Skip to main content
NCBI home page
ACS AuthorChoice logoLink to ACS AuthorChoice
. 2024 Oct 14;15(42):10576–10582. doi: 10.1021/acs.jpclett.4c02329

Local and Symmetry-Resolved Electronic Structure of Liquid Dimethyl Sulfoxide from Resonant Inelastic Soft X-ray Scattering

Lothar Weinhardt †,‡,§,*, Dirk Hauschild †,‡,§, Ralph Steininger †, Constantin Wansorra †,§, Wanli Yang ∥, Clemens Heske †,‡,§
PMCID: PMC11514774  PMID: 39401783

Abstract

graphic file with name jz4c02329_0006.jpg

Dimethyl sulfoxide (DMSO) is an important polar solvent that derives its unique properties from the lone pair and the strong polar bond at the sulfinyl functional group. To derive the local and symmetry-resolved electronic structure of liquid DMSO, we have used resonant inelastic soft X-ray scattering (RIXS) maps at the S L2,3, C K, and O K edges. The experimental data are compared to calculations of spectra based on density functional theory, which allows a detailed analysis of the molecular orbitals throughout the molecule. In the RIXS maps, we find the signature of molecular-field splitting of the S 2p core levels, vibronic coupling, and ultrafast nuclear dynamics on the time scale of the RIXS process.

Dimethyl sulfoxide (DMSO) is a commonly used highly polar solvent. It dissolves a wide range of both polar and nonpolar organic and inorganic compounds and has a comparatively low toxicity, which has led to its widespread use. DMSO has a trigonal pyramidal structure (see Figure S1) with a lone pair at the sulfur atom. Its advantageous properties are strongly defined by the sulfinyl functional group in which the nature of the bond between sulfur and oxygen plays a crucial role. This bond has been intensively investigated, mostly on the basis of density functional theory (DFT) calculations, and described with both double-bond and zwitterionic characteristics.1−3 On the experimental side, the structure of liquid DMSO has been studied using X-ray and neutron diffraction4,5 as well as nuclear magnetic resonance spectroscopy.3

To probe the electronic structure of DMSO, X-ray spectroscopy in the hard6,7 and soft6,8−12 X-ray range has been employed. In an early pioneering study by Sze et al.,6 the X-ray absorption (XAS) spectra of gas phase DMSO were collected at the S L2,3, S L1, C K, O K, and S K edges with a first tentative assignment of spectral features. In a recent S K XAS study, combined with density functional theory (DFT) calculations of the spectra, a signature of hydrogen bonding in liquid DMSO was observed.7 All other recent soft X-ray studies used XAS, X-ray emission spectroscopy (XES), and/or resonant inelastic X-ray scattering (RIXS) at the O K edge to probe different aspects of DMSO from the viewpoint of the sulfinyl oxygen. O K RIXS studies of pure liquid DMSO focused on the S–O bond8 as well as the molecular orbital symmetry, exploiting the angular anisotropy of RIXS.10 Furthermore, the hydrogen-bonding network in DMSO/water mixtures was investigated using XAS9,12 and RIXS.9

In this study, we probe all accessible sites of the molecule by employing RIXS (as well as nonresonant XES) at the S L2,3, C K, and O K edges, in combination with DFT calculations, to derive the first complete picture of the electronic structure of liquid DMSO.

To understand the spectral features in our RIXS maps, we first discuss the experimental nonresonant O K, C K, and S L2,3 XES spectra (black) of DMSO in Figure 1, together with DFT-based simulations of the spectra (blue). The calculated intensities and energies of the individual transitions are shown as colored vertical lines, while the solid blue spectrum was calculated after broadening with Voigt line profiles. The Gaussian widths were kept constant for all transitions (corresponding to an assumed constant instrumental resolution). For the S L2,3 edge, the strongest emission lines are well separated, which allows us to choose the Lorentzian widths separately for each emission line. For the N and O K edges, this is not the case, and as a simple approximation, Lorentzian widths were chosen to increase linearly toward lower emission energies (to account for variations in the lifetimes of the involved core and valence holes13). To align the position of the HOMO (14a′) transition with the experimental data at each edge, the calculated spectra needed to be shifted by only small amounts (<1 eV). The theoretical energy scales for all edges were then stretched by a factor of 1.06 to align with the experiment over the full energy range. For the experimental C K and S L2,3 XES spectra, contributions from higher orders of the O K (for C K) and C K (for S L2,3) emission, excited by higher orders and/or harmonics of the beamline, were subtracted. The energy axes for the O K, C K, and S L2,3 edges are aligned in Figure 1 such that features originating from the same final state are aligned, as also indicated by the dashed vertical lines.

Figure 1.

