Synthesis and crystal structure of bis[(18-crown-6)oxonium]tetrabromomanganese(II)

A new complex compound, bis[(18-crown-6)oxonium]tetrabromomanganese(II), 2[(H3O)+(18-crown-6)]·[MnBr4]2–, was prepared and studied by X-ray diffraction to reveal its unusual cubic crystal structure, space group Fd\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \bar 3 $$\end{document}, a 20.424 Å, and Z 8. In this crystal structure, the complex cation [(H3O)+(18-crown-6)] the point symmetry \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \bar 3 $$\end{document} position and the anion [MnBr4]2− with the point symmetry 23. The complex cation [(H3O)+(18-crown-6)] has a guest-host structure, and, unlike metal complexes by hydrogen bonds between H3O+ hydrogens and 18-crown-6 oxygens, rather than by coordination bonds. The pyramidal cation H3O+ in this crystal structure is statistically disordered, and the tetrahedral anion [MnBr4]2− is reorientationally disordered.