The title compound, (C5H7N2)2[Cu(H2O)6](SO4)2·4H2O [systematic name: bis(2-aminopyridinium) hexaaquacopper(II) bis(sulfate) tetrahydrate], comprises axially elongated hexa-aqua-coordinated octa-hedral Cu(II) ions located on an inversion centre, non-coordinating sulfate anions, 2-amino-pyridinium cations and lattice water mol-ecules. The crystal structure is built of successive inorganic and organic layers extending parallel to (001) that are connected by an extensive three-dimensional hydrogen-bonded network of the type O-H⋯O and N-H⋯O, as well as π-π inter-actions [centroid-centroid distance 3.4140 (14) Å, offset 0.277 Å].
Keywords: 2-aminopyridine; crystal structure; hydrogen bonding; organically templated materials; sulfates; π–π interactions.