Kinetic study of nickel-glycylglycine with ninhydrin in alkanediyl-α,ω-gemini (m-s-m type) surfactant system

Herein, we report the kinetic study of nickel-glycylglycine with ninhydrin in alkanediyl-alpha,omega-gemini (m = 16 and s = 4, 5, 6) surfactant system using UV-vis spectrophotometer. From the results, different rates, binding constants and thermodynamic parameters were evaluated. The critical micelle concentration (cmc) value of geminis with and without both the substrates (ninhydrin and nickel-glycylglycine) was determined by conductivity measurements. The reaction kinetics show first- and fractional-order dependencies on nickel-glycylglycine and ninhydrin, respectively. Effect of gemini surfactants on the title reaction was also seen and pointed out that they are superior over their corresponding conventional surfactant. The catalytic role of gemini surfactants has been discussed in detail. Quantitative analysis of kinetic data was explained by applying Menger-Portnoy model of the micelles. (C) 2017 Elsevier B.V. All rights reserved.