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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. [ABSTRACT FROM AUTHOR]

ABSTRACT Novel compounds with pharmacological activity were synthesized from Pd(II), Fe(III), Cr(III), Ni(II), and Cu(II) ions with 1‐cyclopropyl‐6‐fluoro‐4‐(2‐hydroxy‐phenylimino)‐7‐piperazin‐1‐yl‐1,4‐dihydro‐quinoline‐3‐carboxylic acid (CFAP). The ligand's NH and OH groups allowed it to interact with the metals as a neutral tridentate. The investigated novel compounds were described using 1H and 13C NMR spectra, FT‐IR spectrums, TGA and UV–Vis (conductance of molecules), and CHN‐analysis. Additionally, the pH profile of the CFAP complexes indicated great stability, and the complexes' stability constant was discovered in the solution. To extract important properties for CFAP and its complexes, computational research was used, CFAPCu, CFAPCr, CFAPNi, and CFAPFe have octahedral geometry, while CFAPPd has square planar geometry. To investigate the molecular geometry, density functional theory calculations (DFT) were carried out. The molar ratio and continuous fluctuation data confirmed that the (M:L) ratio was (1:1). In vitro tests were conducted to evaluate Schiff base's antimicrobial action ligand and its metal chelates against fungal and bacterial infections. The findings showed that the antimicrobial efficacy is as follows: When CFAPPd is compared to fluconazol and ofloxacin as reference medications, it is the highly inhibitor complex. The novel CFAP ligand and its complexes were investigated for In vitro carcinogenic potential against Hep‐G2, MCF‐7, and HCT‐116 cell lines. As compared to the medication vinblastine, the results once again demonstrated that CFAPPd is the most active agent. Moreover, the complexes demnstrated strong reactivity in capturing free radicals when their antioxidant activity was investigated. Viscosity, spectral investigations, and gel electrophoreses were used to identify the interaction between metal chelates and DNA. Every examined compound is shown to be an enthusiastic DNA binder by viscosity and spectrophotometric titration investigations. The heightened hydrophobic and electrostatic interactions between aromatic rings could be the cause of this. Ultimately, these compounds could be regarded as promising bioactive substances. [ABSTRACT FROM AUTHOR]

AbstractA Schiff base (imine) ligand, (E)-4-((2-hydroxy-3,5-diiodobenzylidene)amino)-N-(4,6-dimethylpyrimidin-2-yl)benzenesulfonamide (HL), was synthesized by condensation of 3,5-diiodosalicylaldehyde with sulfamethazine. The ligand was then complexed with Zn(II), Cu(II), Ni(II), Co(II) and Fe(II) employing a metal to ligand ratio of 1:2 to form chelates (1-5), [M(L)2(H2O)2]. Characterization was done by UV-visible, FTIR, 1H and 13C NMR spectroscopy, elemental analysis, magnetic moments, thermogravimetric analyses (TGA) and conductance studies. The Schiff base behaved as a bidentate ligand and metal chelates assumed octahedral geometry. MOE-docking was employed to assess binding of the Schiff base (HL) and its chelates (1-5) with 1T2P, 1VVQ, 2W61, 3U2D, 4H8E and 5K18 proteins. Results indicated that Zn(II) chelate (1) and Fe(II) chelate (5) are the most potent compounds. Antibacterial and antibiofilm activities were executed against Enterococcus faecalis, Staphylococcus aureus, Proteus mirabilis and Klebsiella pneumoniae. Antifungal activities were performed against Candida albicans and Aspergillus niger. The Schiff base exhibited moderate antibacterial/antifungal activities that were enhanced on chelation with metal ions. Zinc(II) chelate (1) and Fe(II) chelate (5) show excellent antibacterial/antifungal activities. Complex 2 exhibited good antibiofilm activity. [ABSTRACT FROM AUTHOR]

A thiophene-derived Schiff base ligand (E)-2-morpholino-N-(thiophen-2-ylmethylene)ethanamine was used for the synthesis of M(II) complexes, [TEM(M)X2] (M = Co, Cu, Zn; X = Cl; M = Cd, X = Br). Structural characterization of the synthesized complexes revealed distorted tetrahedral geometry around the M(II) center. In vitro investigation of the synthesized ligand and its M(II) complexes showed considerable anti-urease and leishmanicidal potential. The synthesized complexes also exhibited a significant inhibitory effect on urease, with IC50 values in the range of 3.50–8.05 μM. In addition, the docking results were consistent with the experimental results. A preliminary study of human colorectal cancer (HCT), hepatic cancer (HepG2), and breast cancer (MCF-7) cell lines showed marked anticancer activities of these complexes. [ABSTRACT FROM AUTHOR]

A simple, sensitive, and rapid spectrophotometric method for the determination of Cu(II), Ni(II), Co(II), and Mn(II) ions is proposed based on the complexation of metal ions with a synthesized ligand, 4-methylpiperazine dithiocarbamic acid, formed by the reaction of 4-methyl piperazine and carbon disulfide under cold conditions. The colored complex formed by the reaction of the synthesized ligand with these heavy metals in an aqueous acetonitrile medium exhibits absorbance maxima at 435, 395, 370, and 495 nm for Cu, Ni, Co, and Mn metals, respectively. Beer's law was valid within concentration ranges of 0.34–20.46, 0.49–39.81, 0.47–38.07, and 0.49–11.03 µg/mL for Cu, Ni, Co, and Mn, respectively. Various reaction parameters such as pH, volume of reagent, and solvents were carefully studied and optimized. The limits of detection and limits of quantification for Cu, Ni, Co, and Mn were found to be 1.4, 2.4, 1.1, and 1.1 µg/mL and 4.2, 7.2, 3.3, and 3.3 µg/mL, respectively. The method proved to be sensitive and rapid, requiring only a few minutes for sample analysis. The synthesized ligand and metal(II) 4-methyl piperazine dithiocarbamate complexes, M(4-methylPzdtc)2, were characterized by FTIR. The method was subsequently applied to vegetable and water samples spiked with the cations. The high recoveries of Cu, Ni, Co, and Mn from the proposed method indicate good accuracy and precision. [ABSTRACT FROM AUTHOR]

Mononuclear copper(II) complex [Cu(DBDACH)2](ClO4)2 (1) was synthesized with a cyclohexane-1,2-diamine-based bidentate ligand, N,N'-dibenzyl 1,2-diaminocyclohexane (DBDACH) and characterized by various spectroscopic techniques. The structure of the complex was determined by single-crystal X-ray analysis and shows a distorted square planar geometry around the copper center. DNA binding interactions were interrogated by UV-Vis spectroscopic titration, circular dichroism, and docking studies. These studies confirmed that the copper complex binds with CT-DNA through minor groove interactions and showed a good binding constant of Kb = 2.15 × 104 M−1. The catecholase-like activity of 1 was investigated with model substrate 3,5-di-tert-butylcatechol (3,5-DTBC) to corresponding 3,5-di-tert-butylquinone (3,5-DTBQ) using UV-Vis spectroscopy. The rate of this reaction is 0.89 × 10−3 s−1. The kinetic characteristics of 1 were determined through the Michaelis–Menten equation and a Lineweaver-Burk analysis, yielding Vmax (3.4 × 10−3 M s−1), kM (0.49 × 10−3 M), and kcat (1.45 × 10−2 s−1). [ABSTRACT FROM AUTHOR]

Newly synthesized ligand 2-(2- acetamidophenyl)-2-oxo-N-(pyridin-2-ylmethyl)acetamide and its copper(II) complex were characterized by elemental analyses, FT-IR, UV–Vis., ESR, 1H-NMR, and thermal analysis along with the theoretical quantum chemical studies. Combined experimental and theoretical DFT (density functional theory) studies showed the ligand to be a tridentate ligand with three coordinate bonds. The complex was suggested to be in a distorted octahedral structure with dx2-y2 ground state. The activation energy, ΔE*; entropy ΔS*; enthalpy ΔH* and order of reaction has been derived from differential thermogravimetric (DTA) curve, using Horowitz–Metzeger method. The nujol mull electronic spectrum of the ligand and Cu(II) complex have been recorded and the difference of the excited and ground state densities has also been theoretically calculated and plotted to investigate the movement of electrons on excitation. The Cu(II) complex was evaluated for its antibacterial activity against two bacterial species, namely Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Antifungal screening was performed against two species (Condida albicans and Aspergillus flavus). The complex under investigation was found to possess notable biological activity. Molecular docking investigation predicted different types of non-covalent interactions of the synthesized ligand towards Insulin-like growth factor 1 receptor (ID: 5FXR). [ABSTRACT FROM AUTHOR]

