Abstract
In this contribution, a sensitive colorimetric chemosensor was constructed based on the framework of naphthalimide. And it was characterized by NMR and mass spectroscopic techniques. The solution color changed from yellowish to deep blue with the addition of OH−. The obvious color change can be distinguished by naked eye. Excellent selectivity against other common anions was also observed. Even if the strong Lewis base F− added to the dye solution, no color change was induced. The effects imposed on the obvious color change can be ascribed to the deprotonation of –NH– of bridge unit. The results of structural optimization and molecular orbital calculation uncovered the underlying signal mechanism. Due to the depronotion effect, lowered energy gap (HOMO/LUMO) and electron redistribution leads to the red-shift of longest maximum absorption.
Acknowledgments
This work was supported by the National Natural Science Foundation of China (grant no. 21272060), University Student Renovation Project (grant no. 201410476085), and Program for Innovative Research Team in Science and Technology in University of Henan Province (15IRTSTHN 003). 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).