Molar Conductance Measurements Research Articles

STRUCTURAL FEATURES, COMPUTATIONAL STUDIES AND BIOLOGICAL ANALYSIS: SCHIFF’S BASE LIGAND AND ITS COORDINATION COMPOUNDS

Structure and biological application based analysis has been carried out for Schiff’s base ligand containing nitrogen and sulphur donor atoms and also for a series of its coordination compounds. Ligand benzil-bis(5-amino-1,3,4-thiadiazole-2-thiol) (L) has been prepared and structural features of ligand investigated by elemental analyses, IR, 1 H-NMR, mass spectra and molecular modeling studies. The chemical reaction of the prepared ligand with metal ions afforded mononuclear coordination compounds of Mn(II) and Co(II) metal ions. The characterization of the coordination compounds is being based on the techniques i.e. elemental analysis, infra-red, UV-visible as well as melting point, molar conductivity and magnetic moment measurement. A computational study has been done to understand the miscellaneous coordination modes of ligand to metal ions. Characterization result shows that coordination compounds exhibit a six coordinated geometrical arrangement i.e. octahedral geometry. The biological inhibition zone (antifungal and antibacterial activities) of synthesized compounds, i.e. ligand and its coordination compounds, has been monitored using well diffusion technique

Synthesis, Characterization and Thermogravimetric Study of Some Metal Complexes of Selenazone Ligand Nanoparticles Analogue of Dithizone

A new method for preparing 1,5-diphenylselenocarbazone (selenazone) nanoparticles and their complexes with Pb2+, Cd2+, Co2+, and Ni2+ has been performed using hot methanol solvent. The ligand and its complexes were characterized using FT-IR, UV-Vis, 1H-NMR, 13C-NMR, X-ray powder diffraction (XRD), EI-mass spectrometry, scanning electron microscopy (SEM), HG and flame-atomic absorption spectrophotometer, thermal analysis (TG/DTA), and molar conductance measurements. The molar conductance measurements in all complexes were recorded low values in DMSO, indicating that all the metal complexes were non-electrolytes except the nickel complex that possessed an electrolytic nature. Kinetic and thermodynamic parameters of complexes (A, E, ∆H, ∆S, and ∆G) have been computed using three kinetic models of Coast-Redfern, Broido, and Horowitz-Metzger, that illustrated the decomposition reactions in all steps were nonspontaneous. Thermogravimetric analyses (TG/DTA) were consistent with the atomic spectroscopy data proving that the geometry shape of all the complexes was octahedral.

Anticancer, in vitro cytotoxicity and antimicrobial properties of a Schiff base ligand, 3-((2-(-(1-(2-hydroxyphenyl)ethylidene)amino)ethyl)imino)-N-(p-tolyl)butanamide, and its metal complexes

A Schiff base ligand, 3-((2-(-(1-(2-hydroxyphenyl)ethylidene)amino)ethyl)imino)-N-(p-tolyl)butanamide, was synthesized by the condensation of o-hydroxylacetophenone, p-methylacetoacetanilide and 1,2-ethylenediamine and its V(IV)O, Cr(III), Mn(II), Fe(III), Co(II), Ni(II) and Cu(II) complexes have been prepared. The ligand and metal complexes were characterized analytically and spectroscopically by elemental analysis, HRMS, IR, 1H NMR, 13C NMR and UV-vis spectroscopies and molar conductance and magnetic susceptibility measurements. The ligand and its metal complexes have been evaluated for their cytotoxic activity against Dalton’s Lymphoma Ascites (DLA) cell line by Trypan blue exclusion method. In vivo anticancer studies using the Cu(II) complex in Swiss Albino female mice showed its potential efficiency against EAC-induced ascites tumor and DLA-induced solid tumor with an IC50 value of 46 µg/mL. Also, the complexes were tested for antibacterial and antifungal properties against some Gram-positive bacteria, Staphylococcus aureus, Bacillus cereus and Streptococcus criceti, and Gram-negative bacteria, Escherichia coli, Klebsilla pneumoniae and Pseudomonas aeruginosa and some fungi, Pencillium expansum, Fusarium oxysporum and Aspergillus niger. The complexes exhibited potential antibacterial and antifungal properties than the ligand, H2L, and in some cases even more than those of standard antibacterial and antifungal drugs.

Synthesis, structural, pharmacological and molecular docking simulations studies of Schiff base transition metal complexes procured from acetylacetonyl-4-iminoantipyrine and tyrosine

Schiff base complexes of Cu(II), Ni(II), Co(II), VO(II) and Zn(II) ions have been synthesized by condensation of acetylaceto-4-iminoantipyrine and tyrosine. The structural characterization of compounds has been investigated using elemental analysis, molar conductance and magnetic susceptibility measurements, UV-Vis., FT-IR, ESI-mass, 1H-NMR, 13C-NMR, ESR spectroscopy, cyclic voltammetry, XRD and SEM techniques. The observed analytical data indicate that the metal chelates have the general formula of [ML] type. Powder XRD pattern of Schiff base and its complexes authenticate their crystalline nature. From SEM morphology studies, the reduction grain size of Schiff base in metal chelates was observed which is due to the chelation of the Schiff base. From the IR, electronic absorption spectra and magnetic measurement data, square planar geometry was proposed for the metal complexes except for the [VOL] complex which exhibits square pyramidal geometry. The X-band ESR spectra of [CuL] and [VOL] complexes in DMSO solution were recorded at 77 & 300 K and their spin Hamiltonian parameter values support the proposed geometry. The interactions of the [CuL] complex with CT-DNA were investigated by UV-Vis and absorption titrations. DNA binding interaction studies reveal the hydrophobic interaction between CT-DNA and complexes. Furthermore, analgesic, anti-inflammatory, CNS and antimicrobial studies of the Schiff base and its transition metal complexes were examined and resolved metal complexes have enhanced pharmacological and biological activity when compared to free Schiff base. Molecular docking studies of the complex with DNA and (PDB ID: 6COX) protein were investigated.

Novel Dithiocarbamate Complexes of 2-Methyl-1, 1-Diiodo-1-Telluracyclopentane [C4H7(CH3)TeI2]: Synthesis, Spectroscopic Characterization, Antibacterial Assay and In Silico Molecular Docking Studies

In the present study, a novel series of (2-methyl-1,1-bis-alkyl/aryl dithiocarbamate telluracyclopentane) &(2-methyl-1-Iodo-1-alkyl/aryldithiocarbamate tellura cyclopentane) were synthesised using precursor 2-methyl-1,1-diiodo telluracyclopentane and characterised by IR-, 1HNMR-, 13CNMR-, UV- spectral studies, molar conductance and elemental analysis measurements. The synthesis, characterisation and antibacterial activity in vitro were all discussed. Docking tests were conducted in silico to determine the inhibitor's binding free energy within the molecule. . Autodock 4.2. binding energy, root mean square deviation and hydrogen bond association are all important characteristics to consider. The results show that the selected ligands have binding energies ranging from -4.31 kcal/mol to -8.06 kcal/mol for cyclooxygenase-2 and -3.66 kcal/mol to -6.14 Kcal/mol for alpha-haemolysin and their protein-ligand interactions are displayed using two software programmes, protein-ligand interaction profiler and Pymol.

New solvatochromic complexes of 1,2‐bis[(5,6‐diphenyl‐1,2,4‐triazin3‐yl)hydrazinylidene‐methyl]benzene: Synthesis, spectroscopic, biological, docking, and theoretical studies

A new bistriazine hydrazone ligand (H2L; H2BDTB) is derived from 5,6‐diphenyl‐1,2,4‐triazine‐3‐ylhydrazine (DTH) with o‐phthalaldehyde in ratio (2:1). The Fe(III), Co(II), Ni(II), Cu(II), and Th(IV) complexes (1–5), as well as the Co(II) complex (6) (prepared in the presence of cetyltrimethylammonium bromide [CTAB]), are synthesized. They are characterized by elemental analyses, spectral (ultraviolet–visible [UV–Vis], infrared [IR], mass, 1H NMR, and electron spin resonance [ESR]), magnetic susceptibility, molar conductivity, and thermal gravimetric analysis (TGA) measurements; and morphological structures are scanned by electron microscopy (SEM) that showed rod shape, irregular bulk sheets, and fused aggregated clusters for free ligand, Co(II) complexes (2 and 6), respectively. Moreover, cobalt(II) complex (6) exhibited an octahedral geometry; however, cobalt(II) complex (2) showed square planar geometry as deduced from magnetic moment and UV–Vis measurements. Fluorescence spectra for ligand and its Fe(III) and Th(IV) complexes have been measured in different solvents to investigate their solvatochromic behavior that used to estimate dipole moments either in ground and excited states. The antimicrobial and antitumor activities of free ligand and its complexes were investigated, in addition to molecular docking studies using MOE 2014.0901 software (PDB. I.D.3ce3). The data showed that Co(II) complex (6) can be nominated as one of the most powerful antitumor. The theoretical calculation for bistriazine ligand and its complexes were performed using DFT and PM3, and the data are correlated with the experimental results.

Synthesis, spectroscopic characterization, and thermal studies of novel Schiff base complexes: theoretical simulation studies on coronavirus (COVID-19) using molecular docking

Novel Schiff base ligand was prepared by the condensation of 2,2-(ethylenedioxy)bis(ethylamine) and imidazole-2-carboxaldehyde in a 1:2 ratio, and its complexes with Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), and Cd(II) metal ions were synthesized in a 1:1 ratio. Various methods were used to identify the Schiff base ligand and complexes. Characterization techniques such as infrared, UV, and 1H NMR spectral tests, elemental analysis, molar conductivity, magnetic properties, thermal analysis, BET surface area, and theoretically by DFT were used to help further understanding of the complex structures. For all complexes, the ligand behaved as a neutral tetradentate ligand with NOON donor atoms and spectroscopic studies indicated an octahedral structure. The electrolytic behavior of the complexes was revealed by the molar conductivity measurements. In addition, thermogravimetric analysis was used to investigate the decomposition of the complexes and Schiff base ligand. According to the results obtained, the antibacterial activity of the metal complexes is higher than that of the Schiff base ligand against one or more bacterial species. The results showed that Cd(II) complex exhibits enhanced activity against Aspergillus flavus and Ni(II) complex against Candida albicans than the standard drug ketoconazole. The Mn(II) complex had stronger activity against human breast cancer cell line (MCF-7) than the other complexes. Antiviral drug development is critical in the latest outbreak of a novel coronavirus (SARS-CoV-2). The new coronavirus was screened using molecular docking.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13738-021-02359-w.

Syntheses, Magnetic, Spectral and Biological Studies on the Coordination Compounds of N-(2-Hydroxyphenyl)-C-(3′- Carboxy-2′-Hydroxyphenyl) Thiazolidin-4-One

A dry benzene solution of the Schiff base, N-(2-hydroxyphenyl)-3′-carboxy-2′- hydroxybenzylideneimine upon reacting with mercaptoacetic acid undergoes cyclization and forms N- (2-hydroxyphenyl)-C-(3′-carboxy-2′-hydroxyphenyl)thiazolidin-4-one, LH3 (I). A MeOH solution of I reacts with Ni(II) and UO2(VI) ions and forms the monomeric coordination compounds, [Ni(LH)(MeOH)3] and [UO2(LH)(MeOH)]. The coordination compounds have been characterized on the basis of elemental analyses, molar conductance, molecular weight, spectral (IR, reflectance) studies and magnetic susceptibility measurements. I behaves as a dibasic tridentate OOS donor ligand in these compounds. The compounds are non-electrolytes (M = 4.3-6.4 mho cm2 mol-1) in DMF. Octahedral structure for Ni(II) and UO2(VI) compounds are suggested. LH3 (I) and its complexes while testing with E.Coli. (Gram Negative) and S. Aureus (Gram positive) bacteria show antibacterial activities.

Ru3+, Mn2+, Co2+, Ni2+, Cu2+, and Zn2+ uni-metallic complexes of 3-(-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl) methylene) hydrazono)indolin-2-one, preparation, structure elucidation and antibacterial activity

Ru3+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+ uni-metallic complexes of dihydrazone derived from the condensation of 3-hydrazonoindolin-2-one with 4-formyl antipyrine were synthesized. The resulted dihydrazone and its chelated compounds structurally characterized basing on spectroscopic tools (NMR, FT-IR, EAS, ESI-MS) thermo-gravimetric, elemental, magnetic and molar conductance measurements. This structural elucidation leads us to conclude that the dihydrazone has been performed as a neutral bidentate chelator linked the Ru3+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+ ions via the carbonyl and azomethine of isatin moiety adopting regular or distorted octahedral structures around the central metallic ions. The structural description of dihydrazone and its chelated compounds have been endorsed basing on the Density Functional Theory calculations. The optimized geometry, global reactivity descriptors, and LUMO-HOMO orbitals and of the molecules have been calculated by the DFT-B3LYP method and 6e311G(d,p) basis set. The molecular electrostatic potential picture has been painted utilizing the same level of theory to envision the molecules charge distribution and chemical reactivity. The DFT studies of the designated compounds revealed small HOMO-LUMO gap which is a strong indication to the large reactivity these compounds. The TG analysis has confirmed the complexes chemical formulae and assured that the thermo-degradation processes occur in three or four steps ended with the formation of metal oxide or carbon-contaminated metal oxide residues. The In-vitro antibacterial of dihydrazone and its chelated compounds have been evaluated against E. coli, P. aeruginosa, K. pneumonia and B. subtilis, the observed antibacterial result denoted that Cu2+ and Zn2+ complexes have a good activity in comparation with the free dihydrazone.

