metal-organic compounds
Bis(η5-cyclopentadienyl)bis(2,4,6-trimethylphenyltellurolato)zirconium(IV)
aSchool of Chemistry, University of Southampton, Southampton SO17 1BJ, England
*Correspondence e-mail: m.webster@soton.ac.uk
The structure of the title compound, [Zr(C5H5)2(C9H11Te)2], consists of a zirconium(IV) centre bonded to two η5-coordinated cyclopentadienyl groups and two mesityltellurolate ligands; the discrete molecule has crystallographic twofold rotation symmetry. The structural parameters compared with those in [(η5-Me5Cp)2Zr(TePh)2] [Howard, Trnka & Parkin (1995). Inorg. Chem. 34, 5900–5909] show that the greater steric demands of the bulky mesityl substituents are accommodated by widening Te—Zr—Te (∼8°) and by more acute Zr—Te—C (∼5°) angles, although the Zr—Te distances are essentially the same. The crystal studied exhibited some inversion twinning.
Related literature
For a review, see: Arnold (1995). For related structures, see: Christou et al. (1993); Hector et al. (2008); Howard et al. (1995); Sato & Yoshida (1974).
Experimental
Crystal data
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Data collection: COLLECT (Hooft, 1998) and DENZO (Otwinowski & Minor, 1997); cell COLLECT and DENZO; data reduction: COLLECT and DENZO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.
Supporting information
10.1107/S1600536808009574/sj2480sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536808009574/sj2480Isup2.hkl
To a stirred suspension of Mg turnings (66 mg, 2.72 mmol) in THF (30 ml) was added MesBr (56 mg, 2.82 mmol). The resulting mixture was stirred for 2 h, after which the Grignard was transferred by cannula to a suspension of freshly ground Te powder (300 mg, 2.35 mmol) in THF (10 ml). The mixture turned orange and was stirred for 1 h. Cp2ZrCl2 (345 mg, 1.18 mmol) was dissolved in THF (10 ml) and the Grignard solution added dropwise by cannula, during which time the solution turned red. The reaction was allowed to proceed overnight. The volatiles were removed in vacuo, the residue extracted with CH2Cl2 (20 ml) and filtered through celite. The solvent was removed under reduced pressure, the residue crystallized from Et2O to produce a small number of red crystals. 125Te{1H} NMR (CH2Cl2/CDCl3, 300 K): δTe = 887 p.p.m.
H atoms were placed in calculated positions [C—H = 0.95 (aromatic and Cp) and 0.98 Å (methyl)]. Uiso(H) values for methyl H atoms were set at 1.5Ueq(C) of the bonded C, and the rest at 1.2Ueq(C). Racemic
was allowed in the final The number of Friedel pairs measured is 1405.Data collection: COLLECT (Hooft, 1998) and DENZO (Otwinowski & Minor, 1997); cell
