Synthesis of two new AuIII corrole complexes with unsymmetrically substituted corrole ligands is presented here. The newly synthesized Au-compounds have been characterized by various spectroscopic techniques. The structural characterization of a representative AuIII corrole has also been possible. Electrochemical, UV-vis-NIR/EPR spectroelectrochemical and DFT studies have been used to decipher the electronic structures of various electro-generated species. These are the first UV-vis-NIR/EPR spectroelectrochemical investigations on AuIII corroles. Assignment of redox states of electro-generated AuIII corroles is supported by DFT analysis. In contrast to the metal centered reduction reported in AuIII porphyrins, one electron reduction in AuIII corroles has been assigned to corrole centered on the basis of experimental and theoretical studies. Thus, the AuIII corroles (not the analogous AuIII porphyrin derivatives!) bear a truly redox inactive AuIII center. Additionally, these Au–corrole complexes display NIR electrochromism, the origin of which is all on corrole-centered processes.
The Royal Society of Chemistry