Synthesis of Free-Base 10-Azacorroles

A novel synthetic protocol has been developed for free-base 10-azacorroles. Ni(0)-mediated homocoupling of nitrogen-bridged bisdipyrrin Zn­(II) complexes afforded a series of free-base 5,15-diaryl-10-azacorroles in good yields. Pd­(II) and Cu­(II) complexes have been prepared through metalation of free-base 10-azacorroles. Optical and electrochemical properties of 10-azacorrole metal complexes can be tuned by meso-aryl substituents and central metals. Cyclic voltammetry and theoretical calculations elucidated that the central metals of 10-azacorroles significantly affected their electronic properties.