Multidentate hybrid organotellurium ligands 1-(4-methoxyphenyltelluro)-2- [3-(6-methyl-2-pyridyl)propoxy]ethane (L1) 2-methyl-6-{3-[2-({2-[3- (6-methyl-2-pyridyl)propoxy]ethyl}telluranyl)ethoxy]propyl}pyridine (L 2) and their metal c

Article abstract of DOI:10.1016/j.poly.2005.12.010

4-MeOC₆H₄Te^-Na⁺ and Te ^2- generated in situ by reduction of (4-MeOC₆H ₄Te)₂ and elemental Te, respectively, with sodium borohydride on reaction with 2-[3-(2-chloroetho

Full text of DOI:10.1016/j.poly.2005.12.010

Polyhedron 25 (2006) 1033–1042
www.elsevier.com/locate/poly
Multidentate hybrid organotellurium ligands
1-(4-methoxyphenyltelluro)-2-[3-(6-methyl-2-pyridyl)propoxy]ethane
(L1) 2-methyl-6-{3-[2-({2-[3-(6-methyl-2-pyridyl)propoxy]-
ethyl}telluranyl)ethoxy]propyl}pyridine (L2) and their metal
complexes: Formation of 20-membered metallomacrocycle by L1
a
a,
b
c
Sumit Bali , Ajai K. Singh *, John. E. Drake , Mark. E. Light
a
Department of Chemistry, Indian Institute of Technology, Hauz Khas, New Delhi 110016, India
Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ont., Canada N9B 3P4
b
c
Department of Chemistry, University of Southampton, Southampton SO17 1BJ, UK
Received 22 September 2005; accepted 19 December 2005
Available online 27 January 2006
Dedicated to Professor M.B. Hursthouse.
Abstract
4-MeOC6H4TeꢀNa+ and Te2ꢀ generated in situ by reduction of (4-MeOC6H4Te)2 and elemental Te, respectively, with sodium boro-
hydride on reaction with 2-[3-(2-chloroethoxy)propyl]-6-methylpyridine in N2 atmosphere results in 1-(4-methoxyphenyltelluro)-2-
[3-(6-methyl-2-pyridyl)propoxy]ethane (L1) 2-methyl-6-{3-[2-({2-[3-(6-methyl-2-pyridyl)propoxy]ethyl}telluranyl)ethoxy]propyl}pyridine
(L2) as viscous oils. Their proton and carbon-13 NMR spectra are characteristic. The L2 shows signs of decay within few days. The com-
plexes [PdCl2(L1)]2 (1), [PtCl2(L1)]2 (2), [HgBr2(L1)] (3), [PdCl2(L2)]2 (6), [PtCl2(L2)]2 (7) and [(PdCl2)3(L2)2] (8) have been synthesized and
found to give characteristic 1H and 13C NMR spectra. The 3 on crystallization from acetone:hexane (2:1) mixture gives MeOC6H4HgBr (4)
and [RTe+–HgBr2]Brꢀ (R = –CH2CH2OCH2CH2CH2-(2-(6-CH3–C5H3N))) (5). The crystals of 1, 2 and 4 are subjected to X-ray diffrac-
tion and their structures are solved. The 1 and 2 are 20-membered metallomacrocycles and do not dissociate in solution. The crystals of 1
and 2 have chloroform and benzene, respectively, in the lattice whereas 4 is a linear ArHgBr type species. The Pd/Pt in 1 and 2 has square
˚
planar geometry. The Pd–Te and Pd–N bond lengths in 1 are 2.530(1)/2.5313(9) and 2.097(4) and 2.101(4) A, respectively.
ꢀ 2006 Elsevier Ltd. All rights reserved.
Keywords: Hybrid organotellurium ligands; Metal complexes; Palladium; Platinum; Mercury; Metallomacrocycle; Synthesis; Crystal structure
1. Introduction
organotellurium ligands are compounds of RR0Te type,
where R or R0 has donor sites other than Te. The R and
R0 groups explored are alkyl, aryl and heterocyclic groups
derived from pyridine [7] pyrrolidine [8] and thiophene [9].
However, no example of metallomacrocycle formed by a
hybrid organotellurium ligand was reported until recently,
when we designed a 20-membered metallomacrocycle ring
using the hybrid organotellurium ligand 1-(4-methoxyphe-
nyltelluro)-2-[3-(6-methyl-2-pyridyl)propoxy]ethane (L1)
and platinum(II) for the first time and reported as a
communication [10a]. Now we present the full details of
The interest in tellurium ligands [1–6] has grown in the
last two decades, including hybrid organotellurium ligands
which have also received considerable attention in the last
decade [2] as their numerous examples are reported. Hybrid
*
Corresponding author. Tel.: +91 011 26591379; fax: +91 011
26862037.
E-mail addresses: aksingh@chemistry.iitd.ac.in, ajai57@hotmail.com
(A.K. Singh).
0277-5387/$ - see front matter ꢀ 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2005.12.010

1034
S. Bali et al. / Polyhedron 25 (2006) 1033–1042
synthesis and characterization of L1, related ligand L2 and
their metal complexes (with Pt(II), Pd(II) and Hg(II)). Like
platinum(II), a 20-membered metallomacrocycle is also
formed by palladium(II) with L1. Its crystal structure is
also solved and described in this paper. Moreover, macro-
cyclic ligands containing Te (Te/S, Te/O type) and their
metal complexes are also not unknown [10b]. Metal
complexes of nitrogen, oxygen, sulfur and/or phosphorus
ligands containing large size chelate ring (i.e., metallo-
macrocycles) are well known [11–17]. The complexes
[Cu2(l-dppy)3(MeCN)][BF4]2 (where dppy = 2-(diphenyl-
phosphino)pyridine) [11], trans-[1,8-bis(diphenylphosphino)
-3,6-dioxaoctane-P,P0]carbonyl(ethanol)rhodium(I)hexa
flurophosphate [12], trans-[1,5-bis(diphenylphosphino)-
3-oxapentane-P,P0]carbonylchlororhodium(I) dimer [12],
di-l-[glutaraldehydebis(dimethylhydrazone)]-bis[dichloro-
palladium(II)] [13], [{CoCl2Ph2P(O)CH2CH2P(O)Ph2}2]
[14] and dinuclear platinum(II) complex of the dithioether
ligand 1,5-bis(n-propylthio)pentane [15] are some examples
containing 8–16-membered chelate ring. Two known exam-
ples of metallomacrocycles containing telluroether ligands
are the polymeric silver(I) complex of MeTe(CH2)3TeMe
[16] and the mononuclear Hg(II) complex of 1,6-bis-2-
butyltellurophenyl-2,5-diazahexa-1,5-diene [17] with 24-
and 13-membered rings, respectively. Moreover, the hybrid
macrocyclic ligands (P/S, P/N, P/O) and their complexes
are also well document [17b].
