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Five novel complexes of nickel (II)(1), zinc (II)(2), zirconium (IV)(3), lanthanum (III)(4), thorium (IV)(5), with the dithranol (Dithr) ligand and glycine (Gly) were synthesized and characterized. Their structures were investigated using elemental analysis, molar conductance (Λ), magnetic studies (μeff), spectroscopic methods (FT‐IR, UV–Vis., 1H NMR, XRD), mass spectrometry, TG/DTG and DTA. Findings revealed that Dithr was chelated via two hydroxyl oxygen atoms and carbonyl group while, Gly chelated through carboxylic oxygen and nitrogen atom. All complexes appeared with molar ratio 1:1:1 (M:Dithr:Gly) and were electrolytes with 1:1 for (1), (2) and (3) complexes, 1:2 for (4) complex, and 1:3 for (5) complex according to elemental analysis and molar conductivity data. All metal‐chelates, except Th (IV)‐complex, were confirmed to have lattice water molecules based on their thermal behavior. Average crystalline size of all compounds was calculated using XRD analysis and found in the range 35.50–55.57 nm, indicating the compounds existed as nanocrystalline structure, except zirconium (IV) complex. Then, we studied cytotoxic effects of our synthetic drugs on the survival of an aggressive‐breast‐cancer‐histotype"66cl‐4." Given its involvement in cancer‐metastasis, matrix‐metalloproteinase‐(MMP)‐9 protein expression was evaluated using western‐blotting‐assays. Th(IV)‐complex emerged as the most effective option in inhibiting cancer‐cells‐proliferation (IC50: 9.39 μM), and suppressed expression MMP‐9 levels by 86%, at 25 μM dose, and drug‐binding‐affinity was interpreted via molecular modeling. [ABSTRACT FROM AUTHOR]

Three nickel, copper, and zinc complexes with dicarboxylic acids (3,3′-dithiodipropionic acid (H2dtdp) and fumaric acid (H2fu)) and N-donor ligands (1,10-phenanthroline (phen), N′–methyldipropylenetriamine (mdpta), and N,N,N′,N″,N″-pentamethyldiethylenetriamine (pmdien)) were synthesized. These complexes were characterized using elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Interestingly, [Ni(dtdp)(phen)(H2O)3]∙0.5H2O (1) is a mononuclear complex, where the dtdp dianion employs only one carboxylate group for coordination to the central nickel atom. [(ClO4)(mdpta)Cu(μ-dtdp)Cu(mdpta)(H2O)](ClO4) (2) is a dinuclear copper complex with a dtdp bridge and different coordination on the copper center. [{Zn(pmdien)(H2O)}2(μ-fu)](ClO4)2 (3) is a symmetric dimer with a bridging fumarate ligand. These coordination compounds were tested for their antibacterial activities on Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis bacteria strains. All the complexes show moderate activities on the mentioned strains. [ABSTRACT FROM AUTHOR]

A new crystalline dinuclear Cu(I)/(II) complex (E.F: C32H28Cu2N6O14) (1) of terephthalic acid (TERE) and 1, 10‐Phenathroline (PHEN) was synthesized under one‐pot approach. Structure identification of the complex was carried out using the single crystal XRD technique, which revealed the penta coordination nature of Cu(I)/(II) in a square pyramidal environment. Further, the structural data was supported by employing other spectroscopic studies (UV, ESR, FT‐IR). In addition, the thermal stability and morphology of the complex were elucidated using TGA and SEM‐EDAX analysis. Photoluminescence experiments revealed the capability of 1 to act as a "turn‐off" sensor towards Zn2+ sensing. This luminescence quenching of 1 exhibited a threefold quenching in intensity by achieving a static quenching process corresponding to a limit of detection (LOD) of 3.7 μM. Further, considering the electroactive nature of Cu(I)/(II) complex, the cyclic voltammetric experiments were performed to study its competence to act as a modifier of GCE for the detection of glucose and its excellent potency to act as an effective electroactive material in the detection of glucose solutions. Also, molecular docking of 1 with human bovine serum (HSA) and bovine serum albumin (BSA) was investigated to prove their ability to act as pharmacological agents. [ABSTRACT FROM AUTHOR]

This study was planned to prepare new mixed ligand chelates derived from N‐(4,6‐dimethylpyrimidin‐2‐yl)‐3a,4,5,6,7,7a‐hexahydro‐1H‐benzimidazol‐2‐amine (BIP), and imidazole (I). They identified through CHN study, spectroscopic (NMR, FT‐IR, and UV–Vis), conductivity, magnetic susceptibility, mass analysis, and thermal analysis. Correlation between all results exposed that the BIP ligand performed as a bi‐dentate ligand through NN donation locations, where the co‐ligand shows as N–H monodentate. The optimization for the studied chelates led to the formation of distorted octahedral geometry for BIPICu and BIPIVO chelates, distorted (tetrahedral and square planar) geometry for BIPIAg and BIPIPd chelates, respectively, around the metal salt. The B3LYP level, B3LYP/6‐311G** level for the free ligand, and B3LYP/6–311G**‐LANL2DZ functional level for the solid chelates were used in density functional theory (DFT) calculations. The findings showed that DFT calculations produce conclusions that are consistent with those of the experiments. The resulting compounds' nonlinear optical properties were examined by calculating the hyperpolarizability (β) and molecular polarizability (α) parameters, which gave rise to several unexpected optical properties for the synthesized compounds. Using the agar well diffusion method, the antimicrobial activity of the produced compounds was experimentally confirmed against a subset of G+ and G− bacteria. To ascertain how these substances attach to the targeted protein binding sites, a molecular docking mechanism between the microbially resistant chelates and their suppressed microbial protein pocket receptors was investigated. Also, DNA binding estimated for studied structures was tested by electronic absorption spectrum, viscosity estimation, and gel electrophoresis. Data proposed that all tested compounds link with DNA using an intercalation, electrostatic, and covalent binding mechanism. Moreover, antioxidant performance for studied compounds was governed by radical scavenging techniques in vitro. In addition, an MTT assay has been worked out to explore in vitro cytotoxic impending. All the tested chelates assumed antimicrobial, antitumor, and antioxidant performances that cause them to suggest drugs. [ABSTRACT FROM AUTHOR]

A new Schiff base with ligands (L¹ and L²) has been prepared from cinnamaldehyde with aniline (L¹) and 4-hydroxy-3-methoxybenzaldehyde with o-nitroaniline in 1:1 molar ratio. The mononuclear metal(II) complexes [(ML¹L²)] [M= Co(II), Ni(II), Cu(II) and Zn(II)] have been synthesized and characterized. ML¹L² synthesized from ligand (L¹), metal salts and ligand (L²) molar ratio is 1:1:1. Elemental analyses, IR, NMR, Electronic spectra, SEM and molar conductivity have been obtained to clarify the structure of synthesized metal(II) complexes. Square planar geometry is proposed for CoL¹L², NiL¹L² and ZnL¹L², and distorted square planar geometry for CuL¹L² complex. Antibacterial activity of metal(II) complexes, ML¹L² have been tested against Gram(+) and Gram(-) bacteria and fungi. The anti-inflammatory and anti-diabetic actions of the L¹, L², CuL¹L²complexes have been studied. The anticancer activity of L¹, L² and CuL¹L² have been studied as opposed to MCF-7 using MTT assay method. [ABSTRACT FROM AUTHOR]

5,5-{(1E,1E′)-1,4-Phenylenebis(diazene-2,1-diyl)}bis(quinoline-8-ol) (H2L1) as a new bis-bidentate azo dye primary ligand and its Mn(II) complexes were synthesized by a diazotized reaction of 1,4-diaminobenzene and 8-hydroxyquinoline in 1:2 M ratio. Incorporating of 2-aminobenzoic acid (HL2) as co-ligand with the synthesized mixed ligand complexes of the composition [Mn2(H2L1)(L2)2(X)2(H2O)2]Y, X = (Cl), Y = 2.5 (1); (NO3), Y = nil (3); (OAc), Y = 2 (4) and [Mn2(L1)(L2)2(H2O)4]4H2O (2) were synthesized and characterized. Mn(II) mixed ligand complexes showed polycrystalline natures in the XRD results. The antibacterial activity of H2L1, HL2 and their mixed ligand complexes was tested against different Gram-positive and Gram-negative bacteria (Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas sp. and Klebsiella pneumoniae). Antifungal activity was screened against Fusarium oxysporum, Aspergillus niger and Candida albicans. Mn(II) mixed ligand complexes showed higher activity than other complexes. The cytological effects of Mn(II) mixed ligand complexes on Bacillus cereus, Escherichia coli and Aspergillus niger were studied. Molecular operating environment (MOE) is computational software used to predict and explain the interaction between ligands (H2L1, HL2 and Mn mixed ligand complexes) and receptor proteins of crystal structures of the SARS-CoV-2 (COVID-19) main protease (6WTT), structure of isonicotinimidylated liver alcohol dehydrogenase (7ADH) and crystal structure of E. coli MenB in complex with substrate analog, OSB-NCoA (3T88). The inhibitive effect of novel bis-bidentate azo dye ligand versus C-steel and its adsorption nature was gained in HCl solution (2 M) using implemented techniques of EIS and EFM. By increasing the inhibitor dosage, the results from IE get better. [ABSTRACT FROM AUTHOR]