Synthesis, spectroscopic and biological activity evaluation of Ni(II), Cu(II) and Zn(II) complexes of schiff base derived from pyridoxal and 4-fluorobenzohydrazide

A novel Schiff base ligand, 4-fluoro-N-((3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-4-yl)methylene)benzohydrazide (PLFBH) was synthesized by condensationof pyridoxal and 4-fluorobenzohydrazide. Its complexes with Ni(II), Cu(II), and Zn(II) metal ionswere prepared and characterized by spectroscopic IR, 1H-NMR, UV, LC-MS, ESR, and powder XRD studies and by elemental analysis and thermal analysis, molar conductance, and magnetic susceptibility measurements. The results indicate the geometry of the complexes to be hexa coordinate distorted octahedral. Based on the electronic absorption and fluorescence emission spectra and viscosity studies, an intercalative mode of binding of the complexes with CT-DNA was suggested, which was also supported by DNA docking studies. The docking studies of metal complexes with DNA were carried out using Autodock 4.2. The in vitro anticancer assay for the Cu(II)-PLFBH complex was performed to assess the ability of the complex to inhibit human cell proliferation on HeLa human cervical carcinoma cells, MCF-7 human breast carcinoma cells, and A549 human lung carcinoma cells. The Cu(II)-PLFBH complex exhibited moderate to good inhibitory effect on the cancer cell lines studied. The complexes showed good cleavageability toward plasmid pBR322 DNA. The metal complexes were found to show good antibacterial activity against gram positive bacteria, Staphylococcus aureus and Bacillus cereus and gram negative bacteria Escherichia coli and Pseudomonas aeruginosa cultures,while the ligand showed marginal activity. Supplemental data for this article is available online at https://doi.org/10.1080/15257770.2021.1961271 .

Synthesis, spectroscopic, DFT and docking studies, molecular structure of new Schiff base metal complexes

A Schiff base ligand (H2L) and its complexes have been synthesis and characterized by analytical tools, spectral (IR and 1H NMR), molar conductivity and magnetic moment measurements. The thermal analysis (TG) technique is studied within the temperature range from room temperature to 1000 0C. The IR spectra pointed out that the ligand (H2L) coordinated to the metal ions through two nitrogen and tow oxygen atoms in a binegative mode. The structural formula of the synthesized Schiff base ligand was optimized using Gaussian09 program where the energy gaps and other important theoretical parameters were calculated applying the DFT/B3LYP method. In vitro biological activities of the Schiff base ligand (H2L) and its metal complexes were screened against Gram(+) bacteria (Bacillis subtilis and Staphylococcus aureus) and Gram(-) bacteria (Escherichia coli and Pseudomonas aeruginosa) using agar diffusion method. The results illustrated that the synthesized complexes are biologically active than the Schiff base ligand. Molecular docking study was carried out between the Schiff base ligand and crystal structure of Escherichia Coli, crystal structure of Staphylococcus Aureus, crystal structure of -Bacillus subtilis and crystal structure of P. aeruginosa.

Synthesis, characterization, in vitro antioxidant and antimicrobial activities of diorganotin(IV) complexes derived from hydrazide Schiff base ligands

