Zn Complexes Research Articles

Synthesis, Biological Activity, and the Effect of Ionization Radiation on the Spectral, XRD, and TGA Analysis of Cu(I), Cu(II), Zn(II), and Cd(II) Complexes

New complexes of molecular formulae of [Cu(H2L1)I] (B1), [Cu(H2L)2(ClO4)2](B2), [Zn (H2L)2(H2O)]SO4(B3) and [Cd(H2L)Cl]Cl(B4) of ligand N-phenyl-2-(p-tolylglycyl)hydrazine -1-carbothioamide (B) have been prepared and characterized by 1H-NMR, Mass spectra, FT-IR, elemental analyses, molar conductance, UV–visible spectra, magnetic susceptibility measurements, thermogravimetric analysis (TGA/DTG) and X-ray powder diffraction before and after irradiation. Elemental analyses indicate that the metal complexes have 1:1 (metal/ ligand) (B1 and B4) or 1:2 stoichiometry for complexes (B2 and B3). The results confirmed that gamma ray enhanced the stability of irradiated compounds as compared to non-irradiated compounds. XRD patterns proved that increasing the crystallinity of the samples and the particles is in nanosize range before and after gamma irradiation. These studies revealed that Cu(II) and Zn(II) complexes adopted octahedral geometry, and Cu(I) and Cd(II) complexes were found to be tetrahedral. The theoretical conformational structure analyses were performed using density functional theory for ligand and complexes at B3LYP functional with 6–31G basis set for ligand and LANL2DZ basis set for complexes. The ligand (B, A) and complexes (B1–B4) and (A1–A4) before and after irradiated have been tested for their inhibitory effect on the growth of bacteria against gram-positive (Streptococcus pyogenes) and gram-negative (Escherichia coli). Molecular docking investigation proved that the Zn(II) complex had interesting interactions with active site amino acids of topoisomerase II DNA gyrase enzymes (code: 2XCT).

Spectroscopic studies, antimicrobial activity, and computational investigations of hydrazone ligands endowed metal chelates

Our current efforts are aimed to synthesize 16 complexes of Co (II), Ni (II), Cu (II), and Zn (II) metal ions from heterocyclic hydrazone ligands by condensation reaction of 2,6‐diacetylpyridine with hydrazide derivatives to find out combating agent against microorganism diseases. The synthesized compounds were precisely characterized by various physicochemical and spectroscopic techniques like FT‐IR, UV–Vis, 1H and 13C NMR, magnetic susceptibility, ESR, mass spectrometry, powder XRD, TGA, and SEM that suggested the octahedral geometry of the complexes coordinating via enolic oxygen atoms, azomethine nitrogen atom, pyridine ring nitrogen atom of the hydrazone ligands, and oxygen atom of water molecule. The thermal stability of the complexes was demonstrated by thermal analysis revealing two‐step decompositions leaving behind metal oxide as an end residue. By using serial dilution method, the compounds (1–20) were tested for in vitro antimicrobial activity against four bacterial and two fungal pathogens. Among all the synthesized compounds, complex 16 was most active against B. subtilis, whereas complexes 13, 14, and 15 were most efficient for C. albicans. Moreover, the biological efficacy of H2L3 (3) ligand and its (13–16) complexes were demonstrated by computational methods like molecular docking, MESP, DFT, and ADMET studies that highlight that complexes have more potency than the ligands and may be employed as effective drug for pathogen‐induced malformations.

Co(II), Ni(II), Cu(II) and Zn(II) complexes of 1,8-naphthalimide-based ligand: syntheses, characterizations and evaluation of antibacterial activities

