The formation of metal-free naphthalocyanine (H2Nc) self-assembled monolayers (SAMs) on reconstructed Au(100)hex is investigated by scanning tunneling microscopy (STM) at submonolayer coverage. The STM images show the aggregation of clusters, short stripes, and densely packed islands at the surface. These islands are orientated along two favored surface directions. The molecules’ orientation within these islands is determined. It is shown that the molecules’ axes are aligned parallel to the reconstruction lines along the [011̅] surface direction in both island orientations. When comparing the molecules’ position, the island types are identified as mirror domains. Subsequent thermal annealing induces a slight change in the densely packed island structure. The molecules’ axes are rotated by 5° compared to the reconstruction lines. The offset induces dislocations in the H2Nc structure increasing the unit-cell. A structure model is presented for the densely packed structures before and after annealing. The results are discussed within the context of phthalocyanine (Pc) findings in order to show the influence of the extended side-group system of the H2Nc molecule on the structural formation.

No abstract

No abstract

No abstract

No abstract