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Eya'ane Meva F, Prior TJ, Evans DJ, Shah S, Cespedes O. Iron(III), cobalt(II) and zinc(II) coordination compounds with a carboximidamide ligand: Synthesis, structures and properties. INORG CHEM COMMUN 2020. [DOI: 10.1016/j.inoche.2020.108196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Synthesis, crystal structure, spectroscopic and hirshfeld surface analysis, NCI-RDG, DFT computations and antibacterial activity of new asymmetrical azines. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.128376] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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An Oxalate-Bridged Copper(II) Complex Combining Monodentate Benzoate, 2,2'-bipyridine and Aqua Ligands: Synthesis, Crystal Structure and Investigation of Magnetic Properties. Molecules 2020; 25:molecules25081898. [PMID: 32326057 PMCID: PMC7221668 DOI: 10.3390/molecules25081898] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/12/2020] [Accepted: 04/14/2020] [Indexed: 11/28/2022] Open
Abstract
A dinuclear copper(II) complex of formula [{Cu(bipy)(bzt)(OH2)}2(μ-ox)] (1) (where bipy = 2,2′-bipyridine, bzt = benzoate and ox = oxalate) was synthesised and characterised by diffractometric (powder and single-crystal XRD) and thermogravimetric (TG/DTG) analyses, spectroscopic techniques (IR, Raman, electron paramagnetic resonance spectroscopy (EPR) and electronic spectroscopy), magnetic measurements and density functional theory (DFT) calculations. The analysis of the crystal structure revealed that the oxalate ligand is in bis(bidentate) coordination mode between two copper(II) centres. The other four positions of the coordination environment of the copper(II) ion are occupied by one water molecule, a bidentate bipy and a monodentate bzt ligand. An inversion centre located on the ox ligand generates the other half of the dinuclear complex. Intermolecular hydrogen bonds and π-π interactions are responsible for the organisation of the molecules in the solid state. Molar magnetic susceptibility and field dependence magnetisation studies evidenced a weak intramolecular–ferromagnetic interaction (J = +2.9 cm−1) between the metal ions. The sign and magnitude of the calculated J value by density functional theory (DFT) are in agreement with the experimental data.
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Diversity of Coordination Modes in a Flexible Ditopic Ligand Containing 2-Pyridyl, Carbonyl and Hydrazone Functionalities: Mononuclear and Dinuclear Cobalt(III) Complexes, and Tetranuclear Copper(II) and Nickel(II) Clusters. MAGNETOCHEMISTRY 2019. [DOI: 10.3390/magnetochemistry5030039] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Syntheses, crystal structures and characterization are reported for four new complexes [Cu4Br2(L)4]Br2 (1), [Ni4(NO3)2(L)4(H2O)](NO3)2 (2), [Co2(L)3](ClO4)3 (3) and [Co(L)2](ClO4) (4), where L− is the monoanion of the ditopic ligand N′-(1-(pyridin-2-yl)ethylidene)pyridine-2-carbohydrazide (LH) built on a picolinoyl hydrazone core fragment, and possessing a bidentate and a tridentate coordination pocket. The tetranuclear cation of 1·0.8H2O·MeOH is a strictly planar, rectangular [2 × 2] grid. Two 2.21011 L− ligands bridge adjacent CuII atoms on the short sides of the rectangle through their alkoxide oxygen atoms, and two 2.11111 ligands bridge adjacent CuII atoms on the long sides of the rectangle through their diazine groups; two metal ions are 5-coordinate and two are 6-coordinate. The tetranuclear cation of 2·0.2H2O·3EtOH is a square [2 × 2] grid. The two 6-coordinate NiII atoms of each side of the square are bridged by the alkoxide O atom of one 2.21011 L− ligand. The dinuclear cation of 3·0.8H2O·1.3MeOH contains two low-spin octahedral CoIII ions bridged by three 2.01111 L− ligands forming a pseudo triple helicate. In the mononuclear cation [Co(L)2]+ of complex 4, the low-spin octahedral CoIII center is coordinated by two tridentate chelating, meridional 1.10011 ligands. The crystal structures of the complexes are stabilized by a variety of π–π stacking and/or H-bonding interactions. Compounds 2, 3 and 4 are the first structurally characterized nickel and cobalt complexes of any form (neutral or anionic) of LH. The 2.01111 and 1.10011 coordination modes of L−, observed in the structures of complexes 3 and 4, have been crystallographically established for the first time in coordination complexes containing this anionic ligand. Variable-temperature, solid-state dc magnetic susceptibility and variable-field magnetization studies at 1.8 K were carried out on complexes 1 and 2. Antiferromagnetic metal ion···metal ion exchange interactions are present in both complexes. The study reveals that the cation of 1 can be considered as a practically isolated pair of strongly antiferromagnetically coupled (through the diazine group of L−) dinulear units. The susceptibility data for 2 were fit to a single-J model for an S = 1 cyclic tetramer. The values of the J parameters have been rationalized in terms of known magnetostructural correlations. Spectral data (infrared (IR), ultraviolet/visible (UV/VIS), 1H nuclear magnetic resonance (NMR) for the diamagnetic complexes) are also discussed in the light of the structural features of 1–4 and the coordination modes of the organic and inorganic ligands that are present in the complexes. The combined work demonstrates the ligating flexibility of L−, and its usefulness in the synthesis of complexes with interesting structures and properties.
