Cooperative effect of anion and mole ratio on the coordination modes of an NO2S3-donor macrocycle

Article abstract of DOI:10.1021/ic500594f

Synthesis of an NO₂S₃-macrocycle (L) incorporating a pyridine subunit and its anion and/or mole ratio-dependent coordination modes in the formations of mercury(II) complexes is reported. When the mercury(II) salts with different anio

Full text of DOI:10.1021/ic500594f

Article
pubs.acs.org/IC
Cooperative Effect of Anion and Mole Ratio on the Coordination
Modes of an NO2S3‑Donor Macrocycle
Hyeong-Hwan Lee, In-Hyeok Park, and Shim Sung Lee*
Department of Chemistry and Research Institute of Natural Science, Gyeongsang National University, Jinju 660-701, S. Korea
S
* Supporting Information
ABSTRACT: Synthesis of an NO2S3-macrocycle (L) incor-
porating a pyridine subunit and its anion and/or mole ratio-
dependent coordination modes in the formations of mercury-
(II) complexes is reported. When the mercury(II) salts with
−
different anions (ClO4 or Br−) were reacted with L, the
Hg(ClO4)2 afforded a typical endocyclic complex [HgL]-
(ClO4)2 (1). Meanwhile, the HgBr2 gave an exocyclic complex
[HgLBr2] (2) in which the metal ion exists outside the
macrocyclic cavity. The observed anion effect on the
coordination modes can be explained by the anion
coordination ability toward the metal cation. In the mole ratio variation experiments, notably, the use of 1.5 equiv or above
of HgBr2 in the same reaction condition gave a unique endo/exocyclic dumbbell-type complex 3, [Hg4L2Br6][Hg2Br6]. However,
the formation of the endocyclic Hg(ClO4)2 complex 1 shows no mole ratio dependency. To monitor the observed mole ratio-
dependent exocoordination products as well as their reactivities and reversibility, systematic powder X-ray diffraction (PXRD)
analysis was also applied. From single crystal X-ray and PXRD analyses, it was found that endocyclic complex 1 is not reactive,
but complexes 2 and 3 are reactive and show the reversibility between them in the presence of the corresponding reactants.
dimensional (1D) network complex with an endo-/exocyclic
coordination mode have also been introduced by us.11
INTRODUCTION
■
Over the years, most macrocyclic ligands have been employed
for endocyclic coordination (metal-in-cavity) toward the central
metal ion species.1 Thiamacrocycles, however, frequently form
exocyclic complexes in which the metal ion species exist outside
the cavity because of the preferential exocyclic orientation of
the sulfur donors respect to the cavity.2−6 Because of this
reason, the exocyclic coordination of macrocyclic ligands has
proved to be a useful strategy for generating both discrete7a and
polymeric7b metallo-supramolecular species that often exhibit
unusual structures.
We have previously reported the exocoordination-based
discrete and network structures of supramolecular complexes
incorporating thiamacrocycles, with such systems being
attractive, not only because of their unusual topologies8 but
also because of their application as photophysical sensors.9
Our initial motivations to utilize exocoordination were that
the isolated products are readily influenced by several factors
involving ligands (donor atom) and anions that we can control.
We have reported the anion-controlled endo- and exocyclic
silver(I) complexes with an O3S2-macrocycle, which are
explained by the different anion coordination ability toward
the metal cation.10 On the other hand, we have introduced a
mercury(II)-selective chromoionophoric macrocycle exhibiting
anion-controlled color changes due to the formation of endo-
or exocyclic complexes depending on the coordination ability of
the anions.9a Recently, a sulfur-rich macrocycle incorporating
one pyridine subunit and its Hg(II)/Cu(II) heteronuclear one-
In the course of our ongoing studies to explore the
controlling factors of the coordination modes for the
macrocycles,7b we have been interested in extending our
research to involve a ligand- and anion-directed approach in
terms of crystal engineering. In this work, we therefore
proposed a sulfur-rich mixed donor macrocycle L which
employs a pyridine subunit to accommodate one metal cation
in the cavity and two additional benzo subunits to enhance the
structural rigidity (Chart 1). The 20-membered macrocycle L is
somewhat semiflexible due to the consecutive thioether
segment as bridge heads for the required exocoordination,
and this seems to induce the diversity of the coordination
modes across their respective complexes.
For example, on coordination of a soft metal salt with a
noncoordinating anion to the pyridine as well as other donors,
L might be expected to favor the endocyclic product.11 In
contrast, a soft metal salt with a coordinating anion in the same
condition could result in the formation of the exocyclic one.
