Specific interaction modes in the crystal structures of oligofluorinated tolanes featuring additional electron donor and acceptor groups

A series of partially fluorinated and specifically para-substituted tolanes (1–4) have been synthesized via palladium-catalyzed Sonogashira cross-coupling reaction. The single-crystal structures have been determined by X-ray diffraction. The molecules adopt a geometry being more or less disturbed from planarity due to crystal packing effects. The packing structures are characterized by the formation of molecular stacks achieved through different modes of π⋯π interaction and being accomplished by other types of weak interactions including hydrogen bonds as well as bromo and in particular fluoro involved contacts.