Zeitschrift für chemische Wissenschaften

The (ethylenediamine) dichlorocopper(II) complex, {[Cu(en)]Cl2}n(en:C2H8N2), was synthesized by hydrothermal technique. The X-ray structure of {[Cu(en)]Cl2}n shows that the compound crystallizes as a one dimensional chain with one chlorine that is non-bridging and the other chlorine which is triply bridging. It crystallizes at room temperature in the centrosymmetric space group P21/m. The structure of {Cu(en)Cl2}n was originally reported by Kumara et al. The surrounding copper is best described as distorted octahedral. The crystal structure was stabilized with an extensive network of N-H…Cl classical hydrogen bond interactions. The investigation on that close intermolecular interactions between the molecules via Hirshfeld surface analyses is presented to reveal subtle differences and similarities in the crystal structures. The decomposition of the fingerprint plot area provides a percentage of each intermolecular interaction, allowing for a quantified analysis of close contacts within the crystal. The optimized molecular structure and vibrational spectra were calculated by the Density Functional Theory (DFT) method using the B3LYP function with the LanL2DZ basis set. Good consistency is found between the calculated results and the experimental structure, FTIR, and FT-Raman spectra. The detailed interpretation of the vibrational modes was carried out. Optical transmission measurements performed on thin films of {[Cu(en)]Cl2}n revealed two absorption bands at 3.64 eV and 1.907 eV. The calculated HOMO-LUMO energies reveal that charge transfer occurs within the molecule.

A simple and sensitive spectrophotometric method has been established for the determination of copper in water and soil sample. The method simply involves the chelation of Dimethylglyoxime ligand with Copper under optimal conditions. The method is based on the formation of 1:2 complexes between Copper and Dimethylglyoximine. The optimal condition for the determination of copper was established. The Beer’s law was applicable in the range 0.05 to 0.995 μg/ml. The molar extinction coefficient of the said complex was found to be 1.2 × 105 mol-1 cm-1. The method was successfully applied for the determination of Copper in the water and soil samples.

2-(2-(2-hydroxybenzyliden) hydrazinyl)-2-oxo-N-(pyridine-2-yl) acetamide complexes of Ni(II) and Co(II) prepared. The proposed structures proved based on elemental, DFT, and spectral analysis. The DNA binding affinity and MIC activity against Gram-positive, Gram-negative bacteria, pathogenic C. albicans and A. flavus fungal strain tested.

The ethanol production ability of baker’s yeast (Saccharomyces cerevisiae) and burukutu starter culture were examined on yam starch hydrolyzed with malts of maize and millet. Four substrate treatments which include yam starch (as control), yam starch hydrolyzed with millet malt (B), yam starch hydrolyzed with maize malt (C) and yam starch hydrolyzed with a mixture both millet and maize malt (D) were prepared in duplicate and made up to 600 ml. Baker’s yeast (4.40 g) was inoculated on one set of four while burukutu starter was inoculated on the other set of four and fermented for a period of four days at a temperature of 26°C. The pH was observed to drop as fermentation period increased, the highest ethanol yield of up to 74.5 g/Kg was obtained from starch hydrolyzed with maize malt and inoculated with baker’s yeast. Yam is a potential source of industrial scale ethanol production, there was a significant difference (p<0.05) between maize and millet malts in ethanol yield but between baker’s yeast and burukutu starter culture fermentation there was no significant difference (p<0.05), the interaction between malts and the inoculums was significant (p<0.05). Ethanol yield strongly depends on the hydrolysis of yam starch into fermentable sugar.

