Solvent extraction of antimony(III) with 18-crown-6 from iodide media

Antimony can be quantitatively extracted from 1M sulphuric acid containing 0.25M potassium iodide with 0.02M 18-crown-6 in methylene chloride, and determined spectrophotometrically at 430 nm. Bismuth, tin, antimony and arsenic can be separated by sequential extraction with 18-crown-6 from aqueous phases with appropriately adjusted sulphuric acid and potassium iodide concentrations.     

Solvent extraction separation of cesium with dibenzo-24-crown-8 from picrate solution

Cesium (25 g) was extracted with 0.03M DB-24-crown-8 at pH 3.0 from 0.01M picric acid in the presence of 2 ml methanol. It was stripped with 3 M perchloric acid and was determined by atomic absorption spectrophotometry. The nature of the extracted species was 111. Dichloromethane was a suitable diluent. Nitric and perchloric acid were the best stripping agents. Cesium was not only separated from alkali and alkaline earth elements but also from zirconium, hafnium, thorium, usually present in fission products. The method is applicable for determination of cesium from real samples.     

Quantification of Noncovalent Interactions in Azide–Pnictogen, –Chalcogen,and –Halogen Contacts

The noncovalent interactions between azides and oxygen-containing moieties are investigated through a computational study based on experimental findings. The targeted synthesis of organic compounds with close intramolecular azide–oxygen contacts yielded six new representatives, for which X-ray structures were determined. Two of those compounds were investigated with respect to their potential conformations in the gas phase and a possible significantly shorter azide–oxygen contact. Furthermore, a set of 44 high-quality, gas-phase computational model systems with intermolecular azide–pnictogen (N, P, As, Sb), –chalcogen (O, S, Se, Te), and –halogen (F, Cl, Br, I) contacts are compiled and investigated through semiempirical quantum mechanical methods, density functional approximations, and wave function theory. A local energy decomposition (LED) analysis is applied to study the nature of the noncovalent interaction. The special role of electrostatic and London dispersion interactions is discussed in detail. London dispersion is identified as a dominant factor of the azide–donor interaction with mean London dispersion energy-interaction energy ratios of 1.3. Electrostatic contributions enhance the azide–donor coordination motif. The association energies range from −1.00 to −5.5 kcal mol⁻¹.     

A simple and efficient method for solvent-free iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid by grinding method

<正>Green,mild and efficient iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid in the solidstate by grinding under solvent-free conditions at room temperature.This method provides several advantages such as environmentally friendly,short reaction times,high yields,non-hazardous and simple work-up procedure.     

One-pot synthesis and in vivo biological evaluation of new pyrimidine privileged scaffolds as potent anti-inflammatory agents

Research on Chemical Intermediates - A simple methodology has been developed for the synthesis of diverse members of multifunctionalized 4-hydroxy-2-methyl-6-(phenyl)pyrimidine-5-carbonitrile...     

Isoquinolinium bromochromate： An efficient and stable reagent for bromination of hydroxylated aromatic compounds and oxidation of alcohols

The new chromium(Ⅵ) oxidizing reagent isoquinolinium bromochromate(IQBC) was prepared and characterized.The IQBC has been found to be stable and an efficient solid reagent which can be easily prepared in good yield.It act as an efficient brominating reagent for hydroxylated aromatic compounds as well as good oxidizing reagent for the conversion of alcohols to carbonyl compounds in good to excellent yield.The synthesized isoquinolinium bromochromate is more ideal reagent,with number of specification inclu...     

A bio-oriented anthranilic acid catalyzed synthesis of quinazolin-8 (4H)-one derivatives: Evaluation by green chemistry metrics

An environmental friendly synthetic route has been investigated for the synthesis of quinazolin-8 (4H)-one derivatives in the presence of anthranilic acid as a catalyst. The zwitter ion formed in course of reaction may a play key role in the desired transformations leading good to excellent yields. Evaluation of the present protocol by green chemistry metrics demonstrated that it is highly efficient and eco-compatible.     

A Practical Iodination of Aromatic Compounds by Using Iodine and Iodic Acid

This article describes simple and efficient method for the iodination of different aromatic amines, hydroxy aromatic aldehydes, hydroxy acetophenones and phenols using iodine and iodic acid in ethanol as a solvent. Notable advantages include mild reaction condition, no need of catalyst, short reaction time, simple practical procedure, giving excellent yield of the product.