1
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Hunger D, Suhr S, Bayer V, Albold U, Frey W, Sarkar B, van Slageren J. Precursor molecules for 1,2-diamidobenzene containing cobalt(II), nickel(II) and zinc(II) complexes - synthesis and magnetic properties. Dalton Trans 2024; 53:9852-9861. [PMID: 38804996 DOI: 10.1039/d4dt01115e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Molecular magnetic materials based on 1,2-diamidobenzenes are well known and have been intensively studied both experimentally and computationally. They possess interesting magnetic properties as well as redox activity. In this work, we present the synthesis and investigation of potent synthons for constructing discrete metal-organic architectures featuring 1,2-diamidobenzene-coordinated metal centres. The synthons feature weakly bound dimethoxyethane (dme) ligands in addition to the 1,2-diamidobenzene. We characterize these complexes and investigate their magnetic properties by means of static and dynamic magnetometry and high-field electron paramagnetic resonance (HFEPR). Interestingly, the magnetic and magnetic resonance data strongly suggest a dimeric formulation of these complexes, viz. [MII(bmsab)(dme)]2 (bmsab = 1,2-bis(methanesulfonamido)benzene; dme = dimethoxyethane) with M = Co, Ni, Zn. A large negative D-value of -60 cm-1 was found for the Co(II) synthon and an equally large negative D of -50 cm-1 for the Ni(II) synthon. For Co(II), the sign of the D-value is the same as that found for the known bis-diamidobenzene complexes of this ion. In contrast, the negative D-value for the Ni(II) complex is unexpected, which we explain in terms of a change in coordination number. The heteroleptic Co(II) complex presented here does not feature slow relaxation of the magnetization, in contrast to the homoleptic Co(II) 1,2-diamidobenzene complex.
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Affiliation(s)
- David Hunger
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
| | - Simon Suhr
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
| | - Valentin Bayer
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
| | - Uta Albold
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 34-36, 14195 Berlin, Germany
| | - Wolfgang Frey
- Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Biprajit Sarkar
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
| | - Joris van Slageren
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
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2
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Hagen WR. Broadband EPR Spectroscopy of the Triplet State: Multi-Frequency Analysis of Copper Acetate Monohydrate. Int J Mol Sci 2023; 24:14793. [PMID: 37834243 PMCID: PMC10572876 DOI: 10.3390/ijms241914793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 09/28/2023] [Accepted: 09/28/2023] [Indexed: 10/15/2023] Open
Abstract
Electron paramagnetic resonance spectroscopy is a long-standing method for the exploration of electronic structures of transition ion complexes. The difficulty of its analysis varies considerably, not only with the nature of the spin system, but more so with the relative magnitudes of the magnetic interactions to which the spin is subject, where particularly challenging cases ensue when two interactions are of comparable magnitude. A case in point is the triplet system S = 1 of coordination complexes with two unpaired electrons when the electronic Zeeman interaction and the electronic zero-field interaction are similar in strength. This situation occurs in the X-band spectra of the thermally excited triplet state of dinuclear copper(II) complexes, exemplified by copper acetate monohydrate. In this study, applicability of the recently developed low-frequency broadband EPR spectrometer to S = 1 systems is investigated on the analysis of multi-frequency, 0.5-16 GHz, data from [Cu(CH3COO)2H2O]2. Global fitting affords the spin Hamiltonian parameters gz = 2.365 ± 0.008; gy = 2.055 ± 0.010; gx = 2.077 ± 0.005; Az = 64 gauss; D = 0.335 ± 0.002 cm-1; E = 0.0105 ± 0.0003 cm-1. The latter two define zero-field absorptions at ca. 630, 7730, and 10,360 MHz, which show up in the spectra as one half of a sharpened symmetrical line. Overall, the EPR line shape is Lorentzian, reflecting spin-lattice relaxation, which is a combination of an unusual, essentially temperature-independent, inverted Orbach process via the S = 0 ground state, and a Raman process proportional to T2. Other broadening mechanisms are limited to at best minor contributions from a distribution in E values, and from dipolar interaction with neighboring copper pairs. Monitoring of a first-order double-quantum transition between 8 and 35 GHz shows a previously unnoticed very complex line shape behavior, which should be the subject of future research.
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Affiliation(s)
- Wilfred R Hagen
- Department of Biotechnology, Delft University of Technology, Building 58, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
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3
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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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4
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Taylor WV, Cashman BK, Xie ZL, Ngo KK, Rose MJ. Synthesis and Magnetic Properties of Antimony-Ligated Co(II) Complexes: Stibines versus Phosphines. Inorg Chem 2022; 61:6733-6741. [PMID: 35466675 DOI: 10.1021/acs.inorgchem.1c03366] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Herein, we test the hypothesis that neutral, heavy-atom stibine donors can increase the extent of spin-orbit coupling on light, 3d transition metal. To this end, we developed a novel synthetic route toward coordinating a paramagnetic 3d metal ion─cobalt(II)─with neutral stibine ligands. Such complexes have not been reported in the literature due to the weak σ donor strength of stibines and the hard-soft mismatch between a 3d metal and a 5p ligand─which herein has been overcome using alkylated Sb donors. Magnetometry of [(SbiPr2Ph)2Co(I)2] (1) reveals that the stibine complex 1 exhibits a higher magnitude D value (D = |24.96| cm-1) than the spectroscopically derived value for the corresponding phosphine complex 3 (D = -13.13 cm-1), indicative of large zero-field splitting. CASSCF/NEVPT2 calculations corroborate the experimental D values for 1 and 3, predicting D = -31.9 and -8.9 cm-1, respectively. A re-examination of magnetic parameters across the entire series [(ER3)2Co(X)2] (E = P → Sb; X = Cl → I) reveals that (i) increasingly heavy pnictogens lead to an increased X-Co-X bond angle, which is correlated with larger magnitude D values, and (ii) for a given X-Co-X bond angle, the D value is always higher in the presence of a heavy pnictogen as compared with a heavy halide. Ab initio ligand field theory calculations for 1 (stibine complex) and 3 (phosphine complex) reveal no substantial differences in spin-orbit coupling (ζ = 479.2, 480.2 cm-1) or Racah parameter (B = 947.5, 943.9 cm-1), an indicator of covalency. Thus, some "heavy atom effect" on the D value beyond geometric perturbation is operative, but its precise mechanism(s) of action remains obscure.
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Affiliation(s)
- William V Taylor
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78757, United States
| | - Brenna K Cashman
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78757, United States
| | - Zhu-Lin Xie
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78757, United States
| | - Karen K Ngo
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78757, United States
| | - Michael J Rose
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78757, United States
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5
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Fujiwara Y, Takayama T, Nakazawa J, Okamura M, Hikichi S. Development of a novel scorpionate ligand with 6-methylpyridine and comparison of structural and electronic properties of nickel(II) complexes with related tris(azolyl)borates. Dalton Trans 2022; 51:10338-10342. [DOI: 10.1039/d2dt01548j] [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
A novel anionic tridentate borate ligand with 6-methlpyridyl donor, TpyMe, has been synthesized. Comparison of molecular structures and reactivities of nickel(II)-bromido complexes with tris(azolyl)borate ligands composed of pyridyl, pyrazolyl, or...
