Molar Conductance Measurements Research Articles

Potency of copper(II) complexes towards drug-sensitive and -resistant Plasmodium falciparum: Structure-activity relationship, ROS-generation and proteasome inhibition

The use of copper in medicine has a long history and copper-containing compounds have multiple applications, such as in treating heart disease, arthritis, cancer, parasitic as well as other inflammatory diseases. Here, we investigate structural factors, structure-activity relationship and two mechanisms of action of a series of copper(II) complexes with 1,10-phenanthroline (phen) and/or amino acid ligands towards Plasmodium falciparum (Pf) 3D7 and artemisinin-resistant Pf5202. To achieve this, the following set of copper(II) complexes, viz. [Cu(phen)Cl2] 1, [Cu(phen)2Cl]Cl·2H2O 2, [Cu(phen)(gly)Cl]·2H2O 3, [Cu(phen)(edda)]·5H2O 4, cis-[Cu(gly)2(H2O)] 5 and [Cu(edda)] 6, (gly = glycine; edda = ethylenediamine-N,N’-diacetic acid) were selected, synthesized and characterized by FTIR, elemental analysis, UV-Visible spectroscopy, molar conductivity measurement and magnetic moment. Herein, we report comparison of aqueous copper(II) species, CuCl2 and ligands in inhibiting proteolytic sites of 20S proteasome, generation of reactive oxygen species, hemolysis and antimalarial property. Factors affecting their antimalarial potency are different from those affecting proteasome inhibition and ROS production. Complexes 1 – 4, with IC50 values of about 3 µM towards Pf3D7, were more effective against artemisinin-resistant strain Pf5202 than chloroquine and artemisinin. Evidence of apoptosis of malaria parasite in red blood cells is also presented.

Synthesis , Antibacterial Activity of Sm(III) Complex With L-phenylalanine

Synthesis , Antibacterial Activity of Sm(III) Complex With L-phenylalanine

PH-Responsive switching properties of a water-soluble dinuclear Cu(II) complex containing oximato bridges chelating ligand: Synthesis, crystal structure and computational study

This study presents a combined experimental and computational investigation on a dinuclear Cu(II) complex containing 3-[2-[(ethanol amino)ethyl]imino]-2-butanoneoxime ligand (L). The compound [CuL]2(NO3)2 was studied by IR, UV–Vis spectroscopy, thermogravimetry analysis, and molar conductance measurements. The square-pyramid geometry of the complex was confirmed by both the density functional theory level (DFT) calculation and X-ray crystallography. The complex was halochromic, and its halochromism was studied in an aqueous solution. The original green complex displayed reversible color change to blue in alkaline and colorless in acidic solutions. The pH effect on the visible absorption spectrum of the complex was studied that functions as pH-induced “off–on–off” switches triggered by the protonation and loss of the ligand L in acidic medium and deprotonation of ligand in a basic aqueous solution. Further computational analysis of the electronic structure of the complex was carried out to gain a deeper insight into the properties associated with molecular orbitals. Its electronic spectrum was analyzed, and bands were assigned through the time-dependent density functional theory level (TDDFT) calculation.

New mixed‐ligand iron(III) complexes containing thiocarbohydrazones: Preparation, characterization, and chemical reactivity analysis through theoretical calculations

Five new mixed ligand Fe(III) complexes, namely, [FeL1(acac)] (L1Fe), [FeL2(acac)] (L2Fe), [FeL3(acac)] (L3Fe), [FeL4(acac)] (L4Fe), and [FeL5(acac)] (L5Fe), were synthesized from the reaction of iron(III) acetylacetonate with [ONS] donor dibasic tridentate symmetrical bisthiocarbohydrazone ligands. Synthesized mixed ligand Fe(III) complexes were characterized with infrared spectra, UV‐Vis spectra, mass spectra, elemental analysis, magnetic susceptibility measurements, and thermogravimetric analysis. The molar conductance measurement in DMF solution confirmed that the complexes are nonelectrolytic. TGA analysis results showed that the thermal stability of the ligands and complexes was high. Antioxidant capacity and free radical scavenging activity of the mixed ligand Fe(III) complexes were investigated using CUPRAC and the DPPH radical scavenging method. Mixed ligand Fe(III) complexes showed higher antioxidant activity than ligands and reference compound. Popular conceptual density functional parameters like hardness, electrophilicity, dipole moment, and chemical potential for new ligands and their Fe(III) complexes were calculated and discussed. Chemical reactivity and stabilities of the studied chemical systems were analyzed with the help of well‐known electronic structure principles like maximum hardness principle (MHP), hard and soft acid–base (HSAB) principle, minimum polarizability principle, and minimum electrophilicity principle. L1Fe, which has the highest chemical hardness value, is the most stable complex according to MHP.

