Kinetics of Substitution of Cis-bis (Oxalato) Diaquochromate (III) with Glycine, DL-Alanine and DL-Phenylalanine in Alkaline Medium

The kinetics of interaction among amino acids such as Glycine, DL-alanine and DL-phenylalanine and cisbis( oxalato)diaquochromate(III) has been studied spectrophotometrically in alkaline medium as a function of [Glycine], [DL-alanine] and [DL-phenylalanine]. The effect of pH, temperature and substrate is also studied. The substrate exists predominantly as the diaquospecies and amino acid (Glycine, DL-alanine and DL-phenylalanine) as the zwitterion at the experimental conditions. The substitution reaction has been found to proceed via two steps - amino acid dependent and amino acid independent paths, indicating that the substitution reaction occurs through I_a mechanism in the amino acid dependent path, and the dissociative mechanism in the independent path, showing the higher reactivity of single ended oxalate complex.