Self-assembly versus stepwise synthesis: Heterometal-organic frameworks based on metalloligands with tunable luminescence properties

Article abstract of DOI:10.1002/chem.201301536

A new family of heterometal-organic frameworks has been prepared by two synthesis strategies, in which IFMC-26 and IFMC-27 are constructed by self-assembly and IFMC-28 is obtained by stepwise synthesis based on the metalloligand (IFMC=Institute of Functional Material Chemistry). IFMC-26 is a (3,6)-connected net and IFMC-27 is a (4,8)-connected 3D framework. The metalloligands {Ni(H₄L)}(NO₃)₂ are connected by binuclear lanthanide clusters giving rise to a 2D sheet structure in IFMC-28. Notably, IFMC-26-Eu_xTb_y and IFMC-28-Eu_xTb _y have been obtained by changing the molar ratios of raw materials. Owing to the porosity of IFMC-26, Tb³⁺@IFMC-26-Eu and Eu ³⁺@IFMC-26-Tb are obtained by postencapsulating Tb^III and Eu^III ions into the pores, respectively. Tunable luminescence in metal-organic frameworks is achieved by the two kinds of doping methods. In particular, the quantum yields of heterometal-organic frameworks are apparently enhanced by postencapsulation of Ln^III ions. Copyright

Full text of DOI:10.1002/chem.201301536

FULL PAPER
DOI: 10.1002/chem.201301536
Self-Assembly versus Stepwise Synthesis: Heterometal–Organic Frameworks
Based on Metalloligands with Tunable Luminescence Properties
Shu-Ran Zhang,[a] Dong-Ying Du,[a] Ke Tan,[c] Jun-Sheng Qin,[a] Hui-Qing Dong,[b]
Shun-Li Li,*[b] Wen-Wen He,[a] Ya-Qian Lan,*[b] Ping Shen,[a] and Zhong-Min Su*[a]
Abstract: A new family of heterome-
tal–organic frameworks has been pre-
pared by two synthesis strategies, in
which IFMC-26 and IFMC-27 are con-
structed by self-assembly and IFMC-28
is obtained by stepwise synthesis based
on the metalloACHTUNGTRENNUNGliACHTUNGTRENNUNGgand (IFMC=Institute
of Functional Material Chemistry).
IFMC-26 is a (3,6)-connected net and
clear lanthanide clusters giving rise to
a 2D sheet structure in IFMC-28. Nota-
bly, IFMC-26-EuxTby and IFMC-28-
EuxTby have been obtained by chang-
ing the molar ratios of raw materials.
Owing to the porosity of IFMC-26,
Tb3+@IFMC-26-Eu and Eu3+@IFMC-
26-Tb are obtained by postencapsulat-
ing TbIII and EuIII ions into the pores,
respectively. Tunable luminescence in
metal–organic frameworks is achieved
by the two kinds of doping methods. In
particular, the quantum yields of heter-
ometal–organic frameworks are appa-
rently enhanced by postencapsulation
of LnIII ions.
Keywords: luminescence
organic frameworks
·
metal–
·
metalloli-
IFMC-27 is
framework. The metalloligands {Ni-
(H4L)}(NO3)2 are connected by binu-
a
(4,8)-connected 3D
gands · self-assembly · stepwise syn-
thesis
A
ACHTUNGTRENNUNG
Introduction
dimension to luminescent functionalities. Furthermore, the
highly regular channel structures and controllable pore sizes
of MOFs permit their application in some guest-molecule
adsorption, which can also emit and/or induce lumines-
cence.[5] Besides, another technique can be used for the
preparation of luminescent MOFs through combining quan-
tum dots (QDs) with MOFs. Semiconductor QDs enhance
light harvesting by MOFs through energy transfer from the
QDs to the MOFs.[6] Among these luminescent materials,
lanthanide-based MOFs (LnMOFs) are receiving outstand-
ing attention because of the advantages of the designability
that allows fine-tuned luminescence properties.[7] In general,
LnIII luminescent materials can be classified into two catego-
ries: 1) LnIII ions coordinated directly to the organic linkers/
sensitizers[8] and 2) LnIII ions encapsulated into porous
MOFs.[9] In this context, one can achieve the above-men-
tioned two types of LnMOFs, which possess adjustable lumi-
nescence properties by varying the molar ratios of raw ma-
terials of LnIII ions, and postencapsulating LnIII into porous
MOFs. Nowadays, how to obtain tunable luminescent
LnMOFs has become a prominent topic in fluorescent mate-
rials science.[10]
It remains a labor-intensive endeavor to synthesize new
families of MOF materials that possess a wide range of
chemical functionalities and/or steric environments while re-
taining the crystallinity and porosity of the frameworks.[11]
Self-assembly, as a general approach, is accomplished only
by careful selection of the metal, organic linker, and synthe-
sis conditions.[12] It has proven to be a powerful method for
the design and construction of MOFs with diverse topolo-
gies and aesthetic beauty,[13] but the mechanism is often
masked by the common one-pot mixing procedure. Recent-
Metal–organic frameworks (MOFs) as a new class of crystal-
line materials have been the focus of significant interest due
not only to their structural and chemical diversities but also
to their functional properties and potential applications, for
instance, gas storage, catalysis, separations, drug delivery,
and so on.[1,2] In recent years, MOFs have been especially
promising as multifunctional luminescent materials,[3] and
much effort has been dedicated to this field.[4] Both the inor-
ganic and organic moieties in MOFs can provide the plat-
form to generate luminescence, and metal–ligand charge-
transfer-related luminescence within MOFs can add another
[a] Dr. S.-R. Zhang, Dr. D.-Y. Du, Dr. J.-S. Qin, Dr. W.-W. He,
Dr. P. Shen, Prof. Z.-M. Su
Institute of Functional Material Chemistry
Faculty of Chemistry, Northeast Normal University
Changchun 130024, Jilin (P. R. China)
Fax : (+86) 431-85684009
E-mail: zmsu@nenu.edu.cn
[b] Dr. H.-Q. Dong, Prof. S.-L. Li, Prof. Y.-Q. Lan
Jiangsu Key Laboratory of Biofunctional Materials
College of Chemistry and Materials Science, Nanjing Normal Univer-
sity
Nanjing 210023, Jiangsu (P. R. China)
E-mail: lisl132@nenu.edu.cn
yqlan@njnu.edu.cn
[c] Prof. K. Tan
Biological Scientific and Technical College
Changchun University
Changchun 130022, Jilin (P. R. China)
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/chem.201301536.
Chem. Eur. J. 2013, 19, 11279 – 11286
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
11279

ly, Zhou, Zaworotko, Su, and co-workers[14] have adopted a
stepwise synthesis strategy to explore the synthetic mecha-
nism. The synthesis strategy involves altering either 1) the
metal node or 2) the organic linker after initial crystalliza-
tion.[13b] Stepwise synthesis of heterometal–organic frame-
works is based on the synthesis of a metal complex that is
subsequently connected to another metal ion.[14d] Self-assem-
bly and stepwise synthesis afford different means to modu-
late the physical and chemical properties of MOF structures,
which may increase the use of MOFs as high-performance,
tailor-made materials. Up to now, the exploration and inves-
tigation of the influences of self-assembly and stepwise syn-
thesis on the structures and properties of these materials
have rarely been investigated. It is still a significant chal-
lenge for targeted “design” and “control” tailor-made com-
pounds with expected structures in synthesis chemistry and
materials science.[15]
Metalloligands, which are metal-containing complexes,
have the coordination binding sites for their further coordi-
nation/binding with second metal ions and/or clusters.[16] As
highlighted recently, metalloligands are very appealing to
target some functional MOFs as a result of their straightfor-
ward immobilization of functional sites, such as open metal
sites, catalytically active metal sites, and photoactive metal
sites, in the frameworks for adjusting their functional prop-
erties.[17] Moreover, metalloligands with extra coordination
sites (nitrogen and carboxyl groups) are ideal candidates for
the construction of MOFs through stepwise synthesis.[18]
Hitherto, only a few studies have employed a stepwise syn-
thesis strategy for the preparation of MOFs, especially
based on metalloligands.