Under ultrasound irradiation in an ethanol solvent, a new coordination complex of Cu(II) was successfully synthesized within a 10-min timeframe through the treatment of an imidazole-based ligand (PDI) with a copper-containing salt. The formation of the complex was verified through elemental (CHN) analysis and FT-IR spectroscopy. Additionally, the supramolecular assembly and packing of atoms in the crystalline units of the copper complex were elucidated using single-crystal X-ray diffraction method. The synthesized compound exhibits an ionic nature, featuring a copper(II) cation inside the coordination sphere and a chloride anion outside of the coordination sphere. The coordination environment around the copper cation is achieved through the bonding of the N-atom of the non-protonated PDI ligands and a chloride ion. To maintain a neutral charge, a second chloride ion serves as a counterion. The bond angles surrounding the Cu(II) ion showed a somewhat deformed square planar geometry of the complex. The non-covalent intermolecular interactions were executed by Hirshfeld surface analysis (HSA), while the theoretical studies were conducted using DFT employing the B3LYP/Def2-TZVP level of theory. The consistency between the theoretical findings and experimental data attested to the reliability of the theoretical conclusions. [ABSTRACT FROM AUTHOR]

Novel divalent chelates of Co (II), Cu (II), Zn (II) and Ni (II) were prepared and described of the form [M (NTM)(CH3COO)2] where NTM = [1‐(4‐nitrophenyl)‐1H‐1,2,3‐triazol‐4‐yl)methanol ligand. Elemental analyses, infrared red, 1H and 13CNMR, electronic, magnetic susceptibility, conductivity measurements and X‐ray diffraction studies were used to assess our divalent metal complexes. Moreover, the stability and stoichiometry of the novel metal chelates were examined through the job's method in solutions. Correlation of all spectroscopic techniques states that NTM acts as a bi‐dentate NO ligand to afford octahedral complex geometry for all the investigated metal chelates. Thermodynamic and kinetics factors for various thermal degradation phases were calculated. Moreover, B3LYP/LANL2DZ/6‐311 g(d,p) theoretical study has been applied for estimating the MEP and quantum chemical reactivity descriptors of studied molecules. Moreover, the UV–Vis absorption spectra for the investigated molecules are predicted via the time‐dependent DFT (TD‐DFT) calculations. In addition, MOE‐ docking was tested on two different proteins, the receptor of (3HB5) breast cancer mutant oxidoreductase as well as the receptor of Glucosamine‐6‐phosphate synthase in complex with glucosamine‐6‐ phosphate of (2VF5) E.coli and COVID‐19 protease. The results recommended that the (NTMCo), (NTMNi), (NTMCu) and (NTMZn) complexes showed the highest inhibitory activity compared to the other NTM ligands as antimicrobial and breast cancer candidates. Furthermore, in‐vitro anti‐bacterial, anti‐fungal, cytotoxic and anti‐oxidant performances for the selected ligand as well as its chelates were studied. All metal chelates presented superiority, proceeding free organic ligand ineffective management, definitely NTMCu complex. [ABSTRACT FROM AUTHOR]

A new copper (II) complex containing the mono basic ligand (HL) azo naringenin was synthesized and structurally characterized by analytical, magnetic, and various spectroscopic techniques. An octahedron geometry was proposed for the assigned molecular formula [Cu(L)(CH3COO)(OH2)2]. Processing of powder X‐ray diffraction data for the copper (II) complex in question by the Expo 2014 computer program confirmed the proposed structure inferred from the spectroscopic studies. The DNA binding ability of the free ligand and its copper (II) complex was tested, and the results obtained demonstrated the stronger DNA binding ability of the copper (II) complex over the azo naringenin ligand. The antioxidant potency of copper (II) complex was investigated via the DPPH free radical‐scavenging assay. The present azo naringenin ligand and its copper (II) complex have shown diverse biological potentials including antitumor, antifungal, and antibacterial activities. [ABSTRACT FROM AUTHOR]

The activation of molecular oxygen remains a persistent challenge to the scientific community owing to its poor selectivity, especially towards organic substrates. In biological systems, phenoxazinone synthase and catechol oxidase are two copper-based metalloenzymes that have been extensively studied because of their catalytic properties in the formation of a phenoxazinone core and quinones, which subsequently produce value-added compounds. Inspired by the design of a native catechol oxidase metalloenzyme, two copper(II) complexes (1 and 2) with dipicolylamine (DPA)-derived tridentate ligands L1 (4-methyl-N,N-bis(pyridin-2-ylmethyl)aniline) and L2 (2,4,6-trimethyl-N,N-bis(pyridin-2-ylmethyl)aniline) are synthesized. The tridentate ligands provided similar environmental facilities for attachment with three histidine moieties found in nature and our goal is to understand their biomimicking activity. On the amine nitrogen center, basicity is varied by systematic substitutions via methyl groups, thus affecting the bond strength of the apical chloride atom, which results in increased lability. The ligands were thoroughly characterized using different spectroscopic methods, i.e., FT-IR, 1H NMR, UV-vis spectroscopy, and ESI mass spectrometry. The molecular structures of 1 and 2 were elucidated using single-crystal X-ray diffraction, which confirms their distorted square pyramidal geometries with two distinct chlorines attached in a cis fashion. The investigation of their catalytic abilities was performed under ambient aerobic conditions in methanol with both o-aminophenol and 3,5-ditertbutyl catechol, which provided kinetic values that correlated with their structural modifications. Toluene-appended 1 (kcat 525 h−1 for o-aminophenol and 612 h−1 for 3,5-ditertbutyl catechol) showed almost twice the activities of mesitylene-derived 2 (kcat 255 h−1 for o-aminophenol and 343 h−1 for 3,5-ditertbutyl catechol). Mass spectroscopy supported their probable mechanisms for both substrates and confirmed the involvement of molecular oxygen in the reaction. EPR studies further confirmed radical generation during adduct formation in the case of catechol oxidation. This study offers detailed information regarding metal–ligand cooperation and their biomimicking activity, which directs the importance of designing suitable bioinspired catalysts. [ABSTRACT FROM AUTHOR]

Template condensation of S-methylisothiosemicarbazones of acetyl- or benzoylacetone with 8‑quinolinecarboxaldehyde in the presence of nickel(II) and copper(II) ions gave four new mononuclear coordination compounds [NiL1]I (I), [CuL1I] (II), [NiL2]I (III), and [CuL2I] (IV). The chemical composition of the products was confirmed by elemental analysis, IR spectroscopy, and mass spectrometry, and the crystal structure of compounds I and II was determined by X-ray diffraction analysis (CCDC nos. 2266386, 2266387). X-ray diffraction study revealed a square planar coordination environment of the central ion of the cationic Ni(II) complex and square pyramidal geometry for the molecular Cu(II) complex. [ABSTRACT FROM AUTHOR]

We report the synthesis, characterization and anticancer activity of a new Schiff base (H2L) derived from the condensation of pyridoxamine with pyridoxal and its novel copper(II) and oxidovanadium(IV) complexes: [Cu(HL)Cl] (1), [Cu(LH2)(phen)]Cl2 (2), [Cu(LH2)(amphen)]Cl2 (3), [VIVO(HL)Cl] (4), and [VIVO(LH2)(phen)]Cl2 (5), where phen is 1,10-phenanthroline and amphen is its 5-amino derivative. All compounds were characterized by analytical and spectroscopic techniques, namely FTIR, UV-vis and EPR spectroscopy. Their stability in aqueous media was evaluated, revealing that the presence of the phen co-ligand significantly increases the stability. The ternary Cu(II) complexes (2 and 3) impaired cell viability of osteosarcoma cells (MG-63) (IC50 values of 3.6 ± 0.6 and 7 ± 1.9 μM for 2 and 3), while 1 and the VIVO complexes did not show relevant anticancer activity. Complexes 2 and 3 are also more active than cisplatin (CDDP). Synergistic studies between 2 and sorafenib showed significant synergism on MG-63 cells for the following combinations: 2 (2.0 μM) + sorafenib (10.0 μM) and 2 (2.5 μM) + sorafenib (12.5 μM), whilst the combination of 2 and CDDP did not show synergy. Complex 2 interacts with DNA, inducing significant genotoxic effects on MG-63 cells from 1.0 to 2.5 μM and it increases the ROS levels 880% over basal. Moreover, 2 induces apoptosis at 1.0 and 2.0 μM, while its combination with sorafenib induces apoptosis and necrosis. Finally, compound 2 reduces the cell viability of MG-63 spheroids showing an IC50 value 7-fold lower than that of CDDP (8.5 ± 0.4 μM vs. 65 ± 6 μM). The combination of 2 and sorafenib also showed synergism on spheroids, suggesting that the combination of these drugs improves the anticancer effect against bone cancer cells. [ABSTRACT FROM AUTHOR]

