Synthesis and structures of cobalt(II) complexes of meso-tetraphenyloctaphyrin(1.0.1.0.1.0.1.0)s

Some meso-tetraphenyloctaphyrin(1.0.1.0.1.0.1.0)s and their Co(II) complexes were prepared and characterized on the basis of the ¹H NMR spectra and X-ray crystallography. These octaphyrins have a figure eight structure. The methyl and methylene protons directly bound to the bipyrrole β-position at the crossing point of the figure eight loop were very close to Co(II) and showed their ¹H NMR resonances in the range of 30–300 ppm. The insertion of Co(II) into the octaphyrin with mixed 2,2′-bipyrrole units of different substitution pattern induced transposition of the sterically more congested 2,2′-bipyrrole unit from the crossing point of the figure eight loop to the periphery.