Influence of peripheral electron-withdrawing substituents on the conductivity of zinc phthalocyanine in the presence of gases. Part 2: oxidizing gases

Thin layers of zinc hexadecafluorophthalocyanine ZnF16Pc and of zinc phthalocyanine ZnPc were prepared by vapor deposition. Their conductivity was measured during exposures to the reducing gases NH3 and H2 diluted in N2. The conductivity of ZnF16Pc increases in the presence of NH3 whereas ZnPc exhibits no sensitivity to this gas. Correlatively, the sensitivity to H2 is higher for ZnF16Pc than for ZnPc. This behavior is related to redox potentials of the two phthalocyanines. Gas sensing applications are considered.