Hydrothermal synthesis, crystal structure of two novel coordination polymers based on carboxylic acid ligand containing sulfur

Article abstract of DOI:10.1080/15533174.2013.818030

Two new metal–organic polymers, [Zn(L¹)₂(H₂O)]_n 1 [H₂L¹ = 5-(1-carboxyethyl)-2-(phenylthio)phenylacetic acid] and [La(HL²)₂(L²)₃]_n 2 [

Full text of DOI:10.1080/15533174.2013.818030

Synthesis and Reactivity in Inorganic, Metal-Organic, and
Nano-Metal Chemistry
ISSN: 1553-3174 (Print) 1553-3182 (Online) Journal homepage: http://www.tandfonline.com/loi/lsrt20
Hydrothermal Synthesis, Crystal Structure of two
Novel Coordination Polymers Based on Carboxylic
Acid Ligand containing Sulfur
Long Li , Yuqiu Ding & Kaisheng Diao
To cite this article: Long Li , Yuqiu Ding & Kaisheng Diao (2014): Hydrothermal Synthesis,
Crystal Structure of two Novel Coordination Polymers Based on Carboxylic Acid Ligand
containing Sulfur, Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal
Chemistry, DOI: 10.1080/15533174.2013.818030
To link to this article: http://dx.doi.org/10.1080/15533174.2013.818030
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Date: 01 April 2016, At: 17:29

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Hydrothermal Synthesis, Crystal Structure of two Novel Coordination Polymers Based on
Carboxylic Acid Ligand containing Sulfur
Long Lia, Yuqiu Dinga, Kaisheng Diao*, a, b
aCollege of Chemistry and Chemical Engineering, Guangxi University for Nationalities, Nanning
530006, People’s Republic of China
bGuangxi Key Laboratory of Chemistry and Engineering of Forest Products
(Guangxi University for Nationalities), Nanning 530006, People’s Republic of China
Correspondence e-mail: llgxmd@163.com
Abstract Two new metal–organic polymers of the formula [Zn(L1)2(H2O)]n 1 and
[La(HL2)2(L2)3]n 2 [H2L1 = 5-(1-carboxyethyl)-2-(phenylthio)phenylacetic acid; HL2 =
2-thiophenecarboxylic acid] have been synthesized and characterized by elemental analysis,
fluorescence spectra, and single crystal X-ray diffraction. Polymers 1 and 2 are both coordination
polymers showing one-dimensional and two-dimensional respectively. The two polymers exhibit
interesting supermolecular architecture and exhibit fluorescence at room temperature.
Key Words 5-(1-carboxyethyl)-2-(phenylthio)phenylacetic acid, 2-thiophenecarboxylic acid,
Hydrothermal Synthesis, Fluorescence
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Introduction
As far as we know, as bridging ligands, carboxylates, especially multi-carboxylates, are of
huge interest in the construction of polymeric coordination architectures not only because the
fact that these polymers have a wide range of structural diversities and potential applications as
porous
materials and magnetic materials,but also because these ligands exhibit rich coordination
chemistry. Such as H3BTC, H2PDA and H2OBA are typical multi-carboxylates,are widely used
to synthesis the metal-organic complex and investigate their properties [1-4] However,
Carboxylic Acid Ligands containing Sulfur are rarely reported.
5-(1-carboxyethyl)-2-(phenylthio)phenylacetic acid and 2-thiophenecarboxylic acid are two
typical carboxylate ligands containing Sulfur. In this paper, we report the synthesis, structure of
two novel coordination polymers, [Zn(L1)2(H2O)]n 1 [La(HL2)2(L2)3]n 2. In addition, we
investigate the fluorescence of these complexes.
Experimental
Materials and Instrumentation
All reagents and solvents were used directly as supplied commercially without further
purification. Elemental analysis for C and H was carried out on a Perkin–Elmer 2400 II
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elemental analyzer. Fluorescence spectra was acquired on a Perkin–Elmer instruments LS55
spectrofluorometer.
Synthesis of [ZnL1 (H2O)]n 1
2
A mixture of ZnCl2 (68.2 mg, 0.5 mmol) and H2L1 (316.4 mg, 1.0 mmol) were dissolved in
the mixed solvent (1:1 H2O/EtOH) (20mL). Then an aqueous solution of sodium hydroxide was
added dropwise with stirring to adjust the pH value of the solution being 6. The mixture was kept
heated at 160℃ for 2 days. After cooling to room temperature, the reaction solution was filtered
to remove a small quantity of precipitate. Kept slow evaporation of the filtrate at room
temperature and four days later X-ray quality colorless block-shaped single crystals were
obtained. The crystals were isolated, washed with ethanol and dried at room temperature
(Yield:60% based on Zn). Calcd.For C17H16O5SZn: C 51.28, H 4.02 %. Found: C 51.22, H 4.06
%.
