Cu Atom In Complex Research Articles

Syntheses, structures, and inhibition studies of Jack bean urease by copper(II) complexes derived from a tridentate hydrazone ligand

Urease inhibitors can counteract the negative effects of urease. In this paper, three new copper(II) complexes derived from 3-methyl-N′-(pyridin-2-ylmethylene)benzohydrazide (HL) were prepared. They are [CuBr(CH3OH)L] (1), [Cu(CH3OH)L(NCS)] (2), and [CuL(HL)]·ClO4 (3). The complexes were characterized by infrared and UV–Vis spectra, and single crystal X-ray determination. The Cu atoms in complexes 1 and 2 display square pyramidal coordination, and in complex 3 the Cu atom displays octahedral coordination. Complex 1 shows effective urease inhibitory activity, with IC50 value of 1.46±0.83μM. Molecular docking study of the complexes with Jack bean urease was performed.

Synthesis and crystal structures of N,N'-bis(5-methylsalicylidene)ethane-1,2-diamine and its bromido-, phenolato-, and dicyanoamido-cobridged polymeric copper(II) complex

A bis-Schiff base N,N'-bis(5-methylsalicylidene)ethane-1,2-diamine (H2L) was prepared and characterized by elemental analysis, 1H NMR and 13C NMR spectra, MS, and single crystal X-ray diffraction (CIF file CCDC no. 1022761 (H2L)). Reaction of the Schiff base with copper bromide and sodium dicyanoamide in methanol gave a novel bromido-, phenolato-, and dicyanoamido-cobridged polymeric copper(II) complex, ({Cu2LBr[N(CN)2]}2)n (I). Structure of complex I was characterized by elemental analysis and single crystal X-ray diffraction (CIF file CCDC no. 1022762 (I)). The smallest repeat unit of complex I is a dicyanoamide bridged tetranuclear copper(II) complex moiety, {Cu2LBr[N(CN)2]}2, in which there possesses a crystallographic inversion symmetry. The tetranuclear moieties are further linked through Br atoms, forming a zigzag chain. The chains are further linked by dicyanoamide ligands, forming a 2D network. One Cu atom in complex I is coordinated by two N and two O atoms of the Schiff base ligand and one Br atom, forming square pyramidal geometry. The other Cu atom is coordinated by two N atoms of the Schiff base ligand, two N atoms of dicyanoamide ligands, and one Br atom, forming square pyramidal geometry. The bromido-, phenolato-, and dicyanoamido-cobridged Cu···Cu distances are 4.823(2), 2.955(1), and 7.121(3) A, respectively. The [Cu2L] units are linked by the bridging groups, to form 2D chains along the xy plane.

Synthesis, characterization, and crystal structures of mononuclear and dinuclear copper(II) complexes derived from similar tridentate Schiff bases

ABSTRACTA mononuclear copper(II) complex, [CuL1N3] (1), and a dinuclear copper(II) complex, [Cu2(L2)2(μ1,1-N3)2] (2), where L1 and L2 are the deprotonated forms of 2-[(2-diethylaminoethylimino)methyl]-4,6-difluorophenol (HL1) and 2,4-difluoro-6-[(2-isopropylaminoethylimino)methyl]phenol (HL2), respectively, were prepared. The complexes were characterized by elemental analysis, infrared (IR) and UV–Vis spectra, and single crystal X-ray determination. The crystal of complex 1 crystalizes in the orthorhombic space group Pbca, with unit cell a = 6.9327(7), b = 13.8926(13), c = 31.243(2) Å, V = 3009.1(5) Å3, Z = 8. The crystal of complex 2 crystalizes in the monoclinic space group P21/n, with unit cell a = 20.8686(16), b = 9.4893(16), c = 7.2440(12) Å, β = 94.020(2)°, V = 1431.0(4) Å3, Z = 4. The Cu atom in complex 1 is in square planar geometry, and that in complex 2 is in square pyramidal geometry.

