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The structure of hexa­fluoro­iodium(VII) hexa­fluoro­arsenate, IF6AsF6, has been determined by X-ray diffraction using a single crystal grown from a saturated solution in anhydrous HF. IF6AsF6 crystallizes in the cubic space group Pa\overline{3} with a simple NaCl-like ionic packing. The I and As atoms occupy the 4a and 4b Wyckoff positions, respectively, with \overline{3} symmetry.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270106017719/bc3005sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270106017719/bc3005Isup2.hkl
Contains datablock I

Comment top

Until now, the single-crystal X-ray structure of IF6Sb2F11 represented the only detailed crystallographic study of salts containing the IF6+ cation (Lehmann et al., 2004). IF6AsF6 was first prepared by the reaction of IF7 with AsF5 (Seel & Detmer, 1958, 1959). Powder X-ray diffraction studies of IF6AsF6 were performed later (Beaton, 1966; Christe & Sawodny, 1967). In this work, the structure of IF6AsF6 was determined by single-crystal technique to obtain more precise structural data and to allow a comparison of the cation geometry with that previously found in IF6Sb2F11.

IF6AsF6 crystallizes in the cubic space group Pa3, in agreement with the published data based on X-ray powder diffraction experiments. The structure consists of alternating IF6+ and AsF6 octahedra packed in an NaCl-like arrangement (Fig. 1). The closest As···I distance is 4.705 (1) Å. The I and As atoms are both located at sites with 3 symmetry (the 4a and 4b Wyckoff positions, respectively), resulting in six equal I—F distances and six equal As—F distances. The I—F bond lengths [1.7744 (17) Å] are in the same range as those in IF6Sb2F11 (1.767–1.782 Å at 173 K; Lehmann et al., 2004). The As—F bond lengths 1.7200 (17) Å] are very similar to those in CsAsF6 (1.714 Å; Loss & Röhr, 1998). The neigbouring IF6+ and AsF6 octahedra are mutually tilted, possibly because of packing effects. The geometry of the IF6+ cation in IF6AsF6 is almost identical to that in IF6Sb2F11.

Bond valence analysis of IF6AsF6 gives bond valence sums of 6.972 v.u. (bond valence units) for I and 4.578 v.u. for As (Brese & O'Keeffe, 1991), with contributions of 1.162 v.u. per F1 atom for the former and 0.763 v.u. per F2 atom for the latter.

Experimental top

IF6AsF6 was synthesized by the oxidation of iodium pentafluoride by [Ag(HF)n]2+, prepared by reaction of AgF2 with AsF5 in anhydrous HF: 2[Ag(HF)n]2+(AsF6)2] + IF5 = 2 A g+AsF6 + IF6AsF6 + AsF5. Colourless block-shaped crystals of the title compound were grown from a saturated solution in anhydrous HF. Raman spectra recorded on single crystals were in agreement with literature data for IF6AsF6 (Beaton, 1966; Christe & Sawodny, 1967).

Computing details top

Data collection: CrystalClear (Rigaku Corporation, 1999); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: PATTY in DIRDIF92 (Beurskens et al., 1992); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); software used to prepare material for publication: WinGX (Version 1.70; Farrugia, 1999), enCIFer (Version 1.2; Allen et al., 2004) and Diamond (Version 3.1; Bergerhoff et al., 1996).

