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Acta Crystallogr Sect E Struct Rep Online. 2009 November 1; 65(Pt 11): i78.
Published online 2009 October 17. doi:  10.1107/S1600536809041622
PMCID: PMC2971031

Dipotassium samarium(III) molybdate(VI) phosphate(V), K2Sm(MoO4)(PO4)

Abstract

The title compound, K2Sm(MoO4)(PO4), has been prepared under atmospheric conditions using a high temperature solution growth (HTSG) method. The structure of K2Sm(MoO4)(PO4) is isotypic with other A 2 M(MoO4)(PO4) compounds, where A = Na or K, and M = trivalent rare earth cation. It can be described as being built up from two-dimensional anionic layers with composition [Sm(MoO4)(PO4)]2− that are stacked along the c axis and are inter­connected by K+ cations which are in an eightfold coordination by O atoms. The SmO8, MoO4 and PO4 polyhedra exhibit 2 symmetry.

Related literature

The structures and properties of other molybdate-phosphates with the general formula A 2 M(MoO4)(PO4), where A = Na, K; M = Y, Bi, La—Nd, Sm—Lu, have been reported by Ben Amara & Dabbabi (1987 [triangle]); Komissarova et al. (2006 [triangle]); Ryumin et al. (2007 [triangle]); Zatovsky et al. (2006 [triangle]). For crystallographic background, see: Spek (2009 [triangle]).

Experimental

Crystal data

  • K2Sm(MoO4)(PO4)
  • M r = 483.46
  • Orthorhombic, An external file that holds a picture, illustration, etc.
Object name is e-65-00i78-efi1.jpg
  • a = 12.345 (9) Å
  • b = 7.004 (5) Å
  • c = 19.733 (12) Å
  • V = 1706 (2) Å3
  • Z = 8
  • Mo Kα radiation
  • μ = 9.46 mm−1
  • T = 298 K
  • 0.15 × 0.10 × 0.05 mm

Data collection

  • Rigaku Saturn 70 diffractometer
  • Absorption correction: multi-scan (CrystalClear; Rigaku, 2000 [triangle]) T min = 0.742, T max = 1.000
  • 3660 measured reflections
  • 979 independent reflections
  • 903 reflections with I > 2σ(I)
  • R int = 0.022

Refinement

  • R[F 2 > 2σ(F 2)] = 0.014
  • wR(F 2) = 0.079
  • S = 1.01
  • 979 reflections
  • 61 parameters
  • Δρmax = 0.85 e Å−3
  • Δρmin = −0.99 e Å−3

Data collection: CrystalClear (Rigaku, 2000 [triangle]); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: SHELXTL (Sheldrick, 2008 [triangle]) and DIAMOND (Brandenburg & Putz, 2005 [triangle]); software used to prepare material for publication: SHELXTL.

Table 1
Selected bond lengths (Å)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809041622/wm2263sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809041622/wm2263Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

We thank Dr Yougui Huang and Qingxia Yao for fruitful discussions concerning the crystal structure and for help with graphics.

supplementary crystallographic information

Comment

In recent years, several complex molybdate-phosphates with the general formula A2M(MoO4)(PO4) (A = Na, K; M= Y, Bi, La—Nd, Sm—Lu) have been reported (Ben Amara & Dabbabi, 1987); Komissarova et al., 2006; Ryumin et al., 2007; Zatovsky et al., 2006). Herein, we present synthesis and crystal structure of the title compound, K2Sm(MoO4)(PO4).

X-ray analysis revealed that the compound K2Sm(MoO4)(PO4) crystallizes in the orthorhombic system with space group Ibca (Fig. 1). The asymmetric unit contains one K, one Sm, one Mo, one P and four O atoms. Each of the Mo and P atoms is tetrahedrally coordinated by four O atoms, forming nearly ideal MoO4 and PO4 tetrahedra with two types of Mo–O (1.743 (3) Å, 1.784 (3) Å) and P–O distances (1.533 (3) Å, 1.549 (3) Å), respectively. The Sm atom is surrounded by eight oxygen atoms in a distorted dodecahedral environment with the Sm–O bond distances in the range of 2.339 (3)–2.481 (3) Å. MoO4, PO4 and SmO8 polyhedra are interconnected via corner- or edge-sharing O atoms forming a two-dimensional anionic layer of overall composition [Sm(MoO4)(PO4)]2- extending parallel to the ab-plane, as shown in Fig. 2. Furthermore, the anionic framework delimits large cages in which the K+ cations (coordination number 8) reside to ensure the cohesion of the structure and the neutrality of the compound, resulting in a three-dimensional framework structure.

