π-Sufficient heteroaromatic compounds fused naphthalimide unit as novel solvatochromic fluorophores

The carbazoles 1 and dibenzofurans 2 having naphthalimide unit were synthesized by the cross coupling reaction of 4-bromonaphthalimide 3 with aniline and phenol derivatives followed by the intramolecular cyclization, respectively. The chromophores 1c and 2c substituted methoxy group exhibited the strong fluorescence solvatochromism.