1968/06/01 by Neil Bartlett · 118 citations
Chemistry · Pharmacology, Toxicology and Pharmaceutics · Materials Science · #Inorganic Fluorides and Related Compounds #Fluorine in Organic Chemistry #Silicone and Siloxane Chemistry #Oxidizing agent #Chemistry #Transition metal #Oxide #Fluorine #Ligand (biochemistry) #Crystallography #Inorganic chemistry #Organic chemistry #Catalysis
paper · doi:10.1002/anie.196804331
published in Angewandte Chemie International Edition in English 7(6), 433-439
openalex publication_date 1968/06/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/25
Abstract Some of the transition metal hexafluorides demonstrate an astonishing oxidizing power. In particular may be mentioned PtF 6 , which is capable of oxidizing molecular oxygen or xenon, a process requiring an electron affinity, E(PtF 6 ), > −156 kcal·mole −1 . From a comparative study of all of the hexafluorides of the third transition series the electron affinity is seen to increase regularly in the sequence WF 6 < ReF 6 < OsF 6 < IrF 6 < PtF 6 . The increase in E with unit increase in atomic number of M appears to be ≈ −20 kcal·mole −1 . On the other hand the ability of the hexafluorides to accept F − decreases along this series. This effect enables IrF 6 to be more effective than PtF 6 in the generation of nitrogen oxide trifluoride, ONF 3 , by the oxidative fluorination of nitrosyl fluoride, ONF. Both PtF 6 and IrF 6 interact spontaneously with ONF or O 2 NF to generate fluorine, at or below room temperature. The decrease in F − ‐acceptor ability along the series, which stands in sharp contrast to the increase in electron affinity, suggests that ligand crowding increases sharply across the series from WF 6 to PtF 6 . This accords with the observed decrease in molecular volume along the series, both in the hexafluorides and in the MF 6 − salts. It is clear from this comparison that the species IrF 6 and PtF 6 are close to a minimum volume for this series. The oxide pentafluorides ReOF 5 and OsOF 5 are similar in oxidizing ability to their respective hexafluorides but are poorer F − acceptors. Evidently the ligand crowding in MOF 5 molecules is greater than in MF 6 .