Complexes of a macrocyclic ligand having both mono- and binucleating capability: binuclear Mn(II), Fe(II), Co(II), Ni(II), Zn(II) complexes

Bi-nuclear complexes of 28- atom membered macrocycles derived from 2,6-diacetyl pyridine and the amines 3,3′-diamino dipropylamine or 3,3′-diamino-N-methyl dipropylamine have been prepared by template synthesis on Ag⁺ or Pb²⁺. Template synthesis can also be accomplished, in the case of 3,3′-diamino dipropylamine, but not its N-methyl derivative, on Gp(II) metal ions, with accompanying rearrangement of the macrocycle. All the complexes produced by template synthesis can be transmetallated with the first transition series metal ions M = Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II) to give binuclear and in some cases, mononuclear, derivatives. The binuclear complexes show no evidence of magnetic exchange interaction from magnetic susceptibility measurements in the range 93-300 K. The cyclovoltammetric behaviour of mono- and bi-nuclear Fe(II) complexes is compared.