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6
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Jung J, Benner F, Herbst‐Irmer R, Demir S, Stalke D. Slow Magnetic Relaxation in Mono- and Bimetallic Lanthanide Tetraimido-Sulfate S(NtBu) 4 2- Complexes. Chemistry 2021; 27:12310-12319. [PMID: 33978251 PMCID: PMC8453918 DOI: 10.1002/chem.202101076] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Indexed: 12/16/2022]
Abstract
Lanthanide ions are particularly well-suited for the design of single-molecule magnets owing to their large unquenched orbital angular momentum and strong spin-orbit coupling that gives rise to high magnetic anisotropy. Such nanoscopic bar magnets can potentially revolutionize high-density information storage and processing technologies, if blocking temperatures can be increased substantially. Exploring non-classical ligand scaffolds with the aim to boost the barriers to spin-relaxation are prerequisite. Here, the synthesis, crystallographic and magnetic characterization of a series of each isomorphous mono- and dinuclear lanthanide (Ln=Gd, Tb, Dy, Ho, Er) complexes comprising tetraimido sulfate ligands are presented. The dinuclear Dy complex [{(thf)2 Li(NtBu)2 S(tBuN)2 DyCl2 }2 ⋅ ClLi(thf)2 ] (1c) shows true signatures of single-molecule magnet behavior in the absence of a dc field. In addition, the mononuclear Dy and Tb complexes [{(thf)2 Li(NtBu)2 S(tBuN)2 LnCl2 (thf)2 ] (2b,c) show slow magnetic relaxation under applied dc fields.
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Affiliation(s)
- Jochen Jung
- Institut für Anorganische ChemieGeorg-August Universität GöttingenTammannstraße 437077GöttingenGermany
| | - Florian Benner
- Department of ChemistryMichigan State University578 S Shaw LaneEast LansingMI 48824USA
| | - Regine Herbst‐Irmer
- Institut für Anorganische ChemieGeorg-August Universität GöttingenTammannstraße 437077GöttingenGermany
| | - Selvan Demir
- Department of ChemistryMichigan State University578 S Shaw LaneEast LansingMI 48824USA
| | - Dietmar Stalke
- Institut für Anorganische ChemieGeorg-August Universität GöttingenTammannstraße 437077GöttingenGermany
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7
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Bhowmick I, Newell BS, Shores MP. A systematic study of the influence of ligand field on the slow magnetic dynamics of Co(ii)-diimine compounds. Dalton Trans 2021; 50:10737-10748. [PMID: 34269774 DOI: 10.1039/d0dt01597k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein we report heteroleptic Co(ii) diimine complexes [Co(H2bip)2Cl2] (1), [Co(H2bip)2Br2] (2), [Co(H2bip)3]Br2·1MeOH (3) and [Co(H2bip)2(Me2bpy)]Br2·(MeCN)0.5·(H2O)0.25 (4) (H2bip = 2,2'-bi-1,4,5,6-tetrahydropyrimidine, bpy = 2,2'-dipyridyl, Me2bpy = 4,4'-Me-2,2'-dipyridyl), purposefully prepared to enable a systematic study of magnetic property changes arising from the increase of overall ligand field from σ/π-donor chlorido (1) to π-acceptor 4,4'Me-2,2'bpy (4). The presence of axial and rhombic anisotropy (D and E) of these compounds is sufficient to allow 1-4 to show field-induced slow relaxation of magnetization. Interestingly, we found as the effective ligand field is increased in the series, rhombicity (E/D) decreases, and the magnetic relaxation profile changes significantly, where relaxation of magnetization at a specific temperature becomes gradually faster. We performed mechanistic analyses of the temperature dependence of magnetic relaxation times considering Orbach relaxation processes, Raman-like relaxation and quantum tunnelling of magnetization (QTM). The effective energy barrier of the Orbach relaxation process (Ueff) is largest in compound 1 (19.2 cm-1) and gradually decreases in the order 1 > 2 > 3 > 4 giving a minimum value in compound 4 (8.3 cm-1), where the Raman-like mechanism showed the possibility of different types of phonon activity below and above ∼2.5 K. As a precursor of 1, the tetrahedral complex [Co(H2bip)Cl2] (1a) was also synthesized and structurally and magnetically characterized: this compound exhibits slow relaxation of magnetization under an applied dc field (1800 Oe) with a record slow relaxation time of 3.39 s at 1.8 K.
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Affiliation(s)
- Indrani Bhowmick
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA.
| | - Brian S Newell
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA. and Analytical Resources Core, Center for Materials and Molecular Analysis, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Matthew P Shores
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA.
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8
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Peppel T, Köckerling M. 1-Butyl-3-methylimidazolium tribromido(triphenylphosphane-κ P)nickelate(II) butan-1-ol hemisolvate. IUCRDATA 2021; 6:x210818. [DOI: 10.1107/s241431462100818x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 08/09/2021] [Indexed: 11/10/2022] Open
Abstract
The solvated title salt, (C8H15N2)[NiBr3(P(C6H5)3)]·0.5C4H10O, was obtained in the form of single crystals directly from the reaction mixture. The molecular structure consists of separated 1-butyl-3-methylimidazolium cations, tribromido(triphenylphosphane)nickelate(II) anions and half a solvent molecule of 1-butanol, all connected via multiple hydrogen contacts to form a three-dimensional network. The co-crystallized 1-butanol molecule is disordered and adopts two orientations. The central C—C bonds of both orientations are located on an inversion centre (Wyckoff site 2b of space group P21/n). Thereby, each orientation has again two orientations with the OH group being located either on one or the other side of the C4 alkyl chain. The dried solvent-free compound exhibits a relatively low melting point (m.p. = 412 K).
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9
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Jung J, Legendre CM, Herbst-Irmer R, Stalke D. Exchange Coupling in Binuclear Manganese and Cobalt Complexes with the Tetraimido Sulfate Anion [S(N tBu) 4] 2. Inorg Chem 2021; 60:967-972. [PMID: 33378190 DOI: 10.1021/acs.inorgchem.0c03085] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The (hetero)bimetallic complexes [Cl2Mn(NtBu)2S(tBuN)2Mn{ClLi(THF)3}2] (1), [(acac)Co(NtBu)2S(tBuN)2Co(acac)] (2), and [(acac)Co(NtBu)2S(tBuN)2Li(THF)2] (3), with THF = tetrahydrofuran and acac = acetylacetonate [H2C(C(O)Me)2], were synthesized and investigated for their magnetic properties. While the two different MnII sites in 1 gave a weak coupling of J = -1.00 cm-1, we could observe an appreciable antiferromagnetic coupling of J = -6.08 cm-1 between the two CoII cations in 2, proving the tetraimido sulfate anion to be a challenging but promising linker to enhance magnetic communication between paramagnetic centers. The heterobimetallic complex 3 seems a versatile platform for magnetically interesting d/d, f/d, or f/f mixed-metal complexes.
