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

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ISSN: 2056-9890

Tricaesium dimolybdate(VI) bromide

aSt Petersburg State University, Universitetskaya nab. 7/9, 199034 St Petersburg, Russian Federation
*Correspondence e-mail: a.s.pakhomova@mail.ru

(Received 28 October 2009; accepted 3 November 2009; online 7 November 2009)

The title compound, Cs3(Mo2O7)Br, was synthesized by the reaction of CsNO3, MoO3 and 1-ethyl-3-methyl­imidazolium bromide. Its crystal structure is isotypic with K3(Mo2O7)Br and contains (MoO4)2− tetra­hedra which share an O atom to produce a [Mo2O7]2− dimolybdate(VI) anion with a linear bridging angle and [\overline{6}]m2 symmetry. The anions are linked by Cs atoms (site symmetry [\overline{6}]m2), forming sheets parallel to (001). Br atoms (site symmetry [\overline{6}]m2) are also part of this layer. Another type of Cs atom (3m site symmetry) is located in the inter­layer space and connects the layers via Cs—O and Cs—Br inter­actions into a three-dimensional array.

Related literature

For the isotypic compound K3(Mo2O7)Br, see: Becher & Fenske (1978[Becher, H. J. & Fenske, D. (1978). J. Chem. Res. (S), 167.]). For dimolybdates with similar condensed anions made up of MoO4 tetra­hedra, see: Ce2(MoO4)2(Mo2O7) (Fallon & Gatehouse, 1982[Fallon, G. D. & Gatehouse, B. M. (1982). J. Solid State Chem. 44, 156-161.]); Mg2Mo2O7 (Stadnicka et al., 1977[Stadnicka, K., Haber, J. & Kozłowski, R. (1977). Acta Cryst. B33, 3859-3862.]).

Experimental

Crystal data
  • Cs3(Mo2O7)Br

  • Mr = 782.52

  • Hexagonal, P 63 /m m c

  • a = 6.3993 (5) Å

  • c = 16.4870 (15) Å

  • V = 584.71 (8) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 14.77 mm−1

  • T = 293 K

  • 0.15 × 0.15 × 0.05 mm

Data collection
  • Stoe IPDS-2 diffractometer

  • Absorption correction: integration (X-RED and X-SHAPE; Stoe, 2005[Stoe (2005). X-RED and X-SHAPE. Stoe & Cie, Darmstadt, Germany.]) Tmin = 0.153, Tmax = 0.532

  • 5224 measured reflections

  • 344 independent reflections

  • 338 reflections with I > 2σ(I)

  • Rint = 0.044

Refinement
  • R[F2 > 2σ(F2)] = 0.025

  • wR(F2) = 0.062

  • S = 1.18

  • 344 reflections

  • 20 parameters

  • Δρmax = 0.60 e Å−3

  • Δρmin = −1.21 e Å−3

Table 1
Selected bond lengths (Å)

Mo—O1 1.725 (4)
Mo—O2 1.8764 (7)

Data collection: X-AREA (Stoe, 2007[Stoe (2007). X-AREA. Stoe & Cie, Darmstadt, Germany.]); cell refinement: X-AREA; data reduction: X-RED (Stoe, 2005[Stoe (2005). X-RED and X-SHAPE. Stoe & Cie, Darmstadt, Germany.]); 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: ATOMS (Dowty, 1999[Dowty, E. (1999). ATOMS. Shape Software, Kingsport, Tennessee, USA.]); software used to prepare material for publication: publCIF (Westrip, 2009[Westrip, S. P. (2009). publCIF. In preparation.]).

Supporting information


Comment top

The structure of Cs3(Mo2O7)Br contains one symmetrically independent Mo6+ cation which is tetrahedrally coordinated by O atoms. Two (MoO4)2- tetrahedra share a common O2 atom to form a [Mo2O7]2- dimolybdate(VI) anion. The Mo—O2—Mo bond angle is linear and oriented along [001] (Fig. 1). In other dimolybdates(VI), this fragment differs from linearity and Mo—O—Mo bond angles range from 141.4° (Ce2(MoO4)2(Mo2O7); Fallon & Gatehouse, 1982) to 160.6° (Mg2Mo2O7; Stadnicka et al., 1977). The corner linkage of tetrahedra is associated with bond-length distortions: the <Mo—O1> bond length is 1.725 (4) Å, whereas the <Mo—O2> bond-length is 1.8764 (7) Å; the O—Mo—O bond angles range from 108.34 (14)° (for <O1—Mo—O1>) to 110.58 (13)° (for <O1—Mo—O2>). The structure also contains two symmetrically independent Cs atoms and one Br atom. Cs1 is coordinated by nine O atoms and one Br atom, whereas Cs2 is coordinated by six O atoms and three Br atoms. The <Cs—O> bond lengths are in the range from 3.126 (4) Å to 3.239 (4) Å. The <Cs—Br> bond lengths are 3.4268 (6) Å and 3.6946 (3) Å. The [Mo2O7]2- anions are linked by Cs2 atoms to form sheets running parallel to (001). The three-dimensional connectivity of the structure is provided by Cs1 atoms located in the interlayer (Fig. 2).

