Reaction of copper(II) perchlorate with p-tert-butyl-calix[4]arene-1,3- diacid gives mono-nuclear complex in acetonitrile and dinuclear complex in methanol which have been isolated as their pyridine bound adducts. The dinuclear complex exhibits different characteristics in its EPR and magnetic studies. The reactivity studies clearly indicate that the dinuclear complex has higher catecholase mimetic activity over its mononuclear counterpart owing to its coordination favourability.