Two novel entangled metal-organic networks constructed from 4,4′-bis(2-methylimidazol-1-ylmethyl)biphenyl and dicarboxylates: From polycatenated 2D + 2D → 3D framework to polyrotaxane-like 2D + 2D → 2D layer

Article abstract of DOI:10.1039/c2ce25706h

Two novel entangled metal-organic networks, namely [Cd(bmimbp)(bdc)] _n (1) and [Zn(bmimbp)(tbtpa)]_n (2) (bmimbp = 4,4′-bis(2-methylimidazol-1-ylmethyl)biphenyl, H₂bdc = 1,3-benzenedicarboxylic acid, H₂tbtpa = tetrabromoterephthalic acid), exhibit a polycatenated 2D + 2D → 3D framework and a polyrotaxane-like 2D + 2D → 2D layer, respectively. Moreover, the thermal stabilities and photoluminescent properties are also discussed.

Full text of DOI:10.1039/c2ce25706h

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COMMUNICATION
Two novel entangled metal–organic networks constructed from
4,49-bis(2-methylimidazol-1-ylmethyl)biphenyl and dicarboxylates:
From polycatenated 2D + 2D A 3D framework to polyrotaxane-like 2D
+ 2D A 2D layer{
Di Sun,*a Zhi-Hao Yan,ab Yong-Kai Deng,a Shuai Yuan,a Lei Wang*b and Dao-Feng Suna
Received 8th May 2012, Accepted 15th August 2012
DOI: 10.1039/c2ce25706h
and rods or string elements that can thread through these loops, in
which the different motifs cannot be disentangled without breaking
links. However, until now, polycatenated and polyrotaxane-like
coordination networks have usually been constructed from lower
dimensional motifs (0D A 1D or 2D; 1D A 2D or 3D), but 2D
coordination networks formed from polycatenated or polyrotax-
ane-like coordination networks (2D A 2D or 3D) have, by
comparison, been rarely reported.7 Therefore, further research is
necessary to enrich and develop this field.
Two novel entangled metal–organic networks, namely
[Cd(bmimbp)(bdc)]n (1) and [Zn(bmimbp)(tbtpa)]n (2) (bmimbp
= 4,49-bis(2-methylimidazol-1-ylmethyl)biphenyl, H2bdc = 1,3-
benzenedicarboxylic acid, H2tbtpa = tetrabromoterephthalic
acid), exhibit a polycatenated 2D + 2D A 3D framework and a
polyrotaxane-like 2D
+ 2D A 2D layer, respectively.
Moreover, the thermal stabilities and photoluminescent proper-
ties are also discussed.
As an ongoing investigation on synthesis of novel entangled
networks,8 we selected the conformationally flexible ligand
Recently, mixed ligand assembly strategies incorporating pyridine-
or imidazole-based ligands and polycarboxylates have been
verified as an effective approach for the construction of
coordination networks.1,2 Among these, entangled networks have
attracted particular attention for crystal engineers not only due to
their intrinsic aesthetic appeal and potential properties, but also for
their intricate molecular architectures and topologies.3 There have
been some comprehensive reviews by Robson, Batten, and Ciani’s
groups about fascinating entangled structures and their classifica-
tion.4 Interpenetration as an important subgroup of entanglement,
has been a long-standing fascination for chemists, and a variety of
appealing interpenetrated networks have been constructed.5
Moreover, the rapid advance of crystal engineering has led to
novel and more intricate types of entanglement being discovered,
such as polyrotaxane, polycatenane and polyknotting as well as
self-threading.6 As important members in the realm of entangled
networks, polycatenated and polyrotaxane-like networks have
special structural features: polycatenated networks have a higher
dimensionality than that of the component motifs and polyrotax-
ane-like networks are characterized by the presence of closed loops
4,49-bis(2-methylimidazol-1-ylmethyl)biphenyl (bmimbp) as
a
main ligand, which has two methylene groups between the
biphenyl and imidazole ring which freely rotate around the C–C
bonds, giving different possible conformations such as syn and
anti. Thus it may be possible to yield novel entangled coordination
networks. On the other hand, as indicated by a CSD (Cambridge
Structure Database) survey with the help of ConQuest version
1.3,9 only one bmimbp-based coordination network, [Ni2
(bmimbp)2(dipicolinate)2(H2O)2?4H2O]n, has been documented,10
while other bmimbp-based coordination networks with or without
auxiliary ligands have not yet been disclosed. Given the above
consideration and our previous work, herein, we synthesized and
characterized two novel entangled metal–organic networks,
namely [Cd(bmimbp)(bdc)]n (1) and [Zn(bmimbp)(tbtpa)]n (2)
(bmimbp = 4,49-bis(2-methylimidazol-1-ylmethyl)biphenyl, H2bdc
= 1,3-benzenedicarboxylic acid, H2tbtpa = tetrabromoterephthalic
acid), exhibiting polycatenated 2D + 2D A 3D framework and
polyrotaxane-like 2D + 2D A 2D net, respectively (Scheme 1).
