51
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Biswas S, Tonigold M, Kelm H, Krüger HJ, Volkmer D. Thermal spin-crossover in the [M3Zn6Cl6L12] (M = Zn, FeII; L = 5,6-dimethoxy-1,2,3-benzotriazolate) system: structural, electrochemical, Mössbauer, and UV-Vis spectroscopic studies. Dalton Trans 2010; 39:9851-9. [DOI: 10.1039/c0dt00556h] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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52
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Malaestean IL, Speldrich M, Ellern A, Baca SG, Ward M, Kögerler P. Decanuclear Manganese Isobutyrate Clusters Featuring a Novel MnII8MnIII2Core. Eur J Inorg Chem 2009. [DOI: 10.1002/ejic.200900602] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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53
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Scott RT, Jones L, Tidmarsh I, Breeze B, Laye R, Wolowska J, Stone D, Collins A, Parsons S, Wernsdorfer W, Aromí G, McInnes E, Brechin E. Ferromagnetic NiIIDiscs. Chemistry 2009; 15:12389-98. [DOI: 10.1002/chem.200901865] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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54
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Hammud HH, Holman KT, Masoud MS, El-Faham A, Beidas H. 1-Hydroxybenzotriazole (HOBt) acidity, formation constant with different metals and thermodynamic parameters: Synthesis and characterization of some HOBt metal complexes – Crystal structures of two polymers: [Cu2(H2O)5(OBt)2(μ-OBt)2]·2H2O·EtOH (1A) and [Cu(μ-OBt)(HOBt)(OBt)(EtOH)] (1B). Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2009.03.046] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Cremades E, Cano J, Ruiz E, Rajaraman G, Milios CJ, Brechin EK. Theoretical Methods Enlighten Magnetic Properties of a Family of Mn6 Single-Molecule Magnets. Inorg Chem 2009; 48:8012-9. [DOI: 10.1021/ic900992r] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Eduard Cremades
- Departament de Química Inorgànica and Institut de Recerca de Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 647, 08028 Spain
| | - Joan Cano
- Departament de Química Inorgànica and Institut de Recerca de Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 647, 08028 Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluis Companys 23, 08010 Barcelona, Spain
| | - Eliseo Ruiz
- Departament de Química Inorgànica and Institut de Recerca de Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 647, 08028 Spain
| | - Gopalan Rajaraman
- Dipartimento di Chimica, Università di Firenze, Polo Scientifico di Sesto Fiorentino, 50019 Sesto Fiorentino, Italy
| | - Constantinos J. Milios
- Department of Chemistry, University of Crete, 71003 Herakleion, Greece
- School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, United Kingdom
| | - Euan K. Brechin
- School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, United Kingdom
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Nonanuclear Coordination Compounds Featuring {M9L12}6+Cores (M = NiII, CoII, or ZnII; L = 1,2,3-Benzotriazolate). Eur J Inorg Chem 2009. [DOI: 10.1002/ejic.200900156] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Stamatatos TC, Christou G. Azide groups in higher oxidation state manganese cluster chemistry: from structural aesthetics to single-molecule magnets. Inorg Chem 2009; 48:3308-22. [PMID: 19364123 DOI: 10.1021/ic801217j] [Citation(s) in RCA: 140] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This Forum Article overviews the recent amalgamation of two long-established areas, manganese/oxo coordination cluster chemistry involving the higher Mn(II)/Mn(IV) oxidation states and transition-metal azide (N(3)(-)) chemistry. The combination of azide and alkoxide- or carboxylate-containing ligands in Mn chemistry has led to a variety of new polynuclear clusters, high-spin molecules, and single-molecule magnets, with metal nuclearities ranging from Mn(4) to Mn(32) and with ground-state spin values as large as S = 83/2. The organic bridging/chelating ligands are discussed separately as follows: (i) pyridyl alkoxides [the anions of 2-(hydroxymethyl)pyridine (hmpH), 2,6-pyridinedimethanol (pdmH(2)), and the gem-diol form of di-2-pyridyl ketone (dpkdH(2))]; (ii) non-pyridyl alkoxides [the anions of 1,1,1-tris(hydroxymethyl)ethane (thmeH(3)), triethanolamine (teaH(3)), and N-methyldiethanolamine (mdaH(2))]; (iii) other alcohols [the anions of 2,6-dihydroxymethyl-4-methylphenol (LH(3)) and Schiff bases]; (iv) pyridyl monoximes/dioximes [the anions of methyl-2-pyridyl ketone oxime (mpkoH), phenyl-2-pyridyl ketone oxime (ppkoH), and 2,6-diacetylpyridine dioxime (dapdoH(2))]; (v) non-pyridyl oximes [the anions of salicylaldoxime (saoH(2)) and its derivatives R-saoH(2)]. The large structural diversity of the resulting complexes stems from the combined ability of the azide and organic ligands to adopt a variety of ligation and bridging modes. The combined work demonstrates the synthetic novelty that arises when azide is used in conjunction with alcohol-based chelates, the aesthetic beauty of the resulting molecules, and the often fascinating magnetic properties that these compounds possess. This continues to emphasize the extensive and remarkable ability of Mn chemistry to satisfy a variety of different tastes.
