4-(Dimethyl­amino)­pyridinium octa­aqua­erbium(III) tetra­chloride monohydrate

In the title compound, (C(7)H(11)N(2))[Er(H(2)O)(8)]Cl(4)·H(2)O, the asymmetric unit consists of one 4-(dimethyl­amino)­pyridinium and one octa­aqua­erbium cation balanced by four Cl(−) anions, and one water mol­ecule. The 4-(dimethyl­amino)­pyridinium cation is protonated at the pyridine N atom. The dimethyl­amino group (C/N/C) lies close to the plane of the pyridinium ring, making a dihedral angle of 4.5 (3)°. In the crystal, the [Er(H(2)O)(8)](3+) cations are linked via O—H⋯O and O—H⋯Cl hydrogen bonds, forming two-dimensional networks propagating in the ab plane. These networks are linked via O—H⋯O and O—H⋯Cl hydrogen bonds, forming a three-dimensional network. The 4-(dimethyl­amino)­pyridinium cations are located in the cavities and are linked to the framework via N—H⋯Cl, C—H⋯O and C—H⋯Cl hydrogen bonds.