GREEN SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL STUDIES OF MIXED LIGAND COMPLEXES OF Co (II), Ni (II) and V(III) METALS USING SOME AMINO ACIDS AS LIGANDS

Co (II), Ni (II) and V (III) metal complexes were synthesized mechanochemically using L-Leucine, L-Tyrosine and Creatinine as mixed ligands. The metals and the ligands were grounded using an agate mortar with a pestle. The compounds formed were characterized using their melting/decomposition temperature, solubility, magnetic susceptibility, conductivity measurement, Infrared analysis and scanning electron microscope (SEM). The Metal – ligand ratios were investigated via Job’s method of continuous variation. The shifts of bands (for instance 1693-1677 cm-1 to 1674-1607 cm-1) in C=O and the appearance of new bands in the complexes (683-669 and 713-750 cm-1 indicates the complexation. The lower conductivity measurement values (15.00 to 32.40) µS.cm-1 suggested the non-electrolytic nature of the complexes. The magnetic effective value of the metal complexes showed that all the three complexes are paramagnetic and octahedral. It was concluded that the amino acids (ligands) coordinated in a bidentate way through the nitrogen from the amino group and oxygen from carboxylate. The complexes were screened for their antimicrobial activities against two bacterial isolates (Streptococcus pneumoniae and Klebsiella pneumoniae). All the complexes exhibited good activity against the organisms

Synthesis, Crystal Structure and Optical Properties of 2-(3-(Hexyloxy)-5-Methylphenoxy)-N-(4-Nitrophenyl)acetamide for Anion Detection

In this study, 2-(3-(hexyloxy)-5-methylphenoxy)-N-(4-nitrophenyl)acetamide (sensor L1) was synthesized and characterized by FT–IR, ESI–MS, 1H and 13C NMR spectroscopy, elemental analysis, and single crystal X-ray techniques. The crystal structure and space group of sensor L1 was monoclinic and P21, respectively. The crystal packing of sensor L1 was dominantly linked by two strong hydrogen bonds forming a six membered ring pattern. The binding properties of sensor L1 and various anions (F−, Cl−, Br−, CH3COO−, C6H5COO−, and H2PO4−) were investigated by UV–Vis and 1H NMR spectroscopy in DMSO. The proton resonance signals of sensor L1 and F− greatly changed positions when compared to those of anions. The solution color of sensor L1 changed from pale yellow to orange in the presence of F−. The UV–Vis results indicate that sensor L1 and F− ions underwent an internal charge transfer process. The stoichiometric complex was confirmed by Job’s method, revealing a 1:1 formation for sensor L1 and fluoride. Our results show that sensor L1 is highly selective for fluoride ions over other anions.

Study on the Extraction and Separation of Zinc, Cobalt, and Nickel Using Ionquest 801, Cyanex 272, and Their Mixtures

Both Cyanex 272 (bis (2,4,4-trimethylpentyl) phosphinic acid) and Ionquest 801 (2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester) are commonly used for metal extraction and separation, particularly for zinc, cobalt, and nickel, which are often found together in processing solutions. Detailed metal extractions of zinc, cobalt, and nickel were studied in this paper using Cya-nex 272, Ionquest 801, and their mixtures. It was found that they performed very similarly in zinc selectivity over cobalt. Cyanex 272 performed much better than Ionquest 801 in cobalt separation from nickel. However, very good separation of them was also obtained with Ionquest 801 at its low concentration with separation factors over 4000, indicating high metal loading of cobalt can significantly suppress nickel extraction. Slop analysis proved that two moles of dimeric extractants were needed for one mole extraction of zinc and cobalt, but three moles were needed for the extraction of one mole nickel. A synergistic effect was found between Cyanex 272 and Ionquest 801 for three metal extractions with the synergistic species of M(AB) determined by the Job’s method.

