Copper Complexes Research Articles

Complexes of Copper(II) and Adenine at Various pH: Synthesis and Characterization

The coordination of Cu(II) ion with purine base is pH dependent and versatile. This study describes the synthesis, structuralcomponents and coordination behavior of Cu(II) with adenine. Three complexes of Cu(II) with adenine have been preparedat different pH in aqueous solution and ambient conditions. All synthesized complexes are polycrystalline solids of variouscolors, air-stable and partially soluble in polar solvents. The complexes were characterized by numerous analytical techniques including compositional analyses, Fourier transform infrared and UV-visible analyses, and thermal investigation. The elemental analyses of the complexes established their chemical composition as [Cu(adeninium)Cl3], [Cu(adenine)(H2O)Cl2] and [Cu(H2O)2(adeninato)2]. Analytical results suggest that the adenine nucleobase could act as a cationic (pH: 5), or a neutral (pH: 7), or an anionic (pH: 8) monodentate ligand in pH facilitated aqueous solution. In the structure, the purine moiety, chloride ion and aqua groups are situated around the copper(II) center is basically in a tetrahedral arrangements. Protonation or deprotonation of the adenine and intramolecular interligand hydrogen bond assisted the pH dependent versatile coordinating behavior of purine base. Dhaka Univ. J. Sci. 72(2): 84-90, 2024 (July)

A series of DNA targeted Cu (II) complexes containing 1,8-naphthalimide ligands: Synthesis, characterization and in vitro anticancer activity

Copper(II) complexes are very promising candidates for platinum-based anticancer agents. Herein, three Cu (II) complexes (1–3) containing 1,8-naphthalimide ligands were synthesized and characterized by FT-IR, elemental analysis, ESI-MS and single crystal X-ray diffraction (complex 3). In addition, a control compound (complex 4) without 1,8-naphthalimide ligand was synthesized and characterized. The in vitro anticancer activity of the synthesized complexes against five cancer cell lines and one normal cell line was evaluated by MTS assay. The results displayed the antitumor activity of complexes 1–3 was controlled by the aliphatic chain length of ligands, their cytotoxicity was in the order 3 > 2 > 1, giving the IC50 values ranging from 2.874 ± 0.155 μM to 31.47 ± 0.29 μM against five cancer cell lines. Complex 4 showed less activity in comparison with complex 1–3. Notably, complexes 1–3 displayed much higher selectivity (SI = 2.65 to 10.16) compared to complex 4 (SI = 1.0), indicated that the introduction of 1,8-naphthalimide group not only increased the activity of this series of compounds but also enhanced their specific selectivity to cancer cells. Compound 3 induced apoptosis in cancer cells and blocked the S-phase and G2/M of cancer cells. The interaction with DNA of complexes 3 and 4 was studied by UV/Vis spectroscopic titrations, competitive DNA-binding experiment, viscometry and CD spectra. The results showed that complex 3 interacted with DNA in an intercalating mode, but the interaction mode of compound 4 with DNA was electrostatic interaction.

Spectroscopic and Electrochemical Studies of Interaction of Cu(II) Ion with Different Aliphatic and Aromatic Amine Based Ligands in Aqueous Solutions

The composition and stability constant of the complexes of copper(II) with the ligands 2,2 –bipyridine, 1,10-phenanthroline, saccharin, and ethylenediamine tetraacetic acid (EDTA),were determined, as well as the effect of temperature on the thermodynamic parameters were studied. The metal-to-ligand ratio in the EDTA complex is found 1:1 and in the rest of the cases, the ratio is 1:2. The redox behavior of the Cu (II) / Cu (0) system in the Cu-ligand complex has been studied in KCl solution as a supporting electrolyte. The redox process of the Cu (II) / Cu (0) system in the Cu-sac complex is almost similar to that of the Cu (II) solution in the absence of any ligand. In other cases, the redox process is a single-step 2-electron transfer process. The electron transfer process in all the cases is diffusion-controlled. The values of peak current ratio and peak potential separation are the evidence that the redox processes are quasi-reversible. Dhaka Univ. J. Sci. 72(2): 61-67, 2024 (July)

