3/2/2024 0 Comments Chromium iii sulfideThe magnetic moments per chromium measured at room temperature were 1.74(3)µ B for CrS 3 and 2.62(3)µ B for CrSe 3, supporting the assignment of different oxidation states to chromium in the two materials. The chromium K-edge shift of CrSe 3(Δ E= 5.79 eV) is large for a chromium selenide and provides further evidence for the assignment of the oxidation state of chromium in CrSe 3 as IV. The substances are listed in alphabetical order. Units of solubility are given in grams per 100 millilitres of water (g/100 mL), unless shown otherwise. We formulate CrSe 3 as Cr IV(Se –1 2)Se –II. The table below provides information on the variation of solubility of different substances (mostly inorganic compounds) in water with temperature, at one atmosphere pressure. Each selenium has an average of two chromium neighbours at 2.45 Å, and 0.67 of a selenium neighbour at 2.34 Å. In CrSe 3, chromium is surrounded by an average of six seleniums at a distance of 2.50 Å. The edge shift, Δ E, of the chromium K edge of CrS 3(Δ E= 6.37 eV) relative to chromium metal, is close to that of Cr 2S 3(Δ E= 6.88 eV), supporting the assignment of the oxidation state of chromium as III. The results of sulfur K-edge absorption spectroscopy of CrS 3, Cr 2S 3, VS 4 and α-S suggest that all sulfur is found in one oxidation state, S –1, and we formulate CrS 3 as Cr III(S –1 2) 1.5. The sulfur-edge data can be fitted by two shells containing two chromium neighbours at 2.34 Å and one sulfur neighbour at 2.03 Å. In CrS 3, chromium is surrounded by an average of six sulfurs at 2.35 Å. Structural models based on the distances and coordination numbers obtained from the analysis of these data are presented for CrS 3 and CrSe 3. Extended X-ray absorption fine structure (EXAFS) studies of the amorphous chromium sulfide, CrS 3, the amorphous chromium selenide, CrSe 3, and the crystalline vanadium sulfide model compound, VS 4, have been carried out at both the metal and chalcogen K edges.
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