Abstract
Two naphthalimide based chemosensors were synthesized. Upon the addition of OH− or F−, the solution color turned from pink to blue due to the proton elimination of N-H/O-H. The electron density increased on the nitrogen atom and enhanced the intramolecular charge transfer, which resulted in a red-shift of the absorption band. This color change was reversible with H+/MeOH addition and can be detected with the naked eye. The selectivity of the two dyes toward OH−/F− compared with other anions was investigated. The underlying signal mechanism was interpreted by the HOMO/LUMO potentials. Significantly lowered energy gap supported the red-shift absorption band.
Funding
This work was supported by the National Natural Science Foundation of China (Grant no. 21272060) and Jianxi Key Lab of Organic Chemistry (Grant no. GFZ-KF-201301). This study was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (Grant no. 2014006660).