Halogenation reactions of a ditelluride having bulky aryl groups leading to the formation of organotellurium halides†
Dedicated to Professor Kin‐ya Akiba on the occasion of his 75th birthday.
Abstract
Halogenation reactions of BbtTe‐TeBbt (Bbt; 2,6‐bis[bis(trimethylsilyl)methyl]‐4‐[tris (trimethylsilyl)methyl]phenyl) with SO2Cl2, Br2, and I2 were examined. When 1 equiv of the reagents were used, the corresponding tellurium monohalides were obtained as stable crystalline compounds. Although iodination reaction of BbtTe‐TeBbt using 3 equiv of I2 afforded BbtTeI, treatment of BbtTe‐TeBbt with 3 equiv of SO2Cl2 and Br2 gave the corresponding tellurium trihalides, BbtTeX3(X = Cl, Br), as stable crystalline compounds. Characterization of the obtained tellurium mono‐ and trihalides was achieved by the spectroscopic and crystallographic analyses, together with theoretical calculations. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:405–411, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20698
INTRODUCTION
Monoorgano tellurium trihalides, RTeX3 (X = Cl, Br, I), are known to be stable compounds, which should be good precursors for a variety of organotellurium compounds 1(a). Tellurium trihalides can be readily accessed by the reaction of TeCl4 with the corresponding organic nucleophiles or by the halogenation reaction of the corresponding ditelluride. On the other hand, tellurium monohalides, RTeX (X = Cl, Br, I), are difficult to be isolated as stable compounds due to their inherent instability and high reactivity. It is known that a tellurium monohalide is difficult to be isolated because it undergoes ready trimerization to give a mixture of the corresponding tellurium trihalide and ditelluride (Scheme 1) 1(a),2. Accordingly, tellurium monohalides generated in situ can be used as tellurization reagents. Therefore, kinetic stabilization by the use of bulky substituents or thermodynamic stabilization by the coordination of a heteroatom should be necessary to isolate such reactive tellurium monohalides. Indeed, a few examples of tellurium monohalides stabilized by intramolecular coordination of a heteroatom substituent or steric protection using bulky substituent(s) have been reported so far [1,3–5]. In this report, the controlled synthesis of kinetically stabilized tellurium monohalides and trihalides, RTeX and RTeX3, bearing a bulky aryl substituent, 2,6‐bis[bis(trimethylsilyl)methyl]‐4‐[tris(trimethylsilyl)methyl]phenyl (denoted as Bbt), was successfully achieved by halogenation of Bbt‐substituted ditelluride.
SCHEME 1
RESULTS AND DISCUSSION
2,6‐Bis[bis(trimethylsilyl)methyl]‐4‐[tris(trimethylsilyl)methyl]phenyl (Bbt)‐substituted ditelluride, BbtTe‐TeBbt (1), has already been reported to be isolated by the tellurization reaction of the corresponding stable dibismuthene, BbtBi=BiBbt, using elemental tellurium 6. In this paper, the synthetic method for ditelluride 1 was improved as follows (Scheme 2). To a tetrahydrofuran (THF) solution of BbtLi, prepared by the treatment of BbtBr with 2 equiv of t‐BuLi, an excess amount of elemental tellurium was added, giving the corresponding tritelluride, BbtTe3Bbt (2), the structure of which was determined by spectroscopic and X‐ray crystallographic analyses (Fig. 1). Detellurization reaction of tritelluride 2 with elemental copper afforded BbtTe‐TeBbt (1) in quantitative yield. Although the spectroscopic data of 1 were identical with those previously reported 6, the newly obtained X‐ray crystallographic data of 1 are shown here. The Te–Te bond length, Te–Te–C(Bbt) bond angles, and C(Bbt)–Te–Te–C(Bbt) torsion angle of 1 are 2.74221(15) Å, 110.62(4)° and 110.66(4)°, and 116.45(7)°, respectively, showing that the structural parameters of 1 are similar to those of the previously reported diarylditellurides. For example, structural parameters of PhTeTePh are as follows; C–Te: 2.081(18) Å, 2.150(15) Å; Te–Te: 2.712(2) Å; C–Te–Te: 100.3(5)°, 97.4(4)°; C–Te–Te–C: 91.5°. See 7. That is, it is suggested that the bulky Bbt groups should afford negligible electronic perturbation toward the central Te–Te moiety.
