Effect of Added Dimethyl Sulphoxide on the Solvolysis of Cinnamoyl Chloride in Aqueous Acetone and Acetonitrile
Kinetic studies on solvolysis of cinnamoyl chloride in aqueous acetone and acetonitrile with lesser water content shows an order 2.6 with respect to water and it is comparable to that of benzoyl chloride. The relatively greater enthalpy and lesser negative entropy of activation compared to benzoyl chloride favours an S N 2 mechanism for cinnamoyl chloride rather than addition elimination mechanism. A sharp increase in rate observed in presence of small amounts of DMSO is due to its, strong basic and hydrogen bonding character leading to the liberation of strong nucleophile OH-, relatively greater stabilization of transition state than intial state which lowers the enthalpy and free energy of activation, distruction and interpenetration into the solvation shell of water and its direct interaction with the substrate.
Enolisation Kinetics of m-Nitro Acetophenone
m-Nitroacetophenone was chosen for the study of kinetics of enolisation. The rate of the reaction was studied by iodination. The kinetics of the reaction was monitored under several conditions of variation of ketone concentration, dielectric constant of the medium , temperature, effect of catalyst etc. In addition to this four different amino acids viz. β-alanin, DL-alanin, L-alanin and Glycine were tested as catalyst for the enolisation process. The rate of enolisation was found to increase with the increase in then ketone concentration , percentage composition of the solvent mixture and also with the increase in the dipole moments of the amino acids. Pseudofirst order rate kinetics was operational and the rate constants were found to increase with the increase in the amino acid molarity. Linear plots obtained for log of rate constants versus reciprocal of temperature which were in good agreement with Arrhenius equation. The values of thermodynamic parameters like Entropy (∆S≠) , Enthalpy (∆H≠), energy of activation (∆Ea) and Free energy(∆F≠) were calculated and were found to be 2.6186 e.u. , 20.85 e.u. ,23.46 k cal mol-1 and 20.0 k cal mol-1 respectively.  © 2014 BCREC UNDIP. All rights reserved Received: 31st July 2013; Revised: 8th November 2013; Accepted: 21st November 2013 [ How to Cite : Malhotra, S., Jaspal, D. (2014). Kinetics of the Enolisation Reaction of m-Nitro Acetophe-none Catalyzed by Amino Acids. Bulletin of Chemical Reaction Engineering & Catalysis , 9 (1): 16-22. (doi:10.9767/bcrec.9.1.5258.16-22)] [ Permalink/DOI : http://dx.doi.org/10.9767/bcrec.9.1.5258.16-22 ]
Mean field model of a game for power
Abstract Our aim is to model a game for power (equivalent to total energy) as a dynamical process, where an excess of power possessed by a player allows him to gain even more power. Such a positive feedback is often termed as the Matthew effect. Analytical and numerical methods allow to identify a set of stationary states, i.e. fixed points of the model dynamics. The positions of the unstable fixed points give an insight on the basins of attraction of the stable fixed points. The results are interpreted in terms of modeling of coercive power.