POLARISATION OF THE LIGAND-FIELD SPECTRA OF SOME PLANAR CHELATE COMPLEXES

The polarizations observed in the ligand-field bands of bis-(acetyl- acetonato)copper(II) are explained on a basis, in which the order of energy levels is one that can be inferred from elementary ligand-field theory. It is shown that former assignments arose from an incorrect restriction in the application of vibronic selection rules. In the new interpretation, the two bands at 14,500 and approximates 15,600 cm/sup -1/ are attributed to a single electronic transition. The vibrational effects responsible for its double appearance are-discussed. It is also noted that because of the same error in the application of vibronic selection rules former assignments of the ligand-field spectra of some nickel(II) complexes need not be correct. (auth)