Synthesis, structure and magnetic properties of a binuclear copper(II) complex constructed by a new coordination mode of the tetrachlorophthalate ligand

2016 ◽  
Vol 71 (1) ◽  
pp. 45-49 ◽  
Author(s):  
Jun Zhang ◽  
Jun-Xia Li
Keyword(s):  
Binuclear Complex ◽  
Coordination Mode ◽  
Variable Temperature ◽  
The Other ◽  
Antiferromagnetic Coupling ◽  
Binuclear Copper ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
Variable Temperature Magnetic Susceptibility ◽  
Binuclear Structure

AbstractA binuclear complex [Cu2(tcpa)2(bipy)2(H2O)3] (1) (H4tcpa = tetrachlorophthalic acid, bipy = 2,2′-bipyridine) has been synthesized and structurally characterized. Two independent CuII centers Cu1 and Cu2 are both five-coordinated in distorted square pyramids. The tetrachlorophthalate (tcpa2–) anions show a new coordination mode: one is monodentate at Cu1, and the other displays a bridging μ2-O,O″ fashion linking Cu1 and Cu2, thus forming the binuclear structure of 1. Variable-temperature magnetic susceptibility data show weak antiferromagnetic coupling between the two CuII ions.

Solvent-Dependent Access to Two Different Ni4II Core Topologies from the First Use of Pyridine-2,6-dimethanol in Nickel(II) Cluster Chemistry

2012 ◽  
Vol 65 (12) ◽  
pp. 1608 ◽  
Author(s):  
Konstantina I. Alexopoulou ◽  
Catherine P. Raptopoulou ◽  
Vassilis Psycharis ◽  
Aris Terzis ◽  
Vassilis Tangoulis ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Direct Current ◽  
Variable Temperature ◽  
Structural Features ◽  
The Other ◽  
Cluster Chemistry ◽  
Magnetic Susceptibility Data ◽  
Tetranuclear Cluster ◽  
Susceptibility Data ◽  
Oxygen Atoms

The use of pyridine-2,6-dimethanol, pdmH2, in reactions with nickel(ii) acetate has led to two Ni4 clusters, depending on the solvent. [Ni4(O2CMe)4(pdmH)4]·MeCN (1·MeCN) can be obtained from MeCN and [Ni4(O2CMe)6(pdmH)2(EtOH)2]·1.2EtOH (2·1.2EtOH) from EtOH. Each cluster can be converted into the other in the appropriate solvent. The tetranuclear cluster molecule 1 possesses a distorted cubane {Ni4(μ3-OR)4}4+ core (RO– = pdmH–) with the NiII atoms and the alkoxide-type oxygen atoms from the η3 : η1 : μ3 pdmH– ligands occupying alternate vertices of the cube; four η1 : η1 : μ MeCO2– groups cap four faces of the cube. The four NiII atoms in molecule 2 are located at four vertices of a defective dicubane and are bridged by six oxygen atoms, two μ3 from the η3 : η1 : η1 : μ3 pdmH– ligands and four from four monoatomically bridging MeCO2– groups; peripheral ligation is provided by two η1 : η1 : μ MeCO2– groups and two terminal EtOH ligands. IR data are discussed in terms of the coordination modes of the ligands. Variable-temperature direct-current magnetic susceptibility data of 1 and 2 were modelled with two and three J values respectively, indicating diamagnetic ground states (S = 0). The sign and the magnitude of the J values are discussed in terms of structural features of the complexes.

Manganese(II) Oxazolidine Nitroxide Chelates: Structure, Magnetism, and Redox Properties

2014 ◽  
Vol 67 (11) ◽  
pp. 1618 ◽  
Author(s):  
Ian A. Gass ◽  
Mousa Asadi ◽  
David W. Lupton ◽  
Boujemaa Moubaraki ◽  
Alan M. Bond ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Intramolecular Interaction ◽  
Variable Temperature ◽  
Field Measurements ◽  
X Ray Diffraction ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Variable Temperature Magnetic Susceptibility ◽  
Radical Interaction

The mononuclear oxazolidine nitroxide complex [MnII(L•)2](ClO4)2 (1) (L•, 4-dimethyl-2,2-di(2-pyridyl)oxazolidine N-oxide) has been synthesized and investigated using single-crystal X-ray diffraction, variable-temperature magnetic susceptibility measurements, and electrochemistry. The structural analysis reveals bond lengths compatible with a linear L•–MnII–L• arrangement where the ligands are in the neutral ligand form and the central MnII ion is high spin (S = 5/2). Although analysis of the variable-temperature magnetic susceptibility data suggests a strong antiferromagnetic metal–radical interaction, the radical–radical intramolecular interaction could not be determined unambiguously from such fits. The resultant isolated S = 3/2 ground state is confirmed by low-temperature magnetization versus field measurements. Electrochemical studies reveal similar square schemes and redox intermediates to the previously reported analogues [FeII(L•)2][BF4]2 and [CoII(L•)2][NO3]2.