SCHEME 2
Molecular structures of (a) tritelluride 2 and (b) ditelluride 1. Displacement ellipsoids were drawn at 50% probability level. Hydrogen atoms and hexane (for 2) and benzene (for 1) molecules were omitted for clarity. Selected structural parameters, 2: C–Te: 2.149(13) Å, 2.171(11) Å; Te–Te: 2.6970(13) Å, 2.7279(14) Å; C–Te–Te: 100.3(3)°, 100.9(3)°; Te –Te–Te: 111.74(4)°, 1: C–Te: 2.1543(16) Å, 2.1477(16) Å; Te–Te: 2.74221(15) Å; C–Te–Te: 110.62(4)°, 110.66(4)°; C–Te–Te–C: 116.45(7)°.
Next, chlorination, bromination, and iodination reactions of the overcrowded ditelluride 1 were examined. Treatment of 1 with 1 equiv of sulfuryl chloride or bromine afforded the corresponding tellurium monohalide, BbtTeX [X = Cl (3a) or Br (3b)], whereas similar halogenation reaction of 1 with 3 equiv of halogenation reagent (SO2Cl2 or Br2) resulted in the quantitative formation of the corresponding tellurium trihalide, BbtTeX3 [X = Cl (4a) or Br (4b)]. These results are in contrast to the results of halogenation reactions of the ditelluride bearing bulky m‐terphenyl groups (ArMesTe–TeArMes, ArMes = 2,6‐dimesitylphenyl), where the corresponding Te(IV)‐Te(II) mixed‐valent ditelluride dihalides, ArMesTeX2–TeArMes (X = Cl, Br), were obtained as stable compounds 5. On the other hand, iodination reactions of 1 with I2 afforded the corresponding tellurium iodide regardless of the amount of I2 used (1 or 3 equiv), as in the case of the iodination reaction of ArMesTe–TeArMes. The results of halogenation reactions of BbtTe‐TeBbt (1) were summarized in Table 1.
| Entry | [X] | Equiv. | Product | Yield | Color |
|---|---|---|---|---|---|
| 1 | SO2Cl2 | 1 eq. | BbtTeCl (3a) | 87% | red‐purple |
| 2 | SO2Cl2 | 3 eq. | BbtTeCl3 (4a) | quant. | yellow |
| 3 | Br2 | 1 eq. | BbtTeBr (3b) | 82% | blue |
| 4 | Br2 | 3 eq. | BbtTeBr3 (4b) | quant. | red |
| 5 | I2 | 1 eq. | BbtTeI (3c) | 95% | green |
| 6 | I2 | 3 eq. | BbtTeI (3c) | 95% | green |
As for the related tellurium halides, Seppelt and his coworkers 5 reported the results of theoretical calculations for the methyl‐substituted model compounds, suggesting that the tellurium halides favorably undergo the disproportionation reactions giving Te(IV)‐Te(II) mixed‐valent ditelluride dihalides or a pair of the trihalide and ditelluride, respectively. Especially, the disproportionation reaction of two molecules of tellurium halides as shown in Eq. (1) should be much more favorable than the disproportionation reaction of three molecules of tellurium halides as shown in Eq. (2) (Scheme 4). The halogenation reactions of ditelluride leading to the formation of the mixed valent species of RTeX2‐TeR and those leading to the formation of tellurium trihalides RTeX3 should be discussed. However, the stability of the tellurium monohalides is discussed here as a comparison with the results of Seppelt's group shown in Ref. 5. As a result of our calculations for the Bbt‐substituted tellurium halides [B3PW91/6‐31G(d) (6‐311G(3d) for halogen atoms, TZ(2d) for Te)], it was found that such disproportionation of tellurium chloride and bromide should be endothermic probably due to the steric reason. Therefore, in the reaction of 1 with an excess amount of halogenating reagents, the tellurium trihalides would be formed not by the disproportionation reaction of three molecules of the corresponding tellurium monohalides, but by the direct halogenation of the tellurium monohalides.
