Phenyl derivatives of mercury functionalised in the 2-position with either a formyl or a vinyl group. Crystal structures of Hg[C6H4(CHO)-2]Cl and Hg[C6H4(CH=CH2)-2]2

Article abstract of DOI:10.1016/S0022-328X(00)00699-9

A convenient preparation of Hg[C₆H₄(CH₂OH)-2]Cl (1) involves treatment of dilithiated benzyl alcohol with HgCl₂. 1 is smoothly oxidised to Hg[C₆H₄(CHO)-2]Cl (2) by reaction with pyridinium

Full text of DOI:10.1016/S0022-328X(00)00699-9

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 619 (2001) 293–298
Phenyl derivatives of mercury functionalised in the 2-position with
either a formyl or a vinyl group. Crystal structures of
Hg[C6H4(CHO)-2]Cl and Hg[C6H4(CHꢀCH2)-2]2
Clifton E.F. Rickard, Warren R. Roper* 1, Folau Tutone, Scott D. Woodgate,
L. James Wright* 2
Department of Chemistry, The Uni6ersity of Auckland, Pri6ate Bag 92019 Auckland, New Zealand
Received 30 August 2000; accepted 17 September 2000
Abstract
A convenient preparation of Hg[C6H4(CH2OH)-2]Cl (1) involves treatment of dilithiated benzyl alcohol with HgCl2. 1 is
smoothly oxidised to Hg[C6H4(CHO)-2]Cl (2) by reaction with pyridinium chlorochromate (PCC). The crystal structure of 2
reveals a two coordinate linear arrangement at mercury supplemented by weaker interactions with the aldehyde oxygen atoms
both intramolecularly and intermolecularly. Treatment of
2 with NaI effects symmetrisation with the formation of
Hg[C6H4(CHO)-2]2 (3). Reaction between 3 and the Wittig reagent Ph3PꢀCH2 results in the formation of Hg[C6H4(CHꢀCH2)-2]2
(4). The crystal structure of 4 has been determined. © 2001 Elsevier Science B.V. All rights reserved.
Keywords: Organometallic complexes; o-Vinylphenyl complexes; o-Formylphenyl complexes; Mercury
2. Results and discussion
1. Introduction
2.1. Selecti6e synthesis of Hg[C6H4(CH2OH)-2]Cl (1)
In previous work we have established that a conve-
nient route to coordinatively unsaturated |-aryl deriva-
tives of ruthenium and osmium, M(Ar)Cl(CO)(PPh3)2,
involves treatment of MHCl(CO)(PPh3)3 with HgAr2
[1]. This transfer reaction has proved to be quite gen-
eral and aryl groups bearing various functionalities
have been successfully introduced to ruthenium or os-
mium [2]. Where the functional group is in the ortho-
position and contains a potential donor atom there may
be a chelating interaction with the metal centre, as
observed for example in the o-nitrophenyl derivatives
[3] and in the o-halophenyl derivatives [4]. In connec-
tion with other studies we required phenyl derivatives
of ruthenium and osmium bearing o-formyl and o-vinyl
substituents. It was therefore necessary to have avail-
able the corresponding mercury complexes and in this
paper we describe the syntheses and structures of o-
formylphenyl and o-vinylphenyl derivatives of mercury.
The compound, Hg[C6H4(CH2OH)-2]Cl, seemed to
offer, by the simple chemical transformations outlined
in Scheme 1, convenient routes to the required o-
formylphenyl and o-vinylphenyl derivatives of mercury.
Hg[C6H4(CH2OH)-2]Cl has been described previously,
in rather low yield, as one of the products of the direct
mercuration of benzyl alcohol with Hg(OAc)2 followed
by treatment with NaCl [5]. The mixture from this
reaction contains dimercurated as well as the 2-, and
4-substituted products but these workers were able to
isolate Hg[C6H4(CH2OH)-2]Cl by fractional crystallisa-
tion and to oxidise it readily with KMnO4 to
Hg[C6H4(CO2H)-2]Cl [5]. However, in our hands this
direct mercuration and fractional crystallisation proce-
dure did not give pure Hg[C6H4(CH2OH)-2]Cl, the
product always being contaminated (as revealed by thin
layer chromatography) with Hg[C6H4(CH2OH)-4]Cl.
