
Acta Cryst. (2012). E68, o215-o216 [ doi:10.1107/S1600536811054560 ]
2N,C1}tellurium(IV)The title compound, C9H13Br2ClNTe, was synthesized by reacting [2-(dimethylaminomethyl)phenyl]tellurium(II) chloride with Br2. As a consequence, the Cl and Br atoms are not well ordered but distributed over the three possible positions such that the overall stiochiometry is two Br atoms and one Cl atom. The scrambling of the Br and Cl atoms indicates a small energy barrier for the exchange process between the apical and equatorial positions. Overall, the Te atom geometry is slightly distorted square pyramidal (
= 0.052 for the major component). However, there is a weak secondary interaction between the Te atoms and the disordered Br/Cl atoms of a nearby molecule. The Te-Br and Te-Cl distances in both disorder components fall into two groups; a longer distance for the Br/Cl involved in this secondary interaction [2.6945 (17) Å for Br and 2.601 (9)Å for Cl] and shorter bond distances to the remaining halogen atoms, indicating that this interaction has slightly weakened the Te-X bond, as is the case in the previously reported tribromido structure [Singh et al. (1990). J. Chem. Soc. Dalton Trans. pp. 907-913]. Otherwise, the metrical parameters in the two structures are not significantly different. An intermolecular C-H
Br interaction occurs.
As shown in the reaction scheme (scheme 2), a stirred solution of bis[2-(dimethylaminomethyl)phenyl]ditelluride, 1, (Kaur et al., 1995) (0.5 g, 0.94 mmol) in diethylether (10 ml) was treated with HCl (3 ml in 20 ml distilled water). The reaction mixture was further stirred for 10 min. The resulting reaction mixture was evaporated to one third of its original volume and ethanol (5 ml) was added to get a yellow solid. It was redissolved in ethanol and stored in the refrigerator to get yellow needles of the monochloride, 2.
A stirred solution of 2 (0.2 g, 0.66 mmol) in dry CHCl3 (10 ml) was treated with Br2 (0.37 ml, 2.34 mmol) under N2 at 0° C. The reaction mixture was further stirred for 2 h and then reduced to half volume and kept in freezer to give a yellow crystalline solid, 3, which contained crystals of two morphologies. This is the structure of one of these.
H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms with C—H distances of 0.95 - 0.97 Å [Uiso(H) = 1.2Ueq(OH, CH, CH2) [Uiso(H) = 1.5Ueq(CH3)]. As is discussed above, the 2 Br's and Cl are distributed over the three possible positions. Initially the Br/Cl occupancy in each position was refined as a free variable. These Br and Cl occupancies summed to Br2.03 and Cl0.98. The three free variables were then constrained to match a stoichiometry of Br2 and Cl.
