Hydrogen-bonded supramolecular motifs in trimethoprim–terephthalate–terephthalic acid (2/1/1)

Abstract

In the title compound [2,4-di­amino-5-(3,4,5-tri­methoxy­benzyl)­pyrimidin-1-ium terephthalate terephthalic acid], 2C14H19N4O3+·C8H4O42−·C8H6O4, the trimethoprim mol­ecule is protonated at one of the pyrimidine N atoms. The terephthalate anion and terephthalic acid mol­ecule are centrosymmetric. The carboxyl­ate groups of the terephthalate anion form double hydrogen bonds of type N—H⋯O, resulting in a fork-like interaction with the protonated di­amino­pyrimidine rings.