Transesterification Reaction of Palm Kernel Oil (PKO) on a Bed of Crushed Cashew Nut Shell (CCNS)

Biodiesel (GA1) was produced by the transesterification reaction of palm kernel oil (PKO) and methanol catalysed by crushed cashew nut shaft. Biodiesel samples GA2 – GA4 were also produced from the palm kernel oil using conventional base catalysis by NaOH and crushed cashew nut shaft combined with NaOH. The physico-chemical properties and spectroscopic data of the four samples were found to be similar and compared favourably to those of standard biodiesel. Keywords: Transesterification, palm kernel oil, cashew nut shell, methanolysis, biodiesel

Kinetic And Thermodynamic Studies Of Glucose Oxidase Catalysed Oxidation Reaction of Glucose

The kinetics of oxidation of D-glucose catalysed by the enzyme glucose oxidase has been studied over a wide range of experimental conditions. The reaction velocities increased with increase in the concentrations of the glucose oxidase and glucose, as well as increase in temperature and ionic strength of the solution. The reaction velocity initially increased with increase in pH, reaching a maximum at pH 6.5 and then decreased with further increase in pH. The reaction exhibited saturation kinetics and experimental data were analysed using the Michaelis- Menten equation. Arrhenius activation energy and thermodynamic activation parameters were measured and are reported. The large negative value of entropy of activation \u394S 60 , -148.8JK-1mol-1, and positive value of the enthalpy of activation \u394H 60 , 26.3kJmol-1, give further support to the proposed mechanism. The results are interpreted in terms of a mechanism involving both an oxidative half reaction and a reductive half reaction

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

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Synthesis and X-ray studies of ruthenium(II) complexes containing hydrazine and benzyl isocyanide ligands

The reaction of the polymeric species [{RuCl2(COD)}x] (1; x > 2; COD = cyclo-octa-1,5-diene) and hydrazine hydrate in methanol under reflux gave a pale pink solution from which the salt [Ru(COD)(N2H4)4][BPh4]2.CH3OH (2) was isolated on addition of NaBPh4. Treatment of 2 in refluxing acetone in the presence of the ligand benzyl isocyanide give a complex of stoichiometry [Ru(NH2N=CMe2)2(PhCH2NC)4][BPh4]2 (3) on the substitution of the labile COD ligand. The two compounds have been characterized by elemental analyses, IR and NMR measurements and single-crystal X-ray diffraction studies. The ruthenium in both compounds has a distorted octahedral coordination geometry. KEY WORDS: Cycloocta-1,5-diene, Hydrazine hydrate, Isocyanide, Ruthenium Bull. Chem. Soc. Ethiop. 2013, 27(3), 405-411.DOI: http://dx.doi.org/10.4314/bcse.v27i3.

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

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

Kinetics and mechanism of oxidation of D-xylose and L-arabinose by chromium(VI) ions in perchloric acid medium

The kinetics of oxidation of D-Xylose and L-Arabinose by Cr(VI) ions in perchloric acid medium have been investigated spectrophotometrically under pseudo-first-order conditions. The reactions exhibit first-order rate dependence each on the substrate and oxidant. The order with respect to [H+] is unity while no effect on the reaction rate is found with respect to the ionic strength. The Arrhenius (Ea) and thermodynamic activation parameters (ΔH≠, ΔS≠ and ΔG≠) are evaluated and the reaction mechanism is interpreted in terms of formation of a 1:1 intermediate complex between a protonated chromic acid molecule and a neutral sugar molecule in sharp contrast to the results of our earlier studies on the C6 and C12 sugars

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