Copper Carboxylate Research Articles

In Silico Drug Encapsulation Using 2-Hydroxypropyl-β-CD, Tyrosine Kinase and Tyrosinase Inhibition of Dinuclear Cu(II) Carboxylate Complexes

In recent years, copper carboxylate complexes have garnered significant interest for biological applications. This study focuses on 20 Cu(II) carboxylate complexes selected from our previous research. Due to the hydrophobic nature of these complexes, the 2-hydroxypropyl-β-cyclodextrin (2HPβCD) was employed as a carrier to reduce toxicity and increase solubility for controlling drug delivery. Monte Carlo calculations were performed to confirm the interaction between the optimized structures of Cu(II) complexes and 2HPβCD, forming a host-guest system. All the structures were simulated and optimized using DFT-D calculations in Material Studio 2017. The results indicated that a neutral medium is more favorable for the adsorption of these complexes into 2HPβCD. More negative binding energy values suggested strong and energetically favorable adsorption on 2HPβCD. Complexes 4, 5, and 7 exhibited the highest interaction, making them excellent candidates for drug delivery systems. DFT-D calculations were also used to investigate the release of complexes, revealing that complexes 5, 14, and 19 were difficult to release due to their lowest energy. In contrast, complexes 8, 9, and 16 were found to be most efficient to release due to weak non-covalent interactions with 2HPβCD as we can predict from binding energy obtained by DFT-D. No specific trend was observed in the interaction of the complexes with 2HPβCD. Additionally, the effects of these complexes on c-kit tyrosine kinase and Mushroom tyrosinase were studied by molecular docking. The results demonstrated that all the complexes interacted with the active site of respective receptors through hydrophobic interactions. Complexes containing 1,10-phenanthroline and 2,2-bipyrdine were identified as having a strong, spontaneous binding ability with receptors.

Synthesis, characterization, biological activity, computational evaluation and molecular docking simulation of dimeric Cu(II) carboxylate complexes

Copper(II) carboxylate complexes are important in biological fields. In this study, five new dinuclear Cu(II) complexes having the general formulae [Cu2(Cl-PAA)2(DMSO)2] (1), [Cu2(Cl-PAA)2(phen)2] (2), [Cu2(Cl-PAA)2(bipy)2] (3), [Cu2(Cl-PAA)2(py)2] (4), [Cu2(Cl-PAA)2(Cl-Py)2] (5) were synthesized and characterized by FTIR and UV–Vis spectrophotometry. FTIR study supported the monodentate nature of the carboxylate in complexes 2 and 3 while bidentate bridging behavior of carboxylate was observed in complexes 1, 4 and 5. UV–Vis study revealed the presence of d-d transition in visible region, while charge transfer band was observed in ultraviolet region. Antimicrobial activities of complexes 1–5 were studied among which complexes 1, 2 and 4 showed good activities. The results of antioxidant assay demonstrated that free radical scavenging activity by Cu(II) complex containing 1,10-phenanthroline was higher compared to other complexes. All the synthesized complexes were optimized by DFT-d-based DMol3 module in Material Studio. After that, the quantum chemical parameters containing hardness, softness, and electrophilicity were calculated. Based on value of (ω), complex 2 showed the best biological activity that supported experimental studies. All complexes were investigated by molecular docking with cytochrome P450 14 alpha-sterol demethylase (1ea1), the docking findings demonstrated that complex 2 had the highest interaction with cytochrome P450 due to the biggest interaction energy of complex 2 as compared with other complexes. In addition, according to corrosion studies, complex 2 showed highest coating on the iron (110) surface protecting the iron from corrosion due to high adsorption value.

