Raman Spectroscopy Study of the Reaction between Sodium Sulfide or Disulfide and Sulfur: Identity of the Species Formed in Solid and Liquid Phases.

The reactions of sodium sulfide or disulfide with sulfur, when heated, are examined through Raman spectroscopy. It is shown that whatever the composition of the mixtures, the solid sodium sulfide or disulfide transforms into the crystalline alpha-Na(2)S(4) phase in a first step, with alpha- or beta-Na(2)S(2) as an intermediate. The reaction, which proceeds when the sulfur melts, is assumed to be related to the polymerization-depolymerization mechanism responsible for the formation of smaller rings and sulfur chains in molten S(8).

Polysulfide anions II: structure and vibrational spectra of the S4(2-) and S5(2-) anions. Influence of the cations on bond length, valence, and torsion angle.

The influence of the cations on bond length, valence, and torsion angle of S4(2-) and S5(2-) anions was examined in a series of solid alkali tetra- and pentasulfides by relating their Raman spectra to their known X-ray structures through a force-field analysis. The IR and Raman spectra of BaS4.H2O and the Raman spectra of (NH4)2S4.