Synthesis, spectroscopic characterisation of 1,1,2,3,4,5,6-heptahydro-1,1-di(carboxylato)telluranes and 1,3-dihydro-2λ4-benzotellurole-2,2-diyl dicarboxylates. Crystal structures of 1,1,2,3,4,5,6-heptahydro-1,1-di(benzoato) tellurane and 1,3-dihydro-2λ4-benzotellurole-2,2,-diyl dibenzoate

Article abstract of DOI:10.1016/S0022-328X(02)01594-2

1,1,2,3,4,5,6-Heptahydro-1,1-di(carboxylato)telluranes C₅H₁₀Te(OCOR)₂ (R = OCO, C₆H₅, 4-NO₂C₆H₄, 3,5-(NO₂)₂C₆H₃, 4-OCH₃C₆H₄) and 1,3-dihydro-2λ⁴-benzotellurole-2,2-diyl dicarboxylates C₈H₈Te(OCOR)₂ (R = CH₃, C₆H₅, 4-NO₂C₆H₄, 3,5-(NO₂)₂C₆H₃, 4-OCH₃C₆H₄, 4-NH₂C₆H₄) were obtained from the reactions of 1,1,2,3,4,5,6-heptahydro-1,1-diiodotellurane and 1,3-dihydro-2λ⁴-benzotellurole-2,2-diyl diiodide with silver carboxylates. They were characterised by IR and (¹H, ¹³C, ¹²⁵Te)-NMR spectroscopy. UV, ¹³C/¹²⁵Te CP/MAS spectra and thermogravimetric analysis of representative complexes are also described. The structures of (C₅H₁₀Te(OCOC₆H₅)₂ and C₈H₈Te(OCOC₆H₅)₂ were established by single crystal X-ray diffraction studies. In both cases the immediate coordination geometry about the central Te atom can be described as pseudo trigonal bipyramidal in which two oxygen atoms of the unidentate benzoate groups are in the axial positions, two methylene carbon atoms (attached to Te) of C₅H₁₀ and C₈H₈ groups and the stereochemically active electron lone pair occupy equatorial positions. Te?O secondary bonds directed polymeric (zig-zag chains) associations are present in C₅H₁₀Te(OCOC₆H₅)₂ (cf. trimeric associations in the precursor C₅H₁₀TeI₂) and tetrameric (stair like) associations exist in C₈H₈Te(OCOC₆H₅)₂ (cf. polymeric associations in the precursor C₈H₈TeI₂).

Full text of DOI:10.1016/S0022-328X(02)01594-2

Journal of Organometallic Chemistry 658 (2002) 34ꢁ42
/
www.elsevier.com/locate/jorganchem
Synthesis, spectroscopic characterisation of 1,1,2,3,4,5,6-heptahydro-
1,1-di(carboxylato)telluranes and 1,3-dihydro-2l4-benzotellurole-2,2-
diyl dicarboxylates
Crystal structures of 1,1,2,3,4,5,6-heptahydro-1,1-
di(benzoato)tellurane and 1,3-dihydro-2l4-benzotellurole-2,2-diyl
dibenzoate
Prakash C. Srivastava a,*, Sangeeta Bajpai a, Roli Lath a, Chhabi Ram a,
Meena Srivastava a, Smriti Bajpai a, Ray J. Butcher b, Michael Zimmer c, Michael Veith c
a Chemistry Department, Lucknow University, Lucknow 226007, India
b Chemistry Department, Howard University, Washington DC, WA 20059, USA
c Institut fur Anorganische Chemie, Universitat des Saarlandes, Postfach 15110, D-66041 Saarbrucken, Germany
¨
¨
¨
Received 27 January 2002; accepted 13 May 2002
Abstract
1,1,2,3,4,5,6-Heptahydro-1,1-di(carboxylato)telluranes C5H10Te(OCOR)2 (Rꢀ
/
OCO, C6H5, 4-NO2C6H4, 3,5-(NO2)2C6H3, 4-
OCH3C6H4) and 1,3-dihydro-2l4-benzotellurole-2,2-diyl dicarboxylates C8H8Te(OCOR)2 (Rꢀ
/CH3, C6H5, 4-NO2C6H4, 3,5-
(NO2)2C6H3, 4-OCH3C6H4, 4-NH2C6H4) were obtained from the reactions of 1,1,2,3,4,5,6-heptahydro-1,1-diiodotellurane and 1,3-
dihydro-2l4-benzotellurole-2,2-diyl diiodide with silver carboxylates. They were characterised by IR and (1H, 13C, 125Te)-NMR
spectroscopy. UV, 13C/125Te CP/MAS spectra and thermogravimetric analysis of representative complexes are also described. The
structures of (C5H10Te(OCOC6H5)2 and C8H8Te(OCOC6H5)2 were established by single crystal X-ray diffraction studies. In both
cases the immediate coordination geometry about the central Te atom can be described as pseudo trigonal bipyramidal in which two
oxygen atoms of the unidentate benzoate groups are in the axial positions, two methylene carbon atoms (attached to Te) of C5H10
and C8H8 groups and the stereochemically active electron lone pair occupy equatorial positions. TeÁ Á ÁO secondary bonds directed
polymeric (zig-zag chains) associations are present in C5H10Te(OCOC6H5)2 (cf. trimeric associations in the precursor C5H10TeI2)
and tetrameric (stair like) associations exist in C8H8Te(OCOC6H5)2 (cf. polymeric associations in the precursor C8H8TeI2). # 2002
Elsevier Science B.V. All rights reserved.
Keywords: Tellurium; Carboxylates; Intermolecular secondary bonds; Supramolecular associations
1. Introduction
(C H TeI ) was first synthesised by Ziolo and Gunther
¨
8 8 2
[4] by the reaction of a,a?-dichloro-o-xylene, Te and NaI
in 2-methoxy ethanol. We [5] synthesized 1,3-dihydro-
2l4-benzotellurole-2,2-diyl diiodide with minor modifi-
cation (a,a?-dibromo-o-xylene in place of a,a?-dichloro-
o-xylene) and under easier conditions. Its structure has
been determined by single crystal X-ray diffraction
studies by Ziolo et al. [4,6,7] and existence of supramo-
lecular associations in it through TeÁ Á ÁI secondary
bonds has been described by us [3]. The literature survey
reveals that the reactions of 1,3-dihydro-2l4-benzotel-
lurole-2,2-diyl diiodide were not investigated till 1982
1,1,2,3,4,5,6-Heptahydro-1,1-diiodotellurane (C5H10-
TeI2) was synthesized by Farrar and Gulland [1]. Its
derivatives have been reported from our laboratory [2]
and we [3], recently, reported the X-ray structure of
C5H10TeI2 and supramolecular associations present in
it. 1,3-Dihydro-2l4-benzotellurole-2,2-diyl diiodide
* Corresponding author
E-mail address: pcsrivastava@hotmail.com (P.C. Srivastava).
