Metal(II) coordination compounds of glycine and phenylalanine were synthesized and characterized using infrared and electronic spectroscopic, and magnetic susceptibility measurements. The complexes were tested for antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Methicillin Resistant Staphylococcus aureus (MRSA), Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris and Candida albicans. The stoichiometric reaction between the metal (II) ions and ligands in molar ratio M:L (1:3) [where M = Mn, Co, Ni, Cu and Cd; L= glycine; phenylalanine] resulted in the formation of five-coordinate square pyramidal dinuclear geometry for both copper complexes and six-coordinate octahedral geometry for the other complexes. The spectroscopic and magnetic moment data suggested that the ligands coordinated via both their amino and carboxylate ion moieties. The complexes demonstrated better activities against one or more of the tested microbes than acriflavine, the standard drug used.

, EC and some heavy metals both as regards total, dissolved and particulate fractions. Analysis of the heavy metals was done using flame Atomic Absorption Spectrophotometer. The quantity of these parameters varies with the different roofing materials. In terms of dissolved metals, Fe is the most predominant metal with mean values 0.59 ± 0.29, 0.82 ± 0.14, and 1.04 ± 0.27 mg/L for asbestos, ceramic tiles and metal sheets respectively. The tendency of the roofing materials to release dissolved metals is arranged as follows: Zn, Cr and Fe (metal sheet > Ceramic > asbestos); Cd and Pb (asbestos > ceramic > metal sheet). In terms of particulate metals, the concentration of Cd and Pb are higher in the asbestos than other roofing stuffs. The sequence of their predominance in asbestos is as follows: Pb (0.83±0.55 mg/L) > Cd (0.29 ± 0.07 mg/L). In all the roofs, both particulate and dissolved metals except Zn exceeded WHO permissible limits for drinking water. The high levels of the metals obtained in this study may likely result in consumer complaints since some of the metals are not only carcinogenic but are also liable of impacting bad taste in water.

The reactions between Fe(Phen) 2þ 3 [phen=tris-(1,10) phenanthroline] and Co(CN) 5 X 3) (X=Cl, Br or I) have been studied in aqueous acidic solutions at 25°C and ionic strength in the range I=0.001-0.02 mol dm )3 (NaCl/HCl). Plots of k 2 versus p I, applying Debye-Huckel Theory, gave the values )1.79±0.18, )1.65±0.18 and 1.81±0.10 as the product of charges ðZ A Z B Þ for the reactions of Fe(Phen) 2þ 3 with the chloro-, bromo-and iodo-complexes respectively. Z A Z B of % À2 suggests that the charge on these Co III complexes cannot be )3 but is )1. This suggests the possibility of protonation of these Co III complexes. Protonation was investigated over the range [H + ]=0.0001 )0.06 mol dm )3 and the protonation constants K a obtained are 1.22 · 10 3 , 7.31 · 10 3 and 9.90 · 10 2 dm 6 mol )3 for X=Cl, Br and I, respectively.

Aggregation of sodium lauroylsarcosinate (SLS) in aqueous solutions of methanol, ethanol, propanol and ethylene glycol at 288-313 K has been determined from conductivity measurement in the range 0-20% v/v of additives. The precise values of the critical micelle concentration (CMC) and the degree of counter-ion dissociation of micelles were obtained at each temperature by fitting the specific conductivitysurfactant concentration curve to the integrated form of the Boltzmann-sigmoid equation. The CMC was found to increase with increase in additive concentrations in the case of methanol and ethylene glycol, while it decreases with increase in ethanol and propanol concentration. The equilibrium model of micelle formation was applied to obtain the thermodynamic parameters of micellisation. The Gibbs free energies were observed to vary only slightly with temperature and additive concentrations. Enthalpyentropy compensation was observed for all the systems with a constant compensation temperature of ≈300 K and negative compensation enthalpy.

Effects of varying concentrations of 1,2-ethanediol, 1,2-butanediol and 1,2-hexanediol (glycols) on the micellisation and thermodynamic properties of sodium dodecyl sulphate (SDS) were studied at temperature range 288-313 K by conductometry method. Critical micelle concentration (CMC) of SDS increased in 1,2-ethanediol but decreased in the longer carbon chain glycols in the order: 1,2-hexanediol < 1,2-butanediol < pure water < 1,2-ethanediol. As temperature increased, CMC of SDS increased linearly in 1,2-ethanediol. Conversely, minimum CMC values were observed in 1,2-butanediol and 1,2-hexanediol between 293 K and 303 K at the temperature range studied, indicating more ordered water structure is favoured by the longer hydrocarbon chain glycols. ΔG 0 m values were negative at all temperatures for all glycol concentrations indicating the micellisation process is energetically favourable. Enthalpy-entropy compensation plots gave fairly constant compensation temperature values (≈300 K) for all the systems while compensation enthalpy values were less negative as the glycol concentration increased.