Abstract

Silver nanoparticles (AgNPs) were synthetized and employed in the SERS measures to study the chemical behavior of Nanoparticles (NPs) when Thiacloprid (Thia) interact in the surface of Ag nanospheres (AgNSp) and Ag nanostars (AgNSt) upon excitation of the system with a 785 nm laser. Experimental results display a tendency that have the deactivation of the localized surface plasmon resonance (LSPR) to induce structural changes in Thia. When AgNSp are used, it is possible to observe a mesomeric effect in the cyanamide moiety, as well when AgNSt are used, it is promoted the cleavage of the methylene bridge in Thia to produce two molecular fragments. To analyze the degradation effect caused by the presence of AgNSt, theoretical calculations based on topological parameters described by the atoms in molecules (AIM) theory, Laplacian of the electron density at the bond critical point (BCP), Laplacian bond order (LBO) and bond dissociation energies (BDE) helped us to propose a bond cleavage centered at -CH2- methylene bridge in Thia. This data supports the proposed bond cleavage, as well the HOMO/LUMO analysis supports where the electron flow occurs to determine the site of bond cleavage.