F2 > 4r(F2)) and 536 variable parameters and converged
(largest parameter shift was 0.001 times its esd). All of
the non-hydrogen atoms were treated anisotropically.
Hydrogen atoms were included in idealized positions with
isotropic thermal parameters set at 1.2 times that of the
carbon atom to which they were attached. Table 1 lists
the experimental parameters used for single crystal struc-
ture analysis and crystal data. Selected bond lengths and
angles are given in Table 2. The slightly high residual elec-
tron density may ascribed to the shape of crystals (very
thin plates).
2.2. Synthesis of 1-(4-methoxyphenyltelluro)-
2-[3-(6-methyl-2-pyridyl)propoxy]ethane (L1)
Bis(4-methoxyphenyl)ditelluride (0.46 g, 1.0 mmol) was
dissolved in 30 cm3 of ethanol and the solution set to reflux
under nitrogen atmosphere. A solution of sodium borohy-
dride (0.07 g, 2.0 mmol) made in 5 cm3 NaOH (5%) was
added drop wise to the refluxing solution of the ditelluride
under nitrogen atmosphere until it became colourless due
to the formation of ArTeꢀ Na+. 2-[3-(2-Chloroethoxy)-
propyl]-6-methylpyridine (0.42 g, 2.0 mmol) dissolved in
10 cm3 of ethanol was added to this solution with constant
stirring. The reaction mixture was refluxed further for
2–3 h, cooled to room temperature and poured into ice cold
Table 1
2. Experimental
Crystal data and structure refinement for [PdCl2L1]2 Æ 1.5C6H6
Empirical formula
Formula weight
Temperature (K)
C45H55O4N2Cl4Pd2Te2
1297.71
120(2)
The C and H analyses were carried out with a Perkin–
Elmer elemental analyzer 240 C. Tellurium was estimated
1
by atomic absorption spectrometer. The H and 13C {1H}
˚
Wavelength (A)
0.71073
NMR spectra were recorded on a Bruker Spectrospin
DPX-300 NMR spectrometer at 300.13 and 75.47 MHz,
respectively. IR spectra in the range 4000–250 cmꢀ1 were
Crystal system
Space group
triclinic
ꢀ
P1
˚
a (A)
11.928(5)
12.793(5)
17.578(5)
˚
b (A)
´
recorded on a Nicolet Protege 460 FT-IR spectrometer as
˚
c (A)
KBr and CsI pellets. The conductance measurements were
made in acetonitrile (concentration ꢁ1 mM) using an
ORION conductivity meter model 162. The molecular
weights (concentration ꢁ5 mM) in chloroform were deter-
mined with a Knauer vapour pressure osmometer model
A0280. The melting points determined in open capillary are
reported as such. 2-[3-(2-Chloroethoxy)propyl]-6-methyl-
pyridine was prepared by chlorination of corresponding
alcohol with thionyl chloride [18].
a (ꢁ)
b (ꢁ)
c (ꢁ)
103.604(5)
97.685(5)
108.612(5)
2406(2)
3
˚
Volume (A )
Z
2
Dcalc (g/cm3)
1.791
2.200
1270
0.25 · 0.10 · 0.03
2.98–25.03
ꢀ14 6 h 6 14,
ꢀ15 6 k 6 15,
ꢀ20 6 l 6 20
42792
Absorption coefficient (mmꢀ1
F(000)
)
Crystal size (mm3)
h Range for data collection (ꢁ)
Index ranges
2.1. X-ray crystallography
Reflections collected
Independent reflections
Maximum and minimum
transmission
8483 [Rint = 0.0512]
0.9369 and 0.6092
The X-ray data for 1 was collected (at 120 K) on an
Bruker Nonius Kappa CCD area detector diffractometer,
with u and x scans chosen to give a complete asymmetric
unit. An absorption correction was applied [19]. The
structure was solved by direct methods [20] and was
refined using the WINGX version [21] of SHELX-97 [22].
The final cycle of full-matrix least-squares refinement
was based on 8483 observed reflections (6690 for
Refinement method
full-matrix least-squares on F2
8483/0/536
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [F2 > 4r(F2)]
R indices (all data)
1.051
R1 = 0.0390, wR2 = 0.0882
R1 = 0.0579, wR2 = 0.0965
3.754 and ꢀ1.098
ꢀ3
˚
Largest differential peak and hole (e A
)

S. Bali et al. / Polyhedron 25 (2006) 1033–1042
1035
L2 was extracted into diethyl ether (4 · 30 cm3) from the
aqueous phase. The ether extract was washed with dis-
tilled water (2 · 15 cm3) and dried over anhydrous sodium
sulphate. On evaporating off ether under reduced pressure
Table 2
Selected bond lengths (A) and angles (ꢁ) for [PdCl2(L )]2 Æ 1.5C6H6
1
˚
Te(1)–Pd(1)
Pd(1)–Cl(1)
Pd(1)–Cl(2)
Pd(1)–N(2)
Te(1)–C(1)
Te(1)–C(8)
O(2)–C(10)
O(2)–C(9)
2.530(1)
2.313(2)
2.295(2)
2.097(4)
2.118(5)
2.138(5)
1.423(6)
1.431(6)
Te(2)–Pd(2)
Pd(2)–Cl(3)
Pd(2)–Cl(4)
Pd(2)–N(1)
Te(2)–C(19)
Te(2)–C(26)
O(4)–C(27)
O(4)–C(28)
2.5313(9)
2.306(2)
2.288(2)
2.101(4)
2.114(6)
2.132(6)
1.492(8)
1.377(8)
on
a
rotary evaporator L2 (2-methyl-6-{3-[2-({2-[3-
(6-methyl-2-pyridyl)propoxy]ethyl}telluranyl)ethoxy]propyl}-
pyridine) was obtained as a reddish yellow viscous liquid
that was unstable as it showed the sign of decay within
few days. Yield: ꢁ75%; 1H NMR (CDCl3, 25 ꢁC) (d
versus TMS) 1.96–2.00 (m, 2H, H4), 2.51 (s, 3H, H11),
2.79–2.84 (m, 4H, H5 and H1), 3.45–3.51 (m, 2H, H3),
3.70–3.76 (m, 2H, H2), 6.94–6.96 (m, 2H, H8 and H9),
7.427.46 (m, 1H, H7) 13C {1H} NMR (CDCl3, 25 ꢁC)
(d versus TMS) 3.1 (C1), 23.9 (C11), 29.3 (C4), 34.2 (C5),
69.8 (C2), 76.5 (C3), 119.0 (C9), 119.8 (C7), 135.8 (C8),
157.0 (C6), 160.3 (C10).