0022-328X/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved.
PII: S 0 0 2 2 - 3 2 8 X ( 0 2 ) 0 1 5 9 4 - 2

P.C. Srivastava et al. / Journal of Organometallic Chemistry 658 (2002) 34ꢁ
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42
35
when simultaneously but independently two reports
appeared; one related to the cations of 1,3-dihydro-
2l4-benzotellurole-2,2-diyl diiodide by McWhinnie and
co-workers [8] and the other on the anions of 1,3-
dihydro-2l4-benzotellurole-2,2-diyl diiodide from us [5]
including 1,3-dihydro-2l4-benzotellurole-2,2-diyl dicar-
UV spectral data of the solutions of the complexes in
MeOH were recorded on an Unicam SP 500 spectro-
meter with 10 mm path cell. The thermogravimetric
analyses were carried out on a Thermogravimetric
analyses apparatus fabricated by Fertiliser Corporation
of India Sindri (Bihar). The single crystal X-ray diffrac-
tion studies were carried out at the Chemistry Depart-
ment, Howard University, Washington DC.
boxylates viz. C8H8Te(OCOR)2, [RꢀCH3, CH2Cl,
/
CF3, C6H5]. These dicarboxylates were characterised
by IR and 1H-NMR spectroscopy. Later the single
crystal X-ray diffraction study of C8H8Te(OCOCH3)2,
was reported by Dakternieks and co-workers [9].
In view of no structural study reported for
1,1,2,3,4,5,6-heptahydro-1,1-di(carboxylato)telluranes
and in continuation of our structural studies on
2.2. Synthesis
1,1,2,3,4,5,6-Heptahydro-1,1-diiodotellurane (C5H10-
TeI2) [1] and 1,3-dihydro-2l4-benzotellurole-2,2-diyl
diiodide (C8H8TeI2) [5] were prepared by the literature
methods. C5H10TeI2 was recrystallised from C3H6O to
hypervalent Te(IV) compounds [3,10ꢁ13], in the present
/
investigation, we describe a comprehensive study on
synthesis and characterisation of 1,1,2,3,4,5,6-heptahy-
dro-1,1-dicarboxylato telluranes C5H10Te(OCOR)2
obtain orangeꢁ
crystallised from hot 2-methoxy ethanol to obtain
yellowꢁorange crystals.
/
brown needles and C8H8TeI2 was re-
/
[Rꢀ
OCH3C6H4] and 1,3-dihydro-2l4-benzotellurole-2,2-
diyl dicarboxylates C8H8Te(OCOR)2, [RꢀCH3, C6H5,
4-NO2C6H4, 3,5-(NO2)2C6H3, 4-OCH3C6H4, 4-
/
OCO, C6H5, 4-NO2C6H4, 3,5-(NO2)2C6H3, 4-
1,1,2,3,4,5,6-Heptahydro-1,1-mono(oxalato)tellurane
(1), 1,1,2,3,4,5,6-heptahydro-1,1-di(benzoato)tellurane
(2), 1,1,2,3,4,5,6-heptahydro-1,1-di(4-nitrobenzoato)tel-
lurane (3), 1,1,2,3,4,5,6-heptahydro-1,1-di(3,5-dinitro-
benzoato)tellurane (4), and 1,1,2,3,4,5,6 heptahydro-
1,1-di(4-methoxybenzoato)tellurane (5); 1,3-dihydro-
2l4-benzotellurole-2,2-diyl diacetate (6); -dibenzoate
(7); -di(4-nitrobenzoate) (8); -di(3,5-dinitrobenzoate)
(9);-di(4-methoxybenzoate) (10); -di(4-aminobenzoate)
(11) were prepared by stirring C5H10TeI2 or C8H8TeI2
with freshly prepared silver carboxylates in C3H6O or
CH2Cl2.
/
NH2C6H4]; X-ray structures of C5H10Te(OCOC6H5)2
(2) and C8H8Te(OCOC6H5)2 (7) with reference to
supramolecular associations and thermal effects.
Supramolecular chemistry of organometallic com-
pounds is an area of current interest [3,13,14] because
of their usefulness in materials’ chemistry [14e,14h].
Further thermal effects on organoselenium compounds
have been examined [15] whereas, to our knowledge,
there is no report of thermal effects on organotellur-
iums.
2. Experimental
2.1. Physical measurement
Elemental analyses for C, H, and N were carried out
on an Elemental Analyser Heraeus Carlo Erba 1108 and
Te was estimated volumetrically [5]. IR spectra were
recorded using a Shimadzu 8210 PC FTIR spectrometer
To 1,2,3,4,5,6-heptahydro-1,1-diiodotellurane(2 g,
4.42 mmol) was added freshly prepared silver oxalate
(1.73 g, 8.85 mmol), silver benzoate (2.03 g, 8.86 mmol),
silver 4-nitro benzoate (2.42 g, 8.85 mmol), silver 3,5-
dinitro benzoate (2.82 g, 8.86mo1), silver 4-methoxy
benzoate (2.29 g, 8.85 mmol) in C3H6O (approximately
30 ml). It was stirred for 4 h and filtered to eliminate AgI
and excess silver carboxylate. The filtrate was concen-
in the frequency range 4000ꢁ
350 cmꢂ1 with the samples
/
in KBr discs. The (1H, 13C, 125Te)-NMR spectra were
recorded on a Varian VXR3005 spectrometer in CDCl3,
for all the complexes except those of 1,1,2,3,4,5,6-
heptahydro-1,1-di(3,5-dinitrobenzoato) tellurane (4)
and 1,3-dihydro-2l4-benzotellurole-2,2-diyl di(3,5-dini-
trobenzoate) (9) which were recorded in Me2SO and
C3H6O, respectively. The operating frequency for 125Te-
NMR was 94.752 MHz with a pulse width of 42.88. The
50.3 MHz 13C and 63.2 MHz 125Te CP/MAS solid state
NMR spectral studies were carried out at 3.5 and 4.7
trated under reduced pressure to give complexes 1ꢁ5.
/
Complex 1 yield: 0.85 g (67%), m.p. 120 8C. Anal. Calc.
for C7H10O4Te: C, 29.41; H, 3.50; Te, 44.67. Found: C,
29.35; H, 3.45; Te, 44.62%. Complex 2 yield: 1.20 g
(62%), m.p. 138ꢁ
C, 51.86; H, 4.54; Te, 29.02. Found: C, 51.72; H, 4.45;
Te, 29.00%. Complex 3 yield: 1.46 g (62%), m.p. 128ꢁ
/
140 8C. Anal. Calc. for C19H20O4Te:
KHz at Institut fur Anorganische Chemie Universitat
/
¨
¨
des Saarlandes, Saarbrucken, Germany. 125Te-NMR
130 8C. Anal. Calc. for C19H18O8N2Te: C, 43.05; H,
3.39; N, 5.28; Te, 24.09. Found: C, 43.02; H, 3.32; N,
¨
spectra were referenced to Me2Te (dꢀ/0 ppm). The

36
P.C. Srivastava et al. / Journal of Organometallic Chemistry 658 (2002) 34ꢁ42
/
5.15; Te, 24.05%. Complex 4 yield: 1.65 g (60%), m.p.