Synthesis, Characterization and Antimicrobial Activity of Homonuclear Cu(II) and Ni(II) Schiff Base Complexes

The current study aimed to synthesise, characterise, and investigate the antimicrobial activity of homonuclear Cu(II) and Ni(II) Schiff base complexes. Homonuclear Schiff Base Complexes chelates of Cu(II) and Ni(II) were synthesised. It appears that the complex is a potential metallo-ligand. It forms binuclear complexes when it reacts with two different metal salts, Ni and Cu. Using a Schiff base ligand made from 4-chloro-o-phenylenediamine and 3,5-dichloro-2-hydroxyacetophenone, the homo and hetero binuclear oxygen bridging Cu(II) and Ni(II) complexes were synthesized. Numerous common physicochemical methods, including elemental analysis, spectroscopic, thermal, cyclic voltammetry, and magnetic moment tests, have been used to characterise the synthesised complexes. For the mono- and binuclear compound of Cu(II) & Ni(II), spectral analysis reveals square planer shape. The antibacterial data indicates that the homo-binuclear copper complex is more active than the other mono- and binuclear complexes. Research has been done on the Schiff base and its complexes' anticancer properties.

Local aromatic ring cleaves the global aromatic ring in hexaphyrin(2.1.2.1.2.1)

Novel benzo-bridged hexaphyrin(2.1.2.1.2.1) and its copper complex were synthesized. Single-crystal structures showed typical figure-of-eight Hückel topologies. NMR, NICS, HOMA, ACID, and EDDB analysis supported their non-aromatic properties owning to the strong local aromatic benzo rings cutting the global aromatic ring of the benzo-bridged figure-of-eight hexaphyrin(2.1.2.1.2.1). The redox properties and degenerate HOMOs and LUMOs levels indicate multielectron donating and accepting abilities.

Structural, spectroscopic, fluorescent, and computational studies of binuclear copper (II) and zinc (II) complexes with an asymmetric salamo‐type ligand

Salamo‐type ligand H2L was designed and synthesized and reacted with Cu (II) and Zn (II) acetate, respectively, to obtain two binuclear Cu (II) and Zn (II) complexes: [Cu2(L)2]·2CH3OH (1) and [Zn2(L)2] (2) having the same coordination number but distinct geometries. Complex 1 is a Cu (II) complex containing two crystalline ethanol molecules, where two Cu (II) atoms are surrounded by two utterly deprotonated (L)2− parts, forming slightly twisted tetragonal pyramidal configurations of pentacoordinate. In complex 2, two utterly deprotonated (L)2− parts surround two Zn (II) atoms, forming pentadentate twisted triangular bipyramidal configurations. The complexes were elucidated via IR analyses and ultraviolet spectroscopy. Using DFT theoretical calculation, MEPs, IRI, and Hirshfeld surface analysis to investigate further the molecular interactions and reaction sites. Ultimately, the fluorescence characteristics of H2L and its complexes 1 and 2 were discussed.

Synthesis, structural elucidation, and antibacterial activities of novel copper(II), cobalt(II), and nickel(II) complexes with a bidentate Schiff base ligand against pathogenic bacteria

