Sr 2+ Ion Selective p-tert-Butylthiacalix[4]arene Bearing Two Distal Amide Units

A new thiacalix[4]arene diamide (TCAm) has been prepared and its electrochemical property and complexation behavior toward various metal ions have been investigated by voltammetry. p-tert-Butylthiacalix[4]arene diamide (TCAm) exhibited selectivity toward Sr2+ ion over alkali, alkaline earth and transition metal ions while conventional calix[4]arene diamides showed selective binding property with Ca2+ ion. This is probably due to the bigger size of thiacalix[4]arene than those of calix[4]arene.