Four novel frameworks built by imidazole-based dicarboxylate ligands: Hydro(Solvo)thermal synthesis, crystal structures, and properties

Article abstract of DOI:10.1021/ic902483m

Four novel complexes, {[Ni₄(HEIDC)₄(H ₂O)₈]?2H₂O} (1), {[Mn(HEIDC)(4,4′- bipy)_0.5(H₂O)] H₂O}_n (2), [Mn ₆(EIDC)₄(py)(H₂O)₄]_n (3), and {[Cd₂(EIDC)(H₂EIDC)(4,4′-bipy)_1.5] H₂O}_n (4) (H₃EIDC = 2-ethyl-1H-imidazole-4,5- dicarboxylic acid, 4,4′-bipy = 4,4′-bipyridine, and py = pyridine) have been hydro(solvo)thermally synthesized by fine control over synthetic conditions, such as solvent and pH value, and structurally characterized. It is shown through single-crystal X-ray diffractions that the ligands H ₃EIDC can be either singly, doubly, or triply deprotonated and can coordinate to Ni(II), Mn(II) or Cd(II) ions in μ₂ or μ₃ modes. Compound 1 is a zero-dimensional (0D) symmetrical tetranuclear molecular square. Compound 2 exhibits a two-dimensional (2D) sheet, in which alternate left- and right-handed helical chains are bridged by 4,4′-bipy linkages. Compound 3 assumes a 2D honeycomb-like sheet built up from μ₃-EIDC^3- and Mn(II) atoms. Compound 4 possesses a novel three-dimensional (3D) structure constructed from 2D layer motifs joined by μ₂-HEIDC^2- and 4,4′-bipy bridges. The thermal properties of complexes 1-4 have been determined as well. Also, it is discovered that there exists antiferromagnetic coupling between the Ni(II) or Mn(II) ions in 1 or 2 (3); the best fittings to the experimental magnetic susceptibilities gave J = -10.83 cm^-1 and g = 2.19 for 1, and J = -0.025 cm ^-1, zJ′ = -0.02 cm^-1 and g = 2.0 for 2.

Full text of DOI:10.1021/ic902483m

3
776 Inorg. Chem. 2010, 49, 3776–3788
DOI: 10.1021/ic902483m
Four Novel Frameworks Built by Imidazole-Based Dicarboxylate Ligands:
Hydro(Solvo)thermal Synthesis, Crystal Structures, and Properties
Fuwei Zhang, Zifeng Li, Tiezhu Ge, Hongchang Yao, Gang Li,* Huijie Lu, and Yanyan Zhu
Department of Chemistry, Zhengzhou University, Henan 450052, People’s Republic of China
Received December 18, 2009
0
Four novel complexes, {[Ni (HEIDC) (H O) ] 2H O} (1), {[Mn(HEIDC)(4,4 -bipy) (H O)] H O} (2), [Mn (EIDC) -
4
4
4
2
8
3
2
0
0.5
2
3
2
n
6
(py)(H O) ] (3), and {[Cd (EIDC)(H EIDC)(4,4 -bipy) ] H O} (4) (H EIDC = 2-ethyl-1H-imidazole-4,5-dicarboxylic
0
acid, 4,4 -bipy = 4,4 -bipyridine, and py = pyridine) have been hydro(solvo)thermally synthesized by fine control over
2
4 n
2
2
1.5
3
2
n
3
0
synthetic conditions, such as solvent and pH value, and structurally characterized. It is shown through single-crystal X-ray
diffractions that the ligands H EIDC can be either singly, doubly, or triply deprotonated and can coordinate to Ni(II), Mn(II) or
3
Cd(II) ions in μ or μ modes. Compound 1 is a zero-dimensional (0D) symmetrical tetranuclear molecular square.
2
3
Compound 2 exhibits a two-dimensional (2D) sheet, in which alternate left- and right-handed helical chains are bridged by
0
,4 -bipy linkages. Compound 3assumes a 2D honeycomb-like sheet built up from μ -EIDC and Mn(II) atoms. Compound
3
2
3-
4
4
-
0
possesses a novel three-dimensional (3D) structure constructed from 2D layer motifs joined by μ -HEIDC and 4,4 -bipy
2
bridges. The thermal properties of complexes 1-4 have been determined as well. Also, it is discovered that there exists
antiferromagnetic coupling between the Ni(II) or Mn(II) ions in 1 or 2 (3); the best fittings to the experimental magnetic
-
1
-1
0
-1
susceptibilities gave J = -10.83 cm and g = 2.19 for 1, and J = -0.025 cm , zJ = -0.02 cm and g = 2.0 for 2.
Introduction
properties. Thus, considerable efforts have been devoted to
choose or design various multifunctional bridging ligands.
3
In recent years, increasing attention has been paid to the
design and synthesis of metal-organic frameworks (MOFs),
not only owing to their intriguing variety of architectures but
also because of their potential applications as microporous,
Recently, heterocyclic dicarboxylate ligands have at-
tracted much attention in preparation of interesting poly-
meric frameworks due to their outstanding features of
various coordination fashions under hydrothermal condi-
1
magnetic, nonlinear optical, and fluorescent materials. Gen-
4
tion. In this context, imidazole-4,5-dicarboxylic acid
erally, the preparation of such materials can be influenced by
many factors, such as the nature of organic ligands, the
coordination preference of central metal ion, the crystal-
lization conditions, the metal/ligand ratio, and the reaction
(
H IDC) becomes an excellent candidate for assembling
3
novel MOFs by incorporating appropriate metal ions in
different ways. The reported MOFs based on H IDC
3
2
possess beautiful and interesting topological structures, for
solvent system, etc. It is well-known that the multifunctional
organic ligands play an important role in directing the
extended structure of the resulting complexes, which can
effectively construct MOFs with unique structures and
(
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*
Corresponding author. Fax: þ86-371-67766109. E-mail: gangli@
zzu.edu.cn.
(
1) (a) Morsali, A.; Masoomi, M. Y. Coord. Chem. Rev. 2009, 253, 1882.
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2
004, 43, 1466. (c) Zhang, J.; Li, Z.-J.; Kang, Y.; Cheng, J.-K.; Yao, Y.-G. Inorg.
Chem. 2004, 43, 8085. (d) Tong, M.-L.; Chen, X.-M.; Ye, B.-H.; Ji, L.-N. Angew.
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pubs.acs.org/IC
Published on Web 03/15/2010
r 2010 American Chemical Society

