Synthesis and structure of new aryltellurenyl halides derived from (dmpTe)2 (dmp = 2,6-dimethoxyphenyl)

Article abstract of DOI:10.1016/j.jorganchem.2010.10.003

[RTeTeR] (R = dmp = 2,6-dimethoxyphenyl) (1) reacts with bromine to give [RTeTe(Br)₂R] (2) and [RTeBr₃] (3), and with SOCl ₂ to yield [RTeTe(Cl)₂R] (5) and [RTeCl₃] (6). The recrystallization of compo

Full text of DOI:10.1016/j.jorganchem.2010.10.003

Journal of Organometallic Chemistry 696 (2011) 807e812
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Synthesis and structure of new aryltellurenyl halides derived
from (dmpTe)2 (dmp ¼ 2,6-dimethoxyphenyl)
*
Eliandro Faoro, Gelson Manzoni de Oliveira , Ernesto Schulz Lang, Cesar Bicca Pereira
Departamento de Química, Laboratório de Materiais Inorgânicos, Universidade Federal de Santa María, 97105e900 Santa Maria, RS, Brazil
a r t i c l e i n f o
a b s t r a c t
Article history:
[RTeTeR] (R ¼ dmp ¼ 2,6-dimethoxyphenyl) (1) reacts with bromine to give [RTeTe(Br)2R] (2) and
[RTeBr3] (3), and with SOCl2 to yield [RTeTe(Cl)2R] (5) and [RTeCl3] (6). The recrystallization of compound
3 in acetone produces [RTeBr2(CH2eC(O)eCH3)] (4). The hydrolysis of 2 in aqueous ammonia and
Received 27 August 2010
Received in revised form
30 September 2010
Accepted 1 October 2010
Available online 1 November 2010
methanol containing media affords the methoxy/oxo-derivative [RTe(m-O)(OCH3)]2 (7). All the title
compounds were obtained with good yields, and strong Te/O(methoxy), as well as Te/X (X ¼ Br, Cl)
secondary interactions, support the distorted octahedral configurations shown mostly in the polymeric
compounds 3, 4, 5 and 6. Complexes 2 and 5 close the series of compounds with the structure [RTeTe
(X)2R] (X ¼ Cl, Br, I), started earlier with [RTeTe(I)2R].
Keywords:
Organyltellurium halogenides
Secondary interactions
Supramolecular assemblies
Ó 2010 Elsevier B.V. All rights reserved.
1. Introduction
the Te atom have shown that the aryltellurenyl iodides ArTeI can be
viewed also as key compounds in the syntheses of TeII and TeIV
The reactions of diarylditellurides (RTe)2 with iodine have been
experimentally studied with the purpose of obtaining TeII and TeIV
compounds, as well as mixed-valent aryltellurenyl iodides and
related charge-transfer complexes. It is well known that
uncommon compositions and configurations are characteristic for
these types of compounds [1,2]. Almost as a rule, tellurium(II) and
tellurium(IV) iodide compounds attain all possible combinations of
secondary, interionic interactions. Single monomers and dimers
and also polymeric chains attaining 1D, 2D and 3D networks, as
well as rare polymeric structures with chalcogen atoms presenting
mixed-valence states are often described [3e5]. The chemical and
structural versatility of organyltellurenyl iodides, combined with
the noticeable effect of the ligand R on the stabilization of mixed-
valent aryltellurenyl iodides, led us to the development of func-
tionalized organic substituents to stabilize Te centers in uncommon
assemblies. Recently we have shown that the two methoxy groups
of the unstable intermediary RTeI (R ¼ 2,6-dimethoxiphenyl) are
particularly able to stabilize tellurium iodides in mixed-valent,
unusual compositions [6]. Either the structure of the intermediary
RTeI or the structural features and oxidation states of the resulting
products are dependent upon the substituent R. Former studies [7]
on the influence of the substituent R on the controlled oxidation of
products. After working also with PhTeI (Ph ¼ phenyl), mesTeI
(mes ¼ 2,4,6-trimethylphenyl) and (dmeph)TeI (dmeph ¼ 2,6-
dimetylphenyl) as part of our research on the effects of the ligand R
on the stabilization and structure of aryltellurenyl iodides, we have
recently described the intermediary [tmpTeI]2 (tmp ¼ 2,3,5,6-tet-
ramethylphenyl), as well as seven new iodide complexes derived
from it [8]. The new products corroborate again the versatility of
aryltellurenyl iodides regarding reactivity and structure, as well as
the close dependence of these factors with the substituent R. It is
well known that the chemistry of organyltellurenyl iodides cannot
be carefulness generalized to the lighter halogens chlorine and
ꢀ
bromine (van der Waals radii: 1.75 and 1.85 A, respectively) [9]. The
smaller reactivity of iodine seems to be equalized by its bulk
ꢀ
(1.98 A) and, consequently, by its tendency to achieve complexes
structurally unique, also regarding secondary I/I and I/H inter-
actions. These effects and trends have not been noticeable in
organyltellurenyl bromides and chlorides. Therefore, attempts to
reproduce organyltellurenyl iodides compounds or reactions with
bromine and chlorine can be, in most cases, a very frustrating and
disappointing experience. Moreover, some unexpected results may
prove to be quite rewarding, as we shall see below. We report the
synthesis and the structural characterization of the start complex
(RTe)2 (R ¼ dmp ¼ 2,6-dimethoxyphenyl) (1), and of its derivatives
[RTeTe(Br)2R] (2), [dmpTeBr3] (3), [dmpTeBr2(CH2eC(O)eCH3)] (4),
[RTeTe(Cl)2R] (5), [dmpTeCl3] (6) and [dmpTe(
Compounds 2 and 5 reproduce the same result obtained with I2 [6],
m-O)(OCH3)]2 (7).
