Conductivity anisotropy derived from porphyrin Langmuir-Blodgett films

A new amphiphilic porphyrin copper(II) and its free base are synthesized. They can form condensed and stable monolayers at the water/ air interface. The porphyrin rings are almost perpendicular to the interface due to the single carboxyl. Compared with the UV-Vis spectrum of the solution, that of their Langmuir-Blodgett (LB) films has significant red shifts. The porphyrin LB films exhibit conductivity anisotropy. The dominant conductivities derived from the compressing direction are 2.6 × 10−5 and 8.9 × 10−5 S cm−1, respectively, for porphyrin copper(II) and free base.