crystal structure and ft-ir study of cesium 4-methylbenzenesulfonate
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Crystal structure and FT-IR study of cesium4-methylbenzenesulfonate
Bo Sun, Ying Zhao, Jin-Guang Wu*, Qing-Chuan Yang, Guang-Xian Xu
State Key Laboratory of Rare Earth Materials Chemistry and Applications Peking University, Beijing 100871, People's Republic of China
Received 14 October 1997; accepted 13 March 1998
Abstract
The crystal structure of the title compound has been determined by X-ray diffraction. The crystal is monoclinic, space group
P21/C with a� 13.483(3)A, b� 7.285(1)A, c � 10.352(2)A, b� 110.43(3)8, and Z� 4, V� 952.8(3)A3, Dc� 2.120 g cm23,
l(MoKa) � 0.71073A, m � 4.033 mm21, F(000) � 576, ®nal weighted R � 0.0391 for 1863 unique re¯ections. The cesium
atom is coordinated to six oxygen atoms from ®ve sulfonate groups to form a distorted octahedron. There is no water molecule
and no H-bond network in the complex. FT-IR spectra was also used to characterize the complex. A preliminary infrared
assignment was performed. q 1998 Elsevier Science B.V. All rights reserved
Keywords: Cesium complexes; Crystal structure; FT-IR; 4-methylbezenesulfonate; X-ray diffraction
1. Introduction
Sulfonate compounds have important functions in
many ®elds such as medicine, chemical separation
and catalysis. Some sulfonate compounds can be
used as medicine to treat many kinds of diseases,
e.g. phentolamine mesylate. Ionic exchange resins
containing sulfonic acid group have been extensively
used for separation of mixtures such as rare earth
elements. Sulfonic acid salts are also used as surfac-
tants in light industry. It was discovered that
complexes with good layered structure have great
potential applications in catalysis and chemical
separation [1, 2]. Arylsulfonatenates always have
some layered structure, in the presence of a catalyst
containing cesium 4-methylbenezenesulfonate,
succinic acid or maleic acid can be hydrogenated to
g-butyrolactone [3]. Because sulfonates are hydro-
philic, the majority of arylsulfonates synthesized
from aqueous solutions usually contain water mole-
cules and have complicated hydrogen bond networks
[4±7]. In this paper, we have synthesized the title
complex from aqueous solution and found it contains
no water and no hydrogen bonding. Therefore, it is
specially suitable as a standard sample to study the
FT-IR spectra of other sulfonates.
2. Experimental
2.1. Synthesis
An aqueous solution of CsOH was added to the
aqueous solution of 4-methyl benzenesulfonic acid
until a pH < 6.0 was reached. After ®ltration, the
®ltrate evaporated at room temperature. Colorless
crystals were obtained after several days.
Journal of Molecular Structure 470 (1998) 63±66
0022-2860/98/$ - see front matter q 1998 Elsevier Science B.V. All rights reserved.
PII S0022-2860(98)00385-8
* Corresponding author. Tel. 0086 1 627 51723; Fax: 0086 1 627
51708; e-mail: Wjg@chemms.chem.pku.edu.cn
2.2. Instruments
All diffraction data were collected on a Ragaku
AFC6S diffractometer, with graphite-monochromated
MoKa radiation (l� 0.71073A) at room temperature.
Corrections to the absorption data were made using
the semi-empirical method. The structure was solved
with the direct method using the SHELXTL
PLUS(VMS) program, and re®ned by the full-matrix
least-squares method to determine the coordinates of
non-hydrogen atoms. The coordinates of the hydrogen
atoms were placed at their calculated positions. FT-IR
spectra were recorded of Nujol mulls using a Nicolet
Magna 750-IR spectrometer.
3. Results and discussion
The structure of the title complex is given in Fig. 1.
The coordination structure of cesium atom is shown in
Fig. 2(a). Selected bond lengths and bond angles are
listed in Table 1. In the complex, the cesium atom is
surrounded by six oxygen atoms from ®ve sulfonate
groups. Four sulfonate groups coordinate to the
cesium atom in unidentate fashion, while the other
in bidentate fashion. From Fig. 2(a) and Table 1, it
may be seen that the coordination geometry around
the cesium atom is a distorted octahedron. O(2),
O(2b), O(3a), O(3b) atoms are essentially co-planar
[O(2b), O(3b) are from the same sulfonate group],
with a mean deviation of 0.068A from planarity.
The cesium atom does not lie in the center of the
plane, but is at a distance of 0.8279A from the center.
The three oxygen atoms of each sulfonate group
exhibit different coordination structure: one is
unidentately coordinated to one cesium atom, another
is coordinated to three cesium. atoms, and the third
one to two cesium atoms [see Fig. 2(b)]. From the
B. Sun et al. / Journal of Molecular Structure 470 (1998) 63±6664
Fig. 1. The structure of Cesium 4-methylbenzenesulfonate.
Fig. 2. The coordination of Cs and sulfonate groups in Cesium 4-
methylbenzenesulfonate: (a) each Cs is surrounded by six oxygen
atoms from ®ve sulfonate groups forming a distorted octahedron;
(b) each sulfonate group is coordinated to 5 Cs atoms, so that the
®nal molar ratio of Cs to sulfonate is 1:1.
S±O bond lengths and bond angles, we can see that
the sulfonate group is nearly a regular tetrahedron.
The infrared spectra of cesium 4-methyl-
benezenesulfonate and 4- methylbenzenesulfonic
acid monohydrate were recorded of Nujol mulls to
prevent the sample from absorbing moisture and to
avoid reaction which may take place in KBr pellets
resulting in the change of the structure of sulfonate
groups. The spectra are shown in Fig. 3 and Fig. 4.