ture, for instance, the shielding of 4f orbitals from external
perturbations.[21]
We have obtained a series of heterometallic LnMOFs,
[Ni(L)EuxTby]
mide; IFMC-26-EuxTby: x=1, y=0, IFMC-26-Eu; x=0.5,
y=0.5, IFMC-26-Eu0.5Tb0.5 x=0, y=1, IFMC-26-Tb
(IFMC=Institute of Functional Material Chemistry)) and
[Ni(L)La2A(NO3)3A(dma)](NO3)·2H2O·2DMA (IFMC-27-La)
through self-assembly. Additionally, we have also achieved
[Ni(L)La(H2O)(dmf)2](NO3)·3H2O·DMF (IFMC-28-La) and
[Ni(L)EuxTbyA(H2O)(dmf)2](NO3)·3H2O·DMF (IFMC-28-
ACHTUGNRTNE(NUNG NO3)·5H2O·6DMA (DMA=dimethylaceta-
;
C
E
ACHTUNGTRENNUNG
A
R
ACHTUNGTRENNUNG
C
R
ACHTUNGTRENNUNG
EuxTby: x=1, y=0, IFMC-28-Eu; x=0.6, y=0.4, IFMC-28-
Eu0.6Tb0.4; x=0.5, y=0.5, IFMC-28-Eu0.5Tb0.5; x=0.4, y=
0.6, IFMC-28-Eu0.4Tb0.6; x=0, y=1, IFMC-28-Tb) by com-
bining the metalloACTHNUTRGENNGUliACHUTGTNRENNUG
gand and LnIII through stepwise synthe-
sis. A series of characterizations was carried out on IFMC-
26–28. By taking into account the excellent luminescence
properties of EuIII and TbIII ions, the luminescence proper-
ties of IFMC-26-EuxTby and IFMC-28-EuxTby were investi-
gated in the solid state at room temperature. Meanwhile, we
postencapsulated TbIII and EuIII ions, respectively, into the
pores of IFMC-26-Eu and IFMC-26-Tb and studied the in-
fluence of doping different LnIII ions on fluorescence. To the
best of our knowledge, this is the first time that the effects
on the structures and properties of heterometallic LnMOFs
attained through utilizing self-assembly and stepwise synthe-
sis have been studied in the same system.
Results and Discussion
Our group has successfully constructed a novel coordina-
tion polymer with a special scu net under ionothermal syn-
thesis, based on the ligand 4,4’,4’’,4’’’-{2,2’,2’’,2’’’-[ethane-1,2-
diylbis(azanetriyl)]tetrakis(methylene)tetrakis-(1H-benzo-
[d]imidazole-2,1-diyl)}tetrakis(methylene)-tetrabenzoic acid
(H4L).[19a] Furthermore, we obtained a series of heterometal-
lic Ln-based luminescent materials by the combination of
hydrothermal and ionothermal methods for the first
time.[19b] As a continuation of our work, we took advantage
of H4L, NiII, and LnIII ions through self-assembly, and metal-
Herein, we have adopted two synthesis strategies for
LnMOF preparation. The synthesis method for IFMC-26
and IFMC-27 is self-assembly, and for IFMC-28 is stepwise.
IFMC-26-Eu crystallizes in the orthorhombic space group
Pnna. There is one Ni2+ ion, one Eu3+ ion, and one L4ꢀ
ligand in the crystallographically independent unit. The Ni
atom is octahedrally coordinated by six nitrogen atoms from
one bridging L4ꢀ ligand to form a metallo
ure 1a). Eight carboxylate groups from six different L4ꢀ li-
gands connect two Eu3+ ions to form a mode of [Eu
2A(CO2)8]
(see the Supporting Information, Figure S1a). The metalloli-
gand unit links the [Eu2A(CO2)8] cluster to form an infinite
ACHUTGTNRENNlGU iACTHNGUTRENNUgG and unit (Fig-
CHTUNGTRENNUNG
loligands {Ni
(H4L)}
U
ACHTUNGTRENNUNG
synthesis in solvothermal reactions for heterometallic
LnMOF preparation by taking the following factors into
consideration. 1) LnIII ions have a high affinity and prefer O
to N donors, whereas the 3d metal ions have a tendency to
coordinate with both N and O donors in self-assembly.[20]
Therefore, the coordination sites of H4L can be correspond-
ingly coordinated by LnIII ions and transition metals. 2) NiII
ions are chelated to nitrogen atoms from H4L to form metal-
loligands. Meanwhile, uncoordinated polycarboxylate groups
in metalloligands tend to coordinate with LnIII, which bene-
fits the construction of heterometallic LnMOFs by stepwise
synthesis. 3) LnIII ions display unique luminescence features,
such as high luminescence quantum yield, narrow band-
width, long-lived emission, and large Stokes shift. On the
other hand, LnIII ions have a predominantly electronic struc-
A
CHTUNGTRENNUNG
3D framework. In the 3D net, pairs of adjacent carboxylate
ligands link four adjacent L4ꢀ ligands by sharing four binu-
clear [Eu
19.30ꢁ23.79 ꢂ along the [010] direction (Figure 1b and c).
From the topological analysis, each metalloligand unit is
considered as a 3-connected node (Supporting Information,
Figure S2a) and each [Eu2A(CO2)8] cluster acts as a 6-con-
2ACHTUNGRTNE(NUNG CO2)8] clusters to form a pore with a size of
A
A
CTHUNGTRENNUNG
nected node (Supporting Information, Figure S2b). IFMC-
26-Eu is a (3,6)-connected framework with the Schlꢃfli
symbol of (42·8)(4·82)(44·811) (Figure 1d). The thermal behav-
ACTHNUTRGENNUG CAHTUNGTRENNUGN
ior of IFMC-26-Eu was studied by thermogravimetric analy-
sis (TGA; Supporting Information, Figure S9a). Single-crys-
tal X-ray analysis reveals that IFMC-26-Tb is isostructural
to IFMC-26-Eu. We then took advantage of a mixture of
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Chem. Eur. J. 2013, 19, 11279 – 11286

Heterometal–Organic Frameworks
FULL PAPER
Figure 2. a) Coordination environments of the NiII and LaIII centers in
IFMC-27-La. Symmetry codes: #1: 1ꢀx, 1ꢀy, 1ꢀz; #2: x, 1+y, z; #3:
1ꢀx, ꢀy, 2ꢀz; #4: ꢀ1+x, y, z. b,c) Ball-and-stick and space-filling repre-
sentations of IFMC-27-La viewed from the [100] direction, respectively.
All the hydrogen atoms are omitted for clarity. d) Polyhedral view of the
(4,8)-connected topology network in IFMC-27-La.
Figure 1. a) Coordination environments of the NiII and EuIII centers in
IFMC-26-Eu. Symmetry codes: #1: 0.5ꢀx, 0.5+y, 0.5ꢀz; #2: 0.5ꢀx, 1ꢀy,
z; #3: 1ꢀx, 1ꢀy, 1ꢀz; #4: 1ꢀx, 0.5+y, 0.5+z. b,c) Ball-and-stick and
space-filling representations of IFMC-26-Eu viewed from the [010] direc-
tion, respectively. All the hydrogen atoms are omitted for clarity. d) Poly-
hedral view of the (3,6)-connected topology network in IFMC-26-Eu.
