inorganic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

Li2PtF6 revisited

aAG Fluorchemie, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany
*Correspondence e-mail: florian.kraus@tum.de

Edited by M. Weil, Vienna University of Technology, Austria (Received 30 June 2014; accepted 3 July 2014; online 11 July 2014)

In comparison with previous stucture determinations of Li2PtF6, dilithium hexa­fluorido­platinate(IV) [Graudejus et al. (2000[Graudejus, O., Wilkinson, A. P., Chacón, L. C. & Bartlett, N. (2000). Inorg. Chem. 39, 2794-2800.]). Inorg. Chem. 39, 2794–2800; Henkel & Hoppe (1968[Henkel, H. & Hoppe, R. (1968). Z. Anorg. Allg. Chem. 359, 160-177.]). Z. Anorg. Allg. Chem. 359, 160–177], the current study revealed the Li atom to be refined with anisotropic displacement parameters, thus allowing for a higher overall precision of the model. Li2PtF6 adopts the trirutile structure type with site symmetries of 2.mm, m.mm, ..m and m.2m for the Li, Pt and the two F sites. The Pt—F distances in the slightly distorted PtF6 octa­hedron are essentially similar with 1.936 (4) and 1.942 (6) Å, and the equatorial F—Pt—F angles range from 82.2 (2) to 97.8 (2)°. The Li—F distances in the somewhat more distorted LiF6 octa­hedron are 1.997 (15) and 2.062 (15) Å, with equatorial F—Li—F angles ranging from 76.3 (7) to 99.71 (17)°.

Related literature

Henkel & Hoppe (1968[Henkel, H. & Hoppe, R. (1968). Z. Anorg. Allg. Chem. 359, 160-177.]) reported on the synthesis of Li2PtF6 by direct fluorination of (NH4)2PtCl6 and Li2CO3. The obtained yellow Li2PtF6 was characterized by powder X-ray diffraction and reported to crystallize in the monoclinic crystal system. Graudejus et al. (2000[Graudejus, O., Wilkinson, A. P., Chacón, L. C. & Bartlett, N. (2000). Inorg. Chem. 39, 2794-2800.]) obtained Li2PtF6 in the form of yellow and air-stable crystals from the reaction of LiF with Pt in anhydrous HF under UV-photolysis of F2. The reported space group and unit cell parameters are in accordance with the current redetermination. However, a low precision of the Pt—F bond lengths of only ±0.01 Å was obtained due to many unobserved reflections even at the 2σ level. For synthetic details for the preparation of PtF4, see: Müller & Serafin (1992[Müller, B. G. & Serafin, M. (1992). Eur. J. Solid State Inorg. Chem. 29, 625-633.]).

Experimental

Crystal data
  • Li2PtF6

  • Mr = 322.97

  • Tetragonal, P 42 /m n m

  • a = 4.6427 (1) Å

  • c = 9.1234 (2) Å

  • V = 196.65 (1) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 35.71 mm−1

  • T = 150 K

  • 0.05 × 0.05 × 0.04 mm

Data collection
  • Oxford Diffraction Xcalibur3 diffractometer

  • Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2007[Oxford Diffraction (2007). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]) Tmin = 0.148, Tmax = 1.000

  • 5829 measured reflections

  • 257 independent reflections

  • 184 reflections with I > 2σ(I)

  • Rint = 0.062

Refinement
  • R[F2 > 2σ(F2)] = 0.019

  • wR(F2) = 0.052

  • S = 1.17

  • 257 reflections

  • 19 parameters

  • Δρmax = 2.51 e Å−3

  • Δρmin = −1.33 e Å−3

Data collection: CrysAlis CCD (Oxford Diffraction, 2007[Oxford Diffraction (2007). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]); cell refinement: CrysAlis RED (Oxford Diffraction, 2007[Oxford Diffraction (2007). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: DIAMOND (Brandenburg, 2007[Brandenburg, K. (2007). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: SHELXL97.

Supporting information


Related literature top

Henkel & Hoppe (1968) reported on the synthesis of Li2PtF6 by direct fluorination of (NH4)2PtCl6 and Li2CO3. The obtained yellow Li2PtF6 was characterized by powder X-ray diffraction and reported to crystallize in the monoclinic crystal system. Graudejus et al. (2000) obtained Li2PtF6 in the form of yellow and air-stable crystals from the reaction of LiF with Pt in anhydrous HF under UV-photolysis of F2. The reported space group and unit cell parameters are in accordance with the current redetermination. However, a low precision of the Pt—F bond lengths of only ±0.01 Å was obtained due to many unobserved reflections even at the 2σ level. For synthetic details for the preparation of PtF4, see: Müller & Serafin (1992).

