N-{2-(4-Methoxyphenyltelluro)ethyl}morpholine (L1) and bis{2-(N-morpholino)ethyl}telluride (L2): Synthesis and complexation with palladium(II) and mercury(II). Crystal structures of trans-[PdCl2(L1)2] and trans-[PdCl2(L2)2]

Article abstract of DOI:10.1016/S0022-328X(00)00382-X

The reactions of 4-(2-chloroethyl)morpholine hydrochloride with ArTe^- and Te^2-, generated in situ (under N₂ atmosphere) have resulted in N-{2-(4-methoxyphenyltelluro)ethyl}morpholine (L¹) and bis{2-(N-morpholino)ethyl}telluride (L²), respectively, which are first tellurated derivatives of morpholine. ¹H- and ¹³C{¹H}-NMR spectra of L¹ are as expected but HETCOR experiments are used to assign the overlapping signals of CH₂Te and CH₂N in ¹H-NMR spectrum of L². The complexes of stoichiometries [PdCl₂(L¹/L²)₂] (1/3) and [HgBr₂(L¹/L²)]₂ (2/4) are synthesized. The NMR (¹H and ¹³C{¹H}) spectra of all the four complexes have CH₂Te and ArC-Te signals deshielded with respect to those of free L¹/L², indicating that the two ligands coordinate through Te only. The trans Pd-complexes 1 and 3 are characterized structurally and their Pd-Te bond lengths (average) are 2.596 and 2.600 ?, respectively. The Pd-Cl bonds in 1 are marginally shorter (average 2.312 ?) in comparison to those of 3 (average 2.325 ?). The geometry of palladium is square planar. The Te-C(aryl) is shorter than Te-C(alkyl). The dimeric mercury complexes 2 and 4 appear to be formed through the formation two bromo bridges between Hg atoms.

Full text of DOI:10.1016/S0022-328X(00)00382-X

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 612 (2000) 46–52
N-{2-(4-Methoxyphenyltelluro)ethyl}morpholine (L1) and
bis{2-(N-morpholino)ethyl}telluride (L2): synthesis and
complexation with palladium(II) and mercury(II). Crystal
structures of trans-[PdCl2(L1)2] and trans-[PdCl2(L2)2]
Ajai K. Singh a,*, J. Sooriyakumar a, S. Husebye b, Karl W. Tornroos b
a Department of Chemistry, Indian Institute of Technology, New Delhi 110 016, India
b Department of Chemistry, Uni6ersity of Bergen, 41, Allegaten, N–5007 Bergen, Norway
Received 19 April 2000; received in revised form 10 June 2000
Abstract
The reactions of 4-(2-chloroethyl)morpholine hydrochloride with ArTe− and Te2−, generated in situ (under N2 atmosphere)
have resulted in N-{2-(4-methoxyphenyltelluro)ethyl}morpholine (L1) and bis{2-(N-morpholino)ethyl}telluride (L2), respectively,
which are first tellurated derivatives of morpholine. 1H- and 13C{1H}-NMR spectra of L1 are as expected but HETCOR
experiments are used to assign the overlapping signals of CH2Te and CH2N in 1H-NMR spectrum of L2. The complexes of
stoichiometries [PdCl2(L1/L2)2] (1/3) and [HgBr2(L1/L2)]2 (2/4) are synthesized. The NMR (1H and 13C{1H}) spectra of all the four
complexes have CH2Te and ArCꢀTe signals deshielded with respect to those of free L1/L2, indicating that the two ligands
coordinate through Te only. The trans Pd-complexes 1 and 3 are characterized structurally and their PdꢀTe bond lengths (average)
,
,
are 2.596 and 2.600 A, respectively. The Pd-Cl bonds in 1 are marginally shorter (average 2.312 A) in comparison to those of 3
,
(average 2.325 A). The geometry of palladium is square planar. The TeꢀC(aryl) is shorter than TeꢀC(alkyl). The dimeric mercury
complexes 2 and 4 appear to be formed through the formation two bromo bridges between Hg atoms. © 2000 Elsevier Science
B.V. All rights reserved.