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Stamatatos TC, Pringouri KV, Abboud KA, Christou G. High-spin molecules: A mixed-valence Mn6 octahedron with an S=11 ground state. Polyhedron 2009. [DOI: 10.1016/j.poly.2008.10.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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59
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Datta S, Bolin E, Inglis R, Milios CJ, Brechin EK, Hill S. A comparative EPR study of high- and low-spin Mn6 single-molecule magnets. Polyhedron 2009. [DOI: 10.1016/j.poly.2008.12.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Meally ST, Mason K, McArdle P, Brechin EK, Ryder AG, Jones LF. A F-bridged Mn(ii) molecular square. Chem Commun (Camb) 2009:7024-6. [DOI: 10.1039/b916153h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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62
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Liu H, Tian J, Kou Y, Zhang J, Feng L, Li D, Gu W, Liu X, Liao D, Cheng P, Ribas J, Yan S. Synthesis, structures and magnetic properties of polynuclear mixed-valence MnIIMnIII complexes containing 3-(2-phenol)-5-(pyridin-2-yl)-1,2,4-triazole ligand. Dalton Trans 2009:10511-7. [DOI: 10.1039/b904553h] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Hui Liu
- Department of Chenistry, Nankai University, Weijin Road 94, Tianjin, 300071, PR China
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63
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Milios CJ, Inglis R, Jones LF, Prescimone A, Parsons S, Wernsdorfer W, Brechin EK. Constructing clusters with enhanced magnetic properties by assembling and distorting Mn3 building blocks. Dalton Trans 2009:2812-22. [DOI: 10.1039/b820362h] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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64
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Stoumpos CC, Gass IA, Milios CJ, Lalioti N, Terzis A, Aromí G, Teat SJ, Brechin EK, Perlepes SP. A MnII4cubane and a novel MnII10MnIII4cluster from the use of di-2-pyridyl ketone in manganese acetate chemistry. Dalton Trans 2009:307-17. [PMID: 19089012 DOI: 10.1039/b810835h] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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65
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Biswas S, Tonigold M, Volkmer D. Homo- and Heteropentanuclear Coordination Compounds withTdSymmetry - the Solid State Structures of [MZn4(L)4(L′)6] (M = CoIIor Zn; L = chloride or acac; L′ = 1,2,3-benzotriazolate). Z Anorg Allg Chem 2008. [DOI: 10.1002/zaac.200800296] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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66
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Stamatatos TC, Nastopoulos V, Tasiopoulos AJ, Moushi EE, Wernsdorfer W, Christou G, Perlepes SP. High nuclearity single-molecule magnets: a mixed-valence Mn26 cluster containing the di-2-pyridylketone diolate dianion. Inorg Chem 2008; 47:10081-9. [PMID: 18841928 DOI: 10.1021/ic801342f] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The employment of the dianion (dpkd(2-)) of the gem-diol form of di-2-pyridylketone (dpk) as a tetradentate chelate in manganese chemistry is reported, and the synthesis, crystal structure, and magnetochemical characterization of [Mn26O16(OMe)12(dpkd)12(MeOH)6](OH)6 x solv (3 x solv) are described. The reaction of Mn(ClO4)2 x 6 H2O, dpk, NaOMe, and NEt3 (2:1:4:2) in MeCN/MeOH affords complex 3, which possesses a rare metal topology and is mixed-valence (4 Mn(II), 22 Mn(III)). The complicated [Mn26(mu4-O)10(mu3-O)6(mu3-OMe)12(mu-OR)12](18+) core of 3 consists of an internal Mn(III)16 cage of adjacent Mn4 tetrahedra surrounded by an external Mn(II)4Mn(III)6 shell. The latter is held together by the alkoxide arms of twelve eta(1):eta(2):eta(1):eta(1):mu3 dpkd(2-) groups. Variable-temperature, solid-state direct current (dc), and alternating current (ac) magnetization studies were carried out on 3 in the 1.8-300 K range. Complex 3 is predominantly antiferromagnetically coupled with a resulting S = 6 ground state, a conclusion confirmed by the in-phase (chi'(M)) ac susceptibility data. The observation of out-of-phase (chi''(M)) ac susceptibility signals suggested that 3 might be a single-molecule magnet, and this was confirmed by single-crystal magnetization vs dc field sweeps that exhibited hysteresis, the diagnostic property of a magnet. Combined ac chi''(M) and magnetization decay vs time data collected below 1.1 K were used to construct an Arrhenius plot; the fit of the thermally activated region above approximately 0.1 K gave U(eff) = 30 K, where U(eff) is the effective relaxation barrier. At lower temperatures, the complex exhibits temperature-independent relaxation, characteristic of ground-state quantum tunneling of magnetization between the lowest-lying M(s) = +/-6 levels. The combined work demonstrates the ligating flexibility of dipyridyl-diolate chelates and their usefulness in the synthesis of polynuclear Mn(x) clusters with interesting magnetic properties, without requiring the co-presence of carboxylate ligands.
