POLAROGRAPHIC STUDIES ON COMPLEX-FORMATION OF CRYPTAND[2.2] AND A MACROCYCLIC POLYTHIOETHERAMINE WITH ALKALI OR ALKALINE-EARTH METAL-IONS IN ACETONITRILE

The formation constants for 1 : 1 complexes between Li+ or Na+ and a m onocyclic polyetherdiamine, cryptand[2.2], were evaluated in acetonitr ile at 25+/-0.2 degrees C by three d.c. polarographic analyses: the po sitive shift in E(1/2) of the anodic (mercury dissolution) wave induce d from cryptand[2.2] in the presence of a large excess of LiClO4 and N aClO4; the positive shift in E(1/2) of the cathodic wave of the [HgL]( 2+) complex (L=cryptand[2.2]) in the presence of a large excess of alk ali metal ions; and the negative shift of the cathodic wave of Li+ or Na+ in the presence of a large excess of cryptand[2.2]. The above thre e analyses gave complex formation constants that were consistent with each other within experimental error. In a less solvating medium (benz onitrile), stronger interactions were observed between the cations and cryptand[2.2]. The interaction between alkali metal ions and 1,10-dia za-4,7,13,16-tetrathiacyclooctadecane (ATCO) was very small, even in b enzonitrile. The complex formation constants of [SrL'](2+) and [BaL']( 2+) (L'=ATCO) in acetonitrile were both ca. 10(2.5) by the first two m ethods mentioned above.