ELECTROCHEMICAL STUDY OF AZIDE BRIDGED HETEROBIMETALLIC FILMS OF PORPHYRINS: APPLICATION AS AN IMPEDIMETRIC SENSOR

Abstract

In this study, heterobimetallic films of metalloporphyrins, polyCo(II)PP and polyNi(II)PP, linked with azide (polyCoN3NiPP) were immobilized on a glassy carbon electrode. The intense FTIR absorption band at 2056 cm−1, corresponding to the νasy (N3) of the bridged azide, indicates a μ2-coordination mode of polyCoN3NiPP. The electrochemical characterization of the films clearly shows that the order of deposition significantly affects the charge transfer process, correlated to the organized polymeric structure. The linked azide anion shows a reversible wave exclusively in the configuration polyNi(II)PP deposited over a film of polyCo(II)PP. The Nyquist plots of this electrode, using Fe(CN)63−/Fe(CN) 64− as redox probe, demonstrated a lower Rct and higher Kapp than other configurations. This electrode was applied as an impedimetric sensor for sulfite anion.