SELECTIVE UPHILL TRANSPORT OF CYANIDE ION-MEDIATED BY TETRAPHENYLPORPHINATOMANGANESE (III) COMPLEX THROUGH BULK AND POLYMER-SUPPORTED LIQUID MEMBRANES

The present paper describes the results obtained in a new system for h ydroxide ion coupled transport of cyanide ion (uphill transport). The uphill transport was observed in two liquid membranes containing a tet raphenylporphinatomanganese(III) complex carrier (Mn(III)TPP). One is a bulk liquid membrane (BLM) that consists of a dichloromethane soluti on. The other is a polymer-supported liquid membrane (SLM) that was pr epared by submerging a thin microporous polypropylene film in an o-nit rophenyl n-octyl ether solution. The OH ligand of the complex Mn(III)T PP (OH) is easily substituted with cyanide ion. The equilibrium consta nt of the reaction with cyanide ion is much larger than those with hal ide ions, CH3COO-, and NO3-. Only cyanide ion was transported selectiv ely in the presence of various anions (CN-, Cl-, F-, NO3-, CH3COO-, et c.). We applied simple models to the uphill transport. In the BLM syst em, the flux of cyanide ion is governed by the diffusion processes of cyanide ion and the carrier molecule in the stagnant layers. The thick nesses of the layers and the ligand substitution reaction rate constan ts were estimated. In the SLM system, the flux of cyanide ion is contr olled by the diffusion process of the carrier molecule obeying the Sto kes-Einstein model in the membrane phase.