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: 4] [Impact Index Per Article: 4.0] [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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Van Trieste GP, Reid KA, Hicks MH, Das A, Figgins MT, Bhuvanesh N, Ozarowski A, Telser J, Powers DC. Nitrene Photochemistry of Manganese
N
‐Haloamides**. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202108304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Kaleb A. Reid
- Department of Chemistry Texas A&M University College Station TX 77843 USA
| | - Madeline H. Hicks
- Department of Chemistry Texas A&M University College Station TX 77843 USA
| | - Anuvab Das
- Department of Chemistry Texas A&M University College Station TX 77843 USA
| | - Matthew T. Figgins
- Department of Chemistry Texas A&M University College Station TX 77843 USA
| | - Nattamai Bhuvanesh
- Department of Chemistry Texas A&M University College Station TX 77843 USA
| | - Andrew Ozarowski
- National High Magnetic Field Laboratory Florida State University Tallahassee FL 32310 USA
| | - Joshua Telser
- Department of Biological, Physical and Chemical Sciences Roosevelt University Chicago IL 60605 USA
| | - David C. Powers
- Department of Chemistry Texas A&M University College Station TX 77843 USA
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3
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Van Trieste GP, Reid KA, Hicks MH, Das A, Figgins MT, Bhuvanesh N, Ozarowski A, Telser J, Powers DC. Nitrene Photochemistry of Manganese N-Haloamides*. Angew Chem Int Ed Engl 2021; 60:26647-26655. [PMID: 34662473 DOI: 10.1002/anie.202108304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Indexed: 11/06/2022]
Abstract
Manganese complexes supported by macrocyclic tetrapyrrole ligands represent an important platform for nitrene transfer catalysis and have been applied to both C-H amination and olefin aziridination catalysis. The reactivity of the transient high-valent Mn nitrenoids that mediate these processes renders characterization of these species challenging. Here we report the synthesis and nitrene transfer photochemistry of a family of MnIII N-haloamide complexes. The S=2 N-haloamide complexes are characterized by 1 H NMR, UV-vis, IR, high-frequency and -field EPR (HFEPR) spectroscopies, and single-crystal X-ray diffraction. Photolysis of these complexes results in the formal transfer of a nitrene equivalent to both C-H bonds, such as the α-C-H bonds of tetrahydrofuran, and olefinic substrates, such as styrene, to afford aminated and aziridinated products, respectively. Low-temperature spectroscopy and analysis of kinetic isotope effects for C-H amination indicate halogen-dependent photoreactivity: Photolysis of N-chloroamides proceeds via initial cleavage of the Mn-N bond to generate MnII and amidyl radical intermediates; in contrast, photolysis of N-iodoamides proceeds via N-I cleavage to generate a MnIV nitrenoid (i.e., {MnNR}7 species). These results establish N-haloamide ligands as viable precursors in the photosynthesis of metal nitrenes and highlight the power of ligand design to provide access to reactive intermediates in group-transfer catalysis.
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Affiliation(s)
| | - Kaleb A Reid
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Madeline H Hicks
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Anuvab Das
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Matthew T Figgins
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Nattamai Bhuvanesh
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Andrew Ozarowski
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
| | - Joshua Telser
- Department of Biological, Physical and Chemical Sciences, Roosevelt University, Chicago, IL, 60605, USA
| | - David C Powers
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
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4
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Bone AN, Widener CN, Moseley DH, Liu Z, Lu Z, Cheng Y, Daemen LL, Ozerov M, Telser J, Thirunavukkuarasu K, Smirnov D, Greer SM, Hill S, Krzystek J, Holldack K, Aliabadi A, Schnegg A, Dunbar KR, Xue ZL. Applying Unconventional Spectroscopies to the Single-Molecule Magnets, Co(PPh 3 ) 2 X 2 (X=Cl, Br, I): Unveiling Magnetic Transitions and Spin-Phonon Coupling. Chemistry 2021; 27:11110-11125. [PMID: 33871890 DOI: 10.1002/chem.202100705] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Indexed: 11/11/2022]
Abstract
Large separation of magnetic levels and slow relaxation in metal complexes are desirable properties of single-molecule magnets (SMMs). Spin-phonon coupling (interactions of magnetic levels with phonons) is ubiquitous, leading to magnetic relaxation and loss of memory in SMMs and quantum coherence in qubits. Direct observation of magnetic transitions and spin-phonon coupling in molecules is challenging. We have found that far-IR magnetic spectra (FIRMS) of Co(PPh3 )2 X2 (Co-X; X=Cl, Br, I) reveal rarely observed spin-phonon coupling as avoided crossings between magnetic and u-symmetry phonon transitions. Inelastic neutron scattering (INS) gives phonon spectra. Calculations using VASP and phonopy programs gave phonon symmetries and movies. Magnetic transitions among zero-field split (ZFS) levels of the S=3/2 electronic ground state were probed by INS, high-frequency and -field EPR (HFEPR), FIRMS, and frequency-domain FT terahertz EPR (FD-FT THz-EPR), giving magnetic excitation spectra and determining ZFS parameters (D, E) and g values. Ligand-field theory (LFT) was used to analyze earlier electronic absorption spectra and give calculated ZFS parameters matching those from the experiments. DFT calculations also gave spin densities in Co-X, showing that the larger Co(II) spin density in a molecule, the larger its ZFS magnitude. The current work reveals dynamics of magnetic and phonon excitations in SMMs. Studies of such couplings in the future would help to understand how spin-phonon coupling may lead to magnetic relaxation and develop guidance to control such coupling.
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Affiliation(s)
- Alexandria N Bone
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - Chelsea N Widener
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - Duncan H Moseley
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - Zhiming Liu
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - Zhengguang Lu
- National High Magnetic Field Laboratory, Tallahassee, Florida, 32310, USA
| | - Yongqiang Cheng
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Luke L Daemen
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Tallahassee, Florida, 32310, USA
| | - Joshua Telser
- Department of Biological, Physical and Chemical Sciences, Roosevelt University, Chicago, Illinois, 60605, USA
| | | | - Dmitry Smirnov
- National High Magnetic Field Laboratory, Tallahassee, Florida, 32310, USA
| | - Samuel M Greer
- National High Magnetic Field Laboratory, Tallahassee, Florida, 32310, USA.,Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida, 32306, USA
| | - Stephen Hill
- National High Magnetic Field Laboratory, Tallahassee, Florida, 32310, USA.,Department of Physics, Florida State University, Tallahassee, Florida, 32306, USA
| | - J Krzystek
- National High Magnetic Field Laboratory, Tallahassee, Florida, 32310, USA
| | - Karsten Holldack
- Helmholtz-Zentrum Berlin für Materialien und Energie Gmbh, Institut für Methoden und Instrumente der Forschung mit Synchrotronstrahlung, 12489, Berlin, Germany
| | - Azar Aliabadi
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Institut für Nanospektroskopie, Berlin Joint EPR Laboratory, 12489, Berlin, Germany
| | - Alexander Schnegg
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Institut für Nanospektroskopie, Berlin Joint EPR Laboratory, 12489, Berlin, Germany.,Max Planck Institute for Chemical Energy Conversion, 45470, Mülheim an der Ruhr, Germany
| | - Kim R Dunbar
- Department of Chemistry, Texas A&M University, College Station, Texas, 77842, USA
| | - Zi-Ling Xue
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee, 37996, USA
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5
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Kelai M, Cahier B, Atanasov M, Neese F, Tong Y, Zhang L, Bellec A, Iasco O, Rivière E, Guillot R, Chacon C, Girard Y, Lagoute J, Rousset S, Repain V, Otero E, Arrio MA, Sainctavit P, Barra AL, Boillot ML, Mallah T. Robust magnetic anisotropy of a monolayer of hexacoordinate Fe( ii) complexes assembled on Cu(111). Inorg Chem Front 2021. [DOI: 10.1039/d1qi00085c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The tris pyrazolyl borate ligand imposes a rigid scaffold around Fe(ii) ensuring a robust magnetic anisotropy when the molecules assembled as monolayers suffer from the dissymmetric environment of the substrate/vacuum interface.
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6
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Chapyshev SV, Korchagin DV, Misochko EY. Recent advances in chemistry of high-spin nitrenes. RUSSIAN CHEMICAL REVIEWS 2021. [DOI: 10.1070/rcr4965] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Experimental and theoretical studies on aromatic nitrenes bearing from three to six unpaired electrons and having quartet, quintet, sextet or septet ground spin states, published in the last 15 years are analyzed. A comparative analysis of the magnetic properties of high-spin nitrenes and all other known high-spin organic molecules is performed. Promising areas of practical application of high-spin nitrenes as molecular magnets and as qubits and qudits for quantum computations are discussed.
