Complexes of triethanolamine with cobalt(II), nickel(II) and copper(II) salts

Abstract

Complexes of triethanolamine (TEA) with Co^II, Ni^II, and Cu^II halides, perchlorates, and nitrates have been examined by magnetic, spectroscopic, and X-ray powder techniques. Octahedral complexes, [M(TEA)₂]X₂, are formed with NiX₂(X = Cl^–, Br^–, and NO₃^–) and Co(NO₃)₂ while distorted octahedral complexes of the same stoicheiometry are formed with CoX₂(X = Cl^– or Br^–). The complexes [Cu(TEA)₂]X₂(X = Cl^– or Br^–) are both six-co-ordinate but differ in structure, the complex bromide having a subnormal magnetic-moment resulting from bridging hydroxy-groups. [Cu(TEA)₆]Cl₂, of relatively undistorted octahedral stereochemistry, has also been prepared. It is suggested in this case that the ligand is oxygen bonded, while in examples where it is terdentate a hydroxy-group remains unco-ordinated.