Optimization of Reaction Parameters for the Synthesis and Metal Ion Binding Properties of a Novel Schiff Base Using Response Surface Methodology: Kinetics and Thermodynamic Studies.

This research work described the synthesis and metal ion binding properties of bis(2,2 - methylylidenephenol)diaminoethane a biologically, chemically and industrially important compound to make it more suitable and efficient for industrial scale production. To optimize the relationship between reactions conditions and yield of Co(II)-H2BMPDE, a second order quadratic polynomial equation was generated. The economical operating optimal reaction parameters were 0.30% bis(2,2 - methylylidenephenol)diaminoethane (H2BMPDE), 6.22 g CoCl2.9H2O, temperature of 39.27 °C, extraction time of 14.83 min and HCl concentration of 10-4 M. Based on the optimized reaction parameters, the laboratory yield was 31.70 g, which was in close agreement with the predicted yield of 31.89 μg. Thermodynamic studies indicated that the complexation is feasible, spontaneous, endothermic and involved solvation process. The high regression coefficient observed from the pseudo-second order kinetic model (R² =0.9948) as against pseudo-first order kinetic model (R²=0.3382) indicated that pseudo-second order kinetic model was obeyed and clearly described the complexation process. The complexation of cobalt(II) ions on the H2BMPDE correlated well with both Langmuir (R2 =0.8822) and Freundlich (R² = 0.9979) isotherms. The response surfaces and scale-up experiments indicated that the optimized process conditions could improve the yield of the complex at larger scales. [ABSTRACT FROM AUTHOR]