Trimethylamine N-oxide promoted decarbonylation reactions of molybdenum and tungsten hexacarbonyls with dimethylglyoxime

Decarbonylation of Mo and W hexacarbonyls in the presence of dimethylglyoxime was carried out under the control of trimethylamine N-oxide (TMNO). The two DMG substituted carbonyl complexes were prepared in a one pot synthesis using manipulated Schlenk techniques under dinitrogen in tetrahydrofuran. The Mo complex system was successfully carried out by stirring the mixture of the molybdenum hexacarbonyl and DMG in tetrahydrofuran at room temperature for 18hrs. A similar procedure afforded the starting ligand material for the W complex analogue. However, further refluxing for 6 h gave the desired W complex. The complexes were characterized using 1H NMR, IR, and CHN analyses. Results showed that the reactions produced analytically pure, mono-product dicarbonyl species; Mo(CO)2(DMG)2 I and W(CO)2(DMG)2 II where two DMG moieties were coordinated to the central metal atom through one N and O atoms respectively of each of the oxime groups.Keywords: Bioorganometallic, Metal carbonyl, CO-RMs, Decarbonylation, Trimethylamine N-oxid

ANTI-FUNGAL ACTIVITIES OF m-IODOBENZOIC ACID AND SOME OF ITS METAL DERIVATIVES ON BREAD MUCOR

The anti-fungal activities of alkali and alkaline earth metal iodobenzoates were studied. Calcium iodobenzoate exhibited the highest anti-fungal activities of 74.60% inhibition for 15 ppm while sodium iodobenzoate exhibited the least inhibition of 61.64%. An optimum concentration of all the metal complexes for inhibition was found to be 75 ppm. Although the use of these metals complexes as food preservatives may only be fungi-static and not fungi-toxic, their use in bread preparation might extend the shelf life of bread from 24 hours to 96 hours. KEY WORDS: Anti-fungal activities, Alkali metal iodobenzoates, Alkaline earth metal iodobenzoates, m-Iodobenzoic acid, Bread mucor Bull. Chem. Soc. Ethiop. 2005, 19(2), 301-306

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

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, characterisation, and in vitro anticancer activity of catalytically active indole-based half-sandwich complexes

YesThe synthesis, characterisation and evaluation of the in vitro cytotoxicity of four indole-based half-sandwich metal complexes towards two ovarian cancer cell lines (A2780 and A2780cisR) and one normal prostate cell line (PNT2) are presented herein. Although capable of inducing catalytic oxidation of NADH and able to reduce NAD+ with high turnover frequencies, in cells and in the presence of sodium formate, these complexes also strongly interact with biomolecules such as glutathione. This work highlights that efficient out-of-cells catalytic activity might lead to higher reactivity towards biomolecules, thus inhibiting the in-cells catalytic processes