Synthesis and biological analysis of anti-addiction effect and hepatotoxicity of tow baclofen analogues complexed with β-Cyclodextrin

Aim and Objective : The excessive consumption of alcohol and the installation of a dependence is, in most cases, facilitated by favorable psychological factors which trigger and maintain the behavior of consumption. Examples more frequently encountered in individuals having difficulty with alcohol are in particular: one or more anxiety disorders, deficits in the capacities to manage stress and anxiety. The main objective of this work was study in vivo the anti-addiction effect and hepatotoxicity of tow baclofen analogues complexed with β-Cyclodextrin (βCD) on an alcohol-dependent rat model. Materials and Methods: The synthesis of two analogues ABF1 and ABF2 close to baclofen was reported. The structural determination of the two compounds was confirmed by NMR and IR analysis. The complexation of analogues with βCyclodextrin (βCD) was performed in water at room temperature (25 °C). The interactions of ABF with β-Cyclodextrin, and the stability constant (Ka) of the inclusion complex formed between them were investigated by using UV-visible spectroscopy. The biological effects of baclofen and the two analogues on alcohol dependence were studied in wistar rats. The anti-addiction effect of the analogues was tested by measuring the alcohol intake and the variation of the animal behaviour. The toxicity of the compounds was also analysed on liver injury markers. Results: The amino-3-phenylbutanoic acid (ABF1) and 3,4,5-trihydroxy-N-(methyl-2-acetate) benzamide (ABF2) were synthesized. The complexation of both analogues of baclofen (BF) with β-cyclodextrin (βCD) (ABF- βCD) was realized and confirmed by the stability constant of the inclusion complex (Ka) and Job’s method. The evaluation of anti-addiction activity in vivo showed that ABF1-βCD inhibits the consumption of alcohol at the doses equivalent to those of baclofen. Both baclofen analogues have shown an anxiolytic effect. Regarding the toxicity of the two compounds, our results showed that ABF1-βCD has less toxic effect than baclofen, it reduces the activity of ALT and AST enzymes. Histologically ABF1-βCD has no effect on structure of the liver in addition and has a protective effect against lesions alcohol-induced liver disease. Conclusion: Therefore, it can be suggested that ABF1 analogue combined with β-Cyclodextrin can be used as a treatment for alcohol dependence. Further clinical works are needed to confirm its effectiveness.

Alternative Synthetic Method and Antimicrobial Activity Screening of Co (II) and Cu (II) Complexes of 2-(Acetyloxy) Benzoic Acid (Aspirin)

Mechanochemical synthesis of Co(II) and Cu(II) aspirin complexes was carried out by simple grinding of metal (II) acetates with aspirin without any solvent. Also conventional preparation of the above complexes was carried out for comparison purposes using the solution-based method. The products of mechanochemical synthesis were characterized by comparison of solubility, melting points, conductivity values, magnetic moment and IR analyses with those of ligands and conventional solution-based products. The IR spectral and analytical data of the complexes were similar for both products of the two synthetic routes suggesting the formation of identical compounds. Job’s method analyses suggested 1:2 metal to ligand ratio. The elemental analyses results revealed identical percentage composition of each element found in the products as compared to those of calculated percentages. The complexes have low values of molar conductance (4.24-6.60Ω-1 cm2mol-1 ) implying that they are non-electrolytes in DMSO. The complexes were all soluble in dimethylformamide and dimethylsulfoxide. The complexes were mostly soluble in non-polar solvents. All the products decomposed at a temperature range of 177.0-181.9oC higher than that of their ligand revealing their more stable nature. The magnetic moment values obtained proved the paramagnetic nature of the synthesized complexes. The products and the ligand were screened against three bacteria isolates; Escherichia coli, Kledsiella pneumonia, Staphylococcus aureus and two fungi isolates; Aspergillus fumigatus, Mucus specie for antimicrobial activity. The results shows that the ligand was inactive against all the test organisms; the complexes were active in all test concentration, with only Co(asp)2 complex inactive against Staphylococcus Aureus at a concentration of 15µg/disc.

