Vinyl polymerization

The thermodynamic interaction parameters of the systems, poly (ethyl methacrylate) /n-butanol and poly (methyl methacrylate) /n-butyl bromide and poly (methyl methacrylate)/isoamyl acetate were determined by methods involving phase separation and compared critically with values obtained by other methods. The validity of some of the well-known theoretical equations in the region of phase separation is considered.     

Reactions of bromine and chlorine with osmium hexafluoride

Osmium hexafluoride combines with bromine to form Br₂OsF₆. Solutions of OsF₆ in liquid chlorine are strongly blue or blue violet in colour, and charge transfer interactions are indicated.     

Raman and infrared intensity analysis of CHCl3 and CDCl3

Raman and infrared intensity analysis of CHCl₃ is attempted to determine the bond polarisability derivatives and bond dipole moments and their derivatives respectively, on lines expained in our earlier papers.     

Oxidation studies—V

Oxidation of light and heavy water by peroxy disulphate was studied at 60–70° C. The acid independent and acid dependent rate constants and respective ΔE values were computed. An attempt is made to explain the kinetic isotopic effect observed. A probable mechanism is proposed.     

A Note on Similarity Reductions of Barotropic and Quasi-geostrophic Potential Vorticity Equation

Applying the classical Lie symmetry approach to the barotropic and quasi-geostrophic potential vorticity equation without forcing and dissipation on a β-plane channel, we find a new symmetry, which is not presented in a previous work [F. Huang, Commun. Theor. Phys. （Beijing, China） 42 （2004） 903]. A general finite transformation group is obtained based on the full Lie point symmetry, Furthermore, two new types of similarity reduction solutions are obtained.     

First Stereoselective Total Synthesis of Modiolin

Russian Journal of Organic Chemistry - The first stereoselective total synthesis of the linear pentaketide Modiolin has been performed via Jacobsen’ hydrolytic kinetic resolution and...     

Efficient and Convenient Protocol for the Synthesis of 3,5-Disubstituted 1,2,4-Oxadiazoles Using HClO4-SiO2 as a Heterogeneous Recyclable Catalyst

Silica-supported perchloric acid (HClO₄-SiO₂) was found to be a new, highly efficient, inexpensive, and reusable catalyst for a rapid and efficient synthesis of various 1,2,4-oxadiazoles with good to excellent yields under solvent-free conditions. The present methodology has been effectively utilized for the synthesis of oxolamine, an anti-inflammatory drug.     

Catalytic effect of CTAB reverse micelles on the kinetics of dissociation of bis(2,4,6–tripyridyl-s-triazine) iron(II)

The kinetics of dissociation of bis(2,4,6–tripyridyl-s-triazine) iron(II), ([Fe(TPTZ)₂]²⁺) has been studied in CTAB/chloroform/hexane reverse micellar medium. In the absence of acid, the reaction is immeasurably slow and does not go to completion in conventional aqueous medium but is markedly accelerated and takes place with a rate constant equal to 55.3 × 10^?3 s^?1 and goes to completion in reverse micelles. The significant increase in rate is attributed to the special properties of the water pool in the reverse micelles like low dielectric constant, nucleophilic effect of Br^- ion, and favorable partitioning of TPTZ in the organic phase. The rate of the reaction decreases with increase in W (=[H₂O]/[CTAB]) at constant CTAB concentration and remains constant with increase in CTAB at fixed W. The results are compared with other closely related systems.