INFRARED-SPECTRA OF MONOHYDROXAMIC ACID COMPLEXES OF COPPER, IRON AND NICKEL

A normal coordinate treatment of Cu(MAHA)2, Fe(MAHA)2 and Ni(MAHA)2, (MAHA = N-methylhydroxamic acid) has been carried out, using a 1:1 metal-ligand model and a Urey-Bradley force field. The methyl group was treated as a point mass. Very satisfactory agreements of observed and calculated inplane infrared frequencies were obtained for copper(II) and iron(III); the metal-oxygen bonds are equivalent, having force constants of ca. 1.08 mdyn/ Å. Delocalization does occur over the chelate system resulting in significant double bond character of the CN bond, and to a lesser extent of the NO bond. © 1979.