Synthesis, crystal structure and photoluminescent property of metal-organic frameworks with mixed carboxylate and imidazole-containing ligands

Article abstract of DOI:10.1002/cjoc.201200715

Three new metal-organic frameworks (MOFs), namely [Zn(tib)(PDC)] (1), [Zn₃(tib)₂(CHDC)₃]·8H₂O (2) and [Zn₃(tib)₂(BTC)₂]·4.95H₂O (3) were synthesized by hydrothermal reactions of ZnCl₂ with 1,3,5-tris(1-imidazolyl)benzene (tib) and different carboxylate ligands of 2,6-pyridinedicarboxylic acid (H₂PDC), 1,4-cyclohexanedicarboxylic acid (H₂CHDC) and 1,3,5-benzenetriacetic acid (H₃BTC), respectively. The complexes were characterized by IR, thermogravimetric analysis, single crystal and powder X-ray diffractions. Complex 1 has a binuclear structure, in which one imidazole group of tib is free of coordination, while 2 has three-dimensional (3D) framework with the CHDC-Zn microcycles filled into the tib-Zn 3D net, and 3 is a 2-fold interpenetrating 3D framework with the interconnection of two one-dimensional (1D) chains formed by BTC-Zn and tib-Zn, respectively. The different structures of 1-3 are resulted from the distinct carboxylate ligands. In addition, complexes 1-3 show obvious emissions at room temperature in the solid state.

Full text of DOI:10.1002/cjoc.201200715

FULL PAPER
DOI: 10.1002/cjoc.201200715
Synthesis, Crystal Structure and Photoluminescent Property of
Metal-Organic Frameworks with Mixed Carboxylate and
Imidazole-Containing Ligands†
Su, Zhia(苏志)
Fan, Jiana(樊健)
Okamura, Taka-akib(岡村高明)
Sun, Weiyin*,a(孙为银)
a Coordination Chemistry Institute, State Key Laboratory of Coordination Chemistry, School of Chemistry and
Chemical Engineering, Nanjing National Laboratory of Microstructures, Nanjing University,
Nanjing, Jiangsu 210093, China
b Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka,
Osaka 560-0043, Japan
Three new metal-organic frameworks (MOFs), namely [Zn(tib)(PDC)] (1), [Zn3(tib)2(CHDC)3]•8H2O (2) and
[Zn3(tib)2(BTC)2]•4.95H2O (3) were synthesized by hydrothermal reactions of ZnCl2 with 1,3,5-tris(1-imidazolyl)-
benzene (tib) and different carboxylate ligands of 2,6-pyridinedicarboxylic acid (H2PDC), 1,4-cyclohexanedicar-
boxylic acid (H2CHDC) and 1,3,5-benzenetriacetic acid (H3BTC), respectively. The complexes were characterized
by IR, thermogravimetric analysis, single crystal and powder X-ray diffractions. Complex 1 has a binuclear struc-
ture, in which one imidazole group of tib is free of coordination, while 2 has three-dimensional (3D) framework
with the CHDC-Zn microcycles filled into the tib-Zn 3D net, and 3 is a 2-fold interpenetrating 3D framework with
the interconnection of two one-dimensional (1D) chains formed by BTC-Zn and tib-Zn, respectively. The different
structures of 1—3 are resulted from the distinct carboxylate ligands. In addition, complexes 1—3 show obvious
emissions at room temperature in the solid state.
Keywords zinc(II) complex, metal-organic framework, crystal structure, photoluminescence
Introduction
to understand the formation and structure of MOFs.
In our previous study, two unprecedented homo-
chiral enantiomers [Cd(tib)(1,4-BDC)]•2H2O (L and R)
and one achiral complex [Cd2(tib)(1,4-BDC)2(H2O)]•
2H2O were obtained from one pot reaction with achiral
mixed rigid ligands 1,3,5-tris(1-imidazolyl)benzene (tib)
and 1,4-benzenedicarboxylic acid (1,4-H2BDC).[9b] The
enantiomers show interesting ferroelectric property and
are the first example of helical chain based chiral 3D
complex constructed by two rigid ligands via huge dis-
tortion.[9b] Encouraged by this fantastic result, we chose
some other carboxylic acids together with tib ligand to
react with Zn(II) salt to construct new MOFs.
In this study, we present three new MOFs, namely
[Zn(tib)(PDC)] (1), [Zn3(tib)2(CHDC)3]•8H2O (2) and
[Zn3(tib)2(BTC)2]•4.95H2O (3) with tib and different
carboxylic acids of 2,6-pyridinedicarboxylic acid
(H2PDC), 1,4-cyclohexanedicarboxylic acid (H2CHDC)
and 1,3,5-benzenetriacetic acid (H3BTC), respectively.
