Ligands metal binding energy

The X-ray photoelectron spectra of metal complexes of sulphur-containing ligands sulphur 2/ -binding energies. R. A. Walton, Coord. Chem. Rev., 1980, 31, 183-220 (88). 

In contrast to the peak selectivity just discussed, there is evidence that the larger, more flexible, ligands tend to exhibit plateau selectivity - a reflection that a number of the larger metal ions are accommodated by the cryptand without major variation in binding energy. 

Table 4.44. Properties of bicoordinate metal-ligand complexes for M = Ir+ (see Fig. 4.86) binding energy A E and geometrical parameters (bond length Rml...

The binding energies in Table 4.44 show the expected strong preference for anionic over neutral ligands in complexes of the metal cation. However, the geometries and other properties of these complexes reflect strong covalency effects (albeit enhanced by net ionic attraction) that will principally be considered. 

Fig. 10. A SPR Detection realized in a BIAcore system. A fan of polarized light passes a prism and is focused at the interface to an aqueous phase under conditions of total reflection. An evanescent wave enters the solvent phase. If the prism is coated with a thin gold layer at the interface the free electrons in the metal absorb energy from the evanescent wave for a distinct angle, depending on the refractive index of the solvent near the interface. B The gold layer can be modified with, e.g., a carboxydextrane matrix, where catcher molecules can be immobilized by standard chemistry. If a ligand is applied with the aqueous phase it may interact with the catcher and accumulate in the matrix, causing a shift in the resonance angle. If no specific binding occurs the refractive index in proximity of the sensor is less affected...

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