These entangled fashions in crystal structures, especially the latter,
provided new insights into the entangled structures that can be
achieved by crystal engineering concepts.
aKey Lab of Colloid and Interface Chemistry, Ministry of Education,
School of Chemistry and Chemical Engineering, Shandong University,
Jinan, 250100, P. R. China. E-mail: dsun@sdu.edu.cn
Complexes 1 and 2 were prepared by hydrothermal reaction of
Cd(NO3)2?4H2O or Zn(NO3)2?6H2O, bmimbp, H2bdc or H2tbtpa,
and KOH in methanol–DMF (1 mL, v/v = 1 : 1) (see ESI{). The
compositions of 1 and 2 were further deduced from X-ray single
crystal diffraction, elemental analysis and IR spectra. The solid-
state FT-IR spectra (Fig. S1, ESI{) of complexes 1 and 2 show the
characteristic bands for deprotonated carboxyl groups. The
powder X-ray diffraction (PXRD) patterns of 1 and 2 are
bKey Laboratory of Eco-chemical Engineering, Ministry of Education,
College of Chemistry and Molecular Engineering, Qingdao University of
Science and Technology, Qingdao, 266042, P. R. China.
E-mail: inorchemwl@126.com
{ Electronic supplementary information (ESI) available: Synthetic and
crystallographic details, additional measurements, figures and tables.
CCDC reference numbers 880881 and 880882. For ESI and crystal-
lographic data in CIF or other electronic format see DOI: 10.1039/
c2ce25706h
7856 | CrystEngComm, 2012, 14, 7856–7860
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lographically unique bmimbp ligands, respectively, which are
responsible for the formation of highly undulated sheet. The anti-
bmimbp and m2-bdc in a syn–syn mode link Cd(II) ions to generate
a 2D undulating sheet (Fig. 1b). From a topological viewpoint,
this sheet contains one type of node (Cd1 ion) and two types of
linkers (bmimbp and bdc ligands). In 1, Cd1 ions as 4-connected
nodes are bridged by 2-connected bmimbp and bdc ligands, so the
2D sheet can be simplified to a 44-sql sheet,11 which contains a
˚
window of 10.0 6 17.4 A and exhibits a highly undulated
˚
character with a thickness of about 18 A (Fig. 1c).
A more impressive structural characteristic of complex 1 is that
each highly undulated 2D 44-sql single sheet is simultaneously
penetrated by the two nearest neighbouring ones (one above and
the other below), which have parallel but not coincident mean
planes (Fig. 2). In contrast to simple 2D A 2D interpenetration,12
this resulting structure can be described by a 2D A 3D
‘polycatenated network’ because this network results in the overall
network with a higher dimensionality than each component of the
single motif. The high degree of entanglement is due to: (i) the
large enough windows of the net; (ii) the highly undulated nature
of the single 44-sql sheet. Among the known interpenetrated 44-sql
networks in coordination networks, most examples show 2D A
2D parallel interpenetration or 2D A 3D inclined polycatenation
and only limited 2D A 3D polycatenation structures have been
observed in a parallel mode.13
Scheme 1 Synthetic procedures of 1 and 2.
consistent with the simulated pattern derived from the X-ray single
crystal data, implying that the bulk sample is the same as the single
crystal (Fig. S2, ESI{).
