61459-17-4Relevant articles and documents
Preparations and X-ray crystal structures of iodo-cyclo-heptasulfur hexafluoroantimonate(V) and hexafluoroarsenate(V), S7ISbF6 and S7IAsF6
Passmore, Jack,Sutherland, George,Taylor, Peter,Whidden, Tom K.,White, Peter S.
, p. 3839 - 3845 (2008/10/08)
S7IAsF6 and S7ISbF6 were prepared essentially quantitatively by a variety of routes. Attempts to prepare S8I+ salts were unsuccessful. S7ISbF6 crystallizes in the orthorhombic space group P212121 with a = 11.786 (2) ?, b = 9.187 (1) ?, c = 12.400 (3) ?, and dcalcd = 2.90 Mg m-3 for Z = 4. The structure has been determined by multiple-solution direct methods and refined by least squares to final agreement indices R1 = 0.046 and R2 = 0.061 for 1628 independent reflections with I ≥ 2σ(I). S7IAsF6 crystallizes in the triclinic space group P1 with a = 15.516 (11) ?, b = 11.813 (8) ?, c = 11.650 (8) ?, α = 107.30 (4)°, β = 74.71 (5)°, γ= 104.62 (5)°, and dcalcd = 2.78 Mg m-3 for Z = 6. The structure was refined to a final agreement index R = 0.14. The S7I+ cations in both salts and in (S7I)4S4(AsF6)6 are essentially identical. S7I+ contains a seven-membered sulfur ring with a slightly twisted chair conformation, similar to that of S7, with an exocyclic iodine, and has a geometry similar to that of S7O. The sulfur-iodine bond length is 2.342 (3) ? and corresponds to a bond order of 1. The sulfur-sulfur distances within the ring vary from 1.906 (5) to 2.389 (4) ?. There is one short intracationic iodine-sulfur contact of 3.394 (3) ?. The geometry and bond length variations in S7I+ are discussed and compared with those of related systems. Some experimental observations on Sx(AsF6)2, 19 ≥ x ≥ 16, are presented and the nature of these species is discussed.
