Elektrochemie supramolekularer Systeme
Host and guest compounds self-assemble to supramolecular complexes. Noncovalent bonding donor-acceptor-interactions of supramolecular complexes like that of J. F. Stoddart et al. can be weakened by redox reactions, but the complexes desintegrate. Here, it is described the reversed way. The initial reaction mixture contains a host and a potential guest compound not interacting with each other. The potential guest compound will be transferred in a real guest compound by electrochemical reduction and the supramolecular complexation is induced. Tetracationic, electronwithdrawing cyclophanes with two redoxactive units of 4,4-bipyridindiium respectively 2,7-diazapyrendiium act as host compounds, electronwithdrawing quinones as potential guest compounds. The host and guest compounds and their interaction in complex are characterized and studied by cyclic voltammetry and spectroelectrochemistry. It can be demonstrated that the reduction potentials are shifted, that the cyclophane and the guest compound form an inclusion complex and that the inclusion complexes are low soluble, exclusion complexes well soluble.