Fluoride, chloride, and bromide complexation behaviors of carbon and silicon carbide nanotubes functionalized with phenyl-urea/thiourea derivatives: An ab initio investigation

Designed receptors of phenyl-urea and phenyl-thiourea derivatives and their functionalization on (5,5) armchair carbon and silicon carbide nanotubes were investigated for their fluoride, chloride, and bromide complexation behaviors. Structural, energetic, and electronic properties of phenyl-urea derivatives, phenyl-thiourea derivatives, carbon nanotubes functionalized with phenyl-urea derivatives, silicon carbide nanotubes functionalized with phenyl-urea derivatives, carbon nanotubes functionalized with phenyl-thiourea derivatives, and silicon carbide nanotubes functionalized with phenyl-thiourea derivatives, as well as their complexes with studied ions, were systematically computed using an ab initio method. The results reveal that all studied ions can form stable complexes with the receptors via exothermic processes facilitated by hydrogen bonding interactions. Remarkably, the fluoride ion exhibits the strongest complexation interaction with all designed receptors. Furthermore, the electronic properties of the receptors in gas, water, and DMSO phases are significantly altered upon complexation with studied ions. These findings suggest that all receptors display strong potential for halide ion sensing applications.