Synthesis and structural characterization of a binary metal cluster and a coordination polymer based on the mercury Bis(phenylselenolate) unit

Article abstract of DOI:10.1016/j.poly.2012.06.015

The versatile coordination chemistry of the Bis(phenylselenolate) (Hg(SePh)₂) with Hg(SCN)₂ salt allows the synthesis of a cluster and a 2D coordination polymer. The reaction at low temperature in dimethylformamide (dmf) affords single crystals containing neutral clusters with the formula [Hg₈S(SCN)₂(SePh)₁₂(dmf) ₂] (1). Then, the 2D coordination polymer [Hg(SCN)(SePh)] (2) is obtained in comparable yielding. The use of bis(2-pyridylthio)methane as secondary ligand significantly improves the synthesis of 2, since it is synthesized at room temperature, in a short time and in a good yield. The effects of the weak interactions in the crystal packing were also analyzed.

Full text of DOI:10.1016/j.poly.2012.06.015

Polyhedron 43 (2012) 170–175
Contents lists available at SciVerse ScienceDirect
Polyhedron
journal homepage: www.elsevier.com/locate/poly
Synthesis and structural characterization of a binary metal cluster
and a coordination polymer based on the mercury Bis(phenylselenolate) unit
b
b
a
Ana B. Lago a, , Ernesto S. Lang , Bárbara Tirloni , Ezequiel M. Vázquez-López
⇑
a Departamento de Química Inorgánica, Facultade de Química, Universidade de Vigo, E-36310 Vigo, Galicia, Spain
b Departamento de Química, Laboratório de Materiais Inorgânicos, Universidade Federal de Santa Maria, 97.105-900 Santa Maria, RS, Brazil
a r t i c l e i n f o
a b s t r a c t
Article history:
The versatile coordination chemistry ofthe Bis(phenylselenolate) (Hg(SePh)2) with Hg(SCN)2 saltallows the
synthesis of a cluster and a 2D coordination polymer. The reaction at low temperature in dimethylformam-
ide (dmf) affords single crystals containing neutral clusters with the formula [Hg8S(SCN)2(SePh)12(dmf)2]
(1). Then, the 2D coordination polymer [Hg(SCN)(SePh)] (2) is obtained in comparable yielding. The use
of bis(2-pyridylthio)methane as secondary ligand significantly improves the synthesis of 2, since it is syn-
thesized at room temperature, in a short time and in a good yield. The effects of the weak interactions in the
crystal packing were also analyzed.
Received 27 March 2012
Accepted 8 June 2012
Available online 21 June 2012
Keywords:
Mercury
Selenolate
Cluster
Ó 2012 Elsevier Ltd. All rights reserved.
Coordination polymers
1. Introduction
compounds are thermodynamically and (or) kinetically stable in
these conditions. Nevertheless the synthesis of coordination poly-
Metal chalcogenolate complexes have attracted interest due to
their rich structural chemistry, as well as other materials and bio-
logical applications such as precursor for M/Se materials or model
for active sites of chacolgen-containing metalloproteins [1].
The construction of new organochalcogenide compounds using
Hg(EPh)2 (E = Se, Te) units and suitable metal salts have shown to
be an efficient way to generate new organochalcogenide com-
pounds in form of clusters or polymeric structures [2].
mers and cluster compounds has significant difference features.
For cluster compounds the essential problems are the stability of
the cluster ion itself, the appropriate ligands selection required
and the small-scale quantity of compound obtained in synthesis
[8].
The synthesis of metal coordination polymers has attracted sig-
nificant interest as they represented an important interface between
syntheticchemistryandmaterialscience. Incontrastto coordination
polymers of transition metal ions, the formation of polymers with
heavy metal ions such as mercury(II) seems to be surprisingly sparse
[9]. In addition, multidimensional coordination polymers consisting
of oligonuclearmetalclusters canbe potentialcandidates for various
applications including gas storage and catalysis [10].
