101
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Mezei G, Zaleski CM, Pecoraro VL. Structural and Functional Evolution of Metallacrowns. Chem Rev 2007; 107:4933-5003. [PMID: 17999555 DOI: 10.1021/cr078200h] [Citation(s) in RCA: 433] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Gellert Mezei
- Department of Chemistry, Willard H. Dow Laboratories, University of Michigan, Ann Arbor, Michigan 48108-1005, and Department of Chemistry, Franklin Science Center, Shippensburg University, Shippensburg, Pennsylvania 17257-2200
| | - Curtis M. Zaleski
- Department of Chemistry, Willard H. Dow Laboratories, University of Michigan, Ann Arbor, Michigan 48108-1005, and Department of Chemistry, Franklin Science Center, Shippensburg University, Shippensburg, Pennsylvania 17257-2200
| | - Vincent L. Pecoraro
- Department of Chemistry, Willard H. Dow Laboratories, University of Michigan, Ann Arbor, Michigan 48108-1005, and Department of Chemistry, Franklin Science Center, Shippensburg University, Shippensburg, Pennsylvania 17257-2200
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102
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Luo W, Meng X, Sun X, Xiao F, Shen J, Zhou Y, Cheng G, Ji Z. Synthesis, crystal structure and bioactivity of a novel linear trinuclear nickel(II) complex. INORG CHEM COMMUN 2007. [DOI: 10.1016/j.inoche.2007.07.022] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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103
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Yoon J, Solomon EI. Electronic structures of exchange coupled trigonal trimeric Cu(II) complexes: Spin frustration, antisymmetric exchange, pseudo-A terms, and their relation to O2 activation in the multicopper oxidases. Coord Chem Rev 2007. [DOI: 10.1016/j.ccr.2006.04.012] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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104
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Zhou JH, Liu Z, Li YZ, Song Y, Chen XT, You XZ. Synthesis, structures and magnetic properties of two copper(II) complexes with pyrazole and pivalate ligands. J COORD CHEM 2007. [DOI: 10.1080/00958970500266206] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Jian-Hao Zhou
- a Coordination Chemistry Institute , State Key Laboratory of Coordination Chemistry , Nanjing University , Nanjing 210093, P.R. China
| | - Zheng Liu
- a Coordination Chemistry Institute , State Key Laboratory of Coordination Chemistry , Nanjing University , Nanjing 210093, P.R. China
| | - Yi-Zhi Li
- a Coordination Chemistry Institute , State Key Laboratory of Coordination Chemistry , Nanjing University , Nanjing 210093, P.R. China
| | - You Song
- a Coordination Chemistry Institute , State Key Laboratory of Coordination Chemistry , Nanjing University , Nanjing 210093, P.R. China
| | - Xue-Tai Chen
- a Coordination Chemistry Institute , State Key Laboratory of Coordination Chemistry , Nanjing University , Nanjing 210093, P.R. China
- b State Key Laboratory of Structural Chemistry , Fujian Institute of Research on the Structure of Matter , Fuzhou 350002, P.R. China
| | - Xiao-Zeng You
- a Coordination Chemistry Institute , State Key Laboratory of Coordination Chemistry , Nanjing University , Nanjing 210093, P.R. China
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105
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Mezei G, Rivera-Carrillo M, Raptis RG. Trigonal-prismatic CuII6-pyrazolato cages: structural and electrochemical study, evidence of charge delocalisation. Dalton Trans 2007:37-40. [PMID: 17160172 DOI: 10.1039/b615018g] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hexanuclear CuII-complexes of formula PPN[Cu6(micro3-O)2(micro-4-Rpz)6(micro-4-R'-3,5-Ph2pz)3] have been structurally characterized and the effect of pyrazole substituents on their two consecutive one-electron oxidation processes, leading to (possibly delocalised) mixed-valent products, has been probed by cyclic voltammetry.
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Affiliation(s)
- Gellert Mezei
- Department of Chemistry, University of Puerto Rico, San Juan, PR 00931-3346
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106
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Zhuang W, Zheng X, Li L, Liao D, Ma H, Jin L. Structural diversity and properties of M(ii) 4-carboxyl phenoxyacetate complexes with 0D-, 1D-, 2D- and 3D M-cpoa framework. CrystEngComm 2007. [DOI: 10.1039/b703429f] [Citation(s) in RCA: 54] [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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107
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Croucher PD, Klingele MH, Noble A, Brooker S. Tricopper(ii) complexes of unsymmetrical macrocycles incorporating phenol and pyridine moieties: the development of two stepwise routes. Dalton Trans 2007:4000-7. [PMID: 17828360 DOI: 10.1039/b707905b] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two stepwise approaches to preparing large unsymmetrical macrocycles incorporating diethylenetriamine lateral units are described: the first utilises protecting group chemistry, whereas the second exploits irreversible amide bond formation in the presence of an excess of the amine. In the first approach condensation of two equivalents of N-acetyldiethylenetriamine 1 with 2,6-diformyl-4-methylphenol, followed by a sodium borohydride reduction of the newly formed imine bonds and acidic removal of the protecting groups, yields a phenol-containing "two-armed" precursor as an HCl salt 2. Using the second approach the new pyridine-containing "two-armed" precursor , is prepared from 2,6-dimethylpyridinedicarboxylate and an excess of diethylenetriamine. These two "two-armed" di-primary amine precursors, 2 (after reaction with KOH) and 3, can be condensed with the dicarbonyl head units of choice. The lead templated condensation of 2 with 2,6-diacetylpyridine results in the formation of the macrocyclic dilead(II) complex {[Pb(II)(2)(L1)(Cl)](ClO(4))(2)}(infinity) 4. Transmetallation of 4 with three equivalents of copper(II) perchlorate produces Cu(II)(3)(L1)(OH)(ClO(4))(4) 5. Condensation of 3 with 2,6-diacetylpyridine or 2,6-diformylpyridine in the presence of barium(ii) ions results in the macrocyclic complexes [Ba(II)(H(2)L2)](ClO(4))(2) 6 and [Ba(II)(H(2)L3)](ClO(4))(2) 7, respectively. Copper(II) acetate templates the formation of the crystallographically characterised unsymmetrical macrocyclic complex [Cu(II)(3)(L4)(OH)(NCS)(2)].EtOH, 8.EtOH, from 3, 2,6-diformyl-4-methylphenol and NaNCS.
