Computational study of reaction mechanism of formaldehyde and glycine Schiff base

Theoretical study of reaction mechanism of formaldehyde and glycine was conducted with regard to formation of Schiff base using Spartan ’08 software semi-empirical/parametric model (PM3) and Density Functional Theory [RB3LYP/6-31G (d)] calculations. The mechanism was found to contain four elementary steps comprising two transition states and one intermediate. The transition states are reversible. The consecutive reaction (scheme 3) involves a bimolecular and unimolecular steps. The unimolecular is the rate determining step with a lower k1 value of 1.665x 1021s-1. There was a good agreement between the two methods calculations and the overall reaction was found to be second order and exothermic.