Formation and structural characterization of mercury complexes from Te(R)CH2SiMe3 (R = Ph, CH2SiMe3) and HgCl2

Article abstract of DOI:10.1016/j.jorganchem.2009.05.021

The reaction of HgCl₂ and Te(R)CH₂SiMe₃ [R = CH₂SiMe₃ (1), Ph (2)] in ethanol yielded a mononuclear complex [HgCl₂{Te(R)CH₂SiMe₃}₂] (R = Ph, 3a; R = CH₂SiMe₃, 3b). The recrystallization of 3a or 3b from CH₂Cl₂ produced a dinuclear complex [Hg₂Cl₂(μ-Cl)₂{Te(R)CH₂SiMe₃}₂] (R = Ph, 4a; R = CH₂SiMe₃, 4b). When 3a was dissolved in CH₂Cl₂, the solvent quickly removed, and the solid recrystallized from EtOH, a stable ionic [HgCl{Te(Ph)CH₂SiMe₃}₃]Cl·2EtOH (5a·2EtOH) was obtained. Crystals of [HgCl₂{Te(CH₂SiMe)₂}]·2HgCl₂·CH₂Cl₂ (6b·2HgCl₂·CH₂Cl₂) were obtained from the CH₂Cl₂ solution of 3b upon prolonged standing. The complex formation was monitored by ¹²⁵Te-, and ¹⁹⁹Hg NMR spectroscopy, and the crystal structures of the complexes were determined by single crystal X-ray crystallography.

Full text of DOI:10.1016/j.jorganchem.2009.05.021

Journal of Organometallic Chemistry 694 (2009) 3134–3141
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Formation and structural characterization of mercury complexes
from Te(R)CH2SiMe3 (R = Ph, CH2SiMe3) and HgCl2
*
*
Ludmila Vigo, Pekka Salin, Raija Oilunkaniemi , Risto S. Laitinen
Department of Chemistry, University of Oulu, P.O. Box 3000, FI-90014 Oulu, Finland
a r t i c l e i n f o
a b s t r a c t
Article history:
The reaction of HgCl2 and Te(R)CH2SiMe3 [R = CH2SiMe3 (1), Ph (2)] in ethanol yielded a mononuclear
complex [HgCl2{Te(R)CH2SiMe3}2] (R = Ph, 3a; R = CH2SiMe3, 3b). The recrystallization of 3a or 3b from
CH2Cl2 produced a dinuclear complex [Hg2Cl2(l-Cl)2{Te(R)CH2SiMe3}2] (R = Ph, 4a; R = CH2SiMe3, 4b).
When 3a was dissolved in CH2Cl2, the solvent quickly removed, and the solid recrystallized from EtOH,
a stable ionic [HgCl{Te(Ph)CH2SiMe3}3]Clꢀ2EtOH (5aꢀ2EtOH) was obtained. Crystals of [HgCl2{Te(CH2Si-
Me)2}]ꢀ2HgCl2ꢀCH2Cl2 (6bꢀ2HgCl2ꢀCH2Cl2) were obtained from the CH2Cl2 solution of 3b upon prolonged
standing. The complex formation was monitored by 125Te-, and 199Hg NMR spectroscopy, and the crystal
structures of the complexes were determined by single crystal X-ray crystallography.
Ó 2009 Elsevier B.V. All rights reserved.
Received 24 March 2009
Received in revised form 15 May 2009
Accepted 18 May 2009
Available online 23 May 2009
Keywords:
Telluroether
Mercury complex
X-ray crystallography
NMR spectroscopy
1. Introduction
and related unsymmetric Te(Ph)(CH2SiMe3)2 (2) towards the mer-
cury(II) center. We report the formation of [HgCl2{Te(R)CH2SiMe3}2]
Whereas mercury(II) halides have been reported to form a num-
ber of 1:1 and 1:2 complexes with organic telluroethers, their
structural information is rather sparse [1,2]. The structurally char-
acterized formal 1:1 [HgX2(L)] complexes comprise [HgI2(TePh2)]2
[3], [HgBr2{Te(C6H4OEt)(C6H3[NMe2]Me)]2 [4], [HgBr2{Te(C6H4O-
Me)(C2H4[NC4H8])}] [5], and [HgBr2{Te(C2H4[NC4H8])2}] [5]. Crys-
tal structures of the formal 1:2 [HgX2(L)2] complexes have been
determined for [HgI2(TePh)2] [6] and [HgX2{Te(Ph)[C6H3-
(Me)(NCC6H4(NO2))]}] (X = Cl, Br) [7]. The bidentate ditelluroether
ligand contains two tellurium donor atoms forming a chelate with
the Hg center, and the complex can therefore formally be consid-
ered as a 1:2 complex [8].
(R = Ph, 3a; R = CH2SiMe3, 3b), [Hg2Cl2(l-Cl)2{Te(R)CH2SiMe3}2]
(R = Ph, 4a; R = CH2SiMe3, 4b), [HgCl{Te(Ph)CH2SiMe3}3]Clꢀ2EtOH
(5aꢀ2EtOH) and [HgCl2{Te(CH2SiMe)2}]ꢀ2HgCl2ꢀCH2Cl2 (6bꢀ2HgCl2ꢀ
CH2Cl2). Small amounts of the last complex were formed upon pro-
longed standing of 3b in CH2Cl2. The X-ray structures of 3a, 4a,
5aꢀ2EtOH, and 6bꢀ2HgCl2ꢀCH2Cl2 are also described.
2. Experimental
2.1. General
All reactions and manipulations of air-sensitive reagents and
those involving toxic mercury compounds were carried out under
an argon atmosphere. HgCl2 (Merck), Ph2Te2 (Aldrich), ethanol (Al-
tia), dichloromethane (Lab-Scan), THF (Lab-Scan), and n-hexane
(Lab-Scan) were used as purchased and without further purifica-
tion. PhTeCH2SiMe3 was prepared according to the procedure de-
scribed by Ogura et al. [14] and Te(CH2SiMe3)2 was prepared by
the method of Gysling et al. [9].
N
N
TeBun
BunTe
It has recently been reported that the palladium(II), platinum(II) [9–
11], rhodium [12], and ruthenium(II) [13] complexes containing the
Te(CH2SiMe3)2 (1) [9] ligand show interesting stereochemical fea-
tures. In this contribution we explored the ligand properties of 1
2.2. NMR Spectroscopy
13C{1H}, 125Te, and 199Hg NMR spectra were recorded on a Bruc-
ker DPX400 spectrometer operating at 100.61, 126.28, and
71.56 MHz, respectively. The respective spectral widths were
24.04, 126.58, and 100.00 kHz. The pulse widths were 11.00,
* Corresponding authors. Tel.: +358 8 553 1686 (R. Oilunkaniemi), tel.: +358 8
553 1611 (R.S. Laitinen).
E-mail addresses: raija.oilunkaniemi@oulu.fi (R. Oilunkaniemi), Risto.Laitinen@
oulu.fi (R.S. Laitinen).
10.00, and 19.5
l
s, respectively. 13C{1H} pulse delay was 2.00 s,
that for 125Te was 1.60 s, and for 199Hg 0.1 s. 13C{1H}, 125Te, and
0022-328X/$ - see front matter Ó 2009 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2009.05.021

L. Vigo et al. / Journal of Organometallic Chemistry 694 (2009) 3134–3141
3135
199Hg accumulations contained ca. 1000, 30 000, and 10 000 tran-
sients, respectively. Tetramethylsilane was used as an external
standard for 13C chemical shifts. A saturated solution of Ph2Te2 in
CDCl3 and a 0.1 M solution of HgCl2 in DMSO were used as external
standards for 125Te and 199Hg chemical shifts, respectively. All
spectra were recorded in THF. 13C chemical shifts (ppm) are re-
ported relative to Me4Si, 125Te chemical shifts are reported relative
to neat Me2Te [d (Me2Te) = d (Ph2Te2) + 422] [15], and 199Hg chem-
ical shifts are reported relative to Me2Hg [d (Me2Hg) = d (HgCl2 1 M
in DMSO-d6) ꢁ 1501] [16].
into the solution that was subsequently stirred for 15 min at room
temperature. The solvent was removed by evaporation. In case of
the 1:2 reaction, [HgCl2{Te(R)CH2SiMe3}2] (R = Ph 3a, CH2SiMe3
3b) were formed. The 1:3 reaction also afforded 3a or 3b but in
addition the reaction mixture contained unreacted ligand. The
crude product was filtered and washed with cold ethanol. Upon
recrystallization of the precipitate from CH2Cl2, dinuclear
[Hg2Cl2(l-Cl)2{Te(R)CH2SiMe3}2] (R = Ph 4a, CH2SiMe3 4b) com-
plexes were obtained. The yields of 4a and 4b could be optimized
by involving the initial molar ratio of the reactants of 1:3. The
amounts of starting materials, workup of the reaction solutions,
optimized yields, elemental analyses, and NMR spectroscopic
properties of the isolated products are listed below.
2.3. X-ray crystallography
Diffraction data of 3a, 4a, 5aꢀ2EtOH, and 6bꢀ2HgCl2ꢀCH2Cl2 were
collected on a Nonius Kappa-CCD diffractometer using graphite
2.4.1. [HgCl2{Te(R)CH2SiMe3}2] (R = Ph, 3a; R = CH2SiMe3, 3b)
Complex 3a: HgCl2 (0.101 g, 0.372 mmol), Te(Ph)CH2SiMe3
(0.225 g, 0.770 mmol). The crude product was recrystallized from
ethanol, upon which a white crystalline solid of 3a was formed.
Yield 0.235 g (73.9%). Anal. Calc. for HgCl2Te2C20Si2H32: C, 28.08;
H, 3.77. Found: C, 27.68; H, 3.62%. 13C{1H} NMR: 137.0, 129.2,
127.2, 109.1 ppm (phenyl resonances), ꢁ1.1 ppm (CH3),
ꢁ9.9 ppm (CH2); 125Te NMR: 347 ppm (s), 199Hg NMR: ꢁ1418
ppm (s).
Complex 3b: HgCl2 (0.100 g, 0.368 mmol), Te(CH2SiMe3)2
(0.225 g, 0.745 mmol). The workup was carried out as for 3a. White
solid. Yield 0.241 g (74.7%). Anal. Calc. for HgCl2Te2C16Si4H44: C,
21.94; H, 5.07. Found: C, 22.03; H, 4.89%. 13C{1H}NMR: ꢁ1.1 ppm
(CH3), ꢁ7.4 ppm (CH2); 125Te NMR: 34 ppm (s), 199Hg NMR:
ꢁ1353 ppm (s).
monochromated Mo Ka radiation (k = 0.71073 Å; 55 kV, 25 mA).
Crystal data and the details of structure determinations are given
in Table 1.
Structures were solved by direct methods using SIR-92 [17] and
refined using SHELXL-97 [18] After the full-matrix least-squares
refinement of the non-hydrogen atoms with anisotropic thermal
parameters, the hydrogen atoms were placed in calculated
positions in the aromatic rings (C–H = 0.95 Å), in the CH3 groups
(C–H = 0.98 Å), and in the CH2 groups (C–H = 0.99 Å). The scatter-
ing factors for the neutral atoms were those incorporated with
the programs. WINGX user interface [19] was utilized throughout
the structure solutions and refinements.
2.4. Preparation of the complexes
Two series of reactions were carried out by involving HgCl2 and
Te(Ph)CH2SiMe3 (2) or Te(CH2SiMe3)2 (1) in molar ratios of 1:2, and
1:3. HgCl2 was dissolved in 6 ml of ethanol and 2 or 1 were added
2.4.2. [Hg2Cl2(l-Cl)2{Te(R)CH2SiMe3}2] (R = Ph, 4a; R = CH2SiMe3, 4b)
Complex 4a: HgCl2 (0.105 g, 0.387 mmol), Te(Ph)CH2SiMe3
(0.338 g, 1.158 mmol). After evaporation of ethanol, 0.5 ml of
Table 1
Details of the structure determinations of [HgCl2{Te(Ph)CH2SiMe3}2] (3a), [Hg2Cl2(
[HgCl2{Te(CH2SiMe)2}]ꢀ2HgCl2ꢀCH2Cl2 (6bꢀ2HgCl2ꢀCH2Cl2).
l-Cl)2{Te(Ph)CH2SiMe3}2] (4a), [HgCl{Te(Ph)CH2SiMe3}3]Clꢀ2EtOH (5aꢀ2EtOH), and
3a
4a
5aꢀ2EtOH
6bꢀ2HgCl2ꢀCH2Cl2
Empirical formula
Relative molecular mass
Crystal system
Space group
a (Å)
C20H32Cl2HgSi2Te2
855.33
Monoclinic
C2/c
22.405(5)
11.056(5)
11.087(5)
C20H32Cl4Hg2Si2Te2
1126.82
Monoclinic
P21/n
6.2592(13)
16.072(3)
15.017(3)
C34H60Cl2HgO2Si3Te3
1239.38
C9H24Cl8Hg3Si2Te
1201.43
Triclinic
Triclinic
ꢀ
ꢀ
P1
P1
13.371(3)
13.572(3)
13.909(3)
71.19(3)
84.10(3)
74.29(3)
2299.6(8)
120(2)
7.7139(15)
12.763(3)
15.710(3)
105.40(3)
100.27(3)
106.05(3)
1379.2(5)
120(2)
b (Å)
c (Å)
a
(°)
b (°)
96.992(5)
94.94(3)
c
(°)
V (Å3)
T (K)
2725.9(18)
120(2)
4
1505.1(5)
120(2)
2
Z
2
2
F(0 0 0)
1592
2.084
8.033
0.30 ꢂ 0.15 ꢂ 0.10
1.83–26.00
9966
2686
2529
1024
2.486
1184
1.790
5.432
0.20 ꢂ 0.20 ꢂ 0.09
2.55–26.00
33 473
8907
7897
419
0.0880
0.0448
0.1121
0.0518
0.1179
1.050
1.050, ꢁ1.750
1068
2.893
18.550
0.30 ꢂ 0.20 ꢂ 0.09
1.76–26.00
17 702
5165
4350
209
0.1010
0.0557
0.1505
0.0675
0.1633
1.059
2.772, ꢁ1.852
Dc (g cmꢁ3
)
l
(Mo K
a
) (mmꢁ1
)
12.531
0.20 ꢂ 0.10 ꢂ 0.08
3.50–25.99
22 897
2950
Crystal size (mm)
h Range (°)
Number of reflections collected
Number of unique reflections
Number of observed reflections
Number of parameters
Rint
2768
140
127
0.0757
0.0356
0.0867
0.0414
0.1065
1.212
0.1110
0.0374
0.0849
0.0428
0.0869
1.122
a,b
R1
a,c
wR2
R1 (all data)b
wR2 (all data)c
Goodness-of-fit (GOF)
Max. and min. heights in final difference Fourier synthesis (e Åꢁ3
)
2.766, ꢁ1.859
1.162, ꢁ1.562
a
I P 2
r
(I).
P
P
b
c
R1
=
||Fo| ꢁ |Fc||/ |Fo|.
P
P
wR2 = [ w(F2o ꢁ Fc2)2/ wFo4]1/2
.

3136
L. Vigo et al. / Journal of Organometallic Chemistry 694 (2009) 3134–3141
CH2Cl2 was added and the solution was allowed to stay at room
temperature for few minutes. The solvent was evaporated resulting
in the formation of a yellow paste. 2 ml of n-hexane was added, the
mixture was filtered, and the solution concentrated by evaporation
of the solvent. Upon recrystallization of the crude product from
CH2Cl2, a white crystalline solid of 4a was obtained. Yield 0.135 g
(70.7%). Anal. Calc. for Hg2Cl4Te2C20Si2H32: C, 21.32; H, 2.86. Found:
C, 21.01; H, 2.64%. 13C{1H} NMR: 137.3, 129.6, 127.9, 113.7 ppm
(phenyl resonances), ꢁ0.8 ppm (CH3), ꢁ7. 1 ppm (CH2); 125Te
NMR: 336 ppm (s), 199Hg NMR: ꢁ1416 ppm (s).
2.4.4. [HgCl2{Te(CH2SiMe)2}]ꢀ2HgCl2ꢀCH2Cl2 (6bꢀ2HgCl2ꢀCH2Cl2)
A
small amount of crystals of [HgCl2{Te(CH2SiMe)2}]ꢀ
2HgCl2ꢀCH2Cl2 (6bꢀ2HgCl2ꢀCH2Cl2) were formed upon prolonged
standing of [HgCl2{Te(CH2SiMe3)2}2] (3b) in ethanol. This product
could only be characterized by single crystal X-ray crystallography.
3. Results and discussion
3.1. General
Complex 4b: HgCl2 (0.102 g, 0.376 mmol), Te(CH2SiMe3)2
(0.344 g, 1.139 mmol). The workup of the reaction solution was
similar to that of 4a. White solid. Yield 0.159 g (73.9%). Anal. Calc.
for Hg2Cl4Te2C16Si4H44: C, 16.75; H, 3.87. Found: C, 16.92; H, 3.53%.
13C{1H} NMR: ꢁ0.4 ppm (CH3), ꢁ1.0 ppm (CH2); 125Te NMR:
60 ppm (s), 199Hg NMR: ꢁ1464 ppm (s).
The reactions of one equivalent HgCl2 with two equivalents of
Te(Ph)CH2SiMe3 or Te(CH2SiMe3)2 in ethanol affords good yields
of [HgCl2{Te(R)CH2SiMe3}2] (3a or 3b). The reaction of one equiva-
lent of HgCl2 with three equivalents of Te(Ph)CH2SiMe3 or Te(CH2-
SiMe3)2 in ethanol similarly yields 3a and 3b, but the reaction
solution also contained unreacted ligand. Recrystallization of the
crude product that were obtained from the above reactions by
2.4.3. [HgCl{Te(Ph)CH2SiMe3}3]Clꢀ2EtOH (5a)
using CH2Cl2 affords dinuclear [Hg2Cl2(l-Cl)2{Te(R)CH2SiMe3}2]
HgCl2 (0.108 g, 0.398 mmol), Te(Ph)CH2SiMe3 (0.355 g,
1.216 mmol) When the crude product was dissolved in CH2Cl2,
the solvent removed by evaporation after a few minutes, and the
product was recrystallized from EtOH, white crystalline solid 5a
was obtained. Yield 0.370 g (75.1%). Anal. Calc. for HgCl2Te3O2C34-
Si3H60: C, 32.95; H, 4.88. Found: C, 32.61; H, 4.69%. 13C{1H} NMR:
137.1, 129.4, 128.1, 113.5 ppm (phenyl resonances), 57.4 ppm (eth-
anol CH2), 18.5 ppm (ethanol, CH3), ꢁ1.1 ppm (CH3), ꢁ6.4 ppm
(CH2); 125Te NMR: 304 ppm (s), 199Hg NMR: ꢁ1055 ppm (s).
(R = Ph 4a or CH2SiMe3 4b). 3a and 3b represent typical 1:2 com-
plexes between HgCl2 and the telluroether, and the latter pair
(4a and 4b) is formally a 1:1 complex that shows dinuclear associ-
ation. If 3a was dissolved in CH2Cl2, the solvent quickly removed,
and the solid recrystallized from EtOH,
a
stable ionic
[HgCl{Te(Ph)CH2SiMe3}3]Clꢀ2EtOH (5a.2EtOH) was obtained. Upon
prolonged standing of 3b in CH2Cl2 for several weeks, a small
amount of crystals of [HgCl2{Te(CH2SiMe)2}]ꢀ2HgCl2ꢀCH2Cl2
(6bꢀ2HgCl2ꢀCH2Cl2) were obtained.
3.2. Crystal structures
C13
3.2.1. [HgCl2{Te(Ph)CH2SiMe3}2] (3a)
Cl1
The crystal structure of 3a is shown in Fig. 1 together with the
atomic numbering scheme. Selected bond distances and bond an-
gles are presented in Table 2. The structure consists of discrete
complexes. The coordination sphere around the mercury atom is
a distorted tetrahedron [the largest bond angle is Te(1)–Hg(1)–
Te(1)a of 125.12(3)° and the smallest is Cl(1)–Hg(1)–
Cl(1)a = 103.69(7)°] (for definition of the symmetry operation ‘‘a”,
see Table 2), typical of four-coordinated Hg(II) complexes [7,20–
22]. The two symmetry-equivalent Hg–Te bonds show length of
2.7689(13) Å. It is consistent with the Hg–Te distance reported
for [HgCl2{4-Ph(SB)Te}2] (SB = 2-[4,40-NO2C6H4CH@NC6H3–Me])
(2.800(1)–2.773(1) Å) [7]. The two equivalent Hg–Cl bond lengths
are 2.5202(15) Å. They are slightly longer than those in [HgCl2{4-
Ph(SB)Te}2] [2.496(2)–2.457(2) Å] [7].
C12
Si1
C11
Hg1
C1
Te1
C14
C15
C16
C19
C18
C17
The molecules are packed into two-dimensional planes (see
Fig. 2). The complexes are linked together by ClꢀꢀꢀH hydrogen bonds
both in the plane and between the planes. The shortest in-plane
hydrogen bond is 2.964(2) Å and that between the planes is
Fig. 1. The molecular structure of [HgCl2{Te(Ph)CH2SiMe3}2] (3a) indicating the
numbering of the atoms. Thermal ellipsoids are drawn at the 50% probability level.
Table 2
Selected bond lengths (Å) and angles (°) of [HgCl2{Te(Ph)CH2SiMe3}2] (3a), [Hg2Cl2(
l-Cl)2{Te(Ph)CH2SiMe3}2] (4a), and [HgCl{Te(Ph)CH2SiMe3}3]Clꢀ2EtOH (5aꢀ2EtOH).
3a
4a
5aꢀ2EtOH
Hg(1)–Te(1)
Hg(1)–Cl(1)
2.7689(13)
2.5202(15)
Hg(1)–Te(1)
Hg(1)–Cl(1)
Hg(1)–Cl(2)
2.6796(7)
2.6931(17)
2.3842(17)
Hg(1)–Te(1)
Hg(1)–Te(2)
Hg(1)–Te(3)
Hg(1)–Cl(1)
2.7723(9)
2.7771(8)
2.7497(10)
2.5667(18)
Cl(1)–Hg(1)–Te(1)
Cl(1)–Hg(1)–Te(1)a
Te(1)–Hg(1)–Te(1)a
Cl(1)–Hg(1)–Cl(1)a
105.59(4)
107.50(4)
125.12(3)
103.69(7)
Cl(1)–Hg(1)–Te(1)
Cl(2)–Hg(1)–Te(1)
Cl(1)–Te(1)–Cl(2)
Cl(1)–Hg(1)–Cl(1)b
Hg(1)–Cl(1)–Hg(1)b
102.74(4)
144.66(4)
103.52(6)
86.98(5)
93.02(5)
Te(1)–Hg(1)–Te(2)
Te(1)–Hg(1)–Te(3)
Te(2)–Hg(1)–Te(3)
Te(1)–Hg(1)–Cl(1)
Te(2)–Hg(1)–Cl(1)
Te(3)–Hg(1)–Cl(1)
111.84(3)
114.14(3)
113.53(2)
112.35(5)
101.81(5)
102.09(5)
a
Symmetry operations: ꢁx, y, ꢁz + 21
.
b
Symmetry operations: ꢁx + 1, ꢁy, ꢁz + 2.

L. Vigo et al. / Journal of Organometallic Chemistry 694 (2009) 3134–3141
3137
b
a
Fig. 2. The layer structure of 3a in the solid lattice.
2.865(1) Å. In addition, there is an intramolecular HꢀꢀꢀCl hydrogen
bond of 2.915(2) Å between one of the methylene hydrogen atoms
and chlorine.
coordination geometry in which the Cl–Hg–Te angles span the
range of 101.81(5)–112.35(5)° and the Te–Hg–Te angles are
111.84(3)–114.14(3)°. The Hg–Te and Hg–Cl bond lengths
[2.7497(10)–2.7771(8) and 2.5667(18) Å, respectively] are similar
to those in 3a (see Table 2).
3.2.2. [Hg2Cl2(l-Cl)2{Te(Ph)CH2SiMe3}2] (4a)
The molecular structure of 4a with the atomic numbering
scheme is shown in Fig. 3 and the selected bond distances and an-
gles are shown in Table 2. The formally 1:1 complex of HgCl2 and
Te(Ph)CH2SiMe3 is associated by symmetry into a dinuclear com-
plex, in which two mercury atoms are bridged by two chlorido li-
gands and also coordinated to one terminal chlorido and one
The cation and anion show TeꢀꢀꢀCl close contacts of 3.399(1)–
3.416(1) Å (see Fig. 6). The ions are also linked by two HꢀꢀꢀCl hydro-
gen bonds of 3.052(2) and 3.148(2) Å. There are also hydrogen
bonds between the anion and the solvent molecules. The HꢀꢀꢀCl dis-
tances in the ClꢀꢀꢀH–O arrangement involving the two ethanol mol-
ecules are 2.282(2) and 2.384(2) Å.
telluroether ligand. The mercury atom exhibits
a distorted
pseudo-tetrahedral geometry. The smallest angle is Cl(1)–Hg(1)–
Cl(1)b = 86.98(5)° and the largest angle is Te(1)–Hg(1)–
Cl(2) = 144.66(4)° (for definition of the symmetry operation ‘‘b”,
C12
C13
see Table 2). These values are similar to those in [Hg2Cl2(l-
Cl)2(SePPh3)2] [7], in which the bond angles at mercury span a
range 88.3(1)–136.3(2)°. The bridging Cl–Hg–Cl arrangement is
symmetric with both Hg(1)–Cl(1) and Hg(1)b–Cl(1) bonds exhibit-
ing virtually the same length of 2.6931(17) Å. These bridging bonds
are expectedly longer than the terminal bond Hg(1)–Cl(2) of
C11
Si1
C1
Te1
C18
C17
C19
2.3842(17) Å in agreement with the bond lengths in [Hg2Cl2(l-
C14
C15
Cl)2(SePPh3)2] (2.781(7) and 2.332(7) Å) [21]. The terminal Hg–Cl
bond length in HgCl2{Te(Ph)CH2SiMe3} (3a) [2.5202(17) Å] is be-
tween those of the bridging and terminal Hg–Cl bonds in the dinu-
clear 4a. The terminal bond length Hg(1)–Te(1) of 2.6796(17) Å is
shorter than that in 3a [2.7689(13) Å].
C16
Hg1
Cl1
The HꢀꢀꢀCl hydrogen bonding network link the discrete
[Hg2Cl2(l-Cl)2{Te(Ph)CH2SiMe3}2] (4a) complexes into skewed
Cl2
stacks (see Fig. 4). The shortest intermolecular hydrogen bonds
are 2.822(2) and 3.044(2) Å. In addition, there is one HꢀꢀꢀCl close
contact of 2.932(2) Å.
3.2.3. [HgCl{Te(Ph)CH2SiMe3}3]Clꢀ2EtOH (5a2EtOH)
The structure of 5aꢀ2EtOH with the atomic numbering scheme
is shown in Fig. 5. Selected bond lengths and angles are presented
in Table 2. The structure consists of a [HgCl{Te(Ph)CH2SiMe3}3]+
cation and a Clꢁ anion. Hg(1) shows a slightly distorted tetrahedral
Fig. 3. The molecular structure of [Hg2Cl2(l-Cl)2{Te(Ph)CH2SiMe3}2] (4a) indicating
the numbering of the atoms. Thermal ellipsoids are drawn at the 50% probability
level.

3138
L. Vigo et al. / Journal of Organometallic Chemistry 694 (2009) 3134–3141
b
a
c
Fig. 4. The packing of discrete complexes 4a into skewed stacks.
Only a few cationic mercury-chalcogen complexes are known in
literature, as exemplified by [CH3HgSeC(NH2)2]NO3 [23] and
[HgCl(SeImMe)3]Cl [SeImMe = tris(N-methyl-imidazoline-2-sele-
none)] [20]. The cation of the latter is analogous with that of 5a.
It can be seen from Fig 8a that the lattice consists of two-dimen-
sional layers that are composed of alternating strands of
[HgCl2{Te(CH2SiMe3)2] and HgCl2. The 6b complexes are linked
into polymeric chains by two HgꢀꢀꢀCl interactions of 3.008(4) and
3.078(4) Å:
3.2.4. [HgCl2{Te(CH2SiMe)2}]ꢀ2HgCl2ꢀCH2Cl2 (6bꢀ2HgCl2ꢀCH2Cl2)
The structure of 6b with the atomic numbering scheme is
shown in Fig. 7. Selected bond distances and bond angles are listed
in Table 3. The lattice is formally composed of a 1:1 complex of
Te(CH2SiMe3)2 and HgCl2, discrete HgCl2 moieties, as well as the
TeR2
Hg
Cl Cl
TeR2
Hg
Cl Cl
Cl Cl
Hg
Cl Cl
Hg
solvent of crystallization, CH2Cl2 (see Fig. 8). Mercury shows trigo-
P
nal planar coordination (
aHg = 360°), though the individual bond
angles span a range 103.64(12)–139.83(10)°. The length of the Hg–
Te bond is 2.6519(16) Å and those of the two Hg–Cl bonds are
2.429(4) and 2.542(3) Å. These values are quite consistent with
those of other complexes considered in this paper. The Hg–Cl bond
lengths in the two HgCl2 units are 2.319(4)–2.346(3) Å (see Table
3). They deviate slightly from linearity [the two Cl–Hg–Cl bond an-
gles are 171.06(12) and 172.45(13)°].
TeR2
TeR2
The HgꢀꢀꢀCl interactions expand the trigonal planar coordination of
Hg(1) into a trigonal bipyramid (see Fig. 8). The two strands of
HgCl2 are also involved in HgꢀꢀꢀCl close contacts of 2.797(3)–
3.329(4) Å. They expand the linear coordination of mercury atoms
Hg(2) and Hg(3) into an octahedron. The HꢀꢀꢀCl hydrogen bonds of
3.093(10) Å involving the dichloromethane solvent molecules link
the layers into a three-dimensional structure (see Fig. 8b).
C5
[Hg2Cl2(
l
-Cl)2(SEt2)2]ꢀHgCl2 shows a similar type of lattice with
alternating stacks of dinuclear [Hg2Cl2(
l
-Cl)2(SEt2)2] complexes
C23
and HgCl2 [24]. In a similar fashion as in 6bꢀ2HgCl2ꢀCH2Cl2 the
HgꢀꢀꢀCl contacts of 2.881–3.158 Å expand the coordination environ-
ment of the HgCl2 mercury atom into an octahedron. Similarly, the
distorted tetrahedron of the central atom in the dinuclear complex
is expanded into an octahedron by two weak contacts of 3.558 Å.
C7
C33
C4
O1
C22
C32
C31
C6
O2
Si3
3.3. NMR spectroscopy
C3
Te3
C34
Si2
C21
Cl2
C2
3.3.1. Assignment of the resonances
Cl1
All NMR spectra were recorded in THF. The 125Te and 199Hg
chemical shifts are shown schematically in Fig. 9. It can be seen
that both the 125Te chemical shifts of 3a (347 ppm) and 4a
(336 ppm) as well as their 199Hg chemical shifts (ꢁ1416 and
ꢁ1418 ppm, respectively) are virtually identical. Their 125Te chem-
ical shifts are also close to that of free Te(Ph)CH2SiMe3 (344 ppm in
CDCl3). The tellurium nucleus in 5a is somewhat more shielded
(304 ppm) than those of 3a and 4a. By contrast, the mercury nu-
cleus of 5a is less shielded (ꢁ1055 ppm) than those of 3a and 4a.
These two opposite trends can be explained by the relative elec-
tronegativities of the donor atoms to the central mercury. The dis-
torted tetrahedral coordination environment of 3a shows two
tellurium and two chlorine donors, that of 4a exhibits one tellu-
rium and three chlorine donors two of which bridge two mercury
centers, and that of 5a coordinates to three tellurium and one chlo-
rine donors. The shielding on tellurium decreases with increasing
Te2
C39
C35
C36
C29
C38
Hg1
C24
C28
C27
C37
C19
C25
C18
C1
Si1
C17
Te1
C11
C26
C14
C16
C13
C15
C12
Fig. 5. The crystal structure of [HgCl{Te(Ph)CH2SiMe3}3]Clꢀ2EtOH (5a) indicating
the numbering of the atoms. Thermal ellipsoids are drawn at the 50% probability
level.

L. Vigo et al. / Journal of Organometallic Chemistry 694 (2009) 3134–3141
3139
b
a
c
Fig. 6. Cation–anion interactions in 5aꢀ2EtOH.
number of more electronegative chlorido ligands that are coordi-
nated to mercury. By contrast, the shielding of mercury increases
with increasing number of chlorido ligands.
to that of the free telluroether (26 ppm, see Ref. [10]). It is interest-
ing to note that the 125Te resonances of both 3b and 4b are found
upfield from those of 3a and 4a (see Fig. 9). The smaller shielding of
tellurium in case of 3a and 4a is probably caused by the presence of
more electron withdrawing phenyl substituent on tellurium com-
pared to that of Me3SiCH2ꢁ.
In the case of Te(CH2SiMe3)2, the 125Te chemical shifts of both
3b and 4b (36 and 60 ppm, respectively) lie at a slightly lower field
We further note that whereas the 199Hg chemical shift of
[HgCl2{Te(CH2SiMe3)2}] (3b) lies upfield from that of
Cl32
[HgCl2{Te(Ph)CH2SiMe3]
(3a),
that
of
[Hg2Cl2(l-Cl)2{Te-
(CH2SiMe3)2}2] (4b) lies downfield from [Hg2Cl2(l-Cl)2{Te(Ph)-
CH2SiMe3}2] (4a). The presence of more electron withdrawing phe-
nyl group again plays a role in this trend.
C22
C3
C23
3.3.2. Interconversion pathways
All reactions were monitored by 125Te NMR spectroscopy. The
reaction solution from one equivalent of HgCl2 and two equivalents
of the ligands 2 or 1 in ethanol only showed one resonance due to
3a or 3b, respectively, as could be expected from a simple addition
Si2
Cl31
C21
C2
Cl1
C12
Table 3
Selected bond lengths (Å) and angles (°) of [HgCl2{Te(CH2SiMe)2}]ꢀ2HgCl2ꢀCH2Cl2
(6bꢀ2HgCl2ꢀCH2Cl2).
Te1
Si1
C1
Hg1
Cl6
Bond lengths
Å
Bond angles
°
Hg(1)–Te(1)
Hg(1)–Cl(1)
Hg(1)–Cl(2)
Hg(2)–Cl(2)
Hg(2)–Cl(3)
Hg(2)–Cl(4)
Hg(2)–Cl(5)
Hg(3)–Cl(4)
Hg(3)–Cl(6)
Hg(3)–Cl(1)a
2.6519(16)
2.429(4)
2.542(3)
2.797(3)
2.346(3)
2.953(3)
2.342(3)
2.329(3)
2.319(4)
2.985(3)
Te(1)–Hg(1)–Cl(1)
Te(1)–Hg(1)–Cl(2)
Cl(1)–Hg(1)–Cl(2)
Cl(2)–Hg(2)–Cl(3)
Cl(2)–Hg(2)–Cl(4)
Cl(2)–Hg(2)–Cl(5)
Cl(3)–Hg(2)–Cl(4)
Cl(3)–Hg(2)–Cl(5)
Cl(4)–Hg(2)–Cl(5)
Cl(4)–Hg(3)–Cl(6)
Cl(4)–Hg(3)–Cl(1)a
Cl(6)–Hg(3)–Cl(1)a
Hg(1)–Cl(2)–Hg(2)
Hg(1)–Cl(1)–Hg(3)a
Hg(2)–Cl(4)–Hg(3)
139.83(10)
116.53(9)
103.64(12)
88.46(11)
91.48(11)
98.55(11)
94.12(11)
172.45(13)
88.52(11)
171.06(12)
102.72(11)
86.16(12)
109.49(13)
128.15(15)
94.09(12)
C13
C11
Cl4
Cl2
Hg2
Hg3
Cl5
Cl3
Fig.
