Hydrothermal synthesis and crystal structure of a sulfur-bridged binuclear copper(II) coordination...
-
Upload
xiaojun-gu -
Category
Documents
-
view
212 -
download
0
Transcript of Hydrothermal synthesis and crystal structure of a sulfur-bridged binuclear copper(II) coordination...
Hydrothermal synthesis and crystal structure of a sulfur-bridged
binuclear copper(II) coordination polymer generated
by a spontaneous reduction
Xiaojun Gua, Zhenyu Shia, Jun Penga,*, Yanhui Chena, Enbo Wanga, Ninghai Hub
aDepartment of Chemistry, Institute of Polyoxometalate Chemistry, Northeast Normal University, Changchun 130024, ChinabChangchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022, China
Received 28 February 2004; revised 26 March 2004; accepted 26 March 2004
Abstract
A simultaneous reduction of SO422 to S22 by 2,5-pyridinedicarboxylate under hydrothermal conditions produced a new binuclear
copper(II) coordination polymer [CuS(4,40-bipy)]n (4,40-bipy ¼ 4,40-bipyridine) (1). Single crystal X-ray analysis revealed that compound 1
consisted of sulfur-bridged binuclear copper(II) units with Cu–Cu bonding which were combined with 4,40-bipy to generate a three-
dimensional network constructed from mutual interpenetration of two-dimensional (6,3) nets. Crystal data for 1: C10H8CuN2S, tetragonal
I41=acd; a ¼ 14:0686ð5Þ A, b ¼ 14:0686ð5Þ A, c ¼ 38:759ð2Þ A, Z ¼ 32: Other characterizations by elemental analysis, IR, EPR and TGA
analysis were also described in this paper.
q 2004 Elsevier B.V. All rights reserved.
Keywords: Coordination polymer; Hydrothermal synthesis; Simultaneous reduction; Interpenetration
1. Introduction
The design and synthesis of new coordination polymers
have attracted great attention in recent years due to their
intriguing structural features and potential applications in
catalysis, ion-exchange, non-linear optics, chemical
adsorption and magnetism [1–7]. Particular interest has
been directed towards binuclear copper coordination
polymers because they play an important role in biological
metalloenzymes, industrial catalysis [8,9] and especially
magneto-structural correlations [10]. However, the great
majority of these studies are mainly concentrated on
carboxylate or halogen-bridged copper(II) complexes
[11–13], and a minority on sulfur-bridged species because
the latter are relatively rare. On the other hand, sulfur-
bridged copper(II) coordination polymers are attracting a
great deal of attention owing to their relevance to
biological, rich structural chemistry, non-linear optic and
special reactive properties [14–18]. Therefore, it would be
of interest to synthesize and study the magnetic properties
copper(II)-sulfur coordination polymers. To date, sulfur-
bridged copper coordination polymers are synthesized
usually by conventional solution methodology, while
hydrothermal technique is less exploited. Many fascinating
structures and unexpected reactions can be achieved under
hydrothermal conditions [19–24]. Although, in most cases,
the reaction mechanisms under hydrothermal conditions
are not clear and the control and prediction of crystal
structures are difficult, the architecture of the final product
directly depends on the interplay of the characteristics of
metal ion, ligand and reaction conditions [25]. It is well
accepted that pyridine derivatives can act as good
reductants under hydrothermal conditions [26,27], whereas
a simultaneous reduction of SO422 to S22 by pyridine
derivatives during a self-assembly process has never been
observed. In this paper, we report synthesis and crystal
structure of a novel coordination polymer: [CuS(4,40-
bipy)]n (1). Compound 1 exhibits a three-dimensional
network constructed from mutual interpenetration of two-
dimensional (6,3) nets, in which sulfur-bridged binuclear
copper(II) units are combined with 4,40-bipy to form sheets
of [CuS(4,40-bipy)]-containing cavities with dimensions of
ca. 28 £ 20 A.
0022-2860/$ - see front matter q 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.molstruc.2004.03.036
Journal of Molecular Structure 694 (2004) 219–222
www.elsevier.com/locate/molstruc
* Corresponding author. Tel.: þ86-431-5269765; fax: þ86-431-
5684009.
E-mail address: [email protected] (J. Peng).
2. Experimental
2.1. General procedures
All reagents were purchased commercially and used
without further purification. Elemental analyses (C, H and
N) were performed on a Perkin – Elmer 2400 CHN
Elemental Analyzer. IR spectrum was obtained on Alpha
Centaurt FT/IR spectrometer with KBr pellet in the
400–4000 cm21 region. The EPR spectrum was recorded
on a Japanese JES-FE3AX spectrometer at room tempera-
ture. The TG analysis was performed on a Perkin–Elmer
TGA7 instrument in flowing N2 with a heating rate of
10 8C min21.
2.2. Synthesis
The title compound was hydrothermally synthesized
from the reaction mixture of CuSO4·5H2O (0.5 mmol),
4,40-bipy (0.5 mmol), 2,5-pyridinedicarboxylic acid
(0.5 mmol), NaOH (1 mmol) and H2O (8 ml) at 190 8C for
3 days, followed by slowly cooling (5 8C/h) to room
temperature. Dark red block crystals of 1 were recovered in
30% yield based on 4,40-bipy. C10H8CuN2S (251.8): Calcd
C, 47.66; H, 3.18; N, 11.12 (%). Found C, 47.58; H, 3.24;
N, 11.04 (%).
2.3. X-ray crystallography
The crystal structure of compound 1 was determined by
single-crystal X-Ray diffraction. Crystal data: C10H8CuN2S,
tetragonal I41=acd; a ¼ 14:0686ð5Þ A, b ¼ 14:0686ð5Þ A,
c ¼ 38:759ð2Þ A, Z ¼ 32: The crystal determination for
compound 1 was performed on a Bruker Smart-CCD
diffractometer with Mo Ka Monochromated radiation
(l ¼ 0:71073 A�) at 293 K in the range of 2:078 , u ,
27:458: The structure was solved by direct methods using the
program SHELXL-97 and refined by full-matrix least-
squares methods on F2 using the SHELXL crystallographic
software package. All of the non-hydrogen atoms were
refined anisotropically. Hydrogen atoms were located from
difference Fourier maps. The crystal data and structure
refinement, atomic coordinates, and selected bond lengths
and angles of compound 1 were listed in Tables 1–3.
3. Results and discussion
3.1. Crystal structure
The X-ray single-crystal analysis reveals that compound
1 is a three-dimensional network constructed from mutual
interpenetration of two-dimensional (6,3) nets. The funda-
mental unit is shown in Fig. 1. There is only one
crystallographically unique Cu(II) center in the crystal
structure. The Cu(II) center is coordinated by two nitrogen
atoms from two different 4,40-bipy groups and two sulfurTable 1
Crystallographic data for compound 1
Empirical formula C10H8CuN2S
Formula weight 251.78
T (K) 293(2)
Crystal system Tetragonal
Space group I41=acd
a (A) 14.0686(5)
b (A) 14.0686(5)
c (A) 38.759(2)
V (A3) 7671.4(6)
Z 32
l (A) 0.71073
Crystal size (mm) 0.256 £ 0.157 £ 0.072
Absorption coefficient (mm21) 2.449
u range 2.10–27.468
Limiting indices 0 # h # 18; 0 # k # 12; 1 # l # 50
F(000) 4064
Reflections collected 2204
Independent reflections 2204 ðRint ¼ 0:0000Þ
GOF 1.026
R1; wR2½I . 2sðIÞ� 0.0299, 0.0562
R1; wR2 (all data) 0.0755, 0.0828
Table 2
Selected bond lengths (A) and angles (deg) for compound 1
Cu–N(1) 1.982(3) Cu–N(2) 1.985(3)
Cu–S 2.4212(14) Cu–S#1 2.4524(14)
Cu–Cu#1 2.7585(11) N(1)–C(4) 1.337(6)
N(1)–C(3) 1.327(6) N(2)–C(8) 1.332(5)
N(2)–C(9) 1.358(5)
N(1)–Cu–N(2) 127.43(14) N(1)–Cu–S 108.30(12)
N(2)–Cu–S 103.46(12) N(1)–Cu–S#1 111.17(12)
N(2)–Cu–S#1 99.69(12) S–Cu–S#1 104.48(4)
N(1)–Cu–Cu#1 101.04(10) N(2)–Cu–u#1 131.49(10)
S–Cu–Cu#1 56.06(4) Cu–S–Cu#1 68.94(4)
S#1–Cu–Cu#1 55.00(4)
Table 3
Atomic coordinates ( £ 104) and equivalent isotropic displacement
parameters (A2 £ 103) for compound 1
x y z U(eq)
Cu 674(1) 8212(1) 167(1) 34(1)
S 1007(1) 6572(1) 314(1) 31(1)
N(1) 890(3) 8379(3) 2334(1) 24(1)
N(2) 1268(3) 8937(3) 550(1) 27(1)
C(1) 935(3) 8427(3) 21061(1) 20(1)
C(2) 469(3) 9118(3) 2870(1) 27(1)
C(3) 472(3) 9069(3) 2512(1) 27(1)
C(4) 1357(4) 7723(3) 2518(1) 30(1)
C(5) 1392(4) 7727(3) 2875(1) 31(1)
C(6) 2113(3) 9911(3) 1106(1) 19(1)
C(7) 2246(3) 10,190(3) 769(1) 24(1)
C(8) 1817(3) 9699(3) 505(1) 28(1)
C(9) 1128(3) 8668(4) 883(1) 29(1)
C(10) 1520(3) 9124(3) 1158(1) 25(1)
U(eq) is defined as one third of the trace of the orthogonalized Uij
tensor.
