We can address the question of what happens when a molecule becomes adsorbed onto a surface at two levels; specifically we can aim to identify
- the nature of the adsorbed species and its local adsorption geometry (i.e., its chemical structure and co-ordination to adjacent substrate atoms)
- the overall structure of the extended adsorbate/substrate interface (i.e., the long range ordering of the surface)
The latter topic is covered in detail in Section 6.1, while this section will consider only the local adsorption geometry and adsorbate structure.
Chemisorption, by definition, involves the formation of new chemical bonds between the adsorbed species and the surface atoms of the substrate - basically the same type of bonds that are present in any molecular complex. In considering what type of species may be formed on a metal surface, therefore, it is important not to abandon chemical common sense and, if in doubt, to look for inspiration at the structures of known metal-organic complexes.
Contributors and Attributions
Roger Nix (Queen Mary, University of London)