Cu Atom In Complex Research Articles

Syntheses, Crystal Structures and Antimicrobial Activity of Copper(II) Complexes with the Ligand N,N'-Bis(4-bromosalicylidene)propane-1,2-diamine.

Three new copper(II) complexes, [CuClL] (1), [CuBrL]n (2) and [CuL(NCS)]n (3), derived from the Schiff base 2,4-dichloro-6-((2-pyrrolidin-1-ylethylimino)methyl)phenol (HL) have been prepared and characterized by spectroscopy methods, as well as single crystal X-ray determination. The Cu atom in complex 1 is in square planar coordination, and those in complexes 2 and 3 are in square pyramidal coordination. The Schiff base ligand coordinates to the Cu atoms through phenolate oxygen, imino nitrogen and pyrrolidine nitrogen. The antibacterial activities of the Schiff base and the three copper complexes have been assayed on the bacteria Staphylococcus aureus and Escherichia coli, and the yeast Candida parapsilosis.

Synthesis, Crystal Structures, Photophysical Properties and Antibacterial Activities of Copper(II) Complex Derived from 4-Chloro-2-{[(2,6-dimethylphenyl)imino]methyl}phenol

A new asymmetrical Schiff base ligand, (E)-4-chloro-2-{[(2,6-dimethylphenyl)amino] methyl}phenol(HL), and its mononuclear Cu(Ⅱ) complex have been synthesized. The molecular structures and spectroscopic properties of the ligand and its complex were experimentally characterized by single crystal X-ray diffraction, elemental analysis, FT-IR, NMR and UV-Vis spectroscopic techniques. The analysis confirmed that the Cu atom in complex is generally four-coordinated by one imino N and one phenolic O atoms of a Schiff-base ligand adopting a trans-configuration of N2O2 donor atoms around the metal ion, forming a tetrahedral geometry. Density functional calculation is being carried out on both HL and copper(Ⅱ) complex to investigate changes in structural parameters, energies of the HOMO and LUMO. The results demonstrated that the HOMO and LUMO were effectively separated with the benzene ring of 2,6-dimethylbenzenamine as a donor unit and the benzene ring of 5-chlorosalicylaldehyde as an acceptor unit. The effective HOMO-LUMO separation helps to induce intramolecular charge transfer from the HOMO to the LUMO. The HOMO-LUMO energy gap become smaller when the Schiff base ligand coordinated with Cu(II) ion, most likely due to the interaction of the d-orbitals of copper(Ⅱ) with the HOMO and/or LUMO of the ligand. These theoretical calculations supported the experimentally observed results.The biological assay revealed that both Schiff base and the complex have different antimicrobial activity. The complex has the MIC value of 0.0781 mmol·L-1 against Escherichia coli.

Synthesis, Crystal Structures and Urease Inhibition of Copper(II) and Cobalt(III) Complexes Derived from (((2-(Pyrrolidin-1-yl)ethyl)imino)methyl)naphthalen-2-ol

Three copper(II) and cobalt(III) complexes, [CuL(dca)]n (1), [CuL(N3)]n (2) and [CoL(N3)2(DMF)] (3), where L is the monoanionic form of the Schiff base (((2-(pyrrolidin-1-yl)ethyl)imino)methyl)naphthalen-2-ol (HL), and dca is dicyanamide, have been prepared and characterized by elemental analyses, IR and UV-Vis spectroscopy, as well as single crystal X-ray diffraction. The Cu atoms in complexes 1 and 2 are in square pyramidal coordination, and the Co atom in complex 3 is in octahedral one. Complexes 1 and 2 inhibit the Jack bean urease with IC50 values of 0.25 ± 0.14 and 0.32 ± 0.15 μmol L–1, respectively. Complex 3 show weak activity on Jack bean urease with percentage inhibition of 37%.

Syntheses, X-ray crystal structures and urease inhibition of copper(II) and nickel(II) complexes derived from 5-bromo-2-(((2-(pyrrolidin-1-yl)ethyl)imino)methyl)phenol

Four new copper(II) and two new nickel(II) complexes, [Cu2(μ-Br)2L2] (1), [CuL(μ1,3-NCS)]n (2), [Cu2L2(μ1,3-N3)2] (3), [Cu3Cl2(μ-Cl)2L2] (4), [Ni3L2(μ2-η1:η1-OAc)2(μ2-η2:η1-OAc)2]·2CH3OH (5) and [NiL(μ2-1,5-dca)(OH2)]n (6), where L is the deprotonated form of 5-bromo-2-(((2-pyrrolidin-1-yl)ethyl)imino)methyl)phenol, dca is dicyanoamide, were synthesized and characterized by elemental analyses, infrared and electronic spectroscopy, and single crystal X-ray determination. The Cu atoms in complexes 1–3 and the outer two Cu atoms in complex 4 are in square pyramidal coordination, while the central Cu atom in complex 4 is in square planar geometry. The Ni atoms in complexes 5 and 6 are in octahedral coordination. The co-ligands bromide, thiocyanate, azide, chloride, acetate and dicyanoamide are interesting bridging groups in the construction of the polynuclear complexes with versatile structures. The urease inhibition assay indicates that the copper complexes have effective activities.

