Abstract A novel macrocyclic organotin carboxylate [(n-Bu 2 SnO) 5 L](complex 1)[H 2 L=(3- carboxymethoxy-phenoxy) acetic acid] was synthesized by the reaction of di-n-butyltin oxide with H 2 L and is characterized by elemental analyses ie IR 1 H NMR and UV spectroscopies. X-ray crystallography diffraction analysis reveals that complex 1 is a centrosymmetric macrocycle and contains a penta-nuclear four-fold-ladder-like organo- ...