X-ray single-crystal diffraction analysis{ reveals that 1 is a
polycatenated 2D + 2D A 3D framework based on an undulated
44-sql single sheet. It crystallizes in the triclinic crystal system with
When H2bdc was replaced by H2tbtpa, we obtained complex 2
as a polyrotaxane-like 2D + 2D A 2D network based on a 63-hcb
single sheet. X-ray single-crystal diffraction analysis{ reveals that
the asymmetric unit of 2 contains one Zn(II) ion, one bmimbp
ligand and two halves of tbtpa ligands (Fig. 3a). The Zn1 is located
in a distorted tetrahedral geometry (t4 = 0.93),14 completed by two
O atoms from two different tbtpa ligands and two N atoms from
two different bmimbp. The bond angles around the Zn(II) center
vary from 96.6(3) to 115.0(3)u, and the bond lengths from 1.947(7)
¯
space group of P1 with an asymmetric unit that contains one
Cd(II) ion, two crystallographically unique bmimbp ligands lying
¯
on a site of 1 symmetry and a bdc dianion. As depicted in Fig. 1a,
the Cd1 is six-coordinated by four O atoms and two N atoms from
two different bdc ligands and two different bmimbp ligands,
respectively. The bond angle around the Cd(II) ion vary from
52.43(12) to 136.28(13)u, and the bond lengths from 2.244(3) to
˚
2.584(4) A. The flexible bmimbp ligand in 1 shows an anti
conformation and the two phenyl rings are perfectly coplanar as
imposed by the inversion center. The dihedral angles between
imidazole and phenyl rings are 76.3 and 84.0u for two crystal-
˚
to 2.030(8) A. In 2, bmimbp shows a syn-conformation, different
from that in 1. The dihedral angles between imidazole and phenyl
rings are 73.4 and 89.0u, while this parameter for the two central
phenyl rings is 28.0u. Two crystallographically unique m2-tbtpa
ligands show different coordination conformations, syn–syn and
anti–anti modes, respectively. The two bmimbp ligands link a pair
˚
of Zn(II) centers to form Zn2(bmimbp)2 loops (8.5 6 16.0 A,
…
corresponding to the Zn Zn distance and shortest intracycle C–C
separation).
The extension of Zn2(bmimbp)2 loops into a 2D honeycomb-
like sheet (Fig. 3b) is accomplished by m2-tbtpa with an anti–anti
mode. Each hexagon has four edges represented by the tbtpa
Fig. 1 Crystal structure of 1. Thermal ellipsoid (50%) plot of 1 showing
the coordination environment of the Cd(II) ion (a). Symmetry codes: (i) x
+ 1, y, z; (ii) 2x + 2, 2y 2 1, 2z + 1; (iii) 2x + 1, 2y, 2z + 2. Ball and
stick view of the 2D undulated 44-sql sheet along two different orientations
(b) and (c). Cd: purple; N: blue; O: red; C: grey.
Fig. 2 (a) Simplified single 44-sql sheet constructed by Cd(II) centers
(purple balls) bmimbp (green rods) and bdc ligands (red rods). (b).
Schematic drawing of the 2D + 2D A 3D polycatenated network.
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because these systems require the presence of loops and rods which
can thread the loops. One of the most famous examples similar to
2 is [Zn(1,4-bix)2(NO3)2?4.5H2O]n (bix = bis(imidazol-1-ylmethyl)-
benzene) reported by Robson and co-workers,16 in which both the
loop and rod elements are flexible bix ligands. Following this,
some mixed-ligand polyrotaxane-like networks17 containing flex-
ible N-donors as loop linker and aromatic dicarboxylate as rods,
such as [Co2(1,3-bix)2(bpea)2]n (H2bpea
= biphenylethene-
4,49-dicarboxylic acid), [Cd(tp)(bpp)(H2O)?H2O]n (H2tp = ter-
ephthalic acid, bpp = 1,3-bis(4-pyridyl)propane), and [Co(bimh)
(bpdc)]n (bimh = 1,6-bis(imidazol-1-yl)-hexane, H2bpdc = biphe-
nyl-4,49-dicarboxylate), were also reported.
It has been shown that the variation of entangled fashions in
complexes 1 and 2 are mainly associated with the conformations of
bmimbp ligand and coordination modes of auxiliary dicarbox-
ylates (Table 1). The combination of these two factors are key to
influence the final entangled fashions, which depends on the
competition and adaptability of the components. In 1 and 2, the
main ligand bmimbp adopts the completely different conforma-
tions of anti and syn, respectively. The former contributes to the
formation of a highly undulated sheet and the latter to the loop.