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67
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Zartilas S, Moushi EE, Nastopoulos V, Boudalis AK, Tasiopoulos AJ. Two new coordination polymers containing the triangular [Mn3O(O2CR)6]0/+ units. Inorganica Chim Acta 2008. [DOI: 10.1016/j.ica.2008.03.067] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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68
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Ho KP, Wong WL, Lam KM, Lai CP, Chan TH, Wong KY. A Simple and Effective Catalytic System for Epoxidation of Aliphatic Terminal Alkenes with Manganese(II) as the Catalyst. Chemistry 2008; 14:7988-96. [PMID: 18618538 DOI: 10.1002/chem.200800759] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Kam-Piu Ho
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom Kowloon, Hong Kong SAR
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69
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Stamatatos T, Abboud K, Wernsdorfer W, Christou G. Covalently Linked Dimers of Clusters: Loop- and Dumbbell-Shaped Mn24and Mn26Single-Molecule Magnets. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200801393] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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70
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Stamatatos T, Abboud K, Wernsdorfer W, Christou G. Covalently Linked Dimers of Clusters: Loop- and Dumbbell-Shaped Mn24and Mn26Single-Molecule Magnets. Angew Chem Int Ed Engl 2008; 47:6694-8. [DOI: 10.1002/anie.200801393] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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71
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Manoli M, Collins A, Parsons S, Candini A, Evangelisti M, Brechin EK. Mixed-Valent Mn Supertetrahedra and Planar Discs as Enhanced Magnetic Coolers. J Am Chem Soc 2008; 130:11129-39. [DOI: 10.1021/ja802829d] [Citation(s) in RCA: 206] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Maria Manoli
- School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ U.K., and CNR-INFM National Research Center on “nanoStructures and bioSystems at Surfaces” (S3), Via G. Campi 213/A, 41100 Modena, Italy
| | - Anna Collins
- School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ U.K., and CNR-INFM National Research Center on “nanoStructures and bioSystems at Surfaces” (S3), Via G. Campi 213/A, 41100 Modena, Italy
| | - Simon Parsons
- School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ U.K., and CNR-INFM National Research Center on “nanoStructures and bioSystems at Surfaces” (S3), Via G. Campi 213/A, 41100 Modena, Italy
| | - Andrea Candini
- School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ U.K., and CNR-INFM National Research Center on “nanoStructures and bioSystems at Surfaces” (S3), Via G. Campi 213/A, 41100 Modena, Italy
| | - Marco Evangelisti
- School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ U.K., and CNR-INFM National Research Center on “nanoStructures and bioSystems at Surfaces” (S3), Via G. Campi 213/A, 41100 Modena, Italy
| | - Euan K. Brechin
- School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ U.K., and CNR-INFM National Research Center on “nanoStructures and bioSystems at Surfaces” (S3), Via G. Campi 213/A, 41100 Modena, Italy
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72
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Viciano-Chumillas M, Tanase S, Mutikainen I, Turpeinen U, de Jongh LJ, Reedijk J. Mononuclear Manganese(III) Complexes as Building Blocks for the Design of Trinuclear Manganese Clusters: Study of the Ligand Influence on the Magnetic Properties of the [Mn3(μ3-O)]7+ Core. Inorg Chem 2008; 47:5919-29. [DOI: 10.1021/ic8002492] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marta Viciano-Chumillas
- Gorlaeus Laboratories, Leiden Institute of Chemistry, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands, Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Leiden University, PO Box 9504, 2300 RA Leiden, The Netherlands, and Laboratory of Inorganic Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55 (A.I.Virtasen aukio 1), 00014 Helsinki, Finland
| | - Stefania Tanase
- Gorlaeus Laboratories, Leiden Institute of Chemistry, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands, Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Leiden University, PO Box 9504, 2300 RA Leiden, The Netherlands, and Laboratory of Inorganic Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55 (A.I.Virtasen aukio 1), 00014 Helsinki, Finland
| | - Ilpo Mutikainen
- Gorlaeus Laboratories, Leiden Institute of Chemistry, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands, Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Leiden University, PO Box 9504, 2300 RA Leiden, The Netherlands, and Laboratory of Inorganic Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55 (A.I.Virtasen aukio 1), 00014 Helsinki, Finland
| | - Urho Turpeinen
- Gorlaeus Laboratories, Leiden Institute of Chemistry, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands, Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Leiden University, PO Box 9504, 2300 RA Leiden, The Netherlands, and Laboratory of Inorganic Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55 (A.I.Virtasen aukio 1), 00014 Helsinki, Finland
| | - L. Jos de Jongh