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Affiliation(s)
- Jochen Jung
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraße 4, Göttingen 37077, Germany
| | - Christina M Legendre
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraße 4, Göttingen 37077, Germany
| | - Regine Herbst-Irmer
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraße 4, Göttingen 37077, Germany
| | - Dietmar Stalke
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraße 4, Göttingen 37077, Germany
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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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Shil S, Sen S. Cobaltocene-Coupled Cumulene: A Perspective on Chiral Magnet and Spintronics Device Design. Inorg Chem 2020; 59:16905-16912. [DOI: 10.1021/acs.inorgchem.0c01825] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Suranjan Shil
- Manipal Centre for Natural Sciences, Centre of Excellence, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Sabyasachi Sen
- Department of Physics, JIS College of Engineering, Block-A, Phase-III, Nadia, Kalyani, West Bengal 741235, India
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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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Pyykkönen A, Feher R, Köhler FH, Vaara J. Paramagnetic Pyrazolylborate Complexes Tp 2M and Tp* 2M: 1H, 13C, 11B, and 14N NMR Spectra and First-Principles Studies of Chemical Shifts. Inorg Chem 2020; 59:9294-9307. [PMID: 32558559 DOI: 10.1021/acs.inorgchem.0c01176] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The paramagnetic pyrazolylborates Tp2M and Tp*2M (M = Cu, Ni, Co, Fe, Mn, Cr, V) as well as [Tp2M]+ and [Tp*2M]+ (M = Fe, Cr, V) have been synthesized and their NMR spectra recorded. The 1H signal shift ranges vary from ∼30 ppm (Cu(II) and V(III)) to ∼220 ppm (Co(II)), and the 13C signal shift ranges from ∼180 ppm (Fe(III)) to ∼1150 ppm (Cr(II)). The 11B and 14N shifts are ∼360 and ∼730 ppm, respectively. Both negative and positive shifts have been observed for all nuclei. The narrow NMR signals of the Co(II), Fe(II), Fe(III), and V(III) derivatives provide resolved 13C,1H couplings. All chemical shifts have been calculated from first-principles on a modern version of Kurland-McGarvey theory which includes optimized structures, zero-field splitting, and g tensors, as well as signal shift contributions. Temperature dependence in the Fe(II) spin-crossover complex results from the equilibrium of the ground singlet and the excited quintet. We illustrate both the assignment and analysis capabilities, as well as the shortcomings of the current computational methodology.
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Affiliation(s)
- Ari Pyykkönen
- NMR Research Unit, University of Oulu, P.O. Box 3000, Oulu FI-90014, Finland
| | - Robert Feher
- Department Chemie, Technische Universität München, D-85748 Garching, Germany
| | - Frank H Köhler
- Department Chemie, Technische Universität München, D-85748 Garching, Germany
| | - Juha Vaara
- NMR Research Unit, University of Oulu, P.O. Box 3000, Oulu FI-90014, Finland
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14
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Mondal A, Wu S, Sato O, Konar S. Effect of Axial Ligands on Easy‐Axis Anisotropy and Field‐Induced Slow Magnetic Relaxation in Heptacoordinated Fe
II
Complexes. Chemistry 2020; 26:4780-4789. [DOI: 10.1002/chem.201905166] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Indexed: 11/11/2022]
Affiliation(s)
- Arpan Mondal
- Department of ChemistryIndian Institute of, Science Education and Research, Bhopal Bhopal By-pass Road, Bhauri Bhopal 462066 Madhya Pradesh India
| | - Shu‐Qi Wu
- Institute for Materials Chemistry and Engineering & IRCCSKyushu University 744 Motooka Nishi-ku 819-0395 Fukuoka Japan
| | - Osamu Sato
- Institute for Materials Chemistry and Engineering & IRCCSKyushu University 744 Motooka Nishi-ku 819-0395 Fukuoka Japan
| | - Sanjit Konar
- Department of ChemistryIndian Institute of, Science Education and Research, Bhopal Bhopal By-pass Road, Bhauri Bhopal 462066 Madhya Pradesh India
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15
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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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16
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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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17
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Manesis AC, Musselman BW, Keegan BC, Shearer J, Lehnert N, Shafaat HS. A Biochemical Nickel(I) State Supports Nucleophilic Alkyl Addition: A Roadmap for Methyl Reactivity in Acetyl Coenzyme A Synthase. Inorg Chem 2019; 58:8969-8982. [PMID: 30788970 PMCID: PMC6635881 DOI: 10.1021/acs.inorgchem.8b03546] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
![]()
Nickel-containing
enzymes such as methyl coenzyme M reductase (MCR) and carbon monoxide
dehydrogenase/acetyl coenzyme A synthase (CODH/ACS) play a critical
role in global energy conversion reactions, with significant contributions
to carbon-centered processes. These enzymes are implied to cycle through
a series of nickel-based organometallic intermediates during catalysis,
though identification of these intermediates remains challenging.
In this work, we have developed and characterized a nickel-containing
metalloprotein that models the methyl-bound organometallic intermediates
proposed in the native enzymes. Using a nickel(I)-substituted azurin
mutant, we demonstrate that alkyl binding occurs via nucleophilic
addition of methyl iodide as a methyl donor. The paramagnetic NiIII-CH3 species initially generated can be rapidly
reduced to a high-spin NiII-CH3 species in the
presence of exogenous reducing agent, following a reaction sequence
analogous to that proposed for ACS. These two distinct bioorganometallic
species have been characterized by optical, EPR, XAS, and MCD spectroscopy,
and the overall mechanism describing methyl reactivity with nickel
azurin has been quantitatively modeled using global kinetic simulations.
A comparison between the nickel azurin protein system and existing
ACS model compounds is presented. NiIII-CH3 Az
is only the second example of two-electron addition of methyl iodide
to a NiI center to give an isolable species and the first
to be formed in a biologically relevant system. These results highlight
the divergent reactivity of nickel across the two intermediates, with
implications for likely reaction mechanisms and catalytically relevant
states in the native ACS enzyme. A bioorganometallic model
for acetyl coenzyme A synthase has been developed. This model protein
is able to bind a cationic methyl group via direct addition to the
nickel(I) center. The resultant nickel(III)-methyl species has been
characterized via optical and electron paramagnetic resonance spectroscopy,
and the reduced nickel(II)-methyl state has been characterized using
magnetic circular dichroism and X-ray spectroscopy. Implications for
further reactivity with CO are gleaned from electronic structure analysis
of the nickel-methyl species.