The bibliography includes 214 references.
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7
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S-Functionalized Tripods with Monomethylene Spacers: Routes to Tetrairon(III) Single-Molecule Magnets with Ultrashort Tethering Groups. MAGNETOCHEMISTRY 2020. [DOI: 10.3390/magnetochemistry6040055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The organization of single-molecule magnets (SMMs) on surfaces is a mainstream research path in molecular magnetism. Of special importance is the control of grafting geometry in chemisorbed monolayers on metal surfaces. We herein present the synthesis, solid-state structure, and magnetic characterization of propeller-like tetrairon(III) SMMs containing the shortest-reported tethering groups for gold surfaces. Functionalization of molecular structure is attained using 2-R-2-(hydroxymethyl)propane-1,3-diol tripodal proligands (H3LR). The R substituents comprise a monomethylene spacer and three different terminations known to act as stable precursors of S-Au bonds (R = CH2SCN, CH2SAc and CH2SSnBu). These chemical groups are shown to be chemically compatible with the tetrairon(III) core and to afford fully-functional SMMs in crystalline form and in fair to excellent yields.
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8
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Sanakis Y, Krzystek J, Maganas D, Grigoropoulos A, Ferentinos E, Kostakis MG, Petroulea V, Pissas M, Thirunavukkuarasu K, Wernsdorfer W, Neese F, Kyritsis P. Magnetic Properties and Electronic Structure of the S = 2 Complex [Mn III{(OPPh 2) 2N} 3] Showing Field-Induced Slow Magnetization Relaxation. Inorg Chem 2020; 59:13281-13294. [PMID: 32897702 DOI: 10.1021/acs.inorgchem.0c01636] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The high-spin S = 2 Mn(III) complex [Mn{(OPPh2)2N}3] (1Mn) exhibits field-induced slow relaxation of magnetization (Inorg. Chem. 2013, 52, 12869). Magnetic susceptibility and dual-mode X-band electron paramagnetic resonance (EPR) studies revealed a negative value of the zero-field-splitting (zfs) parameter D. In order to explore the magnetic and electronic properties of 1Mn in detail, a combination of experimental and computational studies is presented herein. Alternating-current magnetometry on magnetically diluted samples (1Mn/1Ga) of 1Mn in the diamagnetic gallium analogue, [Ga{(OPPh2)2N}3], indicates that the slow relaxation behavior of 1Mn is due to the intrinsic properties of the individual molecules of 1Mn. Investigation of the single-crystal magnetization of both 1Mn and 1Mn/1Ga by a micro-SQUID device reveals hysteresis loops below 1 K. Closed hysteresis loops at a zero direct-current magnetic field are observed and attributed to fast quantum tunneling of magnetization. High-frequency and -field EPR (HFEPR) spectroscopic studies reveal that, apart from the second-order zfs terms (D and E), fourth-order terms (B4m) are required in order to appropriately describe the magnetic properties of 1Mn. These studies provide accurate spin-Hamiltonian (sH) parameters of 1Mn, i.e., zfs parameters |D| = 3.917(5) cm-1, |E| = 0.018(4) cm-1, B04 = B42 = 0, and B44 = (3.6 ± 1.7) × 10-3 cm-1 and g = [1.994(5), 1.996(4), 1.985(4)], and confirm the negative sign of D. Parallel-mode X-band EPR studies on 1Mn/1Ga and CH2Cl2 solutions of 1Mn probe the electronic-nuclear hyperfine interactions in the solid state and solution. The electronic structure of 1Mn is investigated by quantum-chemical calculations by employing recently developed computational protocols that are grounded on ab initio wave function theory. From computational analysis, the contributions of spin-spin and spin-orbit coupling to the magnitude of D are obtained. The calculations provide also computed values of the fourth-order zfs terms B4m, as well as those of the g and hyperfine interaction tensor components. In all cases, a very good agreement between the computed and experimentally determined sH parameters is observed. The magnetization relaxation properties of 1Mn are rationalized on the basis of the composition of the ground-state wave functions in the absence or presence of an external magnetic field.
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Affiliation(s)
- Yiannis Sanakis
- Institute of Nanoscience and Nanotechnolgy, National Centre of Scientific Research "Demokritos", Aghia Paraskevi 15310, Attiki, Greece
| | - J Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Dimitrios Maganas
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Alexios Grigoropoulos
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
| | - Eleftherios Ferentinos
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
| | - Marios G Kostakis
- Analytical Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens,15771 Athens, Greece
| | - Vasiliki Petroulea
- Institute of Nanoscience and Nanotechnolgy, National Centre of Scientific Research "Demokritos", Aghia Paraskevi 15310, Attiki, Greece
| | - Michael Pissas
- Institute of Nanoscience and Nanotechnolgy, National Centre of Scientific Research "Demokritos", Aghia Paraskevi 15310, Attiki, Greece
| | | | - Wolfgang Wernsdorfer
- Physikalisches Institut, Karlsruher Institut für Technologie, Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany.,Institute of Quantum Materials and Technologies, Karlsruher Institut für Technologie, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Frank Neese
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Panayotis Kyritsis
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
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9
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Manganese tetraphenylporphyrin bromide and iodide. Studies of structures and magnetic properties. Polyhedron 2020. [DOI: 10.1016/j.poly.2020.114488] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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10
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Cornia A, Barra AL, Bulicanu V, Clérac R, Cortijo M, Hillard EA, Galavotti R, Lunghi A, Nicolini A, Rouzières M, Sorace L, Totti F. The Origin of Magnetic Anisotropy and Single-Molecule Magnet Behavior in Chromium(II)-Based Extended Metal Atom Chains. Inorg Chem 2020; 59:1763-1777. [PMID: 31967457 PMCID: PMC7901656 DOI: 10.1021/acs.inorgchem.9b02994] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Indexed: 02/08/2023]
Abstract
Chromium(II)-based extended metal atom chains have been the focus of considerable discussion regarding their symmetric versus unsymmetric structure and magnetism. We have now investigated four complexes of this class, namely, [Cr3(dpa)4X2] and [Cr5(tpda)4X2] with X = Cl- and SCN- [Hdpa = dipyridin-2-yl-amine; H2tpda = N2,N6-di(pyridin-2-yl)pyridine-2,6-diamine]. By dc/ac magnetic techniques and EPR spectroscopy, we found that all these complexes have easy-axis anisotropies of comparable magnitude in their S = 2 ground state (|D| = 1.5-1.8 cm-1) and behave as single-molecule magnets at low T. Ligand-field and DFT/CASSCF calculations were used to explain the similar magnetic properties of tri- versus pentachromium(II) strings, in spite of their different geometrical preferences and electronic structure. For both X ligands, the ground structure is unsymmetric in the pentachromium(II) species (i.e., with an alternation of long and short Cr-Cr distances) but is symmetric in their shorter congeners. Analysis of the electronic structure using quasi-restricted molecular orbitals (QROs) showed that the four unpaired electrons in Cr5 species are largely localized in four 3d-like QROs centered on the terminal, "isolated" Cr2+ ion. In Cr3 complexes, they occupy four nonbonding combinations of 3d-like orbitals centered only on the two terminal metals. In both cases, then, QRO eigenvalues closely mirror the 3d-level pattern of the terminal ions, whose coordination environment remains quite similar irrespective of chain length. We conclude that the extent of unpaired-electron delocalization has little impact on the magnetic anisotropy of these wire-like molecular species.
