMID: 25119268 DOI: 10.1021/ja5051605] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The quest for the single-molecular magnets (SMMs) based on mononuclear transition-metal complexes is focused on the low-coordinate species. No transition-metal complex with a coordination number of eight has been shown to exhibit SMM properties. Here the magnetic studies have been carried out for a mononuclear, eight-coordinate cobalt(II)-12-crown-4 (12C4) complex [Co(II)(12C4)2](I3)2(12C4) (1) with a large axial zero-field splitting. Magnetic measurements show field-induced, slow magnetic relaxation under an applied field of 500 Oe at low temperature. The magnetic relaxation time τ was fitted by the Arrhenius model to afford an energy barrier of Ueff = 17.0 cm(-1) and a preexponential factor of τ0 = 1.5 × 10(-6) s. The work here presents the first example of the eight-coordinate, mononuclear, 3d metal complex exhibiting the slow magnetic relaxation.
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Affiliation(s)
- Lei Chen
- State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, School of Chemistry and Chemical Engineering, Nanjing University , Nanjing 210093, China
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34
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High-frequency and high-field electron paramagnetic resonance (HFEPR): a new spectroscopic tool for bioinorganic chemistry. J Biol Inorg Chem 2014; 19:297-318. [DOI: 10.1007/s00775-013-1084-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 12/27/2013] [Indexed: 12/27/2022]
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35
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Pettinari C, Marchetti F, Orbisaglia S, Palmucci J, Pettinari R, Di Nicola C, Skelton BW, White AH. Synthesis, Characterization, and Crystal Structures of Scorpionate Complexes with the Hydrotris[3-(2′-thienyl)pyrazol-1-yl]borate Ligand. Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201301153] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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36
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Historical Introduction to Nitrosyl Complexes. NITROSYL COMPLEXES IN INORGANIC CHEMISTRY, BIOCHEMISTRY AND MEDICINE I 2014. [DOI: 10.1007/430_2013_116] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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37
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Martínez-Lillo J, Mastropietro TF, Lhotel E, Paulsen C, Cano J, De Munno G, Faus J, Lloret F, Julve M, Nellutla S, Krzystek J. Highly Anisotropic Rhenium(IV) Complexes: New Examples of Mononuclear Single-Molecule Magnets. J Am Chem Soc 2013; 135:13737-48. [DOI: 10.1021/ja403154z] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- José Martínez-Lillo
- Departament
de Química Inorgànica/Instituto de Ciencia Molecular
(ICMol), Universitat de València, C/Catedrático José
Beltrán 2, 46980 Paterna (València), Spain
| | - Teresa F. Mastropietro
- Centro
di Eccellenza CEMIF.CAL, Dipartimento di Chimica, Università della Calabria, 87030 Arcavacata di Rende, Cosenza, Italy
| | - Elsa Lhotel
- Institut Néel-CNRS, BP
166, 25 Avenue des Martyrs, 38042 Grenoble Cedex 9, France
| | - Carley Paulsen
- Institut Néel-CNRS, BP
166, 25 Avenue des Martyrs, 38042 Grenoble Cedex 9, France
| | - Joan Cano
- Departament
de Química Inorgànica/Instituto de Ciencia Molecular
(ICMol), Universitat de València, C/Catedrático José
Beltrán 2, 46980 Paterna (València), Spain
- Fundació
General de la Universitat de València (FGUV), Universitat de València, 46010 València, Spain
| | - Giovanni De Munno
- Centro
di Eccellenza CEMIF.CAL, Dipartimento di Chimica, Università della Calabria, 87030 Arcavacata di Rende, Cosenza, Italy
| | - Juan Faus
- Departament
de Química Inorgànica/Instituto de Ciencia Molecular
(ICMol), Universitat de València, C/Catedrático José
Beltrán 2, 46980 Paterna (València), Spain
| | - Francesc Lloret
- Departament
de Química Inorgànica/Instituto de Ciencia Molecular
(ICMol), Universitat de València, C/Catedrático José
Beltrán 2, 46980 Paterna (València), Spain
| | - Miguel Julve
- Departament
de Química Inorgànica/Instituto de Ciencia Molecular
(ICMol), Universitat de València, C/Catedrático José
Beltrán 2, 46980 Paterna (València), Spain
| | - Saritha Nellutla
- National
High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - J. Krzystek
- National
High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
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38
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Idešicová M, Titiš J, Krzystek J, Boča R. Zero-Field Splitting in Pseudotetrahedral Co(II) Complexes: a Magnetic, High-Frequency and -Field EPR, and Computational Study. Inorg Chem 2013; 52:9409-17. [DOI: 10.1021/ic400980b] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Monika Idešicová
- Department of Chemistry (FPV), University of SS. Cyril and Methodius, SK-917 01 Trnava,
Slovakia
| | - Ján Titiš
- Department of Chemistry (FPV), University of SS. Cyril and Methodius, SK-917 01 Trnava,
Slovakia
| | - J. Krzystek
- National High
Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Roman Boča
- Department of Chemistry (FPV), University of SS. Cyril and Methodius, SK-917 01 Trnava,
Slovakia
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39