SYNTHESIS, CRYSTAL STRUCTURES AND UREASE INHIBITION OF ZINC(II) AND COPPER(II) COMPLEXES DERIVED FROM 2-AMINO-N’-(1-(PYRIDIN-2-YL)ETHYLIDENE)BENZOHYDRAZIDE

Two mononuclear zinc(II) and copper(II) complexes, [ZnBr(HL)(NCS)] (1) and [CuL2] (2), where HL and L are the ketone and enolate forms of 2-amino-N’-(1-(pyridin-2-yl)ethylidene)benzohydrazide (HL), have been prepared and characterized by elemental analyses, IR and UV-Vis spectroscopy, as well as single crystal X-ray diffraction studies. The Zn atom in complex 1 is in distorted square pyramidal coordination, with the pyridine N, imino N and carbonyl O atoms of the hydrazone ligand HL and the N atom of the thiocyanate ligand in the basal plane, and with the Br atom at the apical position. The Cu atom in complex 2 is in distorted octahedral coordination, with the pyridine N, imino N and enolate O atoms of one hydrazone ligand L, and the imino N atom of the other hydrazone ligand L in the equatorial plane, and with the pyridine N and enolate O atoms of the other hydrazone ligand L at the axial positions. The hydrazone and the complexes have been assayed for their Jack bean urease activity. As a result, the copper complex has effective urease inhibitory activity with IC50 = 11.9 ± 1.3 μmol L–1. Molecular docking study was performed to investigate the interaction between the complex molecule and the enzyme.

Syntheses, characterization, crystal structures and Jack bean urease inhibitory property of NiII, CdII, CuII and FeIII complexes with bis-Schiff bases

Four new nickel(II), cadmium(II), copper(II) and iron(III) complexes, [Ni3(L1)2(μ2-η1:η1-CH3COO)2] (1), [Cd2(L1)2(CH3OH)2] (2), [Cu(L2)] (3) and [Fe2(L3)2(μ2-OCH3)2] (4), where L1, L2 and L3 are the dianionic form of N,N'-bis(5-fluorosalicylidene)-1,3-propanediamine (H2L1), N,N'-bis(3,5-difluorosalicylidene)-1,3-propanediamine (H2L2) and N,N'-bis(4-fluorosalicylidene)-1,3-propanediamine (H2L3), respectively, were prepared. The compounds have been characterized by physico-chemical methods. The structures of the metal complexes were also confirmed by single crystal X-ray diffraction. The Ni atoms in complex 1 are in square pyramidal and octahedral coordination environments. The Cd atoms in complex 2 are in an octahedral coordination environment. The Cu atom in complex 3 is in a tetrahedrally distorted square planar coordination environment. The Fe atoms in complex 4 are in an octahedral coordination environment. The Jack bean urease inhibitory assay indicated that the copper complex displays good activity.

Synthesis, Crystal Structures and Antibacterial Activities of N,N'-Ethylene-bis(3-bromosalicylaldimine) and Its Copper(II) and Cobalt(III) Complexes.

A bis-Schiff base N,N'-ethylene-bis(3-bromosalicylaldimine) (H2L) was prepared from 3-bromosalicylaldehyde and ethane-1,2-diamine. With H2L as ligand, a new copper(II) complex [CuL] (1) and a new cobalt(III) complex [CoL(NCS)(DMF)] (2) were prepared and characterized by physico-chemical methods and single crystal X-ray analysis. X-ray analysis indicates that the Cu atom in complex 1 is in square planar coordination, and the Co atom in complex 2 is in octahedral coordination. The compounds were tested in vitro for their antibacterial activities on Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas fluorescens. Both complexes have effective activities on the bacteria.

Synthesis, Crystal Structures and Urease Inhibition of Mononuclear Copper(II) and Nickel(II) Complexes with Schiff Base Ligands.