Mononuclear later first-row transition metal complexes, [M(L)2] (1–4), where M = Co(II) (1), Ni(II) (2), Cu(II) (3), and Zn(II) (4) incorporating 1,8-naphthalimide based ligand were designed. The complex preparation was achieved by reacting metal nitrates with ligand (L) in 1:2 stoichiometry. The ligand and complexes were characterized with analytical and photophysical techniques. Single crystal X-ray diffraction determines that 3 is square planar. The complexes are highly fluorescent compared to the free ligand. The synthesized ligand (L) and complexes (1–4) were screened for their antibacterial activities against gram-positive [Streptococcus mutans (SM), Staphylococcus aureus (SA)] and gram-negative [Escherichia coli (EC), Klebsiella pneumoniae (KL)] bacterial strains. Ni(II) and Cu(II) complexes exhibited good activity against K. pneumonia and S. aureus compared to the free ligand. Particularly effective against gram-negative bacteria (Klebsiella pneumoniae), Ni(II) complex (2) has a MIC value of 6.25 µM and exhibits similar activity to standard ciprofloxacin. Cu(II) complex (3) is two times more effective than the common antibiotic ciprofloxacin with a MIC value of 3.125 µM against gram-positive bacteria (S. aureus).

Incorporating Catalytic Units into Nanomaterials: Rational Design of Multipurpose Catalysts for CO2 Valorization.

ConspectusCO2 conversion to valuable chemicals is effective at reducing CO2 emissions. We previously proposed valorization strategies and developed efficient catalysts to address thermodynamic stability and kinetic inertness issues related to CO2 conversion. Earlier, we developed molecular capture reagents and catalysts to integrate CO2 capture and conversion, i.e., in situ transformation. Based on the mechanistic understanding of CO2 capture, activation, and transformation at a molecular level, we set out to develop heterogeneous catalysts by incorporating catalytic units into nanomaterials via the immobilization of active molecular catalysts onto nanomaterials and designing nanomaterials with intrinsic catalytic sites.In thermocatalytic CO2 conversion, carbonaceous and metal-organic framework (MOF)-based catalysts were developed for nonreductive and reductive CO2 conversion. Novel Cu- and Zn-based MOFs and carbon-supported Cu catalysts were prepared and successfully applied to the cycloaddition, carboxylation, and carboxylative cyclization reactions with CO2, generating cyclic carbonates, carboxyl acids, and oxazolidinones as respective target products. Reductive conversion of CO2, especially reductive functionalization with CO2, is a promising transformation strategy to produce valuable chemicals, alleviating chemical production that relies on petrochemistry. We explored the hierarchical reductive functionalization of CO2 using organocatalysts and proposed strategies to regulate the CO2 reduction level, triggering heterogeneous catalyst investigation. Introducing multiple active sites into nanomaterials opens possibilities to develop novel CO2 transformation strategies. CO2 capture and in situ conversion were realized with an N-doped carbon-supported Zn complex and MOF materials as CO2 adsorbents and catalysts. These nanomaterial-based catalysts feature high stability and excellent efficiency and act as shape-selective catalysts in some cases due to their unique pore structure.Nanomaterial-based catalysts are also appealing candidates for photocatalytic CO2 reduction (PCO2RR) and electrocatalytic CO2 reduction (ECO2RR), so we developed a series of hybrid photo-/electrocatalysts by incorporating active metal complexes into different matrixes such as porous organic polymers (POPs), metal-organic layers (MOLs), micelles, and conducting polymers. By introducing Re-bipyridine and Fe-porphyrin complexes into POPs and regulating the structure of the polymer chain, catalyst stability and efficiency increased in PCO2RR. PCO2RR in aqueous solution was realized by designing the Re-bipyridine-containing amphiphilic polymer to form micelles in aqueous solution and act as nanoreactors. We prepared MOLs with two different metallic centers, i.e., the Ni-bipyridine site and Ni-O node, to improve the efficiency for PCO2RR due to the synergistic effect of these metal centers. Sulfylphenoxy-decorated cobalt phthalocyanine (CoPc) cross-linked polypyrrole was prepared and used as a cathode, achieving the electrocatalytic transformation of diluted CO2 benefiting from the CO2 adsorption capability of polypyrrole. We fabricated immobilized 4-(t-butyl)-phenoxy cobalt phthalocyanine and Bi-MOF as cathodes to promote the paired electrolysis of CO2 and 5-hydroxymethylfurfural (HMF) and obtained CO2 reductive products and 2,5-furandicarboxylic acid (FDCA) efficiently.