Data collection: CrysAlis PRO (Oxford Diffraction, 2007); cell refinement: CrysAlis PRO (Oxford Diffraction, 2007); data reduction: CrysAlis PRO (Oxford Diffraction, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
| C9H12Br2ClNTe | F(000) = 848 |
| Mr = 457.07 | Dx = 2.341 Mg m−3 |
| Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -P 2ybc | Cell parameters from 3585 reflections |
| a = 7.2854 (3) Å | θ = 5.1–32.5° |
| b = 12.4785 (5) Å | µ = 8.63 mm−1 |
| c = 14.4098 (6) Å | T = 123 K |
| β = 98.200 (4)° | Plate, yellow |
| V = 1296.61 (9) Å3 | 0.63 × 0.50 × 0.10 mm |
| Z = 4 |
| Oxford Diffraction Xcalibur Ruby Gemini diffractometer | 4241 independent reflections |
| Radiation source: Enhance (Mo) X-ray Source | 2981 reflections with I > 2σ(I) |
| graphite | Rint = 0.044 |
| Detector resolution: 10.5081 pixels mm-1 | θmax = 32.6°, θmin = 5.4° |
| ω scans | h = −9→11 |
| Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction, 2007), based on expressions derived by Clark & Reid (1995)] | k = −18→13 |
| Tmin = 0.042, Tmax = 0.409 | l = −16→20 |
| 8229 measured reflections |
| 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)] = 0.038 | Hydrogen site location: inferred from neighbouring sites |
| wR(F2) = 0.056 | H-atom parameters constrained |
| S = 0.96 | w = 1/[σ2(Fo2) + (0.0084P)2] where P = (Fo2 + 2Fc2)/3 |
| 4241 reflections | (Δ/σ)max = 0.001 |
| 141 parameters | Δρmax = 0.91 e Å−3 |
| 1 restraint | Δρmin = −0.92 e Å−3 |
| C9H12Br2ClNTe | V = 1296.61 (9) Å3 |
| Mr = 457.07 | Z = 4 |
| Monoclinic, P21/c | Mo Kα radiation |
| a = 7.2854 (3) Å | µ = 8.63 mm−1 |
| b = 12.4785 (5) Å | T = 123 K |
| c = 14.4098 (6) Å | 0.63 × 0.50 × 0.10 mm |
| β = 98.200 (4)° |
| Oxford Diffraction Xcalibur Ruby Gemini diffractometer | 4241 independent reflections |
| Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction, 2007), based on expressions derived by Clark & Reid (1995)] | 2981 reflections with I > 2σ(I) |
| Tmin = 0.042, Tmax = 0.409 | Rint = 0.044 |
| 8229 measured reflections | θmax = 32.6° |
| R[F2 > 2σ(F2)] = 0.038 | H-atom parameters constrained |
| wR(F2) = 0.056 | Δρmax = 0.91 e Å−3 |
| S = 0.96 | Δρmin = −0.92 e Å−3 |
| 4241 reflections | Absolute structure: ? |
| 141 parameters | Flack parameter: ? |
| 1 restraint | Rogers parameter: ? |
Experimental. CrysAlisPro (Oxford Diffraction, 2007) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897) |
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 | Occ. (<1) | |
| Te | 0.51999 (3) | 0.349798 (17) | 0.583822 (16) | 0.01724 (6) | |