Article
Inorganic Chemistry, Vol. 49, No. 8, 2010 3777
instance one-dimensional (1D) chains, two-dimensional (2D)
sheets, three-dimensional (3D) porous structures, and inter-
penetrating networks. It has been found that the ligand
will provide more useful information of the ethyl substituent
effect in such a ligand.
5
In contrast to the well-studied ligand H IDC, MOFs
3
H IDC not only can be partially or fully deprotonated to
comprised of H EIDC are still rare. Indeed, to the best of
3
3
-
2-
3-
H IDC , HIDC , and IDC but also exhibits very flexible
our knowledge, only one single example of 3D Cd(II) coordi6-
nation polymer was reported by Shuang and co-workers.
Herein, we report the hydro(solvo)thermal syntheses, structu-
ral determinations of four novel complexes, tetranuclear square
[Ni (HEIDC) (H O) ] 2H O (1), 2D coordination polymers
2
5
coordination modes. These interesting findings have promp-
ted us to seek more similar ligands to synthesize more desired
complexes. Thus, we chose one analogue ligand, 2-ethyl-1H-
imidazole-4,5-dicarboxylic acid (H EIDC) with an ethyl
3
4
4
2
8
3
2
0
{[Mn(HEIDC)(4,4 -bipy) (H O)] H O} (2), [Mn (EIDC) -
0.5 2 2 n 6 4
substituent in the two-position of the imidazole group,
because it may introduce additional structural constrain in
controlling the assembly of metal-organic networks. By
doing so, we hope to reveal some structural factors of the
3
(py) (H O) ] (3), and 3D coordination polymer {[Cd (EI-
4
2
4 n
2
0
0
0
DC)(H EIDC)(4,4 -bipy) ] H O} (4) (4,4 -bipy=4,4 -bipy-
ridine, py=pyridine). Single crystal X-ray diffractions reveal
that one to three hydrogen atoms can be removed from the
ligand H EIDC forming H EIDC , HEIDC , or EIDC
anions, and the deprotonated H EIDC (n=1-3) could
coordinate to metal ions in μ or μ modes (Scheme 1). Their
2
1.5
3
2
n
ligand H EIDC for dominating the self-assembly, and this
3
-
2-
3-
3
2
n-
(
3) (a) Ghosh, S. K.; Bharadwaj, P. K. Inorg. Chem. 2004, 43, 2293.
3-n
(b) Guo, H. D.; Guo, X. M.; Wang, X.; Guo, Z. Y.; Su, S. Q.; Zhang, H. J.
2
3
CrystEngComm 2009, 11, 1509. (c) Chen, Z.-L.; Jiang, C.-F.; Yan, W.-H.; Liang,
F.-P.; Batten, S. R. Inorg. Chem. 2009, 48, 4674. (d) Woodward, J. D.; Backov,
R. V.; Abboud, K. A.; Talham, D. R. Polyhedron 2006, 25, 2605. (e) Mu, B.; Li,
F.; Walton, K. S. Chem. Commun. 2009, 2493. (f) Biradha, K.; Fujita, M.
J. Chem. Soc., Dalton Trans. 2000, 3805. (g) Wu, B.; Ren, Z.-G.; Li, H.-X.; Dai,
M.; Li, D.-X; Zhang, Y.; Lang, J.-P. Inorg. Chem. Commun. 2009, 12, 1168.
thermal and magnetic properties have been investigated also.
Experimental Section
General Details. All chemicals were of reagent grade quality
obtained from commercial sources and used without further
(h) Anokhina, E. V.; Jacobson, A. J. J. Am. Chem. Soc. 2004, 126, 3044. (i) Liu,
purification. The organic ligand H
ing to literature procedure.
3
EIDC was prepared accord-
G. F.; Ren, Z. J.; Chen, Y.; Liu, D.; Li, H. X.; Zhang, Y.; Lang, J. P. Inorg. Chem.
Commun. 2008, 11, 221. (j) Hou, H. W.; Fan, Y. T.; Zhang, L. P.; Du, C. X.; Zhu,
Y. Inorg. Chem. Commun. 2001, 4, 168. (k) Hou, H. W.; Song, Y. L.; Fan, Y. T.;
Zhang, L. P.; Du, C. X.; Zhu, Y. Inorg. Chim. Acta 2001, 316, 140. (l) Wu, S. T.;
Long, L. S.; Huang, R. B.; Zheng, L. S. Cryst. Growth Des. 2007, 7, 1746.
7
C, H, and N microanalyses were carried out on a FLASH EA
1112 analyzer. IR data were recorded on a BRUKER TENSOR
27 spectrophotometer with KBr pellets in the 400-4000 cm-
1
(
m) Tao, J.; Zhang, Y.; Tong, M.-L.; Chen, X.-M.; Yuen, T.; Lin, C.-L.; Huang,
X.-Y.; Li, J. Chem. Commun. 2002, 1342.
4) (a) Tian, G.; Zhu, G. S.; Yang, X. Y.; Fang, Q. R.; Xue, M.; Sun, J. Y.;
region. TG-DSC measurements were performed by heating the
-1
sample from 20 to 800 ꢀC at a rate of 10 ꢀC min in air on a
3
(
Netzsch STA 409PC differential thermal analyzer. Variable-
temperature magnetic susceptibility data were obtained on a
SQUID susceptometer (Quantum Design, MPMS-5) in the
temperature range of 2.0-300 K with an applied field of 1000
G. All magnetic data have been corrected for diamagnetism by
Wei, Y.; Qiu, S. L. Chem. Commun. 2005, 1396. (b) Zhao, B.; Chen, X.-Y.;
Cheng, P.; Liao, D.-Z.; Yan, S.-P; Jiang, Z.-H. J. Am. Chem. Soc. 2004, 126,
1
5394. (c) Lang, X.-Q.; Chen, C.; Zhou, X.-H.; Xiao, H.-P.; Li, Y.-Z.; Zuo, J.-L.;
You, X.-Z. Polyhedron 2009, 28, 947. (d) Lin, X.; Blake, A. J.; Wilson, C.; Sun,
X.-Z.; Champness, N. R.; George, M. W.; Hubberstey, P.; Mokaya, R.; Schroeder,
M. J. Am. Chem. Soc. 2006, 128, 10745. (e) Liu, Y.-L.; Kravtsov, V. C.;
Beauchamp, D. A.; Eubank, J. F.; Eddaoudi J. Am. Chem. Soc. 2005, 127, 7266.
0
8
using Pascal s constants.
Preparation of Crystalline [Ni (HEIDC) (H O) ] 2H O (1).
4
4
2
8
3
2
(f) Zhao, X. Q.; Zhao, B.; Shi, W.; Cheng, P.; Liao, D. Z.; Yan, S. P. Dalton Trans.
A mixture of H
(
3
EIDC (36.8 mg, 0.2 mmol), Ni(NO )
O (6:1, 7 mL) was sealed in a
3
2
6H
2
O
3
2
009, 2281. (g) Eubank, J. F.; Walsh, R. D.; Poddar, P.; Srikanth, H.; Larsen, R.
5.8 mg, 0.2 mmol), and EtOH/H
2
W.; Eddaoudi, M. Cryst. Growth Des. 2006, 6, 1453. (h) Yue, Y.-F.; Liang, J.;
Gao, E.-Q.; Yan, Z.-G.; Yan, C.-H. Inorg. Chem. 2008, 47, 6115. (i) Bai, Z.-S.; Qi,
Z.-P.; Lu, Y.; Yuan, Q.; Sun, W.-Y. Cryst. Growth Des. 2008, 8, 1924. (j) Shi, W.;
Chen, X. Y.; Xu, X. N.; Song, S. B.; Zhao, B.; Cheng, P.; Liao, D. Z.; Yan, S. P.
Eur. J. Inorg. Chem. 2006, 4931. (k) Zhao, X.-Q.; Zhao, B.; Ma, Y.; Shi, W.;
Cheng, P.; Jiang, Z.-H.; Liao, D.-Z.; Yan, S.-P. Inorg. Chem. 2007, 46, 5832.
2
5 mL Teflon-lined bomb and heated at 150 ꢀC for 96 h. The
reaction mixture was then allowed to cool to room temperature
at a rate of 10 ꢀC/h. Block-shape crystals of 1 were collected,
washed with methanol, and dried in air. Yield: 86%. Anal. calcd
for C H N O Ni : C, 29.62; H, 3.17; N, 9.87%. Found: C,
2
8
36
8
26
4
-
1
(l) Zhao, B.; Cheng, P.; Chen, X. Y.; Cheng, C.; Shi, S.; Wang, D. Z.; Yan, S. P.;
3
1
0.02; H, 3.01; N, 9.48%. IR (cm , KBr): 3479 s, 2985 w, 1571 s,
273 m, 1130 m, 867 w, 784 m, 751 w, 493 w.
Jiang, Z. H. J. Am. Chem. Soc. 2004, 126, 3012. (m) MacGillivray, L. R.;
Groeneman, R. H.; Atwood, J. L. J. Am. Chem. Soc. 1998, 120, 2676. (n) Nie,
X. L.; Wen, H. L.; Wu, Z. S.; Liu, D. B.; Liu, C. B. Acta Crystallogr., Sect. E:
Struct. Rep. Online 2007, 63, m753.
0
Preparation of Crystalline {[Mn(HEIDC)(4,4 -bipy)0.5(H O)]
2
3
3
H
2 n 3 4
O} (2). A mixture of H EIDC (24.1 mg, 0.13 mmol), MnSO
0
(
5) (a) Sun, Y.-Q.; Zhang, J.; Chen, Y.-M.; Yang, G.-Y. Angew. Chem.,
H O (21.9 mg, 0.13 mmol), 4,4 -bipy (20.2 mg, 0.13 mmol), Et N
2
3
Int. Ed. Engl. 2005, 44, 5814. (b) Maji, T. K.; Mostafa, G.; Chang, H.-C.;
Kitagawa, S. Chem. Commun. 2005, 9, 2436. (c) Liu, Y.-L.; Kravtsov, V.; Walsh,
R. D.; Poddar, P.; Srikanth, H.; Eddaoudi, M. Chem. Commun. 2004, 24, 2806.
(0.056 mL, 0.4 mmol), and deionized water (7 mL) was sealed
in a 25 mL Teflon-lined bomb, which was heated to 150 ꢀC for
9
6 h. After the mixture was cooled to room temperature at a rate
(d) Lu, W.-G.; Su, C.-Y.; Lu, T.-B.; Jiang, L.; Chen, J.-M. J. Am. Chem. Soc.
of 10 ꢀC/h, yellow crystals of 2 were obtained, washed with
distilled water, and dried in air. Yield: 64%. Anal. calcd for
2
006, 128, 34. (e) Liu, Y.-L; Kravtsov, V. C.; Larsen, R.; Eddaoudi, M. Chem.
Commun. 2006, 14, 1488. (f) Zou, R.-Q.; Jiang, L.; Senoh, H.; Takeichi, N.; Xu,
Q. Chem. Commun. 2005, 28, 3526. (g) Lu, J. Y.; Ge, Z. H. Inorg. Chim. Acta
C
12
H
14MnN
H, 4.03; N, 11.87%. IR (cm , KBr): 3451 m, 3205 s, 2903 w,
607 s, 1570 s, 1525 m, 1465 m, 1391 m, 1244 m, 1070 s, 813 m,
634 m.
Preparation of Crystalline [Mn
mixture of H EIDC (36.8 mg, 0.2 mmol), Mn(OAc)
.2 mmol), py (pyridine) (0.2 mL), and deionized water (7 mL)
3 6
O : C, 41.27; H, 3.47; N, 12.04%. Found: C, 40.92;
-
1
2
005, 358, 828. (h) Zhang, X. F.; Huang, D. G.; Chen, F.; Chen, D. G.; Liu, Q. T.
1
Inorg. Chem. Commun. 2004, 7, 662. (i) Zhao, B.; Zhao, X. Q.; Shi, W.; Cheng,
P. J. Mol. Struct. 2007, 830, 143. (j) Rajendiran, T. M.; Kirk, M. L.; Setyawati,
I. A.; Caudle, M. T.; Kampf, J. W.; Pecoraro, V. L. Chem. Commun. 2003, 7, 824.
6
(EIDC)
4
(py)
4
(H
2
O)
4 n
] (3). A
(k) Plieger, P. G.; Ehler, D.-S.; Duran, B.-L.; Taylor, T. P.; John, K. D.; Keizer,
3
2
(34.6 mg,
T. S.; McCleskey, T. M.; Burrell, A. K.; Kampf, J. W.; Haase, T.; Rasmussen, P. G.;
Karr, J. Inorg. Chem. 2005, 44, 5761. (l) Li, C.-J.; Hu, S.; Li, W.; Lam, C. K.;
Zheng, Y.-Z.; Tong, M.-L. Eur. J. Inorg. Chem. 2006, 1931. (m) Gu, J.-Z.; Lu,
W.-G.; Jiang, L.; Zhou, H.-C.; Lu, T.-B. Inorg. Chem. 2007, 46, 5835. (n) Fang,
R.-Q.; Zhang, X.-M. Inorg. Chem. 2006, 45, 4801. (o) Fang, R. Q.; Zhang, X. H.;
Zhang, X. M. Cryst. Growth Des. 2006, 6, 2637. (p) Zhang, M. B.; Chen, Y. M.;
Zheng, S. T.; Yang, G. Y. Eur. J. Inorg. Chem. 2006, 1423. (q) Xu, Q.; Zou,
R.-Q.; Zhong, R.-Q.; Kachi-Terajima, C.; Takamizawa, S. Cryst. Growth Des.
0
(6) Wang, S.; Zhang, L. R.; Li, G. H.; Huo, Q. S.; Liu, Y. L. CrystEng-
Comm 2008, 10, 1662.
(7) (a) Sun, T.; Ma, J. P.; Huang, R. Q.; Dong, Y. B. Acta Crystallogr.,
Sect. E: Struct. Rep. Online 2006, 62, o6751. (b) Alcalde, E.; Dinares, I.; Perez-
Garcia, L.; Roca, T. Synthesis 1992, 395.
2
008, 8, 2458.
(8) Carlin, R. L. Magnetochemistry, Springer: New York, 1986.