Preparation, electrochemical behavior, and variable-temperature magnetic properties of Co(3,5-DBSQ)2 complexes of imidazole- or pyrazole-substituted ligands

2015 ◽  
Vol 93 (7) ◽  
pp. 769-774 ◽  
Author(s):  
Carolyn Dowling ◽  
Danielle R. Dinsdale ◽  
Martin T. Lemaire
Keyword(s):  
Magnetic Susceptibility ◽  
High Spin ◽  
Density Functional ◽  
Variable Temperature ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Magnetic Susceptibility Data ◽  
Valence Tautomerism ◽  
Susceptibility Data ◽  
Variable Temperature Magnetic Susceptibility

Herein we describe the preparation of four new Co(3,5-DBSQ)2 containing known 2-(2-pyridyl)benzimidazole 1, 2,2′-bisbenzimidazole 2, or 2,2-(1H-pyrazole-3,5-diyl)dipyridine 3. We investigate the electronic and variable-temperature magnetic susceptibility properties of these complexes. Complexes containing 2 and 3 are bimetallic and variable-temperature magnetic susceptibility data suggest observation of a stable intermediate (high-spin and low-spin) state for the bimetallic complex with 3, which does undergo valence tautomerism. Complexes 4–6 containing imidazole-based ligands 1 and 2 feature high-spin ground states and no valence tautomerism is observed in these materials. This experimental finding is corroborated with density functional theory calculations, which support the existence of a stable high-spin ground state in these complexes.

Crystal Structures and Magnetic Properties of (2,2'-Dipyridyl)-(3-methoxysalicylaldiminato)copper(II) Perchlorate and (2,2'-Dipyridyl)-(4-methoxysalicylaldiminato)copper(II) Perchlorate

2002 ◽  
Vol 57 (5) ◽  
pp. 519-523 ◽  
Author(s):  
Y. Elerman ◽  
A. Elmali ◽  
I. Svoboda
Keyword(s):  
Magnetic Properties ◽  
Crystal Structures ◽  
Effective Magnetic Moment ◽  
Variable Temperature ◽  
Mixed Ligand ◽  
Dinuclear Complexes ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
Variable Temperature Magnetic Susceptibility ◽  
Dimeric Unit

The mixed-ligand dinuclear complexes (2,2'-dipyridyl)-(3-methoxysalicylaldiminato)copper( II) perchlorate (1) and (2,2'-dipyridyl)-(4-methoxysalicylaldiminato)copper(II) perchlorate (2)were synthesized and their crystal structures determined. Both structures consist of a dimeric unit involving a planar Cu2O2 group. In both structures, the coordination sphere of the Cu atoms can be described as an elongated octahedron where the basal plane is formed by the twoN atoms of the 2,2'-dipyridyl molecule and the two O atoms of the salicylaldehyde anion. The phenoxo O atom is the negative ligand of the monomeric unit. Two apical Cu-O contacts complete the 4+2 coordination of the Cu atoms. They correspond to one of the O atoms of the perchlorate anion and to the O atom of the nearest salicylaldehyde molecule. Variable-temperature magnetic susceptibility data obey the Curie-Weiss law with Θ = -10.3(2) K for 1 and -10.1(2) K for 2. The decrease of the effective magnetic moment from 1.89(7) μB at 300 K to 1.77(7) μB at 70 K for 1 and from 1.88(8) μB at 300 K to 1.76(8) μB at 70 K for 2 and the negative Weiss constants indicate weak antiferromagnetic interactions between the two copper atoms in the dimeric units.

