Crystal structure of tris-(2-methyl-1H-imidazol-3-ium) benzene-1,3,5-tri-carboxyl-ate.

The structure of the title salt, 3C(4)H(7)N(2) (+)·C(9)H(3)O(6) (3-) (1), is reported. The compound is formed with three 2-methyl-imidazolium cations and a fully deprotonated trimesic acid. The structure is disordered over two orientations, which were refined using a split model (90.99: 9.01occupancy ratio). Analysis of bond distances and angles reveals the differences and similarities between compound 1 and the previously published 2-methyl-1H-imidazol-3-ium 3,5-di-carb-oxy-benzoate structure [Baletska et al., (2023 ▸). Acta Cryst. E79, 1088-1092] and tris-(2-methyl-1H- imidazol-3-ium) 5-carb-oxy-benzene-1,3-di-carboxyl-ate 3,5-di-carb-oxy-benzoate [Asprilla-Herrera et al. (2025 ▸). Acta Cryst. E81, 303-309], as well as the neutral counterparts of the ions [Tothadi et al. (2020 ▸). ACS Appl. Mater. Inter-faces, 12, 15588-15594; Hachuła et al. (2010 ▸). J. Chem. Crystallogr. 40, 201-206]. The crystal packing analysis reveals the formation of hydrogen-bonded two-dimensional networks perpendicular to the [111] vector, where neighbouring planes inter-act via extensive π-π stacking.