Complexation of Di and Tetra-Benzyloxy Ether Derivatives of Calix[4]Arene With Alkali Metal Cations

摘要

The synthesis and complexive abilities of 26,28-bis-benzyloxy-25,27-dihydroxy-5,11,17,23-tetra-tert-butyl-calix[4]arene and 25,26,27,28-tetra-benzyloxy-5,11,17,23-tetra-tert-butyl-calix[4]arene towards alkali metal ions Li~+,Na~+,K~+,Rb~+,and Cs~+ in methanol-chloroform mixture have been evaluated at 25 deg C,using UV-Vis spectrophotometric techniques.The results showed that the ligands are capable to complex with all of the alkali cations by 1:1 metal to ligand ratios.The selectivity presented considering the calculated stability constants are in the order Cs~+ > Li~+ > Rb~+ > Na~+ > K~+ and Na~+ approx= Li~+ approx= Rb~+ approx= K~+ > Cs~+ for the first and second ligand,respectively.