225ꢁ230 8C. Anal. Calc. for C19H16O12N4Te: C, 36.79;
H, 2.58; N, 9.03; Te, 20.59. Found: C, 36.72; H, 2.54; N,
9.00; Te, 20.56%. Complex 5 yield: 1.50 g (68%), m.p.
150 8C. Anal. Calc. for C21H24O6Te: C, 50.44; H, 4.80;
Te, 25.54. Found: C, 50.42; H, 4.75; Te, 25.48%.
Selected bond lengths and bond angles for 2 and 7 are
listed in Tables 2ꢁ5. The crystal structures and supra-
molecular associations of 2 and 7 are shown in Figs. 1ꢁ
and 3ꢁ4, respectively.
/
/
/2
/
To 1,3-dihydro-2l4-benzotellurole-2,2-diyl diiodide (2
g, 4.12 mmol) was added freshly prepared silver acetate
(1.38 g, 8.25 mmol), silver benzoate (1.89 g, 8.25 mmol),
silver 4-nitro benzoate (2.26 g, 8.25 mmol), silver 3,5-
dinitro benzoate (2.63 g, 8.25 mmol), silver 4-methoxy
benzoate (2.14 g, 8.25 mmol), silver 4-amino benzoate
(2.01 g, 8.25 mmol) in CH2Cl2 (approximately 30 ml). It
was stirred for 6 h and filtered to eliminate AgI and
excess silver carboxylate. The filtrate was concentrated
3. Results and discussion
3.1. Spectroscopic characterization
Spectroscopic data for (C5H10Te(OCOR)2) 1ꢁ
(C8H8Te(OCOR)2) 6ꢁ11 are given in Tables 6 and 7
,respectively. The IR spectra of 1ꢁ11 display the
characteristic carboxylate group frequencies. The n
asym COO and n sym COO are in the range 1603ꢁ
1650 and 1292ꢁ
1394 cmꢂ1, respectively. Dn (n asym
COOꢁ sym COO) approximately 278ꢁ
353 cmꢂ1
/
5 and
/
/
under reduced pressure to give complexes 6ꢁ11. Com-
/
/
plex 6 yield: 0.34 g (24%), m.p. 150 8C. Anal. Calc. for
C12H14O4Te: C, 41.18; H, 4.00; Te, 36.49. Found: C,
41.10; H, 4.01; Te, 36.46%. Complex 7 yield: 0.42 g
(22%), m.p. 150 8C. Anal. Calc. for C22H18O4Te: C,
55.74; H, 3.80; Te, 26.94. Found: C, 55.72; H, 3.78; Te,
/
/n
/
indicate the presence of unidentate carboxylate groups
in all the complexes [11,12,18] except in the case of 1
(Dnꢀ
/
243 cmꢂ1) which appears to contain bidentate
26.88%. Complex 8 yield: 0.29 g (13%), m.p. 148ꢁ
/
oxalate group [11,19]. The solution (1H, 13C, 125Te)-
NMR data exhibit the characteristic signals at their
expected positions with expected multiplicity. The 13C
150 8C. Anal. Calc. for C22H16O8N2Te: C, 46.84; H,
2.83; N, 4.96; Te, 22.64. Found: C, 46.80; H, 2.77; N,
4.94; Te, 22.60%. Complex 9 yield: 0.90 g (33%), m.p.
CP/MAS solid state NMR of 2 shows CH2Ã
ppm), CH2ÃCH2 (30, 26 ppm), C6H5 (134, 129, 128
ppm), CO (172 ppm) [cf. CH2ÃTe (29.8 ppm), CH2Ã
/
Te (32
118ꢁ120 8C. Anal. Calc. for C22H14O12N4Te: C, 40.39;
/
/
H, 2.14; N, 8.56; Te, 19.52. Found: C, 40.35; H, 2.12; N,
8.54; Te, 19.50%. Complex 10 yield: 0.63 g (29%), m.p.
/
/
CH2 (27.1, 20.4 ppm), C6H5 (132.2, 129.8, 128.1 ppm),
CO (171.8 ppm) in solution 13C-NMR (Table 6)] and
125Te CP/MAS NMR of 2 shows isotropic shift at 902
ppm which is comparable to that of solution 125Te-
160ꢁ
4.12; Te, 23.91. Found: C, 53.91; H, 4.11; Te, 23.86%.
Complex 11 yield: 0.21 g (13%), m.p. 120ꢁ125 8C.
/
162 8C. Anal. Calc. for C24H22O6Te: C, 53.97; H,
/
Anal. Calc. for C22H20O4N2Te: C, 70.21; H, 5.31; N,
7.44; Te, 33.93. Found: C, 70.11; H, 5.25; N, 7.42; Te,
33.91%.
NMR (dꢀ918 ppm).
/
The ultra violet spectra of C8H8TeI2 and C8H8Te-
(OCOC6H5)2 in conjunction with their X-ray structures
in terms of supramolecular associations are described as
follows:
2.3. X-ray measurements
Colourless needle shaped crystals (0.25ꢃ
mm) of complex 2 at [158(2) K], light brown prism
shaped crystals (0.35ꢃ0.67ꢃ0.55 mm) of complex 2 at
[293(2) K] and colourless crystals (0.20ꢃ0.28ꢃ0.34
/
0.4ꢃ
/
0.4
Two maxima in the spectrum of C8H8TeI2 are
observed. The maxima at 271 nm is attributed to (p,
p*) benzoid transition in accordance with the earlier
observations [4,20]. The absorption at 336 nm appears
to be because of the transfer of electron density from the
iodine into the d-orbitals of Te termed as charge-
transfer transition [21,22] presumably, due to TeÁ Á ÁI
secondary bonds in the polymeric associations [3]
existing in C8H8TeI2.
In C8H8Te(OCOC6H5)2 (7), the absorption located at
272 nm is attributed to (p, p*) benzoid transition as in
the case of C8H8TeI2. The absorption at 280 nm is
apparently because of the transfer of electron density
/
/
/
/
mm) of complex 7 at 293(2) K were mounted on a
Bruker P4S diffractometer using graphite monochro-
˚
matic MoꢁKa radiation (0.71073 A). The unit cells were
/
determined from 25 randomly selected reflections using
the automatic search index and least-squares refinement.
