Pyridine N-oxide and quinoline N-oxide complexes with bivalent manganese, cobalt, nickel, copper, and zinc thiocyanates and selenocyanates

Abstract

Pyridine N-oxide (pyo) and quinoline N-oxide (qno) form a variety of complexes with [M(NCX)₂] acceptors (M = Mn, Co, Ni, Cu, or Zn; X = S or Se). Most of the complexes contain octahedrally co-ordinated metal ions; among the structural types identified are monomers {e.g., [Co(pyo)₄(NCS)₂]}, pseudohalide-bridged species {e.g., [Co(pyo)₂(NCS)₂]}, ligand-bridged species {e.g., [N(qno)₂(NCS)₂]}, and ionic complexes {e.g., [Mn(qno)₆][Mn(NCSe)₄]}. Many of the pyridine N-oxide complexes contain co-ordinated water or ethanol, but the quinoline N-oxide complexes do not. Assignments of the metal–ligand vibrations are discussed and compared with those for analogous pyridine complexes.