Carboranylthioamide ligand-supported Rh⋅Rh one-electron σ-bonds

The discovery of chemical bonds propels scientific advancement, and a thorough understanding of bond properties is essential for analyzing reactions and designing molecular architectures. In this work, we systematically investigate the stabilization mechanism of metalloradicals and find that, compared with benzene rings and methyl groups, the pyridyl group with electron-withdrawing properties facilitates the formation of metalloradicals. Additionally, the metalloradical could be further transformed into a dinuclear complex and then formed the first example of a Rh⋅Rh one-electron σ-bond through single-electron oxidation. Interestingly, the Rh⋅Rh one-electron σ-bond-bearing complex could revert to the original dinuclear complex under the reaction with tert -butyl isocyanide. This work considerably expands the diversity of one-electron σ-bond-bearing complexes, bridging the gap between theoretical predictions and experimental validation of Rh⋅Rh one-electron σ-bonds and demonstrating the unique ability of carborane-based ligands to stabilize unconventional bonding architectures.