Hydrogen-bonding patterns in bis(trimethoprim) dipicolinate pentahydrate

In the title compound, 2C(14)H(19)N(4)O(3)(+)center dot C7H3NO42-center dot 5H(2)O, the asymmetric unit contains two trimethoprim cations ( A and B), a dipicolinate anion and five water molecules. One of the picolinate carboxylate groups interacts with cation A via a pair of N-(HO)-O-... hydrogen bonds, forming a ring motif R-2(2)(8). A loop of O-(HO)-O-... hydrogen bonds is formed between four water molecules and the two carboxylate groups to form a supramolecular chain along the a axis. Molecules A and B constitute a base pair via N-(HN)-N-... hydrogen bonds, and these base pairs are cross- linked by N-(HO)-O-... and C-(HO)-O-... hydrogen bonds.