* Corresponding author. Tel.: þ55 55 3220 8757; fax: þ55 55 3220 8031.
E-mail address: manzonideo@smail.ufsm.br (G. Manzoni de Oliveira).
0022-328X/$ e see front matter Ó 2010 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2010.10.003

808
E. Faoro et al. / Journal of Organometallic Chemistry 696 (2011) 807e812
where the methoxy groups of the intermediary RTeI (R ¼ 2,6-
dimethoxiphenyl) are also able to stabilize tellurium iodides in
mixed-valent, unusual compositions.
[
ns(CeH)Me], 1587.0
[
n
(C]C)], 1472.0
[ds(C]CeH)], 1255.0
[nas(CeO)], 1104.6 [das(CeOeC)], 766.5, 740.8 [dout pl(C]CeH)].
2.3. Preparation of [dmpTeBr3] (3)
2. Experimental
To 5 mL of a solution of 0.212 g (0.4 mmol) of 1 in CH2Cl2,
0.063 mL (1.2 mmol) of bromine was added. After 1 h stirring the
red mixture turned colorless and was filtered. Crystals of 3 were
obtained from the solution cooled at ꢁ18 ꢀC. Yield: 90% based on
[dmpTe]2. Properties: yellow, crystalline solid. C8H9Br2.50O2Te
(464.53). Melting point: 114.0e115.2 ꢀC. Anal. Calc.: C, 20.69; H,
All manipulations were conducted under dried nitrogen and
with anhydrous solvents by use of standard Schlenk techniques.
The synthetic procedures for all complexes are resumed in the
Scheme 1.
1.95. Found: C, 20.73; H, 1.91%. IR (KBr): 3004.7 [
n(CeH)Ar], 2931.3
2.1. Preparation of [dmpTe]2 (1)
[
nas(CeH)Me], 2828.4 [ns(CeH)Me], 1586.8 [ (C]C)], 1472.5 [ds(C]
n
CeH)], 1256.2 [nas(CeO)], 1102.5 [das(CeOeC)], 766.3, 739.6 [dout
pl(C]CeH)].
6.02 g (22.8 mmol) of 1-iodine-2,6-dimethoxybenzene, 2.91 g
(22.8 mmol) of tellurium and 0.32 g (45.6 mmol) of lithium powder
were dissolved in 100 mL of tetrahydrofuran (THF). The mixture
was stirred until complete lithium dissolution, ca. 18 h. Thereafter
the reaction vessel was opened to the air, and 5 mL of a dilute
aqueous solution of ammonium chloride was added slowly. The
product was extracted with diethyl ether and the solvent was
evaporated. Recrystallization of the remained red solid from a 3:1
mixture of diethyl ether/CH2Cl2 yielded pure crystals of 1. Yield:
85%. Properties: red, crystalline solid. C16H18O4Te2 (529.50). Melting
point: 131.7e132.9 ꢀC. Anal. Calc.: C, 36.29; H, 3.43. Found: C, 36.27;
2.4. Preparation of [dmpTeBr2(CH2eC(O)eCH3)] (4)
Compound 4 was obtained by dissolution of [dmpTeBr3] (3) in
acetone and further recrystallization. Yield: 86% based on 3. Prop-
erties: light yellow crystalline substance. C11H14Br2O3Te (481.64).
Melting point: 193.4e194.7 ꢀC. Anal. Calc. C, 27.43; H, 2.93. Found:
C, 27.11; H, 2.88%. IR (KBr): 3004.3 [
2836.2 [ns(CeH)Me], 1585.4, [ (C]O)], 1683.1, [
ds(C]CeH)], 1257.2 [nas(CeO)], 1106.5 [das(CeOeC)], 765.8, 730.3
dout pl(CeCeH)].
n
(CeH)Ar], 2931.2 [nas(CeH)Me],
n
n
(C]C)], 1471.9
[
[
H, 3.44%. IR (KBr): 3008.6 [
n
(CeH)Ar], 2932.2 [nas(CeH)Me], 2831.2
(C]C)], 1472.9 ds(C]CeH)], 1255.3
nas(CeO)], 1105.5 [das(CeOeC)], 766.8, 731.2 [dout pl(CeCeH)].
