Electrochemical response of a carbon paste electrode modified with the Methyl-2,4-bis(cyclohexane)dispiro-1,2,3,4,4a,5,6,7-oc-tahydro-(1H,3H)quinazoline-8-carbodithioate ligand Respuesta electroquímica de un electrodo de pasta de carbono modificado con el ligando 2,4-bis(ciclohexano)diespiro1,2,3,4,4a,5,6,7-octahidro-(1H,3H)quinazolina-8-carboditioato de metilo

Abstract

The coordination chemistry of lead(II), an important environmental contaminant, was studied with the nitrogen-sulfur ligand Methyl-2,4–bis(cyclohexane)dispiro-1,2,3,4,4a,5,6,7–octahydro-(1H,3H)quinazoline-8-carbodithioate (LNS). The spectro-scopic evidence (UV/Vis, FTIR), mass spectrometry, thermal analyses (TGA and DSC), indicates the formation of [(LNS)(OH2)(CH3COO)Pb] with lead(II) as well as lead(IV). The LNS ligand was used for the preparation of a carbon paste modified electrode and its electrochemical response was studied, showed an important enhancement for Pb(II) detection that permits lead determination at trace concentrations. Keyword: Chelating agent, lead, lead complexes, carbon paste modified electrode, cyclic voltammetry. Resumen La quimica de coordinacion del plomo(II), un importante elemento quimico contaminante del medioambiente, se estudio utilizando el ligando nitrogeno-sulfurado 2,4-bis(ciclohexano)diespiro-1,2,3,4,4a,5,6,7-octahidro-(1H,3H)quinazolina-8- carboditioato de metilo (L NS). La evidencia espectroscopica (UV/Vis, IRTF), espectrometria de masas, analisis termogravimetrico (TGA y DSC), indican la formacion de un complejo tipo[(L NS)(OH2)(CH3COO)Pb] con plomo(II) y plomo(IV). El ligando (LNS) fue usado en la preparacion de un electrodo de pasta de carbono modificado, y su respuesta electroquimica fue estudiada con buenos resultados hacia de deteccion de plomo(II) en concentraciones traza. Palabras clave: agente quelatante, plomo, complejos de plomo, electrodo de pasta de carbono modificado, voltametria ciclica.