The 2,4,6-Tris(trifluoromethyl)phenyl Substituent: An Ideal Combination of Steric and Electronic Stabilization

The chemistry of the 2,4,6-tris(trifluoromethyl)phenyl substituent (RF) is reviewed. This ligand combines steric bulk with the possibility of electronic stabilization. Despite the electron-withdrawing nature of the CF3 groups, the electrondonating ability via the lone pairs at the fluorine atoms is the most important factor in the stabilization of low-coordinated main-group derivatives. This is demonstrated by a number of X-ray structure determinations which show significant intramolecular metal-fluorine interactions.