Coordination compounds of Co(II), Cu(II), Y(III), Zr(IV) and La(III) ions were synthesized from the N-salicylidene aniline (L) derived from the condensation of aniline with salicylaldhyde and 1,10-phenanthroline (phen) as a secondary mixed ligand. L, phen and their complexes were characterized using various physiochemical methods, such as elemental analyses (CHN), Fourier-transform infrared spectroscopy (FT-IR), molar conductance (Λ), magnetic susceptibility (μeff), proton nuclear magnetic resonance (1H NMR), ultraviolet–visible spectroscopy (UV–Vis) and thermogravimetric analysis (TG/DTG). The analytical and spectroscopic data supporting the chemical formulas of the metal complexes and chelation of L and phen with the metal ions forming octahedral complexes. FT-IR spectra demonstrated that L chelated with metal ions as a bidentate ligand via the oxygen atom of the phenolic group with a band in the range 3378–3437 cm−1 and the nitrogen atom of the azomethine group at 1612 cm−1. In addition, phen chelated through two nitrogen atoms in the range 1525–1565 cm−1. The 1H NMR results confirmed the IR assumption that the ligand connected to the metal ions via the phenolic’s oxygen atom. The molar conductance measurements of the complexes revealed high values of the electrolytic nature of these complexes in the range of 90.40–125.80 S cm2 mol−1. Thermal analysis (TG/DTG) was used to differentiate between coordinated and hydrated water molecules and the thermal stability of the complexes. Finally, the anti-microbial activities of the complexes were investigated against fungi (Candida albicans), Gram-negative bacteria (Escherichia coli and Salmonella typhimurium) and Gram-positive bacteria (Staphylococcus aureus and Micrococcus sp.) using the disc diffusion method. The La(III) complex was significant against C. albicans compared with all other compounds and reference standard control.

The biological properties of Trichoderma Viride fungi allow them to be effectively used in the technologies of crop waste disposal, production of organic, environmentally friendly fertilisers, and prevention of soil diseases of plants. The growth and development of these fungi depend on a number of trace elements that are found in the medium. Copper is of great importance among trace elements. The establishment of the ability to use copper as a stimulator of biomass accumulation of Trichoderma Viride fungi is of scientific and practical interest for national economic needs, which indicates the relevance of the study. The purpose of the study is to establish the effectiveness of the effect of various copper compounds on the growth and development of Trichoderma Viride. To investigate the effect of the metal-biotic on the growth of microorganisms, 0.5 to 10.0 mg/100 cm3 of the element in the form of copper sulphate, mixed ligand complex and copper glycinate were added to the medium with potato dextrose agar (PDA). In the control variant, the element was not added to the nutrient medium. The media were inoculated with the Viridin preparation. Trichoderma Viride growth was recorded on days 4 and 7 of the experiment. It has been experimentally established that the fungal population is affected by the content and source of copper in the medium. It was found that the presence of a biotic metal in the medium in mineral or chelated form is up to 1.0 mg/100 cm3 stimulates the build-up of fungal biomass. It was proved that on the 4th day of cultivation for the introduction of copper into the medium in the amount of 1.0 mg/100 cm3 in the mixed-ligand form, the population of Trichoderma Viride increased by 75.0%. On the 7th day, the increase in the number of fungal cells was 58.3%. It was found that with the introduction in the medium of more than 5.0 mg/100 cm3 copper in any form, the population growth of Trichoderma Viride fungi decreased. The higher the copper content in the medium, the greater the inhibition of fungal cell reproduction. It was generalised that comparing the action of the mixed ligand complex copper, copper glycinate, and copper sulphate, it was found that the latter compound is the most toxic against Trichoderma Viride

An azo dye, (E)-4-((4,5-dimethylthiazol-2-yl)diazenyl)-2-isopropyl-5-methylphenol (L1), was prepared by the reaction of 5-methyl-2-(propan-2-yl)phenol with the diazonium salt of 2-amino-4,5-dimethylthiazole. Characterization was carried out using proton and carbon-13 nuclear magnetic resonance spectroscopy. Coordination compounds of L1 with Mn(III), Fe(III) and Co(III) in a 1:2 metal to ligand mole ratio were subsequently synthesized. Corresponding mixed ligand complexes were also synthesized using 2-hydroxybenzoic acid (L2) as the secondary ligand. The coordination compounds were characterized by electronic and infrared spectrophotoscopy, magnetic susceptibility measurements, and percent metal composition. Subsequently, in silico studies were performed based on the proposed structures of the synthesized compounds to determine their binding affinity and binding site with calf thymus DNA. The results obtained showed that all complexes achieved octahedral geometry. The results also showed that some of the compounds had better affinity for CT-DNA than the standard. [ABSTRACT FROM AUTHOR]

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

The complexes of 4‐(2‐thiazolylazo)resorcinol (TAR) and 2,2′‐bipyridine (bpy), [M(bpy)(TAR)(H2O)]AcO [(M=CoII, CuII, ZnII] and [Mn(bpy)(TAR)AcO] were synthesized and their structure was determined by elemental analysis, thermal analysis (DTA/TGA), IR spectroscopy, molar conductivity, and magnetic measurements. The ligand 4‐(2‐thiazolylazo)resorcinol coordinated to metalII ions via azo and thiazolyl group nitrogens and one oxygen atom of resorcinol, while 2,2′‐bipyridine also contributed two coordination bonds via its nitrogen atoms. The electrochemical profile of the compounds was investigated by cyclic voltammetry (CV) which confirmed their electrochemical activity. The results obtained by CV method pointed out that the electrode reactions were diffusion controlled. The total antioxidant capacities of the ligands and complexes were evaluated by using cupric reducing antioxidant capacity (CUPRAC) method. The complexes displayed more antioxidant activity than their ligands. The Trolox equivalent antioxidant activity (TEAC) values of all complexes exhibited more higher and approximate values to Trolox but bpy ligand did not show any activity. [ABSTRACT FROM AUTHOR]

During the leather tanning process, chromium (Cr) can interact with different macromolecular organics to generate mixed ligand complexes. The removal of organochromium complexes is one of the main difficulties in the treatment of tannery wastewater. In this study, a gelatin-gallic ac-id-Cr(III) (G-GA-Cr) mixed ligand complex was used to examine the effects of ultrasonic on chromium destabilization and removal from the dissolved complexes. To investigate organic destruction and chromium liberation, alkali precipitation or chelating precipitation assisted with ultrasound were conducted, respectively. The findings demonstrate that ultrasonic-assisted alkali precipitation and chelating precipitation, respectively, removed over 50% and 93% of Cr from the complexes. According to the data, ultrasonication weakened the bonds that bound macromolecular ligands together, and depolymerization took place to the point where Cr could interact directly with hydroxide ions or chelating agents. In addition, by applying ultrasonic-assisted chelating precipitation, the chromium concentration could meet the discharge standard and the amount of precipitation was also noticeably decreased. [ABSTRACT FROM AUTHOR]

Two new class of Schiff base ligands were synthesized involving chitosan, thiophene–2–carbaldehyde (L1) and 4–(pyridine-2-yl)–thiosemicarbazide, thiophene–2–carbaldehyde (L2). These ligands were then complexed with Co(II), Ni(II) and Cu(II) metal ions. These chitosan anchored mixed ligand complexes were characterized and their catalytic activities were investigated for the effective oxidation of cyclohexane. The Cu(II) complex (CuL) shows higher catalytic efficiency compared to Co(II) and Ni(II) complexes. The catalytic activity of Cu(II) complex was enhanced by irradiating with different doses of electron beam (EB). The effect of EB irradiation on the spectral, morphological and catalytic activities of the complex was investigated. The EB irradiation significantly enhances the catalytic efficacy of the complex due to cross linking of the polymer chain. The reusability of the catalyst has also been increased on increasing the electron beam irradiation dosage. [ABSTRACT FROM AUTHOR]