Te(1)–Pd(1)–Cl(1)
Te(1)–Pd(1)–Cl(2)
Te(1)–Pd(1)–N(2)
N(2)–Pd(1)–Cl(1)
N(2)–Pd(1)–Cl(2)
Cl(1)–Pd(1)–Cl(2)
C(1)–Te(1)–Pd(1)
C(8)–Te(1)–Pd(1)
C(1)–Te(1)–C(8)
C(13)–N(1)–C(17)
C(13)–N(1)–Pd(2)
C(17)–N(1)–Pd(2)
86.12(5)
94.56(5)
176.9(1)
91.0(1)
Te(2)–Pd(2)–Cl(3)
Te(2)–Pd(2)–Cl(4)
Te(2)–Pd(2)–N(1)
N(1)–Pd(2)–Cl(3)
N(1)–Pd(2)–Cl(4)
Cl(3)–Pd(2)–Cl(4)
C(19)–Te(2)–Pd(2)
C(26)–Te(2)–Pd(2)
C(19)–Te(2)–C(26)
C(31)–N(2)–C(35)
C(31)–N(2)–Pd(1)
C(35)–N(2)–Pd(1)
86.44(4)
93.88(5)
176.6(1)
90.2(1)
88.3(1)
89.5(1)
178.65(6)
100.1(1)
104.9(2)
95.6(2)
120.8(5)
119.8(3)
119.4(4)
176.94(6)
101.1(2)
105.7(2)
95.6(2)
120.5(5)
119.6(4)
119.9(4)
2.4. Synthesis of [PdCl2(L1)]2 (1)
To a solution of L1 (0.20 g, 0.50 mmol) made in 10 cm3
of acetone was added Na2[PdCl4] (0.14 g, 0.50 mmol) dis-
solved in 10 cm3 of water. The resulting mixture was stir-
red for 2 h at room temperature and poured into 100 cm3
of water. The complex was extracted into chloroform
(4 · 25 cm3). The extract was dried over anhydrous
sodium sulphate, concentrated to ꢁ5 cm3 and mixed with
hexane (20 cm3). The resulting yellow solid was filtered,
washed with hexane and dried in vacuo. The single crys-
tals of the complex 1 were grown from benzene. The 1
crystallizes with 1.5 mol of benzene per mole. Yield:
78%; m.p. 125 ꢁC; KM (Xꢀ1 cm2 molꢀ1) 5.8. Anal. Calc.
for C36H46N2O4Te2Pd2Cl4: C, 36.60; H, 3.97; N, 2.31;
Te, 21.62. Found: C, 36.24; H, 3.89; N, 2.31; Te,
21.24%. Mol. wt.: 1144.6 (Calc. 1180.0). 1H NMR
(CDCl3, 25 ꢁC) (d versus TMS) 2.20–2.27 (m, 2H, H4),
3.30–3.31 (m, 4H, H11 and H3), 3.54–3.66 (m, 2H, H5
and H3), 3.77–3.78 (m, 4H, CH3O + H5), 3.78–3.81 (t,
2H, H2), 4.10–4.22 (m, 2H, H1), 6.89–6.94 (m, 2H, ArH
m to Te), 7.12–7.14 (m, 2H, H7 and H9), 7.36 (s, 1H,
CHCl3), 7.56–7.61 (m, 1H, H8), 7.99–8.06 (m, 2H, ArH
o to Te). 13C {1H} NMR (CDCl3, 25 ꢁC) (d versus
TMS) 21.8 (C1), 27.0 (C11), 29.4 (C4), 36.6 (C5), 55.2
(OCH3), 66.7 (C2), 70.3 (C3), 103.9 (Ar–C–Te), 115.5
(C9), 121.6 (Ar–C m to Te), 123.2 (C7), 138.4 (C8),
140.6 (Ar–C o to Te), 158.9 (C10), 161.1 (Ar–C p to
Te), 162.2 (C6).
water (100 cm3) in which 0.1 g of NaOH was dissolved. The
ligand was extracted into chloroform (4 · 50 cm3) from this
aqueous mixture. The extract was washed with water
(2 · 20 cm3) and dried over anhydrous sodium sulphate.
The solvent was evaporated off under reduced pressure
on a rotary evaporator, resulting in red oil, which was
extracted with hexane (30 cm3). On removing hexane from
the extract under reduced pressure on a rotary evaporator
ligand L1 was obtained as yellow viscous oil. Yield: ꢁ70%;
1H NMR (CDCl3, 25 ꢁC) (d versus TMS): 1.91–2.01 (m,
2H, H4), 2.52 (s, 3H, H11), 2.71–2.82 (t, 2H, H1), 2.95–
3.00 (t, 2H, H5), 3.43–3.47 (t, 2H, H3), 3.66–3.70 (t, 2H,
H2), 3.78 (s, 3H, OCH3), 6.73–6.76 (d, 2H, m to Te),
6.93–6.96 (d, 2H, H7 and H9), 7.43 7.48 (t, 1H, H8),
7.65–7.70 (d, 2H, o to Te). 13C {1H} NMR (CDCl3,
25 ꢁC) (d versus TMS) 8.1 (C1), 24.1 (C11), 28.9 (C4), 34.5
(C5) 54.7 (OCH3), 69.4 (C2), 71.8 (C3), 99.8 (ArTe–C),
114.8 (C9), 119.3 (ArC m to Te), 120.1 (C7), 136.4 (C8),
140.6 (ArC o to Te), 157.3 (C10), 160.5 (ArC p to Te),
161.1 (C6).
2.3. Synthesis of 2-methyl-6-{3-[2-({2-[3-(6-methyl-2-
pyridyl)propoxy]ethyl}telluranyl)ethoxy]propyl}pyridine
(L2)
Tellurium powder (0.65 g, 5.0 mmol) and sodium boro-
hydride (0.38 g, 10.0 mmol) solution (made in 10 cm3 of
2.0 M NaOH) were mixed in 50 cm3 of water. The mix-
ture was refluxed for 2 h under nitrogen atmosphere. To
the resulting colourless thin slurry of Na2Te kept under
2.5. Synthesis of [PtCl2(L1)]2 (2)
A solution of L1 (0.20 g, 0.50 mmol) made in 10 cm3 of
acetone was added to K2[PtCl4] (0.20 g, 0.50 mmol) dis-
solved in 10 cm3 of water. The resulting mixture was stir-
red for 3 h at room temperature and poured into 100 cm3
of water. The complex was extracted into chloroform
(4 · 25 cm3). The chloroform extract was dried over anhy-
drous sodium sulphate, concentrated to ꢁ5 cm3 on a
rotary evaporator, and mixed with hexane (20 cm3). The
reflux,
a
solution of 2-[3-(6-methyl-2-pyridyl)prop-
oxy]ethyl chloride (2.13 g, 10.0 mmol) made in 10 cm3 of
ethanol was added drop wise with constant stirring under
nitrogen atmosphere. The mixture was cooled to room
temperature and poured into 100 cm3 of water. The ligand

1036
S. Bali et al. / Polyhedron 25 (2006) 1033–1042
resulting yellow coloured compound was filtered, washed
with hexane. The single crystals suitable for diffraction
were grown from chloroform:hexane (1:1) mixture. The
2 crystallizes with 2 mol of chloroform per mole. Yield:
75%; m.p. 126 ꢁC; KM (Xꢀ1 cm2 molꢀ1) 10.5. Anal. Calc.
