Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270101014342/jz1475sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270101014342/jz1475Isup2.hkl |
Single crystals of K3[SbO4] were obtained from stoichiometric mixtures of K (223.7 mg, 5.72 mmol), KO2 (293.7 mg, 4.12 mmol) and Sb2O3 (482.6 mg, 1.65 mmol). The samples were heated to 975 K in corundum crucibles under an argon atmosphere, and then cooled to 575 K at a rate of 5 K h-1 and to room temperature at 15 K h-1. The X-ray powder patterns of the reaction products can be indexed on the basis of the reported single-crystal data, but show additional weak reflections that cannot be assigned to any known phase. The colourless hygroscopic crystals of the title compound were handled in a dry box and mounted in capillaries filled with dry oil. The room temperature Raman spectra of single crystals of K3[SbO4] and Cs3[SbO4], sealed in Lindemann capillaries, were recorded with a Raman microscope attached to an FT spectrometer (Bruker IFS66V).
Because of the slightly higher values of the atomic displacement parameters of the K atoms, the site occupancy of the three positions was refined for testing purposes, converging on the ideal value of 0.5 to within experimental error. The maximum difference peak of 3.32 e Å-3 lies 0.83 Å from Sb1 and may be attributed to residual absorption errors.
Data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP (Johnson, 1968) and DRAWxtl (Finger & Kroeker, 1999); software used to prepare material for publication: SHELXL97.
K3[SbO4] | Z = 2 |
Mr = 303.05 | F(000) = 280 |
Monoclinic, P2/c | Dx = 5.153 Mg m−3 |
a = 5.7971 (12) Å | Mo Kα radiation, λ = 0.71070 Å |
b = 6.5933 (14) Å | µ = 10.14 mm−1 |
c = 5.4179 (12) Å | T = 293 K |
β = 109.394 (4)° | Irregular, colourless |
V = 195.33 (7) Å3 | 0.20 × 0.15 × 0.10 mm |
Bruker SMART CCD area-detector diffractometer | 468 independent reflections |
Radiation source: fine-focus sealed tube | 422 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.033 |
ω scans | θmax = 28.3°, θmin = 3.1° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −6→7 |
Tmin = 0.192, Tmax = 0.363 | k = −8→7 |
1160 measured reflections | l = −7→6 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.048 | w = 1/[σ2(Fo2) + (0.0848P)2 + 0.0284P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.122 | (Δ/σ)max < 0.001 |
S = 1.24 | Δρmax = 3.32 e Å−3 |
468 reflections | Δρmin = −2.83 e Å−3 |
40 parameters | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 restraints | Extinction coefficient: 0.128 (16) |