SCHEME 3
SCHEME 4
The results of X‐ray crystallographic analysis of Bbt‐substituted tellurium monobromide 3b and monoiodide 3c are shown in Fig. 2. In both cases, the monohalides were found to exhibit dimeric structures in the crystalline state with weak Te–Te interaction. Such weak interaction between heavy main group elements in the crystalline state is well known. In the crystalline state, Te‐I interaction was observed in the case of Mes*TeX (Mes* = 2,4,6‐tri‐t‐butylphenyl, X = Cl, Br, I) 5. On the other hand, ArMesTeI exhibits Te–Te intermolecular interaction with a distance of 4.057(2) Å in the crystalline state 5. Such intermolecular contact between heavier elements would be sensitive toward steric circumstances and/or packing force in the crystalline state (see Ref. 4) 8,9a. Because no good crystal was obtained for tellurium trihalides (4a and 4b), the structural parameters of 4a and 4b have been fully concealed. Therefore, theoretical calculations were performed in order to get some structural information for 4a and 4b. Observed and theoretically optimized structural parameters and the 125Te nuclear magnetic resonance (NMR) chemical shifts are summarized in Table 2. The theoretically optimized structural parameters of 3b and 3c are in good agreement with those observed, supporting the credibility of the theoretical method. In addition, the tellurium trihalides, 4a and 4b, were found to exhibit pseudo‐TBP structures bearing two halogen atoms at the apical positions. The calculated 125Te NMR chemical shifts are in good agreement with the observed values, indicating that the Bbt‐substituted tellurium halides are keeping their mono‐ or trihalide structures even in solution.
Molecular structures of (a) tellurium monobromide 3b and (b) tellurium monoiodide 3c. Displacement ellipsoids were drawn at 50% probability level. Hydrogen atoms and benzene molecules were omitted for clarity. Selected structural parameters, 3b: C–Te: 2.102(5) Å; Te–Br: 2.7048(6) Å; Te–Te*: 3.4533(7) Å; C–Te–Br: 99.72(14)°; 3c: C–Te: 2.112(4) Å; Te–I: 2.7070(5) Å; Te–Te*: 3.4534(6) Å; C–Te–I: 99.94(11)°.
|
Te–X1(eq)a/Å | Te–X2(ap)a/Å | Te–C/Å | C–Te–X1/° | δ125Te(CDCl3) |
|---|---|---|---|---|---|
| Observed | |||||
| BbtTeCl(3a) | – | – | – | – | 1936 |
| BbtTeBr(3b) | 2.7048(6) | – | 2.102(5) | 99.72(14) | 1464 |
| BbtTeI(3c) | 2.7070(5) | – | 2.112(4) | 99.94(11) | 1054 |
| BbtTeCl3(4a) | – | – | – | – | 1291 |
| BbtTeBr3(4b) | – | – | – | – | 1240 |
| Mes*TeClb | 2.384(1) | – | 2.134(3) | 93.41(8) | 1179d |
MesTeCl |
2.330(3) | 2.484(2) 2.504(2) | 2.178(8) | 116.82(9) | 1791d |
| Calculatedc | |||||
| BbtTeCl(3a) | 2.399 | – | 2.116 | 102.5 | 1881 |
| BbtTeBr(3b) | 2.566 | – | 2.119 | 103.9 | 1685 |
| BbtTeI(3c) | 2.816 | – | 2.114 | 105.7 | 1307 |
| BbtTeCl3(4a) | 2.366 | 2.497 2.480 | 2.166 | 112.9 | 1162 |
| BbtTeBr3(4b) | 2.547 | 2.680 2.702 | 2.175 | 114.6 | 1142 |
| BbtTeI3(4c) | 2.814 | 2.982 3.014 | 2.176 | 116.9 | 832 |
| Mes*TeCl | 2.385 | – | 2.149 | 97.8 | 1818 |
| Mes*TeCl3 | 2.360 | 2.490 2.491 | 2.201 | 119.9 | 1121 |
- aX1 and X2 are the halogen atoms located at the equatorial and apical positions, respectively.
- bSee ref. 4.
- cCalculated at GIAO‐B3PW91/6‐31 + G(2d,p)[6‐311G(3d) for halogen atoms, TZ(2d) for Te]//B3PW91/6‐31G(d)[6‐311G(3d) for halogen atoms, TZ(2d) for Te] level.
- dMeasured in CCl4.
The 125Te NMR chemical shifts of BbtTeX (X = Cl, Br, I) shift to upper field region as the elements row of the halogen atom descends. The tendency can be reasonably explained by the electronegativity and/or heavy atom effect. On the other hand, 125Te NMR chemical shifts of the tellurium monohalides, BbtTeX (X = Cl, Br), are in the lower field region than those of the corresponding tellurium trihalides, BbtTeX3 (X = Cl, Br). Such a feature of the 125Te NMR chemical shifts was reproduced by the Geometric optimization and gauge including atomic orbital (GIAO) calculations as shown in Table 2. However, Mes*TeCl (Mes* = 2,4,6‐tri‐t‐butylphenyl) was reported to show upper‐field shifted chemical shift (δTe = 1179) as compared with Mes*TeCl3 (δTe = 1791) 4, in contrast to the case of Bbt‐substituted tellurium monohalides and trihalides. The reason for the difference observed in 125Te NMR chemical shifts between Bbt‐ and Mes*‐substituted tellurium halides is unclear at present. As their 125Te NMR chemical shifts of Mes*TeCl and MesTeCl3 were computed to be 1818 and 1120 ppm, respectively, there is some possibility that the observed chemical shifts for Mes*TeCl and Mes*TeCl3 would be incorrectly reported to each other.
