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The crystal structure of the glaserite-related compound dithallium(I)–molybdate(VI), which at 293 K crystallizes monoclinic, space group C121 with lattice parameters a = 10.565 (3), b = 6.418 (1), c = 8.039 (2) Å, β = 91.05 (4)°, has been determined. The structure was refined as an inversion twin to a final R(Fall) value of 0.0611 for 1006 unique reflections [R(Fobs) = 0.0285 for 644 observed reflections]. Second-harmonic generation measurements led to a value of deff = 5.5 ± 0.5 pm V−1 as an estimation of the second-harmonic conversion efficiency at phase matching. Symmetry mode analysis shows that, in general, primary modes have the highest amplitudes, yet surprisingly some of the secondary modes assume amplitudes of comparable magnitude. A comparison of the phase at 293 K with that at 350 K (space group P\overline{3}m1) shows that the main change can be described as a rotation of the molybdate tetrahedra around the trigonal a(b) axis. The molybdate tetrahedra as well as the octahedra around one of the symmetry-independent Tl atoms are more strongly distorted in the monoclinic phase. The coordination number for the other two Tl atoms is decreased from 12 and 10 in the high-symmetry phase to 10 and 9 in the monoclinic phase. Furthermore, the number of common edges between the Tl and Mo coordination polyhedra is reduced and the common face which is observed between them in the high-temperature phase is changed to a common edge in the low-temperature phase. The contribution of the primary symmetry modes leads exactly to this change in the coordination spheres of the atoms.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768100015597/na0110sup1.cif
Contains datablocks tmo293, global

fcf

Structure factor file (CIF format) https://doi.org/10.1107/S0108768100015597/na0110sup2.fcf
Supplementary material

Computing details top

Data collection: STOE IPDS Software; cell refinement: STOE IPDS Software; data reduction: STOE IPDS Software; program(s) used to solve structure: coordinates from model; program(s) used to refine structure: SHELXL97 (Sheldrick, 1997).