We herein report the synthesis and catalytic application of a new family of dinuclear Cu(I) complexes based on [N,P]-pyrrole ligands. The Cu(I) complexes (4a–d) were obtained in good yields and their catalytic properties were evaluated in the1,3-dipolar cycloaddition of azomethine ylides and electron-deficient alkenes. The air-stable complexes 4a–d exhibited high endo-diasteroselectivity to obtain substituted pyrrolidines, and the catalytic system showed excellent reactivity and wide substitution tolerance. [ABSTRACT FROM AUTHOR]

Two sulfoxide-containing Schiff bases, (E)-(((2-(methylsulfinyl phenyl) imino)methyl)-4-nitrophenol (HL1) and (E)-3,5-dibromo-2-(((2-(methylsulfinyl phenyl)imino)methyl)phenol (HL2), were prepared by condensation and subsequent oxidation reactions. In the presence of triethylamine, reactions of HL1 with 0.5 equivalent of copper acetate, cobalt acetate, nickel acetate and zinc acetate in ethanol afforded four metal complexes: (η2-N,O-L1)Cu(η3-O,N,O-L1) (1) and (η3-O,N,O-L1)2M (M = Co, 2; Ni, 3; Zn, 4), respectively. Similarly, treatment of HL2 with 0.5 equivalent of cobalt acetate and nickel acetate obtained two cobalt/nickel complexes: (η3-O,N,O-L2)2M (M = Co, 5; Ni, 6). Reactions of HL1 and one equivalent of Ru(PPh3)3Cl2 in tetrahydrofuran in the presence of triethylamine afforded a ruthenium(II) complex, (η3-O,N,S-L1)Ru(PPh3)2Cl (7). The molecular structures of HL1 and 1-7 have been confirmed by single-crystal X-ray diffraction. In addition, the UV–Vis, infrared, and fluorescence spectroscopies of 1–7 along with their electrochemical properties were also investigated. [ABSTRACT FROM AUTHOR]

Three novel copper Schiff base complexes, L1Cu(OAc)–L3Cu(OAc), bearing NNO tridentate ligands were synthesized and successfully entrapped in zeolite. All free and encapsulated complexes were fully characterized through experiments combined with theoretical calculations, and were subsequently employed as catalysts to activate H2O2 for degradation of methylene blue (MB). The catalytic activity of free complexes was tunable by substitution effects. The complex L3Cu(OAc) displayed enhanced efficiency by adopting bulky and donor substitutions due to the lower oxidation states. However, the free complexes exhibited modified structural and catalytic properties upon encapsulation into the zeolite. The constraint from the zeolite holes and coordination geometry caused the alteration of electronic structures and subsequently modified the reactivity. This study revealed that upon encapsulation, the larger molecular dimension of L3Cu(OAc) resulted in additional distorted geometry, leading to higher catalytic efficiency for MB degradation with more blue shifts in the UV-Vis spectrum. There was high catalytic activity by LnCu(OAc)-Y compared to that of the free complex, and high recyclability under near neutral conditions. In addition, the catalytic efficiency of L3Cu(OAc)-Y was higher or equivalent compared to other catalysts. This work provides new complexes with NNO tridentate ligands encapsulated inside zeolite and explains the relationship between the modified structure and functionality. [ABSTRACT FROM AUTHOR]

A series of mononuclear Cu(II) complexes were synthesized using a potential tetradentate hydrazone ligand obtained from the reaction between phenylhydrazine groups and 2,5- thiophenedicarboxaldehyde. The structures of ligands and complexes were elucidated through various spectroscopic techniques, confirming their composition. All complexes were found to adopt fourcoordinated geometries, indicating the formation of stable structures. Spectroscopic analysis revealed that the hydrazone ligand coordinated with the Cu(II) metal ions as a dibasic tetradentate ligand by utilizing the phenolic oxygen and azomethine nitrogen atoms. The binding affinity of the complexes with calf thymus DNA (CT-DNA) was investigated using absorption and viscosity measurements, demonstrating their interaction through the intercalation mode. The binding studies showed that the Cu(II) complexes exhibited varying degrees of binding affinity, with Cu(L4) demonstrating the highest affinity, followed by Cu(L1), Cu(L2), and Cu(L3). Moreover, the DNA fragmentation properties of the Cu(II) complexes were evaluated, suggesting their potential utilization in pharmaceutical applications. The obtained results highlight the significance of these novel complexes in the field of medicinal chemistry. [ABSTRACT FROM AUTHOR]

The antibacterial activities of two previously reported copper (II) coordination complexes [Cu(HL1)Cl2] and [Cu(HL2)Cl2], and the two new complexes [Cu(HL3)Cl2] and [Cu(HL4)Cl2], where HL1 is 2-(((pyridin-2-ylmethyl)amino)methyl)phenol, HL2 is 2-((benzyl(pyridine-2-ylmethyl)amino)methyl)phenol, HL3 is 2-(((pyridin-2-ylethyl)amino)methyl)phenol and HL4 is 2-(((pyridin-2-ylmethyl)(quinolin-2-ylmethyl)-amino)methyl)phenol were investigated using agar well plate diffusion assay. The ligands were characterized using elemental analysis, IR, 1H-NMR, 13C-NMR spectroscopy and thermal analysis. The corresponding copper (II) complexes of each ligand were synthesized and characterized using elemental analysis, FT-IR and UV-Visible spectroscopy, electronic spectra and magnetic moment measurements, and thermal analysis. Additionally, a thorough investigation of the copper complexes as potent drug candidates was performed using web-based software SwissADME to predict their physicochemical and pharmacokinetics properties. All copper complexes were stable to air and moisture and showed excellent stability up to 200 °C. Electronic spectra of all copper complexes in methanol consisted of single band at 14,490–15,260 cm−1 depicting ligand field excitation (Cu (II) d–d band). Ligands were completely ineffective on gram positive bacteria; HL1 and HL3 showed moderate to high activity at concentration range of 0.2–1 mg/ml. Copper complexes were found to exhibit moderate to high activity against bacteria as compared to the ligands. SwissADME analysis of all copper (II) complexes justified their candidature as potential candidate for pharmaceutical applications. [ABSTRACT FROM AUTHOR]

In the current research, we have reported the synthesis of eight new Co (II), Ni (II), Cu (II) and Zn (II) metal complexes from aldehyde derivatives and 3,5‐dichlorobenzohydrazide‐based hydrazone ligands (HL1HL2) in an effort to identify a combating agent for infectious ailments. Further, numerous physical and spectral studies were carried out to characterize the compounds and the spectral analysis indicates octahedral geometry around central metal ions in the complexes. The anti‐tuberculosis (TB) activity indicates that the complexes (3–10) are highly active for TB ailment and Zn (II) complex (10) has double efficacy to control the TB dysfunction with MIC value (0.006 ± 0.001 μmol/mL) in comparison with streptomycin (0.010 ± 0.001 μmol/mL) while complexes (6), (8), and (9) are comparably active (0.013 ± 0.001–0.014 ± 0.002 μmol/mL MIC) to inhibit the TB malformation. The antimicrobial investigation affirmed that zinc complex (10) has higher efficacy to control the microbial ailments with 0.0064–0.0129 μmol/mL MIC value. The anti‐inflammatory activity also revealed that the complexes (3–10) are highly active for inflammation and the Zn complex (10) has comparable IC50 value (7.58 ± 0.02 μM) with diclofenac sodium to hinder the inflammation diseases. Furthermore, the computational techniques such as molecular docking, density functional theory, molecular electrostatic potential and absorption, distribution, metabolism, excretion and toxicity studies were conducted against highly active ligand (2) and its complexes (7–10) which advocates that the biological activity of the hydrazone ligands was increased on complexation and the complex (10) has higher potency to control infectious ailments that behave as effective infection inhibitor without any toxic effects. Hence, the present research gives a new insight for in vivo investigation. [ABSTRACT FROM AUTHOR]

