Abstract
The adsorption of 5,14-dihydro-5,7,12,14-tetraazapentacene (DHTAP) on Cu(110) has been investigated at different temperatures and coverages by means of scanning tunneling microscopy (STM) and low-energy electron diffraction (LEED). Our results show that the interaction of DHTAP with the Cu(110) surface differs considerably from that of pentacene on the same surface. The DHTAP molecules are chemisorbed on the surface via strong Cu-N bonds with an adsorption energy of roughly 3 eV/molecule, twice as high as the value for pentacene. We could identify three different ordered superstructures, which are commensurate with the substrate and characterized by the matrices (6 -1 | 1 2), (7 0 | 1 2), and (6 0 | 1 2), respectively.