Interaction of 2-furanylmethyl- and 2-thienylmethyl-amide derivatives of 1,3-di(carboxymethyl)calix[4]arene with metal salts

The synthesis and metal-ion complexation properties of two new derivatives of 1,3-di(carboxymethyl)- p - tert -butylcalix[4]arene, bis(2-thienylmethylamide) 3 and bis(furanylmethylamide) 4 , have been studied using UV/Vis spectrophotometry and, in some cases, 1 H-NMR spectroscopy. The cations examined are alkali metals (Li + , Na + , K + , Rb + and Cs + ), alkaline earth metals (Mg 2+ , Ca 2+ , Sr 2+ and Ba 2+ ), heavy metals (Ag + , Cd 2+ , Hg 2+ and Pb 2+ ), and lanthanides (La 3+ , Nd 3+ , Eu 3+ , Gd 3+ and Yb 3+ ).