Kinetics and Mechanism of Ligand Exchange of Cu(methionine)2 by Polyamines

• Main Authors: Abdul, Moheman, Showkat, Ahmad Bhawani, Khwaja Salahuddin, Siddiqi
• Format: Article
• Language: English
• Published: Oriental Scientific Publishing Company 2022
• Subjects: QD Chemistry
• Online Access: http://ir.unimas.my/id/eprint/41546/4/Kinetics.pdf; http://ir.unimas.my/id/eprint/41546/; https://www.orientjchem.org/; http://dx.doi.org/10.13005/ojc/380632

The kinetics of ligand substitution reaction of Cu(methionine)2 complex by polyamines has been followed conductometrically above pH 9.0 at 25o C. Millimolar solution of the Cu(NO3 ) 2 and methionine in 1:2 molar ratio in water shows increase in conductance with time. When a polyamine (en, dien and trien) is added to the complex, the conductance increases at a rapid rate due to substitution of methionine by polyamine leading to the formation of [Cu(polyamine)2 ]. It was observed that the exchange of methionine by polyamine proceeds in a first order process. Since the rate of the reaction varies with the size of polyamines they can be placed in the following, en>dien>trien. In acidic pH range the absorption spectrum varies negligibly. However, the concentration of methionine does not have any influence on the absorption spectra.