Nian Lin, Hong Kong University of Science and Technology, and colleagues there and at the East China University of Science and Technology, Shanghai, realized that while on-surface polymerization might offer a bottom-up approach for creating macromolecular structures, it is limited by a lack of control leading to disorder and a broad size distribution.

The researchers have functionalized a gold surface with copper porphyrin complexes having both pyridyl and bromine end groups (pictured). They explain that this allows them to template polymerization on the surface taking back control of the process as evidenced by scanning tunneling microscopy. The copper ions, they explain, catalyze the required carbon-carbon bond formation and a kinetic Monte Carlo simulation reveals that it is the rich chemistry of copper that endows the complex with this ability.

The team suggests their findings could give a much-needed push to on-surface synthesis.

• Steering On-Surface Polymerization with Metal-Directed Template,
  Tao Lin, Xue Song Shang, Jinne Adisoejoso, Pei Nian Liu, Nian Lin,
  J. Am. Chem. Soc. 2013.
  DOI: 10.1021/ja311890n