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Anwar MU, Al-Harrasi A, Pilkington M, Gavey EL, Rawson JM. A linear tetranuclear Cu(II) complex exhibiting both ferro and antiferromagnetic couplings: Synthesis, characterization and magneto-structural studies. Polyhedron 2019. [DOI: 10.1016/j.poly.2019.03.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Yahyaoui M, Bouchama A, Anak B, Chiter C, Djedouani A, Rabilloud F. Synthesis, molecular structure analyses and DFT studies on new asymmetrical azines based Schiff bases. J Mol Struct 2019. [DOI: 10.1016/j.molstruc.2018.09.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Tang Q, Wu JQ, Li HY, Feng YF, Zhang Z, Liang YN. Dinuclear Cu(II) complexes based on p
-xylylene-bridged bis(1,4,7-triazacyclononane) ligands: Synthesis, characterization, DNA cleavage abilities and evaluation of superoxide dismutase- and catalase-like activities. Appl Organomet Chem 2018. [DOI: 10.1002/aoc.4297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Qi Tang
- Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China); School of Chemistry and Pharmacy of Guangxi Normal University; Guilin People's Republic of China
| | - Ji-Qing Wu
- Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China); School of Chemistry and Pharmacy of Guangxi Normal University; Guilin People's Republic of China
| | - Hong-Yan Li
- Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China); School of Chemistry and Pharmacy of Guangxi Normal University; Guilin People's Republic of China
| | - Yan-Fang Feng
- Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China); School of Chemistry and Pharmacy of Guangxi Normal University; Guilin People's Republic of China
| | - Zhong Zhang
- Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China); School of Chemistry and Pharmacy of Guangxi Normal University; Guilin People's Republic of China
| | - Yu-Ning Liang
- Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China); School of Chemistry and Pharmacy of Guangxi Normal University; Guilin People's Republic of China
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Anwar MU, Al-Harrasi A, Gavey EL, Pilkington M, Rawson JM, Thompson LK. A new nitrogen rich open chain diazine ligand system: synthesis coordination chemistry and magneto-structural studies. Dalton Trans 2018; 47:2511-2521. [PMID: 29302666 DOI: 10.1039/c7dt03845c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis and coordination chemistry of a new series of open chain diazine based ligands (L3aH2, L3bH2, and L3cH2) is reported. The ligands comprise a central disubstituted bipyridine moiety with two bridging alkoxide oxygen donors, together with diazine and pyridine terminal groups strategically located to coordinate three metal centres. Reactions of L3aH2 and L3bH2 with CuX2 (X- = ClO4, Cl, NO3) yield a trinuclear complex (1) and 1-D copper chains (2, 3). In these complexes the ligands bind copper ions via Nbipyridne, trans Ndiazine, Ohydrazone, and Npyridne donors while vacant sites are occupied by counter ions or solvent molecules (methanol, water, acetonitrile). Reaction of L3cH2 with MnCl2 affords a linear trinuclear Mn complex (4), where the Mn(ii) ions are connected via μ2-Ohydrazone linkers with no N-N bridging. Reaction of L3aH2 with Fe(SO3CF3)2 yields a tetranuclear mixed valence Fe complex (5), in which both trans N-N and Ohydrazone bridging is observed. Magnetic studies reveal the presence of moderate to strong antiferromagnetic interactions in complexes 1-4 while a mix of ferromagnetic and antiferromagnetic interactions is observed in complex 5.
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Affiliation(s)
- Muhammad U Anwar
- University of Nizwa, Chair of Oman's Medicinal Plants and Marine Natural Products, P O Box 33, PC 616, Birkat Almouz., Nizwa, Oman.
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Eya’ane Meva F, Prior TJ, Evans DJ, Mang ER. Crystal structures of N'-amino-pyridine-2-carboximidamide and N'-{[1-(pyridin-2-yl)ethyl-idene]amino}-pyridine-2-carboximidamide. Acta Crystallogr E Crystallogr Commun 2017; 73:1021-1025. [PMID: 28775873 PMCID: PMC5499281 DOI: 10.1107/s2056989017008416] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 06/06/2017] [Indexed: 11/10/2022]
Abstract
The crystal structures of N'-amino-pyridine-2-carboximidamide (C6H8N4), 1, and N'-{[1-(pyridin-2-yl)ethyl-idene]amino}-pyridine-2-carboximidamide (C13H13N5), 2, are described. The non-H atoms in compound 1 are nearly planar (r.m.s. deviation from planarity = 0.0108 Å), while 2 is twisted about the central N-N bond by 17.8 (2)°. Both mol-ecules are linked by inter-molecular N-H⋯N hydrogen-bonding inter-actions; 1 forms a two-dimensional hydrogen-bonding network and for 2 the network is a one-dimensional chain. The bond lengths of these mol-ecules are similar to those in other literature reports of azine and di-imine systems.
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Affiliation(s)
- Francois Eya’ane Meva
- Department of Pharmaceutical Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, PO Box 2701, Cameroon
| | - Timothy John Prior
- Chemistry, School of Mathematics and Physical Sciences, University of Hull, HU6 7RX, England
| | - David John Evans
- Chemistry, School of Mathematics and Physical Sciences, University of Hull, HU6 7RX, England
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Anwar MU, Rawson JM, Gavey EL, Pilkington M, Al-Harrasi A, Thompson LK. Synthesis, characterization and magnetic studies on mono-, di-, and tri-nuclear Cu(ii) complexes of a new versatile diazine ligand. Dalton Trans 2017; 46:2105-2113. [PMID: 28154875 DOI: 10.1039/c6dt04794g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis and coordination chemistry of a new open-chain diazine ligand (L4H2) containing bipyridine, oxime and hydrazone functionalities is reported. Reaction of L4H2 with CuCl2·2H2O affords the mononuclear complex [Cu(L4H2)Cl2] (1) in which the ligand acts as a neutral tridentate N,N',N'' donor, whereas treatment with a large excess of CuCl2·2H2O affords the dinuclear complex [Cu2(L4H)Cl3(CH3OH)(H2O)] (2) in which the ligand is singly-deprotonated at the diazine, offering N,N',N'' and N,N' donor sets to two Cu(ii) ions. Reaction with Cu(NO3)2·3H2O yields the trinuclear complex, [Cu3(L4H)2(CH3OH)4(NO3)4] (3) in which the ligand is again singly deprotonated, but now presents a tetradentate N,N',N'',N'''-donor set to the first Cu(ii) and behaves as an N,O-chelate to a second Cu(ii), with a conformational change from cis to trans at the diazine moiety. When the latter reaction is repeated in the presence of a mild base, a second trinuclear complex is isolated, [Cu3(L4)2(CH3CH2OH)](NO3)2 (4) in which both the diazine and oxime functionalities of the ligand are deprotonated which subsequently bridges all three Cu(ii) ions, acting as an N,N',N'' donor to the first Cu(ii), a N,N' donor to a second Cu(ii) (similar to 2) and as a terminal O-donor to a third Cu(ii) ion. The Cu(ii) ions are linked mutually cis via the two-atom diazine bridge in the case of 2 and 4 and trans in the case of 3. Magnetic studies reveal the presence of weak ferromagnetic interactions in 2 (g = 2.2, J/k = +12.8 K) and strong antiferromagnetic interactions in both 3 and 4 (g = 2.093 J/k = -140 K and g = 2.24 J/k = -300 K respectively).
