Bis[4-(dimethyl-amino)-pyridinium] octa-aqua-chloridolanthanum(III) tetra-chloride trihydrate.

The title organic-inorganic salt, (C(7)H(11)N(2))(2)[LaCl(H(2)O)(8)]Cl(4)·3H(2)O, consists of two 4-(dimethyl-amino)-pyridinium and one [La(H(2)O)(8)Cl](2+) cations, four chloride anions and three solvent water mol-ecules. In the crystal, the various units are connected by N-H⋯Cl, O-H⋯Cl, O-H⋯O and N-H⋯O hydrogen bonds, forming a network of alternating organic and inorganic layers. The 4-(dimethyl-amino)-pyridinium cations stack along the c axis, while the inorganic layers lie parallel to the ac plane. The chloride anions are located between these entities, forming hydrogen bonds with the NH atom of the pyridinium ions and the water mol-ecules. There are also C-H⋯Cl hydrogen bonds present involving one of the 4-(dimethyl-amino)-pyridinium cations, resulting in the formation of a three-dimensional supra-molecular architecture.