Abstract
Both reflection and transmission high-energy electron diffraction patterns obtained from Langmuir–Blodgett (LB) films of a lightly substituted anthracene derivative are interpreted in terms of a quasi-crystalline molecular packing, or secondary structure, which is consistent with the known primary structure of the molecule. The unit cell is orthorhombic, contains four molecules and probably has space group Pba2. The long axis of the aromatic nucleus lies at an angle of 60 ± 1° to the substrate normal in the LB film.