13.64 ꢂ (Figure 2b and c). On further study into the struc-
ture of IFMC-27-La, we find that each tetranuclear metal
cluster is surrounded by eight organic ligands. From the
topological point of view, the [NiN6] can be considered as a
4-connected node (Supporting Information, Figure S4a),
whereas the tetranuclear lanthanum cluster is an 8-connect-
ed node (Supporting Information, Figure S4b). Therefore,
the framework of IFMC-27-La is a rare (4,8)-connected flu-
orite (CaF2) net with the Schlꢃfli symbol of (46)2(412·612·84)
(Figure 2d). The XRPD patterns for IFMC-27-La are pre-
sented in Figure S5 (Supporting Information). The diffrac-
tion peaks of both simulated and as-synthesized patterns
match well in key positions, thus indicating its phase purity.
The thermal behavior of IFMC-27-La is presented in Fig-
ure S9b (Supporting Information).
EuIII and TbIII instead of EuIII and obtained IFMC-26-
Eu0.5Tb0.5. The experimental X-ray powder diffraction
(XRPD) patterns of as-synthesized IFMC-26-Eu0.5Tb0.5 and
IFMC-26-Tb are in good agreement with the simulated dif-
fraction pattern of IFMC-26-Eu, which indicates that the
bulk materials have a (3,6)-connected 3D net framework
similar to IFMC-26-Eu (Supporting Information, Figure S3).
Therefore, only the structure of IFMC-26-Eu is described in
detail.
As an extension of this work, we investigated the reaction
of LaACHTUNGTRENNUNG(NO3)3 and H4L under similar conditions and obtained
IFMC-27-La. Interestingly, the structure of IFMC-27-La is
different from that of IFMC-26-Eu. Single-crystal X-ray
analysis reveals that IFMC-27-La crystallizes in the triclinic
It is advantageous to regard H4L as the moiety of the
metallo
attained the metallo
tional synthesis reaction of H4L and NiII in ethanol solution.
Single-crystal X-ray analysis reveals that the metalloligand
ACHUTGTNRENNUGliACHTUNGTRENNUNG
A
E
N
ACHTUNGTRENNUNG
¯
space group P1. The asymmetric unit of IFMC-27-La in-
ꢀ
cludes a Ni2+ ion, two kinds of La3+, an L4ꢀ ion, three NO3
A
A
ions, and a coordinated dma molecule. The coordination en-
vironments of the Ni atom and La atom are presented in
Figure 2a. The Ni atom coordinates to six nitrogen atoms
from the same L4ꢀ ligand to form a twisted octahedral ge-
ometry [NiN6]. There are two kinds of La atoms linked by
crystallizes in the monoclinic space group C2/c, and the
asymmetric unit includes one Ni atom and one H4L ligand.
Each Ni atom is octahedrally coordinated by six nitrogen
atoms from one ligand (Figure 3a), whereas the carboxylate
groups from the H4L are uncoordinated by any other atoms
to form a discrete structure. The XRPD patterns for the
ꢀ
carboxylate groups and NO3 to form a tetranuclear [La4-
A
N
(dma)2] cluster (Supporting Information, Fig-
metalloACHTNGUTRENNUlG iHCATUNGTRENgNNUG and are shown in Figure S6 (Supporting Informa-
ure S1b), in which La atoms exhibit two different coordina-
tion geometries. La1 coordinates to five oxygen atoms from
tion). The diffraction peaks of both simulated and as-synthe-
sized patterns match well in key positions, thus indicating
ꢀ
three L4ꢀ ligands, four oxygen atoms from two NO3 ions,
phase purity. The thermal behavior of the metallo
displayed in Figure S9c (Supporting Information).
ACHTUNGTRENNUNGliACHTUNGTRENNUNGgand is
and one oxygen atom from coordinated dma. La2 is eight-
coordinated by three oxygen atoms from three L4ꢀ ligands
Taking into account the coordination environment of the
metalloligand, we adopted stepwise synthesis by combining
the metalloligand {Ni(H4L)}(NO3)2 with La(NO3)3 and ob-
ꢀ
and five oxygen atoms from four NO3 ions. Furthermore,
A
A
the adjacent clusters are linked by the L4ꢀ ligands to give a
three-dimensional network. In addition, two adjacent L4ꢀ li-
gands link each other through sharing two tetranuclear [La4-
A
E
E
N
ACHTUNGTRENNUNG
tained IFMC-28-La. Notably, the structure of IFMC-28-La is
completely different from those of IFMC-26-Eu and IFMC-
27-La, displaying a 2D layer structure. Single-crystal X-ray
ACHTUNGTRENNUNG(CO2)8ACHTUNGTRENNUNG(dma)2ACHTUNGTRENNUNG(NO3)6] to form a pore with the size of 3.72ꢁ
Chem. Eur. J. 2013, 19, 11279 – 11286
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11281

S.-L. Li, Y.-Q. Lan, Z.-M. Su et al.
Figure 3. a) Coordination environment of the NiII center in the metallo
ACTHNUTRGNElUNG i-
gand. Symmetry code: #1: ꢀx, y, 0.5ꢀz. b) Coordination environments of
the NiII and LaIII centers in IFMC-28-La. Symmetry codes: #1: 1ꢀx,
ꢀ1ꢀy, ꢀz; #2: ꢀ1+x, 1+y, z; #3: ꢀx, ꢀy, ꢀz; #4: x, 1+y, z. c) Packing
arrangement in IFMC-28-La. All the hydrogen atoms are omitted for
clarity. d) Ball-and-stick view of the topological structure in IFMC-28-La.
Scheme 1. Self-assembly and stepwise synthesis methods for the prepara-
tion of IFMC-26-Eu, IFMC-27-La, and IFMC-28-La.
diffraction studies reveal that IFMC-28-La crystallizes in the
by using a fluorescence microscope equipped with a CCD
camera (Supporting Information, Figure S10). Self-assembly
of the metal ions and clusters (generally termed as nodes)
with organic linkers (connectors) of predetermined shapes
can lead to the construction of MOFs with diverse struc-
tures. IFMC-26-Eu is a (3,6)-connected 3D porous frame-
work, whereas IFMC-27-La is a (4,8)-connected 3D porous
framework. Stepwise synthesis, facilitated by metalloligands,
provides the capability to fine-tune the internal element co-
ordination environments of MOFs and offers unprecedented
opportunities to systematically evaluate and improve the
performance of MOFs. IFMC-28-Eu and IFMC-28-La both
display 2D layer structures that are distinctly different from
that of IFMC-26-Eu and IFMC-27-La. The bright promise
¯
triclinic space group P1. The crystallographically independ-
ent unit contains one metalloligand unit (Figure 3a), one
A
A
La3+ ion, two coordinated dmf molecules, and two water
molecules (Figure 3b). The La atom is nine-coordinated by
six carboxylate oxygen atoms from four H4L ligands, two
oxygen atoms from coordinated dmf, and one water mole-
cule, which generate a binuclear lanthanide cluster [La2-
ACHTUNGTRENNUNG(CO2)6ACHTUNGTRENNUNG(dmf)2ACHTUNGTRENNUNG(H2O)2] (Supporting Information, Figure S1c).
Further study into the nature of this architecture reveals
that IFMC-28-La displays a two-dimensional network in the
ab plane, which is packed in the bc plane as described in
Figure 3c. In addition, in each layer, each L4ꢀ anion connects
three binuclear lanthanide clusters, and each binuclear lan-
thanide cluster connects six L4ꢀ ions. So the L4ꢀ anion and
binuclear lanthanide cluster are considered as 3- and 6-con-
nected nodes (Supporting Information, Figure S7a and S7b).
Such connectivity modes lead to a (3,6)-connected frame-
work (Figure 3d).