Synthesis of [La(HL2)2(L2)3]n 2
The synthesis of 2 was similar to that of 1 except that LaCl3 (150.23 mg, 0.5 mmol) was
used instead of ZnCl2 (68.2 mg, 0.5 mmol) and H2L1 (316.4 mg, 1.0 mmol) was replaced by HL2 .
A week later, colorless block-shaped single crystals were obtained. The crystals were isolated,
washed with ethanol and dried at room temperature (Yield:70% based on La). Calcd.For
C25H17O10S5La: C 38.63, H 2.19 %. Found: C 38.56, H 2.15 %.
X-ray Data Collection and Structure Refinement
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Crystallographic data of complexes were collected on a Bruker SMART CCD
diffractometer with graphite monochromated Mo-Ka radiation (λ = 0.71073 Å) at T = 296 K.
Absorption corrections were applied by using the multi-scan program [5]. The structure was
solved by direct methods and successive Fourier difference syntheses (SHELXS-97), and
anisotropic thermal parameters for all nonhydrogen atoms were refined by full-matrix
least-squares procedure against F2 (SHELXL-97) [6]. All nonhydrogen atoms were refined
anisotropically. Hydrogen atoms were set in calculated positions and refined by a riding mode,
with a common thermal parameter. H atoms for H2O molecules were located in different
synthesis and refined isotropically. The crystallographic data and experimental details for the
structure analysis are summarized in Table 1, the selected bond lengths and angles are listed in
Table 2, meanwhile, the hydrogen-bonds of the complexes are listed in Table 3.
Results and Discussion
Crystal Structure Descriptions
Single crystal X-ray analysis of 1 reveals that the asymmetric unit consists of one Zn(II)
ion, one L1 and one coordinated water. The coordination number of Zn(II) ion in complex 1 is
four, that is not common in complex. Each Zn(II) coordinate with four oxygen atoms
(O1,O3,O4,O5) from the carboxylate of three L1 ligands and one coordinated water, as shown in
Figure 1.The O–Zn bond distances range from 1.945(6) to 1.981(6) Å, The dihedral angle
between two benzene rings in the same L1 ligand is 84.73(6)º.The C-S-C angle is 103.92(6)º. In
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complex 1, the carboxy of L1 linked the adjacent Zn ions together to form a [ZnO4C]n 1-D helical
chain along b direction (Figure 2). Along the spiral chain, the intramolecular separation of
Zn···Zn is 4.325(4) Å, and all L1 ligands connected helices together to be a 2-D coordination
layer along the bc plane (Figure 3a,b). The 2-D layers in complex 1 are packed alongside with
each other through weak C-H···π interactions (Figure 4). Along with this shortest interaction (H6
to the centroid of ring C1-C6: 3.593(6) Å) propagating crystallographic a axis with the formation
of a 3-D supermolecular structure (Figure 5). In addition, the classical hydrogen bonds (O-H···O)
are also exist between the coordinated water and the carboxylate, which just make the 2-D layer
more stable but not contribute to the 3-D structure.
Fluorescence Emission Properties
The photoluminescence behavior of the two complexes were studied in solid state at room
temperature. Complex 1 shows two emission peaks: one at 413 nm and another at 338 nm when
excited at 337 nm, as shown in Figure. 10. The major peak of complex 1, which are dominated
by intraligand π-π* type of fluorescence, and the weak peak at 338 nm can be assigned as a
ligand-to-metal charge transfer (LMCT) transition. Compound 2 exhibits emission around 406
nm upon excitation at 331 nm (Figure. 11), which can be attributed to the (π-π*) transition of the
ligand .
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Conclusion
Within this paper we report the synthesis and characterization of polymers [Zn(L1)2(H2O)]n
1 and [La(HL2)2(L2)3]n 2 by elemental analysis, fluorescence spectra, and single crystal X-ray
diffraction. The above results show that the configuration of ligand plays an important role in
affecting the final structure of the coordination polymers. The successful preparation of the
complexes manifest that the conformations and functions of π-π stacking interactions, hydrogen
bonds and C-H···S interactions are important factors in influencing the architecture of metal-L
ligand complexes. In addition, polymers 1 and 2 are all exhibit fluorescence in solid state at room
temperature.
