Zn(ii) and Cd(ii) coordination polymers assembled by di(1H-imidazol-1-yl) methane and carboxylic acid ligands

Article abstract of DOI:10.1039/c2dt11990k

Five new Zn^II/Cd^II coordination polymers constructed from di(1H-imidazol-1-yl)methane (L) mixed with different auxiliary carboxylic acid ligands formulated as [Zn(L)(H₂L¹) ₂·(H₂O)_0.2]_n (1), {[Zn(L)(L²)]·H₂O}_n (2), {[Cd ₂(L)₂(L²)₂]·2H ₂O}_n (3), {[Cd(L)(L³)]·H ₂O}_n (4) and [Cd(L)(L⁴)]_n (5) (H₃L¹ = 1,3,5-benzenetricarboxylic acid, H ₂L² = 4,4′-oxybis(benzoic acid), H₂L ³ = m-phthalic acid and H₂L⁴ = p-phthalic acid) have been synthesized under hydrothermal conditions and structurally characterized. Four related auxiliary carboxylic acids were chosen to examine the influences on the construction of these coordination frameworks with distinct dimensionality and connectivity. The coordination arrays of 1-5 vary from 1D zigzag chain for 1, 2D (4,4) layer for 2-4, to 2-fold interpenetrated 3D coordination network with the α-Po topology for 5. The thermal and photoluminescence properties of complexes 1-5 in the solid state have also been investigated. The Royal Society of Chemistry 2012.

Full text of DOI:10.1039/c2dt11990k

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PAPER
Zn(II) and Cd(II) coordination polymers assembled by di(1H-imidazol-1-yl)
methane and carboxylic acid ligands†
Xiao-Feng Zhang, Wei-Chao Song,* Qian Yang and Xian-He Bu*
Received 20th October 2011, Accepted 3rd February 2012
DOI: 10.1039/c2dt11990k
Five new ZnII/CdII coordination polymers constructed from di(1H-imidazol-1-yl)methane (L) mixed with
different auxiliary carboxylic acid ligands formulated as [Zn(L)(H2L1)2·(H2O)0.2]n (1), {[Zn(L)
(L2)]·H2O}n (2), {[Cd2(L)2(L2)2]·2H2O}n (3), {[Cd(L)(L3)]·H2O}n (4) and [Cd(L)(L4)]n (5)
(H3L1 = 1,3,5-benzenetricarboxylic acid, H2L2 = 4,4′-oxybis(benzoic acid), H2L3 = m-phthalic acid and
H2L4 = p-phthalic acid) have been synthesized under hydrothermal conditions and structurally
characterized. Four related auxiliary carboxylic acids were chosen to examine the influences on the
construction of these coordination frameworks with distinct dimensionality and connectivity. The
coordination arrays of 1–5 vary from 1D zigzag chain for 1, 2D (4,4) layer for 2–4, to 2-fold
interpenetrated 3D coordination network with the α-Po topology for 5. The thermal and
photoluminescence properties of complexes 1–5 in the solid state have also been investigated.
m-phthalic acid, and H2L4 = p-phthalic acid) have been syn-
thesized with L and four related carboxylate ligands under
Introduction
Coordination polymers have attracted intensive attention in
recent years because of their intriguing structural topologies and
tailor-made applications as functional solid materials.1 However,
persistent research has shown that various factors may play
important roles in constructing coordination polymers, which
result in the complexity and uncertainty of the complexes, and
great contributions have been focused on this field to investigate
the effects and guide the syntheses.2–7 The carboxylate- and
pyridine-based ligands, as well as the combination of them have
been widely used and providing more variability to construct
much more complicated and fantastic topologies with interesting
properties. Recently, some studies focused on choosing the N-
heterocycles and its derivatives with five-membered rings (imi-
dazole, triazole, tetrazolate, etc.) and multicarboxylate as mixed
ligands to construct fantastic structures and topologies.8
However, coordination polymers with the flexible di(1H-imida-
zol-1-yl)methane (L) ligand and carboxylate as the auxiliary
ligand are less documented so far.9
hydrothermal conditions and structurally characterized. X-ray
diffraction analysis of these network solids reveals the remark-
able structural transformation from 1D for 1, to 2D for 2–4, and
3D for 5, respectively. The thermal and photoluminescence pro-
perties of complexes 1–5 have also been investigated.
Experimental
Materials and synthesis
All the chemicals used for synthesis were of analytical grade and
commercially available. L was synthesized according to the lit-
erature method.10 Structures of L and carboxylate ligands used
in this work are shown in Scheme 1.
Synthesis of {[Zn(L)(H2L1)2]·(H2O)0.2}n (1)
1 was hydrothermally synthesized under autogenous pressure. A
mixture of Zn(NO3)2·6H2O (0.5 mmol), L (0.2 mmol), H3L1
To examine the influences of auxiliary carboxylic acids on the
construction of coordination frameworks, a series of new coordi-
nation polymers, including [Zn(L)(H2L1)2·(H2O)0.2]n (1), {[Zn-
(L)(L2)]·H2O}n (2), {[Cd2(L)2(L2)2]·2H2O}n (3), {[Cd(L)-
(L3)]·H2O}n (4) and [Cd(L)(L4)]n (5) (H3L1 = 1,3,5-benzenetri-
carboxylic acid, H2L2 = 4,4′-oxybis(benzoic acid), H2L3
=
Department of Chemistry and Tianjin Key Lab on Metal and Molecule-
based Material Chemistry, Nankai University, Tianjin 300071, China.
E-mail: buxh@nankai.edu.cn; Fax: +86-22-23502458
†Electronic supplementary information (ESI) available. CCDC
849787–849791. For ESI and crystallographic data in CIF or other elec-
tronic format see DOI: 10.1039/c2dt11990k
Scheme 1 The L ligand and carboxylate ligands used in this work.
Dalton Trans., 2012, 41, 4217–4223 | 4217
This journal is © The Royal Society of Chemistry 2012

(0.2 mmol) and H2O (12 mL) was sealed in a Teflon-lined auto-
clave and heated to 140 °C in 12 h. After 48 h, the reaction
vessel was cooled to room temperature in 24 h. Colorless crystals
were collected with a yield of ∼20% based on Zn(NO3)2·6H2O.
FT-IR (KBr pellets, cm−1): 3129b, 1701m, 1568m, 1401s,
1098s, 954w, 744s, 680m, 652m, 541w. Anal. Calcd for
C25H18.4N4O12.2Zn: C, 47.25; H, 2.92; N, 8.82. Found: C,
46.73; H, 2.99; N, 9.05.
2500 diffractometer at 40 kV, 100 mA for a Cu-target tube and a
graphite monochromator. Simulation of the XRPD spectra was
carried out by the single-crystal data and diffraction-crystal
module of the Mercury (Hg) program available free of charge
via http://www.iucr.org.
X-ray data collection and structure determinations
X-ray single-crystal diffraction data for complexes 1–5 were col-
lected on a Rigaku SCX-mini diffractometer at 293(2) K. The
program SAINT11 was used for integration of the diffraction
profiles. All the structures were solved by direct methods using
the SHELXS program of the SHELXTL package and refined by
full-matrix least-squares methods with SHELXL.12 Other non-
hydrogen atoms were located in successive difference Fourier
syntheses and refined with anisotropic thermal parameters on F2.
The hydrogen atoms of the water molecules in 1, 2, and 4 were
added by difference Fourier E-maps and refined isotropically.
The H atoms of the water molecule were not located in the differ-
ence map in 3. Crystallographic data and experimental details for
structural analyses are summarized in Table 1. Selected bond
lengths and angles are listed in Tables S1–S6, ESI.† Hydrogen-
bond parameters are listed in Tables S7–S10, ESI.†
Synthesis of {[Zn(L)(L2)]·H2O}n (2)
Single crystals of 2 suitable for X-ray analysis were obtained by
the similar method as described for 1, except H2L2 was used
instead of H3L1. Yield: ∼30%. FT-IR (KBr pellets, cm−1):
3136b, 3137b, 1601m, 1385s, 1283w, 1231s, 1164w, 1082m,
943w, 877m, 780m, 713w, 655w. Anal. Calcd for
C21H18N4O6Zn: C, 51.70; H, 3.72; N, 11.49. Found: C, 50.72;
H, 3.68; N, 11.92.
Synthesis of {[Cd2(L)2(L2)2]·2H2O}n (3)
3 was hydrothermally synthesized under autogenous pressure. A
mixture of Cd(NO3)2·4H2O (0.5 mmol), L (0.2 mmol), H2L2
(0.2 mmol) and H2O (12 mL) was sealed in a Teflon-lined auto-
clave and heated to 140 °C in 12 h. After 48 h, the reaction
vessel was cooled to room temperature in 24 h. Colorless crystals
were collected with a yield of ∼20% based on Cd(NO3)2·4H2O.
FT-IR (KBr pellets, cm−1): 3415b, 3125b, 1596m, 1541m,
1398s, 1233m, 1162w, 1079w, 965w, 879w, 781w, 615w. Anal.
Calcd for C42H34N8O12Cd2: C, 47.25; H, 3.21; N, 10.50. Found:
C, 47.72; H, 3.48; N, 10.86.
Results and discussion
Crystal structure of the complexes
{[Zn(L)(H2L1)2]·(H2O)0.2}n (1). The single crystal X-ray deter-
mination reveals that complex 1 crystallizes in the monoclinic
space group P21/c and features 1D “zigzag” chains. The coordi-
nation geometry of the ZnII atom is distorted octahedron consid-
ering two weak coordination bonds. The axial positions are
occupied by the nitrogen atoms from two different L ligands,
and the equatorial plane is defined by four oxygen atoms from
two different carboxylate of two separate H2L1 ligands in a
chelating coordination mode considering weak Zn–O contacts
(Fig. 1a). Adjacent ZnII atoms were bridged by the L ligands to
afford a 1D infinite zigzag chain along the a axis, as shown in
Fig. 1b. It should be noted, the H3L1 ligands just partially depro-
tonate, and abundant hydrogen bonding occurs between the resi-
dent carboxylate to form 2D layers in the bc plane (Fig. 1c). The
adjacent 2D layers were further linked by the L ligands to afford
a 3D supramolecular structure (Fig. 1d).
Synthesis of {[Cd(L)(L3)]·H2O}n (4)
Single crystals of 4 suitable for X-ray analysis were obtained by
the similar method as described for 3, except H2L3 was used
instead of H2L2 and two drops of triethylamine were added.
Yield: ∼35% based on Cd(NO3)2·4H2O. FT-IR (KBr pellets,
cm−1): 3119b, 1604m, 1539m, 1387m, 1279w, 1225m, 1091s,
832w, 746m, 661w. Anal. Calcd for C15H14N4O5Cd: C, 40.70;
H, 3.19; N, 12.66. Found: C, 39.79; H, 3.34; N, 12.33.
Synthesis of [Cd(L)(L4)]n (5)
{[Zn(L)(L2)]·H2O}n (2). Complex 2 crystallizes in the mono-
clinic space group P21/n. The asymmetric unit consists of one
ZnII ion, one L ligand, one L2 ligand and one lattice water mol-
ecule. The ZnII is four-coordinate having an irregular tetrahedral
geometry composed of two nitrogen atoms from two L ligands
and two oxygen atoms from two L2 ligands (Fig. 2a). The adja-
cent ZnII atoms were connected by L ligands to yield chains
with a Zn–Zn distance of 9.103(28) Å, which are further linked
by L2 ligands to form a 2D layer. The 2D layer can also be con-
sidered as an undulated sql net by repeating the [Zn4(L)2(L2)2]
unit in the bc plane (Fig. 2b). Notably, the [Zn4(L)2(L2)2] unit
has a square window with dimensions of 9.103(28)–14.899(33)
Å. The free water molecules are located between the adjacent
undulating layers, as shown in Fig. 2c.
Single crystals of 5 suitable for X-ray analysis were obtained by
the similar method as described for 4, except H2L4 was used
instead of H2L3. Yield: ∼25% based on Cd(NO3)2·4H2O. FT-IR
(KBr pellets, cm−1): 3135s, 1583s, 1381s, 1282m, 1082m,
1035w, 927w, 837s, 743s, 652m, 524m. Anal. Calcd for
C15H12N4O4Cd: C, 42.42; H, 2.85; N, 13.19. Found: C, 42.61;
H, 3.12; N, 12.45.
Physical measurements
Elemental analyses were performed on a Perkin-Elmer 240
elemental analyzer. IR spectra were measured on a Tensor 27
OPUS (Bruker) FT-IR spectrometer with KBr pellets. The X-ray
powder diffraction (XRPD) was recorded on a Rigaku D/Max-
4218 | Dalton Trans., 2012, 41, 4217–4223
This journal is © The Royal Society of Chemistry 2012

Table 1 Crystal data and structure refinement parameters for complexes 1–5
Complex reference
1
2
3
4
5
Chemical formula
Formula mass
Crystal system
a/Å
b/Å
c/Å
α (°)
β (°)
C25H18.4N4O12.2Zn
635.41
Monoclinic
10.100(2)
22.427(5)
11.398(2)
90.00
101.35(3)
90.00
2531.4(13)
P21/c
C21H18N4O6Zn
487.76
Monoclinic
8.8150(18)
14.859(3)
15.580(3)
90.00
92.25(3)
90.00
2039.0(7)
P21/n
C42H34N8O12Cd2
1067.57
Orthorhombic
18.061(4)
31.309(6)
15.114(3)
90.00
90.00
90.00
8547(3)
C2221
C15H14N4O5Cd
442.70
Monoclinic
10.234(2)
9.1507(18)
16.895(3)
90.00
103.79(3)
90.00
1536.6(5)
P21/c
C15H12N4O4Cd
424.69
Triclinic
8.0047(16)
9.6594(19)
10.952(2)
101.18(3)
105.39(3)
105.40(3)
754.6(3)
γ (°)
Unit cell volume/Å3
Space group
ˉ
P1
No. of formula units per unit cell, Z
No. of reflections measured
No. of independent reflections
Rint
Final R1 values (I > 2σ(I))
Final wR(F2) values (I > 2σ(I))
Final R1 values (all data)
Final wR(F2) values (all data)
4
4
8
4
2
8071
3450
0.0318
0.0277
0.0528
0.0322
0.0540
25 980
5778
0.1156
0.0792
0.1188
0.1482
0.1363
17 326
3597
0.1205
0.0940
0.1622
0.1426
0.1786
45 281
9812
0.0712
0.0555
0.0859
0.0787
0.0914
15 844
3511
0.0548
0.0432
0.0674
0.0637
0.0719
{[Cd2(L)2(L2)2]·2H2O}n (3). The single-crystal X-ray analysis
reveals that complex 3 crystallizes in the orthorhombic space
group C2221. There are three independent Cd atoms: Cd1, Cd2
and Cd3 in each asymmetric unit of 3 bearing a similar coordi-
nated configuration. Each CdII is six coordinated in a distorted
octahedral geometry by two nitrogen atoms from two L ligands
and four chelate oxygen atoms from two L2 ligands (Fig. 3a and
3b). The adjacent CdII atoms were linked by L ligands along the
a axis and L2 ligands along the c axis to afford 2D layers in the
ac plane. It should be noted, there are two types of 2D layers, in
which the L ligand adopts different dihedral angles between the
two imidazole rings (trans conformation in Fig. 3a, cis confor-
mation in Fig. 3b). These 2D layers stack along the b axis in an
ABAB mode with lattice water molecules between the layers
(Fig. 3c).
atoms are bridged by four bidentate carboxylate groups from two
pairs of symmetry related L4 ligands forming a binuclear unit.
The binuclear units were linked by L4 ligands to afford a 2D
layered network in the ab plane (Fig. 5b). In addition, the
coordination sphere is completed by two nitrogen donors from L
ligands. Each binuclear unit was linked to six adjacent ones by
two pairs of double-bridged L ligands and four L4 ligands,
affording a 3D double interpenetrating framework (Fig. 5c).
Topologically, while the binuclear units are simplified as nodes
and the bridging L and L4 ligands are simplified as the linkers, a
3D 2-fold interpenetrated network with an α-Po topology can be
rationalized as shown in Fig. 5d.
Coordination modes and conformations of the ligands in metal
complexes
{[Cd(L)(L3)]·H2O}n (4). Complex 4 crystallizes in the mono-
clinic space group P21/c. The asymmetric unit consists of one
CdII atom, one L ligand, one L3 ligand and one lattice water
molecule. As shown in Fig. 4a, the center Cd1 is hepta-coordi-
nated by two nitrogen atoms from two L ligands and five
oxygen atoms from three L3 ligands. Two symmetry related CdII
atoms were linked by one pair of carboxylates of two different
L3 ligands in μ2-η2:η1 coordination mode forming a [Cd2] unit.
The [Cd2] units were double-bridged by the other carboxylate of
L3 ligands along the a axis, and further double-bridged by L
ligands along the b axis to afford a 2D layer (Fig. 4b). The
lattice water molecules filled up in the 2D layer. Considering
[Cd2] units as nodes, the double-bridged ligands as linkers, 4
could be simplified as a (4,4)-connected topological net.
Hydrothermal reactions of Zn/Cd salts and the L ligand with
four different aromatic carboxylate ligands give rise to a series
of new coordination frameworks. The flexible L ligand can
adopt varied conformations to meet the geometric requirement of
the metal ions on the construction of the complexes (Chart 1,
Table 2). The L ligand adopts a μ2 bridging coordination mode,
but different conformations. The L ligands adopt cis confor-
mation in 1, 2 and 4, trans conformation in 5, and both confor-
mations in 3, respectively. The secondary carboxylate ligands
can be fully/partially deprotonated for the balance of charge and
mediate the coordination needs of the metal ions to generate
interesting frameworks (Chart 2). In complex 1, the L1 ligands
just partially deprotonate adopting a chelating terminal coordi-
nation mode and the remaining two carboxylate groups took part
in H-bonding interactions. Both 2 and 3 are a 4,4-layer structure
with a single-metal as the node by using a flexible V-shaped L2
ligand; the L2 ligand adopts different coordination modes, bis-
unidentate in 2 and chelating bis-bidentate in 3, respectively.
When introducing a much shorter and rigid L3 ligand in 4, a 4,4-
layer structure with the M2 unit as the node was afforded and the
L3 ligand adopts a chelating bidentate and chelating/bridging
bidentate coordination mode. While using a linear and rigid L4
[Cd(L)(L4)]n (5). Complex 5 crystallizes in the triclinic P1
ˉ
space group. The asymmetric unit consists of one CdII atom, one
L ligand, and two kinds of half L4 ligands. Each CdII atom is
hexa-coordinated in a distorted octahedral geometry by two
nitrogen atoms from two L ligands and four oxygen atoms from
two different L4 ligands (Fig. 5a). One kind of L4 ligand adopts
a chelating bis-bidentate coordination mode, while the other
takes bridging bis-bidentate.13 A pair of symmetry related CdII
This journal is © The Royal Society of Chemistry 2012
Dalton Trans., 2012, 41, 4217–4223 | 4219

Fig. 2 (a) Coordination environment of the Zn(II) ion. (b) The sql net
of 2. (c) Stack of layers containing interlayer water molecules. Symmetry
code: A x + 1/2, −y + 5/2, z − 1/2.
Fig. 1 (a) Coordination environment of the Zn(II) ion. (b) 1D chain of
1. (c) 2D H-bonded layer with H-bonds depicted by the dotted bonds.
(d) The L ligands connected adjacent 2D layers to give rise to the 3D
supramolecular architecture of 1. Symmetry code: A x − 1, y, z.
XRPD and TGA results
X-ray powder diffraction (XRPD) for certain complexes (1–5)
was performed to characterize their purity. The XRPD of the as-
prepared samples are shown in Fig. S1, ESI.† All diffraction
peaks on the curves are in good agreement with the respective
single-crystal structures. To examine the thermal stability of the
obtained coordination polymers, thermogravimetric analyses
(TGA) experiments were carried out (Fig. 6). All five complexes
exhibit high thermal stability. The TG curve of 1 shows the first
weight loss of 3.4% in the temperature range 25–155 °C, which
indicates the exclusion of lattice water molecules and the surface
absorption of moisture; then it vigorously decomposed at temp-
erature higher than 370 °C. For 2, the weight loss attributed to
the gradual release of water molecules is observed in the range
25–173 °C (obsd, 3.5%; calcd, 3.7%). The decomposition of
residual composition occurs at 360 °C, and the final remaining
ligand, a two-fold interpenetrating network with α-Po topology
based on binuclear units was formed. It should be noted, the L4
ligand adopts two kinds of coordination modes: one is the same
as the L2 ligand in 3, the other is bridging bis-bidentate. The
structural differences between 3, 4 and 5 showed that a series of
carboxylate ligands with different shape, size, and flexibility are
critical factors in the formation of these coordination architec-
tures and the different coordination modes of carboxylate ligands
enrich the structural complexity of the Zn/Cd-L-carboxylate
system.
4220 | Dalton Trans., 2012, 41, 4217–4223
This journal is © The Royal Society of Chemistry 2012

Fig. 4 (a) Coordination environment of the Cd(II) ion. (b) Double-
bridged L and L3 ligands connected the binuclear units to form a 2D
layer. Symmetry code: C x, y − 1, z.
water (calcd, 3.4%). Then it could be stable under 330 °C and
decomposed at higher temperature. For 4, the weight loss
between 25 and 190 °C corresponds to the release of water mol-
ecules (obsd, 3.4%; calcd, 4.1%), then it decomposed upon
further heating. Complex 5 is stable under 250 °C, and then it
decomposed at higher temperatures. It should be noted that it
underwent a weight loss of 17.83% from 250 to 360 °C which
may correspond to partial loss of the ligands before it decom-
posed completely.
Luminescence studies
Fig. 3 (a) The formation of a 2D layer based on the Cd2(II) ions,
trans-L and L2 ligands. (b) The formation of a 2D layer based on the
Cd1(II), Cd3(II) ions, cis-L and L2 ligands. (c) Stacking sequence of the
two types of 2D layers in 3 as viewed along the c direction. Symmetry
code: E x, y, z + 1.
Luminescent coordination complexes have attracted great atten-
tion because of their potential applications as chemical sensors,
photochemistry, and electroluminescence displays.14 The syn-
thesis of metal–organic complexes by conjugated organic
spacers and metal centers can be an efficient method for obtain-
ing new luminescence materials, especially for d10 systems.15
The luminescence properties of the free ligand L and their
weight of 17.1% corresponds to ZnO (calcd, 16.7%). For 3, an
initial weight loss of 4.0% corresponds to the loss of solvent
This journal is © The Royal Society of Chemistry 2012
Dalton Trans., 2012, 41, 4217–4223 | 4221

Chart 1 The conformations of the L ligand in complexes 1–5.
Table 2 N⋯N distance between two donor N atoms of the L ligand,
M⋯M separation between the bridging L and dihedral angle of two
imidazole rings
N⋯N
distance (Å)
M⋯M
distance (Å)
Dihedral angle of two
imidazole rings (°)
Complex
1
2
3
6.423
6.020
5.712
5.715
5.935
6.474
10.100
9.103
9.045
9.020
9.151
10.952
95.99
105.16
102.97
91.63
107.35
117.30
4
5
Chart 2 The coordination modes of the carboxylate ligands in com-
plexes 1–5.