Novel Schiff base metal complexes diaqua(4-chloro-2-{[(4-(dimethylamino)phenyl)methylene]amino}phenolato)M(II) ion, (M = copper/cobalt/nickel) have been synthesized using the ligand 4-chloro-2-((4-(dimethylamino)benzylidene)amino)phenol, which was prepared by reacting 2-amino-4-chlorophenol with 4-(dimethylamino)benzaldehyde in a molar ratio of 1:1. The synthesized compounds were characterized based on elemental analysis, FTIR, UV–vis., 1H and 13C NMR, powder XRD, mass spectrometry and magnetic studies. Spectroscopic investigations demonstrated that the metal atom coordinates to a bidentate Schiff base ligand via the azomethine nitrogen and phenolic oxygen. The appropriate molecular geometry for each metal complex has been proposed through the analysis of spectroscopic and analytical data, Specifically, tetrahedral geometry has been proposed for Co(II), Ni(II), and square planar geometry for Cu(II) complex. Theoretical calculations employing Density Functional Theory (DFT) validated the experimental results, elucidating optimized geometries, frontier molecular orbitals, natural bond orbital distributions, molecular electrostatic potentials, non-linear optical properties, IR vibrational modes, and UV absorbance profiles. Additionally, the compounds' biological efficacy was validated through molecular docking against receptors for Gram(+ve) bacteria, Bacillus subtilis (PDB ID: 5H67), Staphylococcus aureus (PDB ID: 3TY7) and Gram(-ve) bacteria, Escherichia coli (PDB ID: 3T88), Proteus vulgaris (PDB ID: 5I39). The outcome revealed that Co(II) complex exhibited highest binding energy with Escherichia coli and Bacillus subtilis while the ligand with Proteus vulgaris (5I39) and Staphylococcus aureus (3TY7). Further the study was extended to the MD Simulation in water for 100 ns to evaluate the binding affinities and its stabilities by analyzing the deviation, fluctuations, and intermolecular interactions. The research presented here showcase the potential of employing a Schiff base ligand and its Co(II) complex in the synthesis of novel, highly potent antibacterial agents to combat emerging diseases, which holds considerable importance in the field of pharmaceutical science—however, in-vitro studies are needed to validate the results.

Physico-chemical and Biological Studies of Some Metal Complexes with Fluorinated Chloramphenicol Derivative

Abstract Due to the prevalence of FF, its complexes with (CoII, NiII, and CuII) were prepared, characterized, and the effect of these metal ions on the biological effectiveness of FF was studied. Elemental analysis; IR and 1H-NMR were used to determine the structures and mode of bonding, TGA, and DSC techniques were used to make thermal analysis for the prepared complexes. TGA was used to study the mechanisms of the thermal decomposition for florfenicol complexes. The prepared complexes are thermally stable and started to decompose after 200οC. Broido’s method was used to determine the activation energy for the prepared compounds, while thermal transitions and kinetic studies were carried out by differential scanning calorimetry technique (DSC). The antimicrobial activity of the complexes of florfenicol with different concentrations (0.005, 0.01, 0.02 μg/mL) was examined by the agar prolixity technique against common human pathogenic Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative). Comparatively, Nickel and Copper complexes showed a higher zone of inhibition against the tested pathogens. The antibiotic complexes were more active than the ligand itself for some breeds.

Copper and nickel complexes based on 4-((4-nitrophenyl)diazenyl)-3-(trifluoromethyl)-1H-pyrazol-5-ol; synthesis, characterization, X-ray studies, DFT calculations, molecular docking and antimicrobial activity

Two new copper(II) and nickel(II) complexes were prepared using 4-((4-nitrophenyl)diazenyl)-3-(trifluoromethyl)-1H-pyrazol-5-ol (ndtp) and well-characterized spectroscopically and thermally and via X-ray studies. X-ray studies confirmed the formation of two octahedral complexes, containing two ndtp and two coordinated DMF molecules. The two complexes were evaluated in vitro against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus cereus. [Ni(ndtp)2(DMF)2] showed an enhanced antibacterial activity against the different bacterial strains compared to the free ligand and that of the [Cu(ndtp)2(DMF)2]. The mean inhibition zones exhibited by [Ni(ndtp)2(DMF)2] were 14.7±0.6, 14.0±1.0, and 16.3±0.6 mm against Escherichia coli, Staphylococcus aureus and Bacillus cereus, respectively. Molecular docking studies of the two complexes were performed with DNA gyrase of Escherichia coli (PDB ID: 6F86) to evaluate the potential antibacterial activities, and it was proved that the complexes were efficient for the receptor.

