A second monoclinic polymorph of 2,4-dimethylanilinium chloride

A second monoclinic polymorph of 2,4-dimethylanilinium chloride, C8H12N+·Cl−, (I), is reported. The unit-cell dimensions differ from those of the first reported monoclinic form, (II) [Yao (2010). Acta Cryst. E66, o1563]. Nevertheless, both compounds crystallize in the monoclinic space group P21/n. As in (II), the protonated amine group in (I) acts as a hydrogen-bond donor to the chloride ion, forming three N—H...Cl hydrogen bonds. The result is a two-dimensional network in the ac plane. The difference in the hydrogen-bond pattern is that in (I) only 12-membered rings are formed whereas in (II), eight-membered and 16-membered rings are formed.