3
778 Inorganic Chemistry, Vol. 49, No. 8, 2010
Zhang et al.
n-
Scheme 1. Coordination Modes of H3-nEIDC Anions (n = 1-3)
9
a
was sealed in a 25 mL Teflon-lined bomb and heated at 160 ꢀC
for 96 h, and then cooled to room temperature at a rate of
the SHELX-97 crystallographic software package. Selected
bond lengths and angles are listed in Table 2.
1
0 ꢀC/h. Colorless flake-shaped crystals of 3 were collected,
Quantum-Chemical Calculation. The optimized geometries,
the Mulliken atomic charge distributions, and the energies of the
frontier molecular orbitals of the free ligands were given by the
GAUSSIAN 03 suite of programs. And all calculations were
carried out at the B3LYP/6-311þþG(d, p) level of theory.
washed with distilled water, and dried in air. Yield: 53% (based
on H EIDC). Anal. calcd for C H N O Mn : C, 39.96; H,
3
48 48 12 20
6
9
b
3
.32; N, 11.65%. Found: C, 39.78; H, 3.52; N, 11.42%. IR
-
1
(
1
cm , KBr): 3440 s, 2847 w, 1570 s, 1446 w, 1374 w, 1245 w,
221 w, 837 s, 699 s.
Preparation of Crystalline {[Cd
0
2
(EIDC)(H EIDC)(4,4 -bipy)1.5]
2
3
Results and Discussion
H O} (4). A mixture of H EIDC (36.8 mg, 0.2 mmol), Cd-
2
n
3
0
Crystal Structures of Crystalline Tetranuclear Square
(
(
NO
3
)
2
4H O (61.6 mg, 0.2 mmol), py (0.2 mL), 4,4 -bipy
2
31.2 mg, 0.2 mmol), and deionized water (7 mL) was sealed in
3
[
ture of 1 can be viewed as being made up of a [Ni
Ni (HEIDC) (H O) ] 2H O (1). The molecular struc-
4 4 2 8 2
3
a 25 mL Teflon-lined bomb and heated at 160 ꢀC for 96 h, and
then cooled to room temperature at a rate of 10 ꢀC/h. Good-
quality colorless crystals for 4 were filtered off, washed with
water, and dried in air. Crystals of 4 are stable in the air. Yield:
-
4
(HEIDC) (H O) ] unit and two noncoordinated water
4
2
8
molecules, which exhibits an interesting molecular square
conformation.
5
1
3
24 7 9 2
6%. Anal. calcd. for C29H N O Cd : C, 41.49; H, 2.85; N,
1.68%. Found: C, 41.15; H, 2.53; N, 11.48%. IR (cm , KBr):
472 s, 1604 w, 1538 m, 1393 s, 1262s, 1221 s, 1121m, 1066 s, 1009
As is shown in Figure 1a, each Ni(II) atom is six-
coordinated and adopts a slightly distorted octahedral
geometry. One of the equatorial planes is defined by
oxygen atoms (O3 and O3A) from two coordinated water
molecules and two nitrogen atoms (N1 and N1A) of two
-
1
w, 859 w, 821 w.
X-ray Crystallography. Crystal data and experimental details
for compounds 1-4 are contained in Table 1. Measurements of
compounds 1-3 were made on a Rigaku Saturn 724þ CCD
diffractometer with a graphite-monochromated Mo KR radia-
2
-
HEIDC ligands (the mean deviation from the plane
˚
(9) (a) Sheldrick, G. M. SHELX-97, Program for the Solution and
Refinement of Crystal Structures; University of G €o ttingen: G €o ttingen, Germany,
tion (λ = 0.71073 A). Polymer 4 was measured on a Rigaku
RAXIS-IV imaging plate area detector with graphite-mono-
˚
1
997. (b) Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb,
chromated Mo KR radiation (λ = 0.71073 A). Single crystals of
M. A.; Cheeseman, J. R.; Montgomery, J. A.; Vreven, T. J.; Kudin, K. N.; Burant,
J. C.; Millam, J. M.; Iyengar, S. S.; Tomasi, J.; Barone, V.; Mennucci, B.; Cossi,
M.; Scalmani, G.; Rega, N.; Petersson, G. A.; Nakatsuji, H.; Hada, M.; Ehara, M.;
Toyota, K.; Fukuda,R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao,
O.; Nakai, H.; Klene, M.; Li, X.; Knox, J. E.; Hratchian, H. P.; Cross, J. B.;
Bakken, V.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.;
Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Ayala, P. Y.; Morokuma,
K.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.; Zakrzewski, V. G.; Dapprich, S.;
Daniels, A. D.; Strain, M. C.; Farkas, O.; Malick, D. K.; Rabuck, A. D.;
Raghavachari, K.; Foresman, J. B.; Ortiz, J. V.; Cui, Q.; Clifford, A. G.; Baboul,
S.; Cioslowski, J.; Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi,
I.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng,C. Y.; Nanayakkara,
A.; Challacombe, M.; Gill, P. M. W.; Johnson, B.; Chen, W.; Wong, M. W.;
Gonzalez, C.; Pople, J. A. Gaussian 03, revision C.02; Gaussian, Inc.,
Wallingford, CT, 2004 (SN: Pople, PC21390756W-4203N).
1-4 were selected and mounted on a glass fiber. All data were
collected at room temperature using the ω-2θ scan technique
and corrected for Lorenz-polarization effects. A correction for
secondary extinction was applied.
The four structures were solved by direct methods and ex-
panded using the Fourier technique. The non-hydrogen atoms
were refined with anisotropic thermal parameters. Hydrogen
atoms were included but not refined. The final cycle of full-matrix
least-squares refinement was based on 958 observed reflections
and 89 variable parameters for 1, 3150 observed reflections and
2
18 variable parameters for 2, 10286observed reflectionsand 231
variable parameters for 3, and 6613 observed reflections and 422
variable parameters for 4. All calculations were performed using

Article
Inorganic Chemistry, Vol. 49, No. 8, 2010 3779
Table 1. Crystallographic Data for Compounds 1-4
1
2
3
4
formula
fw
C
28
H
36
N
8
O
26Ni
4
C
12
H
12
N
3
O
6
Mn
C
48
H
48
N
12
O
20Mn
6
29 24 7 9 2
C H N O Cd
839.35
monoclinic
1135.49
tetragonal
349.19
monoclinic
1442.62
monoclinic
crystal system
crystal size, mm
space group
0.30 ꢀ 0.20 ꢀ 0.20
P4(2)/nnm
14.7651(3)
14.7651(3)
8.8902(3)
90
0.33 ꢀ 0.27 ꢀ 0.13
0.20 ꢀ 0.16 ꢀ 0.15
0.20 ꢀ 0.20 ꢀ 0.20
P2(1)/n
P2(1)/n
P2(1)/c
˚
a, A
13.067(3)
8.5169(17)
13.984(3)
90
116.762(2)
90
1389.6(5)
90
4
0.984
10 274/3150
R(int) = 0.0344
3150/0/218
0.0361
0.1053
1.138
16.722(7)
21.350(8)
16.805(7)
90
102.589(5)
90
5856(4)
1.636
4
1.338
39 184/10 286
R(int) = 0.460
10 286/6/231
0.0933
12.615(3)
12.295(3)
20.242(4)
90
104.1(3)
90
3044.4(11)
1.831
4
1.463
33 603/6613
R(int) = 0.0266
6613/3/422
0.0302
0.0756
1.050
˚
B, A
˚
C, A
R, ꢀ
β, ꢀ
γ, ꢀ
90
90
3
˚
V, A
1938.14(9)
1.946
2
2.2025
9909/958
R(int) = 0.0240
958/2/89
0.0571
0.1848
1.054
-
3
Dc, Mg m
Z
-1
μ, mm
reflns collected/unique
data/restraints/parameters
R
a
b
R
GOF on F
w
0.1627
1.178
-1.303 and 0.858
2
-3
˚
ΔFmin and ΔFmax, e A
-1.037 and -1.036
-0.554 and 0.582
-0.911 and 0.923
˚
being 0.2167 A). The axial positions are occupied by two
coordinated water molecule, and a guest water molecule.
As is shown in Figure 2a, each Mn(II) ion is six-coordinated
by one nitrogen atom and three oxygen atoms from two
2
oxygen atoms (O1 and O1A) from two HEIDC ligands.
-
2
-
The bond lengths of Ni-O and Ni-N from HEIDC
2-
˚
are 2.094(4) and 2.075(5) A, respectively, while the Ni-O
distance from water is 2.075(5) A. The bond angles
individual μ -HEIDC , by one nitrogen atom from a bridg-
2
˚
0
ing 4,4 -bipy, and by one water molecule showing a slightly
distorted octahedral coordination geometry. The Mn-O
around each Ni(II) ion vary from 81.25(15) to 179.5(2)ꢀ.
In 1, each Ni(II) ion is coordinated by two N and two O
˚
bond lengths vary from 2.1283(17)-2.2075(17) A and the
atoms from two separate doubly deprotonated μ -HEI-
Mn-N bond lengths are in the range of 2.231(2)-2.269(2)
A, which are comparable to the previously reported values.
2
2-
12
˚
DC ligands in bis-N,O-chelating fashion (Scheme 1a), as
is found in related octahedral Ni(II) thiocarbohydrazone.
Hence, the four Ni(II) are chelated by four μ -HEIDC
1
0
The bond angles around each Mn(II) ion vary from 73.66(7)
to 174.42(7)ꢀ. Each HEIDC anion adopts a μ -kN,O:kO,
2-
2-
2
2
0
ligands forming eight stable five-membered rings. Conse-
quently, four Ni(II) centers are organized as a symmetrical
O mode (Scheme 1b), and links neighbor Mn(II) ions to
form a 1D left-handed helix around the crystallographic 2
1
2-
˚
axis, with the pitches of 8.5169(17) A, in b-axis (Figure 2b).
molecular square by four μ -HEIDC anions. The four Ni
2
0
atoms are in the same plane (the mean deviation from the
Notably, 4,4 -bipy molecules are parallel within the chains to
˚
plane being 0.000 A, with a distance of 6.375 A between
˚
form a mirror plane (Figure 2c). Therefore, the neighboring
chain must be constructed in a left-handed helix to the
original formed right-handed chain. Thus, two kinds of
adjacent Ni Ni and with four Ni-Ni-Ni angles of 90ꢀ.
3
3 3
13
Furthermore, complex 1 self-assembles 1D open channel
Figure 1b) along the c-axis, which is partially filled with the
ethylfromHEIDC ligands through intermolecular hydro-
0
(
parallel helices are bridged by 4,4 -bipy linkages to lead to a
novel 2D sheet with (6, 3)-net topology (Figure 2c).
2-
gen-bonding interactions (Table 3). The weak C-H OH-
Crystal Structure of Crystalline Polymer [Mn (EIDC) -
6 4
(py) (H O) ] (3). Single-crystal X-ray analysis has re-
4 2 4 n
vealed that compound 3 is in the monoclinic P2 /n space
1
3
3 3
bonding also serves as a spring to link the adjacent molecular
square blocks to form a 3D network (Figure 1b).
Although several molecular square Ni complexes have
group, as is complex 2. It displays an interesting 2D sheet
structure constructed by [Mn (EIDC) ] . Mn(II) ions are
4
1
1
been reported, the compound 1 is the first example of a
complex having an ideal square planar geometry.
3
2 n
located in two different coordination environments. As is
shown in Figure 3a, Mn(1) is six-coordinated by four
oxygen atoms from two individual EIDC in the equato-
Crystal Structure of Crystalline Polymer {[Mn(HEIDC)-
0
3-
(4,4 -bipy) (H O)] H O} (2). Complex 2 crystallizes in
the monoclinic P2 /n space group and exhibits a 2D metal-
0
.5
2
3
2
n
rial plane and by two nitrogen atoms from two individual py
in axial positions, forming a slightly distorted octahedral
geometry. Mn(II) shows a distorted trigonal bipyramidal
environment and is five coordinated with two nitrogen
1
organic framework, which is constructed from alternate 1D
0
left- and right-handed helical chains bridged by 4,4 -bipy.
The asymmetric unit of 2 consists of one Mn(II) ion,
2
-
0
3-
one HEIDC
anion, a half 4,4 -bipy molecule, one
atoms from two individual EIDC and one oxygen atom
from water molecule in the equatorial plane and with two
3-
oxygen atoms from two individual EIDC in axial posi-
tions. The slightly distorted trigonal bipyramidal Mn(III)
(
10) (a) Gang, H.; Dong, G.; Duan, C.-Y.; Hong, M.; Meng, Q.-J. New J.
Chem. 2002, 1371. (b) Manoj, E.; Kurup, P.; M, R.; Fun, H.-K.; Punnoose, A.
Polyhedron 2007, 26, 4451.
(
11) (a) Wasson, A. E.; La Duca, R. L. Polyhedron 2007, 26, 1001.
(
(
2
b) Mikuriya, M.; Minowa, K.; Nagao, N. Inorg. Chem. Commun. 2001, 4, 441.
c) Song, X. Y.; Xu, Y. H.; Li, L. C.; Liao, D. Z.; Jiang, Z. H. Inorg. Chim. Acta
007, 360, 2039. (d) Mandal, D.; Hong, C. S.; Kim, H. C.; Fun, H. K.; Ray, D.
(12) Lobana, T. S.; Kinoshita, I.; Kimura, K.; Nishioka, T.; Shiomi, D.;
Isobe, K. Eur. J. Inorg. Chem. 2004, 356.
(13) (a) Lu, W. G.; Gu, J. Z.; Jiang, L.; Tan, M. Y.; Lu, T. B. Cryst.
Growth Des. 2008, 8, 192. (b) Geng, X. H.; Feng, Y. L.; Lan, Y. Z. Inorg. Chem.
Commun. 2009, 12, 447.
Polyhedron 2008, 27, 2372. (e) Sung, N. D.; Yun, K. S.; Kim, T. Y.; Choi, K. Y.;
Suh, M.; Kim, J. G.; Suh, I. H.; Chin, J. Inorg. Chem. Commun. 2001, 4, 377.