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Affiliation(s)
- Muhammad U Anwar
- University of Nizwa, Chair of Oman's Medicinal Plants and Marine Natural Products, P O Box 33, PC 616, Birkat Almouz, Nizwa, Oman. and Department of Chemistry and Biochemsitry, University of Windsor, 401 Sunset ave, Windsor, ON N9B3P4, Canada.
| | - Jeremy M Rawson
- Department of Chemistry and Biochemsitry, University of Windsor, 401 Sunset ave, Windsor, ON N9B3P4, Canada.
| | - Emma L Gavey
- Department of Chemistry, Brock University, 1812 Sir Isaac Brock Way, St. Cathaerines, ON L2S3A1, Canada
| | - Melanie Pilkington
- Department of Chemistry, Brock University, 1812 Sir Isaac Brock Way, St. Cathaerines, ON L2S3A1, Canada
| | - Ahmed Al-Harrasi
- University of Nizwa, Chair of Oman's Medicinal Plants and Marine Natural Products, P O Box 33, PC 616, Birkat Almouz, Nizwa, Oman.
| | - Laurence K Thompson
- Deptartment of Chemistry, Memorial University, St. John's, Newfoundland A1B 3X7, Canada
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Feng YF, Tang Q, Luo KL, Wu JQ, Zhang Z, Liang YN, Liang FP. Controllable assembly of Cu(ii) coordination compounds based on a flexible zwitterionic benzimidazole–dicarboxylate ligand: synthesis, structural diversity, reversible SCSC transformation and magnetic properties. CrystEngComm 2017. [DOI: 10.1039/c7ce01215b] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reversible SCSC transformation of a paddle-wheel cluster to a 1D linear polymer could be accomplished.
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Affiliation(s)
- Yan-Fang Feng
- School of Chemistry and Pharmacy of Guangxi Normal University
- Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China)
- Guilin 541004
- P. R. China
| | - Qi Tang
- School of Chemistry and Pharmacy of Guangxi Normal University
- Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China)
- Guilin 541004
- P. R. China
| | - Kai-Liang Luo
- School of Chemistry and Pharmacy of Guangxi Normal University
- Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China)
- Guilin 541004
- P. R. China
| | - Ji-Qing Wu
- School of Chemistry and Pharmacy of Guangxi Normal University
- Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China)
- Guilin 541004
- P. R. China
| | - Zhong Zhang
- School of Chemistry and Pharmacy of Guangxi Normal University
- Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China)
- Guilin 541004
- P. R. China
| | - Yu-Ning Liang
- School of Chemistry and Pharmacy of Guangxi Normal University
- Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China)
- Guilin 541004
- P. R. China
| | - Fu-Pei Liang
- School of Chemistry and Pharmacy of Guangxi Normal University
- Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China)
- Guilin 541004
- P. R. China
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Adhikari S, Sutradhar D, Shepherd SL, Phillips RM, Chandra AK, Rao KM. Synthesis, structural, DFT calculations and biological studies of rhodium and iridium complexes containing azine Schiff-base ligands. Polyhedron 2016. [DOI: 10.1016/j.poly.2016.06.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Gil-García R, Gómez-Saiz P, Díez-Gómez V, Donnadieu B, Insausti M, Lezama L, García-Tojal J. Polymorphism and magnetic properties in thiosemicarbazonecopper(II)-sulfate compounds. Polyhedron 2013. [DOI: 10.1016/j.poly.2013.02.061] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Xiang J, Mei P. The reactivity of hydrazones in the presence of Zn(II) ion: Oxidative coupling of hydrazones with alcohol and oxidative cyclization of hydrazones. INORG CHEM COMMUN 2012. [DOI: 10.1016/j.inoche.2012.06.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Dawsey AC, Li V, Hamilton KC, Wang J, Williams TJ. Copper-catalyzed oxidation of azolines to azoles. Dalton Trans 2012; 41:7994-8002. [PMID: 22460353 DOI: 10.1039/c2dt00025c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report herein convenient, aerobic conditions for the oxidation of thiazolines to thiazoles and data regarding the oxidation mechanism. These reactions feature operationally simple and environmentally benign conditions and proceed in good yield to afford the corresponding azoles, thus enabling the inexpensive preparation of valuable molecular building blocks. Incorporation of a novel diimine-ligated copper catalyst, [((Mes)DAB(Me))Cu(II)(OH(2))(3)](2+) [(-)OTf](2), provides increased reaction efficiency in many cases. In other cases copper-free conditions involving a stoichiometric quantity of base affords superior results.
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Affiliation(s)
- Anna C Dawsey
- University of Southern California, 837 Bloom Walk, Los Angeles, California 90089-1661, USA
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Jasinski JP, Golen JA, Praveen AS, Narayana B, Yathirajan HS. 1,2-Bis(3-phenoxybenzylidene)hydrazine. Acta Crystallogr Sect E Struct Rep Online 2012; 68:o81. [PMID: 22259580 PMCID: PMC3254433 DOI: 10.1107/s1600536811052469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Accepted: 12/05/2011] [Indexed: 11/24/2022]
Abstract
Molecules of the title compound, C26H20N2O2, reside on crystallographic centres of inversion located at the mid-point of the N—N bond. The benzylidene ring is essentially coplanar with the central hydrazine group, with an interplanar angle of 4.5 (2)°, whereas the phenyl ring is oriented at 34.0 (3)° with respect to the mean plane of the central 1,2-dibenzylidenehydrazine group. In the crystal, C—H⋯π(arene)-ring interactions link molecules about inversion centres.