Experimental and theoretical evaluation of N-pyridoxal-salicylic acid hydrazide derived copper(II) complex with 2-methylimidazole

This article deals with the experimental and theoretical evaluations of N-pyridoxal-salicylic acid hydrazide (H2pd-sah) 1 and its mixed-ligand copper(II) complex with 2-methylimidazole, [Cu(pd-sah)(MeImdH)] 2. The compounds were characterized based on spectral (UV/Vis. IR) methods, powder-XRD, elemental analysis, and molar conductivity measurements. Both compounds' molecular structure and charge analysis were computed through B3LYP with 6-311 G (d, p) and LANL2DZ basic set using the Gaussian 09 W program package. The time-dependent density functional theory (TD-DFT) approach is used in gas-phase electronic transitions of 2 using the LANL2DZ basis set. Also, the computed UV-Vis based upon TD-DFT results and IR spectra were simulated for comparison with the experimental ones. The molecular structure based on theoretical investigation reveals that compound 2 adopts a distorted square planer N2O2 coordination sphere around the Cu(II). The ONO donor atoms of hydrazone moiety and one nitrogen of 2-methylimidazole constitute the N2O2 basal plane. Moreover, the in-vitro antioxidant activity was evaluated by DPPH assay in both compounds. In addition, Molecular docking studies were performed to predict the binding interaction between compound 2 and the Human Serum Albumin HSA (PDB ID: 1H9Z). Communicated by Ramaswamy H. Sarma

Synthesis, Structure, and Biologic Activity of Some Copper, Nickel, Cobalt, and Zinc Complexes with 2-Formylpyridine N 4-Allylthiosemicarbazone.

A series of zinc(II) ([Zn(H2O)(L)Cl] (1)), copper (II) ([Cu(L)Cl] (2), [Cu(L)Br] (3), [Cu2(L)2(CH3COO)2]·4H2O (4)), nickel(II) ([Ni(HL)2]Cl2·H2O (5)), and cobalt(III) ([Co(L)2]Cl (6)) complexes were obtained with 2-formylpyridine N4-allylthiosemicarbazone (HL). In addition another two thiosemicarbazones (3-formylpyridine N4-allylthiosemicarbazone (HLa) and 4-formylpyridine N4-allylthiosemicarbazone (HLb)) have been obtained. The synthesized thiosemicarbazones have been studied using 1H and 13C NMR spectroscopy, IR spectroscopy, and X-ray diffraction analysis. The composition and structure of complexes were studied using elemental analysis, IR and UV-Vis spectroscopies, molar conductivity, and magnetic susceptibility measurements. Single crystal X-ray diffraction analysis elucidated the structure of thiosemicarbazones HL, HLa, and HLb, as well as complexes 4 and 5. The antiproliferative properties of these compounds toward a series of cancer cell lines (HL-60, HeLa, BxPC-3, RD) and a normal cell line (MDCK) have been investigated. The nickel complex shows high selectivity (SI > 1000) toward HL-60 cell line and is the least toxic. The zinc complex shows the highest selectivity toward RD cell line (SI = 640). The copper complexes (2–4) are the most active molecular inhibitors of proliferation of cancer cells, but exhibit not such a high selectivity and are significantly more toxic. Zinc and copper complexes manifest high antibacterial activity. It was found that calculated at B3LYP level of theory different reactivity descriptors of studied compounds strongly correlate with their biological activity.

