Titanium(IV) tungstosilicate and titanium(IV) tungstophosphate: two new inorganic ion exchangers

Crystalline phases of Ti(IV) tungstosilicate and Ti(IV) tungstophosphate have been synthesised. The ion-exchange capacities of Ti(IV) tungstosilicate and Ti(IV) tungstophosphate have been reported as 0.44 and 0.80 mequiv./g, respectively. Both materials show monofunctional ion-exchange characteristic and are stable in 0.1 M solutions of HNO3, HCl, H2SO4 and acetone and benzene. Ti(IV) tungstosilicate is found to be more stable thermally than Ti(IV) tungstophosphate (loss in ion-exchange capacity was found as 58 and 80%, respectively for samples heated at 200 degrees C). The Kd values for heavy metals such as Pb, Hg, Cd, Sb, Co, Zn, Ni, Fe, Cr etc. have been reported in demineralised water and two surfactant media by batch processes. Cr3+, Fe3+ and Sn4+ are totally adsorbed on both the materials in demineralised water while a decrease in Kd value with increase in concentration of two surfactants is reported. On the basis of Kd values for metal ions, thirteen binary separations and five ternary separations on Ti(IV) tungstosilicate and thirteen different binary separations and four different ternary separations on Ti(IV) tungstophosphate have been achieved. Separation of methylamine from ethylamine has been done by GC on a column packed with Ti(IV) tungstophosphate.     

Diversified Synthetic Strategies for Pyrroloindoles: An Overview

In current scenario, heterocyclic compounds' role in medicinal chemistry has been tremendously increased as they possess wide number of pharmacological activities. One of the common heterocycles include indole skeleton with well‐established biological significance in field of medicinal chemistry. Fusion of indole nucleus with pyrrole heterocycle constitutes pyrroloindole scaffold, which further modifies the existing properties of indole alone. Pyrroloindole is a privileged scaffold found in various types of bioactive entities including natural compounds and exhibits wide variety of pharmacological activities like muscle relaxant, antifungal, antitumor, and antibiotic. Therefore, it is considered as attractive template for drug discovery. From several years, numbers of synthetic strategies have been reported for the synthesis of pyrroloindole and its derivatives, including also natural compounds such as amauromine, yuremamine, and chimonanthines. Here, in this review, we have tried to compile various synthetic strategies of pyrroloindole and its derivatives.     

Application of INAA for phyto-accumulation study of selenium by chickpea plant

The phyto-accumulation efficacy of selenium (Se) from soil by chickpea plant is reported. Chickpea plants were grown in soil having different concentrations (1–4 mg kg^?1) of Se. Samples of soil and different parts of chickpea plants in Se rich soil were analyzed for determination of Se concentrations by instrumental neutron activation analysis (INAA). Samples were irradiated in self-serve facility of CIRUS reactor, BARC, Mumbai at a neutron flux of the order of 10¹³ cm^?2 s^?1. The gamma activity at 264.7 keV of ⁷⁵Se (119.8 d) was measured using a 45% relative efficiency HPGe detector coupled to MCA. Dependence of Se distribution in soil and plants on its spiking concentration was evaluated in this work. The Se concentrations determined in plant parts grown in control soil and in soil spiked with Se (4 mg kg^?1) are in the range of 0.6–0.8 and 65–68 mg kg^?1 respectively.     

Rapid, selective and direct spectrophotometeric determination of aliphatic amines with m-dinitrobenzene

Color reaction has been studied for identification and spectrophotometric determination of aliphatic amines at room temperature by m-dinitrobenzene (m-DNB) as reagent. The λ_max value ranges from 458 to 570 nm. This is a simple and rapid method for determination of aliphatic amines in the acidic, water and acetone medium. Beer's law is verified for methylamine, dimethylamine, trimethylamine and n-butylamine in the range of 0.5–8 mg l⁻¹. The effect of pH on the molar absorptivity is investigated for a representative primary amine i.e. methylamine and it was observed that molar absorptivity increases from acidic to basic pH, with a sharp increase at pH 12. The kinetic of reaction was also studied and found that reaction time has marked effect on the molar absorptivity of electron donor–acceptor (EDA) complex. The detection of methyl amine has been reported in three real samples of water.     

Selective identification of specific aptamers for the detection of non-typhoidal salmonellosis in an apta-impedimetric sensing format

Microchimica Acta - The authors report on an aptamer-based method for the detection of S. Typhimurium. The aptamers were identified by using a modified cell-based SELEX method (cell-SELEX) by...     

Synthesis of lactic acid–Zr(IV) phosphate nanocomposite ion exchanger for green remediation

Lactic acid–Zr(IV) phosphate nanocomposite (LA/ZPNC) ion exchanger was synthesised by sol-gel method. The nanocomposite ion exchanger was characterized by different techniques such as Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy X-ray diffraction (XRD) and thermogravimetric analysis (TGA/DTA/DSC). LA/ZPNC was employed for different physicochemical properties such as ion exchange capacity, elution behaviour, effect of eluent concentration, pH titration and thermal stability. The ion exchange capacity of LA/ZPNC was higher as compared to their inorganic counterpart. pH results indicate the bifunctional nature of nanocomposite. A degradation efficiency of 89.47 % was attained in 4 h of illumination. The distribution coefficient (K _d) studies of LA/ZPNC ion exchanger were investigated for eight different metal ions and found more selective for Al³⁺ with higher K _d value. It was explored for photocatalytic study of methylene blue under solar illumination.     

Preparation and characterization of oxoperoxo tungsten(VI) complexes with morpholinomethyl urea and related ligands

The monooxodiperoxo complexes of tungsten(VI) of the type [WO(O₂)₂ L-L] (where L-L = morpholinomethyl urea, morpholinomethyl thiourea, piperidinomethyl urea, piperidinomethyl thiourea, pyrrolidinomethyl urea, and pyrrolidinomethy thiourea) have been synthesized and characterized by elemental analysis, IR, electronic spectra, magnetic susceptibility, and conductivity measurements, in addition to TGA/DTA. The energy-minimized structures of these complexes have been obtained by molecular modeling using Hyperchem release 7.52. The text was submitted by the authors in English.     

Vapour-liquid equilibria of the two- and three-dimensional monoatomic classical fluids interacting via double Yukawa potential

We have carried out Monte Carlo simulations in Gibbs ensemble for two-and three-dimensional double Yukawa fluid. We have compared liquid-vapour equilibrium curve with that of Lennard-Jones, when parameters occurring in double Yukawa potential are chosen to fit Lennard-Jones potential. The results are in good agreement. The role of repulsive and attractive contributions for the potential on the liquid-vapour coexistence region as well as on critical temperature and critical density has been studied. The critical temperature is found to be more sensitive than the critical density to the variation in repulsive and attractive parts of the potential. Also, the range of the attractive interaction directly influences range of the liquid vapour coexistence region. It has been found that smaller the values of the attractive parameter, larger is the coexistence region.