Ligand Complexes Of Cu Research Articles

Phenanthroline and phenyl carboxylate mixed ligand copper complexes in developing drugs to treat cancer

The success of a classic inorganic coordination compound, Cisplatin, cis-[Pt(NH3)2Cl2], as the first anticancer metallodrug started a field of research dedicated to discovering coordination compounds with antitumor activity, encompassing various metals. Among these, copper complexes have emerged as interesting candidates to develop drugs to treat cancer. In this work, mixed ligand complexes of Cu(II) with diimines (phenanthroline or 4-methylphenanthroline) and 3-(4-hydroxyphenyl)propanoate, phenylcarboxylate or phenylacetate were synthesized. They were characterized in the solid state, including a new crystal structure of [Cu2(3-(4-hydroxyphenyl)propanoate)3(phenanthroline)2]Cl·H2O. The obtained complexes presented a variety of stoichiometries. In solution, complexes were partially dissociated in the corresponding Cu-diimine complex. The complexes bound to the DNA by partial intercalation and groove binding, as assessed by Circular Dichroism, relative viscosity change and UV–Vis titration. The cytotoxicity of the complexes was determined in vitro on MDA-MB-231, MCF-7 (human metastatic breast adenocarcinomas, the first triple negative), MCF-10A (breast nontumoral), A549 (human lung epithelial carcinoma), and MRC-5 (human nontumoral lung epithelial cells), finding an activity higher than that of Cisplatin, although with less selectivity.

IN VITRO ANTICANCER, ANTIOXIDANT AND MOLECULAR DOCKING STUDIES OF 4-AMINOBENZAMIDE METAL COMPLEXES

Objective: Mixed ligand complexes of Cu(II) and Cd(II) with 4-aminobenzamide(4-ABZ) have been synthesized under microwave irradiation and they were characterized by elemental analysis, estimation of metal ion, molar conductivity, magnetic study, FT-IR, Far-IR, electronic spectra, NMR (1H and 13C) and EPR spectral studies. Methods: The data of microanalysis and metal estimation showed that the complexes have the composition of [M(L1)2(L2)2] for Cu(II) and [M(L1)(L2)2] for Cd(II) complex respectively. The conductivity data confirmed the neutral nature of the complexes. The tetrahedral geometry of the Cd(II) complex was confirmed using UV-Visible spectra. The tetragonally distorted octahedral stereochemistry of Cu(II) complex was further confirmed by UV and EPR spectral studies. The diamagnetic nature and probable geometry of Cd(II) complex were also confirmed using NMR spectral studies, which are also compared with free 4-aminobenzamide. The in vitro bio-potential activities of 4-ABA and Cd(II) complex were screened for E. coli and C. Albicans microorganisms by Agar disc diffusion methods. Results: The cancer study of Cu(II) complex and antioxidant activity of DPPH free radical scavenging method of Cd(II) complex were measured and compared with 4-aminobenzamide and standard drugs. The breast cancer studies were also identified using the targeted proteins viz., BRCA1, PR and EGFR by molecular docking study. Conclusion: In the present study, we synthesized new metal complexes of Cu(II) and Cd(II) with 4-ABA and nitrite ion by microwave irradiation method. The analytical data show that the metal-ligand stoichiometry they are non-electrolytes in acetonitrile solution. The spectral data show that the synthesized ligand binds with metal ions through the nitrogen atom of the 4-ABA and oxygen atoms of the nitrite ion.

Anti pathogenic studies of new mixed ligand metal chelates

Drug discovery aimed at the methodical extermination of life-threatening bacterial infection, especially considering the emergence of multi-drug resistance of pathogenic bacteria has remained a challenge for medicinal inorganic chemistry. In this article, the mixed ligand complexes of Cu (II), Co (II), and Ni (II) containing heterocyclic ligands were synthesized and characterized by IR, LC-MS, UV, and TG-DTA. Complexes are screened for Anti-microbial activity against human pathogenic bacteria.