Invasiveness modulation of glioma cells by copper complex-loaded nanoarchitectures

Among the tumors with the highest lethality, gliomas are primary brain tumors associated with common recurrence inclined to metastasize along the neuraxis and occasionally out of the central nervous system. Even though metastasis is the main responsible for death in oncological patients, few dedicated treatments are approved. Therefore, the establishment of effective anti-metastasis agents is the final frontier in cancer research. Interestingly, some copper complexes have demonstrated promising efficacy as antimetastatic agents, but they may cause off-site effects such as the alteration of copper homeostasis in healthy tissues. Thus, the incorporation of copper-based antimetastatic agents in rationally designed nano-architectures can increase the treatment localization reducing the side effects. Here, copper complex loaded hybrid nano-architectures (CuLNAs) are presented and employed to assess the impact of an intracellular copper source on glioma cell invasiveness. The novel CuLNAs are fully characterized and exploited for cell migration modulation in a glioma cell line. The results demonstrate that CuLNAs significantly reduce cell migration without impairing cell proliferation compared to standard gold and copper NAs. A concomitant antimigratory-like regulation of the epithelial-to-mesenchymal transition genes confirmed these results, as the gene encoding for the epithelial protein E-cadherin was upregulated and the other explored mesenchymal genes were downregulated. These findings, together with the intrinsic behaviors of NAs, demonstrate that the inclusion of metal complexes in the nano-architectures is a promising approach for the composition of a family of agents with antimetastatic activity.

Synthesis and characterization of tannic acid–copper complex: A promising anticholinesterase drug

This study aimed to present an optimized synthetic pathway for a complex formed between copper (II) metal ion and tannic acid (TA), which have a variety of pharmacological properties. The study also focused on characterizing this metallodrug, carrying out in vitro antioxidant and acetylcholinesterase enzyme (AChE) inhibition assays, and performing in vivo toxicity assay against zebrafish (Danio rerio), thus expanding the area of study involving syntheses of metal complexes to act as therapeutic agents. Through various characterization techniques, including UV–Vis Absorption Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Thermal Analysis (TG and DTG), 1H Nuclear Magnetic Resonance (1H NMR), Inductively Coupled Plasma with Optical Emission Spectrometry (ICP-OES), and Electron Paramagnetic Resonance (EPR), it was confirmed that the metal ion is coordinated to the ligand, exhibiting distorted planar square geometry with mononuclear copper (3.10 ± 0.10 % copper by ICP-OES). In vitro tests demonstrated that the TA–Cu complex presents antioxidant activity against DPPH (IC50 = 2.26 ± 0.01 µg mL−1) and ABTS (IC50 = 1.91 ± 0.07 µg mL−1) radical scavenging assays. These results were more promising than those obtained for the TA (4.25 ± 0.03 µg mL−1 and 3.37 ± 0.03 µg mL−1, respectively). In the in vitro inhibition of AChE assay, the TA–Cu complex (4.07 ± 0.04 µg mL−1) presented a lower IC50 value than TA (5.80 ± 0.09 µg mL−1), indicating that coordination to the metal center Cu (II) was able to improve the anticholinesterase activity of the free ligand. Furthermore, the TA–Cu complex did not show toxicity in the in vivo test with adult zebrafish for 96 h at the tested doses of 4–40 mg kg−1, with LD50 >40 mg kg−1. Thus, it is estimated that the TA–Cu complex is a metallodrug with anticholinesterase potential, representing a promising strategy for conducting future pre-clinical studies in models of Alzheimer’s disease.

Crafting copper complexes of variable nuclearity and coordination geometry through solvent tailoring: Unveiling novel structure, magnetic insight and computational marvels

The solvent tuning technique has been employed to synthesize two new copper complexes [Cu3(L)(NO3)2(DMSO)4] (1) and [Cu6(L)2(NO3)2(DMF)4(H2O)2(µ-HCOO)2] (2) which display variable nuclearity and coordination geometries. The synthesized complexes further characterized by using spectroscopic, single crystal and powder X-ray diffraction techniques. Supramolecular assembly of the complexes in the solid state is stabilized by a range of intermolecular interactions including O-H⋅⋅⋅O, C-H⋅⋅⋅O, π⋅⋅⋅π and C-H⋅⋅⋅π. Magnetic susceptibility measurements (χT vs T curves) over a wide range of temperature indicate dominant antiferromagnetic interactions between the Cu(II) centres in both complexes, while DFT calculations reveal the nature and amplitude of the main magnetic interactions. Theoretical study further shows strong antiferromagnetic interactions inside the trimeric units of both complexes as well as both weak ferro- and antiferromagnetic interactions among the trimers. The so-obtained J values have been employed to fit the χT vs T curves, using simplified spin models which correctly reproduce the main features of the experimental curves. Thus, this combined experimental and theoretical study provides insight into the magnetic structure of the copper complexes.