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Affiliation(s)
- Paul D Croucher
- Department of Chemistry, University of Otago, PO Box 56, Dunedin, New Zealand
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108
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Roth A, Becher J, Herrmann C, Görls H, Vaughan G, Reiher M, Klemm D, Plass W. Trinuclear Copper(II) Complexes Derived from Schiff-Base Ligands Based on a 6-Amino-6-deoxyglucopyranoside: Structural and Magnetic Characterization. Inorg Chem 2006; 45:10066-76. [PMID: 17140212 DOI: 10.1021/ic0605064] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The trinuclear copper(II) complexes ([CuL1)(mu-ac)Cu(mu-ac)CuL1) (1) and ([CuL2)(mu-ac)Cu(mu-ac)CuL2) (2) of the tridentate aminosaccharide-derived Schiff-base ligands H2L1 [6-N-(salicylidene)amino-6-deoxy-1,2,3-tri-O-methyl-alpha-D-glucopyranoside] and H2L2 [6-N-(3,5-di-tert-butylsalicylidene)amino-6-deoxy-1,2,3-tri-O-methyl-alpha-D-glucopyranoside] were synthesized and structurally characterized. The trinuclear complex units can be described as two terminal copper-ligand moieties bridged by a central copper acetate moiety, with the Cu centers arranged in a triangular fashion. IR and UV/vis spectroscopic studies strongly indicate that the trinuclear structure is maintained in a methanolic solution. The temperature dependence of the magnetic susceptibility of both complexes shows a moderate antiferromagnetic coupling and can be well interpreted by applying a symmetric Cua-Cub-Cua' model with linear spin topology. The fit of the magnetic data affords coupling constants J of -34 and -24 cm(-1) for 1 and 2, respectively [H = -J(SaSb + SbSa')]. For mu-alkoxo-mu-acetato-bridged copper(II) complexes with a large dihedral angle between the adjacent coordination planes, as found in 1 and 2, such an antiferromagnetic coupling is unusual. However, density functional theory calculations of 2 using BP86, B3LYP*, and B3LYP density functionals confirmed a symmetric doublet ground state.
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Affiliation(s)
- Arne Roth
- Institut für Anorganische und Analytische Chemie, Friedrich-Schiller-Universität Jena, Carl-Zeiss-Promenade 10, D-07745 Jena, Germany
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109
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Ouellette W, Prosvirin AV, Chieffo V, Dunbar KR, Hudson B, Zubieta J. Solid-State Coordination Chemistry of the Cu/Triazolate/X System (X = F-, Cl-, Br-, I-, OH-, and SO42-). Inorg Chem 2006; 45:9346-66. [PMID: 17083234 DOI: 10.1021/ic061102e] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hydrothermal reactions of 1,2,4-triazole with the appropriate copper salt have provided eight structurally unique members of the Cu/triazolate/X system, with X = F-, Cl-, Br-, I-, OH-, and SO4(2-). The anionic components X of [Cu3(trz)4(H2O)3]F2 (1) and [Cu6(trz)4Br]Cu4Br4(OH) (4) do not participate in the framework connectivity, acting as isolated charge-compensating counterions. In contrast, the anionic subunits X of [Cu(II)Cu(I)(trz)Cl2] (2), [Cu6(trz)4Br2] (3), [Cu(II)Cu(I)(trz)Br2] (5), [Cu3(trz)I2] (6), [Cu6(II)Cu2(I)(trz)6(SO4)3(OH)2(H2O)] (8), and [Cu4(trz)3]OH.7.5H2O (9.7.5H2O) are intimately involved in the three-dimensional connectivities. The structure of [Cu(II)Cu(I)(trz)2][Cu3(I)I4] (7) is constructed from two independent substructures: a three-dimensional cationic {Cu2(trz)2}n(n+) component and {Cu3I4}n(n-) chains. Curiously, four of the structures are mixed-valence Cu(I)/Cu(II) materials: 2, 5, 7, and 8. The only Cu(II) species is 1, while 3, 4, 6, and 9.7.5H2O exhibit exclusively Cu(I) sites. The magnetic properties of the Cu(II) species 1 and of the mixed-valence materials 5, 7, 8, and the previously reported [Cu3(trz)3OH][Cu2Br4] have been studied. The temperature-dependent magnetic susceptibility of 1 conforms to a simple isotropic model above 13 K, while below this temperature, there is weak ferromagnetic ordering due to spin canting of the antiferromagnetically coupled trimer units. Compounds 5 and 7 exhibit magnetic properties consistent with a one-dimensional chain model. The magnetic data for 8 were fit over the temperature range 2-300 K using the molecular field approximation with J = 204 cm(-1), g = 2.25, and zJ' = -38 cm(-1). The magnetic properties of [Cu3(trz)3OH][Cu2Br4] are similar to those of 8, as anticipated from the presence of similar triangular {Cu3(trz)3(mu3-OH)}(2+) building blocks. The Cu(I) species 3, 4, 6, and 9 as well as the previously reported [Cu(5)(trz)3Cl2] exhibit luminescence thermochromism. The spectra are characterized by broad emissions, long lifetimes, and significant Stokes' shifts, characteristic of phosphorescence.
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Affiliation(s)
- Wayne Ouellette
- Department of Chemistry, Syracuse University, Syracuse, New York 13244, USA
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110
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Mezei G, Raptis RG, Telser J. Trinuclear, Antiferromagnetically Coupled CuII Complex with an EPR Spectrum of Mononuclear CuII: Effect of Alcoholic Solvents. Inorg Chem 2006; 45:8841-3. [PMID: 17054337 DOI: 10.1021/ic061186r] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A rigid trinuclear copper pyrazolato framework supports the solvolytic exchange of mu3-X by mu3-OR ligands (X = Cl and Br; R = alkyl group), converting the trinuclear ferromagnetically coupled S = 3/2 system to antiferromagnetically coupled S = 1/2 in the solid state. In contrast, we propose that, in alcoholic solutions, solvolysis results in unsymmetrical coordination of the Cu3 cluster, magnetically decoupling one Cu center from the other two. This disguises the intact triangular Cu(II)3 system as a mononuclear Cu(II) complex in its electron paramagnetic resonance spectrum.
