organic compounds
4-(Dimethylamino)phenyl ethynyl telluride
aUnitat de Cristal·lografia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
*Correspondence e-mail: mariocapparelli@cantv.net
The title compound, C10H11NTe, is the first organyl ethynyl telluride, R—Te—C≡C—H, to be structurally characterized. In the L-shaped molecule, the aryl moiety, viz. Me2NC6H4Te, is almost perpendicular to the Te—C≡C—H fragment. The Te—Csp2 bond [2.115 (3) Å] is significantly longer than the Te—Csp bond [2.041 (4) Å]. The Te—C≡C group is approximately linear [Te—C—C = 178.5 (4)° and C≡C = 1.161 (5) Å], while the coordination at the Te atom is angular [C—Te—C = 95.92 (14)°]. In the there are Csp—H⋯N hydrogen bonds which are perpendicular to the CNMe2 group; the N atom displays some degree of pyramidalization. Centrosymmetrically related pairs of molecules are linked by Te⋯π(aryl) interactions, with Te⋯Cg = 3.683 (4) Å and Csp—Te⋯Cg = 159.1 (2)° (Cg is the centroid of the benzene ring). These interactions lead to the formation of zigzag ribbons which run along c and are approximately parallel to (110).
Related literature
For general background, see: Dabdoub et al. (1998); Gillespie & Hargittai (1991); Kauffmann & Ahlers (1983); Murai et al. (1994); Petragnani (1994); Potapov & Trofimov (2005); Schulz Lang et al. (2006); Yoshimatsu (2005); Zukerman-Schpector & Haiduc (2001). For related structures, see: Farran et al. (2002). For details of the synthesis, see: Brandsma (1988); Petragnani et al. (1975).
Experimental
Crystal data
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Refinement
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Data collection: SMART (Bruker, 2002); cell SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2009).
Supporting information
10.1107/S1600536809009404/bg2241sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536809009404/bg2241Isup2.hkl
Ethynyl magnesium bromide, HC≡CMgBr, was prepared according to published procedures (Brandsma, 1988). The corresponding diaryl ditelluride, (Me2NC6H4Te)2, was synthesized as reported elsewhere (Petragnani et al., 1975). A dark solution of the diaryl ditelluride (2.0 mmol, 0.94 g) in 40 ml of THF was treated dropwise with bromine (2.0 mmol, 0.32 g, 0.10 ml) in 10 ml of benzene, at 0°C, in N2 atmosphere, while efficient cooling was applied. The Grignard reagent was then added dropwise. Gradual disappearance of the dark color of the solution was observed until it finally became almost colorless when about 10% excess of the reagent was added. After stirring for 30 min at room temperature, the solution was diluted with 50 ml of low boiling point petroleum ether, treated with aqueous NH4Cl and washed with brine. The organic layer was dried over magnesium sulfate and the solvents were evaporated. The residue was purified by flash (silica gel/hexane). Yield 51%. Crystals suitable for X-ray analysis were obtained by slow evaporation of a chloroform solution. The specimen used for data collection was air-protected with a thin coat of Loctite epoxy adhesive.
Hydrogen atoms were placed in calculated positions using a riding atom model with fixed C—H distances [0.93 Å for C(sp) and C(sp2), 0.96 Å for C(sp3)] and Uiso = p Ueq(parent atom) [p = 1.2 for C(sp) and C(sp2), 1.5 for C(sp3)].
Although organotellurium compounds have attracted considerable interest as reagents and intermediates in organic synthesis (Petragnani, 1994), only a limited number of compounds with mono- and ditelluroethyne cores, R—Te—C≡CH and R—Te—C≡C-Te—R', have been reported, in spite of the potential reactivity of the acetylene unit towards addition reactions. We recently reported the syntheses and crystal structures of several symmetrical (R = R') bis(aryltelluro)ethynes, Ar—Te—C≡C-Te—Ar (Farran et al., 2002). On the other hand, only five R—Te—C≡CH derivatives have been prepared so far, with R = Me, Et, iPr, n-Bu and Ph (Kauffmann & Ahlers, 1983; Dabdoub et al., 1998; Potapov & Trofimov, 2005; Yoshimatsu, 2005), and none has been structurally characterized (in addition, calculations for R = HC≡C were carried out by Murai et al., 1994). Here we describe the of the title compound (R = p-Me2NC6H4), the first of an organyl ethynyl telluride to be reported.
