Cocrystallization of melaminium levulinate monohydrate.

Crystals of 2,4,6-triamino-1,3,5-triazin-1-ium levulinate (4-oxopentanoate) monohydrate, C(3)H(7)N(6)(+).C(5)H(7)O(3)(-).H(2)O, are formed via self-assembled hydrogen bonding by cocrystallization of melamine and levulinic acid. Two N-H.N hydrogen bonds and four N-H.O hydrogen bonds connect two melaminium entities such that each of two pairs of N-H.O bonds bridges two H atoms belonging to the amine groups of two different melaminium cations via the carbonyl O atom of one levulinate molecule.