Open Access

The asymmetric unit of the title compound, C28H42N2O5·H2O, consists of one half of the organic mol­ecule and one half-mol­ecule of water, both of which are located on a mirror plane which passes through the central C atoms and the hydroxyl group of the heterocyclic system. The hydroxyl group at the central ring is disordered over two equally occupied positions. The six-membered ring adopts a chair conformation, and the 2-hy­droxy­benzyl substituents occupy the sterically preferred equatorial positions. The aromatic rings make dihedral angles of 75.57 (9)° with the mean plane of the heterocyclic ring. The dihedral angle between the two aromatic rings is 19.18 (10)°. The mol­ecular structure features two intra­molecular phenolic O-H...N hydrogen bonds with graph-set motif S(6). In the crystal, mol­ecules are connected via O-H...O hydrogen bonds into zigzag chains running along the a-axis direction.

In the title ternary co-crystalline adduct, C7H14N4·2C6H5NO3, mol­ecules are linked by two inter­molecular O—H⋯N hydrogen bonds, forming a tricomponent aggregates in the asymmetric unit. The hydrogen-bond formation to one of the N atoms is enough to induce structural stereoelectronic effects in the normal donor→acceptor direction. In the title adduct, the two independent nitro­phenol mol­ecules are essentially planar, with maximum deviations of 0.0157 (13) and 0.0039 (13) Å. The dihedral angles between the planes of the nitro group and the attached benzene rings are 4.04 (17) and 5.79 (17)°. In the crystal, aggregates are connected by C—H⋯O hydrogen bonds, forming a supra­molecular dimer enclosing an R66(32) ring motif. Additional C—H⋯O inter­molecular hydrogen-bonding inter­actions form a second supra­molecular inversion dimer with an R22(10) motif. These units are linked via C—H⋯O and C—H⋯N hydrogen bonds, forming a three-dimensional network.