The structures of 2 and 7 were solved in space group
P21/c. The data were corrected for Lorentz, polarization
and absorption effects. The data were monitored by
measuring three standard reflections at every 97 reflec-
tions. The structures were solved by the routine heavy
atom method SHELXS-86 [16] and Fourier methods and
refined by full-matrix least-squares using the SHELXL-93
program [17] with the non-hydrogen atoms anisotropic
from ÈCÄ/O into the d-orbital of Te termed as charge-
transfer transition [21,22], presumably, due to TeÁ Á ÁO
secondary bonds in the tetrameric supramolecular
associations (present work) existing in C8H8Te-
(OCOC6H5)2.
and hydrogen atoms having fixed isotropic thermal
2
parameters of 0.08 A (Table 1).
˚

P.C. Srivastava et al. / Journal of Organometallic Chemistry 658 (2002) 34ꢁ
/
42
37
Table 1
Crystal data and refinement details for complexes 2 and 7
2 (colourless needle)
2 (brown prism)
7
Empirical formula
Formula weight
Temperature (K)
Crystal system
Space group
C
439.95
19H20O4Te
C19H20O4Te
439.95
C22H18O4Te
473.96
158(2)
Monoclinic
293(2)
Monoclinic
293(2)
Monoclinic
P21/c
10.0876(8)
P21/c
10.2162(8)
P21/c
19.3018(14)
˚
a (A)
˚
b (A)
17.0245(12)
10.6499(8)
17.1596(17)
10.7094(10)
9.2682(7)
10.8086(8)
˚
c (A)
a (8)
b (8)
g (8)
V (A )
Z
m (mmꢂ1
Index ranges
90
108.8100(10)
90
109.551(6)
90
93.5190(10)
90
1731.3(2)
90
1769.2(3)
90
1929.9(2)
3
˚
4
1.738
4
1.700
4
1.566
)
ꢂ125h 512, ꢂ75k 521,
ꢂ125l 513
11 788
05h 513, ꢂ225k 50,
ꢂ135l 513
4289
ꢂ255h 525, ꢂ125k 511,
ꢂ135l 514
20 774
Reflections collected
Independent reflections
Final R indices [I ꢀ2s(I)]
R indices (all data)
3377 (Rintꢀ0.0297)
R1ꢀ0.0186, wR2ꢀ0.0487
R1ꢀ0.0211, wR2ꢀ0.0496
4071 (Rintꢀ0.0164)
R1ꢀ0.0294, wR2ꢀ0.0710
R1ꢀ0.0409, wR2ꢀ0.0755
4696 (Rintꢀ0.0539)
R1ꢀ0.0262, wR2ꢀ0.0623
R1ꢀ0.0380, wR2ꢀ0.0660
3.2. Thermogravimetric analysis
dimeric unit of the complex. The observed percentage
weight loss is 51 in agreement with the theoretical value
With a view to examine the thermal stability and to
obtain monomer of the complexes, thermogravimetric
analysis of two representative complexes viz. C8H8Te(O-
COC6H5)2 (7) and C8H8Te(OCOCH3)2 (6) were carried
out at a heating rate of 5 8C minꢂ1. The pyrolysis
curves are produced in Fig. 5.
of 50. The dimeric unit in the temperature range 420ꢁ
/
640 8C undergoes decomposition to yield tellurium
metal (Found% weight loss 64, Calc.% weight loss 64).
The metal slowly volatilises above 800 8C.
Thermogravimetric data coupled with single crystal
X-ray diffraction data of C8H8Te(OCOC6H5)2, (7)
indicate that there is no appreciable weight loss below
180 8C. After 180 8C the decomposition of the tetra-
meric unit of the complex starts and at 340 8C the mass
corresponds to dimeric unit of the complex. The
observed percentage weight loss is 51 in agreement
with the theoretical value of 50. The dimeric unit in
3.3. Description of the structures of 2 and 7
Colourless needle shaped crystals of 2, light brown
prism shaped crystals of 2 were grown from benzene and
acetone, respectively and colourless crystals of 7 were
grown from acetone at room temperature.
the temperature range 340ꢁ720 8C undergoes decom-
/
position to yield tellurium metal (Found% weight loss
73, Calc.% weight loss 73). Above 800 8C the mass
corresponding to tellurium metal decreases which is
attributed to slow volatilisation of the metal (m.p.
450 8C, b.p. 990 8C). The scheme of decomposition
may be represented as follows:
3.3.1. Description of the structure of
C5H10Te(OCOC6H5)2 (2)
The structure of 2 is shown in Fig. 1. In C5H10Te-
(OCOC6H5)2 the tellurium atom completes a cyclohex-
ane ring with other five carbon atoms in C5H10Te cycle.
The average CÃ
atoms at the other end of cyclohexane ring make an
angle C(3)ÃC(4)ꢀ112.96(2)8. The C5H10Te
C(2)Ã
/
CÃC angles are 1148. The three carbon
/
Ú
/
/
/
/
ring has chair conformation in which part of the ring
is flattened and a part is considerably puckered. A
