Molecular X-ray Spectra of Sulfur and Chlorine Bearing Substances

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.

Distinction and quantification of inorganic sulfur species including thiosulfate by X‐ray fluorescence (WD‐XRF)

“…The fluorescence energies as presented in Table are in good agreement with previously published data from the last 90 years (Figure ). All mean values with the only exception of S Kβ 1 for sulfite (Table ) are within the confidence intervals calculated from the previously published data .…”

“…The fluorescence energies as presented in Table are in good agreement with previously published data from the last 90 years (Figure ). All mean values with the only exception of S Kβ 1 for sulfite (Table ) are within the confidence intervals calculated from the previously published data . For a better comparability of respective fluorescence energies and the possible impact of the historic development of XRF instrumentation, this big amount of 38 data sets was categorised to four time periods: 1920–1949, 1950–1979, 1980–1999 and 2000–2016.…”

“…Energies of X‐ray fluorescence lines for sulfur in different oxidation states: A comparison of values from this work (mean value ± range of dispersion) and previously published data…”

“…All mean values with the only exception of S Kβ 1 for sulfite (Table 3) are within the confidence intervals calculated from the previously published data. For a better comparability of respective fluorescence energies and the possible impact of the historic development of XRF instrumentation, this big amount of 38 data sets was categorised to four time periods: 1920-1949 [7][8][9][10][11][12][13][14][15] , 1950-1979 [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] , 1980-1999 [33][34][35][36][37] and 2000-2016 [6,[38][39][40][41][42][43] . Comparing used instrumentation (see Table S6 for further detailed information) showed that FIGURE 2 Energies of X-ray fluorescence lines for sulfur in different oxidation states: A comparison of values from this work (mean value ± range of dispersion) and previously published data Fluorescence energy (S Kα 1,2 and S Kβ 1 ) and S Kβ′/S Kβ 1 ratio of peak height versus elemental sulfur mass fraction that the main difference between historical and modern devices is their availability.…”

Specific Adsorption of a Bisulfate Anion on a Pt(111) Electrode. Ultrahigh Vacuum Spectroscopic and Cyclic Voltammetric Study

“…There is a great deal of data on electronic configurations of tetrahedral species of the AB 4 type, like HSO 4or SO (B), with 32 valence electrons. [59][60][61][62][63][64][65] From these data we assume that the configuration for bisulfate is (4a 1 ) 2 (3t 2 ) 6 (5a 1 ) 2 (4t 2 ) 6 (1e) 4 -(5t 2 ) 6 (1t 1 ) 6 . In principle, the orbitals of the highest energy for HSO 4 -, 1t 1 , 5t 2 , and 1e, are nonbonding, consisting predomi-nantly of oxygen 2p orbitals.…”