“…In fact, most examples of reported rotaxanes displayed arene (e.g., trityl-based stoppers) or alkane (e.g., functionalized with t -butyl groups) motifs or combinations of them as stoppers, with no properties or functions other than their bulkiness. , There are, however, exceptions, and some early designs already incorporated stopper units with different properties that could play a functional role such as fullerenes or porphyrins, which have continued to be used over the years . Since then, an increasingly amount of potentially functional structures such as peptides or proteins, nanoparticles or inorganic clusters, oligonucleotides, subpthalocyanines, drugs, cyclodextrins or calixarenes, ligands, redox or photo-active groups, or radicals have been progressively incorporated as stopper units in rotaxanes. In this sense, we can highlight functional stoppers with luminescence properties .…”