Experimental

Single crystals of K2Sm(MoO4)(PO4) were obtained by the high temperature solution growth (HTSG) reaction of K2CO3 (2.253 g, 16.3 mmol), Sm2O3 (0.569g, 1.63 mmol), MoO3 (0.939 g, 6.52 mmol) and NH4H2PO4 (3.000 g, 26.1 mmol), with the molar ratio of 10:1:2:8 (K:Sm:Mo:P). The reaction mixture was thoroughly ground in an agate mortar and pressed into a pellet to ensure the best homogeneity and reactivity. The pellet was put into a platinum crucible and calcined at 673 K or 10 h to decompose the salts. Then the crucible was transferred to another furnace and heated at 1223 K for 48 h. Then the sample was cooled from 1173 K at a rate of 4 Kh-1. After boiling for 24 h in water, a few prism-shaped colorless crystals were obtained in very low yield (<5%).

Figures

Fig. 1.
Part of the structure of the title compound, showing the labelling of the atoms. Displacement ellipsoids are drawn at the 50% probability level. [Symmetry codes: (a) - X, 1/2 - Y, Z (b) X, - Y, 1/2 – Z (c) - X, 1/2 + Y, 1/2 – Z (e) X, ...

Crystal data

K2Sm(MoO4)(PO4)F(000) = 1768
Mr = 483.46Dx = 3.764 Mg m3
Orthorhombic, IbcaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -I 2b 2cCell parameters from 369 reflections
a = 12.345 (9) Åθ = 3.1–27.4°
b = 7.004 (5) ŵ = 9.46 mm1
c = 19.733 (12) ÅT = 298 K
V = 1706 (2) Å3Prism, colourless
Z = 80.15 × 0.10 × 0.05 mm

Data collection

Rigaku Saturn 70 diffractometer979 independent reflections
Radiation source: fine-focus sealed tube903 reflections with I > 2σ(I)
graphiteRint = 0.022
Detector resolution: 14.6306 pixels mm-1θmax = 27.5°, θmin = 2.1°
ω scansh = −15→15
Absorption correction: multi-scan (CrystalClear; Rigaku, 2000)k = −9→8
Tmin = 0.742, Tmax = 1.000l = −25→25
3660 measured reflections

Refinement

Refinement on F20 restraints
Least-squares matrix: fullPrimary atom site location: structure-invariant direct methods
R[F2 > 2σ(F2)] = 0.014Secondary atom site location: difference Fourier map
wR(F2) = 0.079w = 1/[σ2(Fo2) + (0.063P)2] where P = (Fo2 + 2Fc2)/3
S = 1.01(Δ/σ)max < 0.001
979 reflectionsΔρmax = 0.85 e Å3
61 parametersΔρmin = −0.99 e Å3

Special details

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. Single crystal of K2Sm(MoO4)(PO4)with dimensions of 0.15 mm×0.10 mm×0.05 mm was selected for single-crystal X-ray diffraction determination. The diffraction data of K2Sm(MoO4)(PO4) were collected on a Rigaku Saturn70 CCD diffractometer with graphite-monochromated Mo—Ka radiation (λ = 0.71073 Å). Intensity data were collected by the narrow frame method at 298 K. The data were corrected for Lorentz factor, polarization, air absorption and absorption due to variations in the path length through the detector faceplate. Absorption corrections based on Multi-scan technique were also applied (CrystalClear. ver. 1.3.5.,Rigaku Corp., Woodlands, TX, 1999). The single-crystal refinement was performed with the program SHELX97. The spacegroup was determined to be Ibca based on systematic absences as well as E-value statistics. The structure was solved by the direct methods and the molybdenum and phosphorus atoms were revealed. Subsequent difference-Fourier syntheses by full-matrix least-squares fitting on F2 allowed localization of potassium and all oxygen atoms. The final structure refinement performed by least-square methods with atomic coordinates and anisotropic thermal parameters resulted in satisfactory residuals. In addition, the final refined solutions obtained for were checked with the ADDSYM algorithm in the program PLATON (Spek, 2009) and no higher symmetries were found.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)

xyzUiso*/Ueq
K10.17099 (8)0.28431 (16)0.09418 (5)0.0233 (3)
Sm10.42384 (2)0.50000.25000.00627 (15)
Mo10.50000.25000.08208 (2)0.01213 (17)
P10.17826 (12)0.50000.25000.0066 (4)
O10.0995 (3)0.6698 (4)0.26009 (13)0.0111 (6)
O20.2522 (3)0.5240 (3)0.18818 (14)0.0113 (6)
O30.4690 (3)0.4533 (5)0.13294 (14)0.0177 (6)
O40.3879 (3)0.1914 (5)0.03256 (15)0.0292 (8)