Synthesis and characterization of Al(III) complex with paracetamol

The complex of Al (111) with paracetamol have synthesized and characterized using UV–Vis, Infrared spectroscopies and melting point. The ligand has been found to behave as tridentate chelating agents. Paracetamol complex coordinate through the carboxylate oxygen, phenolate oxygen atom, and amine group. The complex solubility was evaluated for several solvents and it was found the compound was more soluble in DMSO. Job’s method of continuous variation suggested 1 : 2 metals to ligand stoichiometry for paracetamol complex

Versatile Colorimetric Chemosensor Based on Bis(rhodamine) B Hydrazone for Rapid Detection of Multi-Analytes (Fe3+, Bi3+, Cu2+, and Hg2+) in Aqueous Media

A new bis(rhodamine) B hydrazone L, bearing two rhodamine chromophores, has been designed and synthesised in 70% yield. The chemical structure of the new ligand L was characterised using different spectroscopic techniques. The receptor L was utilised for rapid ‘naked eye’ detection of Fe3+, Bi3+, Cu2+, and Hg2+ in THF–H2O (1:1, v/v) by displaying significant colour changes. The mechanism of detection of metal ions was based on the ring-opening of the spirolactam rings of L upon recognition. UV/Vis spectrometry was employed to investigate L–metal ion interactions in THF–H2O (1:1, v/v). The stoichiometries of the complexes were determined using Job’s method, which revealed 1:2L–metal ion stoichiometries in the case of L–(Fe3+/Bi3+/Hg2+) complexes, while a 1:1L–metal ion stoichiometry was recognised for the L–Cu2+ complex. 1H NMR spectroscopy was applied to study the L–metal ion interactions in DMSO-d6 and results are presented.

Extractive Spectrophotometric Method for the Determination of Glibenclamide by Ion-Pair Complex in Pure Form and Pharmaceutical Formulation

Simple, rapid and sensitive extractive spectrophotometric method is presented for the determination of glibenclamide (Glb) based on the formation of ion-pair complex between the Glb and anionic dye, methyl orange (MO) at pH 4. The yellow colored complex formed was quantitatively extracted into dichloromethane and measured at 426 nm. The colored product obeyed Beer’s law in the concentration range of (0.5-40) μg.ml-1. The value of molar absorptivity obtained from Beer’s data was found to be 31122 L.mol-1.cm-1, Sandell’s sensitivity value was calculated to be 0.0159 μg.cm-2, while the limits of detection (LOD) and quantification (LOQ) were found to be 0.1086 and 0.3292 μg.ml-1, respectively. The stoichiometry of the complex created between the Glb and MO was 1:1 as determined via Job’s method of continuous variation and mole ratio method. The method was successfully applied for the analysis of pharmaceutical formulation.

A Novel Approach Based on Two-Dimensional Correlation Spectroscopy to Determine the Stoichiometric Ratio of Two Substances Involved in Intermolecular Interactions

A novel technique called AOSD@Job’s, combining asynchronous orthogonal sample design scheme (AOSD) with Job’s method, is proposed to estimate the stoichiometric ratio of two substances that form a supramolecular aggregate under intermolecular interactions. First, a mathematical analysis was performed along with the procedure of the AOSD@Job’s method. Then, the validity of the AOSD@Job’s method was manifested by computer simulation on two model systems. Finally, the AOSD@Job’s method was applied on two real chemical systems. The stoichiometric ratio between the coordination complex of Ni2+ and ethylenediaminetetraacetic acid disodium salt (EDTA) was estimated to be 1.0. Benzyl alcohol (BA) and β-cyclodextrin (β-CD) were determined to form a 1 : 1 host–guest complex. These values were consistent with the values reported in the literature. Compared with the traditional Job’s method, the AOSD@Job’s method has an evident advantage since it is still valid even if all the peaks of the supramolecular aggregate severely overlap with the peaks of the substances that form the aggregate.