The crystal structure of the title compound, magnesium pentaoxoditellurate(IV), has been redetermined from a crystal grown from the melt and confirms the previous study [Trömel (1975). Z. Anorg. Allg. Chem. 418, 141–144], but with improved precision. It is isotypic with β-MnTe2O5 and contains MgO6 octahedra and TeO3+1 units, with the latter forming an extended sheet structure. Mg and one O atom occupy special positions with site symmetry 2.
Supporting information
Key indicators
- Single-crystal X-ray study
- T = 295 K
- Mean (g-O) = 0.001 Å
- R factor = 0.018
- wR factor = 0.041
- Data-to-parameter ratio = 31.0
checkCIF/PLATON results
No syntax errors found
Alert level G
ABSTM02_ALERT_3_G The ratio of expected to reported Tmax/Tmin(RR') is < 0.90
Tmin and Tmax reported: 0.126 0.242
Tmin(prime) and Tmax expected: 0.046 0.074
RR(prime) = 0.839
Please check that your absorption correction is appropriate.
0 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
0 ALERT level C = Check and explain
1 ALERT level G = General alerts; check
0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
0 ALERT type 2 Indicator that the structure model may be wrong or deficient
1 ALERT type 3 Indicator that the structure quality may be low
0 ALERT type 4 Improvement, methodology, query or suggestion
Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software; data reduction: HELENA implemented in PLATON (Spek, 2003); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ATOMS (Dowty, 2000); software used to prepare material for publication: SHELXL97.
magnesium pentaoxoditellurate(IV)
top
Crystal data top
MgTe2O5 | F(000) = 624 |
Mr = 359.51 | Dx = 5.169 Mg m−3 |
Orthorhombic, Pbcn | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2n 2ab | Cell parameters from 25 reflections |
a = 7.2391 (9) Å | θ = 11.3–16.1° |
b = 10.658 (1) Å | µ = 12.68 mm−1 |
c = 5.9880 (6) Å | T = 295 K |
V = 462.00 (9) Å3 | Fragment, colourless |
Z = 4 | 0.22 × 0.22 × 0.21 mm |
Data collection top
Enraf–Nonius CAD-4 diffractometer | 1112 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.038 |
Graphite monochromator | θmax = 37.4°, θmin = 3.4° |
ω/2θ scans | h = −12→12 |
Absorption correction: numerical (HABITUS; Herrendorf, 1997) | k = −18→18 |
Tmin = 0.126, Tmax = 0.242 | l = −10→10 |
8781 measured reflections | 3 standard reflections every 300 min |
1210 independent reflections | intensity decay: none |
Refinement top
Refinement on F2 | Primary atom site location: isomorphous structure methods |
Least-squares matrix: full | w = 1/[σ2(Fo2) + (0.0172P)2 + 0.3586P] where P = (Fo2 + 2Fc2)/3 |
R[F2 > 2σ(F2)] = 0.018 | (Δ/σ)max = 0.001 |
wR(F2) = 0.041 | Δρmax = 1.54 e Å−3 |
S = 1.25 | Δρmin = −1.62 e Å−3 |
1210 reflections | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
39 parameters | Extinction coefficient: 0.0928 (16) |
0 restraints | |
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 | x | y | z | Uiso*/Ueq | |
Mg | 0.0000 | 0.44331 (7) | 0.2500 | 0.00966 (14) | |
Te | 0.133353 (13) | 0.154562 (9) | 0.010001 (18) | 0.00856 (5) | |
O1 | 0.19064 (18) | 0.29457 (11) | 0.1816 (2) | 0.0145 (2) | |
O2 | 0.35061 (16) | 0.06582 (12) | 0.0487 (2) | 0.0120 (2) | |
O3 | 0.0000 | 0.06250 (16) | 0.2500 | 0.0156 (3) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Mg | 0.0094 (3) | 0.0092 (3) | 0.0104 (3) | 0.000 | −0.0014 (2) | 0.000 |
Te | 0.00683 (7) | 0.00788 (7) | 0.01098 (8) | 0.00041 (2) | −0.00014 (2) | −0.00088 (2) |
O1 | 0.0138 (5) | 0.0109 (5) | 0.0189 (6) | 0.0010 (4) | −0.0022 (4) | −0.0049 (4) |
O2 | 0.0098 (5) | 0.0123 (5) | 0.0138 (5) | 0.0051 (4) | 0.0015 (4) | 0.0016 (4) |
O3 | 0.0175 (7) | 0.0106 (6) | 0.0186 (8) | 0.000 | 0.0092 (6) | 0.000 |
Geometric parameters (Å, º) top
Mg—O2i | 2.0801 (13) | Te—O2 | 1.8498 (11) |
Mg—O2ii | 2.0801 (13) | Te—O1 | 1.8588 (12) |
Mg—O2iii | 2.0926 (14) | Te—O3 | 1.9900 (9) |
Mg—O2iv | 2.0926 (14) | Te—O1viii | 2.4048 (13) |
Mg—O1v | 2.1413 (14) | Te—Mgviii | 3.2491 (4) |
Mg—O1 | 2.1413 (14) | O1—Teiii | 2.4048 (13) |
Mg—Mgvi | 3.2287 (6) | O2—Mgix | 2.0801 (13) |
Mg—Mgvii | 3.2287 (6) | O2—Mgviii | 2.0926 (14) |
Mg—Teiv | 3.2491 (4) | O3—Tev | 1.9900 (9) |
Mg—Teiii | 3.2491 (4) | | |
| | | |
O2i—Mg—O2ii | 102.24 (8) | O1v—Mg—O1 | 84.48 (7) |
O2i—Mg—O2iii | 78.62 (5) | O2—Te—O1 | 98.71 (6) |
O2ii—Mg—O2iii | 104.82 (5) | O2—Te—O3 | 94.00 (5) |
O2i—Mg—O2iv | 104.82 (5) | O1—Te—O3 | 96.01 (6) |
O2ii—Mg—O2iv | 78.62 (5) | O2—Te—O1viii | 76.55 (5) |
O2iii—Mg—O2iv | 174.67 (8) | O1—Te—O1viii | 98.80 (2) |
O2i—Mg—O1v | 91.08 (5) | O3—Te—O1viii | 163.46 (5) |
O2ii—Mg—O1v | 155.58 (6) | Te—O1—Mg | 123.79 (7) |
O2iii—Mg—O1v | 97.77 (5) | Te—O1—Teiii | 138.70 (7) |
O2iv—Mg—O1v | 78.22 (5) | Mg—O1—Teiii | 91.05 (4) |
O2i—Mg—O1 | 155.58 (6) | Te—O2—Mgix | 146.68 (8) |
O2ii—Mg—O1 | 91.08 (5) | Te—O2—Mgviii | 110.85 (7) |
O2iii—Mg—O1 | 78.22 (5) | Mgix—O2—Mgviii | 101.38 (5) |
O2iv—Mg—O1 | 97.77 (5) | Te—O3—Tev | 120.91 (9) |
Symmetry codes: (i) x−1/2, y+1/2, −z+1/2; (ii) −x+1/2, y+1/2, z; (iii) −x+1/2, −y+1/2, z+1/2; (iv) x−1/2, −y+1/2, −z; (v) −x, y, −z+1/2; (vi) −x, −y+1, −z+1; (vii) −x, −y+1, −z; (viii) −x+1/2, −y+1/2, z−1/2; (ix) x+1/2, y−1/2, −z+1/2. |