Synthesis, Structural Elucidation and DNA-Binding Studies of Centrosymmetric Paddlewheel Copper Carboxylate Complexes

Synthesis, Structural Elucidation and DNA-Binding Studies of Centrosymmetric Paddlewheel Copper Carboxylate Complexes

Centrosymmetric homo- and heteroleptic core paddle-wheel copper(II) carboxylates; Syntheses, crystal structures, antioxidant, anticancer and enzyme inhibition activity

Synthesis and characterization of homo- (C5H7N2)2[Cu2(3,5-F2C6H3CH2COO)6] (1) and heteroleptic [Cu2(3,5-F2C6H3CH2COO)4(2-CH3Py)2] (2) core paddle-wheel copper(II) carboxylates is reported in the present work. The characterization was made by spectroscopic techniques, elemental and single crystal XRD analyses. The single crystal XRD analysis revealed a rare homoleptic anionic copper(II) carboxylate complex (1) consisting 2-aminopyridinium counter cations and a neutral heteroleptic copper(II) carboxylate complex (2) consisting 2-methyl pyridine as a co-ligand. The copper ions adopted a distorted square pyramidal geometry in both the paddle-wheel dimeric complexes. To evaluate the biological potency of the synthesized complexes, in vitro antioxidant, enzymes inhibition and anticancer activities were performed. The synthesized complexes have shown overall better biological activity compared to the ligand acid. Complex 2 was the most potent DPPH (IC50 =180.96 ± 9.04 µg/mL) and •OH (IC50 = 189.51 ± 9.33 µg/mL) radicals scavenger, α-amylase (IC50 = 441.86 µg/mL) and acetylcholinesterase (IC50 = 88.62 µg/mL) inhibitor. Furthermore, complex 2 activity against malignant glioma U-87 cell line (IC50 = 21.95 µg/mL) was also highest among the tested compounds. However, complex 1 with an IC50 value of 51.83 µg/mL has shown somewhat better inhibition of the butyrylcholinesterase enzyme compared to the complex 2 (IC50 = 56.36 µg/mL).

Supramolecular hydrogen-bonded networks formed from copper(II) carboxylate dimers.

The well-known copper carboxylate dimer, with four carboxylate ligands extending outwards towards the corners of a square, has been employed to generate a series of crystalline compounds. In particular, this work centres on the use of the 4-hydroxybenzoate anion (Hhba-) and its deprotonated phenolate form 4-oxidobenzoate (hba2-) to obtain complexes with the general formula [Cu2(Hhba)4-x(hba)xL2-y]x-, where L is an axial coligand (including solvent molecules), x = 0, 1 or 2, and y = 0 or 1. In some cases, short hydrogen bonds result in complexes which may be represented as [Cu2(Hhba)2(H0.5hba)2L2]-. The main focus of the investigation is on the formation of a variety of extended networks through hydrogen bonding and, in some crystals, coordinate bonds when bridging coligands (L) are employed. Crystals of [Cu2(Hhba)4(dioxane)2]·4(dioxane) consist of the expected Cu dimer with the Hhba- anions forming hydrogen bonds to 1,4-dioxane molecules which block network formation. In the case of crystals of composition [Et4N][Cu2(Hhba)2(H0.5hba)2(CH3OH)(H2O)]·2(dioxane), Li[Cu2(Hhba)2(H0.5hba)2(H2O)2]·3(dioxane)·4H2O and [Cu2(Hhba)2(H0.5hba)2(H0.5DABCO)2]·3CH3OH (DABCO is 1,4-diazabicyclo[2.2.2]octane), square-grid hydrogen-bonded networks are generated in which the complex serves as one type of 4-connecting node, whilst a second 4-connecting node is a hydrogen-bonding motif assembled from four phenol/phenolate groups. Another two-dimensional (2D) network based upon a related square-grid structure is formed in the case of [Et4N]2[Cu2(Hhba)2(hba)2(dioxane)2][Cu2(Hhba)4(dioxane)(H2O)]·CH3OH. In [Cu2(Hhba)4(H2O)2]·2(Et4NNO3), a square-grid structure is again apparent, but, in this case, a pair of nitrate anions, along with four phenolic groups and a pair of water molecules, combine to form a second type of 4-connecting node. When 1,8-bis(dimethylamino)naphthalene (bdn, `proton sponge') is used as a base, another square-grid network is generated, i.e. [Hbdn]2[Cu2(Hhba)2(hba)2(H2O)2]·3(dioxane)·H2O, but with only the copper dimer complex serving as a 4-connecting node. Complex three-dimensional networks are formed in [Cu2(Hhba)4(O-bipy)]·H2O and [Cu2(Hhba)4(O-bipy)2]·2(dioxane), where the potentially bridging 4,4'-bipyridine N,N'-dioxide (O-bipy) ligand is employed. Rare cases of mixed carboxylate copper dimer complexes were obtained in the cases of [Cu2(Hhba)3(OAc)(dioxane)]·3.5(dioxane) and [Cu2(Hhba)2(OAc)2(DABCO)2]·10(dioxane), with each structure possessing a 2D network structure. The final compound reported is a simple hydrogen-bonded chain of composition (H0.5DABCO)(H1.5hba), formed from the reaction of H2hba and DABCO.

