A two-dimensional copper polymer constructed from rod-shaped ferromagnetic secondary building units

On the basis of rod-shaped secondary building units (SBUs), a novel two-dimensional (2D) azide–copper polymer, [Cu₃(N₃)₄(anol)₂]_∞ (1; anol = aminoethanol), was synthesized and structurally characterized. Complex 1 is a neutral 2D coordination network consisting of trinuclear copper(II) clusters [Cu₃(N₃)₄(anol)₂] connected with the bridge of end-end (EE) azide group. Magnetic data analysis shows that a metamagnetic behavior is observed for 1 which is associated with significant ferromagnetic coupling intracluster over 4 K.     

Structure and magnetic properties of a novel branch-like one-dimensional cyano-bridged assembly [Cu(L)]3[Fe(CN)6]2·8H2O (L = 6,13-dimethyl-6-nitro-1,4,8,11-tetraazabicyclo[11.1.1]pentadecane)

The one-dimensional coordination polymer like fern branch, [Cu^II(L)]₃[Fe^III(CN)₆]₂·8H₂O (1), which is linked by azamacrocyclic copper(II) complex and iron(III) hexacyanide, has been synthesized and characterized by single crystal X-ray crystallography and magnetic susceptibility measurement (L = 6,13-dimethyl-6-nitro-1,4,8,11-tetraazabicyclo[11.1.1]pentadecane). Compound 1 shows a weak ferromagnetic coupling between the copper(II) and low spin iron(III) ions in the one-dimensional chain structure.     

New μ-oxo-bridged tetranuclear Cu(II) complex with Schiff-base ligand: Synthesis,crystal structure and magnetic properties

A new μ-oxo-bridged Cu(II) complex with cubane-like tetranuclear copper(II) complex, [Cu₄(L¹)₄] · 4H₂O (1) (H₂L¹ = 2-(3-methoxy-salicylidene-amino)-benzyl-alcohol), has been prepared, and structurally characterized by X-ray crystallography. Complex 1 crystallized in the monoclinic space group P₂₁/n and has a tetranuclear core of Cu₄O₄. The temperature dependence of magnetic susceptibility measurements shown that complex 1 exhibits a strong antiferromagnetic interaction with J = −103.4 cm⁻¹.     

Syntheses,structures and photocatalytic properties of two coordination polymers based on bis(1,2,4-triazol-4-ylmethyl)benzene and multicarboxylates

Two coordination polymers {[Cu₄(OH)₂(btrb)₂(btc)₂]·4H₂O}_n (1) and {[Cd₂(btrb)(adc)₂(H₂O)]·H₂O}_n (2) were synthesized with hydrothermal method and characterized (btrb = 1,4-bis(1,2,4-triazol-4-ylmethyl)benzene, btc = 1,3,5-benzenetricarboxylate, adc = 1,3-adamantanedicarboxylate). 1 shows an unusual (3,10)-connected two-dimensional metal–organic framework based on the tetranuclear copper(II) cluster [Cu₄(μ₃-OH)₂]. 2 is an interesting three-dimensional network based on the one-dimensional metal–organic nanotube. 1 shows good photocatalytic activity for the degradation of methyl blue (MB). The luminescence of 2 was investigated.     

A dinuclear copper(II) complex and a zigzag chain iron(II) polymer based on the 4-antipyrine derived Schiff base ligands: The hydroxylation and redox occurred under the solvothermal conditions

A new dinuclear copper(II) compound, [Cu₂(L1-O)₂] (1) (L1 = (4E)-4-(2-hydroxybenzylideneamino)-1,2-dihydro-2,3-dimethyl-1-phenylpyrazol-5-one), and zigzag chain polymer, {[FeCl₂(L2)]}_n (2) (L2 = 1,5-dimethyl-2-phenyl-4-{[(1E)-pyridine-4-ylmethylene]amino}-1,2-dihydro-3H-pyrazol-3-one), were synthesized by solvothermal reactions and structurally characterized. The methyl group hydroxylation and the redox have been observed in the preparation of 1 and 2, respectively.     

Synthesis,crystal structure and magnetic properties of a new cyanide-bridged mixed-valence copper(I)/copper(II) clathrate

A unique cyanide-bridge mixed-valence Cu^I/Cu^II clathrate of formula [Cu^I₂(CN)₃][{Cu^II(tren)}₂(μ-CN)](CF₃SO₃)₂ [tren = tris(2-aminoethyl)amine] containing cyanide-bridged [{Cu^II(tren)}₂(μ-CN)]^3 + binuclear cations stacked between anionic honeycomb layered copper(I) cyanide networks, was synthesized and structurally characterized by single crystal X-ray diffraction. Variable-temperature magnetic susceptibility studies showed that the cyanide bridge mediates a strong antiferromagnetic interaction between the copper(II) centers (J = − 160 cm^− 1, the spin Hamiltonian being defined as H = −J S_A⋅S_B).     