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Affiliation(s)
- Anastasia C Manesis
- Department of Chemistry and Biochemistry , The Ohio State University , 100 W. 18th Avenue , Columbus , Ohio 43210 , United States
| | - Bradley W Musselman
- Department of Chemistry , University of Michigan , 930 N. University Avenue , Ann Arbor , Michigan 48109 , United States
| | - Brenna C Keegan
- Department of Chemistry , Trinity University , One Trinity Place , San Antonio , Texas 78212 , United States
| | - Jason Shearer
- Department of Chemistry , Trinity University , One Trinity Place , San Antonio , Texas 78212 , United States
| | - Nicolai Lehnert
- Department of Chemistry , University of Michigan , 930 N. University Avenue , Ann Arbor , Michigan 48109 , United States
| | - Hannah S Shafaat
- Department of Chemistry and Biochemistry , The Ohio State University , 100 W. 18th Avenue , Columbus , Ohio 43210 , United States
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18
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Magnetostructural correlations in S = 1 trans-[Ni{(OPPh2)(EPPh2)N}2(dmso)2], E = S, Se, and related complexes. Polyhedron 2018. [DOI: 10.1016/j.poly.2018.05.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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19
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Mondal AK, Mondal A, Dey B, Konar S. Influence of the Coordination Environment on Easy-Plane Magnetic Anisotropy of Pentagonal Bipyramidal Cobalt(II) Complexes. Inorg Chem 2018; 57:9999-10008. [DOI: 10.1021/acs.inorgchem.8b01162] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Amit Kumar Mondal
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, 462066 Madhya Pradesh, India
| | - Arpan Mondal
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, 462066 Madhya Pradesh, India
| | - Bijoy Dey
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, 462066 Madhya Pradesh, India
| | - Sanjit Konar
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, 462066 Madhya Pradesh, India
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20
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Li Z, Zhao J, Wang Z, Dai Z. Nickel-mediated allosteric manipulation of G-quadruplex DNAzyme for highly selective detection of histidine. Anal Chim Acta 2018; 1008:90-95. [DOI: 10.1016/j.aca.2017.12.040] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 11/30/2017] [Accepted: 12/11/2017] [Indexed: 11/29/2022]
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21
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Jin XX, Chen XX, Xiang J, Chen YZ, Jia LH, Wang BW, Cheng SC, Zhou X, Leung CF, Gao S. Slow Magnetic Relaxation in a Series of Mononuclear 8-Coordinate Fe(II) and Co(II) Complexes. Inorg Chem 2018. [PMID: 29521502 DOI: 10.1021/acs.inorgchem.7b03071] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of homoleptic mononuclear 8-coordinate FeII and CoII compounds, [FeII(L2)2](ClO4)2 (2), [FeII(L3)2](ClO4)2 (3), [FeII(L4)2](ClO4)2 (4), [CoII(L1)2](ClO4)2 (5), [CoII(L2)2](ClO4)2 (6), [CoII(L3)2](ClO4)2 (7), and [CoII(L4)2](ClO4)2 (8) (L1 and L2 are 2,9-dialkylcarboxylate-1,10-phenanthroline ligands; L3 and L4 are 6,6'-dialkylcarboxylate-2,2'-bipyridine ligands), have been obtained, and their crystal structures have been determined by X-ray crystallography. The metal center in all of these compounds has an oversaturated coordination number of 8, which is completed by two neutral homoleptic tetradentate ligands and is unconventional in 3d-metal compounds. These compounds are further characterized by electronic spectroscopy, cyclic voltammetry (CV), and magnetic measurements. CV measurements of these complexes in MeCN solution exhibit rich redox properties. Magnetic measurements on these compounds demonstrate that the observed single-ion magnetic (SIM) behavior in the previously reported [FeII(L1)2](ClO4)2 (1) is not a contingent case, since all of the 8-coordinate compounds 2-8 exhibit interesting slow magnetic relaxation under applied direct current fields.
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Affiliation(s)
- Xin-Xin Jin
- College of Chemistry and Environmental Engineering , Yangtze University , Jingzhou 434020 , HuBei , P. R. China
| | - Xiao-Xiang Chen
- State Key Laboratory of Rare Earth Materials Chemistry and Applications and PKU-HKU Joint Laboratory on Rare Earth Materials and Bioinorganic Chemistry , Peking University , Beijing 100871 , P. R. China
| | - Jing Xiang
- College of Chemistry and Environmental Engineering , Yangtze University , Jingzhou 434020 , HuBei , P. R. China
| | - Yun-Zhou Chen
- School of Chemistry and Environmental Engineering , Wuhan Institute of Technology , Wuhan 430073 , P. R. China
| | - Li-Hui Jia
- School of Chemistry and Environmental Engineering , Wuhan Institute of Technology , Wuhan 430073 , P. R. China
| | - Bing-Wu Wang
- State Key Laboratory of Rare Earth Materials Chemistry and Applications and PKU-HKU Joint Laboratory on Rare Earth Materials and Bioinorganic Chemistry , Peking University , Beijing 100871 , P. R. China
| | - Shun-Cheung Cheng
- Department of Chemistry , City University of Hong Kong , Tat Chee Avenue, Kowloon Tong , Hong Kong 999077 , P. R. China
| | - Xin Zhou
- College of Chemistry and Environmental Engineering , Yangtze University , Jingzhou 434020 , HuBei , P. R. China
| | - Chi-Fai Leung
- Department of Science and Environmental Studies , The Education University of Hong Kong , 10 Lo Ping Road, Tai Po, NT , Hong Kong 999077 , P. R. China
| | - Song Gao
- State Key Laboratory of Rare Earth Materials Chemistry and Applications and PKU-HKU Joint Laboratory on Rare Earth Materials and Bioinorganic Chemistry , Peking University , Beijing 100871 , P. R. China
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22
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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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23
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Pearson TJ, Fataftah MS, Freedman DE. Enhancement of magnetic anisotropy in a Mn-Bi heterobimetallic complex. Chem Commun (Camb) 2018; 52:11394-11397. [PMID: 27711306 DOI: 10.1039/c6cc06369a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A novel Mn2+Bi3+ heterobimetallic complex, featuring the closest MnBi interaction for a paramagnetic molecular species, exhibits unusually large axial zero-field splitting. We attribute this enhancement to the proximity of Mn2+ to a heavy main group element, namely, bismuth.
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Affiliation(s)
- Tyler J Pearson
- Northwestern University, Department of Chemistry, 2145 Sheridan Rd., Evanston, Il 60208, USA.
| | - Majed S Fataftah
- Northwestern University, Department of Chemistry, 2145 Sheridan Rd., Evanston, Il 60208, USA.
| | - Danna E Freedman
- Northwestern University, Department of Chemistry, 2145 Sheridan Rd., Evanston, Il 60208, USA.
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24
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Chen SY, Cui HH, Zhang YQ, Wang Z, Ouyang ZW, Chen L, Chen XT, Yan H, Xue ZL. Magnetic anisotropy and relaxation behavior of six-coordinate tris(pivalato)-Co(ii) and -Ni(ii) complexes. Dalton Trans 2018; 47:10162-10171. [DOI: 10.1039/c8dt01554f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Magnetic measurements, HFEPR and theoretical calculations have been used to study the magnetic anisotropy of the six-coordinate field-induced single ion magnet (NBu4)[Co(piv)3] and its Ni analogue.
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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
| | - Hui-Hui Cui
- State Key Laboratory of Coordination Chemistry
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210023
- China
| | - Yi-Quan Zhang
- Jiangsu Key Laboratory for NSLSCS
- School of Physical Science and Technology
- Nanjing Normal 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
| | - Lei Chen
- School of Environmental and Chemical Engineering
- Jiangsu University of Science and Technology
- Zhenjiang 212003
- China
| | - Xue-Tai Chen
- State Key Laboratory of Coordination Chemistry
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210023
- 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
- USA
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25
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Mondal AK, Sundararajan M, Konar S. A new series of tetrahedral Co(ii) complexes [CoLX2] (X = NCS, Cl, Br, I) manifesting single-ion magnet features. Dalton Trans 2018; 47:3745-3754. [DOI: 10.1039/c7dt04007e] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The influence of ligand field strength on the magnetic anisotropy of a series of isostructural tetrahedral CoII complexes has been investigated by using a combined experimental and theoretical approach.
