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The mononuclear complex salt, [Cu(C3H5NS2)(C6H8N2S3)]NO3, contains a [C9H13CuN3S5]+ cation and an NO3− anion. All of the non-H atoms of the cation lie on a mirror plane, as do the N and one O atom of the nitrate anion, such that the planes of the cation and anion are mutually orthogonal. The cationic complex adopts a slightly distorted trigonal–planar geometry about the CuI cation. In the crystal, layers parallel to (010) are generated by N—H...O hydrogen bonds, supported by short S...O [3.196 (4) and 3.038 (3) Å] and S...S contacts [3.4392 (13) Å]. Adjacent layers are linked by C—H...O hydrogen bonds and weak π–π stacking interactions [centroid–centroid distance = 4.0045 (10) Å] between the thiazoline rings, forming a three-dimensional network. This stacking also imposes a close contact, of approximately 3.678 Å, between the CuI cations and the centroids of the six-membered chelate rings of molecules in adjacent layers.

Five new copper(II) acrylate complexes (acr is the acrylate anion: C3H3O2) with imidazole derivatives (2-methylimidazole/2-MeIm, 5-methylimidazole/5-MeIm, 2-ethylimidazole/2-EtIm) of type: cis-[Cu(2-RIm)2(acr)2]·xH2O ((1): R = ⁻CH3, x = 2; (4): R = ⁻CH2⁻CH3, x = 0), trans-[Cu(2-RIm)2(acr)2] ((2): R = ⁻CH3; (5): R = ⁻CH2⁻CH3) and trans-[Cu(5-RIm)2(acr)2] ((3): R = ⁻CH3) have been prepared and characterized by elemental analysis, Fourier Transform Infrared spectrometry (FTIR), Electron Paramagnetic Resonance (EPR), electronic reflectance spectroscopy, scanning electron microscopy, and mass spectrometry. The single crystal X-ray diffraction study of complexes (2) and (5) reveals that the copper(II) ion is located on an inversion center and show elongated octahedral geometry completed by two coplanar bidentate acrylates and two unidentate imidazole derivatives displayed in trans positions. For complex (4) the single crystal X-ray diffraction shows that the copper(II) ion is in a distorted octahedral environment which can be easily confused with a trigonal prism completed by two bidentate acrylates and two unidentate imidazole derivatives displayed in cis positions. These results indicate the fact that complexes (4) and (5) are the geometric isomers of the same compound bis(acrylate)-bis(2-ethylimidazole)-copper(II). Complexes (1) and (2), as well as (4) and (5), were produced simultaneously in the reaction of the corresponding copper(II) acrylate with imidazole derivatives in methanol solution. Furthermore, in order to be able to formulate potential applications of the obtained compounds, our next goal was to investigate the in vitro antimicrobial activity of the synthesized complexes against Gram-positive and Gram-negative bacteria, as well as fungal strains, of both clinical and ecological importance (biodeterioration of historical buildings). The trans isomers (2) and (5), followed by (4) have shown the broadest range of antimicrobial activity. In case of (1) and (2) isomers, the trans isomer (2) was significantly more active than cis (1), while the cis isomer (4) proved to be more active than trans (5). Taken together, the biological evaluation results indicate that the trans (2) was the most active complex, demonstrating its potential for the development of novel antimicrobial agents, with potential applications in the biomedical and restoration of architectural monuments fields.

Paper electrophoresis is used for the study of equilibria in binary complex systems in solution. The stability constants of ML and ML2 complex species of some metal ions copper(II), manganese(II) and uranyl(II) with -aminobutenoic acid and hydroxyproline were determined at an ionic strength of 0.1 M and 35 ºC. The stability constants of ML and ML2 complex species of metal(II)--aminobutenoic acid and metal(II)–hydroxyproline were found to be [(7.70 plus or minus 0.03, 6.38 plus or minus 0.11), (3.19 plus or minus 0.02, 2.07 plus or minus 0.09), (7.32 plus or minus 0.05, 5.49 plus or minus 0.12)] and [(8.23 plus or minus 0.05, 7.05 plus or minus 0.03), (3.74 plus or minus 0.06, 3.15 plus or minus 0.09), (7.39 plus or minus 0.11, 6.67 plus or minus 0.02)] for copper(II), manganese(II) and uranyl(II) complexes, respectively.

[Display omitted] • A novel distorted square-pyramidal Cu(II)-picolinate complex was synthesized. • The complex-DNA intercalation was studied using in vitro spectroscopic evaluations. • In silico methods were used to study the interaction at the molecular level. • The complex was cytotoxic against the human breast adenocarcinoma (MCF-7) cells. A new mixed-ligand Cu(II) complex formulated as [Cu(dipic)(amp)(H 2 O)].H 2 O (dipic: pyridine-2,6-dicarboxylic acid, amp: 2-amino-4-methylpyridine), was synthesized and structurally characterized by FTIR spectroscopy, CHN analysis, and the single-crystal X-ray crystallographic method. The complex crystallizes in an orthorhombic space group Pna 2 1, and the coordination environment around the metal center was found to be a pentacoordinate CuN 2 O 2 O W distorted square-pyramidal geometry. In order to systematically explore a detailed in vitro and in silico study of the DNA binding of the title complex, various biophysical (UV–Vis absorption spectroscopy, fluorescence, competitive binding with ethidium bromide) and theoretical (DFT, molecular docking simulation, and QM/MM) methods were applied which revealed that the complex could intercalate with the insertion of the amp ligand between the DNA base pairs. The experimental thermodynamic parameters of the interaction revealed the spontaneity of the process and the domination of the hydrophobic interactions in the association and stabilization of the DNA-Cu(II) complex adduct, which was in line with the docking and QM/MM data. In vitro cytotoxic potential of the complex against the human breast adenocarcinoma (MCF-7) cells was examined using MTT assay, which indicated that cancerous cells showed inhibition in presence of the complex. [ABSTRACT FROM AUTHOR]

• Four Cu(II) complexes of NSAIDs drug mefenamic acid reported. • Five ancillary nitrogen donor ligands are used. • Cu(II) in three different coordination geometry. • Thermal studies and EPR studies are also reported. • Anticancer activity evaluated against NCIH-460 and MDAMB cell lines. Four mixed ligand copper(II) complexes bearing mefenamic acid and different heterocyclic nitrogen donor ligands have been synthesized. A direct one-step metal-ligand complexation method was adopted in synthesizing the complexes. These newly formed complexes are [Cu(mef) 2 (imi) 2 ]; CM-1 , [Cu(mef) 2 (py) 2 ]; CM-2 , [Cu 2 (mef) 4 (apy) 2 ].2CH 3 CN; CM-3 , and [Cu(mef) 2 (nic) 2 (C 2 H 5 OH)]; CM-4 (mef = mefenamato, imi = imidazole, py = pyridine, apy = 2-aminopyridine, and nic = nicotinamide). The complexes were characterized by both analytical and spectral methods. FTIR studies confirmed the mefenamato ligand coordinated via a deprotonated carboxylato oxygen atom to the Cu(II) center. The molecular structures of CM-1 and CM-2 showed both are isostructural and exhibit square-planar geometry around Cu(II). CM-3 crystallized in the dimeric form, each Cu(II) is in five-coordinate geometry, with a structural paddle wheel motif. The resulting square pyramidal geometry in CM-4 is due to the ethanol solvent's coordination on the pyramid's axial position. The crystal lattice of the complexes was stabilized by noncovalent interactions such as N-H···O, C-H···O, C H···π, and π···π. The mononuclear complexes were more stable than the dimeric complex CM-3, revealed by thermogravimetric analysis. In addition, the cytotoxic study of the copper (II) complexes on lung carcinoma cells (NCIH-460) and breast cells (MDAMB) were evaluated using MTT dye (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. [Display omitted] [ABSTRACT FROM AUTHOR]

• Synthesis and characterization of complex Cu-tpmen. • Redox properties of complex Cu-tpmen. • Electrocatalytic oxygen reduction by complex Cu-tpmen. • Electrocatalytic water oxidation by complex Cu-tpmen. The development of catalysts for oxygen reduction reaction (ORR) and water oxidation reaction (WOR) is important for promoting the utilization of renewable energy sources. Catalysts based on Earth-abundant metals are low-cost and benefit the widespread use. Herein a mononuclear copper complex [Cu(tpmen)](ClO 4) 2 (Cu-tpmen) of the pentadentate pyridylalkylamine ligand N,N,N'-tris(2-pyridylmethyl)-N'-methylethylenediamine (tpmen) was synthesized and characterized. The electrochemical properties and the catalysis for the ORR and the WOR by Cu-tpmen in aqueous solutions were studied. Cu-tpmen in pH 7.0 0.1 M phosphate buffer solution (PBS) can boost the ORR with an onset potential at 0.47 V versus the reversible hydrogen electrode (RHE), generating mainly H 2 O 2. The foot-of-the-wave analysis showed that turnover frequency (TOF) of the reduction of O 2 to H 2 O 2 mediated by Cu-tpmen was 6.5 × 104 s−1. Meanwhile, Cu-tpmen exhibited catalytic activities for the WOR with the TOF values of 50.9 s−1 (at pH 7.0) and 8.4 s−1 (at pH 10.5). Cu-tpmen was thus a homogeneous bidirectional ORR/WOR catalyst and the reaction mechanisms were proposed. The synergic effect of the flexibility and the electron-donating ability of tpmen benefited the bidirectional catalytic properties of Cu-tpmen. The bidirectional catalytic properties of a copper(II) complex benefited from the synergic effect of the flexibility and the electron-donating ability of the polypyridine ligand. [Display omitted] [ABSTRACT FROM AUTHOR]

• Two copper complexes containing tridentate ligand was synthesized. • The complexes are halochromic, solvatochromic and thermochromic. • Square-pyramid geometry of complex was confirmed by X ray and DFT calculation. • Reversible structural change in solution is responsible for observed chromotropism. Two copper (II) mononuclear complexes with the general formula [Cu(HL)X 2 ], which L = N- 2-ethanolpicolylamine and X = Cl, Br, were synthesized and characterized by elemental analysis infrared, electronic absorption spectroscopy techniques, and conductivity method. The distorted square pyramidal geometry of [Cu(HL)Cl 2 ] was confirmed by the density functional theory level (DFT) calculation and X-ray crystallography. The complexes are soluble in polar solvents and are chromotropic. It was found both complexes have a similar identity in aqueous solution due to dissociation of halides and hydration. Their chromotropism behavior, including solvato-, thermos- and halochromism, was investigated using visible absorption spectroscopy. The original green complex displayed a reversible color change to blue in alkaline and almost colorless in acidic solutions. The pH effect on the visible absorption spectrum of the complex was studied that functions as pH-induced "off–on-off" switches triggered by the deprotonation of ligand in an alkaline aqueous solution and protonation along with loss of the ligand HL in an acidic medium. The complex also exhibited thermochromism and solvatochromism due to solvation and structural change. Further computational analysis of the electronic structure of the complex in different solvents was executed to gain a deeper insight into the properties associated with molecular orbitals. Its electronic spectrum was analyzed, and bands were assigned through the time-dependent density functional theory level (TDDFT) calculation, together with DFT-based molecular modeling [Display omitted] [ABSTRACT FROM AUTHOR]

Three new synthetic terpyridine copper(II) complexes were characterized. The copper(II) complexes induced apoptosis of three cancer cell lines and arrested T-24 cell cycle in G1 phase. The complexes were accumulated in mitochondria of T-24 cells and caused significant reduction of the mitochondrial membrane potential. The complexes increased both intracellular ROS and Ca2+ levels and activated the caspase-3/9 expression. The apoptosis was further confirmed by Western Blotting analysis. Bcl-2 was down-regulated and Bax was upregulated after treatment with complexes 1–3. The in vivo studies showed that complexes 1 – 3 obviously inhibited the growth of tumor without significant toxicity to other organs. Copper(II) complexes 1 – 3 arrested T-24 cell cycle in G1 phase, accumulated in mitochondria of T-24 cells, and caused mitochondria disfunction leading to apoptosis. Complexes 1 – 3 obviously inhibited the growth of tumor without significant toxicity to other organs. [Display omitted] • Cu(II) complexes 1–3 of terpyridine ligands were synthesized and fully characterized. • 1–3 exhibited strong cytotoxic activity against the tested cancer cell lines. • 1–3 arrested T-24 cell cycle in G1 phase. • 1–3 triggered cells apoptosis via disruption of mitochondrial function. • 1–3 effectively inhibited T-24 tumor growth in vivo without significant toxicity. [ABSTRACT FROM AUTHOR]

