9-Benzyl-6-benzyl­sulfanyl-9H-purin-2-amine

In the title compound, C₁₉H₁₇N₅S, the dihedral angles between the purine ring system (r.m.s. deviation = 0.009 Å) and the S-bound and methyl­ene-bound phenyl rings are 74.67 (8) and 71.28 (7)°, respectively. In the crystal, inversion dimers linked by pairs of N—H...N hydrogen bonds generate R₂²(8) loops. C—H...N inter­actions link the dimers into (100) sheets.

9-Amino­acridin-10-ium 4-amino­benzo­ate dihydrate

The asymmetric unit of the title hydrated salt, C₁₃H₁₁N₂⁺·C₇H₆NO₂⁻·2H₂O, consists of two independent 9-amino­acridinium cations, two 4-amino­benzoate anions and four water mol­ecules. Both 9-amino­acridinium cations are essentially planar, with maximum deviations of 0.034 (1) and 0.025 (2) Å, and are protonated at the pyridine N atoms. The 4-amino­benzoate anions are approximately planar, with dihedral angles of 9.16 (19) and 5.4 (2)° between the benzene ring and the carboxyl­ate group. In the crystal, the two independent anions are connected by N—H...O hydrogen bonds, forming a layer parallel to (100). The layers are connected through the cations by N—H...N and N—H...O hydrogen bonds. The water mol­ecules, which form O—H...O hydrogen-bonded chains along the b-axis direction, connect the anions and the cations by O—H...O, N—H...O and C—H...O hydrogen bonds. The crystal structure also features π–π inter­actions [centroid–centroid distances = 3.6343 (9)–3.8366 (10) Å] and a C—H...π inter­action.

2,6-Di­amino-4-(4-chloro­phen­yl)-1-methyl-1,4-di­hydro­pyridine-3,5-dicarbo­nitrile

In the title compound, C₁₄H₁₂ClN₅, the di­hydro­pyridine ring adopts a shallow boat conformation. The dihedral angle between the plane of this ring and that of the chloro­benzene ring is 69.15 (15)°. In the crystal, mol­ecules are linked by N—H...N and N—H...Cl hydrogen bonds, generating (001) sheets.

2,6-Di­amino-4-chloro­pyrimidinium 4-carb­oxy­butano­ate

In the title mol­ecular salt, C₄H₆ClN₄⁺·C₅H₇O₄⁻, the cation is essentially planar, with a maximum deviation of 0.037 (1) Å for all non-H atoms. The anions are self-assembled through O—H...O hydrogen bonds, forming a supra­molecular zigzag chain with graph-set notation C(8). In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxyl­ate O atoms of the anion via a pair of N—H...O hydrogen bonds with an R₂²(8) ring motif. This motif further self-organizes through N—H...O and O—H...O hydrogen bonds, generating an array of six hydrogen bonds, the rings having graph-set notation R₃²(8), R₂²(8), R₄²(8), R₂²(8) and R₃²(8). In addition, another type of R₂²(8) motif is formed by inversion-related pyrimidinium cations via N—H...N hydrogen bonds, forming a two-dimensional network parallel to (101).