Guntūr, India
Guntūr, India

Time filter

Source Type

Lakshman Kumar Y.,TJPS PG College | Venkata Nadh R.,Gandhi Institute of Technology and Management | Radhakrishnamurti P.S.,TJPS PG College
Russian Journal of Physical Chemistry A | Year: 2016

Kinetics of ruthenium(III) catalyzed oxidation of biologically important sugar alcohols (myo-inositol, D-sorbitol, and D-mannitol) by dichloroisocyanuric acid was carried out in aqueous acetic acid - perchloric medium. The reactions were found to be first order in case of oxidant and ruthenium(III). Zero order was observed with the concentrations of sorbitol and mannitol whereas, a positive fractional order was found in the case of inositol concentration. An inverse fractional order was observed with perchloric acid in oxidation of three substrates. Arrhenius parameters were calculated and a plausible mechanism was proposed. © 2016 Pleiades Publishing, Ltd.


Venkata Nadh R.,UniversityBengaluru Campus | Syama Sundar B.,Yogi Vemana University | Radhakrishnamurti P.S.,TJPS PG College
Russian Journal of Physical Chemistry A | Year: 2016

Kinetics of uncatalyzed and ruthenium(III) catalyzed oxidation of monoethanolamine by N-bromosuccinimide (NBS) has been studied in an aqueous acetic acid medium in the presence of sodium acetate and perchloric acid, respectively. In the uncatalyzed oxidation the kinetic orders are: the first order in NBS, a fractional order in the substrate. The rate of the reaction increased with an increase in the sodium acetate concentration and decreased with an increase in the perchloric acid concentration. This indicates that free amine molecules are the reactive species. Addition of halide ions results in a decrease in the kinetic rate, which is noteworthy. Both in absence and presence of a catalyst, a decrease in the dielectric constant of the medium decreases the kinetic rate pointing out that these are dipole—dipole reactions. A relatively higher oxidation state of ruthenium i.e., Ru(V) was found to be the active species in Ru(III) catalyzed reactions. A suitable mechanism consistent with the observations has been proposed and a rate law has been derived to explain the kinetic orders. © 2016, Pleiades Publishing, Ltd.


Lakshman Kumar Y.,TJPS PG College | Venkata Nadh R.,Vignan University | Radhakrishnamurti P.S.,TJPS PG College
Russian Journal of Physical Chemistry A | Year: 2014

In the oxidation of D-sorbitol and D-mannitol by potassium periodate in alkaline media, substrate inhibition was observed with both substrates, i.e., a decrease in the rate of the reaction was observed with an increase in the concentration of substrate. The substrate inhibition was attributed to the formation of stable complex between the substrate and periodate. The reactions were found to be first order in case of periodate and a positive fractional order with hydroxide ions. Arrhenius parameters were calculated for the oxidation of sorbitol and mannitol by potassium periodate in alkali media. © 2014 Pleiades Publishing, Ltd.


Lakshman Kumar Y.,TJPS PG College | Venkata Nadh R.,Vignan University | Radhakrishnamurti P.S.,TJPS PG College
Bulletin of the Chemical Society of Ethiopia | Year: 2015

Kinetics of reactions of enolisable ketones (S = acetone/2-butanone) with dichloroisocyanuric acid (DCICA) were studied in aqueous acetic acid and perchloric acid media in absence and presence of added chloride ions. The reactions were found to be pseudo zero order and pseudo first order on [DCICA] in absence and presence of chloride ions respectively. Both in presence and absence of chloride ions, first order and fractional order in substrate and perchloric acid were observed respectively. An increase in the rate of reaction was observed with an increase in chloride ion concentration as well as acetic acid composition. The results were interpreted in terms of probable mechanisms involving (i) rate-determining enol formation from the conjugate acid of the ketone (SH+) in the absence of added chloride ions and (ii) rate-determining interaction of SH+ with the most effective molecular chlorine species produced by the hydrolysis of DCICA (rather than a rate-determining interaction of enol with chlorine) in the presence of added chloride ions, prior to the rapid steps of product formation. © 2015 Chemical Society of Ethiopia


Lakshman Kumar Y.,TJPS PG College | Venkata Nadh R.,Vignan University | Radhakrishnamurti P.S.,TJPS PG College
Russian Journal of Physical Chemistry A | Year: 2015

Effect of added chloride ions on kinetics and pathway of reaction between cyclic ketones (five to eight membered rings) and dichloroisocyanuric acid (DCICA) was studied in aqueous acetic acid - perchloric acid medium. Formation of aliphatic dicarboxylic acids as the end products demonstrates the ring cleavage oxidation. Positive effect of acid and negative effect of dielectric constant on the reaction rate reveals a interaction between positive ion (oxidant in the form of H2OCl+) and dipolar substrate molecule. Zero and first orders by oxidant in absence and presence of added chloride ions illustrates the participation of substrate as enolic form of ketone and protonated ketone, respectively, in the rate determining steps. The observed order of reactivity of cyclic ketones (cyclohexanone > cyclooctanone > cyclopentanone > cycloheptanone) was explained on the bases of ring strain, change of hybridization and conformational considerations. The envisaged plausible mechanism based on order of reactants in presence and absence of added chloride ions was substantiated by the order of Arrhenius parameters. © 2015 Pleiades Publishing, Ltd.

Loading TJPS PG College collaborators
Loading TJPS PG College collaborators