Spectrometry, spectrophotometry, pH-potentiometry, and solubility method have been used to study the reactions proceeding in aqueous solutions containing the "metal of life" ion Cu2+ and biologically active substances, succinic acid and (or) one of the amino acids (aminoacetic, glutamic, and aspartic). The general acid protonation constants, composition, and stability constants of homoligand and mixed ligand copper(II) complexes have been determined at ionic strength I = 0.3; for copper(II) succinate of the composition CuC4H4O4⋅2H2O, the solubility constant has been found (logKS = –7.59 ± 0.06). [ABSTRACT FROM AUTHOR]

Benzimidazoles are a very well-known, broad group of compounds containing nitrogen atoms in their structure that can mimic properties of DNA bases. The compounds show not only biological activities but also are used for spectral and catalytic properties. Biological activity of benzimidazoles can be tuned and accelerated in coordination compounds. This minireview is focused on preparation of bis(benzimidazoles), their complexes, and biological properties that can be found from 2015. [ABSTRACT FROM AUTHOR]

Coordination compounds of Co(II), Cu(II), Y(III), Zr(IV) and La(III) ions were synthesized from the N-salicylidene aniline (L) derived from the condensation of aniline with salicylaldhyde and 1,10-phenanthroline (phen) as a secondary mixed ligand. L, phen and their complexes were characterized using various physiochemical methods, such as elemental analyses (CHN), Fourier-transform infrared spectroscopy (FT-IR), molar conductance (Λ), magnetic susceptibility (μeff), proton nuclear magnetic resonance (1H NMR), ultraviolet–visible spectroscopy (UV–Vis) and thermogravimetric analysis (TG/DTG). The analytical and spectroscopic data supporting the chemical formulas of the metal complexes and chelation of L and phen with the metal ions forming octahedral complexes. FT-IR spectra demonstrated that L chelated with metal ions as a bidentate ligand via the oxygen atom of the phenolic group with a band in the range 3378–3437 cm−1 and the nitrogen atom of the azomethine group at 1612 cm−1. In addition, phen chelated through two nitrogen atoms in the range 1525–1565 cm−1. The 1H NMR results confirmed the IR assumption that the ligand connected to the metal ions via the phenolic's oxygen atom. The molar conductance measurements of the complexes revealed high values of the electrolytic nature of these complexes in the range of 90.40–125.80 S cm2 mol−1. Thermal analysis (TG/DTG) was used to differentiate between coordinated and hydrated water molecules and the thermal stability of the complexes. Finally, the anti-microbial activities of the complexes were investigated against fungi (Candida albicans), Gram-negative bacteria (Escherichia coli and Salmonella typhimurium) and Gram-positive bacteria (Staphylococcus aureus and Micrococcus sp.) using the disc diffusion method. The La(III) complex was significant against C. albicans compared with all other compounds and reference standard control. [ABSTRACT FROM AUTHOR]

Complexes of carboxylic acids are very often studied due to their interesting structural, spectral, and magnetic properties. This review is focused on complexes of four dicarboxylic acids, namely, 2,2′-thiodioacetic, 3,3′-thiodipropionic, 3,3′-dithiodipropionic, and fumaric acid. Many of the complexes were characterized by single crystal X-ray analyses. Without the analyses, it is very difficult to predict the coordination mode of carboxylate groups or nitrogen ligands on central atoms. Thus, structural properties are also discussed, as well as potential applications. [ABSTRACT FROM AUTHOR]

The novel Schiff base, (E)-4-((2-hydroxybenzylidene)amino)-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one (L1), and its mixed ligand complexes with 2,4,6-tri(pyridin-2-yl)-1,3,5-triazine as an auxiliary ligand (L2) and different transition metal ions (Mn(II), Fe(III), Co(II), Ni(II), Zn(II) and Cd(II)) were synthesised. The 1H NMR spectra of L1 supported their geometrical structures, which was confirmed by X-ray crystallography. The packing of L1 is dominated by H…H, O…H, H…C, C…C, C…N, C…O and N…H interactions. Density functional theory (DFT) calculations showed excellent straight-line correlations between the calculated and experimental geometric parameters where the most stable isomer of L1 is stabilised by an OH…N hydrogen bond, and which agrees with the reported X-ray structure. The prepared complexes were characterised by elemental analyses, molar conductance measurements, IR, UV–vis, and 1H NMR spectroscopic methods. The elemental analysis data suggested a 1:1:1 [M:L1:L2] ratio for all the complexes. The molar conductance measurements of the complexes indicate their electrolytic nature in DMSO as solvent. The electronic absorption spectral data revealed the existence of an octahedral geometry for all complexes.

The rapid growth and revolution in the area of emerging therapeutics has been able to save the life of millions of patients globally. Besides these developments, the microbes are consistently struggling for their own survival and hence becoming quite more sturdy and incurable to existing drugs. Covid-19 virus and Black Fungus are recent examples of failure of medical preparations and strength of these viruses beyond the imagination of medical practitioners. Henceforth the study has made an extensive survey of exiting literature on heterocyclic schiff bases and their transition metal complexes to look for their potential applicability as antimicrobial agents. The inherent physiognomies of the essential properties of these transition metal complexes including thermodynamic, kinetic and chelating are comparatively modifiable as per requirements. The study has found that the biological applications of these transition metal complexes are well suited to be used as antibacterial and antifungal agents. [ABSTRACT FROM AUTHOR]

Mn(II), Ni(II), Cu(II) complexes with the ionic liquid-supported Schiff base 1-{2-(2-hydroxy-5-chlorobenzylamine)ethyl}-3-methylimidazolium tetrafluoroborate (primary ligand) and 1-methyl imidazole (secondary ligand) and were synthesized and characterized by PXRD, SEM, ESI-MS, UV-Visible, FT-IR, 1H NMR, 13CNMR spectroscopic and various analytical (elemental analysis and magnetic susceptibility measurements) methods. Based on these spectra and spectral data hexa coordinated geometries were assigned for the synthesized mixed ligand metal (II) complexes. Antimicrobial activity of the mixed ligand Mn(II), Ni(II), Cu(II) complexes with respect to the Schiff base against two gram positive (Staphylococcus aureus and Bacillus cereus) and two were gram negative (Escherichia coli and Klebsiella pneumoniae) were conducted to assess their antibacterial activities. The Schiff base along with the mixed ligand complexes exhibited very significant responses for gram positive and negative bacterial samples though maximum inhibition zone was produced by Ni(II) complex while the minimum inhibition zone was produced by Cu(II) complex in plates of Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

Multi-functional protective epoxy coatings were applied to display synergistic resistance properties on the steel/coating interfacial zone of petroleum storage tanks (PST). This work investigated the synthesis of new mixed Ni(II), Pd(II), and Cd(II) complexes of metformin (MF) and 2,2/bipyridine (Bipy) as internal cross-linking accelerators for steel epoxy coatings. The ligands and their complexes were identified by CHN analysis, molar conductance, magnetic tendency, TGA/DTG, FT-IR, 1H NMR, and UV–Visible analysis. FT-IR results underlined that MF and Bipy were chelated with metal ions as bidentate ligands through two imines (–CNH) groups of MF and via two nitrogen of pyridine rings for Bipy. Polyamine cured epoxy coating formulations loaded with the same concentration of MF, Bipy, and mixed complexes were prepared. The corrosion inhibiting demeanor evaluated by the salt spray corrosion trial demonstrated that the minimum corrosion rate (CR) was calculated at 0.00028 mm/y. It also exhibited a superior protection efficiency (PE) of 99.90% for EPO/MC-Ni coating with an outstanding self-healing performance. AFM microstructure survey affirmed the smoothest and harder epoxy composite matrix of EPO/MC-Ni coating without the appearance of protuberances over the coating surface. EIS measurements were carried out using oil wells formation water aggressive medium to affirm the protective mechanism offered by the checked coatings. The electrochemical results displayed that EPO/MC-Ni coating exhibited the best resistance values (Rct = 995 and Rp = 945 kΩ cm2) and achieved the highest protection efficiency at 97.23%. Mechanical efforts on the modified Ni(II) coating layer emphasized the best adhesion pull-off evaluation at 6.7 MPa and impacted resistance of 67.3 J.

