Etude de la structure électronique des hydrocarbures linéaires saturés en fonction de leur taille: II. Mécanisme de relaxation électronique durant la photoémission

The core electron binding energies of the alkanes have been measured in the gas and solid phases by high resolution electron spectroscopy (AlK α). They slowly decrease over a range of 0.6 eV with the increasing size of the molecules in the gas phase. This small chemical shift is explained, with the aid of various theoretical models (CNDO/2 and ΔSCF ab initio), as being a consequence of the relaxation energy variations of the electronic shells during the photoemission. In the solid phase, the magnitude of the polarization or extramolecular relaxation energy amounts to about 10 % of the intramolecular relaxation energy.