This literature discussion is based on a paper describing the ligand-based reductive elimination of a diphosphine from a thorium compound (Organometallics, 2017, ASAP). The thorium compound contains two bidentate NHC ligands providing an opportunity to discuss the coordination of these ligands. The ligand-based reduction is very subtle and would be challenging for students to pick up without some guidance. The compound undergoing reductive elimination also presents an excellent introduction into magnetic nonequivalence and virtual coupling. In addition, the compounds presented in this paper provide the opportunity to do electron counting on f-block compounds.
Upon completing this LO students should be able to
- Use the CBC method to count electrons in the thorium compounds in this paper
- Describe the bonding interaction between a metal and a NHC ligand
- Discuss magnetic nonequivalency and virtual coupling
- Describe ligand-based reductive elimination and rationalize how it occurs in this system