In this study, benzyl bis (thiosemicarbazole) monomer, polymer and poly benzyl bis (thiosemicarbazone) (PBTC) /CeO2 nanocomposites were synthesized through in situ polymerization and their dielectric properties in presence of metal oxide, were investigated. Prepared samples were characterized by Fourier Transform Infrared spectroscopy (FTIR), X-ray Diffraction (XRD), Structure and morphology of prepared nanocomposites were evaluated by Scanning Electron Microscopy (SEM) and XRD techniques. The dielectric properties were investigated in the frequency range 50 Hz - 20 MHz and the temperature range between 40°C to 150°C. The dielectric constant (ε) and dielectric loss (tan δ) is measured for different compositions of nanocomposites. Particle sizes of CeO2 were calculated to be 10 nm from Debye-Scherrer equation. FT-IR verified polymerization of monomers. The dielectric properties of cerium oxide nanocomposite were studied for different frequencies at different temperatures. The dielectric constant and the dielectric loss of the cerium oxide nanocomposite decreased with increase in frequency. The AC electrical conductivity study revealed that the conduction depended on both the frequency and the temperature.

Bioadsorption of Co(II) metal ions from the aqueous medium using Trapa natan peels biomass was examined for preliminary pH, initial metal absorption and contact time. Pretreatment of biomass were carried out with oxidizing agents. The maximum uptake q (mgg-1) for Co(II) obtained by KMnO4 -TNP was about (53.92) as compared to Native- TNP (24.28) at pH 5. The equilibrium and kinetics models were applied over data. The Langmuir and Freundlich equilibrium adsorption models were investigated and observed to the fit the data. The Freundlich model gave better fit than the Langmuir model with R2 value of 0.9951. Kinetic study revealed that adsorption was fast in first 60 minutes and equilibrium was achieved after 120 minutes for Co(II) metal. The suitability of a pseudo second order chemical reaction for the sorption of Co(II) onto this biosorbent was apparent. The results revealed that Trapa natans peels biomass is effective, potential and best beneficial biosorbent for removal of heavy metals.

De-radioactivity is characteristically opposed to the concept of radioactivity. The possible mechanism behind the concept of de-radioactivity involves the intra-trapping, intra-embedding and intra-fixing of the metallic radioisotope or stable isotope within the framework of the novel molecules loaded with the potential transfer of excess electrons to the metal nucleus to suppress the decay of the instable neutron to the proton and electron with the release of energy, stabilising the stable isotopes or metal radioisotopes so strongly as to result in zero dissociation of metal (stable isotope or metal radioisotope) and thus depriving metal radioisotope of its free status - an essential condition of metal radioisotope to decay. The whole study has been based on metal stable isotopes extendable to metal radioisotopes. The novel molecules (SSS-101, SSS-102, SSS-103 and SSS-104) which bring about intra-trapping and intra-fixing of the metal radioisotopes are called Radiostabilisers. Humanity may find a silver lining in this new concept for future safety with its possible wide spectrum practical applications. Radiostabilisers may help in the purification and reclaiming of metal radioisotope(s) contaminated sea-water or water, atmospherics and the nuclear liquid waste materials. The radiostabilisers fail to intra-trap the stable or radioisotopes of hydrogen, helium, carbon, boron, phosphorus, iodine, neon, argon, krypton, xenon, oxygen, fluorine, sulphur and chlorine.

A new set of compounds containing indole nucleus appended with carefully selected amino acids via a triazole linker are identified. These compounds showed substantial antifungal activities against the BWP17 strain of candida albicans. The preliminary screening of the compounds was done by docking in the active site of lanosterol 14-α demethylase enzyme (pdb ID - 3JUS) with ArgusLab.exe software. Subsequently the screened compounds were subjected to in-vivo antifungal assays. The probable mechanism of action of the test compounds was studied by GC analysis of the membrane metabolites. The compounds with tryptophan and histidine substitution were found to be most effective with MIC80 of 50.2 μg/ml and 78.81 μg/ml respectively. In the fungal cells treated with compound 3b the lanosterol levels were found to increase indicating that lanosterol 14-α demethylase enzyme could be the probable target. Additionally, the R6G influx/efflux assay provided the evidence for the fungicidal properties of the test compounds.