Syntheses and characterization of copper complexes of the ligand (2-aminoethyl)bis(2-pyridylmethyl)amine (uns-penp) and derivatives

Synthesis and structural characterization of the copper(I) and copper(II) complexes of the tripodal tetradentate ligand (2-aminoethyl)bis(2-pyridylmethyl)amine (uns-penp) are reported as well as the reactivity of the copper(I) uns-penp complex towards dioxygen. Uns-penp can be easily modified and two copper(II) complexes of these derivatives have been structurally characterized. In the copper(II) complex of an amide derivative of uns-penp, [Cu(acetyl-uns-penp)Cl]ClO4, it is evident that the amide nitrogen is no longer truly sp2 hybridised, a consequence of a weak interaction with the copper(II) ion.