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Affiliation(s)
- Andrea Cornia
- Department of Chemical and Geological Sciences,
University of Modena and Reggio Emilia & INSTM, 41125
Modena, Italy
| | - Anne-Laure Barra
- Laboratoire National des Champs Magnétiques
Intenses-CNRS, Université Grenoble-Alpes, 38042 Grenoble
Cedex 9, France
| | - Vladimir Bulicanu
- Univ. Bordeaux, CNRS, Centre de Recherche
Paul Pascal, CRPP, UMR 5031, 33600 Pessac, France
| | - Rodolphe Clérac
- Univ. Bordeaux, CNRS, Centre de Recherche
Paul Pascal, CRPP, UMR 5031, 33600 Pessac, France
| | - Miguel Cortijo
- Univ. Bordeaux, CNRS, Centre de Recherche
Paul Pascal, CRPP, UMR 5031, 33600 Pessac, France
| | - Elizabeth A. Hillard
- Univ. Bordeaux, CNRS, Centre de Recherche
Paul Pascal, CRPP, UMR 5031, 33600 Pessac, France
| | - Rita Galavotti
- Department of Chemical and Geological Sciences,
University of Modena and Reggio Emilia & INSTM, 41125
Modena, Italy
| | - Alessandro Lunghi
- School of Physics and CRANN Institute,
Trinity College Dublin, Dublin 2,
Ireland
| | - Alessio Nicolini
- Department of Chemical and Geological Sciences,
University of Modena and Reggio Emilia & INSTM, 41125
Modena, Italy
- Department of Physics, Informatics, and Mathematics,
University of Modena and Reggio Emilia, 41125 Modena,
Italy
| | - Mathieu Rouzières
- Univ. Bordeaux, CNRS, Centre de Recherche
Paul Pascal, CRPP, UMR 5031, 33600 Pessac, France
| | - Lorenzo Sorace
- Department of Chemistry “Ugo Schiff”,
University of Florence & INSTM, 50019 Sesto Fiorentino
(FI), Italy
| | - Federico Totti
- Department of Chemistry “Ugo Schiff”,
University of Florence & INSTM, 50019 Sesto Fiorentino
(FI), Italy
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11
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Ferromagnetically-coupled, triangular, [Bu4N]2[CuII3(μ3-Br)2(μ-4-O2N-pz)3Br3] complex revisited: The effect of coordinated halides on spin relaxation properties. Polyhedron 2020. [DOI: 10.1016/j.poly.2019.114258] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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12
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Krzystek J, Schnegg A, Aliabadi A, Holldack K, Stoian SA, Ozarowski A, Hicks SD, Abu-Omar MM, Thomas KE, Ghosh A, Caulfield KP, Tonzetich ZJ, Telser J. Advanced Paramagnetic Resonance Studies on Manganese and Iron Corroles with a Formal d 4 Electron Count. Inorg Chem 2020; 59:1075-1090. [PMID: 31909979 DOI: 10.1021/acs.inorgchem.9b02635] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Metallocorroles wherein the metal ion is MnIII and formally FeIV are studied here using field- and frequency-domain electron paramagnetic resonance techniques. The MnIII corrole, Mn(tpfc) (tpfc = 5,10,15-tris(pentafluorophenyl)corrole trianion), exhibits the following S = 2 zero-field splitting (zfs) parameters: D = -2.67(1) cm-1, |E| = 0.023(5) cm-1. This result and those for other MnIII tetrapyrroles indicate that when D ≈ - 2.5 ± 0.5 cm-1 for 4- or 5-coordinate and D ≈ - 3.5 ± 0.5 cm-1 for 6-coordinate complexes, the ground state description is [MnIII(Cor3-)]0 or [MnIII(P2-)]+ (Cor = corrole, P = porphyrin). The situation for formally FeIV corroles is more complicated, and it has been shown that for Fe(Cor)X, when X = Ph (phenyl), the ground state is a spin triplet best described by [FeIV(Cor3-)]+, but when X = halide, the ground state corresponds to [FeIII(Cor•2-)]+, wherein an intermediate spin (S = 3/2) FeIII is antiferromagnetically coupled to a corrole radical dianion (S = 1/2) to also give an S = 1 ground state. These two valence isomers can be distinguished by their zfs parameters, as determined here for Fe(tpc)X, X = Ph, Cl (tpc = 5,10,15-triphenylcorrole trianion). The complex with axial phenyl gives D = 21.1(2) cm-1, while that with axial chloride gives D = 14.6(1) cm-1. The D value for Fe(tpc)Ph is in rough agreement with the range of values reported for other FeIV complexes. In contrast, the D value for Fe(tpc)Cl is inconsistent with an FeIV description and represents a different type of iron center. Computational studies corroborate the zfs for the two types of iron corrole complexes. Thus, the zfs of metallocorroles can be diagnostic as to the electronic structure of a formally high oxidation state metallocorrole, and by extension to metalloporphyrins, although such studies have yet to be performed.
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Affiliation(s)
- J Krzystek
- National High Magnetic Field Laboratory , Florida State University , Tallahassee , Florida 32310 , United States
| | - Alexander Schnegg
- EPR Research Group , Max Planck Institute for Chemical Energy Conversion , Stiftstraße 34-36 , D-45470 Mülheim Ruhr , Germany.,Berlin Joint EPR Laboratory , Helmholtz-Zentrum Berlin , Kekulestraße 5 , D-12489 Berlin , Germany
| | - Azar Aliabadi
- Berlin Joint EPR Laboratory , Helmholtz-Zentrum Berlin , Kekulestraße 5 , D-12489 Berlin , Germany
| | - Karsten Holldack
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung am Elektronenspeicherring BESSY II , Albert-Einstein-Straße 15 , D-12489 Berlin , Germany
| | - Sebastian A Stoian
- Department of Chemistry , University of Idaho , Moscow , Idaho 83844 , United States
| | - Andrew Ozarowski
- National High Magnetic Field Laboratory , Florida State University , Tallahassee , Florida 32310 , United States
| | - Scott D Hicks
- Department of Chemistry , Purdue University , West Lafayette , Indiana 47907 , United States
| | - Mahdi M Abu-Omar
- Departments of Chemistry and Biochemistry , University of California , Santa Barbara , California 93106-9510 , United States
| | - Kolle E Thomas
- Department of Chemistry , UiT-The Arctic University of Norway , N-9037 Tromsø , Norway
| | - Abhik Ghosh
- Department of Chemistry , UiT-The Arctic University of Norway , N-9037 Tromsø , Norway
| | - Kenneth P Caulfield
- Department of Chemistry , University of Texas at San Antonio (UTSA) , One UTSA Circle , San Antonio , Texas 78249 , United States
| | - Zachary J Tonzetich
- Department of Chemistry , University of Texas at San Antonio (UTSA) , One UTSA Circle , San Antonio , Texas 78249 , United States
| | - Joshua Telser
- Department of Biological, Physical, and Health Sciences , Roosevelt University , Chicago , Illinois 60605 , United States
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13
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Krzystek J, Kohl G, Hansen HB, Enders M, Telser J. Combining HFEPR and NMR Spectroscopies to Characterize Organochromium(III) Complexes with Large Zero-Field Splitting. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00158] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J. Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Gerald Kohl
- Institute of Inorganic Chemistry, Heidelberg University, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
| | - Helge-Boj Hansen
- Institute of Inorganic Chemistry, Heidelberg University, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
| | - Markus Enders
- Institute of Inorganic Chemistry, Heidelberg University, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
| | - Joshua Telser
- Department of Biological, Physical and Health Sciences, Roosevelt University, 430 S. Michigan Avenue, Chicago, Illinois 60605, United States
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14
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Tezgerevska T, Rousset E, Gable RW, Jameson GNL, Sañudo EC, Starikova A, Boskovic C. Valence tautomerism and spin crossover in pyridinophane–cobalt–dioxolene complexes: an experimental and computational study. Dalton Trans 2019; 48:11674-11689. [DOI: 10.1039/c9dt02372k] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Variation of alkyl substituents on pyridinophane ancillary ligands governs temperature-dependent valence tautomeric or spin crossover equilibria in a family of cobalt–dioxolene complexes.
