Structure and properties of plasma-polymerized thin films of polyaniline

Plasma polymerization of aniline and in-situ doping of polvaniline with iodine was carried out using radio frequency glow discharge. Thin films of polyaniline were deposited on platinum and glass. The infrared spectrum shows that the aromatic ring is retained under the plasma conditions. The electrical conductivity measurements indicate that the conductivity increases by more than seven orders of magnitude when the polyaniline is doped by iodine. The scanning electron microscopic studies reveal the formation of irregular pentagons on glass substrate while on platinum, polvaniline forms a fibrillar network. In both the cases a continuous film is obtained.     

Highly selective deblocking of propargyl carbonates in the presence of propargyl carbamates with tetrathiomolybdate

Propargyloxycarbonyl chloride, 1, has been used to protect the hydroxyl and amino functionalities of amino alcohols and aminophenols in one pot using triethylamine or pyridine as a base. The increased reactivity of benzyltriethylammonium tetrathiomolybdate, 2, toward propargyl carbonates over propargyl carbamates is studied in detail and has been exploited further to develop an orthogonal protection strategy for the hydroxyl and amino functionalities. For example, 2-amino-1-butanol, 6a, was treated with 1 to get the N,O-diPoc compound 7a in 90% yield, which when treated with 1.1 equiv of 2 at room temperature removes the Poc group attached to oxygen while leaving the one attached to nitrogen intact to yield compound 8a in 85% yield. This particular observation offers a new protecting strategy where an amine and an alcohol group can be protected simultaneously in one pot, and in a later synthetic step, if the alcohol group has to be deprotected selectively, it can be achieved with 1 equiv of 2.     

Sorption of C6 Alkanes in Aluminophosphate Molecular Sieve, AlPO4-5

Sorption of C₆ alkanes viz.,n-hexane, 2-methylpentane, 2,2-dimethyl butane, 2,3-dimethyl butane, cyclohexane and methyl cyclopentane in AlPO₄-5 is studied and sorption capacity and thermodynamic parameters (H⁰, H, G, S and S_a) at various sorption coverage for these sorbates have been estimated. The initial heat of sorption (H⁰) is found to increase with the degree of branching in the alkane chain. The sorbate-sorbate interactions are found to be more prominent during the sorption of doubly branched alkanes and cyclic alkanes and a higher sorption capacity has been observed for cyclic alkanes. Based on the results obtained, a packing model has been proposed for various C₆ alkanes inside the AlPO₄-5 channel.     

Synthesis of worm-shaped carbon nanofibers over a sodium chloride support

Worm-shaped carbon nanofibers (WCNFs) were synthesized in bulk by chemical vapour deposition at 680 °C using iron carboxylate as catalyst precursors and sodium chloride as catalyst support. The products were characterized by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy and X-ray diffraction method. The purity of the purified products was determined by thermal analysis. The WCNF yield was 6700% relative to catalyst. The simplicity, environmental friendliness and use of easily available low-cost precursors are the advantage of this synthesis technique.     

NOVEL THREE COMPONENT SYNTHESIS OF 1,2,4-TRIAZOLO[3,4-b]THIAZOLES AND THEIR ANTIMICROBIAL ACTIVITY

1,2,4-Triazolo[3,4-b]thiazole derivatives 5a–j have been synthesized by novel multi-component reaction of 2,4-dichloro-5-fluorophenacyl bromide (1), thiosemicarbazide (2), and aromatic carboxylic acids (4) using phosphorous oxychloride as the cyclizing agent. This reaction protocol is simple, efficient, and requires shorter reaction times in comparison to the conventional multi-step synthesis. The products were identified to be same by an alternate synthesis. All the compounds were screened for their antimicrobial activity against some of bacterial and fungal strains.     

Rapid Biosynthesis of Silver Nanoparticles Using Areca Nut (Areca catechu) Extract Under Microwave-Assistance

In this research paper, we report on the rapid synthesis of silver nanoparticles using dried areca nut (Areca catechu). The microwave exposed aqueous areca nut powder when treated with the aqueous silver salt solution yielded irregular shaped silver nanoparticles. The formation and morphology of the nanoparticles are studied using UV–visible spectroscopy, field emission scanning electron microscopy, transmission electron microscopy and atomic force microscopy. The X-ray diffraction studies and energy dispersive X-ray analysis indicate that the particles are crystalline in nature. The understanding of capping of biological moiety is derived from Fourier transform infrared spectroscopy and the thermogravimetric analysis. The green chemistry approach for the synthesis of silver nanoparticles is modest, amenable for large scale commercial production. Further the biologically synthesized silver nanoparticles are known for their potential antibacterial activity.     

Micron Particles of AlN/Al: Efficient,Novel, and Reusable Heterogeneous Catalyst for the Synthesis of Bis(indolyl)methanes

The present work introduces for the first time the catalytic utility of micron particulate aluminium nitride (AlN/Al) as a novel and reusable heterogeneous catalyst for the synthesis of bis(indolyl)methanes involving the electrophilic substitution of indoles on aldehydes. The catalyst is recyclable and works without any significant change in its catalytic activity.     

Convenient Synthesis of 1,3,6-Triene Systems Through Alkylation of 3-Methyl-3-sulfolene.

Abstract: Various 1,3,6-triene systems have been synthesised through alkylation of 3-methyl-3-sulfolene with conjugated aldehydes followed by silylation and subsequent desulfonylation. A new route to synthesis of (+/?)-α-chamigrene, isofokienol and 5-hydroxy-α-farnesene has been described.     

Palladium complex in a room temperature ionic liquid: a convenient recyclable reagent for catalytic oxidation

Palladium (Pd)-catalyzed carbonylation of alcohols proceeds in ionic liquid (IL) media (1-ethyl-3-methylimidazolium hexafluorophosphate). Carbonylation of primary/secondary alcohols to aldehydes/ketones was greatly accelerated by the use of a Pd-based catalyst in the presence of NaOCl as an oxidant. The catalyst was more easier to recycle in the IL [Emim]PF₆ with an equal-proportioned CH₂Cl₂ than in the single CH₂Cl₂ or IL.