A novel hydroxo-bridged cyclic tetranuclear copper(II) complex using the guanazole ligand: Synthesis,crystal structure and thermal analysis

A novel hydroxo-bridged cyclic tetranuclear copper(II) complex with the guanazole ligand (3,5-diamino-1,2,4-triazole = Hdatrz), [Cu₄(datrz)₄(μ₂-OH)₂(NO₃) (H₂O)₆] · (NO₃) · 5(H₂O) (1) has been synthesised and characterised by X-ray crystallography. In 1, the four copper(II) centres are linked by hydroxo bridges and the N1,N2-coordination of the deprotonated guanazole ligands. The core has considerably short Cu⋯Cu distances in the range of 3.3550(4)–3.3611(4) Å. Thermal analysis of 1 reveals that the cyclic framework constructed with hydroxo and guanazole ligands is stable up to 285 °C.     

Synthesis,structure, and properties of two novel copper(II) complexes, [Cu(phen)(L)2]·6H2O and [Cu(phen)3]·(ClO4)2

Two novel copper(II) complexes, namely [Cu(phen)(L)₂]·6H₂O (1) and [Cu(phen)₃]·(ClO₄)₂ (2) have been synthesized under mild condition (HL = 5-methyl-1H-pyrazole-3-carboxylic acid, phen = 1,10-phenanthroline). We report the structural evidence of discrete water decamer conformation in the solid state. These units are found to act as supramolecular glue in the aggregation of mononuclear copper(II) complex to give a three-dimensional network through hydrogen-bonding. The preliminary investigation on the thermal behavior and the anion exchange property of the complexes are presented.     

Comparison of DNA binding and cleavage abilities between mono- and trinuclear copper(II) complexes of benzimidazole derivatives

Two copper(II) complexes, [CuLCl₂] (1) and [Cu₃L′Cl₆] (2) (L = bis(2-benzimidazolylmethyl)amine, L′ = 2,4,6-tris[bis(2′-benzimidazolylmethyl) amine]-1,3,5-triazine), have been synthesized and characterized. Both complexes bind to DNA and cleave the supercoiled pUC19 plasmid DNA into its nicked and linear forms at micromolar concentrations and physiologically relevant conditions. The DNA cleavage efficacy of 1 is higher than that of 2 though its DNA binding ability is lower than the latter. The cleavage mechanism in the presence of hydrogen peroxide appears to be different for 1 and 2.     

A novel 3D POMOF based on dinuclear copper (II)-oxalate complexes and Keggin polyoxoanions with excellent photocatalytic activity

A novel coordination polymer, [Cu₂(btx)₂(C₂O₄)][H₂SiW₁₂O₄₀]·12H₂O (btx = 1,4-bis(triazol-1-ylmethyl)benzene)] (1) has been synthesized by hydrothermal reaction, and characterized by elemental analyses, IR spectroscopy, and single crystal X-ray diffraction. Compound 1 is composed of α-Keggin type [SiW₁₂O₄₀]^4 − polyoxoanions and dinuclear copper (II)-btx complexes. The dinuclear copper (II)-btx complex is a three-dimensional (3D) porous framework, in which the [SiW₁₂O₄₀]^4 − as 4-coordinating guests are encapsulated, forming a novel 3D POMOF with two kinds of open channels along both a and b axes. Additionally, compound 1 shows excellent photocatalytic properties for the degradation of methylene blue (MB) under both visible and ultraviolet (UV) light. The molecular design of 1 not only generates a new POMOF, but also opens a new avenue to produce photocatalytic materials.     

Syntheses,structures and luminescence of three copper(I) cyanide coordination polymers incorporating flexible N-donor ligands

Three copper(I) cyanide coordination polymers, namely [Cu₈(CN)₈(btmb)₂]_n (1), [Cu(CN)(btmb)_0.5]_n (2) and [Cu₂(CN)₂(dpa)]_n (3) (btmb = 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene, dpa = di(4-pyridyl)amine), were synthesized under hydrothermal conditions and characterized by elemental analyses, IR spectra, PXRD and thermogravimetric analyses. Single-crystal X-ray diffraction analyses reveal that complex 1 is an interesting 2D double-layered network constructing from eight distinct Cu(I) centers, eight μ₂-cyanides and two tetradentate cis-btmb ligands. Complex 2 is a ladder-like coordination polymer assembled by CuCN linear chain and bidentate trans-btmb linker. Complex 3 has a 2D wave-like network constructing from CuCN zigzag chain and V-shape dpa spacer. These coordination polymers are thermally stable up to 270–300 °C. They emit blue luminescence originating from ligand-centered emission.     

