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Molecular X-ray Spectra of Sulfur and Chlorine Bearing Substances

Published online by Cambridge University Press:  06 March 2019

G. Andermann
Affiliation:
University of Hawaii, Honolulu, Hawaii 96822
H. C. Whitehead
Affiliation:
University of Hawaii, Honolulu, Hawaii 96822
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Abstract

The interpretation and use of x-ray photon spectra of substances containing second row elements has utilized a number of theoretical models. These models may be divided into three basic categories, namely, the isolated atom model, various molecular models, and a number of solid state models, it is the purpose of this paper to examine critically the validity and limitations of molecular models for interpreting published x-ray photon spectra and spectra obtained by this group on chlorine and sulfur bearing substances.

Chlorine and sulfur bearing substances were chosen for at least three important reasons. First, a great deal of published experimental data already exists on the Kα, Kβ, and L2, 3 transitions of these substances. Second, motivated in part by the long standing controversy concerning possible 3d orbital participation in the bonding of second row elements, there are extensive quantum mechanical calculations for ions containing sulfur and chlorine via simple molecular orbital concepts. Thirdj the availability of accurate photoelectron spectroscopic data on these substances now permits a detailed quantitative comparison of x-ray photon transitions with quantum mechanical calculations.

Detailed evaluation along these lines indicates that for many substances the theoretically calculated energy values are frequently within a few electron volts (or less) of the experimentally observed energies. This study, therefore, tends to substantiate a viewpoint suggested by some recently; namely, that for many substances the starting point in interpreting most of the basic features of soft x-ray spectra should be based upon molecular bonding approaches.

Type
Research Article
Copyright
Copyright © International Centre for Diffraction Data 1970