Eight novel mixed-ligand copper(II) complexes of the type [Cu(L)(phen)](ClO4) (1–8) synthesized from S-methyldithiocarbazate Schiff bases [H(L1)–H(L8)] and 1,10-phenanthroline (phen) ligands have been characterized using various physicochemical, spectroscopic and electrochemical methods. The structures of seven out of the eight Cu(II) complexes have been determined by single crystal X-ray diffraction. The coordination geometry around the Cu(II) ion is distorted square pyramidal (τ, 0.24–0.49). The heterocyclic and azomethine nitrogens along with thiolato sulphur of the deprotonated tridentate ligand (NNS) and one of the imine nitrogens of phen form the equatorial CuN3S square plane, while the other imine nitrogen atom of phen occupies the axial position. The geometry of the Cu(II) center in the solid state is preserved in DMF solution, stabilizing to distorted square pyramidal, as suggested by the low-temperature EPR data g‖ > g⊥ > 2.0. Cyclic voltammetry showed that the Cu(II) complexes display quasi-reversible electrochemistry. The efficiency of the complexes in killing the human lung epithelial adenocarcinoma cells (A549) has also been studied along with the cell viability assay against the noncancerous human lung epithelial cells (L132) under in vitro conditions. They were found to exhibit excellent cytotoxicity against A549 cancer cells without affecting the normal L132 cells. The activity of all the complexes was significantly superior to that of cisplatin. The 2′,7′-dichlorodihydrofluorescein diacetate (DCHF-DA) experiment indicated that cancer cells produce more reactive oxygen species (ROS) than normal cells. Further, they cause cell death mainly through apoptotic mode, as revealed by the observation of a higher percentage of apoptotic cells in acridine orange (AO) or ethidium bromide (EB) or 4′,6′-diamidino-2-phenylindole (DAPI) stained cancer cells. Thus, ROS generation in tumor cells is implicated in cytotoxicity, demonstrating the versatile nature of presently accessible mixed-ligand copper(II) complexes for cancer therapy by means of ROS-induced apoptotic cell death. [ABSTRACT FROM AUTHOR]

An equimolar reaction of 5-chlorosalicylaldehyde and 2-bromo-4-chloroaniline yielded the Schiff base (Z)-2-((2-bromo-4-chlorophenyl)imino)methyl)-4-chlorophenol) (HL), which was used for complexation to Co2+, Ni2+, Cu2+, and Zn2+ metal salts. Elemental and thermogravimetric analyses, conductivity measurements, powder X-ray diffraction, nuclear magnetic resonance (¹H and 13C), infrared, ultravioletvisible, energy dispersive X-ray-scanning electron and mass spectroscopies confirm the Schiff base structure and show mono-nuclear homoleptic complexes of the type ML2 for all metal salts used. The crystal structures of Ni2+ and Cu2+ complexes revealed a perfect square planar geometry around the metal ions, with the ligand acting as bidentate through oxygen and nitrogen atoms of the phenolic and azomethine groups, respectively. The antimicrobial potential of the compounds was evaluated on some selected pathogenic bacteria consisting of Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Klebsiella pneumonioe and Pseudomonas aeruginosa) strains using an in vitro assay. Antioxidant activity was evaluated using the DPPH assay. The complexes showed enhanced activity over the free Schiff base ligand in all the assays. Toxicity studies on WISH-ATCC-CCL-25, human epithelial amnion (normal liver cell lines), and MRC-5-ATCC-CCL-171 (normal human lung fibroblast cell lines) revealed that at lower concentrations, the complexes did not affect the cell lines. A computational study was deployed to investigate the electronic properties of the ligands and the complexes relating to their stability, reactivity, and biological potential. The computational data corroborated sufficiently with the experimental findings. Molecular docking studies demonstrated the compounds' mechanism of action and identified potential binding sites consistent with the in vitro assays. Hirshfeld surface analysis was also performed on selected compounds to reveal qualitative and quantitative intermolecular interactions within the topology crystal network of crystal structures. [ABSTRACT FROM AUTHOR]

The ligand ((E)-((2-hydroxynaphthalen-1-yl)methylidene)amino)urea (HL) and its Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes have been synthesized and characterized by conventional spectroscopic methods, elemental analysis, molar conductivity, and thermal analysis. The complexes show that the ligand disposes of as tridentate anionic (ONO) donor via deprotonated (OH)ring, (C = N)azomethine, and (C = O) functions with a ratio of metal:ligand (1:2) with Mn(II) and Co(II) ions. While, in Ni(II), Cu(II), and Zn(II) complexes, HL acts as monobasic bidentate (NO) donor ligates through deprotonated (OH)ring and (C = N)azomethine with metal:ligand of 1:2. Zn(II) complex adopts tetrahedral and other complexes adopt octahedral geometry. DFT in the material studio package validates the geometry of ligand and metal complexes by measuring bond lengths and angles, HOMO, and LUMO. The thermodynamic and kinetic parameters were estimated from TGA-DTG curves. These complexes provide better activities against human prostatic cell line PC-3 than free ligand which is further verified by molecular docking studies. 3D and 2D molecular interaction of ligand, HL to inhibitory activity to the 2Q7I protein. Highlights: Synthesis of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes of ligand (HL). Elemental analysis, molar conductivity, spectral methods (IR, UV-Vis., ESR, mass, and 1H NMR). The kinetic thermodynamic parameters (ΔE, ΔH, ΔS, and ΔG) are estimated from the TGA-DTG curves. Complexes provide better activities against human prostatic cell line PC-3 than the free ligand. Molecular docking of ligand and complexes with the receptor of prostate cancer (H874Y) hormone. [ABSTRACT FROM AUTHOR]

Centrosymmetric homopolynuclear Cu(II) and Co(II) chelated complexes, [Cu2(L)(H2O)2] (1) and [Co4(L)(μ-OAc)2(CH3OH)4(OAC)2]⋅2CH2Cl2 (2), were synthesized using a new symmetrical methoxy-disubstituted bis(salamo)-type ligand, H4L, with Cu(II) and Co(II) salts in organic solvents. Complexes 1 and 2 were structurally characterized by single-crystal X-ray crystallography. The results indicated that 1 is a five-coordinate dinuclear structure containing Cu(II) and 2 is a tetranuclear Co(II) complex with two distinct six-coordinate environments. Furthermore, 1 and 2 pack into three-dimensional and two-dimensional extended networks, respectively. The UV–Vis spectra, IR spectra, and Hirshfeld surface analyses of the complexes were carried out to further characterize the coordination between H4L and the metal(II) ions. Fluorescence methods were used to interrogate the coordination, where changes in emission with varied amounts of ligand supported solution-phase coordination ratios of H4L with Cu(II) ion of 1:2 and with Co(II) ion of 1:4, respectively. [ABSTRACT FROM AUTHOR]

Mixed ligand (L1L2) (where L1=naphthalene‐1,2‐dione and L2=indoline‐2,3‐dione) and its Mn(II), Cu(II) and Cd(II) complexes (3 a, 3 b, and 3 c, respectively) were prepared and described using analytical analysis, FT‐IR, UV–Vis, magnetic measurements, XRD‐diffraction and molar conductivity. Moreover, the structural properties of the mixed ligand complexes were investigated using mass spectrometry and elemental analysis. These complexes are expected to have octahedral molecular geometry depending on the electronic spectra and magnetic susceptibility tests. The two mixed ligands (L1L2) are bivalent ligands with two oxygen atoms. As an example, the quantum chemical properties, bond lengths, and bond angles were discussed for the Cu(II) complex. The Gaussian09 program was used to optimize the structural formula for the investigated ligand. The energy gaps and other essential theoretical properties were calculated using the DFT/B3LYP approach. The prepared mixed ligand complexes 3 a, 3 b, and 3 c were evaluated for their antibacterial properties. These complexes were tested against both Gram‐positive bacteria (Bacillus subtilis and Staphylococcus aureus) and Gram‐negative bacteria (Escherichia coli and Pseudomonas aeruginosa) using the agar diffusion method. The organic ligands were observed to be less biologically active than the targeted complexes as antimicrobial agents. According to molecular docking, the title compounds have a positive interaction with the crystal structures of Escherichia coli (3HUM), Staphylococcus aureus (5 M18), Bacillus subtilis (5ZW4), and Pseudomonas aeruginosa (4WEL). [ABSTRACT FROM AUTHOR]

Schiff base ligands are chemical compounds having diverse biological activities like industrial, agriculture and pharmaceutical. The current work discusses the evaluation of the biological properties of different synthesized mononuclear Fe(II), Co(II), Ni(II) and Cu(II) complexes. The complexes were synthesized using a condensation reaction which demonstrated the appearance of White, Cream, Black and Green. Biological activities for synthesized metal complexes were assessed against S. aureus, B. cereus, E. coli and P. aeruginosa and by comparing the zones of inhibition it can be depicted that metal complexes are fairly more effective inhibitors of gram-positive bacteria. Furthermore the antioxidant potential of these complexes was also evaluated and it concluded that copper complexes showed promising antioxidant activity which is higher in association with Ni(II), Fe(II), and Co(II). Hence, these metal complexes were biologically active and further studies are required. [ABSTRACT FROM AUTHOR]

