KINETIC-STUDY OF LIGAND-EXCHANGE REACTION OF ANIONS AS LIGANDS ON DAE-SPOROPOLLENIN

The specific rate coefficients and ligand sorption isotherms of Br and I- as ligands on diaminoethyl-sporopollenin were determined as a func tion of pH and temperature between 20 and 60 degrees C. The ligand exc hange rates were measured just after the rapid mixing of the ligand so lution with the resin suspension. The data have also been analyzed to obtain activation parameters Delta G, Delta H, and Delta S for reactio n in the corresponding mixture. A single ligand-exchange process was o bserved; the sorption of ligand increased with decreasing pH and hydra ted radius of ligands and increasing temperature. A reaction mechanism which describe the ligand exchange reaction is proposed. (C) 1996 Aca demic Press, Inc.