Related literature top

For the isostructural compound K3(Mo2O7)Br, see: Becher & Fenske (1978). For dimolybdates with similar condensed anions made up of MoO4 tetrahedra, see: Ce2(MoO4)2(Mo2O7) (Fallon & Gatehouse, 1982); Mg2Mo2O7 (Stadnicka et al., 1977).

Experimental top

The title compound was prepared by the reaction of CsNO3 (0.192 g), MoO3 (0.146 g) and the ionic-liquid salt 1-ethyl-3-methylimidazolium bromide, [emim]Br (0.451 g). The mixture was heated to 453 K for 3 days in a teflon-lined steel autoclave with an internal volume of 20 ml. The obtained crystals were washed out with distilled water and dried in air at room temperature. A suitable colorless plate-shaped single-crystal was selected for X-ray structure analysis.

Computing details top

Data collection: X-AREA (Stoe, 2007); cell refinement: X-AREA (Stoe, 2007); data reduction: X-RED (Stoe, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ATOMS (Dowty, 1999); software used to prepare material for publication: publCIF (Westrip, 2009).

Figures top
[Figure 1] Fig. 1. View of the linear [Mo2O7]2- anion. Ellipsoids are drawn at the 50% probability level. [Symmetry codes: (iv) -y+1, x-y-1, z; (x) -x+y+2, -x, -z-1/2; (xi) -y, x-y-2, -z-1/2; (xii) x, y, -z-1/2; (xvii) -x+y+2, -x+1, z.]
[Figure 2] Fig. 2. The crystal structure of Cs3(Mo2O7)Br in a projection approximately on (110). Cs atoms are represented as light-purple spheres and Br atoms as green spheres; MoO4 tetrahedra are given in yellow and orange. Ellipsoids are drawn at the 50% probability level.
Tricaesium bromide dimolybdate top
Crystal data top
Cs3(Mo2O7)BrDx = 4.445 Mg m3
Mr = 782.52Mo Kα radiation, λ = 0.71073 Å
Hexagonal, P63/mmcCell parameters from 5704 reflections
Hall symbol: -P 6c 2cθ = 2.5–29.5°
a = 6.3993 (5) ŵ = 14.77 mm1
c = 16.4870 (15) ÅT = 293 K
V = 584.71 (8) Å3Plate, colorless
Z = 20.15 × 0.15 × 0.05 mm
F(000) = 680
Data collection top
Stoe IPDS-2
diffractometer
344 independent reflections
Radiation source: fine-focus sealed tube338 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.044
Detector resolution: 6.67 pixels mm-1θmax = 29.2°, θmin = 2.5°
rotation method scansh = 88
Absorption correction: integration
(X-RED and X-SHAPE; Stoe & Cie, 2007)
k = 78
Tmin = 0.153, Tmax = 0.532l = 2122
5224 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)] = 0.025 w = 1/[σ2(Fo2) + (0.0295P)2 + 2.906P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.062(Δ/σ)max < 0.001
S = 1.18Δρmax = 0.60 e Å3
344 reflectionsΔρmin = 1.21 e Å3
20 parametersExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.0306 (16)
Crystal data top
Cs3(Mo2O7)BrZ = 2
Mr = 782.52Mo Kα radiation
Hexagonal, P63/mmcµ = 14.77 mm1
a = 6.3993 (5) ÅT = 293 K