[
[
ns(CeH)Me], 1587.5
[n
[
2.5. Preparation of [RTeTe(Cl)2R] (5)
2.2. Preparation of [RTeTe(Br)2R] (2)
To 5 mL of a solution of 0.212 g (0.4 mmol) of 1 in CH2Cl2,
0.030 mL (0.4 mmol) of SOCl2 was added. After 1 h stirring the
mixture was filtered. Cooling of the solution at ꢁ18 ꢀC led to the
formation of crystals of 5. Yield: 96% based on [dmpTe]2. Properties:
light red crystalline solid. C16H18Cl2O4Te2 (600.40). Melting point:
142.3e143.9 ꢀC. Anal. Calc.: C, 30.01; H, 3.02. Found: C, 29.91; H,
To 5 mL of a solution of 0.212 g (0.4 mmol) of 1 in CH2Cl2,
0.021 mL (0.4 mmol) of bromine was added. After 2 h stirring the
mixture was filtered. Crystals of 2 were obtained from the solution
cooled at ꢁ18 ꢀC. Yield: 95% based on [dmpTe]2. Properties: red,
crystalline substance. C16H18Br2O4Te2 (689.32). Melting point:
143.5e145.1 ꢀC. Anal. Calc.: C, 27.88; H, 2.63. Found: C, 27.79; H,
3.12%. IR (KBr): 3004.3 [
n
(CeH)Ar], 2931.4 [nas(CeH)Me], 2826.5
[ns(CeH)Me], 1585.9
[
n
(C]C)], 1471.5 ds(C]CeH)], 1256.6
[
2.65%. IR (KBr): 3003.2 [
n
(CeH)Ar], 2931.1 [nas(CeH)Me], 2825.2
[nas(CeO)], 1103.5 [das(CeOeC)], 766.5, 739.0 [dout pl(C]CeH)].
(2)
(5)
O
O
O
O
O
O
O
O
Cl
Br
(1)
Te Te
Cl
Te Te
Br
Br2
SOCl2
O
O
O
O
Te Te
3 SOCl2
3 Br2
O
O
O
Cl
Br
(3)
(6)
2
2
Te Cl
Cl
Te Br
Br
Tol. / MeOH
Br2
NH3(aq.)
O
2 CH3C(O)CH3
O
O
O
O
O
O
Te
Te
O
O
O
O
Br
Te
Br
2
+
2 HBr
(7)
O
(4)
Scheme 1. Reactions of (RTe)2 (R ¼ 2,6-dimethoxiphenyl) and of [RTeBr3] discussed in this work.

E. Faoro et al. / Journal of Organometallic Chemistry 696 (2011) 807e812
809
2.6. Preparation of [dmpTeCl3] (6)
To 5 mL of a solution of 0.212 g (0.4 mmol) of 1 in CH2Cl2, 0.090 mL
(1.2 mmol) of SOCl2 was added. After ½ h stirring the red mixture
turned colorless and was filtered. Yellow crystals of 6 were formed
by cooling the filtrate to ꢁ18 ꢀC. Yield: 82% based on [dmpTe]2.
Properties: light yellow crystalline substance. C8H9Cl3O2Te (371.10).
Meltingpoint:109.2e110.5 ꢀC. Anal. Calc.: C, 25.89;H, 2.44. Found:C,
25.38; H, 2.51%. IR (KBr): 3003.3 [
2826.2 [ns(CeH)Me], 1587.3 [ (C]C)], 1471.9 [ds(C]CeH)], 1255.2
nas(CeO)], 1103.6 [das(CeOeC)], 767.2, 741.1 [dout pl(C]CeH)].
n(CeH)Ar], 2931.6 [nas(CeH)Me],
n
[
2.7. Preparation of [dmpTe(m-O)(OCH3)]2 (7)
In 10 mL of a 1:1 mixture of methanol/toluene, 0.212 g
(0.4 mmol) of 1 were dissolved, followed by the addition of
0.021 mL (0.04 mmol) of Br2 (the substitution of Br2 by I2 does not
change the final product). After ½ h stirring the addition of a few
milliliters of dilute aqueous ammonia to the red brown mixture
turned it colorless. After filtration and cooling of the solution to
ꢁ18 ꢀC, crystals of 7 were formed. Yield: 72% based on [dmpTe]2.
Properties: colorless, crystalline substance. C18H24O8Te2 (623.58).