The structure analysis showed that the crystal contains discrete L-shaped molecules of the title compound (Figure 1), in which the aryl moiety, Me2NC6H4Te, is almost perpendicular to the Te—C≡C-H fragment (cf. C—Te—C angle, Table 1), but bent ca 13° towards the C12—C13 side of the ring (cf. C—Te—C—C angles, Table 1), probably to optimize the C—H···N interaction (see below).
As expected, the Te—C(sp2) bond is significantly longer than the Te—C(sp) one. The Te—C≡C moiety is approximately linear, while the coordination at the Te atom is angular, as predicted by the valence-shell electron-pair repulsion (VSEPR) model for an AX2E2 molecule (Gillespie & Hargittai, 1991). The values of these geometric parameters (Table 1) are similar to the ranges observed in several bis(arytelluro)ethynes, Ar—Te—C≡C-Te—Ar (Farran et al., 2002), viz. Te—C(sp2), 2.103 (5)–2.142 (6) Å; Te—C(sp), 2.021 (6)–2.058 (6) Å; C≡C, 1.166 (12)–1.203 (11) Å and C—Te—C, 94.2 (3)–97.2 (2)°, which are substantially smaller than the tetrahedral value (109.5°) due to the repulsion of the lone pairs of electrons on the bonded ones.
In the π(aryl) interactions, similar to those described by Zukerman-Schpector & Haiduc (2001) or Schulz Lang et al. (2006) for Te(IV) compounds, in which centrosymmetrically related pairs of molecules are at Te···Cg 3.683 (4) Å and C(sp)—Te···Cg 159.1 (2)° (Cg = centroid of the phenyl ring at 1 - x, -y, 1 - z). These interactions lead to the formation of zigzag ribbons, made of pairs of chains, which run along c and are approximately parallel to (110) (Figure 2).
the molecules are linked by C(sp)—H···N hydrogen bonds (Table 2) which are perpendicular to the CNMe2 group. The N atom displays some degree of pyramidalization: it is 0.123 (5) Å out of the plane of the three C atoms, towards the H atom. There are also Te···For related literature, see: Brandsma (1988); Dabdoub et al. (1998); Farran et al. (2002); Gillespie & Hargittai (1991); Kauffmann & Ahlers (1983); Murai et al. (1994); Petragnani (1994); Petragnani et al. (1975); Potapov & Trofimov (2005); Schulz Lang, Manzoni de Oliveira & Casagrande (2006); Yoshimatsu (2005); Zukerman-Schpector & Haiduc (2001). [Please divide references into specific categories, eg. synthesis, related structures etc]
Data collection: SMART (Bruker, 2002); cell
SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2009).C10H11NTe | Z = 2 |
Mr = 272.80 | F(000) = 260 |
Triclinic, P1 | Dx = 1.752 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 7.8857 (7) Å | Cell parameters from 1735 reflections |
b = 8.3851 (8) Å | θ = 2.7–25.6° |
c = 9.3364 (9) Å | µ = 2.82 mm−1 |
α = 65.788 (2)° | T = 294 K |
β = 66.922 (1)° | Plate, pale brown |
γ = 83.444 (2)° | 0.36 × 0.30 × 0.10 mm |
V = 517.18 (8) Å3 |
Brruker SMART APEX diffractometer | 2401 independent reflections |
Radiation source: fine-focus sealed tube | 2080 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.012 |
Detector resolution: 8.13 pixels mm-1 | θmax = 28.9°, θmin = 2.6° |
φ and ω scans | h = −10→10 |
Absorption correction: multi-scan (SADABS; Bruker, 2001) | k = −10→10 |
