A new water soluble calixarene: 5,11,17,23-tetrasulphonato-25,27-di(hydroxycarbonylmethoxy)-26,28-dihydroxycalix[4]arene. A thermodynamic and spectroscopic investigation of its proton and copper(ii) complexes

A new water soluble receptor 5,11,17,23-tetrasulphonato-25,27-di (hydroxycarbonylmethoxy)-26,28-dihydroxycalix[4]arene was synthesized and characterized and its proton and copper(II) complexes were studied and compared with the analogous species of the fully carboxylated ligand 5,11,17,23-tetrasulphonato-25,26,27,28-tetrakis(hydroxycarbonylmethoxy)calix[4]arene. ?H° and ?S° values are crucial for understanding the peculiar acid-base properties of the ligand. EPR spectra together with the UV-VIS spectral data reveal the coordination stereochemistry of the copper(II) species.