This article deals with the experimental and theoretical evaluations of N-pyridoxal-salicylic acid hydrazide (H 2 pd-sah) 1 and its mixed-ligand copper(II) complex with 2-methylimidazole, [Cu(pd-sah)(MeImdH)] 2 . The compounds were characterized based on spectral (UV/Vis. IR) methods, powder-XRD, elemental analysis, and molar conductivity measurements. Both compounds' molecular structure and charge analysis were computed through B3LYP with 6-311 G (d, p) and LANL2DZ basic set using the Gaussian 09 W program package. The time-dependent density functional theory (TD-DFT) approach is used in gas-phase electronic transitions of 2 using the LANL2DZ basis set. Also, the computed UV-Vis based upon TD-DFT results and IR spectra were simulated for comparison with the experimental ones. The molecular structure based on theoretical investigation reveals that compound 2 adopts a distorted square planer N 2 O 2 coordination sphere around the Cu(II). The ONO donor atoms of hydrazone moiety and one nitrogen of 2-methylimidazole constitute the N 2 O 2 basal plane. Moreover, the in-vitro antioxidant activity was evaluated by DPPH assay in both compounds. In addition, Molecular docking studies were performed to predict the binding interaction between compound 2 and the Human Serum Albumin HSA (PDB ID: 1H9Z).Communicated by Ramaswamy H. Sarma.

In the title dinuclear Cu II complex, [Cu 2 (NO 3 )(C 24 H 46 N 8 )(H 2 O)](NO 3 ) 3 ·3H 2 O, the two Cu II mol-ecules both have a square-pyramidal geometry, but the ligands in the axial positions are different: a water mol-ecule and a nitrate ion. All nitrate ions, water mol-ecules, and N-H groups are involved in an inter-molecular hydrogen-bond network., (© Ichimaru et al. 2023.)

In the title compound, [Cu(C4H3N2O2)2(H2O)2]·2H2O, the CuII ion is located on an inversion centre and exhibits an axially elongated octahedral coordination geometry. The equatorial plane is formed by two N,O-bidentate 1H-pyrazole-3-carboxylate ligands in a trans configuration. The axial positions are occupied by two water molecules. The mononuclear complex molecules are arranged in layers parallel to the ab plane. Each complex molecule is linked to four adjacent species through intermolecular O—H...O and N—H...O hydrogen bonds that are established between the coordinating water molecules and carboxylate O atoms or protonated N atoms of the organic ligands. These layers are further connected into a three-dimensional network by additional hydrogen bonds involving solvent water molecules and non-coordinating carboxylate O atoms.

The title complex, [Cu(C17H13N2O2)2], crystallizes with two independent molecules in the asymmetric unit. Each CuII atom has a distorted ocahedral coordination environment defined by two N atoms and four O atoms from two tridentate 1-[(E)-(2-methoxyphenyl)diazenyl]naphthalen-2-olate ligands. In the crystal, the two molecules are linked via weak C—H...O hydrogen bonds which in turn stack parallel to [010]. A region of disordered electron density, most probably disordered methanol solvent molecules, was corrected for using the SQUEEZE routine in PLATON [Spek (2015). Acta Cryst. C71, 9–18]. Their formula mass and unit-cell characteristics were not taken into account during refinement.

In the title complex, [Cu2(C8Br4O4)2(C6H16N2)2(H2O)2], the CuII cation is chelated by a tetramethylethane-1,2-diamine ligand and coordinated by a water molecule as well as bridged by two tetrabromophthalate anions in a distorted O3N2 trigonal–bipyramidal geometry. The two symmetry-related tetrabromophthalate anions bridge the two CuII cations, forming a centrosymmetric dinuclear complex in which the Cu...Cu separation is 5.054 (2) Å. Intramolecular classic O—H...O hydrogen bonds and weak C—H...O hydrogen bonds occur in the dinuclear molecule. In the crystal, the molecules are linked by weak C—H...Br and C—H...O interactions into supramolecular chains propagating along the b-axis direction.

The title compound, (C10H21N3)[CuCl4], is composed of one 1-[2-(diethylazaniumyl)ethyl]-3-methylimidazolium dication and a tetrachloridocuprate(II) dianion. The anion adopts a distorted tetrahedral geometry. Bifurcated interionic N—H...Cl hydrogen bonds and several C—H...Cl contacts are observed, leading to a layer-like arrangement of the components parallel to (100).

The title complex, [Cu(C22H19N2O3S2)2], was obtained from the reaction between (Z)-methyl 2-(5-benzylimino-4-benzylcarbamothioyl-3-oxothiolan-2-ylidene)acetate and Cu(NO3)2. The CuII atom is tetracoordinated by two N,S-bidentate ligands, forming a highly distorted tetrahedral environment. The structure displays two intramolecular N—H...O hydrogen bonds.

A new copper(II) complex based on Schiff bases of 3-nitrosalicylaldehyde was synthesized and the crystal was also obtained fortunately. Its structure was well characterized by single-crystal X-ray diffraction and HRMS. The complex showed the strongest binding ability and high selectivity for hydrogen sulfide among other anions (AcO − , H 2 PO 4 − , F − , Cl − , Br − and I − ) at neutral pH in organic-aqueous solutions. The possible mechanism was the copper ion was released and combined with hydrogen sulfide after the anion was added. In addition, the further application of the sensor was applied to hela cells cytotoxicity. The above results indicated the copper(II) complex could be used as a sensor for the detection of HS − in the sample of environment, pharmacy, and etc. More importantly, the copper(II) complex also exhibited effective and wide antibacterial activity. [ABSTRACT FROM AUTHOR]

The interaction of a new macrocyclic copper complex, [CuL(NO 3 ) 2 ] in which L is 1,3,6,10,12,15-hexaaza tricyclo[13.3.1.1 6,10 ] eicosane was investigated in vitro under simulated physiological conditions by multi-spectroscopic techniques and molecular modeling study. The fluorescence spectroscopy and UV absorption spectroscopy indicated the complex interacted with ct-DNA in a groove binding mode while the binding constant of UV–vis and the number of binding sites were 1.0 ± 0.2 × 10 4 L mol − 1 and 1.01, respectively. The fluorometric studies showed that the reaction between the complex with ct-DNA is exothermic (ΔH = 14.85 kJ mol − 1 ; ΔS = 109.54 J mol − 1 K − 1 ). Circular dichroism spectroscopy (CD) was employed to measure the conformational change of DNA in the presence of [CuL(NO 3 ) 2 ] complex. Furthermore, the complex induces detectable changes in the viscosity of DNA. The molecular modeling results illustrated that the complex strongly binds to groove of DNA. Experimental and molecular modeling results showed that Cu(II) complex bound to DNA by a groove binding mode. [ABSTRACT FROM AUTHOR]