- Gorlaeus Laboratories, Leiden Institute of Chemistry, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands, Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Leiden University, PO Box 9504, 2300 RA Leiden, The Netherlands, and Laboratory of Inorganic Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55 (A.I.Virtasen aukio 1), 00014 Helsinki, Finland
| | - Jan Reedijk
- Gorlaeus Laboratories, Leiden Institute of Chemistry, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands, Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Leiden University, PO Box 9504, 2300 RA Leiden, The Netherlands, and Laboratory of Inorganic Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55 (A.I.Virtasen aukio 1), 00014 Helsinki, Finland
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73
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Stamatatos TC, Poole KM, Abboud KA, Wernsdorfer W, O’Brien TA, Christou G. High-Spin Mn4 and Mn10 Molecules: Large Spin Changes with Structure in Mixed-Valence MnII4MnIII6 Clusters with Azide and Alkoxide-Based Ligands. Inorg Chem 2008; 47:5006-21. [DOI: 10.1021/ic800268z] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Theocharis C. Stamatatos
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, Institut Néel-CNRS, BP-166 Grenoble, 25 Avenue des Martyrs, 38042 Grenoble, Cedex 9, France, and Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202-3274
| | - Katye M. Poole
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, Institut Néel-CNRS, BP-166 Grenoble, 25 Avenue des Martyrs, 38042 Grenoble, Cedex 9, France, and Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202-3274
| | - Khalil A. Abboud
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, Institut Néel-CNRS, BP-166 Grenoble, 25 Avenue des Martyrs, 38042 Grenoble, Cedex 9, France, and Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202-3274
| | - Wolfgang Wernsdorfer
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, Institut Néel-CNRS, BP-166 Grenoble, 25 Avenue des Martyrs, 38042 Grenoble, Cedex 9, France, and Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202-3274
| | - Ted A. O’Brien
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, Institut Néel-CNRS, BP-166 Grenoble, 25 Avenue des Martyrs, 38042 Grenoble, Cedex 9, France, and Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202-3274
| | - George Christou
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, Institut Néel-CNRS, BP-166 Grenoble, 25 Avenue des Martyrs, 38042 Grenoble, Cedex 9, France, and Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202-3274
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74
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Liu CM, Zhang DQ, Zhu DB. Solvatomagnetic effect and spin-glass behavior in a 1D coordination polymer constructed from EE-azido bridged MnIII3O units. Chem Commun (Camb) 2008:368-70. [PMID: 18399210 DOI: 10.1039/b715080f] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The non-uniform chain manganese(III) complex constructed from EE-azido bridged MnIII3O units, [MnIII3O(Brppz)3-(MeOH)3(N3)] 2MeOH [1, Brppz = 3-(5-bromo-2-phenolate)-pyrazolate], is the first example of 1D azido-bridged coordination polymer showing both solvatomagnetic effect and spin-glass behavior.
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Affiliation(s)
- Cai-Ming Liu
- Beijing National Laboratory for Molecular Sciences, Center for Molecular Science, Institute of Chemistry, CAS, Beijing, 100080, P. R. China.
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75
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Yang CI, Wernsdorfer W, Tsai YJ, Chung G, Kuo TS, Lee GH, Shieh M, Tsai HL. Mixed-Valence Tetra- and Hexanuclear Manganese Complexes from the Flexibility of Pyridine-Containing β-Diketone Ligands. Inorg Chem 2008; 47:1925-39. [DOI: 10.1021/ic7013368] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Chen-I Yang
- Department of Chemistry, National Cheng Kung University, Tainan, 701, Taiwan, Republic of China, Laboratoire Louis Néel, Centre National de la Recherche Scientifique (CNRS), BP-166, 38042 Grenoble Cedex 9, France, Department of Chemistry, National Taiwan Normal University, Taipei 116, Taiwan, Republic of China, and Instrumentation Center, College of Science, National Taiwan University, Taipei, 106, Taiwan, Republic of China
| | - Wolfgang Wernsdorfer
- Department of Chemistry, National Cheng Kung University, Tainan, 701, Taiwan, Republic of China, Laboratoire Louis Néel, Centre National de la Recherche Scientifique (CNRS), BP-166, 38042 Grenoble Cedex 9, France, Department of Chemistry, National Taiwan Normal University, Taipei 116, Taiwan, Republic of China, and Instrumentation Center, College of Science, National Taiwan University, Taipei, 106, Taiwan, Republic of China
| | - Yu-Jhe Tsai
- Department of Chemistry, National Cheng Kung University, Tainan, 701, Taiwan, Republic of China, Laboratoire Louis Néel, Centre National de la Recherche Scientifique (CNRS), BP-166, 38042 Grenoble Cedex 9, France, Department of Chemistry, National Taiwan Normal University, Taipei 116, Taiwan, Republic of China, and Instrumentation Center, College of Science, National Taiwan University, Taipei, 106, Taiwan, Republic of China
| | - George Chung
- Department of Chemistry, National Cheng Kung University, Tainan, 701, Taiwan, Republic of China, Laboratoire Louis Néel, Centre National de la Recherche Scientifique (CNRS), BP-166, 38042 Grenoble Cedex 9, France, Department of Chemistry, National Taiwan Normal University, Taipei 116, Taiwan, Republic of China, and Instrumentation Center, College of Science, National Taiwan University, Taipei, 106, Taiwan, Republic of China
