Some metal sulphamates and their complexes with diamines and pyridine. Evidence for ambidentate behaviour and linkage isomerism of the sulphamate group

Abstract

A range of metal sulphamates has been prepared and characterised by i.r. and visible spectra and magnetic moments. In [M(H₂O)₄(NH₂SO₃)₂](M = Zn. Co, or Ni) the sulphamate group is co-ordinated via oxygen. On elimination of water, co-ordination via the amino-group occurs, as demonstrated by i.r. spectroscopy. [Cr(H₂O)₃(NH₂SO₃)₃] Involves N-co-ordinated sulphamate. Two forms of copper sulphamate have been prepared involving N- and O-linked sulphamate groups. The N-bonded sulphamatocopper(II) species undergoes ready decomposition to the sulphate complex. Several complexes of metal sulphamates with ethylenediamine, other diamines, and pyridine have been prepared. [Ni(mepn)₂(NH₂SO₃)₂] Is diamagnetic, square planar, but all other Ni^II species are of octahedral or tetragonally distorted octahedral stereochemistry. The electronic spectrum of the D_4h species [Ni(py)₄(NH₂SO₃)₂] has been studied in detail and parameters calculated via a spectrum-fitting procedure. This shows the sulphamate group to be oxygen linked, a conclusion confirmed by i.r. spectroscopy. The other sulphamates [M(py)₄(NH₂SO₃)₂] are also O-linked, except for [Cu(py)₄(NH₂SO₃)₂] which is N-bonded. Some ethylenediamine complexes of copper(II) sulphamate and aminomethanesulphonate are also reported.