Figures top
[Figure 1] Fig. 1. A view of the unit–cell contents of IF6AsF6. IF6+ and AsF6 ions are shown as light and dark grey octahedra, respectively.
(I) top
Crystal data top
AsF12IDx = 3.428 Mg m3
Mr = 429.82Mo Kα radiation, λ = 0.71069 Å
Cubic, Pa3Cell parameters from 48 reflections
Hall symbol: -P 2ac 2ab 3θ = 3.1–29.1°
a = 9.409 (2) ŵ = 7.96 mm1
V = 832.9 (3) Å3T = 200 K
Z = 4Chunk, colorless
F(000) = 7760.3 × 0.3 × 0.2 mm
Data collection top
Rigaku Mercury CCD
diffractometer
230 reflections with I > 2σ(I)
ω scansRint = 0.018
Absorption correction: multi-scan
(Blessing, 1995)
θmax = 29.1°, θmin = 3.8°
Tmin = 0.115, Tmax = 0.2h = 1211
3317 measured reflectionsk = 511
354 independent reflectionsl = 1212
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.021 w = 1/[σ2(Fo2) + (0.0225P)2]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.063(Δ/σ)max < 0.001
S = 1.10Δρmax = 0.72 e Å3
354 reflectionsΔρmin = 0.60 e Å3
24 parametersExtinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.0023 (4)
Crystal data top
AsF12IZ = 4
Mr = 429.82Mo Kα radiation
Cubic, Pa3µ = 7.96 mm1
a = 9.409 (2) ÅT = 200 K
V = 832.9 (3) Å30.3 × 0.3 × 0.2 mm
Data collection top
Rigaku Mercury CCD
diffractometer
354 independent reflections
Absorption correction: multi-scan
(Blessing, 1995)
230 reflections with I > 2σ(I)
Tmin = 0.115, Tmax = 0.2Rint = 0.018
3317 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.02124 parameters
wR(F2) = 0.0630 restraints
S = 1.10Δρmax = 0.72 e Å3
354 reflectionsΔρmin = 0.60 e Å3
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
I0.00000.00000.00000.0214 (2)
As0.00000.50001.00000.0199 (2)
F10.13523 (17)0.06318 (17)0.11527 (15)0.0337 (5)
F20.14038 (17)0.55931 (17)1.10099 (15)0.0351 (5)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
I0.0214 (2)0.0214 (2)0.0214 (2)0.00026 (10)0.00026 (10)0.00026 (10)
As0.0199 (2)0.0199 (2)0.0199 (2)0.00063 (16)0.00063 (16)0.00063 (16)
F10.0299 (10)0.0397 (11)0.0315 (10)0.0035 (8)0.0043 (8)0.0030 (8)
F20.0323 (10)0.0381 (11)0.0349 (10)0.0049 (8)0.0066 (8)0.0016 (8)
Geometric parameters (Å, º) top
I—F1i1.7744 (17)As—F2vi1.7200 (17)
I—F1ii1.7744 (17)As—F2vii1.7200 (17)
I—F11.7744 (17)As—F2viii1.7200 (17)
I—F1iii1.7744 (17)As—F2ix1.7200 (17)
I—F1iv1.7744 (17)As—F21.7200 (17)
I—F1v1.7744 (17)As—F2x1.7200 (17)
F1i—I—F1ii89.62 (7)F2vi—As—F2vii90.24 (8)
F1i—I—F190.38 (7)F2vi—As—F2viii180.00 (7)
F1ii—I—F189.62 (7)F2vii—As—F2viii89.76 (8)
F1i—I—F1iii89.62 (7)F2vi—As—F2ix89.76 (8)
F1ii—I—F1iii90.38 (7)F2vii—As—F2ix180.00 (7)
F1—I—F1iii180.00 (12)F2viii—As—F2ix90.24 (8)
F1i—I—F1iv180.00 (11)F2vi—As—F290.24 (8)
F1ii—I—F1iv90.38 (7)F2vii—As—F290.24 (8)
F1—I—F1iv89.62 (7)F2viii—As—F289.76 (8)
F1iii—I—F1iv90.38 (7)F2ix—As—F289.76 (8)
F1i—I—F1v90.38 (7)F2vi—As—F2x89.76 (8)
F1ii—I—F1v180.00 (7)F2vii—As—F2x89.76 (8)
F1—I—F1v90.38 (7)F2viii—As—F2x90.24 (8)
F1iii—I—F1v89.62 (7)F2ix—As—F2x90.24 (8)
F1iv—I—F1v89.62 (7)F2—As—F2x180.0
Symmetry codes: (i) z, x, y; (ii) y, z, x; (iii) x, y, z; (iv) z, x, y; (v) y, z, x; (vi) z+1, x+1/2, y+3/2; (vii) y1/2, z+3/2, x+1; (viii) z1, x+1/2, y+1/2; (ix) y+1/2, z1/2, x+1; (x) x, y+1, z+2.

Experimental details

Crystal data
Chemical formulaAsF12I
Mr429.82
Crystal system, space groupCubic, Pa3
Temperature (K)200
a (Å)9.409 (2)
V3)832.9 (3)
Z4
Radiation typeMo Kα
µ (mm1)7.96
Crystal size (mm)0.3 × 0.3 × 0.2
Data collection
DiffractometerRigaku Mercury CCD
diffractometer
Absorption correctionMulti-scan
(Blessing, 1995)
Tmin, Tmax0.115, 0.2
No. of measured, independent and
observed [I > 2σ(I)] reflections
3317, 354, 230
Rint0.018
(sin θ/λ)max1)0.685
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.021, 0.063, 1.10
No. of reflections354
No. of parameters24
Δρmax, Δρmin (e Å3)0.72, 0.60

Computer programs: CrystalClear (Rigaku Corporation, 1999), CrystalClear, PATTY in DIRDIF92 (Beurskens et al., 1992), SHELXL97 (Sheldrick, 1997), WinGX (Version 1.70; Farrugia, 1999), enCIFer (Version 1.2; Allen et al., 2004) and Diamond (Version 3.1; Bergerhoff et al., 1996).

 

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