3-Nitro­benzaldehyde

Polymorph I of the title compound, C7H5NO3, is approximately planar: the dihedral angle between the benzene ring and the nitro group is 10.41 (4)° and the aldehyde O atom deviates from the ring plane by 0.165 (1) A. In the crystal, aromatic π–π stacking inter­actions are observed [centroid–centroid separation = 3.7363 (5) A].