Triarylborane substituted naphthalimide as a fluoride and cyanide ion sensor.

Triarylborane substituted naphthalimide 3 was designed and synthesized by the Sonogashira cross-coupling reaction. The electronic absorption and emission spectra of the triarylborane naphthalimide 3 show red shifted absorption and emission as compared to 4-bromonaphthalimide 2. The sensing behaviour of 3 was studied for different anions. The triarylborane naphthalimide 3 selectively detects F(-) and CN(-) ions in the presence of Cl(-), Br(-), I(-) and NO2(-) ions. The effect of F(-) and CN(-) ions on the structure of 3 was studied by performing DFT calculations. The theoretical calculations show good agreement with the experimental results. The detection limits for F(-) and CN(-) were found to be 2.01 × 10(-10) M and 3.94 × 10(-10) M respectively.