Crystal structure of 2-methyl-1H-imidazol-3-ium hydrogen oxalate dihydrate

Single crystals of the title molecular salt, C4H7N2+center dot HC2O4-center dot 2H(2)O, were isolated from the reaction of 2-methyl-1H-imidazole and oxalic acid in a 1:1 molar ratio in water. In the crystal, the cations and anions are positioned alternately along an infinite [010] ribbon and linked together through bifurcated N-H center dot center dot center dot(O,O) hydrogen bonds. The water molecules of crystallization link the chains into (10 (1) over bar) bilayers, with the methyl groups of the cations organized in an isotactic manner.