The complexes are well characterized, and show obvi-
ous photoluminescence property at room temperature in
Metal-organic frameworks (MOFs) have attracted
great attention of chemists in the past decades, not only
because of their intriguing structures and topologies, but
also due to their potential applications in many fields,
such as catalysis, carbon dioxide capture, hydrogen
storage, non-linear optics, chemical sensor and so on.[1-3]
Meanwhile, the structure of MOFs can be affected by
many factors, thus the control synthesis of MOFs with
desired structures and properties is always a great chal-
lenge for crystal engineering.[4,5] We focus on the design
and synthesis of MOFs with imidazole-containing
ligands.[6-8] According to the previously reported works,
the MOFs based on mixed carboxylate and imida-
zole-containing ligands usually have fantastic structural
characters, since the carboxylate groups are versatile
and can have different coordination modes to satisfy the
coordination requirements of metal centers.[9,10] At the
same time, it also added difficulty to predict the final
structure of the MOFs. Thus, further studies are needed
*
E-mail: sunwy@nju.edu.cn (W. Y. Sun); Tel.: 0086-025-83593485; Fax: 0086-025-83314502
Received July 12, 2012; accepted August 30, 2012.
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/cjoc.201200715 or from the author.
Dedicated to the 80th Anniversary of Chinese Chemical Society.
†
2016
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Synthesis, Crystal Structure and Photoluminescent Property of Metal-Organic Frameworks
the solid state.
light-brown block crystals were collected by filtration
and washed by water and ethanol several times. Yield:
ca. 38% based on the Zn(II). IR (KBr pellet) ν: 3434 (s,
br), 1617 (s), 1514 (s), 1379 (s), 1295 (m), 1257 (m),
1115 (m), 1074 (m), 1005 (m), 941 (m), 857 (m), 754
(m), 645 (m), 580 (w) cm － 1. Anal. calcd for
C54H51.9N12O16.95Zn3: C 48.53, H 3.91, N 12.58; found
C 49.04, H 3.76, N 11.97.
Experimental
Materials and general methods
All commercially available chemicals and solvents
are of reagent grade and were used as received without
further purification. The ligand tib was synthesized ac-
cording to the method reported previously.[8b] FT-IR
X-ray crystallography
spectra were recorded in the range of 400—4000 cm－
1
The crystallographic data for 1 and 2 were collected
on a Bruker Smart Apex CCD area-detector diffracto-
meter with graphite-monochromated Mo Kα radiation
(λ＝0.071073 nm) at 20(2) ℃ using the ω-scan tech-
nique. The diffraction data was integrated by using the
SAINT program,[11] which was also used for the intensity
corrections for the Lorentz and polarization effects.
Semi-empirical absorption correction was applied using
the SADABS program.[12] The structures were solved by
direct methods and all non-hydrogen atoms were refined
anisotropically on F2 by the full-matrix least-squares
technique using the SHELXL-97 crystallographic soft-
ware package.[13] Hydrogen atoms of the ligands in the
structures were generated geometrically. In 2, the water
molecules of O7W and O8W disordered into two posi-
tions with site occupancy factors of 0.66(2), 0.34(2) and
0.659(8), 0.341(8), respectively. The data collection for
3 was carried out on a Rigaku RAXIS-RAPID imaging
plate diffractometer at －73 ℃, with graphite-
monochromated Mo Kα radiation (λ＝0.071075 nm).
The structure was solved by direct methods with
SIR92[14] and expanded using Fourier techniques.[15] All
non-hydrogen atoms were refined anisotropically by the
full-matrix least-squares method on F2. Hydrogen atoms
of the ligands in the structure were generated geometri-
cally. The imidazole ring atoms (C31, C32, C33 and
N32), carboxylate oxygen atoms (O3 and O4), and free
water molecule (O8) disordered into two positions with
site occupancy factors of 0.525(8) and 0.475(8), respec-
tively. The atoms O6, C151 (C153), C152 (C154) and
free water molecule (O7) disordered into two positions
with site occupancy factors of 0.623(16), 0.377(16) and
0.60(5), 0.40(5), respectively. The free water molecule
O9 occupied with a factor of 0.475(8). All calculations
were carried out on SGI workstation using the teXsan
crystallographic software package of Molecular Struc-
ture Corporation.[16] Detail of the crystal parameters,
data collection and refinements for 1—3 are summa-
rized in Table 1. Selected bond lengths and angles for
1—3 are listed in Table 2. Hydrogen bonding distances
and angles for 1 are listed in Table S1. Further details
are provided in the Supporting Information.
on a Bruker Vector22 FT-IR spectrophotometer using
KBr pellets. Thermogravimetric analyses (TGA) were
carried out on a simultaneous SDT 2960 thermal ana-
－
1
lyzer under nitrogen with a heating rate of 10 ℃ min .
Powder X-ray diffraction (PXRD) patterns were ob-
tained on a Shimadzu XRD-6000 X-ray diffractometer
with Cu Kα (λ＝0.15418 nm) radiation at room tem-
perature. The luminescence spectra for the powdered
solid samples were measured at room temperature on an
Aminco Bowman Series2 spectrofluorometer with a
xenon arc lamp as light source. In the measurements of
emission and excitation spectra the pass width is 5 nm.