Melting point: 179.5e180.7 ꢀC. Anal. Calc.: C, 34.67; H, 3.88. Found:
Fig. 1. Molecular structure of [dmpTe]2 (1). Hydrogen atoms have been omitted for
clarity. Dashed lines represent secondary interactions. Selected bond lengths [A] and
ꢀ
angles [deg]: Te1eC11 2.130(5), Te1eTe2 2.7055(5), Te2eC21 2.120(6), Te1/O11 3.1638
(2), Te1/O12 3.0938(2), Te1/O21 3.5022(2), Te2/O11 3.4251(2), Te2/O21 3.1363(2),
Te2/O22 3.0751(1), C22eO21 1.352(7), C26eO22 1.362(7), C16eO12 1.367(6),
C12eO11 1.355(6); C11eTe1eTe2 99.90(14), C21eTe2eTe1 101.44(15), C26eC21eC22
120.0(6), C26eC21eTe2 119.4(4), C22eC21eTe2 120.6(4).
C, 34.09; H, 3.95%. IR (KBr): 3005.1 [
2826.1 [ns(CeH)Me], 1588.4 [ (C]C)], 1471.1 [ds(C]CeH)], 1256.4
nas(CeO)], 1103.5 [das(CeOeC)], 765.4, 739.2 [dout pl(C]CeH)].
n(CeH)Ar], 2930.2 [nas(CeH)Me],
n
3. Results and discussion
[
Crystaldataandexperimental conditions for [RTe]2 (R ¼ dmp ¼ 2,6-
dimethoxyphenyl) (1), [RTeTe(Br)2R] (2), [dmpTeBr3] (3),
[dmpTeBr2(CH2eC(O)eCH3)] (4), [RTeTe(Cl)2R] (5), [dmpTeCl3] (6) and
2.8. X-ray structure determinations
Data were collected with a Bruker APEX II CCD area-detector
diffractometer. The structure was solved by direct methods using
SHELXS [10]. Subsequent Fourier-difference map analyses yielded
the positions of the non-hydrogen atoms. Refinements were carried
out with the SHELXL package [10]. All refinements were made by
full-matrix least-squares on F2 with anisotropic displacement
parameters for all non-hydrogen atoms. Hydrogen atoms were
included in the refinement in calculated positions. Crystal data and
more details of the data collection and refinements are contained in
Table 1.
[dmpTe(m-O)(OCH3)]2 (7) are given in Table 1. Figs. 1e7 show the
molecular structures/polymeric associations of the title compounds.
All complexes obtained in this work were achieved starting from
compound 1, [RTeTeR], with initial cleavage of the TeeTe bond and
formation of the intermediary dmpTeX (X ¼ Cl, Br). Because of rapid
dismutation or disproportionation, the compounds RTeX (X ¼ Cl, Br, I)
are very unstable. Their stabilization can also be achieved by using
bulky substituents or coordinating functional groups [11,12]. It is also
known that these species present a relative stability in solution,
although in the literature few reports describe their characteristics in
Table 1
Crystallographic data and refinement parameters for 1, 2, 3, 4, 5, 6 and 7.
1
2
3
4
5
6
7
Empirical formula
Fw
T (K)
Crystal system
C16H18O4Te2
529.50
296(2)
triclinic
P1
C16H18Br2O4Te2
689.32
293(2)
triclinic
P1
C16H18Br5O4Te2
929.06
293(2)
orthorhombic
Pbca
C11H14Br2O3Te
481.64
293(2) K
monoclinic
C2/c
C16H18Cl2O4Te2
600.40
293(2)
monoclinic
P21/c
C8H9Cl3O2Te
371.10
293(2)
orthorhombic
Pbca
C18H24O8Te2
623.58
293(2)
monoclinic
P21/c
Space group
a/Å
b/Å
c/Å
8.3428(5)
10.0205(6)
10.8135(6)
98.480(3)
96.874(4)
96.394(4)
879.99(9)
2
1.998
3.328
0.71073
500
7.9624(3)
10.2422(4)
13.4832(5)
95.939(2)
101.336(2)
109.883(2)
996.42(7)
2
2.298
6.954
0.71073
640
8.1971(9)
14.1122(16)
21.281(2)
90
90
90
2461.8(5)
4
2.507
10.504
0.71073
1700
26.288(3)
12.1942(17)
9.2198(10)
90
90.858(7)
90
2955.2(6)
8
2.165
13.2640(2)
7.50700(10)
20.3157(3)
90
104.7490(10)
90
1956.24(5)
4
2.039
8.0339(3)
13.8130(6)
20.8987(9)
90
90
90
2319.18(17)
8
2.126
3.228
0.71073
1408
10.6486(7)
7.1299(4)
13.9056(8)
90
107.8210(10)
90
1005.10(10)
4
2.060
a
/deg
/deg
b
g
/deg
V/Å3
Z
rcalcd(g cmꢁ3
)
m
(Mo K
/Å
F (000)
a
)(mmꢁ1
)
7.415
0.71073
1808
3.272
0.71073
1136
2.945
0.71073
600
l
Collected reflns.