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Jasinski JP, Golen JA, Praveen AS, Narayana B, Yathirajan HS. 1,2-Bis[(1,3-benzodioxol-5-yl)methylidene]hydrazine. Acta Crystallogr Sect E Struct Rep Online 2012; 68:o7. [PMID: 22259570 PMCID: PMC3254287 DOI: 10.1107/s1600536811050793] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 11/25/2011] [Indexed: 11/10/2022]
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Cui J, Huang L, Lu Z, Li Y, Guo Z, Zheng H. Synthesis and properties of five unexpected copper complexes with ring-cleavage of 3,6-di-2-pyridyl-1,2,4,5–tetrazine by one pot in situ hydrothermal reaction. CrystEngComm 2012. [DOI: 10.1039/c2ce05785a] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Synthesis and structural characterization of 1,2-bis((1H-pyrrol-2-yl)methylene)hydrazine and its Cu(II) complex. J Mol Struct 2011. [DOI: 10.1016/j.molstruc.2011.09.064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Al-Mehana WNA, Shakir RM, Yahya R, Abd Halim SN, Tiekink ERT. (E,E)-1,2-Bis[3-meth-oxy-4-(prop-2-yn-1-yl-oxy)benzyl-idene]hydrazine. Acta Crystallogr Sect E Struct Rep Online 2011; 67:o1659. [PMID: 21837059 PMCID: PMC3152067 DOI: 10.1107/s1600536811022410] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 06/09/2011] [Indexed: 11/10/2022]
Abstract
The complete molecule in the title compound, C22H20N2O4, is generated by the application of an inversion centre. With the exception of the terminal acetylene groups [C—O—C—C = −78.02 (17)°], the remaining atoms constituting the molecule are essentially coplanar. The configuration around the C=N bond [1.282 (2) Å] is E. The formation of supramolecular chains mediated by C—H⋯O interactions, occurring between methylene H and methoxy O atoms, is the most notable feature of the crystal packing.
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Jasinski JP, Golen JA, Chidan Kumar CS, Narayana B, Yathirajan HS. (1 E,2 E)-1,2-Bis(3-bromo-4-methoxybenzylidene)hydrazine. Acta Crystallogr Sect E Struct Rep Online 2011; 67:o1379. [PMID: 21754769 PMCID: PMC3120596 DOI: 10.1107/s1600536811016904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Accepted: 05/04/2011] [Indexed: 11/11/2022]
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Liu D, Chen Z, Qin S, Huang W, Jiang L, Liang F. Synthesis, Characterization, and Properties of Four Metal Complexes with Mulitdentate N-Acyl-Salicylhydrazide Ligands. Z Anorg Allg Chem 2011. [DOI: 10.1002/zaac.201100092] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Synthesis of symmetrical di(pyrimidin-2-yl)-1,2,4-triazoles and di(pyrimidin-2-yl)-1,2,4,5-tetrazines. Russ Chem Bull 2011. [DOI: 10.1007/s11172-010-0317-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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26
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Ghosh T, Pal S. A double helical dicopper(II) complex with biacetyl bis(benzoylhydrazone). Inorganica Chim Acta 2010. [DOI: 10.1016/j.ica.2010.07.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Massoud SS, Chun H, Wen R, Bernal I. Synthesis and Characterization of Nitrato-Triamine-Metal(II) Complexes. Conglomerate Crystallization Part 55. Crystal Structure of [Ni(dien)(O2NO)(ONO2)] (I), {[Cu(dien)-(μ-ONO2)]NO3}∞ (II), [Zn(dien)(O2NO)(ONO2)] (III), [Ni(Medpt)(O2NO)(ONO2)] (IV) and [Cu(Medpt)(ONO2)2] (V). J COORD CHEM 2010. [DOI: 10.1080/0095897021000010026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Salah S. Massoud
- a Department of Chemistry , University of Houston , Houston, TX, 77204-5641, USA
| | - Hyunphil Chun
- a Department of Chemistry , University of Houston , Houston, TX, 77204-5641, USA
| | - Ruiwu Wen
- a Department of Chemistry , University of Houston , Houston, TX, 77204-5641, USA
| | - Ivan Bernal
- a Department of Chemistry , University of Houston , Houston, TX, 77204-5641, USA
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Dragancea D, Addison AW, Zeller M, Foster ME, Prushan MJ, Thompson LK, Revenco MD, Hunter AD. A tetranuclear copper(II) complex with bis(o-aminobenzaldehyde)thiocarbohydrazone. Inorganica Chim Acta 2010. [DOI: 10.1016/j.ica.2010.02.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Biswas C, Drew MGB, Ruiz E, Estrader M, Diaz C, Ghosh A. Synthesis, crystal structure and magnetic properties of three unprecedented tri-nuclear and one very rare tetra-nuclear copper(ii) Schiff-base complexes supported by mixed azido/phenoxo/nitrato or acetato bridges. Dalton Trans 2010; 39:7474-84. [PMID: 20625577 DOI: 10.1039/c0dt00331j] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Chaitali Biswas
- Department of Chemistry, University College of Science, University of Calcutta, 92, A.P.C. Road, Kolkata, 700 009, India
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Synthesis, structures, and spectroscopic properties of copper(I) complexes bearing 7-acetamido-4-methyl-1,8-naphthyridin-2-carbaldehyde azine and 1,2-bis(diphenylphosphino)ethane ligands. OPEN CHEM 2009. [DOI: 10.2478/s11532-009-0087-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractA new ligand napaa (napaa = 7-acetamido-4-methyl-1,8-naphthyridin-2-carbaldehyde azine) and its two dinuclear copper(I) complexes, Cu2(napaa)(dppe)2(ClO4)2 (1) and Cu2(napaa)(PPh3)4(BF4)2 (2) (dppe = 1,2-bis(diphenylphosphino)ethane) and PPh3 = triphenylphosphine) were synthesized and characterized, and the structure of 1 was determined by X-ray crystal analysis. Each copper atom in 1 has a distorted tetrahedral geometry in which the metal center is associated to napaa and dppe ligands displaying chelating coordination modes and the naphthyridine rings of napaa are almost coplanar. The two complexes exhibit similar electronic absorption spectra with λmax at about 366 nm, which can be tentatively assigned to metal-to-ligand charge-transfer (MLCT) transition. The assignment was further supported by density functional theory (DFT) calculations.