A two-step strategy to synthesis new aminoguanidinium complexes: cytotoxic effect and perspectives

The progress of transition metal complexes having anticancer activity has greater influence in cancer therapy. With the anticipation of investigating the anticancer activity and property of the transition metal complexes, Ni(II), Zn(II), and Cd(II) metal complexes of 1-hydroxy-2-naphthoic acid (1H2NA)/2-hydroxy-1-naphthoic acid (2H1NA) with aminoguanidine of ratio 1:1:2 were synthesized and characterized by spectroscopic studies like IR, UV–Vis, Thermal analysis, powder XRD, molar conductivity measurements, antimicrobial, and anticancer studies. Simple salts of 1-hydroxy-2-naphthoic acid (1H2NA)/2-hydroxy-1-naphthoic acid (2H1NA) with aminoguanidine were also prepared in different ratios viz, 1:1 and 1:2. It is characterized by spectroscopic measurements IR, UV, TG-DTA, powder XRD, molar conductivity measurements, and cytotoxic effects were also studied. Nanometal oxides of zinc complexes were prepared and surface morphological studies were investigated. The functional groups were confirmed from IR spectroscopy data. Band gap energies of all the synthesized compounds were calculated from UV–Visible spectroscopy. Various decomposition steps and the thermal stability of the compounds were determined from thermal analysis. From the molar conductivity measurements, it is confirmed that the compounds are electrolytes. SEM and TEM images confirm the rod and hexagonal shape of the respective nanometal oxides. The complexes and nanometal oxides show significant activity against antimicrobials like Staphylococcus aureus, Escherichia coli, and Aspergillus fumigates. The results of present research show that, the synthesized ligands and metal complexes at lower concentration predominantly shows higher cytotoxic activity against cancer cellular lines like MCF-7 and A-549 (human breast cancer cells and human lung cancer cells, respectively). DFT computational studies were carried out using GAUSSIAN 09 W software to understand the bonding mode and chemical parameters of the complexes were calculated using frontier molecular orbital studies.

Spectrophotometric determination of Zr(IV), Hg(II) and U(VI) in solution with their analytical applications: Structural characterization and molecular docking of the solid complexes

Spectrophotometry was used to determine trace amounts of Zirconium(IV), Mercury(II) and Uranium(VI) in environmental, biological, pharmaceutical and industrial samples. The determination depend on the complexation reactions between albendazole reagent and metal ions [Zr(IV), Hg(II) and U(VI)] at 555 nm, 485 nm and 510 nm, respectively. The experimental conditions were explored to reach the optimum conditions for albendazole-metal ions interaction, including detection of a suitable wavelength, medium (pH), reagent concentration, surfactants effect, reaction time and temperature. Under optimum conditions, the complexes displayed apparent molar absorptivities of 0.8350 × 104, 0.6210 × 104 and 0.7012 × 104 L mol−1 cm−1; Sandell’s sensitivity of 0.01092, 0.03230 and 0.03394 µg cm−2 and with linearity ranges of 1.0–120.0, 3.0–200.0 and 1.0–150.0 µg mL−1 for the developed methods, respectively. Furthermore, Elemental analysis, thermal analysis (TGA, DTG), IR, 1HNMR, spectroscopies, electrical molar conductivity and magnetic moment measurements were used to determine the structures and characteristics of the complexes. A careful examination of the IR spectra revealed that the ligand interacted with all of the metal ions described as a bidentate via the oxygen of the carbonyl of the ester moiety and the nitrogen atom of the heterocyclic CN group. An octahedral geometry for Zr(IV), Hg(II) and U(VI) complexes has been postulated based on magnetic and electronic spectrum data. The band gap values indicated that these complexes were semi-conductors and belong to the same class of extremely effective solar materials. The albendazole ligand and its complexes have been biologically tested against a variety of bacterial and fungal strains, and molecular docking studies have been conducted to evaluate the optimal binding site and its inhibitory action.

