Inner-shell electron spectroscopy and chemical properties of atoms and small molecules

Thomas, T. Darrah

Oregon State University

关键词: Electronegativity;    Photoelectron Spectroscopy;    Photoelectron Spectroscopy, Xps, Inner-Shell Ionization Energies;    Excitation;    Chemical Properties;   

DOI  :  10.2172/946170
RP-ID  :  DOE/ER/15583-1
RP-ID  :  FG02-04ER15583
RP-ID  :  946170

美国|英语

来源: UNT Digital Library

【 摘 要 】

The program has been concerned with gas-phase carbon 1s photoelectron spectroscopy of a number of molecules of potential chemical interest. The primary goals have been to determine carbon 1s ionization energies with a view of relating these to other chemical properties such as electronegativity, acidity, basicity, and reactivity, in order to provide a better understanding of these fundamental properties. The role of electron-donating (methyl) and electron-withdrawing (fluoro) substituents on the carbon 1s ionization energies of substituted benzenes has been studied., and these results have been related to measurements of the reactivities of the same molecule as well as to their affinities for protons (basicity). Opportunities for investigation in unplanned areas have arisen, and the program has been modified to take advantage of these. One has been the realization that, under certain circumstances, inner-shell ionization energies may depend on the molecular conformation. Several examples of this phenomenon have been investigated and it has been shown that this technique provides a tool for the measurement of the energy differences between different conformers of the same substance. The other has been the demonstration that photoelectron recoil can lead to the excitation of vibrational modes that are forbidden in the normal view of photoemission and to rotational heating of the molecule that increases with the energy of the exciting radiation.