Benzene-1,2,4,5-tetra­carb­oxy­lic acid bis­(1,3,7-trimethyl-2,3,6,7-tetra­hydro-1H-purine-2,6-dione)

The asymmetric unit of the title co-crystal, C(10)H(6)O(8)·2C(8)H(10)N(4)O(2), comprises a centrosymmetric benzene-1,2,4,5-tetra­carb­oxy­lic acid (LH(4)) mol­ecule and a mol­ecule of caffeine in a general position. LH(4) is nonplanar, with the dihedral angles between the ring and pendent carb­oxy­lic acid groups being 44.22 (7) and 49.74 (7)°. By contrast, the caffeine mol­ecule is planar (r.m.s. deviation = 0.040 Å). Supra­molecular layers parallel to (-1-10) are sustained by carb­oxy­lic acid O—H⋯O(carbon­yl) and O—H⋯N(imidazole) hydrogen bonds, as well as by meth­yl–carbonyl C—H⋯O inter­actions. These stack via π–π inter­actions between the benzene and imidazole rings [inter-centroid distance = 3.4503 (10) Å].