Nickel(II), palladium(II), and platinum(II) complexes of meso-aryl-substituted [26]hexaphyrin have been prepared and structurally
characterized. In mono-metalated complexes, the metal ion is
commonly bound with three pyrrolic nitrogen atoms and one pyrrolic
β-carbon, whereas a bis-Pd(II) complex exhibits a unique structure
involving a Pd−Cα bond. These results reveal novel coordination
abilities of the hexaphyrin that lead to a metal−carbon bond at
either pyrrolic Cβ or Cα position