Synthesis, characterization, and biological evaluation of some metal complexes containing N and S donor atoms

Eight new bipyridine adducts of Zn(II) and Ni(II) dithiocarbamate complexes have been prepared from the reaction of Zn(II) and Ni(II) complexes of N-ethyl-N-phenyldithiocarbamate and 4,4′ dipyridine, 4,4′-dimethyl-2,2′-bipyridine, 4,4′-dimethoxy-2,2′-bipyridine, 4,4′-ditertbutyl-2,2′-bipyridine. The resulting adducts were represented as [M(L1)2(DP)], [M(L1)2(DMeB)], [M(L1)2(DMxB)] and [M(L1)2(DTB)] respectively (where M = Zn or Ni). The structural configuration of these adducts was established using various spectroscopic techniques. The obtained data from the spectroscopic studies revealed a change in the tetrahedral configuration of the parent complexes to octahedral coordination in the adducts due to an additional metal-nitrogen bond. The formation of this bond was established by a considerable shift in the peaks around the metal-nitrogen (M−N) coordination upon the formation of the adducts. The study of biological properties including cytotoxicity, antioxidant, and anti-inflammatory properties were carried out. No noticeable trends were reported in all the studies despite the concentration-dependent profile shown in the assays and the structural similarities of the compounds. These adducts, nevertheless, showed good antioxidant activity in the DPPH assay, with IC50 ranging between 3.78 and 4.87 µg/mL which is better than the standard ascorbic acid (4.96 µg/mL). Also, in the cytotoxicity study, the adducts [Zn(L)2DMeBp] (1) and [Ni(L)2 DTBp] (6) showed the best activity against the mutating human cervical cancer (HeLa) and embryo kidney (HEK 293) cell lines and better than the standard 5-Flurouracil. The molecular docking studies further revealed that the adducts had a good binding affinity to the drug targets used for the study.

Vibrational Spectra of the thioglycolate complexes of Zn(II) and Cd(II), structure and natural bond orbitals

The objective of this research was to characterize the vibrational spectrum of the Zn(II) and Cd(II) thioglycolate complexes, as well as their structures, vibrational analysis and the natural orbitals of bonds, through the infrared spectrum with Fourier transform (FT -IR) and Raman. The thioglycolate complexes of Zn(II) and Cd(II) were synthesized following procedures given by the graphical method, and structural analysis was performed through a theoretical-experimental method using both, the hybrid RHF/MP2:STO-3G and the experimental FT-IR and FT-Raman spectra. Calculations were performed on the optimized structure and harmonic vibrational wavenumbers for both complexes were obtained. Second derivative of the vibrational spectra and deconvolution analysis were also performed. The infrared and Raman spectra show many combination and overtone bands in both cases. Calculated and experimental spectra confirmed the structural hypothesis considering two ATG (thioglycolic acid) with two water molecules in the coordination sphere of the central atoms. The natural bond orbital analysis (NBO) was also carried out to study the Zn(II) and Cd(II) hybridization leading to a pseudo-octahedral geometry for both complexes.

Spectroscopic and theoretical approach of DNA interaction and anticancer studies of bio-pharmaceutically active pyrimidine derived Cu(II) and Zn(II) complexes

New metal(II) complexes (CuL2 and ZnL2) with pyrimidine appended Schiff base ligand (HL) were synthesized and characterized by diverse spectroscopic methods, reveals the proposed structure of metal(II) complexes possess square planar geometry. DNA interaction ability of isolated compounds was studied by UV–Visible, fluorescence, viscometric and electrochemical methods and the results showed that isolated compounds intercalated with calf thymus DNA (CT-DNA). In addition, anticancer activities of HL, CuL2, and ZnL2 have been evaluated by MTT assay, signifying moderate cytotoxic activity on selected cancer cell lines and less toxicity on NHDF normal cell line due to the specific targeting of pyrimidine analogues. Moreover, antioxidant activities of isolated compounds towards diverse free radicals have been studied by spectrophotometric methods. These results showed that CuL2 has better antioxidant ability than HL and ZnL2. Finally, antimicrobial activities of isolated compounds against selected antimicrobial pathogens exposed that CuL2 has better antimicrobial activity on E. coli and C. albicans than other antimicrobial pathogens. The DFT calculations have been done to get the optimized geometry of the ligand and the metal complexes. In order to get a broad understanding of the interactions of these synthesized metal complexes, a detailed molecular docking analysis is taken up.