Synthesis, crystal structures, and antibacterial activity of copper(II) and cobalt(III) complexes derived from 2-[(2-dimethylaminoethylimino)methyl]-4-methylphenol

A new tetranuclear copper(II) complex (I) and a new mononuclear cobalt(III) complex (II) have been synthesized from the Schiff base compound 2-[(2-dimethylaminoethylimino)methyl]-4-methylphenol. The complexes have been characterized by physico-chemical and spectroscopic methods, as well as single crystal X-ray determination (CIF files CCDC nos. 1447778 (I) and 1447779 (II)). The Cu atoms in complex I are in square pyramidal coordination, and the Co atom in complex II is in octahedral coordination. Crystal structures of the complex are stabilized by hydrogen bonds and π···π interactions. The complexes and the Schiff base compound were assayed for antibacterial activities against three Gram-positive bacterial strains (B. subtilis, S. aureus, and St. faecalis) and three Gram-negative bacterial strains (E. coli, P. aeruginosa, and E. cloacae) by MTT method. As a result, the complexes showed effective antimicrobial activity against the microorganisms tested.

Synthesis, Crystal Structures and Antibacterial Activities of Trifluoromethylsulfonate Salts of 2-[(3-Chloropyridinium-2-yl)hydrazonomethyl]-6-methoxyphenol and its Copper(II) and Cobalt(III) Complexes.

A new trifluoromethylsulfonate salt of 2-[(3-chloropyridinium-2-yl)hydrazonomethyl]-6-methoxyphenol, (HL)CF3SO3, and its copper(II) and cobalt(III) complexes, [CuL(OH2)]CF3SO3 · 0.5H2O (1) and [CoL2]CF3SO3 · CH3OH (2), were prepared and characterized by physico-chemical methods and single crystal X-ray analysis. A trifluoromethylsulfonate anion is present in each of the compounds. The Cu atom in complex 1 is coordinated by the phenolate O, imino N and pyridine N atoms of L ligand, giving square planar geometry. The Co atom in complex 2 is coordinated by two phenolate O, two imino N and two pyridine N atoms from two L ligands, giving octahedral geometry. The three compounds were tested in vitro for their antibacterial activities.

Synthesis, crystal structures, and antibacterial activities of manganese(II) and copper(II) complexes derived from 2-bromo-4-chloro-6-[(2-hydroxyethylimino)methyl]phenol

ABSTRACTReaction of the tridentate Schiff base 2-bromo-4-chloro-6-[(2-hydroxyethylimino)methyl]phenol (HL) with manganese and copper salts in the presence of ammonium thiocyanate in methanol afforded a new mononuclear complex, [MnL2]·0.5H2O (1), and a new dinuclear complex, [Cu2L2(NCS)2] (2). The complexes were characterized by single-crystal X-ray diffraction, FT-IR, and elemental analysis. The Mn atom in complex 1 is coordinated by two tridentate Schiff base ligands, forming octahedral coordination. The Cu atom in complex 2 is coordinated by one tridentate Schiff base ligand, and two thiocyanate ligands, forming square pyramidal coordination. The free Schiff base and the complexes were assayed for antibacterial activities. Both complexes are more active against the bacteria than the free Schiff bases. Complex 2 has the MIC value of 0.20 μg mL−1 against Bacillus subtilis.

Copper(II) Complexes With Bis-Schiff Bases: Synthesis, Crystal Structures, and Antibacterial Activities

Reaction of copper perchlorate with the tridentate Schiff bases N,N’-bis(5-methoxysalicylidene)-1,2-ethanediamine (H2L1) and N,N’-bis(5-chlorosalicylidene)-1,3-propanediamine (H2L2), afforded a dinuclear complex, [Cu2(L1)2]·2CH3OH (1), and a mononuclear complex, [CuL2] (2). The complexes were characterized by single-crystal X-ray diffraction, FT-IR, and elemental analysis. The Cu atom in complex 1 is in a square pyramidal coordination, with two phenolate O and two imine N atoms of L1 ligand defining the basal plane, and with one phenolate O atom of another L1 ligand occupying the apical position. The Cu atom in complex 2 is coordinated by two phenolate O and two imine N atoms of L2 ligand, forming a tetrahedrally distorted square planar geometry. The free Schiff bases and the complexes were assayed for antibacterial activities. Both complexes are more active against the bacteria than the free Schiff bases. Complex 2 has the MIC value of 0.10 μg mL−1 against Bacillus subtilis.

