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 [FeII(N–N–N)2]Br[FeIIIBr4] 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.