Experimental top

Single-crystalline Li2PtF6 was obtained by the reaction of LiF and PtF4 in platinum tubes. LiF was purified and dried in a stream of F2:Ar 1:1 at 573 K for 24 hours. PtF4 was synthesized according to literature procedures (Müller & Serafin, 1992). A stoichiometric mixture of the compounds was heated in a sealed platinum ampoule (jacketed in an evacuated fused silica tube) to 973 K with a rate of 30 K/d. After three weeks the ampoule was slowly cooled to room temperature and opened in an argon filled glove box. Yellow crystals of Li2PtF6 were obtained.

Refinement top

The highest residual electron density is 0.85 Å from atom Pt1. Structure data have also been deposited at the Fachinformationszentrum Karlsruhe, D-76344 Eggenstein-Leopoldshafen (Germany), with depository number CSD-414496.

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2007); cell refinement: CrysAlis RED (Oxford Diffraction, 2007); data reduction: CrysAlis RED (Oxford Diffraction, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2007); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. View of the coordination polyhedra around Pt and Li. Displacement ellipsoids are shown at the 70% probability level. [Symmetry codes: (iii) -x, -y, z; (viii) x + 1, y, z; (ix) -x + 1, -y + 1, z; (xiv) y, x, -z; (xv) -y, -x, -z; (xvi) -x, 1 - y, z; (xvii) x + 1/2, -y + 1/2, -z + 1/2; (xviii) -x + 1/2, y + 1/2, -z + 1/2.]
[Figure 2] Fig. 2. The unit cell of Li2PtF6 viewed along [100], with all atoms displayed as spheres with arbitrary radii.
Dilithium hexafluoridoplatinate(IV) top
Crystal data top
Li2PtF6Dx = 5.454 Mg m3
Mr = 322.97Mo Kα radiation, λ = 0.71073 Å
Tetragonal, P42/mnmCell parameters from 3453 reflections
Hall symbol: -P 4n 2nθ = 4.4–34.6°
a = 4.6427 (1) ŵ = 35.71 mm1
c = 9.1234 (2) ÅT = 150 K
V = 196.65 (1) Å3Cuboid, yellow
Z = 20.05 × 0.05 × 0.04 mm
F(000) = 276
Data collection top
Oxford Diffraction Xcalibur3
diffractometer
257 independent reflections
Radiation source: Enhance (Mo) X-ray Source184 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.062
Detector resolution: 16.0238 pixels mm-1θmax = 34.7°, θmin = 4.5°
ϕ and ω scansh = 77
Absorption correction: multi-scan
(CrysAlis RED; Oxford Diffraction, 2007)
k = 77
Tmin = 0.148, Tmax = 1.000l = 1414
5829 measured reflections
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)] = 0.019 w = 1/[σ2(Fo2) + (0.0246P)2 + 2.1946P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.052(Δ/σ)max < 0.001
S = 1.17Δρmax = 2.51 e Å3
257 reflectionsΔρmin = 1.33 e Å3
19 parametersExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.041 (3)
Crystal data top
Li2PtF6Z = 2
Mr = 322.97Mo Kα radiation
Tetragonal, P42/mnmµ = 35.71 mm1
a = 4.6427 (1) ÅT = 150 K
c = 9.1234 (2) Å0.05 × 0.05 × 0.04 mm
V = 196.65 (1) Å3
Data collection top
Oxford Diffraction Xcalibur3
diffractometer
257 independent reflections
Absorption correction: multi-scan
(CrysAlis RED; Oxford Diffraction, 2007)
184 reflections with I > 2σ(I)
Tmin = 0.148, Tmax = 1.000Rint = 0.062
5829 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.01919 parameters
wR(F2) = 0.0520 restraints
S = 1.17Δρmax = 2.51 e Å3
257 reflectionsΔρmin = 1.33 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.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Pt10.00000.00000.00000.0056 (2)
F10.1939 (6)0.1939 (6)0.1599 (4)0.0149 (7)
F20.2958 (10)0.2958 (10)0.00000.0164 (11)
Li10.50000.50000.162 (2)0.019 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Pt10.0054 (2)0.0054 (2)0.0061 (2)0.00022 (14)0.0000.000
F10.0170 (11)0.0170 (11)0.0105 (13)0.0029 (15)0.0009 (10)0.0009 (10)
F20.0165 (18)0.0165 (18)0.016 (2)0.004 (2)0.0000.000
Li10.024 (6)0.024 (6)0.010 (7)0.006 (7)0.0000.000
Geometric parameters (Å, º) top
Pt1—F1i1.936 (4)F1—Li1iv2.062 (15)
Pt1—F1ii1.936 (4)F2—Li1vi1.997 (15)
Pt1—F1iii1.936 (4)F2—Li1vii1.997 (15)
Pt1—F11.936 (4)Li1—F2vi1.997 (15)
Pt1—F2i1.942 (6)Li1—F2viii1.997 (15)
Pt1—F21.942 (6)Li1—F1ix2.010 (4)
Pt1—Li1iv3.081 (19)Li1—F1x2.062 (15)
Pt1—Li1v3.081 (19)Li1—F1xi2.062 (15)
F1—Li12.010 (4)Li1—Li1xii2.96 (4)
F1i—Pt1—F1ii82.2 (2)F2vi—Li1—F2viii84.3 (8)
F1i—Pt1—F1iii97.8 (2)F2vi—Li1—F1ix89.5 (4)
F1ii—Pt1—F1iii180.0 (3)F2viii—Li1—F1ix89.5 (4)
F1i—Pt1—F1180.0F2vi—Li1—F189.5 (4)
F1ii—Pt1—F197.8 (2)F2viii—Li1—F189.5 (4)
F1iii—Pt1—F182.2 (2)F1ix—Li1—F1178.8 (11)
F1i—Pt1—F2i90.0F2vi—Li1—F1x176.0 (7)
F1ii—Pt1—F2i90.0F2viii—Li1—F1x99.71 (17)
F1iii—Pt1—F2i90.0F1ix—Li1—F1x90.5 (4)
F1—Pt1—F2i90.0F1—Li1—F1x90.5 (4)
F1i—Pt1—F290.0F2vi—Li1—F1xi99.71 (17)
F1ii—Pt1—F290.0F2viii—Li1—F1xi176.0 (7)
F1iii—Pt1—F290.0F1ix—Li1—F1xi90.5 (4)
F1—Pt1—F290.0F1—Li1—F1xi90.5 (4)
F2i—Pt1—F2180.00 (19)F1x—Li1—F1xi76.3 (7)
Symmetry codes: (i) x, y, z; (ii) x, y, z; (iii) x, y, z; (iv) y1/2, x+1/2, z+1/2; (v) y+1/2, x1/2, z1/2; (vi) x, y+1, z; (vii) x1, y, z; (viii) x+1, y, z; (ix) x+1, y+1, z; (x) y+1/2, x+1/2, z+1/2; (xi) y+1/2, x+1/2, z+1/2; (xii) x+1, y+1, z.

