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) wit h the polyaromatic hydrocarbons anthracene, phenanthrene, pyrene and triphe nylene have been prepared, and their single-crystal X-ray structures determ ined at 120 K. All of the structures are composed of infinite stacks of alt ernating, almost parallel molecules of OFN and the hydrocarbons, in contras t 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 perfluoro arene species, but is stable over a wide range of differing sizes and shape s. 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-crys tal structure of triphenylene at 150 K is also reported, providing a more a ccurate comparison with that of the 1:1 OFN . triphenylene complex.