Acetic anhydride-promoted one-pot condensation of 2,4-thiazolidinedione with bisulfite adducts of aldehydes

We describe a simple and efficient one-pot method for condensing bisulfite adducts of aromatic aldehydes directly with 2,4-thiazolidinedione catalyzed by acetic anhydride. The two main highlights of this study are the one-pot condensation of bisulfite adducts with 2,4-thiazolidinedione in non-aqueous media and the use of Design of Experiment to understand and optimize the reaction conditions. This methodology was then generalized using other active methylene compounds, such as malononitrile.     

Kinetics and Mechanism of the Ligand Substitution Reaction of the Di-<Emphasis Type="Italic">μ</Emphasis>-hydroxobis(bipyridyl)dipalladium(II) Ion with some Bio-relevant Ligands

The interaction of di-μ-hydroxobis(bipyridyl)dipalladium(II) with the selected bio-relevant ligands: thioglycolic acid (HL¹), glutathione(HL²) and DL-penicillamine(HL³) has been studied spectrophotometrically in aqueous medium as a function of complex and ligand concentrations, pH, and temperature at constant ionic strength. Two consecutive reaction steps are observed: the first step is dependent on the incoming ligand concentration and the second step which is independent, is assigned to ring closure. The activation parameters, conductivity data and IR data obtained also support the proposed mechanism.     

Uncertain constrained optimization by interval-oriented algorithm

This paper deals with an interval-oriented approach to solve general interval constrained optimization problems. Generally, this type of problems has infinitely many compromise solutions. The aim of this approach is to obtain one of such solutions with higher accuracy and lower computational cost. The proposed algorithm is nothing but a different kind of branch and bound algorithm with multi-section division criterion of the search region (or box). In the proposed technique, the prescribed/accepted region is divided into several distinct subregions and in each feasible subregion the interval objective function value is computed. Then the subregion containing the best objective value is found by applying a specific interval ranking rule defined with respect to the pessimistic decision makers’ point of view. The process is continued until the interval width for each variable in the accepted subregion is negligible. Finally, the algorithm converges to a compromise solution in interval form. To illustrate the method and also to test the efficiency as well as the effectiveness of the proposed algorithm, we have solved some numerical examples.     

N-[2-(4-Methoxy-phenyl)-ethyl]-2-(quinolin-8-yloxy)acetamide: a receptor for acid binding

Different hydrates of the receptor, N-[2-(4-methoxy-phenyl)-ethyl]-2-(quinolin-8-yloxy)acetamide (I), and its co-crystals with acetic acid and l(+)α-hydroxy-phenylacetic acid are synthesised and their structures are studied. The acids such as acetic acid, l(+)α-hydroxy-phenylacetic acid quench fluorescence of I. The receptor I shows a fluorescence quenching on interaction with perchloric acid in benzene, whereas in methanol the solution of I results in the generation of a new fluorescence emission at higher wavelengths. The crystal structure of the perchlorate salt is determined to explain the protonation behaviour of the receptor I and the perchlorate salt in methanol leads to fluorescence emission at a place different from that of the parent compound.     

One-pot three-component reaction for the synthesis of biologically important spiro[benzo[f]quinoline-3,3′-indoline] derivatives

A previously unknown class of highly substituted benzoquinoline–spirooxindole are easily prepared by a novel application of a mild and efficient catalyst SbCl₃ for carbon–carbon and carbon–nitrogen bond formation reaction involving isatin, alkyne (dialkyl but-2-ynedioate) with aromatic amine (2-naphthylamine) in a one-pot three-component reaction. This protocol of one-pot synthesis afforded a library of dialkyl 2′-oxo-4H-spiro[benzo[f]quinoline-3,3′-indoline]-1,2-dicarboxylate derivatives, a potential bioactive compound in very good to excellent yields.     

Ripple topography on thin ZnO films by grazing and oblique incidence ion sputtering

We have investigated the formation and growth of nano sized ripple topography on ZnO thin films by 10 keV O¹⁺ bombardment at impact angles of 80° and 60°, varying the ion fluence from 5 × 10¹⁶ to 1 × 10¹⁸ ions/cm². At 80° the ripples are oriented along the ion beam direction whereas at 60° it is perpendicular to the ion beam direction. The developed ion induced structures are characterized by atomic force microscopy (AFM) and the alignment, variation of rms roughness, wavelength and correlation length of the structures are discussed with the existing model and basic concept of ion surface interaction.