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
K10.0327 (6)0.0226 (5)0.0147 (4)−0.0016 (4)−0.0042 (4)−0.0018 (4)
Sm10.0049 (2)0.0050 (2)0.0090 (2)0.0000.0000.00005 (8)
Mo10.0142 (3)0.0153 (3)0.0069 (3)0.00155 (19)0.0000.000
P10.0041 (8)0.0042 (9)0.0115 (8)0.0000.0000.0001 (4)
O10.0065 (13)0.0058 (15)0.0212 (13)0.0000 (12)−0.0006 (11)−0.0018 (11)
O20.0085 (14)0.0139 (14)0.0116 (13)−0.0026 (11)−0.0010 (12)0.0021 (10)
O30.0228 (18)0.0192 (15)0.0112 (13)0.0032 (14)0.0029 (12)−0.0013 (12)
O40.032 (2)0.033 (2)0.0224 (15)−0.0012 (16)−0.0163 (15)0.0016 (14)

Geometric parameters (Å, °)

K1—O4i2.685 (3)Mo1—O4ix1.743 (3)
K1—O22.695 (3)Mo1—O41.743 (3)
K1—O2ii2.768 (3)Mo1—O31.784 (3)
K1—O3ii2.991 (4)Mo1—O3ix1.784 (3)
K1—O43.012 (4)P1—O21.533 (3)
K1—O1iii3.025 (3)P1—O2iii1.533 (3)
K1—O4iv3.184 (4)P1—O1iii1.549 (3)
K1—O3v3.191 (4)P1—O11.549 (3)
Sm1—O1ii2.339 (3)O1—Sm1vi2.339 (3)
Sm1—O1vi2.339 (3)O1—Sm1x2.481 (3)
Sm1—O32.399 (3)O1—K1iii3.025 (3)
Sm1—O3iii2.399 (3)O2—K1iv2.768 (3)
Sm1—O22.451 (3)O3—K1iv2.991 (4)
Sm1—O2iii2.451 (3)O3—K1viii3.191 (4)
Sm1—O1vii2.481 (3)O4—K1i2.685 (3)
Sm1—O1viii2.481 (3)O4—K1ii3.184 (4)
O4i—K1—O2153.25 (10)O3iii—Sm1—O1vii78.98 (10)
O4i—K1—O2ii123.87 (11)O2—Sm1—O1vii133.07 (9)
O2—K1—O2ii79.73 (9)O2iii—Sm1—O1vii145.94 (9)
O4i—K1—O3ii83.90 (10)O1ii—Sm1—O1viii68.11 (13)
O2—K1—O3ii121.45 (10)O1vi—Sm1—O1viii126.05 (8)
O2ii—K1—O3ii61.05 (10)O3—Sm1—O1viii78.98 (10)
O4i—K1—O479.19 (11)O3iii—Sm1—O1viii77.59 (10)
O2—K1—O494.69 (10)O2—Sm1—O1viii145.94 (9)
O2ii—K1—O479.85 (10)O2iii—Sm1—O1viii133.07 (9)
O3ii—K1—O4116.70 (11)O1vii—Sm1—O1viii58.14 (15)
O4i—K1—O1iii146.34 (11)O4ix—Mo1—O4111.8 (2)
O2—K1—O1iii52.27 (9)O4ix—Mo1—O3107.33 (15)
O2ii—K1—O1iii62.16 (9)O4—Mo1—O3109.46 (16)
O3ii—K1—O1iii70.78 (8)O4ix—Mo1—O3ix109.46 (16)
O4—K1—O1iii131.75 (9)O4—Mo1—O3ix107.33 (15)
O4i—K1—O4iv78.43 (8)O3—Mo1—O3ix111.5 (2)
O2—K1—O4iv77.88 (9)O2—P1—O2iii106.9 (3)
O2ii—K1—O4iv157.51 (9)O2—P1—O1iii110.83 (15)
O3ii—K1—O4iv131.29 (10)O2iii—P1—O1iii113.07 (14)
O4—K1—O4iv104.03 (10)O2—P1—O1113.08 (14)
O1iii—K1—O4iv101.61 (9)O2iii—P1—O1110.83 (15)
O4i—K1—O3v98.70 (10)O1iii—P1—O1102.3 (3)
O2—K1—O3v76.53 (10)P1—O1—Sm1vi145.66 (18)