7. The
crystal
structure
of
[HgCl2{Te(CH2SiMe)2}]ꢀ2HgCl2ꢀCH2Cl2
(6bꢀ2HgCl2ꢀCH2Cl2) indicating the numbering of the atoms. Thermal ellipsoids are
a
Symmetry operation: ꢁx, ꢁy, ꢁz + 1.
drawn at the 50% probability level.

3140
L. Vigo et al. / Journal of Organometallic Chemistry 694 (2009) 3134–3141
[HgCl{Te(Ph)CH2SiMe3}3]Cl (5a) was obtained. Upon redissolving
the crystals of 5a in CH2Cl2, 4a was again formed. This indicates that
5a may be an intermediate in the formation of 4a and rationalizes,
why the yield of 4a is maximized by using the molar ratio of 1:3 for
HgCl2 and 2.
reaction. In case of three equivalents of the ligand, the resonance of
the unreacted ligand was also observed in addition to those of 3a
and 3b.
R2Te
Cl
Hg
+
HgCl2 + 2 TeR2
R2Te
Cl
Cl
-
Hg
TeR2
Cl
HgCl2 + 3 TeR2
R2Te
3
TeR2
5
The solvent used for recrystallization plays a significant role in the
formation of the end-products. The recrystallization of the crude
product of the reaction of HgCl2 and 2 or 1 from CH2Cl2 affords
dinuclear complexes 4a or 4b, respectively. Their yields are maxi-
mized, when the molar ratio of HgCl2 and the ligand is 1:3. This
can be explained as follows: Upon short treatment of the crude
product from the reaction of HgCl2 and three equivalents of 2 with
CH2Cl2 followed by recrystallization from EtOH, ionic
R2Te
Hg
Cl
Cl
- 2TeR2
Cl
Cl
Hg
½
+ 2TeR2
TeR2
4
(a)
c
a
b
(b)
Fig. 8. The layer-like packing in [HgCl2{Te(CH2SiMe)2}]ꢀ2HgCl2ꢀCH2Cl2 (6bꢀ2HgCl2ꢀCH2Cl2). (a) The alternating strands of [HgCl2{Te(CH2SiMe3)2}]n and HgCl2 are linked with
HgꢀꢀꢀCl secondary bonding interactions expanding the coordination spheres of mercury into either an octahedron or a trigonal bipyramid. (b) HꢀꢀꢀCl hydrogen bonds link the
layers into a three-dimensional structure.

L. Vigo et al. / Journal of Organometallic Chemistry 694 (2009) 3134–3141
3141
125Te
3a 4a 5a
complex [HgCl2{Te(R)CH2SiMe3}2], the recrystallization from
CH2Cl2 produces a dinuclear complex [Hg2Cl2( -Cl)2{Te(R)CH2-
l
4b 3b
SiMe3}2]. The ionic complex [HgCl{Te(Ph)CH2SiMe3}3]Clꢀ2EtOH is
isolated by treating [HgCl2{Te(Ph)CH2SiMe3}2] with CH2Cl2 for a
short time followed by recrystallization from EtOH. The products
were characterized by X-ray crystallography as well as multinu-
clear NMR. The solid state lattices are formed by discrete molecular
species or ions, but with extensive HꢀꢀꢀCl hydrogen bonding net-
work. In case of 6b, significant secondary HgꢀꢀꢀCl bonding interac-
tions are also observed.
400
300
200
100
0
ppm
Acknowledgments
199Hg
5a
Financial support from Academy of Finland and the Ministry of
Education (L.V.) is gratefully acknowledged.
3b 3a 4a 4b
Appendix A. Supplementary material
CCDC 724692, 724693, 724694 and 724695 contain the supple-
mentary crystallographic data for this paper. These data can be ob-
tained free of charge from The Cambridge Crystallographic Data
Centre via www.ccdc.cam.ac.uk/data_request/cif.
Supplementary data associated with this article can be found, in
the online version, at doi:10.1016/j.jorganchem.2009.05.021.
-1000
-1100
-1200
-1300
-1400
ppm
-1500
Fig. 9. The schematic overview of the 125Te and 199Hg chemical shifts of 3a, 3b, 4a,
4b, and 5aꢀ2EtOH.
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R2Te
Hg
Cl
Cl
R2Te
Cl
Cl
Cl
Hg
TeR2
Hg
½
+ TeR2
Cl
TeR2
3
4
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4. Conclusions
While the reactions of HgCl2 with Te(R)CH2SiMe3 (R = Ph,
CH2SiMe3) (molar ratio of 1:2) in ethanol affords a mononuclear