Co-ordination behaviour of various 2-pyridyl ketones. Part I. Copper(II) halide and perchlorate complexes with di-2-pyridyl ketone and 2-benzoylpyridine

Abstract

Copper(II) perchlorate yields the following hexaco-ordinate complexes with di-2-pyridyl ketone (pyCOpy) and 2-benzoylpyridine (PhCOpy): Cu(pyCOpy)₂(ClO₄)₂(NN-co-ordination), [Cu(pyCOpy)₂(H₂O)₂], (ClO₄)₂(NO-co-ordination), and Cu(PhCOpy)₂(ClO₄)₂. The complexes M(PhCOpy)₂X₂(M = Cu^II or Zn^II; X = Cl or Br) are hexaco-ordinate compounds with weak interaction between the carbonyl group and the metal ion. The nature of the complex Cu(pyCOpy)₂Cl₂,2H₂O is discussed. The compounds Cu(pyCOpy)X₂,ROH (X = Cl or Br; R = Et or Prⁿ)(NO-co-ordination) possibly contain pentaco-ordinate copper(II) whereas Cu(PhCOpy)Cl₂ and Cu(pyCOpy)Cl₂(NN-co-ordination) are considered to be planar complexes. Red-brown Cu(PhCOpy)Br₂ is suggested to be a tetrahedral compound.