Tmin = 0.403, Tmax = 0.754 | l = −10→12 |
3574 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)] = 0.034 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.087 | H-atom parameters constrained |
S = 1.04 | w = 1/[σ2(Fo2) + (0.0487P)2 + 0.1129P] where P = (Fo2 + 2Fc2)/3 |
2401 reflections | (Δ/σ)max = 0.005 |
110 parameters | Δρmax = 0.75 e Å−3 |
0 restraints | Δρmin = −0.35 e Å−3 |
C10H11NTe | γ = 83.444 (2)° |
Mr = 272.80 | V = 517.18 (8) Å3 |
Triclinic, P1 | Z = 2 |
a = 7.8857 (7) Å | Mo Kα radiation |
b = 8.3851 (8) Å | µ = 2.82 mm−1 |
c = 9.3364 (9) Å | T = 294 K |
α = 65.788 (2)° | 0.36 × 0.30 × 0.10 mm |
β = 66.922 (1)° |
Brruker SMART APEX diffractometer | 2401 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2001) | 2080 reflections with I > 2σ(I) |
Tmin = 0.403, Tmax = 0.754 | Rint = 0.012 |
3574 measured reflections |
R[F2 > 2σ(F2)] = 0.034 | 0 restraints |
wR(F2) = 0.087 | H-atom parameters constrained |
S = 1.04 | Δρmax = 0.75 e Å−3 |
2401 reflections | Δρmin = −0.35 e Å−3 |
110 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Te1 | 0.45985 (3) | 0.02042 (3) | 0.26991 (3) | 0.06634 (13) | |
C1 | 0.3522 (5) | 0.1483 (5) | 0.0886 (5) | 0.0612 (8) | |
C2 | 0.2942 (7) | 0.2203 (6) | −0.0170 (6) | 0.0747 (11) | |
H2 | 0.2478 | 0.2779 | −0.1016 | 0.090* | |
C11 | 0.3173 (5) | 0.1554 (5) | 0.4271 (4) | 0.0532 (7) | |
C12 | 0.3748 (5) | 0.3243 (5) | 0.3871 (5) | 0.0608 (9) | |
H12 | 0.4778 | 0.3792 | 0.2894 | 0.073* | |
C13 | 0.2819 (5) | 0.4118 (5) | 0.4899 (5) | 0.0595 (8) | |
H13 | 0.3219 | 0.5256 | 0.4592 | 0.071* | |
C14 | 0.1272 (5) | 0.3316 (4) | 0.6407 (4) | 0.0515 (7) | |
C15 | 0.0702 (5) | 0.1609 (5) | 0.6793 (5) | 0.0568 (8) | |
H15 | −0.0321 | 0.1042 | 0.7771 | 0.068* | |
C16 | 0.1641 (5) | 0.0766 (4) | 0.5739 (5) | 0.0566 (8) | |
H16 | 0.1236 | −0.0362 | 0.6022 | 0.068* | |
N1 | 0.0368 (5) | 0.4146 (5) | 0.7474 (4) | 0.0639 (8) | |
C17 | 0.0794 (7) | 0.5988 (5) | 0.6960 (6) | 0.0714 (11) | |
H171 | 0.0033 | 0.6351 | 0.7852 | 0.107* | |
H172 | 0.0561 | 0.6671 | 0.5949 | 0.107* | |
H173 | 0.2071 | 0.6158 | 0.6739 | 0.107* | |
C18 | −0.1341 (7) | 0.3391 (7) | 0.8888 (6) | 0.0834 (13) | |
H181 | −0.1834 | 0.4182 | 0.9439 | 0.125* | |
H182 | −0.1121 | 0.2302 | 0.9681 | 0.125* | |
H183 | −0.2209 | 0.3184 | 0.8485 | 0.125* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Te1 | 0.0694 (2) | 0.0780 (2) | 0.06248 (18) | 0.02561 (14) | −0.03447 (14) | −0.03496 (14) |
C1 | 0.061 (2) | 0.067 (2) | 0.060 (2) | 0.0095 (17) | −0.0267 (17) | −0.0276 (17) |
C2 | 0.085 (3) | 0.081 (3) | 0.069 (2) | 0.023 (2) | −0.041 (2) | −0.033 (2) |
C11 | 0.0526 (18) | 0.061 (2) | 0.0527 (18) | 0.0111 (15) | −0.0256 (15) | −0.0263 (15) |
C12 | 0.0518 (18) | 0.067 (2) | 0.056 (2) | −0.0026 (16) | −0.0174 (16) | −0.0194 (17) |
C13 | 0.060 (2) | 0.0532 (19) | 0.064 (2) | −0.0041 (16) | −0.0241 (17) | −0.0194 (16) |
C14 | 0.0541 (18) | 0.0528 (18) | 0.0510 (17) | 0.0093 (14) | −0.0274 (15) | −0.0186 (14) |
C15 | 0.0558 (19) | 0.0539 (19) | 0.0522 (18) | −0.0010 (15) | −0.0163 (15) | −0.0163 (15) |
C16 | 0.064 (2) | 0.0460 (17) | 0.061 (2) | 0.0023 (15) | −0.0293 (17) | −0.0174 (15) |
