Surface polymerization: Small 5/2009

The cover image shows a rendering of conjugated poly(para-phenylene) epitaxially grown at the surface of Cu(110) by the Ullmann reaction. The diiodobenzene monomer is dosed onto a substrate held at 500 K. Upon arrival at the substrate, the C–I bonds are catalytically cleaved, and the produced copper-bound phenylene intermediates diffuse on the surface until meeting together and coupling through a C–C bond, subsequently producing straight polymer lines along the [1–10] direction. The formation of these straight lines is demonstrated, as well as the formation of zigzag lines and macrocycles produced by varying the structure of the monomer (1,4- or 1,3-diiodobenzene). For more information, please read the Full Paper “Synthesis of Polyphenylene Molecular Wires by Surface-Confined Polymerization” by F. Rosei et al., beginning on page 592.