The synthesis of some organotin (IV) compounds in the melt-phase

Abstract The melt-phase synthesis of dioctyltin (IV) and triphenyltin (IV) benzoates were carried out using stoichiometric amounts of benzoic acids and the corresponding organotin (IV) compounds. The reagents were ground together in a mortar and fed into a boiling glass tube. A cannula tube was inserted into the boiling tube to discharge accumulated gaseous products. A syringe ensured a continuous flow of dry Nitrogen gas in the reaction vessel. The compounds are known using wet Chemistry. Their syntheses via the melt-phase were in good yields. The physical properties corresponded to those of the similar compounds prepared by wet chemistry. The IR, 1 H and 13 C NMR data indicate that coordination to the tin atom is via carboxylate group

Bis(acetonitrile-kN)dichlorido(h⁴-cycloocta- 1,5-diene)ruthenium(II) acetonitrile monosolvate

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Synthesis and characterization of a tetranuclear Cu(II) coordination polymer containing pyridine-2,6-dicarboxylic acid and 4-amidinopyridine co-ligand

This research demonstrates the preparation of a new coordination polymer, {[Cu4(H2pydc)2(H1apy)(H2O)2DMF].DMF}n, (H2pydc = pyridine-2,6-dicarboxylic acid, H1apy = 4-amidinopyridine) under solvothermal condition by the self-assembly of pyridine-2,6-dicarboxylic acid, 4-midinopyridene and copper(II) acetate. The compound was characterized by elemental analysis and infrared spectroscopic technique. The analysis indicated that the 4-amidinopyridine coordinated to the copper ions through the terminal nitrogen in a monodentate fashion while the pyridine-2,6-dicarboxylic acids coordinated through the carboxylate oxygens in monodentate mode. Both the elemental analysis and the infrared spectroscopic data agreed with the proposed stoichiometry. This result represent the first report of a tetranuclear Cu(II) coordination polymer having coordinated 4-amidinopyridine as the nitrogen donor moiety in its structure

Synthesis and spectroscopic analysis of Schiff Bases of Imesatin and Isatin derivatives

A series of new Schiff bases of Imesatin and Isatin derivatives which have been previously prepared from the reaction of Hydrazine monohydrate, p-phenylenediamine and 4,4- diaminodiphenylmethane with Isatin were reported. The compounds were characterized by elemental analyses, UV-visible, Infrared and Nuclear Magnetic Resonance (1H NMR and 13C NMR) spectroscopic analyses. The synthesized Schiff bases were obtained in moderate to excellent yields between 55.3 – 89.3%. Infrared spectra of all synthesized compounds contain the characteristic azomethine linkage (-CH=N) between 1580 – 1630 cm-1 and the N–H of the Isatin ring signals between δ 8.32 – 10.68 ppm in their 1H NMR spectra. The present work affords reaction pathway that is efficient and operational simplicity for the synthesis of Schiff bases derivatives.Keywords: Schiff bases, isatin, imesatin, spectroscopic analysis, biological activit

Removal of hexavalent chromium from aqueous solutions by adsorption on modified groundnut hull

AbstractThere is an emerging serious threat to the environment from indiscriminate release of heavy metals into the wastewaters and soil from human industrial practices. In this study therefore, the uptake of hexavalent chromium, being among the major pollutants from our industries, by modified and unmodified groundnut hull was investigated. The effects of different conditions of contact time, adsorbate concentration, solution pH, and temperature on sorption process were studied. The adsorbent materials were characterized by Fourier Transform Infrared Spectroscopy (FT-IR). Analysis of the surface morphology by Scanning Electron Microscopy (SEM) revealed a change in morphology upon chromium adsorption. The adsorption process of Cr(VI) ions onto both the unmodified groundnut hull (UGS) and the modified groundnut hull (MGS) is in good agreement with the Langmuir adsorption isotherm and follows the pseudo-second-order kinetic model. According to the equilibrium studies, chromium(VI) ions are better adsorbed by modified groundnut hull

Kinetics of oxidation of D-arabinose and D-xylose by vanadium (V) in the presence of manganese II as homogeneous catalyst

<div align="justify">Kinetics of oxidation of D-arabinose and D-xylose by acidic solution of vanadium (V) ions in the presence of manganese (II) has been reported. First-order dependence of the reaction rate was observed on [sugars] and [H+] at low concentrations throughout the oxidation reaction and a zero-order dependence on [sugar] and [H+] was observed at high concentrations. First-order kinetics with respect to [Mn (II)] was also observed throughout the oxidation for both sugars. The results indicate the effect of Cl- concentration is negligible. The reaction rates increase with the ionic strength of the medium. Various activation parameters were evaluated and provide further support to the proposed mechanism. Formic acid was reported as one of the oxidation products of these sugars. </div

Solvent-free mechanochemical synthesis and X-ray studies of Cu(II) and Ni(II) complexes of 5-(3,4,5-Trimethoxybenzyl)pyrimidine-2,4-diamine (Trimethoprim) in a ball-mill

Solvent-free synthesis of [Cu(CH3COO)2(TMP)2](1) and [Ni(CH3COO)2(TMP)2](2) by ball milling of Cu(CH3COO)2.H2O and Ni(CH3COO)2.4H2O with Trimethoprim in the absence of solvent is described. Conventional synthesis of 1. CH3OH and 2. CH3OH was carried out by the reaction of metal acetate salt and Trimethoprim using the solution-based method (reflux in CH3OH for 2 h) for comparison purposes. The mechanochemical products were characterized by comparison of melting points, conductivity values, spectral data, XRPD patterns with those of free ligand and solution based conventional synthesis products. X-ray diffraction patterns of the complex were similar to the simulated pattern of the complex obtained from single crystal structure suggesting the formation of identical compounds as obtained in solvent medium. The process presented here is operationally simple, environmentally benign and affords excellent yields without the need for solvents or external heating. Clearly, it can present a higher efficiency in terms of materials, energy and time compared to classical solution phase synthesis

Bis(acetonitrile-&amp;#954;N)dichlorido(&amp;#951;4-cycloocta-1,5-diene)ruthenium(II) acetonitrile monosolvate

In the title RuII complex, [RuCl2(C8H12)(C2H3N)2]&amp;#183;CH3CN, the metal ion is coordinated to the centers of each of the double bonds of the cyclooctadiene ligand, to two chloride ions (in cis positions) and to two N-atom donors (from MeCN molecules) that complete the coordination sphere for the neutral complex. The coordination about the RuII atom can thus be considered to be octahedral with a slightly trigonal distortion. There is also one acetonitrile solvent molecule per molecule which is outside the coordination sphere of the ruthenium atom

Synthesis, thermal properties and biological study of metal(II) nicotinamide complexes containing fumarate dianion and fumaric acid: crystal structure of [Ni(H 2 O) 4 (nia) 2 ](fum)·(H 2 fum)

New divalent transition metal nicotinamide (nia) complexes containing fumarate (fum) dianion and fumaric acid (H2fum), [M(H2O)4(nia)2](fum)·(H2fum) [M = Co (1), Cu (2) and Ni (3)] have been synthesized. The compounds were characterized by elemental analyses, IR, UV-vis, XRPD and TGA. Structural analysis of 3 using single crystal X-ray diffraction technique revealed that the Ni(II) ion is coordinated by four aqua and two nicotinamide ligands in an octahedral geometry. The structure of 3 is completed with fumarate (fum²⁻) dianion acting as counter-ion while fumaric acid (H2fum) is present as a molecule of solvation. The three complexes were investigated for biological activities