Filling a Niche in "Ligand Space" with Bulky, Electron-Poor Phosphorus(III) Alkoxides

The chemistry of phosphorus(III) ligands, which are of key importance in coordination chemistry, organometallic chemistry and catalysis, is dominated by relatively electron-rich species. Many of the electron-poor P^III ligands that are readily available have relatively small steric profiles. As such, there is a significant gap in "ligand space" where more sterically bulky, electron-poor P^III ligands are needed. This contribution discusses the coordination chemistry, steric and electronic properties of P^III ligands bearing highly fluorinated alkoxide groups of the general form PR_n (OR^F )_3-n , where R=Ph, R^F =C(H)(CF₃ )₂ and C(CF₃ )₃ ; n=1-3. These ligands are simple to synthesize and a range of experimental and theoretical methods suggest that their steric and electronic properties can be "tuned" by modification of their substituents, making them excellent candidates for large, electron-poor ligands.