New Copper(II) and Nickel(II) Complexes with Bifunctional Tetrazolate-5-carboxylate Ligands: Syntheses, Crystal Structures, and Magnetic Properties

2009 ◽  
Vol 62 (12) ◽  
pp. 1622 ◽  
Author(s):  
A-Qing Wu ◽  
Qi-Yong Chen ◽  
Mei-Feng Wu ◽  
Fa-Kun Zheng ◽  
Feng Chen ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Variable Temperature ◽  
Supramolecular Network ◽  
X Ray Diffraction ◽  
Carboxylate Ligands ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Variable Temperature Magnetic Susceptibility ◽  
Network Variable

Four new complexes with bifunctional tetrazolate-5-carboxylate ligands of 1H-tetrazole-5-formic acid (H2tzf) and 1H-tetrazole-5-acetic acid (H2tza), namely two dinuclear [M(tzf)(H2O)3]2·2H2O (M = Cu 1, Ni 2) and two mononuclear [Cu(tzf)(2,2′-bipy)2]·5H2O 3 and Cu(tza)(2,2′-bipy)H2O 4, were prepared and structurally characterized by single-crystal X-ray diffraction. Two different coordination modes of tetrazolate-5-carboxylate ligands exist: a tridentate N,O-chelated-N-bridged mode in 1 and 2, and a bidentate N,O-chelated mode in 3 and 4, which was first observed for the tetrazolate-5-carboxylate complexes. Extensive hydrogen bonds play an important role in the construction of the supramolecular network. Variable-temperature magnetic susceptibility data show the presence of antiferromagnetic interactions in 1 and 2. The thermogravimetric analyses of complexes 1–4 are also discussed.

A cobalt(II) coordination polymer constructed with the 2-carboxy-phenoxyacetate linker showing a corrugated layer structure: synthesis, structure analysis and magnetic properties

2020 ◽  
Vol 75 (6-7) ◽  
pp. 577-581 ◽  
Author(s):  
Zhong-Xiang Du ◽  
Jun-Xia Li
Keyword(s):  
Coordination Polymer ◽  
Potassium Hydroxide ◽  
Hydrothermal Reaction ◽  
Layer Structure ◽  
Variable Temperature ◽  
Antiferromagnetic Coupling ◽  
Phenoxyacetic Acid ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
Structure Synthesis

AbstractA new binary CoII coordination polymer, [Co(2-cpa)2(H2O)]n (1) has been synthesized by a hydrothermal reaction of cobalt(II) acetate tetrahydrate and 2-carboxy-phenoxyacetic acid (2-H2cpa) in the presence of potassium hydroxide. Structural analysis revealed that the central CoII ion is in an octahedral geometry coordinated with one aqua and five oxygen atoms of three 2-carboxy-phenoxyacetate (2-cpa) ligands. The 2-cpa anions function as pentadentate double bridging chelate-μ3 linkers binding neighboring CoII ions together, to form an unusual corrugated (4,4)-connected layer. Variable-temperature magnetic susceptibility data in the 2–300 K temperature range indicates a weak antiferromagnetic coupling between adjacent cobalt(II) ions.

A new binuclear NiII complex with tetrafluorophthalate and 2,2′-bipyridine ligands: synthesis, crystal structure and magnetic properties

2019 ◽  
Vol 74 (11-12) ◽  
pp. 833-838 ◽  
Author(s):  
Jun-Xia Li ◽  
Zhong-Xiang Du ◽  
Xun Feng
Keyword(s):  
Variable Temperature ◽  
Ferromagnetic Coupling ◽  
X Ray Diffraction ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Variable Temperature Magnetic Susceptibility ◽  
Niii Complex ◽  
Weak Ferromagnetic ◽  
Dinuclear Structure

AbstractA new NiII compound, [Ni2(tfpa)2(bipy)2(H2O)4] (1) with tetrafluorophthalate (tfpa2−) and 2,2′-bipyridine (abbreviated as bipy) ligands, has been synthesized and structurally characterized. The single-crystal X-ray diffraction analysis reveals that the tfpa2− anions act as bis-monodentate linkers connecting NiII centers to form the dinuclear structure of 1. The dimeric units are stabilized by intramolecular π–π stacking and are further connected into a layer through O–HLO hydrogen bonding. Variable-temperature magnetic susceptibility data in the 10–200 K temperature range indicate weak ferromagnetic coupling between the two NiII ions.

