Figure 8
Intermolecular interplanar angle versus shortest cell axis in the crystal structures of 31 of the 32 PAHs analysed by Desiraju & Gavezzotti (1989b) and their classification into four-structure types: β (triangles), γ (crosses), herringbone (HB, rhombi) and sandwich-herringbone (SHB, squares) structures. Orthorhombic structures are highlighted in yellow. The light blue rhomb is the high-pressure monoclinic phase of benzene. Seven structures have been added to the 31 originally classified: the high-pressure forms of pyrene and phenanthrene (blue triangles), benzodicoronene (open red triangle), β-perylene (open red rhomb), pyrene-(II) (open red square) and the orthorhombic polymorph of dibenzanthracene (black square highlighted in yellow). For structural parameters of naphthalene and the polymorphs of phenanthrene and pyrene discussed in the main text, see Table 2. |