The crystal structure of m-tolidine dihydrochloride

Abstract

The crystal structure of m-tolidine dihydrochloride has been determined by two-dimensional Fourier methods. The two phenyl rings in each molecule are mutually inclined at an angle (70.6 ) which brings the two methyl groups into contact. The length of the diphenyl link is 1.525 A. The interatomie distances between carbon atoms in the phenyl rings vary considerably; some of them are unusually short. The molecules lie in sheets which are bound together by ionic forces between the NIt+ groups and the C1-ions. Streaks which occur in photographs of certain specimens are attributed to multiple twinning.