Three Schiff base ligands [H2L1–H2L3] containing nitrogen/oxygen donor atoms and their Co(II), Ni(II), Cu(II) and Zn(II) complexes were synthesized by stirring metal acetates with Schiff base ligands obtained from condensation reaction of 2-amino-6-chloro-4-nitrophenol with 5-chloro salicylaldehyde/3,5-dibromo salicylaldehyde/3-methoxy-5–nitro salicylaldehyde. The structural traits of the synthesized compounds were done by using elemental analysis, spectroscopic techniques (UV–Vis, 1H and 13C NMR, FT-IR), mass spectrometry and some physical studies (XRD, TGA). According to spectral data, ligands behave as a tridentate (ONO) and formed complexes with octahedral geometry. The thermogravimetric analysis revealed that metal complexes decay in multi-steps leaving metal oxide as an end product. Powder XRD study suggested crystalline nature of the compounds. The energy gap (HOMO–LUMO) and molecular electrostatic potential calculation were computed by using DFT/B3LYP/6-31G** basis set. Derived ligands and complexes were explored for in vitro antimicrobial potential toward two gram-positive bacteria, two gram-negative bacteria, i.e., S. aureus, B. subtilis, P. aeruginosa, E. coli, and two fungal strains, i.e., A. niger, C. albicans, through serial dilution method taking ciprofloxacin and fluconazole as standard. The investigated results showed that complexes are more potent than free Schiff base ligands. The Cu(L2)(H2O)3 (0.0115 μmol/mL) and Zn(L2)(H2O)3 (0.0115 μmol/mL) complexes were found to be more active among all the investigated compounds. Additionally, molecular docking studies were also performed for some compounds in the active site of DNA Gyrase enzyme (PDB code: 1AJ6), suggesting good hydrophobic interactions of compounds with the enzyme. [ABSTRACT FROM AUTHOR]

In the current study, uni‐metallic Cu2+, Ni2+, Mn2+, Co2+, and Zn2+ complexes of ONN‐tridentate dihydrazone‐oxime incorporating indolin‐2‐one moiety (HL,1) were synthesized and structurally characterized employing elemental, spectral, thermo‐gravimetric, magnetic, and molar conductivity measurements, to investigate the structure and composition of these new uni‐metallic complexes. According to the results of several analyses, the dihydrazone‐oxime behaved as a mono‐negative or neutral tridentate ONN chelator bound the metal cations in molar ratio (1M:1L) through the isatinic carbonylic oxygen, azomethine nitrogen, and nitrogen atom of deprotonated/protonated oximatic moiety forming uni‐metallic complexes with formulae [M(L)XYZ(H2O)].nH2O (where M = Cu2+ (2–4), Ni2+, Mn2+, Co2+, or Zn2+, X = Cl, CH3COO, or NO3, Y = H2O or 0, Z = H2O or 0, n = 2, 0) and [Cu (HL)(SO4)(H2O)]. The Cu2+ complexes were found to have a tetragonally distorted octahedral or square pyramidal geometry, whereas those of Mn2+, and Ni2+, exhibited a tetrahedral geometry but Co2+ complex demonstrated a distorted octahedral geometry. Based on DFT‐B3LYP technique and 6‐311G++(d,p) basis set, The DFT data confirmed the structural investigation of dihydrazone‐oxime and its complexes, revealing that the complexes reactivity is more than un‐complexed dihydrazone‐oxime. Moreover, quantum chemical parameters of dihydrazone‐oxime and its uni‐metallic complexes like the energies of both lowest unoccupied molecular orbital (ELUMO) and highest occupied molecular orbital (EHOMO), separation energy (ΔE = ELUMO − EHOMO), chemical potential, absolute electronegativity, absolute hardness, and absolute softness were obtained. According to the thermogravimetric analysis, the complexes breakdown in two to four disintegrating phases in range of temperature 25°C to 575°C leaving the oxide of metal or metal oxide contaminated with carbon. In vitro microbicide effect of the un‐complexed dihydrazone‐oxime and its uni‐metallic complexes toward various bacterial and fungal strains was tested by agar‐well diffusion method. It is demonstrated that the complexes are more effective than free dihydrazone‐oxime. The antitumor activity has been also analyzed against three cell lines including prostate adenocarcinoma (PC‐3), ovarian adenocarcinoma (SKOV3), and cervical cancer (HeLa) cell lines. Studies showed that all complexes have greater inhibition activity against the above three cell lines than the free dihydrazone oxime and the most effective compound was the Zn2+ complex (9) with IC50, 27.42, 35.16, and 46.77 μg/ml, respectively. [ABSTRACT FROM AUTHOR]

The reactions of copper chloride and 4′-(4′-substituted-phenyl)-2,2′:6′,2′′-terpyridine ligands bearing nitro (L1), methyl (L2), phenyl (L3), tolyl (L4) and carboxyl (L5) gave five copper compounds (1–5) which have mononuclear structures with their Cu(II) ions five-coordinate in the irregular square pyramidal geometries. Their in vitro biological properties were evaluated by CCK-8 assay, which show remarkable proliferation inhibitive properties on the cancer cell lines including A549, Eca-109, and Bel-7402, and two human normal cell lines (HL-7702 and HLF). The values of IC50 indicate better anticancer activities of these compounds than that of cisplatin. Compound 2 with methyl group exhibits the best anticancer activity, with IC50 value < 2.5 µM on all the tested cancer cells. The interactions of the compounds with DNA were evaluated using UV–Vis absorption titrations, circular dichroism spectroscopy, and DNA viscosity. The complexes show significant insertion binding with DNA sequences and strong intercalator binding mode with DNA sequences. Compounds 1–5 interact with the functional groups of DNA through π···π stacking, van der Waals interactions, hydrophobic interactions, and hydrogen bonds as determined by molecular docking. In addition, strong binding interactions between the five copper(II) complexes and bovine serum albumin (BSA) were studied by fluorescence titration and circular dichroism spectroscopy. [ABSTRACT FROM AUTHOR]

In this study, a comparative study of the catecholase activities and DNA binding of three Cu(II) complexes is described. These complexes are mono-nuclear (1), di-nuclear (2), and poly-nuclear (3) complexes of Cu(II) bound with NNN and NNO tridentate Schiff base ligands. The general formulae of these complexes are [Cu(L1)Cl2] (1), [Cu2(L2)2(μ1.1-CH3COO–)2] (2) and [Cu2(L3)2(μ-N3)(N3)]n (3), where L1, L2 and L3 are heterogenous Schiff base ligands. CT-DNA binding properties of the complexes were studied using UV-vis and fluorescence spectroscopic techniques. Molecular docking studies were performed to gain deep insight into the binding regions of the complexes to DNA. All three of the complexes can effectively catalyze the oxidation of 3,5-ditertiarybutylcatechol (3,5-DTBC) in methanol to its corresponding quinone in the presence of aerial oxygen with first order reaction kinetics that follow Michaelis–Menten enzymatic kinetics with turnover numbers 5.1 × 105 (1), 4.52 × 105 (2) and 4.66 × 105 h−1 (3). Moreover, absorption, fluorescence, and viscosity studies show the possibility of partial intercalative binding of the three Cu(II) complexes with CT-DNA. This binding may be exploited to determine an unknown concentration of DNA and to judge the efficiency of these complexes when investigated in the future as components of pharmaceutical drugs. [ABSTRACT FROM AUTHOR]

