Two-dimensional nanotemplates as surface cues for the controlled assembly of organic molecules

Controlled two-dimensional assembly of organic molecules can be successfully realized by means of surface nanotemplates that provide surface cues for assembly upon adsorption. Examples of such templates are nanostructured surfaces and organic porous networks. in this review, we discuss the formation and use of such templates for controlled molecular assembly. The formation of the organic porous network is typically based on non-covalent interactions, e.g., hydrogen bonds, dipole-dipole interactions, metal-organic coordination bonds together with substrate-mediated molecular interactions. The pores of the network can act as hosts for specific organic molecules. The chemical structure of the molecular building blocks of the porous network has a primary effect on the shape, size, and chemical reactivity of the cavities. Long-range mesoscale reconstructions can also be employed as surface nanotemplates based on the selective adsorption of atomic or molecular species at specific surface sites. Scanning tunneling microscopy is the key tool to study the formation of the nanotemplates as well as the effect of the template in the growth of the ordered organic structures. The reported studies contribute to build the rationale in the design and fabrication of two-dimensional organic networks. The topic covered in this review represents an important challenge in nanotechnology since these findings might have a wide range of applications, e.g., in electronics, sensing, and bio-recognition.