Keywords: N-{2-(4-Methoxyphenyltelluro)ethyl}morpholine; Bis{2-(N-morpholino)-ethyl}telluride; Palladium(II); Mercury(II); Complexes;
Crystal structures
extensively studied and very important in the context of
understanding the ligation of Te vis-a`-vis other donor
atoms. However, the ligand chemistry of some (Tex, Ny)
type of donors is explored. The nitrogen in most of these
ligands is that of an alkyl/aryl amine [13–15] or pyridine
[11b]. To compare the coordination behavior of different
types of nitrogen donors in conjunction with tellurium,
it was thought worthwhile to design tellurium ligands of
(Tex, Ny) type in which nitrogen donor site belongs
to a saturated cyclic amine, morpholine. The ligands
1. Introduction
The ligand chemistry of tellurium has received much
more attention in the late 1980s and 1990s than it had
previously [1]. Tellurium ligands of current interest are
monodentate telluroethers [1b,c], alkyl- and aryl-telluro-
lates [2,3], telluride [4], polytellurides [5] and halotel-
lurium ligands [6]. Tellurium-containing species have also
been used as building blocks for clusters [7,8]. Recently
ditelluroethers [9] have got some attention and complex-
ation of a tritelluroether [11] and cyclic telluroethers [12]
has been also been reported. The telluroethers function-
alized with the groups having other donor atoms (com-
monly known as hybrid telluroethers [10]) are not
* Corresponding author. Tel.: +91-11-6591379; fax: +91-11-
6862037.
E-mail address: aksingh@chemistry.iitd.ernet.in (A.K. Singh).
0022-328X/00/$ - see front matter © 2000 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(00)00382-X

A.K. Singh et al. / Journal of Organometallic Chemistry 612 (2000) 46–52
47
L1 and L2 are therefore synthesized and their complexa-
tion with Hg(II) and Pd(II) is investigated. It has been
noticed that the morpholine nitrogen has weaker ligat-
ing properties in comparison to other nitrogen donor
sites mentioned above. The complexes of L2 are synthe-
sized by the reactions of its freshly prepared sample
with metal-containing species, as it can not be stored
for more than 2 days. The trans-[PdCl2(L1)2] and trans-
[PdCl2(L2)2] are characterized structurally. The results
of these investigations are reported in the present pa-
per. L1 and L2 are the first examples of tellurated
morpholine derivatives.
TMS): 7.6 (C1), 52.3 (C3), 55.0 (OCH3), 59.2 (C2), 66.7
(C4), 101.2 (ArC-Te), 114.7 (ArC m to Te), 140.5 (ArC
o to Te), 160.9 (ArC p to Te). FABMS (m/z): 351
(M+), 320 (M+−OCH3), 265 (M+−OCH3OC4H8N)
237 (M+−OCH3OC4H8NCH2CH2) 114 (OC4H8NCH2-
CH2), 100 (OC4H8NCH2), 86 (OC4H8N).
2.2. Synthesis of L2
Tellurium powder (0.65 g, 5 mmol) was added to
sodium borohydride (0.38 g, 10 mmol) dissolved in an
mixture made of 10 cm3 of 2.0 M NaOH and 50 cm3 of
water. The resulting slurry was refluxed for 2 h under
nitrogen atmosphere. When it became colorless a solu-
tion of 4-(2-chloroethyl)morpholine hydrochloride (1.86
g, 10 mmol) made in 5 cm3 of ethanol was added
dropwise, keeping the reaction under reflux and con-
stant stirring under nitrogen atmosphere. The mixture
was cooled to 25°C and poured into 100 cm3 of ice
cooled water. The ligand L2 was extracted into diethyl
ether from the aqueous phase. The ether extract was
washed with distilled water and dried over anhydrous
Na2SO4. On evaporating off ether under reduced pres-
sure on a rotary evaporator, L2 was obtained as a
yellow viscous liquid, which is unstable as it shows the
sign of decay within a few days. Yield: 50%; \m, 17.3
2. Experimental
The C and H analyses were carried out with a
Perkin–Elmer elemental analyzer 240 C. Tellurium was
estimated volumetrically [16]. The 1H- and 13C{1H}-
NMR spectra were recorded on a Bruker Spectrospin
DPX-300 NMR spectrometer at 300.13 and 75.47
MHz, respectively. The conductance measurements
were made in acetonitrile, using an ORION conductiv-
ity meter model 162. The melting points determined in
open capillary are reported as such. Bis(4-
methoxyphenyl)ditelluride was prepared by the pub-
lished method [17]. 4-(2-Chloroethyl)morpholine
hydrochloride was obtained from Aldrich (USA) and
used as received.
ohm−1 cm2 mol−1 1H-NMR (CDCl3, 25°C): l (vs
.