Synthesis, structures and Helicobacter pylori urease inhibitory activity of copper(II) complexes with tridentate aroylhydrazone ligands

A series of new copper(II) complexes were prepared. They are [CuL1(NCS)] (1), [CuClL1]·CH3OH (2), [CuClL2]·CH3OH (3), [CuL3(NCS)]·CH3OH (4), [CuL4(NCS)]·0.4H2O (5), and [CuL5(bipy)] (6), where L1, L2, L3 and L4 are the deprotonated form of N′-(2-hydroxybenzylidene)-3-methylbenzohydrazide, 4-bromo-N′-(2-hydroxy-5-methoxybenzylidene)benzohydrazide, N′-(2-hydroxy-5-methoxybenzylidene)-3-methylbenzohydrazide and 2-chloro-N′-(2-hydroxy-5-methoxybenzylidene)benzohydrazide, respectively, L5 is the dianionic form of N′-(2-hydroxybenzylidene)-3-methylbenzohydrazide, and bipy is 2,2′-bipyridine. The complexes were characterized by infrared and UV–Vis spectra and single crystal X-ray diffraction. The Cu atoms in complexes 1, 2, 3, 4 and 5 are coordinated by the NOO donor set of the aroylhydrazone ligands, and one Cl or thiocyanate N atom, forming square planar coordination. The Cu atom in complex 6 is in a square pyramidal coordination, with the NOO donor set of L1, and one N atom of bipy defining the basal plane, and with the other N atom of bipy occupying the apical position. Complexes 1, 2, 3, 4 and 5 show effective urease inhibitory activities, with IC50 values of 5.14, 0.20, 4.06, 5.52 and 0.26μM, respectively. Complex 6 has very weak activity against urease, with IC50 value over 100μM. Molecular docking study of the complexes with the Helicobacter pylori urease was performed. The relationship between structures and urease inhibitory activities indicated that copper complexes with square planar coordination are better models for urease inhibition.

Synthesis and crystal and molecular structures of new copper and zinc complexes with aza-14-crown-4 ether having di(α-pyridyl)-substituted bispidine subunit

The complexes [Cu(L)(H2O)](ClO4)2 · 2H2O (I) and [Zn(L)Cl2] · C2H5OH (II), where L is the macrocyclic substituted aza-14-crown-4 ether molecule containing di(α-pyridyl)bispidine insert, were synthesized and studied by X-ray diffraction. The Cu atoms in complex I and the Zn atoms in complex II have equal coordination numbers of 5 and different highly distorted polyhedra (the CuN4O tetragonal pyramid and ZnN3Cl2 trigonal bipyramid). Ligand L in structure I performs the tetradentate tetrachelate (4N) structural function and in II, it performs the tridentate bis-chelate (3N) function. The key difference between the structures of complexes I and II is determined by different conformations of both the aza-macrocycles and bispidine substituents of ligand L.

Synthesis and Crystal Structures of Copper(II) Complexes Derived From 5-Methoxy-2-[(pyridin-2- ylmethylimino)methyl]phenol

The synthesis and crystal structures of two new mononuclear copper(II) complexes, [CuL(H2O)][CuL(H2O)2]·2ClO4 (1) and [CuL(dca)] (2) (HL = 5-methoxy-2-[(pyridin-2-ylmethylimino)- methyl]phenol, dca = dicyanamide anion), are described. The infrared spectra of the complexes have also been discussed. Complex 1 contains a [CuL(H2O)]+ cation, in which the Cu atom adopts a square planar coordination, a [CuL(H2O)2]+ cation, in which the Cu atom adopts a square pyramidal coordination, and two perchlorate anions. The Cu atom in complex 2 is in square planar coordination. The Schiff base ligand coordinates to the Cu atoms through the phenolate O, imine N, and pyridine N atoms.

Copper(II) bromide complexes with acyclic and cyclic pyrimidine-containing phane ligands

Complexes of copper(II) bromide with cyclic and isostructural acyclic phane ligands containing derivatives of pyrimidine nucleobases (cytosine and uracil) were synthesized and characterized. In two cyclic pyrimidinophanes used, the macrocycles included two 6-methylthiocytosine and one 6-methyluracil units linked by polymethylene chains (L3) and two 6-methyluracil units linked by N-containing bridges (L5). Ligand L3 and its isostructural acyclic analogs are coordinated by the Cu2+ ion through the same donor sites (the ring N atoms of the thiocytosine units). The coordination polyhedra of the Cu atom in complexes with cyclic and acyclic ligands are different. Ligand L5 and its isostructural acyclic analog also form copper(II) complexes with different coordination polyhedra involving different donor sites. The acyclic ligand is coordinated by the Cu2+ ion via the bridging N atom, while cyclic ligand L5, via the uracil CO groups (the bridging N atoms become protonated). The resulting complexes are dielectrics.

