Surface ionization coordination chemistry

Whether at equilibrium or not, the surface atoms of a solid are underbonded so they must complete their coordination by forming bonds with HjO, OH, or a ligand from the solution. The surface species can ionize in response to changing pH to produce a surface charge that is responsible for further interactions with solution species. Stumm (1992) summarizes the most important models of the chemistry of the solid/solution interface. 

Given the complicated and variable nature of CO binding to palladium surfaces, it is not surprising that, until fairly recently, theoretical studies have struggled to adequately model palladium surface chemistry. The molecules PdCO and Pd2CO (bridging GO coordination) have been evaluated as models for GO on a palladium surface in a number of studies. The core ionization spectra of these complexes have been calculated and compared to experimental data for... 

Correlation charts can be developed for particular types of coordination. Nitrogen Is electrons from nitrates, nitrites, and azides are readily identified in this way since the chemical shifts differ by several electron-volts. Electron spectroscopy is also useful in determining ionization potentials and in surface chemistry. The average penetration of a photoelectron is in the range 20-50 A. 

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