2-Methyl-3-(4-nitro­phen­yl)acrylic acid

The title compound, C(10)H(9)NO(4), forms R (2) (2)(8) dimers due to inter­molecular O—H⋯O hydrogen bonding in the crystal structure. Two dimers are further linked to each other through two inter­molecular C—H⋯O hydrogen bonds, forming an R (3) (3)(7) ring motif. The nitro groups form an intra­molecular C—H⋯O hydrogen bond mimicking a five-membered ring. As a result of these hydrogen bonds, polymeric sheets are formed. The aromatic ring makes a dihedral angle of 42.84 (8)° with the carboxyl­ate group and an angle of 8.01 (14)° with the nitro group. There is a π-inter­action (N—O⋯π) between the nitro group and the aromatic ring, with a distance of 3.7572 (14) Å between the N atom and the centroid of the aromatic ring.