SYNTHESIS AND COMPLEXING PROPERTIES OF BIS-CROWN ETHERS INCORPORATINGBENZO-15-CROWN-5 AND METALLOCENE

Bis-crown ethers in which the benzo-15-crown-5 units were linked to 1, 1'-positions of metallocene (M = Fe or Ru) with amide, ester, or -C-C- bonds were synthesized. Complexing ability of the compounds with alka li, alkali earth, and transition metal cations were measured by the so lvent extraction method. The results showed that these crown ethers ha d high affinity toward alkali metal cations (Li+, Na+, K+, and Rb+) an d heavy-metal cations (Ag+ and Tl+). The difference of complexing abil ity for metal cations between ferrocene and ruthenocene derivatives co uld not be detected significantly. The extractability of metallocene-b is-crown ethers for metal cations was more larger than that of the cor responding mono-crown ethers, and irregular increments of extractabili ty were explained by assuming the existence of a mixture of 1:1 and 2: 1 complexes.