Hydrogen-bonding interactions in the salts 2,4,6-triaminopyrimidin-1-ium sorbate dihydrate, 2,4,6-triaminopyrimidin-1-ium N-phenylantharanilate and 2,4,6-triaminopyrimidin-1-ium p-toluenesulfonate

Three salts, namely, 2,4,6-triaminopyrimidin-1-ium sorbate dihydrate, C 4 H 8 N 5 + ·C 6 H 7 O 2 − ·2H 2 O, (I), 2,4,6-triaminopyrimidin-1-ium N -phenylanthranilate, C 4 H 8 N 5 + ·C 13 H 10 NO 2 − , (II), and 2,4,6-triaminopyrimidin-1-ium p -toluenesulfonate, C 4 H 8 N 5 + ·C 7 H 7 O 3 S − , (III), were synthesized, characterized by X-ray diffraction techniques and their supramolecular interactions investigated. In all three crystal structures, protonation of the pyrimidine moiety occurs at the N1 position and is reflected in a widening of the C—N—C bond angle. In salts (I)–(III), the primary acid–base interaction occurs through a pair of N—H...O hydrogen bonds to give a heterodimeric R 2 2 (8) synthon. Salts (II) and (III) form a discrete centrosymmetric base pair that produces a homodimeric R 2 2 (8) synthon and salt (I) forms a water-mediated base pair resulting in a tetrameric R 4 4 (12) synthon. The supramolecular patterns exhibited by sulfonate salt (III) mimic the patterns of carboxylate salt (II) and both exhibit a DADA array ( D = donor and A = acceptor) quadruple hydrogen-bonded pattern. The crystal structures of salts (I) and (III) are stabilized by offset and face-to-face aromatic π–π stacking interactions, respectively. The resulting architectures in salts (I)–(III) are a supramolecular sheet with a rosette-like architecture in (I), a supramolecular sheet-like architecture in (II) and a three-dimensional supramolecular network in (III).