The auxiliary dicarboxylates (bdc and tbtpa) adopt the same m2-
g1,g1 coordination mode but different coordination conforma-
tions. The bdc adopts a syn–syn mode in 1, but tbtpa shows both
syn–syn and anti–anti in 2. Notably, steric hindrance of four Br
atoms on tbtpa imposed the plane determined by the carboxyl
group being nearly perpendicular to the central phenyl ring, while
the carboxyl group is nearly coplanar with central phenyl ring for
the bdc ligand. These results show that dicarboxylates and
bmimbp can fine-tune themselves to match with the coordination
preference of metal centers and lower the energetic arrangement in
the self-assembly process.
Fig. 3 Crystal structure of 2. Thermal ellipsoid (50%) plot of 2 showing
the coordination environment of the Zn(II) ion (a). Ball and stick view of a
2D 63-hcb single sheet (b). The polyrotaxane-like 2D + 2D A 2D network.
Symmetry codes: (i) 2x + 1, 2y21, 2z + 2; (ii) 2x, 2y, 2z + 1; (iii) 2x +
1, 2y + 1, 2z + 2.
ligands and two edges replaced by Zn2(bmimbp)2 loops. That is to
say, each Zn atom is connected to three others: two via single m2-
tbtpa bridges and the third one by pairs of bmimbp ligands. In this
analysis, this 2D sheet could be simplified to a 3-connected net
with 63-hcb topology in which the loops are converted into a
2-connected node, resulting in a network description which cannot
properly describe the topology of interpenetration4c as it would
require links to pass through the middle of other links. Thus to
obtain a network description that can be used to further describe
the interpenetration, one must include the 2-membered rings (i.e.,
the ‘‘loops’’), resulting in the overall 4-connected (2?65) topology.
The most striking feature of complex 2 is that two identical 2D
single 63-hcb sheets are interlocked with each other in a 2D A 2D
parallel fashion thus directly leading to the formation of a 2D
polyrotaxane-like structure containing rotaxane-like motifs
(Fig. 3c). As shown in Fig. 4a, the Zn2(bmimbp)2 loops of each
sheet are threaded by one Zn-tbtpa-Zn rod of the other sheet, and
vice versa. Although 2D A 2D parallel interpenetrated 63-hcb nets,
in particular with most typical AgN3 coordination environments,
have appeared in the literature,15 reports of the polyrotaxane-like
network involving a 2D 63-hcb sheet are exceedingly sparse
To investigate the thermal stability of both complexes,
thermogravimetric analysis (TGA) experiments were carried out
in the temperature range of 30–600 uC under a flow of nitrogen
with a heating rate of 10 uC min21 (Fig. 5). They exhibit similar
thermal behaviors. There is no obvious weight loss before 360 and
307 uC for 1 and 2, respectively. Then the frameworks begin to
collapse, accompanying the loss of organic ligands.
The photoluminescence spectra of the complexes 1 and 2 are
shown in Fig. 6. The ligand bmimbp displays photoluminescence
with emission maximum at 323 nm (lex = 300 nm). It can be
Table 1 Comparison of conformations of bmimbp and dicarbox-
ylates in 1 and 2a
1
2
bmimbp
Dicarboxylates
Fig. 4 (a) Stereochemical relationship between a Zn-tbtpa-Zn rod and a
Zn2(bmimbp)2 loop. (b) Schematic view of the simplified polyrotaxane-like
2D + 2D A 2D network in 2.
a
Purple: Cd or Zn; yellow: Br; red: O; blue: N; grey: C.
7858 | CrystEngComm, 2012, 14, 7856–7860
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ylates are key points to influence the final entangled fashions.
Moreover, their thermal stabilities and emissive behaviors were
also discussed.
This work was supported by the NSFC (Grant Nos. 21201110
and 21271117), the Independent Innovation Foundation of
Shandong University (2011GN030), the Special Fund for
Postdoctoral Innovation Program of Shandong Province
(201101007) and the China Postdoctoral Science Foundation
(2012M511010). Dr Sun also thanks the help from Jinan Henghua
Sci. & Tec. Co., Ltd. for the synthesis of the bmimbp ligand.
References
¯
{ Crystal data for 1: C30H26N4O4Cd, M = 618.95, triclinic, space group P1
˚
(no. 2), Z = 2, T = 298(2) K, a = 9.995(2) A, b = 11.410(3) A, c = 11.572(3)
˚
3
˚
˚
A, a = 87.877(4)u, b = 88.749(4)u, c = 83.876(3)u, V = 1311.1(6) A , m(Mo-
Ka) = 0.877, 6456 reflections measured, 4534 unique (Rint = 0.0174) which
were used in all calculations. The final wR2 was 0.1043 (all data) and R1
was 0.0382 (.2s(I)). Crystal data for 2: C30H22Br4N4O4Zn, M = 887.53,
Fig. 5 The TGA curves of 1 and 2.