| | - Ting-Shen Kuo
- Department of Chemistry, National Cheng Kung University, Tainan, 701, Taiwan, Republic of China, Laboratoire Louis Néel, Centre National de la Recherche Scientifique (CNRS), BP-166, 38042 Grenoble Cedex 9, France, Department of Chemistry, National Taiwan Normal University, Taipei 116, Taiwan, Republic of China, and Instrumentation Center, College of Science, National Taiwan University, Taipei, 106, Taiwan, Republic of China
| | - Gene-Hsiang Lee
- Department of Chemistry, National Cheng Kung University, Tainan, 701, Taiwan, Republic of China, Laboratoire Louis Néel, Centre National de la Recherche Scientifique (CNRS), BP-166, 38042 Grenoble Cedex 9, France, Department of Chemistry, National Taiwan Normal University, Taipei 116, Taiwan, Republic of China, and Instrumentation Center, College of Science, National Taiwan University, Taipei, 106, Taiwan, Republic of China
| | - Minghuey Shieh
- Department of Chemistry, National Cheng Kung University, Tainan, 701, Taiwan, Republic of China, Laboratoire Louis Néel, Centre National de la Recherche Scientifique (CNRS), BP-166, 38042 Grenoble Cedex 9, France, Department of Chemistry, National Taiwan Normal University, Taipei 116, Taiwan, Republic of China, and Instrumentation Center, College of Science, National Taiwan University, Taipei, 106, Taiwan, Republic of China
| | - Hui-Lien Tsai
- Department of Chemistry, National Cheng Kung University, Tainan, 701, Taiwan, Republic of China, Laboratoire Louis Néel, Centre National de la Recherche Scientifique (CNRS), BP-166, 38042 Grenoble Cedex 9, France, Department of Chemistry, National Taiwan Normal University, Taipei 116, Taiwan, Republic of China, and Instrumentation Center, College of Science, National Taiwan University, Taipei, 106, Taiwan, Republic of China
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Stamatatos TC, Christou G. Mixed valency in polynuclear MnII/MnIII, MnIII/MnIV and MnII/MnIII/MnIV clusters: a foundation for high-spin molecules and single-molecule magnets. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2008; 366:113-25. [PMID: 17827122 DOI: 10.1098/rsta.2007.2144] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Mixed-valent Mn/O dinuclear and polynuclear molecular compounds containing MnIII are almost without exception trapped valence. Large differences between the strengths of the exchange interactions within MnIIMnIII, MnIIIMnIII and MnIIIMnIV pairs lead to situations where MnIIIMnIV interactions, the strongest of the three mentioned and antiferromagnetic in nature, dominate the intramolecular spin alignments in trinuclear and higher nuclearity mixed-valent complexes and often result in molecules that have large, and sometimes abnormally large, values of molecular spin (S). When coupled to a large molecular magnetoanisotropy of the easy-axis-type (negative zero-field splitting parameter, D), also primarily resulting from individual Jahn-Teller distorted MnIII centres, such molecules will function as single-molecule magnets (molecular nanomagnets). Dissection of the structures and exchange interactions within a variety of mixed-valent Mnx cluster molecules with metal nuclearities of Mn4, Mn12 and Mn25 allows a ready rationalization of the observed S, D and overall magnetic properties in terms of competing antiferromagnetic exchange interactions within triangular subunits, resulting spin alignments and relative orientation of MnIII JT axes. Such an understanding has provided a stepping stone to the identification of a 'magnetically soft' Mn25 cluster whose groundstate spin S value can be significantly altered by relatively minor structural perturbations. Such 'spin tweaking' has allowed this cluster to be obtained in three different forms with three different groundstate S values.
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77
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Mondal KC, Song Y, Mukherjee PS. Self-assembly of a Mn9 nanoscopic mixed-valent cluster: synthesis, crystal structure, and magnetic behavior. Inorg Chem 2007; 46:9736-42. [PMID: 17918827 DOI: 10.1021/ic701018x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A rare Mn9 micro3-oxo-centered mixed-valent cluster [Mn9O7(O2CPh)11(thmn)(py)2 (H2O)3] (1) is prepared by assembling an oxo-centered MnIIMnIII2 triangle, [Mn3O(O2CPh)6(py)2(H2O)].0.5MeCN, as the secondary building unit in the presence of a tripodal alcohol, 1,1,1-tris(hydroxymethyl)nitromethane (H3thmn), as the capping ligand. Complex 1 was formed along with a minor byproduct, [Mn6O2(O2CPh)10(MeCN)4] (2). Complex 1 was characterized by X-ray single-crystal structure analysis and was crystallized in a monoclinic system, space group P2(1)/n, a=16.214(6) A, b=25.874(10) A, c=26.497(10) A, and beta=94.214(7) degrees. The Manganese-oxo-carboxylate core in 1 looks like a funnel. Variable-temperature magnetic studies down to 2 K reveal the existence of dominant ferromagnetic interaction within the cluster. Alternating current susceptibility data of the cluster show strong frequency dependence of both the real and imaginary parts of susceptibility chi' and chi'' below 5 K. Moreover, the calculated relaxation time, tau0=1.2x10(-7) s, and the energy barrier, DeltaE=25 K, are consistent with the single-molecule magnetic behavior of 1.
