Synthesis and crystal structure of methylammonium dicitratoborate

Methylammonium dicitratoborate CH3NH3[(C6H6O7)2B] (I) was synthesized for the first time. The crystal structure of the compound was studied by X-ray crystallography. Crystals of I are triclinic, space group P\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \bar 1 $$\end{document}, a = 8.9726(3) Å, b = 10.1039(3) Å, c = 10.7231(4) Å, α = 66.894(1)°, β = 85.347(1)°, γ = 84.991(2)°, V = 889.57(5) Å3, Z = 2, ρcalcd = 1.580 g/cm3. Crystals of I are built up from large dicitratoborate anions with a spiran structure and methylammonium cations. The crystals have a layered structure. A hydrogen-bond system is formed by seven independent contacts O(N)-H⋯O.