Three mononuclear copper(II) and nickel(II) complexes, [Cu(L1)(NCS)(CH3OH)] (1), [Cu(L2)(NCS)] (2) and [Ni(L2)(N3)] (3), where L1 and L2 are the monoanionic forms of the Schiff bases N'-(pyridin-2-ylmethylene)picolinohydrazide (HL1) and 4-methyl-2-(((pyridin-2-ylmethyl)imino)methyl)phenol (HL2), have been prepared and characterized by elemental analysis, IR and UV-Vis spectroscopy, as well as single crystal X-ray diffraction studies. The Cu atom in complex 1 is in a square pyramidal coordination, with the three N atoms of the ligand L and the N atom of the thiocyanate ligand in the basal plane, and with the methanol O atom at the apical position. The Cu and Ni atoms in complexes 2 and 3 are in square planar coordination, with the three donor atoms of the Schiff base ligands and the terminal N atoms of thiocyanate and azide ligands. Complexes 1 and 2 inhibit the Jack bean urease with IC50 value of 0.33±0.12 and 0.39±0.10 μmol L-1, respectively. Molecular docking study was performed to investigate the interaction between the complexes and the enzyme.

Syntheses, Characterization and Crystal Structures of Dicyanamide Bridged Polynuclear Copper(II) and Zinc(II) Complexes with Urease Inhibitory Activity.

A pair of structurally similar dicyanamide bridged copper(II) and zinc(II) complexes [CuL(dca)]n (1) and [ZnL(dca)]n (2), were prepared from the fluorine containing Schiff base 5-fluoro-2-(((2-hydroxyethyl)imino)methyl)phenol (HL). The compounds were characterized by physico-chemical methods. Structures of the complexes were confirmed by single crystal X-ray diffraction. The Cu atom in complex 1 is in square pyramidal coordination, whereas the Zn atom in complex 2 is in trigonal bipyramidal coordination. The copper complex has effective Jack bean urease inhibitory activity, with IC50 value of 0.14±0.12 μmol L-1.

Copper(II) and cadmium(II) complexes of mono-condensed N,O- or N,N,O-Donor ligands: synthesis, crystal structures, and antibacterial activity

Three new copper(II) and cadmium(II) complexes, [Cu(L1)2] (1), [CuL2(N3)] (2), and [Cd(L3)2] (3), where L1 = 2-bromo-4-chloro-6-cyclohexylaminomethylphenolate, L2 = 2-bromo-4-chloro-6-[(2-morpholin-4-ylethylimino)methyl]phenolate, and L3 = 2-bromo-4-chloro-6-[(3-morpholin-4-ylpropylimino)methyl]phenolate, have been prepared and structurally characterized by X-ray crystallography. The Cu atom in complex 1 is in tetrahedrally distorted square planar geometry. The Cu atom in complex 2 is in square planar geometry. The Cd atom in complex 3 is in octahedral geometry. The complexes exhibited effective activities against B. subtilis, S. aureus and E. coli.

Synthesis, Characterization and Crystal Structures of Schiff Base Copper Complexes with Urease Inhibitory Activity.

Urease inhibitors can inhibit the decomposition rate of urea, and decrease the air pollution caused by ammonia. In this paper, four new copper(II) complexes [CuL(ONO2)]n (1), [Cu2L2(μ1,3-N3)2] (2), [CuBrL] (3), and [CuClL] (4), where L = 5-bromo-2-(((2-methylamino)ethyl)imino)methyl)phenolate, have been synthesized and characterized. The complexes were characterized by elemental analyses, IR and UV-Vis spectroscopy, molar conductivity, and single crystal X-ray diffraction. X-ray analysis reveals that Cu atoms in complexes 1 and 2 are in square pyramidal coordination, and those in complexes 3 and 4 are in square planar coordination. The molecules of the complexes are linked through hydrogen bonds and π···π interactions. The inhibitory effects of the complexes on Jack bean urease were studied, which showed that the complexes have effective activity on urease.

Copper(II) and cadmium(II) complexes of mono-condensed N,O- or N,N,O-Donor ligands: synthesis, crystal structures, and antibacterial activity

Three new copper(II) and cadmium(II) complexes, [Cu(L1)2] (1), [CuL 2 (N3)] (2), and [Cd(L3)2] (3), where L1 = 2-bromo-4-chloro-6-cyclohexylaminomethylphenolate, L2 = 2-bromo-4-chloro-6-[(2-morpholin-4-ylethylimino)methyl]phenolate, and L3 = 2-bromo-4-chloro-6-[(3-morpholin-4-ylpropylimino)methyl]phenolate, have been prepared and structurally characterized by X-ray crystallography. The Cu atom in complex 1 is in tetrahedrally distorted square planar geometry. The Cu atom in complex 2 is in square planar geometry. The Cd atom in complex 3 is in octahedral geometry. The complexes exhibited effective activities against B. subtilis, S. aureus, and E. coli.

