Synthesis and X-ray Crystal Structure Determination of the First Transition Metal Complexes of the Tetracycles Formed by Tetraazamacrocycle−Glyoxal Condensation: PdL*Cl2 (L = Cyclam−Glyoxal Condensate (1), Cyclen−Glyoxal Condensate (2))

Two novel PdII complexes that represent the first examples of transition metal ions complexed to a well-known type of tetracyclic tetraamine formed from the condensation of glyoxal and tetraazamacrocycles have been synthesized and characterized. These ligands, once thought not to bind metal ions, produce unusual structures that should make them useful where rigid but sterically demanding bidentate ligands are needed.