عنوان المقالة: Catalytic Effect of Cationic Gemini Micelles on the Rate of Condensation between Glycyl-DL-Aspartic Acid and Ninhydrin in Absence and Presence of Organic Solvents
The reaction between glycyl-DL-aspartic acid (Gly-DL-Asp) and ninhydrin has
been investigated in cationic gemini surfactants [alkanediyl-a,x-bis (dimethyltetradecylammonium bromide)] (14-m-14). The study was carried out as functions of [Gly-DL-Asp],
[ninhydrin], solvent (v/v %) and [surfactant] at pH = 5.0 and 70 C. The reaction followed
first-order kinetics in [Gly-DL-Asp] and fractional-order kinetics in [ninhydrin]. The
reaction is catalyzed by TTABr/14-m-14. Addition of an organic solvent at fixed [surfactant] increases the absorbance as well as the rate of formation of Ruhemann’s purple.
The results obtained in micellar media are treated quantitatively in terms of pseudophase
and Piszkiewicz kinetic models. The Eyring equation is valid for the reaction over the
range of temperatures used and different activation parameters have been evaluated. The
kinetic data have been used to calculate the micellar binding constants KS for Gly-DL-Asp
and KN for ninhydrin.
د. عادل أحمد محمد سعيد | Dr. Adel Ahmed Mohammed Seaad | 11885