Mixed ligand transition metal(II) complexes: Characterization, spectral, electrochemical studies, molecular docking and bacteriological application

Mixed ligand complexes of Cu(II), Co(II), Ni(II), Mn(II) and Cd(II) with N,N'-1,4-phenylene (2-hyboxynaphthaliden imine) (H2L) as primary ligand and 4-aminoantipyrine (4-AAp) as secondary ligand have been prepared. The newly formed complexes were characterized using elemental analysis, magnetic susceptibility, molar conductance, 1H NMR, UV–Vis., FTIR, X-ray diffraction, mass, thermal analysis and ESR techniques. The elemental analysis, data reveal the formation of [2:1:2] [M: H2L: 4-AAP] complexes. The mode of bonding between Cu(II), Ni(II), Co(Il), Mn(II) and Cd(II) and ligands has been studied by IR spectrophotometry. Electronic absorption spectra and magnetic moment measurements of the mixed-ligand complexes suggest a distorted octahedral geometry around the central metal ion and the anions X− are in the axial positions, for all compounds. The ligands are found to behave in a neutral bidentate manner, through nitrogen atom and oxygen atom of carbonyl group (secondary ligand), whereas H2L (primary ligand) coordinated through nitrogen and OH group as a neutral ligand. FT-IR spectral data shows that the ligand acted as bis-bidentate coordination through ON–NO donor system. The XRD patterns of the ligand and its mixed ligand complexes showed the polycrystalline natures. The ligand and its mixed complexes were studied for their microbial activity against some bacteria and fungi. The ligand in comparison to its mixed ligand complexes (1-5) was screened for their antibacterial activity against Klebsiella pneumoniae, Escherichia coli, Pseudomonas sp., Staphylococcus aureus and Bacillus cereus. Antifungal activities of ligand in comparison to its mixed ligand complexes (1-5) were determined against Fusarium oxysporum, Aspergillus niger and Candida albicans. It was found that the mixed ligand complex (5) is more active than other mixed ligand complexes and penicillin G against Bacillus cereus, Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas sp. The mixed ligand complex (5) is more active than the ligand and other mixed ligand complexes and miconazole against Aspergillus niger. The inhibition efficiency of the prepared ligand (H2L) against the corrosion of P355 carbon steel in HCl (2 M) solution was determined by various electrochemical methods are found to be in reasonable agreement. The morphology of protected P355 carbon steel was test by energy dispersive X-ray and scanning electron microscope (EDX–SEM).

Imino-pyridyl and PPh3 mixed ligand complexes of Cu(I)X (X: I, Br, and Cl): Synthesis, structure, DFT and Hirshfeld surface studies

Three new halide bridged copper(I)complexes [Cu2(µ-L)(µ-X)2)(PPh3)2]n {X: I (1), Br (2) and Cl (3)} have been synthesized by the reaction of Cu(I)X (X: I, Br and Cl) with PPh3 and the polydentate imino-pyridyl ligand L. Interestingly, copper(I) forms coordination polymers with the ligand L and the co-ligand PPh3. These complexes 1, 2 and 3 have been characterized by elemental analysis, IR, UV-Vis, and NMR spectroscopy. The crystal structure of the complex 2 has been determined by single-crystal X-ray analysis. Crystal data for complex 2: triclinic, space group P-1 (no. 2), a = 9.471(10) Å, b = 11.043(11) Å, c = 13.215(18) Å, α = 65.853(18)°, β = 69.94(2)°, γ = 67.350(14)°, V = 1135(2) Å3, Z = 2, T = 296.15 K, μ(MoKα) = 2.806 mm-1, Dcalc = 1.535 g/cm3, 4059 reflections measured (3.462° ≤ 2Θ ≤ 44.818°), 2639 unique (Rint = 0.0637, Rsigma = 0.1621) which were used in all calculations. The final R1 was 0.0700 (I > 2σ(I)) and wR2 was 0.2207 (all data). Hirshfeld surface analysis of the complex 2 showed H···H, N···H and Br···H interactions of 55.9, 14.4 and 4.1%, respectively. MEP of ligand L reflects the whole molecule is reddish yellow in color because of equally distributed electron density over the molecule. For this reason, the ligand is supramolecularly arranged via -{CuI2-µ-X2} rhomboid core in the complex 2. The ligand L is non-emissive at room temperature in dichloromethane, whereas the complexes 1, 2 and 3 are photoluminescent. DFT and Hirshfeld surface studies have also been performed for complex 2.