COLLECT (Hooft, 1998) and DENZO (Otwinowski & Minor, 1997); data reduction: COLLECT (Hooft, 1998) and DENZO (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).[Zr(C5H5)2(C9H11Te)2] | F(000) = 1376 |
Mr = 714.96 | Dx = 1.737 Mg m−3 |
Orthorhombic, Aba2 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: A 2 -2ac | Cell parameters from 7078 reflections |
a = 9.0483 (15) Å | θ = 2.9–27.5° |
b = 21.881 (6) Å | µ = 2.51 mm−1 |
c = 13.806 (4) Å | T = 120 K |
V = 2733.3 (12) Å3 | Plate, red |
Z = 4 | 0.20 × 0.10 × 0.02 mm |
Bruker Nonius KappaCCD diffractometer | 3046 independent reflections |
Radiation source: Bruker-Nonius FR591 rotating anode | 2444 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.059 |
ϕ and ω scans | θmax = 27.5°, θmin = 3.5° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2007) | h = −9→11 |
Tmin = 0.758, Tmax = 0.951 | k = −28→26 |
9201 measured reflections | l = −17→16 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.040 | H-atom parameters constrained |
wR(F2) = 0.087 | w = 1/[σ2(Fo2) + (0.0276P)2 + 1.8865P] where P = (Fo2 + 2Fc2)/3 |
S = 1.05 | (Δ/σ)max = 0.001 |
3046 reflections | Δρmax = 1.50 e Å−3 |
145 parameters | Δρmin = −1.16 e Å−3 |
1 restraint | Absolute structure: Flack (1983), 1405 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.14 (5) |
[Zr(C5H5)2(C9H11Te)2] | V = 2733.3 (12) Å3 |
Mr = 714.96 | Z = 4 |
Orthorhombic, Aba2 | Mo Kα radiation |
a = 9.0483 (15) Å | µ = 2.51 mm−1 |
b = 21.881 (6) Å | T = 120 K |
c = 13.806 (4) Å | 0.20 × 0.10 × 0.02 mm |
Bruker Nonius KappaCCD diffractometer | 3046 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2007) | 2444 reflections with I > 2σ(I) |
Tmin = 0.758, Tmax = 0.951 | Rint = 0.059 |
9201 measured reflections |
R[F2 > 2σ(F2)] = 0.040 | H-atom parameters constrained |
wR(F2) = 0.087 | Δρmax = 1.50 e Å−3 |
S = 1.05 | Δρmin = −1.16 e Å−3 |
3046 reflections | Absolute structure: Flack (1983), 1405 Friedel pairs |
145 parameters | Absolute structure parameter: 0.14 (5) |
1 restraint |
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 | ||
Zr1 | 0.5000 | 0.5000 | −0.06403 (8) | 0.01613 (16) | |
Te1 | 0.74620 (4) | 0.522546 (15) | 0.06201 (7) | 0.02158 (12) | |
C1 | 0.4387 (14) | 0.6120 (4) | −0.0508 (8) | 0.066 (3) | |
H1 | 0.4389 | 0.6355 | 0.0070 | 0.079* | |
C2 | 0.3184 (8) | 0.5854 (4) | −0.0922 (6) | 0.043 (2) | |
H2 | 0.2208 | 0.5869 | −0.0670 | 0.052* | |
C3 | 0.3574 (7) | 0.5607 (3) | −0.1807 (6) | 0.0324 (16) | |
H3 | 0.2915 | 0.5453 | −0.2284 | 0.039* | |
C4 | 0.5054 (9) | 0.5768 (3) | −0.1952 (7) | 0.051 (2) | |
