A novel sodium manganese fluorooxalate crystal Na2Mn2(C2O4)2.5F·2H2O: Synthesis, structure, optical and thermal properties

• Published in: Journal of solid state chemistry 2024-12, Vol.340, p.125031, Article 125031
• Main Authors: Ji, Sen, Kang, Lei, Han, Yanyang, Liu, Shanshan, Liu, Ye, Yang, Xin, Feng, Kai
• Format: Article
• Language: English
• Subjects: 2H2O; Birefringent; Crystal structure; Fluorooxalate; Na2Mn2(C2O4)2.5F; Solvothermal method
• ISSN: 0022-4596
• DOI: 10.1016/j.jssc.2024.125031

A novel three-dimensional sodium manganese fluorooxalate, Na2Mn2(C2O4)2.5F·2H2O, has been obtained by an ionic-liquid-assisted solvothermal method. Na2Mn2(C2O4)2.5F·2H2O crystallizes in the triclinic P1‾ space group with unit cell parameters of a = 7.9129(4) Å, b = 8.8497(4) Å, c = 8.9252(5) Å, α = 74.623(4) o, β = 72.361(5) o, γ = 78.193(4) o, and Z = 2. The basic structural units are Mn1O6F and Mn2O5F polyhedra, which are linked by sharing C2O4 groups and F atoms to build a three-dimensional framework [Mn4(C2O4)5F2]∞34− with Na+ and H2O occupying the pores. The band gap obtained by UV–Vis–NIR diffuse reflectance is 3.24 eV. In addition, Na2Mn2(C2O4)2.5F·2H2O delivers a moderate birefringence of 0.064@550 nm. A novel three-dimensional fluorooxalate Na2Mn2(C2O4)2.5F·2H2O delivers a moderate birefringence. [Display omitted] •A new fluorooxalate compound Na2Mn2(C2O4)2.5F·2H2O is solvothermally synthesized.•Na2Mn2(C2O4)2.5F·2H2O presents a three-dimensional framework [Mn4(C2O4)5F2]∞34−.•Na2Mn2(C2O4)2.5F·2H2O delivers a moderate birefringence of 0.064@550 nm.