When the pyridine and the semiflexible nature of L associated
with the thioether linkage are considered together, however, it
is difficult to predict the coordination behavior in the presence
of an excess amount of the reactants (e.g., mercury(II) salt). On
the basis of this assumption, we have suggested whether minor
factors such as the mole ratio of the reactants (that is, the
Received: March 14, 2014
Published: April 16, 2014
© 2014 American Chemical Society
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Chart 1. Diagram of Cooperative Effect of Anion and Mole Ratio on the Endocyclic and the Exocyclic Coordination Modes
metal-to-ligand ratio) might be employed to control the nature
of the resulting complex type.12 Furthermore, the mole ratio
dependency on the formation of macrocyclic complexes has not
been systematically investigated so far. Thus, we have coupled
the anion approach with the use of the mole ratio variation to
understand the controlling factors of the coordination mode of
the proposed macrocycle.
been probed by X-ray analysis. Powder X-ray diffraction
(PXRD) analysis has also been applied to monitor the observed
mole ratio dependent exocoordination products. To the best of
our knowledge, the observation of mole ratio-dependent
products coupled with such coordination mode has not been
reported previously.
In this work, we have prepared two mercury(II) complexes
RESULTS AND DISCUSSION
■
(1 and 2) of L with different coordination modes, depending
Synthesis of Macrocyclic Ligand (L). Synthesis of the
target macrocycle L involved four steps starting from ditosylate
4 (Scheme 2), with each step proceeding smoothly in
reasonable yield. Dichloride 7 was prepared from dialdehyde
5 and dialcohol 6 using a known procedure.13 L was obtained
by coupling macrocyclization reaction between 7 and dithiol in
the presence of Cs2CO3 under high dilution condition; a
on the anions (ClO4 and Br−) (Scheme 1). Interestingly, on
−
increasing the mole ratio of HgBr2, a new complex with the
endo-/exocyclic coordination was isolated. However, the
formation of the endocyclic product (ClO4 form) shows no
mole ratio dependency. The structural characteristics of the
complexes of L with the different coordination modes have
reasonable yield was obtained (25%). The H and 13C NMR
1
Scheme 1. Hg(II) Complexes of L, Showing Different
Coordination Modes Depending on Anions and Mole Ratios
spectra (Figure S6, Supporting Information) together with
elemental analysis and mass spectra were all in clear agreement
with the proposed structures.
Anion-Dependent Endo- and Exocyclic Complexes (1
and 2). In an attempt to examine the anion dependency on the
coordination modes of the mercury(II) complexes of L,
Hg(ClO4)2 and HgBr2 were used. L dissolved in dichloro-
methane was treated with 1 equiv of each mercury(II) salt in
acetonitrile. Slow evaporation of the solutions afforded the
crystalline products of 1 (ClO4 form) and 2 (Br− form)
−
suitable for X-ray analysis. Using these reaction systems, two
complexes were prepared and structurally characterized
(Figures 1 and 2).
The X-ray analysis revealed that 1 is a typical endocyclic
mononuclear complex of formula [HgL](ClO4)2 in which a
mercury(II) ion is accommodated inside the macrocyclic cavity
(Figure 1a). In 1, the mercury(II) center in the cavity is six-
coordinate, being bound to all donor atoms from L, adopting a
“tight-and-twisted” conformation. The Hg−S bond distances in
1 [2.5730(14)−2.6987(13) Å] are typical, and those of the
Hg−O bonds [Hg1−O1 2.817(4) and Hg1−O2 2.790(3) Å]
show somewhat elongated distances because of the larger cavity
size of L for the mercury(II) complexation. The pyridine
nitrogen appears to bind strongly to the mercury(II) center
[Hg1−N1 2.221(4) Å], which largely contributes to the
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Scheme 2. Synthesis of L
Figure 1. The mercury(II) perchlorate complex 1, [HgL](ClO4)2, showing an endocyclic coordination mode: (a) front view (anions were omitted)
and (b) side view.
Figure 2. The mercury(II) bromide complex 2, [HgLBr2] showing an exocyclic coordination mode: (a) front view and (b) side view.
formation of the endocyclic complex with thiamacrocycles. The
mercury(II) coordination in 1 cannot be described simply in
terms of a regular geometry. The perchlorate anions in 1
remain uncoordinated, with the closest distance between the
Hg and O atoms being av. 3.236(6) Å (Figure 1b). The
adoption of this preferred anion/solvent-uncoordinated
endocyclic mode in 1 is associated with the weaker
coordinating affinity of the anion and solvent molecules
themselves. Unlike other complexes obtained in this work
(see below), 1 shows no reactivity with the excess amount of
reactants such as Hg(ClO4)2 or L in solution.