similar conformation for C5H10Te cycle has been
envisaged by us [3] in 1,2,3,4,5,6-heptahydro-1,1-diiodo
tellurane (X-ray evidence) and in 1,2,3,4,5,6-heptahy-
Almost the same pattern is observed for C8H8Te-
(OCOCH3)2 (6), where there is no appreciable weight
loss below 160 8C. After 160 8C, the complex starts
decomposing and at 420 8C the mass corresponds to

38
P.C. Srivastava et al. / Journal of Organometallic Chemistry 658 (2002) 34ꢁ42
/
Table 2
Table 4
˚
˚
Bond lengths (A) and angles (8) for 2
Bond lengths (A) and angles (8) for 7
Bond lengths
Bond lengths
TeÃC(1)
TeÃO(1B)
O(1A)ÃC(1A)
O(1B)ÃC(1B)
C(1)ÃC(2)
2.127(2)
2.157(1)
1.306(2)
1.312(2)
1.520(3)
1.526(3)
1.501(3)
1.398(3)
1.383(3)
1.390(3)
1.390(3)
1.388(3)
1.385(4)
TeÃC(5)
TeÃO(1A)
O(2A)ÃC(1A)
O(2B)ÃC(1B)
C(2)ÃC(3)
2.132(2)
2.167(1)
1.224(2)
1.222(3)
1.531(3)
1.525(3)
1.390(3)
1.380(3)
1.388(3)
1.498(3)
1.395(3)
1.377(4)
1.389(3)
TeÃC(8)
TeÃO(1B)
2.106(2)
2.141(2)
1.313(3)
1.323(3)
1.384(3)
1.490(31
1.364(4)
1.374(3)
1.389(4)
1.376(4)
1.366(4)
1.503(3)
1.395(3)
1.381(4)
1.396(3)
TeÃC(1)
TeÃO(1A)
2.111(2)
2.143(2)
1.217(3)
1.219(3)
1.398(3)
1.388(4)
1.375(4)
1.379(3)
1.483(3)
1.356(4)
1.380(4)
1.392(3)
1.376(4)
1.379(3)
1.509(3)
O(1A)ÃC(7A)
O(1B)ÃC(7B)
C(1A)ÃC(2A)
C(1A)ÃC(7A)
C(3A)ÃC(4A)
C(5A)ÃC(6A)
C(1B)ÃC(6B)
C(2B)ÃC(3B)
C(4B)ÃC(5B)
C(1)ÃC(2)
O(2A)ÃC(7A)
O(2B)ÃC(7B)
C(1A)ÃC(6A)
C(2A)ÃC(3A)
C(4A)ÃC(5A)
C(1B)ÃC(2B)
C(1B)ÃC(7B)
C(3B)ÃC(4B)
C(5B)ÃC(6B)
C(2)ÃC(3)
C(3)ÃC(4)
C(4)ÃC(5)
C(1A)ÃC(2A)
C(2A)ÃC(7A)
C(4A)ÃC(5A)
C(6A)ÃC(7A)
C(2B)ÃC(7B)
C(3B)ÃC(4B)
C(5B)ÃC(6B)
C(2A)ÃC(3A)
C(3A)ÃC(4A)
C(5A)ÃC(6A)
C(1B)ÃC(2B)
C(2B)ÃC(3B)
C(4B)ÃC(5B)
C(6B)ÃC(7B)
C(2)ÃC(7)
C(4)ÃC(5)
C(6)ÃC(7)
C(3)ÃC(4)
C(5)ÃC(6)
C(7)ÃC(8)
Bond angles
C(1)ÃTeÃC(5)
C(5)ÃTeÃO(1B)
C(5)ÃTeÃO(1A)
C(1A)ÃO(1A)ÃTe
C(2)ÃC(1)ÃTe
C(4)ÃC(3)ÃC(2)
C(4)ÃC(5)ÃTe
O(2A)ÃC(1A)ÃC(2A) 122.11(19) O(1A)ÃC(1A)ÃC(2A) 114.81(16)
C(3A)ÃC(2A)ÃC(7A) 119.67(19) C(3A)ÃC(2A)ÃC(1A) 119.19(18)
C(7A)ÃC(2A)ÃC(1A) 121.12(17) C(4A)ÃC(3A)ÃC(2A) 120.4(2)
C(3A)ÃC(4A)ÃC(5A) 120.1(2)
C(5A)ÃC(6A)ÃC(7A) 120.1(2)
O(2B)ÃC(1B)ÃO(1B) 123.19(18) O(2B)ÃC(1B)ÃC(2B) 121.46(18)
O(1B)ÃC(1B)ÃC(2B) 115.34(17) C(7B)ÃC(2B)ÃC(3B) 120.24(19)
C(7B)ÃC(2B)ÃC(1B) 121.51(18) C(3B)ÃC(2B)ÃC(1B) 118.22(19)
97.89(7) C(1)ÃTeÃO(1B)
85.97(6) C(1)ÃTeÃO(1A)
82.51(6) O(1B)ÃTeÃO(1A)
113.71(12) C(1B)ÃO(1B)ÃTe
115.52(13) C(1)ÃC(2)ÃC(3)
112.96(16) C(5)ÃC(4)ÃC(3)
83.80(7)
86.27(7)
Bond angles
163.60(5)
109.89(12)
115.45(17)
114.27(16)
C(8)ÃTeÃC(1)
C(1)ÃTeÃO(1B)
C(1)ÃTeÃO(1A)
C(7A)ÃO(1A)ÃTe
86.89(8) C(8)ÃTeÃO(1B)
85.94(7) C(8)ÃTeÃO(1A)
87.80(8) O(1B)ÃTeÃO(1A)
118.49(16) C(7B)ÃO(1B)ÃTe
80.86(7)
80.82(7)
160.92(7)
112.46(14)
113.64(12) O(2A)ÃC(1A)ÃO(1A) 123.1(2)
C(2A)ÃC(1A)ÃC(6A) 119.2(2)
C(6A)ÃC(1A)ÃC(7A) 121.2(2)
C(4A)ÃC(3A)ÃC(2A) 120.6(3)
C(6A)ÃC(5A)ÃC(4A) 120.3(3)
O(2A)ÃC(7A)ÃO(1A) 122.9(2)
O(1A)ÃC(7A)ÃC(1A) 114.0(2)
C(2B)ÃC(1B)ÃC(7B) 119.7(2)
C(3B)ÃC(2B)ÃC(1B) 120.0(3)
C(3B)ÃC(4B)ÃC(5B) 120.0(3)
C(5B)ÃC(6B)ÃC(1B) 120.2(3)
O(2B)ÃC(7B)ÃC(1B) 122.9(2)
C(2)ÃC(1)ÃTe
C(3)ÃC(2)ÃC(1)
C(4)ÃC(3)ÃC(2)
C(6)ÃC(5)ÃC(4)
C(2)ÃC(7)ÃC(6)
C(6)ÃC(7)ÃC(8)
C(2A)ÃC(1A)ÃC(7A) 119.6(2)
C(1A)ÃC(2A)ÃC(3A) 119.7(3)
C(3A)ÃC(4A)ÃC(5A) 120.2(3)
C(5A)ÃC(6A)ÃC(1A) 120.1(2)
O(2A)ÃC(7A)ÃC(1A) 123.0(2)
C(2B)ÃC(1B)ÃC(6B) 118.2(2)
C(6B)ÃC(1B)ÃC(7B) 122.2(2)
C(4B)ÃC(3B)ÃC(2B) 120.4(3)
C(4B)ÃC(5B)ÃC(6B) 120.4(3)
O(2B)ÃC(7B)ÃO(1B) 121.9(2)
O(1B)ÃC(7B)ÃC(1B) 115.1(2)
C(4A)ÃC(5A)ÃC(6A) 120.1(2)
C(6A)ÃC(7A)ÃC(2A) 119.55(18)
C(4B)ÃC(3B)ÃC(2B) 119.7(2)
C(4B)ÃC(5B)ÃC(6B) 121.0(2)
C(6B)ÃC(7B)ÃC(2B) 119.6(2)
C(5B)ÃC(4B)ÃC(3B) 119.7(2)
C(5B)ÃC(6B)ÃC(7B) 119.7(2)
106.53(13) C(3)ÃC(2)ÃC(7)
120.30(18) C(7)ÃC(2)ÃC(1)
120.3(2)
120.0(2)
119.8(2)
119.88(17)
120.2(2)
120.7(2)
Symmetry transformations used to generate equivalent atoms.
C(3)ÃC(4)ÃC(5)
C(5)ÃC(6)ÃC(7)
110.96(18) C(2)ÃC(7)ÃC(8)
120.99(18) C(7)ÃC(8)ÃTe
120.04(18)
106.31(14)
Table 3
Bond lengths (A) and angles (8) for 2
˚
Symmetry transformation used to generate equivalent atoms.