• The ligand and its Cu(II), Co(II), Ni(II), Mn(II), and UO 2 (II) complexes are prepared and characterized. • The characterization of the compounds was demonstrated via numerous analytical techniques and studying the thermal stability. • Study the antimicrobial activities of start, ligand and complexes compared to penicillin G and miconazole as standards. • The obtained results revealed that complexes are more effective than start and free ligand. • The interface between the ligand and its metal complexes with calf thymus DNA (CT-DNA) displays hypochromism behavior. Cu(II), Co(II), Ni(II), Mn(II) and UO 2 (II) complexes of 1,5-dimethyl-4-(2-methyl-5-oxo-1-phenyl-1H-pyrazol-4(5H)-ylidene)hydrazainyl)-2-phenyl-1,2-dihydropyrazol-3-one (HL) ligand have been synthesized and characterized by different analytical techniques. FT-IR spectra demonstrated that the ligand under investigation behaves as a di/tridentated center ligand (NO/ONO) through the nitrogen/NH atom of the hydrazon group which is the farthest of the antipyrine moiety and oxygen carbonyl pyrazole/carbonyl antipyrine for heterocyclic moiety and forms a stable six/five-membered chelating ring. The results revealed a tetrahedral geometry for complexes (1 & 4) and an octahedral geometry for complexes (2, 3 & 5). The agar well diffusion method, serial dilution method (MIC), and minimum microbicidal concentration (MMC) were tested to study the antimicrobial activities of start, ligand, and complexes compared to penicillin G and miconazole as standards. The obtained results revealed that complexes are more effective than start and free ligand. The coordination sites of nitrogen atoms of the hydrazon group and oxygen of the carbonyl group as well as the high lipophilicity of the complexes might be the main factors for their good inhibitory action against the tested bacterial and fungal strains. The Ni(II) and Mn(II) complexes were found to be the most potent compounds with inhibition zones ranging from 16 to 27 mm, MIC and MMC values of 5–25 µg/mL, Mn(II) complex was most active against all bacterial strains, whereas Cu(II), Ni(II), Co(II) and UO 2 (II) complexes were most efficient for the fungal strains with inhibition zones ranged from 8 to 19 mm, MIC and MMC values of 45–50 µg/mL. [ABSTRACT FROM AUTHOR]

[Display omitted] A new C 2 -symmetric Schiff base ligand (H 2 L) featuring a core resorcinol bridging unit has been created, utilizing the Duff formylation reaction followed by the Schiff base condensation reaction. The ligand was characterized by various spectroscopic techniques. Cu(II) salts with varying coordinating anions (Cl− and SCN−) in methanol were allowed to react with this ligand in a 2:1 M ratio to create dinuclear Cu(II) complexes. The complexes were isolated in pure form and characterized by, elemental analysis,single crystal X-ray crystallography and various spectroscopic techniques. X-ray analysis discloses that both complexes are dinuclear, where the ligand (H 2 L) being tridentate in nature, coordinates to Cu(II) through its two N donor atoms and one O donor atom in the equatorial positions. The respective anions (−Cl− for 1 and –SCN− for 2) coordinate to Cu(II) to complete its square planar geometry. Temperature dependent magnetic susceptibility measurements indicate weak antiferromagnetic exchange interactions with a coupling constant of J = −5.9(1) cm−1 and g = 2.148(1) for 1 and J = −10.08(1) cm−1 and g = 2.106(1) for 2. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis and characterization of two new mononuclear Cu(II) complexes derived from N-donor ligands. • Comparison between mononuclear tridentate and pentadentate Cu(II) complexes. • Copper complex as a promiscuous catalyst. • Interaction and cleavage of the BSA protein mediated by a Cu(II) complex. • Cytotoxic activity of a Cu(II) complex in two cancer cell lines. In this work, we describe the synthesis and structural and spectroscopic characterizations of two copper(II) complexes, [(Cu)(L1)(Cl 2)].4H 2 O (1), where L1 is 2-(pyridin-2-yl)-1,3-bis(pyridin-2-ylmethyl)-hexahydropyrimidine, and [Cu(L2)](ClO 4) 2 (2), where L2 is N1,N1,N3-tris(pyridin-2-ylmethyl)propane-1,3-diamine. The crystalline structure analysis indicates that both complexes are mononuclear and pentacoordinated compounds. In the case of complex 1 , it bears a neutral charge, with the ligand coordinating to the Cu(II) center in a tridentate manner, utilizing N -donor atoms. Additionally, two cis -chlorido ligands completing the coordination sphere. On the other hand, complex 2 is a cationic complex, with the ligand coordinated in a pentadentate manner, with only N -donor atoms for coordination around the Cu(II). Complex 1 showed catalytic promiscuity, displaying hydrolytic and oxidative activity. The hydrolytic activity was investigated using bis(2,4-dinitrophenyl) phosphate (2,4-BDNPP) as a phosphodiester substrate and applying the Michaelis–Menten approach, obtaining the following kinetic parameters: k cat = 1.21 × 10-4 s−1; K M = 3.35 × 10-3 molL-1. Complex 1 also accelerates the oxidation of the 3,5-di- tert -butylcatechol (3,5-DTBC) substrate with catalytic efficiency equal to 6.11 L mol-1s-1. Interestingly, we demonstrated that this Cu(II) complex 1 can also cleave the very stable peptide bonds from BSA (bovine serum albumin) through an oxidative mechanism using ascorbate as a reducing agent. Complexes 1 and 2 show good cytotoxic activity against two cancer cell lines: A431 from human squamous cell carcinoma and K562 from chronic myeloid leukemia. This study showed that complexes 1 and 2 are selective towards cancer cells. [ABSTRACT FROM AUTHOR]

Novel ligand, (E)-4-((4-(dimethylamino)benzylidene)amino)-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one, L and its nickel, copper, and zinc complexes were designed and physicochemically investigated using various spectroscopic studies. Ligand was additionally characterized by single-crystal X-ray crystallography. DFT and Hirschfeld surface analysis studies were also carried out. The well-characterized compounds were tested for their antimicrobial activities. [Display omitted] A novel series of metal complexes of 3d elements of the type, [MLCl 2 ] [M = Ni(II), Cu(II) & Zn(II), L = ligand] produced from an ampyrone-based ligand was discussed. A thorough investigation was carried out using elemental analyses, LC-MS, FT-IR, 1H- &13C NMR, and thermogravimetric analysis for the ligand and its complexes. The ligand was additionally characterized through single crystal X-ray crystallography, revealing a monoclinic system with the C 2/ c space group, featuring dimensions a = 17.8776(12) Å, b = 6.8982(6) Å, c = 29.862(2) Å, β = 101.170(5)°. Hirshfeld surface analysis was employed to unveil various intermolecular interactions in the ligand. Additionally, theoretical investigations were conducted to have a better understanding of the structures. Moreover, the antimicrobial efficacy of all investigated compounds was assessed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Co2+-, Ni2+-, and Cu2+-complexes of quinxalyl hydrazone derivative are synthesized and characterized. • The antimicrobial (bacteria and fungi) and anticancer potential of Co–, Ni-, and Cu-complexes and their ligand are examined. • Their binding to ct DNA is examined via UV–Visible spectroscopy and hydrodynamic measurements. • Co–, Ni, and Cu-complexes exhibited more biological reactivity over their free ligand based on Tweedy's chelation theory. With the facile condensed carbonyl gourp of 2-hydorxybenzaldehyde with the amino group of quinoxalyl-2-carbohydrazide, a new chelating quinoxalyl hydrazone derivative ligand (H 2 Lpx) was constructed. Its coordination behavior towards three divalent Co2+, Ni2+, and Cu2+ ions was discovered by building up three new metallo-organic complexes (CoLpx, NiLpx, and CuLpx, respectively). Confirmation of their chemical structure was formulated by applying different spectroscopic methods, as well as, the micro-elemental (C,H,N) and thermogravimetric analyses, the conductance, and magnetic evaluations. The inhibition behavior of the free ligand and its metallo-organic complexes against the cell growth of six entitled microorganisms (three fungal and three bacterial types) and three tumors of humans was estimated considering the effective role of the divalent metal ions (Co2+, Ni2+, and Cu2+ ions in their metallo-organic complexes). The interacting nature of H 2 Lpx, CoLpx, NiLpx, and CuLpx, with calf thymus DNA (ct DNA) was manifested within the viscometric, spectrophotometric titrations and gel electrophoresis. The three complexes (CoLpx, NiLpx, and CuLpx) exposed a respectable inhibition attitude more than that of H 2 Lpx depending on the inhibition zone areas of the microbial series growth in mm and the half-inhibition concentration in µM (IC 50) for the tumor cell lines' growth. Establishing of the interacted modes between H 2 Lpx and MLpx with ct DNA was built upon the shifts of the spectral scans for their solutions. In addition, chromism type, Gibb's free energy, and binding constant values (Δ G b ≠ and K b , respectively) helped to distinguish their interacted modes, which supported DNA damage. The bio-action of MLpx complexes was highly modified compared to that of H 2 Lpx towards ct DNA. [ABSTRACT FROM AUTHOR]