TMS): 2.47 (t, 8H, H3), 2.69–2.76 (m, 8H, H1+H2),
3.68 (t, 8H, H4). 13C{1H}-NMR (CDCl3, 25°C): l (vs
TMS): 0.4 (C1), 52.8 (C3), 59.9 (C2), 66.5 (C4).
2.1. Synthesis of L1
Bis(4-methoxyphenyl)ditelluride (0.46 g, 1 mmol) was
dissolved in 30 cm3 of ethanol and the solution set to
reflux under nitrogen atmosphere. The 5% solution of
sodium borohydride made in NaOH (5%) was added to
it dropwise, until it became colorless due to the forma-
tion of ArTe−Na+. 4-(2-Chloroethyl)morpholine hy-
drochloride (0.37 g, 2 mmol) dissolved in 5 cm3 of
ethanol was added with constant stirring. The reaction
mixture was refluxed further for 2–3 h, cooled to 25°C
and poured into ice cooled water (200 cm3). The result-
ing white-colored compound was filtered, dissolved in
diethyl ether and the solution dried over sodium sulfate.
The diethyl ether was evaporated off from the solution
under reduced pressure. The resulting viscous liquid
was dissolved in hexane and the solution was kept at
0–5°C for 24 h. The L1 was separated as white crys-
talline solid and dried in vacuo. Yield, 60%; m.p.
49–50°C. \m, 8.4 ohm−1 cm2 mol−1. Anal. Calc. for
C13H19O2NTe: C, 44.69; H, 5.44; N, 4.01; Te, 36.67.
2.3. Synthesis of [PdCl2(L1)2] (1)
The solution of L1 (0.14 g, 0.4 mmol) was made in 10
cm3 of acetone. The Na2[PdCl4] (0.08 g, 0.2 mmol)
dissolved in 10 cm3 of water was added to it. The
resulting mixture was stirred for 2 h at room tempera-
ture and poured into 100 cm3 of water. The complex 1
was extracted into chloroform (100 cm3). The extract
was dried over anhydrous sodium sulfate, concentrated
to ꢀ10 cm3 with a rotary evaporator, layered with
hexane and kept at 0–5°C for overnight. The reddish
brown crystals were separated and dried in vacuo. The
single crystals of 1 were grown from its chloroform
solution layered with hexane. Yield 70%; m.p. 134°C;
\
m
30.5 ohm−1 cm2 mol−1
.
Anal. Calc. for
C26H38O4N2Te2PdCl2: C, 35.61; H, 4.34; N, 3.31; Te,
29.22. Found: C, 35.94; H, 4.66; N, 3.43; Te, 29.68.
1H-NMR (CDCl3, 25°C): l (vs TMS): 2.56 (t, 8H, H3),
2.84 (t, 4H, H2) 3.42 (t, 4H, H1), 3.66 (t, 8H, H4), 3.80
(s, 3H, OCH3), 6.80–6.83 (d, 2H, ArH m to Te),
7.75–7.78 (d, 2H, ArH o to Te). 13C{1H}-NMR
(CDCl3, 25°C): l (vs TMS): 22.2 (C1), 53.3 (C3), 54.9
(OCH3), 55.2 (C2), 66.5 (C4), 106.2 (ArC-Te), 114.7
(ArC m to Te), 140 (ArC o to Te),160 (ArC p to Te).