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Affiliation(s)
- Gellert Mezei
- Department of Chemistry, University of Puerto Rico, San Juan, Puerto Rico
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111
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Belinsky MI. Isotropic and Antisymmetric Double-Exchange, Zero-Field, Zeeman, and Hyperfine Splittings in Trinuclear Valence-Delocalized [Cu37+] Clusters. Inorg Chem 2006; 45:9096-106. [PMID: 17054370 DOI: 10.1021/ic060732d] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Valence delocalization in the [Cu3(7+)] trimer is considered in the model of the double-exchange coupling, in which full delocalization corresponds to the migration of the single d(x2-y2) hole and relatively strong isotropic double-exchange coupling. Strong double exchange results in the pairing of the individual spins in the delocalized trimer even at room temperature. The model explains the delocalized singlet 1A1 ground state in the planar Cu3(mu3-O) core by strong double exchange with positive double-exchange parameter t(0), whereas the delocalized triplet ground state of the [Cu3(7+)] trimer, which was observed in the Cu3(mu3-S)2 cluster, may be explained by the double exchange with relatively weak positive t(0): 0 < t(0) < 2J (degenerate 3E ground state) or negative t(0) (triplet 3A2 ground state). An analysis of the splitting of the delocalized degenerate 3E term requires inclusion of the antisymmetric double-exchange interaction, which takes into account the spin-orbit coupling in the double-exchange model. The cluster parameter KZ of the antisymmetric double-exchange coupling is proportional to t(0) and anisotropy of the g factor Deltag(parallel)[Cu(II)], KZ << t(0). Antisymmetric double exchange is relatively large in the [Cu3(7+)] cluster with the d(x2-y2) magnetic orbitals lying in the Cu3 plane [Cu3(mu3-O) core], whereas for the d(x2-y2) magnetic orbitals lying in the plane perpendicular to Cu3, antisymmetric double-exchange coupling is weak [Cu3(mu3-S)2 cluster]. The antisymmetric double-exchange coupling results in the linear zero-field splitting DeltaK = 2[equation: see text]KZ (approximately t(0)) of the delocalized degenerate 3E term that leads to strong anisotropy of the Zeeman splittings in the external magnetic field and a complex electron paramagnetic resonance (EPR) spectrum. The delocalized model of hyperfine interaction explains the hyperfine structure [10 hyperfine lines with the relative intensities 1:3:6:10:12:12:10:6:3:1 and the interval a/3] of the EPR transitions in the triplet states that was observed in the EPR spectra of the Cu3(mu3-S)2 cluster.
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Affiliation(s)
- Moisey I Belinsky
- School of Chemistry, Sackler Faculty of Exact Sciences, Tel-Aviv University, Tel Aviv, Ramat Aviv 69978, Israel.
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112
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Yoon J, Solomon EI. Ground-state electronic and magnetic properties of a mu3-oxo-bridged trinuclear Cu(II) complex: correlation to the native intermediate of the multicopper oxidases. Inorg Chem 2006; 44:8076-86. [PMID: 16241158 PMCID: PMC2630029 DOI: 10.1021/ic0507870] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ground-state electronic and magnetic properties of one of the possible structures of the trinuclear Cu(II) site in the native intermediate (NI) of the multicopper oxidases, the mu(3)-oxo-bridged structure, are evaluated using the C(3)-symmetric Cu(3)(II) complex, mu(3)O. mu(3)O is unique in that no ligand, other than the oxo, contributes to the exchange coupling. However, mu(3)O has a ferromagnetic ground state, inconsistent with that of NI. Therefore, two perturbations have been considered: protonation of the mu(3)-oxo ligand and relaxation of the mu(3)-oxo ligand into the Cu(3) plane. Notably, when the oxo ligand is sufficiently close to the Cu(3) plane (<0.3 Angstroms), the ground state of mu(3)O becomes antiferromagnetic and can be correlated to that of NI. In addition, the ferromagnetic (4)A ground state of mu(3)O is found from variable-temperature EPR to undergo a zero-field splitting (ZFS) of 2D = -5.0 cm(-1), which derives from the second-order anisotropic exchange. This allows evaluation of the sigma-to-pi excited-state exchange pathways and provides experimental evidence that the orbitally degenerate (2)E ground state of the antiferromagnetic mu(3)O would also undergo a ZFS by the first-order antisymmetric exchange that has the same physical origin as the anisotropic exchange. The important contribution of the mu(3)-oxo bridge to the ground-to-ground and ground-to-excited-state superexchange pathways that are responsible for the isotropic, antisymmetric, and anisotropic exchanges are discussed.
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113
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Umakoshi K, Kojima T, Arikawa Y, Onishi M. Heteropolynuclear Palladium Complexes with Pyrazolate and Its 3-tert-Butyl Derivatives: The Effect of Heterometal Ions on the Rate of Isomerization. Chemistry 2006; 12:5094-104. [PMID: 16642520 DOI: 10.1002/chem.200501035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The heteropolynuclear complexes [Pd(2)M'(2)(mu-pz)(6)] (M'=Ag (1), Au (2); pzH=pyrazole), HT-[Pd(2)M'(2)(mu-3-tBupz)(6)] (M'=Ag (3 a), Au (4 a); 3-tBupzH=3-tert-butylpyrazole), and HH-[Pd(2)Au(2)(mu-3-tBupz)(6)] (4 b) have been prepared and some of them were structurally characterized. When 3-tert-butylpyrazolate was employed as a bridging ligand, two linkage isomers (head-to-tail (HT) and head-to-head (HH)) arise from the difference in orientation of the substituent groups on the pyrazolate bridges between the two Pd atoms. (1)H NMR spectroscopy has been used to identify and to follow the reversible stereochemical rearrangement of the HH isomer of [Pd(2)Ag(2)(mu-3-tBupz)(6)] (3 b) to form the HT isomer 3 a in CDCl(3) and the HT isomer of [Pd(2)Au(2)(mu-3-tBupz)(6)] (4 a) to form the HH isomer 4 b in C(6)D(6). Kinetic studies of the reaction have established the rate law to be -d(HH)/dt=d(HT)/dt=k(2)[HH]-k(1)[HT] for 3 b and -d(HT)/dt=d(HH)/dt=k(1)[HT]-k(2)[HH] for 4 a, where k(1) and k(2) denote the rate of isomerization from the HT to the HH isomer and that from the HH to the HT isomer, respectively. For typical runs at 50 degrees C in C(6)D(6), k(1)=13.8x10(-5) s(-1), k(2)=18.6x10(-5) s(-1), and K(eq)=k(2)/k(1)=1.24 for 3 b, and k(1)=1.26x10(-5) s(-1), k(2)=3.52x10(-5) s(-1), and K(eq)=k(1)/k(2)=0.36 for 4 a. Temperature-dependent rate measurements reveal DeltaH(not equal) and DeltaS(not equal) to be 100(1) kJ mol(-1) and 0(3) J mol(-1) K(-1) for 3 b and 112(5) kJ mol(-1) and 20(17) J mol(-1) K(-1) for 4 a, respectively. The rate of isomerization is essentially unaffected by the concentration of the complex or by the presence of neutral bridging ligands. These data and observations imply that the isomerization involves an intramolecular exchange process.
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Affiliation(s)
- Keisuke Umakoshi
- Department of Applied Chemistry, Faculty of Engineering, Nagasaki University, Bunkyo-machi, Nagasaki 852-8521, Japan.