Two copper(II) complexes [Cu(H pmoh)(NO 3)(NCS)] (1) and [Cu(peoh)(N 3)] 2 (2) were designed and synthesized by reaction of Cu(NO 3) 2 · 3H 2 O with hydrazone Schiff base ligands,abbreviated with H pmoh and H peoh. H pmoh and H peoh were prepared by condensation reaction of octanoic hydrazide with pyridine-2-carboxyaldehyde and 2-acetylpyridine, respectively. Complexes 1 and 2 were characterized using different analytical techniques such as FT-IR, UV–Vis, IR, EPR and single X-ray diffraction (XRD) analyses as well as computational methods (DFT). The XRD of 1 and 2 shows a mononuclear or a dinuclear structure with the copper(II) centre adopting a slightly distorted square pyramidal geometry. In water-containing solution and in DMSO, 1 and 2 undergo a partial transformation with formation of [Cu(H pmoh)(NO 3)(NCS)] (1) and [Cu(H pmoh)(NO 3)(H 2 O/DMSO)] (1a) in one system and [Cu(peoh)(N 3)] (2a) in the other one, as supported by DFT calculations. Docking simulations confirmed that the intercalation is the preferred binding mode with DNA for 1 , 1a and 2a , but suggested that the minor groove binding is also possible. A significant fluorescence quenching of the DNA–ethidium bromide conjugate was observed upon the addition of complexes 1 and 2 with a quenching constant around 104 M−1 s−1. Finally, both 1 and 2 were examined for anti-cancer activity using MDA-MB-231 (human breast adenocarcinoma) and A375 (malignant melanoma) cell lines through in vitro MTT assay which suggest comparable cancer cell killing efficacy, with the higher effectiveness of 2 due to the dissociation into two [Cu(peoh)(N 3)] units. The synthesis and characterization of two new mononuclear and dinuclear copper(II) complexes with hydrazone Schiff base ligands were reported. Both of them bind to calf thymus-DNA with an intercalative binding and show high cytotoxicity against MDA-MB-231 (human breast adenocarcinoma) and A375 (malignant melanoma) cell lines. [Display omitted] • Two copper(II) complexes with hydrazone Schiff base ligands were studied. • One mononuclear and one dinuclear Cu(II) species were characterized. • Dinuclear complex dissociate into two monomeric Cu(II) moieties in solution. • Both the complexes show interaction with CT-DNA. • Both the complexes are active against MDA-MB-231 and A375 cell lines. [ABSTRACT FROM AUTHOR]

The work reports the pharmacological applications of non-radioactive metal complexes with bis(thiosemicarbazones) and bis(hydrazone)-derived ligands. The antimicrobial, antiparasitic, and antineoplastic effects of these complexes, together with investigations into the interactions of some complexes with biological targets aiming at understanding their modes of action are described. The potential applications of copper(II) complexes with bis(thiosemicarbazones) for treating neurodegenerative diseases and studies on their mechanisms of action are also discussed. [Display omitted] The present work describes the multiple pharmacological applications of non-radioactive metal complexes with bis(thiosemicarbazones) and bis(hydrazone)-derived Schiff base ligands. The antimicrobial, antiparasitic, and antineoplastic effects of these complexes, together with investigations into the interactions of some complexes with biological targets aiming at understanding their modes of action are described. The potential applications of copper(II) complexes with bis(thiosemicarbazones) for treating neurodegenerative diseases and studies on their mechanisms of action are also discussed. [ABSTRACT FROM AUTHOR]

Recently, heteroleptic coordination between essential metallic elements with semicarbazone-based derivatives attracts more consideration for the varied ranges of bioactivities. Semicarbazone-based moiety holding azomethine (C=N) group become flexible ligands, forming stable complexes. Through a stirring and reflux technique, a novel heteroleptic complex of copper (II) was synthesized by reacting two semicarbazone-based derivative ligands, ortho-phthalaldehyde disemicarbazone (L1) and dehydrozingerone semicarbazone (L2), with copper chloride salt in 1 : 1 : 1 molar ratio. Magnetic moment measurement, elemental analyzer, thermogravimetric (TGA) analysis, and several spectroscopic techniques were applied to describe the prepared compounds. The disc diffusion and DPPH methods were actually used to investigate the antibacterial and antiradical potentials, respectively. The obtained data indicates the ligand (L1) has good mean inhibition zones on Staphylococcus aureus (12.42 ± 0.00 mm) and S. pyogenes (11.64 ± 0.12 mm) bacteria. The heteroleptic [Cu(L1) (L2)] complex displayed higher antibacterial actions (13.67 ± 0.52 mm) on Streptococcus pyogenes bacteria. The [Cu(L1) (L2)] complex also shows better antiradical potential (63.7%). Furthermore, the docking result of prepared compounds on S. aureus gyrase confirms the ligands (L1 and L2) and the complex potential molecules possess the smallest binding potential of −8.0 to −8.4 kcal/mol. A higher value was achieved by [Cu(L1) (L2)] complex (−8.4 kcal/mol). Thus, this study indicates an insight towards combining semicarbazone form derivatives of natural source origin with a synthetic compound as ligands through metal coordination could enhance bioactivity. [ABSTRACT FROM AUTHOR]

A series of novel copper(II) phenolate selenoether complexes have been synthesized and structurally characterized for the first time from copper(I) phenanthroline and various substituted ortho-bisphenylselenide- phenol chelating ligands. The synthesized complexes exhibit Jahn--Teller distortion in their geometry and varied from distorted square planar to distorted octahedral by varying the substituent in the bis-selenophenolate ligand. The synthesized complexes electrocatalyze the hydrogen evolution reaction (HER) with a faradaic efficiency of up to 89%, and it was observed that the distorted square pyramidal geometry is the optimum geometry for the maximum efficiency of these copper complexes. [ABSTRACT FROM AUTHOR]

Two architecturally dissimilar coordination complexes, namely, C1 = [CuL1(NO2)]2 and C2 = [CuL2(NO3)] (L1 = (4‐bromo‐2‐[(2‐isobutylaminoethylimino)methyl]phenolate and L2 = (4‐bromo‐2‐[(2‐propylaminoethylimino)methyl]phenolate) have been synthesized from two different organic ligand backbones. The synthesized complexes have been identified using some common techniques like elemental analysis, FT‐IR spectroscopy, and single‐crystal X‐ray analysis. The X‐ray structural analysis revealed that C1 is a dinuclear complex realized through one bridging nitrite anion, whereas for C2, nitrate anions bridge the complexes to accomplish a 1D coordination polymer. C1 and C2 when slashed down by rapid and green mechanical method by using a simple hand grinding technique, mortar and pestle, resulted in NC1 and NC2 nanoparticles, whose average size was characterized by PXRD, SEM, and DLS. As far as we know, this is the first report where the nano‐formulation has been used while maintaining the structural integrity of the Schiff base complex. The proliferative properties of these complexes have been assessed in vitro using human lung carcinoma cell line A549. Being a polymer, the number of metal centers in NC2 is much higher; accordingly, this complex is more vital in terms of biological activity in comparison with NC1. [ABSTRACT FROM AUTHOR]

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

[Display omitted] • Synthesis and characterization of Cu(II) complex of dppy ligand L. • Selective recognition of l -Cysteine and l -Histidine by Cu-dppy complex. • Validation of amino acid detection studies by theoretical investigation. 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(NO 3) 2 L]. The in-situ prepared [Cu(H 2 O) 2 L](NO 3) 2 receptor in aqueous acetonitrile (4:1 v / v, 10 mM HEPES buffer, pH 7.4) medium displayed instantaneous response s 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(H 2 O) 2 L](NO 3) 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(H 2 O) 2 L](NO 3) 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. [ABSTRACT FROM AUTHOR]

Coinage bond interactions observed in the solid state structure of a disordered Schiff base complex have been analyzed through experimental and theoretical studies. Similar interactions found in the crystal structure database have been perceived. [Display omitted] • Synthesis and characterization of a heterometallic copper(II)/potassium(I) Schiff base complex. • Cu⋯Br π-hole coinage bond (CiB) interactions are observed and investigated. • QTAIM and electron localization function (ELF) 2D map have been analyzed to investigate the coinage bond (CiB) interaction. A copper(II)/potassium(I) Schiff base polymeric complex has been synthesized and characterized. Salen-type N 2 O 2 O 2 ′ donor compartmental Schiff base ligand has been used where copper(II) resides in the inner N 2 O 2 core and potassium (I) sits in the outer O 2 O 2 ′ core. Single crystal X-ray analysis revealed that the unintended formation of a disordered bromine atom led to Cu⋯Br π-hole coinage bond (CiB) interaction. The energetics regarding the CiB interactions have been rationalized using DFT calculations, QTAIM, and ELF study. [ABSTRACT FROM AUTHOR]