Synthesis, Structure, and Properties of a Copper(II) Binuclear Complex Based on Trifluoromethyl Containing Bis(pyrazolyl)hydrazone.

A new complex of copper(II) with methyl-5-(trifluoromethyl)pyrazol-3-yl-ketazine (H2L) was synthesized with the composition [Cu2L2]∙C2H5OH (1). Recrystallization of the sample from DMSO yielded a single crystal of the composition [Cu2L2((CH3)2SO)] (2). The coordination compounds were studied by single-crystal X-ray diffraction analysis, IR spectroscopy, and static magnetic susceptibility method. The data obtained indicate that the polydentate ligand is coordinated by both acyclic nitrogen and heterocyclic nitrogen atoms. The cytotoxic activity of the ligand and complex 1 was investigated on human cell lines MCF7 (breast adenocarcinoma), Hep2 (laryngeal carcinoma), A549 (lung carcinoma), HepG2 (hepatocellular carcinoma), and MRC5 (non-tumor lung fibroblasts). The complex was shown to have a pronounced dose-dependent cytotoxicity towards these cell lines with LC50 values in the range of 0.18-4.03 μM.

Investigation of biological activity of oxindole semicarbazones based copper (II) complexes: Synthesis, antimicrobial activities and molecular modelling

Copper (II) acetate reacted with 2-oxindole semicarbazone (2-Hoxsc, H1L), 3-methyl 2-oxindole semicarbazone (3-MeHoxsc, H2L) and 6-Chloro-2-oxindole semicarbazone (6-ClHoxsc, H3L) in 1:2 (M:L) molar ratio to form complexes of general formula, [Cu(L2)] (1L, 1; 2L 2; 3L 3. Stoichiometric ratio of complexes was established using UV–Vis spectroscopy. All the complexes were characterised by the CHN analysis, IR, ESR spectroscopy and Mass spectrometry. From the ESR spectrum, g values obtained (g‖ = 2.20; g⊥ = 2.05) for complex 2 confirms axial symmetry for this complex, whereas a broad isotropic signal in 1 and 3 (giso = 2.060, 1; 2.057, 3) indicates extensive exchange coupling. All the synthesized compounds (ligands and complexes) complexes were examined for their anti-tubercular activity against M. tuberculosis H37RV strain. Compounds were also tested for their anti-bacterial (B. subtilis, K. pneumonia) and antifungal (C. auris, C. albicans) activities. Biological investigations revealed that the antimicrobial activities (anti-TB, antibacterial and antifungal) of ligands get improved on complexation with Cu (II) due to formation of chelate ring, which can make the ligand a more powerful biological agent. Complex 3 has shown excellent anti-TB (MIC = 1.6 g/ml) and antibacterial (ZOI = 26 mm at 5 mg/mL) activities. Strong binding of complex 3 was observed (Kb = 24.22 × 105 M−1) with Human Serum Albumin (HSA) using fluorescence spectroscopy. Molecular modelling of complex 3 was also done with the active site of amino acid of M. tuberculosis enoyl reductase. The minimal binding energy of −10.1 kcal/mol indicated significant intermolecular interaction between M. tuberculosis enoyl reductase and complex 3 and is in well agreement with experimental data.

Synthesis, crystal structure and Hirshfeld surface analysis of a new copper(II) complex based on diethyl 2,2'-(4H-1,2,4-triazole-3,5-di-yl)di-acetate.