Figure 1

Open in a new tab

Nonresonant O K (top), C K (center), and S L2,3 (bottom) XES spectra of DMSO. Experimental spectra (black) are shown in comparison with DFT-based calculations of the spectra (blue). The latter are shown as colored vertical lines, illustrating the intensities and energies of the individual valence hole final states (14a′ to 7a′, as labeled next to the respective lines for O K, C K, and S L3). Theoretical spectra after broadening with Voigt line profiles are shown as solid blue lines.

The three spectra give a quite comprehensive picture of the occupied valence orbitals of DMSO, spreading over an energy range of >20 eV. Except for a few distinct differences (which will be discussed further below), the calculations are in very good agreement with the experimental spectra. This allows us a detailed assignment of the spectral features and a discussion of the spectral intensities based on the iso-density surfaces in Figure 2 and the Löwdin population analysis14 of the involved orbitals in Table S1. The main aspects of this discussion are a suitable local symmetry (p-type for K emission and s- or d-type for L2,3 emission) and the overlap of the orbitals at the respective atomic sites.

Figure 2.

Figure 2

Open in a new tab

Energy diagram and iso-density surfaces (iso-surface value of 0.05 e/Å3) of the occupied and three lowest unoccupied ground state valence orbitals of DMSO. The nonrelativistic S 2p core orbitals are illustrated in the red box at the bottom right.

While this is straightforward for O K and C K XES with a single core level, the situation for S L2,3 XES is more complex. In DMSO, the S 2p core levels experience both spin–orbit and molecular-field splitting.15−17 Because the spin–orbit splitting of ∼1.2 eV18,19 is much larger than the molecular-field splitting ΔEMF, which is ∼0.15 eV in our case (see below), mixing of states with different j values can be neglected16 and splitting into three levels, i.e., one 2p1/2 level and two 2p3/2 levels, is expected. This was discussed in detail by Gel’mukhanov et al. for the S 2p photoemission and L2,3VV Auger spectra of H2S,15,16 giving the wave functions for the molecular-field split 2p3/2 levels as a linear combination ψ = Inline graphic + Inline graphic of atomic eigenfunctions Inline graphic while the wave function ψ = Inline graphic of the 2p1/2 level is undisturbed.16 Coefficients A and B, as well as ΔEMF, can be determined analytically as a function of the S 2p ionization potentials I(S 2px), I(S 2py), and I(S 2pz), calculated without taking the spin–orbit splitting into account.16 Using this approach and the ionization potentials from our StoBe calculations, we estimate a molecular-field splitting ΔEMF of 0.15 eV for the S 2p3/2 levels in DMSO, and we derive the wave functions of the 2p1/2 and 2p3/2 levels. Using the 2p orbitals without spin–orbit splitting (see the iso-density surfaces in Figure 2) as a basis, we obtain Inline graphic = Inline graphic, Inline graphic = Inline graphic + Inline graphic + Inline graphic and Inline graphic = Inline graphic + Inline graphic – Inline graphic In Figure 1, the emission intensities for these three core-level hole initial states Inline graphic and valence hole final state Inline graphic are then simulated by

graphic file with name jz4c02329_m017.jpg

with the Cartesian components of the dipole matrix elements Inline graphic calculated by StoBe and the coefficients cb,CL given above.

While the experimental resolution for the S L2,3 data would be in the range of the expected molecular-field splitting, the sharpest feature in the emission spectra (the 14a′ S L2 emission) has a width of ∼0.5 eV, which we attribute to lifetime, inhomogeneous, and, probably dominating, vibronic broadening. In fact, coupling to the symmetric umbrella bend in the methyl moieties was observed for S 2p photoelectron spectroscopy of dimethyl sulfide,20 and it is reasonable to expect that this also happens for S L2,3 of DMSO. Thus, the molecular-field splitting is too small to be resolved in the experiment. In contrast, the composition of the core levels in terms of S 2px, 2py, and 2pz does directly influence the spectral intensities, as discussed below.

In the following, we discuss the contributions of all valence orbitals to the O K, C K, and S L2,3 XES spectra, starting with the 14a′ orbital (HOMO) and continuing to lower-lying orbitals. We find that the 14a′ and 7a″ orbitals are dominated by O 2p contributions (in a simplified picture representing the lone pair orbitals at the oxygen atom) and give rise to the strongest spectral lines in the O K XES at 527.6 and 526.7 eV, respectively. Furthermore, these orbitals also extend to the S and C atoms, including C 2p and S 3s and 3d contributions, and thus, corresponding emission lines are also found for C K (281.2 and 280.1 eV) and S L2,3 XES (162.6 and 161.3 eV for S L3). While the spectral shape and relative intensities of the broadened theory curve give a good description for C K XES, the HOMO peak in the broadened O K XES calculation appears to be more intense than in the experimental spectrum. There are several factors that might play a role. First, the calculated spectra are broadened with symmetric profiles, while some asymmetry can be expected due to vibrational broadening. This could shift some intensity of the 14a′ line to lower emission energies, decreasing the intensity of the highest-energy peak at 527.5 eV while increasing that of the peak at 526.6 eV. Second, the calculations were performed for an isolated DMSO molecule, while the experiment probes liquid DMSO. In the latter, some influence of the neighboring molecules is expected, in particular for the O lone pairs participating in hydrogen bonding, which has been studied for DMSO/water mixtures.9

For S L2,3, the situation is interesting. Emission involving the 14a′ orbital gives significant intensity with only the Inline graphic or Inline graphic initial state, while nearly no intensity is expected for the Inline graphic state. The situation is then reversed for 7a″, with emission mainly involving the Inline graphic state. We note that the 7a″ intensity is underestimated in the calculation, which might be caused by the interaction with neighboring molecules not included in the calculation.

