A cyclic [4]rotaxane that behaves as a switchable molecular receptor: formation of a rigid scaffold from a collapsed structure by complexation with copper(I) ions
Laboratoire de Chimie Organo-Minérale, Institut de Chimie, UMR 7177 du CNRS, Université de Strasbourg, 4 rue Blaise Pascal, 67070 Strasbourg Cedex, France. sauvage@chimie.u-strasbg.fr