A single crystal X-ray analysis revealed that 2 crystallized in
the monoclinic space group P21/c. In marked contrast to the
metal ion position in 1, the bromide complex 2 shows an
exocoordinated species of formula [HgLBr2] (Figure 2). In this
case, the Hg atom lies outside the cavity. Unlike the six-
coordinated Hg center in 1, the Hg1 atom in 2 is four-
coordinate being bonded by two S donors (S2 and S3) from
one L and two bromide ions to form a distorted tetrahedral
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Figure 3. Crystal structure of mercury(II) bromide complex 3, [Hg4L2Br6][Hg2Br6]: (a) the dumbbell-type complex part and [Hg2Br6] part showing
a weak interaction, (b) coordination environment of the endocyclic Hg1 atom showing a distorted pentagonal bipyramidal geometry, and (c) the
pseudo-one-dimensional structure via the Hg3···S2 interaction (dashed lines, 3.528 Å).
environment, with tetrahedral angles falling in the range
79.82(5)° for S3−Hg1−S2 to 135.64(3)° for Br2−Hg1−Br1.
These large deviations are due to the formation of the presence
of the five-membered chelate ring [Hg1−S2−C−C−S13] via
two Hg−S bonds. The two O, one N, and one S (S1) donors
remain uncoordinated. The Hg−S bond distances [Hg1−S2
2.7329(17) and Hg1−S3 2.6664(17) Å] are slightly longer than
those in 1 [av. 2.6996(9) Å]. The Hg−Br bond distances
[Hg1−Br1 2.5066(9) and Hg1−Br2 2.5002(8) Å] are typical.
With respect to the anion-coordination ability, the preferred
exocoordination mode of 2 is due to the stronger affinity of the
Br− ion toward the Hg center, inducing the metal positioned
outside the cavity.
Recently, some examples of anion-controlled endo- and
exocyclic silver(I)10 and mercury(II)9a complexes with the
macrocycles have been reported by us. Such anion-dependent
endo- and exocoordination modes in the macrocycles are still
rare.
Mole Ratio-Dependent Coordination Modes: An
Endo-/Exocyclic Complex (3). The above anion-dependent
Hg(II) complexes with different coordination modes encour-
aged us to study the possible preparation of the corresponding
Hg(II) complexes both with the endo- and the exocoordination
modes simultaneously. Since the exocyclic mercury(II) bromide
complex 2 has an empty cavity, we assumed that the use of
excess amount of HgBr2 as a reactant can lead to not only the
exocoordination but also the endocoordination.
In the macrocyclic complex part, there are two crystallo-
graphically independent Hg atoms (Hg1 and Hg2) which are
bridged by the Br1 atom to form a dumbbell-shape. The Hg1
atom which locates at the center of the macrocyclic cavity is
seven-coordinate, being bound to a NO2S3-donor set from L in
a highly twisted conformation. One remaining site is occupied
by one Br atom (Br1). The coordination geometry can be best
described as a distorted pentagonal bipyramid with NO2S2
donors from L defining the pentagonal plane, and the axial
positions occupied by one remaining sulfur atom (S2) and one
Br atom (Br1). The S2−Hg1−Br1 angle is 165.05(12)°.
In 3, there are two rhomboidal clusters [Hg2Br6]2−; one links
the two endocyclic mercury(II) complex units via Hg1−Br1
bond [2.768(2) Å] resulting in the formation of the dumbbell-
shape and another one is separated from the complex part with
Hg3···S2 distance of 3.528 Å, which is shorter than the sum of
the van der Waals radii.14 Unlike the typical endo-/exocyclic
complexes in which both metals inside and outside the cavity
bind to the macrocyclic ligand;7,10 in this case, the Hg2 atom
outside the cavity is not directly coordinated by the macrocycle.
The geometric parameters of the both rhomboid-type clusters
are similar to those reported previously for this part.15
Systematic PXRD Studies: Mole Ratio Effect on the
Formations of the Exo- and Endo-/Exocyclic Complexes.
The studies on the coordination modes of the products
associated with the mole ratio of the reactants were provided by
the consecutive PXRD patterns. We performed a series of
experiments in the preparation of HgBr2 complexes with L by
varying the mole ratio of HgBr2/L from 1.0 to 9.0. The
resulting PXRD patterns of the products obtained in each mole
ratio were recorded and compared with the simulated PXRD
patterns of 2 and 3 based on the single crystal X-ray analysis
(Figure 4).
