Studies on the template synthesis, kinetics and mechanism of cadmium(II) complexes of schiff base derived from glycine and ninhydrin

Abstract

N-Diketohydrindylideneglycinatocadmium(II) (schiff base) has been synthesized from glycine-cadmium(II) interaction with ninhydrin and characterized by IR spectra. Kinetics of the reaction has been carried out spectrophotometrically under varying conditions of [ninhydrin], <i>p</i>H and (acetate ion] at different temperatures. During the course of reaction, formation oftwo different coloured products have been observed. The reaction follows a first order kinetics with respect to [glycine-cadmium(II)] and fractional order kinetics with respect to [ninhydrin] for the formation of both products. The reaction proceeds through the complexation of ninhydrin with glycine-cadmium(II) which is the feature of template mechanism (CLAM reaction). On the basis of observed data, probable structure and template mechanism have been proposed for the formation of two coloured products (l_max = 375 and 510 nm). The values of <i>k₁, <i>k₂, K_t, </i> and <i>K'_t </i> calculated from kinetic data are found to be 3.33 x 10^{- 3}s ^{- 1} 6.25 x 10^-4 s^-1, 13.4 and 14.2 respectively.