N1 | 0.070 (2) | 0.0569 (17) | 0.0628 (19) | 0.0078 (14) | −0.0228 (16) | −0.0254 (14) |
C17 | 0.088 (3) | 0.062 (2) | 0.085 (3) | 0.019 (2) | −0.048 (2) | −0.039 (2) |
C18 | 0.076 (3) | 0.095 (3) | 0.073 (3) | 0.013 (2) | −0.015 (2) | −0.043 (2) |
Te1—C1 | 2.041 (4) | C15—C16 | 1.376 (5) |
Te1—C11 | 2.115 (3) | C15—H15 | 0.9300 |
C1—C2 | 1.161 (5) | C16—H16 | 0.9300 |
C2—H2 | 0.9300 | N1—C18 | 1.440 (6) |
C11—C16 | 1.384 (5) | N1—C17 | 1.454 (6) |
C11—C12 | 1.390 (5) | C17—H171 | 0.9600 |
C12—C13 | 1.378 (5) | C17—H172 | 0.9600 |
C12—H12 | 0.9300 | C17—H173 | 0.9600 |
C13—C14 | 1.410 (5) | C18—H181 | 0.9600 |
C13—H13 | 0.9300 | C18—H182 | 0.9600 |
C14—N1 | 1.372 (5) | C18—H183 | 0.9600 |
C14—C15 | 1.407 (5) | ||
C1—Te1—C11 | 95.92 (14) | C15—C16—C11 | 121.8 (3) |
C2—C1—Te1 | 178.5 (4) | C15—C16—H16 | 119.1 |
C1—C2—H2 | 180.0 | C11—C16—H16 | 119.1 |
C16—C11—C12 | 118.1 (3) | C14—N1—C18 | 120.5 (3) |
C16—C11—Te1 | 120.6 (3) | C14—N1—C17 | 120.7 (4) |
C12—C11—Te1 | 121.3 (3) | C18—N1—C17 | 116.6 (4) |
C13—C12—C11 | 121.2 (3) | N1—C17—H171 | 109.5 |
C13—C12—H12 | 119.4 | N1—C17—H172 | 109.5 |
C11—C12—H12 | 119.4 | H171—C17—H172 | 109.5 |
C12—C13—C14 | 121.0 (3) | N1—C17—H173 | 109.5 |
C12—C13—H13 | 119.5 | H171—C17—H173 | 109.5 |
C14—C13—H13 | 119.5 | H172—C17—H173 | 109.5 |
N1—C14—C15 | 121.0 (3) | N1—C18—H181 | 109.5 |
N1—C14—C13 | 121.8 (3) | N1—C18—H182 | 109.5 |
C15—C14—C13 | 117.2 (3) | H181—C18—H182 | 109.5 |
C16—C15—C14 | 120.8 (3) | N1—C18—H183 | 109.5 |
C16—C15—H15 | 119.6 | H181—C18—H183 | 109.5 |
C14—C15—H15 | 119.6 | H182—C18—H183 | 109.5 |
C1—Te1—C11—C16 | 102.7 (3) | C13—C14—C15—C16 | 0.7 (5) |
C1—Te1—C11—C12 | −77.8 (3) | C14—C15—C16—C11 | 0.1 (6) |
C16—C11—C12—C13 | −0.4 (6) | C12—C11—C16—C15 | −0.3 (5) |
Te1—C11—C12—C13 | −179.9 (3) | Te1—C11—C16—C15 | 179.3 (3) |
C11—C12—C13—C14 | 1.2 (6) | C15—C14—N1—C18 | −8.9 (6) |
C12—C13—C14—N1 | 177.8 (4) | C13—C14—N1—C18 | 172.1 (4) |
C12—C13—C14—C15 | −1.3 (5) | C15—C14—N1—C17 | −171.4 (4) |
N1—C14—C15—C16 | −178.4 (3) | C13—C14—N1—C17 | 9.6 (6) |
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···N1i | 0.93 | 2.48 | 3.379 (6) | 163 |
Symmetry code: (i) x, y, z−1. |
Experimental details
Crystal data | |
Chemical formula | C10H11NTe |
Mr | 272.80 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 294 |
a, b, c (Å) | 7.8857 (7), 8.3851 (8), 9.3364 (9) |
α, β, γ (°) | 65.788 (2), 66.922 (1), 83.444 (2) |
V (Å3) | 517.18 (8) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 2.82 |
Crystal size (mm) | 0.36 × 0.30 × 0.10 |
Data collection | |
Diffractometer | Brruker SMART APEX |
Absorption correction | Multi-scan (SADABS; Bruker, 2001) |
Tmin, Tmax | 0.403, 0.754 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3574, 2401, 2080 |
Rint | 0.012 |
(sin θ/λ)max (Å−1) | 0.680 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.034, 0.087, 1.04 |
No. of reflections | 2401 |
No. of parameters | 110 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.75, −0.35 |
Computer programs: SMART (Bruker, 2002), SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997), WinGX (Farrugia, 1999) and PLATON (Spek, 2009).