Mesomorphism and Tribotechnical Characteristics of Lubricant Compositions with Mesogenic Additives Carboxylates Cu(II)

The purpose of the work is to characterize the lubricants based on Llitol-24 and synthetic solidol with additives copper(II) carboxylates when using them in friction nodes in loading conditions and temperature. The lubricant compositions with additives copper(II) carboxylates based on synthetic solidol and Litol-24 form the columnar mesophases depending on thermodynamical conditions and concentration of additives.Methods. We study the lubricant compositions with dielectric spectroscopy and и polarization light microscopy. The studies lubricant compositions are tested on the frictional machines by preceding authors, which performed their synthesis and numerical estimations for their geometry parameters. It is shown, that the columnar mesophase formed by the compositions with copper(II) carboxylates simulates favourable tribological conditions for lubrication (reduction of the friction coefficient at the appointed range of additive concentrations and reduction of wear) and unlike to crystalline phases, shows orientation effects at the surface of interacting surfaces of machine elements and devices. These factsmotivate the study of influence of physicochemical properties and composition on mesomorphism of considered lubricant compositions.Results. In our measurements, we found the main dielectric characteristics of two kinds of the lubricant compositions: dielectric constant and dielectric loss, electroconductivity, dissipation factor, the Arrhenius functions are plotted, and the activation energies of the lubricant compositions we study are calculated. The microphotogram for textures of the lubricant compositions depending on temperature and concentrations are received. The differences in mesomorphic properties of the lubricant compositions with additives Cu(II) valerate and isovalerate are confirmed.The conclusion of the work is that the composition of the lubricant is optimized by the choice of additive concentration, the length of the mesogenic chain of the copper(II) carboxylate molecule and its conformation.

Synthesis and characteristics of four new copper(II) carboxylate complexes with adamantane fragment

The paper considers the results of synthesis, elemental analysis, and spectroscopic methods (IR, UV-vis) of four new copper(II) complexes with anions of 1-adamantanecarboxylic acid, 4-(1-adamantyl)benzoic acid and their L-valine derivatives as ligands. Based on the obtained spectral data, the authors assumed the biyaderic structure of these complexes with bidentate coordination of carboxylate ligands of the type [Cu2+2(RCOO-)4(H2O)2], with RCOO-as carboxylate ligands. The synthesised compounds are of interest as low toxic potential therapeutic agents with anti-inflammatory and anti-cancer activity.

Термическое разложение бензоатов и аминобензоатов Mn (II), Co (II), Ni (II), Cu (II)

The article discusses the main methods for obtaining carbon composite nanomaterials and highlights the thermolysis method as one of them. To understand the essence of thermal decomposition processes as a synthesis method for carbon nanomaterials, thermolysis of aromatic carboxylates of such elements as manganese(II), cobalt(II), nickel(II), and copper(II) was considered. The article thoroughly discusses the synthesis procedure for these metal carboxylates under simple conditions. The thermal decomposition process was carried out in two environments (air as oxidizing one and argon as neutral one) to compare the products obtained. For a detailed study of the decomposition processes of manganese(II), cobalt(II), nickel(II), and copper(II) carboxylates, thermal analysis methods (TG and DSC) were used on a Netzsch 449 Jupiter synchronous thermal analyzer. To study the morphology and composition of the products, the methods of X-ray phase analysis, optical and scanning electron microscopy, and X-ray fluorescence microanalysis were used. The devices used were a Rigaku Ultima IV X-ray diffractometer and a scanning electron microscope with a Jeol JSM-7001F. The mechanisms of thermal decomposition of manganese(II), cobalt(II), nickel(II), and copper(II) carboxylates were suggested. For a more accurate determination of the composition of the synthesis products of manganese(II), cobalt(II), nickel(II), and copper(II) carboxylates and for a more accurate description of the processes of thermal decomposition of these salts, the corresponding aromatic carboxylic acids were also thermally decomposed. The appendix to the article presents thermograms of manganese(II), cobalt(II), nickel(II), and copper(II) aromatic carboxylates.

