Vince LaVallo

Ligand and Catalyst Design with closo-Carborane Anions 

An intriguing alternative to ubiquitous hydrocarbon ligand R-groups are the organomimetic closo-carboranes, which can be thought of as 3-dimensional analogues of Hückel aromatics. The most common closo-carboranes utilized in ligand design are derived from neutral icosahedral o-carborane clusters (o-C2B10H12). Here we will discuss the first utilization of closo-carborane anions, HCB11H11-1 and HCB9H9-1, as substituents in ligand and catalyst design. Such clusters have distinct and superior properties compared to previously investigated ligands containing o-carborane. The synthesis, reactivity, and properties of a variety of anionic phosphine and N-heterocyclic carbene ligands, as well as their metal complexes, will be discussed.