for C36H46N2O4Te2Pt2Cl4: C, 31.82; H, 3.32; N, 2.00;
Te, 18.80. Found: C, 32.91; H, 3.39; N, 2.06; Te,
18.92%. Mol. wt.: 1324.2 (Calc. 1357.3). 1H NMR
(CDCl3, 25 ꢁC) (d versus TMS) 2.22–2.30 (m, 2H, H4),
3.26–3.32 (m, 4H, H11 and H3), 3.55–3.67 (m, 2H, H5
and H3), 3.81–3.84 (m, 4H, CH3O + H5), 3.90–3.92 (t,
2H, H2), 4.12–4.14 (m, 1H, H1), 4.26–4.41 (m, 1H, H1),
6.87–6.94 (m, 2H, ArH m to Te), 7.10–7.13 (m, 2H, H7
and H9), 7.26–7.28 (s, 2H, CHCl3), 7.53–7.61 (m, 1H,
H8), 7.80–7.83 (d, 1H, ArH o to Te), 8.00–8.06 (m, 1H
ArH o to Te). 13C {1H} NMR (CDCl3, 25 ꢁC) (d versus
TMS) 18.9 (C1), 26.8 (C11), 28.0 (C4), 36.3 (C5), 55.3
(OCH3), 66.9 (C2), 70.6 (C3), 99.8 (Ar–Te–C), 115.2
(C9), 122.7 (Ar–C m to Te), 123.8 (C7), 138.4 (C8),
140.6 (Ar–C o to Te), 160.0 (C10), 160.6 (Ar–C p to
Te), 161.2 (C6).
mother liquor was mixed with chloroform (20 ml) and
refluxed for 3 h. The 5 was obtained as solid. It was filtered,
washed with chloroform (2 · 5 cm3) and dried in vacuo. 4:
Yield: 18%; m.p. 115 ꢁC (d); KM (Xꢀ1 cm2 molꢀ1) 6.4. Anal.
Calc. for C7H7OHgBr: C, 27.70; H, 1.80. Found: C, 27.71;
H, 1.82%. Mol. wt.: 379.3 (Calc. 387.6) 1H NMR (DMSO-
d6, 25 ꢁC) (d versus TMS) 3.71 (s, 3H, OCH3), 6.89–6.91 (d,
2H, ArH m to Hg), 7.34–7.37 (ArH o to Hg).
5: Yield: 18%; m.p. 144 ꢁC (d); KM (Xꢀ1 cm2 molꢀ1
)
23.5. Anal. Calc. for C11H16NOTeHgBr3: C, 17.70; H,
2.10; N, 1.87; Te, 17.10. Found: C, 17.30; H, 2.01; N,
1
1.82; Te, 17.03%. Mol. wt.: 732.1 (Calc. 745.9) H NMR
(DMSO-d6, 25 ꢁC) (d versus TMS) 1.82–1.84 (t, 2H, H4),
2.35 (s, 3H, H11), 2.66–2.81 (m, 2H, H5), 3.63–3.68 (m,
2H, H2), 3.75–3.81 (m, 2H, H1), 7.02–7.11 (m, 2H, H7
and H9), 7.68–7.78 (m, 1H, H9).
2.8. Synthesis of [PdCl2(L2)]2 (6)
The freshly prepared sample of L2 (0.24 g, 0.50 mmol)
dissolved in 10 cm3 of acetone was added to Na2[PdCl4]
(0.14 g, 0.50 mmol) dissolved in 10 cm3 of water. The
resulting mixture was stirred for 3 h at room temperature
and poured in 100 cm3 of water. The complex was
extracted with chloroform (4 · 25 cm3). The chloroform
extract was dried over anhydrous sodium sulfate and
concentrated to ꢁ10 cm3 on a rotary evaporator, and
mixed with hexane (20 cm3). The resulting orange col-
oured compound was filtered, washed with hexane and
recrystallized from chloroform:hexane (1:1) mixture.
Yield: 79%; m.p. 139 ꢁC (d); KM (Xꢀ1 cm2 molꢀ1) 7.6.
Anal. Calc. for C22H32N2O2TePdCl2: C, 39.68; H, 4.84;
N, 4.20; Te, 19.30. Found: C, 39.90; H, 4.53; N, 4.34;
Te, 19.12%. Mol. wt.: 658.1 (Calc. 661.0). 1H NMR
(CDCl3, 25 ꢁC) (d versus TMS) 1.69 (m, 2H, H4), 2.02–
2.04 (m, 2H, H04), 2.38–2.42 (m, 3H, H10 1), 2.54 (m, 3H,
H11), 2.84–2.97 (m, 4H, H5 þ H05), 3.35 (m, 2H, H3),
3.53–3.65 (m, 2H, H03), 3.73–3.75 (m, 2 H H2), 3.77–
3.79 (m, 2H, H20), 3.90–4.05 (m, 2H, H1), 6.99–7.15
(m, 2H, H8 + H9), 7.47–7.52 (m, 2H, H08 þ H90 ), 7.55–
2.6. Synthesis of [HgBr2(L1)] (3)
HgBr2 (0.20 g, 0.55 mmol) dissolved in acetone
(20 cm3) was mixed with a solution of L1 (0.22 g,
0.55 mmol) made in chloroform (20 cm3). The resulting
mixture was stirred at room temperature until the ligand
L1 was consumed (as monitored by TLC). The solvent
was removed from the mixture on a rotary evaporator.
The resulting residue was dissolved in 20 cm3 of chloro-
form and filtered through celite. The filtrate was concen-
trated to 10 cm3 and mixed with 20 cm3 of hexane. A
white complex was separated, filtered, dried in vacuo
and recrystallized from acetone–hexane (2:1) mixture.