When 2 equiv of mercury(II) bromide was used in the
reaction with L, as a preliminary condition, a colorless
crystalline product 3 was isolated. Compound 3 features a
discrete type complex with two separated parts of formula
[HgL(μ2-Hg2I6)HgL][Hg2Br6] (Figure 3): one dumbbell-type
macrocyclic mercury(II) complex cation part and one mercury-
(II) bromide cluster anion part. The asymmetric unit of the
macrocyclic complex part contains one L, one endocyclic Hg
atom (Hg1), one exocyclic Hg atom (Hg2), and three Br
atoms.
When the mole ratios are in the range of 1.0−1.3, the PXRD
patterns of the products are coincident with the simulated
pattern of the exocyclic complex 2, suggesting that 2 is an only
product in this region. When the mole ratio reaches 1.4, some
new peaks (denoted with blue reciprocal triangles) are
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Figure 5. (A) PXRD patterns for (a) 2, (b) the solid product
(identified as 3) obtained from the forward reaction of 2 with 4 equiv
of HgBr2, (c) the solid product (identified as 2) obtained from the
reaction of 3 with 4 equiv of L. (d) The solid products (identified as a
mixture of 2 and 3) obtained from the reaction of 3 with 2 equiv of L
and (e) 3. (B) The reversible process between 2 and 3 in the presence
of the corresponding reactants. All the reactions were carried out in
acetonitrile/dichloromethane.
From the observed reactivities and the reversibility, it is
found that the endocyclic complex 1 is not reactive, but both of
the complexes 2 and 3 which involve the exocyclic metal ion
are reactive. These phenomena might be considered as an
indication that such macrocyclic complexes possessing the
exocyclic metal ion could function as a metalloligand to
undergo further complexation reactions.
Figure 4. PXRD patterns of the products by varying the mole ratio of
the reactants (HgBr2/L = 1.0−9.0). The data shown in the bottom and
the top represent the simulated PXRD patterns of 2 and 3,
respectively, based on the single crystal X-ray analysis.
observed, which indicate 3, suggesting a mixture of 2 and 3 was
obtained. However, when the mole ratio increased above 1.5,
the evidence of 2 disappeared and only 3 was obtained. Thus,
we can conclude that as the content of HgBr2 increases, the
exocyclic product 2 is further reacted with the existing excess
salt to form the stable endo/exocyclic species 3. The observed
sudden conversion of the product near the mole ratio 1.4 could
be associated with the conformational change of L from its
flattened form to the highly twisted from as mentioned in
Figures 2 and 3 since L is somewhat semiflexible.
CONCLUSION
■
We have isolated and structurally characterized the anion-
controlled endo- and exocoordinated mercury(II) complexes.
Coupled with the observed anion dependency on the
coordination modes, we found that the mole ratio of the
reactants for the exocoordinated system undergoes further
reaction resulting in an interesting endo-/exocoordinated
species. The systematic PXRD study supports the observed
dependency of the mole ratio as a controlling factor on the
coordination modes. In addition, it was found that the
endocyclic complex is not reactive, but both of the exo- and
endo-/exocylic ones are reactive and show the reversibility
between them in the presence of the corresponding reactants.
Hence, the combined approach of single crystal X-ray analysis
and PXRD analysis has enabled in-depth information
concerning of the coordination mode through changing the
mole ratio of the reactants. We consider that the exocoordi-
nated product is promising to be served as a platform or a
metalloligand to construct the diverse metallosupramolecules.
Further investigations on this and similar systems as well as on
the potential applications are currently in progress.
Over recent years, our group has investigated the rationally
designed macrocycles incorporating sulfur donors in con-
junction with aromatic subunit to prepare diverse types homo-
and heteronuclear endo-/exocyclic complexes from such
system. The present result observed is the first case that the
endo- and the endo-/exocoordinated macrocyclic complexes
can be prepared by varying the mole ratio of the reactants.
Reactivities and Reversibility of the Complexes. As
mentioned above, the endocyclic complex 1 shows no reactivity
with both of the reactants. However, the complexes 2 and 3
which involve the exocyclic mode are reactive with the
mercury(II) salt and L, respectively. The reversibility between
2 and 3 was examined by analyzing the isolated products for the
forward and the reverse reactions in solution (Figure 5). When
2 was reacted with 4 equiv of HgBr2 in acetonitrile/
dichloromethane, we obtained a colorless precipitate which
was identified as 3 by the PXRD data (Figure 5Ab,e).
Oppositely, when 3 was reacted with 4 equiv of L in the
same condition, we confirmed that 2 was obtained as a colorless
precipitate (Figure 5Ac,a), suggesting the reversible conversion
between 2 and 3 in the presence of the corresponding
reactants. Meanwhile, when the amount of HgBr2 (in the
forward reaction) or L (in the reverse reaction) was reduced
from 4 to 2 equiv, a mixture of 2 and 3 was obtained in both
cases (Figure 5Ad).
