Host-guest co-assembly on solid surfaces investigated by scanning tunneling microscopy

Abstract

The host-guest assembly on solid surface is a representative bottom-up approach to build up functional molecular nanostructures, and has attracted great attention in nanoscience and nanotechnology. With the great feature to get <italic>in-situ</italic>, real-time and real-space surface and interface structure information with sub-molecular resolution, scanning tunneling microscopy (STM) has been widely used to explore the host-guest co-assemblies on solid surfaces and reveal the underlying mechanism of the host-guest assembly process. Host and guest molecules can interact in different modes to form the host-guest assemblies. A common mode is that the host molecules self-assemble into two-dimensional nanoporous networks with well-ordered voids which can be filled with suitable guest molecules. Secondly, guest molecules can epitaxially assemble on the monolayer of host molecules to form a second layer with the structure mirroring that of host molecule adlayer. In some special cases, the nanostructures formed by host molecules can coordinately adjust themselves to accommodate guest molecules with different size and shape. Herein, we review the recent progress of the construction of host-guest co-assemblies on solid surfaces.