Yield: 80%; m.p. 130 ꢁC (d); KM (Xꢀ1 cm2 molꢀ1) 7.8
Anal. Calc. for C18H23NO2TeHgBr2: C, 27.97; H, 2.97;
N, 1.81; Te, 16.50. Found: C, 27.71; H, 2.91; N, 1.76;
Te, 16.36%. Mol. wt.: 770.34 (Calc. 773.10). 1H NMR
(CDCl3, 25 ꢁC) (d versus TMS) 1.86–1.89 (m, 2H, H4),
2.46 (s, 3H, H11), 2.71–2.75 (t, 2H, H1), 3.37 (t, 2H,
H5), 3.46 (bs, 2H, H3), 3.65–3.68 (m, 5H, H2 and
OCH3), 6.74–6.77 (d, 2H, m to Te), 6.93–6.97 (m, 2H,
H7 and H9), 7.47–7.52 (t, 1H, H8), 7.68–7.71 (d, 2H, o
to Te), 13C {1H} NMR (CDCl3, 25 ꢁC) (d versus TMS)
24.4 (C1), 24.8 (C11), 28.9 (C4), 34.8 (C5), 55.2 (OCH3),
66.9 (C2), 70.4 (C3), 99.8 (ArTe–C), 114.7 (C9), 116.2
(Ar–C m to Te), 120.9 (C7), 137.1 (C8), 139.3 (ArC o
to Te), 157.3 (C10), 160.5 (Ar–C p to Te), 161.1 (C6).
7.58 (m, 1H, H0 ) 7.60 (m, 1H, H10). 13C {1H} NMR
10
(CDCl3, 25 ꢁC) (d versus TMS) 14.0 (C1), 26.0 ðC0 Þ,
11
26.6 (C11), 28.9 ðC0 Þ, 29.8 (C4), 34.6 ðC0 Þ, 35.8 (C5),
4
68.2 ðC0 Þ, 70.3 (C2), 76.9 (C3), 119.0 ðC0 5Þ, 120.6 (C9),
2
9
121.0 ðC0 Þ, 122.2 (C7), 138.5 (C8), 136.8 ðC0 Þ, 159.0
7
8
(C6), 162.9 (C10) [primes indicate the pendent arm proton
or carbon atoms].
2.9. Synthesis of [PtCl2(L2)]2 (7)
2.7. Formation of MeOC6H4HgBr (4) and
[RTe+–HgBr2]Brꢀ (R = –CH2CH2OCH2CH2CH2-
(2-(6-CH3–C5H3N))) (5)
The freshly prepared sample of L2 (0.24 g, 0.50 mmol)
dissolved in 10 cm3 of acetone was added to K2[PtCl4]
(0.20 g, 0.50 mmol) dissolved in 10 cm3 of water. The
resulting mixture was stirred for 3 h at room temperature
and poured into 100 cm3 of water. The complex was
extracted into chloroform (4 · 25 cm3). The chloroform
extract was dried over anhydrous sodium sulphate,
HgBr2(L1) (3) (0.07 g, 0.09 mmol) was dissolved in ace-
tone–hexane (2:1) mixture and kept for slow evaporation
at 25ꢁC. After 7 days, crystals of 4 were obtained. The

S. Bali et al. / Polyhedron 25 (2006) 1033–1042
1037
concentrated to ꢁ10 cm3 on a rotary evaporator, and
mixed with hexane (20 cm3). The resulting yellow col-
oured compound was filtered, washed with hexane and
recrystallized from chloroform:hexane (1:1) mixture.
Yield: 75%; m.p. 147 ꢁC (d); KM (Xꢀ1 cm2 molꢀ1) 9.0.
Anal. Calc. for C22H32N2O2TePtCl2: C, 35.21; H, 4.26;
N, 3.73; Te, 17.02. Found: C, 35.12; H, 4.21; N, 3.12;
Te, 16.17%. Mol. wt.: 739.2 (Calc. 749.6). 1H NMR
(CDCl3, 25 ꢁC) (d versus TMS) 1.89 (m, 2H, H4), 2.02–
2.08 (m, 2H, H04), 2.35–2.40 (m, 3H, H10 1), 2.53–2.54
(m, 3H, H11), 2.86–2.97 (m, 4H, H5 þ H05), 3.20–3.27
(m, 2H, H3), 3.34–3.40 (m, 2H, H03), 3.56–3.62 (m, 2H,
H02), 3.78–3.79 (m, 2H, H2), 3.84 (m, 2H, H1), 6.69 (m,
2H, H8 + H9), 6.99–7.15 (m, 2H, H08 þ H90 ), 7.48–7.49
7.11–7.12 (m, 2H, H8 and H9), 7.55–7.60 (m, 1H, H7)
13C {1H} NMR (CDCl3, 25 ꢁC) (d versus TMS) 17.3
(C1), 27.6 (C11), 28.9 (C4), 36.4 (C5), 69.7 (C2), 77. 4
(C3), 121.6 (C9), 123.7 (C7), 138.5 (C8), 161.5 (C6),
164.0 (C10).
3. Results and discussion
The ligands L1 and L2 were prepared according to
Eqs. (1) and (2) given below. The ligand L1 was found
stable for two months under ambient conditions.
Thereafter, deposition of white solid starts in the oil,
which is most likely a tellurium dioxide formed by its
oxidative decomposition. However, on storing L2 for
only eight days at room temperature under ambient
conditions TeO2 deposits appear. In N2 atmosphere it
may be stored for one month without any sign of
decomposition.
(m, 1H, H0 ), 7.50–7.58 (m, 1H, H10). 13C {1H} NMR
10
(CDCl3, 25 ꢁC) (d versus TMS) 16.7 (C1), 24.0 ðC0 Þ,
11
27.6 (C11), 28.8 (C4), 29.3 ðC0 Þ, 34.7 ðC0 Þ, 36.4 (C5),
4
69.7 ðC0 Þ, 70.4 (C2), 77.0 (C3), 119.0 ðC0 5Þ, 120.6 (C9),
2
9
8
7
BH4-
O
OMe
3
2
9
N
,
2 atm
-
[4-
Te
MeOC6H4Te]2
+
4-MeOC6H4Te
11
H3C
EtOH, Reflux
ð1Þ
ð2Þ
1
N
N
4
Te
H3C
CH2CH2CH2OCH2CH2Cl
10
6
5
L1
8
7
3
2
9
O
O
BH4-
N
,
2 atm
Te2-
+
11
Water, Reflux
4
N
H C
N
6
Te
1
N
CH3
H3C
(CH2)3O(CH2)2Cl
10
3
5
L2
121.6 ðC0 Þ, 123.5 (C7), 136.7 ðC0 Þ, 138.4 (C8), 161.5
The Pd(II), Pt(II), Hg(II) complexes of L1 and L2 were
prepared according to Eqs. (3)–(8) given below. The 1
crystallizes with 1.5 mol of benzene per mole whereas 2
with 2 mol of chloroform. The complexes 1–3, 6, 7,
and 8 can be stored at room temperature for two months
easily. Single crystals of 6–8 suitable for X-ray diffraction
could not be grown.
7
8
(C6), 164.0 (C10) [primes indicate the pendent arm proton
or carbon atoms].
2.10. Synthesis of [(PdCl2)3(L2)2] (8)
The freshly prepared sample of L2 (0.24 g, 0.50 mmol)
dissolved in 10 cm3 of acetone was added to Na2[PdCl4]
(0.22 g, 0.75 mmol) dissolved in 10 cm3 of water. The
resulting mixture was stirred for 3 h at room temperature
and poured in to 100 cm3 of water. The complex was
extracted with 4 · 25 cm3 of chloroform. The combined
chloroform layer was dried over anhydrous sodium
sulfate and concentrated to ꢁ10 cm3 on a rotary evapo-
rator, and mixed with hexane (20 cm3). The resulting
orange colored compound was filtered, washed with
hexane and recrystallized from chloroform:hexane (1:1)
mixture. Yield: 72%; m.p. 141 ꢁC (d); KM (Xꢀ1 cm2
molꢀ1) 8.7 Anal. Calc. for C44H64N4O4Te2Pd3Cl6: C,
35.21; H, 4.26; N, 3.73; Te, 17.01. Found: C, 35.16; H,
4.24; N, 3.71; Te, 17.00%. Mol. wt.: 1487.2 (Calc.
1499.4). 1H NMR (CDCl3, 25 ꢁC) (d versus TMS)
2.36–2.43 (m, 4H, H4 and H11), 3.13–3.19 (m, 2H, H5),
3.31–3.42 (m, 1H, H3), 3.68–3.94 (m, 5H, H3, H2, H1),
2Na2PdCl4 þ 2L1 ! ½PdCl2ðL1Þꢂ2 ð1Þ þ 4NaCl
ð3Þ
ð4Þ
ð5Þ
ð6Þ
ð7Þ
ð8Þ
2K2PtCl4 þ 2L1 ! ½PtCl2ðL1Þꢂ ð2Þ þ 4KCl
2
HgBr2 þ L1 ! ½HgBr2ðL1Þꢂ ð3Þ
2Na2PdCl4 þ 2L2 ! ½PdCl2ðL2Þꢂ2 ð6Þ þ 4NaCl
2K2PtCl4 þ 2L2 ! ½PtCl2ðL2Þꢂ2 ð7Þ þ 4KCl
3Na2PdCl4 þ 2L2 ! ½ðPdCl2Þ3ðL2Þ2ꢂ ð8Þ þ 6NaCl
Both L1 and L2 and their complexes are highly soluble
in chloroform and dichloromethane and moderately
soluble in acetone. In methanol, ethanol and hexane
the two ligands L1 and L2 are sparingly soluble. However
on crystallization of 3 in acetone:hexane (2:1) mixture,
the cleavage of L1 occurs resulting in MeO C6H4HgBr
(4) and [RTe+–HgBr2]Brꢀ (R = –CH2CH2OCH2CH2CH2-
(2-(6-CH3-C5H3N))) (5) as shown in Eq. (9) given below.

1038
S. Bali et al. / Polyhedron 25 (2006) 1033–1042
Chloroform/Acetone
[HgBr2(L1)]
L1
HgBr2
+
Crystallization from acetone-hexane
2:1 mixture
ð9Þ
[RTe+
HgBr2] Br-
HgBr
MeO
+
(5)
(4)
O
CH2-
R
=
H3C
N
The compound 4 is soluble in common organic solvents
such as chloroform, dichloromethane whereas 5 is insolu-
ble in organic solvents. The crystal structure of 4 is solved
and reported earlier [24]. The molar conductance values
KM of the complexes 1–3, 6, 7, and 8 in acetonitrile at
ꢁ1 mM concentration level have been recorded. The found
values are much lower than the values expected for a 1:1
electrolyte. This suggests that all the complexes 1–3, 6, 7
and 8 are non–electrolytes. The molecular weights of com-
plexes 1–3, 6, 7 and 8 determined in chloroform by vapour
pressure osmometric method were found to be very close to
the values calculated from their molecular formulae. This
indicates that there is no appreciable dissociation of any
of these complexes in the solution. The existence of metal-
lomacrocycles in solution may be further strengthened with
125Te NMR but inadequate solubility of 1 and 2 has
restricted us.
plexes 6 and 7, the m(M–Cl) appears at 351 and 334 cmꢀ1
,
respectively, indicating the presence of two trans M–Cl
bonds (M = Pd or Pt) of a square planar complex. In the
IR spectra of complexes 6 and 7 also, m(Te–C (aliphatic))
appears at lower frequency (458 and 443 cmꢀ1, respec-
tively) when compared to that of free ligand (L2). In the
IR spectrum of 8, the m(M–Cl) due to two trans Pd–Cl
appears at 351 cmꢀ1 while the band at 481 cmꢀ1 may be
assigned to Te–C (aliphatic) vibrations. A red shift in this
band in comparison to that of free L2supports the forma-
tion of M–Te bond. Similar red shifts in m(Te–C (aliphatic))
band in the IR spectra of complexes 1–3 and 6 and 7
(described above) support the involvement of Te in coordi-
nation of the two ligands L1 and L2 with the metal ions.
1
3.2. H NMR spectra
1
In the H NMR spectrum L1, H1 appears deshielded
3.1. Infrared spectra
by ꢁ1.2 ppm as compared to that of 2-[3-2-(chloroeth-
oxy)propyl]-6-methylpyridine as the chlorine is replaced
In the IR spectrum of L1 the bands appearing at
3060 cmꢀ1 are due to C–H (aromatic) vibrations and those
in the region 1456–1588 cmꢀ1 due to C–C (aromatic) vibra-
tions. The C–H (aliphatic) stretching vibrations appear at
2857–2936 cmꢀ1 whereas m(Te–C (aliphatic)) appears at
510 cmꢀ1. In IR spectrum of L2, the bands for C–H (aro-
matic) vibrations are observed at 3058 cmꢀ1 while C–H
(aliphatic) vibrations at 2854–2940 cmꢀ1. The band at
495 cmꢀ1 seems to originate from m(Te–C (aliphatic)). In
the IR spectrum of 1, m(Te–C (aliphatic)) shows red shift
as it appears at 478 cmꢀ1. The m(Pd–Cl) in this spectrum
appears at 357 cmꢀ1 and is characteristic of a trans
Cl–Pd–Cl system. In the IR spectrum of 2, the bands
appearing at 331 cmꢀ1 may be assigned to the asymmetric
stretching of trans Cl–Pt–Cl system. The band at 472 cmꢀ1
seems to arise from Te–C (aliphatic) vibrations and show
red shift of ꢁ23 cmꢀ1. In the IR spectra of 3, 4 and 5 a
band is observed around 295 cmꢀ1 which may be assigned
to Hg–C/N vibrations. This indicates that in 5, pyridine N
interacts with Hg as shown for 3. In the IR spectra of com-
by a tellurium moiety. In the H NMR spectrum of L2,
1
H1 protons merge with H5 protons and appear as a
multiplet with a deshielding of ꢁ1.1 ppm as compared
to 2-[3-(2-chloroethoxy)propyl]-6-methylpyridine again due
to substitution of chlorine with tellurium moiety. In case
of L1 the aromatic protons ortho to Te appear more
deshielded as a doublet than expected as compared to
para to Te which also appear as doublet. The pyridyl pro-
tons H7 and H9 in 1H NMR spectrum of L1 appear
merged as a multiplet whereas the H8 appears as a triplet.
In case of L2 also H7 and H9 appear as multiplet while H8
appears as a triplet. The 1H NMR spectrum of 1 and
2 were found to be similar and somewhat complex in
the alkyl region. In the 1H NMR spectrum of 2, the
two singlets at 7.26–7.28 are due to two chloroform mole-
cules identified in the lattice of its single crystals. The
H1 proton appears to be maximum deshielded (ꢁ1.14–
1.41 ppm) with respect to that of free ligand L1 as it
coordinates through Te. Similarly, deshielding of H5 with
respect to free ligand is also large (ꢁ0.85 ppm) because

S. Bali et al. / Polyhedron 25 (2006) 1033–1042
1039
the ligand also coordinates via pyridine nitrogen, which is
N
Te
M
N
also reflected in the deshielding of H11 by ꢁ1.1 ppm as
compared to free L1. All other CH2 protons also exhibit
deshielding (ꢁ0.1–0.3 ppm). Some of them become non
equivalent (viz. H1, H3 and H5) also. Pyridine and aryl
protons also appear deshielded (ꢁ0.1–0.3 ppm). In the
proton NMR spectrum of 1 also maximum deshielding
occurs for H1 (ꢁ1.31–1.44 ppm) as compared to free
ligand. The broad singlet at 7.24 is due to benzene mole-
cule identified in the lattice of its single crystal. The signal
for H5 and H11 appear deshielded by ꢁ0.6 and 0.3 ppm
respectively, thereby indicating the binding of ligand
through nitrogen pyridine also as in the case of 2. The
rigidity in the complex as compared to free ligand is prob-
ably responsible for the complexity observed in the proton
NMR spectrum of complexes 1 and 2 in the alkyl region.
In the proton NMR spectrum of 3, the coordination shifts
are not found to be significant as expected for a d10 sys-
tem. Thus H1 protons are not deshielded as expected for a
d10 system. However H5 protons appear to be deshielded
by ꢁ0.3 ppm as compared to that of free ligand L1, there
by indicating the binding of pyridyl nitrogen to the metal
centre. All the other protons viz. H1, H3, H4 and the aro-
matic protons of pyridyl ring and methoxy phenyl group
appear at almost the same position as that of free ligand
L1.
Cl
Cl
M
Cl
Cl
N
N
Te
6 / 7 (M = Pd/ Pt)
On reacting L2 with Pd (II) according to Eq. (8), com-
plex 8 results. The additional peaks like that of proton
NMR spectra of 6 and 7 are not observed in its 1H
NMR spectrum. The spectrum not only becomes cleaner
as compared to those of 6 and 7 but the signals also become
1
sharp when compared with those of H NMR spectrum of
6 and 7. The aromatic protons show a deshielding
(ꢁ0.12 ppm). These observations indicate that the free
arm of ligand L2 present in 6/7 coordinates to third Pd
atom to give a structure which is shown below.
Te
N
M
N
N
M
N
Cl
Cl
Cl
M
Cl
Cl
Cl
Te
(8)
N
3.3. 13C {1H} NMR spectra
Hg
The 13C {1H} NMR for 4 and 5 could not be recorded
because of their low solubilities. In the carbon-13 NMR
of 1, the C1 signal exhibits a deshielding of ꢁ13 ppm with
respect to that of L1 thereby indicating the coordination
through Te. In the carbon-13 NMR spectrum of 2 also,
the C1 signal shows ꢁ10 ppm deshielding with respect to
that of L1 while the other carbons are deshielded to a lesser
extent (<4 ppm). In the spectrum of 3, the C1 signal
appears ꢁ16 ppm deshielded with respect to free L1 which
may be due to the coordination of Te to the metal centre.
Additional signals are observed in carbon-13 NMR spec-
trum of 6 in the aliphatic and aromatic regions at d 26.0,
28.9, 34.6, 68.2, 119.0, 121.0, 130.8. Similarly in the car-
bon-13 NMR spectrum of 7 also, additional peaks are
observed at d 24.0, 29.3, 34.7, 69.1, 119.0, 121.6, 136.7
ppm. These extra signals are due to pendant arm of L2
and are corroborated by the proton NMR spectra 6/7.
The carbon-13 NMR spectrum of 8 does not have addi-
tional signals as observed in the case of 6 and 7. This
may be due to the binding of uncoordinated arm of L2 of
6/7 with the metal centre in 8, which is corroborated by
Te
Br
Br
(3) (L1 = Te~N)
Most probably 3 has a tetrahedral structure given above
which is corroborated by 13C NMR and terminal m(Hg–Br)
bands observed in its IR spectrum.
The proton NMR spectrum of 4 and 5 are also charac-
teristic. In the spectrum of 4 aromatic protons ortho and
meta to Hg appear as doublet while OCH3 protons
appear as a singlet. In case of 5 the H1 protons appear
as multiplet and are deshielded by ꢁ1.0 ppm as compared
to those of ligand L1. This kind of decomposition by
which 3 gives 4 and 5 is reported earlier also in tellurium
chemistry [23]. The signals in the proton NMR spectra of
6 and 7 are broad in the aliphatic as well as aromatic
region. Additional signals are also observed in proton
NMR spectrum of 6 and 7 in the aromatic as well as ali-
phatic region. These additional signals are similar to those
of free ligand L2. The multiplication of the signals may be
due to free uncoordinated arm of the ligand L2 in 6 and 7.
