Transport of Potassium Picrate through a Liquid Membrane by Metal-Responsive Carriers

Article abstract of DOI:10.1021/j100057a023

Metal-responsive carriers having three receptors, and conformational variations were synthesized.The transport experiments of potassium picrate using these carriers were performed, and the mechanism was analyzed by numerical simulations.It was found that the rates and the mechanisms of transport of potassium picrate facilitated by these new carriers depend on the conformation of the carriers.That is, the transport rate of potassium picrate by carrier I was fast and potassium picrate was transported easily against its concentration gradient.On the other hand, when carrier I was coordinated by cupric ion, carrier III of cis conformation was formed and the transport rate by this carrier III was slower.The efficient uphill transport of potassium picrate by carrier I arises both from the different extraction equilibrium constants between the aqueous phase containing potassium chloride and the aqueous phase without potassium chloride, and the weak interaction between potassium picrate and carrier I in the organic phase.The numerical simulation of this uphill transport has been performed by using a diffusion-limited process, and the calculated result is consistent with the experimental result.It was also found that the transport rate of potassium picrate depends on the substituents of the nitrogen atoms of diazacrown ether, which affects the interaction between diazacrown ether and potassium picrate.