Supplementary material
CCDC 907642, 938306 contains the supplementary crystallographic data for this paper. These data can be
obtained free of charge via www.ccdc.cam.ac.uk/conts/retrieving.html (or from the Cambridge Crystallographic
Data Centre, 12, Union Road, Cambridge CB2 1EZ, UK;fax: C44 1223 336033; e-mail: deposit@ccdc.cam.ac.uk).
Acknowledgements
This work is supported by the Innovation Project of Guangxi University for Nationalities (gxun-chx2012089),
Guangxi Natural Science Foundation (No. 2013GXNSFAA019091), the Scientific Research Program of Education
Department of Guangxi Zhuang Autonomous Region (Project No.201010LX081), and the Scientific Research
Program of Guangxi University for Nationalities (Project No. 2010QD019).
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References
1. Burchell, C.J., Ferguson, G., Lough, A.J. & Glidewell, C. Hydrogen-bonded sheets in the 1:1
salt of tet-b and trimesic acid. (2001). Acta. Crystallogr. C., 57, 311.
2. Jiang, Y.L., Liu, Q.Y. & Wang, Y.L. Bis(μ-5-carboxybenzene-1,3-dicarboxylato-κ2O1:O3)
bis[(2,2′-bi-1H-imidazole-κ2N3,N3′)zinc]. (2011). Acta. Crystallogr. C., 67, m297.
3. Liu, G.F., Qiao, Z.P., Wang, H.Z., Chen, X.M. & Yang, G. Synthesis, structures and
photoluminescence of three terbium(III) dicarboxylate coordination polymers. (2002). New. J.
Chem., 26, 791.
4. Wu, Q.L., Zhuang, J.C., Luo, Z.R., Yin, X.H. & Zhao, D.D. Syntheses, Crystal Structure, and
Properties of Cu(II) and Zn(II) Complexes with 1, 4-phenylenediacetate and 2, 2′-bipyridine.
(2010). Synth. React. Inorg. Met. -Org. Chem., 40, 790.
5. Blessing, R.H. (1995). Acta Crystallogr A ., 51 , 33.
6. Sheldrick, G. M., SHELXTL97 Program for refining crystal structure refinement. University
of Göttingen, Germany, 1997.
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Table 1. Crystallographic data for complex 1 and 2
Compounds
Empirical formula
Formula weight
Crystal system
space group
1
C17H16O5SZn
397.76
Monoclinic
P21/c
2
C25H17O10S5La
776.60
Monoclinic
Cc
a(Å)
b(Å)
c(Å)
α(°)
18.492(4)
5.4356(12)
19.104(3)
90
20.598(11)
14.272(7)
9.973(5)
90
β(°)
120
90
1651.3(6)
4
1.600
92.477(5)
90
2929(3)
γ(°)
V(Å3)
Z
4
Dc(Mg/m3)
1.761
1.869
μ( mm-1)
1.637
F(000)
816
1536
Crystal size(mm )
θ range
0.38 × 0.35 × 0.33
2.13-28.38
10289
0.36 × 0.34 × 0.31
1.74-28.38
8980
Reflections collected
Independent reflections
Completeness to θ =25.00
Absorption correction
Max. and min. transmission
Data /restraints/parameters
Goodness-of-fit on F
R indices [I>2σ(I)]
3891 [R(int) = 0.0306]
0.999
6092 [R(int) = 0.0337]
0.998
Multi-scan
0.6141 and 0.5750
3891 / 306 / 218
1.020
R1 = 0.0454, wR2 =
0.1176
Multi-scan
0.5950 and 0.5527
6092 / 394 / 370
1.045
R1 = 0.0687, wR2 = 0.1909
R indices (all data)
R1 = 0.0627, wR2
=0.1289
0.760 and -0.994
R1 = 0.0704, wR2 = 0.1927
Largest diff. features (eÅ-3)
2.899 and -2.735
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Table 2. The selected bond lengths (Å) and angles (°) for complex 1 and 2
Complex 1
Zn(1)-O(1)
Zn(1)-O(4)
1.945(3)
1.957(3)
Zn(1)-O(5)
Zn(1)-O(3)
1.973(3)
1.981(3)
O(1)-Zn(1)-O(4)
O(1)-Zn(1)-O(5)
O(4)-Zn(1)-O(5)
Complex 2
95.86(11)
125.98(11)
111.87(11)
O(1)-Zn(1)-O(3)
O(4)-Zn(1)-O(3)
O(5)-Zn(1)-O(3)
102.89(12)
115.26(11)
105.20(12)
La(1)-O(10)
La(1)-O(9)
La(1)-O(6)
2.390(8)
2.420(8)
2.458(9)
2.499(8)
La(1)-O(5)
La(1)-O(1)
La(1)-O(3)
La(1)-O(7)
2.531(8)
2.552(8)
2.573(8)
2.613(8)
La(1)-O(2)
O(10)-La(1)-O(9)
O(9)-La(1)-O(6)
O(9)-La(1)-O(2)
O(2)-La(1)-O(5)
O(5)-La(1)-O(1)
