Phase transition in ordered porphyrin layers on iodide modified Cu(1 1 1): An EC-STM study

The self-assembly of meso-tetra (N-methyl-4-pyridyl) porphyrine tetratosylat (H2TMPyP) on an iodide modified Cu(1 1 1) surface has been studied by means of in situ electrochemical-scanning tunneling microscopy (EC-STM). The I/Cu(1 1 1) surface was found to be a good substrate for the self-assembly of highly ordered layers of porphyrin cations. Furthermore, a reversible structural phase transition within the highly ordered porphyrin layer was observed during variation of the electrode potential, as a consequence of changing electronic properties of the substrate.