CHAPTER 5: Main Group Complexes with N-Heterocyclic Carbenes: Bonding, Stabilization and Applications in Catalysis

This chapter describes recent advances in the field of carbene-stabilized main group complexes. While there are many examples known in the literature, those reported herein will be limited to main group complexes that are not stable as stand-alone “free” species, but which require the carbene as a stabilizing ancillary ligand for isolation. For this reason, the majority of complexes presented will be those where the main group element is in a low valent, or low oxidation state. This chapter will take readers on a trip through the s- and p-block elements, beginning with special considerations regarding the structure and bonding in carbene-stabilized main group species. Carbene-supported main group elements from Groups 1 and 2, as well as 13–17, will be described, and applications in catalysis will also be highlighted when appropriate. Specific attention will be given to discussing the relationship between the σ-donating vs. π-accepting properties of the various carbene ligands and the structural, photophysical, and electrochemical properties as well as the reactivity of the resultant main group complexes.