Synthesis of functionalized aza-macrocycles and the application of their metal complexes in binding processes

Although aza-macrocycles have been thoroughly investigated ever since their discovery because of their interesting binding properties, recent applicat ions of their metal complexes in medical concepts or as binding sites for r ecognition in water have increased the demand for efficient syntheses of fu nctionalized derivatives. We present here two approaches to functionalized aza-macrocycles: substituted cyclams have been obtained by heterogeneous hy drogenation of unsaturated heterocycles, and with established coupling meth ods from peptide chemistry the selective introduction of functional groups and tethering of cyclens was achieved. The ability of Lewis-acidic complexe s of such substituted aza-macrocycles to reversibly form defined aggregates even in neutral aqueous solution was demonstrated with the synthesis of an electron donor - electron acceptor dyad, which is capable of undergoing a very efficient intramolecular photoinduced electron transfer.