Synthesis and characterization of copper(II) hexaazamacrotetracyclic complexes containing organic ligands

Two mononuclear copper(II) complexes Cu(L)(NO₂)](ClO₄) (1) and Cu(L)(MO₄)]₂· 5H₂O (2) (L = 1,3,10, 12,16,19-hexaazatetracyclo17,3,1,1^12.16,0^4.9]tetracosane) have been synthesized and their structures determined. Both compounds show a distorted square-pyramidal geometry with the two secondary and two tertiary amines of the macrocycle and one ligand coordinated at the axial position. Cyclic voltammetry of the complexes gives two one-electron waves corresponding to Cu^II/Cu^III and Cu^II/Cu^I processes. The electronic spectra and electrochemical behavior of the complexes are significantly affected by the nature of the organic ligands.