1-Chloro-2-nitrobenzene: N—O...Cl halogen bonds and aromatic π–π stacking, and thermal vibrations in the vicinity of the melting point

The crystal structure of 1-chloro-2-nitro­benzene, C6H4ClNO2, is made up of mol­ecules which are linked by N—O⋯Cl halogen bonds. These mol­ecular chains are involved in aromatic π–π stacking; the inter­molecular O⋯Cl distance is 3.09 Å. Such short halogen bonds are not common. A rigid-body analysis including the non-rigidly attached rigid group provides the mean-square amplitudes of the mol­ecular translations and librations, and of the inter­nal torsional vibrations of the nitro group. The results reveal the driving role of the torsional vibrations of the nitro group in the phase transition to the liquid phase.