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114
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Ding B, Yi L, Cheng P, Liao DZ, Yan SP. Synthesis and Characterization of a 3D Coordination Polymer Based on Trinuclear Triangular CuII as Secondary Building Units. Inorg Chem 2006; 45:5799-803. [PMID: 16841984 DOI: 10.1021/ic060030o] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The hydrothermal reaction of Cu(II) salts with 1,2,4-triazole (Htrz) in aqueous ammonia yielded a novel metal-organic framework {[Cu3(mu3-O)(mu3-trz)3(OH)(H2O)6]}n (1), which was characterized by single-crystal X-ray diffraction, X-ray powder diffraction, thermogravimetric analysis, IR, and variable-temperature magnetic susceptibility. It crystallizes in cubic, space group Fd3c with a = 24.644(3) A, V = 14967(3) A(3), and Z = 96. Its framework is the first 3D structure using coordinative interactions constructed via trinuclear triangular Cu(II) secondary building units, in which both Cu(II) ions and trz ligands act as three-connected nodes to form a 6.8(2) net. An overall antiferromagnetic behavior was found in the compound.
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Affiliation(s)
- Bin Ding
- Department of Chemistry, Nankai University, Tianjin 300071, People's Republic of China
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115
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Abstract
A spin density functional (SDFT) study of carboxylate-bridged and diazenido-bridged dinuclear gadolinium compounds is presented. Calculated magnetic coupling constants for the carboxylate-bridged structures are in good agreement with experimental data, confirming the ability of the broken symmetry approach used in this work to predict magnetic behavior in such compounds. The systematic trend wherein symmetrically bridged complexes are antiferromagnetically coupled and asymmetrically bridged are ferromagnetically coupled is reproduced by the SDFT calculations. The mechanism underlying magnetic coupling in closed- and open-shell dinuclear complexes is described using a perturbative molecular orbital model that focuses the influence of the 4f(7)-5d exchange interaction on molecular orbitals with significant 5d-orbital character for the complex [[[(Me(3)Si)(2)N](2)(thf)Gd](2)(N(2))]. Open-shell electronic configurations facilitate strong ferromagnetic coupling, whereas in closed-shell systems antiferromagnetic coupling is usually preferred.
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Affiliation(s)
- Lindsay E Roy
- Department of Chemistry, Texas A&M University, College Station, 77842-3012, USA
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116
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Lysenko AB, Govor EV, Krautscheid H, Domasevitch KV. Metal–organic frameworks incorporating Cu3(μ3-OH) clusters. Dalton Trans 2006:3772-6. [PMID: 16883403 DOI: 10.1039/b604804h] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Interaction of 4,4-bi(1,2,4-triazole) (btr) with copper(II) chloride (bromide) in aqueous or aqueous alcohol media led to a series of coordination polymers featuring the formation of mu 3-hydroxotricopper(II) clusters and their integration into 3D frameworks. These unprecedented structures originate in the propagation of trigonal hydroxotricopper(II) clusters bridged by tri- or tetradentate organic ligands. Complex [{Cu3(mu3-OH)}{Cu3(mu3-O)}(mu4-btr)3(H2O)4(OH)2Cl6]Cl.0.5H2O adopts a structure of SrSi2 topology, with eight-fold interpenetration of the coordination frameworks. The structure of [{Cu3(mu3-OH)}2(mu3-btr)6(mu4-btr)(mu-X)X4]X5.nH2O (X = Br, n = 6; X = Cl, n = 8) involves 2D coordination layers [{Cu3(mu3-OH)}(mu3-btr)3]n with an exceptional (3,6)-net topology, which are cross-linked by tetradentate btr ligands and bridging chloride (bromide) ions.
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Affiliation(s)
- Andrey B Lysenko
- Inorganic Chemistry Department, Kiev University, Volodimirska Street 64, Kiev, 01033, Ukraine
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117
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Nefedov SE. Binuclear transition-metal trimethylacetato complexes containing coordinated 3,5-dimethylpyrazole as structural analogues of the active site of natural metalloenzymes. RUSS J INORG CHEM+ 2006. [DOI: 10.1134/s0036023606130031] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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118
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Battaini G, Granata A, Monzani E, Gullotti M, Casella L. Biomimetic Oxidations by Dinuclear and Trinuclear Copper Complexes. ADVANCES IN INORGANIC CHEMISTRY 2006. [DOI: 10.1016/s0898-8838(05)58005-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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119
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Yamada S, Yasui M, Nogami T, Ishida T. Self-assembled meso-helicates of linear trinuclear nickel(ii)–radical complexes with triple pyrazolate bridges. Dalton Trans 2006:1622-6. [PMID: 16547536 DOI: 10.1039/b513618k] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Complexation of 3-nitronyl-nitroxide-substituted pyrazolate (pzNN) and 3-imino-nitroxide-substituted pyrazolate (pzIN) with nickel(II) gave [Ni3(pzNN)6] and [Ni3(pzIN)6], respectively. They were practically isomorphous and characterized as a linear trinuclear structure with neighboring nickel ions triply bridged by pyrazolate moieties. The space groups were P2(1)/n but the molecules have a pseudo three-fold axis. We found polymorphs in the crystals of [Ni3(pzIN)6] depending on the solvate molecules; another space group was a cubic Pa3[combining macron]. The opposite chirality around the inversion center at the central nickel(II) ion leads to a meso-helical symmetry in the whole molecule. The radical oxygen atoms participate in the 6-membered chelation at the terminal nickel(II) ions. Antiferromagnetic couplings were observed in both complexes, which are ascribable to interactions between the nickel and radical spins and between the nickel spins across the pyrazolate bridges.