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Affiliation(s)
- Amit Kumar Mondal
- Department of Chemistry
- Indian Institute of Science Education and Research Bhopal
- Bhauri
- India
| | - Mahesh Sundararajan
- Theoretical Chemistry Section
- Bhabha Atomic Research Centre
- Mumbai 400085
- India
| | - Sanjit Konar
- Department of Chemistry
- Indian Institute of Science Education and Research Bhopal
- Bhauri
- India
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26
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Sasi D, Ramkumar V, Murthy NN. Bite-Angle-Regulated Coordination Geometries: Tetrahedral and Trigonal Bipyramidal in Ni(II) with Biphenyl-Appended (2-Pyridyl)alkylamine N, N'-Bidentate Ligands. ACS OMEGA 2017; 2:2474-2481. [PMID: 31457593 PMCID: PMC6640959 DOI: 10.1021/acsomega.7b00119] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 05/17/2017] [Indexed: 06/10/2023]
Abstract
Two simple biphenyl-appended (2-pyridyl)alkylamine N-bidentate ligands, Le and Lm, having ethylene and methylene spacers between donor groups, with bite angles Le ≈ 100° and Lm ≈ 80°, dictate pseudotetrahedral and trigonal-bipyramidal geometries in six high-spin Ni(II)-halide complexes, [Ni(Le)X2] and [Ni(Lm)2X](ClO4) (where X = Cl-, Br-, I-), respectively. The structures in the solid state, determined using X-ray crystallography, and in solution, determined using spectroscopic methods (UV-vis-NIR and paramagnetic 1H NMR), which complement each other, are described.
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27
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Coste SC, Vlaisavljevich B, Freedman DE. Magnetic Anisotropy from Main-Group Elements: Halides versus Group 14 Elements. Inorg Chem 2017; 56:8195-8202. [DOI: 10.1021/acs.inorgchem.7b00923] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [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
| | - Bess Vlaisavljevich
- 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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28
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Drahoš B, Herchel R, Trávníček Z. Impact of Halogenido Coligands on Magnetic Anisotropy in Seven-Coordinate Co(II) Complexes. Inorg Chem 2017; 56:5076-5088. [PMID: 28406642 DOI: 10.1021/acs.inorgchem.7b00235] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The structural and magnetic features of a series of mononuclear seven-coordinate CoII complexes with the general formula [Co(L)X2], where L is a 15-membered pyridine-based macrocyclic ligand (3,12,18-triaza-6,9-dioxabicyclo[12.3.1]octadeca-1(18),14,16-triene) and X = Cl- (1), Br- (2), or I- (3), were investigated experimentally and theoretically in order to reveal how the corresponding halogenido coligands in the apical positions of a distorted pentagonal-bipyramidal coordination polyhedron may affect the magnetic properties of the prepared compounds. The thorough analyses of the magnetic data revealed a large easy-plane type of the magnetic anisotropy (D > 0) for all three compounds, with the D-values increasing in the order 35 cm-1 for 3 (I-), 38 cm-1 for 1 (Cl-), and 41 cm-1 for 2 (Br-). Various theoretical methods like the Angular Overlap Model, density functional theory, CASSCF/CASPT2, CASSCF/NEVPT2 were utilized in order to understand the observed trend in magnetic anisotropy. The D-values correlated well with the Mayer bond order (decreasing in order Co-I > Co-Cl > Co-Br), which could be a consequence of two competing factors: (a) the ligand field splitting and (b) the covalence of the Co-X bond. All the complexes also behave as field-induced single-molecule magnets with the spin reversal barrier Ueff increasing in order 1 (Cl-) < 2 (Br-) < 3 (I-); however, taking into account the easy-plane type of the magnetic anisotropy, the Raman relaxation process is most likely responsible for slow relaxation of the magnetization. The results of the work revealed that the previously suggested and fully accepted strategy employing heavier halogenido ligands in order to increase the magnetic anisotropy has some limitations in the case of pentagonal-bipyramidal CoII complexes.
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Affiliation(s)
- Bohuslav Drahoš
- Department of Inorganic Chemistry, Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University , 17. listopadu 12, CZ-771 46 Olomouc, Czech Republic
| | - Radovan Herchel
- Department of Inorganic Chemistry, Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University , 17. listopadu 12, CZ-771 46 Olomouc, Czech Republic
| | - Zdeněk Trávníček
- Department of Inorganic Chemistry, Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University , 17. listopadu 12, CZ-771 46 Olomouc, Czech Republic
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29
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Kowalkowska D, Dołęga A, Nedelko N, Hnatejko Z, Ponikiewski Ł, Matracka A, Ślawska-Waniewska A, Strągowska A, Słowy K, Gazda M, Pladzyk A. Structural, spectral and magnetic properties of Ni(ii), Co(ii) and Cd(ii) compounds with imidazole derivatives and silanethiolate ligands. CrystEngComm 2017. [DOI: 10.1039/c7ce00555e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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30
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Takayama T, Nakazawa J, Hikichi S. A pseudotetrahedral nickel(II) complex with a tridentate oxazoline-based scorpionate ligand: chlorido[tris(4,4-dimethyloxazolin-2-yl)phenylborato]nickel(II). Acta Crystallogr C Struct Chem 2016; 72:842-845. [PMID: 27811422 DOI: 10.1107/s2053229616012183] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 07/27/2016] [Indexed: 11/10/2022] Open
Abstract
Poly(pyrazol-1-yl)borates have been utilized extensively in coordination compounds due to their high affinity toward cationic metal ions on the basis of electrostatic interactions derived from the mononegatively charged boron centre. The original poly(pyrazol-1-yl)borates, christened `scorpionates', were pioneered by the late Professor Swiatoslaw Trofimenko and have expanded to include various borate ligands with N-, P-, O-, S-, Se- and C-donors. Scorpionate ligands with boron-carbon bonds, rather than the normal boron-nitrogen bonds, have been developed and in these new types of scorpionate ligands, amines and azoles, such as pyridines, imidazoles and oxazolines, have been employed as N-donors instead of pyrazoles. Furthermore, a variety of bis- and tris(oxazolinyl)borate ligands, including chiral ones, have been developed. Tris(oxazolin-2-yl)borates work as facially capping tridentate chelating ligands in the same way as tris(pyrazol-1-yl)borates. In the title compound, [Ni(C21H29BN3O3)Cl], the NiII ion is coordinated by three N atoms from the facially capping tridentate chelating tris(4,4-dimethyloxazolin-2-yl)phenylborate ligand and a chloride ligand in a highly distorted tetrahedral geometry. The Ni-Cl bond length [2.1851 (5) Å] is comparable to those found in a previously reported tris(3,5-dimethylpyrazol-1-yl)hydroborate derivative [2.1955 (18) and 2.150 (2) Å]. The molecular structure deviates from C3v symmetry due to the structural flexibility of the tris(4,4-dimethyloxazolin-2-yl)phenylborate ligand.