3
780 Inorganic Chemistry, Vol. 49, No. 8, 2010
Zhang et al.
˚
Table 2. Selected Bond Distances (A) and Angles (ꢀ) for Compounds 1-4
a
1
Ni(1)-N(1)
2.075(5)
2.075(5)
167.30(19)
96.2(2)
88.0(3)
93.08(19)
179.5(2)
Ni(1)-O(1)
2.094(4)
Ni(1)-O(3)
N(1)#1-Ni(1)-O(3)
N(1)#1-Ni(1)-N(1)
O(3)-Ni(1)-O(3)#1
O(3)-Ni(1)-O(1)
O(1)-Ni(1)-O(1)#1
N(1)-Ni(1)-O(1)
N(1)-Ni(1)-O(3)
N(1)#1-Ni(1)-O(1)
O(3)#1-Ni(1)-O(1)
81.25(15)
89.12(17)
99.10(16)
86.54(19)
b
2
Mn(1)-O(3)#1
2.1283(17)
2.2074(18)
2.188(2)
86.21(7)
81.66(7)
97.26(7)
163.86(7)
101.12(8)
86.87(8)
86.10(8)
88.86(8)
Mn(1)-O(2)#1
2.1657(18)
2.232(2)
2.269(2)
94.12(7)
91.27(7)
174.42(7)
101.15(7)
73.66(7)
165.45(7)
95.67(7)
Mn(1)-O(1)
Mn(1)-N(1)
Mn(1)-O(1W)
Mn(1)-N(3)
O(3)#1-Mn(1)-O(2)#1
O(2)#1-Mn(1)-O(1W)
O(2)#1-Mn(1)-O(1)
O(3)#1-Mn(1)-N(1)
O(1W)-Mn(1)-N(1)
O(3)#1-Mn(1)-N(3)
O(1W)-Mn(1)-N(3)
N(1)-Mn(1)-N(3)
O(3)#1-Mn(1)-O(1W)
O(3)#1-Mn(1)-O(1)
O(1W)-Mn(1)-O(1)
O(2)#1-Mn(1)-N(1)
O(1)-Mn(1)-N(1)
O(2)#1-Mn(1)-N(3)
O(1)-Mn(1)-N(3)
c
3
Mn(1)-O(3)
2.090(3)
2.117(3)
2.140(3)
2.110(3)
2.139(2)
2.141(4)
2.134(3)
2.147(3)
2.096(3)
2.142(3)
2.169(4)
2.109(3)
2.122(3)
2.155(3)
2.105(3)
2.137(3)
Mn(1)-O(7)#1
2.095(3)
2.296(3)
2.265(5)
2.137(3)
2.162(4)
2.095(4)
2.144(3)
2.149(3)
2.132(3)
2.153(3)
2.121(3)
2.117(3)
2.277(5)
2.134(4)
2.135(3)
Mn(1)-O(6)#1
Mn(1)-N(2)
Mn(1)-O(1)
Mn(1)-N(1)
Mn(2)-O(17)
Mn(2)-O(8)
Mn(2)-O(2)
Mn(2)-N(3)
Mn(2)-N(5)
Mn(3)-O(18)
Mn(3)-N(7)
Mn(3)-O(4)
Mn(3)-O(9)
Mn(3)-N(4)
Mn(4)-O(19)
Mn(4)-O(14)#2
Mn(4)-O(12)
Mn(4)-N(8)
Mn(4)-N(12)#2
Mn(5)-O(16)
Mn(5)-O(11)
Mn(5)-O(10)
Mn(5)-O(13)
Mn(5)-N(9)
Mn(6)-N(11)
Mn(6)-N(6)#3
Mn(6)-O(20)
Mn(6)-O(5)#3
Mn(6)-O(15)
O(6)#1-Mn(1)-O(1)
O(3)-Mn(1)-O(1)
O(7)#1-Mn(1)-O(6)#1
O(6)#1-Mn(1)-O(1)
O(1)-Mn(1)-N(2)
O(3)-Mn(1)-N(2)
O(1)-Mn(1)-N(1)
O(7)#1-Mn(1)-N(1)
O(17)-Mn(2)-O(8)
O(8)-Mn(2)-O(2)
O(8)-Mn(2)-N(5)
O(17)-Mn(2)-N(3)
O(2)-Mn(2)-N(3)
O(18)-Mn(3)-N(7)
N(7)-Mn(3)-O(4)
N(7)-Mn(3)-O(9)
O(18)-Mn(3)-N(4)
O(4)-Mn(3)-N(4)
O(19)-Mn(4)-O(14)#2
O(14)#2-Mn(4)-O(12)
O(14)#2-Mn(4)-N(8)
O(19)-Mn(4)-N(12)#2
O(12)-Mn(4)-N(12)#2
O(11)-Mn(5)-O(10)
O(10)-Mn(5)-O(16)
O(10)-Mn(5)-O(13)
O(11)-Mn(5)-N(9)
O(16)-Mn(5)-N(9)
O(11)-Mn(5)-N(10)
O(16)-Mn(5)-N(10)
N(9)-Mn(5)-N(10)
O(20)-Mn(6)-O(5)#3
O(20)-Mn(6)-O(15)
O(5)#3-Mn(6)-O(15)
N(6)#3-Mn(6)-N(11)
O(15)-Mn(6)-N(11)
178.49(11)
91.61(12)
93.50(11)
178.49(11)
89.16(11)
89.46(13)
91.43(14)
90.91(16)
91.05(10)
175.19(11)
76.64(11)
127.12(12)
77.30(11)
113.94(13)
102.49(11)
76.35(11)
132.79(13)
77.07(11)
96.76(11)
170.52(11)
98.68(11)
121.52(12)
97.55(11)
89.72(11)
90.52(11)
178.77(12)
90.33(13)
88.45(13)
92.40(11)
88.82(12)
177.15(14)
94.87(12)
90.91(12)
174.17(13)
115.68(14)
77.41(12)
O(3)-Mn(1)-O(6)#1
O(3)-Mn(1)-O(7)#1
O(7)#1-Mn(1)-O(1)
N(1)-Mn(1)-N(2)
O(6)#1-Mn(1)-N(2)
O(7)#1-Mn(1)-N(2)
O(6)#1-Mn(1)-N(1)
O(3)-Mn(1)-N(1)
O(17)-Mn(2)-O(2)
O(17)-Mn(2)-N(5)
O(2)-Mn(2)-N(5)
O(8)-Mn(2)-N(3)
N(5)-Mn(2)-N(3)
O(18)-Mn(3)-O(4)
O(18)-Mn(3)-O(9)
O(4)-Mn(3)-O(9)
N(7)-Mn(3)-N(4)
O(9)-Mn(3)-N(4)
O(19)-Mn(4)-O(12)
O(19)-Mn(4)-N(8)
O(12)-Mn(4)-N(8)
O(14)#2-Mn(4)-N(12)#2
N(8)-Mn(4)-N(12)#2
O(11)-Mn(5)-O(16)
O(11)-Mn(5)-O(13)
O(16)-Mn(5)-O(13)
O(10)-Mn(5)-N(9)
O(13)-Mn(5)-N(9)
O(10)-Mn(5)-N(10)
O(13)-Mn(5)-N(10)
O(20)-Mn(6)-N(6)#3
N(6)#3-Mn(6)-O(5)#3
N(6)#3-Mn(6)-O(15)
O(5)#3-Mn(6)-N(11)
O(20)-Mn(6)-N(11)
87.02(12)
179.47(13)
87.87(11)
178.59(15)
91.46(12)
90.39(12)
87.93(15)
89.24(16)
93.74(10)
124.34(12)
100.18(11)
100.16(12)
108.52(13)
90.51(12)
95.37(13)
173.96(13)
113.20(13)
97.85(12)
92.71(11)
119.20(12)
76.82(11)
77.21(11)
119.22(13)
178.76(12)
89.57(11)
90.18(11)
89.39(15)
89.61(15)
89.81(12)
91.22(12)
131.88(14)
76.47(12)
99.03(12)
101.05(12)
112.44(13)