Subtle modifications of N-donor ligands can result in complexes with very different compositions and architectures. In the complex catena-poly[[bis{1-[(1 H-benzotriazol-1-yl)methyl]-1 H-imidazole-κ N3}copper(II)]-μ-benzene-1,3-dicarboxylato-κ3 O1, O1′: O3], {[Cu(C8H4O4)(C10H9N5)2(H2O)]·2H2O} n, each CuII ion is six-coordinated by two N atoms from two crystallographically independent 1-[(1 H-benzotriazol-1-yl)methyl]-1 H-imidazole (bmi) ligands, by three O atoms from two symmetry-related benzene-1,3-dicarboxylate (bdic2−) ligands and by one water molecule, leading to a distorted CuN2O4 octahedral coordination environment. The CuII ions are connected by bridging bdic2− anions to generate a one-dimensional chain. The bmi ligands coordinate to the CuII ions in monodentate modes and are pendant on opposite sides of the main chain. In the crystal, the chains are linked by O-H...O and O-H...N hydrogen bonds, as well as by π-π interactions, into a three-dimensional network. A thermogravimetric analysis was carried out and the fluorescence behaviour of the complex was also investigated. [ABSTRACT FROM AUTHOR]

The reaction of copper(II) salts with Bpy-TEMPO and Tpy-TEMPO (Bpy-TEMPO = [2,2′]Bipyridinyl-5,5′-dicarboxylic acid bis-[(2,2,6,6-tetramethyl-1-oxy-piperidin-4-yl)-amide]; Tpy-TEMPO = 2,2,6,6-tetramethyl-4-(2,2′:6′,2″-terpyridin-4′-yloxy)piperidin-1-oxyl) gave dinuclear Bpy-TEMPO-Cu2(1) and mononuclear Tpy-TEMPO-Cu (2), respectively. The Cu(II) complexes were characterized by single crystal X-ray analysis. In1, Cu(II) has a distorted square pyramidal coordination geometry, with a bridging chloride as the axial ligand. The Cu(II) core in2also exhibited a distorted square pyramidal coordination geometry, with one chloride as an axial ligand. Weak interactions such asπ-interactions and hydrogen bonds are observed in both complexes. When applied as catalysts for the oxidation of benzyl alcohol to benzaldehyde in air,1exhibited higher activity than2for reactions in o-xylene at 60°C with DBU as a base. High yield (67%) of benzaldehyde was observed when using1as a catalyst in a solution of o-xylene with DBU at 60°C. [ABSTRACT FROM AUTHOR]

Five complexes, [Cu(L) 2 ]·4.5H 2 O ( 1 ), [Cu(HL) 2 ](NO 3 ) 2 ·CH 3 OH ( 2 ) {[Cu 2 (L) 2 (NO 3 )(H 2 O) 2 ]·(NO 3 )} n ( 3 ), [Cu 2 (HL) 2 (SO 4 ) 2 ]·2CH 3 OH ( 4 ) and [Cu 4 (L) 4 Cl 4 ]·5H 2 O ( 5 ) based on HL (where HL = 2-acetylpyrazine isonicotinoyl hydrazone) have been synthesized and characterized by X-ray diffraction analyses. The counter anion and organic base during the synthesis procedure influence the structures of the complexes efficiently, which generate five complexes as mono-, bi-, tetra-nuclear and one-dimensional structures. The antitumor activities of the complexes 1 – 5 (except for complex 3 with the poor solubility) against the Patu8988 human pancreatic cancer, ECA109 human esophagus cancer and SGC7901 human gastric cancer cell lines are screened by MTT assay. The results indicate that the chelation of Cu(II) with the ligand is responsible for the observed high cytotoxicity of the copper(II) complexes and the 1:2 copper species 1 and 2 demonstrate lower antitumor activities than that of the 1:1 copper species 4 and 5 . In addition, the in vitro apoptosis inducing activity of the copper(II) complex 5 against SGC7901 cell line is determined. And the results show that the complex can bring about apoptosis of the cancerous cells in vitro . [ABSTRACT FROM AUTHOR]

A novel linear centrosymmetric trinuclear copper(II) Schiff base complex with the chemical formula [{Cu(μ-L)(H 2 O)(μ-NO 3 )} 2 Cu]·H 2 O, where L = N,N′ -bis(2-hydroxy-4-methoxybenzophenone)-2,2-dimethyl-1,3-propanediamine, was synthesized and characterized by elemental analyses, FT-IR spectroscopy, TG-TA and X-ray crystallography. Single X-ray diffraction analysis revealed four μ-phenoxido- and two μ-NO 3 − bridges in the complex. The equatorial plane of the three linearly arranged copper(II) atoms is formed by oxygen and nitrogen atoms of two anionic tetradentate Schiff base ligands, each of them coordinated to one of the terminal copper(II) ions. The central copper(II) ion is located in an inversion centre and bonded to four μ-oxygen atoms of the same ligand. Thermogravimetric analysis of the complex revealed its thermal stability and decomposition pattern. Finally, the complex was used for the preparation of CuO particles by solid state thermal decomposition. [ABSTRACT FROM AUTHOR]

A new complex [Cu(L)(DMF)] ( 1) with benzoic acid (HL) as a ligand is synthesized by the solid phase synthesis method. Crystal data for the complex are as follows: monoclinic, space group P2/ n, a = 10.593(2) Å, b = 10.123(2) Å, c = 16.336(3) Å, β = 93.55(3)°, V = 1748.4(6) Å, D = 1.439 g/cm, Z = 4, F(000) = 780, GOOF = 1.003, final discrepancy factors R = 0.0624, wR = 0.1559. In 1, the Cu(II) ion is coordinated by six oxygen atoms to give a distorted octahedral coordination geometry. The electrochemical, fluorescent, and magnetic properties of 1 are studied. The results show that the electron transfer of 1 is quasi reversible in the electrode reaction corresponding to Cu(II)/Cu(I), and 1 exhibits three relatively strong fluorescent emission peaks at 403, 425, and 454 nm. In addition, complex 1 displays antiferromagnetism in a temperature range of 300 ~ 10 K. [ABSTRACT FROM AUTHOR]

