Porphyrinoids at surfaces
Macrocyclic compounds based on porphyrinoid compounds, are often under the spotlight by virtue of their inspiring biological, photophysical, and photochemical properties, being frequently recognized due to their role in energy metabolism and light harvesting in photosynthesis. They have potential in great number of technological such as photocatalysis, nonlinear optics, molecular photovoltaics, spintronics, biological imaging and sensing, have undoubtedly expanded their use. Interestingly enough, the properties of porphyrinoid compounds can be modulated by structural modifications in the different positions of the peripheral substituents, as well as in the heterocyclic macrocycle, where the metal center directly affects to their electronic and magnetic properties.
Modified macrocycles
Porphyrins and phthalocyanines studied have been largely studied on surfaces as promising structural units to assemble functional layers and nanostructures due to their high versatility and the possibility to incorporate metal ions into the inner macrocycle, giving rise to different reactivity, electronic and magnetic properties, depending on the metal center or the functionalization of the macrocycle. However, on-surface investigations of critical aspects that might affect their properties, such as macrocycle modifications involving the replacement of one or more pyrrolic nitrogens with carbon (carbaporphyrins) or a heteroatom (heteroporphyrins), are scarce to date.
