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

Conjugated compounds associating phenyl or pentafluorophenyl units linked via azomethine 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-H center dot center dot center dot F contacts, pi-pi interactions and furan-perfluorobenzene interactions. The compound with a furan moiety as spacer presents a stacking mode defined by C-H center dot center dot center dot F contacts and pi-pi interactions while the compound based on a furylene-vinylene unit shows a packing pattern exclusively due to strong furan-perfluorobenzene interactions