H4 | 0.5578 | 0.5726 | −0.2544 | 0.062* | |
C5 | 0.5545 (11) | 0.6072 (4) | −0.1164 (10) | 0.067 (4) | |
H5 | 0.6475 | 0.6271 | −0.1110 | 0.081* | |
C6 | 0.7316 (6) | 0.6154 (3) | 0.1121 (5) | 0.0222 (14) | |
C7 | 0.6309 (7) | 0.6307 (3) | 0.1845 (4) | 0.0221 (16) | |
C8 | 0.6241 (7) | 0.6926 (3) | 0.2140 (6) | 0.0278 (15) | |
H8 | 0.5545 | 0.7039 | 0.2624 | 0.033* | |
C9 | 0.7141 (8) | 0.7370 (4) | 0.1756 (6) | 0.0293 (19) | |
C10 | 0.8146 (8) | 0.7201 (3) | 0.1041 (6) | 0.0312 (17) | |
H10 | 0.8773 | 0.7502 | 0.0764 | 0.037* | |
C11 | 0.8248 (6) | 0.6597 (3) | 0.0723 (6) | 0.0261 (14) | |
C12 | 0.5339 (7) | 0.5842 (3) | 0.2340 (5) | 0.0296 (17) | |
H12A | 0.4787 | 0.5611 | 0.1852 | 0.044* | |
H12B | 0.4644 | 0.6052 | 0.2771 | 0.044* | |
H12C | 0.5955 | 0.5562 | 0.2719 | 0.044* | |
C13 | 0.6987 (9) | 0.8020 (4) | 0.2084 (7) | 0.041 (2) | |
H13A | 0.5976 | 0.8161 | 0.1961 | 0.062* | |
H13B | 0.7685 | 0.8278 | 0.1727 | 0.062* | |
H13C | 0.7198 | 0.8046 | 0.2779 | 0.062* | |
C14 | 0.9425 (8) | 0.6443 (4) | −0.0014 (6) | 0.0388 (19) | |
H14A | 0.8958 | 0.6352 | −0.0638 | 0.058* | |
H14B | 0.9984 | 0.6085 | 0.0207 | 0.058* | |
H14C | 1.0097 | 0.6791 | −0.0088 | 0.058* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Zr1 | 0.0179 (3) | 0.0137 (3) | 0.0168 (3) | 0.0028 (3) | 0.000 | 0.000 |
Te1 | 0.02085 (18) | 0.01997 (19) | 0.0239 (2) | 0.00485 (15) | −0.00464 (18) | −0.0039 (2) |
C1 | 0.139 (10) | 0.024 (4) | 0.035 (7) | 0.037 (5) | −0.038 (7) | −0.002 (4) |
C2 | 0.033 (4) | 0.041 (5) | 0.055 (7) | 0.022 (3) | 0.023 (4) | 0.028 (4) |
C3 | 0.049 (4) | 0.014 (3) | 0.035 (4) | −0.002 (3) | −0.028 (4) | 0.003 (3) |
C4 | 0.065 (5) | 0.039 (4) | 0.050 (6) | 0.032 (4) | 0.032 (6) | 0.034 (4) |
C5 | 0.060 (6) | 0.016 (5) | 0.126 (11) | −0.014 (4) | −0.053 (7) | 0.028 (6) |
C6 | 0.022 (3) | 0.022 (3) | 0.022 (4) | 0.006 (2) | −0.004 (3) | −0.006 (3) |
C7 | 0.023 (3) | 0.026 (4) | 0.017 (4) | 0.002 (3) | −0.003 (2) | −0.008 (3) |
C8 | 0.024 (3) | 0.023 (4) | 0.036 (4) | 0.003 (3) | −0.002 (3) | −0.009 (3) |
C9 | 0.025 (4) | 0.031 (5) | 0.032 (5) | −0.002 (3) | −0.002 (3) | −0.013 (4) |
C10 | 0.032 (4) | 0.028 (4) | 0.033 (5) | −0.007 (3) | 0.003 (3) | −0.007 (3) |
C11 | 0.019 (3) | 0.027 (3) | 0.032 (4) | −0.003 (2) | 0.002 (3) | 0.002 (3) |
C12 | 0.037 (4) | 0.028 (4) | 0.023 (4) | −0.002 (3) | 0.002 (3) | −0.004 (3) |
C13 | 0.039 (4) | 0.030 (5) | 0.055 (6) | 0.003 (4) | 0.001 (4) | −0.013 (4) |
C14 | 0.033 (4) | 0.044 (5) | 0.040 (5) | −0.010 (3) | 0.016 (3) | −0.015 (4) |
Zr1—C1 | 2.519 (8) | C5—H5 | 0.9500 |
