Liquid-liquid extraction of alkali and transition metal cations by two biscalix[4]arenes

The synthesis and complexing abilities of the two biscalix[4]arenes with li gating ester and ketone groups in the cone conformation have been performed and determined by extraction and extraction constants measurements. The ca tions studied were the alkali (Li+, Na+, K+, and Cs+) and transition (Ag+, Hg2+, Cu2+, Ni2+, Co2+, Cd2+) metals. It has been observed that ester deriv ative 7 shows a higher affinity toward transition metals than the alkali me tal cations. By contrast, ketone derivative 8 extracts both alkali and tran sition metal cations effectively. Both of compounds 7 and 8 are better extr actants than their monomeric analog 1.