TE
TE
TE
TE
TIE
O1A
O1B
C1
2.167
2.157
2.127
2.132
3.307
163.6
86.3
82.5
83.8
86.0
70.9
O1B
Table 5
Bond lengths (A) and angles (8) for 7
C5
O2AA
97.9
71.6
C1
˚
118.0
O1A
155.2
C5
TEA
TEA
TEA
TEA
TEA
O1AA
O1BB
C1AA
C8AA
O2A
2.143
2.141
2.111
2.106
3.376
160.9
87.8
80.8
94.8
O1A
O2A
O2A
C1A
TEA
1.224
3.307
85.9
80.8
85.4
O1B
169.2
C1A
86.8
160.6
C1
74.6
C8
dro-1,1-dibromo tellurane by Lambert and Keske [23]
(NMR evidence).
Of the five methylene groups, the two methylene
carbon atoms of the C5H10 group are bonded to Te(IV)
apical positions (TeÃ
/
O(1A)ꢀ
2.157(1) A) and the two methylene carbon atoms in
the equatorial plane (ÚC(1)ÃTeÃC(5), 97.89(7)8). The
/
2.167(1), TeÃ
/
O(1B)ꢀ
/
˚
/
/
/
atom with almost equal TeÃ
/
C(1)ꢀ
/
2.127(2) and TeÃ
/
fifth coordination position in the equatorial plane is
apparently occupied by a stereochemically active elec-
tron lone pair. An analogous coordination is shown by
the Te atom in 10,10,-di(trifluoro acetato) phenoxotel-
lurine [24], 1,1,2,3,4,5-hexahydro-1,1-di(benzoato)- and
C(5)ꢀ2.132(2) bond lengths. The coordination geome-
/
try formed by the four closest atoms C(1), C(5), O(1A),
O(1B) is approximately trigonal bipyramidal with the
oxygen atoms of the unidentate benzoate groups in the

P.C. Srivastava et al. / Journal of Organometallic Chemistry 658 (2002) 34ꢁ
/
42
39
is shown by tellurium in 1,1,2,3,4,5-hexahydro-1,1-
di(benzoato) tellurophene [12], di(trifluoro acetate)
diphenyl tellurium [27] and in cis-2-ethoxycycloheptyl
tribromotellurium [29] in which the unshared electron
pair is in the trans position to the organic group.
˚
The TeÁ Á ÁO distance 3.307 A is shorter than the sum
˚
of van der Waals radii (3.60 A) [27,30] and longer than
˚
the sum of covalent radii (2.03 A) [31] and thus
definitely corresponds to a secondary bond [28] but it
is much weaker than in the complex cis-2-ethoxycyclo-
heptyl tribromotellurium [29] where the TeÁ Á ÁO distance
Fig. 1. Crystal structure of 2.
˚
is 2.49 A and in (CH3)2Te(OCOC6H5)2 [11] where it is
˚
2.224 A, but is comparable to the TeÁ Á ÁO distances
1,1-di(4-nitrobenzoato)tellurophene [12]. The O(1B)TeÃ
O(1A) angle of 163.60(5)8 deviates considerably from
linearity with both oxygen atoms pushed away from the
equatorial tellurium lone pair. This fairly large deviation
from linearity has also been observed in acyclic dialkyl-
/
˚
(2.95ꢁ
/
3.02 A) in (p-MeOC6H4)2Te(OCOCH3)2 [25],
˚
3.03 A) in (C6H5)2Te(OCOCF3)2 [27] and 3.083
(2.99ꢁ
/
˚
A in C4H8Te(OCOC6H5)2 [12]. These weak TeÁ Á ÁO
secondary bonds join the molecules to form dimeric
units (Fig. 2) which join together resulting in the
formation of polymeric (zig-zag chains) supramolecular
associations in which Te atom is effectively seven-
coordinate, similar to the coordination shown by tell-
urium through TeÁ Á ÁO secondary bonds in 1,1,2,3,4,5-
[11], diaryl- [25ꢁ27] and heterocyclic tellurium dicar-
/
boxylates [12] and may be attributed to the presence of
TeÁ Á ÁO secondary bonds [28]. The TeÁ Á ÁO secondary
bond brings up the coordination of the Te atom to
octahedral with an unshared electron pair at the vertex
situated in the trans position to one of the CH2 groups
attached to tellurium (the secondary bond itself is in the
trans position to other CH2 group attached to tell-
hexahydro-1,1-di(benzoato)tellurophene
[12]
and
through TeÁ Á ÁS secondary bonds in S,S?-1,3-dihydro-
2l4-benzotellurole-2,2-diyl-O,O,O?,O?-tetraethyl bis-
(dithiophosphate) [C8H8Te{S2P(OEt)2}] [32] whereas
in the precursor (C5H10TeI2) trimeric associations [3]
are present.
urium). The angles OÁ Á ÁTeÃ
/
C(1) and OÁ Á ÁTeÃ
/
C(1A) are
71.6 and 169.28 (Fig. 2), (Table 3). Similar coordination
Table 6
Spectroscopic data for 1ꢁ5
/
Complex
IR (KBr) (cmꢂ1
)
1H-NMR (CDCl3) (ppm)
13C-NMR (CDCl3) (ppm)
125Te-NMR (CDCl3) (ppm)
1
1637 (asym CO)
1394 (sym CO)
505 (TeC)
1.9, 2.3 (ÃCH2ÃC)
3.6 (ÃCH2ÃTe)
28.8, 37.5 (CCH2)
49.8 (TeCH2)
158.2 (CO)
2
3
4
5
1614 (asym CO)
1298 (sym CO)
505 (TeC)
1.8, 2.0 (ÃCH2ÃC)
3.3 (ÃCH2ÃTe)
7.4, 8.0 (C6H5)
20.4, 27.1 (CCH2)
29.8 (TeCH2)
128.1, 129.8
918
2
3
132.2 (C6H5)
171.8 (CO)
(q, JTeHꢀ43 Hz JTeHꢀ11 Hz)
1639 (asym CO)
1315 (sym CO)
518 (TeC)
1.8, 2.0 (ÃCH2ÃC)
3.6 (ÃCH2ÃTe)
7.8, 8.2 (C6H4)
35.0 (CCH2)
45.1 (TeCH2)
128.5, 136.0
144.0 (C6H4)
155.0 (CO)
1622 (asym CO)
1344 (sym CO)
530 (TeC)
1.9, 3.0 (ÃCH2ÃC)