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Affiliation(s)
| | - Elodie Rousset
- School of Chemistry
- University of Melbourne
- Melbourne
- Australia
| | - Robert W. Gable
- School of Chemistry
- University of Melbourne
- Melbourne
- Australia
| | | | - E. Carolina Sañudo
- Departament de Química Inorgànica i Orgànica
- Universitat de Barcelona
- 08028 Barcelona
- Spain
- Institut de Nanociència i Nanotecnologia
| | - Alyona Starikova
- Institute of Physical and Organic Chemistry
- Southern Federal University
- 344090 Rostov on Don
- Russian Federation
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15
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Tao L, Stich TA, Soldatova AV, Tebo BM, Spiro TG, Casey WH, Britt RD. Mn(III) species formed by the multi-copper oxidase MnxG investigated by electron paramagnetic resonance spectroscopy. J Biol Inorg Chem 2018; 23:1093-1104. [PMID: 29968177 DOI: 10.1007/s00775-018-1587-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 06/22/2018] [Indexed: 01/24/2023]
Abstract
The multi-copper oxidase (MCO) MnxG from marine Bacillus bacteria plays an essential role in geochemical cycling of manganese by oxidizing Mn2+(aq) to form manganese oxide minerals at rates that are three to five orders of magnitude faster than abiotic rates. The MCO MnxG protein is isolated as part of a multi-protein complex, denoted as Mnx, which includes one MnxG unit and a hexamer of MnxE3F3 subunit. During the oxidation of Mn2+(aq) catalyzed by the Mnx protein complex, an enzyme-bound Mn(III) species was trapped recently in the presence of pyrophosphate (PP) and analyzed using parallel-mode electron paramagnetic resonance (EPR) spectroscopy. Herein, we provide a full analysis of this enzyme-bound Mn(III) intermediate via temperature dependence studies and spectral simulations. This Mnx-bound Mn(III) species is characterized by a hyperfine-coupling value of A(55Mn) = 4.2 mT (corresponding to 120 MHz) and a negative zero-field splitting (ZFS) value of D = - 2.0 cm-1. These magnetic properties suggest that the Mnx-bound Mn(III) species could be either six-coordinate with a 5B1g ground state or square-pyramidal five-coordinate with a 5B1 ground state. In addition, as a control, Mn(III)PP is also analyzed by parallel-mode EPR spectroscopy. It exhibits distinctly different magnetic properties with a hyperfine-coupling value of A(55Mn) = 4.8 mT (corresponding to 140 MHz) and a negative ZFS value of D = - 2.5 cm-1. The different ZFS values suggest differences in ligand environment of Mnx-bound Mn(III) and aqueous Mn(III)PP species. These studies provide further insights into the mechanism of biological Mn2+(aq) oxidation.
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Affiliation(s)
- Lizhi Tao
- Department of Chemistry, University of California, One Shields Avenue, Davis, CA, 95616, USA
| | - Troy A Stich
- Department of Chemistry, University of California, One Shields Avenue, Davis, CA, 95616, USA
| | - Alexandra V Soldatova
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA, 98195, USA
| | - Bradley M Tebo
- Division of Environmental and Biomolecular Systems, Oregon Health and Science University, Portland, OR, 97239, USA
| | - Thomas G Spiro
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA, 98195, USA
| | - William H Casey
- Department of Chemistry, University of California, One Shields Avenue, Davis, CA, 95616, USA
- Department of Geology, University of California, One Shields Avenue, Davis, CA, 95616, USA
| | - R David Britt
- Department of Chemistry, University of California, One Shields Avenue, Davis, CA, 95616, USA.
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16
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Wang L, Zlatar M, Vlahović F, Demeshko S, Philouze C, Molton F, Gennari M, Meyer F, Duboc C, Gruden M. Experimental and Theoretical Identification of the Origin of Magnetic Anisotropy in Intermediate Spin Iron(III) Complexes. Chemistry 2018; 24:5091-5094. [PMID: 29447424 PMCID: PMC5969241 DOI: 10.1002/chem.201705989] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Indexed: 11/24/2022]
Abstract
The complexes [FeLN2S2X] [in which LN2S2=2,2′‐(2,2′‐bipryridine‐6,6′‐diyl)bis(1,1′‐diphenylethanethiolate) and X=Cl, Br and I], characterized crystallographically earlier and here (Fe(L)Br), reveal a square pyramidal coordinated FeIII ion. Unusually, all three complexes have intermediate spin ground states. Susceptibility measurements, powder cw X‐ and Q‐band EPR spectra, and zero‐field powder Mössbauer spectra show that all complexes display distinct magnetic anisotropy, which has been rationalized by DFT calculations.
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Affiliation(s)
- Lianke Wang
- University of Grenoble Alpes, DCM, CNRS UMR 5250, Grenoble, France
| | - Matija Zlatar
- Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Serbia
| | - Filip Vlahović
- Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, 11000, Belgrade, Serbia
| | - Serhiy Demeshko
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstr. 4, 37077, Göttingen, Germany
| | | | - Florian Molton
- University of Grenoble Alpes, DCM, CNRS UMR 5250, Grenoble, France
| | - Marcello Gennari
- University of Grenoble Alpes, DCM, CNRS UMR 5250, Grenoble, France
| | - Franc Meyer
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstr. 4, 37077, Göttingen, Germany
| | - Carole Duboc
- University of Grenoble Alpes, DCM, CNRS UMR 5250, Grenoble, France
| | - Maja Gruden
- Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, 11000, Belgrade, Serbia
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17
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Tadyszak K, Rudowicz C, Ohta H, Sakurai T. Electron magnetic resonance data on high-spin Mn(III; S = 2) ions in porphyrinic and salen complexes modeled by microscopic spin Hamiltonian approach. J Inorg Biochem 2017; 175:36-46. [DOI: 10.1016/j.jinorgbio.2017.06.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 06/15/2017] [Accepted: 06/19/2017] [Indexed: 10/19/2022]
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18
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Shova S, Vlad A, Cazacu M, Krzystek J, Bucinsky L, Breza M, Darvasiová D, Rapta P, Cano J, Telser J, Arion VB. A five-coordinate manganese(iii) complex of a salen type ligand with a positive axial anisotropy parameter D. Dalton Trans 2017; 46:11817-11829. [DOI: 10.1039/c7dt01809f] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Quantum chemical calculations reproduced well the electronic absorption spectrum and spin Hamiltonian parameters for MnL(NCS).
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Affiliation(s)
- Sergiu Shova
- Inorganic Polymers Department
- “Petru Poni” Institute of Macromolecular Chemistry
- Iasi 700487
- Romania
| | - Angelica Vlad
- Inorganic Polymers Department
- “Petru Poni” Institute of Macromolecular Chemistry
- Iasi 700487
- Romania
| | - Maria Cazacu
- Inorganic Polymers Department
- “Petru Poni” Institute of Macromolecular Chemistry
- Iasi 700487
- Romania
| | - J. Krzystek
- National High Magnetic Field Laboratory
- Florida State University
- Tallahassee
- USA
| | - Lukas Bucinsky
- Institute of Physical Chemistry and Chemical Physics
- Slovak University of Technology
- 81237 Bratislava
- Slovak Republic
| | - Martin Breza
- Institute of Physical Chemistry and Chemical Physics
- Slovak University of Technology
- 81237 Bratislava
- Slovak Republic
| | - Denisa Darvasiová
- Institute of Physical Chemistry and Chemical Physics
- Slovak University of Technology
- 81237 Bratislava
- Slovak Republic
| | - Peter Rapta
- Institute of Physical Chemistry and Chemical Physics
- Slovak University of Technology
- 81237 Bratislava
- Slovak Republic
| | - Joan Cano
- Institut de Ciència Molecular
- Universitat de València
- 46980 Paterna
- Spain
| | - Joshua Telser
- Department of Biological
- Chemical and Physical Sciences
- Roosevelt University
- Chicago
- USA
| | - Vladimir B. Arion
- Institute of Inorganic Chemistry of the University of Vienna
- A1090 Vienna
- Austria
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19
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Dolai M, Mondal A, Liu JL, Ali M. Three novel mononuclear Mn(iii)-based magnetic materials with square pyramidal versus octahedral geometries. NEW J CHEM 2017. [DOI: 10.1039/c7nj02919e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Single crystal X-ray diffraction studies reveal that complexes 1 and 2 have square pyramidal geometry and 3 has octahedral geometry, which showed a dependence of negative anisotropy (D) values on the electronic, geometry and packing effects.