¯
˚
triclinic, space group P1 (no. 2), Z = 2, T = 298(2) K, a = 10.237(12) A, b =
˚
presumed that this peak originate from the p*Ap transition. To
the best of our knowledge, the emission of dicarboxylate belongs
to p*An transitions which is very weak compared to that of the p*
A p transition of the bmimbp, so the dicarboxylates almost have
no contribution to the fluorescent emission of as-synthesized
complexes.18 Upon complexation of these ligands with Cd(II) or
Zn(II) ions, red-shifted emissions are observed at 395 nm for 1 and
410 nm for 2, under 320 nm excitation, respectively. Owing to their
d10 electronic configuration, Cd(II) and Zn(II) are difficult to
oxidize or reduce, so the emissions here are neither metal-to-ligand
charge transfer nor ligand-to-metal charge transfer. Since the
profiles and positions of the emission bands of 1 and 2 are similar
to those observed in the free bmimbp ligand, they can be assigned
mainly to the intraligand transition of bmimbp which is modified
by metal coordination.19 The emissions in the blue region suggests
that both two complexes may be potential blue-light-emitting
materials.
˚
11.827(14) A, c = 14.256(16) A, a = 91.67(2)u, b = 109.35(2)u, c =
3
˚
103.26(2)u, V = 1575(3) A , m(Mo-Ka) = 5.897, 7596 reflections measured,
5390 unique (Rint = 0.0501) which were used in all calculations. The final
wR2 was 0.1523 (all data) and R1 was 0.0532 (.2s(I)).
1 (a) X. B. Zhao, B. Xiao, A. J. Fletcher, K. M. Thomas, D. Bradshaw
and M. J. Rosseinsky, Science, 2004, 306, 1012; (b) L. J. Murray, M.
Dinca˘ and J. R. Long, Chem. Soc. Rev., 2009, 38, 1294; (c) J. R. Li, R. J.
Kuppler and H. C. Zhou, Chem. Soc. Rev., 2009, 38, 1477; (d) Z. J. Lin,
D. S. Wragg, J. E. Warren and R. E. Morris, J. Am. Chem. Soc., 2007,
129, 10334; (e) S. Mukhopadhyay and W. H. Armstrong, J. Am. Chem.
Soc., 2003, 125, 13010; (f) Y. C. Liao, F. L. Liao, W. K. Chang and
S. L. Wang, J. Am. Chem. Soc., 2004, 126, 1320; (g) K. Biradha,
C. Seward and M. J. Zaworotko, Angew. Chem., Int. Ed., 1999, 38, 492;
(h) M. H. Mir, L. L. Koh, G. K. Tan and J. J. Vittal, Angew. Chem., Int.
Ed., 2010, 49, 390; (i) W. B. Lin, L. Ma and O. R. Evans, Chem.
Commun., 2000, 2263; (j) Y. F. Han, W. G. Jia, W. B. Yu and G. X. Jin,
Chem. Soc. Rev., 2009, 38, 3419; (k) K. S. Chichak, S. J. Cantrill, A. R.
Pease, S.-H. Chiu, G. W. V. Cave, J. L. Atwood and J. F. Stoddart,
Science, 2004, 304, 1308.
2 (a) S. Yoon and S. J. Lippard, J. Am. Chem. Soc., 2005, 127, 8386; (b)
D. Bradshaw, T. J. Prior, E. J. Cussen, J. B. Claridge and M. J.
Rosseinsky, J. Am. Chem. Soc., 2004, 126, 6106; (c) T. J. Prior and M. J.
Rosseninsky, Chem. Commun., 2001, 495; (d) S. A. Bourne, J. J. Lu, B.
Moulton and M. J. Zaworotko, Chem. Commun., 2001, 861; (e) J. Tao,
M. L. Tong, J. X. Shi, X. M. Chen and S. W. Ng, Chem. Commun.,
2000, 2043; (f) R. H. Wang, M. C. Hong, J. H. Luo, R. Cao and J. B.
