77846-58-3Relevant academic research and scientific papers
Preparation, X-ray crystal structures, and vibrational spectra of some salts of the As3S4+ and As3Se4+ cations
Christian, Beverley H.,Gillespie, Ronald J.,Sawyer, Jeffery F.
, p. 3410 - 3420 (2008/10/08)
The reactions of α- and β-As4S4 and some arsenic-selenium melts with various oxidants in SO2 as solvent are reported. It is shown by X-ray crystallography that the reactions of As4S4 and a 1:1 As-Se melt with the Lewis acids AsF5 and SbF5 in a 1:3 molar ratio in SO2 give the hexafluoroarsenate and hexafluoroantimonate salts of the novel arsenic chalcogen cations As3S4+ and As3Se4+. Crystals of (As3S4)(SbF6) are yellow plates which crystallize in the orthorhombic space group Pcam with a = 20.453 (4) A?, b = 5.990 (1) A?, c = 9.609 (2) A?, U = 1177.3 (4) A?3, and dc = 3.32 g cm-3 for Z = 4. Crystals of the isomorphous (As3S4)(AsF6) are dark yellow prisms and rhombs with cell dimensions a = 19.962 (4) A?, b = 5.930 (1) A?, c - 9.441 (3) A?, U = 1115.8 (5) A?3, and dc = 3.22 g cm-3 for Z = 4. The compound (As3Se4)(SbF6) forms orange diamond-shaped plates which crystallize in the monoclinic space group P21/m with a = 6.224 (3) A?, b = 9.564 (5) A?, c = 10.643 (5) A?, β = 92.65 (4)°, U = 632.9 (5) A?3, and dc = 4.07 g cm-3 for Z = 2. The structure of the compound (As3S4)(SbF6) was solved by using the Patterson function and refined by least-squares methods to final agreement indices R1 = 0.036 and R2 = 0.043 for 699 observed data. The isomorphous compound (As3S4)(AsF6) has similarly been refined by least-squares methods to final agreement indices R1 = 0.043 and R2 = 0.052 for 546 observed data. The structure of the compound (As3Se4)(SbF6) was solved by using direct methods and has been refined by least-squares to final agreement indices R1 = 0.064 and R2 = 0.082 for 620 observed reflections. The two cations As3S4+ and As3Se4+ are isostructural with crystallographic mirror symmetry and an overall symmetry of Cs. The cage structure of the two cations can be derived by bridging three edges of a tetrahedron of three arsenic and one sulfur or selenium atoms by the remaining sulfur or selenium atoms. Bond distances, bond angles and some significant interionic contact distances in these compounds are discussed. In addition, the Raman and IR spectra of these cations as well as the Raman spectrum of As4S3 and an improved Raman spectrum of the compound α-As4S4 are reported.
