KINETIC STUDY OF CHARGE TRANSFER COMPLEXES OF IODINE WITH SOME CROWN ETHERS IN NONAQUEOUS SOLVENTS

摘要

Charge-transfer complexation of iodine with 15-crown-5(15C5), dicyclohexyl-18-crown-6 (DC18C6), benzo-18-crown-6 (B18C6) and dibenzo-24-crown-8 (DB24C8) has been studied in chloroform (CHCl3), Dichloromethane (DCM) and 1,2-dichloroethane (1,2-DCE) solutions at different time. The results indicated immediate formation of an electron donor-electron acceptor complex; which is followed by two relatively slow consecutive reactions. The pseudo-first-order rate constants for the formation of the ionic intermediate and the final product have been evaluated at 25 °C. The rate of formation of product has been measured as a function of time in different halocarbone solvents. The pseudo first order rate constants were evaluated from the absorbance- time data and found to vary in the order of 1,2-DCE DCM CHCl3.