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

Farrokh Gharib,1* Saeed Taghvaei-Ganjali,2 Mehri Eslamipanah,3 Roksana Mazooji,2 and Shima Ebrahimi2

1 Chemistry Department, Shahid Beheshti University, Tehran, Evin, Iran
Chemistry Department, I. Azad University, North Tehran Branch, Tehran, Iran
Chemistry Department, I. Azad University, Science and Research Campus, Tehran, Hesarak, Iran

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 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+ @ Li+ @ Rb+ @ K+ > Cs+ for the first and second ligand, respectively.

Keywords: complexation, calixarene, alkali cations, stability constant, synthesis