Two furan-2,5-dicarboxylic acid solvates crystallized from dimethylformamide and dimethyl sulfoxide.

Furan-2,5-dicarboxylic acid (FDCA) has been ranked among the top 12 bio-based building-block chemicals by the Department of Energy in the US. The molecule was first synthesized in 1876, but large-scale production has only become possible since the development of modern bio- and chemical catalysis techniques. The structures of two FDCA solvates, namely, FDCA dimethylformamide (DMF) disolvate, C6 H4 O5 ·2C3 H7 NO, (I), and FDCA dimethyl sulfoxide (DMSO) monosolvate, C6 H4 O5 ·C2 H6 OS, (II), are reported. Solvate (I) crystallizes in the orthorhombic Pbcn space group and solvate (II) crystallizes in the monoclinic P-1 space group. In (I), hydrogen bonds form between the carbonyl O atom in DMF and a hydroxy H atom in FDCA. Whilst in (II), the O atom in one DMSO molecule hydrogen bonds with hydroxy H atoms in two FDCA molecules. Combined with intermolecular S...O interactions, FDCA molecules form a two-dimensional network coordinated by DMSO.