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Affiliation(s)
- Malay Dolai
- Department of Chemistry Jadavpur University
- Kolkata 700 032
- India
| | - Abhishake Mondal
- Institut für Anorganische Chemie
- Karlsruher Institut für Technologie (KIT)
- 76131 Karlsruhe
- Germany
- Centre de Recherche Paul Pascal (CRPP)
| | - Jun-Liang Liu
- Centre de Recherche Paul Pascal (CRPP)
- CNRS
- UPR 8641
- F-33600 Pessac
- France
| | - Mahammad Ali
- Department of Chemistry Jadavpur University
- Kolkata 700 032
- India
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20
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Leto DF, Massie AA, Colmer HE, Jackson TA. X-Band Electron Paramagnetic Resonance Comparison of Mononuclear Mn(IV)-oxo and Mn(IV)-hydroxo Complexes and Quantum Chemical Investigation of Mn(IV) Zero-Field Splitting. Inorg Chem 2016; 55:3272-82. [PMID: 27002928 DOI: 10.1021/acs.inorgchem.5b02309] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
X-band electron paramagnetic resonance (EPR) spectroscopy was used to probe the ground-state electronic structures of mononuclear Mn(IV) complexes [Mn(IV)(OH)2(Me2EBC)](2+) and [Mn(IV)(O)(OH)(Me2EBC)](+). These compounds are known to effect C-H bond oxidation reactions by a hydrogen-atom transfer mechanism. They provide an ideal system for comparing Mn(IV)-hydroxo versus Mn(IV)-oxo motifs, as they differ by only a proton. Simulations of 5 K EPR data, along with analysis of variable-temperature EPR signal intensities, allowed for the estimation of ground-state zero-field splitting (ZFS) and (55)Mn hyperfine parameters for both complexes. From this analysis, it was concluded that the Mn(IV)-oxo complex [Mn(IV)(O)(OH)(Me2EBC)](+) has an axial ZFS parameter D (D = +1.2(0.4) cm(-1)) and rhombicity (E/D = 0.22(1)) perturbed relative to the Mn(IV)-hydroxo analogue [Mn(IV)(OH)2(Me2EBC)](2+) (|D| = 0.75(0.25) cm(-1); E/D = 0.15(2)), although the complexes have similar (55)Mn values (a = 7.7 and 7.5 mT, respectively). The ZFS parameters for [Mn(IV)(OH)2(Me2EBC)](2+) were compared with values obtained previously through variable-temperature, variable-field magnetic circular dichroism (VTVH MCD) experiments. While the VTVH MCD analysis can provide a reasonable estimate of the magnitude of D, the E/D values were poorly defined. Using the ZFS parameters reported for these complexes and five other mononuclear Mn(IV) complexes, we employed coupled-perturbed density functional theory (CP-DFT) and complete active space self-consistent field (CASSCF) calculations with second-order n-electron valence-state perturbation theory (NEVPT2) correction, to compare the ability of these two quantum chemical methods for reproducing experimental ZFS parameters for Mn(IV) centers. The CP-DFT approach was found to provide reasonably acceptable values for D, whereas the CASSCF/NEVPT2 method fared worse, considerably overestimating the magnitude of D in several cases. Both methods were poor in reproducing experimental E/D values. Overall, this work adds to the limited investigations of Mn(IV) ground-state properties and provides an initial assessment for calculating Mn(IV) ZFS parameters with quantum chemical methods.
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Affiliation(s)
- Domenick F Leto
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas , 1251 Wescoe Hall Drive, Lawrence, Kansas 66045, United States
| | - Allyssa A Massie
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas , 1251 Wescoe Hall Drive, Lawrence, Kansas 66045, United States
| | - Hannah E Colmer
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas , 1251 Wescoe Hall Drive, Lawrence, Kansas 66045, United States
| | - Timothy A Jackson
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas , 1251 Wescoe Hall Drive, Lawrence, Kansas 66045, United States
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21
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Colmer HE, Howcroft AW, Jackson TA. Formation, Characterization, and O-O Bond Activation of a Peroxomanganese(III) Complex Supported by a Cross-Clamped Cyclam Ligand. Inorg Chem 2016; 55:2055-69. [PMID: 26908013 DOI: 10.1021/acs.inorgchem.5b02398] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although there have been reports describing the nucleophilic reactivity of peroxomanganese(III) intermediates, as well as their conversion to high-valent oxo-bridged dimers, it remains a challenge to activate peroxomanganese(III) species for conversion to high-valent, mononuclear manganese complexes. Herein, we report the generation, characterization, and activation of a peroxomanganese(III) adduct supported by the cross-clamped, macrocyclic Me2EBC ligand (4,11-dimethyl-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane). This ligand is known to support high-valent, mononuclear Mn(IV) species with well-defined spectroscopic properties, which provides an opportunity to identify mononuclear Mn(IV) products from O-O bond activation of the corresponding Mn(III)-peroxo adduct. The peroxomanganese(III) intermediate, [Mn(III)(O2)(Me2EBC)](+), was prepared at low-temperature by the addition of KO2 to [Mn(II)(Cl)2(Me2EBC)] in CH2Cl2, and this complex was characterized by electronic absorption, electron paramagnetic resonance (EPR), and Mn K-edge X-ray absorption (XAS) spectroscopies. The electronic structure of the [Mn(III)(O2)(Me2EBC)](+) intermediate was examined by density functional theory (DFT) and time-dependent (TD) DFT calculations. Detailed spectroscopic investigations of the decay products of [Mn(III)(O2)(Me2EBC)](+) revealed the presence of mononuclear Mn(III)-hydroxo species or a mixture of mononuclear Mn(IV) and Mn(III)-hydroxo species. The nature of the observed decay products depended on the amount of KO2 used to generate [Mn(III)(O2)(Me2EBC)](+). The Mn(III)-hydroxo product was characterized by Mn K-edge XAS, and shifts in the pre-edge transition energies and intensities relative to [Mn(III)(O2)(Me2EBC)](+) provide a marker for differences in covalency between peroxo and nonperoxo ligands. To the best of our knowledge, this work represents the first observation of a mononuclear Mn(IV) center upon decay of a nonporphyrinoid Mn(III)-peroxo center.
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Affiliation(s)
- Hannah E Colmer
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas , Lawrence, Kansas 66045, United States
| | - Anthony W Howcroft
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas , Lawrence, Kansas 66045, United States
| | - Timothy A Jackson
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas , Lawrence, Kansas 66045, United States
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22
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Abstract
EPR spectroscopy combined with quantum chemistry for the investigation of the magnetic anisotropy of MnII, MnIII and MnIV.
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Affiliation(s)
- Carole Duboc
- University Grenoble-Alpes
- CNRS
- UMR 5250
- Département de Chimie Moléculaire
- 38041 Grenoble cedex 9
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23
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Carver G, Thut M, Noble C, Tregenna-Piggott PLW. Theory of High-Spin d(4) Complexes: An Angular-Overlap Model Parametrization of the Ligand Field in Vibronic-Coupling Calculations. J Chem Theory Comput 2015; 4:603-13. [PMID: 26620935 DOI: 10.1021/ct7003484] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new theoretical approach for the calculation of the electronic and molecular structures of octahedrally-coordinated high-spin d(4) complexes is described. A prescription for the construction of an effective (3)T1 + (5)E (O) Hamiltonian from the ligand-field matrices of a complex with general trigonal symmetry is given, where the ligand field is parametrized in terms of the angular-overlap model (AOM). The Jahn-Teller matrices for the (3)T1 + ((5)E⊗e) vibronic Hamiltonian are constructed and the lowest eigenvalues are calculated by a numerical method. The model obviates the need to assume a temperature dependence of bonding parameters, inherent to the conventional ligand-field-theory approach and is applicable over the whole range of vibronic-coupling strengths, as demonstrated by example calculations on the [Mn(OD2)6](3+) cation and MgO:Cr(2+).
