A salt of pyridine-2,3-dicarboxylic (quinolinic) acid with cytosine was obtained wherein a proton was transferred from a carboxyl group of quinolinic acid to a ring N atom in the cytosine molecule. Significant interactions involving O…H contacts were identified in the quinolinate and cytosinium ions.

To broaden the community and encourage researchers to use photocrystallographic methods, review articles, such as that of Hatcher et al.[(2024). Acta Cryst. C80, 585–600], showing the fundamentals of the approaches, most significant examples of such studies, but also guiding the reader through various stages of sample preparation and experiment planning, are very much needed.

Three salts, namely, 2,4,6-triaminopyrimidin-1-ium sorbate dihydrate, 2,4,6-triaminopyrimidin-1-ium N-phenylanthranilate and 2,4,6-triaminopyrimidin-1-ium p-toluenesulfonate were synthesized and characterized by X-ray diffraction techniques and their hydrogen-bonding and π–π stacking interactions investigated.

2,4,6-Triaminopyrimidine is an interesting and challenging molecule due to the presence of multiple hydrogen-bond donors and acceptors. Four new salts have been synthesized and characterized by single-crystal X-ray diffraction techniques and their noncovalent interactions and supramolecular patterns have been investigated.