Abstract
The title compound (systematic name: 2-mercaptoethanaminium chloride), C(2)H(8)NS(+)center dot Cl(-), the hydrochloride salt of cysteamine, in contrast to the previously reported triclinic polymorph [Kim et al. (2002). Polyhedron, 21, 225-228], crystallized in the monoclinic crystal system. In the crystal, the cysteaminium cations are linked to the chloride anions via one S-H center dot center dot center dot Cl and three N-H center dot center dot center dot Cl hydrogen bonds. Two-dimensional slab-like networks are formed, which are stacked in [100]. This arrangement is similar to that observed in the triclinic polymorph.