O(2)-La(1)-O(3)
O(3)-La(1)-O(7)
90.4(4)
101.9(4)
80.9(3)
74.9(3)
138.0(3)
122.8(3)
132.7(3)
O(10)-La(1)-O(6)
O(10)-La(1)-O(2)
O(9)-La(1)-O(5)
O(10)-La(1)-O(1)
O(10)-La(1)-O(3)
O(10)-La(1)-O(7)
O(2)-La(1)-O(7)
144.5(3)
72.5(3)
142.9(3)
76.9(3)
77.0(3)
141.9(3)
70.7(3)
Table 3. Hydrogen-bond geometry (Å) of complexes
D—H···A
Complex 1
D—H
H···A
D···A
D—H···A Symmetry codes
O5-H5D···O1
O5-H5E···O2
Complex 2
0.850
0.850
1.94
1.82
2.785(4)
2.663(4)
169.9
169.5
x,y+1,z
-x,-y+2,-z
O8-H8A···O5
O4-H4A···O1
0.850
0.850
1.83
1.87
2.640(14)
2.670(13)
169.4
166.3
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Figure 1. Coordination environment of Zn(II) ion in complex 1. Thermal ellipsoids are shown at
30% probability, all H atoms are omitted for clarity.
Figure 2. Infinite 1-D helical chain along b direction in complex 1.
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Figure 3. View of the 2-D coordination layer along (a) the b axis and (b) the a axis.
Figure 4. The C-H...π interactions between the L1 ligands.
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Figure 5. 3-D supermolecular structure formed through the weak edge-to-face π-π staking
interactions in 1. As shown in Figure 6 for complex 2, the deprotonation of
2-thiophenecarboxylic acid did not happen completely in complex 2, HL2 and L2 are all exist in
complex 2. All L ligands exhibit chelating bidentate arrangement. In the asymmetric unit of
complex 2, there are one La(III) center, three L2 and two HL2. Each La(III) adopts a slightly
distorted dodecahedron coordination, are eight coordinated by two oxygen atoms(O3,O7) from
the carboxylate of two HL2 and six oxygen atoms(O1,O2,O5,O6,O9,O10) from six different L2.
The angles for O1-La1-O3, O3-La1-O5, O5-La1-O7, O7-La1-O9 and O9-La1-O1 are 70.48(5)º,
70.32(8)º, 71.14(3)º, 74.54(5)º and 76.53(5)º respectively, the five ligands in the [La(HL2)2(L2)3]
unit nearly exhibit a pentagram configuration (Figure 7). HL2 in complex 2 just exhibit
monodentate coordination and L2 in this complex also only show bridging bidentate arrangement.
The carboxylate of the bridging bidentate L2 linked the adjacent La(III) centers together and
extended in a axis direction to be a 1-D chain (Figure 8). The hydrogen bonds (O8-H8A···O5,
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O4-H4A···O1) in the complex also make the 1-D chain more stable. These chains are linked
together to form a 3-D flower style supermolecular structure (Figure 9) through the weak
C-H···S interactions (distance range from 2.958(6) to 3.282(6) Å ).
Figure 6. Ball and stick representation of the coordination environment in complex 2.
Unnecessary H atoms are omitted for clarity.
Figure 7. A Space-filling representation of pentagram configuration in the [La(HL2)2(L2)3] unit
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Figure 8. A view of 1D infinite chain construct with C–O–La. Unnecessary atoms are omitted
for clarity.
Figure 9. 3-D flower style supermolecular structure formed through the weak C-H···S
interactions in 2.
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Figure 10. Emission spectrum of complex 1 at room temperature.
emission
100
80
60
40
20
0
350
400
450
500
550
600
wavelength (nm)
Figure 11. Emission spectrum of complex 2 at room temperature.
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Figure 12. Fluorescence spectrum of HL2 and complex 2 at room temperature.
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