Download citation
Download citation
link to html
The title compound, C20H14Te2, shows a transoid conformation, with a C-Te-Te-C torsion angle of 97.96 (9)°. The Te-Te units show approximate [eta]6 interactions with neighbouring naphthyl groups, forming chains along the c axis. The mol­ecule lies about a crystallographic twofold axis.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270102008284/ta1375sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270102008284/ta1375Isup2.hkl
Contains datablock I

CCDC reference: 192977

Comment top

We have found the diorganoditelluride compounds RTe-TeR to be optimal synthons for the synthesis of new organotellurium metal complexes or clusters (Schulz Lang et al., 1994; Schulz Lang, Gatto & Abram, 2002 Is this the correct citation?). The naphthyl moiety gives rise to various conformational forms with different cell packing, leading to different steric and electronic effects (Sandman et al., 1994; Engman & Cava, 1982; Menon et al., 1996). In this paper, we report the preparation and structural characterization of, and some observations on, the title compound, (I). \sch

Single crystals of (I) were obtained by slow evaporation of a solution in tetrahydrofuran in the presence of air of the crude product from the reaction of 1-naphthylmagnesiumbromide and tellurium in tetrahydrofuran. The asymmetric unit of (I) contains half a molecule of the ditelluride. The complete molecule is generated by the operation of a twofold axis parallel to c on the half molecule. Selected bond distances and angles are given in Table 1.

The Te—Te bond length in (I) of 2.7110 (6) Å is close to that found for the two conformational polymorphs of di(2-naphthyl)ditelluride, 2.7089 (7) and 2.7179 (6) Å (Sandman et al., 1994). The Te—Te—C angle of 97.96 (9)° is within the range found for substituted diphenylditellurides (92.9–101.7°; Schulz Lang et al., 1994). The C—Te—Te—C torsion angle for (I) is 97.96 (9)° and it could be considered a transoid conformation (C—Te—Te—C > 90°). The two polymorphs of di(2-naphthyl)ditelluride have torsion angles of 105.2 (3)° for the trans and 78.6 (2)° for the cis form.

The ditellurium unit is capped on either end by approximate η6 interactions to neighbouring naphthyl groups (Fig. 1). The Te—Te vector is closer to atoms C5 and C10, indicating that the ring interaction is slipped slightly towards the middle of the naphthyl group. The distance from the Te atom to the centroid, Cg, of the C6 ring bonded to the neighbouring Te atom (C1—C5/C10) is 3.683 (2) Å, with a Te—Te—Cg angle of 162.46 (2)°. This forms continuous chains along the c axis. Similar interactions have been found for the transoid form of di(2-naphthyl)ditelluride and diphenylditelluride (Llabres et al., 1972), with Te—Cg distances of 3.620 and 3.601 Å, respectively.

Another interesting example has been observed for bis[8-(dimethylamino)-1-naphthyl]ditelluride (Menon et al., 1996), where the Te—Te bond [2.765 (1) Å] is slightly longer than in (I) and the other examples above. The longer Te—Te distance in this case is presumably due to a strong Te···N interaction.

Experimental top

To a solution of 1-naphthylmagnesium bromide, prepared from 1-bromonaphthalene (16.71 ml, 78.36 mmol) and Mg (1.93 g, 78.36 mmol) in tetrahydrofuran (250 ml), was added Te shot (10.0 g, 78.36 mmol) at room temperature. The Te mixture was stirred under reflux for 3 h and then cooled to 273 K and treated with a saturated solution of NH4Cl (60 ml, vigorous evolution of gas). The mixture was filtered and the solids washed with a saturated aqueous solution of NH4Cl and ether. The organic phase was dried with Na2SO4. Evaporation of the solvent and recrystallization from CHCl3 and petroleum ether afforded the pure product, (I).

Refinement top

The largest peak in the difference map was 0.82 Å from Te, and the deepest hole 0.74 Å from Te.

Computing details top

Data collection: Bruker software Please provide full details; cell refinement: Bruker software Please provide full details; data reduction: Bruker software Please provide full details; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.