All the measurements were carried out under the same
experimental conditions.
Preparation of [Zn(tib)(PDC)] (1)
A mixture of tib (27.6 mg, 0.1 mmol), H2PDC (16.7
mg, 0.1 mmol), ZnCl2 (27.3 mg, 0.2 mmol) and NaOH
(8.0 mg, 0.2 mmol) in H2O (10 mL) was sealed in a 16
mL Teflon lined stainless steel container and heated at
180 ℃ for 3 d. After cooling to the room temperature,
colorless platelet crystals were collected by filtration
and washed by water and ethanol several times. Yield:
ca. 49%. IR (KBr pellet) ν: 3348 (m), 1618 (s), 1578
(m), 1396 (m), 1274 (m), 1190 (m), 1018 (m), 785 (m),
－
1
741 (m), 696 (w) cm . Anal. calcd for C44H30N14O8Zn2:
C 52.14, H 2.98, N 19.35; found C 52.14, H 3.06, N
19.97.
Preparation of [Zn3(tib)2(CHDC)3]•8H2O (2)
The complex was obtained by the same procedure
used for preparation of 1, except that H2CHDC (17.2
mg, 0.1 mmol), instead of H2PDC, was used as the
starting material. Colorless column crystals were col-
lected by filtration with a yield 46% based on Zn(II)
after washing by water and ethanol several times. IR
(KBr pellet) ν: 3398 (m, br), 1621 (s), 1585 (s), 1512 (s),
1409 (m), 1245 (m), 1111 (w), 1074 (m), 1026 (m), 953
－
1
(m), 860 (w), 758 (w), 655 (w) cm . Anal. calcd for
C54H70N12O20Zn3: C 46.22, H 5.03, N 11.98; found C
45.79, H 3.89, N 12.24.
Preparation of [Zn3(tib)2(BTC)2]•4.95H2O (3)
A mixture of tib (27.6 mg, 0.1 mmol), H3BTC (25.2
mg, 0.1 mmol), ZnCl2 (27.3 mg, 0.2 mmol) and NaOH
(12.0 mg, 0.3 mmol) in H2O (10 ml) was sealed in a 16
mL Teflon lined stainless steel container and heated at
180 ℃ for 3 d. After cooling to the room temperature,
Results and Discussion
Crystal structure of [Zn(tib)(PDC)] (1)
The asymmetric unit of 1 contains one Zn(II), one
－
tib and one PDC2 ligand (Figure 1a). The central Zn(II)
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Su et al.
FULL PAPER
with distorted trigonal bipyramid coordination geometry
graphic analysis revealed that complex 2 crystallized in
monoclinic P21/c space group (Table 1). In the asym-
is five-coordinated by two oxygen and one nitrogen
－
atoms from one PDC2 and the other two nitrogen at-
metric unit, there are three independent Zn(II) atoms
－
(Zn1, Zn2 and Zn3), two tib, three CHDC2 ligands
oms from two different tib ligands. The equatorial plane
is formed by three nitrogen atoms (N1, N3A and N7),
while the apical positions are occupied by the two oxy-
gen atoms (O1 and O3). The Zn—O/Zn—N bond
lengths range from 0.1983(2) to 0.2169(2) nm, and the
bond angles around the Zn(II) are in the range of
76.79(8)°—152.55(7)° (Table 2). It is interesting to note
that one imidazole group with N5 of tib ligand does not
participate in the coordination, and thus each tib ligand
(Figure 2a) and eight free water molecules. Both Zn1
and Zn3 atoms are four-coordinated with distorted tet-
rahedral coordination geometry by two nitrogen atom
from two different tib and two oxygen atoms from two
－
distinct CHDC2 ligands. Each Zn2 atom with distorted
trigonal bipyramid coordination geometry is five-coor-
dinated by two nitrogen atoms (N3, N5G) from two dif-
ferent tib and three oxygen atoms (O8E, O11F and
－
O12F) from two distinct CHDC2 ligands. The Zn—N
links two, rather than three, Zn(II) atoms. Meanwhile,
－
the PDC2 acts as a terminal chelating ligand, meaning
and Zn—O bond lengths and the bond angles around
Zn(II) atoms in 2 are comparable with other Zn(II)
coordination polymers.
both carboxylate groups adopting µ1-ŋ1:ŋ0-monodentate
－
coordination mode (Scheme S1a). Two PDC2 , two tib
and two Zn(II) form a binuclear unit with a Zn-Zn dis-
tance of 1.0 nm (Figure 1b). Furthermore, the benzene
ring and the adjacent imidazole ring planes of tib are
nearly parallel with a dihedral angle of 7.19°and a cen-
troid-centroid distance of 0.376 nm, indicating the exis-
tence of π-π interactions, which further link the binu-
clear units to give a two-dimensional (2D) network
(Figure S1).[17] In addition, the C—H…O and C—H…
N hydrogen bonds further link the 2D network to
three-dimensional (3D) framework (Figure 1c and Table
S1).
