. Can. J. Chem.60,2259Chem.60, (1982.The rate of extraction and transport of potassium ions from a basic aqueous solutlon into a chloroform membrane containing a macrocyclic polyether (crown ether) -carboxylic acid has been investigated as a function of the following variables: stirring rate, potassiunl ion concentration, crown ether concentration, proton concentration, buffer concentration and composition, and crown ether-to-potassium ion ratio. Two rate regimes are found, a "zero order" regime where transport rate depends only on the carrier concentration and a "consecutive first order" regime where transport rate depends on the concentration of a crown etherpotassium complex. The kinetic data, together with partition coefficient and interfacial surface tension data, indicate that the rate determining steps in ion extraction occur at the interface. A mechanism involving rate limlting adsorption of carrier or desorption of complex, depending on the experimental conditions, is shown to be consistent with all available data. On a etudik la vitesse de I'extraction et de la transport des ions de potassium d'une phase aqueuse basique B travers une membrane chloroformique, qui contient un macrocycle (ether-couronne) -acide carboxylique, en fonction des parametres suivants: la vitesse d'agitation des phases, la concentration de potassium, la concentration de macrocycle, la concentration de proton, la concentration et la composition de tampon et le rapport des concentrations de potassium et rnacrocycle. I1 y a deux regimes cinetiques; celui d'un "ordre zero" ou la vitesse n'est en fonction que de la concentration de macrocycle et celui d'un "ordre premier consecutif" ou la vitesse est en fonction de la concentration d'un complex du rnacrocycle et potassium. Ces faits, avec les coefficients de partage chloroforme-eau et la tension de la surface d'interface, indiquent I'interface comme site des etapes lentes. On propose une mecanisme ou les etapes lentes sont, soit I'adsorption du macrocycle, soit la desorption du complex selon des conditions experimentaux. Toutes les observations sont consistantes a une telle mecanisme.

The synthesis of three different types of lipophilic 18-crown-6 diacids is described. A didecyl crown ether 2,3-diacid (1) was prepared as a minor product from a diiodide precursor (12) and three-11,12-docosanediol by thallous ethoxide cyclization. The major nonpolymeric products resulted from elimination followed by cyclization to give 15-crown-5 derivatives. A crown ether 11,12-diamide 2,3-diacid (4) was prepared by a similar route involving cyclization of a benzyl protected precursor (26) and N, ,IV'.iV-tetramethyltartaramide (9). Isomeric syn and anti 2,ll(12)-diamide 3,12(ll)-diacid derivatives 6 and 7 were prepared from the known crown ether bisanhydride 8 and alkylamines. The product mixture was separated by chromatography, and the isomers were identified by comparison of acidity and stability constants for complexation with those of closely related syn/anti crown ether acids.

Membranes formed from polyacrylamide derivatives bearing pendant crown ether-carboxylic acid groups act as proton-driven alkali metal ion pumps.

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Das Tetrametliyl‐weinsäurediamid (I) reagiert als Thallium‐Salz mit dem aus Diethylenglykol über den Monobenzylether (IIa) erhaltenen Iodid (IIc) zu einem Bis‐ether (IIIa), der nach Deblockierung zu (IIIb) über Bromid und Halogenaustausch zum Iodid (IIId) führt.