Electronic Structure of Third-Row Elements in Different Local Symmetries Studied by Valence-to-Core X‑ray Emission Spectroscopy

The electronic structure of phosphorus, sulfur, and chlorine in compounds with <i>T</i>_<i>d</i> and <i>C</i>_3<i>v</i> local symmetries was studied with high-resolution Kβ X-ray emission spectroscopy (XES) in the tender X-ray range. Measured spectra are compared to the results of <i>ab initio</i> quantum chemical calculations based on density functional theory (DFT). The spectral structure is reproduced by the model spectra of isolated XO₄^<i>n</i>– and XO₃^<i>n</i>– (X = P, S, or Cl) anions incorporating only the first coordination sphere around the central atom. The main spectral components can be explained by the molecular orbital theory. Finally, the potential of XES spectroscopy combined with DFT calculations to study the electronic structure of third-row elements in a slightly larger molecule is investigated