In the title compound, C15H10ClNO3, a substituted chalcone, the dihedral angle between the benzene rings is 5.1 (7)°. The nitro group makes a dihedral angle of 12.5 (3)° with the benzene ring to which it is attached. In the crystal, weak C-H⋯O inter-actions link the mol-ecules into a one-dimensional array along [010]. The crystal studied was an inversion twin, with a refined ratio for the twin ...

The mol-ecule of the title compound, C(17)H(16)O(3), exists in the E conformation with respect to the central C=C bond, is almost planar(r.m.s. deviation = 0.003 Å) and has an intra-molecular O-H⋯O hydrogen bond, which generates an S(6) ring. In the crystal, mol-ecules are linked by C-H⋯O inter-actions.

In the title compound, C(15)H(10)ClFO, the fluoro-substituted benzene ring forms a dihedral angle of 44.41 (6)° with the chloro-substituted benzene ring. The only significant directional bonds in the crystal are weak C-H⋯π inter-actions.