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Affiliation(s)
- Susumu Yamada
- Department of Applied Physics, University of Electro-Communications, Chofu, Tokyo 182-8585, Japan
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120
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Zhou JH, Cheng RM, Song Y, Li YZ, Yu Z, Chen XT, Xue ZL, You XZ. Syntheses, Structures, and Magnetic Properties of Unusual Nonlinear Polynuclear Copper(II) Complexes Containing Derivatives of 1,2,4-Triazole and Pivalate Ligands. Inorg Chem 2005; 44:8011-22. [PMID: 16241151 DOI: 10.1021/ic050475x] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Novel polynuclear Cu(II) complexes containing derivatives of 1,2,4-trizaole and pivalate ligands, [Cu(3)(mu(3)-OH)(mu-adetrz)(2)(piv)(5)(H(2)O)].6.5H(2)O (1) (adetrz = 4-amino-3,5-diethyl-1,2,4-triazole, piv = pivalate), [Cu(4)(mu(3)-OH)(2)(mu-atrz)(2)(mu-piv)(4)(piv)(2)].2MeOH.H(2)O (2) (atrz = 4-amino-1,2,4-triazole), [Cu(4)(mu(3)-OH)(2)(mu-tbtrz)(2)(mu-piv)(2)(piv)(4)].4H(2)O (3) (tbtrz = 4-tert-butyl-1,2,4-trizaole), and [Cu(4)(mu(3)-O)(2)(mu-admtrz)(4)(admtrz)(2)(mu-piv)(2)(piv)(2)].2[Cu(2)(mu-H(2)O)(mu-admtrz)(piv)(4)].13H(2)O [4 = 4a.2(4b).13H(2)O; admtrz = 4-amino-3,5-dimethyl-1,2,4-triazole], have been prepared and structurally characterized. 1 is an asymmetrical triangular complex containing a [Cu(3)(mu(3)-OH)] core with two Cu---Cu edges spanned by bridging adetrz ligands. 2, 3, and 4a are novel tetranuclear compounds containing a [Cu(4)(mu(3)-O)(2)] or [Cu(4)(mu(3)-OH)(2)] core with Cu---Cu edges spanned by bridging 1,2,4-triazole or pivalate ligands. 4b is a dinuclear compound with one admtrz and one water bridge, and it is the first dinuclear Cu(II) triazole complex with one bridging water molecule. 1 is one of few reported triangular Cu(II) complexes with derivatives of 1,2,4-triazole, while 2, 3, and 4a are the first group of the nonlinear tetranuclear Cu(II) compounds with derivatives of 1,2,4-triazole. Variable-temperature magnetic susceptibility studies on the powder samples of 1-3 reveal the overall antiferromagnetic coupling between Cu(II) ions with J values of -55.6 to -12.8 cm(-1) (1), -216.4 to 0 cm(-1) (2), and -259.8 to 4.8 cm(-1) (3).
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Affiliation(s)
- Jian-Hao Zhou
- Coordination Chemistry Institute, State Key Laboratory of Coordination Chemistry, Nanjing University, People's Republic of China
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121
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Mezei G, McGrady JE, Raptis RG. First Structural Characterization of a Delocalized, Mixed-Valent, Triangular Cu37+ Species: Chemical and Electrochemical Oxidation of a CuII3(μ3-O) Pyrazolate and Electronic Structure of the Oxidation Product. Inorg Chem 2005; 44:7271-3. [PMID: 16212340 DOI: 10.1021/ic050729e] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The chemical or electrochemical one-electron oxidation of the all-CuII complex [Cu3(mu3-O)(mu-pz)3X3]2- leads to its formally CuII2CuIII analogue (pz = pyrazolato anion; X = Cl- and PhCOO-). The X-ray single-crystal structure and density functional theory analysis of the latter agree in revealing the delocalized nature of its mixed-valent Cu3(7+) core.
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Affiliation(s)
- Gellert Mezei
- Department of Chemistry, University of Puerto Rico, San Juan, Puerto Rico 00931-3346
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122
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Casarin M, Corvaja C, Di Nicola C, Falcomer D, Franco L, Monari M, Pandolfo L, Pettinari C, Piccinelli F. One-Dimensional and Two-Dimensional Coordination Polymers from Self-Assembling of Trinuclear Triangular Cu(II) Secondary Building Units. Inorg Chem 2005; 44:6265-76. [PMID: 16124805 DOI: 10.1021/ic050678l] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reactions of pyrazole (Hpz) with some copper(II) carboxylates in the presence of water yield trinuclear copper derivatives characterized by the triangular core [Cu3mu3-OH)(mu-pz)3(RCOO)2] (R = H, C2H5, C3H7). Copper(II) formate gives [Cu3(mu3-OH)(mu-pz)3(HCOO)2(Hpz)2] (1), whereas copper propionate and butyrate afford [Cu3(mu3-OH)(mu-pz)3(C2H5COO)2(EtOH)] (2) and [Cu3(mu3-OH)(mu-pz)3(C3H7COO)2(MeOH)(H2O)] (3), respectively, both containing solvent molecules coordinated to copper atoms. Magnetic susceptibilities are consistent with a single unpaired electron for each trinuclear unit of 1-3, and EPR measurements indicate that higher spin states, generated by exchange coupling between copper atoms, may be populated at room temperature. Density-functional calculations provide the description of the electronic structures of 1-3, allowing, at the same time, the assignment of their UV-vis absorption spectra. X-ray molecular structure determinations show that triangular trinuclear units of 1 are connected to each other through single formate bridges, forming one-dimensional (1D) zigzag coordination polymers, whereas in 2 and 3, two oxygen atoms of two carboxylate ions doubly bridge two copper atoms of different triangles, thus generating hexanuclear units. Moreover, in 2, two other propionate ions link together two hexanuclear units yielding a 12-membered cycle and giving rise to 1D coordination polymers. The supramolecular assemblies of 1-3 are compared to that of the previously reported trinuclear triangular copper(II) derivative [Cu3(mu3-OH)(mu-pz)3(CH3COO)2(Hpz)] (A), where a two-dimensional (2D) coordination polymer is present. The reactions of 3,5-dimethylpyrazole (Hpz) with copper(II) carboxylates in the same conditions yield 1:2 Cu(RCOO)2/Hpz adducts.
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Affiliation(s)
- Maurizio Casarin
- Department of Chemical Sciences, University of Padova, Via Marzolo, 1, I-35131 Padova, Italy
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123
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Mirica LM, Stack TDP. A tris(mu-hydroxy)tricopper(II) complex as a model of the native intermediate in laccase and its relationship to a binuclear analogue. Inorg Chem 2005; 44:2131-3. [PMID: 15792444 DOI: 10.1021/ic048182b] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of a copper(I) complex with a sterically demanding secondary diamine ligand and O2 yields a tris(mu-hydroxy)tricopper(II) complex. This complex is a structural model of the proposed native intermediate in multicopper oxidases, with interesting structural, magnetic, and solution properties.