EXPERIMENTAL SECTION
■
General. All chemicals and solvents used in the syntheses were
reagent grade and were used without further purification. Fourier
transform infrared (FT-IR) spectra were recorded with a Thermo-
Fisher Scientific Nicolet iS 10 FT-IR spectrometer. The elemental
analysis was carried out on a LECO CHNS-932 elemental analyzer.
1
The H NMR spectra were recorded by using a Bruker Advance-300
NMR spectrometer. Mass spectra were obtained by using a Thermo
Scientific LCQ Fleet spectrometer.
CAUTION! Perchlorate salts of metal complexes are potentially
explosive and should be handled with great care.
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Table 1. Crystallographic Data and Structure Refinement for 1−3
1
2
3
formula
C25H27HgCl2NO10S3
869.15
C25H27HgBr2NO2S3
830.07
C50H50Hg6Br6N2O4S6
3097.74
formula weight
temperature
crystal system
space group
Z
173(2)
173(2)
173(2)
orthorhombic
P212121
monoclinic
P21/c
monoclinic
C2/c
4
4
4
a (Å)
12.2583(3)
13.5867(3)
16.9143(4)
90
4.9569(4)
25.526(2)
21.0651(16)
90
34.6711(7)
13.2665(3)
15.1019(3)
90
b (Å)
c (Å)
α (deg)
β (deg)
90
93.611(4)
90
96.8680(10)
90
γ (deg)
V (Å3)
90
2817.07(11)
2.049
2660.1(4)
2.073
6896.5(2)
2.984
Dcalc (g/cm3)
2θmax (deg)
R1, wR2 [I > 2σ(I)]
R1, wR2 [all data]
goodness-of-fit on F2
no. of reflection used [>2σ(I)]
structure determination
refinement
52.00
52.00
52.00
0.0307, 0.0568
0.0358, 0.0585
0.825
0.0461, 0.0793
0.0790, 0.0898
1.012
0.0710, 0.1966
0.0863, 0.2088
1.069
5537 [Rint = 0.0414]
SHELXTL
full-matrix
5207 [Rint = 0.0770]
SHELXTL
full-matrix
6793 [Rint = 0.0545]
SHELXTL
full-matrix
Table 2. Selected Bond Distances (Å) and Bond Angles
(deg) for 1
Table 4. Selected Bond Distances (Å) and Bond Angles
(deg) for 3a
Hg1−N1
Hg1−S2
Hg1−O1
2.221(4)
2.6987(13)
2.817(4)
137.14(12)
67.76(14)
65.55(13)
83.67(4)
76.55(8)
78.24(8)
156.32(8)
82.31(4)
Hg1−S1
Hg1−S3
Hg1−O2
N1−Hg1−S1
N1−Hg1−S2
O2−Hg1−O1
S1−Hg1−S3
S1−Hg1−O2
S2−Hg1−O2
S3−Hg1−O2
2.5730(14)
2.6204(15)
2.790(3)
Hg1−N1
Hg1−O2
Hg1−S2
Hg1−Br1
Hg2−Br3
Hg2−Br3A
Hg3−Br4
Hg3−Br6
2.375(14)
2.765(13)
2.641(5)
2.768(2)
2.568(3)
2.924(3)
2.656(2)
2.530(2)
2.8486(19)
87.13(9)
90.58(6)
132.4(4)
137.6(4)
65.3(4)
Hg1−O1
Hg1−S1
Hg1−S3
Hg2−Br2
Hg2−Br1
Hg3−Br5
Hg3−Br4B
Br3−Hg2A
2.941(13)
2.761(6)
2.710(5)
2.485(3)
2.627(2)
2.530(2)
2.8486(19)
2.924(3)
N1−Hg1−S3
N1−Hg1−O2
N1−Hg1−O1
S1−Hg1−S2
S1−Hg1−O1
S2−Hg1−O1
S3−Hg1−O1
S3−Hg1−S2
128.12(12)
119.32(11)
132.20(11)
88.05(5)
128.59(8)
135.94(9)
71.48(8)
Br4−Hg3B
Hg2−Br3−Hg2A
Hg3−Br4−Hg3B
N1−Hg1−S3
N1−Hg1−S1
N1−Hg1−O1
O2−Hg1−Br1
S1−Hg1−Br1
S2−Hg1−Br1
S2−Hg1−S3
S2−Hg1−O2
S3−Hg1−O1
S3−Hg1−Br1
Br1−Hg2−Br3A
Br2−Hg2−Br1
Br3−Hg2−Br3A
Br4−Hg3−Br4B
Br4B−Hg3−S2
Br5−Hg3−S2
Br6−Hg3−Br5
Br6−Hg3−Br4B
Hg2−Br1−Hg1
N1−Hg1−S2
N1−Hg1−Br1
N1−Hg1−O2
O2−Hg1−O1