Each tib ligand in 2 coordinates with three Zn(II)
atoms using its three imidazole groups to form a 3D
tib-Zn framework (Figure S2), rather than the tib-Zn
－
binuclear unit in 1. The carboxylate groups of CHDC2
adopt two different coordination modes in complex 2:
µ1-ŋ1:ŋ1 chelate and µ1-ŋ1:ŋ0 monodentate, which makes
－
each CHDC2 ligand link two Zn(II) atoms (Scheme
S1b and S1c). It is noteworthy that H2CHDC with a
mixture of cis- and trans-isomers was used, however,
－
only cis-CHDC2 was found in the complex, since the
complexes with cis- or trans-isomer may show different
－
property.[18] Six CHDC2 ligands and six Zn(II) atoms
Crystal structure of [Zn3(tib)2(CHDC)3]•8H2O (2)
form a 54-membered ring (Figure S3), which fills into
the void of the 3D tib-Zn framework to result in the final
structure of complex 2 (Figure 2b). From the topological
When the auxiliary acid changed from H2PDC to
H2CHDC, complex 2 was obtained. X-ray crystallo-
Table 1 Crystallographic data for complexes 1—3
1
2
3
Formula
Mw
C44H30N14O8Zn2
1013.56
293(2)
C54H70N12O20Zn3
1403.33
293(2)
C54H51.9N12O16.95Zn3
1336.31
200
Temp./K
Crystal system
Space group
a/nm
Monoclinic
P21/c
Monoclinic
P21/c
Monoclinic
C2/c
1.20405(14)
1.9514(2)
0.83621(9)
90.909(2)
1.9645(4)
2
2.4972(2)
1.36883(11)
1.82727(14)
101.097(1)
6.1293(8)
4
1.9460(9)
1.6088(8)
1.7973(7)
107.741(19)
5.3593(40)
4
b/nm
c/nm
β/(°)
V/nm3
Z
D/(g•cm－
)
1.714
1.503
1.656
3
F(000)
1032
2848
2742
θ range/(°)
1.7—25.3
9821
1.7—25.0
29795
3.17—25.0
19919
Reflections collected
Independent reflections
GOF on F2
3548
10775
4703
0.95
0.96
1.05
R [I＞2σ(I)]a
0.0404
0.0587
0.0799
wR2 [I＞2σ(I)]b
0.0854
0.1312
0.1869
a R1＝Σ||Fo|－|Fc||/Σ|Fo|; b wR2＝|Σw(|Fo|2－|Fc|2)|/Σ|w(Fo)2|1/2, where w＝1/[σ2(Fo )＋(aP)2+bP]. P＝(Fo ＋2Fc2)/3.
2
2
2018
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Synthesis, Crystal Structure and Photoluminescent Property of Metal-Organic Frameworks
Table 2 Selected bond lengths (nm) and bond angles (°) for
complexes 1—3a
1
Zn1—O1
0.2169(2) Zn1—O3
0.2001(2) Zn1—N7
0.1983(2)
0.2129(2)
0.2002(3)
Zn1—N1
Zn1—N3#1
O1-Zn1-O3
O1-Zn1-N7
O3-Zn1-N1
O3-Zn1-N3#1
N1-Zn1-N3#1
152.55(7) O1-Zn1-N1
96.57(9)
76.79(8)
95.19(9)
98.30(9)
O1-Zn1-N3#1
O3-Zn1-N7
N1-Zn1-N7
100.96(9)
76.90(8)
131.97(10)
118.41(10)
(a)
109.59(10) N3#1-Zn1-N7
2
Zn1—O1
0.1969(4) Zn1—N7
0.1964(3) Zn1—N1
0.2058(4) Zn2—O12#2
0.2000(4) Zn2—N5#4
0.2207(5) Zn3—O9
0.1968(4) Zn3—N11
0.2012(4)
0.2026(4)
0.2037(4)
0.2184(4)
0.2076(4)
0.1934(4)
0.2001(4)
Zn1—O5
Zn2—N3
Zn2—O8#3
Zn2—O11#2
Zn3—O3
Zn3—N9#5
O1-Zn1-O5
O1-Zn1-N7
O5-Zn1-N7
O11#2-Zn2-N3
O12#2-Zn2-N3
O8#3-Zn2-N3
O8#3-Zn2-N5#4
113.66(19) O1-Zn1-N1
107.03(18) O5-Zn1-N1
122.03(16) N1-Zn1-N7
98.18(17)
107.21(15)
105.79(15)
(b)
147.31(16) O11#2-Zn2-O12#2 57.29(15)
90.02(15) O12#2-Zn2-N5#4 110.69(15)
103.18(15) N3-Zn-N5#4
97.79(15)
99.00(16) O8#3-Zn2-O11#2 104.55(16)
O8#3-Zn2-O12#2 145.56(16) O11#2-Zn2-N5#4 94.64(1)
O3-Zn3-O9
95.10(15) O3-Zn3-N9#5
111.44(15) O9-Zn3-N11
104.39(16) N9#5-Zn3-N11
3
117.19(16)
117.02(17)
110.92(15)
O3-Zn3-N11
O9-Zn3-N9#5
Zn1—O1
0.1969(5) Zn1—N12
0.2043(17) Zn2—O5#6
0.1997(13) Zn2—N52#7
0.2014(5)
0.1906(6)
0.2021(7)
122.1(2)
98.6(2)
Zn2—N32#9
Zn2—O3
(c)
O1-Zn1-O1#8
N12-Zn1-N12#8
O5#6-Zn2-O3
O3-Zn2-N52#7
113.5(3)
103.2(3)
109.4(4)
129.5(4)
O1-Zn1-N12#8
O1-Zn1-N12
Figure 1 (a) The ORTEP drawing of 1 with thermal ellipsoids
set to 30% probability level. All H atoms are omitted for clarity.