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Affiliation(s)
- Tomoaki Takayama
- Department of Material & Life Chemistry, Faculty of Engineering, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama City 222-8686, Japan
| | - Jun Nakazawa
- Department of Material & Life Chemistry, Faculty of Engineering, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama City 222-8686, Japan
| | - Shiro Hikichi
- Department of Material & Life Chemistry, Faculty of Engineering, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama City 222-8686, Japan
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31
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Charron G, Malkin E, Rogez G, Batchelor LJ, Mazerat S, Guillot R, Guihéry N, Barra AL, Mallah T, Bolvin H. Unraveling σ and π Effects on Magnetic Anisotropy incis-NiA4B2Complexes: Magnetization, HF-HFEPR Studies, First-Principles Calculations, and Orbital Modeling. Chemistry 2016; 22:16850-16862. [DOI: 10.1002/chem.201602837] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Gaëlle Charron
- Institut de Chimie Moléculaire et des Matériaux d'Orsay; CNRS; Université de Paris-Sud 11; 91405 Orsay Cedex France
- Laboratoire MSC; Université Paris 7 Diderot; Paris France
| | - Elena Malkin
- Laboratoire de Chimie et Physique Quantiques; CNRS; Université Toulouse III; 118 route de Narbonne 31062 Toulouse France
- CTCC; Department of Chemistry; University of Tromsø; 9037 Tromsø Norway
| | - Guillaume Rogez
- Institut de Physique et Chimie des Matériaux de Strasbourg; Université de Strasbourg; 23 rue du Loess, BP 43 67034 Strasbourg Cedex 2 France
| | - Luke J. Batchelor
- Institut de Chimie Moléculaire et des Matériaux d'Orsay; CNRS; Université de Paris-Sud 11; 91405 Orsay Cedex France
| | - Sandra Mazerat
- Institut de Chimie Moléculaire et des Matériaux d'Orsay; CNRS; Université de Paris-Sud 11; 91405 Orsay Cedex France
| | - Régis Guillot
- Institut de Chimie Moléculaire et des Matériaux d'Orsay; CNRS; Université de Paris-Sud 11; 91405 Orsay Cedex France
| | - Nathalie Guihéry
- Laboratoire de Chimie et Physique Quantiques; CNRS; Université Toulouse III; 118 route de Narbonne 31062 Toulouse France
| | - Anne-Laure Barra
- Laboratoire National des Champs Magnétiques Intenses; CNRS; 25 rue des Martyrs, B.P. 166 38042 Grenoble Cedex 9 France
| | - Talal Mallah
- Institut de Chimie Moléculaire et des Matériaux d'Orsay; CNRS; Université de Paris-Sud 11; 91405 Orsay Cedex France
| | - Hélène Bolvin
- Laboratoire de Chimie et Physique Quantiques; CNRS; Université Toulouse III; 118 route de Narbonne 31062 Toulouse France
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32
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Shao D, Zhang SL, Shi L, Zhang YQ, Wang XY. Probing the Effect of Axial Ligands on Easy-Plane Anisotropy of Pentagonal-Bipyramidal Cobalt(II) Single-Ion Magnets. Inorg Chem 2016; 55:10859-10869. [DOI: 10.1021/acs.inorgchem.6b00854] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dong Shao
- State
Key Laboratory of Coordination Chemistry, Collaborative Innovation
Center of Advanced Microstructures, School of Chemistry and Chemical
Engineering, Nanjing University, Nanjing 210023, China
| | - Shao-Liang Zhang
- State
Key Laboratory of Coordination Chemistry, Collaborative Innovation
Center of Advanced Microstructures, School of Chemistry and Chemical
Engineering, Nanjing University, Nanjing 210023, China
| | - Le Shi
- State
Key Laboratory of Coordination Chemistry, Collaborative Innovation
Center of Advanced Microstructures, School of Chemistry and Chemical
Engineering, Nanjing University, Nanjing 210023, China
| | - Yi-Quan Zhang
- Jiangsu
Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, China
| | - Xin-Yi Wang
- State
Key Laboratory of Coordination Chemistry, Collaborative Innovation
Center of Advanced Microstructures, School of Chemistry and Chemical
Engineering, Nanjing University, Nanjing 210023, China
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33
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Soma S, Van Stappen C, Kiss M, Szilagyi RK, Lehnert N, Fujisawa K. Distorted tetrahedral nickel-nitrosyl complexes: spectroscopic characterization and electronic structure. J Biol Inorg Chem 2016; 21:757-75. [DOI: 10.1007/s00775-016-1366-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 06/01/2016] [Indexed: 10/21/2022]
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34
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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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35
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Kruse CP, Deb T, Aboelenen AM, Anderson CM, Petersen JL, Jensen MP. Variable Borohydride Hapticity in Nickel(II) Scorpionate Complexes [(TpR,Me)Ni(ηn‐BH4)]: TpR,Me = hydrotris{3‐R‐5‐methyl‐1‐pyrazolyl}borate; R = Ph, n = 3 vs. R = Me, n = 4. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201501330] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Colin P. Kruse
- Department of Chemistry and Biochemistry Ohio University 45701 Athens Ohio USA
| | - Tapash Deb
- Department of Chemistry and Biochemistry Ohio University 45701 Athens Ohio USA
| | - Ahmed M. Aboelenen
- Department of Chemistry and Biochemistry Ohio University 45701 Athens Ohio USA
| | - Caitlin M. Anderson
- Department of Chemistry and Biochemistry Ohio University 45701 Athens Ohio USA
| | - Jeffrey L. Petersen
- C. Eugene Bennett Department of Chemistry West Virginia University 26506 Morgantown West Virginia USA
| | - Michael P. Jensen
- Department of Chemistry and Biochemistry Ohio University 45701 Athens Ohio USA
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36
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Christian JH, Brogden DW, Bindra JK, Kinyon JS, van Tol J, Wang J, Berry JF, Dalal NS. Enhancing the Magnetic Anisotropy of Linear Cr(II) Chain Compounds Using Heavy Metal Substitutions. Inorg Chem 2016; 55:6376-83. [PMID: 26881994 DOI: 10.1021/acs.inorgchem.5b02545] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Magnetic properties of the series of three linear, trimetallic chain compounds Cr2Cr(dpa)4Cl2, 1, Mo2Cr(dpa)4Cl2, 2, and W2Cr(dpa)4Cl2, 3 (dpa = 2,2'-dipyridylamido), have been studied using variable-temperature dc and ac magnetometry and high-frequency EPR spectroscopy. All three compounds possess an S = 2 electronic ground state arising from the terminal Cr(2+) ion, which exhibits slow magnetic relaxation under an applied magnetic field, as evidenced by ac magnetic susceptibility and magnetization measurements. The slow relaxation stems from the existence of an easy-axis magnetic anisotropy, which is bolstered by the axial symmetry of the compounds and has been quantified through rigorous high-frequency EPR measurements. The magnitude of D in these compounds increases when heavier ions are substituted into the trimetallic chain; thus D = -1.640, -2.187, and -3.617 cm(-1) for Cr2Cr(dpa)4Cl2, Mo2Cr(dpa)4Cl2, and W2Cr(dpa)4Cl2, respectively. Additionally, the D value measured for W2Cr(dpa)4Cl2 is the largest yet reported for a high-spin Cr(2+) system. While earlier studies have demonstrated that ligands containing heavy atoms can enhance magnetic anisotropy, this is the first report of this phenomenon using heavy metal atoms as "ligands".
