N—H...O and O—H...O hydrogen bonds in crystal engineering: trimethoprim hydrogen glutarate

Abstract

In the title compound, C14H19N4O3+·C5H7O4−, trimethoprim (TMP) is protonated. In the glutarate anion, one of the two carboxyl­ic acid groups is deprotonated while the other exists as —COOH. The carboxyl group of the hydrogen glutarate ion makes a hydrogen-bonding pattern with N—H groups of the trimethoprim cation which is similar to the carboxyl­ate group (of Asp-27 of DHFR)-trimethoprim cation interaction observed in trimethoprim–DHFR complexes. Two TMP cations and two hydrogen glutarate anions are arranged about an inversion center so that complementary DDAA arrays of quadruple hydrogen-bonding patterns are formed. The hydrogen glutarate ion bridges the 2-amino and 4-amino groups of TMP. There are also carboxyl–carboxyl­ate hydrogen-bonding interactions involving a head-to-tail arrangement of hydrogen glutarate ions which leads to hydrogen-bonded supramolecular ribbons.