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Prescimone A, Milios CJ, Sanchez-Benitez J, Kamenev KV, Loose C, Kortus J, Moggach S, Murrie M, Warren JE, Lennie AR, Parsons S, Brechin EK. High pressure induced spin changes and magneto-structural correlations in hexametallic SMMs. Dalton Trans 2009:4858-67. [PMID: 19662276 DOI: 10.1039/b902485a] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The first combined high pressure single-crystal X-ray diffraction and high pressure magnetism study of two polymetallic clusters is presented in an attempt to correlate the observed changes in structure with changes in magnetic response without the need for changes in external ligation. At 1.5 GPa the structure of [Mn(6)O(2)(Et-sao)(6)(O(2)CPh(Me)(2))(2)(EtOH)(6)] (1; Et-saoH(2) = 2-hydroxyphenylpropanone)--a single molecule magnet (SMM) with an effective anisotropy barrier of approximately 86 K--and of [Mn(6)O(2)(Et-sao)(6)(O(2)C-naphth)(2)(EtOH)(4)(H(2)O)(2)] 2 both undergo significant structural distortions of their metallic skeletons, which has a direct effect upon the observed magnetic response. The application of hydrostatic pressure on the two compounds (up to 1.5 GPa) flattens the Mn-N-O-Mn torsion angles weakening the magnetic exchange between the metal centres. In both compounds one interaction switches from ferro- to antiferromagnetic, with the Jahn-Teller (JT) axes compressing (on average) and re-aligning differently with respect to the plane of the three metal centres. High pressure dc chi(M)T plots display a gradual decrease in the low temperature peak height and slope, simulations showing a decrease in |J| with increasing pressure with a second antiferromagnetic J value required to simulate the data. The "ground states" change from S = 12 to S = 11 for 1 and to S = 10 for 2. Magnetisation data for both 1 and 2 suggest a small decrease in |D|, while out-of-phase (chi(M)(//)) ac data show a large decrease in the effective energy barrier for magnetisation reversal.
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Shuvaev KV, Abedin TSM, McClary CA, Dawe LN, Collins JL, Thompson LK. Ligand directed self-assembly vs. metal ion coordination algorithm—when does the ligand or the metal take control? Dalton Trans 2009:2926-39. [DOI: 10.1039/b818939k] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Prescimone A, Sanchez-Benitez J, Kamenev KV, Moggach SA, Lennie AR, Warren JE, Murrie M, Parsons S, Brechin EK. High pressure effects on a trimetallic MnII/III SMM. Dalton Trans 2009:7390-5. [DOI: 10.1039/b908718d] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Zhou QJ, Liu YZ, Wang RL, Fu JW, Xu JY, Lou JS. Synthesis, crystal structure and magnetic properties of a trinuclear Cu(II)-pyrazolate complex containing μ 3-OH. J COORD CHEM 2008. [DOI: 10.1080/00958970802238531] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Qi-Ji Zhou
- a College of Pharmacy, Tianjin Medical University , Tianjin 300070, P.R. China
| | - Yan-Zhao Liu
- a College of Pharmacy, Tianjin Medical University , Tianjin 300070, P.R. China
| | - Run-Ling Wang
- a College of Pharmacy, Tianjin Medical University , Tianjin 300070, P.R. China
| | - Jing-Wei Fu
- a College of Pharmacy, Tianjin Medical University , Tianjin 300070, P.R. China
| | - Jing-Yuan Xu
- a College of Pharmacy, Tianjin Medical University , Tianjin 300070, P.R. China
| | - Jian-Shi Lou
- a College of Pharmacy, Tianjin Medical University , Tianjin 300070, P.R. China
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Dragancea D, Addison AW, Zeller M, Thompson LK, Hoole D, Revenco MD, Hunter AD. Dinuclear Copper(II) Complexes with Bis-thiocarbohydrazone Ligands. Eur J Inorg Chem 2008. [DOI: 10.1002/ejic.200701187] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Shi S, Yao TM, Geng XT, Chen L, Ji LN. 1,2-Bis[amino(pyrimidin-2-yl)methylene]hydrazine dihydrate. Acta Crystallogr Sect E Struct Rep Online 2008; 64:o272. [PMID: 21200837 PMCID: PMC2915327 DOI: 10.1107/s1600536807065889] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2007] [Accepted: 12/06/2007] [Indexed: 12/03/2022]
Abstract
The centrosymmetric organic molecule in the title compound, C10H10N8·2H2O, is essentially flat and has a trans configuration. The molecules are linked by intermolecular O—H⋯N, N—H⋯O and N—H⋯N hydrogen bonds to form a linear chain structure.
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Sreerama SG, Mukhopadhyay A, Pal S. Dinuclear triple helical Mn(III), Fe(III) and Co(III) complexes. Polyhedron 2007. [DOI: 10.1016/j.poly.2007.05.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Villiers C, Thuéry P, Ephritikhine M. The first urea azine molecule and its coordination to uranium in the first actinide guanidinate complexes. Chem Commun (Camb) 2007:2832-4. [PMID: 17609791 DOI: 10.1039/b705224c] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The urea azine molecule (CyNH)(2)C=N-N=C(HNCy)(2) (1) was easily prepared by reaction of the carbodiimide CyN=C=NCy and H(2)NNH(2) and this novel type of bis-guanidine proved useful in affording chelating and bridging ligands for the building of polynuclear compounds, as illustrated by the synthesis of the first uranium guanidinate complexes [(THF)(2)Li(mu-Cl)(2)UCl(mu-L)](2) (2) and [UCl(mu-L)(2)UCl(2)(micro-Cl)(2)UCl(mu-L)](2) (3) (L = - 2H); the X-ray crystal structures of compounds - were determined.
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Affiliation(s)
- Claude Villiers
- Service de Chimie Moléculaire, DSM, DRECAM, CNRS URA 331, Laboratoire Claude Fréjacques, CEA Saclay, Bâtiment 125, 91191, Gif-sur-Yvette, France.
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Tandon SS, Dawe LN, Milway VA, Collins JL, Thompson LK. Linear copper ‘chain’ complexes with bulky tritopic hydrazone ligands—structural and magnetic studies. Dalton Trans 2007:1948-53. [PMID: 17702175 DOI: 10.1039/b618067a] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Tritopic 2,6-picolyl-bis-hydrazone ligands with bulky terminal groups derived from phenyl-pyridyl ketone do not form the expected [3 x 3] grids on reaction with copper(II), but instead form Cu8 'pinwheels', and in the present case linear trinuclear, pentanuclear and chain structures also. Direct bridging between copper ions occurs through micro2-N-N diazine groups, and longer O-C-N hydrazone connections, leading to moderately strong antiferromagnetic exchange between adjacent metal centres. Structural and magnetic properties are discussed in the context of specific orthogonal and non-orthogonal bridges, which can be distinguished and quantified.
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Affiliation(s)
- Santokh S Tandon
- Department of Chemistry, Kent State University, Salem Campus, Salem, OH 44460, USA.
