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).5H(2)O (2) (L = 1,3,10, 12,16,19-hexaazatetracyclo[17,3,1,1(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.