| Br1 | 0.2864 (3) | 0.39052 (12) | 0.42535 (11) | 0.0262 (2) | 0.6585 (4) |
| Br2 | 0.7403 (2) | 0.28626 (15) | 0.73580 (13) | 0.0228 (2) | 0.6374 (13) |
| Br3 | 0.7448 (2) | 0.26391 (13) | 0.47988 (10) | 0.0291 (2) | 0.7041 (13) |
| Cl1 | 0.2892 (15) | 0.4029 (7) | 0.4363 (6) | 0.0262 (2) | 0.3415 (4) |
| Cl2 | 0.7179 (11) | 0.2938 (7) | 0.7271 (6) | 0.0228 (2) | 0.3626 (13) |
| Cl3 | 0.7337 (15) | 0.2589 (9) | 0.4931 (7) | 0.0291 (2) | 0.2959 (13) |
| N1 | 0.3019 (4) | 0.4005 (2) | 0.6881 (2) | 0.0190 (6) | |
| C1 | 0.3619 (4) | 0.2094 (2) | 0.5943 (2) | 0.0153 (7) | |
| C2 | 0.3578 (5) | 0.1257 (3) | 0.5303 (3) | 0.0212 (8) | |
| H2A | 0.4292 | 0.1294 | 0.4801 | 0.025* | |
| C3 | 0.2486 (5) | 0.0371 (3) | 0.5405 (3) | 0.0266 (9) | |
| H3A | 0.2463 | −0.0212 | 0.4980 | 0.032* | |
| C4 | 0.1421 (5) | 0.0337 (3) | 0.6134 (3) | 0.0253 (9) | |
| H4A | 0.0673 | −0.0273 | 0.6203 | 0.030* | |
| C5 | 0.1438 (5) | 0.1179 (3) | 0.6758 (3) | 0.0238 (8) | |
| H5A | 0.0695 | 0.1148 | 0.7249 | 0.029* | |
| C6 | 0.2551 (4) | 0.2077 (3) | 0.6667 (2) | 0.0180 (7) | |
| C7 | 0.2670 (5) | 0.2987 (3) | 0.7364 (3) | 0.0210 (8) | |
| H7A | 0.1495 | 0.3041 | 0.7632 | 0.025* | |
| H7B | 0.3689 | 0.2852 | 0.7883 | 0.025* | |
| C8 | 0.3833 (5) | 0.4816 (3) | 0.7561 (3) | 0.0258 (8) | |
| H8A | 0.2979 | 0.4958 | 0.8014 | 0.039* | |
| H8B | 0.4049 | 0.5479 | 0.7229 | 0.039* | |
| H8C | 0.5014 | 0.4549 | 0.7892 | 0.039* | |
| C9 | 0.1283 (5) | 0.4418 (3) | 0.6349 (3) | 0.0268 (9) | |
| H9A | 0.0422 | 0.4613 | 0.6785 | 0.040* | |
| H9B | 0.0719 | 0.3864 | 0.5918 | 0.040* | |
| H9C | 0.1554 | 0.5052 | 0.5991 | 0.040* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Te | 0.02085 (12) | 0.01446 (11) | 0.01669 (11) | −0.00383 (10) | 0.00360 (9) | −0.00064 (9) |
| Br1 | 0.0431 (3) | 0.0156 (5) | 0.0177 (5) | −0.0027 (3) | −0.0030 (3) | −0.0001 (3) |
| Br2 | 0.0143 (5) | 0.0283 (4) | 0.0240 (5) | 0.0002 (3) | −0.0033 (3) | 0.0020 (3) |
| Br3 | 0.0366 (4) | 0.0252 (3) | 0.0299 (6) | −0.0057 (3) | 0.0193 (3) | −0.0062 (3) |
| Cl1 | 0.0431 (3) | 0.0156 (5) | 0.0177 (5) | −0.0027 (3) | −0.0030 (3) | −0.0001 (3) |
| Cl2 | 0.0143 (5) | 0.0283 (4) | 0.0240 (5) | 0.0002 (3) | −0.0033 (3) | 0.0020 (3) |
| Cl3 | 0.0366 (4) | 0.0252 (3) | 0.0299 (6) | −0.0057 (3) | 0.0193 (3) | −0.0062 (3) |
| N1 | 0.0209 (16) | 0.0156 (14) | 0.0207 (16) | −0.0032 (12) | 0.0037 (13) | 0.0001 (11) |
| C1 | 0.0146 (17) | 0.0139 (16) | 0.0159 (17) | −0.0063 (14) | −0.0032 (14) | 0.0001 (12) |
| C2 | 0.0176 (18) | 0.0156 (18) | 0.028 (2) | 0.0011 (14) | −0.0056 (15) | −0.0009 (14) |
| C3 | 0.027 (2) | 0.0149 (18) | 0.034 (2) | 0.0026 (16) | −0.0091 (17) | 0.0010 (15) |
