Sulfur K-Edge Absorption Spectra of Na2SO4, Na2SO3, Na2S2O3, and Na2S2Ox (x=5–8)

Abstract X-Ray absorption spectra of the sulfur K-edges of SO42−, SO32−, S2O32−, and S2Ox2− (x=5–8) were measured with synchrotron radiation. The spectra show similarly strong absorption bands which originate in bound-state transitions to antibonding 3p-type orbitals and in shape resonances related to 3d-type orbitals. The K-edge spectrum for the terminal sulfur atom in S2O32−, however, shows only a bound-state transition. Differences in chemical environments and bonding around the X-ray absorbing atoms are discussed to interpret the spectra.