Stability Constants of Mixed Ligand Complexes of Cu(II) and Atenolol with L-Methionine/L-Cysteine/L-Penicillamine and S- Methyl-L-Cysteine

Stability Constants of Mixed Ligand Complexes of Cu(II) and Atenolol with L-Methionine/L-Cysteine/L-Penicillamine and S- Methyl-L-Cysteine

Cytotoxic and Antimicrobial Activities of Piperazine Bridged dithiocarbamate Homo Binuclear Mixed Ligand Complexes of Cu(II) with Amino acids

A new series of Cu(II) mixed ligand complexes with bridging piperazine dithiocarbamate along with chelated amino acids such as glycine, alanine, phenylalanine, methionine, tyrosine and cystine in the deprotonated form have been prepared. The synthesized complexes are characterized by thermal, elemental, metal, nitrogen and sulphur, UV-Vis, infra-red, ESR Spectral analysis magnetic susceptibility and powder XRD studies. The above studies are used for establishing the structure and composition of the complexes. Biological evaluation such as antibacterial, antifungal and anticancer properties have also been carried out on these complexes based on agar disc diffusion and MTT based assay method respectively

Copper(I) oligomers and polymers with dicyanobenzene and cyanopyridine ligands

The reaction of [Cu(MeCN)4]BF4 with o-, m-, or p-dicyanobenzene (DCB) or o-, m-, or p-cyanopyridine (CPy) in the presence of two equivalents of PPh3 produces DCB- or CPy-bridged copper(I) complexes. Cyclic dimers are formed for the ortho ligands, and zigzag polymers are formed using the para ligands. m-DCB produces a polymer, however m-CPy results in a cyclic trimer. Multiple lattice-bound solvates are formed upon crystallization of the o-DCB dimer from various solvents. A total of 11 X-ray crystal structures are reported for [Cun(PPh3)2n(bridge)n](BF4)n·(solvent): bridge=o-DCB, n=2, solvent (per dimer)=none, ½ CH2Cl2, CH2Cl2, 2 CHCl3/H2O, or 2 THF; bridge=m-DCB, n=∞, solvent=none; bridge=p-DCB, n=∞, solvent=CH2Cl2 (two polymorphs), bridge=o-CPy, n=2, solvent (per dimer)=2 toluene; bridge=m-CPy, n=3, solvent=none; bridge=p-CPy, n=∞, solvent=½ acetone. All complexes are photoluminescent with excitation in the range 340–400nm. The meta complexes emit in the blue region, while the other complexes emit in the green. Dimer complexes of o-DCB exhibit structural flexibility in the central macrocyclic ring. Complexes of m-DCB and p-CPy show orientational disorder in the ligand. Polymeric complexes show helicity. Smaller Stokes shifts are noted for DCB than for CPy complexes, suggesting less excited state distortion for cyanoaromatic ligand complexes of Cu(I).

DNA binding and biological activity of mixed ligand complexes of Cu(II), Ni(II) and Co(II) with quinolones and N donor ligand

Abstract Mixed ligand complexes of Cu(II), Ni(II) and Co(II) have been synthesized by using levofloxacin and bipyridyl and characterized using spectral and analytical techniques. The binding behavior of the Ni(II) and Cu(II) complexes with herring sperm DNA(Hs-DNA) were determined using electronic absorption titration, viscometric measurements and cyclic voltammetry measurements. The binding constant calculated for Cu(II) and Ni(II) complexes are 2.0 x 10 4 and 4.0 x 10 4 M -1 respectively. Detailed analysis reveals that these metal complexes interact with DNA through intercalative binding mode. The nuclease activity of Cu(II) and Ni(II) complexes with ct-DNA was carried out using agarose gel electrophoresis technique. The antioxidant activities for the synthesized complexes have been tested and the antibacterial activity for Ni(II) complex was also checked. Key words: Intercalation, hypochromism, red shift and peak potential.