| C4 | 0.0190 (19) | 0.0184 (18) | 0.035 (2) | −0.0076 (16) | −0.0087 (17) | 0.0080 (15) |
| C5 | 0.0184 (19) | 0.025 (2) | 0.026 (2) | −0.0041 (16) | −0.0018 (16) | 0.0085 (15) |
| C6 | 0.0157 (18) | 0.0150 (17) | 0.0209 (19) | −0.0015 (14) | −0.0055 (14) | 0.0028 (13) |
| C7 | 0.0185 (19) | 0.0224 (19) | 0.023 (2) | 0.0002 (15) | 0.0047 (15) | 0.0055 (14) |
| C8 | 0.025 (2) | 0.026 (2) | 0.027 (2) | −0.0069 (16) | 0.0057 (17) | −0.0086 (15) |
| C9 | 0.021 (2) | 0.025 (2) | 0.034 (2) | 0.0042 (16) | 0.0018 (17) | 0.0005 (16) |
| Te—C1 | 2.114 (3) | C2—H2A | 0.9500 |
| Te—N1 | 2.421 (3) | C3—C4 | 1.393 (5) |
| Te—Cl2 | 2.446 (8) | C3—H3A | 0.9500 |
| Te—Cl3 | 2.450 (11) | C4—C5 | 1.381 (5) |
| Te—Cl1 | 2.601 (9) | C4—H4A | 0.9500 |
| Te—Br3 | 2.6027 (15) | C5—C6 | 1.400 (4) |
| Te—Br2 | 2.6454 (15) | C5—H5A | 0.9500 |
| Te—Br1 | 2.6945 (17) | C6—C7 | 1.511 (5) |
| Te—Cl1i | 3.414 (9) | C7—H7A | 0.9900 |
| Te—Br1i | 3.5441 (17) | C7—H7B | 0.9900 |
| N1—C8 | 1.473 (4) | C8—H8A | 0.9800 |
| N1—C9 | 1.476 (4) | C8—H8B | 0.9800 |
| N1—C7 | 1.488 (4) | C8—H8C | 0.9800 |
| C1—C6 | 1.387 (4) | C9—H9A | 0.9800 |
| C1—C2 | 1.391 (4) | C9—H9B | 0.9800 |
| C2—C3 | 1.382 (5) | C9—H9C | 0.9800 |
| C1—Te—N1 | 76.09 (11) | C8—N1—C7 | 110.7 (3) |
| C1—Te—Cl2 | 88.0 (2) | C9—N1—C7 | 110.5 (3) |
| N1—Te—Cl2 | 84.9 (2) | C8—N1—Te | 110.8 (2) |
| C1—Te—Cl3 | 92.8 (3) | C9—N1—Te | 111.0 (2) |
| N1—Te—Cl3 | 167.3 (2) | C7—N1—Te | 103.81 (18) |
| Cl2—Te—Cl3 | 88.6 (3) | C6—C1—C2 | 121.7 (3) |
| C1—Te—Cl1 | 88.5 (2) | C6—C1—Te | 115.9 (2) |
| N1—Te—Cl1 | 92.0 (2) | C2—C1—Te | 122.3 (2) |
| Cl2—Te—Cl1 | 175.8 (3) | C3—C2—C1 | 119.2 (3) |
| Cl3—Te—Cl1 | 93.9 (3) | C3—C2—H2A | 120.4 |
| C1—Te—Br3 | 95.40 (9) | C1—C2—H2A | 120.4 |
| N1—Te—Br3 | 170.80 (7) | C2—C3—C4 | 119.7 (3) |
| Cl2—Te—Br3 | 91.4 (2) | C2—C3—H3A | 120.2 |
| Cl1—Te—Br3 | 91.2 (2) | C4—C3—H3A | 120.2 |
| C1—Te—Br2 | 87.99 (10) | C5—C4—C3 | 120.9 (3) |
| N1—Te—Br2 | 86.50 (8) | C5—C4—H4A | 119.5 |
| Cl3—Te—Br2 | 86.9 (3) | C3—C4—H4A | 119.5 |
| Cl1—Te—Br2 | 176.5 (2) | C4—C5—C6 | 119.9 (3) |
| Br3—Te—Br2 | 89.75 (6) | C4—C5—H5A | 120.0 |
| C1—Te—Br1 | 86.11 (9) | C6—C5—H5A | 120.0 |
| N1—Te—Br1 | 94.91 (8) | C1—C6—C5 | 118.5 (3) |
| Cl2—Te—Br1 | 173.9 (2) | C1—C6—C7 | 120.2 (3) |
| Cl3—Te—Br1 | 90.4 (3) | C5—C6—C7 | 121.2 (3) |
| Br3—Te—Br1 | 87.89 (5) | N1—C7—C6 | 109.1 (3) |
| Br2—Te—Br1 | 173.41 (5) | N1—C7—H7A | 109.9 |
| C1—Te—Cl1i | 171.06 (19) | C6—C7—H7A | 109.9 |
| N1—Te—Cl1i | 97.34 (17) | N1—C7—H7B | 109.9 |
| Cl2—Te—Cl1i | 97.6 (3) | C6—C7—H7B | 109.9 |
| Cl3—Te—Cl1i | 94.3 (3) | H7A—C7—H7B | 108.3 |
| Cl1—Te—Cl1i | 85.6 (3) | N1—C8—H8A | 109.5 |