(b) The binuclear structure of complex 1. (c) The 3D structure of
complex 1 (π-π interactions: yellow dotted lines; hydrogen bonds:
pink dotted lines).
O5#6-Zn2-N52#7 100.2(2)
O5#6-Zn2-N32#9 119.2(6)
N52#7-Zn2-N32#9 89.1(5)
O3-Zn2-N32#9
109.4(7)
a Symmetry transformations used to generate equivalent atoms:
#1 －x, －y, 1－z; #2 1＋x, 3/2－y, －1/2＋z; #3 －x, 1/2＋y,
1/2－z; #4 x, 5/2－y, －1/2＋z; #5 －1－x, 1/2＋y, 3/2－z; #6 x,
－y＋1, z＋1/2; #7 z, －y, z＋1/2; #8 －x＋1, y, －z＋1/2; #9
－x, y, －z＋1/2.
Crystal structure of [Zn3(tib)2(BTC)2]•4.95H2O (3)
To further investigate the effect of the auxiliary car-
boxylic acid on the structure of coordination polymer,
H3BTC was used to react with ZnCl2 and tib. Complex
3 was obtained under the same conditions for prepara-
tions of 1 and 2. X-ray crystallographic analysis re-
vealed that complex 3 crystallizes in monoclinic C2/c
space group (Table 1). In the asymmetric unit, there are
two crystallographic different Zn(II) atoms: Zn1 and
Zn2. Each Zn1 atom, sitting on a special position with
half occupancy, is four-coordinated with a distorted
view of this complicated 3D framework,[19] the Zn(II)
－
atom, tib and CHDC2 ligands can be simplified as
four-, three- and two-(bridging) connectors, respectively.
Thus, complex 2 can be simplified as a (3,4)-connected
net with Point (Schläfli) symbol of (3•6•72•8•9)-
(3•62•7•9•10)(3•7•8)(6•7•9)(62•7•9•102) (Figure 2c).
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(a)
(a)
(b)
(b)
(c)
Figure 2 (a) The ORTEP drawing of 2 with thermal ellipsoids
set to 30% probability level. All H atoms and free water mole-
cules are omitted for clarity. (b) The 3D structure of complex 2,
－
where the green and red represented tib ligands and CHDC2
(c)
ligands, respectively. (c) The topological view of 3D framework
of complex 2 (green balls for tib ligands, turquoise balls for the
－
Zn(II), red lines for CHDC2 ligands).
tetrahedral coordination geometry by two nitrogen at-
oms (N12 and N12A) from two different tib and two
－
oxygen atoms (O1 and O1A) from two distinct BTC3
ligands (Figure 3a). Each Zn2 atom with distorted tet-
rahedral coordination geometry is four-coordinated by
two oxygen atoms (O3 and O5B) from two different
－
BTC3 and two nitrogen atoms (N32C and N52D) from
two distinct tib ligands.
(d)
Each tib ligand in 3 connects three Zn(II) atoms (one
Zn1 and two Zn2) to form a one-dimensional (1D) chain
Figure 3 (a) The ORTEP drawing of 3 with thermal ellipsoids
set to 30% probability level. All H atoms and free water mole-
cules are omitted for clarity. (b) The 3D structure of complex 3,
－
(Figure S4). Meanwhile, each BTC3 ligand adopts
cis,cis,trans-conformation and links three Zn(II) to form
a 1D infinite ladder-like chain, in which each carboxy-
late group adopts µ1-ŋ1:ŋ0 monodentate coordination
mode (Scheme S1d and Figure S5). The two different
－
where the green and red represented tib ligands and BTC3 li-
gands, respectively. (c) and (d) Space-filling and topological
views of 2-fold interpenetrating 3D framework of complex 3.
