A detailed refinement of the crystal and molecular structure of anthracene

Abstract

A detailed refinement of Mathieson, Robertson & Sinclair's X-ray crystallographic data for anthracene is described. The many calculations needed were carried out on the Manchester University electronic computer. The difference maps indicate some channelling of the electrons along the lines of the bonds. The anisotropie vibrations of the carbon atoms are interpreted in terms of anisotropic translational and rotational oscillations of the molecules. The magnitudes of the angular oscillations agree well with those inferred from Raman spectra. C-C bond lengths with e.s.d.'s of about 0.004 A and bond angles with e.s.d.'s of about 12' are obtained. Close intermolecular approaches explain a very slight buckling of the molecules.