Metal complexes of O-alkyl-1-amidinoureas. Part I. Nickel(II)

Abstract

By the reaction of dicyandiamide with nickel(II) salts in alcohol a series of bis-O-alkyl-1-amidinourea (R-au) complexes have been prepared. These are characterised as Ni(R-au)₂X₂. Magnetic and spectral results indicate that R-au is a strong-field ligand. All the complexes reported are square-planar, diamagnetic, and orange-yellow. A complex in which the ligand itself becomes anionic is also reported. A spectral comparison of these two types of complexes permits an assignment of relative energies for the d orbitals.