In the last issue of Synthetic Metals a review paper appeared co-authored by Corentin Pigot and Frédéric Dumur, two researchers from Aix-Marseille University (“Molecular engineering in 2D surface covalent organic frameworks: Towards next generation of molecular tectons - A mini review” Synthetic Metals 260 (2020) 116265).
This paper covers principle aspects of molecular engineering performed directly on well-defined metal surfaces – a fascinating research area which only emerged a few years ago. Using classical approaches of organic synthesis it is possible to fabricate oligomers, 1D macromolecules and 2D covalent organic frameworks (COFs) directly on single crystalline surfaces of metals such as Au or Ag. The preferable approach is to synthesize a multifunctional molecule (molecules) which could polymerize (oligomerize) on metallic substrate surface through different types of couplings, yielding ordered 2D supramolecular aggregations. It should be noted that surface-confined reactions may proceed differently than reaction of the same molecules carried out in homogenous conditions or even in classical heterogeneous catalytic conditions. The topology and supramolecular organization of surface-confined products can be modified by changing the crystallographic plane to which the substrates are exposed, doping of this surface with a different metal (in such a manner 2D metal organic frameworks (MOsF) can be formed), changing the reaction temperature etc. Especially spectacular results are obtained by combining the fabrication of these 1D or 2D nanoobjects with scanning tunneling microscopy, which frequently provides images of molecular resolution.
This review should be of special interest for researchers working in organic and molecular electronics because many of the fabricated covalent organic frameworks (COFs) are of semiconducting nature. It also provides valuable information to materials chemists, surface chemists and physicists, catalysis and STM specialists. The presented results can be a source of inspiration for the design and elaboration of a large variety of COFs exhibiting desired properties and devoted to specific applications.
-Professor Adam Pron, Editor, Synthetic Metals
Warsaw University of Technology Faculty of Chemistry, Poland
Molecular engineering in 2D surface covalent organic frameworks: Towards next generation of molecular tectons - A mini review is freely available to download for 12 months.