Mixed ligand complexes of Cu(II)/Zn(II) ions containing (m-)/(p-) carboxylato phenyl azo pentane 2,4-dione and 2,2′-bipyridine/1,10 phenanthroline: Synthesis, characterization, DNA binding, nuclease and topoisomerase I inhibitory activity

Metal complexes of type [Cu(L1H)2(bpy)] (1), [Zn(L1H)2(bpy)] (2), [Cu(L2H)2(bpy)] (3) and [Cu(L2H)2(Phen)] (4) (L1H2=3-[N′-(1-acetyl-2-oxo-propylidene)-hydrazino]-benzoic acid, L2H2=4-[N′-(1-acetyl-2-oxo-propylidene)-hydrazino]-benzoic acid, bpy=2,2′-bipyridine, Phen=1,10 phenanthroline) are synthesized and characterized using spectroscopic techniques (FT-IR, 1H NMR, 13C NMR, electronic absorption and emission) and elemental analysis data. The assembly of the complexes involving intramolecular H-bonding is displayed using corresponding crystal structure. Binding of the complexes separately with Calf Thymus DNA is monitored using UV–vis spectral titrations. The displacement of ethidium bromide (EB) bound to DNA by the complexes, in phosphate buffer solution (pH∼7.2) is monitored using fluorescence spectral titrations. Nuclease activity of the complexes follow the order 4>3>1>2. The gel electrophoretic mobility assay measurement in presence of minor groove binder 4′,6-diamidino-2-phenylindole (DAPI), suggests that complexes preferably bind with the minor groove of DNA. Topoisomerase I inhibitory activity of the complexes 3 and 4 inhibit topoisomerase I activity with IC50 values of 112 and 87μM respectively.

Mixed Ligand-Cu(II) Complexes as Antimicrobial Agents: Preparation and Spectroscopic Studies

Three mixed ligand-complexes of Cu(II) were prepared using Schiff base ligands and characterized using analytical and physical techniques. Antimicrobial activities of the above synthesized Cu(II) complexes were performed against selected species of bacteria and fungi. All the three Cu(II) complexes under study showed good antimicrobial activity which was compared with standard antibacterial and antifungal drug.

Thermodynamics, Chemical Speciation and Complex Formation Equilibria Studies of Binary and Mixed Ligand Complexes of Cu(II) with 2,2′-Bipyridyl and Some Aromatic Diamines

The formation of mixed ligand complexes of Cu(II) with 2,2′-bipyridyl (Bipy) in the presence of some selected aromatic diamines (L) (L = 3,4-diamino benzoic acid (DABA), 2-hydazinopyridine (hzpy) or 4-chloro-o-phenylenediamine has been studied by pH-metric titrations. Potentiometric measurements show that ternary complexes are formed in a simultaneous manner. The pH-titrations of the reaction mixtures are shown to yield 1:1:1 ternary complex formation. The equilibrium and formation constants of the resulting ternary complexes have been calculated at I = 0.1 mol·dm−3 of NaNO3. The order of stability in terms of the secondary ligands has been found to be DABA > hzpy > CAPA. The stability of ternary complexes was quantitatively compared with their corresponding binary complexes in terms of the parameters Δlog10K, Δlog10β and log10X. The concentration distributions of various species formed in solution were also evaluated as a function of pH. In addition, the effect of temperature on both the ionization process of the ligands and complex formations for Cu–Bipy–L ternary systems was studied. The thermodynamic parameters were calculated from the temperature dependence of the equilibrium constants and are discussed. The structure of the Cu(II) complexes have been geometrically optimized using the parameterized PM3 semiempirical method.

Synthesis, Spectral and Antimicrobial Activity of Some Mixed Ligand Cu(II) Complexes of Schiff Base 2-[(3-Hydroxy Phenylimino)Methyl]-4-Nitrophenol with Some Amino Acids

The mixed ligand complexes of Cu(II) with 2-[(3-hydroxy phenylimino)methyl]-4-nitrophenol (HPIMNP) as primary ligand and amino acid (valine, alanine or glutamine) as secondary ligand have been synthesised and characterised. The complexes were characterised by elemental analysis, conductivity measurement, 1H NMR, IR and ultraviolet–visible (UV–vis) spectral studies. Schiff base acts as bidentate ligand coordinating through deprotonated phenolic oxygen and azomethine N-atom. The conductivity studies of the complexes in Dimethyl sulphoxide at 10−3 M concentration indicate their non-electrolyte nature. From analytical and spectral data, the stoichiometry of these complexes is found to be 1:1:1 and exhibited octahedral geometry. Tube dilution method has been used to study the antimicrobial activity of Schiff base and its mixed ligand complexes. It was found that the mixed ligand complexes have higher anti-microbial activity than the Schiff base.