Copper(II) and Zinc(II) Complexes Derived from N,N’-Bis(4-bromosalicylidene)propane-1,3-diamine: Syntheses, Crystal Structures and Antimicrobial Activity

A mononuclear copper(II) complex, [CuL] (1), and a phenolato-bridged trinuclear zinc(II) complex, [Zn3Cl2L2(DMF)2] (2), where L is the deprotonated form of N,N'-bis(4-bromosalicylidene)propane-1,3-diamine (H2L), have been prepared and characterized by elemental analyses, IR and UV-Vis spectroscopy, and single crystal X-ray diffraction. The Cu atom in complex 1 is in square planar coordination, while the terminal and central Zn atoms in complex 2 are in square pyramidal and octahedral coordination, respectively. The antibacterial activities of the complexes have been tested on the bacteria Staphylococcus aureus and Escherichia coli, and the yeast Candida parapsilosis.

Synthesis, Crystal Structures, Characterization and Catalytic Property of Copper(II) Complexes Derived from Hydrazone Ligands

A new bromido-coordinated mononuclear copper(II) complex [Cu(HL1)Br2] (1), and a new mononuclear copper(II) complex [CuL2(HL2)]ClO4·0.5H2O (2), with the hydrazone ligands 4-tert-butyl-N'-(1-(pyridin-2-yl)ethylidene)benzohydrazide (HL1) and 4-bromo-N'-(pyridin-2-ylmethylene)benzohydrazide (HL2), have been synthesized and structurally characterized by physico-chemical methods and single crystal X-ray determination. X-ray analysis indicates that the Cu atom in complex 1 is in distorted square pyramidal coordination, and that in complex 2 is in octahedral coordination. The catalytic property for epoxidation of styrene by the complexes was evaluated.

SYNTHESES, CHARACTERIZATION, AND ANTIBACTERIAL PROPERTIES OF COPPER(II) COMPLEXES DERIVED FROM FLUORO-CONTAINING SCHIFF BASES

A centrosymmetric dinuclear copper(II) complex [Cu2(La)2] (1) and two mononuclear copper(II) complexes [Cu(Lb)2] (2) and [Cu(Lc)2] (3), where La, Lb, and Lc are deprotonated anionic forms of 2-((cyclopropylimino)methyl)-4,6-difluorophenol (HLa), 2-((cyclohexylimino)methyl)-4,6-difluorophenol (HLb) and 2,4-difluoro-6-((2-hydroxyethylimino)methyl)phenol (HLc), respectively, are prepared and characterized by elemental analyses, IR and UV-Vis spectra, and single crystal X-ray diffraction. The Cu atoms in complex 1 are in a square pyramidal coordination, while those in complexes 2 and 3 are in a square planar coordination. The complexes exhibit interesting antibacterial activities against P. aeruginosa, S. typhi, and S. aureus.

Syntheses, characterization, and antibacterial properties of copper(II) complexes derived from fluoro-containing Schiff bases

A centrosymmetric dinuclear copper(II) complex [Cu2(La)2] (1) and two mononuclear copper(II) complexes [Cu(Lb)2] (2) and [Cu(Lc)2] (3), where La, Lb, and Lc are deprotonated anionic forms of 2-((cyclopropylimino)methyl)-4,6-difluorophenol (HLa), 2-((cyclohexylimino)me­thyl)-4,6-difluorophenol (HLb) and 2,4-difluoro-6-((2-hydroxyethylimino)methyl)phenol (HLc), respectively, are prepared and characterized by elemental analyses, IR and UV-Vis spectra, and single crystal X-ray diffraction. The Cu atoms in complex 1 are in a square pyramidal coordination, while those in complexes 2 and 3 are in a square planar coordination. The complexes exhibit interesting antibacterial activities against P. aeruginosa, S. typhi, and S. aureus.

Synthesis, crystal structures, and urease inhibitory activity of Schiff base copper and nickel complexes

Urease inhibitors can inhibit the decomposition rate of urea, and decrease the air pollution caused by ammonia. In this paper, three new copper(II) and nickel(II) complexes [Cu2L2(μ1,1-N3)2] (1), [Cu(HL)2]Br2 (2), and [Ni3L2(DMF)2(μ2—η1:η1-CH3COO)2(μ1,1-N3)2] (3), where L = 5-bromo-2-(((2-isopropylamino)ethyl)imino)methyl)phenolate, HL = 5-bromo-2-(((2-iso­propylammonio)ethyl)imino) methyl)phenolate are synthesized and characterized. The complexes are characterized by elemental analyses, IR, UV-Vis spectra, molar conductivity, and single crystal X-ray diffraction. The X-ray analysis indicates that Cu atoms in complexes 1 and 2 are in square pyramidal and square planar coordination, respectively. The Ni atoms in complex 3 are in octahedral coordination. The molecules of the complexes are linked through hydrogen bonds and π⋯π interactions. The inhibitory effects of the complexes on jack bean urease are studied, which show that the copper complexes have a strong inhibitory effect on urease.