13a′ and 12a′ again exhibit significant O 2p contributions, leading to the two prominent O K emission lines at 524.5 and 523.2 eV. These orbitals also have C 2p contributions, and the calculation thus predicts a significant contribution for the C K emission, as well. In contrast, they have only small admixtures of S 3s and 3d, and the corresponding lines are very weak in the S L3 emission; however, they are still visible, because they are well separated from any other line with a larger emission intensity. 6a″, as well as 5a″ through 10a′, are dominated by C 2p contributions with very small overlap with the O atom and no S 3s or 3d contributions. Consequently, the corresponding lines are very strong for C K XES, while they lead to only weak (but distinctive) features in the O K and S L3 XES.

The main contribution to the 9a′ orbital is from S 3s, leading to the most prominent S L2,3 emission lines at 152.6 and 153.8 eV. Because this orbital is well separated from the others and has some minor O 2p and C 2p contributions, we can also identify corresponding peaks in the C K and O K XES. The 3a″ orbital is mainly derived from C 2s and has no overlap and/or the wrong symmetry to lead to an emission line in any of the three spectra. Finally, 8a′ and 7a′ have significant S 3s character, giving two distinct emission lines in the S L2,3 XES. 7a′ also has some O 2p admixture, leading to a weak emission line in the O K XES.

We note some (weak) intensity in the experimental S L2,3 XES at ∼150.5 eV, which has no counterpart in the calculated spectrum. This feature can likely be attributed to “semi-Auger” satellites, which we have previously observed in the S L2,3 emission of alkaline earth metal sulfides.21

In Figure 3, the RIXS maps at the O K, C K, and S L2,3 edges are shown. For the S L2,3 map, contributions from second-order C K emission excited by higher orders and harmonics of the beamline have been subtracted. Emission lines are labeled at the top of each map using the calculated nonresonant emission energies. Along the excitation energy direction (ordinate), the map can be divided into three regions: (1) below the absorption edge, where no emission and only elastically scattered photons (at equal excitation and emission energies) are found, (2) the area at and a few electronvolts above the absorption edge, where significant changes of emission line energies and intensities are observed as a function of excitation energy, and (3) the area at higher excitation energies, where the emission lines do not shift and the spectra are very similar to the nonresonant spectra presented in Figure 1. Along the emission energy direction (abscissa), we can distinguish between the participant region, including and just below the elastic line, and the spectator region at even lower emission energies.

Figure 3.

Figure 3

Open in a new tab

O K (left), C K (center), and S L2,3 (right) RIXS maps of liquid DMSO. The emission intensity is color-coded from blue (low intensity) to white (high intensity) as a function of emission and excitation energies. Above the maps, emission lines are labeled and marked according to their calculated nonresonant emission energies.

In all three maps, we observe significant shifts of the emission lines around the absorption edge, caused by the interaction between the excited electron in one of the LUMO levels (“spectator”) and the final state valence hole; such shifts are often termed “spectator shifts”.22,23 They are strongest for S L2,3 (up to 1.4 eV) and weakest for C K RIXS.

In the participant region, we find loss signals close to the elastic line at all of the absorption edges, which can be attributed to vibrational excitations. Relative to the elastic line, these features have low intensity for O K and S L2,3, while they are much more intense for C K, where strong coupling to the vibrational modes of the -CH3 moieties occurs. This is expected, because the nuclear dynamics on the time scale of the core-hole lifetime that give rise to the coupling25−27 will be stronger for the (light) protons at this functional group. A closer look at the excitation energy region around an hνexc of 287.7 eV, with strong vibrational loss intensity, reveals a significant increase in the relative intensity of the emission line at an hνem of 281.2 eV compared to the nonresonant spectrum, as is also visible in Figure 4a. Such changes in relative intensities as a function of excitation energy can be caused by the angular anisotropy of the X-ray emission process28 for molecules. The linear polarization of the exciting photons (in the plane of the storage ring) can excite only orbitals (and consequently molecules) of a suitable orientation. For processes in which the molecule does not move significantly before emission takes place, this leads to an angular anisotropy of the emission as well, depending on the symmetry of the involved molecular orbitals. For DMSO, a significant effect of the angular anisotropy was found at the O K edge.10 However, for the experimental geometry in our experiment with an angle of 45° between the polarization vector of the exciting photons and the direction of the outgoing photons, an anisotropy effect of only 15% is predicted when using the formalism of Luo et al.,28 which will be further reduced by some movement of the molecules on the time scale of the RIXS process. Instead, we thus attribute the increased intensity at an hνem of 281.2 eV to nuclear dynamics in the core-excited state, leading to the full removal of one of the protons. As an approximate model for the fully dissociated state, we have calculated the C K XES spectrum of DMSO minus one proton, i.e., CH3SOCH2–, which is colored red in Figure 4a. Removing a proton from the -CH3 group changes the orbital structure, with the new HOMO orbital now dominated by the remaining lone pair electrons at the -CH2– moiety (see the iso-density surface in Figure 4a), which gives rise to the strongest peak of the spectrum (red). In a rough approximation, the experimental spectrum can then be described as a weighted sum of the calculated (nonresonant) spectrum of DMSO (representing processes without dissociation) and that of CH3SOCH2– (representing processes with dissociation), which is colored gold in Figure 4a and gives a good description of the experimental spectrum.

