Wurster's crownophanes: an alternate topology for para-phenylenediamine-based macrocycles

Herein, we describe the synthesis and properties of Wurster's crownophanes. These electrochemically active macrocycles can be viewed as cyclophane/crown ether hybrid structures and represent an alternate architecture for the incorporation of phenylenediamine into a macrocyclic framework. The largest member studied showed an affinity for alkaline earth metal cations and ammonium.