Cyclophanes and [2]catenanes as ligands for transition metal complexes: Synthesis, structure, absorption spectra, and excited state and electrochemical properties

Two tetracationic cyclophanes and two [2]catenanes containing paraquat-type units together with one or two transition metal chelating 2,2′-bipyridyl moieties have been synthesized. The metal-binding units have been used to generate novel mono- and binuclear ruthenium(II), rhenium(I), silver(I) (right), and copper(I) complexes.