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Abubekerov M, Gianetti TL, Kunishita A, Arnold J. Synthesis and characterization of coordinatively unsaturated nickel(II) and manganese(II) alkyl complexes supported by the hydrotris(3-phenyl-5-methylpyrazolyl)borate (Tp(Ph,Me)) ligand. Dalton Trans 2013; 42:10525-32. [PMID: 23748480 DOI: 10.1039/c3dt51087e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The synthesis of several nickel(II) and manganese(II) alkyl complexes supported by hydrotris(3-phenyl-5-methylpyrazolyl)borate (Tp(Ph,Me)) ligand is reported. The metal halide complexes Tp(Ph,Me)MnCl(CH3CN) (1) and Tp(Ph,Me)NiCl (4) were used as precursors for synthesis of Tp(Ph,Me)MnCH2Si(Me)3 (2), Tp(Ph,Me)MnCH2Ph (3), Tp(Ph,Me)NiCH2Si(Me)3 (5) and Tp(Ph,Me)NiCH2Ph (6). The resulting Mn(II) and Ni(II) alkyl complexes, 2-3 and 5-6, were characterized by X-ray crystallography, NMR spectroscopy, and FT-IR spectroscopy. X-ray crystallographic analysis revealed distorted tetrahedral geometries for complexes 2-3 and 5 with a κ(3)-Tp(Ph,Me). Complex 6, on the other hand, was found to have a distorted square planar geometry with κ(2)-Tp(Ph,Me) and an η(3)-benzyl ligand. Transformations of 4 and Tp(Ph,Me)CoCl (10) via treatment with NaN3 to yield Tp(Ph,Me)NiN3 (11), Tp(Ph,Me)CoN3 (12), along with the synthesis of (Tp(Ph,Me))2Ni (8) and Tp(Ph,Me)NiCl(3-Ph-5MepzH) (9) are also reported.
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Affiliation(s)
- Mark Abubekerov
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
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40
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Davydov RM, McLaughlin MP, Bill E, Hoffman BM, Holland PL. Generation of high-spin iron(I) in a protein environment using cryoreduction. Inorg Chem 2013; 52:7323-5. [PMID: 24004284 DOI: 10.1021/ic4011339] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
High-spin Fe(1+) sites are potentially important in iron-sulfur proteins but are rare in synthetic compounds and unknown in metalloproteins. Here, we demonstrate a spectroscopically characterized example of high-spin non-heme Fe(1+) in a protein environment. Cryoreduction of Fe(2+)-substituted azurin at 77 K with (60)Co γ radiation generates a new species with a S = (3)/2 (high-spin) Fe(1+) center having D > 0 and E/D ~ 0.25. This transient species is stable in a glycerol-water glass only up to ~170 K. A combination of electron paramagnetic resonance and Mössbauer spectroscopies provides a powerful means of identifying a transient high-spin Fe(1+) site in a protein scaffold.
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Affiliation(s)
- Roman M Davydov
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA
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41
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Chibotaru LF. Ab InitioMethodology for Pseudospin Hamiltonians of Anisotropic Magnetic Complexes. ADVANCES IN CHEMICAL PHYSICS 2013. [DOI: 10.1002/9781118571767.ch6] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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42
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Chandrasekhar V, Sahoo D, Metre RK. Isomorphic Co(ii) and Zn(ii) phosphonates: co-crystal formation of [{M2(η1-DMPzH)4(Cl3CPO3)2}{M(η1-DMPzH)2Cl2}2](toluene)2 (M = Co(ii) and Zn(ii)). CrystEngComm 2013. [DOI: 10.1039/c3ce40997j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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43
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Retegan M, Collomb MN, Neese F, Duboc C. A combined high-field EPR and quantum chemical study on a weakly ferromagnetically coupled dinuclear Mn(iii) complex. A complete analysis of the EPR spectrum beyond the strong coupling limit. Phys Chem Chem Phys 2013; 15:223-34. [DOI: 10.1039/c2cp42955a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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44
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Chibotaru LF, Ungur L. Ab initio calculation of anisotropic magnetic properties of complexes. I. Unique definition of pseudospin Hamiltonians and their derivation. J Chem Phys 2012; 137:064112. [PMID: 22897260 DOI: 10.1063/1.4739763] [Citation(s) in RCA: 499] [Impact Index Per Article: 41.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A methodology for the rigorous nonperturbative derivation of magnetic pseudospin Hamiltonians of mononuclear complexes and fragments based on ab initio calculations of their electronic structure is described. It is supposed that the spin-orbit coupling and other relativistic effects are already taken fully into account at the stage of quantum chemistry calculations of complexes. The methodology is based on the establishment of the correspondence between the ab initio wave functions of the chosen manifold of multielectronic states and the pseudospin eigenfunctions, which allows to define the pseudospin Hamiltonians in the unique way. Working expressions are derived for the pseudospin Zeeman and zero-field splitting Hamiltonian corresponding to arbitrary pseudospins. The proposed calculation methodology, already implemented in the SINGLE_ANISO module of the MOLCAS-7.6 quantum chemistry package, is applied for a first-principles evaluation of pseudospin Hamiltonians of several complexes exhibiting weak, moderate, and very strong spin-orbit coupling effects.