1
Found: C, 44.92; H, 5.74; N, 4.66; Te, 36.44. H-NMR
(CDCl3, 25°C): l (vs TMS): 2.47 (t, 4H, H3), 2.78 (t,
2H, H1) 3.04 (t, 2H, H2), 3.68 (t, 4H, H4), 3.80 ( s, 3H,
OCH3), 6.73–6.76 (d, 2H, ArH m to Te), 7.65–7.68 (d,
2H, ArH o to Te); 13C{1H}-NMR (CDCl3, 25°C): l (vs

48
A.K. Singh et al. / Journal of Organometallic Chemistry 612 (2000) 46–52
2.4. Synthesis of [HgBr2(L1)]2 (2)
mixture was stirred at room temperature until the lig-
and L2 reacted completely (as monitored by TLC). The
solvent from the reaction mixture was removed on a
rotary evaporator. The resulting residue was dissolved
in 20 cm3 of chloroform and filtered through celite. The
filtrate was concentrated to 10 cm3 and mixed with 20
cm3 of hexane. The resulting white-colored compound 4
was filtered. It was recrystallized from chloroform:
hexane (1:1) mixture and dried in vacuo. Yield, 50%; m.
p. 128°C(d). \m, 11.9 ohm−1 cm2 mol−1. Anal. Calc.
for C12H24O2N2TeHgBr2: C, 20.11; H, 3.35; N, 3.91;
Te, 17.50. Found: C, 19.91; H, 3.62; N, 3.69; Te, 17.21.
1H-NMR (CDCl3, 25°C): l (vs TMS): 2.70 (bs, 8H,
H3), 2.76 (t, 4H, H2), 3.16 (bs, 4H, H1), 3.87 (t, 8H, H4).
13C{1H}-NMR (CDCl3, 25°C): l (vs TMS): 15.4 (C1),
53.0 (C3), 55.2 (C2), 65.8 (C4).
The HgBr2 (0.2 g, 0.55 mmol) dissolved in acetone
(15 cm3) was added to a solution of L1 (0.19 g, 0.55
mmol) made in chloroform (20 cm3). The resulting
reaction mixture was stirred at room temperature until
all L1 complexed (as monitored by TLC). Its solvent
was evaporated off under reduced pressure on a rotary
evaporator. The resulting residue was dissolved in 20
cm3 of chloroform and filtered through celite. The
filtrate was concentrated to 10 cm3 with a rotary evapo-
rator and mixed with 20 cm3 of hexane. The resulting
white colored complex 2 was filtered, washed with
hexane and dried in vacuo. The 2 was further crystal-
lized from chloroform: hexane (1:1) mixture. Yield,
60%; m.p. 120°C(d); \m, 10.4 ohm−1 cm2 mol−1. Anal.
Calc. for C13H19O2NTeHgBr2: C, 22.00; H, 2.67; N,
1.97; Te, 18.05. Found: C, 22.51; H, 2.59; N, 2.11; Te,
2.7. X-ray diffraction analysis
1
17.78. H-NMR (CDCl3, 25°C): l (vs TMS): 2.65 (t,
Bruker-AXS SMART2K CCD diffractometer was
used to collect X-ray diffraction data. The reflections
were collected for both the complexes 1 and 3 in excess
of a full sphere. The data were reduced and the struc-
2H, H2), 2.78 (bs 4H, H3), 3.13 (t, 2H, H1), 4.01 (t, 4H,
H4), 3.83 (s, 3H, OCH3), 6.91–6.94 (d, 2H, ArH m to
Te), 7.81–7.84 (d, 2H, ArH o to Te). 13C{1H}-NMR
(CDCl3, 25°C): l (vs TMS): 17.6 (C1), 54.08 (C3), 55.4
(OCH3), 56.9 (C2), 66.1 (C4), 105.0 (ArC–Te), 116.6
(ArC m to Te), 139.8 (ArC o to Te), 160.2 (ArC p to
Te).
tures solved using the programs SMART, SAINT and
SHELXTL [18]. All non-hydrogen atoms were refined
anisotropically and the hydrogen atoms were given an
isotropic displacement factor equal to 1.5 times the
equivalent isotropic displacement factor of the parent
2.5. Synthesis of [PdCl2(L2)2] (3)
carbon atom. The final difference Fourier map for 3
−3
The freshly prepared L2 (0.23 g, 0.6 mmol) was
dissolved in 10 cm3 of acetone. The solution of
Na2[PdCl4] (0.1 g, 0.3 mmol) made in 10 cm3 of water
was added to it. The resulting mixture was stirred for 1
h at room temperature and poured into 100 cm3 of
water. The resulting complex 3 was extracted into chlo-
roform (100 cm3). The extract was dried over anhy-
drous sodium sulfate, concentrated to ꢀ10 cm3 with a
rotary evaporator and mixed with hexane (15 cm3). The
resulting reddish brown compound was separated,
filtered, washed with diethylether and dried in vacuo.