The effectiveness of the use of mixed ligand complexes of Zinc, Manganese and Cobalt in the diets of high-yielding cows in the final period of lactation, and their effect on productivity, nutrients digestibility and nitrogen metabolism in the animals’ body was studied in a scientific economic experiment conducted at the Terezyne Ltd. of Bila Tserkva district, Kyiv region. Five groups of highly productive cows of Holstein, Ukrainian red-spotted and Ukrainian black-spotted dairy breeds were selected on the principle of analogues. The difference in feeding cows of the groups was in the following: - the diet of the control 1st group was balanced to the norm only with trace elements of Selenium, Copper and Iodine. - cows of the 2nd and 3d experimental group were fed with the norm of all trace elements (for the 2nd experimental groupthe norm was provided due to introducing sulfates of Zinc, Manganese, Cobalt, Copper, Selenium Suplex and Potassium iodide; for the 3d experimental group , sulfates of Zinc, Manganese and Cobalt were substituted with their mixed ligand complexes). - for cows of 4th experimental group, the concentration of Zinc, Manganese and Cobalt in 1 kg of dry matter feed was reduced by 11% compared to the group 3. - for the 5thgroup it was 22% lower than in the group 3. The results of the studies show that the use different doses of mixed ligand complexes of Zinc, Manganese, Cobalt in cows feeding with the use of Selenium Suplex, Copper sulfate and Potassium iodide during the final 100 days of lactation did not affect milk productivity. Each cow of the control group in the final period of lactation yielded 2220 kg of natural milk, whereas the cows of the experimental groups 2-5 yielded 40-120 kg more. The difference in the average daily milk yield of 4% fat was 0.5–1.91 kg, and this difference was significant (p

• Preparation of some new mixed ligand complexes and their structural inspection • Geometry optimization for structural verification using DFT calculation • DNA interaction and biomedical evaluation of the prepared compounds • Molecular docking inspection for predicting of the biomedical evaluation The fabrication and structural identification of mixed ligand chelates resulting from 1-(1H-benzimidazol-2-yl) guanidine (BIG = main ligand) and 1,10-Phenanthroline (phen) (secondary ligand). The tested compounds were investigated using TGA, CHN, spectra analysis (FT-IR, Mass spectra, NMR), melting point, magnetic moments, molar conductance, Ultraviolet–Visible spectroscopy as well computational studies. The conductance results showed that the tested Pd(II), VO(II) and Ag(I) chelates have electrolytes in fresh solutions of DMSO lies in the range 38.12–118.87 Ω−1 cm2 mol−1 except, Cu(II) chelate is a non-electrolyte it is value equal 15.16 Ω−1 cm2 mol−1. FT-IR spectrum displays that the tested main ligand is coordinated with metal ions in a bi-dentate behavior with N, N donor sites of the HN=C and C=N. While the second ligand coordinated with metal ions through its N 2 atom in the pyridine ring. Moreover, the obtained analytical data regarding complexation in solution, molar ratio and continuous variation methods suggest 1M: 1 L molar ratio. Also the stability constant of tested complexes was identified in solution state and the formation constants (Kf) were evaluated by applying continuous-variation method. Stability of complexes was arranged by BIGPAg > BIGPVO > BIGPCu > BIGPPPd in agreement with K f values. The pH profile revealed that the wide range of pH stability of the tested complexes is at pH = 4- 10 in most of them. Magnetic and electronic spectra are applied to deduce the coordinating ability of the tested ligands and the geometric structure of the studied chelates. That data of magnetic susceptibility for ternary mixed chelates are locked to an octahedral geometry for Cu(II) & VO(II) chelates due to the data of (μeff = 1.8 and 1.83 B.M) respectively and Pd(II) and Ag(I) chelates are diamagnetic with square planar and tetrahedral geometry, respectively. The TGA study of these studied complexes displays that the hydrated H 2 O, acetate, nitrate, and acetylacetonate anions are removed in the first (45°C-180°C) and second degradation steps followed directly by degradation of the studied ligands in the following stages. The thermodynamic factors, like ΔS*, ΔH*, E*, A and ΔG* are evaluated from the TGA curves and explained. The DFT/B3LYP computation method was applied for the estimation of the MEP, (HUMO & LUMO) energy for the studied compounds. In-silico assay was executed by two different approaches over compounds to evaluate their biological behavior and degree of interaction with biological systems, before practical application. BIGPPd complex displayed priority in interaction with various protein. In-vitro assay was then carried out for compounds against different microbes and BIGPPd showed high antimicrobial activity with inhibition zones are established to be 45.75 ± 0.10 and 41.95 ± 0.05 mm against B. Cereus and G. Candidum at 25 µg/mL. Also, their cytotoxic behavior was examined against MCF-7, HepG2 and HCT-116 carcinoma cell lines, high cytotoxicity was clearly recorded with BIGPPd complex with IC 50 % are established to be (5, 6.25 and 7.14 µg/mL) respectively. Furthermore, antioxidant activity was examined, and the complexes exhibited high reactivity with trapping free radicals. The BIGPPd exhibited significant free radical scavenging activity with an IC 50 value of 20.15 μg/ml. The interaction of metal chelates with DNA was detected by gel electrophoreses, viscosity and spectral studies. Spectrophotometric titration and viscosity studies expose that each of tested complex is an avid binder to DNA. The intrinsic binding constants were calculated for all the tested compounds could bind to Ct-DNA generally through replacement, intercalative mode & minor groove binding of interactions with the sequence: BIGPVO (6.05×104) > BIGPCu > BIGPPd> BIGPAg >BIG (1.16×103). This may be due to enhanced hydrophobic & electrostatic interaction of aromatic rings. Finally, such complexes may be considered as a promising bioactive agent. [Display omitted] [ABSTRACT FROM AUTHOR]

Considering that practically all reactions that involve nucleotides also involve metal ions, it is evident that the coordination chemistry of nucleotides and their derivatives is an essential corner stone of biological inorganic chemistry. Nucleotides are either directly or indirectly involved in all processes occurring in Nature. It is therefore no surprise that the constituents of nucleotides have been chemically altered—that is, at the nucleobase residue, the sugar moiety, and also at the phosphate group, often with the aim of discovering medically useful compounds. Among such derivatives are acyclic nucleoside phosphonates (ANPs), where the sugar moiety has been replaced by an aliphatic chain (often also containing an ether oxygen atom) and the phosphate group has been replaced by a phosphonate carrying a carbon–phosphorus bond to make the compounds less hydrolysis-sensitive. Several of these ANPs show antiviral activity, and some of them are nowadays used as drugs. The antiviral activity results from the incorporation of the ANPs into the growing nucleic acid chain—i.e., polymerases accept the ANPs as substrates, leading to chain termination because of the missing 3′-hydroxyl group. We have tried in this review to describe the coordination chemistry (mainly) of the adenine nucleotides AMP and ATP and whenever possible to compare it with that of the dianion of 9-[2-(phosphonomethoxy)ethyl]adenine (PMEA2− = adenine(N9)-CH2-CH2-O-CH2- PO 3 2 ) [or its diphosphate (PMEApp4−)] as a representative of the ANPs. Why is PMEApp4− a better substrate for polymerases than ATP4−? There are three reasons: (i) PMEA2− with its anti-like conformation (like AMP2−) fits well into the active site of the enzyme. (ii) The phosphonate group has an enhanced metal ion affinity because of its increased basicity. (iii) The ether oxygen forms a 5-membered chelate with the neighboring phosphonate and favors thus coordination at the Pα group. Research on ANPs containing a purine residue revealed that the kind and position of the substituent at C2 or C6 has a significant influence on the biological activity. For example, the shift of the (C6)NH2 group in PMEA to the C2 position leads to 9-[2-(phosphonomethoxy)ethyl]-2-aminopurine (PME2AP), an isomer with only a moderate antiviral activity. Removal of (C6)NH2 favors N7 coordination, e.g., of Cu2+, whereas the ether O atom binding of Cu2+ in PMEA facilitates N3 coordination via adjacent 5- and 7-membered chelates, giving rise to a Cu(PMEA)cl/O/N3 isomer. If the metal ions (M2+) are M(α,β)-M(γ)-coordinated at a triphosphate chain, transphosphorylation occurs (kinases, etc.), whereas metal ion binding in a M(α)-M(β,γ)-type fashion is relevant for polymerases. It may be noted that with diphosphorylated PMEA, (PMEApp4−), the M(α)-M(β,γ) binding is favored because of the formation of the 5-membered chelate involving the ether O atom (see above). The self-association tendency of purines leads to the formation of dimeric [M2(ATP)]2(OH)− stacks, which occur in low concentration and where one half of the molecule undergoes the dephosphorylation reaction and the other half stabilizes the structure—i.e., acts as the "enzyme" by bridging the two ATPs. In accord herewith, one may enhance the reaction rate by adding AMP2− to the [Cu2(ATP)]2(OH)− solution, as this leads to the formation of mixed stacked Cu3(ATP)(AMP)(OH)− species, in which AMP2− takes over the structuring role, while the other "half" of the molecule undergoes dephosphorylation. It may be added that Cu3(ATP)(PMEA) or better Cu3(ATP)(PMEA)(OH)− is even a more reactive species than Cu3(ATP)(AMP)(OH)−. – The matrix-assisted self-association and its significance for cell organelles with high ATP concentrations is summarized and discussed, as is, e.g., the effect of tryptophanate (Trp−), which leads to the formation of intramolecular stacks in M(ATP)(Trp)3− complexes (formation degree about 75%). Furthermore, it is well-known that in the active-site cavities of enzymes the dielectric constant, compared with bulk water, is reduced; therefore, we have summarized and discussed the effect of a change in solvent polarity on the stability and structure of binary and ternary complexes: Opposite effects on charged O sites and neutral N sites are observed, and this leads to interesting insights. [ABSTRACT FROM AUTHOR]

Cu (II), Ni (II), Co (II), and Mn (II) acetato in addition to Cu (II) chloro and nitrato mixed ligand complexes of 4‐([quinolin‐2‐yl]methyleneamino)‐1,2‐dihydro‐2,3‐dimethyl‐1‐phenylpyrazol‐5‐one (L), as a primary ligand and 2,4‐dihydroxy benzaldehyde (H2L), as a secondary ligand have been isolated. The structural features and geometrical arrangements of the synthesized mixed ligand complexes were identified by elemental analysis, Fourier transform infrared spectroscopy (FT‐IR), conductivity measurements, UV‐Vis spectra, magnetic moment measurements, X‐ray diffraction, and electron spin resonance (ESR) spectral and thermogravimetric techniques studies of the mixed ligand complexes confirming the molar ratio 1:1:1 (primary ligand: M: secondary ligand) for Cu (II), Co (II), Mn (II), and UO2(II) chelates. The spectral techniques also confirmed the metal chelates have the formulae (Cu[H2L][L][X]2), where X = Cl− (1); NO3− (2); and (M[L][HL][OAc])YH2O, where M = Cu (II) (3), Co (II) (4); Y = 1, Mn (II) (5); Y = 1 and UO2(II) (6); Y = 2. The kinetic and thermodynamics parameters of the mixed ligand complexes at different decomposition steps were calculated using Coast‐Redfern and Horowiz‐Metzger methods. Also, the antimicrobial activities of ligands and their mixed ligand complexes were screened by Disc Diffusion method. It was found that all mixed ligand complexes (1–6) have high antibacterial activity against Klebsiella pneumoniae than penicillin G. By studying the molecular docking between the quinoline‐2‐carbaldehyde, the ligand and the receptors (Escherichia coli (PDB code: 3t88), Staphylococcus aureus (PDB code: 3q8u), lung cancer (PDB code: 1x2j), and colon cancer (PDB code: 2hq6)), it was found that the ligand is efficient compound for all the receptors than the quinoline‐2‐carbaldehyde. The DNA cleavage properties of the two ligands and their complexes have been investigated by gel electrophoresis and the results showed that complex (1) without H2O2 and complex (6) with H2O2 exhibited a significant partial oxidative cleavage among other complexes. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of Co(II) and Ni(II) mixed ligand complexes are derived from isoniazid, 9-fluorenoneandoxalate. The metal complexes were characterized on the basis of elemental analysis, IR, UV-visible, CV, PXRD, and molar conductance analytical data, viz., all the metal complexes were suggested in an octahedral geometry, respectively. The mixed ligand complexes are formed in the 1:1:2:1 (M:L1:L2:L3) ratios, as found from the elemental analyses, and originate to have the formula [M(L1)(L2)2(L3)]. Where M = Co(II), Ni(II), L1 = isoniazid, L2 = 9-fluorenone, and L3 = oxalate. The molar conductance data reveals that the complexes are non-electrolytes. The cyclic voltammogram of the Co(II) complex revealed that the quasi-reversible single electron transfer process and Ni(II) complex corresponding to a one-electron transfer process were observed during controlled potential electrolysis. IR spectra show that the ligands are coordinated to the metal ions through N and O donor sites of isoniazid-N, 9-fluorenone-O and oxalate-O. Magnetic moment values and UV-visible spectra were used to infer the coordinating of the geometrics of these complexes found to be octahedral. The PXRD patterns suggest that all the complexes are crystalline phases. The metal chelates have been screened for antimicrobial, antioxidant and anti-inflammatory activities, and our findings have been reported, explained and compared with some known antibiotics. [ABSTRACT FROM AUTHOR]

Drug discovery aimed at the methodical extermination of life-threatening bacterial infection, especially considering the emergence of multi-drug resistance of pathogenic bacteria has remained a challenge for medicinal inorganic chemistry. In this article, the mixed ligand complexes of Cu (II), Co (II), and Ni (II) containing heterocyclic ligands were synthesized and characterized by IR, LC-MS, UV, and TG-DTA. Complexes are screened for Anti-microbial activity against human pathogenic bacteria. [ABSTRACT FROM AUTHOR]

Benzimidazoles are a very well-known, broad group of compounds containing nitrogen atoms in their structure that can mimic properties of DNA bases. The compounds show not only biological activities but also are used for spectral and catalytic properties. Biological activity of benzimidazoles can be tuned and accelerated in coordination compounds. This minireview is focused on preparation of bis(benzimidazoles), their complexes, and biological properties that can be found from 2015.

Complexes of carboxylic acids are very often studied due to their interesting structural, spectral, and magnetic properties. This review is focused on complexes of four dicarboxylic acids, namely, 2,2′-thiodioacetic, 3,3′-thiodipropionic, 3,3′-dithiodipropionic, and fumaric acid. Many of the complexes were characterized by single crystal X-ray analyses. Without the analyses, it is very difficult to predict the coordination mode of carboxylate groups or nitrogen ligands on central atoms. Thus, structural properties are also discussed, as well as potential applications.

A series of new mixed ligand metal complexes of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) have been synthesized by the reaction of norfloxacin (NOR) with 3‐(bromoacetyl)coumarin (BAC) in 1:1:1 (Mn+:NOR:BAC) molar ratio, which characterized by elemental analysis, spectroscopic measurements (FT‐IR, UV–Vis) molar conductance, effective magnetic moments, and thermogravimetric analysis (TG) and (DTG). All the complexes soluble in DMSO and the conductivity measurement indicate that the complexes are electrolyte with ratio 1:1 for Mn(II), Fe(II), and Zn(II) and 1:2 for Co(II), Ni(II), and Cu(II). Electronic and magnetic data elucidated the octahedral structure for all complexes. Assorted thermodynamic factors are calculated, and the results are explicated. Molecular modeling calculations (bond angles, dihedral angles, total energy, heat of formation, and dipole moment) confirm the structural geometry of the complexes and indicate the very good agreement between the computed and experimental geometrical parameters. The calculated data for the hardness (η) and absolute softness (σ) showed that all complexes are soft with respect to ligands. The two ligands and their metal complexes have also been screened for their antibacterial and antifungal activity against some selected species; the data showed that the complexes have remarkable potency as compared with the parent ligands. [ABSTRACT FROM AUTHOR]

The mixed ligand coordination compounds containing acesulfamato and N,N-diethylnicotinamide biomolecules of some rare earth metal cations (Eu3+, Tb3+, Ho3+, Er3+ and Yb3+) were synthesized, and their structural properties were investigated. Possible structural formulas have been proposed by determining the chemical composition of molecules (elemental analysis), binding properties (infrared spectroscopy, mass analysis, solid-state UV-vis spectroscopy), thermal degradation properties (TGA / DTA curves). Based on the data collected, it is suggested that rare earth metal cations with a 3+ oxidation state have sextet coordination. The geometries of the structures were thought to be distorted octahedral. The charge balance of the coordination sphere is balanced by a monoanionic acesulfamato located outside the coordination sphere. When the thermal behaviours of the complexes were examined, it was determined that the compounds with Eu3+, Tb3+, and Yb3+ metal cations contained one hydrate water outside the coordination sphere. Hydrate waters do not exist in the Ho3+ and Er3+ metal cation-centred complexes. At the end of the thermal decomposition analysis of all complex structures, it was determined that they leave the relevant metal oxides in the reaction vessels as final decomposition products. [ABSTRACT FROM AUTHOR]

A new class of mixed ligand complexes, [M(L)(phen)2], using a bidentate bischlorophenol ligand H2L (2,2′-methylenebis(4-chlorophenol)) and phenanthroline has been synthesized. All the compounds were characterized by spectral (IR, UV, NMR and mass), magnetic, molar conductivity and cyclic voltammetry studies. The IR spectral data revealed that the bisphenol and phenanthroline ligands coordinate to the metal ions through the formation of M–O and M–N bonds. The electronic and magnetic data indicate the octahedral geometry of the complexes. The ESR spectrum of mononuclear copper complex shows four lines due to hyperfine splitting and the copper + 2 ion is present in octahedral environment. Cyclic voltammograms show two reduction potentials in cathodic direction. The first one at higher potential, − 1.05 to − 1.58 V, is due to the phenanthroline moiety and the second one at − 0.58 to − 0.65 V is due to the metal centered reduction potential. The antimicrobial activity of all the compounds was studied on some human pathogenic bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococci species) and fungi (Candida species, Aspergillus species). Copper complex 3 and cobalt complex 1 show higher antibacterial and antifungal activities, respectively, than the ligand and other complexes. The in-vitro antioxidant activity was spectrophotometrically studied by radical scavenging and reducing power activities. The biological activities of mixed ligand metal complexes are improved through synergistic effect of ligand, co-ligand and metal center. [ABSTRACT FROM AUTHOR]

• Synthesis and characterization of new Co(II) mixed ligand complexes of gabapentin or pregabalin and diimines as co-ligands. • Based on elemental analysis, spectroscopic and magnetic studies tetrahedral geometry for the complexes was proposed. • The synthesized complexes bind to DNA with groove binding mode. • The antimicrobial efficacy against gram positive, gram negative and fungus were evaluated using the synthesized complexes. • Molecular docking studies of the synthesized complexes within active site of PBP4 were performed. A series of Co(II) complexes, both binary and ternary (1–8) obtained from the main ligand gabapentin (Gpn) or pregabalin (Preg) and the coligands Phen, 2-Dipy and 4-Dipy were synthesized in a molar ratio of 1:2 or 1:1:1. Various spectroscopic techniques were employed to interpret the mixed ligand complexes such as XRD, IR, UV–Vis., SEM-EDX, GCMS–, C H N analysis, conductivity measurements, and TG/DTG studies. Within these complexes, the main ligand coordinate to the central metal ion in monodentate manner via COOH, whereas the secondary ligand Phen and 2-Dipy coordinated as bidentate chelating agent through two C N groups while 4-Dipy is bonded as monodentate ligand. Surface morphologies of the complexes were determined by SEM analyses. The complexes' thermal stability and degradation were examined using TGA. Spectroscopic and magnetic studies suggested Td geometry for the complexes. Experiments on the interaction of complexes with calf thymus DNA revealed a groove binding motif. To screen the complexes' antibacterial properties, the well-diffusion method was employed. The complexes (7) and (8) were discovered to have modest activity against Escherichia coli and strong activity against Staphylococcus aureus , Candida albicans, and Aspergillus fumigatus microbes. Molecular docking also revealed the hydrophobic, H-bond, and binding energy interactions with the crystalline penicillin binding protein-4 (PBP4) of E. coli (PDB code: 2exb) and S. aureus (PDB code: 3hun). [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesize of some novel mixed ligand complexes and their structural elucidation. • Geometry optimization for structural verification using DFT calculation. • DNA interaction and biomedical evaluation of the inspected compounds. • Molecular docking inspection for predicting of the biological evaluation. Mixed ligand chelates of Pd(II), Cu(II), VO(II), and Ag(I) with (BIP = 4,6-dimethyl-N-(octahydro-2H-benzimidazol-2-ylidene)pyrimidin-2-amine) as a main ligand and (Phen = 1, 10-phenanthroline) as a second ligand were synthesized. The recently prepared chelates were investigated through CHN analysis, (NMR, Ft-IR, Mass, and UV–Vis) spectra, magnetic moments, molar conductance, TGA, Job s methods and DFT study. The (CHN and Mass) analysis, result expose the formation of structures (1 M: 1BIP: 1Phen) chelates. The two studied ligands are established to perform in as a neutral bi-dentate approach, concluded four N 2 atoms for two ligands. The study of the molar conductance indicated the non-electrolytic features for (Cu(II) and VO(II)) chelates and the electrolytic features for (Ag(I) and Pd(II)) chelates. Thermo-dynamic and Kinetics factors for various thermal degradation phases were calculated. B3LYP/LANL2DZ/6–311 g(d,p) theoretical study has been applied for estimating the MEP, FMO analysis and quantum chemical reactivity descriptors of studied molecules. Practical and computational detail reveals that BIPPCu and BIPPVO complexes possess octahedral geometry around the metal center, BIPPAg complex shows a tetrahedral configuration, and BIPPPd complex has distorted square planar geometry. In vitro anti-microbial and anti-cancer for the studied structures were applied against various strains of microbes and cancer cell lines. The results revealed that all tested chelates showed a higher activity than the free BIP. The tested complexes have been studied to antioxidant potential using DPPH study. The binding of tested chelates with DNA was studied through applying electronic absorption, gel electrophoresis as well as viscosity study, in addition to the intercalating, minor groove and electrostatic approach of DNA interacting were recommended. The studied compounds explained dynamic satisfying performing. Also, the crystal structures of DNA (PDB ID: 454D), human coronavirus Nl63 nucleocapsid protein (PDB ID: 5EPW), breast cancer protein (PDB ID: 3HB5), and Escherichia coli (PDB ID: 2VF5) was performed by molecular docking simulation. Data of docking simulation suggestions are which tested compounds have biological behavior as well as have obvious benefit in the pharmaceutical business. [ABSTRACT FROM AUTHOR]

[Display omitted] • The new CAPh based lanthanide complexes [Ln(NO 3)(L) 2 (bipy)] and [Ln(L) 3 (bipy)] were synthesized. • The CAPh-based europium and terbium nitrate complex crystal structures were solved. • Eu3+ and Tb3+ f-f luminescence with lifetimes 1.7–2.3 ms was observed. Two series of lanthanide coordination compounds, [Ln(NO 3)(L) 2 (bipy)] and [Ln(L) 3 (bipy)], where Ln3+ = Eu, Gd, Tb, with the carbacylamidophosphate CAPh ligand N,N,N′,N′-tetraethyl-N″-(trichloroacetyl) phosphoric triamide HL = Cl 3 CC(O)N(H)P(O)(NEt 2) 2 and α,α'-bipyridine, were synthesized. The complexes were characterized using infrared, ultraviolet diffuse reflection, and luminescence spectroscopy, as well as elemental and X-ray analyses. The bidentate coordination of the deprotonated CAPh ligand was confirmed through the analysis of the complexes' IR spectra and by X-ray analysis of the bis-CAPh Eu(III) and Tb(III) complexes. The emission and excitation solid-state spectra of the Eu(III) and Tb(III) complexes, as well as the f → f luminescence decay times, were measured at room temperature. Phosphorescence spectra of the Gd(III) complexes were measured at 77 K. The lowest ligands' triplet state energy depends on the number of coordinated CAPh ligands in the complexes. The Eu(III) and Tb(III) compounds exhibited a strong metal-centered emission with decay times ranging from 1.72 ms to 2.3 ms. Intrinsic quantum yields (QLn Ln) equal 82 % for [Eu(NO 3)(L) 2 (bipy)] and 70 % for [Eu(L) 3 (bipy)]. The Tb(III) complexes revealed a very efficient ligand-to-metal energy transfer at room temperature. [ABSTRACT FROM AUTHOR]

New complexes of the some trivalent transition metal ions of the uracil such as [M(Ura)3Cl3] and mixed ligand metal complexes with uracil and oxalic acid [M(Ura)2(OA)(OH2)Cl].H2O type, where (Ura)=Uracil, (OA= Oxalic acid dihydrate, (M= Cr+3 and Fe+3) were synthesized and characterized by the elemental analysis, FT.IR, electronic spectra, mass spectra and magnetic susceptibility as well as the conductivity measurements. Six–coordinated metal complexes were suggested for the isolated complexes of Cr+3 and Fe+3 with molecular formulas dependent on the nature of uracil and oxalic acid present. The proposed molecular structure for all complexes with their ions is octahedral geometries. The antibacterial efficiency was tested of metal salts, ligands and metal complexes to the pathogenic bacteria activity have been studied.