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References

Nagel, D. J., “Interpretation of Valence Band X- ray Spectra,” Advances in X- ray Analysis 13, 182-236, Plenum Press, New York (1970).Google Scholar
Best, P. E., “Electronic structures from X- ray Spectra. II. Mostly ClO- 3 and ClO- 4 ,” Jour. Chem. Phys. 49, 2797 (1968).Google Scholar
Urch, D. S., “Direct Evidence for 3d-2pπ-Bonding in Oxy-anions,” Jour. Chem. Soc. A1969, 3026 (1969).Google Scholar
Fischer, D. W., “Use of Soft X- ray Band Spectra for Determining Molecular Orbitalstructure. I. Vanadium Octahedral and Tetrahedral Sites,” Preprint, Air Force Materials Lab. Publication (1970).Google Scholar
Manne, R., “Molecular Orbital Interpretation of X- ray Emission Spectra: Simple Hydrocarbons and Carbon Oxides,” Jour. Chem. Phys. 52, 5733 (1970).Google Scholar
Glen, G. L. and Dodd, C. G., “Use of Molecular Orbital Theory to Interpret X- ray K-absorption Spectral Data,” Jour. Appl. Phys. 39, 5372 (1968).Google Scholar
Gohshi, Y., “Simple Two-Crystal Spectrometer and Its Application to X- ray Spectrochemical Analysis,” Advances in X- ray Analysis 12, 518, Plenum Press, New York (1969).Google Scholar
Andermann, G., Research Grant Proposal, National Science Foundation, “Development of X- ray Spectroscopic Methods” (1968).Google Scholar
Hanke, B. I. and Smith, E. N., “Valence Electron Band Analysis by Ultra-Soft X- ray Fluorescence Spectroscopy,” Jour. Appl. Phys. 37, 922 (1966).Google Scholar
Manne(5) has just shown the importance of ESCA measurements in the interpretation of the Kβ spectra of simple hydrocarbons observed by Mattson and Ehlert (39). The method of interpretation described in the text was developed independently, the emphasis is different, and, of course, includes a simultaneous evaluation of Kθ and Lbands.Google Scholar
Manne, R., “Molecular Orbitals and Inner-Electron-Shell chemical Shifts for Sulfur and Chlorine Oxy-anions,“ Jour. Chem. Phys. 46, 4645 (1967).Google Scholar
For a historical introduction see Compton and Allison (13). For a thorough review of more recent studies, Faessler's reports (14) need to be consulted.Google Scholar
Compton, A. H. and Allison, S. K., “X- rays in Theory and Experiment,” 2nd ed., Van Nostrand Co., Inc., New York (1935).Google Scholar
Faessler, A., “X- ray Spectraand Chemical Combination,” in Landolt- Bornstein Zahlenverte und Funktionen, 6th ed. , Vol. I, Atom-und Molekular physik, Pt. 4, Kristalle, 769868 (1955).Google Scholar
See Best (2) for a discussion of Schnopper‘s work.Google Scholar
Wentzel, A. G., “The Complex structure of X- ray Fluorescence Spectra, “ Z. Physik 31, 445 (1925) ; b. Druyvesteyn, M. J., “Das Röntgenspek'trum zweiter Art,” ibid. 43, 707 (1927).Google Scholar
Parratt, L. G., “Electronic Band structure of Solids by X- ray Spectroscopy,” Rev. Mod. phys. 31, 616 (1959).Google Scholar
Faessler, A. and Mühle, P., “Raman Lines in Compton Scattering,” Phys. Rev. Letters 17, 4 (1966).Google Scholar
Faessler, A. and Wiech, G., “The Occurrence of a Satellite in X- ray Emission Band Spectra,” Phys. Letters 27A, 11 (1968).Google Scholar
Gohshi, Y., “Chemical Effects on X- ray Emission Spectra,” unpublished results (1968).Google Scholar
Tomboulian, D. H., “The Experimental Methods of Soft X- ray Spectroscopy and the Valence Band Spectra of the Light Elements,” in Handbuch der Physik 30, 246304, S., Flugge, editor, Springer- Verlag, Berlin (1957).Google Scholar
Fisher, D. W. and Baun, W. L., “The Influence of Sample Self-Absorption on Wavelength Shifts and Shape Changes in the Soft X- ray Region: The Rare-Earth M Series,” Advances in X- ray Analysis 11, 230-240, Plenum Press, New York (1968).Google Scholar
See e.g., Fischer, D. W., “Chemical Bonding and Valence State-Non Metals,” Advances in X- ray Analysis 13, 159-181, Plenum Press, New York (1970).Google Scholar
As an illustration of using, <μ>2, i.e., ΣC2 ij for correlating theory with experiment, Manne's recent calculations (5) on hydrocarbons, etc. should be consulted.2,+i.e.,+ΣC2+ij+for+correlating+theory+with+experiment,+Manne's+recent+calculations+(5)+on+hydrocarbons,+etc.+should+be+consulted.>Google Scholar
Ballhausen, C. J. and Gray, H. B., “Molecular Orbital Theory,” W. A. Benjamin, Inc., New York, 272 pp. (1965).Google Scholar
While the lifting of the degeneracy of core electrons for less than t symmetry in terms of energy values must be very small, a point well recognized by Manne(11) and Best (2), the proper use of selection rules, particularly with regard to polarization, is viewed as essential.Google Scholar
For application in the infrared see Dows, D. A.., “Physics and Chemistry of Organic Solid State,” Chapter 11 and Supplemental Review, Vol. I, John Wiley and Sons, N. Y. (1963); for uv-visible see McClure, D. S., “Electronic Spectra of Molecules and Ions in Crystals,” Solid State Physics, Advances in Research and Applications, Volume 9, Academic Press, N. Y. (1959).Google Scholar
Fabian, D. J., Editor, “Soft X- ray Band Spectra,” Academic Press, New York (1968).Google Scholar
Santry, D. P. and Segal, G. A., “Approximate Self- Consistent Molecular Orbital Theory IV. Calculations on Molecules Including Elements Sodium through Chlorine,” Jour. Chem. Phys. 47, 158 (1967).Google Scholar
Siegbahn, K., et al., “Electron Spectroscopy for Chemical Analysis,” Air Force Materials Lab. Technical Report AFML-TR-68-189 (1968).Google Scholar
a. Ibid., Appendix 1, p. 219.Google Scholar
b. Ibid, p. 92-94.Google Scholar
For the use of Koopman's theorem see Best (2,40).Google Scholar
Brown, R. D., et al., “Effect of Ionic Lattices on Electronic Structures of Polyatomic Ions. II. Sulfate,” Theor. Chim. Acta 11, 1 (1968).Google Scholar
See for example, Mitra, S. S., “Vibration Spectra Solids,” Solid State Physics, Advances in Research and Applications, Volume 13, Academic Press, New York (1962).Google Scholar
Iwasaki, I., et al., “A New Spectrophotometric Method for the Determination of Small Amounts of Chloride using the Mercuric Thiocyanate Method,” Bull. Chem. Soc. Japan 29, 860 (1956).Google Scholar
Heal, H. G., “The Decomposition of Solid Potassium Perchlorate by 50 Kilovolt X- rays,” Can. Jour. Chem. 31, 91 (1953).Google Scholar
Henke, B. L., private communications.Google Scholar
Cotton, F. A., “Chemical Applications of Group Theory,” Interscience Publishers, New York (1963).Google Scholar
a. Bishop, D. M., Randic, M. and Morton, J. R., “Electronic Structure of Sulfate, Thiosulfate, and Related Ions. I. Calculation of Molecular Orbital Energy Levels,” Jour. Chem. Phys. 45, 1880 (1966);Google Scholar
b. Bishop, D. M., “Molecular Orbital Energy Levels for ‘the Sulfate Ion,” Theor. Chim. Acta 8, 285 (1967).Google Scholar
Mattson, R. A. and Ehlert, R. C., “Carbon Characteristic X- rays from Gaseous Compounds,” Jour. Chem. Phys. 48, 5465 (1968).Google Scholar
Best, P. E., “Comment on the Use of Koopman's Theorem in Photo-electron Spectroscopy,” unpublished results.Google Scholar