Synthesis and cation binding ability of the phosphonoalkyl- and phosphinoylalkyl derivatives of monoaza-18-crown-6

Azacrown ethers with phosphonoalkyl- and phosphinoylalkyl side chains of tw o to five carbon atoms ( 2-4, 7 and 5-6, 8, respectively) were synthesized in acceptable yields. The cation binding ability of the new lariat ethers w as evaluated by the picrate extraction method. Introduction of the P-functi onalised N-substituent resulted in a decrease in the cation extraction abil ity in most cases, but the discrimination between the cations examined was, in some instances, significantly increased.