Phenylselenolate mercury alkyl compounds, PhSeHgMe and PhSeHgEt: Molecular structures, protolytic Hg-C bond cleavage and phenylselenolate exchange

Article abstract of DOI:10.1016/j.poly.2015.06.007

The phenylselenolate mercury alkyl compounds, PhSeHgMe and PhSeHgEt, have been structurally characterized by X-ray diffraction, thereby demonstrating that both compounds are monomeric with approximately linear coordination geometries; the mercury centers do, nevertheless, exhibit secondary Hg...Se intermolecular interactions that serve to increase the coordination number in the solid state. The ethyl derivative, PhSeHgEt, undergoes facile protolytic cleavage of the Hg-C bond to release ethane at room temperature, whereas PhSeHgMe exhibits little reactivity under similar conditions. Interestingly, the cleavage of the Hg-C bond of PhSeHgEt is also more facile than that of the thiolate analog, PhSHgEt, which demonstrates that coordination by selenium promotes protolytic cleavage of the mercury-carbon bond. The phenylselenolate compounds PhSeHgR (R = Me, Et) also undergo degenerate exchange reactions with, for example, PhSHgR and RHgCl. In each case, the alkyl groups preserve coupling to the ¹⁹⁹Hg nuclei, thereby indicating that the exchange process involves metathesis of the Hg-SePh/Hg-X groups rather than metathesis of the Hg-R/Hg-R groups.

Full text of DOI:10.1016/j.poly.2015.06.007

Polyhedron 103 (2016) 307–314
Contents lists available at ScienceDirect
Polyhedron
journal homepage: www.elsevier.com/locate/poly
Phenylselenolate mercury alkyl compounds, PhSeHgMe and PhSeHgEt:
Molecular structures, protolytic Hg–C bond cleavage and
phenylselenolate exchange
⇑
Kevin Yurkerwich, Patrick J. Quinlivan, Yi Rong, Gerard Parkin
Department of Chemistry, Columbia University, New York, NY 10027, USA
a r t i c l e i n f o
a b s t r a c t
Article history:
The phenylselenolate mercury alkyl compounds, PhSeHgMe and PhSeHgEt, have been structurally char-
acterized by X-ray diffraction, thereby demonstrating that both compounds are monomeric with approx-
imately linear coordination geometries; the mercury centers do, nevertheless, exhibit secondary Hgꢀ ꢀ ꢀSe
intermolecular interactions that serve to increase the coordination number in the solid state. The ethyl
derivative, PhSeHgEt, undergoes facile protolytic cleavage of the Hg–C bond to release ethane at room
temperature, whereas PhSeHgMe exhibits little reactivity under similar conditions. Interestingly, the
cleavage of the Hg–C bond of PhSeHgEt is also more facile than that of the thiolate analog, PhSHgEt,
which demonstrates that coordination by selenium promotes protolytic cleavage of the mercury–carbon
bond. The phenylselenolate compounds PhSeHgR (R = Me, Et) also undergo degenerate exchange reac-
tions with, for example, PhSHgR and RHgCl. In each case, the alkyl groups preserve coupling to the
Received 7 April 2015
Accepted 8 June 2015
Available online 15 June 2015
Dedicated to Professor Catherine Housecroft
on the occasion of her 60th birthday. Happy
birthday, Catherine!
Keywords:
Mercury
Selenolate
Thiolate
Methyl
199
Hg nuclei, thereby indicating that the exchange process involves metathesis of the Hg–SePh/Hg–X
groups rather than metathesis of the Hg–R/Hg–R groups.
Ó 2015 Elsevier Ltd. All rights reserved.
Ethyl
1
. Introduction
The interaction between mercury and selenium is of consider-
reactivity towards protolytic cleavage of the Hg–R bonds and
Hg–SePh exchange.
able relevance to the toxicological properties of mercury [1,2].
For example, selenium is an important component of antioxidants
2
. Results and discussion
[
3,4] and coordination to mercury can reduce the bioavailability of
2.1. Synthesis and structural characterization of PhSeHgR
selenium [5,6]. Furthermore, selenium is present in a variety of
biomolecules, such as selenocysteine, selenomethionine, seleno-
neine and Se-methylselenoneine [1,3,7–10], and the binding of
mercury to the active sites of selenoenzymes can inhibit their func-
tions [6]. It has also been reported that selenoamino acids can
cleave the Hg–C bond of methyl mercury species to yield mercury
CO
2
Sodium ethylmercury thiosalicylate, [ðAr )SHgEt]Na, more
commonly known as Thimerosal or Merthiolate [14,15], has long
found applications in a variety of products, including vaccine
preservatives [14,16]. Only recently, however, has the molecular
structure of this compound been determined by X-ray diffraction
and shown to be a two coordinate arylthiolate mercury ethyl
derivative [17]. While other arylthiolate mercury ethyl compounds
have been structurally characterized by X-ray diffraction [17–19],
there are no examples of selenolate counterparts listed in the
Cambridge Structural Database [20,21]. Therefore, it is noteworthy
that we have synthesized the phenylselenolate mercury ethyl com-
2
selenide via (MeHg) Se [11]. In addition to its selenophilicity, the
thiophilicity of mercury is also recognized to be an important con-
tributor to mercury toxicity [2,12,13]. Since organomercury com-
pounds are exceptionally toxic, it is especially pertinent to
investigate the structures of mercury alkyl compounds that feature
sulfur and selenium coordination. Therefore, we describe herein
the molecular structures of PhSeHgR compounds and their
4
plex, PhSeHgEt, via the reaction of diphenyl diselenide with NaBH ,
followed by treatment with EtHgCl (Scheme 1), and determined its
structure by X-ray diffraction (Fig. 1). For comparison, we have also
determined the molecular structure of the methyl derivative,
PhSeHgMe [21a] (Fig. 2).
⇑
Corresponding author.
E-mail address: parkin@columbia.edu (G. Parkin).
http://dx.doi.org/10.1016/j.poly.2015.06.007
277-5387/Ó 2015 Elsevier Ltd. All rights reserved.
0

3
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K. Yurkerwich et al. / Polyhedron 103 (2016) 307–314
Scheme 1. Synthesis of PhSeHgEt.
Fig. 2. Molecular structure of PhSeHgMe.
Fig. 3. Chain-type structure of PhSeHgR.
Fig. 1. Molecular structure of PhSeHgEt (only one of the crystallographically
independent molecules is shown).
the benzimidazole-2-selone derivative, [H(sebenzimMe)]
2
2
HgCl has
Both PhSeHgMe and PhSeHgEt possess approximately linear
coordination geometries, and the Hg–C bond lengths are compara-
ble to related two-coordinate mercury alkyl compounds with sele-
nium donors (Table 1). Linear coordination is common for mercury
bond lengths of 2.5732(5) Å and 2.6090(5) Å [31], while those in
[Hg (SePh ) ][ClO ] range from 2.65 Å to 2.92 Å [32]. Such variabil-
ity in bond lengths is by no means unique to Hg–Se interactions and
is a common feature of dative covalent bonds [33].
2
2 4
4 2
[
22,23] and is often attributed to relativistic effects, although other
Although PhSeHgMe and PhSeHgEt have a primary coordination
number of two, there are secondary Hgꢀ ꢀ ꢀSe intermolecular inter-
actions that serve to increase the coordination number in the solid
state [23]. Specifically, each mercury center of PhSeHgR interacts
with the selenium atoms of three adjacent PhSeHgR molecules.
As such, the extended structure may be considered to be composed
of dinuclear rectangular (PhSeHgR)2 moieties that are linked
together in a chain, as illustrated in Fig. 3. For PhSeHgEt, the inter-
molecular Hgꢀ ꢀ ꢀSe interactions range from 3.42 Å to 3.77 Å, while
the values for PhSeHgMe range from 3.35 Å to 3.72 Å. The thiolate
compounds, PhSHgMe and PhSHgEt, exhibit a similar extended
structure, with intermolecular Hgꢀ ꢀ ꢀS interactions that span the
range of 3.24 Å to 3.78 Å for PhSHgMe and 3.23 Å to 4.45 Å for
PhSHgEt [17]. The phenolate compound PhOHgMe also possesses
a similar type of packing arrangement, with intermolecular
Hgꢀ ꢀ ꢀO interactions in the range of 2.70–3.76 Å [34]. Two of the
interactions [2.702(9) Å and 2.719(9) Å], however, are much smal-
ler than the others, such that the compound has been described as
comprising a stack of loosely associated dimers. In this regard, the
principal difference between the selenolate and phenolate com-
pounds is that each mercury center of PhSeHgR forms three
factors have also been considered [24].
However, while two-coordination is well precedented for mer-
cury, examples of two-coordinate organomercury compounds that
feature a selenium co-ligand are not common. For example, there
are only three other examples of two-coordinate species with a
[
Se–Hg–C] motif that are currently listed in the Cambridge
Structural Database, each of which is methyl derivative
(
a
Table 1) [25–27].
The Hg–C bond length in PhSeHgCH [2.087(6) Å] is within the
3
range observed for the other derivatives (2.04 Å–2.13 Å), while the
Hg–SePh bond lengths of PhSeHgMe [2.4990(13) Å] and PhSeHgEt
[
longer than that in the other arylselenolate organomercury com-
3 6 2
plex, namely (2,4,6-Pr C H )SeHgMe [2.460(3) Å]. For additional
2.4955(14) Å and 2.4940(14) Å] are comparable to, but slightly
i
comparison, these Hg–SeAr bond lengths are similar to those in
the two-coordinate homoleptic derivative, Hg(SePh)
2
[2.4802(2) Å]
t
Bu
[
[
28], and the four-coordinate complex, ½Tm ꢁHgSePh [2.5244(4) Å]
29]. It is, nevertheless, appropriate to point out that significantly
longer Hg–Se bond lengths have been reported for compounds that
feature HgSe dative covalent L-type interactions [30]. For example,
Table 1
Bond length and angle data for selected two coordinate mercury alkyl compounds with selenium co-ligands.
Hg–C (Å)
Hg–Se (Å)
Se–Hg–C (°)
Reference
PhSeHgCH
PhSeHgCH
3
2.087(6)
2.083(9)
2.4990(13)
2.4955(14)
2.4940(14)
2.460(3)
2.477(3)
2.469(4)
177.03(19)
173.6(2)
174.7(3)
175.7(9)
177.0(8)
177.8(11)
This work
This work
2
CH
3
2
.111(10)
(
2,4,6-Pri
(H N) CSeHgMe}[NO
C(H N)CHCH Se]HgMe
3
C
6
H
2
)SeHgMe
2.039(35)
2.13(3)
2.10(4)
[25]
[26]
[27]
{
2
2
3
]
[
O
2
3
2

K. Yurkerwich et al. / Polyhedron 103 (2016) 307–314
309
Table 2
1
99Hg NMR data for two-coordinate organomercury compounds with sulfur and
selenium co-ligands.
d (ppm)
Reference
a
PhSeHgMe
PhSeHgEt
ꢂ688
[21a]
b
ꢂ658
This work
This work
[21a,27]
[21a]
[19e]
[19e]
b
ꢂ815
c
[
O
2
C(H
3
N)CHCH
2
Se]HgMe
ꢂ644
a
PhSHgMe
ꢂ620
b
ꢂ557
b
PhSHgEt
ꢂ730
CO
2
c
ꢂ784
[17]
[
ðAr )SHgEt]Na (thimerosal)
CO
2
H)SHgEt
ꢂ788d
d
[18]
ðAr
(
(
3-H
2
NC
NC
6
H
H
4
S)HgMe
S)HgMe
ꢂ613
ꢂ645
[19c]
[19c]
d
4-H
2
6
4
a
b
c
DMF.
Benzene.
O.
DMSO.
D
2
Fig. 4. Correlation between 2
J
Hg–H and 3
J
Hg–H for mercury ethyl compounds listed in
d
Table 3.
Table 3
1
n
H NMR chemical shift and
JHg–H (n = 2, 3) coupling constant data for mercury ethyl
complexes.a
D
d = d(CH
2
)–
|2JHg–H|a
|3JHg-H|a
Reference
d(CH
3
)
(Hz)
(Hz)
Et
2
Hg
ꢂ0.29
91b
159
120b
232
[40]
PhSeHgEt
0.14
This
workd
[18]
[17]
PhSHgEt
0.20
0.39
162
176
228
250
CO
2
[
ðAr )SHgEt]Na
2
CO HgEt
0.51
193
168
273
252
[18]
[18]
[
ðAr
)SHgEt]
2
CO
2
H)SHgEt
0.54
ðAr
EtHgCl
EtHgBr
EtHgI
0.63
0.65
0.66
0.98
202
214
292
301
[18]
[39a]
[39a]
[39a]
c
c
–
–
c
c
EtHgClO
4
–
–
a
In cases where the signs of the coupling constants have been measured, 2
J
Hg–H
3
are negative, whereas
JHg–H are positive. See Ref. [36].
b
Values of 2
JHg–H = 100 Hz and JHg–H = 128 Hz have also been reported. See Ref.
3
Fig. 5. Non first-order 1H NMR spectra of the ethyl group of PhSeHgEt in benzene:
a) 300 MHz (top), (b) 400 MHz (middle) and (c) 500 MHz (bottom).
[
37].
(
c
Values not reported.
Benzene.
d
for the ethyl group of PhSeHgEt are not first-order, the outer
1
99
2 3
Hg satellite signals of the CH and CH groups exhibit a first
comparable intermolecular Hgꢀ ꢀ ꢀSe interactions, whereas
PhOHgMe favors a single intermolecular Hgꢀ ꢀ ꢀO interaction.
Spectroscopically, PhSeHgEt is characterized by a 1 Hg NMR
order pattern. For example, at 500 MHz, the chemical shift differ-
ence for the outer quartet and outer triplet (which are associated
99
199
1
with the same
Hg spin state) is 0.52 ppm (i.e., 260 Hz), which
is significantly greater than the 3JH–H coupling constant (8 Hz) and
is therefore consistent with a first-order appearance. The inner satel-
lite signals are separated by 0.26 ppm (i.e., 129 Hz) and would also
be expected to exhibit first-order behavior, but the quartet signal
is obscured by the triplet of the primary resonance. The observation
of a first-order pattern for the satellites of PhSeHgEt is in marked
contrast to that observed for EtHgCl at 400 MHz, where the inner
satellites appear as a singlet due to the chemical shifts of the corre-
signal at ꢂ815 ppm in C
6 6
D , which is comparable to the values
reported for related two-coordinate mercury alkyl compounds
with sulfur or selenium co-ligands (Table 2) [35]. The presence of
1
99
the
16.9% abundance) in both the H and C{ H} NMR spectra.
Hg nucleus is also evident from the existence of satellites
1
13
1
(
1
Interestingly, while
Hg–C (63 Hz),
JHg–C (1145 Hz) is considerably larger than
2
2
3
J
JHg–H (159 Hz) is significantly smaller than J
Hg–H
(
232 Hz) [36]. The latter trend has been observed for a variety of
other EtHgX compounds, as illustrated in Table 3, and a plot of
sponding CH
field [18].
2 3
and CH groups being coincidentally equivalent at this
2
2
3
J
J
Hg–H versus
JHg–H is characterized by the empirical expression
Hg–H = 1.43 3JHg–H (Fig. 4). The magnitude of the coupling con-
Examination of the data in Table 3 demonstrates that the differ-
ence in chemical shifts, d = d(CH )–d(CH ), is strongly influenced
by the nature of X [39], ranging from 0.98 ppm for EtHgClO , to
ꢂ0.29 ppm for Et Hg. With respect to the molecular compounds,
the value of d correlates approximately with the electronegativity
of X, with EtHgCl having a value of 0.63 ppm and Et Hg a value of
Hg is the only ethyl mercury com-
stants depends strongly on the nature of X and correlates approx-
imately with its electronegativity [37].
Another interesting spectroscopic feature of PhSeHgEt pertains
to the appearance of the ethyl group in the 1H NMR spectrum.
Specifically, rather than exhibiting the triplet and quartet associ-
D
2
3
4
2
D
2
ated with an A
2
X
3
spin system, additional coupling is present in
ꢂ0.29 ppm [40]. Indeed, Et
2
1
the 300, 400 and 500 MHz H NMR spectra (Fig. 5). The manifesta-
tion of the additional coupling is a consequence of second order
effects and the spectra may be simulated with the following spec-
3
pound of which we are aware for which the CH group is downfield
1
The observation that the outer satellite signals (and likewise the inner satellite
tral parameters: d(CH
2
) = 0.86 ppm, d(CH
3
) = 1.00 ppm, and
199
signals) are associated with the same
Hg spin state is a consequence of the fact that
3
2
J JHg–H have opposite signs.
Hg–H and 3
|
J
H–H| = 7.8 Hz [38]. However, whereas the principal NMR signals

3
10
K. Yurkerwich et al. / Polyhedron 103 (2016) 307–314
Fig. 7. 1H NMR spectra (400 MHz) of the methyl region of (a) PhSeHgMe (top), (b) a
mixture of PhSeHgMe and MeHgCl (middle) and (c) MeHgCl (bottom).
n
Fig. 6. Correlation between
D
d and
J
Hg–H (n = 2, 3) for mercury ethyl compounds
).
listed in Table 3, where d = d(CH
D
2
)–d(CH
3
of the CH
influenced by the nature of X (Table 3), it is relevant to note that
group [41].2 Since the n
JHg–H coupling constants are also
2
n
there are also approximate correlations between
n = 2, 3), as illustrated in Fig. 6.
Dd and
J
Hg–H
(
2.2. Cleavage of the Hg–C bond of PhSeHgR
The toxicity of organomercury compounds is well known [2],
and Nature has developed a detoxification procedure that is
achieved by the combined action of two enzymes, namely (i)
organomercurial lyase (MerB) and (ii) mercuric ion reductase
(MerA) [2,42]. MerB is essential because it catalyzes the protolytic
cleavage of Hg–C bonds; as such, it is important to establish
the factors that influence this reaction. In this regard, while
two-coordinate mercury alkyl compounds of the type RHgX are
notoriously inert towards cleavage of the Hg–C bond under
physiological conditions [43–45], we have demonstrated that
Fig. 8. 1H NMR spectra (400 MHz) of the methyl region of (a) PhSeHgMe (top), (b) a
mixture of PhSeHgMe and PhSHgMe (middle) and PhSHgMe (bottom).
the ttris(2-mercapto-1-t-butylimidazolyl)hydroborato complexes
Bu
½
Tm ꢁHgR (R = Me, Et) undergo facile cleavage of the Hg–C bond
by PhSH at room temperature due to the mercury center being able
to access higher coordination modes [46]. To investigate further
the factors that influence the cleavage of Hg–C bonds, we have
examined the reactivity of PhSeHgR towards PhSH with the inten-
tion of probing the effect of selenolate versus thiolate coordination.
Interestingly, whereas the thiolate compound PhSHgEt reacts
only slowly with PhSH at room temperature, and requires elevated
temperatures to liberate ethane efficiently [19e], the selenolate
compound PhSeHgEt reacts rapidly, with evolution of ethane
3
proceeding over the course of one day at room temperature. As
such, it is evident that coordination by selenium promotes
protolytic Hg–C bond cleavage, a result that is of relevance to the
observation that various selenium-containing biomolecules can
promote demethylation of methyl-mercury species [7e,11].
Also of note, protolytic cleavage of the Hg–Et bond of PhSeHgEt
is significantly more facile than cleavage of the Hg–Me bond. For
example, whereas elimination of ethane from the reaction of
PhSeHgEt and PhSH is complete after a period of 1 day at room
temperature, negligible quantities of methane are liberated from
Fig. 9. 1H NMR spectra (400 MHz) of the ethyl region of (a) PhSeHgEt (top), (b) a
mixture of PhSeHgEt and EtHgCl (middle) and (c) EtHgCl (bottom).
2
For an image of the 1H NMR spectrum of Et
group is downfield of the CH
2
2
Hg in CDCl
3
, which shows that the
chemical shift of the CH
3
group, see the Structural
a mixture of PhSeHgMe and PhSH under comparable conditions.
The observation of more facile Hg–Et rather than Hg–Me bond
cleavage is in accord with the behavior of the corresponding thio-
late system, PhSHgR [19e], but contrasts with the report that
Database for organic compounds: http://sdbs.db.aist.go.jp/sdbs/cgi-bin/direct_fra-
me_top.cgi (SDBS #10645).
The mercury product is tentatively identified as heteroleptic (PhS)Hg(SePh),
2 2
which undergoes redistribution to form a mixture with (PhS) Hg and (PhSe) Hg.
3

K. Yurkerwich et al. / Polyhedron 103 (2016) 307–314
311
Scheme 2. Two mechanisms for degenerate exchange of R groups.
that the exchange averaged alkyl signals in the mixture of PhSeHgR
1
99
and RHgCl retain
Hg coupling (albeit a weighted average of the
exchanging species) indicates that Hg–C bond cleavage does not
occur on the timescale associated with the observed exchange pro-
cess [48,49].
Further evidence that Hg–R bond metathesis in this system is
not facile on the NMR timescale is also provided by the fact that
1
99
1
the
PhSeHgEt exhibits two distinct
Fig. 10), rather than the single signal that would be expected if
Hg{ H} NMR spectrum of a mixture of PhSeHgMe and
1
99
Hg NMR spectroscopic signals
(
the alkyl groups were to undergo exchange.
The above observations are in accord with other studies involv-
ing RHgX compounds which indicate that metathesis involving
Hg–X bonds is more facile than those involving Hg–R bonds
[
50,51], presumably due to the availability of lone pairs on X that
favor 4-centered transition states of the type illustrated in
Scheme 2 [54]. In this regard, it should be noted that although a
previous investigation proposed Hg–R/Hg–R metathesis involving
RHgX compounds (e.g. MeHgI [37]) in order to explain the greater
linewidth of the mercury satellites in the H NMR spectra, it is now
recognized that this observation is more appropriately rationalized
in terms of scalar relaxation of the second kind [52]. Specifically,
Fig. 10. 199Hg{ H} NMR spectra of a mixture of PhSeHgMe and PhSeHgEt.
1
1
4 2 4
protonolysis of RHgI by HClO and H SO exhibits the opposite
trend [43b,45]. The differences observed in these systems
indicate that there is much to be learned regarding the factors
that influence Hg–C bond cleavage and, consequently, mercury
detoxification.
quadrupolar relaxation of the adjacent iodine nucleus induces
199
relaxation of the
Hg nucleus, thereby increasing the linewidth
of the satellite signals relative to the central signal [52,53].
2.3. Degenerate exchange reactions involving PhSeHgR
3
. Summary
PhSeHgR undergo facile degenerate exchange reactions. For
In summary, X-ray diffraction studies demonstrate that the
1
example, H NMR spectroscopic studies demonstrate that a mix-
ture of PhSeHgMe and MeHgCl exhibit a single resonance attribu-
table to the methyl groups (Fig. 7), as does a mixture of PhSeHgMe
and PhSHgMe (Fig. 8).4 A mixture of PhSeHgEt and EtHgCl likewise
exhibit a single set of signals for the ethyl groups (Fig. 9). The obser-
vation of a single set of resonances for the alkyl groups indicates that
the exchange processes are in the fast exchange regime [47]. In
phenylselenolate mercury alkyl compounds, PhSeHgMe and
PhSeHgEt, are best described as monomeric with approximately
linear coordination geometries; the mercury centers do, neverthe-
less, exhibit secondary Hgꢀ ꢀ ꢀSe intermolecular interactions that
serve to increase the effective coordination number. The mer-
cury–carbon bond of PhSeHgEt is readily cleaved by PhSH to
release ethane; significantly, the reaction is more facile than that
of the thiolate analog, PhSHgEt, which thereby demonstrates that
coordination by selenium promotes protolytic cleavage of the mer-
cury–carbon bond. Protolytic cleavage of the Hg–Et bond of
PhSeHgEt is also significantly more facile than cleavage of the
Hg–Me bond, which is of note because a different trend was
reported for the cleavage of RHgI by HX. In addition to reactivity
associated with the Hg–Et bond, the phenylselenolate compounds
PhSeHgR (R = Me, Et) also undergo degenerate exchange reactions
with RHgX (X = Cl, SPh) via metathesis of the Hg–SePh/Hg–X
groups, evidence for which is provided by the observation that
1
99
1
addition, a single
Hg{ H} NMR spectroscopic signal is observed
for a mixture of PhSeHgMe and MeHgCl, and also for a mixture of
PhSeHgEt and EtHgCl.
Two possible mechanisms for the degenerate exchange pro-
cesses involve (i) Hg–R/Hg–R metathesis and (ii) Hg–SePh/Hg–X
5
metathesis, as illustrated in Scheme 2. Of these, the latter is more
1
consistent with the H NMR spectroscopic data. For example, the fact
4
Exchange between PhSeHgMe and MeHgCN on the NMR timescale has also been
reported. See Ref. [21a].
While the Hg–SePh/Hg–X metathesis illustrated in Scheme 2 is depicted as
bimolecular, we note that other exchange mechanisms are possible, including those
that are dissociative in nature.
5
1
the weighted average signal for the alkyl groups in the H NMR
1
99
spectra preserves coupling to the
Hg nuclei.

3
12
K. Yurkerwich et al. / Polyhedron 103 (2016) 307–314
4
. Experimental
solution (20 mL) of sodium borohydride (65 mg, 1.7 mmol). The
yellow solution slowly turned colorless over a period of several
minutes, and the resulting solution was treated with an ethanol
solution (30 mL) of MeHgCl (423 mg, 1.7 mmol). The suspension
was stirred for 2.5 h, allowed to settle, and filtered. The volatile
components of the filtrate were removed in vacuo leaving
PhSeHgMe as a yellow powder (395 mg, 63%). Anal. Calc. for
4
.1. General considerations
NMR spectra were measured on Bruker 300 DPX, Bruker 400
Avance III, and Bruker Avance 500 DMX spectrometers. 1H NMR
spectra are reported in ppm relative to SiMe
erenced internally with respect to the protio solvent impurity (d
.16 for C H, 7.26 for CDCl and 2.50 for Me SO-d ) [54].
C{ H} NMR spectra are reported in ppm relative to SiMe
d = 0) and were referenced internally with respect to the solvent
4
(d = 0) and were ref-
1
PhSeHgMe: C, 22.6; H, 2.2. Found: C, 22.7; H, 2.0. H NMR
2
7
6
D
5
3
2
5
(C
6
D
6
): 0.21 [s,
J
Hg–H = 155, 3 H of C
6
H
5
SeHgCH
3
], 6.93 [m, 3H of
1
3
1
1
C
6
H
5
SeHgMe], 7.59 [m, 2H of C
6
H
5
SeHgMe]; H NMR (CDCl
SeHgCH ], 7.17 [m, 3H of
SeHgMe]. C NMR (CDCl
16.4 [ JHg–C 1080 Hz, 1C of PhSeHgCH ], 126.2 [1C of C Hg],
126.3 [1C of C Hg], 129.1 [2C of C
Hg NMR (C
3
):
4
2
(
(
0.95 [s,
J
Hg–H = 155, 3H of
C
6
H
5
3
d 128.06 for C
6
) [54]. 1 Hg{ H} NMR spec-
Hg (d = 0) and were
/100% value of 17.910822 [55]. Coupling
99
1
C
6
H
5
SeHgMe], 7.56 [m, 2H of C
6
H
5
13
3
):
D
6
and 77.16 for CDCl
3
1
tra are reported in ppm relative to Me
obtained by using the
constants are given in Hertz. IR spectra were recorded as KBr pel-
lets on a Nicolet iS10 FT-IR spectrometer (ThermoScientific), and
the data are reported in reciprocal centimeters. Mass spectra were
obtained on a JEOL JMS-HX110HF tandem mass spectrometer
2
3
6 5
H
N
6
H
5
6 5
H Hg], 135.9 [2C of
1
99
ꢂ1
C
6
H
5
Hg].
6
D
6
): ꢂ658. IR Data (KBr pellet, cm ):
3059 (w), 2990 (w), 2905 (m), 1658 (w), 1572 (s), 1471 (vs),
1431 (s), 1322 (w), 1292 (w), 1263 (w), 1179 (w), 1159 (w),
1067 (s), 1018 (s), 996 (m), 889 (w), 767 (m), 726 (vs), 687 (vs),
+
using fast atom bombardment (FAB). Ph
2
Se
2
was purchased from
663 (s). FAB-MS m/z = 372.0 [M] , M = PhSeHgMe.
Strem Chemicals, EtHgCl was purchased from Alfa Aesar and all
other chemicals were purchased from Sigma–Aldrich. CAUTION:
All mercury compounds are toxic and appropriate safety precautions
must be taken in handling these compounds.
4.4. Synthesis of PhSeHgEt
An ethanol solution (60 mL) of diphenyl diselenide (274 mg,
0
.88 mmol) was treated with an ethanol solution (15 mL) of
sodium borohydride (66 mg, 1.7 mmol). The yellow solution slowly
turned colorless over a period of several minutes and the resulting
solution was treated with an ethanol solution (25 mL) of EtHgCl
4
.2. X-ray structure determinations
Single crystal X-ray diffraction data were collected on a Bruker
(
466 mg, 1.76 mmol). The suspension was stirred for 10 h, allowed
Apex II diffractometer and crystal data, data collection and refine-
ment parameters are summarized in Table 4. The structures were
solved using direct methods and standard difference map tech-
niques, and were refined by full-matrix least-squares procedures
to settle, and filtered. The volatile components of the filtrate were
removed in vacuo leaving PhSeHgEt as a yellow powder (488 mg,
7
1
2%). Anal. Calc. for PhSeHgEt: C, 24.9; H, 2.6. Found: C, 25.0; H,
1
3
.6.
H
NMR (C
CH ], 0.99 [q,
m, 3H of C SeHgEt], 7.59 [m, 2H of C
6
D
6
,
500 MHz): 0.85 [t,
J
J
H–H = 8, 3H of
H–H = 8, 2H of PhSeHgCH CH ], 6.92
SeHgEt]; H NMR
2
on F with SHELXTL (Version 2008/4) [56].
3
PhSeHgCH
[
2
3
2
3
1
6
H
5
6
H
5
3
4.3. Synthesis of PhSeHgMe
(CDCl , 500 MHz): 1.37 [t, JH–H = 8, 3H of PhSeHgCH CH ], 1.80
3
2
3
3
[
q,
J
H–H = 8, 2H of PhSeHgCH
2
3
CH
3
], 7.17 [m, 3H of C
6
H
5
SeHgEt],
1
2
PhSeHgMe was synthesized by a method related to that in the
Hg–C
7.55 [m, 2H of C H SeHgEt]. C NMR (C D ): 13.6 [ J = 63 Hz,
1C of PhSeHgCH CH ], 31.8 [ J
Hg–C
6
5
6
6
1
literature [21a]. An ethanol solution (50 mL) of diphenyl
diselenide (264 mg, 0.85 mmol) was treated with an ethanol
1145 Hz, 1C of
2
3
PhSeHgCH CH ], 126.1 [1C of C H HgEt], 129.2 [2C of C H HgEt],
2
3
6
5
6
5
1
6 5
36.1 [2C of C H HgEt] (note: the ipso carbon is obscured by the
1
3
2
solvent);
PhSeHgCH
1
C
NMR (CDCl
3
): 14.0 [ JHg–C = 63 Hz, 1C of
], 32.4 [ JHg–C 1145 Hz, 1C of PhSeHgCH CH ],
HgEt], 126.4 [1C of C HgEt], 129.1 [2C of
Hg NMR (C
): ꢂ815. IR
Table 4
1
2
CH
3
2
3
Crystal, intensity collection and refinement data.
26.3 [1C of C
6
H
5
6 5
H
PhSeHgMe
PhSeHgEt
199
C
6
H
5
HgEt], 135.9 [2C of C
H
6 5
HgEt].
6 6
D
ꢂ1
Lattice
orthorhombic
monoclinic
Data (KBr pellet, cm ): 3066 (w), 3053 (w), 2965 (m), 2942 (m),
Formula
Formula weight
Space group
a (Å)
b (Å)
c (Å)
C
7
H
8
HgSe
C
8
H
10HgSe
385.71
P2 /c
2
(
7
919 (w), 2855 (m), 1573 (s), 1471 (s), 1433 (s), 1372 (w), 1295
w), 1172 (m), 1066 (m), 1017 (s), 997 (m), 960 (w), 896 (w),
30 (vs), 690 (vs), 663 (s), 672 (m), 615 (w). FAB-MS m/z = 386.0
371.68
Pbcn
24.803(12)
9.758(5)
7.041(3)
90
1
14.275(5)
17.858(7)
7.239(3)
90
91.743(6)
90
1844.7(12)
8
200(2)
0.71073
2.778
+
[M] , M = PhSeHgEt.
a
(°)
b (°)
(°)
4.5. Reactivity of PhSeHgEt towards PhSH
90
90
c
3
V (Å )
1704.2(14)
8
6 6
A solution of PhSeHgEt (10 mg, 0.026 mmol) in C D (0.7 mL)
Z
was treated with PhSH (2.7 lL, 0.026 mmol) and transferred to
an NMR tube equipped with a J. Young valve. The reaction was
monitored by H NMR spectroscopy, thereby demonstrating the
T (K)
k (Å)
200(2)
0.71073
2.897
22.249
30.71
24879
2631
1
ꢂ3
qcalc. (g cm
)
ꢂ1
release of C
panied by the formation of a precipitate which is assigned as a
rapidly interconverting mixture of (PhS)Hg(SePh), (PhS) Hg and
PhSe) Hg in solution.
2 6
H over a period of 1 day at room temperature, accom-
l
(Mo K ), (mm
a
)
20.559
29.61
27354
5165
h maximum (°)
No. of data collected
No. of data used
No. of parameters
2
(
2
82
181
R
1
[I > 2
wR [I > 2
[all data]
wR [all data]
GOF
r
(I)]
0.0297
0.0549
0.0682
0.0653
1.008
0.0836
0.0372
0.0570
0.1059
0.0726
1.007
4.6. Reactivity of PhSeHgMe towards PhSH
2
r(I)]
R
1
2
6 6
A solution of PhSeHgMe (10 mg, 0.027 mmol) in C D (0.7 mL)
was treated with PhSH (2.8
lL, 0.027 mmol) and transferred to
R
int
0.0653
an NMR tube equipped with a J. Young valve. The sample was

K. Yurkerwich et al. / Polyhedron 103 (2016) 307–314
313
monitored by 1H NMR spectroscopy, thereby demonstrating that
References
there is negligible formation of CH
temperature.
4
over a period of 1 day at room
[
1] (a) R.C. Prince, J. Gailer, D.E. Gunson, R.J. Turner, G.N. George, I.J. Pickering, J.
Inorg. Biochem. 101 (2007) 1891;
(
(
(
b) J. Gailer, Coord. Chem. Rev. 251 (2007) 234;
c) J. Gailer, Appl. Organomet. Chem. 16 (2002) 701;
d) M.L.A. Cuvin-Aralar, R.W. Furness, Ecotoxicol. Environ. Safety 21 (1991)
4
.7. NMR spectroscopic investigation of degenerate exchange involving
PhSeHgMe and MeHgCl
3
(
48;
e) T. Ikemoto, T. Kunito, H. Tanaka, N. Baba, N. Miyazaki, S. Tanabe, Arch.
Environ. Contam. Toxicol. 47 (2004) 402;
A solution of PhSeHgMe (6 mg, 0.016 mmol) and MeHgCl (4 mg,
.016 mmol) in C (0.7 mL) was transferred to an NMR tube
equipped with a J. Young valve. The sample was examined by
(
(
(
f) L. Magos, M. Webb, T.W. Clarkson, Crit. Rev. Toxicol. 8 (1980) 1;
g) M.A.K. Khan, F. Wang, Environ. Toxicol. Chem. 28 (2009) 1567;
h) D.-Y. Yang, Y.-W. Chen, J.M. Gunn, N. Belzile, Environ. Rev. 16 (2008) 71.
0
6 6
D
1
H
NMR spectroscopy, thereby demonstrating a single resonance
attributable the mercury methyl groups. Similarly, a solution con-
sisting of PhSeHgMe (7 mg, 0.019 mmol) and MeHgCl (5 mg,
[2] (a) T. Syversen, P.J. Kaur, Trace Elem. Med. Biol. 26 (2012) 215;
(
(
(
b) T.W. Clarkson, L. Magos, Crit. Rev. Toxicol. 36 (2006) 609;
c) J. Mutter, J. Naumann, C. Guethlin, Crit. Rev. Toxicol. 37 (2007) 537;
d) M. Berlin, R.K. Zalups, B.A. Fowler, Mercury in Handbook on the Toxicology
(0.7 mL) was examined by 1 Hg{ H} NMR,
99
1
0
.020 mmol) in C
6
D
6
of Metals, third ed., Elsevier Academic Press Inc, San Diego, 2007. p 675–729
Chapter 33).
3] (a) M. Roman, P. Jitaru, C. Barbante, Metallomics 6 (2014) 25;
(
thereby demonstrating a single resonance.
[
(
(
b) J. Lu, A. Holmgren, J. Biol. Chem. 284 (2009) 723;
c) L.V. Papp, J. Lu, A. Holmgren, K.K. Khanna, Antioxid. Redox Signal. 9 (2007)
4
.8. NMR spectroscopic investigation of degenerate exchange involving
7
(
7
(
9
(
75;
d) L.V. Papp, A. Holmgren, K.K. Khanna, Antioxid. Redox Signal. 12 (2010)
93;
e) L.A. Wessjohann, A. Schneider, M. Abbas, W. Brandt, Biol. Chem. 388 (2007)
97;
f) U. Tinggi, Environ. Health Prev. Med. 13 (2008) 102;
(g) M. Ninomiya, D.R. Garud, M. Koketsu, Coord. Chem. Rev. 255 (2011) 2968;
h) L.R. Ferguson, N. Karunasinghe, S.T. Zhu, A.H. Wang, Mutat. Res. Fundam.
Mol. Mech. Mutagen. 733 (2012) 100;
PhSeHgMe and PhSHgMe
A solution of PhSeHgMe (6 mg, 0.016 mmol) and PhSHgMe
(
6 6
5 mg, 0.015 mmol) in C D (0.7 mL) was transferred to an NMR
tube equipped with a J. Young valve. The sample was examined
by H NMR spectroscopy, thereby demonstrating a single reso-
nance attributable to the mercury methyl groups.
1
(
(
(
i) R. Naithani, Mini-Rev. Med. Chem. 8 (2008) 657;
j) M. Valko, C.J. Rhodes, J. Moncol, M. Izakovic, M. Mazur, Chem. Biol. Interact.
1
(
60 (2006) 1;
k) H. Tapiero, D.M. Townsend, K.D. Tew, Biomed. Pharmacother. 57 (2003)
134;
4
.9. NMR spectroscopic investigation of degenerate exchange involving
PhSeHgEt and EtHgCl
(
(
(
(
l) G. Bjelakovic, D. Nikolova, L. Gluud, R.G. Simonetti, C. Gluud, JAMA 297
2007) 842;
m) C. Michiels, M. Raes, O. Toussaint, J. Remacle, Free Radical Biol. Med. 17
1994) 235;
A solution of PhSeHgEt (5 mg, 0.013 mmol) and EtHgCl (3 mg,
0
.011 mmol) in C
equipped with a J. Young valve. The sample was examined by
6 6
D (0.7 mL) was transferred to an NMR tube
1
H
(n) J. Chen, M.J. Berry, J. Neurochem. 86 (2003) 1.
4] (a) J. Köhrle, Biochimie 81 (1999) 527;
(
(
(d) Carland, M.; Fenner, T. in Metallotherapeutic Drugs and Metal-Based
Diagnostic Agents: The Use of Metals in Medicine, John Wiley and Sons,
Hoboken, NJ, 2005, Chapter 17.;
[
NMR spectroscopy, thereby demonstrating a single resonance
attributable the mercury ethyl groups. Similarly, a solution consist-
ing of PhSeHgEt (15 mg, 0.039 mmol) and EtHgCl (10 mg,
b) C.C. Reddy, E.J. Massaro, Fundam. Appl. Toxicol. 3 (1983) 431;
c) D.V. Frost, P.M. Lish, Ann. Rev. Pharmacol. Toxicol. 15 (1975) 259;
(1.5 mL) was examined by 1 Hg{ H} NMR,
99
1
0
.038 mmol) in C
D
6 6
thereby demonstrating a single resonance.
(
4
e) C. Sanmartín, D. Plano, M. Font, J.A. Palop, Curr. Med. Chem. 18 (2011)
635;
(
(
f) L.H. Duntas, J. Clin. Endocrinol. Metab. 95 (2010) 5180;
g) L. Schomburg, Nat. Rev. Endocrinol. 8 (2012) 160;
4
.10. NMR spectroscopic investigation of exchange involving
PhSeHgMe and PhSeHgEt
(h) E.R.T. Tiekink, Dalton Trans. 41 (2012) 6390.
5] (a) I. Falnoga, M. Tušek- Zˇ nidari cˇ , Biol. Trace Elem. Res. 119 (2007) 212;
(
(
[6] (a) F. Wang, M. Lemes, M.A.K. Khan, in: Y. Cai, G. Liu, N. O’Driscoll (Eds.),
Environmental Chemistry and Toxicology of Mercury, John Wiley & Sons, New
Jersey, 2012. Chapter 16;
[
b) I. Falnoga, M. Tušek- Zˇ nidari cˇ , P. Stegnar, Biometals 19 (2006) 283;
c) C. Sasakura, K.T. Suzuki, J. Inorg. Biochem. 71 (1998) 159.
A solution of PhSeHgMe (6 mg, 0.016 mmol) and PhSeHgEt
1
99
1
(
6 mg, 0.016 mmol) in C
6
D
6
(0.7 mL) was examined by
Hg{ H}
NMR spectroscopy, which showed independent signals for
PhSeHgMe and PhSeHgEt, thereby indicating that exchange of
methyl and ethyl groups is not facile on the NMR timescale.
(
b) N.V.C. Ralston, C.R. Ralston, J.L. Blackwell III, L.J. Raymond, Neurotoxicology
9 (2008) 802;
c) C.M.L. Carvalho, E.-H. Chew, S.I. Hashemy, J. Lu, A. Holmgren, J. Biol. Chem.
83 (2008) 11913.
7] (a) Y. Yamashita, M. Yamashita, J. Biol. Chem. 285 (2010) 18134;
2
(
2
Acknowledgments
[
(
(
b) Y. Yamashita, T. Yabu, M. Yamashita, World J. Biol. Chem. 1 (2010) 144;
c) Y. Yamashita, H. Amlund, T. Suzuki, T. Hara, M.A. Hossain, T. Yabu, K.
Research reported in this publication was supported by the
National Institute of General Medical Sciences of the National
Institutes of Health under Award Number R01GM046502. The con-
tent is solely the responsibility of the authors and does not neces-
sarily represent the official views of the National Institutes of
Health.
Touhata, M. Yamashita, Fish. Sci. 77 (2011) 679;
d) M. Yamashita, Y. Yamashita, T. Ando, J. Wakamiya, S. Akiba, Biol. Trace
Elem. Res. 156 (2013) 36;
e) M. Yamashita, Y. Yamashita, T. Suzuki, Y. Kani, N. Mizusawa, S. Imamura, K.
Takemoto, T. Hara, M.A. Hossain, T. Yabu, K. Touhata, Mar. Biotechnol. 15
2013) 559.
[8] Y. Ogra, Y. Anan, Biol. Pharm. Bull. 35 (2012) 1863.
9] M. Klein, L. Ouerdane, M. Bueno, F. Pannier, Metallomics 3 (2011) 513.
(
(
(
[
[
[
10] (a) C. Jacob, G.I. Giles, N.M. Giles, H. Sies, Angew. Chem., Int. Ed. Engl. 42
(2003) 4742;
Appendix A.
(
(
b) G. Roy, B.K. Sarma, P.P. Phadnis, G. Mugesh, J. Chem. Sci. 117 (2005) 287;
c) L.A. Silks, Phosphorus, Sulfur Silicon Relat. Elem. 136 (1998) 611.
CCDC 1057236–1057237 contains the supplementary crystallo-
graphic data for this paper. These data can be obtained free of
charge via http://www.ccdc.cam.ac.uk/conts/retrieving.html, or
from the Cambridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: (+44) 1223-336-033; or e-mail:
deposit@ccdc.cam.ac.uk.
11] M.A.K. Khan, F.Y. Wang, Chem. Res. Toxicol. 23 (2010) 1202.
[12] H.C. Tai, C. Lim, J. Phys. Chem. A 110 (2006) 452.
[
[
[
13] (a) J.P.K. Rooney, Toxicology 234 (2007) 145;
b) G. Guzzi, C.A.M. La Porta, Toxicology 244 (2008) 1.
(
14] D.A. Geier, L.K. Sykes, M.R. Geier, J. Toxicol. Environ. Health Part B 10 (2007)
575.
15] H.M. Powell, W.A. Jamieson, Am. J. Hygiene 13 (1931) 296.

3
14
K. Yurkerwich et al. / Polyhedron 103 (2016) 307–314
[
16] (a) H. Ohno, R. Doi, Y. Kashima, S. Murae, T. Kizaki, Y. Hitomi, N. Nakano, M.
Harada, Bull. Environ. Contam. Toxicol. 73 (2004) 777;
and EtHgCl and could possibly indicate the existence of an equilibrium with a
dimeric form. In this regard, it is worth noting that PhHgOMe is dimeric in
benzene, while other PhHgOR derivatives exist as an equilibrium mixture of
monomer and dimers. See: A.J. Bloodworth, J. Chem. Soc. C (1970) 2051.
[39] (a) D.F. Evans, J.P. Maher, J. Chem. Soc. (1962) 5125;
(
(
b) S. Gil, I. Lavilla, C. Bendicho, J. Anal. At. Spectrom. 22 (2007) 569;
c) A. Fagundes, M.C.A. Marzochi, M. Perez, A. Schubach, A. Ferreira, J.P. Silva,
T. Schubach, K.B.F. Marzochi, Acta Trop. 101 (2007) 25;
d) B.K. Meyer, A. Ni, B. Hu, L. Shi, J. Pharm. Sci. 96 (2007) 3155.
17] J.G. Melnick, K. Yurkerwich, D. Buccella, W. Sattler, G. Parkin, Inorg. Chem. 47
2008) 6421.
(
(b) P.T. Narasimhan, M.T. Rogers, J. Am. Chem. Soc. 82 (1960) 34.
[
[40] It is important to note that data illustrating the opposite trend in d(CH
d(CH ) chemical shifts of EtHgX compounds have been compiled, as illustrated
by Tables 6 and 7 in: V.S. Petrosya, O.A. Reutov, J. Organomet. Chem. 76 (1974)
123. However, there are discrepancies in these data. For example, d(CH ) and
d(CH ) for Et Hg in CCl
are listed as ꢂ1.27 and ꢂ1.01, respectively, in Table 6,
but are listed as 1.27 and 1.01 in the text on p. 130. Furthermore, values of 0.06
and 0.37 ppm are reported for Et Hg in Table 7. It is possible that these
3
) and
(
2
[
[
18] W. Sattler, K. Yurkerwich, G. Parkin, Dalton Trans. (2009) 4327.
19] For some structurally characterized arylthiolate mercury methyl and related
compounds, see Ref. [17] and
3
2
2
4
(
(
a) C. Chieh, Can. J. Chem. 56 (1978) 560;
b) A. Castiñeiras, W. Hiller, J. Strähle, J. Bravo, J.S. Casas, M. Gayoso, J. Sordo, J.
2
Chem. Soc., Dalton Trans. (1986) 1945;
c) X. Almagro, W. Clegg, L. Cucurull-Sánchez, P. González-Duarte, M. Traveria,
J. Organomet. Chem. 623 (2001) 137;
discrepancies are a result of different chemical shift conventions in the early
literature.
[41] R.E. Dessy, T.J. Flautt, H.H. Jaffé, G.F. Reynolds, J. Chem. Phys. 30 (1959) 1422.
[42] (a) M.J. Moore, M.D. Distefano, L.D. Zydowsky, R.T. Cummings, C.T. Walsh, Acc.
Chem. Res. 23 (1990) 301;
(
(
(
d) J.H. Aupers, R.A. Howie, J.L. Wardell, Polyhedron 16 (1997) 2283;
e) J.G. Melnick, K. Yurkerwich, G. Parkin, Inorg. Chem. 48 (2009) 6763.
[
[
20] Cambridge Structural Database (Version 5.33). 3D Search and Research Using
the Cambridge Structural Database, F.H. Allen, O. Kennard, Chemical Design
Automation News, 1993, vol. 8 (1), pp. 1 & 31–37.
21] For examples of organomercury selenolate compounds that are not listed in
the Cambridge Structural Database, see:
(b) C.T. Walsh, M.D. Distefano, M.J. Moore, L.M. Shewchuk, G.L. Verdine, FASEB
J. 2 (1988) 124.
[43] (a) M.M. Kreevoy, J. Am. Chem. Soc. 79 (1957) 5927;
(b) M.M. Kreevoy, R.L. Hansen, J. Am. Chem. Soc. 83 (1961) 626.
[44] (a) H. Strasdeit, A. von Döllen, W. Saak, M. Wilhelm, Angew. Chem., Int. Ed. 39
(2000) 784;
(b) M. Wilhelm, S. Deeken, E. Berssen, W. Saak, A. Lützen, R. Koch, H. Strasdeit,
Eur. J. Inorg. Chem. (2004) 2301.
[45] W.A. Nugent, J.K. Kochi, J. Am. Chem. Soc. 98 (1976) 5979.
[46] J.G. Melnick, G. Parkin, Science 317 (2007) 225.
(
(
a) A.J. Canty, A.J. Carty, S.F. Malone, J. Inorg. Biochem. 19 (1983) 133;
b) E. Pelletier, F. Sauriol, I. Wharf, Inorg. Chim. Acta 138 (1987) 99.
[
22] (a) J.S. Casa, M.S. García-Tasende, J. Sordo, Coord. Chem. Rev. 193–195 (1999)
83;
2
(
(
b) C.E. Holloway, M. Melník, J. Organomet. Chem. 495 (1995) 1;
c) D.L. Rabenstein, Acc. Chem. Res. 11 (1978) 100.
[47] R.G. Bryant, J. Chem. Educ. 60 (1983) 933.
[
[
23] (a) J.G. Wright, M.J. Natan, F.M. MacDonnell, D.M. Ralston, T.V. O’Halloran,
Prog. Inorg. Chem. 38 (1990) 323;
[48] J.W. Faller, Dynamic NMR spectroscopy in organometallic chemistry, in: R.H.
Crabtree, D.M.P. Mingos (Eds.), Comprehensive Organometallic Chemistry III,
vol. 1, Elsevier, Oxford, 2007. Chapter 1.15.
(
b) L.G. Kuz’mina, Y.T. Struchkov, Croat. Chem. Acta 57 (1984) 701.
24] (a) P. Pyykkö, J.-P. Desclaux, Acc. Chem. Res. 12 (1979) 276;
[49] Furthermore, the observation of 199Hg satellites in the 1H NMR spectra of
individual samples of PhSeHgR and RHgX indicates that degenerate Hg–R/Hg–
(
(
(
b) P. Pyykkö, Chem. Rev. 88 (1988) 563;
c) M. Kaupp, H.G. von Schnering, Inorg. Chem. 33 (1994) 2555;
d) J.A. Tossell, D.J. Vaughan, Inorg. Chem. 20 (1981) 3333.
1
99
77
R metathesis does not occur. We also note that neither
Hg– Se coupling
199
1
nor long range
the 1H NMR spectra of PhSeHgR. Since long range
observed in mercury alkyl and aryl compounds,
Hg– H coupling involving the phenyl group are observed in
199
1
[
[
[
[
25] M. Bochmann, A.P. Coleman, A.K. Powell, Polyhedron 11 (1992) 507.
26] A.J. Carty, S.F. Malone, N.J. Taylor, J. Organomet. Chem. 172 (1979) 201.
27] A.J. Carty, S.F. Malone, N.J. Taylor, A.J. Canty, J. Inorg. Biochem. 18 (1983) 291.
28] T.J. Emge, M.D. Romanelli, B.F. Moore, J.G. Brennan, Inorg. Chem. 49 (2010)
Hg– H coupling has been
a–d
the absence of these
couplings may possibly be associated with facile exchange of the
phenylselenolate ligand.
7
304.
(a) G. Singh, G.S. Reddy, J. Organomet. Chem. 42 (1972) 267;
(b) P.J. Banney, P.R. Wells, Aust. J. Chem. 24 (1971) 317;
(c) B. Wrackmeyer, R. Contreras, Annu. Rep. NMR Spectrosc. 24 (1992) 267;
(d) D.C. Bebout, M.M. Garland, G.S. Murphy, E.V. Bowers, C.J. Abelt, R.J.
Butcher, Dalton Trans. (2003) 2578.
[
[
29] J.G. Melnick, K. Yurkerwich, G. Parkin, J. Am. Chem. Soc. 132 (2010) 647.
30] (a) M.L.H. Green, J. Organomet. Chem. 500 (1995) 127;
(
b) G. Parkin, in: R.H. Crabtree, D.M.P. Mingos (Eds.), Comprehensive
Organometallic Chemistry III, vol. 1, Elsevier, Oxford, 2007. Chapter 1.01;
(
(
c) J.C. Green, M.L.H. Green, G. Parkin, Chem. Commun. 48 (2012) 11481;
d) M.L.H. Green, G. Parkin, J. Chem. Educ. 91 (2014) 807.
[50] (a) R.D. Bach, A.T. Weibel, J. Am. Chem. Soc. 98 (1976) 6241;
(b) R.D. Bach, A.T. Weibel, J. Am. Chem. Soc. 97 (1975) 2575.
[51] L.L. Murrell, T.L. Brown, J. Organomet. Chem. 13 (1968) 301.
[52] M. Bruch, NMR Spectroscopy Techniques, second ed., Marcel Dekker, New
York, 1996.
[
[
31] (a) J.H. Palmer, G. Parkin, Polyhedron 52 (2013) 658;
b) J.H. Palmer, G. Parkin, J. Am. Chem. Soc. 137 (2015) 4503.
32] (a) K. Brodersen, G. Liehr, M. Rosenthal, G. Thiele, Z. Naturforsch., B 33 (1978)
227;
b) K. Brodersen, G. Liehr, M. Rosenthal, Chem. Ber. Recl. 110 (1977) 3291.
(
1
(
[53] R.B. Simpson, J. Chem. Phys. 46 (1967) 4775.
[54] H.E. Gottlieb, V. Kotlyar, A. Nudelman, J. Org. Chem. 62 (1997) 7512.
[55] (a) R.K. Harris, E.D. Becker, S.M.C. De Menezes, R. Goodfellow, P. Granger, Pure
Appl. Chem. 73 (2001) 1795;
[
[
[
33] A. Haaland, Angew. Chem., Int. Ed. Engl. 28 (1989) 992.
34] A.J. Canty, J.W. Devereux, B.W. Skelton, A.H. White, Can. J. Chem. 84 (2006) 77.
35] For other compilations of
1
99
Hg NMR data of mercury thiolate compounds, see
(b) R.K. Harris, E.D. Becker, S.M.C. De Menezes, P. Granger, R.E. Hoffman, K.W.
Zilm, Pure Appl. Chem. 80 (2008) 59.
Ref. [23a] and L. Carlton, D. White, Polyhedron 9 (1990) 2717.
[
36] In cases where the signs of the coupling constants for mercury ethyl
[56] (a) G.M. Sheldrick, SHELXTL, An Integrated System for Solving, Refining and
Displaying Crystal Structures from Diffraction Data, University of Göttingen,
Göttingen, Federal Republic of Germany, 1981;
2
3
compounds have been measured,
positive. See: F.A.L. Anet, J.L. Sudmeier, J. Magn. Reson. 1 (1969) 124.
37] J.V. Hatton, W.G. Schneider, W. Siebrand, J. Chem. Phys. 39 (1963) 1330.
J
Hg–H are negative, whereas
JHg–H are
[
[
(b) G.M. Sheldrick, Acta Crystallogr. A64 (2008) 112.
1
38] We note, however, that the
H NMR chemical shifts of PhSeHgEt are
concentration dependent. Similar variations are also observed for MeHgCl