Synthesis, spectral studies and antimicrobial evaluation of transition metal complexes of bidentate Schiff base ligands derived from 4-amino quinoline

Coordination compounds of Co(II) , Ni(II), Cu(II) and Zn(II) of the type [M(L1-2)2(H2O)2] were obtained from Schiff base ligands [HL1-2] by the condensation reaction of 5-bromosalicyldehyde/5-chlorosalicyldehyde with 4-amino quinoline using methanol as a solvent in (1:1) molar ratio. The metal complexes were synthesized by reacting the aqueous methanolic solution of metal acetates M(CH3COO)2xH2O with the hot methanolic solution of their respective Schiff base ligands in (1:2) molar ratio. Various physicochemical techniques i.e. elemental analysis, molar conductance measurements, magnetic moment studies and different spectral studies (1H NMR, 13C NMR, UV–Vis, FT-IR, ESR) and mass spectrometry were used for characterization of compounds. The spectral data confirmed the bidentate nature (NO) of Schiff base ligands coordinating through nitrogen atom of azomethine group and oxygen atom of hydroxyl group resulting in the formation of octahedral geometry of all metal complexes. The Schiff base ligands and their transition metal complexes were screened against two gram-positive bacterial species i.e. (S. aureus, B. subtilis), two-gram negative bacterial species i.e. (E. coli, P. aeruginosa) and two fungal species (A. niger and C. albicans) using serial dilution method with ciprofloxacin and fluconazole as reference drug. The results obtained from antimicrobial studies showed that metal complexes are more active than their respective Schiff base ligands. Complex 5 and 6 are potent antimicrobial agent.

Ni(II), Zn(II), and Fe(III) complexes derived from novel unsymmetrical salen-type ligands: preparation, characterization and some properties

By using a half-salen ligand (HL) and substituted salicylaldehydes, new unsymmetrical salen-type ligands (H2L1, H2L2, and H2L3) and their Ni(II), Zn(II) and Fe(III) complexes were synthesized. The compounds were characterized based on elemental analysis, IR, 1H NMR, X-ray diffraction (for HL), spectroscopy, mass spectrometry, magnetic moment, molar conductance measurements, and thermal analysis (TGA). The unsymmetrical salen ligands, during complexation, are attached to the metal by two imine nitrogen atoms and two phenolic oxygen atoms in all complexes; in the Fe(III) complexes, the fifth coordination is completed by chloride. Square planar geometry or distorted square planar geometry for [NiL1-3], [ZnL1-3], and square pyramidal geometry for [FeL1-3Cl] are proposed. Conductance measurements suggest non-electrolytic nature of the metal complexes. Thermogravimetric analysis showed that the complexes exhibit higher stability than the ligands. The electrochemical properties of the compounds were studied by cyclic voltammetry. HOMO-LUMO energy levels and electrochemical band gaps (E′ g) were calculated. The solid state electrical conductivity of the iodine-doped compounds was measured and their semiconductor properties were determined. In addition, fluorescence properties of ligands and Zn(II) complexes were investigated.

Synthesis, spectroscopic and physico-chemical studies of novel pigments derived from Lithol Rubine

PurposeThe pursuit of manufacturing new inks with low financial cost is an urgent economic demand. Thus, the purpose of this paper is to synthesize some new pigments derived from Lithol Rubine (LR) via a successful simple route and to investigate their physicochemical properties for usage in the inks industry.Design/methodology/approachTwo novel pigments were generated during the reaction of LR with Mn(II) and Co(II) salts in ethanolic solutions. The obtained pigments were isolated as solid compounds and characterized through elemental analysis, UV–vis, Fourier transform infrared, 1H NMR spectra, oil absorption, specific gravity, melting point, molar conductivity and magnetic moment measurements. Their dyeing and durability characteristics were examined using American Standard Testing Methods. The synthesized pigments were then applied in inks formulation.FindingsThe printing inks containing the two new pigments (LR–Mn and LR–Co) were compared to (GF 59-606 and GF 59-616), respectively. The results of this study showed that the performance of newly prepared pigments was comparable to that of commercial pigments currently in use in the inks industry.Practical implicationsLR and its new derivative pigments can be used in other different applications such as paper coating, crayon, rubber and paint industries.Originality/valueThe authors designed an efficient synthesis for some novel pigments. The synthesis technique is featured by a short reaction time, high yields and ease of use. The pigments developed would be good and cost-effective substitute for the original commercially available and expensive pigments used in the inks industry.