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Sreerama SG, Mukhopadhyay A, Pal S. Tridentate facial coordination mode of an unsymmetrical tetradentate diazine ligand in an iron(III) complex. INORG CHEM COMMUN 2006. [DOI: 10.1016/j.inoche.2006.07.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Sreerama SG, Pal S. Dinuclear Triple Helicates with Diazine Ligands: X-ray Structural, Electrochemical, and Magnetic Studies. Inorg Chem 2005; 44:6299-307. [PMID: 16124809 DOI: 10.1021/ic050704f] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of dinuclear complexes of Mn(III), Fe(III), and Co(III) with two diazine Schiff bases, H2salhn and H2mesalhn, is reported. The Schiff bases are prepared by condensation reactions of hydrazine with salicylaldehyde (H2salhn) and with 2-hydroxyacetophenone (H2mesalhn) in 1:2 mol ratio. X-ray crystallographic characterization reveals triple helical structures of [Co2(salhn)3], [Co2(mesalhn)3], and [Fe2(mesalhn)3]. In each complex, three dinucleating O,N,N,O donor ligands provide three diazine (=N-N=) bridges between the metal ions and facial O3N3 coordination spheres around them. The ligands are twisted about the N-N single bond and coordinate to the two metal ions in a helical fashion to generate the triple helical structure. The dicobalt(III) complex of mesalhn2- is D3-symmetric, while the diiron(III) analogue is very close to being of this symmetry. On the other hand, the dicobalt(III) complex of salhn2- significantly deviates from the ideal D3-symmetry due to the large range covered by the twist angles of the three ligands. In the crystal lattice of these complexes, intermolecular C-H...O, C-H...N, O-H...O, C-H...Cl, and pi-pi interactions involving the complex and the solvent molecules lead to one- and two-dimensional supramolecular structures. The complexes [Fe2(mesalhn)3] and [Co2(mesalhn)3] are redox active and display two successive metal-centered reductions on the cathodic side of Ag/AgCl reference electrode. Weak antiferromagnetic spin-coupling is operative between the two metal ions in [Mn2(salhn)3] (J = -0.57(1) cm(-1)) and in [Fe2(mesalhn)3] (J = -2.82(4) cm(-1)).
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Ye BH, Sun AP, Wu TF, Weng YQ, Chen XM. Tapes of Cyclic Water Tetramers in the Double-Helical Complex[Cd2(bpa)2Cl4]·6 H2O. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200400956] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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44
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Lee CJ, Cheng SC, Lin HH, Wei HH. Ferromagnetic exchange in μ-alkoxo-μ-dicarboxylato double bridged tetranuclear copper(II) complexes: [Cu4(L-X)2(μ-C4H4O4)(dmf)2] (L=1,3-bis(5-X-salicylideneamino)-2-propanol, X=Br, Cl). INORG CHEM COMMUN 2005. [DOI: 10.1016/j.inoche.2004.11.031] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Grove H, Kelly TL, Thompson LK, Zhao L, Xu Z, Abedin TSM, Miller DO, Goeta AE, Wilson C, Howard JAK. Copper(II) complexes of a series of alkoxy diazine ligands: mononuclear, dinuclear, and tetranuclear examples with structural, magnetic, and DFT studies. Inorg Chem 2004; 43:4278-88. [PMID: 15236541 DOI: 10.1021/ic040036i] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Picolyl hydrazide ligands have two potentially bridging functional groups (micro-O, micro-N-N) and consequently can exist in different coordination conformers, both of which form spin-coupled polynuclear coordination complexes, with quite different magnetic properties. The complex [Cu(2)(POAP-H)Br(3)(H(2)O)] (1) involves a micro-N-N bridge (Cu-N-N-Cu 150.6 degrees ) and exhibits quite strong antiferromagnetic coupling (-2J = 246(1) cm(-)(1)). [Cu(2)(PZOAPZ-H)Br(3)(H(2)O)(2)] (2) has two Cu(II) centers bridged by an alkoxide group with a very large Cu-O-Cu angle of 141.7 degrees but unexpectedly exhibits quite weak antiferromagnetic exchange (-2J = 91.5 cm(-)(1)). This is much weaker than anticipated, despite direct overlap of the copper magnetic orbitals. Density functional calculations have been carried out on compound 2, yielding a similar singlet-triplet splitting energy. Structural details are reported for [Cu(2)(POAP-H)Br(3)(H(2)O)] (1), [Cu(2)(PZOAPZ-H)Br(3)(H(2)O)(2)] (2), [Cu(2)(PAOPF-2H)Br(2)(DMSO)(H(2)O)].H(2)O (3), [Cu(4)(POMP-H))(4)](NO(3))(4).2H(2)O (4), and PPOCCO (5) (a picolyl hydrazide ligand with a terminal oxime group) and its mononuclear complexes [Cu(PPOCCO-H)(NO(3))] (6) and [Cu(PPOCCO-H)Cl] (7). Compound 1 (C(12)H(13)Br(3)Cu(2)N(5)O(4)) crystallizes in the monoclinic system, space group P2(1)/c, with a = 15.1465(3) A, b = 18.1848(12) A, c = 6.8557(5) A, beta = 92.751(4) degrees, and Z = 4. Compound 2 (C(10)H(13)Br(3)Cu(2)N(7)O(4)) crystallizes in the triclinic system, space group P, with a = 9.14130(1) A, b = 10.4723(1) A, c = 10.9411(1) A, alpha = 100.769(1), beta = 106.271(1) degrees, gamma = 103.447(1) degrees, and Z = 2. Compound 3 (C(23)H(22)Br(2)Cu(2)N(7)O(5.5)S) crystallizes in the monoclinic system, space group P2(1)/c, with a = 12.406(2) A, b = 22.157(3) A, c = 10.704(2) A, beta = 106.21(1) degrees, and Z = 4. Compound 4(C(52)H(48)Cu(4)N(20)O(18)) crystallizes in the monoclinic system, space group P2(1)/n, with a = 14.4439(6) A, b = 12.8079(5) A, c = 16.4240(7) A, beta = 105.199(1) degrees, and Z = 4. Compound 5 (C(15)H(14)N(4)O(2)) crystallizes in the orthorhombic system, space group Pna2(1), with a = 7.834(3) A, b = 11.797(4) A, c = 15.281(3) A, and Z = 4. Compound 6(C(15)H(13)CuN(5)O(5)) crystallizes in the monoclinic system, space group P2(1)/c, with a = 8.2818(9) A, b = 17.886(2) A, c = 10.828(1) A, beta = 92.734(2) degrees, and Z = 4. Compound 7 (C(15)H(13)CuClN(4)O(2)) crystallizes in the orthorhombic system, space group Pna2(1), with a = 7.9487(6) A, b = 14.3336(10) A, c = 13.0014(9) A, and Z = 4. Density functional calculations on PPOCCO are examined in relation to the anti-eclipsed conformational change that occurs on coordination to copper(II).
