Reactivity of copper(I) and (II) and zinc(II) complexes of bis-(t-butyl)thiosalen and the crystal structure of the stable Cu(I) complex
摘要:
A study of the de-t-butylation properties of the N2S2 ligand N,N'-bis{[2-(1,1-dimethylethylthio)phenyl]methylene}-ethane-1,2-diamine (L-1) has shown that in contrast to its behaviour with Ni(II) it will not undergo de-t-butylation, using the conventional conditions, with Cu(I) or Zn(II) and not cleanly with Cu(II). The air stable perchlorate salt of the Cu(I) complex of L-1 has been isolated and its crystal structure determined. The complex has a distorted tetrahedral structure in which the ligand binds in such a way as to produce the diastereomeric form of the complex in which both t-butyl groups are directed away from the centre of the molecule and from each other. Cyclic voltammetry in nitromethane indicated that the Cu(II) complex of L-1 is chemically unstable, which was verified during synthetic studies in which it was seen to be prone to both hydrolysis and partial de-t-butylation. Spectroscopic and conductometric evidence suggest that in the ZnCl2 complex of L-1 coordination of chloride occurs to the exclusion of both thioether moieties.