Comprehensive Biological, Photodegradation, Density Functional Theory, and Docking Exploration of Zn(II) and Mn(II) complexes of Piroxicam

AbstractThe biological evaluation of coordination complexes is an active research area ascribed to structural modification and synergistic action due to metal ions. The mononuclear complexes of Zn(II) and Mn(II) piroxicam were evaluated for their encyclopedic biological activities, DFT, and docking exploration. Different antioxidant methods were used to assess their antioxidant potential. DNA cleavage and protein binding properties of the complexes were monitored through gel electrophoresis and UV‐visible spectrophotometry. The low IC50 value of both complexes implies more potency than the piroxicam. The percent cleavage and binding constant values indicated that the complexes bind with DNA and BSA more efficiently than the piroxicam. In SD rats, complexes were screened for analgesic, anti‐anxiety, anti‐inflammatory, and anti‐hyperglycemic effects. The complexes demonstrated statistically significant results for in‐vivo analysis. Photodegradation results of the metal complexes under UV lamp exhibited abrupt degradation than the piroxicam. Docking results also validate a better propensity of both complexes to bind with DNA and BSA. Hydrogen bonding and Van der Waals forces play a key role in stabilizing complexes in DNA and BSA binding pockets. These metal complexes have evident therapeutic potential more than piroxicam and could be promising drugs for relieving pain, anxiety, inflammation, and associated comorbidities with good pharmacodynamic properties.

Synthesis, structure and property investigation of a three-dimensional Zn(II) metal–organic frameworks

A new three-dimensional Zn(II) complex named [Zn(1,3-BMIB)(TBIP)⋅2H2O][Formula: see text] (1) (containning 1,3-BMIB = 1,3-bis(2-methyl-1H-imidazol-1-yl)benzene, H2TBIP=5-tert-butyl isophthalic acid) had been prepared by hydrothermal synthesis. Systematic structural characterization, especially the single crystal X-ray diffraction method, discreetly reveal the complex 1 exhibits three-dimensional (3D) framework with CdSO4 topology. The 3D crystrals 1 display solid-state fluorescence behavior at room temperature, indicating the potential of the candidate materials for absorbing and using visible light. The photocatalytic properties of compound 1 were estimated through the model photodecomposition dye pollutants using methylene blue (MB) and rhodamine B (RhB) under visible light irradiation.

Novel Fluorescent Tetrahedral Zinc (II) Complexes Derived from 4-Phenyl-1-octyl-1H-imidazole Fused with Aryl-9H-Carbazole and Triarylamine Donor Units: Synthesis, Crystal Structures, and Photophysical Properties.

We present here the design, synthesis, and photophysical properties of two novel fluorescent zinc (II) complexes, ZnCl2(ImL1)2 and ZnCl2(ImL2)2, containing 4-(1-octyl-1H-imidazol-4-yl)-N,N-diphenyl-[1,1-biphenyl]-4-yl)-4-amine ImL1 and 9-(4-(1-octyl-1H-imidazol-4-yl)-[1,1-biphenyl]-4-yl)-9H-carbazole ImL2 ligands. The newly synthesized free ligands and their zinc (II) complexes were characterized using several spectroscopic techniques; their structures were identified by single-crystal X-ray diffraction; and their photophysical properties have been studied in the context of their chemical structure. The ZnCl2(ImL1)2 and ZnCl2(ImL2)2 complexes showed good thermal stability at 341 °C and 365 °C, respectively. Photophysical properties, including UV-Vis absorption spectra in ethanol solution and photoluminescence (PL) in both solid state and ethanol solution, were determined. UV-Vis adsorption data indicated that both free ligands had similar UV-Vis absorption properties, while their Zn (II) complexes had distinctive absorption characteristics. The fluorescence spectra show that both ligands and their corresponding Zn (II) complexes emit violet to cyan luminescence in the solid state at room temperature, while in ethanol solution at the same temperature, they exhibit efficient photoluminescence properties in the UV-A emission spectral region. Because of these photophysical properties, the synthesized ligands and their cognate Zn (II) complexes can be used as scaffolds for the potential development of optoelectronic materials.

