As an approach to obtaining molecular semiconductors with high conductivity, it was attempted to lower the activation energy of conduction by enlarging the π-conjugated system in porphyrin materials. An anthraporphyrin (ZnTAnP) has been synthesized for the first time, and the spectroscopic, electrochemical and semiconductive properties have been characterized as a function of increasing molecular size, in the order: tetraphenylporphyrin (ZnTPP), tetrabenzoporphyrin (ZnTBP), tetranaphthaloporphyrin (ZnTNP), and ZnTAnP. With enlargement of the macrocycle, the Q band shifts to the red, and the absolute values of oxidation and reduction potentials become smaller. Room temperature conductivities of air-doped ZnTPP, ZnTBP, ZnTNP, and ZnTAnP thin films are < 10-11, 4 × 10-10, 3 × 10-4 and 1 × 10-7 Ω-1 cm-1, respectively. The smaller conductivity of ZnTAnP appears due to the formation of a stable charge transfer complex with oxygen.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry