Non-covalent interaction in metal cation-directed assembly of supramolecular architectures: Synthesis, characterization and crystal structures

Article abstract of DOI:10.1016/j.poly.2012.04.001

Three new complexes [Zn(NCS)₂L₂] (1), [Hg(SCN) ₂L₂] (2) and [Mn(NCS)₂L₄] (3), have been synthesized by the self-assembly of 4-imidazolychalcone (abbreviated as L) with M(SCN)₂ (M

Full text of DOI:10.1016/j.poly.2012.04.001

Polyhedron 43 (2012) 1–7
Contents lists available at SciVerse ScienceDirect
Polyhedron
journal homepage: www.elsevier.com/locate/poly
Non-covalent interaction in metal cation-directed assembly of supramolecular
architectures: Synthesis, characterization and crystal structures
Feng Jin a,b, Fei-Xia Zhou a, Xiao-Fei Yang a, Long-Huai Cheng a, Ya-Ya Duan a, Hong-Ping Zhou a,
,
⇑
Lin Kong a, Fu-Ying Hao a,b, Jie-Ying Wu a, Yu-Peng Tian a,c,d
a Department of Chemistry, Anhui University, Hefei 230039, PR China
b Department of Chemistry, Fuyang Normal College, Fuyang 236041, PR China
c State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, PR China
d State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
Three new complexes [Zn(NCS)2L2] (1), [Hg(SCN)2L2] (2) and [Mn(NCS)2L4] (3), have been synthesized by
the self-assembly of 4-imidazolychalcone (abbreviated as L) with M(SCN)2 (M = Hg2+, Zn2+, Mn2+). The
complexes have been characterized by spectroscopic and crystallographic methods. 1H NMR spectra of
complexes 1–3 present that metal ions have effect on the chemical shifts of protons of coordinated
groups. Three complexes illustrate different molecular structures due to the different coordinated modes
of the metal ions. In the title complexes, the coordination geometries of Zn, Hg and Mn ions are tetrahe-
dral N4, N2S2 and octahedral N6, respectively. Finally, hydrogen bonding interactions assemble the differ-
ent coordination units into higher-dimensional frameworks. The results show that the metal ion and
weak non-covalent interactions play important roles in the construction of the final supramolecular
structures.
Received 7 March 2012
Accepted 1 April 2012
Available online 7 June 2012
Keywords:
Complex
Non-covalent interaction
Carbonyl
Thiocyanate
Paramagnetic ion
Metal-organic framework
Ó 2012 Published by Elsevier Ltd.
1. Introduction
new chalcone derivative containing imidazolyl and carbonyl group
via Claisen–Schmidt condensation of acetophenone with 4-imidaz-
During the past few decades, the design and synthesis of supra-
molecular structures based on strong coordinate bonds and multi-
ple weak non-covalent forces, such as intermolecular hydrogen
bonding interactions, has become one of the most active fields in
coordination chemistry and crystal engineering due to their fasci-
nating structural features and potential applications as functional
materials [1–6]. The non-covalent forces are weaker than the coor-
dinate bonds, however, they are common and play critical roles in
forming the supramolecular structures due to their significant con-
tribution to the self-assembly process [7–11]. More work has been
focused on the weak non-covalent forces in the design and synthe-
sis of supramolecular structures.
It is well known that the assembly process can be affected by
many factors, such as the choice of ligands, anions, metal ions,
and so on [12–16]. Carbonyl group, which widely exists in organic
and biological systems, plays a crucial role in stabilizing both the
extended crystal structures of small molecules and biological sys-
tems through various weak intermolecular interactions generated
via carbonyl group [1]. Thus, we have designed and synthesized a
olylbenzaldehyde. The ligand is expected to create not only coordi-
nate bond through imidazolyl nitrogen atom but also
intermolecular non-covalent interaction via carbonyl oxygen atom
in the assembly of the complexes.
At the same time, the rational selection of anions is very impor-
tant because the anions can control and adjust the topologies of
coordination frameworks through coordinate bonds or non-cova-
lent interactions. In coordination chemistry, thiocyanate has been
widely used as anion and coligand for the construction of the coor-
dination complex [17–21]. It can coordinate to metals by either the
sulfur or the nitrogen atom, or both. The most important is that,
when thiocyanate acts as a terminal ligand, the uncoordinated sul-
fur or nitrogen atom is often involved in intermolecular or intra-
molecular hydrogen bonding and other weak interactions, which
play extremely important roles to regulate and stabilize the supra-
molecular structure.
It is clear that different metal ions have different coordination
modes. In construction of higher-dimensional complex architec-
tures, Zn(II) often shows low coordination number of four with tet-
rahedral coordination geometry [12,13,22]. However, Mn(II) ion has
attracted our interest, due to its high coordination number and the
magnetic properties of its complex [23]. Hg(II) complexes have
been widely studied because of their structural diversities and
⇑
Corresponding author. Tel.: +86 551 5107105; fax: +86 551 5107342.
E-mail address: zhpzhp@263.net (H.-P. Zhou).
0277-5387/$ - see front matter Ó 2012 Published by Elsevier Ltd.
http://dx.doi.org/10.1016/j.poly.2012.04.001

2
F. Jin et al. / Polyhedron 43 (2012) 1–7
attractive optical properties [24]. In order to probe the influence of
metal ions on the supramolecular construction, a study was carried
out with different metal salts having the same thiocyanate ions.
Herein, three different structural supramolecular complexes based
(1H), 7.876 (s, 1H), 7.983, 8.022 (d, J = 15.6 Hz, 1H), 8.053, 8.074
(d, J = 8.4 Hz, 2H), 8.172, 8.191 (d, J = 7.6 Hz, 2H), 8.405 (s, 1H).
13C NMR: (100 MHz, CD3COCD3), d (ppm): 189.07 (C-5), 142.87
(C-7), 138.19 (C-4), 137.51 (C-11), 135.56 (C-12), 133.19 (C-1),
133.02 (C-8), 130.55 (C-10), 130.13 (C-13), 128.79 (C-2), 128.55
on the reaction of 4-imidazolychalcone and M(SCN)2 (M = Hg2+
,
Zn2+, Mn2+) were obtained by self-assembling. In the molecular
structure of 1, Zn(II) ion is four coordinated by two nitrogen atoms
of the imidazolyl groups and two nitrogen atoms of thiocyanate
ions. However, in the molecular structure of 2, Hg(II) ion is four
coordinated by two imidazolyl nitrogen atoms and two sulfur
atoms of thiocyanate ions to form a S2N2 distorted tetrahedral
geometry. For that of 3, Mn(II) ion is in a N6 distorted octahedral
geometry. Finally, higher-dimensional structures are formed
through different weak non-covalent forces due to the different
coordination modes of metal ions. Here, we present the synthesis,
spectroscopy characterization and crystal structures of complexes
1–3.
(C-3), 122.13 (C-6), 120.12 (C-9), 117.72 (C-14). IR m
(cmꢀ1):
653(s), 699(s), 727(m), 778(s), 832(s), 985(s), 1019(m), 1058(s),
1108(m), 1185(m), 1219(s), 1308(s), 1336(s), 1486(m), 1552(s),
1574(s), 1600(s), 1663(s), 3093(s). MS (EI) (m/z): Anal. Calc. for
C
18H14N2O: 274.11 [M]+. Found: 274.11 [M]+. UV–Vis (DMF): kmax
(nm): 328.
2.2.2. Synthesis of Zn(NCS)2L2 (1)
Complex 1 was prepared by layering method at room tempera-
ture. A clear methanol solution (15 mL) of Zn(NCS)2 (18.10 mg,
0.1 mmol) was carefully layered onto a solution of 4-imidazoly-
chalcone (54.86 mg, 0.2 mmol) in chloroform (15 mL). Yellow nee-
dle-shaped crystals suitable for X-ray diffraction were obtained by
slow interlayer diffusion. Yield: 51.03 mg, 70%. Anal. Calc. for
2. Experimental
C
38H28ZnN6O2S2: C, 62.50; H, 3.86; N, 11.51. Found: C, 62.20; H,
3.53; N, 11.20%. 1H NMR: (400 MHz, CD3COCD3), d (ppm): 7.176
(s, 1H), 7.574, 7.593, 7.612 (t, J = 7.6 Hz, 2H), 7.672, 7.691, 7.709
(t, J = 7.6 Hz, 1H), 7.795, 7.815 (d, J = 8.4 Hz, 2H), 7.821 (1H),
7.919 (s, 1H), 7.992, 8.031 (d, J = 15.6 Hz, 1H), 8.066, 8.087 (d,
J = 8.4 Hz, 2H), 8.173, 8.192 (d, J = 7.6 Hz, 2H), 8.456 (s, 1H). IR
2.1. General
All commercially available chemicals are of analytical grade and
used without further purification. The solvents were purified by
conventional methods. 4-Imidazolylbenzaldehyde was synthesized
according to the methods reported [25].
m
(cmꢀ1): 654(s), 694(s), 725(m), 777(s), 832(s), 982(s), 1018(s),
1067(s), 1220(s), 1311(m), 1338(s), 1525(s), 1577(w), 1604(s),
1663(s), 2093(s), 3120(m).
2.2. Synthesis
2.2.1. Synthesis of 4-imidazolychalcone (L)
2.2.3. Synthesis of Hg(SCN)2L2 (2)
A methanol solution (40 mL) of NaOH (4.00 g, 0.1 mol) was
added dropwisely to a stirred methanol (20 mL) solution of 4-imi-
dazolylbenzaldehyde (1.72 g, 10 mmol) and acetophenone (1.20 g,
10 mmol) in a round-bottom flask at room temperature. The yel-
low solid product formed immediately. After filtration, the product
was washed by methanol and water, dried in vacuo. Yield: 2.33 g,
85%. Anal. Calc. for C18H14N2O: C, 78.81; H, 5.14; N, 10.21. Found: C,
78.50; H, 5.48; N, 10.01%. 1H NMR: (400 MHz, CD3COCD3), d (ppm):
7.145 (s, 1H), 7.573, 7.592, 7.611 (t, J = 7.6 Hz, 2H), 7.671, 7.690,
7.708 (t, J = 7.6 Hz, 1H), 7.779, 7.800 (d, J = 8.4 Hz, 2H), 7.815
Complex 2 was prepared by the same synthetic procedure
to complex 1 using Hg(SCN)2 (31.70 mg, 0.1 mmol) instead of
Zn(NCS)2 to react with 4-imidazolychalcone (54.86 mg, 0.2 mmol).
Yellow rhomboid single crystals were obtained. Yield: 51.90 mg,
60%. Anal. Calc. for C38H28HgN6O2S2: C, 52.74; H, 3.26; N, 9.71.
Found: C, 52.43; H, 3.59; N, 9.48%. 1H NMR: (400 MHz, CD3COCD3),
d (ppm): 7.186 (s, 1H), 7.576, 7.595, 7.614 (t, J = 7.6 Hz, 2H), 7.675,
7.694, 7.712 (t, J = 7.6 Hz, 1H), 7.791, 7.812 (d, J = 8.4 Hz, 2H), 7.823
(1H), 7.930 (s, 1H), 8.003, 8.042 (d, J = 15.6 Hz, 1H), 8.072, 8.093 (d,
J = 8.4 Hz, 2H), 8.179, 8.198 (d, J = 7.6 Hz, 2H), 8.460 (s, 1H). IR
Table 1
Crystal data and structure refinement for complexes 1–3.
Complex
1
2
3
Empirical formula
Formula weight
T (K)
C
38H28ZnN6O2S2
C38H28HgN6O2S2
865.37
298(2)
C74H56MnN10O4S2
1268.35
298(2)
730.15
298(2)
k (Å)
0.71069
monoclinic
P2/c
19.13(3)
5.798(8)
16.58(2)
107.48(2)
1754(4)
2
0.71069
monoclinic
C2/c
37.945(5)
5.950(5)
15.930(5)
105.259(5)
3470(3)
4
0.71069
monoclinic
C2/c
34.425(5)
10.949(5)
17.827(5)
104.172(5)
6515(4)
4
Crystal system
Space group
a (Å)
b (Å)
c (Å)
b (°)
V (Å3)
Z
Dcalcd (g cmꢀ3
F(000)
)
1.382
752
1.657
1704
1.293
2636
Crystal size (mm)
Reflections collected
Unique reflections
Parameters
0.30 ꢁ 0.20 ꢁ 0.20
0.30 ꢁ 0.20 ꢁ 0.20
0.30 ꢁ 0.20 ꢁ 0.20
9177
11587
5727
2989
222
1.129
3042
223
1.016
3063
412
1.127
GOF on F2
R1 [I > 2
wR2 [I > 2
qmin/max (e Åꢀ3
r
(I)]
0.0591
0.1324
0.413/ꢀ0.359
0.0300
0.0700
0.726/ꢀ0.432
0.0659
0.1780
0.759/ꢀ0.559
r(I)]
D
)

F. Jin et al. / Polyhedron 43 (2012) 1–7
3
Table 2
Selected bond distances (Å) and angles (°) for complexes 1–3.
Complex 1
Bond lengths
Zn1–N1
1.999(4)
Zn1–N3
1.938(4)
Bond angles
N(1)–Zn(1)–N(1)#1
N(1)–Zn(1)–N(3)#1
104.6(2)
107.9(2)
N1–Zn1–N3
N(3)–Zn(1)–N(3)#1
109.9(2)
116.1(3)
Complex 2
Bond lengths
Hg(1)–N(1)
2.328(4)
Hg(1)–S(1)
2.447(2)
Bond angles
N(1)–Hg(1)–N(1)#2
N(1)#2–Hg(1)–S(1)
88.8(2)
113.2(1)
N(1)–Hg(1)–S(1)
S(1)–Hg(1)–S(1)#2
102.0(1)
130.2(9)
Complex 3
Bond lengths
Mn(l)–N(5)
Mn(l)–N(2)
2.205(6)
2.271(5)
Mn(l)–N(4)
2.264(5)
Bond angles
N(4)#3–Mn(l)–N(2)
N(5)–Mn(l)–N(4)#3
N(5)–Mn(l)–N(2)#3
92.4(2)
88.8(2)
90.6(2)
N(5)–Mn(l)–N(4)
N(5)–Mn(l)–N(2)
N(4)–Mn(l)–N(2)
91.2(2)
89.4(2)
87.6(2)
Symmetry transformations used to generate equivalent atoms: #1: ꢀx + 2, y, ꢀz + 3/2; #2: ꢀx + 2, y, ꢀz + 1/2; #3: ꢀx + 1,
ꢀy + 2, ꢀz + 2.
m
(cmꢀ1): 654(s), 698(s), 758(m), 781(s), 832(s), 986(m), 1018(s),
3. Results and discussion
3.1. Crystal structures
1067(s), 1221(s), 1257(w), 1309(m), 1337(s), 1521(s), 1576(w),
1604(s), 1662(s), 2116(s), 3118(m).
2.2.4. Synthesis of Mn(NCS)2L4 (3)
3.1.1. Crystal structure of Zn(NCS)2L2 (1)
The same synthetic procedure as for 1 was used except that
Zn(NCS)2 was replaced by Mn(NCS)2 (17.11 mg, 0.1 mmol) and a
1:4 metal-to-ligand molar ratio was adopted, giving yellow rhom-
Single-crystal X-ray diffraction analysis reveals that complex 1
crystallizes in the monoclinic space group P2/c. In the molecular
structure of complex 1, Zn(II) ion is four coordinated by two nitro-
gen atoms of the imidazolyl groups (L) and two nitrogen atoms of
thiocyanate anions to form a distorted tetrahedral geometry. The
thiocyanate group is coordinated in a linear fashion through the
nitrogen atom. The Zn–N bond lengths are 1.999(3) and
1.938(4) Å, respectively, which are within the normal range [22].
The bond angles around the zinc atom are in the range of
104.6(2)–116.1(3)° (Table 2).
In the crystal structure, two intermolecular hydrogen bonding
interactions based on one S atom of thiocyanate are formed, which
are crucial in the formation of the higher-dimensional structure.
The multiple Sꢂ ꢂ ꢂH hydrogen bonds arise from the nature of the
unsaturated coordination of sulfur atom. The neighboring mole-
cules of 1 are linked by intermolecular C(1)–H(1)ꢂ ꢂ ꢂS hydrogen
bonding interactions (the distance of H(1)ꢂ ꢂ ꢂS is 2.881 Å, and the
C(1)–H(1)ꢂ ꢂ ꢂS angle is 144.5°) to form a one-dimensional structure
along the b axis, as shown in Fig. 1a. The one-dimensional struc-
tures are interconnected by C(3)–H(3)ꢂ ꢂ ꢂS hydrogen bonding (the
distance of H(3)ꢂ ꢂ ꢂS is 2.923 Å, and the C(3)–H(3)ꢂ ꢂ ꢂS angle is
160.4°) to aggregate in a two-dimensional sheet framework paral-
lel to the bc plane (Fig. 1b). No hydrogen bonding interaction based
on carbonyl O atom is found in 1, which may be attributed to the
larger separation between the molecules caused by the linear thio-
cyanate groups [1].
boid single crystals. Yield: 107.70 mg, 85%. Anal.
Calc. for
C
74H56MnN10O4S2: C, 70.07; H, 4.45; N, 11.04. Found: C, 70.38; H,
4.12; N, 11.38%. 1H NMR: (400 MHz, CD3COCD3), d (ppm): 7.594,
7.610 (J = 6.4, 2H), 7.675, 7.691 (J = 6.4, 1H), 7.784, 7.820 (3H),
7.993 (s, 1H), 8.032, 8.071 (3H), 8.178, 8.195 (d, J = 6.8, 2H). IR
m
(cmꢀ1): 659(m), 688(s), 723(m), 777(s), 827(s), 961(s), 1012(s),
1058(s), 1216(s), 1305(s), 1338(s), 1445(w), 1493(m), 1521(s),
1576(s), 1600(s), 1661(s), 2054(s), 3129(w).
2.3. Physical measurements
Elemental analyses were carried out on Perkin-Elmer 240 ana-
lyzer. One-dimensional and two-dimensional NMR spectra were
recorded on a Bruker AVANCE III spectrometer in DMSO-d6 with
TMS as internal standard and the proton resonance at 400 MHz
and the carbon resonance at 100 MHz. The mass spectra were ob-
tained on a Micromass GCT-MS spectrometer. IR spectra were re-
corded from KBr discs in the 4000–40 cmꢀ1 range on a nicolet
Nexus 870 spectrophotometer. Ultraviolet visible (UV–Vis) absorp-
tion spectrum was obtained in DMF solutions (10ꢀ5 mol Lꢀ1) using
a Shimadzu UV-3600 UV–Vis–NIR spectrophotometer.
2.4. Crystal structures determination and refinement
The X-ray diffraction measurements were performed on a Bru-
ker SMART CCD area detector using graphite monochromated Mo
3.1.2. Crystal structure of Hg(SCN)2L2 (2)
K
a
radiation (k = 0.71069 Å) at 298(2) K. Intensity data were col-
Single-crystal X-ray diffraction analysis reveals that complex 2
crystallizes in the monoclinic space group C2/c. The coordination
modes of thiocyanate in complexes 2 and 1 are different because
of the hard-soft acid–base (HSAB) concept. The Hg(II) ion of com-
plex 2 is coordinated with two S atoms of thiocyanate anions
and two N atoms of imidazolyl groups to form a distorted tetrahe-
dral geometry. The Hg–S and Hg–N bond lengths are 2.446(2) and
2.328(4) Å, respectively, which are within the normal range [24b].
lected in the variable -scan mode. The structures were solved
x
by direct methods and difference Fourier syntheses. The non-
hydrogen atoms were refined anisotropically and hydrogen atoms
were introduced geometrically. Calculations were performed with
SHELXTL-97 program package [26]. Details of the crystal parameters,
data collections and refinements are listed in Table 1, and selected
bond distances and angles are given in Table 2.

4
F. Jin et al. / Polyhedron 43 (2012) 1–7
Fig. 1. (a) The one-dimensional structure of 1 formed by C(1)–H(1)ꢂ ꢂ ꢂS hydrogen bonding interactions. Hydrogen atoms not participating in hydrogen bonding are omitted for
clarity. (b) The two-dimensional structure of 1 formed by C(1)–H(1)ꢂ ꢂ ꢂS and C(3)–H(3)ꢂ ꢂ ꢂS hydrogen bonding interactions. Hydrogen atoms not participating in hydrogen
bonding are omitted for clarity.
Fig. 2. (a) The one-dimensional structure in 2 formed by intermolecular C–Hꢂ ꢂ ꢂO hydrogen bonding interactions. Hydrogen atoms not participating in hydrogen bonding are
omitted for clarity. (b) The two-dimensional structure in 2 formed by intermolecular C–Hꢂ ꢂ ꢂO and C–Hꢂ ꢂ ꢂN hydrogen bonding interactions. Hydrogen atoms not participating
in hydrogen bonding are omitted for clarity.
The bond angles around the Hg(II) ion are in the range of 88.8–
130.2°.
anions in the axial positions. The Mn–N bond lengths are 2.205(6),
2.264(5) and 2.271(5) Å, respectively, which fall within the normal
range [23e,g]. The bond angles around the manganese atom are in
the range of 87.6(2)–92.4(2)°, as shown in Table 2.
In the crystal structure, thiocyanate N atom and carbonyl O
atom play important roles in the formation of the higher-dimen-
sional structure. As shown in Fig. 2a, the molecules of 2 are linked
by intermolecular C(8)–H(8)ꢂ ꢂ ꢂO hydrogen bonding interactions
(the distance of H(8)ꢂ ꢂ ꢂO is 2.601 Å, and the C(8)–H(8)ꢂ ꢂ ꢂO angle
is 131.26°) to form a one-dimensional structure along the b axis.
The one-dimensional structures are interconnected by C(3)–
H(3)ꢂ ꢂ ꢂN(3) hydrogen bonding (the distance of H(3)ꢂ ꢂ ꢂN(3) is
2.678 Å, and the C(3)–H(3)ꢂ ꢂ ꢂN(3) angle is 162.01°) to aggregate
in a two-dimensional sheet framework parallel to the bc plane
(Fig. 2b).
In the six-coordinated crystal structure of complex 3, multiple
intermolecular hydrogen bond interactions based on carbonyl O
atom and thiocyanate S atom are formed in the supramolecular
structure, which play key roles in the formation of the final struc-
ture. It is worth mentioning that three hydrogen bond interactions
based on O(2), including C(34)–H(34)ꢂ ꢂ ꢂO(2), C(24)–H(24)ꢂ ꢂ ꢂO(2)
and C(28)–H(28)ꢂ ꢂ ꢂO(2) are formed. The distances of
H(34)ꢂ ꢂ ꢂO(2), H(24)ꢂ ꢂ ꢂO(2) and H(28)ꢂ ꢂ ꢂO(2) are 2.618, 2.465 and
2.637 Å, respectively, and the C(34)–H(34)ꢂ ꢂ ꢂO(2), C(24)–
H(24)ꢂ ꢂ ꢂO(2) and C(28)–H(28)ꢂ ꢂ ꢂO(2) angles are 123.58°, 150.15°
and 144.02°, respectively. As shown in Fig. 3a, the neighboring
molecules are linked each other through the C(32)–H(32)ꢂ ꢂ ꢂS
hydrogen bond interactions to generate one-dimensional struc-
3.1.3. Crystal structure of Mn(NCS)2L4 (3)
Mn(II), a metal in the first transition series, exhibits N-coordina-
tion. In the molecular structure of complex 3, Mn(II) ion assumes a
slightly distorted octahedral coordination geometry. Four N atoms
from four different imidazolyl groups are coordinated to the metal
ionin theequatorialsites, withtwonitrogenatomsfromthiocyanate
ture. Additionally, intermolecular C(25)–H(25)ꢂ ꢂ ꢂ
p(imidazolyl)
interaction with H(25)ꢂ ꢂ ꢂcentroid distance of 3.354 Å provides fur-
ther stability to the chain. The neighboring chains are linked

F. Jin et al. / Polyhedron 43 (2012) 1–7
5
Fig. 3. (a) The one-dimensional structure in 3 formed by intermolecular C(32)–H(32)ꢂ ꢂ ꢂS hydrogen bonding interactions and C(25)–H(25)ꢂ ꢂ ꢂ
p
interactions. Hydrogen atoms
not participating in hydrogen bonding are omitted for clarity. (b) The two-dimensional structure in 3 formed by intermolecular C(24)–H(24)ꢂ ꢂ ꢂO(2), C(28)–H(28)ꢂ ꢂ ꢂO(2) and
C(32)–H(32)ꢂ ꢂ ꢂS hydrogen bonding interactions. Hydrogen atoms not participating in hydrogen bonding are omitted for clarity. (c) The three-dimensional structure of 3.
Hydrogen atoms not participating in hydrogen bonding are omitted for clarity.
through C(24)–H(24)ꢂ ꢂ ꢂO(2) and C(28)–H(28)ꢂ ꢂ ꢂO(2) hydrogen
bond interactions to form two-dimensional structure, as shown
in Fig. 3b. It is the C(23)–H(23)ꢂ ꢂ ꢂO(1), as well as C(34)–
H(34)ꢂ ꢂ ꢂO(2) hydrogen bond interactions that link the adjacent lay-
ers to form three-dimensional supramolecular structure, as shown
in Fig. 3c. The distances of H(23)ꢂ ꢂ ꢂO(1) and H(32)ꢂ ꢂ ꢂS are 2.639
and 2.977 Å, respectively, and the C(23)–H(23)ꢂ ꢂ ꢂO(1) and C(32)–
H(32)ꢂ ꢂ ꢂS angles are 140.51° and 142.69°, respectively. It is the var-
ious types of intermolecular hydrogen bonding interactions that
contribute to the construction of the three-dimensional supramo-
lecular structure.
Making a comparison, the difference between 1 and 2 is that the
thiocyanate anion is coordinated in a linear fashion through the
nitrogen atom in 1, and a bent fashion through the sulfur atom
in 2. In addition, no carbonyl O atom but only thiocyanate S atoms
participates in the formation of 2D structure via hydrogen bonding
interactions in 1, while in the case of 2, thiocyanate N atom and
carbonyl O atom contribute to the construction of the 2-D struc-
ture through hydrogen bonding interactions. The result may be
caused by the difference of coordinated modes of thiocyanate
ions and metal ions. Compared with 1 and 2, because Mn(II) is
coordinated by four 4-imidazolychalcone ligands, multiple Oꢂ ꢂ ꢂH

6
F. Jin et al. / Polyhedron 43 (2012) 1–7
Fig. 4. The 1H NMR spectra of free ligand and complexes 1–3.
hydrogen bonds are formed in complex 3, which contribute to the
construction of the 3-D structure. The remarkable difference
among the structures of 1, 2 and 3 reveals that the coordination
modes of the metals have a remarkable influence on the structures
of the complexes.
cases can be observed in complexes 1–3. The overlapped peaks of
the vinyl-H can also be assigned with the help of 13C NMR and 2D
HSQC NMR spectra. Take complex 2 for example, Peaks at d 120.41
and 142.77 ppm are assigned to C-9, 90 and C-7, respectively
(Fig. S5 of Supporting Information), and they show correlation with
the signals in the region of d H 7.823–7.791 ppm in the HSQC spec-
trum (Fig. S6 of Supporting Information), indicating that the over-
lapped peaks at d H 7.823–7.791 ppm can be assigned as the
signals of H-9, 90 and H-7. Among them, peaks at d H 7.791 and
7.812 ppm are assigned as the signals of H-9, 90 and peak at d H
7.823 and the other overlapped peak are assigned as the signals of
H-7. By contrast, the 1H NMR spectra of complexes 1–3 are different
from that of free ligand, as shown in Fig. 4. In complexes 1 and 2, the
resonances of the three protons of imidazolyl shift downfield relative
to the corresponding protons of free ligand. The results are surely
caused by the electron-withdrawing effects imposed by the coordi-
nated metals. There are almost no changes in the signals of the other
hydrogen atoms relative to the free ligand. However, in complex 3, it
is interesting to note that the signals of three hydrogen atoms of
imidazolyl vanish completely, and the signals of the other hydrogen
atoms become weaker and some peaks overlap seriously, which is
mainly caused by pronounced shielding of coordinated paramagnetic
Mn(II) ion. As is well known, paramagnetic ions can cause enhanced
nuclear relaxation, molecular alignment in the magnetic field, and
various crosscorrelation effects at the same time, which have previ-
ously been studied in detail [28–33]. The same results were obtained
when the 1H NMR spectrum measurement was performed in a higher
concentration solution of complex 3. All results of spectroscopy char-
acterization agree well with the crystal structures analyses.
3.2. Spectroscopy characterization
The structures of complexes 1–3 have been confirmed by ele-
mental analyses, IR spectra, and 1H NMR spectra. In the IR spectra
of complexes 1 and 3, the intense m
(CN) stretching bands of NCSꢀ
at 2093 and 2054 cmꢀ1, respectively, indicate that thiocyanate ions
act as terminal N-bonded ligands, and intense absorption at
2116 cmꢀ1 for 2 corresponds to the terminal S-bonded thiocyanate
groups [27], which agree with the crystal structures analyses. The
characteristic bands of the C@C and C@N stretching mode of L are
observed in the range 1663–1521 cmꢀ1
.
The 1H NMR spectrum of ligand agrees well with its structure
and displays 14 proton resonances (Fig. S2 of Supporting Informa-
tion). The resonances at d H 8.405, 7.876, and 7.145 can be assigned
to three hydrogen atoms of imidazolyl. Peaks at d H 8.022 and 7.983
are assigned to one vinyl-H (H-6) based on the coupling constant
15.6 Hz which is a typical coupling constant for trans forms. The rest
of resonances can be assigned easily. However, the peaks of other vi-
nyl-H (H-7) cannot be found clearly in the 1H NMR spectrum. It can
be assigned with the help of 13C NMR and 2D HSQC NMR spectra
(Figs. S3 and S4 of Supporting Information). Peaks at d 120.12 and
142.87 ppm are assigned to C-9, 90 and C-7, respectively, and they
show correlation with the signals in the region of d H 7.816–
7.779 ppm in the HSQC spectrum, indicating that the overlapped
peaks at d H 7.816–7.779 ppm can be assigned as the signals of
H-9, 90 and H-7. Among them, peaks at d H 7.779 and 7.800 ppm
are assigned as the signals of H-9, 90 and peak at d H 7.816 and the
other overlapped peak are assigned as the signals of H-7. Similar
4. Conclusion
Three new complexes containing different metal cations have
been synthesized and characterized structurally. In complexes 1–

F. Jin et al. / Polyhedron 43 (2012) 1–7
7
[13] C. Jiang, Z.P. Yu, S.J. Wang, C. Jiao, J.M. Li, Z.Y. Wang, Y. Cui, Eur. J. Inorg. Chem.
(2004) 3662.
[14] H. Chun, J. Seo, Inorg. Chem. 48 (2009) 9980.
[15] Y.H. He, Y.L. Feng, Y.Z. Lan, Y.H. Wen, Cryst. Growth Des. 8 (2008) 3586.
[16] Y.Q. Gong, R.H. Wang, D.Q. Yuan, W.P. Su, Y.G. Huang, C.Y. Yue, F.L. Jiang, M.C.
Hong, Polyhedron 26 (2007) 5309.
[17] H.P. Zhou, Y. Xie, Y.P. Tian, Inorg. Chem. Commun. 9 (2006) 351.
[18] Q. Yu, Y.F. Zeng, J.P. Zhao, Q. Yang, X.H. Bu, Cryst. Growth Des. 10 (2010)
1878.
[19] H. Zhang, X.M. Wang, B.K. Teo, Coord. Chem. Rev. 183 (1999) 157.
[20] H. Zhang, D.E. Zelmon, B.K. Teo, Inorg. Chem. 39 (2000) 1868.
[21] J.M. Rivera, H. Reyes, R. Santillan, Chem. Mater. 18 (2006) 1174.
[22] (a) H.K. Liu, W.Y. Sun, D.J. Ma, K.B. Yu, W.X. Tang, Chem. Commun. (2000) 591;
(b) H.F. Zhu, W.Z.T. Okamura, B.L. Fei, W.Y. Sun, N. Ueyama, New J. Chem. 26
(2002) 1277;
3, the transitional metal ions involved are Zn, Hg and Mn ions,
where the coordination geometries of Zn, Hg and Mn ions are tet-
rahedral N4, N2S2 and octahedral N6, respectively. The different
weak non-covalent forces are generated in the three structures be-
cause of the different coordination modes of Zn, Hg and Mn ions.
Higher-dimensional supramolecular structures are formed through
the weak non-covalent forces. The results show that the metal ions
and weak non-covalent forces play important roles in the construc-
tion of complex supramolecular structures.
Acknowledgments
(c) J. Xia, Y. Xu, S.A. Li, W.Y. Sun, K.B. Yu, W.X. Tang, Inorg. Chem. 40 (2001)
2394;
(d) J. Fan, H.F. Zhu, T. Okamura, W.Y. Sun, W.X. Tang, N. Ueyama, Inorg. Chem.
42 (2003) 158;
(e) R.G. Xiong, J.L. Zuo, X.Z. You, Inorg. Chem. 36 (1997) 2472;
(f) Y.W. Li, H. Ma, Y.Q. Chen, K.H. He, Z.X. Li, X.H. Bu, Cryst. Growth Des. 12
(2012) 189.
This work was supported by Program for New Century Excellent
Talents in University (China), Doctoral Program Foundation of -
Ministry of Education of China (20113401110004), Science and
Technological Fund of Anhui Province for Outstanding Youth
(10040606Y22), National Natural Science Foundation of China
(21071001), Natural Science Foundation of Education Committee
of Anhui Province (KJ2012A024), the 211 Project of Anhui Univer-
sity, the Team for Scientific Innovation Foundation of Anhui Prov-
ince (2006KJ007TD), Ministry of Education Funded Projects Focus
on Returned Overseas Scholar, and Anhui University Student Inno-
vative Experiment Plan (XJ103575023, KYXL201100337).
[23] (a) Y.F. Yue, E.Q. Gao, C.J. Fang, T. Zheng, J. Liang, C.H. Yan, Cryst. Growth Des. 8
(2008) 3295;
(b) H.L. Sun, B.Q. Ma, S. Gao, S.R. Batten, Cryst. Growth Des. 5 (2005) 1331;
(c) H.L. Sun, S. Gao, B.Q. Ma, G. Su, S.R. Batten, Cryst. Growth Des. 5 (2005)
269;
(d) D.F. Li, S. Gao, L.M. Zheng, W.Y. Sun, T. Okamura, N. Ueyamac, W.X. Tang,
New J. Chem. 26 (2002) 485;
(e) B.L. Fei, W.Y. Sun, Y.A. Zhang, K.B. Yu, W.X. Tang, J. Chem. Soc., Dalton
Trans. (2000) 2345;
(f) H.R. Wen, C.F. Wang, Y. Song, J.L. Zuo, X.Z. You, Inorg. Chem. 44 (2005)
9039;
Appendix A. Supplementary data
(g) J. Fan, L. Gan, H. Kawaguchi, W.Y. Sun, K.B. Yu, W.X. Tang, Chem. Eur. J. 9
(2003) 3965.
CCDC 832300, 831607, and 831608 contains the supplementary
crystallographic data for 1, 2, and 3, respectively. These data can be
obtained free of charge via http://www.ccdc.cam.ac.uk/conts/
retrieving.html, or from the Cambridge Crystallographic Data Cen-
tre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: (+44) 1223-336-
033; or e-mail: deposit@ccdc.cam.ac.uk. Supplementary data asso-
ciated with this article can be found, in the online version, at
http://dx.doi.org/10.1016/j.poly.2012.04.001.
[24] (a) H.P. Zhou, Y.P. Tian, J.Y. Wu, J.Z. Zhang, D.M. Li, Y.M. Zhu, Z.J. Hu, X.T. Tao,
M.H. Jiang, Y. Xie, Eur. J. Inorg. Chem. (2005) 4976;
(b) H.P. Zhou, J.H. Yin, L.X. Zheng, P. Wang, F.Y. Hao, W.Q. Geng, X.P. Gan, G.Y.
Xu, J.Y. Wu, Y.P. Tian, X.T. Tao, M.H. Jiang, Y.H. Kan, Cryst. Growth Des. 9 (2009)
3789;
(c) H.P. Zhou, P. Wang, L.X. Zheng, W.Q. Geng, J.H. Yin, X.P. Gan, G.Y. Xu, J.Y.
Wu, Y.P. Tian, Y.H. Kan, X.T. Tao, M.H. Jiang, J. Phys. Chem. A 113 (2009)
2584;
(d) H.P. Zhou, X.P. Gan, X.L. Li, Z.D. Liu, W.Q. Geng, F.X. Zhou, W.Z. Ke, P.
Wang, L. Kong, F.Y. Hao, J.Y. Wu, Y.P. Tian, Cryst. Growth Des. 10 (2010)
1767.
[25] F. Jin, H.P. Zhou, X.C. Wang, Z.J. Hu, J.Y. Wu, J.X. Yang, Y.P. Tian, M.H. Jiang,
Polyhedron 26 (2007) 1338.
References
[26] G.M. Sheldrick, SHELXTL V.51 Software Reference Manual, Bruker AXS, Inc.,
[1] C.Q. Wan, T.C.W. Mak, Cryst. Growth Des. 11 (2011) 832.
[2] D. Singh, J.B. Baruah, Cryst. Growth Des. 11 (2011) 768.
[3] E. Yang, J. Zhang, Y.G. Yao, Inorg. Chem. 43 (2004) 6525.
[4] L. Han, H. Valle, X.H. Bu, Inorg. Chem. 46 (2007) 1511.
[5] H.K. Liu, W.Y. Sun, W.X. Tang, J. Chem. Soc., Dalton Trans. (2002) 3886.
[6] E.Y. Cheung, K. Fujii, F. Guo, K.D.M. Harris, S. Hasebe, R. Kuroda, Cryst. Growth
Des. 3 (2011) 3313.
[7] A.P.S. Pannu, P. Kapoor, R. Kapoor, Polyhedron 30 (2011) 1691.
[8] X.L. Wang, J. Li, A.X. Tian, D. Zhao, G.C. Liu, H.Y. Lin, Cryst. Growth Des. 31
(2011) 3456.
[9] X.W. Wang, J.Z. Chen, J.H. Liu, Cryst. Growth Des. 7 (2007) 1227.
[10] J. Luo, T. Lei, Y.G. Ma, J. Am. Chem. Soc. 131 (2009) 2076.
[11] T. Honda, T. Nakanishi, Kei Ohkubo, J. Am. Chem. Soc. 132 (2010) 10155.
[12] Z. Su, J. Fan, T. Okamura, M.S. Chen, S.S. Chen, W.Y. Sun, N. Ueyama, Cryst.
Growth Des. 10 (2010) 1911.
Madison, Wisconsin, USA, 1997.
´
[27] B. Machura, J. Palion, A. Switlicka, J. Mrozin´ ski, R. Kruszynski, Polyhedron 30
(2011) 2499.
[28] D. Capsoni, M. Bini, V. Massarotti, P. Mustarelli, G. Chiodelli, C.B. Azzoni, M.C.
Mozzati, L. Linati, S. Ferrari, Chem. Mater. 20 (2008) 4291.
[29] G.L. Abbati, A. Cornia, A.C. Fabretti, A. Caneschi, D. Gatteschi, Inorg. Chem. 37
(1998) 3759.
[30] D. Capsoni, M. Bini, S. Ferrari, P. Mustarelli, V. Massarotti, M.C. Mozzati, A.
Spinella, J. Phys. Chem. 114 (2010) 13872.
[31] G. Pintacuda, M. John, X.C. Su, G. Otting, Acc. Chem. Res. 40 (2007) 206.
[32] M. John, A.Y. Park, G. Pintacuda, N.E. Dixon, G. Otting, J. Am. Chem. Soc. 127
(2005) 17190.
[33] C.P. Grey, N. Duprè, Chem. Rev. 104 (2004) 4493.