Unexpected Cu and Zn speciation patterns in the broiler feed-animal-excreta system revealed by XAS spectroscopy

Trace minerals such as copper (Cu) and zinc (Zn) are animal nutrition supplements necessary for livestock health and breeding performance, yet they also have environmental impacts via animal excretion. Here we investigated changes in Cu and Zn speciation from the feed additive to the broiler excreta stages. The aim of this study was to assess whether different Cu and Zn feed additives induce different Cu and Zn speciation patterns, and to determine the extent to which this speciation is preserved throughout the feed-animal-excreta system. Synchrotron-based X-ray absorption spectroscopy (XAS) was used for this investigation. The principal findings were: (i) in feed, Cu and Zn speciation changed rapidly from the feed additive signature (Cu and Zn oxides or Cu and Zn sulfates) to Cu and Zn organic complexes (Cu phytate and Zn phytate). (ii) in the digestive tract, we showed that Cu and Zn phytate were major Cu and Zn species; Cu sulfide and Zn amorphous phosphate species were detected but remained minor species. (iii) in fresh excreta, Cu sulfide and Zn amorphous phosphate were major species. These results should help to: (i) enhance the design of future research studies comparing different feed additive performances; (ii) assess Cu and Zn bioavailability in the digestive tract; (iii) gain further insight into the fate of Cu and Zn in cultivated soils when poultry manure is used as fertilizer.

Nano metal complexes of a new carbohydrazone based ligand as potential antitumor agents: Structural elucidation, thermal behavior, molecular modeling, docking simulation, DNA cleavage, and AC conductivity studies

New carbohydrazone ligand DCCHP, were prepared by condensing 5,6-diphenyl-4-carbohydrazide-3(2H)-pyridazinone and 3-formyl chromone. Moreover, the new nano Co(II), Ni(II), Cu(II), Zn(II), Fe(III) complexes, and oxovanadium(IV), dioxouranium(VI) complexes of the ligand DCCHP, in addition of new mixed-ligand complexes using 8-HQ or 2,2′-bipy as an auxiliary ligand, were synthesized. The newly synthesized compounds have been characterized using a variety of analytical and spectroscopic techniques. The results showed that the ligand acted as tridentate towards the metal ions. The complexes exhibited octahedral geometries. According to TEM analysis, the particles of the investigated complexes were located at the nanoscale with spherical and stick shaped. The computational molecular properties revealed that the examined metal complexes may have higher chemical reactivity than the free ligand. The inhibitory activity of the investigated compounds with DNA molecules [of the dodecamer sequence (PDB ID: 1BNA)] were studies by molecular docking simulation. The docking findings showed strong interactions of both the ligand and its Cu(II) complex 7 with DNA. The results of antimicrobial activities showed enhancement in activity of the free ligand upon coordination with the metal ions. Moreover, the nano Cu(II) complex 9 and the nano Zn(II) complex 12 exhibited strong antitumor activities against Hepatocellular carcinoma cell line (HepG-2 cells) with IC50 values smaller than the standard drug cis-platin and may be act as promising antitumor agents against HepG-2 cells. The DNA cleavage investigation demonstrated the capacity of the ligand and its nano Cu(II) complex 7 to destroy DNA. The electrical conductivity study in solid-state confirmed that the ligand and its Cu(II) complexes had semiconducting properties.

The static and frequency‐dependent second‐ and third‐order nonlinear optical properties of Zn(II) and Ni(II) complexes of 4‐methoxypyridine‐2‐carboxylic acid: A detailed experimental and theoretical study

Novel Zn(II) and Ni(II) complexes, [Zn(MeOPic)2(H2O)2] and [Ni(MeOPic)2(H2O)2] (MeOHPic = 4‐methoxypyridine‐2‐carboxylic acid [4meOHPic]), have been prepared and characterized by X‐ray diffraction (XRD), Fourier transform infrared (FTIR), and ultraviolet–visible (UV–Vis) techniques. Crystal structure analysis demonstrated that the 4meOHPic ligand is coordinated as a two‐dentate ligand through N and O atoms to central metal ions, and both of the complexes have distorted octahedral coordination geometry. The DFT‐B3LYP/6‐311++G(d,p)/LanL2DZ level was executed to perform DFT calculations for the Zn(II) complex with singlet spin state and the Ni(II) complex with triplet spin state. The UV–Vis electronic absorption spectra and natural bonding orbital (NBO) analyses also demonstrated that ligand–ligand and metal–ligand charge transfer interactions occur in Zn(II) and Ni(II) complexes. However, static and frequency‐dependent first‐order hyperpolarizability (β) parameters were found to be low because of the centrosymmetric crystal structures. As for the second‐order hyperpolarizabilities, the quadratic electro‐optical Kerr effect γ (−ω;ω,0,0) and electric field induced second harmonic generation γ (−2ω;ω,ω,0) parameters were calculated as 13.04 × 10−36 and 2258.9 × 10−36 esu for Ni(II) complex. Accordingly, it was demonstrated that Ni(II) complex is a potential candidate for third‐order nonlinear optical (NLO) materials.

Spectral Characterization and Antimicrobial Activity of Chenodeoxycholic Acid Complexes with Zn(II), Mg(II), and Ca(II) Ions

Chenodeoxycholic acid (CA) is a naturally occurring bile acid that is produced in the liver from cholesterol. Three CA complexes using Zn(II), Mg(II), and Ca(II) ions were synthesized to examine the chelation tendencies of CA towards these metal ions. The complexation reaction of CA with the metal ions under investigation was conducted with a 1:1 molar ratio (CA to metal) at 60–70 °C in neutralized media, which consisted of a binary solvent of MeOH and H2O (1:1). The resulting CA complexes were characterized using elemental data (metal, H, C, and Cl analysis) and spectral data (UV–visible, FT-IR, and 1H NMR). The results suggested that CA in anion form utilized oxygen atoms of the carboxylate group (-COO−) to capture Zn(II), Mg(II), and Ca(II) ions. This produced complexes with the general compositions of [Zn(CA)(H2O)Cl], [Mg2(CA)2(H2O)4Cl2], and [Ca2(CA)2(H2O)4Cl2]·2H2O, respectively. The Kirby–Bauer disc diffusion assay was then used to explore the bioactivity of the CA complexes toward three fungal species (Aspergillus niger, Candida albicans, and Penicillium sp.), three Gram-positive bacteria (Staphylococcus aureus, Streptococcus pneumoniae, and Bacillus subtilis), and two Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli). The Ca(II) and Mg(II) complexes exhibited marked inhibitory effects on the cell growth of the fungal species Aspergillus niger with potency equal to 127 and 116% of the activity of the positive control, respectively. The Zn(II) and Ca(II) complexes strongly inhibited the growth of Penicillium sp., while the Zn(II) and Mg(II) complexes showed strong growth inhibition towards the Gram-negative species Pseudomonas aeruginosa.

Regulatory Effects Mediated by Enteromorpha prolifera Polysaccharide and Its Zn(II) Complex on Hypoglycemic Activity in High-Sugar High-Fat Diet-Fed Mice.

In order to investigate and develop functional foods of marine origin with hypoglycemic activity, Enteromorpha prolifera polysaccharide-Zn(II) (EZ) complex was first prepared by marine resourced E. prolifera polysaccharide (EP) and ZnSO4 and their anti-diabetes activities against high-sugar and high-fat-induced diabetic mice were evaluated. The detailed structural characterization of EZ was elucidated by UV-Vis spectroscopy, infrared spectroscopy, and monosaccharide composition determination. The pharmacological research suggests that EZ has a potent hypoglycemic effect on high-sugar and high-fat-induced diabetic mice by inhibiting insulin resistance, improving dyslipidemia, decreasing inflammatory status, repairing pancreas damage, as well as activating the IRS/PI3K/AKT signaling pathway and regulating GLUT2 gene expression. At the same time, microbiota analysis indicates that a high dose of EZ could enhance the abundance of dominant species, such as Staphylococcaceae, Planococcaceae, Muribaculaceae, Aerococcaceae, and Lacrobacillaceae, in intestinal microbiota distribution. Thus, EZ could be considered as a potential candidate for developing an ingredient of functional foods for Zn(II) supplements with hypoglycemic activity.

Synthesis, crystal structure, antifungal activities, Hirshfeld surface analysis and molecular docking studies of (2-cycloheptylidenehydrazene-1-carbothioamide) and its complex bis(2-cycloheptylidenehydrazene-1-carbothioamide)Zn(II)

Single crystals of (2-cycloheptylidenehydrazene-1-carbothioamide) and its complex bis(2-cycloheptylidenehydrazene-1-carbothioamide)Zn(II) were synthesized. The ligand is in Monoclinic crystal system with empirical formula C8H15N3S and space group P2,1/c with unit cell parameters as a = 12.7532(8) Å, b = 11.7043 (11) Å, c = 13.3287 (9) Å, α = 90°, β = 92.269° and γ = 90° Zinc(II) complex of this ligand [(C8H14N3S)2 Zn] crystallises in Triclinic crystal system with space group P1 and unit cell parameters as a = 8.2143(11) Å, b = 10.2155(13) Å, c = 13.6845(16) Å, α= 84.295(4)°, β= 78.785(4)° and γ= 68.220(4)°. From crystal data analysis, (2-cycloheptylidenehydrazene-1-carbothioamide) exist as a dimer with one cycloheptylidene ring in chair conformation and the second ring in twist chair conformation and for the synthesized Zn(II) complex which is in distorted tetrahedral geometry by geometry index value, one Cycloheptylidene ring is in chair conformation and the other ring is in twist chair conformation. Totally four intermolecular H-bonds are present in the ligand, two of them makes possible the dimeric existence and also one S of each dimer makes other two H-bonds and makes possible the three dimensional arrangement in its lattice structure. From the data of complex, there are two intra molecular H-bonds between C(1)-H—S(1) and C(14)-H—S(2) making the structure rigid and also four inter molecular H-bonds by each carbothioamide moiety of the molecule resulting in a three dimensional sheet like arrangement. Extensive electron delocalisation in carboothiamide moiety of both the molecules are confirmed by the corresponding bond lengths. Both these compounds are proved to be highly promising antifungal agents against the organism Candida Albicans compared to the standard drug Clotrimazole in invitro studies as well as computational docking studies.

Synthesis, characterization, spectroscopic study and biological evaluation of Zn(II), Ni(II), and Cu(II)complexes derived from(1-methyl-1H-imidazol-2-yl)methanol

This study focuses on the synthesis, the structural studies of four new divalent metal coordination complexes of (1-methyl-1H-imidazol-2-yl)methanol (Hmim), and the assessment of their antimicrobial activity against five pathogenic microorganisms as well as their antioxidant potential. M(II) complexes were prepared by condensation of Hmim with Zn(OAc)2, Cu(OAc)2, NiCl2·6H2O, or CuCl2 in dry 1,2-dimethoxyethane at rt.. The ligand and its complexes have been characterized systematically by elemental analysis, FT-IR and UV–vis spectroscopy, and single-crystal X-ray diffraction. In [Zn(Hmim)2(OAc)2] (1)four donor atoms surround the metal ion displaying tetra-coordinated compound in distorted tetrahedral geometry, while in [Cu(Hmim)3OAc].AcOH (2), the Cu(II) ion is coordinated by three Hmim ligands and one acetate ligand displaying a tetragonally distorted octahedral environment. In [Ni(Hmim)2(H2O)2]Cl2(3), and [Cu(Hmim)3]Cl2 (4), the ligand is coordinated to M(II) ions in bidentate fashion exhibiting a distorted octahedral environment, the chloride anions act only as counter ions. The free ligand and its complexes 1–4 were tested in vitro for their antimicrobial activity against the growth of five strains including Gram (+) and Gram (-) bacteria, a Gram (+) phytopathogenic bacteria, a yeast and a fungus using the agar diffusion method. The SAR study of the antibacterial activity revealed significant differences in their inhibition activity profile, where 1 gave the best results displaying significant inhibition effects with a broad spectrum. The free-radical scavenging activity of synthesized compounds was investigated through their DPPH radical scavenging capacity, and has shown moderate to interesting antioxidant potential.