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Affiliation(s)
- Hilde Grove
- Department of Chemistry, Memorial University, St. John's, Newfoundland A1B 3X7, Canada
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Escrivà E, García-Lozano J, Martínez-Lillo J, Nuñez H, Server-Carrió J, Soto L, Carrasco R, Cano J. Synthesis, crystal structure, magnetic properties, and theoretical studies of [(Cu(mepirizole)Br)2(mu-OH)(mu-pz)] (mepirizole=4-methoxy-2-(5-methoxy-3-methyl-1H-pyrazol-1-yl)-6-methylpyrimidine; pz=pyrazolate), a novel mu-pyrazolato-mu-hydroxo-dibridged copper(II) complex. Inorg Chem 2004; 42:8328-36. [PMID: 14658885 DOI: 10.1021/ic034126j] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel mu-pyrazolato-mu-hydroxo-dibridged copper(II) complex has been synthesized and structurally characterized: [(Cu(mepirizole)Br)2(mu-OH)(mu-pz)] (mepirizole=4-methoxy-2-(5-methoxy-3-methyl-1H-pyrazol-1-yl)-6-methylpyrimidine; pz=pyrazolate). The title compound crystallizes in the monoclinic system, space group P2(1)/c, with a=15.618(2) A, b=15.369(3) A, c=16.071(3) A, and beta=112.250(1) degrees. The structure is built up of dinuclear [(Cu(mepirizole)Br)2(mu-OH)(mu-pz)] units with five-coordinated copper(II) ions (CuBrN3O chromophores) linked by mu2-OH and mu2-pyrazolato bridges that are well separated from each others. The intramolecular copper-copper distance is 3.378(3) A. Magnetic susceptibility data show that the copper atoms are strongly antiferromagnetically coupled with J=-770 cm(-1). The obtained triplet-singlet energy gap is compared with those reported for a series of related dimers. The strong antiferromagnetic coupling arising from the complementarity of the hydroxo and pyrazolato bridges has been discussed on the basis of DFT calculations.
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Affiliation(s)
- Emilio Escrivà
- Departament de Química Inorgànica, Universitat de València, c/Vicent Andrés Estellés, s/n, 46100 Burjassot (València), Spain.
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Milway VA, Niel V, Abedin TSM, Xu Z, Thompson LK, Grove H, Miller DO, Parsons SR. Octanuclear and Nonanuclear Supramolecular Copper(II) Complexes with Linear “Tritopic” Ligands: Structural and Magnetic Studies. Inorg Chem 2004; 43:1874-84. [PMID: 15018506 DOI: 10.1021/ic030113u] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The structures and magnetic properties of self-assembled copper(II) clusters and grids with the "tritopic" ligands 2poap (a), Cl2poap (b), m2poap (c), Cl2pomp (d), and 2pomp (e) are described [ligands derived by reaction of 4-R-2,6-pyridinedicarboxylic hydrazide (R = H, Cl, MeO) with 2-pyridinemethylimidate (a-c, respectively) or 2-acetylpyridine (d, R = Cl; e, R = H)]. Cl2poap and Cl2pomp self-assemble with Cu(NO(3))(2) to form octanuclear "pinwheel" cluster complexes [Cu(8)(Cl2poap-2H)(4)(NO(3))(8)].20H(2)O (1) and [Cu(8)(Cl2pomp-2H)(4)(NO(3))(8)].15H(2)O (2), built on a square [2 x 2] grid with four pendant copper arms, using "mild" reaction conditions. Similar reactions of Cl2pomp and 2pomp with Cu(ClO(4))(2) produce pinwheel clusters [Cu(8)(Cl2pomp-2H)(4)(H(2)O)(8)](ClO(4))(8).7H(2)O (3) and [Cu(8)(2pomp-2H)(4)(H(2)O)(8)](ClO(4))(8) (4), respectively. Heating a solution of 1 in MeOH/H(2)O produces a [3 x 3] nonanuclear square grid complex, [Cu(9)(Cl2poap-H)(3)(Cl2poap-2H)(3)](NO(3))(9).18H(2)O (5), which is also produced by direct reaction of the ligand and metal salt under similar conditions. Reaction of m2poap with Cu(NO(3))(2) produces only the [3 x 3] grid [Cu(9)(m2poap-H)(2)(m2poap-2H)(4)](NO(3))(8).17H(2)O (6) under similar conditions. Mixing the tritopic ligand 2poap with pyridine-2,6-dicarboxylic acid (picd) in the presence of Cu(NO(3))(2) produces a remarkable mixed ligand, nonanuclear grid complex [Cu(9)(2poap-H)(4)(picd-H)(3)(picd-2H)](NO(3))(9).9H(2)O (7), in which aromatic pi-stacking interactions are important in stabilizing the structure. Complexes 1-3 and 5-7 involve single oxygen atom (alkoxide) bridging connections between adjacent copper centers, while complex 4 has an unprecedented mixed micro-(N-N) and micro-O metal ion connectivity. Compound 1 (C(76)H(92)N(44)Cu(8)O(50)Cl(4)) crystallizes in the tetragonal system, space group I, with a = 21.645(1) A, c = 12.950(1) A, and Z = 2. Compound 2 (C(84)H(88)N(36)O(44)Cl(4)Cu(8)) crystallizes in the tetragonal system, space group I, with a = 21.2562(8) A, c = 12.7583(9) A, and Z = 2. Compound 4 (C(84)H(120)N(28)O(66)Cl(8)Cu(8)) crystallizes in the tetragonal system, space group I4(1)/a, with a = 20.7790(4) A, c = 32.561(1) A, and Z = 4. Compound 7(C(104)H(104)N(46)O(56)Cu(9)) crystallizes in the triclinic system, space group P, with a = 15.473(1) A, b = 19.869(2) A, c = 23.083(2) A, alpha = 88.890(2) degrees, beta = 81.511(2) degrees, gamma = 68.607(1) degrees, and Z = 2. All complexes exhibit dominant intramolecular ferromagnetic exchange coupling, resulting from an orthogonal bridging arrangement within each polynuclear structure.