K3[SbO4] | V = 195.33 (7) Å3 |
Mr = 303.05 | Z = 2 |
Monoclinic, P2/c | Mo Kα radiation |
a = 5.7971 (12) Å | µ = 10.14 mm−1 |
b = 6.5933 (14) Å | T = 293 K |
c = 5.4179 (12) Å | 0.20 × 0.15 × 0.10 mm |
β = 109.394 (4)° |
Bruker SMART CCD area-detector diffractometer | 468 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 422 reflections with I > 2σ(I) |
Tmin = 0.192, Tmax = 0.363 | Rint = 0.033 |
1160 measured reflections |
R[F2 > 2σ(F2)] = 0.048 | 40 parameters |
wR(F2) = 0.122 | 0 restraints |
S = 1.24 | Δρmax = 3.32 e Å−3 |
468 reflections | Δρmin = −2.83 e Å−3 |
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. |
x | y | z | Uiso*/Ueq | ||
Sb1 | 0.5000 | 0.86977 (8) | 0.2500 | 0.0110 (4) | |
O1 | 0.2733 (11) | 0.3322 (9) | 0.5407 (12) | 0.0151 (11) | |
O2 | 0.3045 (11) | 0.0986 (8) | 0.0005 (11) | 0.0121 (11) | |
K1 | 0.5000 | 0.3832 (4) | 0.2500 | 0.0385 (10) | |
K2 | 0.0000 | 0.1253 (5) | 0.2500 | 0.0437 (12) | |
K3 | 0.0000 | 0.6099 (6) | 0.2500 | 0.0516 (13) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Sb1 | 0.0151 (6) | 0.0086 (6) | 0.0084 (5) | 0.000 | 0.0027 (3) | 0.000 |
O1 | 0.018 (3) | 0.016 (2) | 0.009 (2) | 0.002 (2) | 0.001 (2) | −0.002 (2) |
O2 | 0.015 (2) | 0.016 (2) | 0.004 (2) | 0.000 (2) | 0.0011 (19) | −0.0006 (18) |
K1 | 0.045 (2) | 0.034 (2) | 0.036 (2) | 0.000 | 0.0133 (18) | 0.000 |
K2 | 0.046 (2) | 0.037 (2) | 0.043 (3) | 0.000 | 0.007 (2) | 0.000 |
K3 | 0.055 (3) | 0.051 (3) | 0.054 (3) | 0.000 | 0.024 (2) | 0.000 |
Sb1—O1i | 1.949 (6) | K1—O1xiii | 2.387 (6) |
Sb1—O1ii | 1.949 (6) | K1—K1ii | 3.116 (3) |
Sb1—O2iii | 2.047 (6) | K1—K1iii | 3.116 (3) |
Sb1—O2iv | 2.047 (6) | K1—Sb1ii | 3.1813 (15) |
Sb1—O2v | 2.091 (6) | K1—Sb1iii | 3.1813 (15) |
Sb1—O2vi | 2.091 (6) | K1—K3ii | 3.2446 (5) |
Sb1—K1ii | 3.1813 (15) | K2—O1xiv | 2.279 (6) |
Sb1—K1iii | 3.1813 (15) | K2—O2xi | 2.355 (6) |
Sb1—Sb1vii | 3.2074 (8) | K2—O2xv | 2.355 (6) |
Sb1—Sb1viii | 3.2075 (8) | K2—O2xiv | 2.561 (6) |
Sb1—K1 | 3.208 (3) | K2—K2xvi | 3.173 (3) |
Sb1—K2ii | 3.2444 (5) | K2—K2xi | 3.173 (3) |
O1—Sb1ii | 1.949 (6) | K2—K3 | 3.195 (7) |
O1—K1ii | 2.355 (6) | K2—K3ix | 3.2229 (19) |
O1—K1 | 2.387 (6) | K2—K3xii | 3.2229 (19) |
O1—K2 | 2.279 (6) | K2—Sb1ii | 3.2444 (5) |
O1—K3ix | 2.266 (6) | K3—O1i | 2.266 (6) |
O1—K3 | 2.585 (7) | K3—O1ix | 2.266 (6) |
O2—Sb1iii | 2.047 (6) | K3—O1xiv | 2.585 (7) |
O2—Sb1x | 2.091 (6) | K3—O2iv | 2.657 (7) |
O2—K1 | 2.370 (6) | K3—O2xii | 2.657 (7) |
O2—K2xi | 2.355 (6) | K3—K3ix | 3.072 (4) |
O2—K2 | 2.561 (6) | K3—K3xii | 3.072 (4) |
O2—K3xii | 2.657 (7) | K3—K2ix | 3.2229 (19) |
