INFLUENCE OF STRUCTURAL-CHANGES ON THE ION SELECTIVITIES OF MAGNESIUMIONOPHORES BASED ON MALONIC-ACID DIAMIDES

In an investigation of octamethylene bis(malonic acid diamides) and th eir selectivities for magnesium, it was found that presence of seconda ry amides within the particular ionophore played a considerable role i n the enhancement of magnesium selectivity. Similar effects in other i onophores, i.e. tris(malonic acid diamides), were thus systematically looked at with the help of selectivity measurements with the hope of o ptimizing the number of secondary and tertiary amides so as to improve the magnesium selectivity. The syntheses of several investigated tris (malonic acid diamide) isologues are equally reported.