2-Amino­pyridine and citric acid mixed in 1:1 and 3:1 ratios in ethanol yielded crystals of two 2-amino­pyridine citric acid salts, viz. C5H7N2 +·C6H7O7 − (I) and 3C5H7N2 +·C6H5O7 3− (II). Salt I is formed by the protonation of the pyridine N atom and deprotonation of the central carb­oxy­lic group of the acid, while in II all three carb­oxy­lic groups of the acid are deprotonated and the charges are compensated for by three 2-amino­pyridinium cations.

The title molecule, C11H8F3NO3, adopts a cis configuration across the –C=C– double bond in the side chain and the dihedral angle between the phenyl ring and side chain is 47.35 (1)°. The –COOH group adopts a syn conformation (O=C—O—H = 0°), unlike the anti conformation observed in related maleamic acids. In the crystal, inversion dimers linked by pairs of O—H...O hydrogen bonds are connected via N—H...O hydrogen bonds and C—H...O interactions into (100) sheets, which are cross-linked by another C—H...O interaction to result in a three-dimensional network. The Hirshfeld surface fingerprint plots show that the highest contribution to surface contacts arises from O...H/H...O contacts (26.5%) followed by H...F/F...H (23.4%) and H...H (17.3%).

No abstract