Synthesis of a novel thiadiazine derivative and electrochemical properties for Pb2+ transfer across water/1,2-dichloroethane interface

The transfer of Pb2+ facilitated by interfacial complexation with 5-(4-phenoxyphenyl)-6H-1,3, 4-thiadiazin-2-amine (PPTA) at the polarized water/1,2-dicholoroethane (1,2-DCE) interface was investigated by cyclic voltammetry. We synthesized the thiadiazine derivative, PPTA, firstly. The transfer was performed at different metal concentrations and scan rates, and the obtained voltammetric transfer peaks toward Pb2+ ion over other divalent cations (Zn2+, Co2+, Ni2+, Cd2+, Hg2+, and Cu2+) were reversible. The dependence of the half-wave potentials of the Pb2+ ion on the concentration of PPTA in the organic phase indicates that the ion transfer is facilitated by the formation of 1:2 (metal:ligand) complex in the organic phase with the association constant (lgβ2) of (17.1±0.2). © Editorial office of Acta Physico-Chimica Sinica.