K1—O1ii | 2.354 (6) | K3—K2xii | 3.2229 (19) |
K1—O1i | 2.354 (6) | K3—K1ii | 3.2446 (5) |
K1—O2xiii | 2.370 (6) | ||
O1i—Sb1—O1ii | 93.8 (3) | K2—O1—K1 | 92.1 (2) |
O1i—Sb1—O2iii | 95.7 (2) | K1ii—O1—K1 | 82.2 (2) |
O1ii—Sb1—O2iii | 92.3 (2) | Sb1ii—O1—K3 | 175.4 (3) |
O1i—Sb1—O2iv | 92.3 (2) | K3ix—O1—K3 | 78.27 (19) |
O1ii—Sb1—O2iv | 95.7 (2) | K2—O1—K3 | 81.8 (2) |
O2iii—Sb1—O2iv | 168.3 (3) | K1ii—O1—K3 | 82.0 (2) |
O1i—Sb1—O2v | 90.1 (3) | K1—O1—K3 | 81.9 (2) |
O1ii—Sb1—O2v | 170.2 (2) | Sb1iii—O2—Sb1x | 101.6 (3) |
O2iii—Sb1—O2v | 78.4 (3) | Sb1iii—O2—K2xi | 99.0 (2) |
O2iv—Sb1—O2v | 93.1 (2) | Sb1x—O2—K2xi | 93.5 (2) |
O1i—Sb1—O2vi | 170.2 (2) | Sb1iii—O2—K1 | 91.9 (2) |
O1ii—Sb1—O2vi | 90.1 (3) | Sb1x—O2—K1 | 98.6 (2) |
O2iii—Sb1—O2vi | 93.1 (2) | K2xi—O2—K1 | 161.8 (3) |
O2iv—Sb1—O2vi | 78.4 (3) | Sb1iii—O2—K2 | 166.7 (3) |
O2v—Sb1—O2vi | 87.6 (3) | Sb1x—O2—K2 | 91.7 (2) |
Sb1ii—O1—K3ix | 105.8 (3) | K2xi—O2—K2 | 80.28 (18) |
Sb1ii—O1—K2 | 100.0 (2) | K1—O2—K2 | 85.8 (2) |
K3ix—O1—K2 | 90.3 (2) | Sb1iii—O2—K3xii | 90.45 (19) |
Sb1ii—O1—K1ii | 95.9 (2) | Sb1x—O2—K3xii | 167.9 (3) |
K3ix—O1—K1ii | 89.8 (2) | K2xi—O2—K3xii | 85.2 (2) |
K2—O1—K1ii | 163.4 (3) | K1—O2—K3xii | 80.18 (19) |
Sb1ii—O1—K1 | 93.9 (2) | K2—O2—K3xii | 76.26 (18) |
K3ix—O1—K1 | 159.4 (3) |
Symmetry codes: (i) x, −y+1, z−1/2; (ii) −x+1, −y+1, −z+1; (iii) −x+1, −y+1, −z; (iv) x, −y+1, z+1/2; (v) x, y+1, z; (vi) −x+1, y+1, −z+1/2; (vii) −x+1, −y+2, −z+1; (viii) −x+1, −y+2, −z; (ix) −x, −y+1, −z+1; (x) x, y−1, z; (xi) −x, −y, −z; (xii) −x, −y+1, −z; (xiii) −x+1, y, −z+1/2; (xiv) −x, y, −z+1/2; (xv) x, −y, z+1/2; (xvi) −x, −y, −z+1. |
Experimental details
Crystal data | |
Chemical formula | K3[SbO4] |
Mr | 303.05 |
Crystal system, space group | Monoclinic, P2/c |
Temperature (K) | 293 |
a, b, c (Å) | 5.7971 (12), 6.5933 (14), 5.4179 (12) |
β (°) | 109.394 (4) |
V (Å3) | 195.33 (7) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 10.14 |
Crystal size (mm) | 0.20 × 0.15 × 0.10 |
Data collection | |
Diffractometer | Bruker SMART CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.192, 0.363 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 1160, 468, 422 |
Rint | 0.033 |
(sin θ/λ)max (Å−1) | 0.666 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.048, 0.122, 1.24 |
No. of reflections | 468 |
No. of parameters | 40 |
Δρmax, Δρmin (e Å−3) | 3.32, −2.83 |
Computer programs: SMART (Bruker, 1999), SAINT (Bruker, 1999), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP (Johnson, 1968) and DRAWxtl (Finger & Kroeker, 1999), SHELXL97.
