Abstract: Reaction of 2-HOC₆H₄CHO with X-R-X [R=- CH₂CH₂-, - (CH₂)₃-, - (CH₂)₄-, -(CH₂)₆-, -CH₂CH₂(OCH₂CH₂)₂-, X=Br, p-CH₃C₆H₄SO₃-] in the presence of K₂CO₃ in DMF gave 2-OHC-C₆H₄-OROC₆H₄CHO-2, which were condensed with 4'-aminobenzo-15-crown-5 to give five new schiff base type bis-crown ethers. Reduction of these schiff bases with LiAlH₄ gave secondary amine type bis-crown ethers. Results of conductivity measurement showed that these bis-crown ethers formed 2 : 1 (crown ether : metal ion) sandwich type complexes with potassium, rubidium chlorides or formed 1 : 1 complexes with sodium ion. In addition, the bis-crown ethers were used as an active substance in PVC membrane potassium ion selective electrodes, and the liner range, selective coefficient were also measured.

Key words: Bis-crown ethers, Schiff base, Conductiometry, Ion selective electrode