A comparative study of the structures, NMR properties and magnetic behaviour of complexes of cobalt(II) with octamethylpyrophosphoramide and nonamethylimidodiphosphoramide

The structure of the complex Co(NIPA)3(ClO4)2 has been determined by X-ray diffraction analysis and found to be very close to that of the corresponding OMPA complex. The magnetic susceptibilities of the OMPA and NIPA complexes have been measured by a thermomagnetic method and have allowed the calculation of χ| and χ⊥, the susceptibilities along the principal axes of the complex. The magnetic properties of the isomorphous nickel compounds have been studied for comparison. Results give evidence for the greater magnetic anisotropy of the NIPA complexes.