Article
Inorganic Chemistry, Vol. 49, No. 8, 2010 3781
Table 2. Continued
d
4
Cd(1)-N(4)
2.249(2)
2.350(2)
2.376(2)
2.297(2)
2.355(2)
2.355(2)
2.381(2)
2.211(2)
2.381(2)
159.40(9)
93.88(9)
88.60(9)
73.07(8)
167.84(8)
91.05(9)
75.20(8)
92.63(9)
93.24(9)
86.76(9)
180.00(9)
106.33(8)
84.80(8)
73.67(8)
95.20(8)
180.00(16)
74.02(8)
105.98(8)
88.04(9)
88.04(8)
91.96(9)
91.96(8)
180.00(9)
Cd(1)-N(1)
2.315(2)
2.427(3)
2.391(2)
2.297(2)
2.361(2)
2.361(2)
2.398(2)
2.211(2)
2.398(2)
106.67(9)
99.12(9)
71.34(8)
86.55(8)
120.82(8)
92.90(10)
146.53(8)
180.00(16)
86.76(9)
93.24(9)
73.67(8)
95.20(8)
106.33(8)
84.80(8)
180.00(16)
105.98(8)
74.02(8)
180.00(10)
91.96(9)
91.96(8)
88.04(9)
88.04(8)
Cd(1)-O(5)
Cd(1)-N(3)
Cd(1)-N(6)
Cd(1)-O(1)
Cd(2)-N(7)#1
Cd(2)-N(7)
Cd(2)-N(2)#2
Cd(2)-O(7)
Cd(2)-N(2)#3
Cd(2)-O(7)#1
Cd(3)-O(4)#5
Cd(3)-O(8)#6
Cd(3)-N(5)#4
Cd(3)-N(5)#5
Cd(3)-O(4)#4
Cd(3)-O(8)
N(4)-Cd(1)-N(1)
N(1)-Cd(1)-O(5)
N(1)-Cd(1)-N(6)
N(4)-Cd(1)-O(1)
O(5)-Cd(1)-O(1)
N(4)-Cd(1)-N(3)
O(5)-Cd(1)-N(3)
O(1)-Cd(1)-N(3)
N(7)#1-Cd(2)-N(2)#2
N(7)#1-Cd(2)-N(2)#3
N(2)#2-Cd(2)-N(2)#3
N(7)-Cd(2)-O(7)#1
N(2)#3-Cd(2)-O(7)#1
N(7)-Cd(2)-O(7)
N(2)#3-Cd(2)-O(7)
N(5)#4-Cd(3)-N(5)#5
N(5)#5-Cd(3)-O(4)#5
N(5)#5-Cd(3)-O(4)#4
N(5)#4-Cd(3)-O(8)
O(4)#5-Cd(3)-O(8)
N(5)#4-Cd(3)-O(8)#6
O(4)#5-Cd(3)-O(8)#6
O(8)-Cd(3)-O(8)#6
N(4)-Cd(1)-O(5)
N(4)-Cd(1)-N(6)
O(5)-Cd(1)-N(6)
N(1)-Cd(1)-O(1)
N(6)-Cd(1)-O(1)
N(1)-Cd(1)-N(3)
N(6)-Cd(1)-N(3)
N(7)#1-Cd(2)-N(7)
N(7)-Cd(2)-N(2)#2
N(7)-Cd(2)-N(2)#3
N(7)#1-Cd(2)-O(7)#1
N(2)#2-Cd(2)-O(7)#1
N(7)#1-Cd(2)-O(7)
N(2)#2-Cd(2)-O(7)
O(7)#1-Cd(2)-O(7)
N(5)#4-Cd(3)-O(4)#5
N(5)#4-Cd(3)-O(4)#4
O(4)#5-Cd(3)-O(4)#4
N(5)#5-Cd(3)-O(8)
O(4)#4-Cd(3)-O(8)
N(5)#5-Cd(3)-O(8)#6
O(4)#4-Cd(3)-O(8)#6
a
b
c
Symmetry transformations used to generate equivalent atoms: #1: x, -y þ 3/2, -z þ 1/2. #1: -x þ 3/2, y þ 1/2. #1: x þ 1/2,
d
-
#
y - 1/2, zþ 1/2;#2: x þ 1/2, -y - 3/2, zþ 1/2;#3: x - 1/2, -y - 1/2, z - 1/2. #1: -x, -y, -z; #2:x - 1, y, z; #3:-x þ 1, -y, -z;
4: x, -y þ 1/2, z - 1/2; #5: -x, y þ 1/2, -z þ 1/2; #6: -x, -y þ 1, -z.
atom has in its pseudoequatorial plane the oxygen atom O18
from the coordinated water molecule) and two nitrogen
atoms N4 and N7 from two EIDC units; the oxygen atoms
O4 and O9 (from the two EIDC units) occupy the
pseudoaxial sites. The Mn-O bond lengths vary from 2.090-
assembled in a 3D framework with three Cd(II) atoms,
0
3-
(
one and a half 4,4 -bipy molecules, one EIDC anion,
and one H EIDC anion in each asymmetric unit.
3-
-
2
3-
The three crystallographically independent Cd(II) ions
(Figure 4a) exhibit different coordination environments.
Cd(I) is six-coordinated with two oxygen (O1, O5) and two
˚
(
3)-2.147(3) A and the Mn-N bond lengths fall in the range
˚
3-
of 2.134(3)-2.296(3) A. The Mn-O bond distances are
slightly shorter than those of complex 2. The coordination
environments of Mn(II) atoms are similar to those of Zn(II)
atoms in a recent reported compound with the similar ligand
H IDC, {[Zn (IDC) (bpy) ] (bpy) 8H O} .
3
In 3, each EIDC anion adopts a μ -kN,O:kO,O :kN ,
nitrogen (N4, N6) atoms from two individual μ -EIDC and
3
-
μ -H EIDC , and two nitrogen (N1, N3) atoms from two
individual 4,4 -bipy molecules. Cd(II) is six-coordinated with
two oxygen (O7A, O7) and two nitrogen (N7A, N7) atoms
2
2
0
14
3-
3
2
-
3
3
3
2
n
from two individual μ -EIDC in the equatorial plane and
3
3
0
0
3
with two nitrogen (N2B, N2C) atoms from two individual
0
0
O mode (Scheme 1c) to bridge three Mn(II) ions in N,O-
0
4,4 -bipy molecules in axial positions. Cd(III) is six-coordi-
nated with four oxygen (O4D, O4E, O8, O8F) and two
0
0
chelating, O,O -chelating, and N ,O -chelating. The over-
all structure of 3 is a 2D honeycomb-like sheet of
3
-
nitrogen (N5D, N5E) atoms from two individual μ -EIDC
3
-
[
Mn (EIDC) ] containing infinite 24-membered rings
3 2 n
and two individual μ -H EIDC . TheCd-O bond distances
2
2
(
Figure 3b). Each 24-membered ring forms a hexagon
˚
ranging from 2.350(2) to 2.398(2) A and Cd-N bond
distances varying from 2.11(2) to 2.427(3) A are consistent
3
-
and is formed by six μ -EIDC anions, two octahedral
˚
3
Mn(II), and four trigonal bipyramidal Mn(II) cations.
The honeycomb-like sheet of 3 is similar to the structural
motifs of [Zn (IDC) ] and [Co (IDC) ] in compounds
16
with the previously reported values. Obviously, in 4, all
metal sites exhibit octahedronal coordination geometry.
Interestingly, singly deprotonated H EIDC and triply
deprotonated EIDC coexist in 4, and they adopt two
-
3
2 n
3
2 n
2
1
4
{
(
[Zn (IDC) (bpy) ] (bpy) 8H O}
2
bpy) )] 6H O DMF} , respectively.
3
and {[Co (IDC) -
2
3-
3
2
3
3
3
n
3
1
5
0
0
3
2
3
n
types of coordination modes, namely μ -kN, O:kN ,O
2
Crystal Structure of Crystalline Polymer {[Cd (EIDC)-
2
0 0
Scheme 1d), and μ -kN, O:kO:kN ,O (Scheme 1e). As is
3
(
0
(
lizes in the monoclinic space group P2(1)/c, which is
H EIDC)(4,4 -bipy) ] H O} (4). Complex 4 crystal-
3-
2
1.5
3
2
n
shown in Figure 4b, each EIDC anion bridges three
0
0
Cd(II) atoms in N,O-chelating, O-bridging, and N ,O -
chelating coordination modes to form a 1D infinite chain
(
14) Lu, W. G.; Jiang, L.; Feng, X. L.; Lu, T. B. Cryst. Growth Des. 2006,
, 564.
15) Wang, Y. L.; Yuan, D. Q; Bi, W. H; Li, X.; Li, X. J.; Li, F.; Cao, R.
Cryst. Growth Des. 2005, 5, 1849.
6
(
(16) Lu, W. G.; Jiang, L.; Feng, X. L.; Lu, T. B. Cryst. Growth Des. 2008,
8, 986.

