Polyether carriers, noncyclic

THE STRUCTURES OF NONCYCLIC POLYETHER CARRIERS EXHIBITING LITHIUM ION-SELECTIVE TRANSPORT... 

Table 2 shows the results of the competitive transport of alkali metal ions through a chloroform liquid membrane. Apparently, the selectivity of these carriers for the lithium ion increases as follows 4<5<6< The kind of one terminal substituent, X, depends significantly on the selectivity of the noncyclic polyether carriers. 

In conclusion, these noncyclic polyether compounds result in the drastic change of their conformation by the uptake of cation(Scheme 3), that is, the formation of the hydrophobic wall, pseudocavity, and the stacking between aromatic rings, then the salt of the polyether carriers can be solubilized in organic solvent and diffused easily across a chloroform liquid membrane. Then, at the other boundary the smooth release of cation which is driven by proton potential occurs. 

On the basis of the consideration mentioned-above, some noncyclic polyether compounds were newly prepared and their ability in cation transport was examined by using them as a carrier. It is expected that polyether i exhibits the most excellent ability of selective transport among them because polyether 1 has been designed to form a spherical conformation with a thick hydrophobic external wall and deep pseudocavity according to the hypothesis proposed. Polyether, were prepared by the procedure as depicted in Scheme 2. 

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