Sb1—O1i | 1.949 (6) | O1—K3v | 2.266 (6) |
Sb1—O2ii | 2.047 (6) | O1—K3 | 2.585 (7) |
Sb1—O2iii | 2.091 (6) | O2—K1 | 2.370 (6) |
O1—K1iv | 2.355 (6) | O2—K2vi | 2.355 (6) |
O1—K1 | 2.387 (6) | O2—K2 | 2.561 (6) |
O1—K2 | 2.279 (6) | O2—K3vii | 2.657 (7) |
O1i—Sb1—O1iv | 93.8 (3) | O1iv—Sb1—O2iii | 170.2 (2) |
O1i—Sb1—O2ii | 95.7 (2) | O2ii—Sb1—O2iii | 78.4 (3) |
O1iv—Sb1—O2ii | 92.3 (2) | O2viii—Sb1—O2iii | 93.1 (2) |
O2ii—Sb1—O2viii | 168.3 (3) | O2iii—Sb1—O2ix | 87.6 (3) |
O1i—Sb1—O2iii | 90.1 (3) |
Symmetry codes: (i) x, −y+1, z−1/2; (ii) −x+1, −y+1, −z; (iii) x, y+1, z; (iv) −x+1, −y+1, −z+1; (v) −x, −y+1, −z+1; (vi) −x, −y, −z; (vii) −x, −y+1, −z; (viii) x, −y+1, z+1/2; (ix) −x+1, y+1, −z+1/2. |
In the crystal structures of the known alkali metal (A) antimonates(V), [SbO6] octahedra form the important structural building blocks. In compounds with a low alkali metal content, these octahedra are connected via common edges to form complex three-dimensional channel structures (A = K: Hong, 1974; A = Rb or Cs: Hirschle et al., 2001). A similar structural chemistry is exhibited by compounds of the formula AMO3, which are known for nearly all alkali metals and which display the ilmenite or the defect pyrochlore structure. In the series of alkali-metal-rich antimonates A3SbO4, only the first (A = Li: Skakle et al., 1996) and the last (A = Cs: Hirschle & Röhr, 2000) members have been characterized by single-crystal data. Hoppe and co-workers (Schwedes & Hoppe, 1972) inferred from indexed powder patterns that Na3SbO4 is isotypic with the Li compound, and unindexed powder patterns by Duquenoy (Duquenoy, 1974; Josien & Duquenoy, 1980) indicate an isotypic relationship between the Rb and Cs compounds. Whereas the crystal structures of the Li (and Na) phase show chains of edge-sharing [SbO6] octahedra, the Cs (and Rb) compounds are characterized by isolated [SbO4]3- tetrahedra. The title compound is thus at the boundary between two structure families, which makes it a likely candidate for polytypic behaviour.
K3[SbO4] crystallizes in the monoclinic spacegroup P2/c with the Na3[BiO4] (Schwedes & Hoppe, 1972) structure type. In the crystal structure, [SbO2O4/2]3- octahedra are connected via two trans-oriented edges to form chains running parallel to the crystallographic c axis (Fig. 1); the Sb atoms are located on the twofold axis at 1/2,y,1/4.
The two terminal Sb—O bond lengths are 1.949 (6) Å (Sb—O1), whereas the bridging Sb—O bonds (Sb—O2) are significantly longer, at 2.047 (6) and 2.091 (6) Å, respectively. The O—Sb—O bond angles in the octahedra vary from 78.4 (3) to 95.7 (2)°.
The three crystallographically independent K+ cations all lie on twofold axes {K1: 1/2,y,1/4 [2(f)]; K2, K3: 0,y,1/4 [2(e)]} and are also located at the centres of the O-octahedra [K—O 2.266 (6)–2.657 (7) Å]. The structure can thus alternatively be described as a cubic close-packed arrangement of O2- ions, with the K+ and Sb5+ cations located in all the octahedral holes, i.e. an order variant of the NaCl structure.
Whereas the corresponding Li (Skakle et al., 1996) and Na (Schwedes & Hoppe, 1972) compounds are isotypic with the title compound, Cs3[SbO4] (Hirschle & Röhr, 2000) and Rb3[SbO4] (only characterized via indexed powder patterns) form structures with isolated [SbO4]3- tetrahedra and significantly shorter Sb—O bond distances. The main differences between the two structure families are also easily seen in the Raman spectra of Cs3[SbO4] and the title compound (Fig. 3): in the Cs compound, the totally symmetric stretching mode of the slightly distorted [SbO4] tetrahedra gives rise to strong bands at 710 and 722 cm-1 (Sb—O 1.78–1.89 Å). In the spectrum of K3[SbO4], the Sb—O stretching modes are shifted towards smaller wavenumbers: the band at 670 cm-1 can be assigned to the terminal Sb—O stretching mode [Sb—O1 1.949 (6) Å], while the two bands at 607 and 567 cm-1 result from the two longer bridging Sb—O2 bonds.