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Affiliation(s)
- Liviu M Mirica
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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124
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Mohamed AA, Pérez LM, Fackler JP. Unsupported intermolecular argentophilic interaction in the dimer of trinuclear silver(I) 3,5-diphenylpyrazolates. Inorganica Chim Acta 2005. [DOI: 10.1016/j.ica.2004.09.020] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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125
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Yamase T, Ishikawa E, Fukaya K, Nojiri H, Taniguchi T, Atake T. Spin-frustrated (VO)36+-triangle-sandwiching octadecatungstates as a new class of molecular magnets. Inorg Chem 2005; 43:8150-7. [PMID: 15578855 DOI: 10.1021/ic049669n] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Spin-frustrated polyoxometalates, K(11)H[(VO)(3)(SbW(9)O(33))(2)].27H(2)O (1) and K(12)[(VO)(3)(BiW(9)O(33))(2)].29H(2)O (2), containing approximately equilateral and isosceles (VO)(3)(6+)-triangles (V(IV)...V(IV) separation of 5.4-5.5 A) sandwiched by two diamagnetic alpha-B nonatungstate ligands ([SbW(9)O(33)](9)(-) and [BiW(9)O(33)](9)(-)) with approximate D(3)(h) symmetry, are found to show magnetization jumps with distinct hysteresis for the S = (1)/(2) <--> S = (3)/(2) level crossing under fast sweeping pulsed magnetic fields (approximately 10(3) T/s) at T < or = 0.5 K. This unusual phenomenon is attributed to the theoretical prediction of half step magnetization, which is expected for an antiferromagnetic spin triangle with antisymmetrical Dzyaloshinky-Moriya interaction. The degeneracy of the S = (1)/(2) states for 1 is removed by slightly lower symmetry effects of triangular structure for 2. The calorimetry of 1 and 2 shows the heat capacity anomaly at 2 < or = T < or = 20 K which is associated with a thermal excitation from the S = (1)/(2) ground states to the S = (3)/(2) state at zero field. Zero-field splitting energies (5-7 K) between S = (1)/(2) and S = (3)/(2) states for 1 and 2, readily estimated by the level-crossing field for the magnetization, allow us to measure the hyperfine-structural 22 lines due to three equivalent I = (7)/(2) (51)V nuclei, the fine-structural triplet line of the S = (3)/(2) excited state, and the g anisotropy on the high-frequency ESR spectra. The spin-frustrated (VO)(3)(6+)-triangle for 1 and 2 is a good model of the magnetization between pure quantum states S = (1)/(2) and (3)/(2) and provides a new class of single-molecule magnets.
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Affiliation(s)
- Toshihiro Yamase
- Chemical Resources Laboratory, Tokyo Institute of Technology, R1-21, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
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126
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Du M, Zhao X, Guo J, Bu X, Ribas J. Towards the Design of Linear Homo-Trinuclear Metal Complexes Based on a New Phenol-Functionalised Diazamesocyclic Ligand: Structural Analysis and Magnetism. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200400618] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Miao Du
- College of Chemistry and Life Science, Tianjin Normal University, Tianjin 300074, P. R. China, Fax: (internat.) +86‐22‐23540315
| | - Xiao‐Jun Zhao
- College of Chemistry and Life Science, Tianjin Normal University, Tianjin 300074, P. R. China, Fax: (internat.) +86‐22‐23540315
- Department of Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Jian‐Hua Guo
- College of Chemistry and Life Science, Tianjin Normal University, Tianjin 300074, P. R. China, Fax: (internat.) +86‐22‐23540315
| | - Xian‐He Bu
- Department of Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Joan Ribas
- Departament de Química Inorgànica, Universitat de Barcelona, Diagonal, 647, 08028 Barcelona, Spain
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127
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Nyui T, Nogami T, Ishida T. Organic kagomé lattice consisting of trimeric pyrazole and oxime supramolecular synthons from 3-pyrazolecarboxaldoxime. CrystEngComm 2005. [DOI: 10.1039/b512977j] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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128
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Mukhopadhyay S, Mandal D, Chatterjee PB, Desplanches C, Sutter JP, Butcher RJ, Chaudhury M. Bi- and Trinuclear Copper(II) Complexes of a Sterically Constrained Phenol-Based Tetradentate Ligand: Syntheses, Structures, and Magnetic Studies. Inorg Chem 2004; 43:8501-9. [PMID: 15606199 DOI: 10.1021/ic049271r] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Copper(II) complexes (1-3) of a sterically constrained phenol-based tetradentate N(2)O(2) ligand 1,4-bis(2-hydroxy-3,5-dimethylbenzyl)piperazine (H(2)L) have been reported. The associated anions of the copper(II) ion precursors have profound influence on the stoichiometry of the products. Thus, with perchlorate ion, the product is a binuclear compound [Cu(2)L(2)] (1), while with coordinating anions viz. Cl(-) and N(3)(-), the products [Cu(3)L(2)Cl(2)(H(2)O)].1/2H(2)L (2) and [Cu(3)L(2)(N(3))(2)(CH(3)OH)].4H(2)O (3) have triangulo trinuclear composition. The syntheses, X-ray structures, and spectroscopic and magnetic properties of these complexes are described. Compound 1 has a noncentrosymmetric structure with a rectangular Cu(2)(OPh)(2) core. It appears to be a rare example of a phenolato-bridged Cu(II) dimer exhibiting ferromagnetic interactions (J = 0.93 cm(-)(1)), a behavior in agreement with the theoretical predictions but seldom observed experimentally. In compounds 2 and 3, the copper centers are triangularly disposed, and the molecules have a shape much like that of a butterfly. The terminal copper centers Cu(1) and Cu(2) in 2 and 3 have distorted square pyramidal geometry, connected to each other by a bridging chloro- (in 2) or azido ligand (in 3) in "end to end" fashion. The central copper center (Cu(3) in 2 and Cu in 3) in both the compounds has distorted square planar geometry. The separations between the metal centers, viz. Cu(1)...Cu(2), Cu(2)...Cu(3), and Cu(3)...Cu(1), are 4.826, 3.214, and 3.244 A, respectively, in 2. The corresponding distances in 3 are 5.590, 3.178, and 3.485 A, respectively. The overall magnetic behaviors in 2 and 3 are consistent with antiferromagnetic interactions between the spin centers. In 3, the exchange couplings between the terminal and central copper centers J(Cu(1))(-)(Cu) and J(Cu(2))(-)(Cu) appear to be equal (-234 cm(-)(1)), resulting in an S = (1)/(2) ground state at temperatures near or below 77 K.
