The interpretation of sulfur K-edge XANES spectra: a case study on thiophenic and aliphatic sulfur compounds.
Sulfur K-edge XANES has been measured for three sulfur model compounds, dibenzothiophene, dibenzothiophene sulfone, and aliphatic sulfur (DL-methionine). The spectra have been simulated with Density Functional Theory (DFT) by using a number of methods, including the half-core-hole approximation. Dipole transition elements were calculated and the transitions were convoluted with linearly increasing Gaussian functions in the first 20 eV of the near-edge region. In the case of dibenzothiophene, relaxation of the first excited states in the presence of the core-hole gave a further improvement. The theoretical results reproduce well the features of the spectra and give insight in the relation between geometric structure and molecular orbitals. Though DL-methionine and dibenzothiophene show a similar sharp rise of the white line, their molecular levels are quite different, pointing out the difficulties in finding useful "fingerprints" in the spectra for specific compounds.
Mijovilovich
A
A
Inorganic Chemistry and Catalysis group, Debye Institute for Nanomaterials Research, Department of Chemistry, Utrecht University, Sorbonnelaan 16, 3584CA, Utrecht, The Netherlands.
Pettersson
L G M
LG
Mangold
S
S
Janousch
M
M
Susini
J
J
Salome
M
M
de Groot
F M F
FM
Weckhuysen
B M
BM
D008715:Methionine / Q000737:chemistry*; D008958:Models, Molecular; D013057:Spectrum Analysis; D013457:Sulfur Compounds / Q000737:chemistry*; D013876:Thiophenes / Q000737:chemistry*; D014965:X-Rays
D013457:Sulfur Compounds; D013876:Thiophenes; C058517:dibenzothiophene 5-oxide; D008715:Methionine; C016366:dibenzothiophene