Two distinct reaction mechanisms are proposed for the reactions of1,5 and6 with nucleophiles as against those of11,12 and16. The former set undergoes the reactions through carbocation type intermediates2 and3 as efficiently as the stable carbocation4 does, even under similar and very mild conditions. The compounds from the latter group do not form the carbocations under the same conditions and undergo only direct substitution by strong nucleophiles.

N-Bromo-arylsulphonamides of different oxidizing strengths are used for studying the kinetics of oxidation of D-fructose and D-glucose in aqueous alkaline medium. The results are analysed and compared with those from the sodium salts of N-bromo-benzenesulphonamide and N-bromo-4-methylbenzenesulphonamide. The reactions show zero-order kinetics in [oxidant], fractional order in [Fru/Glu] and nearly first order in [OH^-]. Rates of oxidation of fructose are higher than those for glucose with the same oxidant. Similarly,E_a values for glucose oxidations are higher than those for fructose. The results are explained by a suitable mechanism and the related rate law is deduced. The effective oxidising species in the reactions of N-bromo-arylsulphonamides is Br⁺. The oxidative strengths of the latter therefore depend on the ease with which Br⁺ is released from them. The ease with which Br⁺ is released from N-bromo-arylsulphonamides depends on the electron density on the nitrogen atom of the sulphonamide group, which in turn depends on the nature of the substituent on the benzene ring. The validity of the Hammett equation has also been tested for oxidation of both fructose and glucose. Enthalpies and entropies of activations of the oxidations by all the N-bromo-arylsulphonamides correlate well. The effect of substitution onE_a and logA of the oxidations is also considered

We have modelled for the first time a chemodosimeter for As(III) detection in water. The chemodosimeter modelled is a 1,3-dithiole-2-thione derivative with an anthracene unit which has been previously described as a chemodosimeter for Hg(II) detection. Quantum chemical calculations at the DFT level have been used to describe the binding energies and selectivity of the chemodosimeter. We find that the dosimeter action is intrinsically dependent on the thiophillic affinity and the coordination sphere of the metal ion. Binding studies for a series of metal ions: Pb(II), Cd(II), Hg(II), Ni(II) and As(III) followed by an analysis of the complete reaction pathway explains the high selectivity of the dosimeter towards As(III). The dosimeter efficiency is calculated as 66% for As(III)-ion.

The electrocatalytic activity of Ag-doped lanthanum chromites electrode materials viz., LaCr_0.4Ag_0.6O₃ and LaCr_0.7Ag_0.3O₃ prepared by decomposing the precursor complex is studied. Pure LaCrO₃ is synthesized by combustion route using oxalic acid as a fuel. The decomposition behaviour of the assynthesized powder obtained in the latter method is characterized by TGA-DTA and XRD. Both the precursor complex and the as-synthesized powder are calcined at 900°C for 7 and 10 h, respectively. XRD of the final product after calcinations indicated the formation of perovskite phase with minor amounts of impurity phases of component oxides in the Ag-doped lanthanum chromites and pure perovskite phase in the undoped one. The surface morphology of the perovskites is studied by SEM. The electrocatalytic activity of the perovskite powders for borohydride oxidation is studied by using cyclic voltammetry (CV) at a catalyst loading of 0.7 mgcm⁻² for both Ag-doped and undoped LaCrO₃ coated on glassy carbon substrate. Calibration plots are obtained by plotting the anodic peak current versus concentration of borohydride in the range of 20-100 mM. The sensitivities of the three perovskites towards borohydride oxidation indicated that LaCr_0.4Ag_0.6O₃ is the best among all the perovskites studied giving a value of 1.395 𝜇A/mM.

Three 1,5-benzodiazepines viz., 𝑁₅-chloroacetyl-, 𝑁₅-piperazinoacetyl- and N5 -morpholinoacetyl-2,2,4-trimethyl-1H-1,5-benzodiazepines have been synthesized. The structural characterisation and the conformational preferences of the compounds have been carried out using IR, 1D and 2D NMR spectral data. The NMR spectral data show that the 𝑁-acetyltetrahydro-1,5-benzodiazepines prefer to exist in boat conformation with exo orientation of >C=O at 𝑁₅ position in the solution state. The X-ray crystal structure of 𝑁₅-morpholinoacetyl-2,2,4-trimethyl-1H-1,5-benzodiazepine also supports boat conformation in the solid state. The antimicrobial activity for 𝑁-acetyltetrahydro-1,5-benzodiazepines have been carried out. 𝑁-morpholinoacetyl-2,2,4-trimethyl-1H-1,5-benzodiazepine demonstrated better antibacterial and antifungal activities.