The thermal behavior of IFMC-28-La was studied by
TGA (Supporting Information, Figure S9d). Inspired by
IFMC-26-EuxTby, we investigated the solvothermal reactions
of EuIII/TbIII ions with different ratios by stepwise synthesis
and obtained a family of LnMOFs: IFMC-28-Eu, IFMC-28-
Eu0.6Tb0.4, IFMC-28-Eu0.5Tb0.5, IFMC-28-Eu0.4Tb0.6, and
IFMC-28-Tb. On comparison of the experimental XRPD
patterns of as-synthesized IFMC-28-Eu, IFMC-28-Eu0.6Tb0.4,
IFMC-28-Eu0.5Tb0.5, IFMC-28-Eu0.4Tb0.6, and IFMC-28-Tb
with the simulated diffraction pattern of IFMC-28-La, the
very high degree of correspondence between the patterns in-
dicates that the bulk materials have the same structure as
IFMC-28-La (Supporting Information, Figure S8).
of the new metalloACTHNUGTRENNUGliACHUTNGTRENNUGgand approach to assemble MOF mate-
rials with functional sites will initiate extensive research on
the exploration and discovery of new functional MOFs. The
two different synthesis methods discussed above exemplify a
highly efficient and controllable approach to construct mul-
tifunctional MOFs.
The luminescence properties of IFMC-26-EuxTby and
IFMC-28-EuxTby in the solid state were investigated at
room temperature. Excitation and emission spectra of H4L
are presented in Figure S11a (Supporting Information).
IFMC-26-Eu yields an intense red luminescence when excit-
ed at 253 nm, which is assigned to the characteristic transi-
7
tions 5D0! FJ (J=0–4) of EuIII ions (Figure 4a). Two intense
5
7
emission bands at 616 and 700 nm correspond to D0! F2
7
and 5D0! F4, whereas the weaker emission bands at 592
5
7
5
7
and 653 nm originate from D0! F1 and D0! F3.[22] Under
excitation at 291 nm, IFMC-26-Tb exhibits typical fluores-
cence peaks at 489, 545, 584, and 621 nm, which are attribut-
5
7
A series of LnMOFs, IFMC-26, IFMC-27, and IFMC-28,
has been successfully achieved, which proves that we can
design and control this system by using self-assembly and
stepwise synthesis strategies (Scheme 1; Supporting Infor-
mation, Scheme S1). To present the dimensions and shapes
of the crystals, we have displayed their optical images taken
ed to D4! FJ (J=3–6) transitions[23] (Figure 4b). The decay
curve of transition 5D0! F2 (616 nm) for IFMC-26-Eu is
7
well-fitted by a biexponential function, which yields the life-
time value of tia =11.04 ms (Supporting Information,
Table S2). Similarly, for IFMC-26-Tb, the decay curve of
transitions (545 nm) is well-fitted by a biexponential func-
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Chem. Eur. J. 2013, 19, 11279 – 11286

Heterometal–Organic Frameworks
FULL PAPER
EuIII ion and implies a red emission light.[24] The medium-
5
7
strong emission band at 592 nm corresponds to the D0! F1
(magnetic-dipole) transition, which is fairly insensitive to
the environment of the EuIII ion.[21b] As shown in Fig-
5
7
ure S15a in the Supporting Information, the D0! F2 transi-
tion is clearly stronger than the D0! F1 transition with an
5
7
7
7
intensity ratio of about 2.4 for I
G
ACHTUNGTRENNUNG
indicating the absence of inversion symmetry at the Eu3+
site. IFMC-28-Tb yields a green luminescence under excita-
tion at 298 nm, which is assigned to the characteristic transi-
tions of D4! FJ (J=3–6) of the TbIII ions. The most intense
5
7
5
7
emission band at 545 nm corresponds to D4! F5, whereas
5
the weaker emission band at 622 nm originates from D4!
7F3 (Supporting Information, Figure S15b). Through tuning
the ratios of EuIII/TbIII, the compounds IFMC-28-EuxTby
(x=0.6, y=0.4, IFMC-28-Eu0.6Tb0.4; x=0.5, y=0.5, IFMC-
28-Eu0.5Tb0.5; x=0.4, y=0.6, IFMC-28-Eu0.4Tb0.6) were suc-
cessfully prepared. The intensities of red and green arising
from EuIII and TbIII emissions can be shifted corresponding-
ly. At the same time, the emission spectra were also record-
ed under similar conditions (Figure 4c). The emission band
at 545 nm corresponds to the 5D4! F5 transition of TbIII,
7
Figure 4. Emission spectra of a) IFMC-26-Eu, b) IFMC-26-Tb, and
whereas the two emission bands at 592 and 619 nm originate
c) IFMC-28-Eu, IFMC-28-Eu0.6Tb0.4
Eu0.4Tb0.6, and IFMC-28-Tb.
,
IFMC-28-Eu0.5Tb0.5
,
IFMC-28-
from D0! F1 and D0! F2 transitions of EuIII, respectively.
5
7
5
7
The fluorescence lifetime of IFMC-28-Eu was measured
5
7
from the decay curve of the D0! F2 transition (619 nm) by
fitting with a biexponential function, to yield the lifetime
value of tia =11.37 ms (Supporting Information, Table S2).
tion, to yield the lifetime value of tia =6.53 ms (Supporting
Information, Table S2). It is expected that H4L is a promis-
ing system for developing compounds with tunable lumines-
cence properties. IFMC-26-Eu0.5Tb0.5 was obtained success-
fully. As we expected, the intensities of red and green that
originate from EuIII and TbIII emissions can be fine-tuned
correspondingly (Supporting Information, Figure S12).
Owing to the porosities of IFMC-26-Eu and IFMC-26-Tb,
LnIII ions were postencapsulated into the pores to obtain
tunable luminescent materials by soaking the samples in
DMA solutions of nitrate salts of Tb3+ and Eu3+ for 72 h.
The successful Ln3+ loading was proved by the emission
spectra of Tb3+@IFMC-26-Eu and Eu3+@IFMC-26-Tb (Sup-
porting Information, Figure S13a and S13b). In addition, the
crystalline integrities of IFMC-26-Eu and IFMC-26-Tb are
retained as demonstrated by XRPD (Supporting Informa-
tion, Figure S14). Notably, the lifetime of EuIII in Tb3+
@IFMC-26-Eu and Eu3+@IFMC-26-Tb shows longer Ln3+
lifetimes of 7.15 and 7.94 ms than that of IFMC-26-Eu0.5Tb0.5
(tia =6.33 ms). The lifetime of TbIII in Tb3+@IFMC-26-Eu
and Eu3+@IFMC-26-Tb shows longer Ln3+ lifetime of 6.72
and 8.57 ms than that of IFMC-26-Eu0.5Tb0.5 (tia =5.22 ms,
Supporting Information, Table S2).
5
7
Meanwhile, the decay curve of D4! F5 transitions (545 nm)
for IFMC-28-Tb is well-fitted by a biexponential function,
to yield a lifetime value of tia =12.25 ms. Moreover, both the
EuIII and TbIII decay curves in IFMC-28-Eu0.6Tb0.4, IFMC-
28-Eu0.5Tb0.5, and IFMC-28-Eu0.4Tb0.6 were also investigated.
7
The EuIII decay curves detected at 5D0! F2 transitions
(619 nm) of IFMC-28-Eu0.6Tb0.4, IFMC-28-Eu0.5Tb0.5, and
IFMC-28-Eu0.4Tb0.6 are well-fitted by biexponential func-
tions with lifetime values of tia =8.78, 18.43, and 10.86 ms, re-
spectively. Meanwhile, the TbIII decay curves monitored at
7
5D4! F5 transitions (545 nm) of IFMC-28-Eu0.6Tb0.4, IFMC-
28-Eu0.5Tb0.5, and IFMC-28-Eu0.4Tb0.6, which are well-fitted
by exponential functions, yield lifetime values of tia =6.95,
11.32, and 9.29 ms, respectively (Supporting Information,
Table S2).
