A study of electronic spectra of square planar copper(II) and nickel(II) complexes by circular dichroism

Using optically active 1,2-propylenediamine we have synthesized several ligands to form square planar Cu(II) and Ni(II) complexes with optical activity. The CD(circular dichroism) and AB (absorption) spectra of these compounds were measured. The broad absorption bands were resolved in the CD spectra into each component due to a d-d transition, to which a specific d-d transition was assigned. It was found that in these compounds the change in the central atom from Cu(II) to Ni(II) dose not alter the main feature of CD and AB spectra. This seems to be the general rule for the planar Cu(II) and Ni(II) complexes.