To avoid this difficult separation of isomers a selective
synthesis of Hg[C6H4(CH2OH)-2]Cl was sought. Meyer
and Seebach showed that double deprotonation of ben-
zyl alcohol with butyl lithium in the presence of
1 *Corresponding author. Tel.: +64-9-3737999 ext. 8320; fax: +
64-9-3737422; e-mail: w.roper@auckland.ac.nz
2 *Corresponding author.
0022-328X/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(00)00699-9

294
C.E.F. Rickard et al. / Journal of Organometallic Chemistry 619 (2001) 293–298
Table 1
Data collection and processing parameters a
Compound
2
4
Empirical formula
Molecular weight
Temperature (K)
C7H5ClHgO
341.15
203
C16H14Hg
406.86
200
,
Wavelength (A)
0.71073
Monoclinic
P21/c
0.71073
Orthorhombic
Pbcn
Crystal system
Space group
Unit cell dimensions
,
a (A)
7.4413(3)
10.9583(3)
9.5083(3)
102.5130(10)
756.93(4)
4
2.994
608
20.61
15.5833(2)
10.820592)
15.9340(3)
,
b (A)
,
c (A)
i (°)
V (A )
3
,
2686.78(8)
8
2.012
1520
Z
Dcalc (g cm−3
F(000)
)
v (mm−1
)
11.43
Crystal size (mm)
q(Min–max) (°)
Reflections collected
Independent reflections
0.21×0.16×0.08 0.45×0.21×0.03
2.8–26.0
4728
2.3–27.3
15678
1482
2960
Scheme 1. Synthesis of o-formylphenyl and o-vinylphenyl derivatives
of mercury.
[Rint=0.0551]
0.098–0.289
w(F2o−F2c)2
1.067
0.0482
0.1315
[Rint=0.0674]
0.079–0.725
w(F2o−F2c)2
1.055
0.0443
0.1311
A (min–max)
Function minimised
Goodness-of-fit on F2
R (observed data)
R (all data)
Least-squares weights a, b
0.089, 0.000
+3.43 and
−2.97
0.068, 3.354
+1.89 and
−1.78
Difference map (min and
−3
,
max) (e A
)
a R=Fo−Fc/Fo; wR2={[w(F2o−F2c)2]/[w(F2o)2]}1/2
[2(F2o)+a*P2+b*P]; P=(Fo2+2F2c)/3.
; weight=1.0/
1. The IR spectrum of 2 shows absorptions at 1694,
Fig. 1. Molecular geometry of Hg[C6H4(CHO)-2]Cl (2).
1661, and 1632 cm−1 in the region expected for an
1
aldehyde function. The H-NMR spectrum of 2 shows
the resonances expected for the aromatic protons as a
TMEDA, followed by addition of Me3SnCl provided a
convenient way to prepare Me3Sn[C6H4(CH2OH)-2] [6].
Accordingly, dilithiated benzyl alcohol was treated with
HgCl2 (see Scheme 1) to produce pure Hg[C6H4(CH2-
OH)-2]Cl (1) in 56% yield.
two proton multiplet at 7.57–7.61, and as apparent
doublets at 7.74 (3JHH=7.3 Hz) and 7.90 ppm (3JHH
=
7.4 Hz). A resonance at 10.14 ppm is assigned to the
aldehyde proton. In the 13C-NMR spectrum signals for
the tertiary aromatic carbons occur at 129.58, 135.75,
135.99 and 137.62 ppm, while the resonance for the
aldehyde carbon appears at 193.69 ppm. A single crys-
tal X-ray diffraction study was performed on this com-
pound to examine whether the aldehyde oxygen
interacts with the mercury.