2020
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Synthesis, Crystal Structure and Photoluminescent Property of Metal-Organic Frameworks
℃.
kinds of 1D chains interconnected to form the final 3D
framework of 3 (Figure 3b). It is noteworthy that there
are open channels with size of 1.73 nm×0.73 nm in the
single 3D net of 3 along the c direction, which allows
another identical net to penetrate, namely, the entire
structure of 3 is a 2-fold interpenetrated 3D framework
(Figure 3c). Using the same topological analysis method
Furthermore, the phase purity of the complexes was
confirmed by the powder X-ray diffraction (PXRD)
measurements and the results are given in Figure S8,
where the as-synthesized pattern is consistent with the
simulated one from the corresponding complex.
Photoluminescence properties of the complexes 1—3
－
for complex 3, the Zn(II), tib and BTC3 ligands can be
Inorganic-organic hybrid coordination polymers, es-
pecially those with d10 metal centers, have been investi-
gated for photoluminescent properties, because of their
potential applications as fluorescence-emitting materi-
als.[23] In the present work, the emission spectra of Zn(II)
complexes 1—3 together with tib, H2PDC, H2CHDC
and H3BTC ligands, were measured in the solid state at
room temperature, and all the measurement were ex-
cited at a wavelength of 360 nm. Intense emission bands
were observed at 405 nm for the free tib ligand, which
are same as those reported previously,[24] and no obvi-
ous emission band was detected for free H2PDC,
H2CHDC and H3BTC ligands. As shown in Figure 4,
intense emissions were observed at 396, 400 and 407
nm for complexes 1—3, respectively. The emissions of
complexes 1—3 are tentatively ascribed to the intrali-
gand transition of tib due to their similarity. And the
observed red or blue shift of the emission maximum
between the complexes and the ligand is considered to
mainly originate from the influence of the coordination
of the ligand to the metal atom. In addition, it is note-
worthy that complexes 2 and 3 showed intense emission
compared with free tib ligand and 1 at room temperature,
which may be attributed to the different rigidity of the
crystal packing in the solid state.
viewed as four-, three- and three-connector, respectively.
Thus, complex 3 can be simplified as (3,4)-connected
net with Point (Schläfli) symbol of (4•82)2(4•85)2-
(82•10)2(86) (Figures 3d and S6).
Effect of the auxiliary carboxylate ligands
The structural differences between complexes 1—3
are mainly ascribed to the effect of the auxiliary car-
bxylate ligands. As it is known, the coordination abili-
ties/modes and the flexibilities of the auxiliary carboxy-
late ligands are the most important factors to affect the
MOFs’ structures.[20] For example, the previously re-
ported complexes [Zn(tib)(1,3-BDC)]•H2O (4) and
[Zn2(tib)(1,4-BDC)Cl2]•2H2O (5) were synthesized un-
der the same reaction conditions except that 1,3-H2BDC
(1,3-benzenedicarboxylic acid) and 1,4-H2BDC were
used, instead of the auxiliary carboxylate ligands of
H2PDC, H2CHDC and H3BTC used in this work.[21]
－
Complex 4 is a 2D (4,4) network, where the 1,3-BDC2
works as simple bridging ligand, while 5 is a different
2D network constructed by Zn4(tib)2 and Zn4(1,4-BDC)2
subunits. Comparing complexes 1 and 4, it is clear that
－
the PDC2 ligand is much easier to chelate one metal
ion as the terminal ligand due to the existence of the
center nitrogen atom, which blocks the extension of the
unit to higher dimensional framework, and leads to the
formation of zero-dimensional (0D) binuclear structure
of 1. By comparing the flexible cyclohexane skeleton in
2 and the rigid benzene one in 5, it is obvious that the
－
flexible CHDC2 is much easier to satisfy the coordi-
nation requirement of the metal ion to form high-di-
－
mensional framework. As far as the BTC3 , it has three
flexible carboxylate groups which can satisfy the re-
quirement of metal center to form complicated 3D
frameworks.[22] The results of present study further con-
firm that the auxiliary carboxylate ligands are versatile
and important in construction of MOFs.
Figure 4 Emission spectra of 1—3 and tib ligand in the solid
state at room temperature.
TGA and PXRD
Thermogravimetric analyses (TGA) were carried out
for the synthesized complexes, and the results are
shown in Figure S7. No obvious weight loss was found
for complex 1 until the decomposition of the framework
occurred at ca. 420 ℃. For 2, the weight loss of 9.74%
was observed before 180 ℃ corresponding to the re-
lease of free water molecules (calcd. 10.26%), and fur-
ther decomposition occurred at 350 ℃. Complex 3
shows a weight loss of 6.05% before 160 ℃ corre-
sponding to the departure of free water molecules (calcd.
6.60%); further weight loss was observed at about 410
Conclusions
Three new coordination polymers have been suc-
cessfully synthesized under hydrothermal conditions by
reactions of tib ligand together with auxiliary carboxy-
late ligands and ZnCl2. The structural differences be-
tween complexes 1—3 and previously reported 4 and 5
are mainly ascribed to the different auxiliary carboxy-
late ligands. Meanwhile, the synthesized complexes
have high stabilities and show obvious photolumines-
Chin. J. Chem. 2012, 30, 2016—2022
© 2012 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.cjc.wiley-vch.de
2021

Su et al.
