Synthesis and structural studies of some first row transition metal complexes of acetone nicotinoyl hydrazone

Summary Acetone nicotinoyl hydrazone (ANII) complexes of the types M(ANH)Cl₂ · nEtOH and M(ANH-H)₂ H₂O (where M = Mn^II Fe^II, Co^II, Ni^II, Cu^II or Zn^II and n = 0,1 or 2) have been prepared and their structures studied by molar conductance, i.r. and electronic spectra, and room temperature magnetic measurements. All the complexes arc nonionic in a 0.001 M solution of formic acid. Magnetic and electronic spectral studies show that all the complexes are spin-free regular or distorted octahedra except Mn(ANH)Cl₂ and Co(ANH)CI₂ which are tetrahedral. The distorted octahedral geometry of Cu(ANH-H)₂ · H2O has also been confirmed from its sold state e.s.r spectrum at 77 K. From i.r. spectral studies, ANH has been found to act as a tridentate ligand in all the complexes except Mn(ANH)Cl₂ where it behaves as a bidentate ligand.