Effect of β-cyclodextrin, surfactants and solvent on the reactions of the recently synthesized Schiff base and its Cu(II) complex with cyanide ion

Abstract

The kinetic of the reactions of the recently synthesized Schiff base (PABST) and its complex with Cu(II) (Cu-PABST) with CN − in a 30:70 (v/v) mixture of DMF:water was investigated at pH 6.0 and 10.0, respectively, using multivariate curve resolution alternative least squares (MCR-ALS) method. The effects of different parameters such as volume percent of DMF, pH and surfactants and β-cyclodextrin (β-CD), on observed rate constant of the reactions were investigated. Cetyltrimethylammonium bromide (CTAB) decreased the rate constant of PABST reaction and increased the rate constant of Cu-PABST reaction with CN −. Sodium dodecyl sulfate (SDS) and Triton X-100 decreased the rate constant of both reactions. Also the stability constant for the inclusion complexes of PABST and Cu-PABST, and observed rate constants for the reactions of β-CD-PABST and β-CD-Cu-PABST) with CN − were determined. β-CD decreased the rate constant of PABST reaction with CN − by protecting iminium groups of the Schiff base, while β-CD increased the rate constant of the reaction of Cu-PABST with CN −.