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Affiliation(s)
- Graham Carver
- Laboratory for Neutron Scattering, PSI, CH-5232 Villigen, Switzerland, Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland, and Centre for Magnetic Resonance, The University of Queensland, Brisbane, Australia
| | - Markus Thut
- Laboratory for Neutron Scattering, PSI, CH-5232 Villigen, Switzerland, Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland, and Centre for Magnetic Resonance, The University of Queensland, Brisbane, Australia
| | - Christopher Noble
- Laboratory for Neutron Scattering, PSI, CH-5232 Villigen, Switzerland, Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland, and Centre for Magnetic Resonance, The University of Queensland, Brisbane, Australia
| | - Philip L W Tregenna-Piggott
- Laboratory for Neutron Scattering, PSI, CH-5232 Villigen, Switzerland, Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland, and Centre for Magnetic Resonance, The University of Queensland, Brisbane, Australia
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24
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Brazzolotto D, Gennari M, Yu S, Pécaut J, Rouzières M, Clérac R, Orio M, Duboc C. An Experimental and Theoretical Investigation on Pentacoordinated Cobalt(III) Complexes with an Intermediate S=
1 Spin State: How Halide Ligands Affect their Magnetic Anisotropy. Chemistry 2015; 22:925-33. [DOI: 10.1002/chem.201502997] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Indexed: 11/06/2022]
Affiliation(s)
| | | | - Shengying Yu
- Univ. Grenoble Alpes, DCM, CNRS UMR 5250; 38000 Grenoble France
| | - Jacques Pécaut
- Univ. Grenoble Alpes, CEA, INAC-SCIB; 38000 Grenoble France
| | - Mathieu Rouzières
- CNRS, CRPP, UPR 8641; F-33600 Pessac France
- Univ. Bordeaux, CRPP, UPR 8641; F-33600 Pessac France
| | - Rodolphe Clérac
- CNRS, CRPP, UPR 8641; F-33600 Pessac France
- Univ. Bordeaux, CRPP, UPR 8641; F-33600 Pessac France
| | - Maylis Orio
- Aix Marseille Université, ISM2, CNRS UMR 7313; 13397 Marseille France
| | - Carole Duboc
- Univ. Grenoble Alpes, DCM, CNRS UMR 5250; 38000 Grenoble France
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25
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Krzystek J, Telser J, Li J, Subramanian MA. Magnetic Properties and Electronic Structure of Manganese-Based Blue Pigments: A High-Frequency and -Field EPR Study. Inorg Chem 2015; 54:9040-5. [DOI: 10.1021/acs.inorgchem.5b01306] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- J. Krzystek
- 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
| | - Jun Li
- Department
of Chemistry, Oregon State University, Corvallis, Oregon 97331, United States
| | - M. A. Subramanian
- Department
of Chemistry, Oregon State University, Corvallis, Oregon 97331, United States
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26
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Cazacu M, Shova S, Soroceanu A, Machata P, Bucinsky L, Breza M, Rapta P, Telser J, Krzystek J, Arion VB. Charge and Spin States in Schiff Base Metal Complexes with a Disiloxane Unit Exhibiting a Strong Noninnocent Ligand Character: Synthesis, Structure, Spectroelectrochemistry, and Theoretical Calculations. Inorg Chem 2015; 54:5691-706. [DOI: 10.1021/acs.inorgchem.5b00229] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Maria Cazacu
- “Petru Poni” Institute of Macromolecular Chemistry, Alea Gr. Ghica Voda 41A, 700487 Iasi, Romania
| | - Sergiu Shova
- “Petru Poni” Institute of Macromolecular Chemistry, Alea Gr. Ghica Voda 41A, 700487 Iasi, Romania
| | - Alina Soroceanu
- “Petru Poni” Institute of Macromolecular Chemistry, Alea Gr. Ghica Voda 41A, 700487 Iasi, Romania
| | - Peter Machata
- Institute of Physical Chemistry and Chemical Physics, Faculty of
Chemical and Food Technology, Slovak University of Technology, Radlinského
9, SK-81237 Bratislava, Slovak Republic
| | - Lukas Bucinsky
- Institute of Physical Chemistry and Chemical Physics, Faculty of
Chemical and Food Technology, Slovak University of Technology, Radlinského
9, SK-81237 Bratislava, Slovak Republic
| | - Martin Breza
- Institute of Physical Chemistry and Chemical Physics, Faculty of
Chemical and Food Technology, Slovak University of Technology, Radlinského
9, SK-81237 Bratislava, Slovak Republic
| | - Peter Rapta
- Institute of Physical Chemistry and Chemical Physics, Faculty of
Chemical and Food Technology, Slovak University of Technology, Radlinského
9, SK-81237 Bratislava, Slovak Republic
| | - Joshua Telser
- Department of Biological, Chemical and
Physical Sciences, Roosevelt University, 430 South Michigan Avenue, Chicago, Illinois 60605 United States
| | - J. Krzystek
- National
High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310 United States
| | - Vladimir B. Arion
- Faculty of Chemistry, Institute of Inorganic
Chemistry, University of Vienna, Währinger Strasse 42, A-1090 Vienna, Austria
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27
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Schax F, Suhr S, Bill E, Braun B, Herwig C, Limberg C. A Heterobimetallic Superoxide Complex formed through O2Activation between Chromium(II) and a Lithium Cation. Angew Chem Int Ed Engl 2014; 54:1352-6. [DOI: 10.1002/anie.201409294] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Indexed: 11/11/2022]
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28
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Schax F, Suhr S, Bill E, Braun B, Herwig C, Limberg C. Bildung eines heterobimetallischen Superoxidkomplexes durch Sauerstoffaktivierung zwischen Chrom(II) und einem Lithiumkation. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201409294] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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29
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Rigamonti L, Cornia A, Nava A, Perfetti M, Boulon ME, Barra AL, Zhong X, Park K, Sessoli R. Mapping of single-site magnetic anisotropy tensors in weakly coupled spin clusters by torque magnetometry. Phys Chem Chem Phys 2014; 16:17220-30. [DOI: 10.1039/c4cp02462a] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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30
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Singh SK, Rajaraman G. Probing the Origin of Magnetic Anisotropy in a Dinuclear {MnIIICuII} Single-Molecule Magnet: The Role of Exchange Anisotropy. Chemistry 2014; 20:5214-8. [DOI: 10.1002/chem.201304357] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 02/27/2014] [Indexed: 11/07/2022]
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31
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Pedersen KS, Sigrist M, Weihe H, Bond AD, Thuesen CA, Simonsen KP, Birk T, Mutka H, Barra AL, Bendix J. Magnetic Interactions through Fluoride: Magnetic and Spectroscopic Characterization of Discrete, Linearly Bridged [MnIII2(μ-F)F4(Me3tacn)2](PF6). Inorg Chem 2014; 53:5013-9. [DOI: 10.1021/ic500049w] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Kasper S. Pedersen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Marc Sigrist
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
- Institut Laue-Langevin, F-38042 Grenoble Cedex 9, France
| | - Høgni Weihe
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Andrew D. Bond
- Department
of Physics and Chemistry, University of Southern Denmark, Campusvej
55, 5230 Odense
M, Denmark
| | - Christian Aa. Thuesen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Kim P. Simonsen
- School of Conservation, The Royal Academy of Fine Arts Schools of Architecture, Design and Conservation, Esplanaden
34, DK-1263 Copenhagen, Denmark
| | - Torben Birk
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Hannu Mutka
- Institut Laue-Langevin, F-38042 Grenoble Cedex 9, France
| | - Anne-Laure Barra
- Laboratoire National des Champs Magnétiques
Intenses, CNRS, BP 166, F-38042 Grenoble Cedex 9, France
| | - Jesper Bendix
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
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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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33
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Pedersen KS, Sigrist M, Weihe H, Tregenna-Piggott PL, Schau-Magnussen M, Dreiser J, Mutka H, Barra AL, Bendix J. MnIII zero-field splitting parameters and weak exchange interactions in a cyanide-bridged {MnIII–IrIII–MnIII} cluster. INORG CHEM COMMUN 2012. [DOI: 10.1016/j.inoche.2012.07.045] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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34
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El Hallak F, Neugebauer P, Barra AL, van Slageren J, Dressel M, Cornia A. Torque-detected ESR of a tetrairon(III) single molecule magnet. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 223:55-60. [PMID: 22975235 DOI: 10.1016/j.jmr.2012.08.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Accepted: 08/11/2012] [Indexed: 06/01/2023]
Abstract
Single-crystal studies on anisotropic ESR-active materials can be conveniently carried out using torque-detected (TD) ESR, a novel technique which brings to ESR the sensitivity typical of torque magnetometry (TM). This method, which is easily operated in high magnetic fields and in a wide range of frequencies, was applied to investigate magnetic anisotropy in crystals of a tetrairon(III) single-molecule magnet with an S=5 ground state. TDESR was supported by TM measurements carried out in situ and provided an accurate estimate of the second-order axial anisotropy parameter D and of the longitudinal fourth-order contribution B(4)(0). The results were validated through a parallel angle-resolved investigation by traditional high-frequency ESR on the same material.