The title compound, bis-[μ-2,2'-(4H-1,2,4-triazole-3,5-di-yl)di-acetato]-bis-[di-aqua-copper(II)] dihydrate, [Cu2(C6H5N3O4)2(H2O)4]·2H2O, is a dinuclear octa-hedral CuII triazole-based complex. The central copper atoms are hexa-coordinated by two nitro-gen atoms in the equatorial positions, two equatorial oxygen atoms of two carboxyl-ate substituents in position 3 and 5 of the 1,2,4-triazole ring, and two axial oxygen atoms of two water mol-ecules. Two additional solvent water mol-ecules are linked to the title mol-ecule by O-H⋯N and O⋯H-O hydrogen bonds. The crystal structure is built up from the parallel packing of discrete supra-molecular chains running along the a-axis direction. Hirshfeld surface analysis suggests that the most important contributions to the surface contacts are from H⋯O/O⋯H (53.5%), H⋯H (28.1%), O⋯O (6.3%) and H⋯C/C⋯H (6.2%) inter-actions. The crystal studied was twinned by a twofold rotation around [100].

Experimental and theoretical studies for instantaneous detection of l-cysteine and l-histidine using a simple Cu(II)-dppy complex

Developing simple and effective receptors for instantaneous detection of l-amino acids is vital for the recognition of life-threatening diseases in their early stage. Here, we report the synthesis and characterization of 2,6-di(pyrazin-2-yl)pyridine (dppy) based ligand L (L = 2,2′-(4-(3,4-diethoxyphenyl)pyridine-2,6-diyl)dipyrazine) and its copper (II) complex, [Cu(NO3)2L]. The in-situ prepared [Cu(H2O)2L](NO3)2 receptor in aqueous acetonitrile (4:1 v/v, 10 mM HEPES buffer, pH 7.4) medium displayed instantaneous responses towards biologically important bio-thiol l-Cysteine (Cys) and essential amino acid l-Histidine (His) over other l-amino acids through UV–Visible absorption spectral studies. Additionally, the competitive experiments confirmed that in-situ prepared [Cu(H2O)2L](NO3)2 receptor selectively detects Cys (1 equivalent) in the presence of other l-amino acids. The detection limits of Cys and His were calculated to be 8.23 × 10−7 M and 2.55 × 10−6 M, respectively. The density functional theory (DFT) calculation shows that selectivity of [Cu(H2O)2L](NO3)2 towards Cys is due to the reduction of Cu(II) to Cu(I) in the presence of Cys, while Cys is oxidized to cystine (Cys-Cys). For His, selectivity observed due to the formation of [Cu(His)2] moiety between Cu(II) ion with one His via N,O coordination mode and another His via N,N,O-coordination mode.

Substituents' Effect on the Photophysics of Trinuclear Copper(I) and Silver(I) Pyrazolate-Phosphine Cages.

A series of structurally similar trinuclear macrocyclic copper(I) and silver(I) pyrazolate complexes bearing various short-bite diphosphine R2PCH(R')PR2 ligands are reported. Upon diphosphine coordination, the planar geometry of the initial complexes undergoes bending along the line between two metal atoms coordinated to the phosphorus moieties. The complexes based on dcpm ligands (R = cyclohexyl, R' = H, Ph) do not exhibit dynamic behavior in solution at room temperature on the 31P NMR time scale as it was previously observed for similar trinuclear copper complexes bearing the dppm (R = Ph, R' = H) scaffold. All copper(I) complexes exhibit thermally activated delayed fluorescence (TADF) behavior in the solid state. Importantly, the use of aliphatic substituents on the phosphorus atoms instead of aromatic ones leads to an almost double increase in the quantum efficiency (ΦPL) of photoluminescence by eliminating nonradiative decay from the 3LCPh states of the dppm aromatic rings. The higher donating ability of the substituents in the pyrazolate ligand (CF3 vs CH3) lowers the energy of the metal-centered excited state, allowing for a significant metal impact on the T1 state. Finally, the Ag(I) complex displays an emission efficiency of approximately 14%, being the highest among known trinuclear silver(I) pyrazolate homometallic derivatives.

