Studies on Tetraaza[14]tetraene Complexes of Nickel(II) and Copper(II)

The nickel(II) and copper(II) complexes of tetraaza[14]tetraene were prepared and investigated by means of electronic, vibrational, ESCA and ESR spectroscopy. Judging from the ligand-field spectra, these complexes assume the square-planar configurations. The spin Hamiltonian parameters of the copper(II) complex are also consistent with those for the square-planar coordination. The ESCA spectrum of the metal-free tetraaza[14]tetraene showed double nitrogen ls peaks, whereas that of the complexes exhibited a single nitrogen ls peak.