Molecular and Crystal Structure of Low Melting Nitrotoluene Isomers

The molecular and crystal structures of low melting isomers of nitrotoluene (orto- and meta- derivatives) have been determined. The single crystals of o- and m-isomers have been grown using the miniature zone melting in situ crystallization technique. It is found that m-nitrotoluene undergoes on cooling an order−disorder phase transition from monoclinic to triclinic phase at about 200 K. X-ray diffraction analysis and quantum calculations on the MP2/6-31G** level show that all nitrotoluenes have similar structural parameters close to those found in toluene and nitrobenzene. In crystals of the isomers studied, molecules are linked in sheets by short N−O···H interactions.