S1−Hg1−O2
S1−Hg1−O1
S2−Hg1−S1
125.56(8)
99.2(4)
94.4(4)
66.3(5)
Table 3. Selected Bond Distances (Å) and Bond Angles
(deg) for 2
131.7(4)
72.3(3)
101.6(3)
84.74(12)
165.05(12)
82.12(15)
78.5(3)
Hg1−S2
Hg1−Br1
Br1−Hg1−S3
Br2−Hg1−S3
Br2−Hg1−S2
2.7329(17)
2.5066(9)
103.23(4)
116.56(4)
103.33(4)
Hg1−S3
Hg1−Br2
Br1−Hg1−S2
Br2−Hg1−Br1
S3−Hg1−S2
2.6664(17)
2.5002(8)
102.20(4)
135.64(3)
79.82(5)
69.7(3)
81.05(16)
110.1(3)
89.83(15)
155.4(3)
81.2(3)
S2−Hg1−O1
S3−Hg1−S1
154.3(3)
93.26(10)
88.86(8)
119.30(10)
88.14(9)
89.42(6)
159.01(10)
80.01(10)
120.38(7)
109.05(7)
S3−Hg1−O2
Br1−Hg1−O1
Br2−Hg2−Br3A
Br2−Hg2−Br3
Br3−Hg2−Br1
Br4−Hg3−S2
Br5−Hg3−Br4B
Br5−Hg3−Br4
Br6−Hg3−S2
Br6−Hg3−Br4
Synthesis and Characterization of L. Cesium carbonate (5.05 g,
15.5 mmol) was dissolved in DMF (2000 mL) in a 3 L round-bottom
flask. 2-Mercaptoethyl sulfide (1.59 g, 10.3 mmol) and dichloride 7
(4.01 g, 10.3 mmol) were dissolved in DMF (30 mL) and placed in a
50 mL glass syringe. The contents of the syringe were added dropwise
at a regular rate (0.6 mL·h−1) into the DMF solution under a nitrogen
atmosphere with the aid of microprocessor controlled syringe pump at
45−50 °C over 50 h. After being cooled to room temperature, the
reaction mixture was filtered and the solvent evaporated. Water (100
mL) was added, and the mixture was extracted with dichloromethane.
The organic phase was dried over anhydrous sodium sulfate and
filtered and the solvent was removed to give yellow crude mixture.
Flash column chromatography (SiO2, n-hexane/ethyl acetate = 8:2)
afforded the product as a white solid in 25% yield. Mp: 119−121 °C.
IR (KBr, pellet) 3021, 2927, 2873, 1596, 1491, 1450, 1288, 1237,
1097, 1012, 1096, 782, 753 cm−1. Anal. Calcd for C25H27NO2S3: C,
63.93; H, 5.79; N, 2.98; S, 20.48. Found: C, 63.81; H, 5.94; N, 3.03; S,
108.28(11)
116.93(11)
121.53(9)
74.78(9)
97.59(7)
122.22(7)
89.71(11)
110.65(7)
a
Symmetry operations: (A) −x + 2, y, −z + 3/2; (B) −x + 3/2, −y +
1/2, −z.
20.46. 1H NMR (300 MHz, CDCl3, δ): 7.79−6.91 (11H, aromatic, see
Figure S6a, Supporting Information), 5.11 (s, 4H, PyCH2O), 3.71 (s,
4H, ArCH2S), 2.235 (t, 4H, ArCH2SCH2CH2), 2.23 (t, 4H,
ArCH2SCH2); 13C NMR (75 MHz, CDCl3, δ) 156.5, 156.2, 137.7,
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Inorganic Chemistry
Article
130.9, 128.5, 127.9, 122.6, 121.7, 112.3, 71.9, 32.4, 31.6, 29.5. Mass
spectrum m/z (ESI): 492.33 (L + Na)+.
REFERENCES
■
(1) (a) Pedersen, C. J. J. Am. Chem. Soc. 1967, 89, 7017. (b) Lindoy,
L. F. The Chemistry of Macrocyclic Complexes; Cambridge University
Press: Cambridge, U.K., 1989. (c) Lehn, J.-M. Supramolecular
Chemistry, Concept and Perspectives; VCH: Weinheim, Germany,
1995. (d) Izatt, R. M.; Pawlak, K.; Bradshaw, J. S. Chem. Rev. 1995,
95, 2529.