FULL PAPER
Fan, J.; Shu, M. H.; Okamura, T. -a.; Li, Y. Z.; Sun, W. Y.; Tang, W.
X.; Ueyama, N. New J. Chem. 2003, 27, 1307.
cent emissions at room temperature in the solid state.
[9] (a) Su, Z.; Chen, M.; Okamura, T. -a.; Chen, M. S.; Chen, S. S.; Sun,
W. Y. Inorg. Chem. 2011, 50, 985; (b) Su, Z.; Chen, M. S.; Fan, J.;
Chen, M.; Chen, S. S.; Luo, L.; Sun, W. Y. CrystEngComm 2010, 12,
2040; (c) Su, Z.; Fan, J.; Okamura, T. -a.; Sun, W. Y.; Ueyama, N.
Cryst. Growth Des. 2010, 10, 3515.
[10] (a) Soubeyrand-Lenoir, E.; Vagner, C.; Yoon, J. W.; Bazin, P.; Ragon,
F.; Hwang, Y. K.; Serre, C.; Chang, J. S.; Llewellyn, P. L. J. Am.
Chem. Soc. 2012, 134, 10174; (b) He, K. H.; Li, Y. W.; Chen, Y. Q.;
Song, W. C.; Bu, X. H. Cryst. Growth Des. 2012, 12, 2730; (c) Sun,
D.; Yan, Z. H.; Liu, M. J.; Xie, H. Y.; Yuan, S.; Lu, H. F.; Feng, S. Y.;
Sun, D. F. Cryst. Growth Des. 2012, 12, 2902.
[11] SAINT, version 6.2, Bruker AXS, Inc., Madison, WI, 2001.
[12] Sheldrick, G. M. SADABS, University of Göttingen, Göttingen,
Germany, 1997.
[13] Sheldrick, G. M. SHELXL-97, Program for Crystal Structure Re-
finement, University of Göttingen, Göttingen, Germany, 1997.
[14] Altomare, A.; Burla, M. C.; Camalli, M.; Cascarano, M.;
Giacovazzo, C.; Guagliardi, A.; Polidori, G. J. Appl. Crystallogr.
1994, 27, 435.
Supplementary Material
CCDC 891618—891620 contain the supplementary
crystallographic data for 1—3. The data can be obtained
free of charge via the Internet at http://www.ccdc.ca-m.
ac.uk/conts/retrieving.html or from the Cambridge
Crystallographic Data Centre, 12 Union Road, Cam-
bridge CB2 1EZ, UK. Email: deposit@ccdc.cam.ac.uk.
Acknowledgement
This work was financially supported by the National
Basic Research Program of China (No. 2010CB923303)
and the National Natural Science Foundation of China
(Nos. 91122001 and 21021062).
References
[15] Beurskens, P. T.; Admiraal, G.; Beurskens, G.; Bosman, W. P.; de
Gelder, R.; Israel, R.; Smits, J. M. M. DIRDIF94: The DIRDIF-94
Program System, Technical Report of the Crystallography Labora-
tory, University of Nijmegen, The Netherlands, 1994.
[16] teXsan: Crystal Structure Analysis Package, Molecular Structure
Corporation, The Woodlands, TX, 1999.
[17] Su, Z.; Wang, Z. B.; Sun, W. Y. J. Coord. Chem. 2011, 64, 170.
[18] Mori, W.; Sato, T.; Kato, C. N.; Takei, T.; Ohmura, T. Chem. Rec.
2005, 5, 336.
[19] Balaban, A. T. From Chemical Topology to Three-Dimensional
Geometry, Plenum Press, New York, 1997.
[20] (a) Choi, H. S.; Suh, M. P. Angew. Chem., Int. Ed. 2009, 48, 6865; (b)
Shao, K. Z.; Zhao, Y. H.; Wang, X. L.; Lan, Y. Q.; Wang, D. J.; Su, Z.
M.; Wang, R. S. Inorg. Chem. 2009, 48, 10; (c) Ene, C. D.; Madalan,
A. M.; Maxim, C.; Jurca, B.; Avarvari, N.; Andruh, M. J. Am. Chem.
Soc. 2009, 131, 4586; (d) Chen, X. D.; Zhao, X. H.; Chen, M.; Du,
M. Eur. J. Chem. 2009, 12974.
[1] (a) Yaghi, O. M.; O’Keeffe, M. Chem. Rev. 2012, 112, 675; (b) Yoon,
M.; Srirambalaji, R.; Kim, K. Chem. Rev. 2012, 112, 1196; (c) Cui, Y.
J.; Yue, Y. F.; Qian, G. D.; Chen, B. L. Chem. Rev. 2012, 112, 1126.