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Affiliation(s)
- Fadi El Hallak
- 1. Physikalisches Institut, Universität Stuttgart, D-70550 Stuttgart, Germany
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35
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Ye S, Neese F. How Do Heavier Halide Ligands Affect the Signs and Magnitudes of the Zero-Field Splittings in Halogenonickel(II) Scorpionate Complexes? A Theoretical Investigation Coupled to Ligand-Field Analysis. J Chem Theory Comput 2012; 8:2344-51. [PMID: 26588967 DOI: 10.1021/ct300237f] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
This work presents a detailed analysis of the physical origin of the zero-field splittings (ZFSs) in a series of high-spin (S = 1) nickel(II) scorpionate complexes Tp*NiX (Tp* = hydrotris(3,5-dimethylpyrazole)borate, X = Cl, Br, I) using quantum chemical approaches. High-frequency and -field electron paramagnetic resonance studies have shown that the complexes with heavier halide ligands (Br, I) have greater magnitudes but opposite signs of the ZFSs compared with the chloro congener (Desrochers, P. J.; Telser, J.; Zvyagin, S. A.; Ozarowski, A.; Krzystek, J.; Vicic, D. A. Inorg. Chem.2006, 45, 8930-8941). To rationalize the experimental findings, quantum chemical calculations of the ZFSs in this Ni(II) halide series have been conducted. The computed ZFS using wave-function-based ab initio methods (state-averaged CASSCF, NEVPT2, and SORCI) are in good agreement with the experiment. For comparison, density functional theory was only marginally successful. The ligand-field analysis demonstrates that the signs and magnitudes of the ZFSs are subtly determined by the trade-off between the negative contributions from the (1,3)A1(1e→2e) transitions relative to the positive contributions from the remaining d-d excited states. The term from (1,3)A1(1e→2e) stems from the structural feature that the metal center displaces out of the equatorial plane, and gains the importance when heavier halide ligand is involved.
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Affiliation(s)
- Shengfa Ye
- Max-Planck Institute for Bioinorganic Chemistry , Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Frank Neese
- Max-Planck Institute for Bioinorganic Chemistry , Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
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36
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Krzystek J, Ozarowski A, Zvyagin SA, Telser J. High Spin Co(I): High-Frequency and -Field EPR Spectroscopy of CoX(PPh3)3 (X = Cl, Br). Inorg Chem 2012; 51:4954-64. [DOI: 10.1021/ic202185x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- J. Krzystek
- National High Magnetic Field
Laboratory (NHMFL), Florida State University, Tallahassee, Florida 32310, United States
| | - Andrew Ozarowski
- 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 (HZDR), 01314 Dresden, Germany
| | - Joshua Telser
- Department of Biological, Chemical
and Physical Sciences, Roosevelt University, Chicago, Illinois 60605, United States
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Vergnani L, Barra AL, Neugebauer P, Rodriguez-Douton MJ, Sessoli R, Sorace L, Wernsdorfer W, Cornia A. Magnetic Bistability of Isolated Giant-Spin Centers in a Diamagnetic Crystalline Matrix. Chemistry 2012; 18:3390-8. [DOI: 10.1002/chem.201103251] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Indexed: 11/09/2022]
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38
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Prasad TK, Poneti G, Sorace L, Rodriguez-Douton MJ, Barra AL, Neugebauer P, Costantino L, Sessoli R, Cornia A. Magnetic and optical bistability in tetrairon(iii) single molecule magnets functionalized with azobenzene groups. Dalton Trans 2012; 41:8368-78. [DOI: 10.1039/c2dt30172e] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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39
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Cox N, Ames W, Epel B, Kulik LV, Rapatskiy L, Neese F, Messinger J, Wieghardt K, Lubitz W. Electronic structure of a weakly antiferromagnetically coupled Mn(II)Mn(III) model relevant to manganese proteins: a combined EPR, 55Mn-ENDOR, and DFT study. Inorg Chem 2011; 50:8238-51. [PMID: 21834536 DOI: 10.1021/ic200767e] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
An analysis of the electronic structure of the [Mn(II)Mn(III)(μ-OH)-(μ-piv)(2)(Me(3)tacn)(2)](ClO(4))(2) (PivOH) complex is reported. It displays features that include: (i) a ground 1/2 spin state; (ii) a small exchange (J) coupling between the two Mn ions; (iii) a mono-μ-hydroxo bridge, bis-μ-carboxylato motif; and (iv) a strongly coupled, terminally bound N ligand to the Mn(III). All of these features are observed in structural models of the oxygen evolving complex (OEC). Multifrequency electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR) measurements were performed on this complex, and the resultant spectra simulated using the Spin Hamiltonian formalism. The strong field dependence of the (55)Mn-ENDOR constrains the (55)Mn hyperfine tensors such that a unique solution for the electronic structure can be deduced. Large hyperfine anisotropy is required to reproduce the EPR/ENDOR spectra for both the Mn(II) and Mn(III) ions. The large effective hyperfine tensor anisotropy of the Mn(II), a d(5) ion which usually exhibits small anisotropy, is interpreted within a formalism in which the fine structure tensor of the Mn(III) ion strongly perturbs the zero-field energy levels of the Mn(II)Mn(III) complex. An estimate of the fine structure parameter (d) for the Mn(III) of -4 cm(-1) was made, by assuming the intrinsic anisotropy of the Mn(II) ion is small. The magnitude of the fine structure and intrinsic (onsite) hyperfine tensor of the Mn(III) is consistent with the known coordination environment of the Mn(III) ion as seen from its crystal structure. Broken symmetry density functional theory (DFT) calculations were performed on the crystal structure geometry. DFT values for both the isotropic and the anisotropic components of the onsite (intrinsic) hyperfine tensors match those inferred from the EPR/ENDOR simulations described above, to within 5%. This study demonstrates that DFT calculations provide reliable estimates for spectroscopic observables of mixed valence Mn complexes, even in the limit where the description of a well isolated S = 1/2 ground state begins to break down.
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Affiliation(s)
- Nicholas Cox
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany.
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40
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Grirrane A, Pastor A, Galindo A, Álvarez E, Mealli C, Ienco A, Orlandini A, Rosa P, Caneschi A, Barra A, Sanz JF. Thiodiacetate–Manganese Chemistry with N ligands: Unique Control of the Supramolecular Arrangement over the Metal Coordination Mode. Chemistry 2011; 17:10600-17. [PMID: 21834105 DOI: 10.1002/chem.201100988] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Indexed: 11/06/2022]
Affiliation(s)
- Abdessamad Grirrane
- Departamento de Química Inorgánica, Universidad de Sevilla, Aptdo. 1203, 41071 Sevilla (Spain), Fax: (+34) 954‐557‐153
- Present address: Instituto de Tecnología Química, CSIC, Universidad Politécnica de Valencia, 46022 Valencia (Spain)
| | - Antonio Pastor
- Departamento de Química Inorgánica, Universidad de Sevilla, Aptdo. 1203, 41071 Sevilla (Spain), Fax: (+34) 954‐557‐153
| | - Agustín Galindo
- Departamento de Química Inorgánica, Universidad de Sevilla, Aptdo. 1203, 41071 Sevilla (Spain), Fax: (+34) 954‐557‐153
| | - Eleuterio Álvarez
- Instituto de Investigaciones Químicas, Consejo Superior de Investigaciones Científicas, Universidad de Sevilla, Avda. Américo Vespucio 49, Isla de La Cartuja, 41092 Sevilla (Spain)
| | - Carlo Mealli
- Consiglio Nazionale delle Ricerche, Istituto di Chimica Composti Organometallici, Via Madonna del piano 10, 50019 Sesto Fiorentino, Firenze (Italy)
| | - Andrea Ienco
- Consiglio Nazionale delle Ricerche, Istituto di Chimica Composti Organometallici, Via Madonna del piano 10, 50019 Sesto Fiorentino, Firenze (Italy)
| | - Annabella Orlandini
- Consiglio Nazionale delle Ricerche, Istituto di Chimica Composti Organometallici, Via Madonna del piano 10, 50019 Sesto Fiorentino, Firenze (Italy)
| | - Patrick Rosa
- Dipartimento di Chimica and CNR‐ INSTM RU of Firenze, Università di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino (Italy)
- Present address: CNRS, Université de Bordeaux, ICMCB, 87 avenue du Dr. A. Schweitzer, Pessac, F‐33608 (France)
| | - Andrea Caneschi
- Dipartimento di Chimica and CNR‐ INSTM RU of Firenze, Università di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino (Italy)
| | - Anne‐Laure Barra
- Laboratoire National des Champs Magnétiques Intenses‐CNRS, UJF, BP166, 25 Avenue des Martyrs, 38042 Grenoble Cedex 9 (France)
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41
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Cox N, Rapatskiy L, Su JH, Pantazis DA, Sugiura M, Kulik L, Dorlet P, Rutherford AW, Neese F, Boussac A, Lubitz W, Messinger J. Effect of Ca2+/Sr2+ substitution on the electronic structure of the oxygen-evolving complex of photosystem II: a combined multifrequency EPR, 55Mn-ENDOR, and DFT study of the S2 state. J Am Chem Soc 2011; 133:3635-48. [PMID: 21341708 DOI: 10.1021/ja110145v] [Citation(s) in RCA: 182] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The electronic structures of the native Mn(4)O(x)Ca cluster and the biosynthetically substituted Mn(4)O(x)Sr cluster of the oxygen evolving complex (OEC) of photosystem II (PSII) core complexes isolated from Thermosynechococcus elongatus, poised in the S(2) state, were studied by X- and Q-band CW-EPR and by pulsed Q-band (55)Mn-ENDOR spectroscopy. Both wild type and tyrosine D less mutants grown photoautotrophically in either CaCl(2) or SrCl(2) containing media were measured. The obtained CW-EPR spectra of the S(2) state displayed the characteristic, clearly noticeable differences in the hyperfine pattern of the multiline EPR signal [Boussac et al. J. Biol. Chem.2004, 279, 22809-22819]. In sharp contrast, the manganese ((55)Mn) ENDOR spectra of the Ca and Sr forms of the OEC were remarkably similar. Multifrequency simulations of the X- and Q-band CW-EPR and (55)Mn-pulsed ENDOR spectra using the Spin Hamiltonian formalism were performed to investigate this surprising result. It is shown that (i) all four manganese ions contribute to the (55)Mn-ENDOR spectra; (ii) only small changes are seen in the fitted isotropic hyperfine values for the Ca(2+) and Sr(2+) containing OEC, suggesting that there is no change in the overall spin distribution (electronic coupling scheme) upon Ca(2+)/Sr(2+) substitution; (iii) the changes in the CW-EPR hyperfine pattern can be explained by a small decrease in the anisotropy of at least two hyperfine tensors. It is proposed that modifications at the Ca(2+) site may modulate the fine structure tensor of the Mn(III) ion. DFT calculations support the above conclusions. Our data analysis also provides strong support for the notion that in the S(2) state the coordination of the Mn(III) ion is square-pyramidal (5-coordinate) or octahedral (6-coordinate) with tetragonal elongation. In addition, it is shown that only one of the currently published OEC models, the Siegbahn structure [Siegbahn, P. E. M. Acc. Chem. Res.2009, 42, 1871-1880, Pantazis, D. A. et al. Phys. Chem. Chem. Phys.2009, 11, 6788-6798], is consistent with all data presented here. These results provide important information for the structure of the OEC and the water-splitting mechanism. In particular, the 5-coordinate Mn(III) is a potential site for substrate 'water' (H(2)O, OH(-)) binding. Its location within the cuboidal structural unit, as opposed to the external 'dangler' position, may have important consequences for the mechanism of O-O bond formation.