We studied the complexation of titanium(IV) with 2,2',3,4-tetrahydroxy-3'-nitro-5'-sulfoazobenzene (R) in the presence of cationic surfactants (CSs) cetylpyridinium chloride (CPCl), cetylpyridinium bromide (CPBr), and cetyltrimethylammonium bromide (CTMABr). In the presence of cationic surfactants, mixed-ligand complexes are formed with the ratio of components : H4R– : CS = 1 : 2 : 2. The optimal pH values of the complex formation were found: 4.5 for ( (H3R2–)2 and 3.5 for mixed-ligand complexes ( (H3R2–)2(CPCl)2, ( (H3R2–)2(CPBr)2, and ( (H3R2–)2(CTMABr)2. We also investigated the effect of time, temperature, and concentrations of the reacting components on the formation of mixed-ligand complexes. The Beer law is observed in the concentration range of ( (H3R2–)2, ( (H3R2–)2(CPCl)2, ( (H3R2–)2(CPBr)2, and ( (H3R2–)2(CTMABr)2 of 0.10–1.8, 0.10–1.92, 0.10–1.92, and 0.08–1.92, respectively. The effect of foreign ions and masking substances on the determination of titanium(IV) as mixed-ligand complexes was studied. We developed a procedure for the spectrophotometric determination of trace amounts of titanium in sea sand taken from the Caspian Sea coast near the Turkan village. [ABSTRACT FROM AUTHOR]

A mixed ligand copper(II) complex, namely, [Cu(BPy)(Gly)Cl]⋅2H2O (CuC) (BPy=2,2′‐bipyridine and Gly=glycine), was synthesized and characterized. The synthesized CuC complex was tested as inhibitor to effectively mitigate the corrosion of copper in alkaline solutions using the linear sweep voltammetry (LSV) and linear polarization resistance (LPR) techniques. For the sake of comparison, such two D.C. electrochemical techniques were also applied to the Cu/OH− interface in the presence of the two studied free ligands, namely, BPy and Gly. The results showed that the three studied compounds acted as mixed‐type inhibitors, with CuC being the most efficacious one. The adsorption of the inhibitor is confirmed from X‐ray photoelectron spectroscopy (XPS) profiles by the appearance of organic chlorine as well as pyridine and amine nitrogen bonds. Based on XPS data, it was presumed that the corrosion inhibitor stimulates the formation of Cu2CO3(OH)2 species at the electrode surface since, in the case of a corroded reference sample (in absence of inhibitors), its proportion is trivial. The reactivity of the isolated inhibitors was analyzed by computing several quantum chemical parameters based on the density functional theory (DFT). A good correlation was found between these parameters and the anticorrosive performance. Additionally, Monte Carlo simulation studies were applied to find the best configurational space of ligands and their complex on the Cu(111) surface. [ABSTRACT FROM AUTHOR]

A new route to synthesize nano-sized Ti(IV) mixed ligand complexes have been investigated by the reaction of titanium(IV) chloride with ammonium salts of dithiophosphate and 3(2'-hydroxyphenyl)-5-(4- substituted phenyl) pyrazolines. The resultant complex is then treated with H2S gas to get sulfur bridged dimer of Ti(IV) complex, a precursor of TiS2. The morphology of the complexes was studied by employing XRD which shows that all the complexes are amorphous solid. Molecular weight measurements, elemental analysis in conjugation with spectroscopic (IR, ¹ H NMR, 13C NMR and 31P NMR) studies revealed the dimeric nature of the complexes in which pyrazoline and dithiophosphate are bidentate. Scanning electron microscopic image and XRD indicate that the particles are in the nano range (50 nm). Putting all the facts together, coordination number six is proposed for titanium with octahedral geometry. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of Co(II) and Ni(II) mixed ligand complexes are derived from isoniazid, 9-fluorenoneandoxalate. The metal complexes were characterized on the basis of elemental analysis, IR, UV-visible, CV, PXRD, and molar conductance analytical data, viz., all the metal complexes were suggested in an octahedral geometry, respectively. The mixed ligand complexes are formed in the 1:1:2:1 (M:L1:L2:L3) ratios, as found from the elemental analyses, and originate to have the formula [M(L1)(L2)2(L3)]. Where M = Co(II), Ni(II), L1 = isoniazid, L2 = 9-fluorenone, and L3 = oxalate. The molar conductance data reveals that the complexes are non-electrolytes. The cyclic voltammogram of the Co(II) complex revealed that the quasi-reversible single electron transfer process and Ni(II) complex corresponding to a one-electron transfer process were observed during controlled potential electrolysis. IR spectra show that the ligands are coordinated to the metal ions through N and O donor sites of isoniazid-N, 9-fluorenone-O and oxalate-O. Magnetic moment values and UV-visible spectra were used to infer the coordinating of the geometrics of these complexes found to be octahedral. The PXRD patterns suggest that all the complexes are crystalline phases. The metal chelates have been screened for antimicrobial, antioxidant and anti-inflammatory activities, and our findings have been reported, explained and compared with some known antibiotics.

The mixing of one mole of 2,2'-bipyridine-3,3'-dicarboxylic acid (bpdc) with two mole of potassium hydroxide (KOH) in methanol were refluxed for (half hour), followed by addition of one mole methanol solution of MCl2.nH2O (where M=Co, Ni or Cu). The mixture was refluxed for (2 hours) to give colored complexes of the metal ions of [M(bpdc)(H2O)4]. The [M(bpdc)(H2O)4] were reacted with one mole of 2-Mercapto-5-phenyl-1,3,4-oxadiazole (phozSH) producing the colored mixed ligand complexes with general formula [M(bpdc)(phozSH)(H2O)3] in which the metal ions coordinated to the ligand through O-atoms of carboxyl group in (bpdc) and N-atom of (phozSH) ligand. The ligands and complexes are well identified by using Furrier transform infrared spectroscopy, 1H-NMR, 13C-NMR, Electronic spectroscopy, CHNS analysis, Melting point, conductivity measurement. The Antioxidant activity were screened for all the complexes by the use of 2, 2-diphenyl-1-picrylhydrazyl (DPPH) method. [ABSTRACT FROM AUTHOR]

The reaction between 1,10-phenanthroline (phen) and a nitric acid solution of platinum was studied. It was shown that, in contrast to the earlier studied reactions with pyridine and piperazine, no solid phases were formed by the salts of anionic platinum(IV) nitrato complexes with the phenanthrolinium cation in this case due to their high solubility. The new molecular platinum(IV) complex containing 1,10-phenanthroline [Pt(phen)(NO3)4] (1) was prepared upon long-term exposure. The salt (phenH)4(NO3)2[Pt(NO3)6] (2) was synthesized by the reaction between phenanthrolinium dinitrate (phen · 2HNO3) and the salt (Bu4N)2[Pt(NO3)6] in acetonitrile with a high yield. The crystal structure of complexes 1 and 2 was characterized by X-ray diffraction. Complex 2 was studied by IR spectroscopy, thermal analysis, and solid-state magic-angle spinning (SS-MAS) 195Pt NMR spectroscopy. The results of this work could be used to develop the synthesis of new platinum complexes and for the preparation of platinum-containing heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