Figure 4.

Figure 4

Open in a new tab

(a) Experimental C K spectra of DMSO with nonresonant (XES; hνexc = 319 eV) and resonant (RIXS; hνexc = 287.7 eV) excitation (black), in comparison with calculations for DMSO (blue) and DMSO minus one proton, i.e., CH3SOCH2– (red; see the text). The iso-density surface (iso-surface value of 0.05 e/Å3) of the HOMO of CH3SOCH2– is also shown. (b) Experimental S L2,3 spectrum at nonresonant (XES; hνexc = 184 eV) and S L3 spectrum at resonant (RIXS; hνexc = 166.9 eV) excitation (black), in comparison with the UV absorbance spectrum of DMSO digitized from ref (24) (red).

For S L2,3 RIXS, significant spectral changes can be observed as a function of the excitation energy. As discussed above, strong spectator shifts are observed, which is illustrated by dashed lines in Figure 4b, where the nonresonant S L2,3 spectrum is compared with the S L3 spectrum resonantly excited at 166.9 eV. In addition to the shifts, a significant broadening of the 9a′ emission line is observed for resonant excitation. This could be caused by stronger lifetime broadening of this particular final state, an increased level of vibronic coupling, and/or an overlap of different close-lying final state configurations with the spectator electron in different formerly unoccupied valence states.

In the emission energy region between 159 and 163 eV, where emission with final state holes in the 14a′ and 7a″ is expected, we find three distinct features for excitation at an hνexc of 166.9 eV. At this energy, we expect very closely lying resonances involving the 8a″ and 15a′ orbitals (see also the discussion of Figure 5 below) that are expected to strongly overlap if vibrational broadening is included. This gives a total of four possible electronic final states. Discussing this in an energy loss picture, we compare with the UV absorbance spectrum of DMSO24 (colored red in Figure 4b). The electronic initial and final states are the same for RIXS and UV absorption, and disregarding nuclear dynamics in the RIXS process, we expect the energetics to be very similar. In the energy loss picture, we have thus aligned the zero of the energy scale of the absorption spectrum with the elastic line of the RIXS spectrum and find a good agreement between the energy positions in RIXS and UV absorption, as indicated by the dashed lines. In contrast, the relative intensities are very different, which is expected by the different transition matrix elements involved (Kramers–Heisenberg formalism for RIXS and Fermi’s golden rule for UV absorption). We tentatively assign the lowest-energy emission line at 160.4 eV to the (7a″)−1(8a″)1 final state, the center line at 161.0 eV to the (7a″)−1(15a′)1 or (14a′)−1(8a″)1 final state, and the highest-energy emission line at 161.8 eV to the (14a′)−1(15a′)1 final state.

Figure 5.

Figure 5

Open in a new tab

O K, C K, and S L2,3 partial fluorescence yield XAS spectra (black), extracted from the RIXS maps in Figure 3, in comparison to calculated XAS spectra. Colored vertical lines represent energies and intensities of individual transitions, while the blue curves show the calculations broadened by a Gaussian with a full width at half-maximum of 0.7 eV. Below the two lowest transitions, the corresponding (ground state) orbital assignment is given.

Figure 5 shows partial fluorescence yield (PFY) XAS spectra extracted from the maps in Figure 3 by integrating the emission intensity over the entire emission energy range of each RIXS map (excluding the elastic line). Calculated spectra are shown for comparison. For S L2,3 XAS, spectra were simulated in an analogous way as for XES. Depending on the edge, the calculations indicate changes in the energetic order of the orbitals involved in the two lowest absorption resonances. For the O K and S L2,3 XAS, the first resonance involves the 14a′ orbital and the second resonance the 8a″ orbitals, while this is reversed for the C K XAS. The calculated spectra qualitatively reproduce the spectral features of the experimental spectra, but some relative intensities are different. In particular, spectral features are better defined for the calculation, which can be attributed to vibrational envelopes present in the experiment but not included in the calculation, as well as saturation effects that often affect XAS spectra collected with PFY.

