A facile synthesis of 2,3,6,7-tetrabromonaphthalene diimides toward new π-extended naphthalene diimides

A 2,3,6,7-tetrabromonaphthalene diimide (2) was readily synthesized in high yield from 2,3,6,7-tetrabromonaphthalene dianhydride by an improved dehydrohalogenation-based imidization reaction. The further nucleophilic aromatic substitution (SNAr) reaction of 2 with potassium cyanocarbonimidodithioate afforded a new π-extended naphthalene diimide (1), which exhibits n-type behavior in organic transistors and interesting response to F− among halide anions in solutions.