N—H...O, O—H...O hydrogen-bonded supramolecular sheet formation in the bis(2-aminoanilinium) fumarate, 3-methylanilinium hydrogen fumarate and 4-chloroanilinium hydrogen fumarate salts

Abstract

In bis(2-aminoanilinum) fumarate, 2C6H9N2+·C4H2O42−, (I), the asymmetric unit consists of two aminoanilinium cations and one fumarate dianion, whereas in 3-methylanilinium hydrogen fumarate, C7H10N+·C4H3O4−, (II), and 4-chloroanilinium hydrogen fumarate, C6H7ClN+·C4H3O4−, (III), the asymmetric unit contains two symmetry-independent hydrogen fumate anions and anilinium cations with a slight difference in their geometric parameters; the two salts are isostructural. In (II) and (III), the carboxylic acid H atoms of the anions are disordered across both ends of the anion, with equal site occupancies of 0.50. Both the 4-chloroanilinium cations of (III) are disordered over two orientations with major occupancies fixed at 0.60 in each case. The hydrogen fumarate anions of (II) and (III) form one-dimensional anionic chains linked through O—H...O hydrogen bonds. Salts (II) and (III) form two-dimensional supramolecular sheets built fromR44(16),R44(18),R55(25) andC22(14) motifs extending parallel to the (010) plane, whereas in (I), an (010) sheet is formed built from twoR43(13) motifs, twoR22(9) motifs and anR44(18) motif.