Transmembrane transport of copper(i) by imidazole-functionalised calix[4]arenes.

Here we present the first synthetic transmembrane transporters for Cu ⁺ . Calix[4]arenes with two imidazole groups have a linear coordination motif, which allows selective extraction of Cu ⁺ into chloroform. Transmembrane transport of Cu ⁺ into liposomes was investigated with a newly developed assay and the results open the way to biomedical applications of these Cu ⁺ ionophores.