The mononucleating hydrazone ligand LH3, a condensation product of salicyloylhydrazine and (2-formylphenoxy)acetic acid, was synthesized and its coordination behavior with first row transition metal(II) ions was investigated by isolating and elucidating the structure of the complexes using elemental analysis, conductivity and magnetic susceptibility measurements, as well as IR, 1H-NMR, electronic and EPR spectral techniques. The ligand forms mononuclear metal(II) complexes of the type [CoLH(H2O)2], [NiLH(H2O)2, [CuLH] and [ZnLH]. The ligand field parameters, Dq, B and b values, in the case of the cobalt and nickel complexes support not only the octahedral geometry around the metal ion, but also imply the covalent nature of the bonding in the complexes. The EPR study revealed the presence of a spin exchange interaction in the solid copper complex and the covalent nature of the bonding. The 1H-NMR study of the zinc(II) complex indicated the non-involvement of the COOH group in the coordination. The physico-chemical study supports for the presence of octahedral geometry around cobalt(II), nickel(II) and tetrahedral geometry around copper(II) and zinc(II) ions.

A series of 2,2′:6′,2″-terpyridine (TPY) based aromatic heterocyclic compounds, extended by thiophene, 4-dibenzothiophene, and thiazole units at theparaposition of the central pyridine ring in TPY, are described in this paper. A new compound, 4′-(4′-dibenbenzothiophene-5-thiophene-2-yl)-2,2′:6′,2″-terpyridine (La), serves as a tridentate ligand to react with Cu(NO3)2·3H2O and CuCl2·2H2O, respectively, to produce two different Cu(II) complexes [Cu(La)2](NO3)2and [CuLaCl2] with 1 : 2 and 1 : 1 metal/ligand ratios. Dibenzothiophene is first introduced to TPY via the thiophene bridge. The alterations incisandtransconfiguration, dihedral angles between adjacent aromatic rings, and photophysical properties have been observed before and after Cu(II) complexation, which has been verified by their crystal structures, UV–vis and fluorescence spectra. [ABSTRACT FROM AUTHOR]

Employing 1-(2-methoxybenzyl)-2-(2-methoxyphenyl)-1H-benzimidazole (bpb) as a monodentate ligand, a new greenish-blue copper(II) complex, [Cu(bpb)2(NO3)2] (1a), has been synthesized.1ahas been characterized analytically and spectroscopically. The X-ray crystal structure of1areveals that it adopts acisdisposition with respect to the ligands. The solid state structure of1ais stabilized by intramolecular offset face-to-faceπ–πstacking. Non-covalent supramolecular edge-to-face C–H⋯πinteractions with neighboring molecules give 1-D supramolecular chains that further lead to the formation of an assembled 3-D supramolecular metal-organic framework via hydrogen bonding interactions.1ashows blue fluorescence most likely due to intramolecular offset face-to-faceπ–πstacking. At room temperature,1ais one-electron paramagnetic. It shows a rhombic EPR spectrum withg1 = 2.12,g2 = 2.42, andg3 = 2.52 in the solid state at liquid nitrogen temperature. In cyclic voltammetry,1adisplays a one-electron oxidative Cu(II)/Cu(III) couple. Our DFT calculations, corroborate the observed experimental results of1a. [ABSTRACT FROM AUTHOR]

The development of coordination complexes to activate hydrogen peroxide (H 2 O 2 ) selectively is a goal that has long been pursued. As highly reactive intermediates, the high-valent metal-oxo species play important roles in many biological and industrial catalytic oxidation processes. To improve the catalytic efficiency of metal complexes, the peroxide O O bond should be cleaved heterolytically to decrease the decomposition of H 2 O 2 into O 2 and H 2 O. In this work, we provide a simple method to obtain coordination complex catalysts based on iminodiacetic acid (IDA), copper(II) ions and pyridine derivatives. Catalytic activity tests showed that the introduction of 4-aminopyridine ligands resulted in an enhanced catalytic activity of the IDA/Cu(II)/4-ampy complex. A series of designed experiments proved that high-valent copper-oxo species ([ O Cu III (IDA)(4-ampy) 2 ] species) were formed in the IDA/Cu(II)/4-ampy complex system in the presence of hydrogen peroxide. The [ O Cu III (IDA)(4-ampy) 2 ] species were detected by in-situ high-definition electrospray ionization mass spectrometry, and has been considered as the possible active species during H 2 O 2 activation catalyzed by the IDA/Cu(II)/4-ampy complex (with the molar ratio of IDA/Cu(II)/4-ampy being greater than 1:1:2). A mechanism has been proposed based on the results of electron paramagnetic resonance and density functional theory calculations. [ABSTRACT FROM AUTHOR]

The reactions of copper(II) chloride dihydrate and three bulky Schiff base ligands derived from rimantadine and salicylaldehyde (or methoxy-substituted salicylaldehydes), generated C38H48CuN2O2(1), C40H52CuN2O4(2), and C40H52CuN2O4(3), respectively. These complexes were characterized by infrared spectra, UV–vis, elemental analysis and molar conductance. X-ray single-crystal diffraction analysis reveals that1has two different spatial configurations,1aand1b. For1a, each asymmetric unit consists of one mononuclear copper(II) molecule. For1b, each asymmetric unit consists of two copper(II) mononuclear molecules. All the complexes crystallize in the monoclinic system,P21/cspace group for1aand2;P21/nspace group for1b;C2/cspace group for3. Each complex for1–3consists of one copper(II) and two corresponding deprotonated ligands. The central copper(II) in all complexes is four-coordinate via two nitrogens and two oxygens from the corresponding Schiff base ligands. The geometry around copper in1a,1b,and2is distorted square planar, but square planar in3. [ABSTRACT FROM PUBLISHER]

New dimer complexes of zinc(II), copper(II) and nickel(II) were synthesized using the Schiff base ligand which was formed by the condensation of 2-aminothiophenol and 2-hydroxy-5-methyl benzaldehyde. This tridentate Schiff base ligand was coordinated to the metal ions through the NSO donor atoms. In order to prevent the oxidation of the thiole group during the formation of Schiff base and its complexes, all of the reactions were carried out under an inert atmosphere of argon. The X-ray structure of the Schiff base ligand showed that in the crystalline form the SH groups were oxidized to produce a disulfide Schiff base as a new double Schiff base ligand. The molar conductivity values of the complexes in dichloromethane implied the presence of non-electrolyte species. The fluorescence properties of the Schiff base ligand and its complexes were also studied in dichloromethane. The products were characterized by FT-IR, 1 H NMR, UV/Vis spectroscopies, elemental analysis, and conductometry. The crystal structure of the double Schiff base was determined by single crystal X-ray diffraction. Furthermore, the density functional theory (DFT) calculations were performed at the B3LYP/6-31G(d,p) level of theory for the determination of the optimized structures of Schiff base complexes. [ABSTRACT FROM AUTHOR]

Two new one dimensional (1D) cyanide complexes, namely [M(4-aepy) 2 (H 2 O) 2 ][Pt(CN) 4 ], (4-aepy = 4-(2-aminoethyl)pyridine M = Cu(II) ( 1 ) or Zn(II) ( 2 )), have been synthesized and characterized by vibrational (FT-IR and Raman) spectroscopy, single crystal X-ray diffraction, thermal and elemental analyses techniques. The crystallographic analyses reveal that 1 and 2 are isomorphous and isostructural, and crystallize in the monoclinic system and C2 space group. The Pt(II) ions are coordinated by four cyanide-carbon atoms in the square-planar geometry and the [Pt(CN) 4 ] 2− ions act as a counter ion. The M(II) ions display an N 4 O 2 coordination sphere with a distorted octahedral geometry, the nitrogen donors belonging to four molecules of the organic 4-aepy that act as unidentate ligands and two oxygen atoms from aqua ligands. The crystal structures of 1 and 2 are similar each other and linked via intermolecular hydrogen bonding, Pt⋯π interactions to form 3D supramolecular network. Vibration assignments of all the observed bands are given and the spectral features also supported to the crystal structures of the complexes. [ABSTRACT FROM AUTHOR]

In an effort to better understand the biological efficacy of the tridentate aroyl hydrazone Cu(II) complexes, the Cu(II) complex of di-2-pyridyl ketone isonicotinoyl hydrazone ligand (HL), {[Cu(L)(HO)]·HO·NO} ( C1) was synthesized and characterized. Single crystal X-ray study reveals that complex C1 forms 1D zigzag chains in solid state. In water, the hydrolysis of the 1D zigzag chains was observed, and finally formation of monomeric species. In vitro studies revealed that complex C1 showed significantly more anticancer activity than the ligand alone. Investigation of the anticancer mechanisms of C1, confirmed that the Cu(II) complex exhibit a strong capacity to promote productions of reactive oxygen species (ROS), leading to caspase-dependent apoptotic cell death. [ABSTRACT FROM AUTHOR]

Three mononuclear Cu(II) complexes Cu(HL 1 )Cl 2 ( 1 ), Cu(HL 2 )Cl 2 ( 2 ), and Cu(L 3 )SCN ( 3 ) have been synthesized based on chelating hydrazone ligands HL 1 , HL 2 , and HL 3 , respectively. These new compounds gave satisfactory IR-spectroscopic data and were further characterized by elemental and X-ray diffraction analyses. Their urease inhibitory evaluation was tested in vitro against jack bean urease. The results showed that the inhibitory activities of the copper complexes are all superior to the positive reference. Enzyme kinetics studies were undertaken to estimate the inhibition mechanism of the copper complexes. Molecular docking simulations have been performed to rationalize their binding models. In addition, their interactions with serum albumin were also studied. [ABSTRACT FROM AUTHOR]

The coordination compound of the antihypertensive ligand irbesartan (irb) with copper(II) (CuIrb) was synthesized and characterized by FTIR, FT-Raman, UV-visible, reflectance and EPR spectroscopies. Experimental evidence allowed the implementation of structural and vibrational studies by theoretical calculations made in the light of the density functional theory (DFT). This compound was designed to induce structural modifications on the ligand. No antioxidant effects were displayed by both compounds, though CuIrb behaved as a weak 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenger (IC = 425 μM). The measurements of the contractile capacity on human mesangial cell lines showed that CuIrb improved the antihypertensive effects of the parent medication. In vitro cell growth inhibition against prostate cancer cell lines (LNCaP and DU 145) was measured for CuIrb, irbesartan and copper(II). These cell lines have been selected since the angiotensin II type 1 (AT1) receptor (that was blocked by the angiotensin receptor blockers, ARB) has been identified in them. The complex exerted anticancer behavior (at 100 μM) improving the activity of the ligand. Flow cytometry determinations were used to determine late apoptotic mechanisms of cell death. Graphical Abstract: Experimental and DFT characterization of an irbesartan copper(II) complex has been performed. The complex exhibits low scavenging activity against DPPH and significant growth inhibition of LNCaP and DU 145 prostate cancer cell lines. Flow cytometry determinations were used to determine late apoptotic mechanisms of cell death. This compound improved the antihypertensive effect of irbesartan. This effect was observed earlier for the mononuclear Cu-candesartan complex, but not in structurally modified sartans forming dinuclear or octanuclear Cu-sartan compounds. [ABSTRACT FROM AUTHOR]

To construct the model of metallohydrolase, two inclusion complexes [MLCl 2 (β-CD)] ( 1 , M = Zn(II); 2 , M = Cu(II); L = N,N′ -bis(2-pyridylmethyl)amantadine; β-CD = β-cyclodextrin) were synthesized by mixing β-CDs with the pre-synthesized complexes G1 , [ZnLCl 2 ] and G2 , [CuLCl 2 ]. Structures of G1 , G2 , 1 and 2 were characterized by X-ray crystallography, respectively. In solution, two chloride anions of G1 and G2 underwent ligand exchange with solvent molecules according to ESI-MS analysis. The chemical equilibrium constants were determined by potentiometric pH titration. The kinetics of bis(4-nitrophenyl) phosphate (BNPP) hydrolysis catalyzed by G1 , G2 , 1 and 2 were examined at pHs ranging from 7.50 to 10.50 at 308 ± 0.1 K. The pH profile of rate constant of BNPP hydrolysis catalyzed by 1 exhibited an exponential increase with the second-order rate constant of 2.68 × 10 − 3 M − 1 s − 1 assigned to the di-hydroxo species, which was approximately an order of magnitude higher than those of reported mono-Zn(II)-hydroxo species. The high reactivity was presumably hydroxyl-rich microenvironment provided by β-CDs, which might effect in stabilizing either the labile zinc-hydroxo species or the catalytic transition state. [ABSTRACT FROM AUTHOR]