Weng, Chem. Commun., 2003, 1018; (g) F. N. Dai, H. Y. He and D. F.
Sun, J. Am. Chem. Soc., 2008, 130, 14064; (h) S.-M. Fang, M. Hu, Q.
Zhang, M. Du and C.-S. Liu, Dalton Trans., 2011, 40, 4527; (i) B. Li, J.
Tao, H.-L. Sun, O. Sato, R.-B. Huang and L.-S. Zheng, Chem.
Commun., 2008, 2269; (j) Z.-H. Zhang, S.-C. Chen, J.-L. Mi, M.-Y. He,
Q. Chen and M. Du, Chem. Commun., 2010, 46, 8427; (k) Q. X. Jia, H.
Tian, J. Y. Zhang and E. Q. Gao, Chem.–Eur. J., 2011, 17, 1040; (l) W.
T. Ai, H. Y. He, L. J. Liu, Q. J. Liu, X. L. Lv, J. Li and D. F. Sun,
CrystEngComm, 2008, 10, 1480.
In summary, we have presented two novel entangled mixed-
ligand metal–organic networks, which vary from polycatenated
2D + 2D A 3D framework to polyrotaxane-like 2D + 2D A 2D
layer. The structural comparison suggests that the conformations
of bmimbp ligand and coordination modes of auxiliary dicarbox-
3 (a) K. M. Park, D. Whang, E. Lee, J. Heo and K. Kim, Chem.–Eur. J.,
2002, 8, 498; (b) V. Niel, A. L. Thompson, M. C. Mun˜oz, A. Galet,
A. E. Goeta and J. A. Real, Angew. Chem., Int. Ed., 2003, 42, 3760; (c)
J. A. Aitken and M. G. Kanatzidis, J. Am. Chem. Soc., 2004, 126,
11780; (d) L. Q. Ma and W. B. Lin, Angew. Chem., Int. Ed., 2009, 48,
3637; (e) Y. Gong, Y. C. Zhou, T. F. Liu, J. Lu, D. M. Proserpio and
R. Cao, Chem. Commun., 2011, 47, 5982; (f) R. L. LaDuca, Coord.
Chem. Rev., 2009, 253, 1759; (g) X. F. Kuang, X. Y. Wu, R. M. Yu,
J. P. Donahue, J. S. Huang and C. Z. Lu, Nat. Chem., 2010, 2, 461; (h)
O. Shekhah, H. Wang, M. Paradinas, C. Ocal, B. Schupbach,
A. Terfort, D. Zacher, R. A. Fischer and C. Woll, Nat. Mater., 2009,
8, 481; (i) A. S. Degtyarenko, P. V. Solntsev, H. Krautscheid, E. B.
Rusanov, A. N. Chernega and K. V. Domasevitch, New J. Chem., 2008,
32, 1910; (j) H. He, D. Yuan, H. Ma, D. Sun, G. Zhang and H.-C.
Zhou, Inorg. Chem., 2010, 49, 7605; (k) X. Zhao, H. He, T. Hu, F. Dai
and D. Sun, Inorg. Chem., 2009, 48, 8057.
Fig. 6 The photoluminescence spectra of 1, 2 and bmimbp ligand.
This journal is ß The Royal Society of Chemistry 2012
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View Article Online
4 (a) V. A. Blatov, L. Carlucci, G. Ciani and D. M. Proserpio,
CrystEngComm, 2004, 6, 378; (b) I. A. Baburin, V. A. Blatov, L.
Carlucci, G. Ciani and D. M. Proserpio, CrystEngComm, 2008, 10,
1822; (c) S. R. Batten and R. Robson, Angew. Chem., Int. Ed., 1998, 37,
1460; (d) S. R. Batten, CrystEngComm, 2001, 3, 67; (e) L. Carlucci, G.
Ciani and D. M. Proserpio, Coord. Chem. Rev., 2003, 246, 247.
5 (a) L. Carlucci, G. Ciani and D. M. Proserpio, CrystEngComm, 2003, 5,
269; (b) Z. Su, J. Fan, T. Okamura, M. S. Chen, S. S. Chen, W. Y. Sun
and N. Ueyama, Cryst. Growth Des., 2010, 10, 1911; (c) J. Fan, H. F.
Zhu, T. A. Okamura, W. Y. Sun, W. X. Tang and N. Ueyama, Inorg.
