2-Hydr­oxy-5-nitro­benzaldehyde

The title compound, C(7)H(5)NO(4), is essentially planar, with a maximum deviation from the mean plane of 0.0116 (11) Å for the hydr­oxy O atom. The mol­ecular and crystal structure are stabilized by intra- and inter­molecular inter­actions. An intra­molecular O—H⋯O hydrogen bond generates a six-membered ring, producing an S(6) ring motif. The C—H⋯O inter­actions result in the formation of C(5) chains and R (2) (2)(8) rings forming an approximately planar network parallel to (10[Image: see text]). These planes are inter­connected through π–π inter­actions [centroid–centroid distance 3.582 (2) Å].