Spectrophotometric determination of Fe(III) with tiron in the presence of cationic surfactant and its application for the determination of iron in Al-alloys and Cu-based alloys

A sensitive Spectrophotometric method for the determination of iron with tiron and a cationic surfactant, cetylpyridinium chloride, at pH 5.6 is reported. The complex is extracted into a chloroform-propan-2-ol (41) mixture and shows maximum absorbance at 520 nm. Beer's law is obeyed in the range 1–14 g/ml with an average molar absorptivity of 15800 l mol^–1 cm^–1. The molar ratio as determined by Job's method for Fe:tiron:CPC is 143. Interferences by various ions are examined. Zr, Ti and Mo interfere heavily. The method is applied for the determination of iron in Al-based and Cu-based alloys, using appropriate masking agents.     

Extraction-spectrophotometric determination of nickel as Ni-(PAR)2-(CTAB)2 complex in polymetallic sea-bed nodules and steels

A red, water-soluble complex of nickel with PAR can be extracted into chloroform with CTAB at pH 7.0. The system obeys Beer's law upto 0.5 μg/ml with a molar absorptivity of 45 200 L·mol^?1·cm^?1 at 540 nm. Job's method of continuous variations revealed that the composition of the extracting species is 1:2:2 for nickel:PAR:CTAB. Based on this extraction, a highly sensitive and selective spectrophotometric method for the determination of nickel in polymetallic sea-bed nodules and in steels, after prior separation of iron and manganese, was developed. The standard deviation was 0.04–0.127 μg for 5–25 μg of nickel.     

A highly diastereoselective approach to tetrahydrofurans via [3+2] cycloadditions of silylmethyl-substituted cyclopropanes with aldehydes and ketones

An efficient and highly diastereoselective synthesis of highly substituted tetrahydrofurans from the reaction of a vicinal t-butyldiphenylsilylmethyl-substituted cyclopropyl diester with aldehydes and ketones has been developed. The 2,5-cis-disubstitution predominates over the 2,5-trans-disubstitution by as much as 12:1. The reaction with cyclic ketones generates spiro-fused tetrahydrofurans in good yields.     

Preparation and deployment of indigenous 125I-seeds for the treatment of prostate cancer: Dawn of prostate brachytherapy in India

‘Permanent seed implantation’ using ¹²⁵I- seeds has emerged as an effective treatment modality for management of prostate cancer. An indigenous technology for the production of ¹²⁵I brachytherapy sources (‘BARC ¹²⁵I Ocu-Prosta seed’) has been developed. In this current work, we describe an overview of our experience on large scale production of ¹²⁵I brachytherapy sources, their quality assessment, in vivo bio-evaluation and initial experience on their journey from bench to bed-side for the treatment of prostate cancer.     

Excellent Suzuki–Miyaura catalytic activity of a new Pd(II) complex with sulfonamide–Schiff base ligand

A new air‐stable Pd(II) complex containing a sulfonamide–Schiff base ligand has been synthesized, characterized and investigated as a catalyst for the Suzuki–Miyaura reactions of aryl halides with arylboronic acids. Theoretical calculations (B3LYP) and spectroscopic evidence suggest that the sulfonamide–Schiff base coordinates to the Pd centre through sulfonamide nitrogen (? SO₂NH₂) rather than imine (? CH?N). The complex shows excellent cross‐coupling activity with aryl bromides in water at room temperature and aryl chlorides in isopropanol at 60°C. Copyright © 2016 John Wiley & Sons, Ltd.     

The functionality of the hybrid systems driven by molecular dimension of the guest copper Schiff‐base complexes entrapped in Zeolite‐Y

On encapsulation inside the supercage of zeolite‐Y planar Cu (II)–Schiff base complexes show the modified structural, optical and functional properties. The electronic effect of the different substituent groups present in the catalyst plays the decisive role towards their reactivity in the homogeneous phase but after the encapsulation in zeolite Y, reactivity is mainly governed by the molecular dimensions of the guest complexes rather than the electronic factor of the substituent groups attached on them. These systems are well characterized with the help of different characterization tools like XRD analysis, SEM ‐ EDX, AAS, FTIR, XPS, DSC, TGA, BET and UV–Visible spectroscopy and the comparative optical and catalytic studies have provided a rational explanation of enhanced reactivity of zeolite encapsulated metal complexes for various oxidation reactions compared to their corresponding solution states.     

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.     

Polyvinylpyrrolidone–polycaprolactone block copolymer micelles as nanocarriers of anti-TB drugs

A range of polyvinylpyrrolidone–polycaprolactone diblock copolymers with varying chain lengths were synthesized by Atom Transfer Radical Polymerisation (ATRP) using bromo-polycaprolactone as macroinitiator and copper(I) bromide/bipyridine catalytic system. The copolymers self-assembled in solution into core–shell micelles with sizes varying from 150 to 205 nm and critical micelle concentration of the order of 10⁻⁵ to 10⁻⁶ M. Front line anti-Tuberculosis drugs Rifampicin (RIF), Pyrazinamide (PZA) and Isoniazid (INH) were successfully encapsulated within the micelle hydrophobic core singly or in dual combination. The effect of length of hydrophobic and hydrophilic segments on drug loading, micelle size and drug release was investigated. Determination of binding constants showed that RIF binds more strongly to the micelle core than PZA and INH, leading to highest drug loading content. All drugs were released in vitro (PBS solution at 37 °C) in a sustained manner with zero-order kinetics and followed the order INH > PZA > RIF.