c = 16.4870 (15) Å0.15 × 0.15 × 0.05 mm
V = 584.71 (8) Å3
Data collection top
Stoe IPDS-2
diffractometer
344 independent reflections
Absorption correction: integration
(X-RED and X-SHAPE; Stoe & Cie, 2007)
338 reflections with I > 2σ(I)
Tmin = 0.153, Tmax = 0.532Rint = 0.044
5224 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.02520 parameters
wR(F2) = 0.0620 restraints
S = 1.18Δρmax = 0.60 e Å3
344 reflectionsΔρmin = 1.21 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
Cs11.33330.33330.04215 (3)0.0227 (2)
Cs20.66670.66670.25000.0265 (3)
Mo1.00000.00000.13619 (4)0.0166 (2)
O10.8543 (4)0.2913 (7)0.0994 (2)0.0274 (9)
O21.00000.00000.25000.029 (2)
Br1.33330.33330.25000.0365 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cs10.0239 (3)0.0239 (3)0.0204 (3)0.01194 (14)0.0000.000
Cs20.0274 (3)0.0274 (3)0.0246 (4)0.01372 (17)0.0000.000
Mo0.0183 (3)0.0183 (3)0.0130 (4)0.00917 (14)0.0000.000
O10.0328 (18)0.018 (2)0.0265 (18)0.0091 (10)0.0023 (7)0.0046 (15)
O20.040 (4)0.040 (4)0.008 (4)0.0200 (19)0.0000.000
Br0.0434 (6)0.0434 (6)0.0227 (7)0.0217 (3)0.0000.000
Geometric parameters (Å, º) top
Cs1—O1i3.126 (4)Cs2—O2xv3.6946 (3)
Cs1—O1ii3.126 (4)Cs2—O2xiv3.6946 (3)
Cs1—O1iii3.126 (4)Cs2—O23.6946 (3)
Cs1—O1iv3.3441 (12)Cs2—Brxvi3.6946 (3)
Cs1—O1v3.3441 (12)Mo—O1iv1.725 (4)
Cs1—O13.3441 (12)Mo—O1xvii1.725 (4)
Cs1—O1vi3.3441 (12)Mo—O11.725 (4)
Cs1—O1vii3.3441 (12)Mo—O21.8764 (7)
Cs1—O1viii3.3441 (12)Mo—Cs1xviii4.0067 (4)
Cs1—Br3.4268 (6)Mo—Cs1xvi4.0067 (4)
Cs1—Cs1ix3.9475 (5)Mo—Cs2xviii4.1438 (4)
Cs1—Cs1iii3.9475 (5)Mo—Cs2xix4.1438 (4)
Cs2—O1x3.239 (4)O1—Cs1iii3.126 (4)
Cs2—O1v3.239 (4)O1—Cs1xvi3.3441 (12)
Cs2—O1xi3.239 (4)O2—Moxii1.8764 (7)
Cs2—O13.239 (4)O2—Cs2xviii3.6946 (3)
Cs2—O1xii3.239 (4)O2—Cs2xix3.6946 (3)
Cs2—O1xiii3.239 (4)Br—Cs1xii3.4268 (6)
Cs2—Brxiv3.6946 (3)Br—Cs2xix3.6946 (3)
Cs2—Br3.6946 (3)Br—Cs2vi3.6946 (3)
O1i—Cs1—O1ii70.37 (12)O1v—Cs2—O2xv50.04 (7)
O1i—Cs1—O1iii70.37 (12)O1xi—Cs2—O2xv108.73 (3)
O1ii—Cs1—O1iii70.37 (12)O1—Cs2—O2xv108.73 (3)
O1i—Cs1—O1iv68.67 (13)O1xii—Cs2—O2xv108.73 (3)
O1ii—Cs1—O1iv104.90 (6)O1xiii—Cs2—O2xv108.73 (3)
O1iii—Cs1—O1iv137.64 (3)Brxiv—Cs2—O2xv60.0
O1i—Cs1—O1v104.90 (6)Br—Cs2—O2xv60.0
O1ii—Cs1—O1v137.64 (3)O1x—Cs2—O2xiv108.73 (3)
O1iii—Cs1—O1v68.67 (13)O1v—Cs2—O2xiv108.73 (3)
O1iv—Cs1—O1v112.36 (6)O1xi—Cs2—O2xiv50.04 (7)
O1i—Cs1—O168.67 (13)O1—Cs2—O2xiv108.73 (3)
O1ii—Cs1—O1137.64 (3)O1xii—Cs2—O2xiv108.73 (3)
O1iii—Cs1—O1104.90 (6)O1xiii—Cs2—O2xiv50.04 (7)
O1iv—Cs1—O149.43 (14)Brxiv—Cs2—O2xiv60.0
O1v—Cs1—O165.19 (14)Br—Cs2—O2xiv180.0
O1i—Cs1—O1vi137.64 (3)O2xv—Cs2—O2xiv120.0
O1ii—Cs1—O1vi68.67 (13)O1x—Cs2—O2108.73 (3)
O1iii—Cs1—O1vi104.90 (6)O1v—Cs2—O2108.73 (3)
O1iv—Cs1—O1vi112.36 (6)O1xi—Cs2—O2108.73 (3)