Figures top
[Figure 1] Fig. 1. A view of the molecule of (I) with the atomic labelling scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms have been omitted for clarity. The dashed lines indicate η6 interactions. [Symmetry codes: (i) -x, y, 1/2 - z; (ii) -x, 2 - y, -z; (iii) x, 2 - y, 1/2 + z.]
alpha-naphthylditelluride top
Crystal data top
C20H14Te2F(000) = 952
Mr = 509.52Dx = 2.015 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
a = 16.675 (3) ÅCell parameters from 2734 reflections
b = 7.8710 (14) Åθ = 5.5–54.7°
c = 14.339 (3) ŵ = 3.47 mm1
β = 116.839 (3)°T = 293 K
V = 1679.2 (5) Å3Block, red
Z = 40.22 × 0.10 × 0.10 mm
Data collection top
Bruker area-detector
diffractometer
1648 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.032
ϕ and ω scansθmax = 28.0°, θmin = 2.7°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 1922
Tmin = 0.537, Tmax = 0.707k = 1010
5118 measured reflectionsl = 1818
1952 independent reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.028Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.069All H-atom parameters refined
S = 0.97 w = 1/[σ2(Fo2) + (0.0421P)2]
where P = (Fo2 + 2Fc2)/3
1952 reflections(Δ/σ)max = 0.001
128 parametersΔρmax = 1.30 e Å3
0 restraintsΔρmin = 0.49 e Å3
Crystal data top
C20H14Te2V = 1679.2 (5) Å3
Mr = 509.52Z = 4
Monoclinic, C2/cMo Kα radiation
a = 16.675 (3) ŵ = 3.47 mm1
b = 7.8710 (14) ÅT = 293 K
c = 14.339 (3) Å0.22 × 0.10 × 0.10 mm
β = 116.839 (3)°
Data collection top
Bruker area-detector
diffractometer
1952 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1648 reflections with I > 2σ(I)
Tmin = 0.537, Tmax = 0.707Rint = 0.032
5118 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0280 restraints
wR(F2) = 0.069All H-atom parameters refined
S = 0.97Δρmax = 1.30 e Å3
1952 reflectionsΔρmin = 0.49 e Å3
128 parameters
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
xyzUiso*/Ueq
Te0.031918 (14)0.90588 (3)0.178213 (16)0.04972 (11)
C10.0527 (2)1.1008 (4)0.0789 (3)0.0440 (7)
C20.0237 (3)1.2638 (5)0.1012 (3)0.0564 (9)
C30.0751 (3)1.4011 (5)0.0400 (4)0.0643 (10)
C40.1556 (3)1.3707 (5)0.0440 (3)0.0587 (9)
C50.1885 (2)1.2023 (4)0.0711 (2)0.0455 (7)
C60.2713 (3)1.1693 (6)0.1591 (3)0.0595 (9)
C70.3023 (3)1.0072 (6)0.1848 (3)0.0666 (11)
C80.2522 (3)0.8716 (5)0.1239 (3)0.0634 (10)
C90.1716 (2)0.8979 (4)0.0374 (3)0.0502 (8)
C100.1365 (2)1.0645 (4)0.0079 (2)0.0400 (7)
H20.028 (2)1.279 (5)0.158 (3)0.041 (9)*
H30.056 (3)1.519 (6)0.053 (3)0.082 (13)*
H40.196 (3)1.456 (5)0.083 (3)0.060 (11)*
H60.306 (3)1.263 (5)0.198 (3)0.057 (10)*
H70.357 (3)0.989 (6)0.243 (4)0.083 (14)*
H80.274 (3)0.764 (6)0.139 (3)0.068 (13)*
H90.138 (3)0.801 (5)0.004 (3)0.071 (12)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Te0.04689 (16)0.05640 (16)0.04025 (15)0.01063 (9)0.01472 (11)0.00079 (9)
