Ram Achal Misra

Enzymatic synthesis and various properties of poly(catechol)

Abstract Poly(catechol) was prepared by using peroxidase as a catalyst in two types of solvent systems: an aqueous dioxane solution and a reverse micellar solution. Peroxidases derived from two sources, horseradish (HRP) and soybean (SBP), were employed as catalyst. The structure of the prepared polymer was elucidated by infrared analysis. Enzymatically prepared film of poly(catechol) at a Pt electrode was subjected to cyclic voltammetric studies in aqueous HCl medium and phosphate buffer pH 6.5. Thermal studies of the polymer were performed by thermogravimetric analysis. The iodine-labelled polymers showed low electrical conductivity in the range of 10 −6 to 10 −9 S cm −1 . The magnetic susceptibility and surface morphological property of the polymer were also studied.

Electrochemical synthesis and properties of poly(3-methylthiophene): Novel synthesis of poly(3-methylthiophene) with pentachlorostannate and hexachloroantimonate

Poly(3-methylthiophene) (P3-MeT) doped with different anions were prepared electrochemically in the presence of tetraalkylammonium salts. The new poly(3-methylthiophene) SnCl and SbCl (P3-MeT SnCl5 and P3-MeT SbCl6) were prepared electrochemically using tetra-n-butylammonium pentachlorostannate and tetra-n-butylammonium hexachloroantimonate as the supporting electrolytes. The effect of current density, salt concentration, reaction temperature, and the nature of solvents on the polymer yield and polymer conductivities have been investigated. Cyclic voltammetry of poly(3-methylthiophene) has been examined at platinum electrode in 1,2-dichloroethane medium containing n-Bu4NSnCl5, Bu4NSbCl6, and Bu4NClO4 as the supporting electrolytes in the range of −1.0 to 1.7 V versus SCE in the presence and absence of 3-methylthiophene. Electrical conductivity, magnetic susceptibility measurements, and structural determination by elemental analysis and infrared studies were also made. Scanning electron microscopy revealed a globular, branched, fibrous and a spongy, fibrous morphology of poly(3-methylthiophene) SnCl, ClO, and SbCl, respectively. The thermal analysis of the polymers was also investigated. Possible causes for the observed lower conductivity of these polymers have also been discussed.

Electrochemical Synthesis and Properties of Poly (3-Methylthiophene) Doped with Pentachlorostannate Anion

The preparation and properties of organic conducting polymers have been a rapidly developing area over the last few years. Special attention of researchers is directed at polymer based on aniline and five membered heterocyclic compounds such as pyrrole and thiophene. Conducting polymers are an interesting class of synthetic metals which find applications in a wide variety of technological avenues as electroactive meterials.

Reactivity of Superoxide Ion with Organohalogens and Chalcones

The cathodically in situ generated superoxide anion radical a proven bioactive species is a multipotent reagent. As an effective nucleophile it reacts with organohalogens in an addition-elimination process to afford the corresponding phenols. The cleavage of chalcones (enones) to carboxylic acid(s) occurs in a facile step with superoxide mediated (O2- /O2) reaction. The reactivity of superoxide anion radical with chalcones in the presence of henzoyl chloride as an affector is different and leads to radical dimer products. The plausible mechanisms have been proposed for the above reactions on the basis of product identification and cyclic voltammetric studies.