(2) (a) Wolf, R. E.; Hartman, J. R.; Storey, J. M. E.; Foxman, B. M.;
Cooper, S. R. J. Am. Chem. Soc. 1987, 109, 4328. (b) Robinson, G. H.;
Sangokoya, S. A. J. Am. Chem. Soc. 1988, 110, 1494. (c) Hill, S. E.;
Feller, D. J. Phys. Chem. A 2000, 104, 652.
(3) Heller, M.; Sheldrick, W. S. Z. Anorg. Allg. Chem. 2004, 630, 1191.
(4) (a) Rottgers, T.; Sheldrick, W. S. J. Solid State Chem. 2000, 152,
271. (b) Rottgers, T.; Sheldrick, W. S. Z. Anorg. Allg. Chem. 2001, 627,
1976. (c) Heller, M.; Sheldrick, W. S. Z. Anorg. Allg. Chem. 2004, 630,
1869. (d) Heller, M.; Teichert, O.; Sheldrick, W. S. Z. Anorg. Allg.
Chem. 2005, 631, 709. (e) Heller, M. Z. Anorg. Allg. Chem. 2006, 632,
441.
(5) Huang, D.; Zhang, X.; Mclnnes, E. J. L.; McMaster, J.; Blake, A.
J.; Davies, E. S.; Wolowska, J.; Wilson, C.; Schroder, M. Inorg. Chem.
2008, 47, 9919.
(6) Stephen, E.; Blake, A. J.; Carter, E.; Collison, D.; Davies, E. S.;
Edge, R.; Lewis, W.; Murphy, D. M.; Wilson, C.; Gould, R. O.; Holder,
A. J.; McMaster, J.; Schroder, M. Inorg. Chem. 2012, 51, 1450.
(7) (a) Lee, E.; Lee, S. Y.; Lindoy, L. F.; Lee, S. S. Coord. Chem. Rev.
2013, 257, 3125. (b) Park, S.; Lee, S. Y.; Park, K.-M.; Lee, S. S. Acc.
Chem. Res. 2012, 45, 391.
(8) (a) Park, S.; Lee, S. Y.; Lee, S. S. Inorg. Chem. 2010, 49, 1238.
(b) Lee, J. Y.; Kim, H. J.; Jung, J. H.; Sim, W.; Lee, S. S. J. Am. Chem.
Soc. 2008, 130, 13838. (c) Lee, J. Y.; Lee, S. Y.; Sim, W.; Park, K.-M.;
Kim, J.; Lee, S. S. J. Am. Chem. Soc. 2008, 130, 6902. (d) Lee, S. Y.;
Park, S.; Kim, H. J.; Jung, J. H.; Lee, S. S. Inorg. Chem. 2008, 47, 1913.
(e) Lee, J. Y.; Lee, S. Y.; Seo, J.; Park, C. S.; Go, J. N.; Sim, W.; Lee, S.
S. Inorg. Chem. 2007, 46, 6221. (f) Yoon, I.; Seo, J.; Lee, J.-E.; Park, K.-
M.; Lah, M. S.; Lee, S. S. Inorg. Chem. 2006, 45, 3487. (g) Kim, H. J.;
Sultana, K. F.; Lee, J. Y.; Lee, S. S. Cryst. Growth Des. 2010, 12, 1494.
(h) Ju, H.; Lee, S. S. Cryst. Growth Des. 2012, 12, 4972.
(9) (a) Lee, S. J.; Jung, J. H.; Seo, J.; Yoon, I.; Park, K.-M.; Lindoy, L.
F.; Lee, S. S. Org. Lett. 2006, 8, 1641. (b) Lee, S. J.; Lee, J.-E.; Seo, J.;
Jeong, I. Y.; Lee, S. S.; Jung, J. H. Adv. Funct. Mater. 2007, 17, 3441.
(c) Lee, H.; Lee, S. S. Org. Lett. 2009, 11, 1393.
Preparation of 1, [HgL](ClO4)2. A dichloromethane (1 mL)
solution of L (19.9 mg, 0.0424 mmol) was allowed to diffuse slowly
into an acetonitrile (1 mL) solution of Hg(ClO4)2 (16.9 mg, 0.0424
mmol) in a capillary tube (i.d. 5 mm). Slow evaporation of the solution
gave colorless crystalline 1 that proved suitable for X-ray analysis
(yield: 87%). Mp: 217−218 °C (decomp.). IR (KBr pellet): 2991,
−
−
2936, 1495, 1456, 1234, 1096 (ClO4 ), 805, 765, 735, 623 (ClO4 ),
1040, 777 cm−1; Anal. Calc for [C26H29HgCl4NO10S3]: C, 32.72; H,
3.06; N, 1.47; S, 10.08. Found: C, 32.76; H, 3.09; N, 1.70; S, 10.03%.
