Formation of cryptatium species in solution: electrochemistry of bipyridyl-, bipyrimidyl-, and bithiazole-based cryptates

The redox properties of Na+, Ca2+ and La3+ cryptates of tris(bipyridyl) (1-Na+, 1-Ca2+, 1-La3+) and Na+ complexes of five ligands were determined by cyclic voltammetry in DMF solution. The cyclic voltammograms of 1-Na+, 1-Ca2+ and 1-La3+ were similar containing three reducible ligands resulting to three, evenly spaced and quasi-reversible redox couples. There was only one reducible ligand for 2-Na+ and for 6-Na+ which resulted to an anticipated one redox wave.