Surface Science Approaches to Molecular Nanostructures

Abstract

The self-assembly of large organic adsorbates on solid surfaces is driven by subtle energy balances between adsorbate-adsorbate and adsorbate-substrate interactions. Understanding these interactions is a key step towards the rational design and large-scale production of ordered, two-dimensional organic nanostructures which may find applications in (opto)electronic devices, sensors and surface catalysts. Due to the reduced dimensionality at surfaces, new phenomena arise which can only be understood by combining both experimental and theoretical methods and knowledge from chemistry and physics. In this short review, we illustrate the richness of surface chemical phenomena at the hand of four case studies which are selected to highlight the potential as well as the current limitations in controlling molecular self-assembly at surfaces.

Atomistic insight into the adsorption site selectivity of stepped Au(111) surfaces

“…This has hitherto prevented a detailed understanding of atomic and molecular self-assembly phenomena on vicinal Au͑111͒ surfaces that have highlighted a striking adsorption site selectivity. [7][8][9][10][11] For instance, polycyclic aromatic hydrocarbons preferen-tially adsorb on kinks, then on step lines facing fcc regions and finally on those facing hcp ones 8,9,12 and a similar behavior is observed for C 60 . 11 For the adsorption of 1-nitronaphthalene on Au͑111͒, a tentative explanation of the step selectivity was proposed by Vladimirova et al 13 who performed density-functional-theory ͑DFT͒ calculations which assumed that the region beneath the step was not reconstructed.…”

Long-range surface faceting induced by chemisorption of PTCDA on stepped Ag(111) surfaces

“…Such "manipulations" can induce changes of sticking probability, chemical bonding, or orientation of molecular adsorbates, or can lead to potentially drastic changes of surface reactivity and catalytic efficiency. They can also be used to create regular patterns or superstructures on a surface [1,2], the properties of which can then be investigated [3] or taken as (nanostructured) template for the further growth of molecules with tailored properties [4][5][6][7] or as tailored interface in a metal-organic device.…”

Controlling the Dimensionality of On-Surface Coordination Polymers via Endo- or Exoligation

“…Organic and metal–organic networks − generated on metal surfaces have been shown to alter the electronic properties of the substrate and to serve as templates for the formation of host–guest complexes, − giving rise to complex forms of aggregation.…”