Binding of a coordinatively unsaturated mercury(II) thiolate compound by carboxylate anions

Article abstract of DOI:10.1021/ic101587h

Reactions of [Hg(Tab)₂](PF₆)₂ (TabH = 4-(trimethylammonio)benzenethiol) (1) with acetic acid (HAc), propanoic acid (HPro), salicylic acid (HSal), benzoic acid (HBez), malonic acid (H ₂Mal), oxalic acid (H_2<

Full text of DOI:10.1021/ic101587h

Inorg. Chem. 2011, 50, 503–516 503
DOI: 10.1021/ic101587h
Binding of a Coordinatively Unsaturated Mercury(II) Thiolate Compound by
Carboxylate Anions
Xiao-Yan Tang,†,‡,§ Ai-Xia Zheng,† Hai Shang,† Rong-Xin Yuan,§ Hong-Xi Li,† Zhi-Gang Ren, and Jian-Ping Lang*,†,‡
†College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123,
People’s Republic of China, ‡State Key Laboratory of Coordination Chemistry, Nanjing University,
Nanjing 210093, People’s Republic of China, and §Jiangsu Laboratory of Advanced Functional Materials,
Changshu Institute of Technology, Changshu 215500, People’s Republic of China
Received August 5, 2010
Reactions of [Hg(Tab)2](PF6)2 (TabH = 4-(trimethylammonio)benzenethiol) (1) with acetic acid (HAc), propanoic
acid (HPro), salicylic acid (HSal), benzoic acid (HBez), malonic acid (H2Mal), oxalic acid (H2Oxa), adipic acid (H2Adi),
or methylimindiacetic acid (H2Meida) in the presence of Et3N gave rise to a family of mercury(II)-thiolate-carboxylate
compounds, [Hg(Tab)2(Ac)](PF6) 0.5H2O (2 0.5H2O), [Hg(Tab)2(Pro)](PF6) (3), [Hg(Tab)2(Sal)](PF6) MeOH
3
3
3
(4 MeOH), [Hg(Tab)2(Sal)](Sal) MeOH (5 MeOH), [Hg(Tab)2(Bez)](PF6) H2O (6 H2O), [Hg(Tab)2(HMal)]-
(Mal)0.5 H2O (7 H2O), [{Hg(Tab)2}2( μ-Oxa)](PF6)2 H2O (8 2H2O), [{Hg(Tab)2}2( μ-Adi)](PF6)2 (9), [Hg( μ-Tab)-
3
3
3
3
3
3
3
( μ-Adi)]2n (10), and [Hg(Tab)2(Meida)] 2.5H2O (11 2.5H2O). These compounds were characterized by elemental
3
3
analysis, IR spectra, UV-vis spectra, 1H NMR, and single-crystal X-ray crystallography. Each mercury(II) atom in
[Hg(Tab)2]2þ dication of 2-7 is further coordinated by two oxygen atoms from one Ac-, Pro-, Sal-, Bez-, Mal2- or
HMal- anion, forming a unique seesaw-shaped coordination geometry. In 8 or 9, two [Hg(Tab)2]2þ dications are
connected by one bridging oxalate or adipate dianion to generate a dimeric structure with each mercury(II) center
adopting a seesaw-shaped geometry. In 10, a pair of octahedrally coordinated mercury(II) atoms are bridged by two
sulfur atoms of two Tab ligands to form a [Hg( μ-Tab)2Hg]4þ fragment, which is further connected to its equivalent
ones via four adipate dianions, thereby forming a rare two-dimensional network. In 11, the mercury(II) atom in the
[Hg(Tab)2]2þ dication is coordinated by one nitrogen and two oxygen atoms from one Meida2- dianion to have a
rare square pyramidal geometry. The formation of 2-11 from 1 may be applicable to mimicking the interactions of the
mercury(II) sites of Hg-MerR and Hg-MT with various amino acids encountered in nature.
Introduction
NCS-, I-), the naturally encountered inorganic anions (e.g.,
Cl-, NO2-, NO3-), organic amines and nitrogen heterocyclic
compounds (e.g., 1,2-diaminoethane, pyridine, 1,10-phenan-
throline, N-methylimidazole) were investigated.1 In most of
these reactions, the unsaturated coordination geometry of the
mercury(II) center in 1, involving a linear S-Hg-S unit with
In our previous studies, we reported the preparation of the
mononuclear mercury(II) complex [Hg(Tab)2](PF6)2 (TabH=
4-(trimethylammonio)benzenethiol) (1) using a zwitterionic
thiol TabHPF6.1a Complex 1 was employed as a potential
model complex for mimicking the reactivity of unsaturated
HgS2 sites in the detoxification of mercury by metallothioneins
(MTs),2 in DNA binding-proteins,3 and in the mercury reduc-
tase and organomercury lyase,4 and metalloregulatory protein
(MerR).5 The reactions of 1 with some donor ligands (e.g., Tab,
(2) (a) Stillman, M. J.; Law, A. Y. C.; Szymanska, J. A. In Chemical
Toxicology and Clinical Chemistry of Metals; Brown, S. S., Savoy, J., Eds.;
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*To whom correspondence should be addressed. E-mail: jplang@
suda.edu.cn.
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Zhang, Y.; Chen, Z. N.; Lang, J. P. Eur. J. Inorg. Chem. 2004, 4247. (c) Chen,
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r
2010 American Chemical Society
Published on Web 12/14/2010
pubs.acs.org/IC

504 Inorganic Chemistry, Vol. 50, No. 2, 2011
Tang et al.
strong bonding to sulfur atoms, was further completed by
additional donor ligands. The sulfur atoms of Tab ligands in
1 were also witnessed to further bind to additional metal atoms.
In a rare case, one of the Hg-S(Tab) bonds in 1 was broken up
and the rest mercury(II)/Tab species were rearranged into
different mercury(II)/Tab compounds.1a Considering that or-
ganic carboxylic acids are always encountered in nature, can
they, like those inorganic anions and organic amines, react with
1 and change the geometry of the mercury(II) center in 1?
Reactions of organic or inorganic mercury(II) compounds
with various carboxylic acids and amino acids have been
well documented and some mercury compounds con-
taining acetate,6 nicotinate,7 R-picolinate,8 pyridine-2,6-
dicarboxylate,9 pyridyl-acetate,10 2-amino-4-phenylbutyrate,11
2-pyrazinecarboxylate,12 2,6-diamino-hexanoate,13 cysteine,14
homocysteine,15 S-methyl-cysteine,16 methionine,16a,17 penicil-
lamine,17a,18 proline,19 serine,20 alanine,21 tryptophan,15 N-
acetyl-DL-tryptophan,22 and dipeptide glycylglycine23 have
been structurally characterized. However, the interactions
between the carboxylic acids and the mercury(II)/thiolate
compounds, especially those containing the unsaturated
HgS2 site, seem almost unexplored. In this article, we deliber-
ately selected two alkyl carboxylic acids [acetic acid (HAc) and
propanoic acid (HPro)], two aryl acids [salicylic acid (HSal)
and benzoic acid (HBez)], three dicarboxylic acids [malonic
acid (H2Mal), oxalic acid (H2Oxa), adipic acid (H2Adi)], and
one amino acid [methylimindiacetic acid (H2Meida)] to react
with 1 in the presence of Et3N, and a set of mercury(II)-thiolate-
carboxylate compounds (2-11) were isolated and characterized.
Herein we report the reactions of 1with these carboxylic acids and
their isolation and spectral and structural characterization.
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Results and Discussion
Synthetic and Spectral Aspects. Reactions of 1 and
various carboxylic acids are relatively straightforward.
Treatment of 1 with a slight excess acetate acid or
propionic acid in MeOH/H2O under the presence of
Et3N gave rise to the mononuclear compound [Hg(Tab)2-
(Ac)](PF6) 0.5H2O (2 0.5H2O) or [Hg(Tab)2(Pro)](PF6)
3
3
(3) as colorless blocks in 77% yield (2 0.5H2O) or 92%
3
yield (3) (Scheme 1). When 1 reacted with 1 or 2 equiv of
salicylic acid, it afforded the expected compounds [Hg-
(Tab)2(Sal)](PF6) MeOH (4 MeOH) or [Hg(Tab)2(Sal)]-
3
3
(Sal) MeOH (5 MeOH) as long needles in 87% yield
3
3
(4 MeOH) or 78% yield (5 MeOH). The similar reac-
3
3
tions of 1 with benzoic acid in 1: 1 or 1: 2 molar ratio only
generated [Hg(Tab)2(Bez)](PF6) H2O (6 H2O) in 86%
yield.
3
3
In addition, several carboxylic diacid ligands were also
introduced into the mercury/thiolate system and several
Hg/Tab/polycarboxylate compounds were isolated. For
instance, the reaction of 1 with malonic acid in the
presence of Et3N did not produce the expected dimeric
compound {[Hg(Tab)2]2( μ-Mal)}(PF6)2, but formed a
mononuclear compound [Hg(Tab)2(HMal)](Mal)0.5 H2O
(7 H2O) as colorless blocks in 82% yield (Scheme 2). An
3
3
analogous reaction of 1 with oxalic acid afforded a dimeric
compound [{Hg(Tab)2}2( μ-Oxa)](PF6)2 2H2O (8 2H2O)
3
3
in 89% yield. Intriguingly, the reaction of 1 with equimolar
adipic acid in MeOH led to the formation of an expected
dimeric compound [{Hg(Tab)2}2( μ-Adi)](PF6)2 (9) in 81%
yield (Scheme 3). However, the similar reaction with same
components in a ratio of 1:2 gave rise to a rare polymeric
compound [Hg( μ-Tab)( μ-Adi)]2n (10). In this reaction, one
Tab ligand in [Hg(Tab)2]2þ of 1 was replaced by the adipate
dianion while each mercury(II) center is coordinated by two
doubly bridging Tab ligands and four doubly bridging adi
dianions as described later in this article. The formation of 10
might be ascribed to its low solubility in MeCN.
Finally, treatment of 1 with methylimindiacetic acid
followed by a standard workup afforded the neutral
compound [Hg(Tab)2(Meida)]2 2.5H2O (11 2.5H2O)
3
3
(Scheme 4), in which one N and two O atoms of Meida
bind to the center mercury atom. It is noted that in the
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(23) Corbeil, M. C.; Beauchamp, A. L. Can. J. Chem. 1986, 64, 148.

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Inorganic Chemistry, Vol. 50, No. 2, 2011 505
Scheme 1. Reactions of 1 with Acetic Acid, Propionic Acid, Salicylic acid, and Benzoic acid in the Presence of Et3N
Scheme 2. Reactions of 1 with Malonic Acid and Oxalic Acid in the Presence of Et3N
Scheme 3. Reactions of 1 with 1 or 2 Equivalents of Adipic Acid in the Presence of Et3N

506 Inorganic Chemistry, Vol. 50, No. 2, 2011
Tang et al.
Scheme 4. Reactions of 1 with Methylimidizole Diacid in the Presence
of Et3N
formation of 2-11, the carboxylic acid was deprotonated
by Et3N, thereby forming a protonated [Et3NH]þ cation.
Part of the resulting carboxylate anion in 5 and 7 worked
as a counteranion for the resulting [Hg(Tab)2L]þ (L=Sal-,
Mal2-) cation. The eliminated [PF6]- anion may combine
[Et3NH]þ to form [Et3NH]PF6, which may remain in solu-
tion during the crystallization.
Figure 1. UV-vis curves for the acetonitrile solutions of 1.0 ꢀ 10-5
M
for 1, 2.0 ꢀ 10-5 M for 2, 2.0 ꢀ 10-5 M for 3, 1.0 ꢀ 10-5 M for 4, 1.0 ꢀ
10-5 M for 5, 1.0 ꢀ 10-5 M for 6, 1.0 ꢀ 10-5 M for 7, 2.0 ꢀ 10-5 M for 8,
1.0 ꢀ 10-5 M for 9, 2.0 ꢀ 10-5 M for 10, 2.0 ꢀ 10-5 M for 11, and 1.0 ꢀ
10-5 M for Tab.
Compounds 2-11 were stable toward oxygen and
moisture, and readily soluble in dimethylsulfoxide (DMSO),
dimethylformamide (DMF), MeCN, and insoluble in
MeOH, EtOH, CH2Cl2, and benzene. The elemental ana-
lyses were consistent with their chemical formula. Com-
pound 2, 3, or 11 exhibits νa(COO) and νs(COO) of the
related carboxylate anion at 1552 (2), 1547 (3), or 1589 (11)
and 1490 (2), 1491 (3), or 1489 (11) cm-1, respectively.24 In
the IR spectra of 4-6, the bands at 1558/1488 cm-1 (4),
1585/1488 cm-1 (5), or 1548/1489 cm-1 (6) can be assigned
to be the symmetric and asymmetric C-O stretching vibra-
tions of salicylate or benzolate ligand. In the case of 7, the
presence of the characteristic band at 1732 cm-1 indicates
that the deprotonation of malonic acid is incomplete, though
it shows ν(CdO) at 1621 and 1489 cm-1. Inthe IR spectraof
8-10, a strong band at 1655 (8), 1630 (9), or 1638 (10) cm-1
may be assigned to be the C-O stretching vibration for a
tetradentate bridging oxalate or adipate. In the IR spectra of
2-4, 6, 7, and 9, bands at about 838 and 558 cm-1 may be
assignable to the characteristic P-F stretching vibrations of
PF6-. The absorption peaks at 3400-3500 cm-1 are as-
signed to ν(OH) of the uncoordinated water molecules. In
show much shifting from those of the corresponding ones of
1.1a The results suggest that binding of the carboxylate
anions to the mercury(II) centers of 2-11 in DMSO-d6
solution may be weak.
As shown in Figure 1, the electronic spectra of 2-11 in
MeCN exhibit a strong and broad absorption with max-
ima values ranging from 258 to 290 nm and a long
absorption tail to about 400 nm. Those main absorption
bands observed in the spectra of 2-11 are blue-shifted
with respect to the absorption band at 314 nm of the Tab
ligand,1a which may be ascribed to the ligand(Tab)-
to-metal charge transfer (LMCT).25 When additional
carboxylate anions are introduced into the [Hg(Tab)2]2þ
linear framework of 1, the main absorptions observed in
the spectra of 2-10 look similar and are slightly blue-
shifted relative to that of 1, which may reflect that the
mercury(II) atoms in 2-10 adopt a different coordination
environment. Currently it is difficult to clearly and accu-
rately correlate the UV-vis absorption data (the position
and/or intensity of the bands), for example, with structural
features like Hg-S bond lengths, S-Hg-S angles, or
other structural properties. However, we could still find
some interesting correlations through comparison with
those of the existing mercury(II) thiolate compounds
(Table 1). As observed in Hg(II)-MerR/MT, [Hg(SR)2]
1
the H NMR spectra of 2-7 and 9-11 in DMSO-d6 at
ambient temperature, resonances related to the protons of
the carboxylate anions are assigned as follows: a singlet at
1.69 ppm for methyl protons of acetate (2), multiplets at
1.88-1.93 ppm and 0.89-0.93 ppm for methylene and
methyl protons of propionate (3), multiplets at 7.62-7.65
ppm, 7.09-7.15 ppm, 6.55-6.62 ppm (4 and 5), and a broad
singlet at 4.05 ppm (4) or 4.08 ppm (5) for phenyl and
hydroxyl protons of Sal ligand (4 and 5), multiplets at
7.80-7.82 ppm and 7.29-7.37 ppm for phenyl protons of
benzoate (6), multiplets at 2.97-2.99 ppm (7), 1.94 ppm and
1.43 ppm (9), 1.90 ppm and 1.50-1.52 ppm (10) for methy-
lene protons of Mal or Adi ligands, singlet at 2.16 ppm and
multiplets at 2.94 ppm for methyl and methylene protons of
Meida ligand (11). It is noted that resonances related to the
protons of the Tab ligand in 2-11 feature multiplets in the
region of 7.51-7.72 ppm for its phenyl groups of the Tab
ligands and a singlet at about 3.53 ppm for the methyl
protons of its NMe3 unit. These peaks exhibited some shifts
from those of the corresponding ones of the free ligand Tab
[δ 7.36-7.53 (m, 4H, Ph), 3.36 (9H, m, NMe3)], but did not
i
(R = Et and Pr),26 mercury plastocyanin,26d and other
metallothioneins,27 the low-energy UV transitions of
228-250 nm may reflect the two- and three-coordination
environments, while those at the range of 280-310 nm
may represent a four-coordination geometry. The main
absorptions in 2-10 are in the range of 258-268 nm,
suggesting that the coordination geometry around the Hg
atom in these compounds may not be trigonally or
tetrahedrally coordinated but in-between three and
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Article
Inorganic Chemistry, Vol. 50, No. 2, 2011 507
Table 1. Principal Electronic Transitions in 1-11, Tab, and Other Mercury(II)
pounds 2-7 possess a similar structure that consists of one
[Hg(Tab)2L]þ (L = Ac- (2), Pro- (3), Sal- (4 and 5), Bez-
Thiolate Compounds
(6) and HMal- (7)) cation and one PF6 (or Sal- and
-
compound
λmax, nm
ref.
25a
25b
Mal2-) anion. The perspective views of the [Hg(Tab)2L]þ
cations of 2-7 are depicted in Figure 2, and their important
bond lengths and angles are compared in Table 2. In each
cation of 2-7, the mercury(II) center adopts a distorted
seesaw-shaped coordination, coordinated by two sulfur
atoms from two Tab moieties and two oxygen atoms from
one carboxylate anion (Ac- for 2, Pro- for 3, Sal- for 4 and
5, Bez- for 6 and HMal- for 7).
[Hg(L-Cys)4peptide]a
[Hg6Cl8(SCH2CH2NH3)8]]
280
273
Cl4 4H2O
3
[Hg9Br15(SCH2CH2NH3)9]-
(Cl0.8Br0.2)3
268, 339 (sh)b
25b
[Hg(SEt)2]
[Hg(SPri)2]
228, 282 (sh)
228, 262 (sh)
235, 260 (sh)
240, 260 (sh), 290 (sh)
304
247, 280 (sh)
253
283
320, 267 (sh)
287, 312 (sh)
271
263
258
26a
26a
26a
26a
26b, 26c
26d
26e
27
1a
1a
1a
1h
1h
1h
1h
[Et4N][Hg(SBut)3]
Hg-MerRc
Hg7-MTd
Hg-plastocynanin
Hg-MT1e
Neurospora Hg3-MT
Tab
[Hg2(Tab)6](PF6)4
[Hg(Tab)2(SCN)2]
[Hg(Tab)2(phen)](PF6)2
[Hg(Tab)2(2,20-bipy)](PF6)2
[Hg(Tab)2(dap)](PF6)2
[Hg(Tab)2(dpt)](PF6)2
In the crystals of 2 0.5H2O, 3, 4 MeOH, 5 MeOH,
3
3
3
and 6 H2O, abundant intramolecular and intermolecular
hydrogen bonding interactions are observed. For 2
3
3
-
0.5H2O, the PF6 anions are positioned in-between the
[Hg(Tab)2(Ac)]þ cations, which leads to interactions of
fluorine atoms with hydrogen atoms of the methyl
groups from the Tab ligands and the hydrogen atoms
of the acetate anions. For instance, O2 atom of the Ac-
anion has an intramolecular hydrogen-bonding interac-
tion with the hydrogen atom of the phenyl groups
f
g
h
264
257
i
1
2
272
268
1a
this work
this work
this work
this work
this work
this work
this work
this work
this work
this work
[C2 O2] and an intermolecular hydrogen-bonding
interaction with the hydrogen atom of methyl groups
3 3 3
3
4
5
6
7
8
9
10
11
267
261
264
267
258
264
265
268
[C18 O2]. In addition, the F4 atom interacts with the
hydrogen atoms from the methyl group of Tab ligand
3 3 3
[C9 F4] and the methyl group of acetic anion
3 3 3
[C19 F(4)]. All the hydrogen-bonding interactions
3 3 3
result in forming a two-dimensional (2D) hydrogen-
bonded network extended in the ab plane (Figure 3a).
Furthermore, these layers are further connected via the
hydrogen-bonding interactions between O1 atom of one
acetate anion and hydrogen atom of the phenyl groups
290
a
L-Cys = L-cysteine. b sh=shoulder. c MerR=metalloregulatory pro-
tein. d MT=metallothionein. e MT1=Cicer arietinum (chickpea) MT1.
f phen=phenanthroline. g 2,20-bipy=2,20-bipyridine. h dap=1,3-diami-
nopropane. i dpt=dipropylenetriamine.
from one Tab ligand [O1 C5] and hydrogen atom of
the methyl groups [O1 C8; O1 C9], between S2
3 3 3
3 3 3
3 3 3
four-coordinated. These absorptions are similar to those
of the mercury(II)/Tab/amine compounds reported pre-
viously, [Hg(Tab)2(L)](PF6)2 (L = phenanthroline, 2,20-
bipyridine, 1,3-diaminopropane, dipropylenetriamine).1h
As described later in this article, each mercury(II) center
in 2-9 adopts a similar seesaw-shaped coordination geom-
etry to that found in the aforementioned mercury(II)/
Tab/amine compounds, though that of 10 takes a dis-
torted octahedral geometry. Compared to other mercury-
(II)/Tab/carboxylate compounds, the absorption peak in
11 (290 nm), red-shifted relative to that of 1, may indicate
existence of a different coordination geometry of the
mercury(II) center coordinated by a different set of donor
atoms. It is noted that compounds 9 and 10 contain the
sameset of ligandsbutdifferentstructures(asshown bythe
X-ray crystallographic studies), but their spectral data are
quite similar. Is 10 stable in solution or is it converted to 9?
We measured the positive electrospray ion (ESI) mass
spectra of 9 and 10 in MeCN. In both cases we did
not observe the expected [{Hg(Tab)2}2( μ-Adi)]2þ peak.
However, we obtained the same peak at m/z 268.06
corresponding to the [Hg(Tab)2]2þ cation (see Supporting
Information, Figure S5). This result suggests that the
adipate anions in 9 and 10 may not strongly coordinate
to the mercury(II) centers and be readily cleaved in polar
solvents like MeCN, which may lead to similar spectral
data for both compounds in solution.
and hydrogen atom from the methyl group [S2
C17], and between F5 and hydrogen atom from the
3 3 3
methyl group [F5 C16], generating a three-dimen-
sional (3D) hydrogen-bonded net (Supporting Informa-
tion, Figure S1).
3 3 3
In the case of 3, the oxygen atom of the Pro- anion
interacts with the hydrogen atoms of the phenyl or methyl
groups of Tab to afford one intramolecular hydrogen-
bond [C6 O2] and intermolecular hydrogen-bonds
3 3 3
[C12 O2; C16 O2], forming a one-dimensional
3 3 3
3 3 3
(1D) chain extending along the b axis. Such a chain is
further linked by the hydrogen-bonds formed by the
-
fluorine atoms of PF6 interactions with the hydrogen
atoms of the methyl groups of Tab [C9 F5; C17 F2;
3 3 3
3 3 3
C18 F2], thereby giving a 2D network extended along
the ab plane (Figure 3b).
3 3 3
For 4 MeOH, there are two intermolecular hydrogen-
bonds between O3 and O2 atoms [O3 O2] and between
3
3 3 3
the hydrogen atom from the methyl group and O4 atom
from the MeOH molecule [C9 O4], and a set of inter-
3 3 3
molecular hydrogen-bonds between the hydrogen atom
of the hydroxyl group from the MeOH molecule or the
hydrogen atom from the methyl group of one Tab ligand
and the O1 atom from the Sal- anion [O4 O1;
3 3 3
C16 O1], and between the S1 atom from one Tab
3 3 3
ligand and the hydrogen atom from the phenyl group
[C3 S1], and between the fluorine atom from one PF6
-
3 3 3
Crystal Structures of 2 0.5H2O, 3, 4 MeOH, 5 MeOH,
6 H2O, and 7 H2O. X-ray analysis revealed that com-
anion and the hydrogen atom from the methyl group of
one Tab ligand [C8 F5], giving a 2D layer network
3
3
3
3
3
3 3 3

508 Inorganic Chemistry, Vol. 50, No. 2, 2011
Tang et al.
Figure 2. (a) View ofthe [Hg(Tab)2(Ac)]þ cationin 2. (b) View ofthe [Hg(Tab)2(Pro)]þ cation in 3. (c) View of the [Hg(Tab)2(Sal)]þ cationin 4. (d) Viewof
the [Hg(Tab)2(Sal)]þ cation in 5. (e) View of the [Hg(Tab)2(Bez)]þ cation in 6. (f) View of one of the two discrete [Hg(Tab)2(HMal)]þ cations in 7. All
hydrogen atoms are omitted for clarity.
extending along the bc plane (Figure 4a). Furthermore,
this layer is connected to its neighboring ones via the
intermolecular hydrogen-bonding interactions between
the hydrogen atom of the methyl group of one Tab ligand
and the fluorine atom from one PF6- anion to form a 3D
hydrogen-bonded structure (Supporting Information,
Figure S2).
In the crystal of 6 H2O, the water solvent molecules
and the PF6 anions are located in-between the
3
-
[Hg(Tab)2(Bez)]þ cations. These water molecules are
involved in hydrogen bonding interactions [O3 O1;
3 3 3
O3 F4]. Furthermore, the fluorine atoms interact with
3 3 3
the hydrogen atoms of methyl groups of Tab to afford
one intramolecular hydrogen-bond [C9 F2] and two
3 3 3
In the crystal of 5 MeOH, one discrete salicylate anion
intermolecular hydrogen-bonds [C16 F6; C17 F6],
3 3 3
3
3 3 3
and one MeOH molecule are positioned between the
[Hg(Tab)2(sal)]þ cations. The hydrogen-bonding interac-
tions among the cation, the salicylate anion, and the
MeOH solvent molecule afforded eight intramolecular
hydrogen-bonds [O3 O2; O6 O5; O7 O4; C7 O4;
forming a 2D wave-like network extending along the bc
plane (Figure 4c).
Crystal Structures of 8 2H2O and 9. X-ray analysis
3
revealed that 8 and 9 hold a similar structure that consists
of one {[Hg(Tab)2]2( μ-L)}2þ (L=Oxa2- for 8; L = Adi2-
for 9) and two PF6- anions. The perspective views of the
3 3 3
3 3 3
3 3 3
3 3 3
C7 O5; C12 O7; C16 O7; C18 O7] and three
intermolecular hydrogen-bonds [C17 O2; C17 O6;
C18 O6], forming a 1D chain running along the a axis.
3 3 3 3 3 3 3 3 3 3 3 3
{[Hg(Tab)2]2( μ-Oxa)}2þ and the [Hg(Tab)2( μ-Adi)]2
2þ
3 3 3
3 3 3
dications are showed in Figures 5a and 5b. Their pertinent
bond lengths and angles are given in Table 2. In the
dication of 8 or 9, two [Hg(Tab)2]2þ fragments are linked
by one oxalate or adipate double bridge via four Hg-O
bonds to form a dimeric structure with a 2-fold axis going
3 3 3
Two chains are connected via another three hydrogen-
bonding interactions between the O4 atom of the discrete
salicylate anion and the hydrogen atom of the methyl group
[C7 O4; C8 O4; C9 O4], giving a 1D ribbon ex-
3 3 3
3 3 3
3 3 3
tending the a-axis (Figure 4b). Each ribbon is further linked
by a series of hydrogen-bonds between the oxygen atom of
the coordinated salicylate anion and the hydrogen atom of
the methyl group [C7 O1; C17 O3; C9 O3], generat-
through the Hg1 Hg1A contact (8) or a 2-fold axis
3 3 3
located at the center of the C21-C21A bond (9). Each
mercury atom in such a dimer takes a seesaw-shaped
coordination, coordinated by two sulfur atoms from Tab
ligands and two oxygen atoms from one oxalate or
adipate dianion.
3 3 3
3 3 3
3 3 3
ing a 3D hydrogen-bonded structure (Supporting Informa-
tion, Figure S3).

Article
Inorganic Chemistry, Vol. 50, No. 2, 2011 509
˚
Table 2. Selected Bond Lengths (A) and Angles (deg) in 2-11
Compound 2
Table 2. Continued
Hg(2)-S(3)
2.393(3)
2.669(9)
2.471(10)
155.23(12)
102.4(2)
92.37(2)
158.28(12)
110.68(3)
67.9(3)
88.41(3)
100.8(3)
104.67(3)
65.78(3)
Hg(2)-S(4)
2.383(4)
2.572(9)
2.481(10)
130.98(12)
92.6(2)
92.48(2)
133.10(12)
93.33(3)
64.79(3)
96.33(3)
91.4(3)
Hg(2)-O(5)
Hg(2)-O(7)
Hg(1)-N(5)
Hg(2)-N(6)
Hg(1)-S(1)
Hg(1)-O(1)
2.3752(19)
2.641(6)
151.22(7)
100.37(15)
92.57(13)
Hg(1)-S(2)
Hg(1)-O(2)
2.3752(19)
2.506(5)
50.31(17)
100.09(15)
116.10(13)
S(1)-Hg(1)-S(2)
S(2)-Hg(1)-O(1)
S(2)-Hg(1)-O(3)
S(3)-Hg(2)-S(4)
N(5)-Hg(1)-S(1)
N(5)-Hg(1)-O(1)
S(4)-Hg(2)-O(5)
S(4)-Hg(2)-O(7)
N(6)-Hg(2)-S(3)
N(6)-Hg(2)-O(5)
O(1)-Hg(1)-O(3)
S(1)-Hg(1)-O(1)
S(1)-Hg(1)-O(3)
O(5)-Hg(1)-O(7)
N(5)-Hg(1)-S(2)
N(5)-Hg(1)-O(3)
S(3)-Hg(2)-O(5)
S(3)-Hg(2)-O(7)
N(6)-Hg(2)-S(4)
N(6)-Hg(2)-O(7)
S(1)-Hg(1)-S(2)
S(2)-Hg(1)-O(1)
S(2)-Hg(1)-O(2)
O(1)-Hg(1)-O(2)
S(1)-Hg(1)-O(1)
S(1)-Hg(1)-O(2)
Compound 3
Hg(1)-S(1)
Hg(1)-O(1)
2.360(2)
2.540(6)
154.54(7)
92.47(17)
87.06(14)
Hg(1)-S(2)
Hg(1)-O(2)
2.370(2)
2.582(6)
50.41(18)
105.94(17)
118.18(14)
96.62(3)
67.9(3)
S(1)-Hg(1)-S(2)
S(2)-Hg(1)-O(1)
S(2)-Hg(1)-O(2)
O(1)-Hg(1)-O(2)
S(1)-Hg(1)-O(1)
S(1)-Hg(1)-O(2)
Compound 4
In the crystal of 8 2H2O, the dications are further
connected by the hydrogen-bonding interaction between
3
Hg(1)-S(1)
Hg(1)-O(1)
S(1)-Hg(1)-S(2)
S(2)-Hg(1)-O(1)
S(2)-Hg(1)-O(2)
2.335(3)
2.551(7)
173.36(11)
92.4(2)
Hg(1)-S(2)
2.348(3)
2.857(7)
48.59(2)
94.0(2)
-
the F6 atom of one PF6 anion and the hydrogen atom
from the methyl group [C7 F6; C8 F6], forming a
Hg(1)-O(2)
O(1)-Hg(1)-O(2)
S(1)-Hg(1)-O(1)
S(1)-Hg(1)-O(2)
3 3 3
3 3 3
1D ladder-like chain. This chain is further linked by the
hydrogen-bonding interaction between one fluorine atom
and the hydrogen atoms from the methyl group
[C9 F5; C7 F2], affording a 2D layer structure
101.53(2)
83.91 (2)
Compound 5
3 3 3
(Figure 5c).
For 9, there is one intramolecular hydrogen-bonding
3 3 3
Hg(1)-S(1)
Hg(1)-O(1)
S(1)-Hg(1)-S(2)
S(2)-Hg(1)-O(1)
S(2)-Hg(1)-O(2)
2.338(2)
2.553(7)
Hg(1)-S(2)
Hg(1)-O(2)
2.347(2)
2.638(6)
50.4(2)
92.19(18)
83.70(17)
174.04(8)
93.76(17)
100.44(17)
O(1)-Hg(1)-O(2)
S(1)-Hg(1)-O(1)
S(1)-Hg(1)-O(2)
interaction between the O atom of the Adi2- anion and
the hydrogen atom of the phenyl group with C6 [C6
3 3 3
Compound 6
O1], and eight intermolecular hydrogen -bonding inter-
actions between the oxygen atom of the Adi2- anion and
the hydrogen atom of methyl groups with C8 or C16
[C8 O1; C16 O1], or between the fluorine atom of
Hg(1)-S(1)
Hg(1)-O(1)
S(1)-Hg(1)-S(2)
S(2)-Hg(1)-O(1)
S(2)-Hg(1)-O(2)
2.3391(16)
2.517(4)
Hg(1)-S(2)
Hg(1)-O(2)
2.3469(16)
2.842(4)
48.39(12)
93.89(11)
94.57(9)
171.91(5)
93.94(11)
89.13(9)
O(1)-Hg(1)-O(2)
S(1)-Hg(1)-O(1)
S(1)-Hg(1)-O(2)
3 3 3
3 3 3
one PF6- anion and the H atom of the methyl group with
C7, C9, C16 or C18 atom [C7 F1; C9 F1; C9 F4;
C9 F5; C16 F5; C18 F2], forming a 3D hydro-
3 3 3
3 3 3
3 3 3
Compound 7
3 3 3
3 3 3
3 3 3
gen-bonded structure (Figure 5d).
Hg(1)-S(1)
2.354(2)
Hg(1)-S(2)
2.359(2)
Crystal Structure of 10. An X-ray analysis revealed that
10 has a [Hg2( μ-Tab)2( μ-Adi)2] molecule, in which two
mercury(II) centers are bridged by two Tab ligands
forming a [Hg( μ-Tab)2Hg]4þ fragment (Figure 6a). Each
mercury(II) center in this fragment is further chelated by
two adipate anions to form a strongly distorted octahe-
Hg(2)-S(3)
2.3550(19)
2.745(5)
2.607(5)
163.65(7)
98.93(7)
104.52(13)
163.26(7)
95.36(12)
77.35(12)
Hg(2)-S(4)
2.3557(19)
2.503(5)
2.780(5)
49.43(7)
94.64(7)
91.23(13)
48.54 (7)
100.51(12)
109.47(12)
Hg(1)-O(1)
Hg(1)-O(2)
Hg(2)-O(4)
Hg(2)-O(3)
S(1)-Hg(1)-S(2)
S(2)-Hg(1)-O(1)
S(2)-Hg(1)-O(2)
S(3)-Hg(2)-S(4)
S(4)-Hg(2)-O(5)
S(4)-Hg(2)-O(6)
O(1)-Hg(1)-O(2)
S(1)-Hg(1)-O(1)
S(1)-Hg(1)-O(2)
O(5)-Hg(2)-O(6)
S(3)-Hg(2)-O(5)
S(3)-Hg(2)-O(6)
dral coordination geometry. The Hg Hg separation
3 3 3
˚
(3.6210(4) A) is in good agreement with those in these
similar Hg(II)/thiolate dimeric compounds such as
Compound 8
˚
[Hg2(Tab)6]Y (3.637(2) A, Y=(PF6)4; 3.592(2) A, Y =
˚
Hg(1)-S(1)
Hg(1)-O(1)
S(1)-Hg(1)-S(2)
S(2)-Hg(1)-O(1)
S(2)-Hg(1)-O(2)
2.3411(17)
2.593(4)
Hg(1)-S(2)
Hg(1)-O(2)
2.3341(17)
2.770(4)
62.46(6)
78.44(11)
106.46(11)
1
(PF6)Cl11) and [Et4N][Hg2(SMe)6] (3.631(6) A), but
28
˚
174.37(6)
105.98(11)
78.89(11)
O(1)-Hg(1)-O(2)
S(1)-Hg(1)-O(1)
S(1)-Hg(1)-O(2)
shorter than those in [Hg( μ-Tab)(Tab)Cl]2Cl2 H2O
3
˚
˚
(3.996(3) A), [Hg( μ-Tab)(Tab)Cl]2X2 (4.094(5) A, X =
1
NO2; 4.020(2) A, X=NO3). As shown in Table 2, the
˚
˚
Compound 9
mean bridging Hg-S bond length (2.6328(16) A) is
comparable to those in [Hg( μ-Tab)(Tab)Cl]2(NO2)2
Hg(1)-S(1)
Hg(1)-O(1)
S(1)-Hg(1)-S(2)
S(2)-Hg(1)-O(1)
S(2)-Hg(1)-O(2)
2.364(2)
2.459(6)
147.68(7)
93.22(14)
94.47(14)
Hg(1)-S(2)
2.376(2)
2.653(6)
51.23(17)
118.85(14)
108.36(14)
˚
(2.693(16) A), [Hg2(Tab)6]Y (2.6895(13) A, Y = (PF6)4;
˚
Hg(1)-O(2)
˚
2.6945(12) A, Y = (PF6)Cl11) and [Et4N]2[Hg2(SMe)6]
O(1)-Hg(1)-O(2)
S(1)-Hg(1)-O(1)
S(1)-Hg(1)-O(2)
˚
(2.668(2) A), but shorter than those in [Hg( μ-Tab)-
(Tab)Cl]2Cl2 H2O (2.7496(16) A) and [Hg( μ-Tab)(Tab)-
˚
Cl]2(NO2)2 (2.755(2) A). Topologically, each resulting
˚
3
Compound 10
[Hg2( μ-Tab)2( μ-Adi)2] molecule works as a planar four-
connecting node, which is interconnected to its four
equivalent ones via four adipate dianions, thereby form-
ing a unique 2D network extending along the bc plane
(Figure 6b).
Hg(1)-S(1)
2.4147(15)
2.644(4)
93.52(4)
93.94(11)
89.13(9)
Hg(1)-O(1)
2.377(4)
2.184(4)
48.39(12)
93.89(11)
94.57(9)
Hg(1)-O(2)
Hg(1)-O(3)
S(1)-Hg(1)-S(1A)
S(2)-Hg(1)-O(1)
S(2)-Hg(1)-O(2)
O(1)-Hg(1)-O(2)
S(1)-Hg(1)-O(1)
S(1)-Hg(1)-O(2)
Compound 11
Hg(1)-S(1)
Hg(1)-O(1)
2.389(3)
2.571(9)
Hg(1)-S(2)
Hg(1)-O(3)
2.401(4)
2.706(9)
(28) Bowmaker, G. A.; Dance, I. G.; Dobson, B. C.; Rogers, D. A. Aust.
J. Chem. 1984, 37, 1607.

510 Inorganic Chemistry, Vol. 50, No. 2, 2011
Tang et al.
Figure 3. (a) 2D network extended along the ab plane formed via hydrogen-bonding interactions in 2 0.5H2O (looking down the c axis). (b) 2D network
3
extended along the ab plane formed via hydrogen bonding interactions in 3 (looking down the c axis).
Crystal Structure of 11 2.5H2O. Compound 11 2.5H2O
interactions occurred between hydrogen atoms from
water molecules and oxygen atoms from Meida ligands
[O9 O2; O9 O4; O10 O6; O10 O8; O11 O8]
3
3
crystallizes in the orthorhombic space group Pbca and its
asymmetric unit consists of two crystallographically inde-
pendent [Hg(Tab)2(Meida)] molecules and five H2O solvent
molecules. Because the two [Hg(Tab)2(Meida)] molecules
are structurally similar, only one of them is presented in
Figure 7a. The pertinent bond lengths and angles of the two
molecules are compared in Table 2. Each [Hg(Tab)2] frag-
ment in two molecules is further chelated with one nitrogen
and two oxygen atoms from one Meida ligand to form a
rare distorted square pyramidal coordination geometry. The
3 3 3
3 3 3
3 3 3
3 3 3
3 3 3
or oxygen atoms from water molecules [O12 O11;
O12 O10; O13 O4] or between hydrogen atoms
3 3 3
3 3 3
3 3 3
from methyl groups of the Tab ligands and oxygen atoms
from the Meida ligands [C7 O4; C16 O8] into a 3D
hydrogen-bonded structure (Supporting Information,
Figure S4).
3 3 3
3 3 3
Variations in the Configurations of [Hg(Tab)2] Units of
2-11. Because of the coordination of carboxylate ligands
at the Hg center, the original trans-configuration of the
[Hg(Tab)2] unit of 1 is changed in 2-11. First, two Tab
ligands rotate around the S-Hg-S line by some degrees.
For instance, in 4-6 and 8, two Tab ligands turn around
the S-Hg-S string by about 150° with the dihedral
angles between N1S1Hg1 and N2S2Hg1 planes of 23.8°
(4), 38.5° (5), 26.6° (6) and 35.6° (8). However, the two
Tab groups in 11 turn by about 90° around the S1-
Hg1-S2 line or S3-Hg2-S4 line, which makes the two
Tab groups be oriented almost in the vertical direction
with a dihedral angle between the similar planes being
76.75(2)° or 78.59(2)°. In the case of 2, 3, 7, and 9, the two
Tab units almost retain the original trans-configuration,
with some slight rotation of both groups around the
S-Hg-S line because their dihedral angles are 145.5°
(2), 160.4° (3), 156.8°, and 157.6° (7), and 164.2° (9).
Second, the two Tab groups swing from left to right along
the S-Hg-S line. Such a swing causes the deviation of
the two N(Tab)-S-Hg angles in 2-11 from those of the
corresponding ones in 1 (104.16°). The steric hindrance
among the carboxylate anions and two Tab groups
enlarges the N(Tab)-S-Hg angle and both Tab groups
thus understandably swing outward. The N(Tab)-S-Hg
angles are 110.924°/112.584° (2), 110.425°/111.745° (3),
109.324°/109.401° (4), 107.961°/107.369° (5), 110.039°/
109.465° (6), 103.38°/109.25°/111.43°/108.06° (7), 111.501°/
109.553° (8), 112.52°/110.63° (9), and 111.825°/104.043°/
109.084°/106.689° (11). In the cases of 7 or 11, one N(Tab)-
S-Hg angle is smaller than that in 1, suggesting that the two
Tab groups slightly swing inward. Third, the rotation of the
two phenyl groups of the Tab ligands in 2-9 and 11 is
observed. As described previously, the two phenyl groups of
1 are in a parallel position. Both groups in 2-9 and 11 are
˚
average Hg-S bond distance of 2.395(2) A is comparable to
these of the aforementioned Hg/Tab compounds. The mean
˚
Hg-N bond length (2.476(10) A) is comparable to that of
the complex containing similar HgS2O2N coordination en-
vironment such as [Hg(SMe)(CH3COO)(MePy)]n (2.418(4)
˚
A), but shorter than that in [Hg(SEt)(CH3COO)(Py)]n
(2.656(2) A),29a and longer than those of the corresponding
˚
ones of some five-coordinated Hg(II) compounds such as
[HgI(Pic)(Hpic)] (2.298(3) A; Hpic = picolinic acid)8a and
˚
˚
[HgL(ClO4)2] (2.365(2) A; L = 3,11,19-trithia[3.3.3]pyridi-
nophane).29b The mean Hg-O bond length of 2.637(9) A is
˚
slightly somewhat longer than those in [Hg(SMe)(CH3-
˚
COO)(MePy)]n (2.545(3) A) and [Hg(SEt)(CH3COO)(Py)]n
(2.510(2) A).29a In the crystal of 11 2.5H2O, two [Hg(Tab)2-
˚
3
(Meida)] molecules are arranged around 2-fold screw axes to
a pseudochiral dimeric species [Hg(Tab)2(Meida)]2.
In 11 2.5H2O, there exist abundant intra- and inter-
molecular hydrogen-bonding interactions among the
[Hg(Tab)2(Meida)] molecule and water solvent mole-
cules. There are five intramolecular hydrogen-bonding
interactions between sulfur atom of the Tab ligand and
the hydrogen atom of the methyl group with C17
3
[C17 S1] and C27 [C27 S3], between oxygen atoms
3 3 3 3 3 3
of the Meida ligand and hydrogen atoms from solvated
water molecules O8 [O11 O8] or from methyl groups of
Tab ligand O7 [C17 O7], and between the oxygen
3 3 3
3 3 3
atoms and the hydrogen atoms from water molecules
O13 [O13 O12]. The intermolecular interactions
3 3 3
[C17 O6; C26 O5; C25 O5; C26 S3; O44
3 3 3 3 3 3 3 3 3 3 3 3
3 3 3
O13; C34 O2; C36 O1] led to the formation of chain
3 3 3
3 3 3
structure extended along the b axis (Figure 7b). Because
of the existence of solvated water molecules in the lattice,
these chains are further linked via the hydrogen bonding

Article
Inorganic Chemistry, Vol. 50, No. 2, 2011 511
158.28(12)° for 11, remarkably deviate from 180.00° in 1.
Finally, although the anion basicity seems of no effect on the
types of structures, there is a correlation between the anion
structure and the types of structures observed. For example,
the two Tab units in 2, 3, and 7 almost retained their original
trans configuration in 1 when its mercury center is bound
by alkyl carboxylate anions such as Ac-, Pro-, Mal2-
anions while those in 4,5,and6adopted the cis configuration
when the mercury center in 1 is bound by aryl carboxylate
anions like Sal- and Bez- anions.
The Hg-S bond lengths and S-Hg-S angles of 2-11
are also changed because of the coordination of carboxy-
late ligands at the Hg center (Table 2). The average Hg-S
˚
˚
bond distances of 2.3752(19) A for 2, 2.365(2) A for 3,
˚
˚
˚
2.342(3) A for 4, 2.343 (2) A for 5, 2.343 (16) A for 6, 2.356
˚
(2) A for 7, 2.3376(17) A for 8, and 2.370 (2) A for 9 are
longer than that of 1 (2.331(3) A). The longest Hg-S
˚
˚
˚
bond length is observed in 6. As shown in Table 3, these
mean Hg-S bond lengths are shorter that those of the
four-coordinated mercury(II)/thiolate compounds such
˚
as [Hg(4-SpyH)2(4-Spy)2] (2.520(2)-2.577(3) A, 4-Spy =
pyridine-4-thiolate) and [HgL4]- (2.527(2)-2.552(2) A
˚
˚
for L = 4-chlorobenzenethiolate; 2.520(3) A for L = 2-
˚
phenylbenzenethiolate; 2.551(3) A for L=2-(N-methyl-
carbamoyl)phenylthiolate),30 but are close to those in Hg/
Tab/N-donor ligand compounds and EXAFS data for
the tricoordinated mercury centers in Hg-MerR,31 Hg7-
MT,32 and Hg18-MT.33 We assumed that the Hg-S bond
˚
lengths in the range of 2.338(2)-2.415(2) A are special for
the seesaw-shaped [HgS2O2] coordination geometry. The
Hg-O bond lengths vary in a relatively large range. The
shortest and longest Hg-O bond lengths are observed in
˚
˚
10 (2.184(4) A) and 4 (2.857(7) A), respectively. The mean
˚
˚
Hg-O bond lengths, 2.574(5) A for 2, 2.561(6) A for 3,
2.704(7) A for 4, 2.5955 A for 5, 2.6795(4) A for 6, 2.659(4)
˚
˚
˚
˚
A for 7, 2.6815(4) A for 8, 2.556(6) A for 9, 2.514(4) A for
˚
˚
˚
˚
10, and 2.629(9) A for 11 are comparable to those found in
29
˚
[Hg(SEt)(Ac)Py]n (2.510(4) A), [Hg(SMe)(Ac)( μ-MePy)]n
34
(2.591(5) A), and [Hg(SMe)(Ac)Py]n (2.555(3) A),35a and
˚
˚
longer than that in [Hg(2-Spy)(Ac)]n (2.483(4) A).35b Most
˚
of these Hg-O bonds may be considered as a coordinative
bond. However, the longer Hg-O bonds like those in 4
(2.857(7) A) are very weak, which implies that the mercury
˚
atoms may form ionic bonds with the added carboxylates.
Even in such a case, the geometry of the mercury(II) center in
4 still got somewhat changed relative to that of 1. Therefore
this may provide some implication that the geometry of the
Figure 4. (a) 2D network of 4 MeOH (looking long the a axis) extend-
3
ing along the bc plane. (b) View of a section of the 1D ribbon formed via
hydrogen-bonding interactions in 5 MeOH (extending along the a axis).
3
(c) 2D network of 6 H2O extending along the bc plane. All hydrogen
3
(29) (a) Canty, A. J.; Raston, C. L.; White, A. H. Aust. J. Chem. 1979, 32,
311. (b) Vetrichelvan, M.; Lai, Y. H.; Mok, K. F. Eur. J. Inorg. Chem. 2004, 2086.
(30) (a) Silver, A.; Koch, S. A.; Millar, M. Inorg. Chim. Acta 1993, 9, 205.
(b) Choudhury, S.; Dance, I. G.; Guerney, P.; Rae, A. D. Inorg. Chim. Acta 1983,
70, 227. (c) Kato, M.; Kojima, K.; Okamura, T.; Yamamoto, H.; Yamamura, T.;
Ueyama, N. Inorg. Chem. 2005, 44, 4037. (d) Anjali, K. S.; Vittal, J. J.; Dean,
P. A. W. Inorg. Chim. Acta 2003, 79, 351. (e) Manceau, A.; Nagy, K. L. Dalton
Trans. 2008, 1421.
(31) (a) Penner-Hahn, J. E.; Tsang, H. T.; O’Halloran, T. V.; Wright, J.
Physica B 1989, 158, 117. (b) Jaliehvand, F.; Leung, B. O.; Izadifard, M.;
Damian, E. Inorg. Chem. 2006, 45, 66.
(32) Hasnain, S. S. In Synchrotron Radiation in Chemistry and Biology II;
Mandelkow, E., Ed.; Springer-Verlag: New York, 1988; p 73.
(33) (a) Jiang, D. T.; Heald, S. M.; Sham, T. K.; Stillman, M. J. J. Am.
Chem. Soc. 1994, 116, 11004. (b) Lu., W. H.; Kasrai, M.; Bancroft, G. M.;
Stillman, M. J.; Tan, K. H. Inorg. Chem. 1990, 29, 2561.
(34) Puff, H.; Sievers, R.; Elsner, G. Z. Anorg. Allg. Chem. 1975, 413, 37.
(35) (a) Canty, A. J.; Raston, C. L.; White, A. H. Aust. J. Chem. 1978, 31,
677. (b) Wang, S. N.; Junior, J. P. F. Inorg. Chem. 1989, 28, 2615.
atoms except those related to hydrogen bonding interactions are omitted
for clarity.
found to rotate by some degrees along the S-N(Tab) line to
deviate from the original parallel position. The dihedral
angle between the phenyl groups of the Tab ligands in 2-9
and 11 are 13.4° (2), 11.8° (3), 16.3° (4), 18.3° (5), 16.4° (6),
12.5°/75.6° (7), 11.6° (8), and 6.7° (9), respectively. In the
case of 11, two Tab ligands are almost in vertical positions
with the dihedral angle of 87.4° and 80.4°. Fourthly, for 4-6
and 8, their S-Hg-S angles, 173.36(11)° for 4, 174.04(8)°
for 5, 171.91(5)° for 6, and 174.37(6)° for 8, are found to
deviate slightly from 180.00° in 1. However, the S-Hg-S
angles, 151.22(7)° for 2, 154.54(7)° for 3, 163.65(5)°/
163.67(5)° for 7, and 147.68(7)° for 9, and 155.23(12)°/

512 Inorganic Chemistry, Vol. 50, No. 2, 2011
Tang et al.
Figure 5. (a) Viewof the{[Hg(Tab)2]2( μ-Oxa)}2þ dicationof8. Symmetrytransformationsusedtogenerateequivalentatoms, A:-x, y, -z þ 1/2. (b)View
of the [Hg(Tab)2( μ-Adi)]22þ dianion of 9. Symmetry transformations used to generate equivalent atoms, A: -x, 1/2 þ y, 1/2 - z. (c) 2D layer structure
formed by the hydrogen-bonding interactions in 8 2H2O. (d) View of a 3D hydrogen-bonded structure of 9 looking along the c axis. All hydrogen atoms
3
except those involved in hydrogen bonding interactions are omitted for clarity.
Figure 6. (a) View of the dimeric [Hg2( μ-Tab)2( μ-Adi)2] fragment in 10. (b) View of the 2D network of 10 extending along the bc plane. All hydrogen
atoms have been omitted for clarity.
mercury(II) atom in the mercury(II)-containing proteins
may be affected by the added anions even though the
mercury atoms form ionic bonds with them.
found to undergo changes in 2-11 in three ways: the rotation
of the two Tab groups around the S-Hg-S line, the swing of
the two Tab groups along the S-Hg-S line, and the rotation
of the two phenyl groups of the Tab ligands along the
S-N(Tab) line. These configuration variations result in the
changes of the Hg-S bond lengths and the S-Hg-S bond
angles in 2-11. Because the Hg-S bond lengths of
Conclusions
In this paper, we have demonstrated the interesting reac-
tivity of the precursor complex 1 toward alkyl carboxylic
acids (acetic acid, propionic acid) and aryl acids (benzoic
acid, salicylic acid) or dicarboxylic acids (oxalic acid, malonic
acid, adipic acids, methylimindiazole acid), and successful
isolation of 10 new mercury(II)-Tab-carboxylate compounds
(2-11). According to their X-ray analysis, the linear coordi-
nation geometry of mercury(II) center in 1 is converted into
a seesaw-shaped coordination (2-9), a distorted octahedral
coordination (10), or a distorted square pyramidal five-
coordination (11) when the Hg center is coordinated by
these carboxylate anions. The latter two geometries for the
mercury(II) centers in 10 and 11 are uncommon in mercury
thiolate chemistry. Similar to the mercury-Tab-amine com-
pounds, the trans configuration of the dication of 1 is also
˚
2.334-2.401 A in 2-9 do not fall among those of compounds
containing the tetrahedrally coordinated mercury(II) atoms,
they may be established for the seesaw-shaped four-coordi-
nated [HgS2O2]. In addition, the UV-vis absorption data of
2-11 might correlate with their structural features to some
extent when compared with those of the existing mercury(II)-
thiolate compounds. According to these results, we could
derive two important implications for the related biological
systems. One is that the geometry of the mercury(II) sites of
mercury(II)-MerR and mercury(II)-MT might be changed
when they encounter naturally existing carboxylic acids or
amino acids from these proteins, which is of importance in
understanding the structural data of mercury(II)-MerR and

Article
Inorganic Chemistry, Vol. 50, No. 2, 2011 513
tion geometry. The biological anions might play an important
role in these transformations because they work as multitopic
ligands to bind the mercury centers and make the coordina-
tion surrounding of the mercury(II) center changed. We are
currently extending this work by investigating the reactions of
1 with the transition or main group metal ions (Zn(II), Cd(II),
Hg(II), Pb(II)).
Experimental Section
General Procedures. Compound 1 was prepared according to
the literature method.1a Other chemicals and reagents were
obtained from commercial sources and used as received. All
Solvents were predried over activated molecular sieves and
refluxed over appropriate drying agents and freshly distilled
prior to use. IR spectra were recorded on a Varian 1000 FT-IR
spectrometer as KBr disks (4000-400 cm-1). UV-vis spectra
were measured on a Varian 50 UV-visible spectrophotometer.
Elemental analyses for C, H, and N were performed on a Carlo-
Erba CHNO-S microanalyzer. 1H NMR spectra were recorded
at ambient temperature on a Varian UNITYplus-400 spectrom-
eter. 1H NMR chemical shifts were referenced to the DMSO-d6
signal.
Figure 7. (a) View of the molecular structure of [Hg(Tab)2(Meida)] in
11. All hydrogen atoms and H2O molecules are omitted for clarity. (b)
View of the chain structure formed via hydrogen bonding interactions in
Synthesis. [Hg(Tab)2(Ac)](PF6) 0.5H2O (2 0.5H2O). To a
3
3
solution of 1 (0.825 g, 1 mmol) in MeCN (15 mL) was added a
solution containing acetic acid (0.124 g, 2 mmol) in H2O (2 mL).
The resulting colorless solution was neutralized by Et3N to
pH=7 and stirred at ambient temperature for 0.5 h and filtered.
Diethyl ether (40 mL) was layered onto the filtrate at ambient
11 2.5H2O. All hydrogen atoms except those involved in hydrogen
3
interactions or H2O molecules are omitted for clarity.
temperature for two weeks, forming colorless blocks of 2
˚
3
Table 3. Hg-S and Hg-O Bond Lengths (A) in 1-11 and Other Mercury(II)
0.5H2O, which were collected by filtration, washed by Et2O
and dried in vacuo. Yield: 0.67 g (77% based on Hg). Anal.
Calcd. for C20H30F6HgN2O2.5PS2: C, 32.11; H, 4.04; N, 3.74.
Found: C, 32.32; H, 3.83; N, 3.89. IR (KBr disk): 3406 (br), 3041
(w), 2972 (w), 1576 (m), 1552 (s), 1490 (s), 1405 (m), 1128 (m),
1010 (m), 962 (w), 842 (s), 745 (w), 654 (w), 559 (s) cm-1. UV-vis
Thiolate or Carboxylate Compounds
compound
[Hg(Cys)2]2-a
Hg-S
Hg-O
ref.
36a
36b
14
31a, 31b
36a
33
2.32-2.36
2.43-2.45
2.329-2.355
2.42-2.43
2.33-2.42
2.41-2.42
[Hg(Cys)3]4-
[Hg(HCys)(H2Cys)]Cl 0.5H2O
3
1
(MeCN, λmax(nm (ε M-1 cm-1))): 268 (97000). H NMR (400
Hg-MerR b
Hg7-MTc
Hg18-MT
MHz, (CD3)2SO): δ 7.51-7.66 (m, 8H, Ph), 3.54 (s, 18H,
NMe3), 1.69 (s, 3H, Me).
[Hg2(Ac)3(NO3)]n
[Hg(nico)Br]n
Hg(R-picolinate)2
2.464
6
7
8a
8b
9a
9b
9c
[Hg(Tab)2(Pro)](PF6) (3). Compound 3 was prepared as
colorless plates in a manner similar to that described for the
preparation of 2, using 1 (0.825 g, 1 mmol) in 15 mL of MeCN
and propanoic acid (0.150 g, 2 mmol) in H2O (2 mL). Yield: 0.69
g (92% based on Hg). Anal. Calcd. for C21H31F6HgN2O2PS2: C,
33.49; H, 4.15; N, 3.72. Found: C, 33.52; H, 3.97; N, 3.81. IR
(KBr disk): 3028 (w), 2984 (2), 1575 (m), 1547 (s), 1491 (s), 1406
(m), 1363 (w), 1129 (m), 1011 (w), 960 (m), 838 (s), 745 (w), 632
(w), 559 (s) cm-1. UV-vis (MeCN, λmax(nm (ε M-1 cm-1))): 267
(84000). 1H NMR (400 MHz, (CD3)2SO): δ 7.51-7.65 (m, 8H,
Ph), 3.52 (s, 18H, NMe3), 1.88-1.93 (m, 2H, CH2), 0.89-0.93
(m, 3H, Me).
d
2.415
2.481
2.471
2.470
2.638
2.586
2.651
2.726
[Hg(pydc)2](piperazinium) 6H2O e
3
f
{(Hpyda)2[Hg(pydc)Cl)]2 2H2O}n
3
[Hg(pydc)I2]Lg
[Hg4(proline)2Cl8]
MeHg(alanine)
19b
21a
[Hg12(alanine)(NO3)8] 2H2O
3
2.122-2.225 21c
1a
1
2.331(3)
2.3752(19) 2.574(5)
2
3
4
5
6
7
this work
this work
this work
this work
this work
this work
2.365(2)
2.342(3)
2.343(2)
2.343(16)
2.356(2)
2.561(6)
2.704(7)
2.5955
2.6795(4)
2.659(5)
[Hg(Tab)2(Sal)](PF6) MeOH (4 MeOH).Compound 4 MeOH
3
3
3
was prepared as colorless needles in a manner similar to that described
for the preparation of 2, using1(0.825 g, 1 mmol) in 15 mL of MeCN
and salicylic acid (0.190 g, 1 mmol) in MeOH (3 mL) and H2O
(1 mL). Yield: 0.73 g (87% based on Hg). Anal. Calcd. for
C26H35F6N2HgO4PS2: C, 36.77; H, 4.15; N, 3.30. Found: C, 36.54;
H, 4.36; N, 3.47. IR (KBr disk): 3429 (m), 3043(w), 1624 (w), 1585
(w), 1557 (w), 1488 (m), 1457 (w), 1380 (w), 1355 (w), 1258 (w), 1126
8
2.3376(17) 2.6815 (4) this work
9
10
11
2.370(2)
2.4147(15) 2.514(4)
2.3915 2.629(9)
2.556(6)
this work
this work
this work
a Cys=cysteine. b MerR=metalloregulatory protein. c MT=metal-
lothionein. d nico=nicotinate. e pyda=2,6-pyridinediamine. f H2pydc=2,
6-pyridinedicarboxylic acid. L=1,10-(butane-1,4-diyl)bis(1H-benzimida-
zol-3-ium).
(w), 1010 (w), 959 (w), 840 (s), 707 (w), 667 (w), 559 (m) cm-1
.
UV-vis (MeCN, λmax(nm (ε M-1 cm-1))): 261 (86000). 1H NMR
(400 MHz, (CD3)2SO): δ 7.70-7.72 and 7.58-7.60 (m, 8H, Ph
in Tab), 7.62-7.64 (m, 1H, Ph in Sal), 7.10-7.15 (m, 1H, Ph
in Sal), 6.57-6.62 (m, 2H, Ph in Sal), 4.08 (br, 1H, OH), 3.53 (s,
18H, NMe3).
g
mercury(II)-MT derived from EXAFS, NMR, UV-vis, and
Raman spectroscopic studies. The other is that during detoxi-
fication, the coordination geometry of mercury(II) that is
transferred or released might vary from linear to T-shaped to
seesaw-shaped to square pyramidal to octahedral coordina-
[Hg(Tab)2(Sal)](Sal) MeOH (5 MeOH).Compound 5 MeOH
3
3
3
was prepared as long colorless needles in a manner similar to that
described for the preparation of 4, using 1 (0.825 g, 1 mmol) in
15 mL of MeCN and salicylic acid (0.379 g, 2 mmol) in MeOH

514 Inorganic Chemistry, Vol. 50, No. 2, 2011
Tang et al.

Article
Inorganic Chemistry, Vol. 50, No. 2, 2011 515
(5 mL) and H2O (2 mL). Yield: 0.66 g (78% based on Hg). Anal.
Calcd. for C33H40HgN2O7S2: C, 47.10; H, 4.79; N, 3.33. Found: C,
47.25; H, 4.41; N, 3.62. IR (KBr disk): 3420 (m), 3041 (w), 1624 (w),
1585 (m), 1488 (s), 1455 (m), 1384 (s), 1301 (w), 1257 (w), 1127 (w),
1085 (w), 1035 (w), 1010 (w), 950 (w), 857 (s), 758 (w), 706 (w), 667
(w), 558 (w) cm-1. UV-vis (MeCN, λmax(nm (ε M-1 cm-1))): 264
(104000). 1H NMR (400 MHz, (CD3)2SO): δ 7.70-7.72 and 7.59-
7.61 (m, 4H, Ph in Tab), 7.62-7.65 (m, 2H, Ph in sal), 7.09-7.13(m,
2H, Ph in sal), 6.55-6.60 (m, 4H, Ph in sal), 4.05 (br, 1H, OH), 3.54
(s, 9H, NMe3).
2860 (w), 1567 (s), 1487 (s), 1457 (w), 1390 (s), 1314 (m), 1294
(m), 1263 (w), 1125 (w), 1013 (w), 959 (w), 847 (w), 747 (w), 555
(w) cm-1. UV-vis (MeCN, λmax(nm (ε M-1 cm-1))): 268
(102000). 1H NMR (400 MHz, (CD3)2SO): δ 7.58-7.72 (m,
4H, Ph), 3.54 (s, 9H, NMe3), 1.90 (m, 2H, CH2), 1.50-1.52 (m,
4H, CH2).
[Hg(Tab)2(Meida)] 2.5H2O (11 2.5H2O). Compound 11
3
3
3
2.5H2O was prepared as colorless blocks in a manner similar
to that described for the preparation of 2, using 1 (0.825 g, 1
mmol) in 15 mL of MeCN and methylimindiacetic acid (0.292 g,
2 mmol) in H2O (3 mL). Yield: 0.52 g (72% based on Hg). Anal.
Calcd. for C23H38HgN3O6.5S2: C, 38.09; H, 5.29; N, 5.80.
Found: C, 38.31; H, 5.40; N, 5.98. IR (KBr disk): 3389 (s),
3031 (m), 2961 (m), 2913 (m), 1589 (s), 1489 (s), 1403 (s), 1308 (s),
1252 (w), 1128 (w), 1098 (m), 1035 (w), 1010 (m), 958 (m), 888
(m), 848 (m), 823 (m), 746 (m), 546 (m) cm-1. UV-vis (MeCN,
[Hg(Tab)2(Bez)](PF6) H2O (6 H2O). Compound 6 H2O
3
3
3
was prepared as colorless prisms in a manner similar to that
described for the preparation of 2, using 1 (0.825 g, 1 mmol) in
15 mL of MeCN and benzoic acid (0.244 g, 2 mmol) in MeOH
(4 mL) and H2O (2 mL) at pH = 8. Yield: 0.70 g (86% based on
Hg). Anal. Calcd. for C25H32F6HgN2O2.5PS2: C, 37.06; H, 3.98;
N, 3.46. Found: C, 37.33; H, 3.71; N, 3.75. IR (KBr disk): 3415
(m), 1594 (w), 1548 (w), 1489 (s), 1375 (m), 1126 (w), 1085 (w),
λ
max(nm (ε M-1 cm-1))): 290 (76500). 1H NMR (400 MHz,
D2O): δ 7.448-7.453 (m, 8H, Ph), 3.48 (s, 18H, NMe3), 2.94 (m,
4H, CH2), 2.16 (s, 3H, Me in Meida).
1010 (w), 958 (w), 838 (s), 723 (w), 676 (w), 559 (m) cm-1
.
1
UV-vis (MeCN, λmax(nm (ε M-1 cm-1))): 267 (148800). H
NMR (400 MHz, (CD3)2SO): δ 7.55-7.65 (m, 8H, Ph in Tab),
7.80-7.82 (m, 2H, Ph in Bez), 7.29-7.37 (s, 3H, Ph in Bez), 3.49
(s, 18H, NMe3).
X-ray Structure Determinations. Single crystals of 2 0.5H2O,
3
3, 4 MeOH, 5 MeOH, 6 H2O, 7 H2O, 8 2H2O, 9, 10, and
11 2.5H2O suitable for X-ray analysis were obtained directly
3
3
3
3
3
3
from the above preparations. All measurements were made on a
Rigaku Mercury CCD X-ray diffractometer by using graphite
monochromated Mo KR (λ = 0.71073 A) radiation. Each single
crystal was mounted at the top of a glass fiber, and cooled at
[Hg(Tab)2(HMal)](Mal)0.5 H2O (7 H2O). Compound 7 2H2O
3
3
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was prepared as colorless blocks in a manner similar to that
described for the preparation of 2, using 1 (0.825 g, 1 mmol) in
15 mL of MeCN and malonic acid (0.208 g, 2 mmol) in H2O(5mL).
Yield: 0.58 g (82% based on Hg). Anal. Calcd. for C22.5H32-
HgN2O7S2: C, 38.21; H, 4.56; N, 3.96. Found: C, 38.42; H, 3.73;
N, 3.83. IR (KBr disk): 3462 (m), 3033 (m), 2974 (m), 1735 (s),
1584(m), 1490 (s), 1420 (w), 1127 (w), 1010 (m), 958 (m), 838 (m),
747 (w), 559 (w) cm-1. UV-vis (MeCN, λmax(nm (ε M-1 cm-1))):
264 (73000). 1H NMR (400 MHz, D2O): δ7.53-7.65 (m, 16 H, Ph),
3.51 (s, 18H, NMe3), 2.97-2.99 (m, 6H, CH2).
193 K for 2 0.5H2O, 3, 4 MeOH, 6 H2O, 7 H2O, 8 2H2O, 9,
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10, and 11 2.5H2O, 213 K for 5 MeOH in a stream of gaseous
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nitrogen. Diffraction data were collected at ω mode with a
detector-to-crystal distance of 35 mm. Cell parameters were
refined by using the program Crystalclear (Rigaku and MSc,
Ver. 1.3, 2001) on all observed reflections. The collected data
were reduced by using the program CrystalClear (Rigaku and
MSc, Ver. 1.3, 2001), and an absorption correction (multiscan)
was applied. The reflection data were also corrected for Lorentz
and polarization effects.
[{Hg(Tab)2}2( μ-Oxa)](PF6)2 2H2O (8 2H2O). Compound
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8 2H2O was prepared as colorless blocks in a manner similar
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The crystal structures of 2 0.5H2O, 3, 4 MeOH, 5 MeOH,
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to that described for the preparation of 2, using 1 (0.825 g,
1 mmol) in 15 mL of MeCN and oxalic acid (0.180 g, 2 mmol) in
MeOH (3 mL) and H2O (2 mL). Yield: 0.65 g (89% based on
Hg). Anal. Calcd. for C38H56F12Hg2N4O4P2S4: C, 31.43; H,
3.89; N, 3.86. Found: C, 31.71; H, 3.77; N, 3.99. IR (KBr disk):
3430 (m), 3045 (w), 1604 (s), 1489 (s), 1413 (w), 1312 (w), 1234
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6 H2O, 7 H2O, 8 2H2O, 9, 10, and 11 2.5H2O were solved by
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direct methods and refined on F2 by full-matrix least-squares
using anisotropic displacement parameters for all non-hydrogen
atoms.37 The H2O molecule in 2 0.5H2O was found to be
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disordered over two positions with an occupancy factor of
0.598/0.402 for O(1)/O(1A). The hydrogen atoms of the H2O
and MeOH solvent molecules in 2 0.5H2O, 4 MeOH, 5
(w), 1127 (m), 1010 (w), 957 (w), 846 (s), 746 (w), 559 (m) cm-1
.
UV-vis (MeCN, λmax(nm (ε M-1 cm-1))): 258 (90500). 1H
NMR (400 MHz, (CD3)2SO): δ 7.58-7.72 (m, 8H, Ph), 3.53
(s, 18H, NMe3).
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MeOH, 6 H2O, 7 H2O, 8 2H2O, and 11 2.5H2O were located
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from Fourier maps and their O-H bond distances were re-
strained to be equal to 0.85. All other hydrogen atoms were
[{Hg(Tab)2}2( μ-Adi)](PF6)2 (9). Compound 9 was prepared
as colorless blocks in a manner similar to that described for the
preparation of 2, using 1 (0.825 g, 1 mmol) in 15 mL of MeCN
and adipic acid (0.146 g, 1 mmol) in H2O (3 mL). Yield: 0.61 g
(81% based on Hg). Anal. Calcd. for C42H60F12Hg2N4O4P2S4:
C, 33.53; H, 4.02; N, 3.72. Found: C, 30.42; H, 3.73; N, 3.89. IR
(KBr disk): 3441 (m), 3095 (w), 3045 (w), 2966 (w), 1655 (s), 1585
(m), 1490 (s), 1404 (w), 1313 (w), 1280 (w), 1232 (w), 1127 (m),
1009 (w), 958 (w), 845 (s), 746 (w), 711 (w), 558 (s) cm-1. UV-vis
(MeCN, λmax(nm (ε M-1 cm-1))): 265 (114000). 1H NMR (400
MHz, (CD3)2SO): δ 7.56-7.70 (m, 8H, Ph), 3.54 (s, 18H,
NMe3), 1.94 (m, 2H, CH2), 1.43 (m, 4H, CH2).
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placed in geometrically idealized positions (C-H = 0.98 A for
methyl groups; C-H = 0.95 A for phenyl groups) and con-
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strained to ride on their parent atoms with Uiso(H) = 1.5Ueq(C)
for methyl groups and Uiso(H) = 1.2Ueq(C) for phenyl groups.
Important crystal data and collection and refinement param-
eters for 2 0.5H2O, 3, 4 MeOH, 5 MeOH, 6 H2O, 7 H2O,
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8 2H2O, 9, 10, and 11 2.5H2O are given in Table 4.
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Acknowledgment. This work was financially supported by
the National Natural Science Foundation of China (20525101,
20871088, and 90922018), the Nature Science Key Basic Research
of Jiangsu Province for Higher Education (09KJA150002), the
Specialized Research Fund for the Doctoral Program of higher
Education of Ministry of Education (20093201110017), the State
Key Laboratory of Coordination Chemistry of Nanjing Univer-
sity, the Qin-Lan and the “333” Projects of Jiangsu Province, and
the “Soochow Scholar” Program and the Program for Innovative
Research Team of Suzhou University. The authors also highly
[Hg( μ-Tab)( μ-Adi)]2n (10). Compound 10 was prepared as
colorless blocks in a manner similar to that described for the
preparation of 2, using 1 (0.825 g, 1 mmol) in 15 mL of MeCN
and adipic acid (0.292 g, 2 mmol) in H2O (3 mL). Yield: 0.75 g
(75% based on Hg). Anal. Calcd. for C30H42Hg2N2O8S2: C,
35.19; H, 4.13; N, 2.74. Found: C, 35.40; H, 3.87; N, 2.98. IR
(KBr disk): 3418 (m), 3057 (w), 2947 (w), 2933 (w), 2909 (w),
(36) (a) Hasnain, S. S. In Synchrotron Radiation in Chemistry and Biology
II; Mandelkow, E., Ed.; Springer-Verlag: New York, 1988; p 73. (b) Eichhofer, A.;
Buth, G. Eur. J. Inorg. Chem. 2005, 4160.
(37) Sheldrick, G. M. SHELXS-97 and SHELXL-97, Program for the
€
€
X-ray Crystal Structure Solution; University of Gottingen: Gottingen, Germany,
1997.

516 Inorganic Chemistry, Vol. 50, No. 2, 2011
Tang et al.
appreciated the helpful comments from the editor and the re-
viewers.
10, and 11 2.5H2O (CIF), and views of the hydrogen-
bonded networks for 2 0.5H2O, 3, 4 MeOH, 5 MeOH,
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6 H2O, 7 H2O, 8 2H2O, 9, 10, and 11 2.5H2O in PDF format.
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Supporting Information Available: Crystallographic data of
2 0.5H2O, 3, 4 MeOH, 5 MeOH, 6 H2O, 7 H2O, 8 2H2O, 9,
This material is available free of charge via the Internet at http://
pubs.acs.org.
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