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Affiliation(s)
- L F Chibotaru
- Afdeling Kwantumchemie en Fysicochemie, Katholieke Universiteit Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
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45
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Forshaw AP, Smith JM, Ozarowski A, Krzystek J, Smirnov D, Zvyagin SA, Harris TD, Karunadasa HI, Zadrozny JM, Schnegg A, Holldack K, Jackson TA, Alamiri A, Barnes DM, Telser J. Low-Spin Hexacoordinate Mn(III): Synthesis and Spectroscopic Investigation of Homoleptic Tris(pyrazolyl)borate and Tris(carbene)borate Complexes. Inorg Chem 2012; 52:144-59. [DOI: 10.1021/ic301630d] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Adam P. Forshaw
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003, United
States
| | - Jeremy M. Smith
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003, United
States
| | - Andrew Ozarowski
- National High Magnetic
Field Laboratory (NHMFL), Florida State University, Tallahassee, Florida 32310, United States
| | - J. Krzystek
- National High Magnetic
Field Laboratory (NHMFL), Florida State University, Tallahassee, Florida 32310, United States
| | - Dmitry Smirnov
- National High Magnetic
Field Laboratory (NHMFL), Florida State University, Tallahassee, Florida 32310, United States
| | - S. A. Zvyagin
- Dresden High Magnetic Field Laboratory (HLD), Helmholtz-Zentrum Dresden-Rossendorf, D-01314
Dresden, Germany
| | - T. David Harris
- Department
of Chemistry, Northwestern University,
Evanston, Illinois 60208, United States
| | | | - Joseph M. Zadrozny
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Alexander Schnegg
- Helmholtz-Zentrum für Materialien
und Energie, Institut für Silizium-Photovoltaik, D-12489 Berlin, Germany
| | - Karsten Holldack
- Helmholtz-Zentrum für Materialien und Energie, Institut für Methoden und Instrumente der Forschung mit Synchrotronstrahlung, D-12489 Berlin, Germany
| | - Timothy A. Jackson
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Ahmad Alamiri
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, Illinois 60605, United
States
| | - Diane M. Barnes
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, Illinois 60605, United
States
| | - Joshua Telser
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, Illinois 60605, United
States
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46
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Eaton SS, Eaton GR. The world as viewed by and with unpaired electrons. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 223:151-63. [PMID: 22975244 PMCID: PMC3496796 DOI: 10.1016/j.jmr.2012.07.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2012] [Revised: 07/26/2012] [Accepted: 07/27/2012] [Indexed: 06/01/2023]
Abstract
Recent advances in electron paramagnetic resonance (EPR) include capabilities for applications to areas as diverse as archeology, beer shelf life, biological structure, dosimetry, in vivo imaging, molecular magnets, and quantum computing. Enabling technologies include multifrequency continuous wave, pulsed, and rapid scan EPR. Interpretation is enhanced by increasingly powerful computational models.