Synthesis, spectral and thermal studies of new Schiff base copper(II) complexes with their biological effect on Entomopathogenic nematodes

AbstractNew Schiff base ligands; (Z)‐1,5‐diphenyl‐2‐((thiophen‐2‐ylmethylene)amino)‐1H‐pyrrole‐3‐carbonitrile (L1); or (Z)‐2‐((2,4‐dihydroxybenzylidene)amino)‐1,5‐diphenyl‐1H‐pyrrole‐3‐carbonitrile (H2L2) and their Cu(II) complexes have been isolated and characterized using elemental analysis, spectral (FT‐IR, 1H NMR, UV/vis, EPR), molar conductivity and magnetic moment measurements, in addition to thermal techniques. FT‐IR spectra established that the Schiff base L1 coordinates as neutral bidentate or tridentate ligand. While the Schiff base H2L2 ligates as neutral or monobasic bidentate ligand. The EPR spectra indicated covalent nature of complexes [CuL1(OH)]Cl.2H2O (1), [CuL1(OH)(H2O)2]NO3.2H2O (2), [Cu(H2L2)Cl(H2O)3]Cl.H2O (5) and [Cu(HL2)NO3(H2O)3].H2O (6). The biological effect of Cu(II) ions, current ligands and complexes (1, 5) on the mortality and rate of reproduction of Entomopathogenic nematodes (Heterorhabditis bacteriophora and Steinernema carpocapsae) was studied. The results showed that, the obtained Schiff base ligands and their Cu(II) complexes make detoxification of the lethal effect of Cu(II) ions on the beneficial Entomopathogenic nematodes and complex (1) scored the highest reproduction potential.

Metal complexes of a new azo ligand 2-[2′-(5-nitrothiazolyl) azo]-4-methoxyphenol (NTAMP): Synthesis, spectral characterization, and theoretical calculation

A new ligand 2-[2′-(5-Nitrothiazolyl) azo]-4-methoxyphenol (NTAMP) was synthesized using the coupling reaction between 2-amino-5-nitrothiazole and 4-methoxyphenol in an alkaline solution. The complexes of Co(III), Ni(II), and Cu(II) were synthesized by the direct reaction of the ligand with the appropriate metal salt. The ligand (NTAMP) and its metal complexes were characterized using different techniques including UV–vis, FT-IR, mass spectroscopy, 1H NMR, TGA-DTG, elemental analysis CHNS, and magnetic moment. Based on the results, the molar ratio of metal to ligand [M:L] of each metal complex was [2:1]. Molar conductance measurements for the synthesized complexes revealed an electrolytic nature of Co(III) complex with the ratio of 1:1 and non-electrolytic for the remaining complexes. Further, the ligand and its complexes were tested for their in-vitro activity against Staphylococcus aureus (gram-positive), Escherichia coli (gram-negative), and the fungus Penicillium spp. In general, all the tested compounds showed activity against the examined microorganisms, particularly Ni(II) complex, which was more active than others. In addition, Density Functional Theory (DFT) was used to discuss the optimization energy, HOMO, LUMO, and some physical properties of the studied complexes.

Metal complexes of hydrazone–oxime derivative as promising in vitro antimicrobial agents against some fungal and bacterial strains

In this study, Cu2+, Co2+, Ni2+, Mn2+, Zn2+, Fe3+, VO2+, and UO22+ complexes derived from a NNO tridentate chelating hydrazone–oxime, namely, N′‐((2E,3Z)‐3‐(hydroxyimino)butan‐2‐ylidene)benzohydrazide (H2L,1) were prepared. The elemental, thermo‐gravimetric, spectral, molar conductivity, and magnetic measurements were applied to elucidate the compositions and structures of these new compounds. In addition to the density functional theory (DFT), studies were employed to acquire optimal structures and quantum chemical parameters. The analyses indicate that the chelator reacted as a neutral or mononegative tridentate ligand bonded to the metal ions via the enolic/ketonic carbonylic oxygen, protonated/deprotonated oximatic nitrogen, and azomethine nitrogen atoms adopting square planar or distorted octahedral geometry. The structural characterization of hydrazone–oxime and its complexes was supported by DFT calculations according to the DFT‐B3LYP procedure and 6‐311+G(d,p) basis set. The theoretical data revealed that the reactivity of the complexes is greater than the free hydrazone–oxime (H2L,1), and there is a good agreement between the practical and theoretical data. The thermogravimetric investigation shows that the complexes break down in two to four decomposing steps in temperature range extended from 50 to 1000°C. In vitro antimicrobial activity data demonstrated an increase in activity of the hydrazone–oxime (H2L,1), upon chelation, and some metal complexes show enhanced antibacterial and antifungal agents.