Leaching a complex copper–cobalt oxide ore from Zebesha Mine in Zambia, a novel method

The study focused on leaching complex copper–cobalt oxide ore from Zebesha Mine in Zambia. The chemical analysis indicated the presence of cobalt, copper, nickel, manganese and iron as base metals. Copper is predominantly found in malachite and a small portion in heterogenite mineral along with cobalt, iron, manganese and nickel. The leaching process involved using solutions containing iron: ferrous sulphate, FeSO4·7H2O; ferrous ammonium sulphate, (NH4)2Fe(SO4)2·6H2O; and ferric sulphate, Fe2(SO4)3. The effects of temperature and salt concentrations were studied alongside metal content determination through titration-atomic absorption spectroscopy techniques. It was observed that the preferential dissolution of copper occurred with Fe2 (SO4)3 while temperatures above 70°C leaching with FeSO4·7H2O resulted in the recovery of over 80% of manganese and cobalt. This study suggests that ferrous containing lixiviants can effectively promote the manganese and cobalt dissolution but are not efficient for extracting copper. Furthermore, using Fe2(SO4)3 may allow for selective leaching of copper.

Copper(II) Methacrylate Complexes with Imidazole Derivatives-Structural, Spectral and Antitumor Features.

A series of five novel copper(II) complexes with imidazole derivatives having general core Cu(R-Im)2(Macr)2 (Macr = methacrylate anion; R-Im = 2-methylimidazole/2-MeIm, 4-methylimidazole/4-MeIm, 2-ethylimidazole/2-EtIm, 2-isopropylimidazole/2-iPrIm) has been synthesized and characterized by elemental analysis, Fourier Transform Infrared spectroscopy (FTIR), electronic reflectance spectroscopy, cyclic voltammetry, thermal analysis and single crystal X-ray diffraction. All complexes crystalize in a monoclinic crystal system and form a complex supramolecular network developed through hydrogen bonds. The stereochemistry of the copper ion is distorted octahedral except for the compound with 4-methylimidazole for which the geometry is square-pyramidal. The imidazole derivatives act as unidentate while methacrylate ions are chelated except for compound with 4-methylimidazole where is unidentate. All ligands and complexes inhibited B16 murine melanoma cells in a micromolar range, but the complex with 2-isopropylimidazole was more active. Furthermore, all species do not affect the healthy BJ cells in the concentration range used for assays.

Serial triphenylpropionic acid and N,N'-chelator mixed ligands Cu(II) complexes: Structure and biological properties

Three distinct copper(II) complexes were synthesized using 3,3,3-Triphenylpropionic acid (TPPA) and varying N,N'-chelators, resulting in unique structural and biological properties. The complexes [Cu(TPPA)2(Bipy)(H2O)2·(H2O)] (1), [Cu(TPPA)2(Phen)(H2O)2·0.5(H2O)] (2), and [Cu(TPPA)2(MeBipy)·2(C2H3N)] (3) were thoroughly characterized using single-crystal X-ray diffraction, PXRD, FT-IR, and NMR techniques to confirm their distinct geometries and coordination environments (TPPA=3,3,3-Triphenylpropionic acid, Bipy=2,2′-Bipyridine, Phen=1,10-Phenanthroline, and MeBipy=5,5′-Dimethyl-2,2′-Dipyridyl). Hirshfeld surface analysis provided quantitative insights into the molecular interactions within the complexes, while molecular docking studies revealed a strong binding affinity to PI3K kinase, with calculated binding energies of −10.4, −10.5, and −11.7 kcal/mol for complexes 1, 2, and 3, respectively. DNA fluorescence spectroscopy demonstrated significant ct-DNA binding, with the quencher rate coefficients of 0.1278 for complex 1, 0.2664 for complex 2, and 0.2434 for complex 3. When compared to sodium penicillin, which exhibited an OD600 value of 0.06, complex 2 and complex 3 demonstrated moderate antibacterial activity against Staphylococcus aureus with OD600 values of 0.176 and 0.219, respectively. The IC50 values of complexes 1, 2, and 3 in HepG2 cancer cell inhibition assays were determined to be 0.588, 0.357, and 0.397 μM, respectively. These results demonstrate their superior cytotoxicity compared to Cisplatin and Carboplatin. The findings suggest that these complexes may offer promising avenues for further research and development in antimicrobial and anticancer therapies.