Synthesis, characterization, molecular modeling and biological activity of mixed ligand complexes of Cu(II), Ni(II) and Co(II) based on 1,10-phenanthroline and novel thiosemicarbazone

A combined experimental and computational study of novel mixed ligand Cu(II), Ni(II) and Co(II) complexes of 2-(1-(2-phenyl-hydrazono)-propan-2-ylidene)hydrazine-carbothioamide (TPHP) and 1,10-phenanthroline (1,10-Phen) have been synthesized. The complexes have been characterized by elemental analyses, IR, solid reflectance, magnetic moment, 1HNMR and molar conductance. Spectral data showed that the 1,10-phenanthroline acts as neutral bidentate ligand coordinating to the metal ion through two nitrogen donor atoms and thiosemicarbazone acts as monobasic tridentate coordinating through two imine-N and thiolate sulphur groups. The geometry of the studied M(II) complexes has been fully optimized using parameterized PM3 semiempirical method. It was observed that the M–S bond length is longer than that of M–Cl in the isolated complexes and the M–N bond length is shorter than that of M–Cl. Also, valuable information is obtained from calculations of molecular parameters for all complexes including net dipole moment of the metal complexes, values of binding energy, which proved that the complexes are more stable than the free ligand. The metal chelates have been screened for their antimicrobial activities using the disc diffusion method against different selected types of bacteria (G+: Bacillus subtillis RCMB 010067, Staphylococcus aureus RCMB 010028); G−: Pseudomonas aeuroginosa RCMB 010043, Escherichia coli RCMB 010052)) and fungi (Aspergillus flavus RCMB 02568, Pencicillium italicum RCMB 03924, Candida albicans RCMB 05031, Geotricum candidum RCMB 05097). Finally, structure–activity relationship studies were investigated with the aim to correlate physico-chemical properties that may be related to the antimicrobial action of the studied compounds. Protonation constant of (TPHP) ligand and stability constants of its M(II) complexes were determined by potentiometric titration method in 70%:30% DMSO–water mixture at 0.1moldm−3 NaCl.

Synthesis and Characterization of Mixed Ligand Complexes of Cu(Phen)2(ClO4 )2 with Some Aromatic Ligands

Five mixed-ligand complexes of copper(II) with 1, 10-phenanthroline and some selected aromatic ligands such as imidazole, 2-aminopyridine, 4- dimethylaminobenzonitrile, 2,2'dipyridylketone, 4-methylimidazole-5-carboxaldehyde have been synthesized and characterized by microanalyses, spectroscopic and room temperature magnetic susceptibility measurements. The microanalyses data is satisfactory with the formation of the prepared complexes. The infrared spectra of the complexes reveal the involvement of the donor groups of the selected aromatic compounds attached to the copper metal in the formation of the mixed-ligand complexes. The electronic spectra in the visible region show the high energy, high intensity peaks between 13,647 cm -1 and 15,322 cm -1 . The mass spectra of the complexes are supportive of the microanalytical data.

Synthesis and Characterization of Mixed Ligand Complexes of Cu(II)-Oxalate-Amino Acids (Aspartic acid and Cysteine)

Synthesis and Characterization of Mixed Ligand Complexes of Cu(II)-Oxalate-Amino Acids (Aspartic acid and Cysteine)

Copper(I)/silver(I)-phosphine-N-{(2-pyridyl)methyliden}-6-coumarin complexes: Syntheses, structures, redox interconversion, photophysical properties and DFT computation