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Affiliation(s)
- Kartik Chandra Mondal
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
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78
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The use of methylsalicyloxime in manganese chemistry: A triangle and its oxidation to a rod. Inorganica Chim Acta 2007. [DOI: 10.1016/j.ica.2007.06.031] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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79
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Stamatatos TC, Foguet-Albiol D, Lee SC, Stoumpos CC, Raptopoulou CP, Terzis A, Wernsdorfer W, Hill SO, Perlepes SP, Christou G. "Switching on" the properties of single-molecule magnetism in triangular manganese(III) complexes. J Am Chem Soc 2007; 129:9484-99. [PMID: 17622145 DOI: 10.1021/ja072194p] [Citation(s) in RCA: 186] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The reaction between oxide-centered, triangular [MnIII3O(O2CR)6(py)3](ClO4) (R = Me (1), Et (2), Ph (3)) compounds and methyl 2-pyridyl ketone oxime (mpkoH) affords a new family of Mn/carboxylato/oximato complexes, [MnIII3O(O2CR)3(mpko)3](ClO4) [R = Me (4), Et (5), and Ph (6)]. As in 1-3, the cations of 4-6 contain an [MnIII3(mu3-O)]7+ triangular core, but with each Mn2 edge now bridged by an eta1:eta1:mu-RCO2- and an eta1:eta1:eta1:mu-mpko- group. The tridentate binding mode of the latter causes a buckling of the formerly planar [MnIII3(mu3-O)]7+ core, resulting in a relative twisting of the three MnIII octahedra and the central O2- ion now lying approximately 0.3 A above the Mn3 plane. This structural distortion leads to ferromagnetic exchange interactions within the molecule and a resulting S = 6 ground state. Fits of dc magnetization data for 4-6 collected in the 1.8-10.0 K and 10-70 kG ranges confirmed S = 6 ground states, and gave the following D and g values: -0.34 cm(-1) and 1.92 for 4, -0.34 cm(-1) and 1.93 for 5, and -0.35 cm(-1) and 1.99 for 6, where D is the axial zero-field splitting (anisotropy) parameter. Complexes 4-6 all exhibit frequency-dependent out-of-phase (chi" M) ac susceptibility signals suggesting them possibly to be single-molecule magnets (SMMs). Relaxation rate vs T data for complex 4 down to 1.8 K obtained from the chi" M vs T studies were supplemented with rate vs T data measured to 0.04 K via magnetization vs time decay studies, and these were used to construct Arrhenius plots from which was obtained the effective barrier to relaxation (Ueff) of 10.9 K. Magnetization vs dc field sweeps on single-crystals of 4.3CH2Cl2 displayed hysteresis loops exhibiting steps due to quantum tunneling of magnetization (QTM). The loops were essentially temperature-independent below approximately 0.3 K, indicating only ground-state QTM between the lowest-lying Ms = +/-6 levels. Complexes 4-6 are thus confirmed as the first triangular SMMs. High-frequency EPR spectra of single crystals of 4.3CH2Cl2 have provided precise spin Hamiltonian parameters, giving D = -0.3 cm(-1), B40 = -3 x 10(-5) cm(-1), and g = 2.00. The spectra also suggest a significant transverse anisotropy of E > or = 0.015 cm(-1). The combined work demonstrates the feasibility that structural distortions of a magnetic core imposed by peripheral ligands can "switch on" the properties of an SMM.
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80
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Manoli M, Johnstone R, Parsons S, Murrie M, Affronte M, Evangelisti M, Brechin E. A Ferromagnetic Mixed-Valent Mn Supertetrahedron: Towards Low-Temperature Magnetic Refrigeration with Molecular Clusters. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200701027] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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81
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Manoli M, Johnstone RDL, Parsons S, Murrie M, Affronte M, Evangelisti M, Brechin EK. A Ferromagnetic Mixed-Valent Mn Supertetrahedron: Towards Low-Temperature Magnetic Refrigeration with Molecular Clusters. Angew Chem Int Ed Engl 2007; 46:4456-60. [PMID: 17511009 DOI: 10.1002/anie.200701027] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Maria Manoli
- School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ, UK
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82
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Lee SC, Stamatatos TC, Hill S, Perlepes SP, Christou G. High-frequency EPR characterization of a triangular Mn3 single-molecule magnet. Polyhedron 2007. [DOI: 10.1016/j.poly.2006.10.052] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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83
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Prescimone A, Wolowska J, Rajaraman G, Parsons S, Wernsdorfer W, Murugesu M, Christou G, Piligkos S, McInnes EJL, Brechin EK. Studies of a linear single-molecule magnet. Dalton Trans 2007:5282-9. [DOI: 10.1039/b713163a] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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84
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Synthesis, crystal structure and magnetism of a single-molecule magnet, [Mn16O16(OMe)6(OAc)16(MeOH)3(H2O)3]·6H2O, and of a mixed bridge 1D chain, [Mn(μ-OMe)(μ-OAc)2]n. Polyhedron 2007. [DOI: 10.1016/j.poly.2006.05.044] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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85
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Baca SG, Stoeckli-Evans H, Ambrus C, Malinovskii ST, Malaestean I, Gerbeleu N, Decurtins S. Synthesis, crystal structures and magnetic properties of trinuclear oxo-centered homo- and mixed-valence manganese pivalate complexes with imidazole (Im) and 1-methylimidazole (1-MeIm): and. Polyhedron 2006. [DOI: 10.1016/j.poly.2006.07.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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86
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Bai YL, Tao J, Wernsdorfer W, Sato O, Huang RB, Zheng LS. Coexistence of Magnetization Relaxation and Dielectric Relaxation in a Single-Chain Magnet. J Am Chem Soc 2006; 128:16428-9. [PMID: 17177353 DOI: 10.1021/ja066679+] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel single-chain magnet, [MnIII3O(Meppz)3(EtOH)4(OAc)] (1), has been successfully synthesized from a secondary building block [MnIII3O(Meppz)3(EtOH)5Cl] (2) with an S = 1 ground state. SCM 1 exhibits both magnetization relaxation and dielectric relaxation properties.