As shown above, the intensities of red and green originat-
ing from EuIII and TbIII ion emissions can be effectively
tuned by changing the molar ratios of raw materials and
postencapsulation. We have successfully achieved tunable
luminescence in MOFs by two kinds of doping methods. Ex-
perimental inductively coupled plasma results are listed in
Table S3 in the Supporting Information, which shows the
corresponding contents of EuIII and TbIII in the final prod-
ucts. In addition, the quantum yields of IFMC-26-Eu,
IFMC-26-Tb, IFMC-26-EuxTby, Tb3+@IFMC-26-Eu, Eu3+
@IFMC-26-Tb, and IFMC-28-EuxTby are also presented in
Table S3 (Supporting Information). Notably, the quantum
yields of Tb3+@IFMC-26-Eu and Eu3+@IFMC-26-Tb are
clearly higher than those of IFMC-26-EuxTby and IFMC-28-
Excitation and emission spectra of the metalloACTHNUTRGNENGlU iCAHUTGTNRENUgNG and are
shown in Figure S11b (Supporting Information). Upon exci-
tation at 298 nm, IFMC-28-Eu displays narrow and charac-
5
7
teristic peaks at 592, 619, 646, and 690 nm due to D0! FJ
(J=0–4) transitions of the EuIII ion (Supporting Informa-
tion, Figure S15a). The most intense emission at 619 nm is
5
7
attributed to the D0! F2 (electric-dipole) transition, which
is hypersensitive to the coordination environment of the
Chem. Eur. J. 2013, 19, 11279 – 11286
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
11283

S.-L. Li, Y.-Q. Lan, Z.-M. Su et al.
764 (s), 716 (m), 645 (w), 563 (w), 423 cmꢀ1 (m); elemental analysis calcd
(%) for C90H116N17O22Ni Eu0.5Tb0.5: C 53.98, H 5.85, N 11.89, Eu 3.79, Tb
3.97; found: C 53.92, H 5.93, N 11.95, Eu 3.75, Tb 3.92.
EuxTby, which may be caused by the environments of EuIII
and TbIII. In Tb3+@IFMC-26-Eu and Eu3+@IFMC-26-Tb,
the postencapsulated EuIII and TbIII are free Eu3+ and Tb3+
ions, whereas EuIII and TbIII in IFMC-26-EuxTby and IFMC-
28-EuxTby coordinate to the carboxylate groups of H4L to
form inorganic–organic hybrid materials. Moreover, the
quantum yield of IFMC-26-Eu0.5Tb0.5 is relatively higher
than that in IFMC-26-Eu, IFMC-26-Tb, and IFMC-28-
EuxTby, thereby revealing that the quantum yields are not
only related to the molar ratios of EuIII and TbIII ions, but
also to the structures of the complexes. As far as we know,
this is the first time that the quantum yields for the ratio of
LnIII ions and postencapsulated LnIII ions in LnMOFs have
been compared.
Synthesis of IFMC-26-Tb, [Ni(L)Tb]
was synthesized by a procedure similar to that used for IFMC-26-Eu with
Tb(NO3)3·6H2O (0.05 g, 0.11 mmol) instead of Eu(NO3)3·6H2O (0.05 g,
ACHTUNGTREN(NNUG NO3)·5H2O·6DMA: IFMC-26-Tb
A
ACHTUNGTRENNUNG
0.11 mmol). The light purple crystals were isolated by washing with
DMA and dried at room temperature. Yield: 55% based on H4L. IR
(KBr): n˜ =3423 (s), 2937 (m), 1615 (s), 1454 (s), 1414 (s), 1327 (m), 1262
(m), 1186 (w), 1087 (w), 1017 (w), 960 (w), 897 (w), 748 (s), 716 (m), 597
(m), 478 (m), 424 cmꢀ1 (m); elemental analysis calcd (%) for
C90H116N17O22NiTb: C 53.89, H 5.84, N 11.87, Tb 7.92; found: C 53.83, H
5.89, N 11.94, Tb 7.85.
Synthesis of IFMC-27-La, [Ni(L)La
A mixture of H4L (0.04 g, 0.36 mmol), NiCl2·6H2O (0.15 g, 0.63 mmol),
La(NO3)3·6H2O (0.04 g, 0.09 mmol), DMA (5 mL), and H2O (2 mL) was
2ACHTUNGNERTU(NGN NO3)3ACHTUNTREG(NNGUN dma)]ACTHNUGRTNE(NUGN NO3)·2H2O·2DMA:
AHCTUNGTRENNUNG
sealed in a Teflon-lined stainless steel container and heated in an auto-
clave at 1208C for 4 days. The autoclave was cooled to room tempera-
ture, the container was removed, and 3 drops of HNO3 were added. The
container continued to be heated at 1408C for 4 days. After the autoclave
was cooled to room temperature, light purple crystals were obtained,
which were isolated by washing with DMA and dried at room tempera-
ture. Yield: 52% based on H4L. IR (KBr): n˜ =3390 (s), 2934 (m), 1597
(s), 1548 (s), 1482 (s), 1452 (s), 1402 (s), 1329 (s), 1179 (w), 1111 (w),
1083 (w), 1016 (m), 941 (w), 894 (w), 854 (w), 765 (s), 743 (m), 714 (m),
667 (m), 611 (m), 474 cmꢀ1 (w); elemental analysis calcd (%) for
C78H83N17O25NiLa2: C 46.95, H 4.20, N 11.94, La 13.92; found: C 46.89, H
4.27, N 11.99, La 13.85.
Conclusion
A series of heterometallic LnMOFs has been prepared by
self-assembly and stepwise synthesis. For the first time, a
comparison has been made of the structures and properties
of IFMC-26–28, which were obtained by the two different
synthesis strategies. A wide variety of tunable luminescence
was successfully attained not only by changing the molar
ratios of LnIII ions, but also through postencapsulating TbIII
and EuIII ions into the pores of IFMC-26-Eu and IFMC-26-
Tb, respectively. Notably, the quantum yields are clearly en-
hanced by postencapsulating TbIII and EuIII ions into the
pores of IFMC-26. The quantum yields are related to both
the molar ratios of EuIII and TbIII ions and the structures of
the complexes. Therefore, such doping of heterometallic
LnMOFs can be a strategy for preparing multifunctional lu-
minescent materials. This work provides two different
routes, self-assembly and stepwise synthesis, for the prepara-
tion of novel and functional heterometallic LnMOFs, as well
as offering examples of crystalline materials with tunable lu-
minescence. In addition, studies of the precisely tunable
white-light emission of this system are currently under way.
Synthesis of the metallo
G
N
0.5ACHTUGNNERTN(NUG H4L)0.5]ACHTUNGTERN(GNUN NO3)·4CH3CH2OH: H4L
(0.02 g, 0.18 mmol) and NiAHCTNUGTRENNNUG
dissolved in ethanol (10 mL) with stirring. The two solutions were mixed
in a 25 mL beaker and then three drops of HCl were added. The mixture
was stirred for an additional 5 min and filtered to remove the precipitate.
The clear solution was left in the air for 3 days. Light pink crystals were
obtained, which were isolated by washing with ethanol and dried at room
temperature. Yield: 59% based on H4L. IR (KBr): n˜ =3381 (s), 1709 (s),
1614 (m), 1478 (s), 1453 (s), 1382 (s), 1178 (m), 1110 (m), 1041 (w), 1017
(w), 940 (w), 894 (w), 833 (m), 747 (s), 711 (m), 430 cmꢀ1 (w); elemental
analysis calcd (%) for C41H52N6O11Ni0.5: C 59.02, H 6.29, N 10.08; found:
C 58.97, H 6.35, N 10.15.
Synthesis of IFMC-28-La, [Ni(L)La
ACHTUGNTRNEU(NNG H2O)ACHTUNGTREG(NNNU dmf)2]ACTHUNGTRENNUNG
mixture of the metalloligand (0.04 g, 0.05 mmol), LaCAHTUNGTRENNUNG
A
U
0.16 mmol), DMF (5 mL), and H2O (3 mL) was sealed in a Teflon-lined
stainless steel container. The container was heated to 1108C for 4 days
resulting in light pink crystals, which were isolated by washing with DMF
and dried at room temperature. Yield: 59% based on H4L. IR (KBr): n˜ =
3388 (s), 2924 (m), 1602 (s), 1546 (s), 1484 (s), 1452 (s), 1397 (s), 1328 (s),
1174 (m), 1110 (m), 1079 (m), 1013 (w), 927 (w), 892 (w), 856 (w), 747
(m), 527 (m), 421 cmꢀ1 (m); elemental analysis calcd (%) for
C72H79N12O17NiLa: C 54.12, H 4.92, N 11.79, La 8.35; found: C 54.05, H
5.01, N 11.83, La 8.26.
Experimental Section
Synthesis of IFMC-26-Eu, [Ni(L)Eu]
ACHTUNGTRENNUNG
Synthesis of IFMC-28-Eu, [Ni(L)Eu
IFMC-28-Eu was synthesized by a procedure similar to that used for
IFMC-28-La with Eu(NO3)3·6H2O (0.05 g, 0.11 mmol) instead of La-
(NO3)3·6H2O (0.07 g, 0.16 mmol). The light pink crystals were isolated by
washing with DMF and dried at room temperature. Yield: 52% based on
H4L. IR (KBr): n˜ =3420 (s), 2933 (s), 1623 (s) 1556 (s), 1493 (s), 1403 (s),
1181 (m), 1108 (m), 1015 (m), 937 (w), 920 (w), 894 (w), 859 (s), 808 (w),
784 (m), 739 (s), 715 (m), 674 (w), 646 cmꢀ1 (w); elemental analysis calcd
(%) for C72H79N12O17NiEu: C 54.70, H 4.88, N 11.69, Eu 9.06; found: C
54.63, H 4.95, N 11.78, Eu 9.01.
ACHTUNGNERTU(GNN H2O)ACHTUNRTGEG(NNUN dmf)2]CATHNUGTERN(NUGN NO3)·3H2O·DMF:
0.36 mmol), NiCl2·6H2O (0.15 g, 0.63 mmol), EuACHTUNGTRENNUNG
0.11 mmol), DMA (6 mL), and H2O (4 mL) were sealed in a Teflon-lined
stainless steel container. The container was heated to 1208C for 4 days,
which resulted in light purple crystals that were isolated by washing with
DMA and dried at room temperature. Yield: 54% based on H4L. IR
(KBr): n˜ =3419 (s), 3061 (m), 2935 (s), 1616 (s), 1543 (s), 1415 (s), 1262
(m), 1181 (m), 1107 (w), 1016 (m), 965 (w), 895 (w), 808 (m), 747 (s), 646
(w), 593 (m), 475 (w), 422 cmꢀ1 (m); elemental analysis calcd (%) for
C90H116N17O22NiEu: C 54.08, H 5.86, N 11.92, Eu 7.60; found: C 54.02, H
5.92, N 11.98, Eu 7.53.
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
Synthesis
(NO3)·3H2O·DMF: IFMC-28-Eu0.6Tb0.4 was synthesized by a procedure
similar to that used for IFMC-28-La with Eu(NO3)3·6H2O (0.05 g,
0.11 mmol) and Tb(NO3)3·6H2O (0.03 g, 0.07 mmol) instead of La-
ACHTNUGTRENN(UGN NO3)3·6H2O (0.07 g, 0.16 mmol). The light pink crystals were isolated by
of
IFMC-28-Eu0.6Tb0.4
,
[Ni(L)Eu0.6Tb0.4ACTHNGUTREN(UNG H2O)ACHTUNGTRENNUNG(dmf)2]-
Synthesis of IFMC-26-Eu0.5Tb0.5: IFMC-26-Eu0.5Tb0.5 was synthesized by
AHCTUNGTRENNUNG
a procedure similar to that used for IFMC-26-Eu with Eu
(0.02 g, 0.05 mmol) and Tb(NO3)3·6H2O (0.04 g, 0.09 mmol) instead of
Eu(NO3)3·6H2O (0.04 g, 0.09 mmol). The light purple crystals were isolat-
ACHTNUGRTNE(NUGN NO3)3·6H2O
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
G
ACHTUNGTRENNUNG
ed by washing with DMA and dried at room temperature. Yield: 58%
based on H4L. IR (KBr): n˜ =3385 (s), 2931 (s), 1628 (s), 1414 (s), 1298
(m), 1179 (m), 1084 (w), 1015 (m), 939 (w), 859 (m), 833 (w), 785 (m),
washing with DMA and dried at room temperature. Yield: 52% based
on H4L. IR (KBr): n˜ =3419 (s), 2933 (s), 1625 (s), 1478 (s), 1326 (s), 1180
11284
www.chemeurj.org
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2013, 19, 11279 – 11286

Heterometal–Organic Frameworks
FULL PAPER
(m), 1015 (m), 937 (w), 920 (w), 859 (m), 832 (w), 784 (m), 738 (s), 715
(m), 646 (w), 561 (w), 476 (w), 424 cmꢀ1 (m); elemental analysis calcd
(%) for C72H79N12O17NiEu0.6Tb0.4: C 53.61, H 4.87, N 11.67, Eu 5.43, Tb
3.78; found: C 53.56, H 4.94, N 11.76, Eu 5.37, Tb 3.81.
Xie, C. D. Wu, M. C. Das, R. Gill, K. M. Thomas, B. L. Chen, Nat.
Commun. 2011, 2, 204–210; c) Z. Y. Guo, H. Wu, G. Srinivas, Y. M.
Zhou, S. C. Xiang, Z. X. Chen, Y. T. Yang, W. Zhou, M. OꢄKeeffe,
B. L. Chen, Angew. Chem. 2011, 123, 3236–3239; Angew. Chem. Int.
Ed. 2011, 50, 3178–3181; d) Y. E. Cheon, M. P. Suh, Angew. Chem.
2009, 121, 2943–2947; Angew. Chem. Int. Ed. 2009, 48, 2899–2903;
e) H. L. Jiang, T. Akita, T. Ishida, M. Haruta, Q. Xu, J. Am. Chem.
Soc. 2011, 133, 1304–1306; f) F. Wang, Y. X. Tan, H. Yang, H. X.
Zhang, Y. Kang, J. Zhang, Chem. Commun. 2011, 47, 5828–5830;
g) J. S. Qin, D. Y. Du, W. L. Li, J. P. Zhang, S. L. Li, Z. M. Su, X. L.
Wang, Q. Xu, K. Z. Shao, Y. Q. Lan, Chem. Sci. 2012, 3, 2114–2118;
h) J. A. Mason, K. Sumida, Z. R. Herm, R. Krishna, J. R. Long,
Energy Environ. Sci. 2011, 4, 3030–3040; i) S. Liu, Z. Xiang, Z. Hu,
X. Zheng, D. Cao, J. Mater. Chem. 2011, 21, 6649–6653; j) W. G. Lu,
D. Q. Yuan, T. A. Makal, J. R. Li, H. C. Zhou, Angew. Chem. 2012,
124, 1612–1616; Angew. Chem. Int. Ed. 2012, 51, 1580–1584;
k) Y. N. Gong, M. Meng, D. C. Zhong, Y. L. Huang, L. Jiang, T. B.
Lu, Chem. Commun. 2012, 48, 12002–12004; l) P. Pachfule, Y. F.
Chen, J. W. Jiang, R. Banerjee, Chem. Eur. J. 2012, 18, 688–694.
[2] a) J. R. Li, H. C. Zhou, Nat. Chem. 2010, 2, 893–898; b) C. Y. Sun,
C. Qin, C. G. Wang, Z. M. Su, S. Wang, X. L. Wang, G. S. Yang,
K. Z. Shao, Y. Q. Lan, E. B. Wang, Adv. Mater. 2011, 23, 5629–5632;
c) D. Zhao, S. W. Tan, D. Q. Yuan, W. G. Lu, Y. H. Rezenom, H. L.