In summary, the complete electronic structure of liquid DMSO has been investigated by using RIXS at the O K, C K, and S L2,3 edges. Via comparison to DFT-based spectra calculations, the data allow a local and symmetry-resolved analysis of the orbital structure of DMSO. The calculated molecular orbitals are analyzed in terms of their atom- and symmetry-resolved Löwdin gross populations. We find some orbitals mostly located at individual atoms, while others are delocalized over several atoms or the entire molecule. The analysis of the S L2,3 XES spectra requires that molecular-field splitting of the S 2p levels be taken into account, which strongly influences the relative intensities involving the 2p1/2 and molecular-field split 2p3/2 levels. The RIXS maps at all three absorption edges exhibit significant spectator shifts as a function of the excitation energy. Furthermore, we find strong vibronic coupling and the ultrafast removal of a proton on the time scale of the RIXS process for excitation at the -CH3 moieties of the molecule. We describe this in a simplified computational model, which can serve as an approach for other molecular systems without the need for an explicit molecular dynamics treatment.

Methods

Pure liquid DMSO (99% purity, purchased from VWR) was measured with RIXS and XES using the flow-through liquid cell of our solid and liquid spectroscopic analysis (SALSA) endstation29 at beamline 8.0.1 of the ALS. The high transmission of SALSA’s variable line space grating soft X-ray spectrometer30 allows the collection of full RIXS maps, where the X-ray emission intensity is color-coded as a function of excitation and emission energies.30−32 During the measurements, the DMSO sample was continuously pumped through the liquid cell, replacing the probed volume several hundred times per second. In SALSA, the liquid is separated from the vacuum of the experimental station by thin (∼100 nm) membranes made from Si3N4 (for the O and C K edges; SILSON) or amorphous carbon (for the S L2,3 edge; JAVU AB). We routinely monitor for spectral contributions of molecular fragments that might deposit on the membranes during the measurements but could not find any such contributions during the DMSO experiments reported here. The emission and excitation energy scales were calibrated using the prominent features of the XES spectrum of liquid water and the elastically scattered peak, respectively, as described in the Supporting Information.

The XES and XAS spectra at the C K, O K, and S L2,3 edges of an isolated DMSO molecule were calculated using the StoBe-DeMon package.33 The modified generalized gradient approximation (GGA) exchange and correlation functionals of Becke and Perdew34−36 and double-ζ (for hydrogen) and triple-ζ (for carbon, oxygen, and sulfur)37 bases were employed for geometry optimization and single-point calculations. For core-excited atoms, diffuse IGLO-III basis sets38 were used. XAS and XES transition probabilities were calculated by the half core-hole transition potential method39 and based on the ground state, respectively. The transition energies were calculated with a Δ(Kohn–Sham self-consistent field) approach that includes differential relativistic effects associated with the removal of one electron from the 1s orbital.39 In the case of C emission, the role of the two indistinguishable carbon atoms needs to be briefly discussed. In the gas phase, the core hole would delocalize over the two carbon sites and an interference term for the cross section would need to be considered.27,40 For liquid DMSO (as in our study), we do not need to include this interference term because the symmetry is (slightly) broken, thus localizing the core hole at one of the two sites.

Acknowledgments

This research used resources of the Advanced Light Source, which is a U.S. Department of Energy Office of Science User Facility under Contract DE-AC02-05CH11231. The authors gratefully acknowledge the outstanding support by the ALS safety team, in particular Doug Taube and Alyssa Brand.

Supporting Information Available

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.jpclett.4c02329.

  • Description of the energy calibration procedure, molecular structure of DMSO, and Löwdin population analysis of the orbitals of DMSO (PDF)

The authors declare no competing financial interest.

Supplementary Material

jz4c02329_si_001.pdf (178.8KB, pdf)

