Core-Fluorinated Naphthalene Diimides: Synthesis, Characterization, and Application in N-Type Organic Field-Effect Transistors

A series of difluoro- and tetrafluoro-substituted naphthalene diimides (NDIs) were synthesized by halogen exchange reactions of corresponding bromo-NDIs with CsF in dioxane. Two strong electron acceptor molecules 6 and 8 with low-lying LUMO energy levels of -4.27 and -4.54 eV were obtained, starting from tetrafluoro-NDI. Organic field-effect transistors (OFETs) based on these fluorinated NDIs were fabricated by vapor deposition, exhibiting n-channel field-effect character under ambient conditions with the highest mobility of 0.1 cm(2) V(-1) s(-1).