Complexes of manganese(II), iron(II), cobalt(II), and nickel(II) with the new α,α′,α″-tri-imine, 2,6-(dibenzothiazol-2-yl)pyridine

Abstract

The new α,α′,α″-tri-imine, 2,6-(dibenzothiazol-2-yl)pyridine (N–N–N), has been prepared and its structure has been confirmed by its mass spectrum. The mono-ligand complexes M(N–N–N) Cl₂(M = Mn, Fe, Co, Ni), M(N–N–N)X₂(M = Fe, Co; X = Br, NCS), Fe(N–N–N) I₂, and M (N–N–N)(NO₃)₂(M = Co, Ni) have been obtained. Spectral data indicate that the iron and cobalt complexes (where X = Cl, Br, I, or NCS) are five-co-ordinate but the complexes M(N–N–N)(NO₃)₂(M = Co, Ni) and Ni(N–N–N)Cl₂ are octahedral. The manganese complex may be either five- or six-co-ordinate. All the complexes are spin-free and have normal magnetic moments.

The bis-ligand complexes [M(N–N–N)₂](ClO₄)₂,nH₂O (M = Fe, Co), [Co(N–N–N)₂](BF₄)₂,4H₂O, and [Fe^II(N–N–N)₂]Br[Fe^IIIBr₄] were also obtained. The moment of [Fe(N–N–N)₂](ClO₄)₂,3H₂O is temperature dependent, ranging from 4·49 B.M. at 313 K to 2·23 B.M. at 83 K. The moment of the cation in [Fe(N–N–N)₂]Br[FeBr₄] shows normal Curie–Weiss behaviour with but slight variation with temperature, varying from 5·23 to 4·85 B.M. over the temperature range 298–83 K.