Unique reflns.
GOF (F2)
18059
4996
0.944
0.0436
0.0933
18013
4777
1.031
0.0175
20117
2520
1.233
0.0508
0.1581
13571
3620
0.994
0.0375
0.0886
20371
5655
1.028
0.0187
0.0374
11599
2729
0.969
0.0377
0.0716
5196
2739
1.031
0.0271
0.0652
a
R1
b
wR2
0.0413
P
P
a
R1
¼
jjFoj ꢁ jFcjj= jFoj.
P
P
wR2 ¼ f wðFo2 ꢁ Fc2Þ2= wðFo2Þ2g1=2
.
b

810
E. Faoro et al. / Journal of Organometallic Chemistry 696 (2011) 807e812
Fig. 4. Pseudo-dimeric assembling of [dmpTeBr2(CH2eC(O)eCH3)] (4), Hydrogen
atoms have been omitted for clarity. Dashed lines represent secondary interactions.
0
ꢀ
Symmetry code: ( ) ¼ 1 ꢁ x, y, 1.5 ꢁ z. Selected bond lengths [A] and angles [deg]:
Te1eBr1 2.7202(6), Te1eBr2 2.6468(6), Te1eC11 2.101(4), Te1eC1 2.135(5), C1eC2
1.510(6), O1eC2 1.212(5), C2eC3 1.474(7), O12eC16 1.368(5), O12eC18 1.431(6),
O11eC12 1.350(6), O11eC17 1.427(5), Te1/O1 2.8990(3), Te1/O11 3.3459(3),
Te1/O12 2.8224(4), Te1/ Br20 3.8086(4); C11eTe1eC1 101.94(17), C11eTe1eBr2
88.31(11), C1eTe1eBr2 89.42(13),C11eTe1eBr1 89.50(11), C1eTe1eBr1 87.07(14),
Br2eTe1eBr1 175.393(18), C2eC1eTe1 106.5(3), O1eC2eC3 123.5(4), O1eC2eC1 119.9
(4), C3eC2eC1 116.6(4), C11eTe1/ Br20 138.68(0), C1eTe1/O12 153.42(1).
Fig. 2. Molecular structure of [RTeTeBr2R] (2). Hydrogen atoms have been omitted for
clarity. Dashed lines represent secondary interactions. Selected bond lengths [A] and
ꢀ
angles [deg]: Te1eBr1 2.6878(3), Te1eBr2 2.7424(3), Te2eTe1 2.7401(2), Te1eC11
2.103(2), Te2eC21 2.103(2), C26eO22 1.368(3), C22eO21 1.363(3), C18eO12 1.433(3),
O11eC12 1.362(3), O11eC17 1.437(3), O12eC16 1.355(3), O22eC28 1.430(3), O21eC27
1.425(3), Te1/O11 2.880(2), Te1/O22 2.937(2), Te2/O12 2.854(0), Te2/O21 2.929
(3); C11eTe1eBr1 88.82(6), C11eTe1eTe2 99.41(6), Br1eTe1eTe2 97.548(8),
C11eTe1eBr2 89.32(6), C21eTe2eTe1 95.70(6), Br1eTe1eBr2 169.747(9),
Te2eTe1eBr2 92.703(8),O22eC26eC21 115.44(19), O21eC22eC21 114.5(2).
the Te/O distances are 3.1638(2) (Te1/O11), 3.0938(2) (Te1/O12)
the solid state. As examples of the influence of the size of the substit-
uent on the stabilization of such intermediary, we have reported the
tetrameric structure of PhTeI [13], while the use of a very bulky R
allowed the isolation of Mes*TeI (Mes* ¼ 2,4,6-tri-tert-butylphenyl),
which exhibits discrete molecules, although in the solid state also
ꢀ
and 3.5022(2) A (Te1/O21). The sum of the Te/O van der Waals radii is
II
IV
ꢀ
3.58 A [9], and in the mixed-valent {Te /Te } complex [RTeTe(Br)2R]
(2) these interactions are comparatively stronger, measuring 2.880(2)
ꢀ
(Te1/O11), 2.854(0) (Te2/O12) and 2.937(2) A (Te1/O22) (see
ꢀ
Fig. 2). Complex 2 represents the first compound of this series which
reproduces partially the organyltellurenyl iodide chemistry: the
mixed-valent complex [RTeTe(I)2R] (R ¼ dmp) was first obtained by
stirring (dmpTe)2 with iodine (1:1) in CH2Cl2 for 2 h at ꢁ10 ꢀC with
further crystallization at ꢁ18 ꢀC [6]. The Te/O(methoxy) contacts
present in the title compounds are also able to support a given struc-
ture, as in the case of complex 3, [dmpTeBr3]: Fig. 3 shows that the
pseudo octahedral configuration of 3 is only possible because of the
shortening of the Te1/O11 contact (2.812(0)), simultaneously with
the elongation of the (in the same plane lying) Te1/O12 distance
presents Te/I (3.727) and I/I (3.818 A) intermolecular contacts [14].