The single crystals of 3 were grown by keeping over
night (at 0–5°C) its solution made in dichloromethane
and layered with diethylether. Yield, 80%; m.p. 142°C.
,
shows a large maximum of ca. 3 e A
close to the Pd
position (too close for a bond). This is about twice as
much as usual for heavy metal complexes and may in
part be due to the relatively poor crystal quality of 3.
3. Results and discussion
The ligands L1 and L2 are synthesized by the reac-
tions given in Eqs. (1) and (2). The L2 is an unstable
viscous liquid and shows the visible signs of decay
within a few days
\
m,
37.4 ohm−1 cm2 mol−1
.
Anal. Calc. for
C24H48O4N4Te2PdCl2: C, 32.36; H, 5.40; N, 6.30; Te,
28.76. Found: C, 32.09; H, 6. 01; N, 6.28; Te, 28.50.
1H-NMR (CDCl3, 25°C): l (vs TMS): 2.56 (bs, 8H,
H3), 2.80–2.84 (t, 4H, H3), 3.03 (bs, 4H, H1), 3.70–3.76
(t, 4H, H4). 13C{1H}-NMR (CDCl3, 25°C): l (vs TMS):
15.0 (C1), 53.2 (C3), 56.2 (C2), 66.8 (C4).
(1)
(2)
of synthesis. Consequently its satisfactory elemental
analyses could not be obtained. The reaction of freshly
2.6. Synthesis of [HgBr2(L2)]2 (4)
prepared L2 with Pd(II) and Hg(II) in
a 1:2
To a solution of HgBr2 (0.2 g, 0.55 mmol) made in
acetone (15 cm3) was added freshly prepared L2 (0.19 g,
0.55 mmol) dissolved in chloroform (20 cm3). The
(metal:ligand) ratio stabilizes the ligand. The reactions
of L1 and L2 with palladium(II) in a 1:1 molar ratio
have resulted in insoluble materials which defied all

A.K. Singh et al. / Journal of Organometallic Chemistry 612 (2000) 46–52
49
Fig. 1. HETCOR spectrum of L2.
attempts of their characterization, probably due to their
polymeric nature. Both the ligands and all four com-
plexes (1–4) are soluble in common organic solvents
crystal structure of 3 (Fig. 3) corroborates this conclu-
sion. The most plausible geometry of mercury in com-
plexes 2 and 4 appears to be tetrahedral. The two
bromide ions bridge the Hg atoms. However, all at-
tempts to grow single crystals of 2 and 4 have failed.
1
and non-ionic in nature. H- and 13C{1H}-NMR spec-
tra of L1 are characteristic. In its mass spectrum the
molecular ion peak appears at m/z 351. The CH2N and
1
CH2Te signals in H-NMR spectrum of L2 merge to-
3.1. Crystal structures of 1 and 3
gether, as supported by its HETCOR spectrum (Fig. 1).
1
In H-NMR spectra of complexes 1 and 2 the CH2Te
The molecular structures of 1 and 3 are shown in
Figs. 2 and 3 and crystal structures in Table 1. Their
selected bond lengths and angles are given in Table 2.
There are many similarities in the two structures. Both
signal appears down field (ꢀ0.6 and 0.4 ppm , respec-
tively) in comparison to that of free L1. Similarly in
13C{1H}-NMR spectra of complexes 1 and 2, C1 and
ArC-Te signals depict a down field shift (ꢀ10–15 ppm
and 3.5–4.5 ppm, respectively, with respect to that of
L1). The CH2N signals exhibit insignificant shift in the
spectra of both the complexes. These observations sug-
gest that L1 in both the complexes 1 and 2, is coordi-
nated through Te only. The structural characterization
1
of 1 (Fig. 2) supports such an inference. In H-NMR
spectra of complexes 3 and 4 CH2Te and CH2N signals
appear separately but only first exhibit deshielding
(ꢀ0.45 to 0.70 ppm) with respect to that of free L2.
