Zinc(II) and cadmium(II) complexes of Schiff bases derived from amino acids and pyridine-3-carboxaldehyde: Synthesis, crystal structures, and fluorescence

Article abstract of DOI:10.1080/00958972.2010.500664

Two d10 Schiff-base complexes, Zn₂(L₁) ₂(H₂O)₆ SO₄ (1) and Cd(L ₂)₂(H₂O)₄ (2) [HL1 = 3-((pyrid-3-yl)-methylene)aminobenzoic acid; HL2 = 4-((pyrid-3-yl)-methylene) aminobenzoic acid], have been synthesized and structurally characterized by elemental analyses, FT-IR spectra, and thermal studies, as well as single crystal X-ray diffraction. Complex 1 is a dinuclear macrocyclic structure with 22-membered rings and is assembled into a 3-D sandwich supramolecular network motif through H-bonding interactions; 2 is a mononuclear structure and is interlinked through H-bonding and stacking contacts to generate another 3-D supramolecular network. Furthermore, fluorescent properties of the two complexes are also reported.

Full text of DOI:10.1080/00958972.2010.500664

This article was downloaded by: [MacEwan University Libraries]
On: 16 October 2014, At: 10:40
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered
office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK
Journal of Coordination Chemistry
Publication details, including instructions for authors and
subscription information:
http://www.tandfonline.com/loi/gcoo20
Zinc(II) and cadmium(II) complexes
of Schiff bases derived from amino
acids and pyridine-3-carboxaldehyde:
synthesis, crystal structures, and
fluorescence
Zhi-Li Fang a & Qi-Xiang Nie b
a School of Basic Science , East China Jiaotong University ,
Nanchang 330013, P.R. China
b School of Civil Engineering and Architecture , East China
Jiaotong University , Nanchang 330013, P.R. China
Published online: 13 Jul 2010.
To cite this article: Zhi-Li Fang & Qi-Xiang Nie (2010) Zinc(II) and cadmium(II) complexes
of Schiff bases derived from amino acids and pyridine-3-carboxaldehyde: synthesis, crystal
structures, and fluorescence, Journal of Coordination Chemistry, 63:13, 2328-2336, DOI:
10.1080/00958972.2010.500664
To link to this article: http://dx.doi.org/10.1080/00958972.2010.500664
PLEASE SCROLL DOWN FOR ARTICLE
Taylor & Francis makes every effort to ensure the accuracy of all the information (the
“Content”) contained in the publications on our platform. However, Taylor & Francis,
our agents, and our licensors make no representations or warranties whatsoever as to
the accuracy, completeness, or suitability for any purpose of the Content. Any opinions
and views expressed in this publication are the opinions and views of the authors,
and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content
should not be relied upon and should be independently verified with primary sources
of information. Taylor and Francis shall not be liable for any losses, actions, claims,
proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or
howsoever caused arising directly or indirectly in connection with, in relation to or arising
out of the use of the Content.
This article may be used for research, teaching, and private study purposes. Any
substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing,
systematic supply, or distribution in any form to anyone is expressly forbidden. Terms &

Conditions of access and use can be found at http://www.tandfonline.com/page/terms-
and-conditions

Journal of Coordination Chemistry
Vol. 63, No. 13, 10 July 2010, 2328–2336
Zinc(II) and cadmium(II) complexes of Schiff bases derived
from amino acids and pyridine-3-carboxaldehyde: synthesis,
crystal structures, and fluorescence
ZHI-LI FANGy and QI-XIANG NIE*z
ySchool of Basic Science, East China Jiaotong University, Nanchang 330013, P.R. China
zSchool of Civil Engineering and Architecture, East China
Jiaotong University, Nanchang 330013, P.R. China
(Received 23 September 2009; in final form 22 April 2010)
Two d10 Schiff-base complexes, Zn2(L1)2(H2O)6 Á SO4 (1) and Cd(L2)2(H2O)4 (2) [HL1 ¼
3-((pyrid-3-yl)-methylene)aminobenzoic acid; HL2 ¼ 4-((pyrid-3-yl)-methylene)aminobenzoic
acid], have been synthesized and structurally characterized by elemental analyses, FT-IR
spectra, and thermal studies, as well as single crystal X-ray diffraction. Complex 1 is a dinuclear
macrocyclic structure with 22-membered rings and is assembled into a 3-D sandwich
supramolecular network motif through H-bonding interactions; 2 is a mononuclear structure
and is interlinked through H-bonding and ꢀ ꢀ ꢀ ꢀ ꢀ stacking contacts to generate another 3-D
supramolecular network. Furthermore, fluorescent properties of the two complexes are also
reported.