Novel Zn- and Cd-Schiff base complexes as the potent anticancer agents: Synthesis, spectral characterization and theoretical study

A novel unsymmetrical bidentate Schiff base ligand and its complexes, with the common formula of MLX2 (M(II) = Zn(II) and Cd(II); X− = Cl−, Br− and I−), using a reaction between 1,2-diaminobenzene and (E)-3-(4-(Dimethylamino) phenyl) acrylaldehyde were successfully synthesized. The structure of all the as-made compounds was identified by techniques including 1H NMR,13C NMR, ESI-mass, FT-IR, UV–Vis, melting point and molar conductivity. The analytical and spectral data confirmed the metal to ligand ratio of 1:1 in the Zn(II) and Cd(II) complexes. The anticancer activity of the compounds on cancer cells was investigated on HCT116 cell line, where the MTT method was used to screen cytotoxicity effects. The flow cytometry method also was used to determine the mechanism of cell death. Our data reveal that CdLCl2 can block the cell cycle and induction apoptosis. In addition, using Gaussian 16 program, the structure of the samples was optimized, and some important properties such as enthalpy change, entropy change and total energy were extracted. The molecular electrostatic potential, nonlinear optical properties, natural bond orbital and frontier molecular orbitals analysis were calculated for all compounds. Further, the electrophilic and nucleophilic sites, energy gap, ionization potential, electron affinity, natural population analysis and natural atomic orbitals were studied.

Synthesis, Characterisation and Biological Activity of New Co, Ni, Zn and Cd Polymeric Complexes Derived from Dithiocarbamate Ligand

Synthesis, Characterisation and Biological Activity of New Co, Ni, Zn and Cd Polymeric Complexes Derived from Dithiocarbamate Ligand

Synthesis, spectroscopic, thermal analysis and in vitro cytotoxicity, anticholinesterase and antioxidant activities of new Co(II), Ni(II), Cu(II), Zn(II), and Ru(III) complexes of pyrazolone-based Schiff base ligand

Metal-based drugs have gained significant importance in medicine in recent years. In this research, a series of new Co(II), Ni (II), Cu (II), Zn(II), and Ru(III) complexes of a Schiff base ligand, (1,5-dimethyl-4-((1-(3-nitrophenyl)ethylidene) amino)-2-phenyl-1,2-dihydro-3H-pyrazol-3-one), were prepared for the first time in excellent yields, and characterized by elemental analysis, FT-IR, 1H NMR, 13C NMR, ICP-OES, and thermal analysis. The in vitro antiproliferative, anticholinesterase, and antioxidant properties of complexes 1–5 were evaluated. The cytotoxic effects of complexes 1–5 on the viability of colon cancer (DLD-1), breast cancer (MDA-MB-231), and healthy lung (Wl-38) cell lines were investigated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method in vitro. The anticancer activities of the ligand and its metal complexes were lower than those of the reference drug, cisplatin. In anticholinesterase activity studies, complex 4 (88.46±0.45% inhibition) in butyrylcholinesterase (BChE) assay showed a higher inhibitory effect than the standard compound galanthamine with 78.14±0.55% inhibition. In antioxidant assays, some complexes showed higher antioxidant activities than standard antioxidant butylated hydroxytoluene (BHT). Among the prepared complexes, complex (4) (IC50=5.91±0.17 µM) in ABTS assay showed the highest antioxidant activity compared to BHT (IC50=16.19±0.17 µM). Also, this complex (IC50=10.17±0.36 µM) showed the best antioxidant activity in CUPRAC assay compared to BHT (IC50=39.37±0.12 µM).