[2] (a) Sumida, K.; Rogow, D. L.; Mason, J. A.; McDonal, T. M.; Bloch,
E. D.; Herm, Z. R.; Bae, T. H.; Long, J. R. Chem. Rev. 2012, 112,
724; (b) Suh, M. P.; Park, H. J.; Prasad, T. K.; Lim, D. W. Chem. Rev.
2012, 112, 782.
[3] (a) Li, J. R.; Sculley, J. L.; Zhou, H. C. Chem. Rev. 2012, 112, 896;
(b) Kreno, L. E.; Leong, K.; Farha, O. K.; Allendorf, M.; Duyne, R.
P. V.; Hupp, J. T. Chem. Rev. 2012, 112, 1105.
[4] (a) Chang, Y. C.; Wang, S. L. J. Am. Chem. Soc. 2012, 134, 9848; (b)
Fraha, O. M.; Wilmer, C. E.; Eryazici, L.; Hauser, B. G.; Parilla, P.
A.; O’Neill, K.; Sarjeant, A. A.; Nguyen, S. T.; Snurr, R. Q.; Hupp, J.
T. J. Am. Chem. Soc. 2012, 134, 9860; (c) Yang, L. S.; Lu, H. M.
Chin. J. Chem. 2012, 30, 1040; (d) Wu, Y. J.; Yu, L. L.; Chen, M. L.;
Han, W.; Wang, L. D.; Gao, X.; Liu, Q. Chin. J. Chem. 2012, 30,
1045.
[21] (a) Su, Z.; Xu, J.; Fan, J.; Liu, D. J.; Chu, Q.; Chen, M. S.; Chen, S.
S.; Liu, G. X.; Wang, X. F.; Sun, W. Y. Cryst. Growth Des. 2009, 9,
2801; (b) Su, Z.; Fan, J.; Okamura, T.-a.; Chen, M. S.; Chen, S. S.;
Sun, W. Y.; Ueyama, N. Cryst. Growth Des. 2010, 10, 1911.
[22] (a) Zhu, H. F.; Zhang, Z. H.; Sun, W. Y.; Okamura, T.-a.; Ueyama,
N. Cryst. Growth Des. 2005, 5, 177; (b) Zhu, H. F.; Fan, J.; Oka-
mura, T.-a.; Zhang, Z. H.; Liu, G. X.; Yu, K. B.; Ueyama, N. Inorg.
Chem. 2006, 45, 3941.
[23] (a) He, Y. H.; Feng, Y. L.; Lan, Y. Z.; Wen, Y. H. Cryst. Growth Des.
2008, 8, 3586; (b) Wang, X. W.; Chen, J. Z.; Liu, J. H. Cryst.
Growth Des. 2007, 7, 1227; (c) Gong, Y. Q.; Wang, R. H.; Yuan, D.
Q.; Su, W. P.; Huang, Y. G.; Yue, C. Y.; Jiang, F. L.; Hong, M. C.
Polyhedron 2007, 26, 5309.
[5] (a) Jacobs, T.; Clowes, R.; Cooper, A. I.; Hardie, M. J. Angew.
Chem., Int. Ed. 2012, 51, 5192; (b) Huang, W. Y.; Chen, Z. L.; Zou,
H. H.; Liu, D. C.; Liang, F. P. Chin. J. Chem. 2012, 30, 1052.
[6] (a) Chen, S. S.; Chen, M.; Takamizawa, S.; Chen, M. S.; Su, Z.; Sun,
W. Y. Chem. Commun. 2011, 47, 752; (b) Chen, S. S.; Chen, M.;
Takamizawa, S.; Wang, P.; Lv, G. C.; Sun, W. Y. Chem. Commun.
2011, 47, 4902.
[7] (a) Zhao, W.; Song, Y.; Okamura, T. -a.; Fan, J.; Sun, W. Y.; Ueyama,
N. Inorg. Chem. 2005, 44, 3330; (b) Wan, S. Y.; Huang, Y. T.; Li, Y.
Z.; Sun, W. Y. Microporous Mesoporous Mater. 2004, 73, 101; (c)
Sui, B.; Fan, J.; Okamura, T. -a.; Sun, W. Y.; Ueyama, N. New J.
Chem. 2001, 25, 1379.
[8] (a) Fan, J.; Sun, W. Y.; Okamura, T. -a.; Tang, W. X.; Ueyama, N.
Inorg. Chem. 2003, 42, 3168; (b) Fan, J.; Gan, L.; Kawaguchi, H.;
Sun, W. Y.; Yu, K. B.; Tang, W. X. Chem. Eur. J. 2003, 3965; (c)
[24] Li, L.; Fan, J.; Okamura, T.-a.; Li, Y. Z.; Sun, W. Y.; Ueyama, N.
Supramol. Chem. 2004, 16, 361.
(Pan, B.; Qin, X.)
2022
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© 2012 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2012, 30, 2016—2022