Alterations in the electronic structure of adsorbed zinc(II) etioporphyrin I (ZnEtio) through interaction with bridging oxygen vacancies on TiO2(110) were studied by scanning tunnelling microscopy and spectroscopy at cryogenic temperatures under ultrahigh vacuum conditions. Upon lateral manipulation of ZnEtio molecules above surface oxygen vacancies, the highest occupied molecular orbital shifts away from the Fermi level. The magnitude of the shift rapidly decreased with increasing distance of the molecule from the vacancy, indicating a highly localized interaction

Localized Interaction of Single Porphyrin Molecules with Oxygen Vacancies on TiO2(110). Lackinger, M., Janson, M.S., Ho, W.: Journal of Chemical Physics, 2012, 137[23], 234707