3.6 (ÃCH2ÃTe)
18.8, 29.2 (CCH2)
38.5 (TeCH2)
120.1, 127.9
8.9, 9.0 (C6H13
)
138.3 (C6H3)
165.4 (CO)
1650 (asym CO)
1326 (sym CO)
510 (TeC)
1.8, 2.0 (ÃCH2ÃC)
3.2 (ÃCH2ÃTe)
3.8 (ÃOCH3)
20.8, 27.5 (CCH2)
30.2 (TeCH2)
55.8 (OCH3)
113.8, 124.8,
132.1 (C6H4)
172.0 (CO)
6.9, 8.1(C6H4)

40
P.C. Srivastava et al. / Journal of Organometallic Chemistry 658 (2002) 34ꢁ42
/
Table 7
Spectroscopic data for 6ꢁ11
/
Complex
IR (KBr) (cmꢂ1
)
1H-NMR (CDCl3) (ppm)
13C-NMR (CDCl3) (ppm)
125Te-NMR (CDCl3) (ppm)
6
1645 (asym CO)
1292 (sym CO)
502 (TeC)
4.47 (ÃCH2ÃTe)
7.25 (C6H4)
1.90 (CH3)
22.1 (CH3)
46.3 (TeCH2)
128.1, 130.5,
139.4 (C6H4)
178.5 (CO)
1070
2
(q, JTeHꢀ42 Hz)
7
8
1624 (asym CO)
1323 (sym CO)
555 (TeC)
4.73 (ÃCH2ÃTe)
7.34 (C6H4)
7.88 (C6H5)
46.8 (TeCH2)
128.1, 128.4
130.4 (C6H4)
131.9, 132.7
139.5 (C6H5)
173.1 (CO)
1078
2
(q, JTeHꢀ42 Hz)
1633 (asym CO)
1321 (sym CO)
530 (TeC)
4.78 (ÃCH2ÃTe)
7.31 (C6H4)
8.07,
46.8 (TeCH2)
127.5, 128.0
129.0 (C6H4)
130.0, 130.2
136.0 (C6H4)
171.0 (CO)
1103
(q; 2JTeHꢀ43 Hz)
8.21(C6H5)
9
1628 (asym CO)
1346 (sym CO)
540 (TeC)
4.92 (ÃCH2ÃTe)
7.36 (C6H4)
8.90, 8.99 (C6H3)
10
1612 (asym CO)
1325 (sym CO)
549 (TeC)
4.68 (ÃCH2ÃTe)
7.26 (C6H4)
3.81 (OCH3)
6.81,
30.1 (OCH3)
46.7 (TeCH2)
124.3, 128.0,
130.4 (C6H4)
132.2, 139.6 (C6H4)
172.9 (CO)
1064
2
(q, JTeHꢀ41 Hz)
7.84 (C6H4)
11
1603 (asym CO)
1321 (sym CO)
530 (TeC)
4.76 (ÃCH2ÃTe)
7.26 (C6H4)
6.58, 7.73 (C6H4)
1064
2
(q, JTeHꢀ38 Hz)
3.3.2. Description of the structure of
C8H8Te(OCOC6H5)2 (7)
The structure of 7 is shown in Fig. 3. The two
methylene carbon atoms of the C8H8 group are bonded
to the Te(IV) atom with almost equal TeÃ
/
C bond
˚
lengths TeÃC(l)ꢀ2.111(2) and TeÃC(8)ꢀ2.106(2) A.
/
/
/
/
The coordination geometry formed by the four closest
atoms C(l), C(8), O(1A), O(1B) is approximately trigo-
nal bipyramidal with the oxygen atoms in the apical
positions [TeÃ
/
O(1A)ꢀ
/
2.143(2), TeÃ
/
O(1B)ꢀ2.141(2)
/
˚
A] and the two carbon atoms in the equatorial plane
Fig. 2. Molecules of 2 connected through TeÁ Á ÁO secondary bonds
(broken).
Although by using different solvents for crystalliza-
tion, it was possible to isolate two type of crystals
colourless needles (m.p. 138ꢁ
light brown prisms (m.p. 148ꢁ
/
140 8C) from benzene and
150 8C) from acetone
/
and initially we speculated them to be polymorphs but
on the basis of X-ray diffraction data (Table 1), we
conclude that they are not polymorphs.
Fig. 3. Crystal structure of 7.

P.C. Srivastava et al. / Journal of Organometallic Chemistry 658 (2002) 34ꢁ
/
42
41
[C(1)Ã
/
TeÃ
/
C(8)ꢀ86.89(8)8]. The fifth coordination po-
/
sition, in the equatorial plane, is apparently occupied by
a stereochemically active lone pair of electrons. The
O(1A)Ã
/
TeÃO(1B) angle of 160.92(7)8 deviates consider-
/
ably from linearity with both oxygen atoms pushed
away from the equatorial tellurium lone pair. This
pseudotrigonal bipyramidal arrangement around tell-
urium and fairly large deviation of Ú
linearity is in accordance with the literature reports as
quoted above [11,12,25ꢁ27] and may be attributed to
/
OÃ
/
TeÃ
/
O from
/
the presence of TeÁ Á ÁO secondary bonds [28].
As discussed above (Section 3.3.1) in the case of
C5H10Te(OCOC6H5)2 (2), the TeÁ Á ÁO secondary bond in
C8H8Te(OCOC6H5)2 (7) brings up the coordination of
the tellurium atom to octahedral with an unshared
electron pair at the vertex situated in the trans position
to one of the Ã
(the secondary bond itself is in the trans position to the
other ÃCH2 group attached to tellurium). The angles
TeAÃO(2A)ÃC(1) and TeAÃO(2A)ÃC(8) are 160.6 and
/
CH2 groups attached to tellurium atom
/
/
/
/
/
74.68 (Table 5). Similar coordination is shown in the
other organotellurium complexes [12,27,29] in which the
unshared electron pair is in the trans position to the
Fig. 5. (a) Pyrolysis curve of 6. (b) Pyrolysis curve of 7.
respectively. The CÃ
/
C bond lengths in C6H4, cycle are
˚
organic group. The TeÁ Á ÁO (3.376 A) corresponds to a
˚
of the order of 1.385 A. In the precursor C8H8TeI2, three
secondary bond [28] and is comparable to the TeÁ Á ÁO
secondary bond in 2. These weak TeÁ Á ÁO secondary
bonds join together four C8H8Te(OCOC6H5)2 (7) mo-
lecules (Fig. 4) resulting in tetrameric (stair like)
supramolecular associations whereas in the precursor
(C8H8TeI2) three dimensional polymers [3] are present.