The human topoisomerase IB inhibition and the antiproliferative activity of 3-(4-bromophenyl)-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone HPyCT4BrPh alone and its copper(II) complex [Cu(PyCT4BrPh)Cl] was investigated. [Cu(PyCT4BrPh)Cl] inhibits both the DNA cleavage and religation step of the enzyme, whilst the ligand alone does not display any effect. In addition we show that coordination to copper(II) improves the cytotoxicity of HPyCT4BrPh against THP-1 leukemia and MCF-7 breast cancer cells. The data indicate that the copper(II) thiosemicarbazone complex may hit human topoisomerase IB and that metal coordination can be useful to improve cytotoxicity of this versatile class of compounds. [ABSTRACT FROM AUTHOR]

Stable Cu(II) and Mo(VI) complexes with the Schiff base ligand 3-methoxy-2-hydroxobenzaldehyde S -ethyl-isothiosemicarbazone (H 2 L) were prepared in good yields. The complexes were fully characterized by analytical and spectroscopic techniques. Single-crystal X-ray crystallography reveals the copper and molybdenum complexes have distorted square planar and octahedral geometries respectively. H 2 L acts as a tridentate ONN donor ligand. The ligand is presented in mono-negative (amido) and di-negative (imino) forms in the Cu(II) and Mo(VI) complexes respectively. The thermogravimetric analysis of the complexes shows CuO and MoO 3 as residues. The computed parameters from DFT calculations for structure optimizations and vibrational frequencies are in good agreement with the experimental data. The NBO calculations show the majority of the electron density of the donor atoms tends to be on the central atoms since the calculated formal charges for the central Cu(II) and Mo(VI) ions are much smaller than +2 and +6. [ABSTRACT FROM AUTHOR]

A novel one-dimensional (1D) coordination polymer, {[Cu(hmpH) 2 Cu(hmp)(hmpH)Co(μ-CN) 4 (CN) 2 ]·2H 2 O} n ( 1 ) (hmpH = 2-pyridinemethanol), was synthesized and characterized by elemental analysis, spectral (FT-IR, Raman and EPR) methods, thermal analysis, single crystal X-ray diffraction and magnetic measurement techniques. In 1 , the Co(III) ions are six coordinated with six cyanide-carbon atoms in a octahedral arrangement. The Cu1 and Cu2 ions are coordinated with two cyanide-nitrogen atom, two nitrogen and two oxygen atoms from chelating two hmpH and hmpH/hmp ligands, respectively. The hmpH ligand in the complex has behaved as both anionic ligand (with its hydroxyl group being deprotonated) and as neutral form with the preserved OH group. The hydrogen bonding interactions between the crystal water molecules and hydroxyl group of hmpH ligands extends structure to the two dimensional (2D) supramolecular structure. The 2D layers were extended into 3D supramolecular networks by π⋯π and C–H⋯π interactions between pyridine rings of hmpH ligands. Variable temperature magnetic susceptibility measurement recorded in the 10–300 K range showed the presence of a very small antiferromagnetic within chains through CN bridges. Thermal stability and decomposition reactions of the complex take place in the temperature range 30–950 °C in a dry air atmosphere. [ABSTRACT FROM AUTHOR]

To evaluate the biological preference of chiral drug candidates for molecular target DNA, the synthesis and characterization of a chiral copper(II) complex ( 2 ) of a chiral ligand N , N ′-(pyridin-2-ylmethylene) dehydroabietylamine ( 1 ) was carried out. The interactions of 1 and 2 with salmon sperm DNA were investigated by viscosity measurements, UV, fluorescence and circular dichroism (CD) spectroscopic techniques. Absorption spectral, emission spectral and viscosity analysis reveal that 1 and 2 interacted with DNA through intercalation and 2 exhibited a higher DNA binding ability. In the absence/presence of ascorbic acid, 1 and 2 cleaved supercoiled pBR322 DNA by single-strand and 2 displayed stronger DNA cleavage ability. In addition, in vitro cytotoxicity of 1 and 2 against HeLa, SiHa, HepG-2 and A431 cancer cell lines study show that they exhibited effective cytotoxicity against the tested cell lines, notably, 2 showed a superior cytotoxicity than the widely used drug cisplatin under identical conditions, indicating it has the potential to act as effective anticancer drug. Flow cytometry analysis indicates 2 produced death of HeLa cancer cells through an apoptotic pathway. Cell cycle analysis demonstrates that 2 mainly arrested HeLa cells at the S phase. The study represents the first step towards understanding the mode of the promising chiral rosin-derivative based copper complexes as chemotherapeutics. [ABSTRACT FROM AUTHOR]

Binary [Cu(PAIC)(H 2 O) 2 ]·H 2 O ( 1 ) and mixed ligand [Cu(PAIC)(L)]·2H 2 O complexes, where PAIC = phenylalanine imidazole carboxylic acid, L = diimine coligands [2,2′-bipyridine (bpy) ( 2 ) and 1,10-phenanthroline (phen) ( 3 )] have been synthesized and fully characterized by analytical and spectral techniques. The X-ray structure of [Cu(PAIC)(phen)]·2H 2 O ( 3 ) shows a N 4 O coordination with square pyramidal geometry around the copper (II) atom. The spin Hamiltonian parameters calculated for the complexes account for the distorted square planar structure and rules out the possibility of a trigonal bipyramidal structure. Interaction of the complexes ( 1–3 ) with calf thymus DNA (CT DNA) was studied by using different techniques (absorption titration, fluorescence quenching and thermal melting) and the studies suggest that these complexes bind to CT DNA through intercalation. The DNA-binding affinity of the complexes has further been explained by DFT computational results. Binding activity of Bovine serum albumin (BSA) reveals that the complexes can strongly quench the intrinsic fluorescence of BSA through a static quenching mechanism. DNA cleavage experiments using plasmid DNA pUC 19 show that the complexes exhibit efficient chemical nuclease activity even in the absence of any external additives. The cytotoxicity of the complexes against human normal cell line (HBL 100) and human breast cancer cell line (MCF-7) shows that metal complexation of the ligands results in a significant enhancement in the cell death of MCF-7. Finally, docking studies on DNA and protein binding interactions were performed. [ABSTRACT FROM AUTHOR]