Four new mixed ligand complexes Me(II)/phenylalanine (phe)/HL [HL =4-(4-bromophenylaminoisonitrosoacetyl) biphenyl and Me = Co, Ni, Cu, Zn] were synthesized. These complexes are formulated as: [CoL(phe)(H2O)2], [NiL(phe)(H2O)2], [CuL(phe)(H2O)2] and [ZnL(phe)(H2O)2]. All the compounds were characterized by elemental analyses, FT-IR, magnetic susceptibility measurements, TG/DTA and cyclic voltammetry (CV) experiments. IR spectral data confirmed the coordination of the oxime ligand to the metal ions through the oxime and carbonyl oxygen. The geometrical structures of the complexes have been found to be octahedral. The measured molar conductance values of the complexes in DMF are in agreement with the nonelectrolytic nature of the complexes. The elemental analyses confirm a 1:1:1 [metal:HL:L(phenylalanine)] molar ratio. Thermal behavior of the compound was investigated by thermal gravimetric analysis (TG) and differential thermal analysis (DTA) techniques. All the complexes were transformed into metal oxides after thermal degradation. The electrochemical properties of both ligand and their complexes were analyzed by cyclic voltammetry (CV) using glassy carbon electrode in DMF solution containing 0.1 M TBAP as supporting electrolyte. [ABSTRACT FROM AUTHOR]

Mixed ligand complexes of Cu (II), Co (II) and Zn (II) with 2-((4-(1-(4-chlorophenylimino) ethyl)phenylimino)methyl)phenol (L) and histidine (His) have been prepared and diagnosed by ¹H and 13C NMR, FT-IR and electronic spectral data, thermal gravimetric, molar conductance and metal analysis measurements. The ligand (L) shows a bidentate nature and the coordination occurs through N and O atoms of imine group and phenol group respectively whereas (His) behave as tridentate ligand, coordinating through the -NH2 group and carboxylate oxygen group and N atoms of imidazole ring. The analytical studies for three complexes have shown octahedral structure. The anticancer activity was screened against human cancer cell such Follicular Thyroid Cancercells (FTC-133). The results indicate that the metal ion complexes show increase cytotoxicity in proliferation to cell lines. Antioxidant activities were shown the mixed ligand complexes have high reactivity. Antioxidant activity by determine the Effect of the compounds on Liver action of Enzyme (ALP,GOTandGPT) in (CCl4 )processing Albino Male Mice. Anti-bacterial activity has been achieved toward three kinds of bacteria (Pseudomonas auroginosa, Staphylococcus aurus and Escherichia coli). [ABSTRACT FROM AUTHOR]

The formation of Ni(II), Cd(II) and Cu(II)-complexes (C1-C3) respectively were synthesized from Schiff base and Isatin ligands. These complexes have been characterized using C.H.N analyzer, thermal analysis, FT-IR, U.V-Visible, 1HNMR and 13CNMR. From the resultant data, the suggested structure ofall complexes have octahedral geometry expect the Cucomplex was distorted octahedral geometry. Referring to this geometry, the Schiff base coordinates as a bidentate with metal ions through nitrogen atom of azomethine and sulfur atom of thiol group, while Isatin coordinates through two carbonyl groups. The two ligands and their complexes were studies their bacterial activity and gave a differentiated response. In addition, the complexes have been studied as anticorrosion activity and showed good inhibitions. [ABSTRACT FROM AUTHOR]

Hydroxypyridinone and hydroxypyranone are known to be used for the treatment of iron overload by chelation therapy for a long time. Both the ligands have their own side effects when used as medicines. In the present study homo and mixed ligand complexes of both the ligands with iron were prepared and characterized by UV-visible spectrophotometry, Potentiometric study, IR spectroscopy, SEM/EDX and XRD. Overlay spectra obtained from UV-visible spectroscopy of our studied system show the formation of different types of species and confirm that mixed ligand complex is different from the other two systems. Potentiometric titration curves of homo and mixed ligand complexes show the formation of different types of species at different pH and confirm the formation of mixed ligand complex. The comparative results of SEM images of these systems show different surface topologies and hence conform to the formation of mixed ligand complex. [ABSTRACT FROM AUTHOR]

A series of [M(A)(L)] (where M=Co(II),Ni(II), Cu(II), Zn(ll),Cd(ll) and Pd(II), A=3-aminophenol and L= dithiocarbamate ligand) complexes have been prepared.the new dithiocarbamate compound was characterized using elemental analyses, FT-IR, UV-VIS spectroscopy magnetic moments, 1H and 13C NMRforligand, thermal gravimetric analysis (TGA), differential thermal gravimetric (DTG). The antibacterial activities of synthesized compound were studied against Esherichia Coli, Staphylococcus aureus, Proteus mirabilis and Pseudomonsaerugino, for antifungal activity against Candida albicans and Candida tropicalis. [ABSTRACT FROM AUTHOR]

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Metal (M): primary ligand (HL 1): co-ligand (HL 2) complexes; characterized by analytical and spectroscopic techniques. The results of the elemental analysis show the formation of [HL1:M:HL2] complexes. The ligands act as a mononegative bidentate chelating agent coordinating through C=O, NH 2 and two OH groups by replacement of a proton from the latter groups. The interface between HL 2, complexes and calf thymus DNA (CT-DNA) displays hypochromism behavior. Antimicrobial properties of ligands and the synthesized complexes were also screened versus G+ve bacteria (S. aureus and B. cereus), G-ve bacteria (K. pneumoniae , Pseudomonas sp. and E. coli , and fungi (F. oxysporum , A. niger , and C. albicans). The obtained results revealed the strong antimicrobial action of metal complexes with MIC, MBC and MFC values ranged from 5 to 45 µg/ml. HL 1 showed higher antimicrobial and antioxidant activities than HL 2 and major of the prepared metal complexes. All metal mixed ligand complexes inhibited the multidrug-resistant bacterium; Klebsiella pneumoniae compared to the standard antibiotic, penicillin G. Also, all metal mixed ligand complexes showed potent antifungal activities against both Aspergillus niger , and Candida albicans. [Display omitted] • Metal (M): primary ligand (HL 1): co-ligand (HL 2) complexes are prepared and characterized. • The molecular docking between the proteins receptors and the ligands and its mixed ligand metal complexes was studied. • Antimicrobial properties of ligands and its metal complexes are screened versus G+ve bacteria, G-ve bacteria and fungi. The results revealed the strong antimicrobial action of metal complexes with MIC, MBC and MFC values ranged from 5-45 μg/ml. • HL 1 ligand showed higher antimicrobial and antioxidant activities than HL 2 and major of the prepared metal complexes. The current work was designed to prepare novel 1:1:1 Metal (M): primary ligand (HL 1): co-ligand (HL 2) complexes; [Cu(L 1)(L 2)(OH 2) 2 ] (1) , [Co(L 1)(L 2)]H 2 O (2) , [Ni(L 1)(L 2)(OH 2) 2 ] 0·.75H 2 O (3) and [Mn(L 1)(L 2)(OH 2) 2 ] 4·.5H 2 O (4) and [UO 2 (L 1)(L 2)] (5) from ligands 7-Formyl-8-hydroxyquinoline (oxine) (HL 1), 2-aminophenol (HL 2) and characterized by analytical and spectroscopic techniques. FTIR, mass spectra, ESR techniques, elemental analysis, and thermal analysis were used to characterize the newly formed complexes. The results of the elemental analysis show the formation of [HL 1 :M:HL 2 ] complexes. The ligands act as a mononegative bidentate chelating agent coordinating through C = O, NH 2 and two OH groups by replacement of a proton from the latter groups. The molecular docking between the protein receptors and the ligand (HL 1), ligand (HL 2) and its mixed ligand metal complexes (1 – 5) was studied. The interface between HL 2, complexes and calf thymus DNA (CT-DNA) displays hypochromism behavior. The binding value constant (Kb) are calculated and found to be 5.29 × 103, 8.49 × 104, 2.45 × 105, 2.96 × 104 and 1.16 × 104, 3.08 × 104 M−1 for HL 2 and its mixed ligand metal complexes (1 – 5) , respectively. Antimicrobial properties of ligands and the synthesized complexes were also screened versus G + ve bacteria (S. aureus and B. cereus), G-ve bacteria (K. pneumoniae , Pseudomonas sp. and E. coli , and fungi (F. oxysporum , A. niger , and C. albicans). The obtained results revealed the strong antimicrobial action of metal complexes with MIC, MBC and MFC values ranging from 5 to 45 µg/ml. HL 1 showed higher antimicrobial and antioxidant activities than HL 2 and major of the prepared metal complexes. All metal mixed ligand complexes inhibited the multidrug-resistant bacterium; Klebsiella pneumoniae compared to the standard antibiotic, penicillin G. Also, all metal mixed ligand complexes showed potent antifungal activities against both Aspergillus niger and Candida albicans. [ABSTRACT FROM AUTHOR]