References

  1. Chesnut D. B.; Quin L. D. Nature of Bonding in the Sulfuryl Group. J. Comput. Chem. 2004, 25 (5), 734–738. 10.1002/jcc.20003. [DOI] [PubMed] [Google Scholar]
  2. Clark T.; Murray J. S.; Lane P.; Politzer P. Why Are Dimethyl Sulfoxide and Dimethyl Sulfone Such Good Solvents?. J. Mol. Model 2008, 14 (8), 689–697. 10.1007/s00894-008-0279-y. [DOI] [PubMed] [Google Scholar]
  3. Wen Y.-C.; Kuo H.-C.; Jia H.-W. Multinuclear NMR Spectroscopy for Differentiation of Molecular Configurations and Solvent Properties between Acetone and Dimethyl Sulfoxide. J. Mol. Struct. 2016, 1109, 154–160. 10.1016/j.molstruc.2016.01.004. [DOI] [Google Scholar]
  4. Onthong U.; Megyes T.; Bakó I.; Radnai T.; Grósz T.; Hermansson K.; Probst M. X-Ray and Neutron Diffraction Studies and Molecular Dynamics Simulations of Liquid DMSO. Phys. Chem. Chem. Phys. 2004, 6 (9), 2136–2144. 10.1039/B311027C. [DOI] [Google Scholar]
  5. Reuter H. Structural Parameters of Dimethyl Sulfoxide, DMSO, at 100 K, Based on a Redetermination by Use of High-Quality Single-Crystal X-Ray Data. Acta Crystallographica Section E Crystallographic Communications 2017, 73 (10), 1405–1408. 10.1107/S2056989017012464. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Sze K. H.; Brion C. E.; Tronc M.; Bodeur S.; Hitchcock A. P. Inner and Valence Shell Electronic Excitation of Dimethyl Sulfoxide by Electron Energy Loss and Photoabsorption Spectroscopies. Chem. Phys. 1988, 121 (2), 279–297. 10.1016/0301-0104(88)90034-1. [DOI] [Google Scholar]
  7. Vogt L. I.; Cotelesage J. J. H.; Dolgova N. V.; Titus C. J.; Sharifi S.; George S. J.; Pickering I. J.; George G. N. X-Ray Absorption Spectroscopy of Organic Sulfoxides. RSC Adv. 2020, 10 (44), 26229–26238. 10.1039/D0RA04653A. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Atak K.; Engel N.; Lange K. M.; Golnak R.; Gotz M.; Soldatov M.; Rubensson J.-E.; Kosugi N.; Aziz E. F. The Chemical Bond in Carbonyl and Sulfinyl Groups Studied by Soft X-Ray Spectroscopy and Ab Initio Calculations. ChemPhysChem 2012, 13 (13), 3106–3111. 10.1002/cphc.201200314. [DOI] [PubMed] [Google Scholar]
  9. Engel N.; Atak K.; Lange K. M.; Gotz M.; Soldatov M.; Golnak R.; Suljoti E.; Rubensson J.-E.; Aziz E. F. DMSO–Water Clustering in Solution Observed in Soft X-Ray Spectra. J. Phys. Chem. Lett. 2012, 3 (24), 3697–3701. 10.1021/jz301665s. [DOI] [PubMed] [Google Scholar]
  10. Dierker B.; Suljoti E.; Atak K.; Lange K. M.; Engel N.; Golnak R.; Dantz M.; Hodeck K.; Khan M.; Kosugi N.; Aziz E. F. Probing Orbital Symmetry in Solution: Polarization-Dependent Resonant Inelastic Soft x-Ray Scattering on Liquid Micro-Jet. New J. Phys. 2013, 15 (9), 093025 10.1088/1367-2630/15/9/093025. [DOI] [Google Scholar]
  11. Takamuku T.; Tokuda T.; Uchida T.; Sonoda K.; Marekha B. A.; Idrissi A.; Takahashi O.; Horikawa Y.; Matsumura J.; Tokushima T.; Sakurai H.; Kawano M.; Sadakane K.; Iwase H. Hydrogen Bonds of the Imidazolium Rings of Ionic Liquids with DMSO Studied by NMR, Soft X-Ray Spectroscopy, and SANS. Phys. Chem. Chem. Phys. 2018, 20 (18), 12858–12869. 10.1039/C8CP00963E. [DOI] [PubMed] [Google Scholar]
  12. Nagasaka M. Site Selective Analysis of Water in Hydrogen Bond Network of Aqueous Dimethyl Sulfoxide Solutions by Oxygen K-Edge X-Ray Absorption Spectroscopy. J. Mol. Liq. 2022, 366, 120310 10.1016/j.molliq.2022.120310. [DOI] [Google Scholar]
  13. Weinhardt L.; Fuchs O.; Umbach E.; Heske C.; Fleszar A.; Hanke W.; Denlinger J. D. Resonant Inelastic Soft X-Ray Scattering, x-Ray Absorption Spectroscopy, and Density Functional Theory Calculations of the Electronic Bulk Band Structure of CdS. Phys. Rev. B 2007, 75 (16), 165207 10.1103/PhysRevB.75.165207. [DOI] [Google Scholar]