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Affiliation(s)
- Suman Mukhopadhyay
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700 032, India
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129
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Yoon J, Mirica LM, Stack TDP, Solomon EI. Spectroscopic Demonstration of a Large Antisymmetric Exchange Contribution to the Spin-Frustrated Ground State of a D3 Symmetric Hydroxy-Bridged Trinuclear Cu(II) Complex: Ground-to-Excited State Superexchange Pathways. J Am Chem Soc 2004; 126:12586-95. [PMID: 15453791 DOI: 10.1021/ja046380w] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The magnetic and electronic properties of a spin-frustrated ground state of an antiferromagnetically coupled 3-fold symmetric trinuclear copper complex (TrisOH) is investigated using a combination of variable-temperature variable-field magnetic circular dichroism (VTVH MCD) and powder/single-crystal EPR. Direct evidence for a low-lying excited S = (1)/(2) state from the zero-field split ground (2)E state is provided by the nonlinear dependence of the MCD intensity on 1/T and the nesting of the VTVH MCD isotherms. A consistent zero-field splitting (Delta) value of approximately 65 cm(-1) is obtained from both approaches. In addition, the strong angular dependence of the single-crystal EPR spectrum, with effective g-values from 2.32 down to an unprecedented 1.2, requires in-state spin-orbit coupling of the (2)E state via antisymmetric exchange. The observable EPR intensities also require lowering of the symmetry of the trimer structure, likely reflecting a magnetic Jahn-Teller effect. Thus, the Delta of the ground (2)E state is shown to be governed by the competing effects of antisymmetric exchange (G = 36.0 +/- 0.8 cm(-1)) and symmetry lowering (delta = 17.5 +/- 5.0 cm(-1)). G and delta have opposite effects on the spin distribution over the three metal sites where the former tends to delocalize and the latter tends to localize the spin of the S(tot) = (1)/(2) ground state on one metal center. The combined effects lead to partial delocalization, reflected by the observed EPR parallel hyperfine splitting of 74 x 10(-4) cm(-1). The origin of the large G value derives from the efficient superexchange pathway available between the ground d(x2-y2) and excited d(xy) orbitals of adjacent Cu sites, via strong sigma-type bonds with the in-plane p-orbitals of the bridging hydroxy ligands. This study provides significant insight into the orbital origin of the spin Hamiltonian parameters of a spin-frustrated ground state of a trigonal copper cluster.
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Affiliation(s)
- Jungjoo Yoon
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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130
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Casarin M, Corvaja C, Di Nicola C, Falcomer D, Franco L, Monari M, Pandolfo L, Pettinari C, Piccinelli F, Tagliatesta P. Spontaneous Self-Assembly of an Unsymmetric Trinuclear Triangular Copper(II) Pyrazolate Complex, [Cu3(μ3-OH)(μ-pz)3(MeCOO)2(Hpz)] (Hpz = Pyrazole). Synthesis, Experimental and Theoretical Characterization, Reactivity, and Catalytic Activity. Inorg Chem 2004; 43:5865-76. [PMID: 15360235 DOI: 10.1021/ic049260y] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The almost quantitative formation of the triangular trinuclear copper derivative [Cu3(3-OH)(-pz)3(MeCOO)2(Hpz)] (1) (Hpz = pyrazole), has been simply achieved by adding Hpz to an ethanol solution of Cu(MeCOO)2 x H2O. An X-ray molecular structure determination shows that 1 is completely unsymmetric and that trinuclear units result assembled in an extended bidimensional network formed through acetate bridges and hydrogen bonds. EPR and magnetic measurements are consistent with the presence of a single unpaired electron. Theoretical density functional calculations carried out for S = 1/2 provide a thorough description of the electronic structure of 1, allowing a detailed assignment of its UV-vis absorption spectrum. Compound 1 reacts with MeONa, yielding [Cu3(micro3-OH)(micro-pz)3(MeCOO)(MeO)(Hpz)] (2) and [Cu3(micro3-OH)(micro-pz)3(MeO)2(Hpz)] (3) through the substitution of one and two acetate ions, respectively, with MeO- ion(s). The spontaneous self-assembly of the triangular trinuclear Cu3 moiety seems to occur only with pyrazole as can be inferred by the results obtained in the reactions of copper(II) acetate with some substituted pyrazoles leading to the formation of mononuclear [Cu(MeCOO)2(L)2] (4-8) and dinuclear [Cu(MeCOO)2(L)]2 (9-11) (L = substituted pyrazole) compounds. Also the presence of acetate ions seems to play a leading role in determining the formation of the trinuclear triangular arrangement, as indicated by the formation of a mononuclear derivative, [Cu(CF3COO)2(Hpz)]2 (compound 12), in the reaction of copper(II) trifluoroacetate with pyrazole. Compounds 1-3, as well as some other mono- and dinuclear copper(II)-substituted pyrazole complexes, have been tested as catalyst precursors in cyclopropanation reaction, observing the formation of products in a syn:anti ratio opposite that normally reported.
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Affiliation(s)
- Maurizio Casarin
- Department of Chemical Sciences, University of Padova, Via Marzolo 1, I-35131 Padova
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131
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Effect of copper-substitution on the structure and nuclearity of Cu(II)-pyrazolates: from trinuclear to tetra-, hexa- and polynuclear complexes. Inorganica Chim Acta 2004. [DOI: 10.1016/j.ica.2004.05.022] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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132
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Effect of pyrazole-substitution on the structure and nuclearity of Cu(II)-pyrazolato complexes. Inorganica Chim Acta 2004. [DOI: 10.1016/j.ica.2004.03.016] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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133
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Synthesis of a serious of copper(II)-pyrazolyl complexes in different solvents and anions. INORG CHEM COMMUN 2004. [DOI: 10.1016/j.inoche.2004.04.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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134
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Ma S, Zhu W, Gao S, Guo Q, Xu M. Synthesis, Structure and Magnetic Properties of a μ‐Carboxylato‐Bridged Ferromagnetic Trinuclear Copper(
II
) Complex with Lariat Tetraazacrown Ether as Ligand. Eur J Inorg Chem 2004. [DOI: 10.1002/ejic.200300273] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Shu‐Lan Ma
- Department of Chemistry, Beijing Normal University, Beijing 100875, P. R. China, Fax: (internat.) + 86‐10‐62200567
| | - Wen‐Xiang Zhu
- Department of Chemistry, Beijing Normal University, Beijing 100875, P. R. China, Fax: (internat.) + 86‐10‐62200567
| | - Song Gao
- State Key Laboratory of Rare Earth Materials Chemistry and Application, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Qian‐Ling Guo
- Department of Chemistry, Beijing Normal University, Beijing 100875, P. R. China, Fax: (internat.) + 86‐10‐62200567
| | - Miao‐Qiong Xu
- Department of Chemistry, Beijing Normal University, Beijing 100875, P. R. China, Fax: (internat.) + 86‐10‐62200567
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135