Synthesis, Characterization, Crystal Structures, and Urease Inhibition of Copper(II) and Zinc(II) Complexes Derived from Benzohydrazones

A new copper(II) complex [Cu(L1)(NCS)(CH3OH)] (1) and a new zinc(II) complex [ZnCl2(HL2)]·CH3OH (2), derived from 4-bromo-N'-(pyridin-2-ylmethylene)benzohydrazide (HL1) and 4-methoxy-N'-(pyridin-2-ylmethylene)benzohydrazide (HL2), were prepared and characterized by elemental analysis, IR and UV-Vis spectroscopy and single crystal X-ray diffraction. The hydrazone HL1 coordinates to the Cu atom in enolate form, while the hydrazone HL2 coordinates to the Zn atom in carbonyl form. Single crystal structural analyses indicate that the hydrazones coordinate to the metal atoms through the pyridine N, imino N, and enolate/carbonyl O atoms. The Cu atom in complex 1 is in square pyramidal coordination, and the Zn atom in complex 2 is in trigonal-bipyramidal coordination. The inhibitory effects of the complexes on Jack bean urease were studied, which show that the copper complex has strong activity on urease.

Synthesis, characterization, crystal structure of novel Cu (II), Co (III), Fe (III) and Cr (III) complexes with 2‐hydroxybenzaldehyde‐4‐allyl‐S‐methylisothiosemicarbazone: Antimicrobial, antioxidant and in vitro antiproliferative activity

2‐Hydroxybenzaldehyde‐4‐allyl‐S‐methylisothiosemicarbazone and Cu (II), Co (III), Fe (III) and Cr (III) complexes were synthesized and characterized. The new obtained compounds were investigated by elemental analysis, magnetic susceptibility measurements, molar electric conductivity, IR, 1H NMR, 13C NMR, UV–Vis spectroscopy. In addition, the structure of the ligand and six complexes has been determined by single‐crystal X‐ray diffraction analysis. The Cu atom in complex 3 is penta‐coordinated in a distorted square–pyramidal coordination geometry, while the metals in complexes 5–9 are in a distorted octahedral environment. For all compounds the antimicrobial activity was studied on a series of standard strains, such as Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Salmonella abony and Candida albicans. The in vitro antiproliferative activity of the ligand and complexes was screened on human leukemia HL‐60 cells, human cervical epithelial HeLa cells, human epithelial pancreatic adenocarcinoma BxPC‐3 cells, human muscle rhabdomyosarcoma spindle and large multinucleated RD cells. The primary screening on a wider series of cancer cells showed that copper coordination compound 2 manifests high activity towards HeLa, BxPC‐3 and RD cancer cells, which is three–six times higher than the activity of doxorubicin. The selectivity index that is the ratio between the IC50 value for the normal MDCK cells and IC50 values for the cancer cells varies in the range 2.44–21.17. This index is 5.5–11 times higher for the copper coordination compound 2 than for the doxorubicin. Cr (III), Fe (III) and Co (III) coordination compounds 6–9 manifest high antioxidant activity towards ABTS•+ that exceeds 47–67 times the activity of Trolox.

Syntheses, Characterization, and Antibacterial Property of Polynuclear Cobalt(III) and Copper(II) Complexes Derived from Similar Tridentate Schiff Bases

An end-on azido-bridged trinuclear cobalt(III) complex [Co3(L1)2(μ1,1-N3)4(N3)2(OMe)(MeOH)] (I) and a phenolato-bridged dinuclear copper(II) complex [Cu2(L2)2(NCS)2] (II), where L1 is the deprotonated form of 2-((2-(dimethylamino)ethylimino)methyl)-4-fluorophenol, and L2 is the deprotonated form of 2-((3-(dimethylamino)propylimino)methyl)-4-fluorophenol, have been prepared and characterized by elemental analyses, IR and UV-Vis spectra, and single crystal X-ray diffraction (CIF files CCDC nos. 1023376 (I); 1023377 (II)). The Co atoms in complex I are in octahedral coordination, and the Cu atoms in complex II are in square pyramidal coordination. The antibacterial properties have been tested on some bacteria and yeast.