Keywords: Schiff base; H-bonding and ꢀ ꢀ ꢀ ꢀ ꢀ stacking interactions; Crystal structures;
Fluorescence
1. Introduction
The design and construction of metal coordination polymers based on metal ions and
multifunctional bridging ligands are of interest due to their intriguing topologies
and potential applications as functional materials [1–9]. The design and synthesis of
metal Schiff-base complexes through appropriate Schiff-base bridging ligands that are
capable of binding to metal ions are well-known examples in heterogeneous catalysis,
biological activity, magnetism, and photochemistry [10–17]. Through rational design,
various structures have already been obtained, such as helical-chain complexes [18, 19],
macrocycle complexes [20–23], and interpenetrated complexes [24]. It has been
thought that novel properties and potential applications would emerge from unusual
molecular structures and much effort toward the synthesis of unusual complexes
with useful physical–chemical properties and intriguing structural topologies has been
made [25–27].
*Corresponding author. Email: nieqixiang@126.com
Journal of Coordination Chemistry
ISSN 0095-8972 print/ISSN 1029-0389 online ß 2010 Taylor & Francis
DOI: 10.1080/00958972.2010.500664

Zinc(II) and cadmium(II) Schiff bases
2329
Aromatic amino acids and pyridine-3-carboxaldehyde can be condensed into
Schiff-base ligands after the dehydration of an amino and a carbonyl by nucleophilic
addition, and used to construct unusual metal coordination polymers based on the
following considerations: (i) the Schiff base is a multifunctional ligand with both
pyridine and carboxylate available to coordinate with metal ions; (ii) the designed
Schiff-base ligand through the adjusting sites of pyridine and carboxylate can be
optimized to construct different metal coordination polymers. In addition, d10 metal
ions can tolerate various coordination numbers and geometries and can also exhibit
excellent luminescent properties when bound to functional ligands [28, 29].
In this report, we synthesized two new d10 Schiff-base complexes, Zn2(L1)2(H2O)6 Á
SO4 (1) and Cd(L2)2(H2O)4 (2) [HL1 ¼ 3-((pyrid-3-yl)-methylene)aminobenzoic acid;
HL2 ¼ 4-((pyrid-3-yl)-methylene)aminobenzoic acid]. Both complexes were structurally
characterized by elemental analyses, thermal analyses, infrared (IR) spectra, and single
crystal X-ray diffraction. Single crystal X-ray structure analysis revealed that 1 is a
dinuclear macrocyclic structure, forming a 3-D supramolecular network via H-bonding,
while 2 is a mononuclear structure which is assembled into a 3-D supramolecular
network motif via H-bonding and ꢀ ꢀ ꢀ ꢀ ꢀ stacking interactions. Both complexes exhibit
intense fluorescent emissions at room temperature.
2. Experimental
2.1. Materials and physical measurements
All materials and reagents were obtained commercially and used without purification.
Elemental (C, H, N) analyses were performed on a Perkin-Elmer 240 element analyzer.
