On Pentafluoroorthotellurates and Related Compounds

This Review surveys the properties and applications of the pentafluoroorthotellurate ("teflate", OTeF5) ligand and highlights the syntheses of the known teflate-based compounds across the periodic table. Due to the accessibility to several useful teflate transfer reagents and its unique properties, including strong electron-withdrawing character, considerable steric bulk, and stability against oxidation, a variety of intriguing p-block and d-block species have been reported. These encompass highly reactive Lewis acids, versatile weakly coordinating anions, neutral and cationic noble gas compounds, and a wide number of transition metal complexes. The lower analogues of the pentafluoroorthochalcogenate group, OSeF5 and OSF5, are described as well, although fewer examples are known. Recent progress in the derivatization of the OTeF5 group to cis- and trans-PhTeF4O or trans-(C6F5)2TeF3O moieties is also discussed, opening pathways to exciting new research directions.