Synthesis,crystal structure,and magnetism of a binuclear Cu(II) complex with a single end-to-end bridged azido ligand

A binuclear copper(II) complex, [Cu₂(μ _1,3-N₃)(N₃)(pmp)₂(ClO₄)]ClO₄ (pmp = 2-((pyridin-2-yl) methoxy)-1,10-phenanthroline), was synthesized with a single azide as end-to-end bridge ligand, and pmp and perchlorate as ligands. In the crystal, Cu(II) is in a distorted square pyramidal geometry, and a single azide bridges equatorial-axial linking two Cu(II) ions with separation of 5.851 Å. There are π?π stacking interactions involving 1,10-phenanthroline rings. The variable-temperature (2–300 K) magnetic susceptibilities were analyzed using a binuclear Cu(II) magnetic formula and it indicates that there is a very weak ferromagnetic coupling with 2J = 2.82 cm^?1.     

Synthesis, characterization and crystal structures of manganese (Ⅱ) complexes containing nitronyl nitroxide and its reduced derivative

Two novel adducts of formula Mn(hfac)2( NITPhCl )2 (1) and [Mn(hfac)2(IMHPhCl)]2(NIT-PhCl)·0.5H2O (2), where hfac = hexafluoroacetylacetonate, NITPhCl = 2-(3-chlorophenyl)-4,4,5,5-tetram-ethylimidazolyl-1-oxyl-3-oxide, IMHPhCl = 2-(3-chlorophenyl)-4, 4, 5, 5-tetramethylimidazolyl-3-oxide, have been prepared by the reaction of Mn(hfac)2·2H2O with NITPhCl. Compound 1 is triclinic, space group P-1with a = 1.3003(3) nm, 6 = 1.3138(3) nm,c = 1.4931 (3) nm, α = 83.74(3)°, β = 77.77(3)°, γ = 60.59(3)°, V=2.171(1)nm3, Z = 2. Compound 2 is triclinic, space group P-1 with a = 1.2994(3) nm, b = 1.4841(3) nm, c = 2.1031 (4) nm, a = 92.30(3)° ,p = 98.68(3)°, γ = 97.89(3)°, V= 3.964(2)nm3, Z = 2. Each manganese atom is hexacoordinated in both compounds and compound 2 is organized inchains by hydrogen bonds between neighboring pairs of NITPhCl and IMHPhCl.     

Synthesis,crystal structure and magnetic properties of a nickel(II) complex containing a 2-pyridyl-substituted nitronyl nitroxide

A new complex of formula [Ni(NIT2Py)₂Cl(H₂O)]Cl·2CH₃OH, where NIT2Py is 2-(2′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, was synthesized and characterized structurally and magnetically. The structure consists of a [Ni(NIT2Py)₂Cl(H₂O)]⁺ ion, a chloride anion and two methanol molecules. The nickel(II) ion lies in a distorted octahedral environment; two nitrogen atoms and two oxygen atoms from NIT2Py ligands from the basal plane; one oxygen atom from a water molecule and one chloride anion occupy axial positions. Variable temperature magnetic susceptibility data show that there is strong antiferromagnetic coupling between the nickel(II) ion and nitronyl nitroxide radicals. The results suggest that the sign of the magnetic interaction depends on structural and ligand effects.     

Syntheses,crystal structures and magnetic properties of a new thienyl-substituted nitronyl nitroxide and its copper(II) complex

A new building block for molecule-based magnetic materials???thiophene-substituted nitronyl nitroxide, NIT2-thp, [1, NIT2-thp?=?4,4,5,5-tetramethyl-2-(thiophenal-2-yl)imidazoline-1-oxyl-3-oxide] and its copper(II) complex [Cu(hfac)₂]₃(NIT2-thp)₂ (2) (hfac?=?hexafluoroacetylacetonate) have been synthesized and characterized structurally and magnetically. For 1, dimers were formed and arranged through intermolecular interactions, the shortest contact between nitroxide groups is 4.115?Å among adjacent dimers. In 2 two types of copper interaction with 1 give three colinear Cu(II) ions linked by two μ???1,4 bridging nitroxide ligands. The central metal ion is in a distorted octahedron, axially coordinated by two nitroxide oxygen atoms, while the two external metal ions are in distorted square-pyramidal environments with the nitroxide oxygen atom coordinated in the basal plane. Magnetic susceptibility data for 1 and 2 have been measured in the range 3–300?K. There are antiferromagnetic interactions (J?=??3.89?cm^?1) between the dimers of 1 and also ferromagnetic interactions in 2. The magnetic properties of 1 and 2 are discussed in connection with their crystal structures.     