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Yamada S, Ishida T, Nogami T. Supramolecular triangular and linear arrays of metal–radical solids using pyrazolato-silver(i) motifs. Dalton Trans 2004:898-903. [PMID: 15252475 DOI: 10.1039/b312406a] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
New chelating radical ligands pzNNH, pzINH, and pzbisINH (3-pyrazolyl nitronyl nitroxide, 3-pyrazolyl imino nitroxide, and pyrazole-3,5-diyl bis(imino nitroxide), respectively) were prepared. Complexation of these ligands with Ag+ gave [Ag(pzNN)]n, [Ag(pzIN)]6, and [Ag(pzbisIN)]n containing the corresponding anionic forms of the ligands. From the X-ray crystal structure analysis, [Ag(pzIN)]6 was characterized as a dimer of almost planar triangular moieties where the pyrazolate worked as a bridge, and metal-metal bonds brought about dimerization of triangles. [Ag(pzbisIN)]n was characterized as a uniform zigzag chain consisting of pyrazolate bridges and Ag ions with a cis-Npz-Ag-Npz coordination structure. Antiferromagnetic interactions observed could be analyzed based on the structures determined for both compounds. Ferromagnetic coupling was observed in [Ag(pzNN)]n, and a polymeric structure was assumed although the crystal structure could not be determined. Novel supramolecular architectures using pyrazolate-substituted imino nitroxides have been developed, using the unique coordinative versatility of the pyrazolate derivatives
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Affiliation(s)
- Susumu Yamada
- Department of Applied Physics and Chemistry, The University of Electro-Communications, Chofu, Tokyo 182-8585, Japan
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136
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Liu X, de Miranda MP, McInnes EJL, Kilner CA, Halcrow MA. Antisymmetric exchange in two tricopper(ii) complexes containing a [Cu3(μ3-OMe)]5+core. Dalton Trans 2004:59-64. [PMID: 15356742 DOI: 10.1039/b311980g] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Reaction of CuX2(X-=Cl- or Br-) with 2 molar equivalents of 3[5]-(2,4,6-trimethylphenyl)pyrazole (HpzMes) in MeOH in the presence of NaOH yields [Cu3X(HpzMes)2(micro-pzMes)3(micro3-OMe)]X (X-=Cl- or Br-). Crystal structures of these compounds show almost identical triangles of Cu(II) ions, centred by a triply bridging methoxide ligand and with three edge-bridging pyrazolide groups. The mesityl substituents on the bridging pyrazolide ligands are arranged in HT, HH, TT fashion. chi(M)T for both compounds decreases steadily with decreasing temperature, reaching 0.40 cm(3) mol(-1) K at 70 K before decreasing further below 40 K. This low temperature behaviour could not be interpreted using conventional superexchange Hamiltonians, but was reproduced by an alternative model that incorporated an additional antisymmetric exchange term. This interpretation was confirmed by the Q-band EPR spectra of the two compounds. NMR experiments show that the structures of these compounds are not retained in solution, in contrast to other closely related tricopper compounds. These are the first examples of triangular Cu(II) compounds bearing a [Cu3micro3-OR)]5+(R is not equal to H) core motif, and the first triangular compounds showing antisymmetric exchange to have been analysed by both susceptibility and EPR measurements.
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Affiliation(s)
- Xiaoming Liu
- Department of Chemistry, University of Leeds, Woodhouse Lane, Leeds, UKLS2 9JT
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137
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Seeber G, Kögerler P, Kariuki BM, Cronin L. Supramolecular assembly of ligand-directed triangular {CuII3Cl} clusters with spin frustration and spin-chain behaviour. Chem Commun (Camb) 2004:1580-1. [PMID: 15263927 DOI: 10.1039/b402487g] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Triangular [Cu(II)3Cl] clusters, containing a chloro ligand in an unprecedented trigonal planar coordination mode, are assembled in a 3-D array by the combination of coordinative and hydrogen-bonded interactions, which result in magnetically isolated 1-D chains exhibiting a combination of spin frustration and spin-chain behaviour.
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Affiliation(s)
- Georg Seeber
- Department of Chemistry, University of Glasgow, Glasgow, UK G12 8QQ
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138
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Boca R, Dlhán L, Mezei G, Ortiz-Pérez T, Raptis RG, Telser J. Triangular, ferromagnetically-coupled CuII 3-pyrazolato complexes as possible models of particulate methane monooxygenase (pMMO). Inorg Chem 2003; 42:5801-3. [PMID: 12971746 DOI: 10.1021/ic0344416] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Magnetic susceptibility and EPR studies show that trinuclear Cu(II)-pyrazolato complexes with a Cu(3)(mu3-X)2 core (X = Cl, Br) are ferromagnetically coupled: J(Cu-Cu) = +28.6 cm(-1) (X = Cl), +3.1 cm(-1) (X = Br). The orderly transition from an antiferromagnetic to a ferromagnetic exchange among the Cu centers of Cu(3)(mu3-X) complexes, X = O, OH, Cl, Br, follows the change of the Cu-X-Cu angle from 120 degrees to approximately 80 degrees. The crystal structures of [Bu4N]2"[Cu3(mu3-Br)2(mu-pz*)3Br3] (pz* = pz (1a) or 4-O2N-pz (1b), pz = pyrazolato anion, C(3)H(3)N(2)(1-)) are presented.
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Affiliation(s)
- Roman Boca
- Department of Chemistry, University of Puerto Rico, San Juan, Puerto Rico 00931-3346
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Umakoshi K, Yamauchi Y, Nakamiya K, Kojima T, Yamasaki M, Kawano H, Onishi M. Pyrazolato-bridged polynuclear palladium and platinum complexes. Synthesis, structure, and reactivity. Inorg Chem 2003; 42:3907-16. [PMID: 12793829 DOI: 10.1021/ic026196g] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cyclic trinuclear complexes [Pd(3)(mu-pz)(6)] (1) and [Pd(3)(mu-4-Mepz)(6)] (2) and dinuclear complex [Pd(2)(mu-3-t-Bupz)(2)(3-t-Bupz)(2)(3-t-BupzH)(2)] (3) have been prepared by the reactions of [PdCl(2)(CH(3)CN)(2)] with pyrazole (pzH), 4-methylpyrazole (4-MepzH), and 3-tert-butylpyrazole (3-t-BupzH), respectively, in CH(3)CN in the presence of Et(3)N. In the absence of the base, treatment of [PdCl(2)(CH(3)CN)(2)] with pzH gave the mononuclear complex, [Pd(pzH)(4)]Cl(2) (6). The reaction of [PtCl(2)(C(2)H(5)CN)(2)] with pzH in the presence of Et(3)N under refluxing in C(2)H(5)CN afforded the known dimeric Pt(II) complex, [Pt(pz)(2)(pzH)(2)](2) (7). The protons participating in the hydrogen bonding in 3 and 7 are easily replaced by silver ions to give the heterotetranuclear complex [Pd(2)Ag(2)(mu-3-t-Bupz)(6)] (4) and the heterohexanuclear complex [Pt(2)Ag(4)(mu-pz)(8)] (5). The complexes 1-6 are structurally characterized.
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Affiliation(s)
- Keisuke Umakoshi
- Department of Applied Chemistry, Faculty of Engineering, Nagasaki University, Bunkyo-machi, Nagasaki 852-8521, Japan.
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Akilan P, Thirumavalavan M, Kandaswamy M. Lateral macrobicyclic tricompartmental ligands: synthetic, spectral, magnetic, electrochemical and kinetic aspects of binuclear copper(II) complexes. Polyhedron 2003. [DOI: 10.1016/s0277-5387(03)00195-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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