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Affiliation(s)
- Yue-Ling Bai
- Department of Chemistry, State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, P. R. China
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87
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Milios CJ, Manoli M, Rajaraman G, Mishra A, Budd LE, White F, Parsons S, Wernsdorfer W, Christou G, Brechin EK. A Family of [Mn6] Complexes Featuring Tripodal Ligands. Inorg Chem 2006; 45:6782-93. [PMID: 16903735 DOI: 10.1021/ic060676g] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The synthesis and magnetic properties of four new Mn complexes containing tripodal alcohol ligands are reported: [Mn6(OAc)6(H2tea)2(tmp)2].2MeCN (1.2MeCN), [Mn6(acac)4(OAc)2(Htmp)2(H2N-ep)2] (2), [Mn6(OAc)8(tmp)2(py)4].2py (3.2py), and [Mn6(OAc)8(thme)2(py)4].2py (4.2py) [H3tea, triethanolamine; H3tmp, 1,1,1-tris(hydroxymethyl)propane; H2N-H2ep, 2-amino-2-ethyl-1,3-propanediol; H3thme, 1,1,1-tris(hydroxymethyl)ethane]. All complexes are mixed-valent with a [Mn(III)2Mn(II)4] oxidation assignment and are constructed from four edge-sharing triangles but differ slightly in that complexes 1 and 2 display a [Mn(III)2Mn(II)4(mu2-OR)6(mu3-OR)4]4+ core, while complexes 3 and 4 feature [Mn(III)2Mn(II)4(mu2-OR)2(mu3-OR)4]8+ and [Mn(III)2Mn(II)4(mu2-OR)4(mu3-OR)4]6+ cores, respectively. dc and ac magnetic susceptibility studies in the 2-300 K range for complexes 1-4 reveal the presence of dominant antiferromagnetic exchange interactions, leading to ground states of S = 0 for 1 and 2, while complexes 3 and 4 display S = 4 ground states with D = -0.44 and -0.58 cm(-1), respectively. Single-molecule magnetism behavior was confirmed for 3 and 4 by the presence of sweep-rate and temperature-dependent hysteresis loops in single-crystal M vs H studies at temperatures down to 40 mK. Theoretical density functional calculations were used to evaluate the individual pairwise exchange interactions present, confirming the diamagnetic ground states for 1 and 2 and the S = 4 ground states for 3 and 4.
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Affiliation(s)
- Constantinos J Milios
- School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, U.K
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88
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Collison D, McInnes EJL, Brechin EK. Tetrahedra, Super‐Tetrahedra, Bipyramids, Boxes and More: Polymetallic Clusters of Benzotriazole. Eur J Inorg Chem 2006. [DOI: 10.1002/ejic.200600206] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- David Collison
- School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Eric J. L. McInnes
- School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Euan K. Brechin
- School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ, UK
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89
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Yang CI, Chung G, Kuo TS, Shieh M, Tsai HL. A New Hexanuclear Manganese Complex Exhibits Superparamagnetic Behavior. CHEM LETT 2006. [DOI: 10.1246/cl.2006.724] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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90
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Aromí G, Brechin EK. Synthesis of 3d Metallic Single-Molecule Magnets. STRUCTURE AND BONDING 2006. [DOI: 10.1007/430_022] [Citation(s) in RCA: 815] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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91
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Jones LF, Jensen P, Moubaraki B, Berry KJ, Boas JF, Pilbrow JR, Murray KS. Heptanuclear iron(iii) triethanolamine clusters exhibiting ‘millennium dome’-like topologies and an octanuclear analogue with ground spin states of S = 5/2 and 0, respectively. ACTA ACUST UNITED AC 2006. [DOI: 10.1039/b602858f] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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92
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Sañudo EC, Smith AA, Mason PV, Helliwell M, Aromí G, Winpenny REP. Polynuclear vanadium complexes from thermal decomposition of [V3O(O2CPh)6(H2O)3]Cl. Dalton Trans 2006:1981-7. [PMID: 16609768 DOI: 10.1039/b510105k] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Solid-state decomposition of [V3O(O2CPh)6(H2O)3]Cl at 300 degrees C followed by alcoholysis of the product gives the new vanadium complexes [V6O6(PhCO2)6(CH3O)6(CH3OH)3] (1), [V6O6(PhCO2)6(C2H5O)6(C2H5OH)3] (2), [V6O6(PhCO2)6(C3H7O)6(C3H7OH)3] (3), [V6O6(PhCO2)6(C4H9O)6(C4H9OH)3] (4) and [V4O4(OCH3)6(O2CPh)2(HOCH3)2] (5). Complexes 2, 3 and 5 have been crystallographically characterised. DC magnetic susceptibility studies on complex shows antiferromagnetic coupling leading to a S = 0 spin ground state.