3
782 Inorganic Chemistry, Vol. 49, No. 8, 2010
Zhang et al.
ligands H EIDC and H IDC have two features: (i) The
3
3
negative Mulliken atomic charges mainly distribute on the
oxygen and nitrogen atoms. The Mulliken charges are
-
-
0.66499 for O1, -0.65854 for O2, -0.68904 for O3,
0.64712 for O4, -0.52367 for N5, and -0.49327 for N6
in the free ligand H IDC, and -0.66617 for O1, -0.66085
3
for O6, -0.69129 for O2, -0.65133 for O13, -0.53170 for
N7, and -0.49906 for N6 in the free ligand H EIDC
3
(Table 4). These values indicate that the oxygen and nitrogen
atoms of the two ligands all have potential ability of coordi-
nating to metal ions. So H IDC and H EIDC can show vari-
ous coordination modes under appropriate reaction condi-
3
3
5,6
tions. This finding can be confirmed by both previous and
our present experimental results. It is also interesting to
n-
compare the coordination modes of the H3 EIDC spe-
-n
cies in 1-4. In 1, the imidazole-H and COO-H are
2-
removed from the ligand H EIDC to form the HEIDC
3
unit. Two COO-H are deprotonated in 2 also leading to the
HEIDC unit. The triply deprotonated EIDC units can
be found in 3. In 4, there are two different deprotonated
2-
3-
-
3-
forms, H EIDC (imidazole-H removed) and EIDC
2
(triply deprotonated). (ii) Compared with the free ligand
H IDC, the introduction of ethyl group into H EIDC has
3
3
some effect on the Mulliken charge distributions of the oxy-
gen and nitrogen atoms. As is discussed above, the Mulliken
charge distributions of oxygen and nitrogen atoms in
H EIDC all increase slightly, which shows that the coordi-
3
nation abilities of these atoms may be enhanced, especially
of O13, O6, and O7 atoms. However, the substituent elec-
tronic effect of the ethyl unit in the ligand H EIDC is not
3
remarkable. This can be further confirmed by calculating the
highest occupied molecular orbital (HOMO) distributions
of the free ligands H IDC and H EIDC (see Supporting
Figure 1. (a) Molecular square structure of the tetranuclear Ni(II)
complex 1 (hydrogen atoms and solvent molecules omitted for clarity).
3
3
(b) A 3D solid-state network of 1 constructed by intermolecular hydro-
gen-bonding interactions containing 1D open channels along the c-axis.
Information, Figure S1). It can be seen from the figure S1,
that the electron density of the HOMO in H EIDC has no
3
significant change in comparison with the H IDC. There-
3
fore, the steric effect of the ethyl unit in H EIDC should be
3
a
˚
Table 3. Hydrogen Bond Distances (A) and Angles (ꢀ) for 1
given more consideration. When H IDC or H EIDC react
3
3
D-H
3 3 A
d(H
3 3 3 A)
d(D
3 3 3 A)
—(DHA)
3
with Ni(NO ) under similar solvent EtOH/H O and tem-
3
2
2
O(2)-H(2A) O(2)#2
3 3
1.264(15)
1.966(18)
2.09(4)
2.496(7)
2.808(6)
2.890(10)
162(8)
171(9)
158(9)
3
perature conditions, two different structural complexes, octa-
nuclear complex [Ni (H IDC) (HIDC) ] 8EtOH 18H O
O(3)-H(3W2) O(2)#3
5q
3
3 3
3 3
8
2
8
4
3
3
2
O(3)-H(3W1) O(3)#4
3
and tetranuclear complex 1 are produced. Obviously, the
steric hindrance of the ethyl group may hold the H EIDC
a
Symmetry transformations used to generate equivalent atoms: #2: y þ
-
1
/2, x - 1/2, z; #3: -y þ 3/2, -x þ 3/2, -z; #4: -x þ 3/2, y, -z þ 1/2.
2
to link more Ni(II) ions.
The stoichiometry of the starting materials is important
for the formations of complexes 1-4. The reactions of metal
˚
Figure 4b) with the Cd2 Cd3 distance of 6.1473(12) A
(
along the b-axis. Furthermore, the 1D infinite chains are
3
3 3
0
linked to a 2D layer by bridging 4,4 -bipy (Figure 4c). It is
noteworthy that adjacent layers are pillared by μ -
salts and H EIDC in a molar ratio of 1:1, 1:1, 1:1, and 1:1
3
have respectively produced the crystals of 1-4 successfully,
while other stoichiometry has failed to produce suitable
crystals or has given products with low yields (about 1.5%).
It is to be pointed out that complex 1 has been obtained
with high yield by the solvothermal reaction of Ni(NO3)2
and H EIDC in an EtOH-H O (6:1) mixed solution. In
2
-
0
0
H EIDC ligands in N,O-chelating and N ,O -chelating
2
0
coordination modes. Finally, the μ -4,4 -bipy bridge can
2
pass through the adjacent layer to connect two layers to
result in an interpenetrating 3D framework (Figure 4d).
Synthesis and Characterization. As is aforementioned
in the Introduction Section, the factors governing the reac-
tion and formation of the hydrothermal product are com-
plicated. The position and type of functional groups on the
ligands are crucial for the generation of supramolecular
frameworks. In order to predict the ethyl substituent effect
3
2
the preparation of 1, the change in organic solvent or the
adoption of hydrothermal synthesis cannot result in any
crystalline products of 1, but some unidentified powder.
The results indicate that the forming of the framework of
1 is considerably influenced by the nature of the solution.
In addition, we have also attempted to replace the Ni(II)
with Mn(II) in the synthesis of 2, only leading to the
formation of a mononuclear complex [Mn(H EIDC) -
in our ligand, H EIDC, the optimized geometries and the
3
Mulliken atomic charge distributions of the free ligand
H EIDC and the related ligand H IDC have been calculated
3
3
2
2
by the B3LYP/6-311þþG(d, p) level of theory. The com-
(H O) ] 3H O (Supporting Information, Figure S2)
2 2 2
rather than an Mn(II) analogue of 1. This fact also implies
3
puted results (Scheme 2 and Table 4) reveal that the free

Article
Inorganic Chemistry, Vol. 49, No. 8, 2010 3783
Figure 2. (a) Coordination arrangements of the Mn(II) in complex 2 (hydrogen atoms and solvent molecules omitted for clarity). (b) The 1D left-handed
helical chain of [Mn(HEIDC)] and 1D right-handed helical chain of Mn(HEIDC)] around the 2 axis. (c) The 2D sheet comprising infinite helical chains
n
n
1
0
bridged by 4,4 -bipy linkages.
-
that the formation of tetranuclear structure in 1 is metal
ion dependent.
which suggests that the anion NO3 plays an important role
in the formation of 1. The similar cases can be found in the
syntheses of 2-4. However, the anion effect in the construc-
tion of coordination complexes is ambiguous.
The selection of coligands in the synthesis process of com-
plexes 1-4 has been based on two aspects, as follows: First,
the coligands sometimes play important roles in directing the
In conclusion, by fine control over synthetic conditions
such as solvent, pH values, metal/ligand molar ratio, and
coligands the reproducibility of our experiments is good.
The IR spectra display characteristic absorption bands
for water molecules, carboxylate, imidazolyl units and
pyridyl units. Compounds 1-4 show strong and broad
absorption bands in the range of 3400-3500 cm- , which
indicates the presence of hydrogen-bonded water mole-
cules. The coordination of the carboxylate can be seen
from the absorption bands in the frequency range
5
extended structure of the resulting complex. When we use
0
4,4 -bipy as auxiliary ligands, one novel 2D framework 2and
one 3D polymer 4 have been prepared. Second, during the
13a
reactions, some coligands such as prz (piperazine) or py
have served not only as an auxiliary ligand but also as a
deprotonated agent due to its strong alkalinity. In the
preparation of 3 or 4, py has been adopted mainly to adjust
pH values; also it can coordinate to the central metal ions
and benefit the crystallization of polymer 3.
1
-
1
-
-
The selection of the appropriate multidentate ligand to
link paramagnetic metal ions is a powerful way for the
building of molecular magnetic materials. Ni(II) and Mn(II)
ions are good candidates, which can be linked by carboxylate
or N-containing ligands to form extended coordination
networks allowing for sufficiently strong magnetic exchange.
The Cd(II) cation is able to coordinate simultaneously to
both O- and N-containing ligands to obtain intriguing
architectures. Thus, Ni(II), Mn(II), and Cd(II) ions are
1340-1610 cm in 1-4 due to ν (COO ) and ν (COO )
as
s
vibrations respectively. The strong bands in the range of
-
1
1610-1570 cm in complexes 1-4 imply the CdN and
CdC stetching bands of imidazole ring in H EIDC.
3
Compounds 1-3 show similar thermal behaviors, but
are different from 4. The TG curves for 1-4 are shown in
Figure 5, and the DSC curves for 1-4 are illustrated in
(Supporting Information, Figure S3).
There are two small endothermic peaks at 184.0 and
283.9 ꢀC and one very strong exothermic peak at 423.0 ꢀC
on the DSC curve of polymer 1. The first weight loss of
2.2% (calculated 1.6%) occurs at about 150 ꢀC, which is
attributed to the loss of free water molecules. The second
weight loss of 72.30% between 250 and 460 ꢀC corre-
selected by us to react with H EIDC in the presence of (or
3
without) coligands. It is noteworthy that the anion of metal
salt may affect the crystal shape of the final product. If the
Ni(NO ) is changed to Ni(OAc) or NiSO in the synthesis
3
2
2
4
of 1, then only a small crystalline powder can be generated,