Synthesis,structure, and properties of a 1-D copper(II) complex with nitronyl nitroxide radicals

A 1-D chain complex [Cu(NIT4Py)(IDA)]_∞ (NIT4Py = 2-(4′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and IDA = iminodiacetate) has been prepared and characterized by single-crystal X-ray diffraction, IR, TGA, and magnetic analysis. Each Cu(II) is five-coordinate with distorted square pyramidal geometry. Each IDA bridges two Cu(II) ions via one carboxylate which occupies the axial site of Cu(II), leading to a chain structure composed of Cu(II)-radical cations and IDA anions. In the complex, there exist three magnetic exchange pathways, (i) interaction between units of (Cu(II)-NIT4Py) through IDA, (ii) Cu(II)-NIT4Py interaction, and (iii) NIT4Py-NIT4Py interaction through space. Compared with the first two magnetic interactions, the last magnetic exchange interaction should be too weak to be counted because of the large distance of the neighboring NIT4Py molecules (4.993 Å). Analysis of the magnetic properties was performed using the Bleany–Bowers (dimer) model, showing that the complex exhibited both weak antiferromagnetic interaction between the Cu(II) and NIT4Py, and between the units of (Cu(II)-NIT4Py) through IDA with exchange coupling parameters J = ?7.28 cm^?1 and zJ′ = ?0.40 cm^?1.     

Synthesis,crystal structure and magnetic properties of a new binuclear copper(II)-copper(II) complex of a macrocyclic oxamide

The binuclear metal complex [Cu(μ-exoO₂)cyclamCu(bpy)](ClO₄)₂·H₂O (bpy?=?2,2′-bipyridine and (exoO₂)cyclam?=?1,4,8,11-tetraazacyclotradecanne-2,3-dione) has been synthesized and characterized by single-crystal X-ray analysis and spectroscopic and magnetic measurements. The structure consists of homobinuclear [Cu(μ-exoO₂)cyclamCu(bpy)]²⁺ cations, a weakly coordinated water molecule and perchlorate ions. In each binuclear unit, Cu1, coordinated by four nitrogen atoms of the macrocyclic organic ligand is connected to Cu2 via the exo-cis oxygen atoms of the macrocyclic ligand with Cu···Cu separations of 5.151?Å; Cu2 assumes square-pyramidal geometry. Magnetic properties measured at 2–300?K show antiferromagnetic exchange between adjacent copper(II) ions.     

Synthesis,crystal structure and properties of a 1D copper(II) complex with 1,5,9-triazacyclododecane bridged by p -benzenebicarboxylate

A 1D complex [{[Cu₂([12]aneN₃)₂(p-paa)(H₂O)₂](ClO₄)₂}[Cu₂([12]aneN₃)₂(p-paa)₂]] _n ([12]aneN₃ = 1,5,9-triazacyclododecane, p-paa = p-benzenebicarboxylate) has been synthesized and structurally characterized. The complex contains two different binuclear copper(II) moieties. One part includes a binuclear copper(II) unit and non-coordinated perchlorate anions. A neutral binuclear copper(II) part which forms a zigzag chain structure via the bridging p-paa ligand completes the unit-cell. Elemental analysis, IR, UV-Vis spectra and magnetic properties for the complex have also been determined. Magnetic susceptibilities in the solid state are measured over the temperature range from 77 to 300 K, showing a weak antiferromagnetic coupling with a best fit J ₁ = ?3.09 cm^?1, J ₂ = ?5.279 cm^?1, g = 2.099 and R = 1.226 × 10^?5.     

Synthesis,crystal structure,and DNA binding of a new oxalato-bridged binuclear zinc(II) complex

A new binuclear zinc(II) complex bridged by μ-oxalate, and end-capped with 2,2′-bipyridine (bpy), [Zn₂(ox)(bpy)₄](ClO₄)₂ · H₂O, has been synthesized and characterized by elemental analyses, molar conductance, IR, and electronic spectra and single-crystal X-ray diffraction. The single-crystal X-ray analysis reveals that the [Zn₂(ox)(bpy)₄]²⁺ cation has two zinc(II) centers bridged by a planar bis(bidentate) oxalate group with Zn···Zn distance of 5.482(3) Å; each zinc(II) is in a distorted octahedral environment. The crystal structure is stabilized by non-classical C–H···O hydrogen bonds and π–π stacking interactions to form a 3-D supramolecular structure. The interaction of the complex with calf-thymus DNA (CT-DNA) was explored by using electronic and fluorescence spectra and viscosity measurements. The results reveal that the complex intercalates with CT-DNA with intrinsic binding constant of 4.1 × 10⁴ M^?1.     