Antiferromagnetic Coupling In A (μ-Hydroxo)(μ-Pyrazolato)Dicopper(II) Complex. Synthesis, Crystal Structure, Magnetic Properties, And Theoretical Studies

2001 ◽  
Vol 56 (8) ◽  
pp. 719-727 ◽  
Author(s):  
H. Kara ◽  
Y. Elerman ◽  
K. Prout
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Variable Temperature ◽  
Magnetic Behaviour ◽  
Antiferromagnetic Coupling ◽  
Theoretical Studies ◽  
Powdered Sample ◽  
Structural Factors ◽  
Binuclear Copper ◽  
Ligand Orbital

Preparation, crystal structure and magnetic properties of a 3,5-dimethylpyrazolate bridged binuclear copper(II) complex [Cu2(L1)(3,5 prz)] (L1 = 1,3-Bis(2-hydroxy-1-napthylideneamino) propan-2-ol) (1) are reported. Variable-temperature magnetic susceptibility measurements for a powdered sample of the complex were carried out in the temperature range 5 - 350 K and analysed to obtain values of the parameter J in the exchange Hamiltonian H = -2JS1·S2 . In the dicopper(II) complex [Cu2(L2)(3,5 prz)], (L2 = l,3-Bis(2-hydroxy-5-chlorosalicylideneamino) propan-2-ol) (2) reported recently the antiferromagnetic interaction is much less than that of 1 (-27 = 440 cm-1 ), as result which is difficult to explain in terms of structural factors on the basis of widely accepted criteria. The differences in the magnetic behaviour now have been rationalized using the “ligand orbital complementary” concept

Syntheses, crystal structures, and magnetism of one-dimensional complexes generated from copper(II) and carbamyldicyanomethanide bridging ligand

2004 ◽  
Vol 82 (3) ◽  
pp. 483-489 ◽  
Author(s):  
Jing-Min Shi ◽  
Qing-Yun Liu ◽  
Wen Xu ◽  
Lin Meng ◽  
Peng Cheng ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Variable Temperature ◽  
Ligand Complex ◽  
Bridging Ligands ◽  
Magnetic Susceptibility Data ◽  
One Dimensional ◽  
X Ray Crystallography ◽  
Susceptibility Data ◽  
Bridging Ligand ◽  
Chain Complexes

Two one-dimensional chain complexes, {[Cu(cda)2H2O]·H2O}n (1) and {[Cu(cda)(H2O)2]·(ClO4)·3H2O}n (2) (cda = carbamyldicyanomethanide anion) have been synthesized and their crystal structures determined by X-ray crystallography. The copper(II) ions in 1 are bridged by two µ1,5-cda bridging ligands, whereas in 2 the copper(II) ions are connected by a single µ1,5-cda ligand. Complex 1 is red while 2 is green. Variable-temperature magnetic susceptibility data indicate that there is a very weak antiferromagnetic interaction between the bridged copper(II) ions in both 1 and 2.Key words: synthesis, crystal structure, copper complex, polynitrile ligand, magnetism.

scholarly journals Synthesis, Characterization and Magnetic Studies of a Tetranuclear Manganese(II/IV) Compound Incorporating an Amino-Alcohol Derived Schiff Base

2018 ◽  
Vol 4 (4) ◽  
pp. 57 ◽  
Author(s):  
Madhusudan Nandy ◽  
Shyamapada Shit ◽  
Georgina Rosair ◽  
Carlos Gómez-García
Keyword(s):  
Variable Temperature ◽  
Mixed Valence ◽  
Antiferromagnetic Coupling ◽  
Redox Behavior ◽  
X Ray Diffraction ◽  
Tetrahedral Cluster ◽  
Magnetic Studies ◽  
X Ray ◽  
Variable Temperature Magnetic Susceptibility ◽  
Physicochemical Methods

A new tetranuclear mixed-valence manganese(II/IV) compound [MnIIMnIV3(μ-Cl)3(µ3-O)(L)3] (1) (where H3L = (3E)-3-((Z)-4-hydroxy-4-phenylbut-3-en-2-ylideneamino)propane-1,2-diol) has been synthesized and characterized by different physicochemical methods. Single crystal X-ray diffraction analysis reveals that 1 is a tetrahedral cluster consisting of a Mn4Cl3O4 core in which the only Mn(II) ion is joined through three μ2-O bridges to an equilateral triangle of Mn(IV) ions, which are connected by a μ3-O and three μ2-Cl bridges. The redox behavior of 1 was studied by cyclic voltammetry. Variable temperature magnetic susceptibility measurements of 1 revealed predominant antiferromagnetic coupling inside the Mn4Cl3O4 cluster.

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