dimensional polymers are present linked through TeÁ Á ÁI
˚
secondary bonds. TeÁ Á ÁI bond length is 2.902(7) A. The
˚
Te bond lengths are of the order of 1.38 A [3]. In
CH2Ã
/
2, TeÁ Á ÁO secondary bonds directed polymeric (zig-zag
chains) supramolecular associations are present. The
˚
TeÁ Á ÁO bond length is 3.307 A. The H2C(1)Ã
/
Te,
˚
Te bond lengths are 2.127(2) and 2.132(2) A,
H2C(5)Ã
/
3.3.3. Supramolecular associations
respectively and CÃ
/
C bond lengths of C5H10Te cycle are
˚
of the order of 1.525(3) A. In the precursor C5H10Te2,
On comparing the supramolecular associations pre-
sent in C8H8Te(OCOC6H5)2 (7), C5H10Te(OCOC6H5)2
(2) [present work] and earlier reported C4H8Te(O-
COC6H5)2 [12] vis-a-vis in their precursors C8H8TeI2,
C5H10TeI2, C4H8TeI2, [3], it is observed that in 7
tetrameric (stair like) supramolecular associations, di-
trimeric aggregates are present; the units are linked
˚
through TeÁ Á ÁI secondary bonds (4.065, 3.870 A) and
˚
IÁ Á ÁI (3.722 A) secondary bonds. The CH2Ã
/
Te bond
C bond lengths in C5H10Te cycle are of
lengths and CÃ
/
˚
the order of 2.131(1) and 1.43(4) A, respectively. In
C4H8Te(OCOC6H5)2, zig-zag polymeric chain based
supramolecular associations are directed through
rected through TeÁ Á ÁO secondary bonds, are present
˚
(Fig. 4). TeÁ Á ÁO bond length is 3.376 A. The H2C(8)Ã
/
Te,
˚
Te bond lengths are 2.106(2) and 2.111(2) A
H2C(1)Ã
/
TeÁ Á ÁO secondary bonds. The TeÁ Á ÁO secondary bond
˚
distance is 3.083 A. The CH2Ã
A and CÃ
/
Te bond lengths 2.119(4)
˚
˚
C bond lengths are of the order of 1.519 A
/
[12]. In the precursor C4H8TeI2, the zig-zag two
dimensional ribbons, interlinked through TeÁ Á ÁI second-
ary bonds, arc present. The TeÁ Á ÁI bond length is 3.808
˚
˚
A. The CH2Ã
/
Te bond lengths are 2.157(7) A and CÃ
/C
˚
bond lengths are of the order of 1.51(2) A [3].
These results demonstrate that the change of iodide
with benzoate group leads to:
a) Tellurium is hexa- and hepta-coordinated in the
precursors whereas C8H8Te(OCOC6H5)2 (7) con-
Fig. 4. Molecules of 7 connected through TeÁ Á ÁO secondary bonds
tains
hexacoordinated
tellurium,
C5H10Te-
(broken).

42
P.C. Srivastava et al. / Journal of Organometallic Chemistry 658 (2002) 34ꢁ42
/
[7] J.D. McCullough, C. Knobler, R.F. Ziolo, Inorg. Chem. 24
(1985) 1814.
(OCOC6H5)2 (2) and C4H8Te(OCOC6H5)2 [12]
contain heptacoordinated tellurium.
[8] A. Rubaie, W.R. McWhinnic, P. Granger, S. Chapelle, J.
Organomet. Chem. 234 (1982) 287.
b) There is no change in the conformation of tellurium
heterocycles (C8H8Te, C5H10Te and C4H8Te).
c) The polymeric supramolecular association of
C8H8TeI2 is changed into tetrameric (stair like)
supramolecular association in C8H8Te(OCOC6H5)2
(7).
[9] J.O. Bogason, D. Dakternieks, S. Husebye, K. Maartmann-Moe,
H. Zhu, Phosphorus Sulfur Silicon 71 (1992) 13.
[10] P.C. Srivastava, H.G. Schmidt, H.W. Roesky, Z. Naturforsch.
Teil. B 50 (1995) 695.
[11] P.C. Srivastava, A. Sinha, S. Bajpai, H.G. Schmidt, M. Nolte-
meyer, J. Organomet. Chem. 575 (1999) 261.
d) The trimeric supramolecular aggregates in
C5H10TeI2 are changed into polymeric (zig-zag
chain) supramolecular associations in C5H10Te(O-
COC6H5)2 (2).
e) The zig-zag ribbon based supramolecular associa-
tion in C4H8TeI2 is changed into polymeric zig-zag
chain based supramolecular association in
C4H8Te(OCOC6H5)2 [12].
[12] P.C. Srivastava, S. Bajpai, R.J. Butcher, J. Organomet. Chem. 586
(1999) 119.
[13] H.W. Roesky, R.J. Butcher, S. Bajpai, P.C. Srivastava, Phospho-
rus Sulfur Silicon 161 (2000) 135.
[14] (a) J.-M. Lehn, Angew. Chem. Int. Ed. Engl. 27 (1988) 89;
(b) F. Vogtle, Supramolecular Chemistry, Wiley, Chichester,
¨
1991;
(c) J.-M. Lehn, Supramolecular Chemistry, VCH, Weinheim,
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(d) G.R. Desiraju, Angew. Chem. Int. Ed. Engl. 34 (1995) 2311;
(e) J.C. Calabrese, L.-T. Cheng, J.C. Green, S.R. Marder, W.
Tam, J. Am. Chem. Soc. 113 (1991) 7227;
4. Supplementary material
(f) I. Haiduc, F.T. Edelmann, Supramolecular Organometallic
Chemistry, Wiley, VCH, Weinheim, New York, 1999;
(g) I. Haiduc, J.Z. Schpector, Phosphorus Sulfur Silicon 171
(2001) 171;
Crystallographic data for the structural analysis
(excluding structure factors) has been deposited with
the Cambridge Crystallographic Data Center, CCDC
nos. 138546 and 170225 for compounds 2 and 7. Copies
of this information may be obtained free of charge from
The Director, CCDC, 12 Union Road, Cambridge CB2
(h) D. Braga, F. Grepioni, G.R. Desiraju, Chem. Rev. 98 (1998)
1375.
[15] S. Patai, Z. Rappoport, The Chemistry of Organic Selenium and
Tellurium Compounds, vol. 1 (Chapter 4), Wiley, Chichester,
1986, p. 157.
1EZ, UK (Fax: ꢄ44-1223-336033; email: deposit@
/
[16] G.M. Sheldrick, Crystallographic Computing 3, Oxford Univer-
sity Press, London, 1986, p. 175.
[17] G.M. Sheldrick, SHELXL-93, Program for Crystal structure
ccdc.cam.ac.uk or www:http://www.ccdc.cam.ac.uk).
Refinement, University of Gottingen, 1993.
¨
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[19] Y. Maeda, R. Okawara, J. Organomet. Chem. 10 (1967) 247.
[20] K.K. Chatterjee, B.E. Douglas, Spectrochim. Acta 21 (1965)
1625.
Acknowledgements
P.C.S. is thankful to the Department of Science and
technology, Government of India and University Grants
Commission, New Delhi for the financial support. The
authors are grateful to the Regional Sophisticated
Instrumentation Centres, CDRI Lucknow and IIT
Bombay for elemental and spectral analysis. R.J.B.
wishes to acknowledge funding from the DoD-URI
program to upgrade the diffractometer.
[21] P.W. Atkins, Physical Chemistry, Oxford University Press,
Oxford OX 2 6DP, 1978, p. 589.
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