Cation Exchange Induced Tunable Properties of a Nanoporous Octanuclear Cu(II) Wheel with Double-Helical Structure

A double-helical octanuclear Cu(II) wheel 1 with 2.88 nm diameter was prepared through the reaction of a clinical medicine, telmisartan, with copper sulfate. Central copper ions can be partially replaced by bivalent zinc and cobalt ions and fully exchanged by trivalent iron ions. The properties of central metal ion-exchanged variants are much different from those of 1. Central metal ion exchange might be regarded as a powerful and effective method to modify properties from one crystalline material to another only by varying central metal ions under moderate conditions.