Lattice-directed construction of metal-organic molecular wires of pentacene on the Au(110) Surface

The construction of metal-organic molecular wires is important for the design of specific functional devices but has been a great challenge for experimental technology. Here we report the formation of one-dimensional metal-organic structures by direct deposition of pentacene molecules on the Au(110) surface with subsequent thermal annealing. These metal-organic molecular wires were systematically explored by scanning tunneling microscopy (STM) and density functional theory calculations. At submonolayer coverage, during annealing at ∼470 K, the adsorbed molecules induce both Au(110)-(1 × 3) surface reconstruction, where two atomic rows are missing every three rows on the Au(110) surface, with the end-to-end pentacene configuration and Au(110)-(1 × 6) surface reconstruction, where five rows are missing every six rows on the surface, with the side-by-side configuration. Further annealing at ∼520 K results in Au-adatom-coordinated metal-organic molecular wires with a new side-by-side configuration of pentacene molecules on the Au(110)-(1 × 6) surface. The Au adatoms linking neighboring pentacene molecules, indicated by bright features in the STM image, were strongly evidenced by the STM simulations. Therefore, metal-organic molecular wires of pentacene on Au(110) were achieved through coordination bonds between native Au atoms and the -CH- groups of pentacene molecules.