We have synthesized new diorganotin(IV) complexes of the type R2SnL (where R; methyl, ethyl, butyl and phenyl) of Schiff base ligands N'-(5-chloro-2-hydroxybenzylidene)thiophene-2-carbohydrazide (H2L1), N'-(4-(diethylamino)-2-hydroxybenzylidene)thiophene-2-carbohydrazide (H2L2), N'-(3,5-dibromo-2-hydroxybenzylidene)thiophene-2-carbohydrazide (H2L3) and N'-(2-hydroxy-5-methoxy-3-nitrobenzylidene)thiophene-2-carbohydrazide (H2L4). Spectroscopic methods (FT-IR, UV–vis, 1H, 13C and 119Sn NMR), elemental analysis, mass spectrometry, melting point and molar conductance measurements were used to elucidate the structures of compounds (1-20). The spectroscopic data indicated that the Schiff bases are tridentate (NOO) in nature and coordinated to the tin metal through enolic oxygen, azomethine nitrogen and aromatic hydroxyl oxygen donor atoms to display pentacoordinated geometry around the central tin metal. To examine the biological profile, the synthesized compounds were tested for in vitro antimicrobial activity against different bacterial and fungal strains by using serial dilution method which revealed that compounds Bu2SnL3 (15) and Ph2SnL3 (16) were most active antimicrobial agent. The compounds were further tested for antioxidant activity by using DPPH (1,1-diphenyl-2-picrylhydrazyl) assay. Complex Ph2SnL3 (16) exhibited highest antioxidant potential with lowest IC50 value (2.95 μM) among all the tested compounds.

Synthesis, Biological and In Silico Studies of a Tripodal Schiff Base Derived from 2,4,6-Triamino-1,3,5-triazine and Its Trinuclear Dy(III), Er(III), and Gd(III) Salen Capped Complexes.

A tripodal Schiff base ligand, 2,4,6-Tris(4-carboxybenzimino)-1,3,5-triazine (MT) and its trinuclear Dy(III), Er(III), and Gd(III) complexes were synthesized. These were characterized using UV-visible, IR, 1H, and 13C NMR spectroscopies, elemental analysis, and molar conductivity measurements. The spectral studies indicate that the ligand is hexadentate and coordinates to the Ln(III) ions through the oxygen atoms of the carboxylic group. The trinuclear complexes were characterized as being bridged by carboxylate anions to the Dy(III), Er(III), and Gd(III) salen centers and displaying a coordination number of six. Biological studies revealed that MT is more active against the test micro-organisms relative to the trinuclear complexes. Acute toxicity studies revealed that MT is safe and has a wide range of effective doses (ED50). In vivo antimalarial studies indicate that MT could serve as an effective antimalarial agent since it has parasitemia inhibition of 84.02% at 50 mg/kg and 65.81% at 25 mg/kg, close to the value (87.22%) of the standard drug—Artesunate. Molecular docking simulation studies on the compounds against SARS-CoV-2 (6Y84) and E. coli DNA gyrase (5MMN) revealed effective binding interactions through multiple bonding modes. The binding energy calculated for Er(III)MT-6Y84 and Er(III)MT-5MMN complexes showed active molecules with the ability to inhibit SARS-CoV-2 and E. coli DNA gyrase.

Spectroscopic studies, DFT calculations, thermal analysis, anti-cancer evaluation of new metal complexes of 2-hydroxy-N-(4-phenylthiazol-2-yl)benzamide

2-Hydroxy-N-(4-phenylthiazol-2-yl)benzamide was reacted with Cr(III), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Ag(I) metal ions to synthesize the corresponding coordination compounds. From the study, 2-hydroxy-N-(4-phenylthiazol-2-yl)benzamide was rearranged to 2-hydroxy-N-(4-phenyl-1,3-thiazole-2-yl)carboxymidic acid (HL) due to the keto-enol tautomeric forms, where the enol form is more dominant. The structures of the HL ligand and the newly synthesized coordination compounds have been characterized by elemental analysis, IR, UV-Visible, 1H NMR, ESR and mass spectral data, in addition to thermal gravimetric analysis (TGA) and magnetic and molar conductance measurements. The ligand behaves as a monobasic bidentate ON sites, where the bidentate binding of the ligand involving the phenolic oxygen and azomethine nitrogen. The binding modes of the coordination compounds were further confirmed using Gaussian 09 software. The complexes of Co(II), Cu(II), Zn(II), and Ag(I) were tested in vitro against human colon carcinoma cells (HCT-116). The IC50 values showed dramatic toxicity results for cobalt(II), copper(II) and zinc(II) complexes versus human colon carcinoma (HCT-116) cell line, compared to African green monkey kidney (VERO) normal cell line. According to the results of the IC50 values obtained for Co(II), Cu(II), Zn(II), and Ag(I) 1.5, 1.0, 1.8 and 7.3 μg/ml, respectively, compared to the reference drug (2.49 μg/ml), Co(II), Cu(II), Zn(II) compounds are considered strong antitumor agent while Ag(I) compound can be considered as a weak one. For both antifungal and antibacterial activities, HL and all its coordination compounds were evaluated. HL ligand has only high activity against B. subtilis and C. albicans while Co(II) and Zn(II) compounds have the highest activity against S. aureus, P. aeruginisa, B. subtilis and E. coli.

