Magnetic carbon nanotube as a highly stable and retrievable support for the heterogenization of sulfonic acid and its application in the synthesis of 2-(1H-tetrazole-5-yl) acrylonitrile derivatives

In the present study, a novel magnetic carbon nanotube functionalized by chlorosulfonicacid (Fe₃O₄-CNT-SO₃H) with nanotube morphology decorated by the spherical nanoparticles was prepared, characterized and introduced as a retrievable magnetic heterogeneous nanocatalyst for green synthesis a variety of 2-(1H-tetrazole-5-yl) acrylonitrile via multicomponent domino Knoevenagel condensation/ 1,3-dipolar cycloaddition reaction between aromatic aldehydes, malononitrile, and sodium azide under solvent free conditions. The catalyst was magnetically separated from the reaction system by an outer magnetic force and recycled up to five runs without a remarkable loss in its efficiency. The as-preparedacidic magnetic nanocomposite was characterized by different techniques inclusive Fourier transform infrared, thermogravimetric analysis, energy dispersive X-ray, field emission scanning electron microscopy, X-ray diffraction, vibrating sample magnetometry, CHNS elemental analysis, and acid-base titration. Easy workup, affordability, elimination of volatile and toxic solvents, and high yield of products are some merits of this protocol.     

Photolytic decarboxylation of α-arylcarboxylic acids mediated by HgF2 under a dioxygen atmosphere

Mercuric fluoride (HgF₂), as a light-sensitive inorganic compound, in the presence of dioxygen is able to convert various α-aryl- and α,α-diarylcarboxylic acids into the corresponding aldehydes and ketones selectively under photoirradiation via trapping of the benzylic radical by O₂.     

Oxidation of oleic acid and oleic acid/sodium chloride(aq) mixture droplets with ozone: changes of hygroscopicity and role of secondary reactions

The heterogeneous reactions of oleic acid (OL) and oleic-acid/sodium-chloride(aq) (OL/NaCl(aq)) mixture droplets with ozone are studied at two relative humidities (RH). The reactions were monitored concomitantly using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FT-IR) for the organic species and UV-vis spectrometry for the ozone concentration in order to investigate reaction rate discrepancies reported in literature as well as the oxidation mechanism. The less volatile products were identified and resolved by a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR-MS). This led to identification of 13 organic molecules (up to 45 carbons). Identified products were predominantly composed by nananoic acid and azelaic acid. Our results suggest that the propagation reaction is possibly initiated by a secondary reaction such as the stabilized Criegee intermediates reacting with oleic acid. For hygroscopic properties, the ATR-IR spectra at high RH (87 +/- 5%) showed that the hydrophobic oleic acid droplets can take up water slightly when exposed to ozone. For internally mixed OL/NaCl(aq) droplets, the hygroscopic properties of the droplets upon ozone exposure were found to be complex; hygroscopic properties or the growth factors of the droplets are altered as the oxidation products of oleic acid exist concurrently with NaCl(aq). Furthermore, the concentration of ozone was monitored to examine the kinetics of the oxidation reaction. The integrated ozone profile recorded by UV-vis spectrometry showed the consumed ozone represents only 30 +/- 2% of total oleic acid and hence confirmed the existence of secondary reactions. A kinetic model was used to simulate an ozone temporal profile that could only be described if the secondary reactions were included. The discrepancy of ozone uptake coefficients according to the OL and ozone measurements as well as their atmospheric implications are herein discussed.     

One‐pot,four‐component synthesis of 1,3,4‐oxadiazole derivatives containing a ferrocene unit and their antimicrobial activity

A four‐component reaction between aromatic carboxylic acids, (N‐isocyanimino)triphenylphosphorane, ferrocenecarbaldehyde and dibenzylamine is reported. This approach is an efficient, simple and high‐yield procedure for the synthesis of 1,3,4‐oxadiazole derivatives containing a ferrocene unit. The antimicrobial activities of the products were investigated against Staphylococcus aureus and Pseudomonas aeruginosa in in vitro and in vivo assays. Copyright © 2015 John Wiley & Sons, Ltd.     

Conversion of methanol to 2,2,3-trimethylbutane (triptane) over indium(III) iodide

InI3 is able to catalyze the conversion of methanol to a mixture of hydrocarbons at 200 degrees C with one highly branched alkane, 2,2,3-trimethylbutane (triptane), being obtained in high selectivity. The mechanism for InI3-catalyzed reactions appears to be basically the same as that proposed for the previously studied ZnI2-catalyzed system in which sequential methylation of olefins is followed by competing reactions of the resulting carbocation: proton loss to give the next olefin vs hydride transfer to give the corresponding alkane. Although the reaction conditions and typical triptane yields achievable with ZnI2 and InI3 are quite similar, the two systems behave rather differently in a number of important particulars, including significant differences between the detailed product distributions. Most of the differences in behavior can be ascribed to the stronger Lewis acidity of InI3, including the ability to activate some alkanes, the higher activity for methylation of arenes, and the fact that methanol conversion can be observed at somewhat lower temperatures with InI3 than with ZnI2.     

Decorations of graphene oxide with cisplatin toward investigation of fluorescence quencher on regulatory sequence of BRCA1 and BRCA2

Journal of the Iranian Chemical Society - Herein, we investigated the interaction of cisplatin loaded on GO (GO@CDDP) with two regulatory sequences, BRCA1 and BRCA2, synthesized from ssDNA based on...     

Coherent Control of the Goos-Hänchen Shifts in a Four-Level N Type Atomic Medium

The behavior of the Goos-Hänchen (GH) shifts of the reflected and transmitted probe light beams is theoretically investigated. In a fixed geometrical configuration, the effect of quantum interference induced by spontaneous emission on the phase control of the GH shifts is analyzed in this paper. It is found that in a four-level N-type atomic system as an intracavity medium, the GH shifts of the reflected and transmitted probe light beam are completely phase dependent.