BIBRACCHIAL DIAZATETRALACTAMS - SIDE-CHAIN EFFECTS ON CATION-BINDING AND IONOPHORIC PROPERTIES

The formation constants in THF solutions of calcium complexes diazatet ralactams bearing two side-chains were found in the range 4.6 < log be ta(ML) < 8.2 and follow the substituent sequence Boc < Me similar to C H(2)CO(2)Me < CH(2)CONMe(2) < CH(2)Py. This side-chain effect was agai n observed in liquid-liquid extraction studies either with calcium or zinc picrates. Efficient zinc extraction constitutes the main differen ce with the dioxatetralactam series. The metallic ion transport across a chloroformic membrane studied with the pyridine derivative agrees w ell with extraction data, Specific ionophoric properties were evidence d with ion-selective electrodes.