A new 1-D alternating copper(II) polymer, [Cu2(L)(OAc)4]n(1) (L = 5-chloro-2-(pyridine-2-yl)benzo[d]thiazole), has been isolated and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy, and magnetic susceptibility. The complex crystallized in the triclinic space group P-1,a = 8.2277(16) Å,b = 9.4233(19) Å,c = 15.831(3) Å,α = 103.38(3)°,β = 99.95(3)°,γ = 92.70(3)°,V = 1171.3(4) Å3, and comprises a 1-D polymer linked by three kinds of acetate-bridging modes in an alternating manner. UV–visible and fluorescence spectra revealed that1is bound to CT-DNA in a partial intercalation mode. Through gel electrophoresis assays,1displayed an efficient oxidative cleavage activity on supercoiled plasmid DNA (pUC19) in the presence of H2O2. Magnetic measurements were performed from 2 to 300 K, and the experimental results were satisfactorily reproduced withJ1 = –160 ± 20 cm−1,J2 = 5.8 ± 0.2 cm−1,zJ′ = 0.381 ± 0.005 cm−1andg = 2.1, showing antiferromagnetic coupling between Cu1 and Cu1i, ferromagnetic exchange between Cu2 and Cu2ii, and a weak ferromagnetic molecular field correction accounting for all interspecies interactions. [ABSTRACT FROM AUTHOR]

A new copper(II) complex [Cu(bmbp)Cl]·DMF, where bmbp is 4-butyloxy-2,6-bis(1-methyl-2-benzimidazolyl)pyridine, was synthesized and characterized by X-ray single-crystal structure analysis. The complex crystallizes in triclinic, space group P-1 with a = 8.4551(3) Å, b = 12.8262(4) Å, c = 14.7111(5) Å, α = 64.335(3)°, β = 75.314(3)°, γ = 86.749(2)°, V = 1388.42(8) Å, Z = 2. The Cu(II) ion adopts a distorted trigonal bipyramidal geometry coordinated by three nitrogen atoms of the ligand and two chloride atoms. TG analysis showed that the complex has high thermal stability. Electrochemical measuring exhibited an irreversible one-electron transfer process. DPPH radical scavenging assay showed that the ligand and its Cu(II) complex exhibited much lower antioxidant activity than that of ascorbic acid. Graphical abstract: [ABSTRACT FROM AUTHOR]

Novel [ L n MCl 2 ] complexes (L n = L A , L B ; M = Co, Cu, Zn) containing the N , N -chelating ligands N , N -bis((1H-pyrazol-1-yl)methyl)cyclopentanamine ( L A ) and N , N -bis((3,5-dimethyl-1H-pyrazol-1-yl)methyl)cyclopentanamine ( L B ) have been synthesized and characterized. The X-ray crystal structures of the Co(II) and Cu(II) complexes revealed that the ligands are coordinated in an N , N , N -tridentate manner, resulting in distorted trigonal bipyramidal geometries through the coordinative interaction of the nitrogen atom of the cyclopentylamine moiety and the metal centers. [ L A ZnCl 2 ] showed a distorted tetrahedral geometry involving a non-coordinative interaction of the N amine atom and the Zn(II) center, resulting in the formation of an eight membered chelate ring. [ L A CoCl 2 ] exhibited the highest catalytic activity (7.67 × 10 4 g PMMA/mol Co h) for the polymerization of MMA in the presence of MMAO at 60 °C and yielded PMMA with a high molecular weight ( M w ) (11.2 × 10 5 g/mol) and narrower polydispersity index (PDI) 1.01 compared to its Cu(II) and Zn(II) analogs. Syndiotactic enriched PMMA was obtained with T g in the range 120–132 °C. The introduction of bulky methyl substituents played an influential role on controlling the catalytic activities while the syndiotacticities remained unaffected. [ABSTRACT FROM AUTHOR]

In an effort to better understand the biological efficacy of the tridentate aroyl hydrazone Cu(II) complexes, three Cu(II) complexes of acetylpyridine benzoyl hydrazone (HL), [Cu(L)(NO 3 ) (H 2 O)]·H 2 O ( C1 ), [Cu(L) 2 ] ( C2 ) and [Cu(L)(HL)]·(NO 3 )(Sas) ( C3 ) (Sas = salicylic acid) were synthesized and characterized. X-ray crystal structures and infrared (IR) spectra of the complexes reveal that the L − ligand of C1 and C2 are predominantly in the enolate resonance form, while one L − ligand in C3 is represented enolate resonance form and the other HL ligand exhibits keto resonance form. All Cu(II) complexes showed significantly more anticancer activity than the ligand alone. Interestingly, the Cu complexes where the ligand/metal ratio was 1:1 ( C1 ) rather than 2:1 ( C2 and C3 ) had higher antitumor efficacy. Moreover, the 1:1 Cu/ligand complex, C1 , promotes A549 cell apoptosis possibly through the intrinsic reactive oxygen species (ROS) mediated mitochondrial pathway, accompanied by the regulation of Bcl-2 family proteins. [ABSTRACT FROM AUTHOR]

The title compound, [Cu4(CH3COO) 6 (C16H23N2O)2], lies across a twofold rotation axis. The asymmetric unit contains two independent CuII ions. The symmetry-unique terminal CuII ion is O,N,N'-coordinated by a 2-{[(2,2,6,6-tetramethylpiperidin-4-yl)imino]meth-yl}phenolate ligand and an O atom from an acetate group in a slightly distorted square-planar coordination environment. The symmetry-unique central CuII ion is coordinated by a different O atom from the same acetate group and by four bridging acetate ligands, which connect the asymmetric unit into a dimeric complex and form a distorted square-pyramidal coordination environment. Within the complex there are two symmetry-equivalent intramolecular N--H⋯O hydrogen bonds. In the crystal, weak C--H⋯O hydrogen bonds link the complex molecules, forming a three-dimensional network. [ABSTRACT FROM AUTHOR]