| Br3—Te—Cl1i | 91.49 (17) | N1—C8—H8B | 109.5 |
| Br2—Te—Cl1i | 97.76 (16) | H8A—C8—H8B | 109.5 |
| Br1—Te—Cl1i | 88.46 (16) | N1—C8—H8C | 109.5 |
| C1—Te—Br1i | 169.81 (9) | H8A—C8—H8C | 109.5 |
| N1—Te—Br1i | 94.83 (7) | H8B—C8—H8C | 109.5 |
| Cl2—Te—Br1i | 95.9 (2) | N1—C9—H9A | 109.5 |
| Cl3—Te—Br1i | 96.7 (2) | N1—C9—H9B | 109.5 |
| Cl1—Te—Br1i | 87.2 (2) | H9A—C9—H9B | 109.5 |
| Br3—Te—Br1i | 93.93 (5) | N1—C9—H9C | 109.5 |
| Br2—Te—Br1i | 96.16 (5) | H9A—C9—H9C | 109.5 |
| Br1—Te—Br1i | 90.15 (4) | H9B—C9—H9C | 109.5 |
| C8—N1—C9 | 109.9 (3) | ||
| C1—Te—N1—C8 | 149.1 (2) | Br3—Te—C1—C6 | 161.9 (2) |
| Cl2—Te—N1—C8 | 59.9 (3) | Br2—Te—C1—C6 | 72.3 (2) |
| Cl3—Te—N1—C8 | 119.3 (12) | Br1—Te—C1—C6 | −110.6 (2) |
| Cl1—Te—N1—C8 | −123.0 (3) | Br1i—Te—C1—C6 | −41.9 (7) |
| Br2—Te—N1—C8 | 60.3 (2) | N1—Te—C1—C2 | 162.6 (3) |
| Br1—Te—N1—C8 | −126.2 (2) | Cl2—Te—C1—C2 | −112.2 (4) |
| Cl1i—Te—N1—C8 | −37.1 (3) | Cl3—Te—C1—C2 | −23.7 (4) |
| Br1i—Te—N1—C8 | −35.6 (2) | Cl1—Te—C1—C2 | 70.1 (3) |
| C1—Te—N1—C9 | −88.6 (2) | Br3—Te—C1—C2 | −21.0 (3) |
| Cl2—Te—N1—C9 | −177.7 (3) | Br2—Te—C1—C2 | −110.5 (3) |
| Cl3—Te—N1—C9 | −118.4 (12) | Br1—Te—C1—C2 | 66.5 (3) |
| Cl1—Te—N1—C9 | −0.6 (3) | Br1i—Te—C1—C2 | 135.2 (4) |
| Br2—Te—N1—C9 | −177.4 (2) | C6—C1—C2—C3 | −1.9 (5) |
| Br1—Te—N1—C9 | −3.8 (2) | Te—C1—C2—C3 | −178.8 (2) |
| Cl1i—Te—N1—C9 | 85.2 (3) | C1—C2—C3—C4 | 1.2 (5) |
| Br1i—Te—N1—C9 | 86.7 (2) | C2—C3—C4—C5 | 0.0 (5) |
| C1—Te—N1—C7 | 30.2 (2) | C3—C4—C5—C6 | −0.6 (5) |
| Cl2—Te—N1—C7 | −59.0 (3) | C2—C1—C6—C5 | 1.3 (5) |
| Cl3—Te—N1—C7 | 0.4 (13) | Te—C1—C6—C5 | 178.4 (2) |
| Cl1—Te—N1—C7 | 118.2 (3) | C2—C1—C6—C7 | 178.4 (3) |
| Br2—Te—N1—C7 | −58.60 (19) | Te—C1—C6—C7 | −4.5 (4) |
| Br1—Te—N1—C7 | 114.94 (19) | C4—C5—C6—C1 | 0.0 (5) |
| Cl1i—Te—N1—C7 | −156.0 (2) | C4—C5—C6—C7 | −177.1 (3) |
| Br1i—Te—N1—C7 | −154.50 (19) | C8—N1—C7—C6 | −158.5 (3) |
| N1—Te—C1—C6 | −14.5 (2) | C9—N1—C7—C6 | 79.5 (3) |
| Cl2—Te—C1—C6 | 70.7 (3) | Te—N1—C7—C6 | −39.6 (3) |
| Cl3—Te—C1—C6 | 159.2 (4) | C1—C6—C7—N1 | 33.4 (4) |
| Cl1—Te—C1—C6 | −107.0 (3) | C5—C6—C7—N1 | −149.6 (3) |
| Symmetry codes: (i) −x+1, −y+1, −z+1. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| C7—H7A···Br2ii | 0.99 | 2.96 | 3.839 (4) | 149. |
| Symmetry codes: (ii) x−1, y, z. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| C7—H7A···Br2i | 0.99 | 2.96 | 3.839 (4) | 149. |
| Symmetry codes: (i) x−1, y, z. |
RJB acknowledges the NSF–MRI program (grant CHE-0619278) for funds to purchase the diffractometer. HBS acknowledges the DST for funding and PR acknowledges the CSIR for a fellowship.