Jiang, L. Q. Wang, H. C. Zhou, Adv. Mater. 2011, 23, 90–93; d) Z.
Ma, B. Moulton, Coord. Chem. Rev. 2011, 255, 1623–1641; e) F. Ke,
Y. P. Yuan, L. G. Qiu, Y. H. Shen, A. J. Xie, J. F. Zhu, X. Y. Tian,
L. D. Zhang, J. Mater. Chem. 2011, 21, 3843–3848; f) R. C. Huxford,
J. D. Rocca, W. Lin, Curr. Opin. Chem. Biol. 2010, 14, 262–268;
g) D. Y. Du, J. S. Qin, T. T. Wang, S. L. Li, Z. M. Su, K. Z. Shao,
Y. Q. Lan, X. L. Wang, E. B. Wang, Chem. Sci. 2012, 3, 705–710;
h) X. Zhu, H. Y. Zheng, X. F. Wei, Z. Y. Lin, L. G. Guo, B. Qiu,
G. N. Chen, Chem. Commun. 2013, 49, 1276–1278; i) D. Hermann,
H. Emerich, R. Lepski, D. Schaniel, U. Ruschewitz, Inorg. Chem.
2013, 52, 2744–2749.
[3] a) P. Falcaro, S. Furukawa, Angew. Chem. 2012, 124, 8557–8559;
Angew. Chem. Int. Ed. 2012, 51, 8431–8433; b) A. Zaꢅm, H. Nozary,
L. Guꢆnꢆe, C. Besnard, J. Lemonnier, S. Petoud, C. Piguet, Chem.
Eur. J. 2012, 18, 7155–7168; c) H. H. Li, W. Shi, K. N. Zhao, Z. Niu,
H. M. Li, P. Cheng, Chem. Eur. J. 2013, 19, 3358–3365; d) P. R.
Matthes, C. J. Hçller, M. Mai, J. Heck, S. J. Sedlmaier, S. Schmie-
chen, C. Feldmann, W. Schnick, K. Mꢇller-Buschbaum, J. Mater.
Chem. 2012, 22, 10179–10187; e) C. J. Hçller, K. Mꢇller-Buschbaum,
Inorg. Chem. 2008, 47, 10141–10149; f) R. Decadt, K. V. Hecke, D.
Depla, K. Leus, D. Weinberger, I. V. Driessche, P. V. D. Voort, R. V.
Deun, Inorg. Chem. 2012, 51, 11623–11634; g) H. B. Zhang, X. C.
Shan, L. J. Zhou, P. Lin, R. F. Li, E. Ma, X. G. Guo, S. W. Du, J.
Mater. Chem. C 2013, 1, 888–891.
[4] a) B. L. Chen, L. B. Wang, Y. Q. Xiao, F. R. Fronczek, M. Xue, Y. J.
Cui, G. D. Qian, Angew. Chem. 2009, 121, 508–511; Angew Chem.
Int. Ed. 2009, 48, 500–503; b) B. L. Chen, L. B. Wang, F. Zapata,
G. D. Qian, E. B. Lobkovsky, J. Am. Chem. Soc. 2008, 130, 6718–
6719; c) M. P. Suh, Y. Cheon, E. Lee, Coord. Chem. Rev. 2008, 252,
1007–1026; d) J. Rocha, L. D. Carlos, F. A. A. Paz, D. Ananias,
Chem. Soc. Rev. 2011, 40, 926–940; e) B. Chen, S. Xiang, G. Qian,
Acc. Chem. Res. 2010, 43, 1115–1124; f) O. Shekhah, J. Liu, R. A.
Fischer, C. Wçll, Chem. Soc. Rev. 2011, 40, 1081–1106; g) G. Fꢆrey,
Chem. Soc. Rev. 2008, 37, 191–214; h) R. J. Kuppler, D. J. Timmons,
Q. R. Fang, J. R. Li, T. A. Makal, M. D. Young, D. Yuan, D. Zhao,
W. Zhuang, H. C. Zhou, Coord. Chem. Rev. 2009, 253, 3042–3066;
i) L. Chen, K. Tan, Y. Q. Lan, S. L. Li, K. Z. Shao, Z. M. Su, Chem.
Commun. 2012, 48, 5919–5921; j) F. Y. Yi, W. T. Yang, Z. M. Sun, J.
Mater. Chem. 2012, 22, 23201–23209; k) S. Dang, E. Ma, Z. M. Sun,
H. J. Zhang, J. Mater. Chem. 2012, 22, 16920–16926.
Synthesis
(NO3)·3H2O·DMF: IFMC-28-Eu0.5Tb0.5 was synthesized by a procedure
similar to that used for IFMC-28-La with Eu(NO3)3·6H2O (0.04 g,
0.09 mmol) and Tb(NO3)3·6H2O (0.04 g, 0.11 mmol) instead of La-
ACHTUNGTRENNUNG(NO3)3·6H2O (0.07 g, 0.16 mmol). The light pink crystals were isolated by
of
IFMC-28-Eu0.5Tb0.5
,
[Ni(L)Eu0.5Tb0.5ACTHNGUTREN(UNG H2O)ACHTUNGRTEN(NUNG dmf)2]-
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
ACHTUNGTRENNUNG
washing with DMA and dried at room temperature. Yield: 53% based
on H4L. IR (KBr): n˜ =3419 (s), 2932 (s), 1625 (s), 1543 (s), 1478 (s), 1327
(s), 1181 (m), 1015 (m), 920 (w), 807 (w), 784 (m), 739 (s), 715 (m), 675
(w), 646 (w), 593 (w), 477 (w), 424 cmꢀ1 (m); elemental analysis calcd
(%) for C72H79N12O17NiEu0.5Tb0.5: C 53.59, H 4.87, N 11.67, Eu 4.52, Tb
4.73; found: C 53.53, H 4.92, N 11.73, Eu 4.46, Tb 4.66.
Synthesis
(NO3)·3H2O·DMF: IFMC-28-Eu0.4Tb0.6 was synthesized by a procedure
similar to that used for IFMC-28-La with Eu(NO3)3·6H2O (0.03 g,
0.07 mmol) and Tb(NO3)3·6H2O (0.05 g, 0.11 mmol) instead of La-
ACHTUNGTRENNUNG(NO3)3·6H2O (0.07 g, 0.16 mmol). The light pink crystals were isolated by
of
IFMC-28-Eu0.4Tb0.6
,
[Ni(L)Eu0.4Tb0.6ACTHNGUTREN(UNG H2O)ACHTUNGRTEN(NUNG dmf)2]-
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
ACHTUNGTRENNUNG
washing with DMA and dried at room temperature. Yield: 54% based
on H4L. IR (KBr): n˜ =3408 (s), 2932 (s), 1616 (s), 1478 (s), 1414 (s), 1180
(m), 1162 (m), 1108 (m), 949 (w), 920 (w), 894 (m), 831 (w), 808 (w), 784
(m), 751 (s), 715 (m), 646 (w), 611 (w), 424 cmꢀ1 (m); elemental analysis
calcd (%) for C72H79N12O17NiEu0.4Tb0.6: C 53.57, H 4.87, N 11.66, Eu
3.61, Tb 5.67; found: C 53.49, H 4.94, N 11.74, Eu 3.56, Tb 5.49.
Synthesis of IFMC-28-Tb, [Ni(L)Tb
IFMC-28-Tb was synthesized by a procedure similar to that used for
IFMC-28-La with Tb(NO3)3·6H2O (0.05 g, 0.11 mmol) instead of La-
(NO3)3·6H2O (0.07 g, 0.16 mmol). The light pink crystals were isolated by
ACHTUNGNERTU(GNN H2O)ACHTUNRTGEG(NNUN dmf)2]CATHNUGTERN(NUGN NO3)·3H2O·DMF:
ACHTUNGTRENNUNG
ACHTUNGTRENNUNG
washing with DMF and dried at room temperature. Yield: 53% based on
H4L. IR (KBr): n˜ =3448 (s), 2934 (s), 1633 (s), 1497 (s), 1265 (s), 1188
(m), 1107 (w), 1081 (m), 1016 (s), 939 (w), 860 (w), 831 (w), 746 (m), 715
(m), 645 (w), 592 (m), 475 (m), 424 cmꢀ1 (m); elemental analysis calcd
(%) for C72H79N12O17NiTb: C 53.48, H 4.86, N 11.65, Tb 9.44; found: C
53.43, H 4.93, N 11.72, Tb 9.38.
