Synthesis and characterization of bis(hydrazinium) tetra-(thiocyanato-N)-cobalt(II) and -nickel(II) dihydrates; crystal structure of the cobalt complex

Abstract

Bis(hydrazinium)tetra(thiocyanato-N)cobalt-(II) and-nickel(II) dihydrates, (N₂H₅)₂M(NCS)₄·2H₂O (M = Co or Ni) have been prepared by the reaction of the corresponding N₂H₅M(N₂H₃CO₂)₃·H₂O with thiocyanic acid. The structure of the cobalt complex has been determined by single-crystal X-ray diffraction studies. The cobalt ion is six-co-ordinated with an octahedral geometry generated by two hydrazinium cations and four N-bonded thiocyanate ligands. Of significance is the presence of both linear and angular Co–NCS linkages (in the same molecule) and the N₂H₅⁺ ions in cis positions. The nickel complex is isostructural with the cobalt complex.