Open Access

Augusto Rivera, Jicli José Rojas, Jaime Ríos-Motta, Michael Bolte

• In the crystal of the title co-crystalline adduct, C8H16N4·C8H9ClO, (I), prepared by solid-state reaction, the mol­ecules are linked by inter­molecular O—H⋯N hydrogen bonds, forming a D motif. The aza­adamantane structure in (I) is slightly distorted, with N—CH2—CH2—N torsion angles of 10.4 (3) and −9.0 (3)°. These values differ slightly from the corresponding torsion angles in the free aminal cage (0.0°) and in related co-crystalline adducts, which are not far from a planar geometry and consistent with a D2d mol­ecular symmetry in the tetra­aza­tri­cyclo structure. The structures also differ in that there is a slight elongation of the N—C bond lengths about the N atom that accepts the hydrogen bond in (I) compared with the other N—C bond lengths. In the crystal, the two mol­ecules are not only linked by a classical O—H⋯N hydrogen bond but are further connected by weak C—H⋯π inter­actions, forming a two-dimensional supra­molecular network parallel to the bc plane.