C10.0477 (18)0.0447 (17)0.0406 (17)0.0026 (12)0.0210 (14)0.0009 (12)
C20.053 (2)0.057 (2)0.056 (2)0.0098 (17)0.0222 (19)0.0091 (17)
C30.077 (3)0.0397 (19)0.081 (3)0.0054 (18)0.040 (2)0.0031 (18)
C40.072 (3)0.047 (2)0.066 (3)0.0118 (18)0.040 (2)0.0085 (17)
C50.0500 (18)0.0481 (18)0.0432 (18)0.0103 (14)0.0254 (15)0.0061 (14)
C60.055 (2)0.069 (3)0.051 (2)0.0188 (19)0.0211 (18)0.0149 (19)
C70.054 (2)0.076 (3)0.054 (2)0.0060 (19)0.010 (2)0.000 (2)
C80.062 (2)0.056 (2)0.059 (3)0.0067 (18)0.016 (2)0.0104 (18)
C90.051 (2)0.0456 (18)0.047 (2)0.0025 (15)0.0165 (16)0.0014 (15)
C100.0435 (17)0.0432 (17)0.0362 (16)0.0028 (12)0.0205 (13)0.0011 (12)
Geometric parameters (Å, º) top
Te—C12.135 (3)C5—C61.412 (5)
Te—Tei2.7110 (6)C5—C101.428 (4)
Te—C1ii3.856 (3)C6—C71.363 (6)
C1—C21.358 (5)C6—H60.94 (4)
C1—C101.419 (4)C7—C81.393 (6)
C2—C31.412 (6)C7—H70.93 (5)
C2—H20.89 (3)C8—C91.372 (5)
C3—C41.360 (6)C8—H80.90 (5)
C3—H30.97 (5)C9—C101.420 (4)
C4—C51.420 (5)C9—H90.97 (4)
C4—H40.94 (4)
C1—Te—Tei97.96 (9)C4—C5—C10119.1 (3)
C1—Te—C1ii71.93 (11)C7—C6—C5120.8 (4)
Tei—Te—C1ii164.08 (5)C7—C6—H6121 (2)
C2—C1—C10120.1 (3)C5—C6—H6118 (2)
C2—C1—Te117.7 (3)C6—C7—C8120.1 (4)
C10—C1—Te122.2 (2)C6—C7—H7119 (3)
C1—C2—C3121.7 (4)C8—C7—H7121 (3)
C1—C2—H2116 (2)C9—C8—C7121.0 (4)
C3—C2—H2122 (2)C9—C8—H8119 (3)
C4—C3—C2119.7 (4)C7—C8—H8120 (3)
C4—C3—H3117 (3)C8—C9—C10120.9 (3)
C2—C3—H3124 (3)C8—C9—H9119 (2)
C3—C4—C5120.8 (4)C10—C9—H9120 (2)
C3—C4—H4124 (3)C1—C10—C9123.9 (3)
C5—C4—H4115 (3)C1—C10—C5118.6 (3)
C6—C5—C4121.2 (3)C9—C10—C5117.5 (3)
C6—C5—C10119.7 (3)
Symmetry codes: (i) x, y, z+1/2; (ii) x, y+2, z.

Experimental details

Crystal data
Chemical formulaC20H14Te2
Mr509.52
Crystal system, space groupMonoclinic, C2/c
Temperature (K)293
a, b, c (Å)16.675 (3), 7.8710 (14), 14.339 (3)
β (°) 116.839 (3)
V3)1679.2 (5)
Z4
Radiation typeMo Kα
µ (mm1)3.47
Crystal size (mm)0.22 × 0.10 × 0.10
Data collection
DiffractometerBruker area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.537, 0.707
No. of measured, independent and
observed [I > 2σ(I)] reflections
5118, 1952, 1648
Rint0.032
(sin θ/λ)max1)0.661
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.028, 0.069, 0.97
No. of reflections1952
No. of parameters128
H-atom treatmentAll H-atom parameters refined
Δρmax, Δρmin (e Å3)1.30, 0.49

Computer programs: Bruker software Please provide full details, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 (Farrugia, 1997), SHELXL97.

Selected geometric parameters (Å, º) top
Te—C12.135 (3)Te—Tei2.7110 (6)
C1—Te—Tei97.96 (9)
Symmetry code: (i) x, y, z+1/2.
 

Follow Acta Cryst. C
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds