Theoretical study of chemosensors for fluoride anion and optical properties of the derivatives of organosilicon 1,8-naphthalimide

The interactions between chemosensors, organosilicon 1,8-naphthalimide derivatives, and different (F−, Cl−, Br−, and AcO−) anions have been theoretically investigated using Density functional theory (DFT) approaches. Theoretical investigations have been performed to explore the optical and electronic properties of the colorimetric fluoride anion chemosensors. It turned out that the unique selectivity of chemosensors for F− is ascribed to their ability of the cleavage of OSi bond of the host sensors. The frontier molecular orbitals (FMOs) analyses have turned out that the vertical electronic transitions of chemosensors and their anions are characterized as intramolecular charge transfer (ICT). The study of substituent effects suggests that the substituted derivatives with nitrobenzene (1), anisole (2), benzo[c][1,2,5]thiadiazole (3), benzo[c]thiophene (4), and 2-phenylthiophene (5) fragments are expected to be promising candidates for colorimetric fluoride anion chemosensors.