A Bis-(carbone) Pincer Ligand and Its Coordinative Behavior toward Multi-Metallic Configurations

Carbones are divalent carbon(0) species that contain two lone pairs of electrons. Herein, we have prepared the first known stable and isolable free bis-(carbone) pincer framework with a well-defined solid-state structure. This bis-(carbone) ligand is an effective scaffold for forming monometallic (Ni and Pd) and trinuclear heterometallic complexes with Au-Pd-Au, Au-Ni-Au, and Cu-Ni-Cu configurations. Sophisticated quantum-theoretical analyses found that the metal-metal interactions are too weak to play a significant role in upholding these multi-metallic configurations; rather, the four lone pairs of electrons within the bis-(carbone) framework are the main contributors to the stability of the complexes.

Automated summary

Divalent carbon(0) species, carbones, with two lone pairs of electrons have been prepared in this study. The first known stable and isolable free bis-(carbone) pincer framework was synthesized, which serves as an effective scaffold for forming monometallic and trinuclear heterometallic complexes. Quantum-theoretical analyses showed that the stability of these complexes is mainly attributed to the four lone pairs of electrons within the bis-(carbone) framework, rather than metal-metal interactions.