Addison, A. W., Rao, T. N., Reedijk, J., van Rijn, J. & Verschoor, G. C. (1984). J. Chem. Soc. Dalton Trans. pp. 1349–1356.
Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887–897.
Cobbledick, R. E., Einstein, F. W. B., McWhinnie, W. R. & Musa, F. H. (1979). J. Chem. Res. (S), p. 145.
Kaur, R., Singh, H. B. & Butcher, R. J. (1995). Organometallics, 14, 4755–4763.
Oxford Diffraction (2007). CrysAlis PRO, CrysAlis RED and CrysAlis CCD. Oxford Diffraction Ltd, Abingdon, England.
Panda, A., Mugesh, G., Singh, H. B. & Butcher, R. J. (1999). Organometallics, 18, 1986–1993.
Rivkin, B. B., Maksimenko, A. A. & Sadekov, I. D. (1991). Zh. Obshch. Khim. 61, 1154–1162.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Singh, H. B. & McWhinnie, W. R. (1985). J. Chem. Soc. Dalton Trans. pp. 821–825.
Singh, H. B., Sudha, N. & Butcher, R. J. (1992). Inorg. Chem. 31, 1431–1435.
Singh, H. B., Sudha, N., West, A. A. & Hamor, T. A. (1990). J. Chem. Soc. Dalton Trans. pp. 907–913.
Unlike their selenium analogues, simple aryltellurenyl halides are thermally unstable and polymeric in nature. However, it has been shown that they can be stabilized by intramolecular coordination and thus be isolated and structurally characterized (Singh & McWhinnie, 1985; Singh et al., 1990; Singh et al., 1992; Panda et al., 1999). Previously the structures {2-[(S)-1-(dimethylamino)ethyl]phenyl}tellurium(IV) trichloride (Singh et al. 1992) and 2-(dimethylaminomethyl)phenyl]tellurium(IV) tribromide (Singh et al. 1990) have been published. In this report the structure of 2-(dimethylaminomethyl)phenyl]tellurium(IV)dibromide chloride is presented in which the 2Br's and Cl are distributed over the three possible sites. The scrambling of the Br/Cl position indicates a small energy barrier for the exchange process between the axial and equatorial positions. The synthesis of similar dibromochloro derivatives of Te have been reported previously although no crystal structures were completed (Cobbledick et al., 1979; Rivkin et al., 1991).
Overall the molecule is slightly distorted square pyramidal [τ = 0.052 for the major component (Addison et al., 1984]. However there is a weak secondary interaction between the Te and Br/Cl of an adjoining molecule. The Te—Br and Te—Cl distances in both molecules fall into two groups; a longer distance for the Br/Cl involved in this secondary interaction (2.6945 (17)Å for Br and 2.601 (9)Å for Cl) and shorter bond distances to the remaining halogens, indicating that this interaction has slightly weakened the Te—X bond, as is the case in the previously reported polymorph. Otherwise, the metrical parameters in both polymorphs are not significantly different.