3
784 Inorganic Chemistry, Vol. 49, No. 8, 2010
Zhang et al.
losing weight from 240 to 465 ꢀC, corresponding to the de-
3-
composition of the EIDC and py (observed 62.3%, calcu-
lated 62.2%). The decomposed reactions end at 561.5 ꢀC. The
final residue is 6MnO (observed 32.0%, calculated 31.5%).
There are two strong exothermic peaks at 401.2 and
5
21.7 ꢀC on the DSC curve of compound 4. It first loses
the crystallized water molecules in the temperature range
of 41-157 ꢀC (observed 2.8%, calculated 2.1%), and
second loses weight from 332 to 524 ꢀC corresponding
0
2-
to the decomposition of 4,4 -bipy and H EIDC and
2
3
-
EIDC units (observed 67.5%). Finally, a plateau region
is observed from 524 to 800 ꢀC. A white amorphous
residue is 2CdO (observed 29.7%, calculated 30.5%).
In conclusion, the IR data and thermal data of com-
plexes 1-4 are in reasonable agreement with the crystal
structure analysis.
Magnetic Properties. Polymer 1: Variable-tempera-
ture magnetic study on 1 is carried out over the temperature
range of 2.0-300 K. The variation of the inverse of the
-
1
magnetic susceptibility, χm and χ T of 1 are shown in
m
-
1
Figure 6a. The thermal evolution of χM obeys the Cur-
ie-Weiss law, χ = C/(T - θ) in the temperature range of
M
6
0-300 K with Weiss constant, θ, of -48.69 K and Curie
3 -1
constant, C , of 5.170 cm K mol . It can be seen from
Figure 6a, at 300 K, χ T is equal to 4.450 cm K mol and
M
3
-1
M
is slightly below the spin-only value of four uncoupled
(
3
SNi = 1, g = 2.20) nickel(II) ions (4.83 cm K mol ).
-1 17
As the temperature is lowered, the χ T value steadily
M
3
-1
decreases to 0.143 cm K mol at 2.0 K. Such behavior
can be referred to as the presence of an antiferromagnetic
exchange behavior between the neighbor Ni(II) ions.
As is shown in the crystallographic part, the complex 1 is
2-
made up of Ni entities where the ligand HEIDC acts as a
4
bridge to afford a square system (Figure 1a). Obviously, we
can expect that the magnetic pathways between the two
neighbor Ni(II) ions are the same in polymer 1. That is to
say, the four Ni(II)-HEIDC-Ni(II) couplings are equal.
Taking into account this fact, we can use a single coupling
constant J. Thus, for a square arrangement of four metal
centers, a D [2 ꢀ 2] grid, the spin Hamiltonian of the form
Figure 3. (a) Coordination environments of Mn(II) atom in polymer 3
hydrogen atoms omitted for clarity). (b) The 2D honeycomb-like with 24-
membered hexagonal rings (pyridine and coordinated water molecules
omitted for clarity).
(
4
h
of eq 1 can be used to describe the magnetic properties of the
sponds to the loss of coordinated water molecules and
compound with S = 1:
2
-
HEIDC . The remaining weight of 25.1% corresponds
to the percentage (calculated 25.6%) of the Ni and O
components, indicating that the final product is 4NiO.
The TG-DSC curves have been obtained under flowing
air for a crystalline sample of 2 in the temperature range of
^
^ ^
^ ^
^ ^
^ ^
H ¼ -2JðS1S2 þ S2S3 þ S3S4 þ S4S1Þ
ð1Þ
20-800 ꢀC. TG data show that polymer 2 is stable up to
169.9 ꢀC then loses weight from 169.9 to 254.9 ꢀC (observed
10.43%, calculated 10.25%), corresponding to losses of
both solvent water and coordinated water molecules.
Subsequently, a plateau region is observed from 204.2 to
2
corresponding to the decomposition of 4,4 -bipy and
HEIDC units (observed 23.50%, calculated 22.88%).
A white amorphous residue is MnO (observed 21.11%,
calculated 20.20%). One very strong exothermic peak at
54.9 ꢀC. It keeps losing weight from 254.9 to 367.3 ꢀC
0
2-
The allowed eigenvalues were then substituted into the
following modified equation:
1
8
2
2
2
2
4
63.3 ꢀC can be observed on the DSC curve of polymer 2.
For polymer 3, there is one weak endothermic peak
Ng β A
Ng β
ð1 -FÞ þ TIP
3kT
χM
¼
F þ
kT B
3
(
213.5 ꢀC), one weak exothermic peak (335.1 ꢀC), and one
strong exothermic peak (408.6 ꢀC) in the DSC curve. It loses
coordinated water molecules in the temperature range of
(17) Demeshko, S.; Leibeling, G.; Dechert, S.; Meyer, F. Dalton Trans.
2
006, 3458.
110-210 ꢀC (observed 5.7%, calculated 6.3%). It keeps
(18) Kahn, O. Molecular Magnetism; VCH: New York, 1993.

Article
Inorganic Chemistry, Vol. 49, No. 8, 2010 3785
Figure 4. (a) The segment of polymer 4, showing the local coordination environments of Cd(II) ions (hydrogen atoms and solvent molecules omitted for
0
3
-
3-
clarity). (b) 1D chain along the b-axis based on Cd(II) and μ
3
-EIDC . (c) 2D layer constructed from μ
3
-EIDC (Scheme 1e) and 4,4 -bipy. (d) 3D
2-
0
framework along the a-axis built by 2D layers, μ
2
-HEIDC (Scheme 1d) and 4,4 -bipy (hydrogen atoms and solvent molecules omitted for clarity).
where A = 108 þ 6exp(18a) þ 42exp(14a) þ 66exp(10a) þ
56exp(8a) þ 30exp(6a) þ 168exp(4a); B = 90 þ exp(20a)
þ 3exp(18a) þ 11exp(14a) þ exp(12a) þ 13exp(10a) þ
be found in the references. For example, Arora and co-
workers have reported the ferromagnetic exchange interac-
2
-
1
tion (J=1.0 cm ) mediated by syn-anti carboxylate bridg-
ing of an approximately square planar complex {[Ni (L )]-
II
1
24exp(8a) þ 5exp(6a) þ 14exp(4a); a = -J/kT. Other para-
1
meters of N, β, K, g, TIP, and T have their usual meanings,
while F is the fraction of paramagnetic impurity.
[ClO ]} CH CN (L (-) = 3-[N-methyl-{2-(pyridine-2-
3
20a
4
4
3
yl)ethyl}amino]propionate).
have studied the antiferromagnetic interaction of [2 ꢀ 2]
molecular grid nickel(II) complex [Ni (pop) (HCOO) ]
Moroz and co-workers
The best fitting for the data in the range of 2-300 K gives
-
1
J = -10.83 cm , g = 2.19, F = 0.0433, TIP = 0.00569
4
4
4
3
P
3
-1
-4
2
20b
0
cm mol , with R = 5.2 ꢀ 10 , [R = [ (χ - χcalc) /
obs
7H O (Hpop=2-hydroxyimino-N -[1-(2-pyridyl)ethy-
2
P
1
/2
χ
Although there are some reports about magnetic proper-
]
].
lidene]propanohydrazone) with a new polydentate oxime-
containing Schiff base ligand and have fitted the magnetic
obs
19
-1
ties of tetranuclear Ni(II) complexes, the studies of mag-
netic properties concerning molecular square built by four
Indeed, only several examples can
parameter of the complex (J = -14.7(1) cm ). Meng and
co-workers have described the antiferromagnetic coupling
among the Ni(II) ions of two similar approximately square
10,17,20
Ni(II) ions are rare.

3
786 Inorganic Chemistry, Vol. 49, No. 8, 2010
Zhang et al.
a
3 3
Scheme 2. The Optimized Geometries of the Free Ligands H IDC and H EIDC
a
The blue ball represents N atom, the red ball represents O atom and the gray ball represents C atom.
Table 4. Mulliken Atomic Charge Distributions of the Free Ligands H
and H IDC
3
EIDC
given the theoretically fitted J value. Compared with
the strong antiferromagnetic coupling interactions of
3
4
the previous molecular square Ni(II) [Ni(HL )] [PF ]
H
3
IDC
Mulliken charge
H
3
EIDC
4
6 4
3
2
0c
4
.5EtOH 2.8H O (H L = bis(2-pyridyl ketone)thiocar-
0
3
2 2
atom number
atom number
Mulliken charge
bohydrazone), the J value of our complex is relatively low,
which is close to the value of the complex [Ni (pop) -
O1
O2
O3
O4
N5
N6
C7
C8
-0.66499
-0.65854
-0.68904
-0.64712
-0.52367
-0.49327
0.80744
0.01044
0.05658
0.78105
0.24933
0.50665
0.48765
0.23673
0.54074
O1
O6
O2
O13
N7
N4
C10
C8
C9
C12
C11
C14
C17
H15
H16
H18
H19
H20
H21
-0.66617
-0.66085
-0.69129
-0.65133
-0.53170
-0.49906
0.80683
0.01558
0.05461
0.77963
0.44052
-0.43529
-0.56473
0.22625
0.23251
0.20938
0.20176
0.20415
0.54017
4
4
2
0b
(HCOO) ] 7H O.
4
Obvious, this is due to the long
˚
3
2
Ni Ni separation (6.375 A) and the complicated path-
3 3
3
2-
way by the ligand HEIDC
.
Polymer 2: Variable-temperature magnetic suscept-
ibility of 2 is measured in the 2.0-300 K temperature
range. The variation of the inverse of the magnetic sus-
C9
-1
ceptibility, χM and χ T of 2 are shown in Figure 6b.
M
C10
C11
H12
H13
H14
H15
-1
The thermal evolution of χM
obeys the Curie-Weiss
law, χM = C/(T - θ) in the range of 6.8-300 K with a
Weiss constant, θ, of -10.438 K and a Curie constant,
M
3
C , of 4.478 cm K mol , respectively. At 300 K, the
-1
3
-1
χ T value is 4.301 cm K mol (5.86 μB), which is close
M
3
-1
to the value of 4.38 cm K mol (5.92 μB) expected for
magnetically isolated high-spin Mn(II) (SMn = 5/2, g =
2.0) and is near the reported polymers (H NMe )[Mn-
2 2
2
planar complexes [Ni(HL )] [PF ]
10a
2
(H L = bis(2-acet-
(tzdc)] 0.5H O (tzdc = 1,2,3-trizole-4,5-dicarboxylate)
2
3
4
6 4
2
3
(4.31 cm K mol
-1 21
3
ylpyridine)thiocarbazone) and [Ni(HL )] [PF ] 4EtOH
)
and [Mn
2
(btr)(μ-ox)
2
(H
2
O)] 2H
(btr = 4,4 -bis-1,2,4-triazole, ox = oxalate anion) (4.32
2
O
3
4
6 4
3
3
0
20c
3
H O (H L = bis[phenyl(2-pyridyl)thiocarbazone), not
2
2
3
cm K mol
-1 22
)
in the literature. On lowering the tem-
perature, the χ T value decreases smoothly, and below
M
3
7 K it decreases abruptly to a minimum of 0.409 cm K
(
19) (a) Efthymiou, C. G.; Papatriantafyllopoulou, C.; Alexopoulou,
4
N. I.; Raptopoulou, C. P.; Bo ꢁc a, R.; Mrozinski, J.; Bakalbassis, E. G.;
Perlepes, S. P. Polyhedron 2009, 28, 3373. (b) Biswas, B.; Pieper, U.;
Weyhermuller, T.; Chaudhuri, P. Inorg. Chem. 2009, 48, 6781. (c) Manca, G.;
Cano, J.; Ruiz, E. Inorg. Chem. 2009, 48, 3139. (d) Ran, J. W.; Zhang, S. Y.; Xu,
B.; Xia, Y. Z.; Guo, D.; Zhang, J. Y.; Li, Y. H. Inorg. Chem. Commun. 2008,
1, 73. (e) Aromí, G.; Bouwman, E.; Burzurí, E.; Carbonera, C.; Krzystek, J.;
Luis, F.; Schlegel, C.; van Slageren, J.; Tanase, S.; Tea, S. J. Chem.;Eur. J.
008, 14, 11158. (f) Moragues-Canovas, M.; Helliwell, M.; Ricard, L.; Riviere,
E.; Wernsdorfer, W.; Brechin, E.; Mallah, T. Eur. J. Inorg. Chem. 2004, 2219.
g) Pavlishchuk, V. V.; Kolotilov, S. V.; Addison, A. W.; Prushan, M. J.;
Schollmeyer, D.; Thompson, L. K.; Weyhermuller, T.; Goreshnik, E. A. Dalton
Trans. 2003, 1587. (h) Mikuriya, M.; Tanaka, K.; Inoue, N.; Yoshioka, D.; Lim,
J. W. Chem. Lett. 2003, 32, 126. (i) Du, M.; Bu, X.-H.; Guo, Y.-M.; Zhang, L.; Liao,
D.-Z.; Ribas, J. Chem. Commun. 2002, 1478. (j) Pavlishchuk, V. V.; Kolotilov, S. V.;
Addison, A. W.;Prushan, M. J.; Schollmeyer, D.; Thompson, L. K.; Goreshnik, E. A.
Angew. Chem., Int. Ed., Engl. 2001, 40, 4734. (k) Clemente-Juan, J. M.; Chansou,
B.; Donnadieu, B.; Tuchagues, J. P. Inorg. Chem. 2000, 39, 5515. (l) Saalfrank,
R. W.; Trummer, S.; Reimann, U.; Chowdhry, M. M.; Hampel, F.; Waldmann, O.
Angew. Chem., Int. Ed., Engl. 2000, 39, 3492. (m) Fallah, M. S. E.; Rentschler, E.;
Caneschi, A.; Gatteschi, D. Inorg. Chim. Acta 1996, 247, 231.
-
1
mol at 2 K. The negative θ value and the χ T vs T curve
M
reveal typical antiferromagnetic interactions between the
Mn(II) centers in polymer 2.
2-
According to the structural data, the μ -HEIDC
2
1
units link the Mn(II) ions into infinite chains. Hence the
0
2
2D layer has been constructed by 4,4 -bipy bridging these
chains. Obviously, there are two pathways to transmit the
(
0
magnetic interactions: μ -HEIDC- and 4,4 -bipy-bridge,
2
whereas the super exchange interactions between Mn(II)
(20) (a) Arora, H.; Lloret, F.; Mukherjee, R. Dalton Trans. 2009, 9759.
(b) Moroz, Y. S.; Kulon, K.; Haukka, M.; Gumienna-Kontecka, E.; Kozlowski,
H.; Meyer, F.; Fritsky, I. O. Inorg. Chem. 2008, 47, 5656. (c) He, C.; Duan, C.-Y.;
Fang, C.-J.; Liu, Y. J.; Meng, Q.-J. J. Chem. Soc., Dalton Trans. 2000, 1207.
(21) Zhang, W. X.; Xue, W.; Li, J. B.; Zheng, Y. Z.; Chen, X. M.
CrystEngComm 2008, 10, 1770.
(22) Huang, Y. Q.; Cheng, P. Inorg. Chem. Commun. 2008, 11, 66.

Article
Inorganic Chemistry, Vol. 49, No. 8, 2010 3787
Figure 5. The TGA curves for complexes 1-4.
0
ions by the 4,4 -bipy-bridge can be ignored because of the
0
long length of 4,4 -bipy ligands. On the other hand, until
now, no appropriate theory model has been established to
determine the magnetic coupling constant between metal
ions for a 2D layer polymeric complex. In order to
evaluate the magnetic interactions in 2, we employ an
approximate approach that has been used for similar
2
2,23
cases.
The magnetic susceptibility of 2 has been fitted
2
4
to the Fisher model of the isotropic Heisenberg anti-
ferromagnet, and later modified by Wagner and Fried-
berg for a Mn system of spin 5/2 which is
2
5
2þ
2
2
Ng β SðS þ 1Þ 1 þ u
χ ¼
3
KT
1 -u
where u is the well-known Langevin function defined as
u = coth[JS(S þ 1)/kT] - kT/[JS(S þ 1)] with g = 2.0,
S = 5/2 for Mn(II), and N, β, K, g, and T have their usual
meanings. Due to further assembly of the 1D chains into a
2D MOF, the fit function can be modified to include the
interchain coupling. The function, therefore, is
2
6
χ
χM
¼
1
0
2
2
-ð2zJ =Ng β Þχ
0
where J is the interchain exchange coupling constant and
z is the number of the nearest neighbor chains. The best
fitting for the data in the range of 2-300 K gives J =
-
1
0
-1
-
3
0.025 cm , zJ = -0.02 cm , and g = 2.0, with R =
P
P
-
4
2
1/2
.5ꢀ 10 , [R = [ (χ - χcalc) / χobs
]
]. The nega-
M M
Figure 6. Plots of experimental χ T vs T and 1/χ vs T of (a) 1, (b) 2,
obs
and (c) 3.
tive coupling constant J confirms the existence of an
antiferromagnetic exchange within in polymer 2.
-
1
mol (5.73 μB), which is slightly below the expected
Polymer 3: Variable-temperature magnetic study on 3
is performed over the temperature range of 2.0-300 K.
The variation of the inverse of the magnetic susceptibility,
3
-1
value of 4.38 cm K mol (5.92 μB) for magnetically
isolated high-spin Mn(II) (SMn= 5/2, g =2.0). This value
decreases smoothly to 0.444 cm K mol at 2 K. The
rapid decreases of χ T below 70 K and the negative θ
value are attributed to antiferromagnetic interactions
between Mn(II) centers in polymer 3.
As is mentioned in the crystallographic part, the 2D
structure of 3 can be viewed as chains linked by organic
ligands. Thus, we tried to theoretically fit the experimen-
tal data by the equation as in the case of polymer 2.
Unfortunately, we could not get a satisfactory result.
Obviously, the magnetic pathways between neighbor
Mn(II) ions of 3 are complicated, which could not be
simply dealt with as the case in 2. However, compared
3
-1
-
1
χM and χ T of 3 are shown in Figure 6c. The thermal
M
-
1
M
evolution of χM obeys the Curie-Weiss law, χM
=
C/(T - θ) in the whole temperature range with the Weiss
constant, θ, of -19.381 K and the Curie constant, C , of
M
3
-1
3
4
.39 cm K mol . At 300 K, the χ T value is 4.11 cm K
M
(
23) (a) Yao, Y. L.; Che, Y. X.; Zheng, J. M. Cryst. Growth Des. 2008, 8,
2
299. (b) Liu, B. L.; Xiao, H.-P.; Nfor, E. N.; Song, Y.; You, X. Z. Inorg. Chem.
Commun. 2009, 12, 8.
(
(
(
24) Fisher, M. E. Am. J. Phys. 1963, 32, 343.
25) Wagner, G. R.; Friedberg, S. A. Phys. Lett. 1964, 9, 11.
26) McElearney, J. N.; Merchant, S.; Carlin, R. L. Inorg. Chem. 1973, 12,
9
06.

3
788 Inorganic Chemistry, Vol. 49, No. 8, 2010
Zhang et al.
with the Weiss constant of 2 and 3 (θ: -10.438 and
Compounds 1-3 all show antiferromagnetic interactions
between the neighbor metal centers.
-
19.381 K, respectively), it is obvious that the antiferro-
magnetic coupling in 3 is stronger than that in 2, which
mainly results from the difference between their struc-
tures.
Acknowledgment. We gratefully acknowledge the fi-
nancial support by the National Natural Science Founda-
tion of China (20501017) and by the Key Project of Chinese
Ministry of Education (207067). We acknowledge the
project sponsored by the Scientific Research Foundation
for the Returned Overseas Chinese Scholars of Chinese
Ministry of Education and the Natural Science Founda-
tion of Henan Education Department (2007150040;
Because Cd(II) ion has no unpaired electrons, complex
is expected to be diamagnetic.
4
Conclusion
In summary, a series of novel metal-organic complexes
with architectural diversity has been successfully synthesized
under hydro(solvo)thermal conditions by fine control over
2009A150028) and Associate Professor Qingling Meng for
helpful advice.
solvent and pH values. The organic ligand H EIDC displays
3
various coordination modes, which can generate interesting
structures with metal ions ranging from molecular square
and two- to three-dimensional pillared layer structures.
Supporting Information Available: Crystallographic data in
CIF and pdf formats. This material is available free of charge via
the Internet at http://pubs.acs.org.