Similarly in 13C{1H}-NMR spectra of the two com-
plexes, C1 signal undergoes a down field shift of ꢀ15
ppm. On the basis of these observations it may be
inferred that L2 also ligates through Te only. The
Fig. 2. Molecular structure of trans-[PtCl2(L1)2] (1).

50
A.K. Singh et al. / Journal of Organometallic Chemistry 612 (2000) 46–52
,
to the standard statistical value (2.326(43) A) found in
four-coordinate Pd compounds with terminal Cl− lig-
ands [25a].
,
The TeꢀC bond lengths vary from 2.152 to 2.160 A
,
(ave. 2.154 A) for the alkyl groups in the two ligands.
In 1, average value of TeꢀC(phenyl) bond lengths is
,
,
2.130 A. The standard statistical values of 2.158(30) A
3
,
for a TeꢀC(sp ) bond and 2.116(20) A for a TeꢀC(aryl)
bond [25b], are very close to those observed for
TeꢀC(alkyl/aryl) bonds of 1 and 3. The CꢀC, CꢀN and
CꢀO bond lengths have normal values. The morpholine
rings in 1 and 3 have the usual chair conformation.
Table 1
Fig. 3. Molecular structure of trans-[PtCl2(L2)2] (3).
Crystal and structure refinement data
1
3
Empirical formula
Formula weight
Temperature (K)
C26H38N2O4Te2PdCl2 C24H48N4O4Te2PdCl2
of them are trans square planar co-ordination com-
pounds of the type [PdCl2(RTeR%)2] (R=R% for 3).
There is no exact symmetry in either of them, however
in the latter, co-ordination plane is a pseudo mirror
plane and there is a pseudo center of symmetry at the
position of palladium. The tellurium atoms in both the
complexes have distorted pyramidal geometry, which
may also be described as distorted tetrahedral, if a lone
pair presumably occupies one corner. The lone pairs on
two Te atoms of 1 or 3 have a trans orientation with
respect to the linear TeꢀPdꢀTe system. The organic
groups present on the two tellurium atoms in each
complex are in an orientation of least steric interaction.
In 1 the two 4-MeOC6H5 groups present on different
Te atoms are also trans to TeꢀPdꢀTe system.
875.08
889.16
123(2)
123(2)
,
Wavelength (A)
0.71073
Monoclinic
P21/c
0.71073
Monoclinic
P21/c
Crystal system
Space group
Unit cell dimensions
,
a (A)
12.9165(5)
10.7030(3)
22.5642(8)
90
12.5813(12)
12.1953(12)
22.3070(2)
90
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
99.32(5)
90
106.09(9)
90
3
,
V (A )
Z
3078.1(8)
4
3288.4(6)
4
Dcalc (g m−3
)
1.888
1.796
Absorption coefficient 2.668
(mm−1
F(000)
2.500
)
1696
1744
The average values of Pd(II)ꢀTe bond lengths in 1
Crystal size (mm3)
q range for data
collection (°)
Absorption
corrections
0.40×0.19×0.09
1.60–33.19
0.48×0.38×0.18
1.68–31.00
,
and 3 are very similar (2.596 and 2.600 A, respectively).