Synthesis,characterization, crystal structure and non-isothermal dehydration kinetics of a copper(II) complex

A three-dimensional complex, [CuL₂(H₂O)]₂ (HL?=?3-hydroxy-1-adamantanecarboxylic acid), C₄₄H₆₄Cu₂O₁₄, was synthesized under hydrothermal conditions from CuCO₃?·?Cu(OH)₂ and HL. The crystal structure of the complex was determined by X-ray crystallography and its thermal behavior and IR spectra examined. The non-isothermal dehydration kinetics of the complex were investigated using the Achar differential method.     

Synthesis,crystal structure and magnetic property of a one-dimensional copper(II) complex with 2,5-dimethylpyrazine-1,4-dioxide as bridging ligand

A one-dimensional polynuclear copper(II) complex [Cu(μ_1,6-dmpzdo)(SCN)₂] _n (where dmpzdo?=?2,5-dimethylpyrazine-1,4-dioxide) has been synthesized and its crystal structure determined by X-ray crystallography. The coordination geometry of Cu(II) atom is a square plane and each Cu(II) ion is connected by two μ_1,6-dmpzdo bridging ligands, leading to the formation of a one-dimensional chain. ESR spectra indicate magnetic coupling between the bridged Cu(II) ions. The fitting of the variable-temperature magnetic susceptibility data (4–300?K) gave 2J?=??68.69?cm^?1.     

Synthesis, crystal structure and DFT analysis of a new trinuclear complex of copper

The new trinuclear complex [Cu₂(μ-L)₂CuCl₂] has been synthesized and characterized by elemental analysis, IR, UV-Vis and X-ray spectroscopy, where L is a dianionic tetradentate Schiff base ligand with N₂O₂ donor atoms. The molecular structure of [Cu₂(μ-L)₂CuCl₂] was determined by X-ray crystallography. In the complex, the most remarkable aspect of the trinuclear complex is that it adopts a bent structure for the three copper atoms, with a Cu1Cu3Cu2 intramolecular angle of approximately 90.62(2)°. All three copper atoms are five coordinate, with a slightly distorted square pyramidal geometry. In the two terminals moieties, the basal plane of the square pyramidal is formed by two oxygen atoms and two nitrogen atoms of the Schiff base ligand, and the apical position at the Cu atom is occupied by the bridging Cl1 anion. The Cu1Cl1Cu2 angle is 110.51(5)°. The central copper atom also has a five-coordinate, slightly distorted square pyramidal geometry, with four phenolato oxygens belonging to the Schiff base ligands from Cu(salpn) units describing the square planar base and the Cl anions being apical. The optimized structure of the complex has been studied using the B3LYP/6-31G(d)/LanL2TZf level of theory. The calculation shows that all the copper atoms are five coordinate with distorted square pyramidal structures, which is consistent with experimental data.     

Synthesis,crystal structure and magnetic properties of a novel complex containing a diamagnetic metal ion and thiazole-substituted nitronyl nitroxide radicals

The synthesis, crystal structure and magnetic properties of a novel diamagnetic metal complex containing thiazole-substituted nitronyl nitroxide radicals, [HgCl₂(NIT2-thz)₂] (NIT2-thz?= 2-(2′-thiazole)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), is reported. The mercury(II) ion has distorted tetrahedral coordination involving two chloride atoms and two thiazole nitrogen atoms. Magnetic susceptibility data show that there are intramolecular antiferromagnetic interactions between the radicals in the complex.     

Synthesis,crystal structure,and DNA-binding studies of a one-dimensional copper(II) polymer bridged both by oxamidate and thiocyanato ligands

A new one-dimensional copper(II) polymer, [Cu₄(dmapox)₂(SCN)₄(CH₃OH)₂] _n , where dmapox is the dianion of N,N′-bis[3-(dimethylamino)propyl]oxamide, was synthesized and characterized by elemental analysis, conductivity measurement, IR, and electronic spectral studies. The crystal structure of the copper(II) complex has been determined by X-ray single-crystal diffraction. The complex crystallizes in triclinic, space group P ? 1 and exhibits infinite one-dimensional copper(II) polymeric chain bridged both by bis-tridentate μ-trans-dmapox and μ-1,3-thiocyanato ligand. The environment around the copper(II) atom can be described as distorted square-pyramid. The Cu···Cu separations through the oxamidate and thiocyanato bridges are 5.246(2) Å (Cu1–Cu1ⁱ), 5.2649(14) Å (Cu2–Cu2ⁱⁱ), and 5.8169(15) Å (Cu1–Cu2), respectively. The interaction of the copper(II) complex with herring sperm DNA (HS-DNA) has been investigated by using absorption and emission spectral and electrochemical techniques and viscometry. The results reveal that the copper(II) complex may interact with DNA in the mode of groove binding with the intrinsic binding constant of 2.56 × 10⁵ M^?1.     

