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 (1)H NMR spectra and X-ray crystallography. These octaphyrins have a figure eight structure. The methyl and methylene protons directly bound to the bipyrrole beta-position at the crossing point of the figure eight loop were very close to Co(H) and showed their (1)H 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. (c) 2006 Elsevier B.V. All rights reserved.