As expected, in the course of the reactions described in this work, the
stabilization of dmpTeX (X ¼ Cl, Br) has occurred through different
routes, driven by the substituent dmp, the stoichiometry and the
reactivityof Cl and Br. With exception of the starting reagent 1, inallthe
title complexes the tellurium centers interact in a relatively strong
manner with the oxygen atoms of the two methoxyphenyl groups.
Wada et al. [15,16] have discussed this kind of interactions, including
the dependence of the rotational barrier of the Ar-group. In (RTe)2 (1)
ꢀ
(3.2983(3) A). This effort, to keep O11 in the same plane that Br1, Br2
and Br3 in as much as possible, is also visible in the distortion of the
Fig. 5. Polymeric association of the molecules [RTeTeCl2R] (5). Dashed lines represent
secondary bonds. Hydrogen atoms have been omitted for clarity. Symmetry code:
0
00
ꢀ
Fig. 3. Polymeric assembling of [dmpTeBr3]n (3). Hydrogen atoms have been omitted
for clarity. Dashed lines represent secondary interactions. Symmetry code: (0) 0.5 þ x, y,
( ) ¼ x, 1 þ y, z; ( ) ¼ x, ꢁ1 þ y, z. Selected bond lengths [A] and angles [deg]: Te1eC11
2.1064(17), Te1eCl1 2.4914(5), Te1eCl2 2.5889(5), Te1eTe2 2.74208(17), Te2eC21
2.1089(18), O21eC22 1.361(2), O22eC26 1.367(2), Te1/O11 2.9271(15), Te1/O12
3.2451(12), Te1/O22 2.9266(13), Te2/O12 2.8201(14), Te2/O21 2.9882(16),
Te2/O22 3.1834(12), Cl2/ Te20 3.7837(5); C11eTe1eCl1 88.63(5), C11eTe1eCl2 87.45
(5), Cl1eTe1eCl2 173.356(18), C11eTe1eTe2 99.83(5), Cl1eTe1eTe2 94.338(14),
00
ꢀ
1.5 ꢁ z; ( ) ¼ ꢁ0.5 þ x, y, 1.5 ꢁ z. Selected bond lengths [A] and angles [deg]: Br2eTe1
2.6896(13), Br1eTe1 2.6322(13), Br3eTe1 2.429(2), C11eTe1 2.109(9), O11eC12 1.362
(11), O12eC16 1.380(13), Te1/O11 2.812(0), Te1/O12 3.2983(3), Te1/ Br20 3.473(0),
Br2/ Te100 3.473(0); Br3eTe1eBr1 94.20(7), Br3eTe1eBr2 83.09(6), Br1eTe1eBr2
175.18(4), C11eTe1eBr1 88.3(3), C11eTe1eBr2 88.3(3), C11eTe1eBr3 100.9(3),
C16eC11eTe1 128.1(8), C12eC11eTe1 111.0(7), C12eO11eC17 119.2(8), C16eO12eC18
118.3(8), C11eTe1/ Br20 169.53(0), Br3eTe1/O11 149.95(0).
Cl2eTe1eTe2
91.616(12),C21eTe2eTe1 95.65(5),
C22eO21eC27
118.03(16),
C12eO11eC17 118.30(15), Te1eCl2/ Te20 121.01(2), Te2eTe1/O11 150.59(3),
C11eTe1/O22 159.90(6), Te1eTe2/O21 134.39(3), C21eTe2/O12 166.90(6).

E. Faoro et al. / Journal of Organometallic Chemistry 696 (2011) 807e812
811
ꢀ
is the shorter one, with 2.429(2)
A
{Br2eTe1 ¼ 2.6896(13);
Br1eTe1 ¼ 2.6322(13)}, a nucleophilic attack to Te1 in this position is
not suprising, since the bond Te1eBr3 seems to be the more vulner-
able, on the contrary of the bonds Te1eBr1/Te1eBr2, both stereo-
chemically and simetrically favoured. The eletrophilic substitution of
methyl ketones with aryltellurium trichlorides with formation of
acylmethyl(aryl)tellurium dichlorides has been already fully discussed
by Chauhan and co-workers [17]. Complex 4 attains two secondary
ꢀ
Te/Br interactions with 3.8086(4) A; these Te/Br contacts allow 4 to
configure a twisted dimeric assembly, in which the two “monomeric”
units present a distorted octahedral geometry, with the Br ligands in
the axial position. Although the Te/Br contacts are only a litle bit
ꢀ
shorter than the sum of the Te/Br van der Waals radii, 3.91 A [9], it is
reasonable to assume that they play a significant role in the structural
stabilization of the compound. [DmpTeTe(Cl)2Dmp] (5) replicates the
main structure and the Te/O(methoxy) interactions of complex 2,
n
n
0
0
achieving a polymeric association extended through Cl2 /Te2
ꢀ
secondary contacts, with a distance of 3.7837(5) A, in the border of the
sum of the van der Waals radii of both atoms (tellurium and chlorine),
3.81 A [9]. Complex 5 closes the series of mixed-valent aryltellurenyl
Fig. 6. Polymeric assembly of [dmpTeCl3] (6). Dashed lines represent secondary bonds.