Spectroscopic and theoretical studies on some carbohydrazone complexes and evaluation of their biological potency, catalytic, and ionophore activities

In this work, Co2+, Ni2+, Cu2+, Pd2+, and UO22+ complexes of a carbohydrazone isatin ligand (H3L), are synthesized and structurally elucidated via various physic-chemical approaches (elemental analyses, magnetic, and molar conductance measurements, in addition to IR, NMR, UV–vis, PXRD, GC-MS, and ESR spectral studies). The low value of Ʌm suggested the non-electrolytic nature of the complexes. The proposed geometries were recognized using DFT optimization. Thermal degradation and kinetic parameters of the degradation stages were gauged. Optical bandgaps energies were assessed, and their values hinted at the photovoltaic features of the complexes. ESR spectrum of Cu2+ complex pointed out the existence of the last electron in dz2 ground orbital verifying its distorted (compressed) octahedral structure. A study of electrochemical behavior for Co2+ ions in the presence and absence of the ligand reinforced the successful condensation between Co2+ ions and the ligand. Pd2+ complex was investigated for its action in oxidative degradation of an organic azo-dye and exhibited encouraging activity. A new carbon paste electrode for Ni(II) ions determination based on Nˊ, 2-bis(Z)-2-oxoindolin-3-ylidene)hydrazine-1-carbohydrazide ionophore was investigated. The isolated compounds were assessed for their biological activity (antimicrobial activity, ABTS, and SOD-activity), and molecular docking studies were predestined against E. coli and S. aureus targets.

Synthesis, identification, biological activity and anti-cancer activity Studies of Hetrocyclic Ligand Azo-schiff Base with Au(III) Complex

This research involved preparation of 2-((E)-(1H-benzo.[d]imidazol-2-yl).diazenyl)-4-(((4-bromophenyl)imino)methyl)phenol and Au(III) complex which was prepared by mixing solution of metal salt with ligand solution at mole ratio[ M:L] 1:1 . Compounds prepared were identified by FT- IR,, elemental analyses (C.H.N). Molar conductance measurements, magnetic susceptibility UV-Visb. The biological activity of the compounds prepared were examined against the susceptible organisms Streptococcus, (Gram. Positive) and Escherichia coli ,(Gram .negative), as antibacterial and Penicillium. Sp and Aspergillus Niger as antifungal, The prepared compounds checked for anti-cancer activity; activity of anti-tumor against of breast cancer for human

Synthesis, Characterization, DFT, and Antibacterial Evaluation of Some Complexes of Co (II), Ni(II), Cu(II), Zn (II), and Cd (II) with Schiff Ligand

A Synthesized from a new neutral tridentate N2O Schiff base 4-(4-hydroxy-2-methoxybenzylidene)amino)-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one with serine amino acid ligand forms stable complexes with many ions such as Co (II), Ni (II), Cu (II),Zn(II), and Cd (II). The complexes were recognized in term of their elemental analysis, 1H-NMR, UV-Vis, XRD, thermal analysis (T.G,DTA,DSC), and calculation theoretical studies (DFT) were used to characterize the complexes. The ligand acts like a tridentate chelating agent according to physicochemical and spectral results, the ligand acts like a tridentate chelating agent IR, UV-Vis, molar conductivity, and magnetic susceptibility measurements, all refer to an octahedral geometry the general composition of all complexes [M(L)2] is (M=Co(II), Ni(II). Cu(II),Zn(II), and Cd(II) L= (K4-AMetB-Ser). Concluded through studies that,the coordination sites were established to be oxygen of the carboxyl COO- and two atoms nitrogen of the azomethine (CH=N) group based on the studies. The complexes non-electrolytic nature is verified by the lower conductivity data. Finally the antibacterial activity of the ligand and its complexes was tested against Staphylococcus aureus, Escherichia coli, and Pseudomonas aereuguinosa it was found that these compounds show different activity of inhibition bacteria growth.

