ESR properties of Supramolecular Assemblies Containing Nitroxide Radicals

Supramolecular chemistry is the branch of chemistry concerned with the coalescence of molecules into non covalent ensembles. Supramolecular complexes are temporarily and weakly bound groups of two or more molecules and their formation is a dynamic process taking place, in most cases, at rates comparable to the time scale of X-band EPR spectroscopy. In this communication it will be shown that the combined use of specifically designed nitroxide probes and ESR provides a detailed description of supramolecular architecture in solution. In particular, it will be reported the results obtained by studying the complexation behaviour of cyclodextrins, cucurbiturils and protected metal nanoparticles. The construction of noncovalent multi-component nitroxide radicals and their characterization in solution by ESR spectroscopy will also be illustrated.