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

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.