The assignments of the bands related to the sulfonate
group are listed in Table 2. In the IR spectra of the
complex, the absence of broad bands in the 2700±
1700 cm21 region, which is usually attributed to the
H-bonding of the ligand, indicates that the H-bonding
is eliminated in the complex, consistent with the
results from the crystal structure determination. The
coordination of Cs to the sulfonate group results in the
elimination of the H-bonding bands in the spectra of
the sulfonate group. Signi®cant band shifts and
narrowing of bands are observed. These two
compounds show nas(SO3) and ns(SO3) in the
1330±1100 cm21 and 1060±1000 cm21 regions,
respectively. From the splitting of peaks in the
1250±1150 cm21 region, the coordination structure
of the sulfonate group in the complex may be
inferred. The band at 1120.3 cm 2 1 was assigned
to naS±O(1)±CsD, 7 [see Fig. 2(b)]. The two bands
B. Sun et al. / Journal of Molecular Structure 470 (1998) 63±66 65
Table 1
Selected bond lengths (A) and angles(8)
Cs±O(1) 3.707(4) Cs±O(2) 3.050(4)
Cs±O(1a) 3.017(4) Cs±O(2a) 3.194(4)
Cs±O(2b) 3.119(5) Cs±O(3a) 3.056(5)
Cs±O(3b) 3.344(5) S±O(1) 1.441(5)
S±O(2) 1.452(4) S±O(3) 1.442(5)
O(1)±CsD 3.017(4) O(2)±CsC 3.194(4)
O(2)±CsE 3.119(5) O(3)±CsB 3.056(5)
O(3)±CsE 3.344(5)
O(1)±Cs±O(2) 40.0(1) O(1)±CS±O(1a) 130.2(1)
O(2)±Cs±O(1a) 98.3(1) O(1)±Cs±O(2a) 83.0(1)
O(2)±Cs±O(2a) 120.8(1) O(1a)±Cs±O(2a) 139.6(1)
O(1)±Cs±O(2b) 92.0(1) O(2)±Cs±O(2b) 114.5(1)
O(1a)±Cs±O(2b) 83.3(1) O(2a)±Cs±O(2b) 71.8(1)
O(2)±Cs±O(3a) 74.1(1) O(1a)±Cs±O(3a) 131.0(1)
O(2a)±Cs±O(3a) 74.6(1) O(2b)±Cs±O(3a) 144.6(1)
O(1)±Cs±O(3b) 65.0(1) O(2)±Cs±O(3b) 72.5(1)
O(1a)±Cs±O(3b) 79.0(1) O(2a)±Cs±O(3b) 101.7(1)
O(2b)±Cs±O(3b) 43.3(1) O(3a)±Cs±O(3b) 137.9(1)
O(1)±S±O(2) 111.6(3) O(1)±S±O(3) 115.5(3)
O(2)±S±O(3) 111.7(3)
Fig. 3. The IR spectrum of cesium 4-methylbenzenesulfonate (a) and 4-methylbenzenesulfonic acid monohydrate (b) in the 4000±400 cm21
region.
at 1190.3 and 1182.4 cm-1 were assigned to the anti-
symmetric stretching vibrations nasS±O(3)±CsB and
nasS±O(3)±CsE, the three bands at 1212.6, 1223.5 and
1245.3 cm21 were attributed to the antisymmetric
stretching vibration nasS±O(2)±CsC, nasS±O(2)±
CsE and nasS±O(2)±Cs. das(SO3) and ds(SO3) were
observed in the 580±550 cm21 and 490 cm21 regions,
respectively. The bands shift in this region is not as large
as those in the 1250±1150 cm21 region. In the complex,
das(SO3) and ds(SO3) occur at 559.7 and 495.2 cm21,
while in the ligand they are at 566.4 and 493.1 cm21,
respectively. The band in the 600±550 cm21 region is a
combination of several absorptions.
Acknowledgements
This study was supported by National Natural
Sciences Foundation of China (no. 29671002).
References
[1] T.J. Pinnavania, Science 220 (1983) 365.
[2] G. Cao, T.E. Mallouk, Inorganic Chemistry 30 (1991) 1434.
[3] Jpn. Kokai Tokky Koho JP 05, 222, 022[93, 222, 0221]/
(Cl.C07D307/33).
[4] Y. Ohki, Y. Suzuki, T. Takeuchi, A. Ouchi, Bulletin of the
Chemical Society of Japan 61 (1988) 393.
[5] Y. Ohki, Y. Suzuki, M. Nakamura, Bulletin of the Chemical
Society of Japan 58 (1985) 2968.
[6] P. Starynowicz, Acta Cryst. C48 (1992) 1414.
[7] J.W. Bats, P. Coppens, Acta Cryst. B31 (1975) 1467.
B. Sun et al. / Journal of Molecular Structure 470 (1998) 63±6666
Fig. 4. The IR spectrum of cesium 4-methylbenzenesulfonate (a) and 4- methylbenzenesulfonic acid monohydrate (b) in the 1300±400 cm21
region.
Table 2
The assignment of bands of ligand and complex in the FT-IR spectra
Ligand Complex Assignments
2668.9(vb)
2234.5(vb) nO-H
1924.0(w)
1846.1 (b)
1255.2(sh) 1245.3(sh)
1192.3 (sh) 1223.5(vs)
1179.4(sb) 1212.6(vs,sh)
1126.1 (vs) 1190.3(vs) nas SO3
1117.4(vs,sh) 1182.4(vs,sh)
1120.3(m)
1036.2(s) 1035.8(s) nsSO3
1007.4(s) 1012.6(s)
579.6(m, sh) 559.7(vs) das SO3
566.4(m)
493.1 (w) 495.2(w) ds SO3
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