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
2 Chemistry Department, I. Azad University, North Tehran Branch, Tehran, Iran
3 Chemistry Department, I. Azad University, Science and Research Campus, Tehran, Hesarak, Iran

Absrtract
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