Hydrogen atoms have been omitted for clarity. Symmetry code: (0) ¼ 0.5 þ x, y, 1.5 ꢁ z;
ꢀ
00
ꢀ
( ) ¼ ꢁ0.5 þ x, y, 1.5 ꢁ z. Selected bond lengths [A] and angles [deg]: Te1eC11 2.102(5),
Te1eCl1 2.4660(13), Te1eCl2 2.3014(14), Te1eCl3 2.5185(12), O11eC12 1.360(6),
O12eC16 1.353(6), Te1/O11 2.773(4), Te1/O12 3.323(4), Te1/ Cl300 3.387(1), Cl3/
Te10 3.387(1); C11eTe1eCl2 102.32(15), C11eTe1eCl1 88.36(14), Cl2eTe1eCl1 89.57
(5), C11eTe1eCl3 87.48(14), Cl2eTe1eCl3 85.38(5), Cl1eTe1eCl3 172.63(5),
C12eO11eC17 118.6(4), C16eO12eC18 118.6(4), C11eTe1/Cl300 166.36(16),
Cl1eTe1/O11 103.69(8).
halides with the structure [RTeTe(X)2R] (R ¼ dmp; X ¼ Cl, Br, I), started
with [RTeTe(I)2R] [6]. Beckmann and co-workers [18] have obtained
the analogue series [PhTeTe(Br)2Ph] and [RTeTe(X)2R] (R ¼ 2,6-
Mes2C6H3; X ¼ Cl, I). Complex [dmpTeCl3] (6) is structurally equivalent
to complex 3 e according to the unit cell parameters of 3 and 6 shown
in Table 1, their crystals are virtually isomorphic e with a similar
n
0
n
0
polymeric, zigzag type configuration, attained through Te1 /Cl3
phenyl ring between the two methoxy bonds (see Fig. 3). The axial
ꢀ
secondary bonds, with a distance of 3.387(1) A. The pseudo octahedral
structure of the compound is also achieved with support of the
equatorial Te1/O11 bond (2.773(4)), while the opposite 0T0 e1/O12
n
n
bonds C11eTe1 /Br2 0 of the distorted polymeric octahedra in 3 are
mainly linear, with 169.53(0)ꢀ. The dissolution of complex 3 in acetone
and further recrystallization leads to the substitution of Br3 by one
CH3COCHꢁ2 anion, with HBr elimination and formation of
[dmpTeBr2(CH2eC(O)eCH3)] (4). Although in 3 the distance Br3eTe1
0
ꢀ
contact measures 3.323(4) A. The axial bondsC11eTe1/ Cl3 are (as in
3), predominantly linear, with 166.36(16)ꢀ. The reported similar
compound 2,4,6-t-Bu3C6H2TeCl3 [19] appears as dimer, through
secondary Te/Cl bonds,unlike 6, which shows a polymeric assembly.
Complex [dmpTe(
and further methoxy ligands to the tellurium centers of the starting
reagent 1. A similar binuclear -O structure of tellurium has been
m-O)(OCH3)]2 (7) results from the insertion of m-oxo
m
already described, although no references have been made about the
occurrence of a TeeTe bond [20]. Tellurium atoms e van der Waals
ꢀ
radium of 2.06 A [9] e belonging to the same molecule do not use to
stay too far from each other. As examples of TeeTe distances in
different halogen compounds of 2,6-dimethoxyphenyl, we can cite
ꢀ
2.7055(5) A in compound 1, 2.7401(2) in 2, 2.74208(17) in 5, and 2.757
ꢀ
(4)/2.855(16) A in the iodides [RTeTe(I)2R] and [R2TeTeR2][Te4I14],
respectively [6]. In the case of compound 7 the TeeTe distance is quite
ꢀ
longer, 3.1585(2) A, but even so, it seems more plausible to assume that
the m-oxo bridges occur as a consequence of the proximity of the
tellurium atoms, instead attributing the proximity of the Te centers to
the occurrence of the oxo bridges. Finally, the concepts of supramo-
lecular chemistry are very appropriate to most of the complexes pre-
sented in this work, as is routine in the chemistry of aryltellurenyl
halides, principally because of the halogen/H secondary interactions.
Complexes 2, 5 and 6 attain one-dimensional chains along the a (2, 6)
and b axes, and compound 3 grows as bi-dimensional layers in the
plane ab.
