Experimental and theoretical studies of carbazole-based Schiff base as a fluorescent Fe3+ probe

Synthesis of a new (E)-N1-((9-ethyl-9H-carbazol-3-yl)methylene)-5-nitrobenzene-1,2-diamine as a fluorescent chemosensor for selective detection of Fe3+ ion over a number of other metal ions is described. The method for the synthesis of the carbazole Schiff base was based on the condensation of carbazole-3-carbaldehyde with 4-nitro-ophenyldiamine in dimethylformamide in a moderate yield. The structure of the final compound was characterized by 1H NMR, 13C NMR, IR, mass spectrometry, and single crystal X-ray diffraction. The final compound exhibited exceptional selective and sensitive turn-on fluorescence response to the Fe3+ cation.