O1v—Cs1—O1vi112.36 (6)O1—Cs2—O250.04 (7)
O1—Cs1—O1vi146.20 (13)O1xii—Cs2—O250.04 (7)
O1i—Cs1—O1vii104.90 (6)O1xiii—Cs2—O2108.73 (3)
O1ii—Cs1—O1vii68.67 (13)Brxiv—Cs2—O2180.0
O1iii—Cs1—O1vii137.64 (3)Br—Cs2—O260.0
O1iv—Cs1—O1vii65.19 (14)O2xv—Cs2—O2120.0
O1v—Cs1—O1vii146.20 (13)O2xiv—Cs2—O2120.0
O1—Cs1—O1vii112.36 (6)O1x—Cs2—Brxvi129.96 (7)
O1vi—Cs1—O1vii49.43 (14)O1v—Cs2—Brxvi129.96 (7)
O1i—Cs1—O1viii137.64 (3)O1xi—Cs2—Brxvi71.27 (3)
O1ii—Cs1—O1viii104.90 (6)O1—Cs2—Brxvi71.27 (3)
O1iii—Cs1—O1viii68.67 (13)O1xii—Cs2—Brxvi71.27 (3)
O1iv—Cs1—O1viii146.20 (13)O1xiii—Cs2—Brxvi71.27 (3)
O1v—Cs1—O1viii49.43 (14)Brxiv—Cs2—Brxvi120.0
O1—Cs1—O1viii112.36 (6)Br—Cs2—Brxvi120.0
O1vi—Cs1—O1viii65.19 (14)O2xv—Cs2—Brxvi180.0
O1vii—Cs1—O1viii112.36 (6)O2xiv—Cs2—Brxvi60.0
O1i—Cs1—Br138.29 (8)O2—Cs2—Brxvi60.0
O1ii—Cs1—Br138.29 (8)O1iv—Mo—O1xvii108.34 (14)
O1iii—Cs1—Br138.29 (8)O1iv—Mo—O1108.34 (14)
O1iv—Cs1—Br73.60 (6)O1xvii—Mo—O1108.34 (14)
O1v—Cs1—Br73.60 (6)O1iv—Mo—O2110.58 (13)
O1—Cs1—Br73.60 (6)O1xvii—Mo—O2110.58 (13)
O1vi—Cs1—Br73.60 (6)O1—Mo—O2110.58 (13)
O1vii—Cs1—Br73.60 (6)Mo—O1—Cs1iii152.3 (2)
O1viii—Cs1—Br73.60 (6)Mo—O1—Cs2109.37 (16)
O1x—Cs2—O1v100.09 (14)Cs1iii—O1—Cs298.33 (11)
O1x—Cs2—O1xi67.58 (11)Mo—O1—Cs199.46 (8)
O1v—Cs2—O1xi142.54 (6)Cs1iii—O1—Cs175.10 (6)
O1x—Cs2—O1142.54 (6)Cs2—O1—Cs199.88 (7)
O1v—Cs2—O167.58 (11)Mo—O1—Cs1xvi99.46 (8)
O1xi—Cs2—O1142.54 (6)Cs1iii—O1—Cs1xvi75.10 (6)
O1x—Cs2—O1xii67.58 (11)Cs2—O1—Cs1xvi99.88 (7)
O1v—Cs2—O1xii142.54 (6)Cs1—O1—Cs1xvi146.20 (13)
O1xi—Cs2—O1xii67.58 (11)Moxii—O2—Mo180.0
O1—Cs2—O1xii100.09 (14)Moxii—O2—Cs2xviii90.0
O1x—Cs2—O1xiii142.54 (6)Mo—O2—Cs2xviii90.0
O1v—Cs2—O1xiii67.58 (11)Moxii—O2—Cs290.0
O1xi—Cs2—O1xiii100.09 (14)Mo—O2—Cs290.0
O1—Cs2—O1xiii67.58 (11)Cs2xviii—O2—Cs2120.0
O1xii—Cs2—O1xiii142.54 (6)Moxii—O2—Cs2xix90.0
O1x—Cs2—Brxiv71.27 (3)Mo—O2—Cs2xix90.0
O1v—Cs2—Brxiv71.27 (3)Cs2xviii—O2—Cs2xix120.0
O1xi—Cs2—Brxiv71.27 (3)Cs2—O2—Cs2xix120.0
O1—Cs2—Brxiv129.96 (7)Cs1xii—Br—Cs1180.0
O1xii—Cs2—Brxiv129.96 (7)Cs1xii—Br—Cs2xix90.0
O1xiii—Cs2—Brxiv71.27 (3)Cs1—Br—Cs2xix90.0
O1x—Cs2—Br71.27 (3)Cs1xii—Br—Cs290.0
O1v—Cs2—Br71.27 (3)Cs1—Br—Cs290.0
O1xi—Cs2—Br129.96 (7)Cs2xix—Br—Cs2120.0
O1—Cs2—Br71.27 (3)Cs1xii—Br—Cs2vi90.0
O1xii—Cs2—Br71.27 (3)Cs1—Br—Cs2vi90.0
O1xiii—Cs2—Br129.96 (7)Cs2xix—Br—Cs2vi120.0
Brxiv—Cs2—Br120.0Cs2—Br—Cs2vi120.0
O1x—Cs2—O2xv50.04 (7)
Symmetry codes: (i) xy, x1, z; (ii) y+2, x+y+1, z; (iii) x+2, y1, z; (iv) y+1, xy1, z; (v) x+y+2, x, z; (vi) x+1, y, z; (vii) x+y+3, x+1, z; (viii) y+1, xy2, z; (ix) x+3, y, z; (x) x+y+2, x, z1/2; (xi) y, xy2, z1/2; (xii) x, y, z1/2; (xiii) y, xy2, z; (xiv) x1, y1, z; (xv) x, y1, z; (xvi) x1, y, z; (xvii) x+y+2, x+1, z; (xviii) x, y+1, z; (xix) x+1, y+1, z.