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Affiliation(s)
- Nicholas Cox
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany.
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42
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Tancini E, Rodriguez-Douton MJ, Sorace L, Barra AL, Sessoli R, Cornia A. Slow Magnetic Relaxation from Hard-Axis Metal Ions in Tetranuclear Single-Molecule Magnets. Chemistry 2010; 16:10482-93. [DOI: 10.1002/chem.201001040] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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43
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Krzystek J, Swenson DC, Zvyagin SA, Smirnov D, Ozarowski A, Telser J. Cobalt(II) “Scorpionate” Complexes as Models for Cobalt-Substituted Zinc Enzymes: Electronic Structure Investigation by High-Frequency and -Field Electron Paramagnetic Resonance Spectroscopy. J Am Chem Soc 2010; 132:5241-53. [PMID: 20329727 DOI: 10.1021/ja910766w] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J. Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, Dresden High Magnetic Field Laboratory (HLD), Forschungszentrum Dresden-Rossendorf, D-01314 Dresden, Germany, and Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, Illinois 60605
| | - Dale C. Swenson
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, Dresden High Magnetic Field Laboratory (HLD), Forschungszentrum Dresden-Rossendorf, D-01314 Dresden, Germany, and Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, Illinois 60605
| | - S. A. Zvyagin
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, Dresden High Magnetic Field Laboratory (HLD), Forschungszentrum Dresden-Rossendorf, D-01314 Dresden, Germany, and Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, Illinois 60605
| | - Dmitry Smirnov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, Dresden High Magnetic Field Laboratory (HLD), Forschungszentrum Dresden-Rossendorf, D-01314 Dresden, Germany, and Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, Illinois 60605
| | - Andrew Ozarowski
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, Dresden High Magnetic Field Laboratory (HLD), Forschungszentrum Dresden-Rossendorf, D-01314 Dresden, Germany, and Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, Illinois 60605
| | - Joshua Telser
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, Dresden High Magnetic Field Laboratory (HLD), Forschungszentrum Dresden-Rossendorf, D-01314 Dresden, Germany, and Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, Illinois 60605
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Tangen E, Conradie J, Franz K, Friedle S, Telser J, Lippard SJ, Ghosh A. Electronic Structure of a Paramagnetic {MNO}6 Complex: MnNO 5,5-Tropocoronand. Inorg Chem 2010; 49:2701-5. [DOI: 10.1021/ic901860x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Espen Tangen
- Department of Chemistry and Center for Theoretical and Computational Chemistry, University of Tromsø, N-9037 Tromsø, Norway
| | - Jeanet Conradie
- Department of Chemistry and Center for Theoretical and Computational Chemistry, University of Tromsø, N-9037 Tromsø, Norway
- Department of Chemistry, University of the Free State, 9300 Bloemfontein, Republic of South Africa
| | - Katherine Franz
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Simone Friedle
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Joshua Telser
- Department of Biological, Chemical, and Physical Sciences, Roosevelt University, Chicago, Illinois 60605
| | - Stephen J. Lippard
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Abhik Ghosh
- Department of Chemistry and Center for Theoretical and Computational Chemistry, University of Tromsø, N-9037 Tromsø, Norway
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45
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Geiger RA, Chattopadhyay S, Day VW, Jackson TA. A Series of Peroxomanganese(III) Complexes Supported by Tetradentate Aminopyridyl Ligands: Detailed Spectroscopic and Computational Studies. J Am Chem Soc 2010; 132:2821-31. [DOI: 10.1021/ja910235g] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Robert A. Geiger
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas, Lawrence, Kansas 66045
| | - Swarup Chattopadhyay
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas, Lawrence, Kansas 66045
| | - Victor W. Day
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas, Lawrence, Kansas 66045
| | - Timothy A. Jackson
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas, Lawrence, Kansas 66045
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46
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Nieto I, Bontchev RP, Ozarowski A, Smirnov D, Krzystek J, Telser J, Smith JM. Synthesis and spectroscopic investigations of four-coordinate nickel complexes supported by a strongly donating scorpionate ligand. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2009.05.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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47
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48
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Margheriti L, Mannini M, Sorace L, Gorini L, Gatteschi D, Caneschi A, Chiappe D, Moroni R, de Mongeot FB, Cornia A, Piras FM, Magnani A, Sessoli R. Thermal deposition of intact tetrairon(III) single-molecule magnets in high-vacuum conditions. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2009; 5:1460-1466. [PMID: 19283797 DOI: 10.1002/smll.200801594] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A tetrairon(III) single-molecule magnet is deposited using a thermal evaporation technique in high vacuum. The chemical integrity is demonstrated by time-of-flight secondary ion mass spectrometry on a film deposited on Al foil, while superconducting quantum interference device magnetometry and alternating current susceptometry of a film deposited on a kapton substrate show magnetic properties identical to the pristine powder. High-frequency electron paramagnetic resonance spectra confirm the characteristic behavior for a system with S = 5 and a large Ising-type magnetic anisotropy. All these results indicate that the molecules are not damaged during the deposition procedure keeping intact the single-molecule magnet behavior.
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Affiliation(s)
- Ludovica Margheriti
- Department of Chemistry, University of Firenze INSTM Research Unit, ISTM-CNR (URT Firenze), Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
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49
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Sorace L, Sangregorio C, Figuerola A, Benelli C, Gatteschi D. Magnetic Interactions and Magnetic Anisotropy in Exchange Coupled 4f-3d Systems: A Case Study of a Heterodinuclear Ce3+-Fe3+Cyanide-Bridged Complex. Chemistry 2009; 15:1377-88. [DOI: 10.1002/chem.200801638] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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50
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Romain S, Duboc C, Neese F, Rivière E, Hanton L, Blackman A, Philouze C, Leprêtre JC, Deronzier A, Collomb MN. An Unusual Stable Mononuclear MnIIIBis-terpyridine Complex Exhibiting Jahn-Teller Compression: Electrochemical Synthesis, Physical Characterisation and Theoretical Study. Chemistry 2008; 15:980-8. [DOI: 10.1002/chem.200801442] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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