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93
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94
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Rajaraman G, Sañudo EC, Helliwell M, Piligkos S, Wernsdorfer W, Christou G, Brechin EK. Magnetic and theoretical characterization of a ferromagnetic Mn(III) dimer. Polyhedron 2005. [DOI: 10.1016/j.poly.2005.03.046] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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95
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Stamatatos TC, Foguet-Albiol D, Stoumpos CC, Raptopoulou CP, Terzis A, Wernsdorfer W, Perlepes SP, Christou G. Initial Example of a Triangular Single-Molecule Magnet from Ligand-Induced Structural Distortion of a [MnIII3O]7+ Complex. J Am Chem Soc 2005; 127:15380-1. [PMID: 16262396 DOI: 10.1021/ja0558138] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of [Mn3O(O2CR)6(py)3](ClO4) (R = Me, Et) with methyl 2-pyridyl ketone oxime (mpkoH) in a 1:3 molar ratio in MeOH/MeCN leads to [Mn3O(O2CR)3(mpko)3](ClO4) in 80-90% isolated yield. Ferromagnetic exchange interactions between the three MnIII ions in the nonplanar [MnIII3O]7+ triangular core lead to a spin ground state of S = 6; single-crystal studies reveal the temperature and sweep rate dependent hysteresis loops expected for a single-molecule magnet.
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96
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Zaleski CM, Depperman EC, Dendrinou-Samara C, Alexiou M, Kampf JW, Kessissoglou DP, Kirk ML, Pecoraro VL. Metallacryptate Single-Molecule Magnets: Effect of Lower Molecular Symmetry on Blocking Temperature. J Am Chem Soc 2005; 127:12862-72. [PMID: 16159280 DOI: 10.1021/ja050951i] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The structural characterization of complexes [Mn(II)4Mn(III)22(pdol)12(OCH3)12(O)16(N3)6] (1) and [Mn(II)4Mn(III)22(pdol)12(OCH3)12(O)16(OH)2(H3O)(OCH3)3].ClO4.5CH3OH (2), where pdol(2-) is di-2-pyridyl methanediol, reveals that each has a metallacryptand shell that encapsulates a manganese oxide core. Variable-temperature direct current magnetic susceptibility measurements on 2 indicate a paramagnetic ground state that results from an overall antiferromagnetic interaction in the cluster, with chiT values decreasing from 300 K (51.2 cm3 K mol(-1)) to 2 K (19.8 cm3 K mol(-1)). Variable-temperature alternating current magnetic susceptibility measurements imply that both 1 and 2 behave as single-molecule magnets. Fitting the frequency-dependent out-of-phase magnetic susceptibility to the Arrhenius equation yields an effective energy barrier, Ueff, to magnetization relaxation of 16.5 +/- 0.7 K (11.5 +/- 0.5 cm(-1)) for 1 and 36.2 +/- 2.0 K (25.1 +/- 1.4 cm(-1)) for 2. The larger value for 2 is in agreement with the lower molecular symmetry, larger magnetoanisotropy, and higher ground spin state of 2 compared to those of 1. This observation suggests a new strategy for increasing the blocking temperatures in high-nuclearity manganese clusters.
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Affiliation(s)
- Curtis M Zaleski
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, USA
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97
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Piligkos S, Rajaraman G, Soler M, Kirchner N, van Slageren J, Bircher R, Parsons S, Güdel HU, Kortus J, Wernsdorfer W, Christou G, Brechin EK. Studies of an Enneanuclear Manganese Single-Molecule Magnet. J Am Chem Soc 2005; 127:5572-80. [PMID: 15826195 DOI: 10.1021/ja042302x] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of [Mn(3)O(O(2)CMe)(6)(py)(3)] with the tripodal ligand H(3)thme (1,1,1-tris(hydroxymethyl)ethane) affords the enneanuclear complex [Mn(9)O(7)(O(2)CCH(3))(11)(thme)(py)(3)(H(2)O)(2)] 1.1MeCN.1Et(2)O. The metallic skeleton of complex 1 comprises a series of 10 edge-sharing triangles that describes part of an idealized icosahedron. Variable temperature direct current (dc) magnetic susceptibility data collected in the 1.8-300 K temperature range and in fields up to 5.5 T were fitted to give a spin ground state of S = (17)/(2) with an axial zero-field splitting parameter D = -0.29 cm(-)(1). Ac susceptibility studies indicate frequency-dependent out-of-phase signals below 4 K and an effective barrier for the relaxation of the magnetization of U(eff) = 27 K. Magnetic measurements of single crystals of 1 at low temperature show time- and temperature-dependent hysteresis loops which contain steps at regular intervals of field. Inelastic neutron scattering (INS) studies on complex 1 confirm the S = (17)/(2) ground state and analysis of the INS transitions within the zero-field split ground state leads to determination of the axial anisotropy, D = -0.249 cm(-)(1), and the crystal field parameter, B(4)(0) = 7(4) x 10(-)(6) cm(-)(1). Frequency domain magnetic resonance spectroscopy (FDMRS) determined the same parameters as D = -0.247 cm(-)(1) and B(4)(0) = 4.6 x 10(-)(6) cm(-)(1). DFT calculations are fully consistent with the experimental findings of two Mn(II) and four Mn(III) ions "spin up" and three Mn(IV) ions "spin down" resulting in the S = (17)/(2) spin ground state of the molecule, with D = -0.23 cm(-)(1) and U = 26.2 K.
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Affiliation(s)
- Stergios Piligkos
- School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ, UK
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98
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