CONCLUSION
We demonstrated that the chlorination, bromination, and iodination reactions of the ditelluride having Bbt groups, BbtTe‐TeBbt (1), leading to the formation of the corresponding tellurium monohalides (3a, 3b, 3c) and trihalides (4a, 4b). The 125Te NMR spectral data and structural features were revealed and characterized by the experimental results and theoretical calculations. It was found that the bulky Bbt group would suppress the disproportionation of the tellurium halides. As a result, the Bbt‐substituted tellurium monohalides, BbtTeX (X = Cl, Br, I), were obtained as stable compounds. Further investigation is currently in progress on the reactivity of the tellurium monohalides 3 and trihalides 4.
EXPERIMENTAL
General Procedures
All reactions were carried out under an argon atmosphere or in a degassed and sealed tube, unless otherwise noted. All solvents were purified by standard methods and then dried using an Ultimate Solvent System (Glass Contour Company, Nashua, NH) 10. Benzene‐d6 for the NMR spectroscopy was dried using a potassium mirror prior to use. Preparative thin‐layer chromatography (PTLC) and column chromatography were performed with Merck (Darmstadt, Germany) Kieselgel 60 PF254. Preparative gel permeation liquid chromatography (GPLC) was performed on an LC‐908 or 918 equipped with JAI‐gel 1H and 2H columns (Japan Analytical Industry Co., Ltd., Osaka, Japan) with toluene as an eluent. 1H NMR (300 MHz) and 13C NMR (75 Hz) spectra were measured in C6D6 or CDCl3 with a JEOL (Osaka, Japan) AL‐300 spectrometer using C6HD5 (δ = 7.15 ppm) or CHCl3 (δ = 7.25 ppm) for 1H NMR spectra, and C6D6 (δ = 128.0 ppm) or CDCl3 (δ = 77.0 ppm) for 13C NMR spectra as internal standards, respectively. 125Te NMR (94 MHz) spectra were measured in C6D6 or CDCl3 with a JEOL AL‐300 spectrometer using Ph2Te2 (δ = 450 ppm) as an external standard. Elemental analyses were performed by the Microanalytical Laboratory of the Institute for Chemical Research, Kyoto University. BbtBr was prepared according to the procedures reported in the literature. Chemical data for BbtTe‐TeBbt (1) was shown in the literature 6.
Synthesis of BbtTeTeTeBbt (2)
To a THF solution (20 mL) of BbtBr (1.00 g, 1.42 mmol), t‐BuLi (1.67 M pentane solution, 1.87 mL, 3.12 mmol) was added under vigorous stirring at −78°C. After 1 h, elemental tellurium (544 mg, 4.26 mmol) was added to the solution. The reaction mixture was stirred at this temperature for 3 h and then at room temperature for 1 h. The resulting dark brown solution was added to a saturated solution of potassium ferricyanide in 10% NaOH aqueous solution (5 mL). The mixture was stirred for 30 min and extracted with hexane (50 mL × 3 times). The solution was dried with MgSO4. After filtration, the solvents were removed under vacuum to give (BbtTe)2Te (2, 670 mg, 0.415 mmol, 59%). 2: dark green crystals, mp 264°C (decomp); 1H NMR (300 MHz, C6D6): δ = 0.31 (s, 72H), 0.34 (s, 54H), 3.46 (s, 4H), 7.07 (s, 4H); 125Te NMR (94 MHz, C6D6): δ = 355, 424; elemental analysis calcd (%) for C60H134Si14Te2: C44.17, H 8.28; found: C44.01, H 8.19.
Synthesis of BbtTeTeBbt (1)
(BbtTe)2Te (2, 100 mg, 0.0613 mmol) was dissolved in dioxane (30 mL) and then Cu powder was added to the dark red solution. The suspension was refluxed for 10 h, then the color of the solution changed from dark red to dark green. The reaction mixture was filtered and then the filtrate was evaporated to remove the solvent. The recrystallization of the residue from CH2Cl2/EtOH afforded (BbtTe)2 (1) (88.8 mg, 0.0589 mmol, 96%) as dark green crystals.