FT-IR spectra were recorded from KBr pellets at 4000–400 cmꢁ1 on a Nicolet 5DX
spectrometer. Thermogravimetric analyses (TGA) wereꢁc1arried out on a Perkin-Elmer
TGA 7 TG analyzer with a heating rate of 10ꢂC min from room temperature to
700ꢂC under nitrogen. Fluorescence spectra were recorded with an F-2500 FL
Spectrophotometer analyzer.
2.2. Synthesis of 1 and 2
Zn2(L1)2(H2O)6 Á SO4 (1). The Schiff base 3-((pyrid-3-yl)-methylene)aminobenzoic
acid (HL1) was synthesized by the condensation of 1 mmol pyridine-3-carboxaldehyde
and 1 mmol 3-aminobenzoic acid in an anhydrous methanol solution. Complex 1 was
synthesized from the reaction of 1 mmol HL1 and 1 mmol ZnSO4 Á 7H2O in 75%
methanol : water (3 : 1; v/v) mixture. Colorless block single crystals were obtained at
room temperature by slow evaporation of the solvent over a period of several days.
Anal. Calcd (%) for C26H30Zn2N4O14S: C, 39.73; H, 3.82; N, 7.13. Found (%):
C, 39.71; H, 3.79; N, 7.15. (KBr pellet) (cmꢁ1): 651, 698, 769, 827, 885, 933, 1031, 1053,
1091, 1151, 1394, 1438, 1473, 1541, 1591, 1606, 1631, 3091, 3109, 3412.
Cd(L2)2(H2O)4 (2). The Schiff base 4-((pyrid-3-yl)-methylene)aminobenzoic acid
(HL2) was prepared by the condensation of 1 mmol pyridine-3-carboxaldehyde
and 1 mmol 4-aminobenzoic acid in an anhydrous methanol solution. Complex 2 was
synthesized from the reaction of 1 mmol HL2 and 1 mmol Cd(NO3)2 ꢀ 4H2O in 75%

2330
Z.-L. Fang and Q.-X. Nie
Table 1. Crystallographic data and structure refinement summary for 1 and 2.
1
2
Empirical formula
Formula weight
Crystal system
Space group
C
785.34
Monoclinic
C2/c
26H30Zn2N4O14
S
C26H32CdN4O8
634.91
Monoclinic
P21/c
ꢂ
˚
Unit cell dimensions (A, )
a
b
c
ꢁ
ꢃ
ꢄ
33.6305(1)
11.9798(4)
7.6933(2)
90.00
97.5400(10)
90.00
3072.73(16), 4
1608
1.698
1.706
1.031
13.6111(1)
7.1768(1)
13.7381(1)
90.00
110.387(1)
90.00
1257.93(2), 2
644
3
˚
Volume (A ), Z
F (000)
Calculated density (mg cmꢁ3
)
1.676
0.927
1.017
Absorption coefficient (mmꢁ1
Goodness-of-fit on F2
Crystal size (mm3)
)
0.21 ꢃ 0.17 ꢃ 0.12
0.20 ꢃ 0.17 ꢃ 0.15
R1 ¼ 0.0198, wR2 ¼ 0.0479
R1 ¼ 0.0273, wR2 ¼ 0.0515
Final R indices [I 4 2ꢅ(I )]
R indices (all data)
R1 ¼ 0. 0.0406, wR2 ¼ 0.0948
R1 ¼ 0.0600, wR2 ¼ 0. 1055
P
P
P
P
2
2
R1 ¼ kFoj ꢁ jFck/ jFoj; wR2 ¼ {
[
WðFo2 ꢁ Fc2Þ ]/ ðFo2Þ }1/2
.
methanol : water (3 : 1; v/v). Two weeks later suitable single crystals of 2 were obtained
at room temperature by slow evaporation of the solvent. Anal. Calcd (%) for
C26H32CdN4O8: C, 49.14; H, 5.04; N, 8.82. Found (%): C, 49.11; H, 5.01; N, 8.84.