New copper carboxyl-ate pyrene dimers: synthesis, crystal structure, Hirshfeld surface analysis and electrochemical characterization.

Two new copper dimers, namely, bis-(dimethyl sulfoxide)-tetra-kis-(μ-pyrene-1-carboxyl-ato)dicopper(Cu-Cu), [Cu2(C17H9O2)4(C2H6OS)2] or [Cu2(pyr-COO-)4(DMSO)2] (1), and bis-(di-methyl-formamide)-tetra-kis-(μ-pyrene-1-carboxyl-ato)dicopper(Cu-Cu), [Cu2(C17H9O2)4(C3H7NO)2] or [Cu2(pyr-COO-)4(DMF)2] (2) (pyr = pyrene), were synthesized from the reaction of pyrene-1-carb-oxy-lic acid, copper(II) nitrate and tri-ethyl-amine from solvents DMSO and DMF, respectively. While 1 crystallized in the space group P , the crystal structure of 2 is in space group P21/n. The Cu atoms have octa-hedral geometries, with four oxygen atoms from carboxyl-ate pyrene ligands occupying the equatorial positions, a solvent mol-ecule coordinating at one of the axial positions, and a Cu⋯Cu contact in the opposite position. The packing in the crystal structures exhibits π-π stacking inter-actions and short contacts through the solvent mol-ecules. The Hirshfeld surfaces and two-dimensional fingerprint plots were generated for both compounds to better understand the inter-molecular inter-actions and the contribution of heteroatoms from the solvent ligands to the crystal packing. In addition, a Cu2+/Cu1+ quasi-reversible redox process was identified for compound 2 using cyclic voltammetry that accounts for a diffusion-controlled electron-donation process to the Cu dimer.

Synthesis and characterization of a novel copper carboxylate complex and a copper complex-coated polyether sulfone membrane for efficient degradation of methylene blue dye under UV irradiation: the single crystal X-ray structure of the copper carboxylate complex.

Synthesis of a novel binuclear Cu(II) carboxylate complex under ambient laboratory conditions is presented. The complex exhibits a paddle wheel structure in which the axial positions are occupied by two copper atoms instead of two water molecules. The synthesized complex was characterized by single-crystal X-ray crystallography, FT-IR, X-ray diffraction, and UV-visible spectroscopy techniques. The thermal stability of the metal complex was studied by the thermogravimetric analysis study. The synthesized metal complex was employed for the synthesis of metal complex-coated polyether sulfone (PES) membranes which were characterized before and after filtration using the FESEM technique. The photocatalytic efficiency of the metal complex was studied for the degradation of methylene blue dye under UV irradiation in the presence of H2O2 and was compared with the photodegradation efficiency of the metal complex-coated polyether sulfone (PES) membrane.

Designing and Exploration of the Biological Potentials of Novel Centrosymmetric Heteroleptic Copper(II) Carboxylates.

Copper(II) complexes with a general formula [Cu2(3,4-F2C6H3CH2COO)4(L)2], where L = 2-methylpyridine (1) and 3-methylpyridine (2), are reported here. The FTIR spectra of the complexes confirmed the bridging bidentate coordination mode of the carboxylate ligand. The low (475 and 449 cm-1) and strong (727 & 725 cm-1) intensity bands in the FTIR spectra, due to Cu-N stretches and pyridyl ring vibrations, confirmed coordination of the 2-/3-methyl pyridine co-ligands in complexes 1 and 2, respectively. A binuclear paddlewheel structural arrangement with a square pyramidal geometry was confirmed for copper atoms in the complexes via single-crystal X-ray analysis. The DPPH, •OH radical, and α-amylase enzyme inhibition assays showed higher activities for the complexes than for the free ligand acid. The binding constant (Kb = 1.32 × 105 for 1 and 5.33 × 105 for 2) calculated via UV-VIS absorption measurements and docking scores (-6.59 for 1 and -7.43 for 2) calculated via molecular docking showed higher SS-DNA binding potential for 2 compared to 1. Viscosity measurement also reflected higher DNA binding ability for 2 than 1. Both complexes 1 and 2 (docking scores of -7.43 and -6.95, respectively) were found to be more active inhibitors than the free ligand acid (docking score of -5.5159) against the target α-amylase protein. This in silico study has shown that the herein reported compounds follow the rules of drug-likeness and exhibit good potential for bioavailability.

