Competition between π–π or furan–perfluorophenyl stacking interactions in conjugated compounds prepared from azomethine connections

Conjugated compounds associating phenyl or pentafluorophenyl units linked viaazomethine bonds to a central furan or furylene–vinylene moiety have been synthesized. The crystal structures of compounds end capped with perfluorophenyl units are analyzed in terms of intermolecular interactions involving the C–HF contacts, π–π interactions and furan–perfluorobenzene interactions. The compound with a furan moiety as spacer presents a stacking mode defined by C–H–F contacts and π–π interactions while the compound based on a furylene–vinylene unit shows a packing pattern exclusively due to strong furan–perfluorobenzene interactions.