Although this compound is a polycyclic aromatic hydrocarbon, severe intramolecular steric interactions force the anthracene nucleus to be greatly distorted from planarity, with an end-to-end twist of 66 degrees. Even so, this compound is perfectly stable under ordinary conditions. For a brief communication describing its synthesis, X-ray crystal structure, and physical properties, see "9,18-Diphenyltetrabenz[a,c,h,j]anthracene: A Remarkably Twisted Polycyclic Aromatic Hydrocarbon." R. A. Pascal, Jr., W. D. McMillan, and D. Van Engen, J. Am. Chem. Soc. 1986, 108 5652-5653.