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Affiliation(s)
- Victoria A Milway
- Department of Chemistry, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3X7, Canada
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Patra S, Miller TA, Sarkar B, Niemeyer M, Ward MD, Lahiri GK. An unusual dinuclear ruthenium(III) complex with a conjugated bridging ligand derived from cleavage of a 1,4-dihydro-1,2,4,5-tetrazine ring. Synthesis, structure, and UV-vis-NIR spectroelectrochemical characterization of a five-membered redox chain incorporating two mixed-valence states. Inorg Chem 2003; 42:4707-13. [PMID: 12870962 DOI: 10.1021/ic034131n] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Reaction of [Ru(acac)(2)(CH(3)CN)(2)] with 3,6-bis(3,5-dimethylpyrazol-1-yl)-1,4-dihydro-1,2,4,5-tetrazine (H(2)L) results in formation of an unexpected dinuclear complex [(acac)(2)Ru(III)(L(1))Ru(III)(acac)(2)] (1) in which the bridging ligand [L(1)](2)(-) contains an (-)HN[bond]C[double bond]N[bond]N[double bond]C[bond]NH(-) unit arising from two-electron reduction of the 1,4-dihydro-1,2,4,5-tetrazine component of H(2)L. The crystal structure of complex 1 confirms the oxidation assignment of the metal ions as Ru(III) and clearly shows the consequent arrangement of double and single bonds in the bridging ligand, which acts as a bis-bidentate chelate having two pyrazolyl/amido chelating sites. Cyclic voltammetry of the complex shows the presence of four reversible one-electron redox couples, assigned as two Ru(III)/Ru(IV) couples (oxidations with respect to the starting material) and two Ru(II)/Ru(III) couples (reductions with respect to the starting material). The separation between the two Ru(III)/Ru(IV) couples (Delta E(1/2) = 700 mV) is much larger than that between the two Ru(II)/Ru(III) couples (Delta E(1/2) = 350 mV) across the same bridging pathway, because of the better ability of the dianionic bridging ligand to delocalize an added hole (in the oxidized mixed-valence state) than an added electron (in the reduced mixed-valence state), implying some ligand-centered character for the oxidations. UV-vis-NIR spectroelectrochemical measurements were performed in all five oxidation states; the Ru(II)-Ru(III) mixed-valence state of [1](-) has a strong IVCT transition at 2360 nm whose parameters give an electronic coupling constant of V(ab) approximately 1100 cm(-1), characteristic of a strongly interacting but localized (class II) mixed-valence state. In the Ru(III)-Ru(IV) mixed-valence state [1](+), no low-energy IVCT could be detected despite the strong electronic interaction, possibly because it is in the visible region and obscured by LMCT bands.
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Affiliation(s)
- Srikanta Patra
- Department of Chemistry, Indian Institute of Technology-Bombay, Powai, Mumbai-400076, India
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Xu Z, Thompson LK, Milway VA, Zhao L, Kelly T, Miller DO. Self-assembled dinuclear, trinuclear, tetranuclear, pentanuclear, and octanuclear Ni(II) complexes of a series of polytopic diazine based ligands: structural and magnetic properties. Inorg Chem 2003; 42:2950-9. [PMID: 12716187 DOI: 10.1021/ic0206950] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The nickel coordination chemistry of a series of polytopic diazine (N-N) based ligands has been examined. Self-assembly reactions lead to examples of dinuclear, trinuclear, tetranuclear, pentanuclear, and octanuclear complexes, all of which exhibit magnetic exchange coupling, with antiferromagnetic and ferromagnetic examples. Structural details are presented for [(L1)(2)Ni(2)(H(2)O)(2)](NO(3))(4).3H(2)O (1), [(L2)(2)Ni(3)(H(2)O)(2)](NO(3))(6).8H(2)O (2), [(L3)(4)Ni(4)(H(2)O)(8)] (NO(3))(4).8H(2)O (3), [(L4)(2)Ni(5)(H(2)O)(10)(NO(3))](NO(3))(7).8H(2)O (4), and [(L5)(4)Ni(8)(H(2)O)(8)](BF(4))(8).16H(2)O (5). Compound 1 crystallizes in the monoclinic system, space group P2(1)/c, with a = 14.937(1) A, b = 18.612(2) A, c = 20.583(2) A, beta = 108.862(2) degrees, Z = 4. Compound 2 crystallizes in the orthorhombic system, space group P2(1)2(1)2, with a = 21.771(4) A, b = 13.700(2) A, c = 20.017(3) A, Z = 4. Compound 3 crystallizes in the tetragonal system, space group P4(3), with a = 12.9483(7) A, c = 33.416(3) A, Z = 4. Compound 4 crystallizes in the triclinic system, space group P(-)1, with a = 12.6677(8) A, b = 18.110(1) A, c = 19.998(1) A, alpha = 100.395(1) degrees, beta = 109.514(1) degrees, gamma = 109.686(1) degrees, Z = 2. Compound 5 crystallizes in the monoclinic system, space group P2(1)/n, with a = 21.153(5) A, b = 35.778(9) A, c = 21.823(5) A, beta = 97.757(6) degrees, Z = 4. The linear trinuclear Ni(II) complex (2) has a cis-N-N single bond bridge, and a water bridge linking the central Ni(II) to each external Ni(II) center in each of two similar trinuclear subunits, and exhibits intramolecular ferromagnetic exchange (J = 5.0 cm(-1)). A novel octanuclear metallacyclic ring structure exists in 5, with trans-N-N single bond bridges linking adjacent Ni(II) centers, leading to quite strong intramolecular antiferromagnetic exchange (J = -30.4 cm(-1)).
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Affiliation(s)
- Zhiqiang Xu
- Department of Chemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1B 3X7
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Trinuclear complexes of a series of ‘tritopic’ hydrazide ligands—structural and magnetic properties. Polyhedron 2003. [DOI: 10.1016/s0277-5387(03)00069-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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