A Schiff Base Expanded Porphyrin Macrocycle that Acts as a Versatile Binucleating Ligand for Late First-Row Transition Metals

The coordination chemistry of the Schiff base polypyrrolic octaaza
macrocycle 1 toward late first-row transition metals was investigated. Binuclear complexes with the divalent cations Ni(II), Cu(II),
and Zn(II) and with the monovalent cation Cu(I) were prepared
and characterized. Air oxidation of the Cu(I) ions in the latter
complex to their divalent oxidation state resulted in a change in
the coordination mode relative to the macrocycle.