Mass spectrum m/z (ESI): 335.4 [Hg(L)]2+.
Preparation of 2, [HgBr2L]. A dichloromethane (1 mL) solution of
L (20.2 mg, 0.0430 mmol) was allowed to diffuse slowly into a
acetonitrile (1 mL) solution of HgBr2 (15.5 mg, 0.0430 mmol) in a
capillary tube (i.d. 5 mm). Slow evaporation of the solution gave
colorless crystalline 2 that proved suitable for X-ray analysis (yield:
88%). Mp: 148−149 °C (decomp.). IR (KBr pellet): 3059, 2968,
2912, 1591, 1489, 1453, 1245, 1223, 1009, 798, 757, 750 cm−1; Anal.
Calc for [C25H27HgBr2NO2S3]: C, 36.17; H, 3.28; N, 1.69; S, 11.59.
Found: C, 36.29; H, 3.28; N, 1.66; S, 11.87%. Mass spectrum m/z
(ESI): 749.9 [HgBrL]+.
̈
Preparation of 3, [Hg4Br6L2][Hg2Br6]. Preparation of 3, HgBr2
(20.1 mg, 0.0428 mmol) in acetonitrile was added to a solution of L
(30.8 mg, 0.0856 mmol) in dichloromethane (1 mL). Slow
evaporation of the solution afforded a colorless crystalline product 3
suitable for X-ray analysis (yield: 83%). Mp: 230−232 °C (decomp).
IR (KBr pellet): 3059, 2914, 1600, 1480, 1456, 1403, 1235, 1223,
̈
1103, 1050, 1036, 790, 765 cm− 1
; Anal. Calc for
[C29H34Hg6Br12N3O2.5S3]: C, 20.31; H, 1.93; N, 1.75; S, 6.02.
Found: C, 20.72; H, 1.86; N, 1.54; S, 6.46%. Mass spectrum m/z
(FAB): 750.1 [HgBrL]+ (the molecular ion peak is not shown).
X-ray Crystallographic Analysis. All data were collected on a
Bruker SMART APEX II ULTRA diffractometer equipped with
graphite monochromated Mo Kα radiation (λ = 0.71073 Å) generated
by a rotating anode. The cell parameters for the compounds were
obtained from a least-squares refinement of the spot (from 36
collected frames). Data collection, data reduction, and semiempirical
absorption correction were carried out using the software package of
APEX2.16a All of the calculations for the structure determination were
carried out using the SHELXTL package.16b In all cases, all non-
hydrogen atoms were refined anisotropically, and all hydrogen atoms
except coordinated water molecules were placed in idealized positions
and refined isotropically in a riding manner along with the their
respective parent atoms. Relevant crystal data collection and
refinement data for the crystal structures of 1−3 are summarized in
Table S1, Supporting Information.
(10) Kim, H. J.; Lee, S. S. Inorg. Chem. 2008, 47, 10807.
(11) Lee, E.; Lee, S. S. Inorg. Chem. 2011, 50, 5803.
(12) Lee, E.; Kim, J.-Y.; Lee, S. S.; Park, K.-M. Chem.Eur. J. 2013,
19, 13638.
(13) Janssen, R. J. A.; Lindoy, L. F.; Matthews, O. A.; Meehan, G. V.;
Sobolev, A. N.; White, A. H. J. Chem. Soc., Chem. Commun. 1995, 735.
(14) Bondi, A. J. Phys. Chem. 1964, 68, 441.
(15) Rogers, R. D.; Bond, A. H.; Wolff, J. L. J. Coord. Chem. 1933, 29,
187.
ASSOCIATED CONTENT
* Supporting Information
■
S
Analytical data, geometric parameters of crystalline complexes,
PXRD patterns, and X-ray crystallographic files (CIFs). This
material is available free of charge via the Internet at http://
pubs.acs.org. The CIF files can be obtained free of charge from
the Cambridge Crystallographic Data Centre via www.ccdc.
cam.ac.uk/data_request/cif CCDC Numbers 975092−975094
(for compounds 1−3) for this paper.
(16) (a) Bruker, APEX2 Version 2009.1-0 Data Collection and
Processing Software; Bruker AXS Inc.: Madison, WI, 2008. (b) Bruker,
SHELXTL-PC Version 6.22 Program for Solution and Refinement of
Crystal Structures; Bruker AXS Inc.: Madison, WI, 2001.
AUTHOR INFORMATION
Corresponding Author
*E-mail: sslee@gnu.ac.kr.
■
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
This work was supported by NRF (2011-0011064 and
2012R1A4A1027750).
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