X. Gu et al. / Journal of Molecular Structure 694 (2004) 219–222220
bridged-ligands to form binuclear copper(II) units with
Cu–Cu distance of 2.759 A. The Cu–N bond lengths vary
from 1.982(3) to 1.985(3) A, and the Cu–S bond lengths
range from 2.4212(14) to 2.4524(14) A. The N(S)–Cu–
S(N) bond angles range from 99.69(12) to 127.43(14)8.
Thus, all Cu centers display distorted tetrahedral coordi-
nation geometry. Each 4,40-bipy adopts a bismonodentate
bridging mode to link two sulfur-bridged binuclear
copper(II) units (Cu2S2). It should be noted that the two
pyridine rings in the two independent 4,40-bipy are twisted
by 22.7(6) and 16.5(4)8, respectively. Based on this
connection mode, all Cu2S2 units are combined by 4,40-
bipy to form hexagonal rings (size ca. 28 £ 20 A), which
form a two-dimensional (6,3) net (see Fig. 2).
In the packing arrangement of compound 1, there are
four crystallographically identical yet topologically inde-
pendent (6,3) nets that can be grouped into two sets, one
with two vertical and parallel nets and the other with two
horizontal and parallel nets. These networks interpenetrate
with mutual interlocking of the hexagons to result in
a three-dimensional framework (see Fig. 3). However,
there does not exist bond interaction among the interlock-
ing two-dimensional (6,3) nets. Interpenetration in nature is
a space-filling effect to produce dense framework, but,
surprisingly, the interpenetrating two-dimensional net-
works do not fill up all the pore space formed by one
independent two-dimensional network. A perspective view
of compound 1 clearly shows there are one-dimensional
channels (size ca. 2 £ 4 A) along the c axis (see Fig. 4).
It is interesting to note that SO422 ions were reduced to
S22 by 2,5-pyridinedicarboxylate under hydrothermal
conditions, at the same time, 2,5-pyridinedicarboxylate
transforms into pyridine. To the best of our knowledge, this
reduction reaction in constructing coordination polymers is
unique. To verify this deduction, we repeated the reaction
without adding 2,5-pyridinedicarboxylic acid and did not
Fig. 1. ORTEP drawing of 1 showing the local coordination environment of
Cu(II) with thermal ellipsoids at 50% probability. Hydrogen atoms are
omitted for clarity.
Fig. 2. Perspective view of the 2D (6,3) net in 1.
Fig. 3. The independent interlocking planar nets in 1. The S atoms are
omitted for clarity.
Fig. 4. Plots of the 3D structure of 1 along the c axis.
X. Gu et al. / Journal of Molecular Structure 694 (2004) 219–222 221
obtain compound 1.
SO224 þ C5H3NðCOOÞ222 !
Cu2þþ4;40-bipy
190 8C
S22 þ C5H5N þ CO2
3.2. IR spectrum
In the infrared spectrum of compound 1, absorption
bands from 1608.5 to 1411.7 cm21 are attributed to the
pyridine ring breathing bands of 4,40-bipy.
3.3. EPR spectrum
The EPR spectrum of compound 1 exhibits the Cu2þ
signal at 293 K with g ¼ 2:0332; which is consistent with
the result of valence sum calculations.
3.4. Thermal analysis
Thermogravimetric (TG) analysis was carried out under
N2 with a heating rate of 10 8C min21. The TG curve of
compound 1 (shown in Fig. 5) indicates three steps of
weight loss. The first two stages of weight loss are 61.89%
(calcd: 62.15%) in the temperature range 190–320 8C,
corresponding to the release of the 4,40-bipy ligands. The
third weight loss occurs from 320 to 520 8C, due to the
release of part of sulfur. After decomposition of compound
1 at high temperature, the weight of the residue (,31.29%)
is responded to Cu2S (calcd: 31.90%).
4. Conclusion
In summary, we have successfully synthesized a novel
coordination polymer consisting of two-dimensional (6,3)
nets under hydrothermal conditions. The result reveals that
SO422 ions are reduced to S22 ions by 2,5-pyridinedicarboxy-
late under hydrothermal conditions. This provides a possible
method to in situ generate sulfur-contained coordination
polymers.
Acknowledgements
This research was financially supported by the National
Science Foundation of China (20271011).
