On the Relation Between Core Electron Binding Energies and Atomic Charge

Abstract

It is suggested that the term, a, describing the difference between gas phase and solid state XPS data is related to the molar polarizability P by the general expression a = b p−1/3 + c From previously obtained values of the parameters b and c (b= 8.30 eV cm mol^−1/3 and c= 4.15 eV) we can derive the binding energy of gaseous carbon atoms, E_b = 296.4 eV. The close agreement with the experimentally found E_b = 296.2 eV is regarded as a validification of the above-mentioned formula and also of the concept of atomic charge.

By using literature data of core electron binding energies for a series of alkanes and their corresponding polarizabilities we have derived parameters of the above-mentioned relation, b = 8.1 eV cm mol^−1/3 and c = 3.34 eV. The fair agreement is regarded as favouring the model used.

In order to perform these latter operations we have made ab initio calculations of the mean atomic charges of the alkanes.

Key Words:

• XPS
• core electron binding energies
• molar polarizabilities
• atomic charge