Figures top
[Figure 1]
[Figure 2]
[Figure 3]
[Figure 4]
Dithallium (I)-Molybdate (VI) top
Crystal data top
MoO4Tl2F(000) = 944
Mr = 568.68Dx = 6.931 Mg m3
Monoclinic, C2Mo Kα radiation, λ = 0.71069 Å
Hall symbol: C 2yCell parameters from 1132 reflections
a = 10.565 (3) Åθ = 2.5–25.9°
b = 6.4178 (13) ŵ = 61.16 mm1
c = 8.039 (2) ÅT = 293 K
β = 91.05 (4)°Hexagonal prismatic, yellow
V = 545.0 (3) Å30.09 × 0.08 × 0.003 mm
Z = 4
Data collection top
STOE IPDS
diffractometer
644 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.057
Graphite monochromatorθmax = 25.9°, θmin = 2.5°
Absorption correction: gaussian
?
h = 1212
Tmin = 0.050, Tmax = 0.796k = 77
2138 measured reflectionsl = 99
1006 independent reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullCalculated w = 1/[σ2(Fo2) + (0.P)2]
where P = (Fo2 + 2Fc2)/3
R[F2 > 2σ(F2)] = 0.029(Δ/σ)max = 0.001
wR(F2) = 0.039Δρmax = 0.96 e Å3
S = 0.71Δρmin = 0.93 e Å3
1006 reflectionsExtinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
66 parametersExtinction coefficient: 0.00092 (4)
0 restraintsAbsolute structure: Flack H D (1983), Acta Cryst. A39, 876-881
Primary atom site location: modelAbsolute structure parameter: 0.159 (16)
Crystal data top
MoO4Tl2V = 545.0 (3) Å3
Mr = 568.68Z = 4
Monoclinic, C2Mo Kα radiation
a = 10.565 (3) ŵ = 61.16 mm1
b = 6.4178 (13) ÅT = 293 K
c = 8.039 (2) Å0.09 × 0.08 × 0.003 mm
β = 91.05 (4)°
Data collection top
STOE IPDS
diffractometer
1006 independent reflections
Absorption correction: gaussian
?
644 reflections with I > 2σ(I)
Tmin = 0.050, Tmax = 0.796Rint = 0.057
2138 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0290 restraints
wR(F2) = 0.039Δρmax = 0.96 e Å3
S = 0.71Δρmin = 0.93 e Å3
1006 reflectionsAbsolute structure: Flack H D (1983), Acta Cryst. A39, 876-881
66 parametersAbsolute structure parameter: 0.159 (16)
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
Tl10.00000.00000.00000.0300 (5)
Tl20.00000.0506 (3)0.50000.0309 (5)
Tl30.33358 (12)0.0071 (4)0.17767 (15)0.0377 (5)
Mo10.6623 (2)0.0257 (5)0.3081 (2)0.0172 (6)
O10.6911 (15)0.0510 (19)0.5099 (15)0.051 (4)
O20.5627 (17)0.2330 (18)0.2873 (18)0.048 (5)
O30.8026 (14)0.080 (2)0.2167 (18)0.051 (4)
O40.5837 (17)0.1848 (19)0.2007 (18)0.047 (5)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Tl10.0328 (9)0.0296 (13)0.0278 (8)0.0000.0034 (7)0.000
Tl20.0428 (10)0.0265 (11)0.0235 (9)0.0000.0004 (8)0.000
Tl30.0369 (6)0.0490 (11)0.0272 (7)0.0030 (7)0.0023 (5)0.0007 (9)
Mo10.0197 (11)0.0161 (17)0.0157 (12)0.0017 (10)0.0008 (10)0.0026 (14)
O10.090 (13)0.049 (7)0.014 (7)0.007 (8)0.011 (8)0.004 (6)
O20.068 (13)0.044 (7)0.032 (10)0.040 (7)0.019 (9)0.021 (6)
O30.037 (10)0.069 (8)0.049 (10)0.015 (7)0.015 (8)0.010 (7)
O40.065 (13)0.049 (9)0.029 (11)0.016 (8)0.022 (10)0.000 (6)
Geometric parameters (Å, º) top
Tl1—O4i2.725 (12)Mo1—O21.702 (13)
Tl1—O4ii2.725 (12)Mo1—O31.702 (14)
Tl1—O3iii2.789 (14)Mo1—O11.717 (12)
Tl1—O3iv2.789 (14)Mo1—O41.798 (13)
Tl1—Tl33.7784 (18)O1—Tl3viii2.557 (13)
Tl1—Tl3v3.7784 (18)O2—Tl2ix2.749 (12)
Tl2—O2vi2.749 (12)O3—Tl3ix2.781 (13)
Tl2—O2vii2.749 (12)O3—Tl1x2.789 (14)
Tl3—O1viii2.557 (13)O4—Tl1xi2.725 (12)
Tl3—O3vi2.781 (13)
O4i—Tl1—O4ii84.1 (7)O1viii—Tl3—O3vi74.4 (4)
O4i—Tl1—O3iii89.7 (4)O1viii—Tl3—Tl1105.0 (4)
O4ii—Tl1—O3iii74.5 (4)O3vi—Tl3—Tl185.4 (3)
O4i—Tl1—O3iv74.5 (4)O2—Mo1—O3109.9 (8)
O4ii—Tl1—O3iv89.7 (4)O2—Mo1—O1114.5 (7)
O3iii—Tl1—O3iv158.9 (5)O3—Mo1—O1109.0 (7)
O4i—Tl1—Tl358.5 (4)O2—Mo1—O4105.1 (7)
O4ii—Tl1—Tl3120.3 (4)O3—Mo1—O4110.1 (7)
O3iii—Tl1—Tl362.0 (3)O1—Mo1—O4108.1 (7)
O3iv—Tl1—Tl3117.7 (3)Mo1—O1—Tl3viii150.1 (7)
O4i—Tl1—Tl3v120.3 (4)Mo1—O2—Tl2ix132.4 (7)
O4ii—Tl1—Tl3v58.5 (4)Mo1—O3—Tl3ix110.7 (6)
O3iii—Tl1—Tl3v117.7 (3)Mo1—O3—Tl1x154.1 (7)
O3iv—Tl1—Tl3v62.0 (3)Tl3ix—O3—Tl1x91.1 (4)
Tl3—Tl1—Tl3v178.63 (7)Mo1—O4—Tl1xi169.8 (8)
O2vi—Tl2—O2vii84.3 (7)
Symmetry codes: (i) x1/2, y+1/2, z; (ii) x+1/2, y+1/2, z; (iii) x+1, y, z; (iv) x1, y, z; (v) x, y, z; (vi) x1/2, y1/2, z; (vii) x+1/2, y1/2, z+1; (viii) x+1, y, z+1; (ix) x+1/2, y+1/2, z; (x) x+1, y, z; (xi) x+1/2, y1/2, z.

Experimental details

Crystal data
Chemical formulaMoO4Tl2
Mr568.68
Crystal system, space groupMonoclinic, C2
Temperature (K)293
a, b, c (Å)10.565 (3), 6.4178 (13), 8.039 (2)
β (°) 91.05 (4)
V3)545.0 (3)
Z4
Radiation typeMo Kα
µ (mm1)61.16
Crystal size (mm)0.09 × 0.08 × 0.003
Data collection
DiffractometerSTOE IPDS
diffractometer
Absorption correctionGaussian
Tmin, Tmax0.050, 0.796
No. of measured, independent and
observed [I > 2σ(I)] reflections
2138, 1006, 644
Rint0.057
(sin θ/λ)max1)0.615
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.029, 0.039, 0.71
No. of reflections1006
No. of parameters66
Δρmax, Δρmin (e Å3)0.96, 0.93
Absolute structureFlack H D (1983), Acta Cryst. A39, 876-881
Absolute structure parameter0.159 (16)

Computer programs: STOE IPDS Software, coordinates from model, SHELXL97 (Sheldrick, 1997).

 

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