(KBr pellet) (cmꢁ1): 597, 696, 790, 891, 979, 1053, 1205, 1300, 1334, 1361, 1408, 1429,
1494, 1519, 1593, 2318, 2351, 2476, 2547, 2839, 2970, 3030, 3064, 3128, 3145, 3203.
2.3. X-ray crystallography
Single crystal X-ray diffraction data collections for 1 and 2 were performed on a Bruker
Apex II CCD diffractometer operating at 50 kV and 30 mA using Mo-Kꢁ radiation
˚
(ꢂ ¼ 0.71073 A) at 293 K. Data collection and reduction were performed using SMART
and SAINT software [30]. A multi-scan absorption correction was applied using
SADABS [30]. The two structures were solved by direct methods and refined by full-
matrix least squares on F2 using the SHELXTL program package [30]. Hydrogens were
located from difference Fourier maps and a riding mode. The crystal parameters and
details of the data collection and refinement are given in table 1. Selected bond lengths
and angles are given in table 2. Hydrogen bonds are given in table 3.
3. Results and discussion
3.1. Synthesis and characterization
The synthesis of 1 and 2 is described in the experimental section. In IR spectra, a strong
peak at 1591 cmꢁ1 for 1 and 1593 cmꢁ1 for 2 are attributed to C¼N stretch. The
features at 1541, 1394 cmꢁ1 for 1 and 1519, 1361 cmꢁ1 for 2 are associated with the

Zinc(II) and cadmium(II) Schiff bases
2331
ꢂ
˚
Table 2. Selected bond distances (A) and angles ( ) for 1 and 2.
1
Zn(1)–O(1)
Zn(1)–O(2)
Zn(1)–O(1w)
Zn(1)–O(2w)
Zn(1)–O(3w)
Zn(1)–N(1)i
2.201(3)
2.186(3)
2.138(3)
2.024(3)
2.099(3)
2.072(4)
O(3w)–Zn(1)–O(1w)
O(2w)–Zn(1)–O(2)
N(1)i–Zn(1)–O(2)
O(3w)–Zn(1)–O(2)
O(1w)–Zn(1)–O(2)
O(2w)–Zn(1)–O(1)
176.9(1)
155.1(1)
98.0(1)
93.1(1)
89.6(1)
95.6(1)
O(2w)–Zn(1)–N(1)i
O(2w)–Zn(1)–O(3w)
N(1)i–Zn(1)–O(3w)
O(2w)–Zn(1)–O(1w)
N(1)i–Zn(1)–O(1w)
106.7(1)
N(1)i–Zn(1)–O(1)
O(3w)–Zn(1)–O(1)
O(2w)–Zn(1)–O(1)
O(2)–Zn(1)–O(1)
157.7(1)
91.4(1)
91.3(1)
59.7(1)
89.5(1)
89.2(1)
88.7(1)
89.0(1)
2
Cd(1)–O(2w)
Cd(1)–N(1)
Cd(1)–O(1W)
2.2871(15)
2.3185(16)
2.3384(16)
N(1)–Cd(1)–N(1)i
180.0
94.32(6)
85.68(6)
O(2w)i–Cd(1)–O(1w)
O(2w)–Cd(1)–O(1w)
O(2w)i–Cd(1)–O(2w)
O(2w)i–Cd(1)–N(1)
O(2w)–Cd(1)–N(1)
180.0
87.69(6)
92.33(5)
N(1)–Cd(1)–O(1w)
N(1)i–Cd(1)–O(1w)
88.17(6)
91.79(6)
i
i
Symmetry codes 1: ꢁx þ 1/2, ꢁy þ 3/2, ꢁz; 2: ꢁx þ 1, ꢁy, ꢁz þ 1.
Table 3. Hydrogen bond data for 1 and 2.
d(D–H) (A) d(H ꢀ ꢀ ꢀ A) (A) d(D ꢀ ꢀ ꢀ A) (A) ff(DHA) (ꢂ)
˚
˚
˚
D–H ꢀ ꢀ ꢀ A
1
O(1w)–H(1w) ꢀ ꢀ ꢀ O(3)i
O(1w)–H(1w) ꢀ ꢀ ꢀ O(5)ii
O(1w)–H(2w) ꢀ ꢀ ꢀ O(1)iii
O(2w)–H(3w) ꢀ ꢀ ꢀ O(4)i
O(2w)–H(3w) ꢀ ꢀ ꢀ O(6)ii
O(2w)–H(4w) ꢀ ꢀ ꢀ O(4)iv
O(2w)–H(4w) ꢀ ꢀ ꢀ O(4)v
O(2w)–H(5w) ꢀ ꢀ ꢀ O(1)iii
O(3w)–H(6w) ꢀ ꢀ ꢀ O(6)vi
O(3w)–H(6w) ꢀ ꢀ ꢀ O(5)vii
0.82(1)
0.82(1)
0.81(1)
0.82(1)
0.82(1)
0.78(1)
0.78(1)
0.82(1)
0.78(1)
0.78(1)
2.02(1)
1.91(1)
2.01(4)
2.10(1)
2.05(2)
2.13(1)
1.96(2)
2.00(4)
2.03(2)
2.03(2)
2.808(1)
2.703(1)
2.810(5)
2.864(1)
2.724(2)
2.851(1)
2.731(2)
2.753(2)
2.802(2)
2.688(2)
160(1)
163(4)
169(4)
154(2)
139(2)
155(1)
169(2)
152(2)
168(2)
141(1)
2
O(1w)–H(1w) ꢀ ꢀ ꢀ O(2)i
O(1w)–H(2w) ꢀ ꢀ ꢀ O(2)ii
O(2w)–H(3w) ꢀ ꢀ ꢀ O(2)iii
O(2w)–H(4w) ꢀ ꢀ ꢀ O(1)ii
0.82(2)
0.82(2)
0.81(2)
0.82(2)
1.99(2)
2.03(2)
1.98(2)
1.88(2)
2.804(2)
2.836(2)
2.765(2)
2.689(2)
173(2)
170(2)
163(2)
173(2)
Symmetry transformations used to generate equivalent atoms for 1: i 1/2 ꢁ x, 1/2 ꢁ y, 2 ꢁ z; ii 1/2 þ x,
1/2 ꢁ y, 1/2 þ z; iii x, ꢁy, 1/2 þ z; iv 1/2 ꢁ x, 1/2 ꢁ y, 2 ꢁ z; v 1/2 þ x, 1/2 ꢁ y, 1/2 þ z; vi 1/2 ꢁ x, 1/2 ꢁ y,
vii
i
ii
iii
1 ꢁ z; 1/2 þ x, 1/2 ꢁ y, ꢁ1/2 þ z; for 2: 1 þ x, 3/2 ꢁ y, 1/2 þ z; 2 ꢁ x, 2 ꢁ y, ꢁz; 1 þ x, 5/2 ꢁ y,
1/2 þ z.
asymmetric (COO) and symmetric (COO) stretching. A broad band at 3412 and
3203 cmꢁ1 for 1 and 2, respectively, may be assigned to ꢆ(O–H) of water.
3.2. Crystal structures
3.2.1. The structure of 1. Single crystal X-ray structure analysis shows that 1 is a
dinuclear macrocyclic structure, belonging to a monoclinic crystal system space

2332
Z.-L. Fang and Q.-X. Nie
Figure 1. View of the asymmetric unit of 1. All hydrogens were omitted for clarity.
group C2/c. An ORTEP view of the asymmetric unit of 1 is shown in figure 1. In the
dinuclear structure, each Zn(II) is in a distorted octahedral coordination geometry,
˚
defined by one pyridyl nitrogen (Zn–N ¼ 2.072(4) A), two carboxyl oxygens and three
˚
aqua ligands [Zn–O ¼ 2.024(3) ꢄ 2.201(3) A] [31]. The Schiff-base ligand has an imine
˚
bond length of 1.260(5) A, clearly indicating almost double-bond character [32]. Two
symmetrically related L1 ligands interlink two Zn(II) ions to generate a 22-membered
˚
macrocyclic host unit with a Zn ꢀ ꢀ ꢀ Zn separation of 10.6(1) A. The pyridyl and phenyl
moieties of L1 are non-coplanar with a dihedral angle of 22.67(3)ꢂ. Opposite corners
of the host unit, made up of Zn(OH2)3, play a crucial role in assembly of the structure
of 1. The corners act as both H-bonding donors and acceptors (table 3), resulting in
a smooth layer in the bc-plane. The H-bonding acceptors of independent SO24ꢁ situate
in the middle of the layers, interconnecting adjacent layers via intermolecular
H-bonding interactions to form a 3-D sandwich supramolecular network (figure 2).
3.2.2. The structure of 2. Single crystal X-ray structure analysis shows that 2
is mononuclear, crystallizing in a monoclinic crystal system space group P21/c.
An ORTEP view of the asymmetric unit of 2 is shown in figure 3. The Cd(II) lies on
an inversion center and is coordinated by two nitrogens from two L2 ligands and four
˚
waters in a distorted octahedral geometry. The distances [Cd–O ¼ 2.288(1)–2.340(2) A;
˚
Cd–N ¼ 2.318(2) A) fall in normal ranges [33]. The bond distance of the imine
˚
(1.266(3) A) confirms the double-bonded character of the Schiff-base ligand. The
dihedral angle between pyridyl and phenyl of L2 is 32.96ꢂ. In 2, the deprotonated L2
is an H-bond acceptor, while in the central unit, Cd(OH2)4 is a H-bond donor; as a
result, a 3-D supramolecular network is generated (figure 4). The network is further
stabilized by ꢀ–ꢀ stacking interactions. The centroid–centroid distance and dihedral

Zinc(II) and cadmium(II) Schiff bases
2333
Figure 2. Packing diagram of 1. The hydrogen bonds are indicated by dashed lines.
Figure 3. View of the asymmetric unit of 2. All hydrogens were omitted for clarity.
ꢂ
˚
angle between pyridyl plane and phenyl plane are 3.635 A and 4.08 , respectively,
indicating a normal ꢀ ꢀ ꢀ ꢀ ꢀ contact [34].
3.3. Thermal and luminescent properties
For 1, TGA studies indicated first weight loss (13.7%) in the range of 61–150ꢂC,
attributed to the loss of six molecules of water (Calcd 13.8%). In the range 150–323ꢂC,

2334
Z.-L. Fang and Q.-X. Nie
Figure 4. Packing diagram of 2. The hydrogen bonds and ꢀ–ꢀ stacking interactions are indicated by
dashed lines.
Figure 5. Solid state fluorescent emission spectra of HL1 and 1.
little weight is lost indicating a stable framework. The second weight loss of 64.9%
(Calcd 65.4%) from 323 to 623ꢂC corresponds to the loss of the Schiff base. The final
residual weight is 21.0% (Calcd 20.8%) corresponding to ZnO.
For 2, the first weight loss (11.5%) from 89ꢂC to 132ꢂC corresponds to the loss
of four molecules of water (Calcd 11.3%). A stable framework exists over 298ꢂC.
The second weight loss of 67.9% between 298ꢂC and 548ꢂC is attributed to the loss
of the Schiff base (Calcd 68.4%). Upon further heating, the mass is unchanging with
a weight of 20.1%, corresponding to CdO (Calcd 20.2%) (Supplementary material).
Owing to the excellent luminescent properties of d10 metal ions, the solid state
photoluminescence of HL1, HL2, 1, and 2 were investigated at room temperature.
Upon excitation at 305 nm, the emission spectrum of 1 shows a broad emission with

Zinc(II) and cadmium(II) Schiff bases
2335
Figure 6. Solid state fluorescent emission spectra of HL2 and 2.
the maximum located at 402 nm, whereas free HL1 displays a typical ligand-based
fluorescent emission (422 nm) as evident by the obvious vibronic structure (figure 5).
Therefore, we tentatively ascribe the fluorescence to metal-perturbed, ligand-centered
transitions, probably mixed with some ligand to metal charge transfer character [35–37].
Upon excitation at 285 nm, the maximal emission of 2 at 346 nm (figure 6) is essentially
the same as that of free HL2; therefore, we believe that the observed luminescence of 2
can be ascribed to ligand-based ꢀ ꢀ ꢀ ꢀ ꢀ* transitions.
4. Conclusion
We report two new d10 metal Schiff-base complexes exhibiting excellent photolumines-
cence at room temperature. Characterization of the two complexes was by elemental
analyses, FT-IR, thermal studies, and X-ray structural analyses. Use of this successful
synthetic approach provides us with a potential route to other metal Schiff-base
complexes with interesting structures, topologies, and properties.
Supplementary material
Crystallographic data for the structure reported in this article have been deposited with
the Cambridge Crystallographic Data Centre, CCDC No. 686227 and No. 686228.
Copies of this information may be obtained free of charge from the Director, CCDC,
12 Union Road, Cambridge, CB2 1EZ, UK (Fax: þ44 1223 336 033, E-mail:
deposit@ccdc.cam.ac.uk or www: http://www.ccdc.cam.ac.uk), or is also be available
from the author on request.
Acknowledgment
This work was financially supported by East China Jiaotong University.

2336
Z.-L. Fang and Q.-X. Nie
References
[1] C. Benneli, D. Gatteschi. Chem. Rev., 102, 2369 (2002).
[2] P.J. Stang, B. Olenyuk. Acc. Chem. Res., 30, 502 (1997).
[3] S. Batten, R. Robson. Angew. Chem. Int. Ed., 37, 1460 (1998).
[4] A.K. Cheetham, G. Ferey, T. Loiseau. Angew. Chem. Int. Ed., 38, 3268 (1999).
[5] M. Eddaoudi, D.B. Moler, H.L. Li, B.L. Chen, T.M. Reineke, M. O’Keeffe, O.M. Yaghi. Acc. Chem.
Res., 34, 319 (2001).
[6] J. Lisowski, P. Starynowicz. Inorg. Chem., 38, 1351 (1999).
[7] U. Mueller, M. Schubert, F. Teich, H. Puetter, K. Schierle-Arndt, J.J. Pastre. Mater. Chem., 16, 626
(2006).
[8] K. Kumazawa, K. Biradha, T. Kusukawa, T. Okano, M. Fujita. Angew. Chem. Int. Ed., 42, 3909 (2003).
[9] E.A. Behrens, D.M. Poojary, A. Clearfield. Chem. Mater., 8, 1236 (1996).
[10] A.S. Abu-Surrah, H.M. Abdel-Halim, F.M. Al-Qaisi. Z. Anorg. Allg. Chem., 634, 956 (2008).
[11] R.T. Ruck, E.N. Jacobsen. J. Am. Chem. Soc., 124, 2882 (2002).
[12] Z.H. Chohan, M. Arif, M. Sarfraz. Appl. Organomet. Chem., 21, 294 (2007).
[13] M.S. Iqbal1, I.H. Bukhari, M. Arif. Appl. Organomet. Chem., 19, 864 (2005).
[14] C.M. Qi, X.X. Sun, S. Gao, S.L. Ma, D.Q. Yuan, C.H. Fan, H.B. Huang, W.X. Zhu. Eur. J. Inorg.
Chem., 3663 (2007).
[15] M. Yuan, F. Zhao, W. Zhang, F. Pan, Z.-M. Wang, S. Gao. Chem. Eur. J., 13, 2937 (2007).
[16] J. Sanchez-Marin, J.P. Malrieu. J. Am. Chem. Soc., 107, 1985 (1985).
[17] S. Knoblauch, F. Hartl, D.J. Stufkens, H. Hennig. Eur. J. Inorg. Chem., 303 (1999).
[18] C. Janiak, A.C. Chamayou, M. Uddin, K.S. Hagen, M. Enamullah. Dalton Trans., 19, 3698 (2009).
[19] G. Bhargavi, M.V. Rajasekharan, J.P. Tuchagues. Inorg. Chim. Acta, 360, 1819 (2007).
[20] C.G. Yan, L. Li, W.L. Liu. J. Coord. Chem., 62, 2118 (2009).
[21] Y. Yamadaa, S. Takenouchia, Y. Miyoshia, K. Okamotob. J. Coord. Chem., 62, 996 (2009).
[22] M. Fondo, A.M. Garcia-Deibe, N. Ocampo, J. Sanmartin, M.R. Bermejo. Polyhedron, 27, 2585 (2008).
[23] S. Sreedarana, K. Shanmuga Bharathia, A. Kalilur Rahimana, K. Rajesha, G. Nirmalaa, L. Jagadishb,
V. Kaviyarasanb, V. Narayanana. Polyhedron, 27, 1867 (2008).
[24] Q. Wang, J.Y. Zhang, C.F. Zhuang, Y. Tang, C.Y. Su. Inorg. Chem., 48, 287 (2009).
[25] O. Kotova, S. Semenov, S. Eliseeva, S. Troyanov, K. Lyssenko, N. Kumina. Eur. J. Inorg. Chem., 3467
(2009).
[26] S. Salehzadeh, M.D. Ward, H. Adams. Inorg. Chem. Commun., 12, 433 (2009).
[27] P.F. Yan, W.B. Sun, C.H. Li, G.M. Nie, T. Gao, Z.Y. Yue. J. Coord. Chem., 60, 1973 (2007).
[28] A.X. Zhu, J.P. Zhang, Y.Y. Lin, X.M. Chen. Inorg. Chem., 47, 7389 (2008).
[29] Y.C. Qiu, Z.H. Liu, Y.H. Li, H. Deng, R.H. Zeng, M. Zeller. Inorg. Chem., 47, 5122 (2008).
[30] Bruker Advanced X-ray Solutions. APEXII (Version 3.1.2), Bruker AXS Inc., Madison, Wiskonsin,
USA (2004); G.M. Sheldrick. SHELXL-97, Program for X-ray Crystal Structure Refinement, University
of Gottingen, Gottingen, Germany (1997).
¨
¨
[31] Y.C. Qiu, K.N. Wang, Y. Liu, H. Deng, F. Sun, Y.P. Cai. Inorg. Chim. Acta, 360, 1819 (2007).
[32] C.J. Brown, M.L. Colclough. Acta Cryst. C, 39, 300 (1983).
[33] Z.X. Du, J.X. Li, L.Y. Wang. J. Coord. Chem., 62, 2411 (2009).
[34] E.C. Lee, D. Kim, P. Jurecka, P. Tarakeshwar, P. Hobza, K.S. Kim. J. Phys. Chem. A, 111, 3446 (2007).
[35] Q. Zhang, J.P. Ma, P. Wang, Z.Q. Shi, Y.B. Dong, R.Q. Huang. Cryst. Growth Des., 8, 2581 (2008).
[36] T.Z. Yu, W.M. Su, W.L. Li, Z.R. Hong, R.N. Hua, M.T. Li, B. Li, Z.Q. Zhang, Z.Z. Hu. Inorg. Chim.
Acta, 359, 2246 (2006).
[37] H.Y. Wu, N. Wang, S.T. Yue, Y.L. Liu. J. Coord. Chem., 62, 2511 (2009).