Low-temperature solvothermal fluorination method and synthesis of La4Ni3O8Fx oxyfluorides via the La4Ni3O8 infinite-layer intermediate.

A novel facile solvothermal fluorination method was developed for metastable oxyfluorides preparation by filling anion vacancies in parent structures. High solubility of XeF 2 in acetonitrile and polarity of the solvent allowed for lower reaction temperature. The validity of the method was demonstrated by the preparation of a known oxyfluoride, SrCoO 2. 5 F 0.5 , at unprecedented low temperature (100 ​°C). Additionally, two new oxyfluorides with idealized stoichiometry of La 4 Ni 3 O 8 F 1 and La 4 Ni 3 O 8 F 2 , were prepared by the solvothermal fluorination via the La 4 Ni 3 O 8 infinite-layer intermediate. The proposed method allows preparation of metastable oxyfluorides, utilizes only inexpensive commercial autoclaves and can potentially find widespread utilization in materials synthesis. A facile solvothermal fluorination method was developed for metastable oxyfluorides preparation, which allowed the synthesis of new La 4 Ni 3 O 8 F 2 oxyfluoride. Image 1 [ABSTRACT FROM AUTHOR]