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Affiliation(s)
- Sandra S Eaton
- Department of Chemistry and Biochemistry, University of Denver, Denver, CO 80208, USA
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47
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Cobalt(II) scorpionate-like complexes obtained from in situ synthesized ligand created in [Co(0)–1-hydroxymethyl-3,5-dimethylpyrazole–VOSO4–NH4SCN] system. Polyhedron 2012. [DOI: 10.1016/j.poly.2012.08.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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48
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Schweinfurth D, Demeshko S, Khusniyarov MM, Dechert S, Gurram V, Buchmeiser MR, Meyer F, Sarkar B. Capped-Tetrahedrally Coordinated Fe(II) and Co(II) Complexes Using a “Click”-Derived Tripodal Ligand: Geometric and Electronic Structures. Inorg Chem 2012; 51:7592-7. [DOI: 10.1021/ic300392e] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- David Schweinfurth
- Institut für
Anorganische
Chemie, Universität Stuttgart, Pfaffenwaldring
55, D-70550, Stuttgart, Germany
| | - Serhiy Demeshko
- Institut für Anorganische
Chemie, Georg-August Universität Göttingen, Tammanstrasse 4, D-37077, Göttingen, Germany
| | - Marat M. Khusniyarov
- Department Chemie und Pharmazie, Friedrich-Alexander Universität Erlangen-Nürnberg, Egerlandstrasse 1, D-91058, Erlangen, Germany
| | - Sebastian Dechert
- Institut für Anorganische
Chemie, Georg-August Universität Göttingen, Tammanstrasse 4, D-37077, Göttingen, Germany
| | | | - Michael R. Buchmeiser
- Institut für Polymerchemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550,
Stuttgart, Germany
| | - Franc Meyer
- Institut für Anorganische
Chemie, Georg-August Universität Göttingen, Tammanstrasse 4, D-37077, Göttingen, Germany
| | - Biprajit Sarkar
- Institut für
Anorganische
Chemie, Universität Stuttgart, Pfaffenwaldring
55, D-70550, Stuttgart, Germany
- Institut für Chemie und
Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstrasse 34-36, D-14195, Berlin, Germany
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49
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Mathies G, Almeida RM, Gast P, Moura JJG, Groenen EJJ. Multifrequency EPR study of Fe3+ and Co2+ in the active site of desulforedoxin. J Phys Chem B 2012; 116:7122-8. [PMID: 22612627 DOI: 10.1021/jp3025655] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The understanding of the electronic structure of S > 1/2 transition-metal sites that show a large zero-field splitting (ZFS) of the magnetic sublevels benefits greatly from study by electron-paramagnetic-resonance (EPR) spectroscopy at frequencies above the standard 9.5 GHz. However, high-frequency EPR spectroscopy is technically challenging and still developing. Particularly the sensitivity of high-frequency EPR spectrometers is often too low to apply the technique in the study of transition-metal sites in proteins and enzymes. Here we report a multifrequency EPR study (at 9.5, 94.9, and 275.7 GHz) of the active site of the protein desulforedoxin, both in its natural Fe(3+) form and substituted with Co(2+). The 275.7 GHz EPR spectra made it possible to determine the ZFS parameters of the Fe(3+) site with high precision. No 275.7 GHz spectrum could be observed of the Co(2+) site, but based on 9.5 GHz spectra, its ZFS parameters could be estimated. We find that the typical variation in the geometry of the active site of a protein or enzyme, referred to as conformational strain, does not only make the detection of EPR spectra challenging, but also their analysis. Comparison of the EPR results on the active site of desulforedoxin to those of the closely related active site of rubredoxin illustrates the necessity of explicit quantum-chemical calculations in order to interrelate the electronic and geometric structure of biological transition-metal sites.
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Affiliation(s)
- Guinevere Mathies
- Department of Physics, Huygens Laboratory, Leiden University, The Netherlands
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50
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Chiang KP, Scarborough CC, Horitani M, Lees NS, Ding K, Dugan TR, Brennessel WW, Bill E, Hoffman BM, Holland PL. Characterization of the Fe-H bond in a three-coordinate terminal hydride complex of iron(I). Angew Chem Int Ed Engl 2012; 51:3658-62. [PMID: 22374689 PMCID: PMC3740144 DOI: 10.1002/anie.201109204] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Indexed: 11/11/2022]
Affiliation(s)
- Karen P. Chiang
- Department of Chemistry, University of Rochester, Rochester, NY 14627 USA, Fax: +1-585-276-0205
| | | | - Masaki Horitani
- Department of Chemistry, Northwestern University, Evanston, IL 60208 USA
| | - Nicholas S. Lees
- Department of Chemistry, Northwestern University, Evanston, IL 60208 USA
| | - Keying Ding
- Department of Chemistry, University of Rochester, Rochester, NY 14627 USA, Fax: +1-585-276-0205
| | - Thomas R. Dugan
- Department of Chemistry, University of Rochester, Rochester, NY 14627 USA, Fax: +1-585-276-0205
| | - William W. Brennessel
- Department of Chemistry, University of Rochester, Rochester, NY 14627 USA, Fax: +1-585-276-0205
| | - Eckhard Bill
- Max-Planck-Institut für Bioanorganische Chemie, Mülheim an der Ruhr, D45470, Germany
| | - Brian M. Hoffman
- Department of Chemistry, Northwestern University, Evanston, IL 60208 USA
| | - Patrick L. Holland
- Department of Chemistry, University of Rochester, Rochester, NY 14627 USA, Fax: +1-585-276-0205
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