Arene-perfluoroarene interactions in crystal engineering.: Part 3.: Single-crystal structures of 1 : 1 complexes of octafluoronaphthalene with fused-ring polyaromatic hydrocarbons

Molecular complexes of 1:1 stoichiometry of octafluoronaphthalene (OFN) with the polyaromatic hydrocarbons anthracene, phenanthrene, pyrene and triphenylene have been prepared, and their single-crystal X-ray structures determined at 120 K. All of the structures are composed of infinite stacks of alternating, almost parallel molecules of OFN and the hydrocarbons, in contrast to the herringbone or c-type (flattened herringbone) packing of the pure components. It is clearly shown that the stacking motif does not require a close correlation between the molecular geometry of the arene and perfluoroarene species, but is stable over a wide range of differing sizes and shapes. Thus, the arene-perfluoroarene interaction is of general importance as a supramolecular synthon. The molecular geometries of the components are not affected by complexation, indicating the absence of charge transfer in the complexes. The role of close C-H . . .F-C and C-F . . .F-C intermolecular contacts between stacks is discussed. A re-determination of the single-crystal structure of triphenylene at 150 K is also reported, providing a more accurate comparison with that of the 1:1 OFN . triphenylene complex.