Zr1—C2 | 2.519 (7) | C6—C7 | 1.393 (9) |
Zr1—C3 | 2.455 (7) | C6—C11 | 1.398 (9) |
Zr1—C4 | 2.470 (7) | C7—C8 | 1.415 (9) |
Zr1—C5 | 2.504 (8) | C7—C12 | 1.507 (9) |
Zr1—C3i | 2.455 (7) | C8—C9 | 1.375 (11) |
Zr1—C4i | 2.470 (7) | C8—H8 | 0.9500 |
Zr1—C5i | 2.504 (8) | C9—C10 | 1.393 (11) |
Zr1—C2i | 2.519 (7) | C9—C13 | 1.499 (12) |
Zr1—C1i | 2.519 (8) | C10—C11 | 1.395 (9) |
Zr1—Te1 | 2.8694 (10) | C10—H10 | 0.9500 |
Zr1—Te1i | 2.8694 (10) | C11—C14 | 1.512 (9) |
Te1—C6 | 2.150 (7) | C12—H12A | 0.9800 |
C1—C2 | 1.360 (13) | C12—H12B | 0.9800 |
C1—C5 | 1.390 (15) | C12—H12C | 0.9800 |
C1—H1 | 0.9500 | C13—H13A | 0.9800 |
C2—C3 | 1.382 (12) | C13—H13B | 0.9800 |
C2—H2 | 0.9500 | C13—H13C | 0.9800 |
C3—C4 | 1.399 (10) | C14—H14A | 0.9800 |
C3—H3 | 0.9500 | C14—H14B | 0.9800 |
C4—C5 | 1.350 (13) | C14—H14C | 0.9800 |
C4—H4 | 0.9500 | ||
C3—Zr1—C3i | 98.0 (4) | C2—C1—C5 | 107.3 (9) |
C3—Zr1—C4i | 82.9 (3) | C2—C1—Zr1 | 74.3 (5) |
C3i—Zr1—C4i | 33.0 (2) | C5—C1—Zr1 | 73.3 (6) |
C3—Zr1—C4 | 33.0 (2) | C2—C1—H1 | 125.9 |
C3i—Zr1—C4 | 82.9 (3) | C5—C1—H1 | 125.9 |
C4i—Zr1—C4 | 85.7 (5) | Zr1—C1—H1 | 125.9 |
C3—Zr1—C5i | 102.3 (4) | C1—C2—C3 | 109.6 (7) |
C3i—Zr1—C5i | 53.6 (2) | C1—C2—Zr1 | 74.3 (4) |
C4i—Zr1—C5i | 31.5 (3) | C3—C2—Zr1 | 71.3 (4) |
C4—Zr1—C5i | 115.4 (5) | C1—C2—H2 | 125.1 |
C3—Zr1—C5 | 53.6 (2) | C3—C2—H2 | 125.1 |
C3i—Zr1—C5 | 102.3 (4) | Zr1—C2—H2 | 125.1 |
C4i—Zr1—C5 | 115.4 (5) | C2—C3—C4 | 105.8 (7) |
C4—Zr1—C5 | 31.5 (3) | C2—C3—Zr1 | 76.4 (4) |
C5i—Zr1—C5 | 146.4 (6) | C4—C3—Zr1 | 74.1 (4) |
C3—Zr1—C2i | 130.0 (3) | C2—C3—H3 | 126.3 |
C3i—Zr1—C2i | 32.2 (3) | C4—C3—H3 | 126.3 |
C4i—Zr1—C2i | 52.8 (2) | Zr1—C3—H3 | 126.3 |
C4—Zr1—C2i | 112.2 (3) | C5—C4—C3 | 108.9 (8) |
C5i—Zr1—C2i | 52.3 (3) | C5—C4—Zr1 | 75.6 (5) |
C5—Zr1—C2i | 121.5 (3) | C3—C4—Zr1 | 72.9 (4) |
C3—Zr1—C2 | 32.2 (3) | C5—C4—H4 | 125.2 |
C3i—Zr1—C2 | 130.0 (3) | C3—C4—H4 | 125.2 |
C4i—Zr1—C2 | 112.2 (3) | Zr1—C4—H4 | 125.2 |
C4—Zr1—C2 | 52.8 (2) | C4—C5—C1 | 108.3 (8) |
C5i—Zr1—C2 | 121.5 (3) | C4—C5—Zr1 | 72.9 (5) |
C5—Zr1—C2 | 52.3 (3) | C1—C5—Zr1 | 74.5 (6) |
C2i—Zr1—C2 | 162.2 (4) | C4—C5—H5 | 125.6 |
C3—Zr1—C1i | 133.6 (3) | C1—C5—H5 | 125.6 |
C3i—Zr1—C1i | 53.5 (3) | Zr1—C5—H5 | 125.6 |
C4i—Zr1—C1i | 52.8 (3) | C7—C6—C11 | 120.6 (6) |
C4—Zr1—C1i | 135.3 (3) | C7—C6—Te1 | 119.9 (5) |
C5i—Zr1—C1i | 32.1 (3) | C11—C6—Te1 | 119.5 (5) |
C5—Zr1—C1i | 152.7 (3) | C6—C7—C8 | 117.7 (6) |
C2i—Zr1—C1i | 31.3 (3) | C6—C7—C12 | 123.0 (6) |
C2—Zr1—C1i | 151.2 (3) | C8—C7—C12 | 119.3 (6) |
C3—Zr1—C1 | 53.5 (3) | C9—C8—C7 | 122.6 (7) |
C3i—Zr1—C1 | 133.6 (3) | C9—C8—H8 | 118.7 |
