Macrocyclic systems derived from crown-annelated terthiophene involving a median EDOT unit havebeen synthesized by coupling diiodooligooxyethylene chains and bis(2-cyanoethylsulfanyl)terthiopheneunder high dilution conditions. The metal cation complexing properties of the compounds have beenanalyzed using 1H NMR, UV−vis spectroscopy, and cyclic voltammetry. These various experimentsprovide consistent results showing that one of the compounds exhibits interesting complexing propertiesfor Pb2+.