Fig. 6 The TGA diagram for complexes 1–5.
complexes in the solid state at room temperature were investi-
gated. As shown in Fig. 7, there are the main emission bands
(374, 334 and 394 nm; λex = 310, 280, 280 nm, respectively) for
complexes 1–3, whereas an intense emission band with wave-
length at 354 nm upon excitation at 280 nm for the free ligand
L, which indicate these emissions may probably be assigned to
Fig. 5 (a) Coordination environment of the Cd(II) ion. (b) L4 ligands
connected the binuclear units to form a 2D layer. (c) View of the 2-fold
interpenetrated 3D structure. (d) α-Po topology network of 5. Symmetry
codes: A −x + 1, −y + 1, −z + 1; B x, y, z − 1.
4222 | Dalton Trans., 2012, 41, 4217–4223
This journal is © The Royal Society of Chemistry 2012

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Fig. 7 Solid-state photoluminescent spectra of complexes 1–5 and the
free ligand L at room temperature.
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the intraligand (π–π*) transfer of the L ligands. For complexes 4
and 5, the main emission bands (427 and 437 nm; λex = 330,
310 nm) may be assigned to the intraligand (π–π*) transfer of
the L3 or L4 ligands, respectively.16 The relative intensity of the
free ligand compared to the complexes might be assigned to the
strong conjugation and intermolecular interaction between the
molecule segments of the free ligand.17
8 For examples: (a) S. Han, J. L. Manson, J. Kim and J. S. Miller, Inorg.
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E. Richardson and J. R. Eyler, J. Phys. Chem. A, 2004, 108, 9892; (e) B.-
Q. Ma, K. L. Mulfort and J. T. Hupp, Inorg. Chem., 2005, 44, 4912;
(f) A. P. Nelson, D. A. Parrish, L. R. Cambrea, L. C. Baldwin, N.
J. Trivedi, K. L. Mulfort, O. K. Farha and J. T. Hupp, Cryst. Growth
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Z. Su, W.-Y. Sun and N. Ueyama, Cryst. Growth Des., 2010, 10, 812;
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J. Ribas, Inorg. Chem., 2006, 45, 162; (i) W.-C. Song, Q. Pan, P.-
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Struct. Rep. Online, 2006, E62, 606; (b) S. Jin, D. Wang and W. Chen,
Inorg. Chem. Commun., 2007, 10, 685; (c) S.-W. Jin and W.-Z. Chen,
Polyhedron, 2007, 26, 3074; (d) C.-M. Jin, Z. Zhu, M.-X. Yao and X.-
G. Meng, CrystEngComm, 2010, 12, 358; (e) Q. Yang, X.-F. Zhang, J.-
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10 R. M. Claramunt, J. Heterocycl. Chem., 1983, 20, 1245.
11 A. X. S. Bruker, SAINT Software Reference Manual, Madison, WI,
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12 G. M. Sheldrick, SHELXL-97, Program for refinement of crystal struc-
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Conclusions
A series of ZnII/CdII coordination polymers have been prepared
under hydrothermal conditions exhibiting a systematic variation
of architectures from 1D zigzag chain to 3D double interpene-
trating networks by the employment of di(1H-imidazol-1-yl)
methane and different carboxylic acid ligands. The present study
suggests that the variation of auxiliary ligands may play impor-
tant roles in forming related structures.
Acknowledgements
We thank the financial support from the NNSF of China
(21031002 and 51073079) and the Natural Science Fund of
Tianjin, China (10JCZDJC22100).
13 J.-C. Dai, X.-T. Wu, Z.-Y. Fu, C.-P. Cui, S.-M. Hu, W.-X. Du, L.-M. Wu,
H.-H. Zhang and R.-Q. Sun, Inorg. Chem., 2002, 41, 1391.
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