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Affiliation(s)
- Jonathan H Christian
- Department of Chemistry and Biochemistry, Florida State University , Tallahassee, Florida 32306, United States
| | - David W Brogden
- Department of Chemistry, University of Wisconsin - Madison , 1101 University Avenue Madison, Wisconsin 53706, United States
| | - Jasleen K Bindra
- Department of Chemistry and Biochemistry, Florida State University , Tallahassee, Florida 32306, United States
| | - Jared S Kinyon
- Department of Chemistry and Biochemistry, Florida State University , Tallahassee, Florida 32306, United States
| | - Johan van Tol
- National High Magnetic Field Laboratory, Florida State University , 1800 East Paul Dirac Drive, Tallahassee, Florida 32306, United States
| | - Jingfang Wang
- Department of Chemistry and Biochemistry, Florida State University , Tallahassee, Florida 32306, United States
| | - John F Berry
- Department of Chemistry, University of Wisconsin - Madison , 1101 University Avenue Madison, Wisconsin 53706, United States
| | - Naresh S Dalal
- Department of Chemistry and Biochemistry, Florida State University , Tallahassee, Florida 32306, United States
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37
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Tak H, Lee H, Kang J, Cho J. A high-spin nickel(ii) borohydride complex in dehalogenation. Inorg Chem Front 2016. [DOI: 10.1039/c5qi00206k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A mononuclear high-spin (η2-BH4) nickel(ii) complex bearing a macrocyclic tridentate N-donor ligand was prepared and its reactivity was investigated in dehalogenation reactions.
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Affiliation(s)
- Hyeonwoo Tak
- Department of Emerging Materials Science
- Daegu 42988
- Korea
| | - Hyunjoo Lee
- Department of Emerging Materials Science
- Daegu 42988
- Korea
| | - Joongoo Kang
- Department of Emerging Materials Science
- Daegu 42988
- Korea
| | - Jaeheung Cho
- Department of Emerging Materials Science
- Daegu 42988
- Korea
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38
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Dey M, Dutta S, Sarma B, Deka RC, Gogoi N. Modulation of the coordination environment: a convenient approach to tailor magnetic anisotropy in seven coordinate Co(ii) complexes. Chem Commun (Camb) 2016; 52:753-6. [DOI: 10.1039/c5cc07397a] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Subtle modulation of the coordination environment in seven coordinate Co(ii) complexes leads to a remarkable deviation in the axial zero field splitting parameter (D) in a predictable fashion.
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Affiliation(s)
- Mamon Dey
- Department of Chemical Sciences
- Tezpur University
- Napaam-784028
- India
| | - Snigdha Dutta
- Department of Chemical Sciences
- Tezpur University
- Napaam-784028
- India
| | - Bipul Sarma
- Department of Chemical Sciences
- Tezpur University
- Napaam-784028
- India
| | - Ramesh Ch. Deka
- Department of Chemical Sciences
- Tezpur University
- Napaam-784028
- India
| | - Nayanmoni Gogoi
- Department of Chemical Sciences
- Tezpur University
- Napaam-784028
- India
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39
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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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40
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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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41
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Damon PL, Liss CJ, Lewis RA, Morochnik S, Szpunar DE, Telser J, Hayton TW. Quantifying the Electron Donor and Acceptor Abilities of the Ketimide Ligands in M(N═C(t)Bu2)4 (M = V, Nb, Ta). Inorg Chem 2015; 54:10081-95. [PMID: 26419513 PMCID: PMC4659433 DOI: 10.1021/acs.inorgchem.5b02017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Addition of 4 equiv of Li(N═C(t)Bu2) to VCl3 in THF, followed by addition of 0.5 equiv of I2, generates the homoleptic V(IV) ketimide complex, V(N═C(t)Bu2)4 (1), in 42% yield. Similarly, reaction of 4 equiv of Li(N═C(t)Bu2) with NbCl4(THF)2 in THF affords the homoleptic Nb(IV) ketimide complex, Nb(N═C(t)Bu2)4 (2), in 55% yield. Seeking to extend the series to the tantalum congener, a new Ta(IV) starting material, TaCl4(TMEDA) (3), was prepared via reduction of TaCl5 with Et3SiH, followed by addition of TMEDA. Reaction of 3 with 4 equiv of Li(N═C(t)Bu2) in THF results in the isolation of a Ta(V) ketimide complex, Ta(Cl)(N═C(t)Bu2)4 (5), which can be isolated in 32% yield. Reaction of 5 with Tl(OTf) yields Ta(OTf)(N═C(t)Bu2)4 (6) in 44% yield. Subsequent reduction of 6 with Cp*2Co in toluene generates the homoleptic Ta(IV) congener Ta(N═C(t)Bu2)4 (7), although the yields are poor. All three homoleptic group 5 ketimide complexes exhibit squashed tetrahedral geometries in the solid state, as determined by X-ray crystallography. This geometry leads to a d(x(2)-y(2))(1) ((2)B1 in D(2d)) ground state, as supported by DFT calculations. EPR spectroscopic analysis of 1 and 2, performed at X- and Q-band frequencies (∼9 and 35 GHz, respectively), further supports the (2)B1 ground-state assignment, whereas comparison of 1, 2, and 7 with related group 5 tetra(aryl), tetra(amido), and tetra(alkoxo) complexes shows a higher M-L covalency in the ketimide-metal interaction. In addition, a ligand field analysis of 1 and 2 demonstrates that the ketimide ligand is both a strong π-donor and strong π-acceptor, an unusual combination found in very few organometallic ligands.
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Affiliation(s)
- Peter L. Damon
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Cameron J. Liss
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, 430 S. Michigan Ave. Chicago, Illinois 60605-1394 United States
| | - Richard A. Lewis
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Simona Morochnik
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - David E. Szpunar
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, 430 S. Michigan Ave. Chicago, Illinois 60605-1394 United States
| | - Joshua Telser
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, 430 S. Michigan Ave. Chicago, Illinois 60605-1394 United States
| | - Trevor W. Hayton
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
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42
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Stavretis SE, Atanasov M, Podlesnyak AA, Hunter SC, Neese F, Xue ZL. Magnetic Transitions in Iron Porphyrin Halides by Inelastic Neutron Scattering and Ab Initio Studies of Zero-Field Splittings. Inorg Chem 2015; 54:9790-801. [DOI: 10.1021/acs.inorgchem.5b01505] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shelby E. Stavretis
- Department of Chemistry, The University of Tennessee, Knoxville, Tennessee 37996, 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
| | - Andrey A. Podlesnyak
- Quantum Condensed
Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Seth C. Hunter
- Department of Chemistry, The University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Frank Neese
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße
34-36, D-45470 Mülheim
an der Ruhr, Germany
| | - Zi-Ling Xue
- Department of Chemistry, The University of Tennessee, Knoxville, Tennessee 37996, United States
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43
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Saber MR, Dunbar KR. Ligands effects on the magnetic anisotropy of tetrahedral cobalt complexes. Chem Commun (Camb) 2015; 50:12266-9. [PMID: 25183324 DOI: 10.1039/c4cc05724d] [Citation(s) in RCA: 160] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The effect of ligands with heavy donor atoms on the magnetic anisotropy of the pseudo-tetrahedral cobalt complexes, Co(quinoline)2I2 (1) and Co(EPh3)2I2 (2-3) (E = P, As) has been investigated. The axial zero-field splitting parameter D was found to vary from +9.2 cm(-1) in 1 to -36.9 cm(-1) in 2 and -74.7 cm(-1) in 3. Compounds 2 and 3 exhibit slow relaxation of the magnetization up to 4 K under an applied dc field, indicating SMM behavior.
