Classical and advanced chemical sciences
Ferromagnetic FeCo nanoparticles were prepared by a simple one-pot polyol process and followed by simple annealing treatment. The prepared ferromagnetic FeCo nanoparticles have a spherical shape and the size was controlled by the annealing temperature. Importantly, single FeCo phase was obtained at 400°C and these samples have spherical shape and size about 50 nm. While at a higher temperature (at 600°C) the nanoparticles have very lower aggregation and have higher coercivity. The prepared FeCo nanoparticle at low temperature with excellent magnetic properties is to be considered as a potential candidate for many applications
Keywords: Ferromagnetic, FeCo, nanoparticles, polyol, vibrating sample magnetometer
The copper nanoparticles grafted on carbon microsphere is employed for an efficient one-pot three-component synthesis of spirooxoindole derivatives involving isatin, malononitrile and enolizable ketones such as 3-methyl-1-phenyl-2-pyrazolin-5-one, 3-methyl-1-(2-chlorophenyl)-2-pyrazoline 5-one, 4-hydroxy-6-methyl-2-pyrone and 1-methyl-4-hydroxyquinoline-2-one. The cheap starting material, easy separation, high catalytic efficiency and reusability of the catalyst for several times without loss of its efficiency, good yield of products, and simple workup are promising features of the reaction in 1:1 (v/v) aqueous-alcoholic medium.
Keywords:Heterogeneous catalyst; spirooxoindoles; Enolisable ketones; copper nanoparticle/C.
The low-temperature X-ray structure, and magnetic properties of (MePhenetNH2)2[CuBr4] (MePhenetNH2=N-methyl-2-phenylethylammonium) (1) are reported. The compound was 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 C2/c. In the structure, the tetrabromidocuprate ions are packed into zig-zag chains parallel to the c-axis which are stabilized by hydrogen bonds between the ammonium cations and bromide anions. Magnetic measurements (1.8-310 K) indicate weak antiferromagnetic interactions propagated via the two-halide exchange pathway through short Br…Br contacts. Fitting the data with the S = ½ uniform chain model gave J = -7.7(1) K with C = 0.403(1).
Keywords: tetrabromocuprate, antiferromagnetism, crystal structure
Materials and environmental chemistry
The green Dakin reactions can be performed by employing gallic acid as an oxidizing agent. Implementation of gallic acid helps to avoid the usage of catalyst, ligand and any toxic or hazardous oxidizing agent. Gallic acid accelerates the conversion of the atmospheric oxygen into hydrogen peroxide, which helps in the oxidation of aldehydes in situ. Mango peel, potato peel, pomegranate pomace, grape pomace extract contains the rich source of gallic acid that performs the oxidations in a natural feedstock. The best results were obtained by mango peel as well as potato peel extract giving excellent yields with minimum time at room temperature. The ‘aqueous extract of banana’ (AEB), in the said conversion plays a dual role of catalyst and a base. The reported work can be considered as environment-friendly Dakin oxidation, as it is carried out in a neat AEB at room temperature under aerobic conditions with low reaction time and better yield.
Keywords: Dakin reaction; gallic acid; water extract of banana; mango peel; potato peel; pomegranate pomace; grape pomace
We have been able to synthesize a diverse new group of condensed phosphate polymers in the systems MeI2O–MeIII2O3–P2O5–H2O (where MeI represents Ag, Na, Cs, and MeIII represents gallium, scandium and indium. The structural arrangement of synthesized condensed phosphates is ascertained using X-ray spectral analysis, X-ray diffraction and IR spectroscopy. An interesting approach to the synthesis of double compounds containing Ga, In, Sc and monovalent metals, including Ag, resulting in the production of double phosphates is described.
Keywords: synthesis; condensed phosphates; polyphosphates; cyclotetraphosphate; cyclododecaphosphate; gallium, indium, scandium
Toxic metals have been excessively released into the environment due to rapid industrialization and have created a major global concern. Cadmium, zinc, copper, nickel, lead, mercury and chromium are often detected in industrial wastewaters. Various methods are available in literature although some of them facing difficulties to be applied. The present study, bagasse from sugarcane industry was used to remove chromium(VI) ions from wastewater. This study presents the adsorption behavior of hexavalent chromium from wastewater using low cost adsorbent modified sugarcane bagasse with citric acid (SCB). The effect of the initial concentration of chromium(VI), biosorbent dosage, temperature, contact time, and pH were studied. It was found that maximum % removal of chromium(VI) is obtained 92.19 % at pH 1.2 and contact time 40 min. The removal is decreased with increase in concentration and also pH. The maximum biosorption capacities qe of chromium(VI) ions by SCB was 13.5 mg g-1. This work proved that treated bagasse can be used as an efficient adsorbent material for removal of heavy metals from wastewater such as chromium(VI).
Keywords: Adsorption; sugarcane bagasse; hexavalent chromium; citric acid