Synthesis,crystal structure,and magnetic properties of a new Fe(II) complex with reduced radical ligands

A new Fe(II) complex, [Fe(HIM2Py)₂(N(CN)₂)₂]?·?2H₂O (HIM2py?=?1-hydroxyl-2(2′-pyridyl)-4,4,5,5-tetramethyl-4,5-dihydro-1?H-imidazole), has been synthesized and characterized. The X-ray analysis reveals that HIM2py ligands are coordinated to iron as an unusual six-membered bidentate chelate with κ²N(py), O(HIM) mode. The variable-temperature magnetic susceptibility suggests that weak antiferromagnetic interactions exist in the complex.     

Synthesis of a novel copper(II) complex and its crystal structure

One novel chiral copper(II) complex was successfully synthesized from the reaction of chiral 1,3-thiazolidine-2-thione ligand with CuCl₂ in dichloromethane in the presence of Et₃N and DMAP at room temperature. Its unique crystal structure was unambiguously disclosed by X-ray analysis. The crystal is tetragonal, space group I4(1), space group a=15.0875(11), b=15.0875(11), c=19.362(3) Å, =90, β=90, γ=90°, V=4407.4(8) ų, Z=8, ρ_calc=1.639 mg cm⁻³.     

Tridentate (NNO) Schiff-base copper(II) complex: synthesis,crystal structure,and magnetic study

A new azido adduct of a tridentate Schiff-base copper(II) complex has been synthesized and characterized structurally and magnetically. X-ray single crystal structure analysis reveals that the asymmetric unit of [Cu₂(L)₂(µ_1,1-N₃)₂][Cu(L)(N₃)] (1) [HL = 1-(N-ortho-hydroxyacetophenimine)-2,2-diethyl-aminoethane] has two independent moieties. One of these forms a dimer, containing end-on azido bridges, with its center of inversion related equivalents. The complex crystallizes in monoclinic space group P₂1/c with a = 10.112(2), b = 31.938(4), c = 9.718(2) Å and β = 95.00(2)°. Variable temperature magnetic susceptibility data show antiferromagnetic interactions between copper(II) centers.     

Synthesis,crystal structure and properties of a copper(II) complex with the tripod ligand tris ( N -methylbenzimidazol-2-ylmethyl)amine and 4-hydroxycinnamate

A five-coordinate copper complex with the tripod ligand tris(N-methylbenzimidazol-2-ylmethyl)amine (Mentb) and 4-hydroxycinnamate, with the composition [Cu(Mentb)(4-hydroxycinnamate)](ClO₄)?·?0.5DMF, was synthesized and characterized by means of elemental analyses, electrical conductivities, thermal analyses, IR, and UV. The crystal structure of the copper complex has been determined by single-crystal X-ray diffraction, and shows that the Cu^II atom is bonded to a tris(N-methylbenzimidazol-2-ylmethyl)amine (Mentb) ligand and a 4-hydroxycinnamate through four N atoms and one O atom, giving a distorted trigonal-bipyramidal coordination geometry (τ?=?0.78), with approximate C₃ molecular symmetry. Cyclic voltammograms of the copper complex indicate a quasireversible Cu⁺²/Cu⁺ couple. Electron spin resonance data confirm the trigonal–bipyramidal structure and indicate g _∥?<?g _⊥ with a very small value of A _∥ (57?×?10^?4?cm^?1).     

Synthesis,crystal structure and electronic properties of bis(N-2-bromophenyl-salicydenaminato)copper(II) complex

A new series of complexes of the type bis(N-substituted-salicydenaminato)copper(II) (1–9), have been synthesized and characterized by IR, UV–Vis and elemental analysis methods. The molecular structure of bis(N-2-bromophenyl-salicydenaminato)copper(II) (6), was determined using X-ray crystallography. There are two independent molecules in the structure. Each shows a neutral, mononuclear, four-coordinate, square-planar trans-Cu[N₂O₂] geometry and, in each, the Cu atom and the ligating atoms are coplanar. The chelating N–Cu–O angle is 91.39(11)° for molecule one and 91.20(11)° for molecule two, whereas the non-chelating N–Cu–O angles are 88.61(11) and 88.80(11)°, respectively. The trans-N–Cu–N and trans-O–Cu–O bond angles are 180°. The electronic absorption spectra of copper(II) complexes (1–9), indicate that the d–d band energy is dependent on the nature and position of substituent on phenyl ring of the salicyldenimine ligand. The UV–Vis spectra in various solvents were measured and a relationship between absorption spectra and dielectric constant of the solvents is reported.