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Affiliation(s)
- Mohamed R Saber
- Department of Chemistry, Texas A&M University, College Station, TX 77842-3012, USA.
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44
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Denysenko D, Jelic J, Reuter K, Volkmer D. Postsynthetic Metal and Ligand Exchange in MFU-4l: A Screening Approach toward Functional Metal-Organic Frameworks Comprising Single-Site Active Centers. Chemistry 2015; 21:8188-99. [DOI: 10.1002/chem.201406564] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 03/11/2015] [Indexed: 02/06/2023]
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45
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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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46
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Deb T, Jensen MP. Electrophilic alkylation of pseudotetrahedral nickel(II) arylthiolate complexes. Inorg Chem 2015; 54:87-96. [PMID: 25494529 DOI: 10.1021/ic5018328] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A kinetic study is reported for reactions of pseudotetrahedral nickel(II) arylthiolate complexes [(Tp(R,Me))Ni-SAr] (Tp(R,Me) = hydrotris{3-R-5-methyl-1-pyrazolyl}borate, R = Me, Ph, and Ar = C6H5, C6H4-4-Cl, C6H4-4-Me, C6H4-4-OMe, 2,4,6-Me3C6H2, 2,4,6-(i)Pr3C6H2) with organic electrophiles R'X (i.e., MeI, EtI, BzBr) in low-polarity organic solvents (toluene, THF, chloroform, dichloromethane, or 1,2-dichloroethane), yielding a pseudotetrahedral halide complex [(Tp(R,Me))Ni-X] (X = Cl, Br, I) and the corresponding organosulfide R'SAr. Competitive reactions with halogenated solvents and adventitious air were also examined. Akin to reactions of analogous and biomimetic zinc complexes, a pertinent mechanistic question is the nature of the reactive nucleophile, either an intact thiolate complex or a free arylthiolate resulting from a dissociative pre-equilibrium. The observed kinetics conformed to a second-order rate law, first order with respect to the complex and electrophile, and no intermediate complexes were observed. In the absence of a mechanistically diagnostic rate law, a variety of mechanistic probes were examined, including kinetic effects of varying the metal, solvent, electrophile, and temperature, as well as the 3-pyrazolyl and arylthiolate substituents. Compared to zinc analogues, the effect of Ni-SAr covalency is also of interest herein. The results are broadly interpreted with respect to the disparate mechanistic pathways.
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Affiliation(s)
- Tapash Deb
- Department of Chemistry and Biochemistry, Ohio University , Athens, Ohio 45701, United States
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47
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Deb T, Anderson CM, Ma H, Petersen JL, Young VG, Jensen MP. Scorpionato Halide Complexes [(Tp
Ph,Me
)Ni–X] [X = Cl, Br, I; Tp
Ph,Me
= Hydrotris(3‐phenyl‐5‐methyl‐1‐pyrazolyl)borate]: Structures, Spectroscopy, and Pyrazole Adducts. Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201402897] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Tapash Deb
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, U.S.A., http://www.ohio.edu/chemistry/faculty/jensen.php
| | - Caitlin M. Anderson
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, U.S.A., http://www.ohio.edu/chemistry/faculty/jensen.php
| | - Huaibo Ma
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, U.S.A., http://www.ohio.edu/chemistry/faculty/jensen.php
| | - Jeffrey L. Petersen
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, U.S.A
| | - Victor G. Young
- X‐ray Crystallographic Laboratory, Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, U.S.A
| | - Michael P. Jensen
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, U.S.A., http://www.ohio.edu/chemistry/faculty/jensen.php
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48
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Deb T, Anderson CM, Chattopadhyay S, Ma H, Young VG, Jensen MP. Steric and electronic effects on arylthiolate coordination in the pseudotetrahedral complexes [(Tp(Ph,Me))Ni-SAr] (Tp(Ph,Me) = hydrotris{3-phenyl-5-methyl-1-pyrazolyl}borate). Dalton Trans 2014; 43:17489-99. [PMID: 25341014 DOI: 10.1039/c4dt02726d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Synthesis and characterization of several new pseudotetrahedral arylthiolate complexes [(Tp(Ph,Me))Ni-SAr] (Tp(Ph,Me) = hydrotris{3-phenyl-5-methyl-1-pyrazolyl}borate; Ar = Ph, 2,4,6-(i)Pr3C6H2, C6H4-4-Cl, C6H4-4-Me, C6H4-4-OMe) are reported, including X-ray crystal structures of the first two complexes. With prior results, two series of complexes are spanned, [(Tp(Ph,Me))Ni-S-2,4,6-RC6H2] (R'' = H, Me, (i)Pr) plus the xylyl analogue [(Tp(Ph,Me))Ni-S-2,6-Me2C6H3], as well as [(Tp(Ph,Me))Ni-S-C6H4-4-Y] (Y = Cl, H, Me, OMe), intended to elucidate steric and/or electronic effects on arylthiolate coordination. In contrast to [(Tp(Me,Me))Ni-SAr] analogues that adopt a sawhorse conformation, the ortho-disubstituted complexes show enhanced trigonal and Ni-S-Ar bending, reflecting the size of the 3-pyrazole substituents. Moreover, weakened scorpionate ligation is implied by spectroscopic data. Little spectroscopic effect is observed in the series of para-substituted complexes, suggesting the observed effects are primarily steric in origin. The relatively electron-rich and encumbered complex [(Tp(Ph,Me))Ni-S-2,4,6-(i)Pr3C6H2] behaves uniquely when dissolved in CH3CN, forming a square planar solvent adduct with a bidentate scorpionate ligand, [(κ(2)-Tp(Ph,Me))Ni(NCMe)(S-2,4,6-(i)Pr3C6H2)]. This adduct was isolated and characterized by X-ray crystallography. Single-point DFT and TD-DFT calculations on a simplified [(κ(2)-Tp)Ni(NCMe)(SPh)] model were used to clarify the electronic spectrum of the adduct, and to elucidate differences between Ni-SAr bonding and spectroscopy between pseudotetrahedral and square planar geometries.
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Affiliation(s)
- Tapash Deb
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, USA.
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49
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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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50
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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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