In contrast, sulfide anions showed clear sign of oxidation. The S K-edge XANES of the "collapsed" phase (Fig. ) featured an increase of its main absorption peak by ca. 0.6 eV and emergence of a pre-edge peak at 2469 eV, similar to that in BaS2 (but not in BaS) (Fig. ) which is diagnostic for oxidised [S2] 2-species, corresponding to a transition to antibonding σ* levels . Two Raman bands occur in the region 390-510 cm -1 (Fig. ), typical of sulfide dianions [Sx] 2-stretching modes . Steudel's empirical relationship between S-S bond length dSS (Å) and wavenumber νSS (cm -1 ): d SS =2.57-9.47×10 •ν SS gave dSS = 2.12 and 2.16-2.17 Å for νSS = 473 and 420-430 cm -1 , respectively. The two bands implied the presence of two slightly different species of sulfide dimers in the sample. Despite the evidence for full metal deintercalation from sulfide layers, bulk chemical analysis by ICP-MS (Table ) revealed residual Cu and Li after the 5th-step (Fig. ). Mole ratios of Sr/Mn/Cu/Li = 2.00/1.07/0.35/0.13 (Sample 1) and 2.00/1.07/0.24/0.23 (Sample 2) revealed 0.5 equiv. of residual Cu and Li per Mn ion.