Synthesis, Characterization, DNA Binding and Cytotoxicity of Copper(II) Phenylcarboxylate Complexes

Coordination compounds of copper exhibit cytotoxic activity and are suitable for the search for novel drug candidates for cancer treatment. In this work, we synthesized three copper(II) carboxylate complexes, [Cu2(3-(4-hydroxyphenyl)propanoate)4(H2O)2]·2H2O (C1), [Cu2(phenylpropanoate)4(H2O)2] (C2) and [Cu2(phenylacetate)4] (C3), and characterized them by elemental analysis and spectroscopic methods. Single-crystal X-ray diffraction of C1 showed the dinuclear paddle-wheel arrangement typical of Cu–carboxylate complexes in the crystal structure. In an aqueous solution, the complexes remain as dimeric units, as studied by UV-visible spectroscopy. The lipophilicity (partition coefficient) and the DNA binding (UV visible and viscosity) studies evidence that the complexes bind the DNA with low Kb constants. In vitro cytotoxicity studies on human cancer cell lines of metastatic breast adenocarcinoma (MDA-MB-231, MCF-7), lung epithelial carcinoma (A549) and cisplatin-resistant ovarian carcinoma (A2780cis), as well as a nontumoral lung cell line (MRC-5), indicate that the complexes are cytotoxic in cisplatin-resistant cells.

Infrared spectroscopy reveals the reactivity of fatty acids on copper surfaces and its implications for cultural heritage objects

The reactivities of various fatty monoacids and diacids on copper metal-containing surfaces were investigated through reflection–absorption infrared spectroscopy. The formation of copper carboxylates is detected on pure copper surfaces, while copper and zinc carboxylates are simultaneously formed on brass surfaces. Following the decrease of acid carbonyl and the formation of carboxylate infrared bands, it is shown that fatty monoacids C8 and C10 react with clean/polished copper and its zinc alloy within 2–4 h, while those with chains > C12 react within days. At the end of the processes, only the corresponding metal carboxylates are detected in all cases. An explanation for the above is offered on a molecular mobility and acidity basis, where the lower monoacids (liquids in room temperature), also having lower pKa values, favor higher reaction rates. Furthermore, it is argued that longer-chain fatty monoacids, when deposited from their solutions, allow for favorable orientation resulting in self-assembled monolayer-type molecular packing on the copper surface, which may additionally rationalize the slower reaction. Interestingly, fatty diacids do not form any carboxylate products under the same conditions, as it is argued that their molecules may efficiently pack as self-assembled multilayers on copper and ultimately protect it. The possible implications of the fatty monoacid and diacid behavior on the archaeological organic residues level and regarding the stability of copper alloys are discussed.

Rare coordination behavior of triethanolamine ligand in [Cu(H3tea)2](3,4-dimethoxycinnamate)2·2H2O: Synthesis, characterization, single crystal X-ray structure determination, Hirshfeld calculation and molecular docking studies