The broadness of these signals may arise due to exchange
between pendant and coordinated arms of L2. The most
plausible structure of 6 and 7 may be presumed to be
dimeric as shown below:
1
its H NMR spectrum. However, the compounds 6,7 and
8 do not have adequate solubility for 125Te NMR. More-
over, failure to grow their single crystals suitable for X-
ray diffraction has compelled us to propose structures with
limited evidences.

1040
S. Bali et al. / Polyhedron 25 (2006) 1033–1042
3.4. Crystal structure
with distances of 4.625(5), 8.921(5), 4.630(5), and
9.081(5) A, respectively. However, the rectangle is twisted
˚
The details of the crystal structures of 2 and 4 have
already been reported by us [10,24] and their molecular
structures are shown in Figs. 2 and 3 for comparative
purposes. The data for crystal and structure refinement
of 1 are given in Table 1, selected bond lengths and
angles in Table 2 and the molecular structure in Fig. 1.
The immediate environment around Pd in 1 is essentially
square planar consisting of the two trans Cl atoms along
with the Te atom of one bridging ligand and the N atom
of the other. This results in the formation of a 20-mem-
bered metallomacrocycle ring as has been reported for 2
(Fig. 2).
such that the dihedral angles for Te(1)–Pd(1)ꢃ ꢃ ꢃPd(2)–
N(1) and N(1)–Pd(1)ꢃ ꢃ ꢃPd(2)–Te(2) are 31.2(2)ꢁ and
31.7(2)ꢁ, respectively, when viewed down
the
˚
Pd(1)ꢃ ꢃ ꢃPd(2) vector (8.905(2) A). The related Cl(1)–
Pd(1)ꢃ ꢃ ꢃPd(2)–Cl(3) and Cl(2)–Pd(1)ꢃ ꢃ ꢃPd(2)–Cl(4) dihe-
dral angles are 26.8(2)ꢁ and 26.0(2)ꢁ, respectively. The
C3OC2 chain of the long sides of the macrocyclic rectan-
gle are arranged so that the C3O section forms a roughly
regular zig-zag chain but the final C2 section deviates
from this forming a trough-like arrangement at Te. This
can be expressed by looking at the torsion angle of C(9)–
O(2)–C(10)–C(11) which is ꢀ77.6(6)ꢁ as opposed to that
˚
The Pd–Cl bond lengths 2.313(2)/2.295(2) A are compa-
˚
rable to those (2.131(11) ave. A) reported for three trans
PdCl2L2 complexes, where L represents ligands bonding
to Pd through Te [25,26]. In 1, where a pyridine nitrogen
is trans to Te, the Pd–Te bond lengths of 2.530(1)/
˚
2.5313(9) A are considerably shorter than the sum of the
˚
˚
respective covalent radii of 2.63 A [1.31 A square planar
˚
Pd(II) and 1.32 A (tetrahedral Te)] and also shorter than
those reported earlier (2.594(8) ave. A) for the three com-
˚
pounds with two trans Te-ligands [25,26]. Conversely, the
˚
Pd–N bond lengths of 2.097(4) and 2.101(4) A in 1 are
longer than the sum of the respective covalent radii,
˚
˚
2.06 A and also longer than that reported (2.086(2) A) for
a Pd–Te bond cis to Te [8]; also consistent with the strong
trans influence of tellurium. The bond angles at Te and
nitrogen are as expected for trigonal pyramidal and trigo-
nal planar geometry, respectively. The Te–C(aryl) bond
˚
lengths 2.114(6)/2.118(5) A are shorter than Te–C(alkyl)
bond lengths 2.132(6)/2.138(5) A and close to the earlier
reported values of 2.116(20) and 2.158(30) A [27],
˚
˚
respectively.
A distinguishing feature of the 20-membered metallo-
macrocycle ring can be described as an approximate rect-
angle (or tetragon) denoted by the four sides Te(1)
ꢃ ꢃ ꢃN(2), N(2)ꢃ ꢃ ꢃTe(2), Te(2)ꢃ ꢃ ꢃN(1), and N(1)ꢃ ꢃ ꢃTe(1)
Fig. 2. Molecular structure of [PtCl2(L1)]2 Æ 2CHCl3 (2).
Fig. 1. Molecular structure of [PdCl2(L1)]2 Æ 1.5C6H6 (1).

S. Bali et al. / Polyhedron 25 (2006) 1033–1042
1041
5. Supplementary material
CCDC-285432 contains the supplementary crystallo-
graphic data for 1. These data can be obtained free of
charge at www.ccdc.cam.ac.uk/conts/retrieving.html [or
from the Cambridge Crystallographic Data Centre, 12,
Union Road, Cambridge CB2 1EZ, UK; fax: (internat.)
+44 1223 336 033, e-mail: deposit@ccdc.cam.ac.uk].
Acknowledgements
A.K.S. thanks Council of Scientific and Industrial
Research (India) for the Project No. 01(1849)/03/EMR-
II. J.E.D. thanks the University of Windsor for financial
support. We are pleased to have had the opportunity to
collaborate on occasions with such a distinguished X-ray
crystallographer as Professor Mike Hursthouse and on a
personal note J.E.D. thanks Mike for his much valued
friendship’’.
References
Fig. 3. Molecular structure of 4-MeOC6H4HgBr (4).
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[2] A.K. Singh, S. Sharma, Coord. Chem. Rev. 209 (2000) 49.
[3] A.K. Singh, Proc. Indian Acad. Sci. (Chem. Sci.) 114 (2002) 357.
[4] (a) E.G. Hope, W. Levason, Coord. Chem. Rev. 12 (1993) 109;
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of ꢀ176.7(6)ꢁ for the zig-zag section of C(12)–C(11)–
C(10)–O(2). A similar geometry is observed along the
other long edge with both troughs pointing in the same
direction.
The relationship between the macrocycle and the solvate
is such that one benzene molecule slots into the base of the
macrocycle so that pairs of CH groups appear to be asso-
ciated with two chlorine atoms H(39)ꢃ ꢃ ꢃCl(3), H(40)ꢃ ꢃ ꢃ
Cl(3) and H(41)ꢃ ꢃ ꢃCl(1), H(42)ꢃ ꢃ ꢃCl(1) and also with that
of an adjacent macrocycle below H(37)ꢃ ꢃ ꢃCl(1)0,
H(38)ꢃ ꢃ ꢃCl(1)0. However the contact distances are all
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˚
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˚
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4. Conclusion
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The potentially multidentate ligands 1-(4-methoxy-
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The L1 is used to design 20-membered metallomacocycles
with Pd(II) and Pt(II). The 1 and 2 are the first examples
of the formation of 20-membered metallomacrocycle ring
by a hybrid organotellurium ligand. The decomposition
of L1 in its mercury complex appears to be metal pro-
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