Self-Assembly and Local Manipulation of Au-Pyridyl Coordination Networks on Metal Surfaces

Using scanning tunnelling microscopy (STM), we demonstrate that Au-pyridyl coordination can be used to assemble two-dimensional coordination network structures on metal surfaces. The polymorphism of the coordination network structures can be manipulated at both the micro-and nanoscale. Using the same organic ligand, we assembled two distinct polymorphic network structures, which were assisted by threefold Au-pyridyl coordination on Ag(111) with predeposited Au atoms (alpha-network), and by twofold Au-pyridyl coordination on Au(111) (beta-network), respectively. Specifically on the Au(111) surface, single-oriented beta-network domains as large as approximate to 400 nm were selected by thermal annealing. We ascribe this global control strategy to distinct Au bonding modes tuned by moleculesubstrate interactions. Using an STM tip, we succeeded in creating a-network domains (approximate to 10 nm) locally within the homogeneous b-network domain areas on Au(111) in a controlled manner.