Selective Supramolecular Membrane Transport of cis and trans Diastereoisomers of the Diamminebis(ethane-1,2-diamine)cobalt(III) Cation by the Natural Ionophore Lasalocid A

Abstract

Carrier-mediated transport of the cis and trans diastereoisomers of the diamminebis (ethane-1,2-diamine)cobalt(III) cation across a chloroform membrane by the natural ionophore lasalocid A is reported. In the case where individual isomers were run, no significant difference in their transport behaviour was observed. However, a competitive transport experiment in which equimolar concentrations of the cis and trans isomers of the above cation were present in the source phase led to enhanced transport of the trans isomer relative to the cis. Under the conditions employed, the final cis-to-trans ratio in the receiving phase was 1 : 3.