Synthesis, anti‐proliferative activities, docking studies, and computational calculations of novel isonicotinic mixed complexes

AbstractIn this investigation, we studied the mixing of two ligands, isonicotinohydrazide (L1) and 3‐hydroxyisonicotinic acid (L2), with different metal ions to afford the corresponding stable metal complexes. Consequently, intensive physico‐chemical analysis including elemental analysis, UV–visible, Fourier transform infrared (FT‐IR), thermogravimetric analysis (TGA), mass, 1H nuclear magnetic resonance (NMR), X‐ray diffraction (XRD), magnetic, and molar conductance measurements has been performed. The thermal stability of all complexes was determined using TGA, and the kinetic parameters were obtained using the Coats–Redfern method. Both the degree of crystallinity and the unit cell of all complexes were determined utilizing XRD studies. Furthermore, these metal complexes exhibited excellent anti‐proliferative activity against human breast cancer (MCF‐7) and human liver cancer (HepG2) cell lines against the doxorubicin drug. The Co(II) complex outperformed all other metal complexes in terms of activity, which was confirmed by molecular docking stimulation via the binding energy with amino acids in a structural complex of Kaposi's sarcoma‐associated herpesvirus (KSHV) thymidylate synthase (PDBID:5H38) and the ternary complex of KRIT1 bound to both the Rap1 GTPase and the Heart of Glass (HEG1) cytoplasmic tail (PDBID:4hdq) and shortage. Moreover, these metal complexes were optimized via theoretical investigation through a density functional theory (DFT)/B3LYP/LANL2DZ basis set to confirm the stability of these metals theoretically and detect frontier molecular orbitals (FMO), electrostatic potential (ESP), energy gap, and physical computational calculations. Eventually, the electrochemical features were explored using cyclic voltammetry (CV) and electrochemical impedance spectra (EIS).

Spectroscopic and antimicrobial studies of Cr(III), Mn(II) and Co(II) complexes with a tetradentate macrocyclic ligand

Complexes of Cr(III), Mn(II) and Co(II) with a tetradentate macrocyclic ligand i.e. 2,6,12,16,21,22-hexaaza;3,5,13,15-tetraphenyltricyclo[15,3,1,17–11]docosa;1(21),2,5, 7,9,11(22),12,15,17,19-decaene (L). These complexes were characterized by elemental analysis, molar conductance measurements, magnetic susceptibitity measurements, mass, 1H NMR, IR, electronic and EPR spectral studies. These spectral studies suggest an octahedral geometry for Cr(III), Mn(II) and Co(II) complexes. The ligand and its complexes have been screened in vitro against some species of bacteria and plant pathogenic fungi.

Synthesis and Spectral Studies of Mixed Ligand Complexes of Trivalent Metal Ions

Novel three mixed ligand complexes derived from the interaction of Cr(III), Fe(III) and La(III) ions with a Schiff base resulted from the condensation process of 2-aminophenol and 2-hydroxy acetophenone(HL1) as a primary ligand (HL1) and anthranilic acid (L2) as a secondary ligand. The formed mixed ligand complexes were synthesized and characterized using elemental analysis, FTIR, 1HNMR, UV–visible and mass spectroscopy as well as molar conductance and magnetic measurements. The obtained results revealed that the mixed ligand complexes were formed in 1:1:1[L1ML2] ratio and non-electrolytic in nature.

SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL STUDIES OF SOME METAL (II) COMPLEXES OF TRIDENTATE LIGAND DERIVED FROM ETHYLENEDIAMINE, NITROBENZALDEHYDE AND AMINOBENZOPHENONE

The Schiff base ligand and its metal complexes derived from ethylenediamine, nitrobenzaldehyde and aminbenzophenone were prepared using hydrated metal salts of Ni(II), Co(II) and Mn(II) and characterized by molar conductivity, magnetic susceptibility measurement elemental analysis, FTIR, GC-MS, UV-Vis spectroscopy and (1H, 13C) NMR spectra. Some physical parameters were obtained using molar conductance measurement and melting point determination. From the analytical and spectroscopic data, N donor atoms of the Schiff base ligand and N of NH2 group participated in coordination with metal (II) ions proposed to be a tridentate ligand and octahedral geometry was proposed for the complexes of Co, Ni while tetrahedral geometry proposed for Mn respectively. The antimicrobial activity of the ligand and its metal complexes were compared with the standard drugs Amoxicillin and Nystatin by screening them against isolates of two Gram-positive, three Gram-negative and two fungal strain, using agar well diffusion method for bacteria while the fungal cultures were maintained on Sabouraud liquid medium. The results obtained showed that the metal complexes were more potent against Gram-positive bacterial and fungi than the free ligand, while the ligand showed greater activity against Gram-negative bacterial than the metal complexes.

Preparation and Characterization of some Transition Metal Complexes with di -2- Quinolinone Dibenzylidine Ligand and their Adducts with 1,10 – Phenanthroline

The present work includes the preparation with complexes of the general formula [M2L2] Cl4 and [M2L2(1,10-phen)2] Cl4 were M= Mn (II), Fe (II), Co (II), Ni (II), Cu (II) and Zn (II) L = di -2- quinolinone dibenzylidine 1,10-phen = 1,10phenanthroline The ligand was prepared by condensation reaction of N-aminoquinoline-2-one with terphaldehyde (2:1) and characterized by infrared and proton NMR. The complexes number (1-6) prepared into (2:2) (M: L) molar ratio respectively while complex number (7-12) prepared into (2:2:2) (M: L: 1,10–phen) molar ratio respectively. The I.R spectra data suggest the involvement of nitrogen atom of azomethine group and oxygen atom of carbonyl group of the ligand in coordination to central metal ion. The synthesized complexes were characterized by elemental analysis, molar conductance, magnetic susceptibility, and spectral measurements (UV – Vis, IR). Elemental analysis data proposed 2:2 (metal: ligand) and 2:2:2 (1,10-phen). The molar conductance measurements showed 1:4 electrolytes complexes, Further more magnetic moment measurements and electronic spectra indicated that the complexes of the type [M2L2] Cl4 possess a tetrahedral geometry while complexes of the type [M2L2(1,10-phen)2] Cl4 possess an octahedral geometry.

Synthesis, theoretical study, molecular docking and biological activity of nano tridentate (E)-2-((3-hydoxyphenyl)methyl)phenol metal complexes

A new series of transition metal complexes of Schiff base (E)-2-((3-hydoxyphenyl)methyl)phenol (H2L) with Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) have been synthesized and characterized using elemental analysis, IR, UV–Vis spectra, mass spectra, reflectance spectra, molar conductance measurements, magnetic susceptibility measurements, 1H NMR spectroscopy, thermal and X-ray diffraction analyses. The infrared spectral data showed that the chelation of the ligand towards transition metal ions occurs through two deprotonated phenolic oxygen atoms and azomethine nitrogen (ONO) in binegative tridentate manner. The XRD patterns of the complexes have sharp diffraction peaks indicating that these complexes are a mixture of crystalline and amorphous phases. The molecular structures of the Schiff base ligand and its metal complexes were optimized theoretically and the quantum chemical parameters were calculated. Molecular docking was used to predict the efficiency of binding between the Schiff base ligand and the receptors and found that the receptor of Staphylococcus aureus shows the best interaction than the receptor of Escherichia coli with Schiff base ligand. The synthesized ligand and its metal complexes were also screened for their antibacterial and antifungal activity against bacterial species and fungi. The activity data showed that the metal complexes are found to have antibacterial and antifungal activity higher than the parent ligand.