Anders Fahlman

Molecular Spectroscopy by Means of ESCA II. Sulfur compounds. Correlation of electron binding energy with structure

Electron spectra from an extensive series of sulfur compounds have been studied. A correlation has been established between the observed position of inner electron lines of sulfur and structure. The influence of structure on the electron binding energies is discussed in terms of a calculated atomic charge, based on the concepts of electronegativity and partial ionic character of bonds. The results are useful for the study of bonding and structure in sulfur chemistry, and are applied particularly to the discussion of the sulfur-oxygen bond (S=O).

Charge transfer in transition metal carbides and related compounds studied by ESCA

Abstract Electron spectroscopic measurements of binding energy shifts of Cl s electrons in Group 4 b , 5 b and 6 b carbides and of core electrons in Ti and V compounds are presented. The results are discussed and compared with X-ray spectroscopic investigations and energy band calculations. It is shown that electrons are transferred from the metal to the carbon atoms when a carbide of this type is formed.

Ionization energies in methane and ethane measured by means of ESCA

Abstract Ionization energies for the molecular orbitals in methane and ethane are obtained by means of the ESCA technique. In methane the 2a 1 electrons are found at a binding energy of 23.1 eV; in ethane the 2a 1 level is split up in two levels due to the interaction between the carbon atoms.

The KLL Auger spectrum of fluorine

The KLL Auger spectrum of fluorine (Z=9) has been studied in three different fluoride salts. Five Auger lines are observed in each compound in accordance with extreme LS coupling theory. A cation dependence of the Auger transition energies and line-widths is observed. The energy shifts are in agreement with a theoretical model.

AUGER SPECTRA FOR ELEMENTS OF LOW ATOMIC NUMBER

KLL Auger spectra for the light elements sodium (Z=11) and magnesium (Z=12) have been studied. All five lines predicted by the extremeLS coupling theory are observed. A comparison is made with intensities predicted by the inter-configuration interaction theory ofAsaad. Agreement is obtained for the transition intensities to the three differentKLL configurations; however, theory does not give correct relative intensities within the 2s2 2p4 configuration. The measured Auger energies are compared with those calculated from the semi-empirical expression ofAsaad andBurhop and modified byHörnfeldt et al. Good agreement is obtained when we use electron binding energies measured by the ESCA method.

Chemical shift in Auger spectra

Abstract A chemical shift of several eV has been observed for the Auger transition KL 2 L 3 ( 1 D 2 ) in sulfur corresponding to the two oxidation numbers 6 + and 2 − . Comparison is made with electron spectroscopic measurements of chemical shifts of the sulfur K and L levels.

Structure studies of sulphur compounds by esca

Abstract Results, obtained by means of the ESCA-technique (Electron Spectroscopy for Chemical Analysis), are reported on the correlation between the binding energy of the inner electrons of sulphur and the chemical state and environment, with particular emphasis on the sulphuroxygen bond. A charge-binding energy correlation is established which can be used for the estimation of charge on sulphur in compounds with uncertain structure or composition.

Electron spectroscopic evidence of the thiolsulphonate structure of cystine S-dioxide

Abstract Application of electron spectroscopy (ESCA) has directly and conclusively proved, that cystine S -dioxide possesses a thiolsulfonate structure.

An electron spectroscopic determination of theLI energy in the elements Sodium (Z=11) to Copper (Z=29)

Energies of atomic electrons in theK andL shells of eighteen elements of low atomic numbers have been measured by electron spectroscopy. Tabulated values for theLI energies are shown to be in need of considerable revision. AluminumKα radiation is shown to have high potentialities for ESCA studies.

Excitation lines and multiple ionization in Auger spectra

Satellite lines of a new type and excessively large continuous distributions of energy degraded electrons are observed in theKLL Auger spectra of potassium, chlorine, and sulfur. The lines are tentatively interpreted as due to a process that is characteristic of the atom more than of the entire solid and the excessive number of electrons in the continuous distributions is interpreted as due to multiple ionization.