Structure versus electrical behavior in films of homoassociates of diprotonated meso-tetrakis(4-sulfonato-phenyl)porphyrin

Abstract

The gel-like films obtained from the homoassociation of diprotonated meso-tetrakis(4-sulfonatophenyl)porphyrin show structural changes depending on their water content, which is determined by the affinity for water of the ionic species segregated from the homoassociation process. These materials, in which NaCl or H 2 SO 4 are segregated, were studied and their electrochemical behavior at several water contents was examined. The behavior of humid films was clearly different from dry films. The pH2O value, which determines the separation between the dry and humid behavior, depends on the type of the ionic species segregated in the homoassociation. This is briefly discussed in relation to the design of humidity sensors.