2-(2,2-Bis-benzylamino-1-cyano-vinyl)-benzonitrile: A Selective Turn-off Fluorescent Cu2+ Sensor

摘要

We report design and synthesis of three 2–(2,2–bis–(alkylamino)– 1–cyano–vinyl)benzonitriles and studied their metal ion sensing property. The Cu~(2+) ion selectively quenches the fluorescence of 2–(2,2–bis–benzylamino–1–cyano–vinyl)–benzonitrile 4 in acetonitrile. The effect of Cu~(2+) ion on the electronic structure of 4 was studied by TD–DFT calculations. The theoretical calculations showed good agreement with the experimental results. The detection limit of Cu~(2+) ion from copper nitrate for the 2–(2,2–bis–benzylamino–1–cyano–vinyl)–benzonitrile was upto 0.05 ppm (0.8 mM). The formation of copper complex of 4 was confirmed by HRMS.