Experimental details

Crystal data
Chemical formulaCs3(Mo2O7)Br
Mr782.52
Crystal system, space groupHexagonal, P63/mmc
Temperature (K)293
a, c (Å)6.3993 (5), 16.4870 (15)
V3)584.71 (8)
Z2
Radiation typeMo Kα
µ (mm1)14.77
Crystal size (mm)0.15 × 0.15 × 0.05
Data collection
DiffractometerStoe IPDS2
diffractometer
Absorption correctionIntegration
(X-RED and X-SHAPE; Stoe & Cie, 2007)
Tmin, Tmax0.153, 0.532
No. of measured, independent and
observed [I > 2σ(I)] reflections
5224, 344, 338
Rint0.044
(sin θ/λ)max1)0.685
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.025, 0.062, 1.18
No. of reflections344
No. of parameters20
Δρmax, Δρmin (e Å3)0.60, 1.21

Computer programs: X-AREA (Stoe, 2007), X-RED (Stoe, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ATOMS (Dowty, 1999), publCIF (Westrip, 2009).

Selected bond lengths (Å) top
Mo—O11.725 (4)Mo—O21.8764 (7)
 

Acknowledgements

This work was supported by a President of the Russian Federation Grant for Young Doctors of Science (to SVK, grant No. MD-407.2009.5).

References

First citationBecher, H. J. & Fenske, D. (1978). J. Chem. Res. (S), 167.  Google Scholar
First citationDowty, E. (1999). ATOMS. Shape Software, Kingsport, Tennessee, USA.  Google Scholar
First citationFallon, G. D. & Gatehouse, B. M. (1982). J. Solid State Chem. 44, 156–161.  CrossRef CAS Web of Science Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationStadnicka, K., Haber, J. & Kozłowski, R. (1977). Acta Cryst. B33, 3859–3862.  CrossRef CAS IUCr Journals Web of Science Google Scholar
First citationStoe (2005). X-RED and X-SHAPE. Stoe & Cie, Darmstadt, Germany.  Google Scholar
First citationStoe (2007). X-AREA. Stoe & Cie, Darmstadt, Germany.  Google Scholar
First citationWestrip, S. P. (2009). publCIF. In preparation.  Google Scholar

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