Classical and Advanced Chemical Sciences
The photocatalytic activity of hexagonal (h-) WO3 nanoparticles (NPs) and nanowires (NWs) was investigated and compared with the performance of monoclinic (m-) WO3 nanoparticles in the aqueous photo-bleaching reaction of methyl orange (MO) under UV irradiation. It has been known that the m-WO3 is better photocatalyst than the h-WO3, but due to the advantageous morphology we investigated whether the h-WO3 NWs can reach the photo-efficiency of the m-WO3 NPs. The h-WO3 was successfully synthesized in NW and NP morphology using a microwave (MW) assisted hydrothermal procedure starting from Na2WO4 and thermal annealing of hexagonal ammonium tungsten bronze (HATB), (NH4)0.33-xWO3, respectively. We found that the h-WO3 NWs exhibited almost three times higher photoactivity than the h-WO3 NPs. The improved performance of the NWs can be attributed to the enlarged surface area and the good charge carrier ability of the nanowire morphology. The catalytic tests also confirmed that the morphological effect could lead to as high photoactivity in the case of h-WO3 NWs as exhibited by the m-WO3 NPs.
Keywords: WO3, hexagonal, monoclinic, nanoparticle, nanowire, photocatalysis
Schiff base derived from the condensation of 3-(p-bromophenyl)-1-phenyl-1H-pyrazolecarboxaldehyde with 4-amino-3-mercapto-1,2,4-triazin-5-one and its Co(II), Ni(II), Cu(II) and Zn(II) metal complexes have been synthesized in 1:1 and 1:2 molar ratios. Ligand and its metal complexes are characterized by various physicochemical techniques. On the basis of these techniques, octahedral geometry deduced for Co(II), Ni(II) and Zn(II) complexes and square planar for Cu(II) complexes. Low molar conductance values of all the metal complexes reveal their non-electrolytic nature. All the synthesized complexes have been screened in vitro for antibacterial activity against S. aureus, B. subtilis, P. aeruginosa and E. coli and antifungal activity against C. albicans and S. cerevisiae. It has been found that metal complexes show promising biological activity as compared to ligand. Schiff base and its metal complexes have been screened against human breast cancer cell lines by using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. In vitro anticancer cell lines results indicate that metal complexes exhibit significant activity on MCF-7.
Keywords: Schiff base; Metal complexes; Cell lines; 1H-NMR; 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide Assay; antimicrobial activity
The synthesis, structure, and magnetic properties of [Cu(5-NO2-2-HOPy)(pz)2(H2O)] (ClO4)2∙H2O (pz = pyrazine) (1) are reported. Crystals were characterized using IR, combustion analysis, X-ray powder diffraction, single crystal X-ray diffraction, and temperature-dependent magnetic susceptibility measurements. Compound 1 crystallizes in the monoclinic space group P21/c. The crystal structure consists of copper/pyrazine chains parallel to the c-axis with terminal pyrazine groups found perpendicular to the bridging pyrazine molecules creating a zig-zag chain structure. The 1D-system exhibits weak antiferromagnetic interactions of J = -7.58 K with no measurable interchain interactions.
3-Acylcoumarins were obtained in high yields from ortho-hydroxybenzaldehydes and ethyl acetoacetate or ethyl benzoylacetate in acetonitrile in the presence of a catalytic amount of nano-ZnO.
Keywords: Acyl coumarins, nanocatalysis, zinc oxide
Materials and Environmental Chemistry
In the present study, the chemical characteristics of the Mirosala well water are studied. Statistical analysis have been carried out by calculating of basic statistical parameters, anomalies (extremes and outliers) and correlation coefficients between different pairs of variables. The levels of some chemical parameters of the well water are compared with the World Health Organization directives for drinking water. From the results of field work and laboratory analyses it was found out that Mirosala well water fulfils the criteria set by the WHO. The statistical regression analysis showed that electrical conductivity is in high significant positive relationship with consumption of KMnO4 and a moderately high positive correlation relationship with pH, Fe2+, NO2- and Ca2+ (possible sign of lithology influence). No correlation was found with SiO2, hardness, NO3-, Cl-, Mg2+ and HCO3-. In the water sample S3 outlier value of SiO2 (31.9 mg L-1) was registered, as possible sign of lithology influence. The distribution of low pollutants has been described as lithologically and non lithologically controlled factor.
Keywords: Quality assessment; correlation coefficients; well water; Mirosala, statistical analysis
The increased concern about toxic effects of pesticide exposure led to the necessity of its monitoring using rapid, sensitive and selective analytical tools because traditional instrumental techniques are often time-consuming, labor intensive and need tedious prior separation or purification steps. The electrochemical sensors can overcome disadvantages of the traditional techniques, MIP-based sensors offer a high degree of selectivity in binding target analytes in the presence of their interferents make them ideal for determination of pesticides in complex environmental samples. This review provides a general overview of MIP-based sensors in the assessment of pesticides in environmental samples using voltammetry as transduction mechanism.
Keywords: Molecular imprinting polymer (MIP); voltammetric sensors; pesticides; environmental samples
Industrial and Engineering Chemistry, Biotechnology
Reverse osmosis (RO) system has been effectively applied on a large scale throughout the world for the treatment of effluent and the polluted water. The Arab countries and some other affluent countries have the credit of successfully running such large scale plants without minding for the cost factor involved in such projects. Here the polluted effluent is treated using RO technology in order to remove the pollutants. The investigator has taken an attempt has been made to find out in the impact of Iron Industry Effluent and also to know about the quality of Iron Industry effluents after the treatment of using R O plant. Reverse osmosis has been successfully applied on a large scale for the treatment of effluent and the polluted water. In the present study the Iron Industry effluent are treated using RO plant and treatment can be recommended to all Iron Industries. The same reverse osmosis method can also be applied to other industry effluent.
Keywords: Iron industry; effluent treatment; reverse osmosis