2.2. Synthesis of Hg[C6H4(CHO)-2]Cl (2) from
oxidation of 1 with PCC
The oxidation of alcohols to aldehydes with pyri-
dinium chlorochromate (PCC) is a well-known proce-
dure in organic chemistry [7], and there is even
precedent for this procedure effecting oxidation of an
alcohol function in a complex alkyl ligand bound to
2.3. Crystal structure of Hg[C6H4(CHO)-2]Cl (2)
Crystals of 2 suitable for X-ray analysis were grown
from ethanol–benzene. The molecular geometry of this
complex is depicted in Fig. 1 and selected interatomic
distances and bond angles are given in Table 2. The
structure reveals a linear arrangement about the mer-
cury atom which is bonded both to a chloride and an
mercury [8]. Room temperature oxidation of
a
dichloromethane solution of 1 with PCC (see Scheme 1)
proved to be an effective way to prepare pure
Hg[C6H4(CHO)-2]Cl (2) in better than 70% yield. Com-
pound 2 is much more soluble in organic solvents than

C.E.F. Rickard et al. / Journal of Organometallic Chemistry 619 (2001) 293–298
295
,
o-formylphenyl group. The oxygen of the aldehyde
group is pointing towards the mercury, the mercury–
distance of 2.824(7) A in 2 is within the range of
observed mercury–oxygen bond lengths. Despite this
bonding interaction, the phenyl ring is not appreciably
tilted since the HgꢁC(1)ꢁC(2) angle (119.8(9)°) is only
slightly less than the HgꢁC(1)ꢁC(6) angle (121.3(7)°).
An examination of the packing geometry of complex 2
reveals that the mercury atom is effectively four coordi-
nate, since each mercury atom has two oxygen interac-
tions. One is intramolecular, and the other is
intermolecular, from an aldehyde oxygen of a neigh-
bouring molecule (see Fig. 2). The HgꢁO distance for
,
oxygen distance being 2.824(7) A. A survey of 494
compounds containing mercury–oxygen bonds in the
Cambridge Crystallographic Database reveals an aver-
,
age mercury–oxygen bond length of 2.538 A, with a
,
standard deviation of 0.273 A. The mercury–oxygen
Table 2
a
,
Selected bond lengths (A) and angles (°) for 2
Bond lengths
HgꢁC(1)
HgꢁCl
,
the intermolecular interaction is 2.989(13) A, slightly
longer than that observed for the intramolecular inter-
2.056(10)
2.326(3)
2.824(7)
2.989(13)
1.208(13)
2.83
HgꢁO
,
action (2.824(7) A). The O(A)ꢁHgꢁO(B) angle is
HgꢁOc1
161.19(7)° and the C(1)ꢁHgꢁCl angle is 173.8(2)°. A
OꢁC(7)
,
second intermolecular interaction (2.83 A) exists be-
ClꢁH(7A)
tween the aldehyde hydrogen and a neighbouring chlo-
ride. The consequence of these combined interactions is
that a zig-zag chain is formed (see Fig. 2).
Bond angles
C(1)ꢁHgꢁCl
C(1)ꢁHgꢁO
ClꢁHgꢁO
OꢁHgꢁOc1
HgꢁC(1)ꢁC(2)
HgꢁC(1)ꢁC(6)
173.8(2)
71.9(3)
108.41(17)
161.19(7)
119.8(7)
121.3(7)
2.4. Symmetrisation of Hg[C6H4(CHO)-2]Cl (2) to
Hg[C6H4(CHO)-2]2 (3)
Treatment of compound 2 with hydrazine hydrate in
ethanol, or with basic sodium stannite, or alternatively
with copper and ammonia all failed to effect the desired
a Symmetry transformations: c1−X, Y+1/2, 1/2−Z.
Table 3
,
Selected bond lengths (A) and angles (°) for 4
symmetrisation
of
Hg[C6H4(CHO)-2]Cl
to
Hg[C6H4(CHO)-2]2. However, Hg[C6H4(CHO)-2]2 (3)
was obtained in good yield by treatment of compound
2 with NaI in acetone (see Scheme 1). The IR spectrum
of compound 3 includes many absorptions in the 1770–
1550 cm−1 range appropriate for an aromatic aldehde.
Bond lengths
HgꢁC(11)
HgꢁC(21)
C(12)ꢁC(17)
C(17)ꢁC(18)
C(22)ꢁC(27)
C(27)ꢁC(28)
2.092(7)
2.096(6)
1.471(13)
1.325(12)
1.458(11)
1.337(12)
1
The H-NMR spectrum shows resonances for the aro-
matic protons as apparent triplets at 7.50 ppm (3JHH
=
7.6 Hz) and 7.71 (3JHH=7.2 Hz), and apparent
doublets at 7.81 (3JHH =7.2 Hz) and 7.93 ppm
(3JHH=7.2 Hz). The aldehyde proton resonance is ob-
served as a singlet at 10.27 ppm. The 13C-NMR spec-
trum shows resonances for the aromatic carbons at
127.97, 134.29, 135.14, 139.10, 143.97 (Cq) and 168.47
ppm (Cq). A resonance assigned to the aldehyde carbon
is observed at 195.48 ppm.
Bond angles
C(11)ꢁHgꢁC(21)
C(16)ꢁC(11)ꢁC(12)
C(16)ꢁC(11)ꢁHg
C(12)ꢁC(11)ꢁHg
C(18)ꢁC(17)ꢁC(12)
C(26)ꢁC(21)ꢁC(22)
C(26)ꢁC(21)ꢁHg
C(22)ꢁC(21)ꢁHg
C(28)ꢁC(27)ꢁC(22)
178.2(3)
118.7(7)
119.2(5)
122.1(7)
128.5(9)
118.8(7)
118.6(5)
122.4(6)
128.7(8)
2.5. Synthesis of Hg[C6H4(CHꢀCH2)-2]2 (4)
Drefahl and Lorentz have reported that the para-
substituted compound, Hg[C6H4(CHO)-4]2 can be con-
verted smoothly into Hg[C6H4(CHꢀCH2)-4]2 by
treatment with Ph3PꢀCH2 [9]. Accordingly, compound
3
was treated with Ph3PꢀCH2 to produce
Hg[C6H4(CHꢀCH2)-2]2 (4) in high yield (see Scheme 1).
In the H-NMR spectrum of 4 the three protons of the
1
vinyl group are apparent from the presence of three
doublet of doublet resonances with a geminal coupling
constant of 1 Hz and vicinal coupling constants of 17
Hz (trans) and 11 Hz (cis), respectively. In the 13C-
Fig. 2. Section of chain in the crystal of Hg[C6H4(CHO)-2]Cl (2).

296
C.E.F. Rickard et al. / Journal of Organometallic Chemistry 619 (2001) 293–298
Hg[C6H4(CHO)-2]Cl, the structure of Hg[C6H4-
(CHꢀCH2)-2]2 shows neither intramolecular nor inter-
molecular interactions.
4. Experimental
4.1. General procedures and instruments
Standard laboratory procedures were followed as
have been described previously [10]. Infrared spectra
(4000–400 cm−1) were recorded as Nujol mulls be-
tween KBr plates on a Perkin–Elmer Paragon 1000
spectrometer. NMR spectra were obtained on a Bruker
DRX 400 spectrometer at 25°C. 1H-, and 13C-NMR
spectra were obtained operating at 400.1 (1H) and 100.6
(13C) MHz, respectively. Resonances are quoted in
Fig. 3. Molecular geometry of Hg[C6H4(CHꢀCH2)-2]2 (4).
1
ppm, coupling constants in Hertz, and H-NMR spec-
NMR spectrum of 4 the vinyl carbons appear at 140.72
(methine) and 114.68 (methylene), while the mercury-
bound carbon appears at 170.69 ppm.
tra referenced to either tetramethylsilane (0.00 ppm) or
the proteo-impurity in the solvent (7.25 ppm for
CHCl3). 13C-NMR spectra were referenced to CDCl3
(77.00 ppm). Mass spectra were recorded using the fast
atom bombardment technique with a Varian VG 70-SE
mass spectrometer. Elemental analyses were obtained
from the Microanalytical Laboratory, University of
Otago.
2.6. Crystal structure of Hg[C6H4(CHꢀCH2)-2]2 (4)
The molecular geometry of this complex is depicted
in Fig. 3 and selected interatomic distances and bond
angles are given in Table 3. As expected the structure
reveals a linear arrangement about the mercury atom,
(C(11)ꢁHgꢁC(21), 178.2(3)°), with almost identical
4.2. Preparation of Hg[C6H4(CH2OH)-2]Cl (1)
,
HgꢁC distances of 2.092(7) and 2.096(6) A. The
Benzyl alcohol (1.406 g, 13 mmol) and TMEDA
(3.02 g, 26 mmol) were dissolved in pentane (25 ml) at
0°C. To this vigorously stirred solution was added
n-butyllithium (1.6 mol l−1 in hexane) (18.2 ml, 26
mmol). The first half of the addition was done slowly
over 10 min. The solution was a light brown colour at
the end of the addition. This light brown solution was
then heated under reflux for 11 h, under nitrogen. The
resulting dark brown suspension was decanted off from
insoluble materials and pentane (20 ml) was added. The
resulting suspension was cooled in a dry ice–acetone
bath and HgCl2 (2.715 g, 10 mmol) dissolved in te-
trahydrofuran (5 ml) was added. The mixture was
stirred as it warmed to room temperature. The mixture
was then extracted with three portions of water (50 ml)
and the combined extracts then neutralised by the
addition of dry ice to yield pure 1 as a white microcrys-
talline solid (2.503 g, 56% yield), which was filtered and
dried in vacuo. M.p. 128°C. m/z 343.98707:
C7H7HgOCl requires 343.98391. Anal. Found: C,
25.31; H, 1.95. Calc. for C7H7HgOCl: C, 24.50; H,
molecule is not quite planar with a twist angle between
the two phenyl rings of 14.1(2)°. The vinyl groups are
on opposite sides of the CꢁHgꢁC vector and the CꢁC
double bonds point away from the mercury. Each vinyl
group is almost in the plane of the phenyl ring to which
it is attached. The CꢁC bond distances in the vinyl
,
groups are 1.325(12) and 1.337(12) A. There are no
significant intermolecular interactions.
3. Conclusions
A
convenient
Hg[C6H4(CH2OH)-2]Cl has been devised from reaction
of dilithiated benzyl alcohol with HgCl2.
and
selective
synthesis
of
Hg[C6H4(CH2OH)-2]Cl can be smoothly oxidised to
Hg[C6H4(CHO)-2]Cl by reaction with pyridinium
chlorochromate without any damage to the HgꢁC
bond. The crystal structure of Hg[C6H4(CHO)-2]Cl re-
veals a complicated geometry where there are both
intramolecular and intermolecular HgꢁO interactions
involving the aldehyde oxygen atoms. Symmetrisation
of Hg[C6H4(CHO)-2]Cl and subsequent reaction with
the Wittig reagent, Ph3PꢀCH2, results in the formation
of Hg[C6H4(CHꢀCH2)-2]2. Unlike the structure of
1
2.06%. IR (cm−1): 3232, 3053, 2922, 1202, 1025. H-
NMR (CDCl3; l): 4.75 (s, 2H, CH2), 7.24–7.4 (m, 4H,
C6H4). 13C-NMR (CDCl3; l): 65.52 (s, CH2), 144.98 (s,
quaternary, C6H4), 137.01 (s, C6H4), 129.03 (s, C6H4),
128.01 (s, C6H4), 127.81 (s, C6H4).

C.E.F. Rickard et al. / Journal of Organometallic Chemistry 619 (2001) 293–298
297
4.3. Preparation of Hg[C6H4(CHO)-2]Cl (2)
yellow orange solution. This solution was left to stand
at room temperature for 14 h. Saturated NH4HCO3 (10
ml) was added and the resulting orange solution ex-
tracted three times with dichloromethane (30 ml). The
combined extracts were then dried with CaCl2 and the
solvent removed under reduced pressure. The solid
product was recrystallised from 80% ethanol and final
purification was effected by chromatography on a short
silica column using dichloromethane as eluent. Re-
moval of solvent afforded pure 4 as an off-white crys-
talline solid (0.672 g, 72% yield). M.p. 76–78°C. m/z
408.07950, C8H7Hg requires 408.08018. Anal. Found:
C, 47.14; H, 3.49. Calc. for C8H7Hg: C, 47.23; H,
Compound 1 (0.533 g, 16 mmol) was dissolved in
dichloromethane (100 ml), and added to a suspension
of pyridinium chlorochromate (0.5022 g, 23 mmol) in
dichloromethane (200 ml) at r.t. A dark brown
coloured suspension was slowly formed. After 2 h the
brown suspension was filtered through a Celite pad,
and the filtrate passed down a short silica column to
remove coloured impurities. The dichloromethane was
removed from the eluant on a rotary evaporator and
ethanol (20 ml) was added to give white needles of pure
2 (0.391 g, 74% yield). m/z 341.9720; C7H5ClHgO
requires 341.9735. Anal. Found: C, 24.65; H, 1.47.
Calc. for C7H5ClHgO: C, 24.71; H, 1.21%. IR (cm−1):
3130, 1694, 1661, 1632, 1607, 1575, 1562, 1399, 1295,
1261, 1199, 1162, 1115, 1070, 1050, 1016, 957, 843, 826,
1
3.47%. IR(cm−1): 1620, 1412, 978, 907, 774, 737. H-
3
NMR (CDCl3; l): 5.38 (dd, 1H, CHꢀCH2, JHH=11,
3
2
2JHH=1); 5.83 (dd, 1H, CHꢀCH2, JHH=17, JHH
=
1); 7.13 (dd, 1H, CHꢀCH2, 3JHH=17, 3JHH=11);
7.27–7.64 (m, 4H, C6H4). 13C-NMR (CDCl3; l): 114.68
(s, CHꢀCH2); 140.72 (s, CHꢀCH2); 170.69 (s, quater-
nary, C6H4); 145.59 (s, quarternary, C6H4); 137.4 (s,
C6H4); 128.05 (s, C6H4); 127.66 (s, C6H4); 126.6 (s,
C6H4).
1
806, 761, 696, 662. H-NMR (CDCl3; l): 7.57–7.61 (m,
3
2H, C6H4); 7.74 (t, apparent, 1H, C6H4, JHH=7.3);
3
7.90 (d, apparent, 1H, C6H4, JHH=7.4); 10.14 (s, 1H,
CHO). 13C-NMR (C6D6; l): 129.58 (s, C6H4); 135.75
(s, C6H4); 135.99 (s, C6H4); 137.62 (s, C6H4); 193.69 (s,
CHO).
4.4. Preparation of Hg[C6H4(CHO)-2]2 (3)
4.6. X-ray crystal structure determinations for
complexes, 2 and 4
Compound 2 (1.00 g, 2.90 mmol) was added to a
solution of NaI (4.35 g, 29 mmol) in acetone (100 ml)
X-ray data collection for 2 and 4 was on a Siemens
SMART diffractometer with a CCD area detector, using
graphite monochromated Mo–Ka radiation (u=
,
previously dried over 4 A molecular sieves. A white
flocculant solid formed immediately, and the reaction
mixture was stirred for a further 25 min. The solution
was then filtered through a Celite pad and the volume
of the filtrate reduced to ca. 1 ml. Water (10 ml) was
added dropwise to give pure 3 as a white crystalline
solid, which was recovered by filtration (622 mg, 52%).
m/z 412.0385; C14H10HgO2 requires 412.0387. Anal.
Found: C, 40.93; H, 2.45. Calc. for C14H10HgO2: C,
40.32; H, 1.92%. IR (cm−1): 3116, 1772, 1693, 1680,
1659, 1651, 1631, 1581, 1556, 1453, 1294, 1261, 1193,
,
0.71073 A). Data were integrated and Lorentz and
polarisation correction applied using SAINT [11] soft-
ware. Semi-empirical absorption corrections were ap-
plied based on equivalent reflections using SADABS [12].
The structures were solved by Patterson and Fourier
methods and refined by full-matrix least-squares on F2
using programs SHELXS [13] and SHELXL [14]. All non-
hydrogen atoms were refined anisotropically and hy-
drogen atoms were included in calculated positions and
refined with a riding model with thermal parameter
20% greater than Uiso of the carrier atom. Crystal data
and refinement details are given in Table 1.
1
1117, 839, 790, 751, 6661, 426. H-NMR (CDCl3; l):
3
7.50 (t, apparent, 1H, C6H4, JHH=7.6); 7.71 (t, appar-
3
ent, 1H, C6H4, JHH=7.2); 7.81 (d, apparent,1H, C6H4,
3
3JHH=7.2); 7.93 (d, apparent, 1H, C6H4, JHH=7.2);
10.27 (s, 1H, CHO). 13C-NMR (C6D6; l): 127.97 (s,
C6H4); 134.29 (s, C6H4); 135.14 (s, C6H4); 139.10 (s,
C6H4); 143.97 (s, C6H4 quaternary); 168.47 (s, C6H4
quaternary); 195.48 (s, CHO).
5. Supplementary material
Crystallographic data (excluding structure factors)
for the structures reported here have been deposited
with the Cambridge Crystallographic Data Centre,
CCDC Nos. 147452 and 147453 for 2 and 4, respec-
tively. Copies of this information may be obtained free
of charge from The Director, CCDC, 12 Union Road,
Cambridge CB2 1EZ, UK (Fax: +44-1223-336033;
e-mail: deposit@ccdc.cam.ac.uk or www: http://
www.ccdc.cam.ac.uk).
4.5. Preparation of Hg[C6H4(CHꢀCH2)-2]2 (4)
A solution of Ph3P(CH3)Br (4.086 g, 11 mmol) and
n-butyllithium (1.6 mol l−1 in hexane) (7.15 ml, 11
mmol) in THF (20 ml) was stirred at room temperature
for 2 h. To this solution was added dropwise, a solution
of 3 (0.94 g, 2 mmol) in THF (20 ml). A precipitate
formed immediately which dissolved over 4 h to leave a

298
C.E.F. Rickard et al. / Journal of Organometallic Chemistry 619 (2001) 293–298
[2] A.M. Clark, C.E.F. Rickard, W.R. Roper, L.J. Wright, J.
Acknowledgements
Organomet. Chem. 598 (2000) 262.
[3] G.R. Clark, C.E.L. Headford, W.R. Roper, L.J. Wright,
V.P.D. Yap, Inorg. Chim. Acta 220 (1994) 261.
[4] C.E.F. Rickard, W.R. Roper, S.D. Woodgate, L.J. Wright, J.
Organomet. Chem. 607 (2000) 27.
[5] T. Ukai, Y. Yamamoto, M. Yotsuzuka, J. Pharm. Soc. Jpn. 75
(1955) 493.
[6] N. Meyer, D. Seebach, Chem. Ber 113 (1980) 1304.
[7] G. Piancatelli, A. Scettri, M. D’Auria, Synthesis (1982) 245.
[8] P. Kocovsky´, V. Dunn, J.M. Grech, J. Srogl, W.L. Mitchell,
Tetrahedron Lett. 31 (1996) 5585.
We thank the Marsden Fund, administered by the
Royal Society of New Zealand, for supporting this
work and for granting a PhD Scholarship to F.T. We
also thank the University of Auckland Research Com-
mittee for partial support of this work through grants-
in-aid and through the award of a Doctoral Scholarship
to S.D.W.
[9] G. Drefahl, D. Lorenz, J. Prakt. Chem. 24 (1964) 106.
[10] S.M. Maddock, C.E.F. Rickard, W.R. Roper, L.J. Wright,
Organometallics 15 (1996) 1793.
References
[11] SAINT, Area detector integration software, Siemens Analytical
Instruments Inc., Madison, Wisconsin, USA, 1995.
[12] G.M. Sheldrick, SADABS, Program for semi-empirical absorp-
tion correction, University of Go¨ttingen, Go¨ttingen, Germany,
1977.
[13] G.M. Sheldrick, SHELXS-97, Program for crystal structure deter-
mination, University of Go¨ttingen, Go¨ttingen, Germany, 1977.
[14] G.M. Sheldrick, SADABS, Program for crystal structure refine-
ment, University of Go¨ttingen, Go¨ttingen, Germany, 1977.
[1] (a) W.R. Roper, L.J. Wright, J. Organomet. Chem. 142 (1977)
C1. (b) C.E.F. Rickard, W.R. Roper, G.E. Taylor, J.M. Wa-
ters, L.J. Wright, J. Organomet. Chem. 389 (1990) 375. (c)
M.M.P. Ng, W.R. Roper, L.J. Wright, Organometallics 13
(1994) 2563. (d) G.R. Clark, M.M.P. Ng, W.R. Roper, L.J.
Wright, J. Organomet. Chem. 491 (1995) 219. (e) K. Hu¨bler, U.
Hu¨bler, W.R. Roper, L.J. Wright, J. Organomet. Chem. 526
(1996) 199. (f) A.M. Clark, C.E.F. Rickard, W.R. Roper, L.J.
Wright, J. Organomet. Chem. 545 (1997) 619.
.