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.

Graphical abstractmeso-Tetraphenyloctaphyrin(1.0.1.0.1.0.1.0) with mixed 2,2′-bipyrrole units of different substitution pattern was metallated with Co(II). The X-ray crystallography and 1H NMR spectroscopy indicated that metallation induced transposition of the 2,2′-bipyrrole units having 3,3′-di-iso-butyl substituents from the crossing point of the figure eight loop to the periphery.Figure optionsDownload full-size imageDownload as PowerPoint slide