Te1—C1 | 2.041 (4) | C1—C2 | 1.161 (5) |
Te1—C11 | 2.115 (3) | ||
C1—Te1—C11 | 95.92 (14) | C2—C1—Te1 | 178.5 (4) |
C1—Te1—C11—C16 | 102.7 (3) | C1—Te1—C11—C12 | −77.8 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···N1i | 0.93 | 2.48 | 3.379 (6) | 162.9 |
Symmetry code: (i) x, y, z−1. |
Acknowledgements
The authors gratefully acknowledge the financial support of the European Union (project No. CI1*.0574.ES). JF thanks the Generalitat de Catalunya for an FI grant and MVC thanks the Ministerio de Educación y Cultura of Spain for a sabbatical grant (project No. SAB95-0281). The sample studied was kindly provided by Professor L. Torres-Castellanos. The X-ray measurements were carried out at the Servei de Difracció de Raigs X (UAB).
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Although organotellurium compounds have attracted considerable interest as reagents and intermediates in organic synthesis (Petragnani, 1994), only a limited number of compounds with mono- and ditelluroethyne cores, R—Te—C≡CH and R—Te—C≡C-Te—R', have been reported, in spite of the potential reactivity of the acetylene unit towards addition reactions. We recently reported the syntheses and crystal structures of several symmetrical (R = R') bis(aryltelluro)ethynes, Ar—Te—C≡C-Te—Ar (Farran et al., 2002). On the other hand, only five R—Te—C≡CH derivatives have been prepared so far, with R = Me, Et, iPr, n-Bu and Ph (Kauffmann & Ahlers, 1983; Dabdoub et al., 1998; Potapov & Trofimov, 2005; Yoshimatsu, 2005), and none has been structurally characterized (in addition, molecular orbital calculations for R = HC≡C were carried out by Murai et al., 1994). Here we describe the crystal structure of the title compound (R = p-Me2NC6H4), the first of an organyl ethynyl telluride to be reported.
The structure analysis showed that the crystal contains discrete L-shaped molecules of the title compound (Figure 1), in which the aryl moiety, Me2NC6H4Te, is almost perpendicular to the Te—C≡C-H fragment (cf. C—Te—C angle, Table 1), but bent ca 13° towards the C12—C13 side of the ring (cf. C—Te—C—C angles, Table 1), probably to optimize the C—H···N interaction (see below).
As expected, the Te—C(sp2) bond is significantly longer than the Te—C(sp) one. The Te—C≡C moiety is approximately linear, while the coordination at the Te atom is angular, as predicted by the valence-shell electron-pair repulsion (VSEPR) model for an AX2E2 molecule (Gillespie & Hargittai, 1991). The values of these geometric parameters (Table 1) are similar to the ranges observed in several bis(arytelluro)ethynes, Ar—Te—C≡C-Te—Ar (Farran et al., 2002), viz. Te—C(sp2), 2.103 (5)–2.142 (6) Å; Te—C(sp), 2.021 (6)–2.058 (6) Å; C≡C, 1.166 (12)–1.203 (11) Å and C—Te—C, 94.2 (3)–97.2 (2)°, which are substantially smaller than the tetrahedral value (109.5°) due to the repulsion of the lone pairs of electrons on the bonded ones.
In the crystal structure the molecules are linked by C(sp)—H···N hydrogen bonds (Table 2) which are perpendicular to the CNMe2 group. The N atom displays some degree of pyramidalization: it is 0.123 (5) Å out of the plane of the three C atoms, towards the H atom. There are also Te···π(aryl) interactions, similar to those described by Zukerman-Schpector & Haiduc (2001) or Schulz Lang et al. (2006) for Te(IV) compounds, in which centrosymmetrically related pairs of molecules are at Te···Cg 3.683 (4) Å and C(sp)—Te···Cg 159.1 (2)° (Cg = centroid of the phenyl ring at 1 - x, -y, 1 - z). These interactions lead to the formation of zigzag ribbons, made of pairs of chains, which run along c and are approximately parallel to (110) (Figure 2).