Effect of calcination temperature induced structural modifications on the photocatalytic efficacy of Fe2O3-ZrO2 nanostructures: mechanochemical synthesis.

Water contamination due to organic pollutants is a challenging issue around the globe, and several attempts have been made to deal with this issue. Out of which, the semiconductor-based photocatalytic process had gained much attention and proved to be an efficient, easy, and economical process for the removal of organic dyes from aqueous solutions. For this purpose, the iron oxide-zirconium dioxide nanocomposite (Fe2O3-ZrO2 NC) was prepared via a simple mechanochemical process using a mortar and pestle, followed by a calcination process at 300, 600, and 900 °C. Different physicochemical analyses were carried out in order to investigate the successful synthesis of Fe2O3-ZrO2 NC and the effect of temperature on the crystallinity, surface area, pore size, phase composition, sample morphology, and particle/crystallite size. The Fe2O3-ZrO2 NCs were subjected to a photocatalytic test under solar light irradiation against fluorescein dye in an aqueous medium, and the photocatalytic performance was examined under the influence of calcination temperatures, pH, catalyst dose, and initial concentration. The stability of the Fe2O3-ZrO2 NCs was also checked by recycling them for five reuse cycles.

Ethyl 6-(4-cyclo-propyl-1H-1,2,3-triazol-1-yl)pyridine-3-carboxyl-ate.

In the title compound, C13H14N4O2, which has approximate mirror symmetry, the dihedral angles between the triazole ring and the cyclo-propane and pyridine rings are 87.1 (2) and 7.60 (9)°, respectively. In the crystal, inversion dimers linked by pairs of both C-H⋯N and C-H⋯O inter-actions generate R 2 (2)(6) and R 2 (2)(18) loops, respectively. Further C-H⋯N inter-actions form R 2 (2)(10) loops and link the dimers into [110] chains.

Ethyl 2-[1-(3-methyl-but-yl)-4-phenyl-1H-1,2,3-triazol-5-yl]-2-oxo-acetate.

In the title compound, C17H21N3O3, the non-planar (r.m.s. deviation = 0.212 Å) ethyl (oxo)acetate group is oriented towards the phenyl substituent. The triazole and benzene rings are twisted with respect to each other, making a dihedral angle of 41.69 (6)°. In the crystal, mol-ecules are arranged into centrosymmetric R 2 (2)(10) dimers via pairs of C-H⋯O inter-actions involving the ethyl (oxo)acetate groups. In addition, the triazole rings show π-π stacking inter-actions, with their centroids at a distance of 3.745 (2) Å.

Synthesis and cyclisation of 1,4-disubstituted semicarbazides.

Semicarbazides, besides possessing medicinal properties, also find wide applications in agriculture and industry. We report in this article the synthesis of the four 1,4-disubstituted semicarbazides: 1-cinnamoyl-4-phenyl semicarbazide (1), 1-oleyl-4-phenyl semicarbazides (2), 1,1',1''-tricitryl-4,4',4''-triphenyl semicarbazide (3) and 1-benzoyl-4-phenyl semicarbazide (4), by the condensation of four different hydrazides: cinnamic acid hydrazide (5), oleic acid hydrazide (6), citric acid hydrazide (7) and benzoic acid hydrazide (8). The acid hydrazides were prepared by the condensation of four different acids with phenyl isocyanate. The semicarbazides were also subjected to acid catalysed intramolecular cyclisation. The cyclisation of (1) and (2) afforded substituted 1,3,4-oxadizoles: 2-cinnamoyl-5-aminophenyl 1,3,4-oxadizoles (9) and 2-oleyl-5-aminophenl 1,3,4-oxadizoles (10), respectively, in high yield, while no cyclisation occurred in the cases of (3) and (4). The products in each case have been identified on the basis of melting points and IR spectral studies.

Studies on the chemical constituents of Phyllanthus emblica.

Phytochemical investigations on Phyllanthus emblica have resulted in the isolation of the two new flavonoids, kaempferol-3-O-alpha-L-(6''-methyl)-rhamnopyranoside (1) and kaempferol-3-O-alpha-L-(6''-ethyl)-rhamnopyranoside (2). Their structures were determined on the basis of extensive spectroscopic studies including 2D-NMR experiments.