Crystal structure of 2-methyl-1H-imidazol-3-ium 3,5-dicarboxybenzoate

The structure of the title salt, C4H7N2+center dot C9H5O6- (1), is reported. The compound is built from a protonated 2-methylimidazole and a singly deprotonated trimesic acid. Detailed analysis of bond distances and angles for both ions reveals subtle differences compared with their neutral molecule counterpart. Analysis of the crystal packing in compound 1 reveals the formation of undulating chains by the ions through hydrogen bonding. The chains stack along the b axis through pi-pi interactions and interconnect with other chains in an out-of-phase arrangement along the ac plane through further hydrogen-bonding interactions.