A new μ1,5-dicyanamide bridged cyclic tetranuclear copper (II) complex with 1,5,9-triazacycledodecane ligands: structure,ESR spectroscopic and magnetic properties

The tetranuclear complex [Cu₂L₂(dca)₂(ClO₄)₂]₂ (1) (L = 1,5,9-triazacyclododecane, dca = dicyanamide [N(CN)₂]⁻) has been synthesized and its crystal structure, ESR spectra and magnetic properties determined. The complex contains a tetranuclear copper (II) moiety in which two dimeric units are bridged by two dca ligands. In each dimeric moiety the two copper (II) ions are bridged by one μ_1,5-dicyanamide ligand. Magnetic susceptibilities for the complex in the solid state are measured over the temperature range 4–300 K. The complex shows a weak antiferromagnetic coupling with a best fit J value −0.436 cm⁻¹. The μ_1,5-dicyanamide bridges are the principal pathway for the super-exchange interaction and the weak antiferromagnetic coupling of the complex is interpreted in term of the μ_1,5-dicyanamide ligand behavior as a poor magnetic mediator.     

Syntheses,structures and magnetic property of two copper complexes with cyclic dimer and 2D herringbone-like network built from helical motif

Two copper(II) complexes, Cu₂{3,5-(NO₂)₂sal}₂(2,2′-bipy)₂ · 0.5H₂O (1) and [Cu₂{3,5-(NO₂)₂sal}₂(4,4′-bipy)(H₂O)₂]_n (2) (3,5-(NO₂)₂sal = 3,5-dinitrosalicylate, 2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridine), were synthesized by hydrothermal reactions and characterized by single crystal X-ray analysis. There are discrete cyclic binuclear structure in 1 and 2D herringbone-like network structure in 2, although bridging ligand 3,5-(NO₂)₂sal in 1 and 2 has same coordination model. Variable temperature magnetic measurement reveals small ferromagnetic interactions in complex 1.     

Syntheses,structures and photoluminescence of Ln(III)–Cu(I) coordination polymers based on benzimidazole-5-carboxylate and oxalate ligands

Three novel Ln(III)–Cu(I) coordination polymers, namely [LnCu(Hbic)₃(ox)_0.5] [Ln = Sm (1), Dy (2), Hbic = benzimidazole-5-carboxylate, ox = oxalate] and [EuCu(Hbic)₂(ox)H₂O]·2H₂O (3) have been hydrothermally synthesized and stucturally characterized. Both complexes 1 and 2 display the same unusual 2D layer heterometallic coordination frameworks that are built up by dimeric [Ln₂(Hbic)₆] cores and oxalate ligands by sharing Cu(I) ions. Complex 3 represents 1D polymeric chain architecture constructed from Eu₂Cu₂ ring units and oxalate ligands. Furthermore, the luminescent property of complex 3 has also been investigated.     

A new Cu-based metal-organic framework built upon infinite 1D rod-shaped secondary building units

A new Cu(II) metal-organic framework {[Cu_1.5(1,3-bdc)(dtb)(OH)(H₂O)](H₂O)}_n (1) (1,3-H₂bdc = 1,3-benzenedicarboxylic acid, dtb = 1,3-di-(1,2,4-triazole-4-yl)benzene), has been synthesized and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, elemental analysis, and IR spectra. Compound 1 features a 3-D open framework constructed by infinite 1D rod-shaped [Cu₃(OH)₂]_n chains as secondary building units. The magnetic property of the complex has also been investigated.     

