Syntheses and Characterization of the Mixed-Valent Manganese(II/III) Fluorides Mn2F5 and Mn3F8

Jascha Bandemehr; Fabian Zimmerhofer; Sergei I Ivlev; Clemens Pietzonka; Kim Eklund; Antti J Karttunen; Hubert Huppertz; Florian Kraus

doi:10.1021/acs.inorgchem.1c01833

Syntheses and Characterization of the Mixed-Valent Manganese(II/III) Fluorides Mn₂F₅ and Mn₃F₈

Inorg Chem. 2021 Sep 6;60(17):12651-12663. doi: 10.1021/acs.inorgchem.1c01833. Epub 2021 Aug 25.

Authors

Jascha Bandemehr¹, Fabian Zimmerhofer², Sergei I Ivlev¹, Clemens Pietzonka¹, Kim Eklund³, Antti J Karttunen³, Hubert Huppertz², Florian Kraus¹

Affiliations

¹ Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany.
² Institut für Allgemeine, Anorganische und Theoretische Chemie, Universität Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria.
³ Department of Chemistry and Materials Science, Aalto University, 00076 Aalto, Finland.

PMID: 34431300
DOI: 10.1021/acs.inorgchem.1c01833

Abstract

We obtained single crystals of the binary mixed-valent fluorides Mn₂F₅ and Mn₃F₈ using a high-pressure/high-temperature approach. Mn₂F₅ crystallizes isotypic to CaCrF₅ in the monoclinic space group C2/c (No. 15), with a = 8.7078(8) Å, b = 6.1473(6) Å, c = 7.7817(7) Å, β = 117.41(1)°, V = 369.80(6) Å³, Z = 4, and mC28 at T = 173 K. Mn₃F₈ crystallizes in the monoclinic space group P2₁ (No. 4) with a = 5.5253(2) Å, b = 4.8786(2) Å, c = 9.9124(4) Å, β = 92.608(2)°, V = 266.92(2) Å³, Z = 2, and mP22 at T = 183 K and presents a new structure type. Crystal-chemical reasoning, CHARDI calculations, and quantum-chemical calculations allowed for the assignment of the oxidation states of the Mn atoms. In both bulk compounds, MnF₂ was present as an impurity, as evidenced by powder X-ray diffraction and IR and Raman spectroscopy.