Oxidation of thiols by sodium N-haloarylsulfonamides

The methods for direct titration of thiols with N-halorylsulfonamides in the presence of KI were evaluated by studying the oxidation of 2-mercaptobenzoic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 2-naphthyl mercaptan, 2-mercaptoethanol, mercaptosuccinic acid, thiophenol, p-chlorothiophenol, Bu mercaptan, and monothioglycerol, with chloramine-T (CAT), bromamine-T (BAT) and bromamine-B (BAB). The optimum conditions were established. The precision was poorer for titrations with CAT. BAB gave better precision and accuracy for the determination of all ten thiols studied, and is recommended for use

Study of Cocrystallization of Nickel Ion with Copper Ammonium Sulphate Using 63Ni Tracer

1207-120

Novel pyrochlore-structured bismuth iron antimonates: structural, impedance and electrochemical studies

A moderate pyrochlore solid solution range of 0.00 ≤ x ≤ 0.64 was observed in the Bi3.36Fe2.08+xSb2.56-xO14.56-x (BFS) system prepared by solid-state reaction at 925 ◦C for 2 days. The overall charge compensation required a one-to-one cationic replacement and oxygen vacancies, i.e. Sb5+ ↔Fe3+ - O2– . BFS cubic pyrochlores showed their refined lattice parameters varying linearly in the range of 10.4284 (8)-10.4513(8), thus obeying the Vegard’s rule. The measured crystallite sizes by both Scherrer and Williamson-Hall methods were found to be in the range of 46–67 nm; whilst, the larger grain sizes in the range of 0.2–2.9 μm were calculated using scanning electron microscopy (SEM) analysis. The AC impedance analysis also verified a few electrical responses of BFS pyrochlores: (i) BFS pyrochlores had moderate dielectric constants in the range of 24–35 and dielectric losses in the order of 10− 1 at room temperature and 1 MHz, (ii) BFS pyrochlores were not electrically homogeneous with bulk capacitances in the order of 10− 12 Fcm− 1 , (iii) a non-Debye type and temperature-dependent relaxation process were discernible and (iv) the movement of charge carrier were either in the long-range or short-range migration subjected to time availability. In addition, BFS pyrochlore thin films had a good capacitive behaviour and electrochemical reversibility, according to the cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) analyses. All these excellent properties rendered BFS pyrochlores to be a suitable material for Class 1 ceramic capacitors