Two new metal–organic frameworks based on cyclic dodecanuclear copper units

Two new metal–organic frameworks based on cyclic-type dodecanuclear copper units, (Me₄N)₆[Cu₁₂(OMe)₆(pz)₆(BTC)₆]·18H₂O 1 and (Me₄N)₆[Cu₁₂(OH)₆(pz)₆(BTC)₆]·21H₂O 2 (pz = pyrazolate, BTC = 1,3,5-benzenetricarboxylate), have been prepared by the solvothermal reactions of copper salts, Hpz and H₃BTC ligands. The cyclic-type Cu₁₂ unit in 1 and 2 is constructed by twelve Cu^II ions linked together by μ₂-OH or μ₂-OMe and unidentate carboxylate groups at the inner- and μ-pz and bidentate carboxylate groups at the outer surface of the toroid. In 1 and 2, each Cu₁₂ unit is connected to 12 other units by BTC linkers, leading to 12-connected three-dimensional porous frameworks. The photocatalytic investigations indicate that compounds 1 and 2 exhibit photocatalytic activity for the degradation of RhB.     

A tetranuclear pyrophosphate-bridged Cu(II) complex with 4,4′-bipyridine and 1,10-phenanthroline: Synthesis,structural, and magnetic properties

A new tetranuclear pyrophosphate-bridged Cu(II) complex with 4,4′-bipyridine and 1,10-phenanthroline [Cu₄(phen)₄(bpy)₂(P₂O₇)₂]·10H₂O (1) has been hydrothermal synthesized and characterized by single-crystal X-ray analysis, element analysis, IR spectroscopy, TG analysis, and UV–vis spectra. Variable-temperature magnetic susceptibility measurements show the occurrence of antiferromagnetic interactions between the neighbor Cu(II) centers in 1. The analysis of the magnetic data in the whole temperature range allows the determination of the value of the intramolecular magnetic coupling (J = − 13.16 cm^− 1).     

Synthesis and characterization of dinuclear copper(II) complexes, [Cu2([20]-DCHDC)(La)2] (La = N3−, NCS− or S2O32−) with tetraazadiphenol macrocyclic ligand having cyclohexane rings

The chiral dinuclear tetraazadiphenol macrocyclic copper(II) complexes [Cu₂([20]-DCHDC)(L_a)₂] {H₂[20]-DCHDC = 14,29-dimethyl-3,10,18,25-tetraazapentacyclo-[25,3,1,0^4,9,1^12,16,0^19,24]ditriacontane-2,10,12,14,16(32),17,27(31),28,30-decane-31,32-diol; L_a = N₃^? (II), NCS^? (IV) or S₂O₃^2? (V)} has been synthesized and structurally characterized by elemental analysis, conductance, electronic and IR spectra as well as FAB-MS method. Crystal structure of [Cu₂([20]-DCHDC)(N₃)₂]·2CH₃OH (III) determined by X-ray crystallography reveal the two square pyramidal copper centers bridged by the two phenoxide oxygen atoms, with large Cu–O–Cu angles {100.88(10)°}.     

A new complex based on chelate copper coordination with divacant polyanion ligand [γ-PW10O36]7−

A new complex based on decatungstophosphate and chelated copper atoms, [Hen][Cu(en)₂(H₂O)]₂ · {[Cu(en)₂(H₂O)] · [γ-PW₁₀O₃₆]} · 9H₂O (1) (en = ethylenediamine) has been synthesized by conventional methods and characterized by single crystal X-ray diffraction, IR spectra and electronic spectra. The structure analysis of 1 indicates that the complex contains a divacant polyanion [γ-PW₁₀O₃₆]⁷⁻ connected with a chelated copper atom. Magnetic susceptibility measurement for 1 in the temperature range 2–300 K reveals the occurrence of intermolecular antiferromagnetic interactions between chelate copper (II) complexes at lower temperature.     

Alkoxo- and carboxylato-bridged hexanuclear copper(II) complex: Synthesis,structure and magnetic properties

Reaction of copper(II) nitrate trihydrate with N,N-dimethylethanolamine (dmea) and pivalic acid in methanol led to the hexanuclear copper(II) complex Cu₆(η¹:μ₂-C₄H₁₀NO)₄(η¹:η¹:μ₂-C₅H₉O₂)₄(η¹:μ₁-C₅H₉O₂)₂(μ₃-OH)₂ (1). The crystal structure of 1 indicates that hexametallic centers are bridged by the μ₃-alkoxo, dmea oxygens, and the μ₂-dicarboxylato oxygen atoms of pivalate ions. Furthermore, in the asymmetric unit, three types of copper ions have been found labeled as Cu₁, Cu₂ and Cu₃. The Cu₂ takes a distorted octahedral shape, whereas Cu₁ and Cu₃ adopt square pyramidal geometries. The complex 1 shows strong antiferromagnetic interactions through the oxo groups within the dimeric units (J = − 82.6 to − 25.8 cm^− 1) and weak antiferromagnetic couplings between the dimers (J = − 10.9 and 0.8 cm^− 1).