References
[1] M. Eddaoudi, D.B. Moler, H.L. Li, B.L. Chen, T.M. Reineke,
M. O’Keeffe, O.M. Yaghi, Acc. Chem. Res. 34 (2001) 319.
[2] M. Fugita, Y.J. Kwon, S. Washizu, K. Ogura, J. Am. Chem. Soc. 116
(1994) 1151.
[3] W.B. Lin, Z.Y. Wang, L. Ma, J. Am. Chem. Soc. 121 (1999) 11249.
[4] J.S. Seo, D. Whang, H. Lee, S.I. Jun, J. Oh, Y.J. Jeon, K. Kim, Nature
404 (2002) 982.
[5] H. Kou, J. Tang, K. Liao, S. Gao, P. Cheng, Z. Jiang, G. Yan, B. Wang,
J.P. Chansou, Inorg. Chem. 40 (2001) 4839.
[6] O.M. Yaghi, G.M. Li, Angew. Chem. Int. Ed. 34 (1995) 207.
[7] Y.G. Li, N. Hao, Y. Lu, E.B. Wang, Z.H. Kang, C.W. Hu, Inorg.
Chem. 42 (2003) 3119.
[8] G. Henkel, A. Muller, S. Weissgraber, G. Buse, T. Soulimane,
G.C.M. Steffens, H.F. Nolting, Angew. Chem. Int. Ed. 34 (1995) 1488.
[9] T. Ohta, T. Tachiyama, K. Yoshizawa, T. Yamabe, T. Uchida,
T. Kitagawa, Inorg. Chem. 39 (2000) 4358.
[10] K. Geetha, S.K. Tiwary, A.R. Chakravarty, G. Ananthakrishna,
J. Chem. Soc., Dalton Trans. (1999) 4463.
[11] R. Cao, Q. Shi, D.F. Sun, M.C. Hong, W.H. Bi, Y.J. Zhao, Inorg.
Chem. 41 (2002) 6161.
[12] S. Ferlay, A. Jouaiti, M. Loi, M.W. Hosseini, A.D. Cian, P. Turek,
New J. Chem. (2003) 1801.
[13] J.Y. Lu, Coord. Chem. Rev. 246 (2003) 327.
[14] M.E. Helton, P. Chen, P.P. Paul, Z. Tyekla, R.D. Sommer,
L.N. Zakharov, A.L. Rheingold, E.I. Solomon, K.D. Karlin, J. Am.
Chem. Soc. 125 (2003) 1161.
[15] T. Rasmussen, B.C. Berks, J.S. Loehr, D.M. Dooley, W.G. Zumft,
A.J. Thomson, Biochemistry 39 (2000) 12753.
[16] Y.Y. Niu, Y.L. Song, H.G. Zheng, D.L. Long, H.K. Fun, X.Q. Xin,
New J. Chem. (2001) 945.
[17] Y. Li, J. Lu, J.Q. Xu, X.B. Cui, Y.H. Sun, Q.X. Yang, L.Y. Pan, J. Mol.
Struct. 690 (2004) 131.
[18] P. Chen, K. Fujisawa, M.E. Helton, K.D. Karlin, E.I. Solomon, J. Am.
Chem. Soc. 125 (2003) 6393.
[19] X.M. Zhang, M.L. Tong, X.M. Chen, Angew. Chem. Int. Ed. 41
(2002) 1029.
[20] K.V. Domasevitch, G.D. Enright, B. Moulton, M.J. Zaworotko,
J. Solid State Chem. 152 (2000) 280.
[21] Y. Wang, J.H. Yu, M. Guo, R.R. Xu, Angew. Chem. Int. Ed. 42 (2003)
4089.
[22] Y.X. Li, Y.H. Li, X.R. Zeng, R.G. Xiong, X.Z. You, H.K. Fun, Inorg.
Chem. Commun. 6 (2003) 1144.
[23] J.Y. Lu, B.R. Cabrera, R.J. Wang, J. Li, Inorg. Chem. 38 (1999) 4608.
[24] J. Tao, Y. Zhang, M.L. Tong, X.M. Chen, T. Yuen, C.L. Lin, X.Y.
Huang, J. Li, Chem. Commun. (2002) 1342.
[25] S.O.H. Gutschke, M. Molinier, A.K. Powell, R.E.P. Winpenny,
P.T. Wood, Chem. Commun. (1996) 823.
[26] W. Chen, H.M. Yuan, J.Y. Wang, Z.Y. Liu, J.J. Xu, M. Yang,
J.S. Chen, J. Am. Chem. Soc. 125 (2003) 9266.
[27] J.Y. Lu, A.M. Babb, Inorg. Chem. 41 (2002) 1339.
Fig. 5. The TG curve of compound 1.
X. Gu et al. / Journal of Molecular Structure 694 (2004) 219–222222