Herein, unusual and rare coordination behavior of triethanolamine (H3tea) ligand in copper(II) carboxylate complex; [Cu(H3tea)2](3,4-DMC)2·2H2O; DMC = 3,4-dimethoxycinnamate, has been explored and structurally reported for the first time. Synthesis and crystallization of the complex has been achieved at ambient conditions using methanol-water (4:1 v/v) as a solvent mixture after very slow evaporation. Furthermore, the complex is characterized by elemental analyses, spectroscopic methods (UV–Visible, FT-IR) and structure elucidation has been carried out by single crystal X-ray structure analyses. X-ray structure determination of the complex revealed the presence of [Cu(H3tea)2]2+ as a cation and two moieties of 3,4-dimethoxycinnamate as anions forming a second sphere coordination complex. Various weak (non-covalent) interactions such as CH∙∙∙O, and OH∙∙∙O impart an important role in the lattice stabilization of a second sphere coordination complex. Hirshfeld surface calculations clearly revealed the existence of interplay of non-covalent interactions in lattice stabilization. The theoretical calculation also suggested the total interaction energies in this complex, i.e. 32.6 kj.mol−1. In addition, molecular docking investigations of this complex clearly showed that there is substantial protein-ligand interaction with best binding scores of -7.2, -7.3, -7.9 kcal/mol against 4GKU, 3W4P, 5CGX and -5.8, -7.8 kcal/mol against 4HFZ, 1D5R proteins lesser than parent acid i.e. 3,4-dimethoxycinnamic acid indicating the potential of this complex; [Cu(H3tea)2](3,4-DMC)2·2H2O as antibacterial and anticancer agent respectively.

Synthesis and crystal structure of the copper (II) carboxylate with 2,2-bipyridine, [Cu(4-mba)2(bipy)(H2O)

The new Cu(II) carboxylate complex, aqua(2,2'-bipyridine-κ2N,N')bis(4-methylbenzoato-κO)copper(II) [Cu(4-mba)2(bipy)(H2O)] (4-mba: 4-methylbenzoate, bipy: 2,2'-bipyridine) was synthesized, and the molecular structure of the complex was characterized by the single crystal X-ray diffraction technique. The X-ray diffraction analysis indicated that the asymmetric unit comprises an independent molecule. Crystal data for [Cu(4-meb)2(2,2-bipy)(H2O)]: Triclinic, space group P-1 (no. 2), a = 7.0452(13) Å, b = 11.260(2) Å, c = 16.635(3) Å, α = 103.543(7)°, β = 91.002(7)°, γ = 104.106(6)°, V = 1240.4(4) Å3, Z = 2, T = 296 K, μ(MoKα) = 0.918 mm-1, Dcalc = 1.360 g/cm3, 51364 reflections measured (5.054° ≤ 2Θ ≤ 57.38°), 6258 unique (Rint = 0.0398, Rsigma = 0.0284) which were used in all calculations. The final R1 was 0.0392 (I > 2σ(I)) and wR2 was 0.1021 (all data). The Cu(II) ion was found to be coordinated with two nitrogen atoms of the 2,2'-bipyridine ligand, two oxygen atoms of the 4-methyl benzoate molecule, and one oxygen atom of the aqua ligand. In the three-dimensional supramolecular architecture, molecules are connected through pairs of O-H···O and C-H···O intermolecular interactions, consisting of chains. The molecule also demonstrates Cg···Cg intermolecular interactions between six-membered rings of 2,2'-bipyridine.

Attachable/Detachable Sheets Containing Foam-Rubber Layers with Super Deodorant Functions

Two-layered sheets consisting of a cellulose-nanofibril-containing foam-rubber layer and a base film or nonwoven sheet were developed as attachable/detachable sheets with super deodorant functions. TEMPO-oxidized cellulose nanofibrils with copper carboxylate groups (TOCNs-Cu) were composited with foam-rubber layers, which were coated on base films and sheets. These TOCNs-Cu-containing foam sheets adsorb H2S and NH3 gases well because these gas molecules are chemically or physically trapped by the foam layers. The TOCNs-Cu moieties are primarily located at the air/rubber interfaces in the foam-rubber layer. The peel and tack strengths of the TOCNs-Cu-containing foam sheets are appropriate for manual foam sheet attachment to, and detachment from, flat glass plates and plastic/ceramic boards. The H2S- and NH3-adsorption behaviors are affected by the air permeability of the base film or nonwoven sheet. Transmission electron microscopy images show that TOCNs-Cu aggregates are located at the air/rubber interfaces, which results in super deodorant functions.

