Preponderant role of pentafluorophenyl moieties for tuning the electronic properties of extended benzodifuran-azomethine derivatives

From a central 3,7-bis(perfluorophenyl)-BDF unit, the extension performed with electron acceptor perfluorophenyl groups and/or electron donor N,N-dimethylamino groups via an imine link leads to symmetrical AAA and DAD or dissymmetrical DA materials. X-Ray solid state structures were also studied, revealing a strong involvement of the perfluorinated phenyl group in the arrangement. The two symmetrical derivatives show emission properties in solvents which are quenched in the solid state whereas the DA derivative shows opposite behavior with Aggregation Induced Emission (AIE) properties.