  14. Löwdin P. On the Non-Orthogonality Problem Connected with the Use of Atomic Wave Functions in the Theory of Molecules and Crystals. J. Chem. Phys. 1950, 18 (3), 365–375. 10.1063/1.1747632. [DOI] [Google Scholar]
  15. Svensson S.; Ausmees A.; Osborne S. J.; Bray G.; Gel’mukhanov F.; Ågren H.; Naves de Brito A.; Sairanen O.-P.; Kivimäki A.; Nõmmiste E.; Aksela H.; Aksela S. Observation of an Anomalous Decay Ratio between the Molecular Field Split Levels in the S 2p Core Photoelectron and LVV Auger Spectrum of H2S. Phys. Rev. Lett. 1994, 72 (19), 3021–3024. 10.1103/PhysRevLett.72.3021. [DOI] [PubMed] [Google Scholar]
  16. Gel’mukhanov F.; Ågren H.; Svensson S.; Aksela H.; Aksela S. Theory of Auger Spectra for Molecular-Field-Split Core Levels. Phys. Rev. A 1996, 53 (3), 1379–1387. 10.1103/PhysRevA.53.1379. [DOI] [PubMed] [Google Scholar]
  17. Børve K. J. On the Calculation of Molecular Field Splitting in S 2p Photoelectron Spectra. Chem. Phys. Lett. 1996, 262 (6), 801–806. 10.1016/S0009-2614(96)01141-4. [DOI] [Google Scholar]
  18. Durbin T. D.; Lince J. R.; Didziulis S. V.; Shuh D. K.; Yarmoff J. A. Soft X-Ray Photoelectron Spectroscopy Study of the Interaction of Cr with MoS2(0001). Surf. Sci. 1994, 302 (3), 314–328. 10.1016/0039-6028(94)90836-2. [DOI] [Google Scholar]
  19. Mullins D. R.; Lyman P. F.; Overbury S. H. Interaction of S with W(001). Surf. Sci. 1992, 277 (1), 64–76. 10.1016/0039-6028(92)90612-A. [DOI] [Google Scholar]
  20. Børve K. J.; Sæthre L. J.; Svensson S. Molecular-Field Splitting in S2p Photoelectron Spectra of Dimethyl Sulfide and Sulfur Dichloride. Chem. Phys. Lett. 1999, 310 (5–6), 439–444. 10.1016/S0009-2614(99)00825-8. [DOI] [Google Scholar]
  21. Weinhardt L.; Hauschild D.; Fuchs O.; Steininger R.; Jiang N.; Blum M.; Denlinger J. D.; Yang W.; Umbach E.; Heske C. Satellite-Dominated Sulfur L2,3 X-Ray Emission of Alkaline Earth Metal Sulfides. ACS Omega 2023, 8 (5), 4921–4927. 10.1021/acsomega.2c07228. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Ågren H.; Luo Y.; Gelmukhanov F.; Jensen H. J. Aa. Screening in Resonant X-Ray Emission of Molecules. J. Electr. Spectr. Rel. Phenom. 1996, 82 (1–2), 125. 10.1016/S0368-2048(96)03041-1. [DOI] [Google Scholar]
  23. Weinhardt L.; Benkert A.; Meyer F.; Blum M.; Wilks R. G.; Yang W.; Bär M.; Reinert F.; Heske C. Nuclear Dynamics and Spectator Effects in Resonant Inelastic Soft X-Ray Scattering of Gas-Phase Water Molecules. J. Chem. Phys. 2012, 136 (14), 144311. 10.1063/1.3702644. [DOI] [PubMed] [Google Scholar]
  24. Gollnick K.; Stracke H.-U. Direct and Sensitized Photolysis of Dimethyl Sulfoxide in Solution. Pure Appl. Chem. 1973, 33 (2), 217–246. 10.1351/pac197333020217. [DOI] [Google Scholar]
  25. Hennies F.; Polyutov S.; Minkov I.; Pietzsch A.; Nagasono M.; Ågren H.; Triguero L.; Piancastelli M.-N.; Wurth W.; Gel’mukhanov F.; Föhlisch A. Dynamic Interpretation of Resonant X-Ray Raman Scattering: Ethylene and Benzene. Phys. Rev. A 2007, 76 (3), 032505 10.1103/PhysRevA.76.032505. [DOI] [Google Scholar]
  26. Weinhardt L.; Weigand M.; Fuchs O.; Bär M.; Blum M.; Denlinger J. D.; Yang W.; Umbach E.; Heske C. Nuclear Dynamics in the Core-Excited State of Aqueous Ammonia Probed by Resonant Inelastic Soft x-Ray Scattering. Phys. Rev. B 2011, 84 (10), 104202 10.1103/PhysRevB.84.104202. [DOI] [Google Scholar]
  27. Gel’mukhanov F.; Odelius M.; Polyutov S. P.; Föhlisch A.; Kimberg V. Dynamics of Resonant X-Ray and Auger Scattering. Rev. Mod. Phys. 2021, 93 (3), 035001 10.1103/RevModPhys.93.035001. [DOI] [Google Scholar]
  28. Luo Y.; Ågren H.; Gel’mukhanov F. Polarization Anisotropy in Resonant X-Ray Emission from Molecules. Phys. Rev. A 1996, 53 (3), 1340 10.1103/PhysRevA.53.1340. [DOI] [PubMed] [Google Scholar]