• Schiff base ligand and the corresponding Cu(II), Zn(II) and Pd(II) complexes were synthesized and characterized. • The synthesized compounds were tested for antibacterial, antifungal and DNA binding studies. • The copper(II) complex showed enhanced biological activity. • In silico studies showed strong interactions between the complexes with the S. aureus nucleoside diphosphate kinase receptor. Synthesis of salen type Schiff base ligand by the condensation of butane 1,4-diamine with 5-bromosalicyaldehyde has been done. Further, three new mononuclear Schiff based complexes of Cu(II), Zn(II) and Pd(II) have been prepared by the reaction of the Schiff base ligand with appropriate metal salts. The developed Schiff base ligand and metal complexes of Cu(II), Zn(II) and Pd(II) have been well characterized by various spectroscopic techniques like UV–Vis, FT-IR, 1H-NMR, 13C-NMR, EPR, Mass and powder XRD. All the synthesized Schiff base compounds have been tested for antibacterial, antifungal, hemolysis assay and DNA binding activities. The zone inhibition measurements revealed the supremacy and enhanced efficiency of metal complexes as compared to free ligand. The molecular modelling studies were carried to analyze the bonding affinity and inhibition probability of the synthesized complexes with the S. aureus nucleoside diphosphate kinase receptor. The in-silico pharmacokinetics studies such as Lipinski's rule, Veber's rule, drug-likeness score and physiochemical parameters analysis predicted the drug-likeness of the synthesized compounds. [Display omitted] [ABSTRACT FROM AUTHOR]

• The novel Cu(II), Co(II), and Fe(II) complexes of N 3 S 2 type pentadentate Schiff base were synthesized and characterized. • All compounds were tested against Gram-positive, Gram-negative, and yeast strains for antibacterial activity. • Synthesized compounds were compared to the stable free radical DPPH for antioxidant activity. • In docking study, all the metal complexes, especially Co(II) complex [CoL], have a higher binding affinity than free ligand. • Docking indicated that all compounds had a strong negative affinity for S. aureus amino acids. The compound H 2 L, which is a ligand with five coordinating atoms, consisting of three nitrogen atoms and two sulfur atoms (N 3 S 2), was reacted with Fe(OAc) 2 , Cu(OAc) 2.H 2 O, and Co(OAc) 2 ·4H 2 O to form the corresponding metal complexes ([FeL], [CuL], [CoL]). Many techniques, including NMR (for ligand), FT-IR, UV–Vis, elemental analysis, and molar conductivity, were used to characterize the synthesized compounds. According to the spectrum of data, complex molecule structures have a distorted triangular bipyramidal geometry with five coordination locations. The compounds that exhibit non-electrolyte behavior in solution do not possess any conductivity features. Evaluation was performed to determine the antioxidant activity of the synthesized compounds in comparison to the stable free radical DPPH. The ligand and its metal complexes were evaluated for antibacterial activity against several Gram-positive and Gram-negative bacteria, as well as a yeast strain. In comparison to the common antibiotic Amoxycillin/Clavulanic Acid (AMC-30), the Schiff base ligand (H 2 L) and its Cu(II) metal complex showed noticeably larger inhibitory zones against S. aureus. All the compounds showed a high negative binding affinity for S. aureus amino acid molecules when they were docked. The results indicated that the metal complexes, particularly the cobalt complex, exhibited a higher affinity for binding compared to the free ligand. [Display omitted] [ABSTRACT FROM AUTHOR]

Synthesis, characterization and magnetic property of two Cu(II) based coordination polymers (CPs) involving chromone based chelating ligand and dicyanamide bridging ligand are reported. Both CPs are isostructural and isomorphous compounds of polymeric linear chain. Both the compounds exhibit antiferromagnetic interactions. [Display omitted] • Two Cu(II)-chromone based coordination polymers (CP 1 and 2) are described. • CP 1 and 2 are isostructural and isomorphous compounds of polymeric linear chain. • Both of them show antiferromagnetic interactions. Synthesis, characterization and magnetic properties of two Cu(II)-based coordination polymers (CPs, [{Cu(L1)(N(CN) 2)}(ClO 4)] n L1 = 3-(((2-(diethylamino)ethyl)imino)methyl)-4H-chromen-4-one (1) and [{Cu(L2)(N(CN) 2)}(ClO 4)] n L2 = 3-(((2-(dimethylamino)ethyl)imino)methyl)-4H-chromen-4-one (2)) involving chromone based chelating ligands and dicyanamide bridging ligands are reported. Both compounds have been characterized by physicochemical methods and the crystal structures have been determined by X-ray diffraction analysis, disclosing that they are isostructural and isomorphous compounds of polymeric linear chains where the central metal has adopted distorted square pyramidal coordination geometry. The magnetic studies reveal that the synthesized compounds show a prevailing paramagnetic behavior. Only below 15 K does a weak antiferromagnetic interaction become effective in these systems, and they have been further analyzed and interpreted. [ABSTRACT FROM AUTHOR]

A hetero di nuclear complex [Zn(o -phen)LCu(OAc)] (K3 compound), where, H 3 L = o -HOC 6 H 4 C(H)=N−NH−C(OH)=N−N C(H)−C 6 H 4 OH- o , o -phen = 1,10-phenanthroline, and OAc = CH 3 COO− was synthesized. The Schiff base ligand in its keto form used for synthesis was derived from the condensation of salicylaldehyde and carbohydrazide, however, the Schiff base was found to coordinate in its enol form (L3−) as it was confirmed from the reported crystal structure of K3 compound. The K3 compound displayed significant antibacterial activity in both planktonic and biofilms of the test organisms, Pseudomonas aeruginosa and Staphylococcus aureus. The anti-quorum sensing activity was investigated in P. aeruginosa to determine the effect of the K3 compound on bacterial chemo-signaling networks that collectively control bacterial virulence, including twitching motility, swarming motility, rhamnolipids, pyocyanin and, exopolysaccharide production. The synthesized novel hetero Zn(II)/Cu(II)-based di-nuclear complex [Zn(o -phen)LCu(OAc)], K3 compound exhibited potent antibacterial and antibiofilm properties against P. aeruginosa and S. aureus , with significant biofilm disruption, inhibition, and anti-quorum sensing effects, making it a promising candidate for further investigation as a potential antibacterial agent. [Display omitted] • A Metal complex having Zn2+ & Cu2+ was prepared to evaluate its bactericidal impact against P. aeruginosa and S. aureus. • The K3 Compound displayed significant antibacterial activity in planktonic and biofilms of P. aeruginosa and S. aureus. • The K3 compound inhibited the production of acyl-homoserine lactones (AHLs). • K3 compound reduced the quorum sensing ability of P. aeruginosa by inhibiting cellular events associated with the virulence. [ABSTRACT FROM AUTHOR]

The article titled "Retraction Note: Crystal Structures and Inhibiting Human Cardiac Myoma Cells Activity of Co(II) and Cu(II)-based Coordination Polymers Constructed from 4-(1 H-pyrazole-4-yl)Benzoic Acid and 4,4'-Bipyridine Ligands" has been retracted by the Editor-in-Chief and the Publisher due to evidence of systematic manipulation of the publication process. The investigation found issues such as unsupported citations, non-standard phrasing, anomalies in figures, and discrepancies in ethics approval statements. The authors have not responded to correspondence regarding the retraction. Springer Nature, the publisher, remains neutral in regards to jurisdictional claims and institutional affiliations. [Extracted from the article]

This study aimed to synthesize two novel Schiff-base ligands through the condensation between N-(2-aminoethyl)pyrazoles and 2-hydroxy-1-naphthaldehyde, which are: NaphPz ((E)-1-(((2-(1H-pyrazol-1-yl)ethyl)imino)methyl)naphthalen-2-ol)) and NaphDPz ((E)-1-(((2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl)imino)methyl)naphthalen-2-ol). These novel pyrazole-imines were synthesized, characterized and used as copper (II) ion complexing agents. Different synthetic routes have been adapted to obtain the [Cu(NaphPz)Cl], [Cu(NaphDPz)Cl] and [Cu(NaphPz)2] complexes in the solid state, the first two in the crystalline form and the latter as a powder. The minimum metal–ligand stoichiometry for the three complexes was defined by TGA–DSC thermoanalytical data and by single-crystal X-ray diffraction for the crystalline samples which belong to the P21/n space group. The products of the thermal decomposition of the material were also monitored by TGA–DSC/FT-IR in air and N2 atmospheres in order to suggest how thermal decomposition of the organic portion of the complex occurs. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations compared to experimental results (UV-Vis and FT-IR) show a high degree of correlation. From HOMO/LUMO orbitals, the main major charge distributions, responsible for the absorption bands of the complexes, were determined. [ABSTRACT FROM AUTHOR]