Chem., 2003, 42, 158; (d) D. Zhao, D. J. Timmons, D. Q. Yuan and
H. C. Zhou, Acc. Chem. Res., 2011, 44, 123; (e) Y. Gong, Y. C. Zhou,
T. F. Liu, J. Lu, D. M. Proserpio and R. Cao, Chem. Commun., 2011,
47, 5982; (f) S. B. Ren, L. Zhou, J. Zhang, Y. Z. Li, H. B. Du and X. Z.
You, CrystEngComm, 2009, 11, 1834; (g) M. C. Das, H. Xu, Z. Y.
Wang, G. Srinivas, W. Zhou, Y. F. Yue, V. N. Nesterov, G. D. Qian
and B. L. Chen, Chem. Commun., 2011, 47, 11715; (h) X. M. Zhang and
X. M. Chen, Eur. J. Inorg. Chem., 2003, 413; (i) S. Bureekaew, H. Sato,
R. Matsuda, Y. Kubota, R. Hirose, J. Kim, K. Kato, M. Takata and S.
Kitagawa, Angew. Chem., Int. Ed., 2010, 49, 7660.
6 (a) X.-L. Wang, C. Qin, E.-B. Wang, Y.-G. Li, Z.-M. Su, L. Xu and L.
Carlucci, Angew. Chem., Int. Ed., 2005, 44, 5824; (b) Y.-Q. Lan, S.-L. Li,
J.-S. Qin, D.-Y. Du, X.-L. Wang, Z.-M. Su and Q. Fu, Inorg. Chem.,
2008, 47, 10600; (c) C. Qin, X.-L. Wang, E.-B. Wang and Z.-M. Su,
Inorg. Chem., 2008, 47, 5555; (d) F. Luo, Y.-T. Yang, Y.-X. Che and
J.-M. Zheng, CrystEngComm, 2008, 10, 981; (e) L.-F. Ma, Y.-Y. Wang,
J.-Q. Liu, G.-P. Yang, M. Du and L.-Y. Wang, CrystEngComm, 2009,
11, 1800.
7 (a) X. L. Zhang, C. P. Guo, Q. Y. Yang, W. Wang, W. S. Liu, B. S.
Kang and C. Y. Su, Chem. Commun., 2007, 4242; (b) X. Q. Lv, M. Pan,
J. R. He, Y. P. Cai and C. Y. Su, CrystEngComm, 2006, 8, 847; (c) Z. Y.
Fu, X. T. Wu, J. C. Dai, L. M. Wu, C. P. Cui and S. M. Hu, Chem.
Commun., 2001, 1856; (d) C. S. A. Fraser, M. C. Jennings and R. J.
Puddephatt, Chem. Commun., 2001, 1310; (e) G. F. Liu, B. H. Ye, Y. H.
Ling and X. M. Chen, Chem. Commun., 2002, 1442; (f) A. J. Blake, N.
R. Champness, A. Khlobystov, D. A. Lemenovskii, W. S. Li and M.
Schro¨der, Chem. Commun., 1997, 2027; (g) J. Yang, J. F. Ma, S. R.
Batten and Z. M. Su, Chem. Commun., 2008, 2233.
(f) D. Sun, H.-J. Hao, F.-J. Liu, H.-F. Su, R.-B. Huang and L.-S.
Zheng, CrystEngComm, 2012, 14, 480.
9 (a) F. H. Allen, Acta Crystallogr., Sect. B: Struct. Sci., 2002, 58, 380; (b)
Cambridge Structure Database search, CSD Version 5.28 (November
2006) with 15 updates January (2007–Feb 2012).
10 T.-F. Liu, W.-F. Wu, C.-Q. Wan, C.-H. He, C.-H. Jiao and G.-H. Cui,
J. Coord. Chem., 2011, 64, 975.
11 (a) V. A. Blatov, M. O’Keeffe and D. M. Proserpio, CrystEngComm,
2010, 12, 44; (b) I. A. Baburin, V. A. Blatov, L. Carlucci, G. Cianib and
D. M. Proserpio, CrystEngComm, 2008, 10, 1822; (c) I. A. Baburin,
V. A. Blatov, L. Carlucci, G. Cianib and D. M. Proserpio, Cryst.
Growth Des., 2008, 8, 519.
12 (a) J.-Q. Liu, Y.-Y. Wang, L.-F. Ma, G.-L. Wen, Q.-Z. Shi, S. R. Batten
and D. M. Proserpio, CrystEngComm, 2008, 10, 1123; (b) K. A. Hirsch,
S. R. Wilson and J. S. Moore, Inorg. Chem., 1997, 36, 2960; (c) L.
Carlucci, G. Ciani, D. M. Proserpio and S. Rizzato, CrystEngComm,
2002, 4, 413; (d) Y.-B. Dong, P. Wang, R.-Q. Huang and M. D. Smith,
Inorg. Chem., 2004, 43, 4727; (e) S. R. Batten, B. F. Hoskins and R.
Robson, Chem.–Eur. J., 2000, 6, 156; (f) L. Carlucci, G. Ciani, D. M.
Proserpio and S. Rizzato, CrystEngComm, 2002, 4, 121; (g) M. Du, X. J.
Jiang and X. J. Zhao, Chem. Commun., 2005, 5521.
13 (a) B. Xu, Z. J. Lin, L. W. Han and R. Cao, CrystEngComm, 2011, 13,
440; (b) Y. Y. Liu, Z. H. Wang, J. Yang, B. Liu, Y. Y. Liu and J. F. Ma,
CrystEngComm, 2011, 13, 3811; (c) M. Yang, F. L. Jiang, Q. H. Chen,
Y. F. Zhou, R. Feng, K. C. Xiong and M. C. Hong, CrystEngComm,
2011, 13, 3971; (d) X. Zhao, J. Dou, D. Sun, P. Cui, D. Sun and Q. Wu,
Dalton Trans., 2012, 41, 1928; (e) D. Sun, Q.-J. Xu, C.-Y. Ma, N.
Zhang, R.-B. Huang and L.-S. Zheng, CrystEngComm, 2010, 12, 4161;
(f) F.-J. Liu, D. Sun, H.-J. Hao, R.-B. Huang and L.-S. Zheng,
CrystEngComm, 2012, 14, 379.
14 L. Yang, D. R. Powell and R. P. Houser, Dalton Trans., 2007, 955.
15 (a) J. Konnert and D. Britton, Inorg. Chem., 1966, 5, 1193; (b) S. R.
Batten, B.F. Hoskins and R. Robson, New J. Chem., 1998, 22, 173; (c)
K. V. Domasevitch, I. Boldog, E. B. Rusanov, J. Hunger, S. Blaurock,
M. Schroder and J. Sieler, Z. Anorg. Allg. Chem., 2005, 631, 1095.
16 B. F. Hoskins, R. Robson and D. A. Slizys, Angew.Chem., Int. Ed.
Engl., 1997, 36, 2336.
17 (a) J. Yang, J.-F. Ma, S. R. Batten and Z.-M. Su, Chem. Commun.,
2008, 2233; (b) Y. Liu, Y. Qi, Y.-Y. Lv, Y.-X. Che and J.-M. Zheng,
Cryst. Growth Des., 2009, 9, 4797; (c) G. H. Wang, Z. G. Li, H. Q. Jia,
N. H. Hu and J. W. Xu, Cryst. Growth Des., 2008, 8, 1932.
18 W. J. Chen, Y. Wang, C. Chen, Q. Yue, H. M. Yuan, J. S. Chen and
S. N. Wang, Inorg. Chem., 2003, 42, 944.
8 (a) H. Y. He, D. Q. Yuan, H. Q. Ma, D. F. Sun, G. Q. Zhang and H. C.
Zhou, Inorg. Chem., 2010, 49, 7605; (b) X. L. Zhao, H. Y. He, T. P. Hu,
F. N. Dai and D. F. Sun, Inorg. Chem., 2009, 48, 8057; (c) D. X. Wang,
H. Y. He, X. H. Chen, S. Y. Feng, Y. Z. Niu and D. F. Sun,
CrystEngComm, 2010, 12, 1041; (d) H.-J. Hao, D. Sun, F.-J. Liu, R.-B.
Huang and L.-S. Zheng, Cryst. Growth Des., 2011, 11, 5475; (e) T. Hu,
X. Zhao, X. Hu, Y. Xu, D. Sun and D. Sun, RSC Adv., 2011, 1, 1682;
19 X. Y. Yi, H. C. Fang, Z. G. Gu, Z. Y. Zhou, Y. P. Cai, J. Tian and
P. K. Thallapally, Cryst. Growth Des., 2011, 11, 2824.
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