In previous studies, bis(2-pyridylthio)methane (2bpytm)
(Scheme 1) have been extensively used to prepare metal–organic
frameworks with different metal centers allowing the isolation of
different structural motifs [11]. Furthermore, cleavage and partial
oxidation of 2bpytm have led to the isolation of diverse compounds
resulting from C–S bond scission [12]. So that, to date the organic
molecule 2bpytm has shown to be a multifunctional compound.
In previous works we have investigated the reaction of
Hg(EPh)2 with halide mercury salts HgX2 yielding clusters with
the general formula [Hg3X3(EPh)3].2dmso [3] and other larger clus-
ters as [Hg6(
-Br)Br3] [5].
We have also studied the opening of the six-membered ring
Hg3Te3 of [Hg3Cl3(
l-Br2)Br2(l-TePh)8(py)2] [4] and [Hg8(l-n-C3H7Te)12-
(l
l
-TePh)3]Á2dmso by redissolution with dmso,
reacting with Co[Hg(SCN)4] to afford the polymeric compound
[(dmso)2Co(NCS)4(Hg-TePh)2]n [6].
Nevertheless, the use of the pseudohalide Hg(SCN)2 as mercury
salt precursor give rise to new neutral cluster or polymeric com-
pounds, shown the great versatility of the thiocyanate anion as li-
gand. The SCNÀ anion exhibit several remarkable peculiarities that
is (i) variety of bonding modes (terminal or bridging), (ii) it can act
as N-bonded or S-bonded to the metal and, (iii) it can act as accep-
tor or donor in different weak interactions [7].
2. Experimental
2.1. Materials and physical measurements
On the other hand, the synthesis of chemical compounds at
room temperature and atmospheric pressure are possible if these
Elemental analyses (C, H, N, S) were carried out with a Fisons
EA-1108 microanalyser. Melting points (m.p.) were measured with
a Gallenkamp MBF-595 apparatus. IR spectra were recorded from
KBr discs (4000–400 cmÀ1) with a Jasco FT/IR-6100 spectrometer.
⇑
Corresponding author.
E-mail address: ablago@uvigo.es (A.B. Lago).
0277-5387/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.poly.2012.06.015

A.B. Lago et al. / Polyhedron 43 (2012) 170–175
171
S
N
N
Yield:60%. M.p. 165 °C. Anal. calc. forC14H10N2S2Se2Hg2: C, 20.15;
H, 1.21; N, 3.36; S, 7.67. Found: C, 20.28; H, 1.30; N, 3.30; S, 7.35%. IR
S
(KBr, cmÀ1): 3437, [
m
s(C–H)]; 2096, [
ms (S=C=N)]; 1570, 1473, 1436
[m
s (C=C)]; 1063, 1019, 998 [d(C=C–H)]; 733,6846 cmÀ1 [d(C=C–H)].
Scheme 1. The molecular structure of the ligand 2bpytm.
2.3. Crystallography
TGA was performed on a SETSYS Evolution Setaram thermogravi-
Crystallographic data of 1 and 2 were collected on a Bruker Kap-
pa Apex II CCD diffractometer at 293 K using graphite monochro-
metric analyzer in flowing N2 with a heating rate of 10 °C minÀ1
.
X-ray powder diffraction (XRPD) characterization was performed
using a Siemens D-5000 diffractometer with Cu K radiation
(k = 1.5418 Å) over the range 5.0–60.0° in steps of 0.20° (2h) with
mated Mo K
a radiation (k = 0.71073 Å) and were corrected for
a
Lorentz and polarization effects. The frames were integrated with
the Bruker SAINT [14] software package and the data were corrected
for absorption using the program SADABS [15].
a count time per step of 5.0 s.
The structures were solved by direct methods using the pro-
gram SHELXS97 [16]. All non-hydrogen atoms were refined with
anisotropic thermal parameters by full-matrix least-squares calcu-
lations on F2 using the program SHELXL97 [17]. Hydrogen atoms
were inserted at calculated positions and constrained with isotro-
pic thermal parameters. Drawings were produced with MERCURY
[18] program and special computations for the crystal structure
discussions were carried out with PLATON [19]. Crystal data and
structure refinement data are listed in Table 1.
