Copper 1,19-Diaza-21,24-Dicarbacorrole: A Corrole Analog with an N-N Linkage Stabilizes Ground-State Singlet Organocopper.

A copper complex of a heterocorrole analogue with an N-N linkage, 1,19-diaza-21,24-dicarbadibenzocorrole (Cu-5), was successfully synthesized via oxidative metalation-cyclization of a tetrapyrrolic precursor. The N-N linkage in the skeleton ofCu-5, which serves as a mediator of pi-electron delocalization, features an 18 pi aromatic system. The electronic structure ofCu-5is best described as a ground-state singlet species stabilized by the distinct NNCC coordination core. This finding shows how the ligand's design can be used to modulate the Cu3dx2-y2orbital energy, thereby making such compounds invaluable for copper-based catalytic applications.