Experimental details

Crystal data
Chemical formulaLi2PtF6
Mr322.97
Crystal system, space groupTetragonal, P42/mnm
Temperature (K)150
a, c (Å)4.6427 (1), 9.1234 (2)
V3)196.65 (1)
Z2
Radiation typeMo Kα
µ (mm1)35.71
Crystal size (mm)0.05 × 0.05 × 0.04
Data collection
DiffractometerOxford Diffraction Xcalibur3
diffractometer
Absorption correctionMulti-scan
(CrysAlis RED; Oxford Diffraction, 2007)
Tmin, Tmax0.148, 1.000
No. of measured, independent and
observed [I > 2σ(I)] reflections
5829, 257, 184
Rint0.062
(sin θ/λ)max1)0.801
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.019, 0.052, 1.17
No. of reflections257
No. of parameters19
Δρmax, Δρmin (e Å3)2.51, 1.33

Computer programs: CrysAlis CCD (Oxford Diffraction, 2007), CrysAlis RED (Oxford Diffraction, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2007).

 

Acknowledgements

The author would like to thank the Deutsche Forschungsgemeinschaft for his Heisenberg fellowship, Professors R. Hoppe and B. Müller (Giessen, Germany) for the generous donation of Pt tubes and Pt used in this work, and Solvay Fluor for the donation of F2.

References

First citationBrandenburg, K. (2007). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationGraudejus, O., Wilkinson, A. P., Chacón, L. C. & Bartlett, N. (2000). Inorg. Chem. 39, 2794–2800.  Web of Science CrossRef PubMed CAS Google Scholar
First citationHenkel, H. & Hoppe, R. (1968). Z. Anorg. Allg. Chem. 359, 160–177.  CrossRef CAS Web of Science Google Scholar
First citationMüller, B. G. & Serafin, M. (1992). Eur. J. Solid State Inorg. Chem. 29, 625–633.  Google Scholar
First citationOxford Diffraction (2007). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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ISSN: 2056-9890
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