C4i—Zr1—C1 | 135.3 (3) | C7—C8—H8 | 118.7 |
C4—Zr1—C1 | 52.8 (3) | C8—C9—C10 | 118.2 (7) |
C5i—Zr1—C1 | 152.7 (3) | C8—C9—C13 | 119.9 (7) |
C5—Zr1—C1 | 32.1 (3) | C10—C9—C13 | 121.8 (8) |
C2i—Zr1—C1 | 151.2 (3) | C9—C10—C11 | 121.2 (7) |
C2—Zr1—C1 | 31.3 (3) | C9—C10—H10 | 119.4 |
C1i—Zr1—C1 | 171.7 (5) | C11—C10—H10 | 119.4 |
C3—Zr1—Te1 | 135.49 (14) | C10—C11—C6 | 119.6 (6) |
C3i—Zr1—Te1 | 94.75 (19) | C10—C11—C14 | 118.1 (6) |
C4i—Zr1—Te1 | 125.22 (16) | C6—C11—C14 | 122.3 (6) |
C4—Zr1—Te1 | 108.2 (2) | C7—C12—H12A | 109.5 |
C5i—Zr1—Te1 | 119.3 (3) | C7—C12—H12B | 109.5 |
C5—Zr1—Te1 | 82.0 (2) | H12A—C12—H12B | 109.5 |
C2i—Zr1—Te1 | 73.43 (16) | C7—C12—H12C | 109.5 |
C2—Zr1—Te1 | 118.2 (2) | H12A—C12—H12C | 109.5 |
C1i—Zr1—Te1 | 87.3 (3) | H12B—C12—H12C | 109.5 |
C1—Zr1—Te1 | 87.7 (3) | C9—C13—H13A | 109.5 |
C3—Zr1—Te1i | 94.75 (19) | C9—C13—H13B | 109.5 |
C3i—Zr1—Te1i | 135.49 (14) | H13A—C13—H13B | 109.5 |
C4i—Zr1—Te1i | 108.2 (2) | C9—C13—H13C | 109.5 |
C4—Zr1—Te1i | 125.22 (16) | H13A—C13—H13C | 109.5 |
C5i—Zr1—Te1i | 82.0 (2) | H13B—C13—H13C | 109.5 |
C5—Zr1—Te1i | 119.3 (3) | C11—C14—H14A | 109.5 |
C2i—Zr1—Te1i | 118.2 (2) | C11—C14—H14B | 109.5 |
C2—Zr1—Te1i | 73.43 (16) | H14A—C14—H14B | 109.5 |
C1i—Zr1—Te1i | 87.7 (3) | C11—C14—H14C | 109.5 |
C1—Zr1—Te1i | 87.3 (3) | H14A—C14—H14C | 109.5 |
Te1—Zr1—Te1i | 105.34 (5) | H14B—C14—H14C | 109.5 |
C6—Te1—Zr1 | 108.06 (16) | ||
Zr1—Te1—C6—C7 | 77.0 (5) | Te1i—Zr1—Te1—C6 | −79.80 (19) |
Zr1—Te1—C6—C11 | −103.8 (5) |
Symmetry code: (i) −x+1, −y+1, z. |
Experimental details
Crystal data | |
Chemical formula | [Zr(C5H5)2(C9H11Te)2] |
Mr | 714.96 |
Crystal system, space group | Orthorhombic, Aba2 |
Temperature (K) | 120 |
a, b, c (Å) | 9.0483 (15), 21.881 (6), 13.806 (4) |
V (Å3) | 2733.3 (12) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 2.51 |
Crystal size (mm) | 0.20 × 0.10 × 0.02 |
Data collection | |
Diffractometer | Bruker Nonius KappaCCD diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2007) |
Tmin, Tmax | 0.758, 0.951 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 9201, 3046, 2444 |
Rint | 0.059 |
(sin θ/λ)max (Å−1) | 0.650 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.040, 0.087, 1.05 |
No. of reflections | 3046 |
No. of parameters | 145 |
No. of restraints | 1 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 1.50, −1.16 |
Absolute structure | Flack (1983), 1405 Friedel pairs |
Absolute structure parameter | 0.14 (5) |
Computer programs: COLLECT (Hooft, 1998) and DENZO (Otwinowski & Minor, 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEPII (Johnson, 1976).