Structure investigation, density functional theory, and biostudy of synthesized dihydrazone incorporating isatin moiety and its homo‐bimetallic complexes

AbstractSeven homo‐bimetallic complexes derived from 3‐(‐(1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)methylene)hydrazono)indolin‐2‐one with Fe3+, Co2+, Cu2+, and UO22+have been prepared and structurally investigated using elemental and thermo‐gravimetric analyses and spectral, magnetic, and molar conductivity measurements. This structural investigation leads us to conclude that the bis‐hydrazone has behaved as neutral tetradentate chelator chelated to the Fe3+, Co2+, Cu2+, and UO22+ions via the carbonyl and azomethine groups adopting distorted octahedral structure for Fe3+, Co2+, and Cu2+complexes (2–5), whereas the Cu2+complexes (6–7) have square planar structures. The structural characterization of bis‐hydrazone and its chelated compounds has been supported by density functional theory calculations. The optimized geometry, global reactivity descriptors, and lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) of the molecules have been calculated in accordance with the density functional theory (DFT)‐Beckee3eLeeeYangeParr (B3LYP) technique and 6e311G(d,p) basis set. The molecular electrostatic potential image was also drawn by the DFT‐B3LYP technique and 6e311G(d,p) basis set to envision the charge distribution and chemical reactivity on the molecules. The bioeffect of bis‐hydrazone and its chelated compounds was assessed against bacterial strainsBacillus subtilis,Escherichia coli, as well as fungal strainsCanadian albicansandAspergillus niger. The observed data imply encouraging bioeffect of some of these complexes in comparing with the free bis‐hydrazone or amphotericin B (AmB) against all fungalC. albicansandA. niger.

Synthesis and Characterization of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes with 2-Carboxy benzaldehyde Aroylhydrazones

A new metal complexes have been synthesized by a reaction of metal compounds contained Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) with two kinds of ligands that are 2-carboxy benzaldehyde 4-methylbenzoylhydrazone(CBMH) and 2-carboxy benzaldehyde picolinoyl hydrazine (CBPH), the ligands (CBMH and CBPH) were prepared by condensation of 2-carboxy benzaldehyde with 4-methylbenzoyl hydrazide or picolinoyl hydrazide, respectively. In fact, complexes[M(L-H)2]. xH2O were characterized by elemental analysis, molar conductance, magnetic susceptibility, and spectral measurements (UV-Vis, IR,). The hydrazones CBMH and CBPH act as monobasic tridentate ligands, in all their complexes. The ligand CBMH coordinated to the metal ions through the azomethine nitrogen, the carboxyl group oxygen, and the amide carbonyl group oxygen atoms, while the ligand CBPH coordinated through the carboxyl group oxygen, the azomethine nitrogen, and the pyridine ring nitrogen atoms. Physico-chemical studies suggest octahedral geometry for all metal(II) complexes.

Characterization and biological effectiveness of synthesized complexes of Palladium (II) from imine compounds

Abstract This article involved synthesizing of novel Palladium (II) complexes as follows: The imine compounds were prepared by reacting of aldehydes with the following nitrogen compounds: 4-methylbenzene-1,2-diamine, naphthalene-1,8-diamine, and 4-chloro-5-methyl benzene -1,2-di amine and sublimated into ethanol. The reaction was continued by thin layer chromatography (TLC), the imine compounds were determined by spectrophotometry of FT-IR UV-Visible, 1H-NMR. The palladium complexes were synthesizing from the reaction of the prepared imine compounds after they were dissolved using ethanol and palladium salt (PdCl2), which was dissolved by using absolute ethanol with 4 drops of 11.6 N of HCl acid and the mixture was raised for 3 hours, when the amine compounds reacted with the Palladium ion (II), this interaction leads to the formation of palladium complexes, the reaction was continued by thin layer chromatography (TLC), the complexes were spectrophotometrically characterized by measuring ultraviolet-visible and infrared rays, mass spectrometry, molar conductivity measurement. An important role in knowing the geometric shape of the complexes has proven that the palladium complexes have a square planer shape. Two types of bacteria were used, namely (Gram-Positive and Gram-Negative), and these types are: Staphylococcuus Aureus (Gram-Positive) and Escherichia coli (Gram-negative). Where they were chosen because they cause a number of diseases and both have a different nature of resistance to antibiotics and pharmaceuticals, as a number of prepared palladium complexes were selected to measure their effectiveness on these types of bacteria using the diffusion method. The results were good for some concentrations. © 2020 NIODC. All rights reserved