Structural, electrochemical and spectroelectrochemical study on the geometric and electronic structures of [(corrolato)AuIII]n (n = 0, +1, −1) complexes

Abstract

Synthesis of two new Au^III 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 Au^III 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 Au^III corroles. Assignment of redox states of electro-generated Au^III corroles is supported by DFT analysis. In contrast to the metal centered reduction reported in Au^III porphyrins, one electron reduction in Au^III corroles has been assigned to corrole centered on the basis of experimental and theoretical studies. Thus, the Au^III corroles (not the analogous Au^III porphyrin derivatives!) bear a truly redox inactive Au^III center. Additionally, these Au–corrole complexes display NIR electrochromism, the origin of which is all on corrole-centered processes.