Studies on the Uptake of Some Complex Cations of Copper by Molecular Sieves 4A and 5A

Abstract

Abstract Studies on the uptake of Cu2+ and a few of its complex cations (i.e., [Cu(NH3)4]2+, [Cu(en)]2+, [Cu(en)2]2+, [Cu(pn)]2+, [Cu(pn)2]2+, and [Cu(tea)]2+, where en, pn, and tea represent ethylenediamine, propylenediamine, and triethanolamine respectively) by molecular sieves 4A and 5A were undertaken using batch equilibration procedure. [Cu(pn)]2+, [Cu(en)2]2+, [Cu(pn)2]2+, and [Cu(tea)]2+ showed very little affinity for the zeolite phases, while the uptake of Cu2+ and [Cu(en)]2+ was comparatively higher. [Cu(NH3)4]2+ occupied a position in between these two sets. During the equilibration of [Cu(en)]2+ and [Cu(pn)]2+ some side reactions could be observed leading to the conclusion that the 1:1 complex species underwent disproportionation, generating Cu2+ and an equivalent amount of [Cu(en)2]2+ or [Cu(pn)2]2+. These conclusions drawn from the batch equilibration studies were confirmed by appropriate column experiments.