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.