Acknowledgment
Fig. 7. Molecular structure of [dmpTe(m-O)(OCH3)]2 (7). Hydrogen atoms have been
omitted for clarity. Dashed lines represent secondary bonds. Symmetry code:
This work was supported with funds from PRONEX-CNPq/
FAPERGS (Brazil).
0
ꢀ
( ) ¼ 1 ꢁ x, ꢁy, 2 ꢁ z. Selected bond lengths [A] and angles [deg]: Te1eO2 1.895(2),
Te1eO1 1.996(2), Te1eC11 2.123(3), Te1eO20 2.142(2), O11eC12 1.361(4), O2eTe10
2.142(2), O1eC1 1.422(4), O12eC16 1.351(4), Te1/O11 2.930(1), Te1/O120 3.061(2);
O2eTe1eO1 88.78(10), O2eTe1eC11 106.39(11), O1eTe1eC11 91.63(11), O2eTe1eO20
77.23(10), O1eTe1eO20 164.80(9), C11eTe1eO20 86.73(10), O2eTe1eTe10 41.42(7),
Appendix A. Supplementary material
O1eTe1eTe10 129.92(7),
C11eTe1eTe10
97.50(9),
O20eTe1eTe10
35.82(6),
C12eO11eC17 118.0(3), Te1eO2eTe10 102.77(10), C1eO1eTe1 121.8(2), C16eO12eC18
117.6(3), O2eTe1/O11 153.27(0),C11eTe1/O120 154.41(0).
CCDC 790695e790701 contain the supplementary crystallo-
graphic data for 1, 2, 3, 4, 5, 6 and 7, respectively. These data can be

812
E. Faoro et al. / Journal of Organometallic Chemistry 696 (2011) 807e812
[8] E. Faoro, G. Manzoni de Oliveira, E. Schulz Lang, C. Bicca Pereira, J. Organomet.
Chem. 695 (2010) 1480e1486.
[9] A. Bondi, J. Phys. Chem. 68 (1964) 441e452.
[10] G.M. Sheldrick, Acta Cryst. A64 (2008) 112e122.
[11] W.-W. du Mont, H.U. Meyer, S. Kubiniok, S. Pohl, W. Saak, Chem. Ber. 125
(1992) 761e766.
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: (þ44) 1223 336
033; or e-mail: deposit@ccdc.cam.ac.uk.
[12] K. Giselbrecht, B. Bildstein, F. Sladky, Chem. Ber. 122 (1989) 1255e1256.
[13] E. Schulz Lang, R.M. Fernandes Jr., E.T. Silveira, U. Abram, E.M. Vázquez-López,
Z. Anorg. Allg. Chem. 625 (1999) 1401e1404.
References
[14] T.M. Klapötke, B. Krumm, I. Schwab, Acta Crystallogr. E61 (2005)
o4045eo4046.
[15] M. Asahara, S. Taomoto, M. Tanaka, T. Erabi, M. Wada, J. Chem. Soc., Dalton
Trans. (2003) 973e979.
[16] M. Asahara, M. Tanaka, T. Erabi, M. Wada, J. Chem. Soc., Dalton Trans. (2000)
3493e3499.
[17] A.K.S. Chauhan, P. Singh, R.C. Srivastava, A. Duthie, A. Voda, Dalton Trans.
(2008) 4023e4028.
[1] E. Faoro, G. Manzoni de Oliveira, E. Schulz Lang, Polyhedron 28 (2008) 63e68
and references cited therein.
[2] E. Faoro, G. Manzoni de Oliveira, E. Schulz Lang, J. Organomet. Chem. 694
(2009) 1557e1561.
[3] H.M.K.K. Pathirana, J.H. Reibenspies, E.A. Meyers, R.A. Zingaro, Acta Crys-
tallogr. C47 (1991) 516e519.
[4] S. Hauge, K. Maroy, T. Odegard, Acta Chem. Scand. Ser. A 42 (1988) 56e60.
[5] E. Faoro, G. Manzoni de Oliveira, E. Schulz Lang, J. Organomet. Chem. 691
(2006) 5867e5872.
[18] J. Beckmann, M. Hesse, H. Poleschner, K. Seppelt, Angew. Chem. Int. Ed. 46
(2007) 8277e8280.
[19] J. Beckmann, S. Heitz, M. Hesse, Inorg. Chem. 46 (2007) 3275e3282.
[20] J. Beckmann, P. Finke, M. Hesse, B. Wettig, Angew. Chem. Int. Ed. 47 (2008)
9982e9984.
[6] G. Manzoni de Oliveira, E. Faoro, E. Schulz Lang, Inorg. Chem. 48 (2009)
4607e4609.
[7] E. Schulz Lang, U. Abram, J. Strähle, Z. Anorg. Allg. Chem. 623 (1997) 1968e1972.