Crystal structure of 2,4-diamino-6-oxo-3,6-dihydropyrimidin-1-ium p-toluenesulfonate

Abstract

In the title salt, C4H7N4O+·C7H7O3S−, the 2,6-diamino-4-oxo-1,3-dihydropyrimidin-1-ium cation interacts with the sulfonate group of the p-toluenesulfonate anion via a pair of N—H...O hydrogen bonds, forming a hetero-synthon R22(8) that mimics the role of a carboxylate. The self-assembled cations form a homo-synthon R21(6) motif which is further linked with the sulfonate anion via N—H...O hydrogen bonds to generate an R32(10) ring motif. The three motifs are fused together and extended as supramolecular ribbons along the b-axis direction. Adjacent ribbons are further linked via N—H...O hydrogen bonds to form an annulus, with an R44(20) ring motif, resulting in a tunnel-like arrangement propagating along [010]. There are slipped parallel π–π stacking interactions [inter-centroid distance = 3.6539 (7) Å], between the tunnel-like polymer chains, forming slabs parallel to (100).

Keywords

• crystal structure
• diaminopyrimidines
• triaminopyrimidines
• p-toluenesulfonate
• hydrogen bonding
• N—H...O hydrogen bonds
• π–π stacking interactions