Derivados de tiourea como receptores en sensores de Pb(II): descripción teórica y experimental

Thiourea derivatives have been used as receptors in the development of selective electrodes to metallic ions (ISEs). Among the receptors used in the construction of ISEs to Pb(II) ions are: 1benzoyl-3,3-dimethylthiourea (1), 1-(2-furoyl)-3,3-dimethylthiourea (2) and 1-(2-thiophenyl)3,3-dimethylthiourea (3). Although, there are several analytical studies on the performance of those sensors, the development of theoretical models is important to elucidate the differences observed in their response. In this work, the density functional B3LYP and the 6-311G (d, p) basis set was used to calculate the geometry, the electronic structure, the IR spectra, the energies of the HOMO-LUMO orbitals and the global reactivity parameters of these molecules. The calculated parameters were related with those of the analytical response characteristics for the constructed sensors. A good correspondence between theoretical and experimental parameters was found and could be established the order of reactivity: (3)> (1) ≈ (2) for the studied receptors.