  29. Blum M.; Weinhardt L.; Fuchs O.; Bär M.; Zhang Y.; Weigand M.; Krause S.; Pookpanratana S.; Hofmann T.; Yang W.; Denlinger J. D.; Umbach E.; Heske C. Solid and Liquid Spectroscopic Analysis (SALSA) - a Soft x-Ray Spectroscopy Endstation with a Novel Flow-through Liquid Cell. Rev. Sci. Instrum. 2009, 80 (12), 123102. 10.1063/1.3257926. [DOI] [PubMed] [Google Scholar]
  30. Fuchs O.; Weinhardt L.; Blum M.; Weigand M.; Umbach E.; Bär M.; Heske C.; Denlinger J.; Chuang Y. D.; McKinney W.; Hussain Z.; Gullikson E.; Jones M.; Batson P.; Nelles B.; Follath R. High-Resolution, High-Transmission Soft x-Ray Spectrometer for the Study of Biological Samples. Rev. Sci. Instrum. 2009, 80 (6), 63103. 10.1063/1.3133704. [DOI] [PubMed] [Google Scholar]
  31. Fuchs O.; Zharnikov M.; Weinhardt L.; Blum M.; Weigand M.; Zubavichus Y.; Bär M.; Maier F.; Denlinger J. D.; Heske C.; Grunze M.; Umbach E. Comment on “Isotope and Temperature Effects in Liquid Water Probed by X-Ray Absorption and Resonant X-Ray Emission Spectroscopy” - Fuchs et al. Reply. Phys. Rev. Lett. 2008, 100 (24), 249802 10.1103/PhysRevLett.100.249802. [DOI] [PubMed] [Google Scholar]
  32. Weinhardt L.; Fuchs O.; Fleszar A.; Bär M.; Blum M.; Weigand M.; Denlinger J. D.; Yang W.; Hanke W.; Umbach E.; Heske C. Resonant Inelastic Soft X-Ray Scattering of CdS: A Two-Dimensional Electronic Structure Map Approach. Phys. Rev. B 2009, 79 (16), 165305 10.1103/PhysRevB.79.165305. [DOI] [Google Scholar]
  33. Hermann K.; Pettersson L. G. M.; Casida M. E.; Daul C.; Goursot A.; Koester A.; Proynov E.; St-Amant A.; Salahub D. R. Contributing Authors: Carravetta V.; Duarte H.; Friedrich C.; Godbout N.; Guan J.; Jamorski C.; Leboeuf M.; Leetmaa M.; Nyberg M.; Patchkovskii S.; Pedocchi L.; Sim F.; Triguero L.; Vela A.. StoBe-deMon, ver. 3.1; 2011.
  34. Becke A. D. Density-Functional Exchange-Energy Approximation with Correct Asymptotic Behavior. Phys. Rev. A 1988, 38 (6), 3098–3100. 10.1103/PhysRevA.38.3098. [DOI] [PubMed] [Google Scholar]
  35. Perdew J. P. Density-Functional Approximation for the Correlation Energy of the Inhomogeneous Electron Gas. Phys. Rev. B 1986, 33 (12), 8822–8824. 10.1103/PhysRevB.33.8822. [DOI] [PubMed] [Google Scholar]
  36. Perdew J. P. Erratum: Density-Functional Approximation for the Correlation Energy of the Inhomogeneous Electron Gas. Phys. Rev. B 1986, 34 (10), 7406–7406. 10.1103/PhysRevB.34.7406. [DOI] [PubMed] [Google Scholar]
  37. Godbout N.; Salahub D. R.; Andzelm J.; Wimmer E. Optimization of Gaussian-Type Basis Sets for Local Spin Density Functional Calculations. Part I. Boron through Neon, Optimization Technique and Validation. Can. J. Chem. 1992, 70 (2), 560–571. 10.1139/v92-079. [DOI] [Google Scholar]
  38. Kutzelnigg W.; Fleischer U.; Schindler M.. The IGLO-Method: Ab-Initio Calculation and Interpretation of NMR Chemical Shifts and Magnetic Susceptibilities. In Deuterium and Shift Calculation. NMR Basic Principles and Progress; Springer: Heidelberg, Germany, 1990. [Google Scholar]
  39. Triguero L.; Pettersson L. G. M.; Ågren H. Calculations of Near-Edge x-Ray-Absorption Spectra of Gas-Phase and Chemisorbed Molecules by Means of Density-Functional and Transition-Potential Theory. Phys. Rev. B 1998, 58 (12), 8097–8110. 10.1103/PhysRevB.58.8097. [DOI] [Google Scholar]
  40. Gel’mukhanov F.; Ågren H. Resonant Inelastic X-Ray Scattering with Symmetry-Selective Excitation. Phys. Rev. A 1994, 49 (6), 4378–4389. 10.1103/PhysRevA.49.4378. [DOI] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

jz4c02329_si_001.pdf (178.8KB, pdf)

Articles from The Journal of Physical Chemistry Letters are provided here courtesy of American Chemical Society

RESOURCES