CuO Nanoparticls Thermally Synthesized From a Since-Wheel Copper(II) Complex

The broad properties of nanostructured materials based on transition metal oxides have received great attention from researchers. Copper (II) Oxide (CuO) due to its excellent physical and chemical properties, has numerous potential applications. Among the different methods previously reported to prepare CuO nanoparticles (CuO NPs) such as sonochemical, sol-gel, and electrochemical techniques, this study proposes an easeful, simple, and cost-effective method to synthesize CuO NPs by thermal decomposition of a coordination complex i.e., a binuclear copper (II) carboxylate complex.

Synthesis and Crystal Structure of two Copper (II) Carboxylate Complexes with Ethelyenediamine

A new crystal of, [Cu (OH2)2 (en)2] 4-oxidobenzoate and [Cu(OH2)2 (en)2] (3,5-dinitrobenzoate)2 Where (en = ethylenediamine) have- been synthesize, and the resulting complexes has been analyzed on the base of CHN analyses, IR spectral, Electronic spectra, single- crystal X-ray- diffraction method and magnetic susceptibility. In both complexes cations have a distorted octahedral CuN4O2 around copper (II), surrounded by two molecules of ethylenediamine and two water molecules. The cations [Cu (en) 2(OH2)2]2+ of both complexes are associated to carboxylate anions by hydrogen bonding in addition to electrostatic forces.

Synthesis, crystal structure elucidation, DNA-binding and micellization behavior of copper(II) carboxylate complexes

Three new oxygen bridged binuclear and mononuclear copper(II) complexes having general formulae [L2Cu(2,2′-bipyridine)2CuL2] (A), [L′2Cu(2,2′-bipyridine)H2O] (B), [L″2Cu(2,2′-bipyridine)2CuL″2] (C) where L = ortho-nitrophenyl acetate, L′ = para-methoxyphenyl acetate and L″ = para-bromophenyl acetate have been prepared and characterized spectroscopically as well as structurally. The geometry around each Cu(II) ion was found square pyramidal in all the complexes. FT-IR data of the complexes were in agreement with that of the single crystal XRD. Electronic absorption spectra indicated broad absorption bands with λmax = 671, 715 and 700 nm typical of Cu2+ with 2B1g as ground state in A-C, respectively. Crystalline nature of the complexes was ascertained from its powder XRD spectra which showed several peaks in 2θ range 5–30. Electrochemistry yielded two redox pairs conforming to irreversible Cu(III)/Cu(II) and Cu(II)/Cu(I) processes typical of complexes with Cu2+ redox centers. Complex-surfactant interactions were studied via conductometry and absorption spectrophotometry. DNA binding abilities of complexes A-C were studied via absorption spectrophotometry, cyclic voltammetry, spectrofluorometry and viscosity measurement. The former three techniques yielded excellent intrinsic binding constant values for complexes. The excellent DNA-binding potency heralds the biological importance of the synthesized complexes.

Synthesis, structural characterization, DNA interaction, dye adsorption properties and theoretical studies of copper (II) carboxylates

Two new copper (II) carboxylates viz. [Cu2(μ–2-chlorobenzoato-O,O')4(2-methoxybenzaldehyde)2] (1) and [Cu(μ–3,5-dinitrobenzoato-CO,O)(μ–3,5-dinitrobenzoato-NO,O)][Cu2(μ–3,5-dinitrobenzoato-CO,O′)](μ1MeOH)2 (2) containing 2-chlorobenzoic acid and 3,5-dinitrobenzoic acid respectively were synthesized, and characterized by elemental analyses, spectroscopic methods, topological analysis and single crystal XRD studies. Moreover, the synthesized complexes have been screened for the DNA binding ability through UV-Visible and fluorescence spectroscopy indicating moderately strong non-intercalative mode of interaction. Structural studies reveals that compound 1 possesses dinuclear paddle-wheel structure whereas compound 2 is 3D polymer. Asymmetric/monoclinic unit of compound 2 contains a mononuclear unit in combination with a dinuclear entity. DFT calculations combined with QTAIM and NCI plot computational tools have been used to analyze their solid-state supramolecular assemblies focusing on the role of halogen···halogen interactions in 1 and π-hole O···N pnictogen bonding in 2 involving the nitro groups. Finally, the dye adsorption property of the complexes was studied to ascertain their efficacy in removal of toxic dye molecules from aqueous medium. Compound 2 exhibits moderate dye removal efficiency.