Zr1—C1 | 2.519 (8) | Zr1—C5 | 2.504 (8) |
Zr1—C2 | 2.519 (7) | Zr1—Te1 | 2.8694 (10) |
Zr1—C3 | 2.455 (7) | Te1—C6 | 2.150 (7) |
Zr1—C4 | 2.470 (7) | ||
Te1—Zr1—Te1i | 105.34 (5) | C7—C6—C11 | 120.6 (6) |
C6—Te1—Zr1 | 108.06 (16) | ||
Zr1—Te1—C6—C7 | 77.0 (5) | Te1i—Zr1—Te1—C6 | −79.80 (19) |
Zr1—Te1—C6—C11 | −103.8 (5) |
Symmetry code: (i) −x+1, −y+1, z. |
Acknowledgements
The authors thank the EPSRC for support (grant EP/C001176/1) and for access to the Chemical Database Service at Daresbury Laboratory.
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Thiolate ligands (RS-) form complexes with most metals and metalloids in the Periodic Table. In contrast, much less is known about corresponding selenolates (RSe-), and few tellurolate (RTe-) complexes have been characterized in detail (Arnold, 1995). The latter include [(η5-Me5Cp)2Zr(TePh)2] prepared from [(η5-Me5Cp)2Zr(CO)2], PhOH and Ph2Te2, (Howard et al., 1995) and [(η5-Cp)2Zr(TePh)2] prepared from [(η5-Cp)2ZrCl2] and PhTeLi, (Sato & Yoshida, 1974). We have recently characterized a range of complexes of Ti, Zr and Hf (M) of type [(η5-Cp)2M(SetBu)2] and shown that these complexes serve as single-source precursors for LPCVD (low pressure chemical vapour deposition) of MSe2 films (Hector et al., 2008), but that the corresponding t-butyltellurolates decompose to deposit elemental tellurium. During attempts to improve the stability of the tellurato-complexes, we obtained crystals of the title complex which we now report.
Red crystals of the title compound (I) were obtained in poor yield by reaction of [(η5-Cp)2ZrCl2] with (Me3C6H2)TeMgBr in anhydrous THF solution. The discrete molecule has 2-fold crystallographic symmetry, and shows the typical metallocene geometry with η5-coordinated Cp rings (Zr—C 2.455 (7)–2.519 (8) Å, 2.49 (3) Å (av)) rather shorter than those in [(η5-Me5Cp)2Zr(TePh)2] (2.56 (5) Å (av)) (Howard et al., 1995), but similar to those in the silyltellurolate [(η5-Cp)2Zr{TeSi(SiMe3)3}2] (2.50 (1) Å (av)) (Christou et al., 1993). The Zr—Te distances in [(η5-Cp)2Zr{TeSi(SiMe3)3}2] (2.866 (1) Å), [(η5-Cp)2Zr(TeC6H2Me3)2] (2.869 (1) Å), and [(η5-Me5Cp)2Zr(TePh)2] (2.87 (2) Å) are very similar as are the Te—C distances in the last two compounds (2.150 (7) and 2.12 (2) Å respectively). A more notable difference is in the Te—Zr—Te and Zr—Te—C angles between [(η5-Cp)2Zr(TeC6H2Me3)2] and [(η5-Me5Cp)2Zr(TePh)2] with Te—Zr—Te 105.34 (5) ° versus 97.2 (1) °, and Zr—Te—C 108.06 (16) ° versus 113.1 (7) °, consistent with the greater steric effects of the mesityl groups.