Mixed ligand complexes of Cu(I) and Ag(I) with bis(diphenylphosphino)methane (dppm)/1,2-bis(diphenylphosphino)ethane (dppe) and N-{(2-pyridyl) methyliden}-6-coumarin (L) have been synthesized and characterized by elemental analyses, conductivity, 1H NMR, UV–Vis and fluorescence spectral data. The coordination of dppm to M(I) forms a binuclear metallacycle, [(L)M(μ-dppm)2M(L)](X)2 (X=NO3 or ClO4), and one of the complexes has been characterized by single crystal X-ray structure analysis. The dppe ligand is a bidentate chelator, which is supported by the X-ray structure of [Cu(dppe)(L)]ClO4. In the Ag(I) complex, dppe is serving as a bridging agent to form the binuclear complex [(L)Ag(μ-dppe)Ag(L)](NO3)2, and NO3− asymmetrically chelates Ag(I), which exhibits solvent polarity dependent coordination. In a coordinating polar solvent, like MeCN, the nitrate group dissociates and shows conductivity, while in nitrobenzene the complex is non-conducting and supports no dissociation. The complexes are more fluorescent than free L. Cyclic voltammetry shows a Cu(II)/Cu(I) quasireversible couple, while the Ag(I) complexes exhibit deposition of Ag(0) on the electrode surface. The coulometric and Cl2 oxidation of the Cu(I) complexes have isolated Cu(II) complexes that are established by spectroscopic and magnetic data. The electronic configuration of the complexes is assessed by DFT computation, and the spectral and redox properties are explained.

Cu(II)-Catalyzed Olefin Migration and Prins Cyclization: Highly Diastereoselective Synthesis of Substituted Tetrahydropyrans

Metal-ligand complexes of Cu(OTf)(2) with an appropriate bisphosphine ligand have been shown to effectively catalyze the formation of substituted tetrahydropyrans via a sequential olefin migration and Prins-type cyclization. This methodology provides convenient access to a variety of functionalized tetrahydropyrans in excellent diastereoselectivities and good to excellent yields.

Stability Constants of Mixed Ligand Complexes of Cu(II) and Ni(II) with Some Amino Acids and Phosphates

The binary and ternary metal complexes of Cu(II) & Ni(II) with some amino acids (leucine, isoleucine & serine) as primary ligand and pyrophosphate (PP), adenosine‐5´‐triphosphate (ATP), as secondary ligand have been studied potentiometrically at 35 °C and a constant ionic strength (1.0 mol dm-3 KNO3). The formation of various binary and ternary complexes has been inferred from the corresponding titration curves. The Irving & Rossotti titration technique has been applied to determine the formation constants corresponding to various complexation equilibria.

Synthesis and thermal studies of mixed ligand complexes of Cu(II), Co(II), Ni(II) and Cd(II) with mercaptotriazoles and dehydroacetic acid

A series of new mixed ligand complexes of cobalt(II), nickel(II), copper(II) and cadmium(II) have been synthesized with 3benzyl1H4[(2 methoxybenzylidine) amino]1, 2, 4triazole5 thione (MBT), 3bezyl1H4[(4chlorobenzylidine) amino]1, 2, 4triazole5thione (CBT), 3benzyl 1H4[(4nitrobenzylidine)amino]1, 2, 4triazole 5thione (NBT) and dehydroacetic acid sodium salt (Nadha). The mixed ligand complexes have been characterized by elemental analysis, spec troscopic spectral measurements (IR, UVVis.), molar conductance, magnetic measurements and thermal studies. The stoichiometry of these com plexes is M:L1:L2 = 1:1:1, 1:2:1 or 1:1:2 where L1 = NBT, CBT and MBT and L2 = Nadha. Tetrahedral structure was proposed for all Cd(II) mixed ligand complexes while the square planar geometry was proposed for Cu(II) mixed ligand complex with NBT. Octahedral structure was proposed for Ni(II), Co(II) mixed ligand complexes and Cu(II) mixed ligand complexes with CBT and MBT ligands. The thermal decomposition study of the prepared complexes was monitored by TG, DTG and DTA analysis in dynamic nitrogen atmosphere. TG, DTG and DTA studies confirmed the chemical formulations of theses complexes. The kinetic parameters were determined from the the thermal decomposition data using the graphical methods of CoatsRedfern and HorwitzMetzger. Thermodynamic parameters were calculated using standard relations.