A theoretical study describing the sensing mechanism of the novel triarylborane substituted naphthalimide molecule

Theoretical methods (DFT/TD-DFT) were applied to study the sensing mechanism of triarylborane naphthalimide. The free-energy and binding-energy change revealed more feasibility and binding affinity of fluoride in comparison to cyanide anion. FMO revealed the absence of the intramolecular charge transfer (ICT) character in the molecular receptor 3; however, the anion added products (3CN and 3F) showed the presence of ICT that is responsible for inducing the fluorescence quenching. Furthermore, the electrophilic nature of the boron atom has been explained via natural population analysis, which indicates that the boron site is active for the nucleophilic addition of cyanide and fluoride anions.