O2ii—K1—O3v119.10 (9)P1—O1—Sm1x99.81 (16)
O3ii—K1—O3v86.19 (11)Sm1vi—O1—Sm1x111.05 (13)
O4—K1—O3v156.35 (10)P1—O1—K1iii91.19 (13)
O1iii—K1—O3v58.87 (8)Sm1vi—O1—K1iii90.67 (9)
O4iv—K1—O3v52.93 (8)Sm1x—O1—K1iii112.46 (9)
O1ii—Sm1—O1vi165.83 (15)P1—O2—Sm196.39 (15)
O1ii—Sm1—O388.61 (10)P1—O2—K1104.95 (15)
O1vi—Sm1—O394.68 (10)Sm1—O2—K1128.43 (12)
O1ii—Sm1—O3iii94.68 (10)P1—O2—K1iv144.03 (15)
O1vi—Sm1—O3iii88.61 (10)Sm1—O2—K1iv94.74 (11)
O3—Sm1—O3iii153.13 (16)K1—O2—K1iv94.39 (10)
O1ii—Sm1—O290.20 (9)Mo1—O3—Sm1134.48 (17)
O1vi—Sm1—O277.48 (9)Mo1—O3—K1iv126.79 (14)
O3—Sm1—O274.39 (11)Sm1—O3—K1iv90.36 (10)
O3iii—Sm1—O2132.14 (11)Mo1—O3—K1viii99.04 (13)
O1ii—Sm1—O2iii77.48 (9)Sm1—O3—K1viii109.51 (11)
O1vi—Sm1—O2iii90.20 (9)K1iv—O3—K1viii86.78 (10)
O3—Sm1—O2iii132.14 (11)Mo1—O4—K1i132.86 (18)
O3iii—Sm1—O2iii74.39 (11)Mo1—O4—K1115.37 (15)
O2—Sm1—O2iii60.33 (15)K1i—O4—K194.75 (10)
O1ii—Sm1—O1vii126.05 (8)Mo1—O4—K1ii100.26 (13)
O1vi—Sm1—O1vii68.11 (13)K1i—O4—K1ii120.73 (12)
O3—Sm1—O1vii77.59 (10)K1—O4—K1ii80.58 (9)

Symmetry codes: (i) −x+1/2, y, −z; (ii) −x+1/2, y−1/2, z; (iii) x, −y+1, −z+1/2; (iv) −x+1/2, y+1/2, z; (v) x−1/2, −y+1, z; (vi) −x+1/2, −y+3/2, −z+1/2; (vii) x+1/2, y, −z+1/2; (viii) x+1/2, −y+1, z; (ix) −x+1, −y+1/2, z; (x) x−1/2, y, −z+1/2.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: WM2263).

References

  • Ben Amara, M. & Dabbabi, M. (1987). Acta Cryst. C43, 616–618.
  • Brandenburg, K. & Putz, H. (2005). DIAMOND Crystal Impact GbR, Bonn, Germany.
  • Komissarova, L. N., Ryumin, M. A., Bobylev, A. P., Zhizhin, M. G. & Danilov, V. P. (2006). Russ. J. Inorg. Chem.51, 397–403.
  • Rigaku (2000). CrystalClear Rigaku Corporation, Tokyo, Japan.
  • Ryumin, M. A., Komissarova, L. N., Rusakov, D. A., Bobylev, A. P. & Zhizhin, M. G. (2007). Russ. J. Inorg. Chem.52, 717–724.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Spek, A. L. (2009). Acta Cryst. D65, 148–155. [PMC free article] [PubMed]
  • Zatovsky, I. V., Terebilenko, K. V., Slobodyanik, N. S., Baumer, V. N. & Shishkin, O. V. (2006). J. Solid State Chem.179, 3550–3555.

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