The sum of covalent radii of square planar Pd(II) (1.31
Numerical
integration
Full matrix least
squares on F2
55 352
Numerical
integration
Full matrix least
squares on F2
55 056
,
,
,
A) and pyramidal Te(II) (1.32 A) [19] is 2.63 A and
comparable with the present averages. In square planar
Pd complexes having two trans PdꢀTe bonds viz.,
trans-dichlorobis(tellurapentane-Te)palladium(II) [20],
trans - bis(thiocyanato)bis[di(3 - trimethylsilylpropyl)tel-
luride]palladium(II) [21], bis(tetraphenylphosphonium)
bis(tetratellurido) palladate(II) dimethylformamide sol-
vate [22] and its unsolvated version [23], the PdVTe
Refinement method
Reflections collected
Independent
reflections
11 291
10 487
(Rint=0.0425)
11 291/0/337
(Rint=0.0307)
0487/0/334
Data/restraints/
parameters
,
bond lengths are in the range from 2.584 to 2.606 A
Goodness of fit on F2 1.065
Final R indices
1.479
,
(average 2.593A). These values are consistent with the
[I\2|(I)]
R1
wR2
R indices all data
R1
wR2
PdꢀTe bond lengths of 1 and 3. The trans influence of
other ligands relative to that of Te donor site affects the
PdꢀTe bond lengths, when they are trans to Te. A
0.0237
0.0478
0.0577
0.1279
0.0344
0.0496
0.658
0.0609
0.1286
3.288
,
TeꢀPd bond trans to a PdꢀCl bond is close to 2.52 A
[9a,10b], and on the other hand trans to PdꢀP it is
Largest differential
,
closer to 2.63 A [9a,24]. The PdꢀCl bonds in 1 are
peak and hole
−3
,
marginally shorter (average 2.312 A) in comparison to
,
(e A
)
−0.590
−3.453
,
those of 3 (average 2.325 A). They are also comparable

A.K. Singh et al. / Journal of Organometallic Chemistry 612 (2000) 46–52
51
Table 2
Selected bond lengths (A) and bond angles (°) of 1 and 3
for complex 3. Copies of this information may be
obtained free of charge from: The Director, CCDC, 12
Union Road, Cambridge CB2 1EZ, UK (Fax: +44-
1223-336-033; e-mail: deposit@ccdc.cam.ac.uk or www:
http://www.ccdc.cam.ac.uk).
,
Bond length
Bond angle
Complex 1
PdꢀTe(1)
PdꢀTe(2)
PdꢀCl(1)
PdꢀCl(2)
Te(1)ꢀC(1A)
Te(1)ꢀC(8A)
Te(2)ꢀC(1B)
Te(2)ꢀC(8B)
2.5865(2)
2.6052(2)
2.3110(4)
3.3120(4)
2.129(2)
2.156(2)
2.130(2)
2.152(2)
Te(1)ꢀPdꢀTe(2)
Te(1)ꢀPdꢀCl(1)
Te(1)ꢀPdꢀCl(2)
Te(2)ꢀPdꢀCl(1)
Te(2)ꢀPdꢀCl(2)
Cl(1)ꢀPdꢀCl(2)
PdꢀTe(1)ꢀC(1A)
PdꢀTe(1)ꢀC(8A)
C(1A)ꢀTe(1)ꢀC(8A)
PdꢀTe(2)ꢀC(1B)
PdꢀTe(2)ꢀC(8B)
C(1B)ꢀTe(1)ꢀC(8B)
177.282(6)
96.069(12)
84.853(12)
87.125(12)
97.974(12)
179.24(2)
99.68(5)
107.64(5)
94.40(7)
97.74(4)
Acknowledgements
A.K.S. and J.S. thank Department of Science and
Technology (India) for financial assistance.
105.00(5)
95.65(7)
References
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Complex 3
PdꢀTe(1)
PdꢀTe(2)
PdꢀCl(1)
PdꢀCl(2)
Te(1)ꢀC(6A)
Te(1)ꢀC(6B)
Te(2)ꢀC(6C)
Te(2)ꢀC(6D)
2.5975(6)
2.6021(6)
2.3215(2)
2.329(2)
2.160(6)
2.160(6)
2.152(6)
2.155(6)
Te(1)ꢀPdꢀTe(2)
Te(1)ꢀPdꢀCl(1)
Te(1)ꢀPdꢀCl(2)
Te(2)ꢀPdꢀCl(2)
Te(2)ꢀPdꢀCl(1)
PdꢀTe(1)ꢀC(6A)
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C(6A)ꢀTe(1)ꢀC(6B)
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101.5(2)
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4. Conclusion
The first tellurated derivatives of morpholine, N-{2-
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bis{2-(N-morpholino)ethyl}telluride (L2) are synthe-
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Crystallographic data for the structural analysis have
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