Synthesis of BbtTeX (3a: X = Cl, 3b: X = Br, 3c: X = I)
To a solution of 1 (100 mg, 0.0664 mmol) in CH2Cl2 (5 mL), a solution of halogenation reagents (SO2Cl2: 8.96 mg, 0.0664 mmol for 3a, Br2: 10.6 mg, 0.0664 mmol for 3b, I2: 16.8 mg, 0.0664 mmol for 3c) in CH2Cl2 (5 mL) was added at −78°C. After stirring for 1 h, the solvent was removed under reduced pressure. The recrystallization of the residue from hexane gave 3a–c (3a: 91.0 mg, 0.116 mmol, 87%; 3b: 90.6 mg, 0.109 mmol, 82%; 3c: 110 mg, 0.125 mmol, 95%), respectively.
BbtTeCl (3a): red‐purple crystals, mp 161°C (decomp); 1H NMR (300 MHz, C6D6): δ = 0.25 (s, 27H), 0.28 (s, 36H), 1.80 (s, 1H), 2.89(s, 1H), 3.44 (s, 1H); 13C NMR(75 MHz, C6D6): δ = 1.49, 5.54, 14.4, 23.4, 124.6, 133.8, 151.1, 154.9; 125Te NMR(94 MHz, C6D6) δ = 1881, (94 MHz, CDCl3) δ = 1936.
BbtTeBr (3b): blue crystals, mp 178.0–180.0°C; 1H NMR(300 MHz, C6D6): δ = 0.22 (s, 36H), 0.31 (s, 27H), 3.45 (s, 2H), 7.14 (s, 2H); 13C NMR(75 MHz, C6D6): δ = 1.54, 5.54, 23.4, 40.7, 124.6, 130.0, 150.8, 155.2; 125Te NMR(94 MHz, C6D6) δ = 1601, (94 MHz, CDCl3) δ = 1464; elemental analysis calcd (%) for C30H67Si7Te: C 43.31, H 8.12; found: C 43.04, H 7.89.
BbtTeI (3c): green crystals, mp 180.6–182.0°C (decomp); 1H NMR (300 MHz, C6D6): δ = 0.25 (s, 36H), 0.31(s, 24H), 3.48 (s, 2H), 7.07 (s, 2H); 13C NMR(75 MHz, C6D6) δ = 1.67, 5.53, 40.3, 56.0, 123.1, 124.6, 149.8, 155.1; 125Te NMR (94 MHz, C6D6): δ = 938, (94 MHz, CDCl3) δ = 1054; elemental analysis calcd (%) for C30H74Si7ITe : C 40.99, H 7.68; found: C 40.72, H 7.75.
Synthesis of BbtTeX3 (4a: X = Cl, 4b: X = Br) and Reaction of 1 with 3 equiv of I2
To a solution of 1 (100 mg, 0.0664 mmol) in CH2Cl2 (5 mL), a solution of halogenation reagents (SO2Cl2: 29.9 mg, 0.221 mmol for 4a, Br2: 31.8 mg, 0.221 mmol for 4b, I2: 50.4 mg, 0.221 mmol) in CH2Cl2 (5 mL) was added at −78°C. After stirring for 1 h, the solvent was removed under reduced pressure. The recrystallization of the residue from hexane gave 4a (106 mg, 0.116 mmol, 93%), 4b (130 mg, 0.131 mmol, 99%), and 3c (110 mg, 0.125 mmol, 95%), respectively. 4a: yellow crystals, mp 121°C (decomp); 1H NMR(300 MHz, C6D6) δ = 0.2–0.4 (m, 63H), 1.88 (brs, 1H), 3.38(brs, 1H), 6.85 (brs, 1H), 7.11 (brs, 1H); 125Te NMR(94 MHz, C6D6) δ = 1620, (94 MHz, CDCl3) δ = 1291; elemental analysis calcd (%) for C30H67Cl3Si7Te : C, 41.98; H, 7.87; found: C 42.24, H 7.89. 4b: red crystals, mp 190°C (decomp); 1H NMR(300 MHz, C6D6): δ = 0.3–0.4 (m, 63H), 1.99 (brs, 1H), 3.49 (brs, 1H), 6.80 (brs, 1H), 7.06 (brs, 2H); 125Te NMR(94 MHz, C6D6) δ = 1251, (94 MHz, CDCl3)δ = 1240; elemental analysis calcd (%) for C30H67Si7Br3Te: C 36.33, H 6.81; found: C 36.05, H 6.81.
