Experimental and theoretical studies of carbazole-based Schiff base as a fluorescent Fe$^{3+}$ probe

Authors : Hakan KANDEMİR, Abdulkadir KOÇAK, Süreyya Oğuz TÜMAY, Bünyemin ÇOŞUT, Yunus ZORLU, İbrahim Fazil ŞENGÜL

Pages : 221-236

View : 17 | Download : 7

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :Synthesis of a new insert ignore into journalissuearticles values(E);-N1-insert ignore into journalissuearticles values(insert ignore into journalissuearticles values(9-ethyl-9H-carbazol-3-yl);methylene);-5-nitrobenzene-1,2-diamine as a fluorescent chemosensor for selective detection of Fe$^{3+}$ 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-o-phenyldiamine in dimethylformamide in a moderate yield. The structure of the final compound was characterized by $^{1}$H NMR, $^{13}$C NMR, IR, mass spectrometry, and single crystal X-ray diffraction. The final compound exhibited exceptional selective and sensitive turn-on fluorescence response to the Fe$^{3+}$ cation. The fluorescent intensity of the final compound was increased 20-fold and the stoichiometry ratio of the final compound to Fe$^{3+}$ was 1:1. The association constant and detection limit for Fe$^{3+}$ ion were predicted from fluorescence titrations as insert ignore into journalissuearticles values(1.36 $\pm $ 0.09);.10$^{4}$ M$^{-1}$ and 1.0 to 6.0 $\mu $M, respectively. The photophysical behavior of the compound was further explored by DFT methods. The predicted UV-Vis spectrum by TDDFT calculations was compared to the observed absorption spectrum of the targeted compound.
Keywords : Schiff base, carbazole, Fe ^ 3 ion, sensor, fluorescence enhancement, TD DFT calculations