Synthesis and crystal structures of two mixed-ligand Cu(II) complexes of tripyridyldiamine

Two novel Cu(II) complexes, [Cu(H2tpda)(acac)](ClO4)0.5Cl0.5 · H2O, [Cu(H2tpda)(NO3)]ClO4 (2) (H2tpda = tripyridyldiamine) have been synthesized, and characterized by X-ray analyses, elemental analyses, IR, UV and ESR spectra. Single crystal X-ray diffraction revealed that the Cu atom in complex 1 is coordinated to three N atoms from H2tpda and two oxygen atoms from acac with an approximately trigonal bipyramidal geometry. The molecules are assembled through intermolecular hydrogen bonds and π–π stacking, affording a two dimensional network. In complex 2, the Cu atom is coordinated with three N atoms from H2tpda and two oxygen atoms from in addition to a weak coordination with one oxygen from , resulting in an irregular octahedral environment, and the molecules are also connected by intermolecular hydrogen bonding and π–π stacking, affording a one dimensional structure.

Facile Oxidation-Based Synthesis of Sterically Encumbered Four-Coordinate Bis(2,9-di-tert-butyl-1,10-phenanthroline)copper(I) and Related Three-Coordinate Copper(I) Complexes

A new oxidation-based synthetic route was developed for synthesis of Cu(I) complexes with weakly coordinating ligands, leading to the synthesis of the elusive [Cu(dtbp)2]+ (dtbp, 2,9-di-tert-butyl-1,10-phenanthroline) complex that may be useful as a sensor or as a dye for dye-sensitized solar cells. An acetone solution of either 1 or 2 equiv of dtbp was added to excess Cu(0) and 1 equiv of AgY (Y is O3SCF3-, BF4-, SbF6-, or B(C6F5)4-) in a nitrogen-filled glove box. Following filtration and evaporation under vacuum, crystallization from CH2Cl2 and hexanes results in X-ray quality crystals of Cu(dtbp)(O3SCF3) (1), Cu(dtbp)(BF4) (2), [Cu(dtbp)(acetone)][SbF6] (3), [Cu(dtbp)2][B(C6F5)4].CH2Cl2 (4.CH2Cl2), [Cu(dtbp)2][BF4].CH2Cl2 (5.CH2Cl2), and [Cu(dtbp)2][SbF6].CH2Cl2 (6.CH2Cl2). Complexes 1-6 were characterized by X-ray crystallography and NMR. The Cu atom in complexes 1-3 exhibited distorted trigonal coordination geometries, reflecting the steric effect of the bulky tert-butyl substituents. The structures of the pseudotetrahedral complexes 4, 4.CH2Cl2, 5.CH2Cl2, and 6.CH2Cl2 revealed the longest average Cu-N distances (2.11 A, 2.11 A, 2.10 A, and 2.11 A, respectively) in this class of compounds-longer by more than three standard deviations from the average.

Copper complexes derived from 1-(2-carboxybenzoyl)thiosemicarbazide (H 3L): syntheses, characterization and crystal structure of [Cu 3L 2(Py) 6](HIm)(H 2O) 2

The reaction of CuCl 2·2H 2O with 1-(2-carboxybenzoyl)thiosemicarbazide (H 3L) and imidazole (HIm) in NaOH gave a Cu II complex, which was crystallized from pyridine (Py) to give complex 1, [Cu 3L 2(Py) 6(HIm)](H 2O) 2. The complex molecule contains a linear Cu 3 array in which the central copper atom at the crystallographic inversion centre has an octahedral environment and the other two Cu atoms are square pyramidal, each bridged to the central Cu atom via the L group, with the atoms O(1) and N(2) chelating to Cu(1), and the atoms N(1), S and O(2) to Cu(2). The carboxylate groups coordinate to the metal atoms in a unidentate fashion. Complex 2, [Cu 2(H 3L) 2Cl 2](H 2O) 3, obtained by the reaction of CuCl 2·2H 2O with H 3L has been characterized by IR, UV, NMR ( 1H and 13C) spectra, and TGA and molar conductance measurements. The ESR and magnetic moment measurements show that the Cu atoms in complex 2 are in the Cu 1 oxidation state.