X‐Ray Crystallographic Analysis of 1, 2, 3b, and 3c
The intensity data were collected on a RIGAKU (Osaka, Japan) Saturn70 CCD(system) with VariMax Mo Optic using Mo K α adiation (λ=0.71070 Å). Single crystals suitable for X‐ray analysis were obtained by slow recrystallization from benzene (for 1, 3b, 3c) and hexane (for 2). The single crystals were mounted on a glass fiber. The structures were solved by a direct method (SHELXS‐97) 11 and refined by full‐matrix least‐squares procedures on F2 for all reflections (SHELXL‐97) 12. All hydrogen atoms were placed using AFIX instructions, whereas all other atoms were refined anisotropically. Crystal data for [1·benzene]: C66H140Si14Te2, m = 1582.24, t = 103(2) K, triclinic, P‐1 (no.2), a = 12.9892(1) Å, b = 18.1075(2) Å, c = 18.9071(2) Å, α = 90.8888(4)°, β = 99.8048(4)°, γ = 90.5319(8)°, V = 4381.18(8) Å3, Z = 2, Dcalc = 1.199 gcm−3, μ=0.890 mm−1, 2θmax = 51.0, 38805 measured reflections, 16142 independent reflections (Rint = 0.0285), 781 refined parameters, GOF = 1.062, R1 = 0.0245 and wR2 = 0.0620 [I>2σ(I)], R1 = 0. 0261 and wR2 = 0.0633 [for all data], largest different peak and hole 0.849 and ‐0.328 e Å−3. Crystal data for [2·0.5hexane]: C63H141Si14Te3, m = 1674.82, t = 103(2) K, triclinic, P‐1 (no.2), a = 9.2543(3) Å, b = 14.5597(5) Å, c = 33.1032(14) Å, α = 77.9436(18)°, β = 90.917(2)°, γ = 87.680(3)°, V = 4357.0(3) Å3, Z = 2, Dcalc = 1.277 gcm−3, μ=1.223 mm−1, 2θmax = 51.0, 38909 measured reflections, 16107 independent reflections (Rint = 0.2398), 764 refined parameters, GOF = 1.003, R1 = 0.0916 and wR2 = 0.1499 [I>2σ(I)], R1 = 0.2409 and wR2 = 0.2034 [for all data], largest different peak and hole 1.752 and −0.955 e.Å−3. Crystal data for [3b·benzene]: C36H73BrSi7Te, m = 910.08, t = 103(2) K, triclinic, P‐1 (no.2), a = 12.3761(2) Å, b = 18.9663(2) Å, c = 21.6485(2) Å, α = 99.9955(5)°, β = 94.1515(5)°, γ = 103.9852(11)°, V = 4821.17(10) Å3, Z = 4, Dcalc = 1.254 gcm−3, μ=1.642 mm−1, 2θmax = 50.0, 39282 measured reflections, 16595 independent reflections (Rint = 0.0449), 853 refined parameters, GOF = 1.216, R1 = 0.0911 and wR2 = 0.3039 [I >> 2σ(I)], R1 = 0.0975 and wR2 = 0.3242 [for all data], largest different peak and hole 8.662 and −2.576 e.Å−3. Crystal data for [3c·benzene]: C36H73ISi7Te, m = 957.07, t = 103(2) K, triclinic, P‐1 (no.2), a = 12.3795(4) Å, b = 18.9885(5) Å, c = 21.6496(5) Å, α = 100.0553(11)°, β = 94.0338(12)°, γ = 103.869(3)°, V = 4831.3(2) Å3, Z = 4, Dcalc = 1.316 gcm−3, μ=1.451 mm−1, 2θmax = 51.0, 42907 measured reflections, 17849 independent reflections (Rint = 0.0649), 853 refined parameters, GOF = 1.018, R1 = 0.0493 and wR2 = 0.1145 [I>2σ(I)], R1 = 0.0789 and wR2 = 0.1306 [for all data], largest different peak and hole 3.727 and −1.650 e.Å−3. CCDC 795125–795128 contains the supplementary crystallographic data for [1·benzene], [2·0.5hexane], [3b·benzene], and [3c·benzene], respectively. These data can be obtained free of charge via http://www.ccdc.cam.ac.uk/conts/retrieving.html, or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; Fax: (+44) 1223‐336‐033; or e‐mail: deposit@ccdc.cam.ac.uk.
