Synthesis, Crystal and Electronic Structure of the Sulfido Ferrate Oxide, Cs₁₁[Fe₅S₈]₂[O]

Abstract

The sulfido ferrate oxide Cs 11 [Fe 5 S 8 ] 2 [O] was synthesized at a maximum temperature of 1170 K from samples containing Fe, Cs 2 S 2 and CsO 2 as well as by substituting CsO 2 as oxygen source with Fe 2 O 3 . In the crystal structure (tetragonal, tI84, SG I4/mmm, a = 1199.34(2), c = 1411.65(2) pm, Z = 2, R 1 = 0.0188) two crystallographically different iron ions, which are present in a 1:4 atomic ratio, are tetrahedrally coordinated by S ligands [d(Fe-S) = 228.8-238.3 pm].

[Cs6Cl][Fe24Se26]: A Host–Guest Compound with Unique Fe–Se Topology

“…Here the corresponding separation is 3.26 o na verage ( Figure 2d). This is almosti dentical to the CsÀCl separation in the host-guest compound [Cs 6 Cl][RE 21 Ch 34 ] (RE = Dy,H o, Ch = S, Se, Te )o f3 .27 , [22] in whicht he charges add up properly with only RE + 3 .M oreover,C lw as identified in fitting relative amounts, as estimated from EDX data. Thus, am inor iron deficiency in the title compound is the most probablee xplanation,b ut cannotb eu nambiguously resolved with the diffraction data at hand.…”

“…Or this charge deficit could also be accounted for if Cl was completely replaced with O that enters as an impurity in the solid‐state reaction from the Fe metal. However, the expected Cs−O separation is about 2.86 Å, as taken from Cs 2 O and Cs 11 [Fe 5 S 8 ] 2 O, in which O is octahedrally coordinated by Cs. Here the corresponding separation is 3.26 Å on average (Figure d).…”

“…The strongly ionic guest [A 6 Cl] 5 + (A = Cs, K) occurs within strongly covalenth ostl atticesi na tl east three well-characterized compounds:b artonite, [9,10] djerfisherite, [11] and [Cs 6 Cl] [RE 21 Ch 34 ]( RE = Dy,H o, Ch = S, Se, Te ). [21] By comparing bartonite with [Cs 6 Cl][RE 21 Ch 34 ], it is evident that the resulting charge of the host lattice is important for the overall periodicity of the [A 6 Cl] 5 + ion. The higher the chargeo ft he chalcogenide-based host, the shorter the distance between the guest ions, as expected.…”

Purification‐Free, Small‐Scale Synthesis of Isothiocyanates by Reagentless Fragmentation of Polymer‐Supported 1,4,2‐Oxathiazoles

“…For the cations Fe II/III of the single chain A (thin dashed lines in Figure 4), spin‐up and spin‐down states are compensated due to the AFM coupling. Similar to the layered ferrates,34 the Fe II states of the double chains [Fe(21) to Fe(24)] show a large dispersion ranging from –6 eV to the Fermi level (thick black lines in Figure 4). The strong mixing with the sulfur p states indicates a pronounced covalency of the Fe II –S bonding.…”

“…in the tetramers of Cs 8 [Fe 4 S 10 ] exhibit an even more positive Bader charge of q = +1.135 4. For several other mixed‐valent chain ferrates3 and the cluster compound Cs 7 [Fe 4 S 8 ] (formal Fe valence: +2.25; Bader charge: q = +0.9604) and the layered ferrates(II)34 the calculated Bader charges always follow the formal average oxidation state. The Fe II /Fe III distribution is further substantiated by the tDOS of the FP bandstructure calculation itself (see below).…”