organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
ISSN 0108-2701
Bis(1-naphthyl) ditelluride
Ernesto Schulz Lang,* Robert Alan Burrow and
Edson Tarabal Silveira
Departamento de Qu Âõ mica, Universidade Federal de Santa Maria, Santa Maria, RS,
97119-900, Brazil
Figure 1
A view of the molecule of (I) with the atomic labelling scheme.
Received 4 April 2002
Accepted 7 May 2002
Online 20 June 2002
Displacement ellipsoids are drawn at the 30% probability level and H
atoms have been omitted for clarity. The dashed lines indicate ꢀ
6
1
interactions. [Symmetry codes: (i) � x, y, � z; (ii) � x, 2 � y, � z; (iii) x,
2
1
2
The title compound, C H Te , shows a transoid conforma-
2
2 � y, + z.]
2
0
14
ꢀ
tion, with a CÐTeÐTeÐC torsion angle of 97.96 (9) . The
6
TeÐTe units show approximate ꢀ interactions with neigh-
bouring naphthyl groups, forming chains along the c axis. The
molecule lies about a crystallographic twofold axis.
ꢀ
range found for substituted diphenyl ditellurides (92.9±101.7 ;
Schulz Lang et al., 1994). The CÐTeÐTeÐC torsion angle for
ꢀ
(I) is 97.96 (9) and this may be considered a transoid
conformation (CÐTeÐTeÐC > 90 ). The two polymorphs of
ꢀ
Comment
ꢀ
bis(2-naphthyl) ditelluride have torsion angles of 105.2 (3)
ꢀ
We have found the diorganoditelluride compounds RTeÐTeR
to be optimal synthons for the synthesis of new organo-
tellurium metal complexes or clusters (Schulz Lang et al., 1994;
Schulz Lang, Gatto & Abram, 2002; Schulz Lang, Zan et al.,
for the trans and 78.6 (2) for the cis form.
The ditelluride unit is capped on either end by approximate
6
ꢀ
interactions to neighbouring naphthyl groups (Fig. 1). The
TeÐTe 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
2
002). The naphthyl moiety gives rise to various conforma-
tional 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).
centroid, Cg, of the C ring (C1±C5/C10) bonded to the
6
Ê
neighbouring Te atom is 3.683 (2) A, with a TeÐTeÐCg angle
ꢀ
of 162.46 (2) . This forms continuous chains along the c axis.
Similar interactions have been found for the transoid form of
bis(2-naphthyl) ditelluride and diphenyl ditelluride (Llabres et
Ê
al., 1972), with TeÐCg distances of 3.620 and 3.601 A,
respectively.
Another interesting example has been observed with bis[8-
(
dimethylamino)-1-naphthyl] ditelluride (Menon et al., 1996),
Ê
where the TeÐTe bond [2.765 (1) A] is slightly longer than in
I) and the other examples mentioned above. The longer TeÐ
(
iTne t ed r ias ct at ino cne . in this case is presumably due to a strong TeÁ Á ÁN
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-naphthylmagnesium bromide
and tellurium in tetrahydrofuran. The asymmetric unit of (I)
contains half a molecule of the ditelluride. The complete
molecule is generated by the operation on the half molecule of
a twofold axis parallel to c. Selected bond distances and angles
are given in Table 1.
Experimental
To a solution of 1-naphthylmagnesium bromide, prepared from
1
7
7
-bromonaphthalene (16.71 ml, 78.36 mmol) and Mg (1.93 g,
8.36 mmol) in tetrahydrofuran (250 ml), was added Te shot (10.0 g,
8.36 mmol) at room temperature. The Te mixture was stirred under
re¯ux for 3 h and then cooled to 273 K and treated with a saturated
solution of NH Cl (60 ml, vigorous evolution of gas). The mixture
was ®ltered and the solids washed with a saturated aqueous solution
4
of NH Cl and ether. The organic phase was dried with Na SO .
4
Ê
The TeÐTe bond length in (I) of 2.7110 (6) A is close to
that found for the two conformational polymorphs of bis(2-
4
2
Ê
naphthyl) ditelluride, 2.7089 (7) and 2.7179 (6) A (Sandman et
Evaporation of the solvent and recrystallization from CHCl and
3
petroleum ether afforded pure (I).
ꢀ
al., 1994). The TeÐTeÐC angle of 97.96 (9) is within the
Acta Cryst. (2002). C58, o397±o398
DOI: 10.1107/S0108270102008284
# 2002 International Union of Crystallography o397