The nature of the central atom of the cluster 1 as sulfur was con-
firmedbyX-rayphotoelectronspectroscopy(XPS)onthesinglecrys-
tal and elemental analysis of the solid. However, when selenium is
included as the central atom, the thermal parameter is 0.749(7)
against 0.0369(4) with sulfur atom. Refinement of the model consid-
ering a S/Se disorder at this position were also unsuccessful.
2.2. Synthesis
2.2.1. [Hg8S(SCN)2(SePh)12(dmf)2] (1)
A solution of Hg(PhSe)2 [13] (0.102 g, 0.2 mmol) in dmf (10 mL)
was added dropwise to a solution of Hg(SCN)2 (0.062 g, 0.2 mmol)
in dmf (10 mL). The resulting solution was stirred for 4 h at room
temperature. The mother liquor afforded crystals at 4 °C in 15 days
that were identified as 1.
Yield: 0.041 g, 35% based on Hg(PhSe)2. M.p. 130 °C. Anal. calc.
for C80H74N4S3O2Se12Hg8: C, 25.47; H, 1.98; N, 1.49; S, 2.55. Found:
C, 25.65; H, 1.72; N, 1.62; S, 2.73%. IR (KBr, cmÀ1): 3433, [
ms(C–H)];
2109, [ms (S=C=N)]; 1638, [ms (C=O)]; 1570, 1470, 1434 [ms (C=C)];
1064, 1018, 998 [d(C=C–H)]; 733,686 cmÀ1 [d(C=C–H)].
3. Result and discussion
2.2.2. [Hg(SCN)(SePh)] (2)
Compound 2 was obtained as a by-product of the synthesis of 1
andalsoinpresenceofthesecondaryligand bis(2-pyridylthio)meth-
ane (2bpytm) [11a].
Method (a): Once single crystals of 1 were filtered off, the
mother liquor afforded new crystals after 5 days at 4 °C that were
identified as 2. Yield: 30%.
In this paper we describe the synthesis and structural charac-
terization of two kind of compounds: the discrete cluster
[Hg8S(SCN)2(SePh)12(dmf)2] (1) and the 2D coordination polymer
[Hg(SCN)(SePh)] (2). The organic molecule 2bpytm contributes to
the isolation of the coordination polymer 2.
Both compounds were obtained by mild synthetic strategies
from equimolar mixture of the both metal salts, in a relatively
short time and were clearly stable under normal atmosphere and
at room temperature. The compounds were characterized by ele-
mental analysis, infrared spectroscopy and single-crystal X-ray dif-
fraction. The powder X-ray diffraction experiments were compared
with the simulated from the crystals structure showing that the
crystal is representative of the bulk materials (Supplementary
Information). The surface analysis technique X-ray photoelectron
spectroscopy (XPS) show that the atomic relation Hg:Se:S is
1:1:1 in 2 and 2:3:1 in 1. The %w of Hg:Se:S is according with
the values expected (Supplementary Information).
Method (b): A solution of 2bpytm (0.047 g, 0.2 mmol) in a 1:2
mixture of ethyl acetate and acetonitrile (5 mL) was added drop-
wise to a solution of Hg(SCN)2 (0.062 g, 0.2 mmol) in the same sol-
vent mixture (5 mL) together with dmf (2 mL). The resulting
solution was stirred for 4 h and a solution of Hg(PhSe)2 (0.102 g,
0.2 mmol) in dmf (5 mL) was added dropwise, and stirred for 4 h
more. Crystals suitable for X-ray diffraction were obtained from
the mother liquor in one day at room temperature.
Table 1
Crystal and structure refinement data.
Compound
1
2
The melting point of the cluster compound is considerably low-
er than polymeric compound 2. Thermogravimetric analysis (TGA)
of compound 2 shows that the thermal decomposition occurs in
two-step process between r.t. and 475 °C. The first weight loss of
46% between 165 °C and 300 °C suggests that both ligands are
cleaved in this step (theorethical weight loss of 51%).
The infrared spectra of both compounds show the characteristic
absorption bands of the phenyl rings [20]. A broad band with a
medium intensity is observed in 1 at 2109 cmÀ1 due to the thiocy-
anate acting as terminal group. These bands indicate that the thio-
cyanate group acts as monodentate ligand, most probably through
the sulfur atoms [21]. On the other hand, the thiocyanate group
that forms a bridge between two mercury atoms in 2, shows a
Empirical formula
Formula weight
T (K)
Crystal system
Space group
Unit cell dimensions
a (Å)
b (Å)
c (Å)
A (°)
b (°)
C
80H74O2S3N4Se12Hg8 C14H10S2N2Se2Hg2
3771.85
100(2)
orthorhombic
Pbcn
829.46
293(2)
monoclinic
P21/c
13.6141(2)
25.7190(5)
26.1983(4)
90
90
90
9173.1(3)
4
2.731
10.8907(6)
10.9479(5)
7.3598(3)
90
100.771(2)
90
862.03(7)
2
3.196
c
(°)
V (Å3)
Z
qcalc (g cmÀ3
)
Absorption coefficient
(mmÀ1
F(000)
Crystal size (mm)
18.211
22.248
)
6776
0.24 Â 0.05 Â 0.04
736
0.052 Â 0.132 Â 0.203
Scheme 2. The formation of precurssor PhSeHgX.

172
A.B. Lago et al. / Polyhedron 43 (2012) 170–175
Fig. 1. Structure of cluster 1 (the H atoms are omitted for clarity) and schematic representation showing the position of SCNÀ ligands and solvent molecules.
strong intensity band at 2096 cmÀ1. The spectrum of 1 also dis-
Table 2
plays a m
(C=O) band at 1638 cmÀ1 absorption bands due to the
Selected bond lengths (Å) and angles (°) for 1.
dmf molecules present in the cluster.
Distances
Compound 1 and 2 were isolated as co-product from the same
reaction, performed in dmf solvent. Firstly, 1 was obtained after
15 days as a crystalline. Single crystals of the polymeric compound
2 were obtained 5 days later. Compound 1 may be obtained at r.t as
well as at 4 °C but 2 is isolated immediately afterward. Decompo-
sition was observed at higher temperatures (40, 80 and 100 °C) and
not reaction was observed at lower temperatures (À20 °C).
Compound 2 is the only product isolated when the reaction is
performed in the presence of 2bpytm and, consequently, in a high-
er yield than in the absence of 2bpytm. Moreover, the reaction time
is noticeably shortened.
In previous work we observed that secondary ligands such as
2bpytm are able to stabilize the intermediary PhSeHgX (X = Cl,
Br, I) [20] formed initially- in coordination solvents- according to
the reaction represented in Scheme 2 to afford polymeric cages.
However, the exact role of secondary ligands in the assembly of
the polymeric compounds is not yet identified.
Surprisingly, the central atom of the cluster 1 is a sulfur atom
and consequently it means sulfurization and spontaneous self-
assembly processes. The formation of S2À and CNÀ from SCNÀ by
oxidants and mediated for metals were documented by Schug
and co-workers previously. Although thiocyanate was identified
as sulfur source before [22], the mechanism responsible for the
C–S cleavage is poorly understood and several different pathways
have been proposed [23]. It is noteworthy the role of the aprotic
Hg(4)–O(1S)
S–Hg(1)
2.469(7)
2.5571(11)
Se(6)–Hg(3)
S–Hg(3)
2.6607(9)
2.5831(9)
Angles
C(11)–Se(1)–Hg(4)
C(11)–Se(1)–Hg(1)
Hg(4)–Se(1)–Hg(1)
C(21)–Se(2)–Hg(1)
C(21)–Se(2)–Hg(2)
Hg(1)–Se(2)–Hg(2)
C(31)–Se(3)–Hg(2)#1
C(31)–Se(3)–Hg(1)
Hg(2)#1–Se(3)–Hg(1)
C(41)–Se(4)–Hg(3)
C(41)–Se(4)–Hg(2)
Hg(3)–Se(4)–Hg(2)
C(51)–Se(5)–Hg(4)
C(51)–Se(5)–Hg(3)
Hg(4)–Se(5)–Hg(3)
C(61)–Se(6)–Hg(4)#1
C(61)–Se(6)–Hg(3)
Hg(4)#1–Se(6)–Hg(3)
Hg(1)#1–S–Hg(1)
Hg(1)#1–S–Hg(3)#1
Hg(1)–S–Hg(3)#1
Hg(1)#1–S–Hg(3)
Hg(1)–S–Hg(3)
106.8(3)
97.2(3)
89.03(3)
97.4(3)
105.7(3)
94.27(3)
106.8(3)
96.2(3)
98.02(3)
94.1(3)
105.8(3)
95.71(3)
106.4(3)
104.6(3)
91.23(3)
106.3(3)
105.3(3)
87.67(3)
103.77(6)
105.315(9)
111.630(9)
111.630(9)
105.315(9)
118.33(7)
Se(3)–Hg(1–Se(1)
S(1)–Hg(2)–Se(3)#1
S(1)–Hg(2)–Se(2)
Se(3)#1–Hg(2)–Se(2)
S(1)–Hg(2)–Se(4)
Se(3)#1–Hg(2)–Se(4)
Se(2)–Hg(2)–Se(4)
S–Hg(3)–Se(4)
111.82(3)
115.03(7)
103.55(8)
113.25(3)
103.27(7)
112.47(3)
108.39(3)
105.87(3)
97.20(3)
121.10(3)
100.975(14)
112.61(3)
114.93(3)
96.29(18)
105.5(2)
123.60(3)
98.6(2)
116.10(3)
111.16(3)
129.4(7)
110.09(5)
102.01(2)
113.49(3)
100.86(5)
116.72(3)
S–Hg(3)–Se(5)
Se(4)–Hg(3)–Se(5)
S–Hg(3)–Se(6)
Se(4)–Hg(3)–Se(6)
Se(5)–Hg(3)–Se(6)
O(1S)–Hg(4)–Se(6)#1
O(1S)–Hg(4)–Se(5)
Se(6)#1–Hg(4)–Se(5)
O(1S)–Hg(4)–Se(1)
Se(6)#1–Hg(4)–Se(1)
Se(5)–Hg(4)–Se(1)
C(1S)–O(1S)–Hg(4)
Se(7)–Hg(1)–Se(2)
Se(7)–Hg(1)–Se(3)
Se(2)–Hg(1)–Se(3)
Se(7)–Hg(1)–Se(1)
Se(2)–Hg(1)–Se(1)
Hg(3)#1–S–Hg(3)
#1 = Àx + 1, y, Àz + 1/2.
Fig. 2. View of the supramolecular organization in 1 showing details of the CHÁ Á ÁN interactions along de c axis.

A.B. Lago et al. / Polyhedron 43 (2012) 170–175
173
Table 3
mation of these compounds argues against the existence of the
cluster compound in dmf solution.
Selected bond lengths (Å) and angles (°) for 2.
Distances
C(7)–N
C(7)–S(1)
N–Hg(1)#1
1.157(7)
1.661(9)
2.459(8)
S(1)–Hg(1)
Se(1)–Hg(1)
Se(1)–Hg(1)#2
2.601(2)
2.5459(8)
2.6038(9)
4. Structural studies
4.1. Cluster compound 1
Angles
C(7)–S(1)–Hg(1)
C(1)–Se(1)–Hg(1)
C(1)–Se(1)–Hg(1)#2
Hg(1)–Se(1)–Hg(1)#2
98.6(5)
Se(1)–Hg(1)–Se(1)#3
N(1)–Hg(1)–S(1)
Se(1)–Hg(1)–S(1)
Se(1)#3–Hg(1)–S(1)
139.42(5)
95.4(3)
119.71(9)
95.65(8)
101.2(3)
102.8(3)
95.37(4)
The compound 1 crystallizes in the orthorhombic space group
Pbcn. The structure is similar to other compounds with the formula
[M8E(EPh)12X4]2À (where X = anion) studied before [1,24]. Chalco-
genide clusters with mercury are rare and 1 is, to the best or our
knowledge, the only neutral complex with the general formula
[M8E(EPh)12X4] (X = anion or solvent). In this compound coexists
a sulfido ligand with selonolate ones. Moreover two thiocyanate
anions and two dmf solvent molecules are present in the molecular
structure.
A central sulfur atom linked in a tetrahedral environment to
four mercury atoms constitutes the core of the cluster (Fig. 1 right).
Refinement of the structure including the central atom as selenium
or disordered model (with different S/Se occupancies) were unsuc-
cessful. Each of these four inner mercury atoms is bound, through
three double bridging SePhÀ ligands (Se1 to Se6) to outer mercury
atoms (Hg2 and Hg4), which also form a tetrahedron. So that, the
eight mercury atoms as well as the central sulfur atom have a dis-
torted tetrahedral coordination sphere (Table 2). In addition, Hg2 is
bound to a sulfur atom of the thiocyanate ligand and Hg4 is bound
to an oxygen atom belonging to a dmf solvent molecule. This kind
of structure has been described as centro-S-tetrahedro-Hg-icosae-
#1 = Àx + 1,Ày,Àz; #2 = x,Ày + 1/2,z + ½; #3 = x,Ày + 1/2,z À 1/2.
coordinative solvent molecules for obtaining single crystals. of the
stable cluster (Fig. 1).
Reaction with Hg(SCN)2 differs from the analogous halides in
several respects. Firstly, the bitopic character of the SCNÀ makes
possible the coordination through both the nitrogen and the sulfur
atoms. Although, the tetrahedral mercury complexes are almost al-
ways S-bonded [7], the bridge coordinative mode in 2, leads to the
less common tetrahedral N-bonded. Moreover the free nitrogen
atoms in 1 offer the possibility to increase the dimensionality of
the compound through weak interactions. In fact, CHÁ Á ÁN interac-
tions are responsible for the supramolecular arrangement in the
cluster (vide infra).
The free N atom and the nature of thiocyanate ligand with the
variety of bonding modes (terminal as well as bridging) encourage
us to use this cluster as building block for the synthesis of new com-
pounds. The use of acceptor metal centers could give rise to new
ternary compounds through the bound to the free nitrogen atom.
In these sense, various synthetic attempts involving the use of the
cluster as building block have been unsuccessful. In fact, when
equimolar mixtures of Hg(SCN)2 and Hg(PhSe)2 were reacted with
nickel(II) and manganese(II) chlorides the compound [Hg5Cl3
(PhSe)7] [20] was always isolated, however [Hg8SeCl4(PhSe)12][-
Co(dmf)6] [2] was obtained when the cobalt(II) salt was used. For-
dro-(l-SePh)12-tetrahedro-tetrahedro-Hg-tetrahedro-(SePh)4 or as
well as four Hg inside and four Hg outside the triangular faces of
an (Se)12 icosahedron [24] and the eight mercury atoms bridge
the triangular faces. Hg–S distances in the central sulfur atom are
approximately 0.1 Å shorter than the Hg–Se distances (Table 2).
Each cluster stacks with adjacent ones through weak intermo-
lecular CH. . .N hydrogen bonds that furnishing a 3D supramolecu-
lar architecture (Fig. 2). The thiocyanate molecules are essential for
Fig. 3. 2D layer of [Hg(SCN)(SePh)] (2) showing in detail the (Hg2S2C2N2) core together with a representation in the bc plane and the sandwich-like fashion. View in the ac
plane of the 3D architecture in 2 showing details of the stacking interactions.
p–p

174
A.B. Lago et al. / Polyhedron 43 (2012) 170–175
the formation of the final organization due to two CHÁ Á ÁN weak
interactions with a CÁ Á ÁN distances of 3.32 and 3.66 Å. In this
way the molecules are not packed very efficiently, as evidence by
the calculated density of 2.765 mg mÀ3 and the packing index
[25] of 67%.
Whereas it is clear the role of the thiocyanate ligand in the
supramolecular arrangement, solvent molecules do not take part
in the supramolecular arrangement of the cluster.
perature has proved to be essential for the stabilization of both
compounds. Thiocyanate ligand shows a different but crucial role;
In 1, is responsible for the supramolecular organization of the clus-
ter and in 2, is co-responsible for the polymerization of the com-
pound but, do not take part in the supramolecular array. 2 is
synthesized in less time and with high yield when 2bpytm mole-
cule was used.
Acknowledgement
4.2. Polymeric compound 2
A.B.L. thanks to Xunta de Galicia for a postdoctoral-fellowship
‘‘Ángeles Alvariño’’.
Selected interatomic distances and angles are listed in Table 3
and the coordination environment of the mercury atom is shown
in Fig. 3, together with the numbering scheme used. The com-
pound is a 2D coordination polymer that crystallizes in the mono-
clinic P21/c space group. The layers are formed by 8-membered
metallocycles (Hg2S2C2N2) bounded to others by means of four
PhSeÀ units along the ac plane. The construction of these macrocy-
cles is based on the combination of two angular coordination mer-
cury environments and two linear thiocyanate ligands. Mercury
and selenium atoms form zig-zag chains along the c axis with
the phenyl rings point alternately, up and down. The double thio-
cyanate ligands are responsible to link these chains along the b axis
(Fig. 3). The layer can be described as a sandwich-like structure
with an organometallic core forming by selenium, mercury and
thiocyanate units and the organic phenyl groups pointed out the
layer (Fig. 3).
Appendix A. Supplementary data
CCDC 838439 and 838440 contains the supplementary crystal-
lographic data for 1 and 2, respectively. These data can be obtained
free of charge via http://www.ccdc.cam.ac.uk/conts/retriev-
ing.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. Supplementary data associated
with this article can be found, in the online version, at http://
dx.doi.org/10.1016/j.poly.2012.06.015.
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Two SCNÀ anions bridge two mercury(II) ions via N and S atoms
(mode
jS:jN) with bond distance of Hg–N = 2.459(8) Å and Hg–
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the Hg–S distance is clearly shortly than the Hg–N distance [26].
There is only one example reported in the CSD database where
the (l)jS:jN double bridge thiocyanate ligands present bigger
Hg–S distances (2.512; 2.589 Å) than Hg–N distances (2.465;
2.536 Å) [27]. The HgÁ Á ÁHg separation due to the SCN-bridge is
5.887 Å, whereas de HgÁ Á ÁHg distance through selenium atom is
3.809 Å.
The mercury metal center has a coordination number of four
and the environment is a distorted tetrahedral with a Se2NS coor-
dination sphere, with the Hg–Se distances around the typical value
of 2.5–2.6 Å (Table 3).
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tion, responsible for the 3D supramolecular array (Fig. 3). The adja-
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p–p
a
3.729(7) Å and the interplanar dihedral angle is 0°).
In this case the aprotic solvent is essential to obtain single crys-
tals but do not take part in the structure of the compound. The
polymeric compound presents a packing Kitaigorodskii index
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The reaction of Hg(SePh)2 with Hg(SCN)2 allows the isolation
and structural characterization of the new binary cluster
[Hg8S(SCN)2(SePh)12(dmf)2] (1) and the 2D coordination polymer
[Hg(SCN)(SePh)] (2). Synthesis conditions such as solvent or tem-

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