Synthetic flux-promoting polyether models: Cation flux dependence on polyoxyethylene chain length

A novel class of cyclic polyoxyethylene derivatives incorporating a polyben zylated oxane system has been prepared via ruthenium-catalyzed ring-closing metathesis. These polyethers were incorporated into phospholipid vesicles and shown to facilitate transmembrane sodium transport. Maximum efficiency in sodium flux occurred when polyoxygenated chain lengths were similar to t he leaflet thickness in bilayers. It is proposed that polyethers dimerize i n order to function. The association constants of these polyethers with alk ali metal cations and methyl ammonium ion have been evaluated using Cram's picrate extraction method.