X-ray crystallography: Single-crystal X-ray diffraction data were record-
ed on a Bruker APEXII CCD diffractometer with graphite-monochro-
mated MoKa radiation (l=0.71069 ꢂ) at 293 K. Absorption corrections
were applied by using the multiscan technique. All the structures were
solved by the Direct Method of SHELXS-97 and refined by full-matrix
least-squares techniques using the SHELXL-97 program within WINGX.
The solvent molecules are highly disordered, and attempts to locate and
refine the solvent peaks were unsuccessful. Contributions to scattering
due to these solvent molecules were removed by using the SQUEEZE
routine of PLATON; structures were then refined again using the data
generated. Crystal data are summarized in Table S1 in the Supporting In-
formation. CCDC-921351 (IFMC-26-Eu), 921352 (IFMC-27-La), 921353
(IFMC-28-La), 921354 (the metalloACHTNUGTRENNUGliACHUTNTGRENgUNG and), and 921355 (IFMC-26-Tb)
contain the supplementary crystallographic data for this paper. These
data can be obtained free of charge from The Cambridge Crystallograph-
ic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
Acknowledgements
This work was financially supported by Pre-973 Program
(2010CB635114), the National Natural Science Foundation of China
(Nos. 21001020 and 21271089), and the program of Jiangsu Specially Ap-
pointed Professor, the project funded by the Priority Academic Program
Development of Jiangsu Higher Education Institutions, and Graduate In-
novation Fund of Jilin University (No. 20121048).
[5] Y. J. Cui, Y. F. Yue, G. D. Qian, B. L. Chen, Chem. Rev. 2012, 112,
1126–1162.
[6] a) D. Buso, J. Jasieniak, M. D. H. Lay, P. Schiavuta, P. Scopece, J.
Laird, H. Amenitsch, A. J. Hill, P. Falcaro, Small 2012, 8, 80–88;
b) S. Jin, H. J. Son, O. K. Farha, G. P. Wiederrecht, J. T. Hupp, J.
Am. Chem. Soc. 2013, 135, 955–958.
[1] a) M. Eddaoudi, J. Kim, N. Rosi, D. Vodak, J. Wachter, M.
OꢄKeeffe, O. M. Yaghi, Science 2002, 295, 469–472; b) S. C. Xiang,
Z. J. Zhang, C. G. Zhao, K. L. Hong, X. B. Zhao, D. R. Ding, M. H.
Chem. Eur. J. 2013, 19, 11279 – 11286
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
11285

S.-L. Li, Y.-Q. Lan, Z.-M. Su et al.
[7] a) S. Dang, J. H. Zhang, Z. M. Sun, J. Mater. Chem. 2012, 22, 8868–
8873; b) G. J. He, D. Guo, C. He, X. L. Zhang, X. W. Zhao, C. Y.
Duan, Angew. Chem. 2009, 121, 6248–6251; Angew. Chem. Int. Ed.
2009, 48, 6132–6135; c) L. Li, S. Q. Zhang, L. Han, Z. H. Sun, J. H.
Luo, M. C. Hong, Cryst. Growth Des. 2013, 13, 106–110; d) B. A.
Blight, R. Guillet-Nicolas, F. Kleitz, R. Y. Wang, S. N. Wang, Inorg.
Chem. 2013, 52, 1673–1675.
5395–5399; Angew. Chem. Int. Ed. 2009, 48, 5291–5295; c) J. R. Li,
D. J. Timmons, H. C. Zhou, J. Am. Chem. Soc. 2009, 131, 6368–
6369; d) A. Schoedel, L. Wojtas, S. P. Kelley, R. D. Rogers, M. Ed-
daoudi, M. J. Zaworotko, Angew. Chem. 2011, 123, 11623–11626;
Angew. Chem. Int. Ed. 2011, 50, 11421–11424; e) H. N. Wang, X.
Meng, G. S. Yang, X. L. Wang, K. Z. Shao, Z. M. Su, C. G. Wang,
Chem. Commun. 2011, 47, 7128–7130.
[8] a) B. V. Harbuzaru, A. Corma, F. Rey, J. L. Jordꢈ, D. Ananias, L. D.
Carlos, J. Rocha, Angew. Chem. 2009, 121, 6598–6601; Angew.
Chem. Int. Ed. 2009, 48, 6476–6479; b) Y. J. Cui, H. Xu, Y. F. Yue,
Z.Y. Guo, J. C. Yu, Z. X. Chen, J. K. Gao, Y. Yang, G. D. Qian, B. L.
Chen, J. Am. Chem. Soc. 2012, 134, 3979–3982; c) R. M. P. Colo-
drero, K. E. Papathanasiou, N. Stavgianoudaki, P. Olivera-Pastor,
E. R. Losilla, M. A. G. Aranda, L. Leꢉn-Reina, J. Sanz, I. Sobrados,
D. Choquesillo-Lazarte, J. M. Garcꢊa-Ruiz, P. Atienzar, F. Rey, K. D.
Demadis, A. Cabeza, Chem. Mater. 2012, 24, 3780–3792.
[9] a) J. An, C. M. Shade, D. A. Chengelis-Czegan, S. Petoud, N. L.
Rosi, J. Am. Chem. Soc. 2011, 133, 1220–1223; b) Y. Q. Lan, H. L.
Jiang, S. L. Li, Q. Xu, Adv. Mater. 2011, 23, 5015–5020; c) W. W.
He, S. L. Li, G. S. Yang, Y. Q. Lan, Z. M. Su, Q. Fu, Chem.
Commun. 2012, 48, 10001–10003; d) D. F. Sava, L. E. S. Rohwer,
M. A. Rodriguez, T. M. Nenoff, J. Am. Chem. Soc. 2012, 134, 3983–
3986.
[10] a) M. D. Allendorf, C. A. Bauer, R. K. Bhakta, R. J. Houk, Chem.
Soc. Rev. 2009, 38, 1330–1352; b) D. P. Yan, G. O. Lloyd, A. Delori,
W. Jones, X. Duan, ChemPlusChem 2012, 77, 1112–1118; c) C.
Serre, F. Millange, C. Thouvenot, N. Gardant, F. Pellꢆ, G. Fꢆrey, J.
Mater. Chem. 2004, 14, 1540–1543; d) W. J. Rieter, K. M. L. Taylor,
H. An, W. Lin, W. Lin, J. Am. Chem. Soc. 2006, 128, 9024–9025;
e) K. C. Stylianou, R. Heck, S. Y. Chong, J. Bacsa, J. T. A. Jones,
Y. Z. Khimyak, D. Bradshaw, M. J. Rosseinsky, J. Am. Chem. Soc.
2010, 132, 4119–4130.
[15] Y. L. Bai, J. Tao, R. B. Huang, L. S. Zheng, Angew. Chem. 2008, 120,
5424–5427; Angew. Chem. Int. Ed. 2008, 47, 5344–5347.
[16] M. C. Das, Q. S. Guo, Y. B. He, J. Kim, C. G. Zhao, K. L. Hong,
S. C. Xiang, Z. J. Zhang, K. M. Thomas, R. Krishna, B. L. Chen, J.
Am. Chem. Soc. 2012, 134, 8703–8710.
[17] M. C. Das, S. C. Xiang, Z. J. Zhang, B. L. Chen, Angew. Chem. 2011,
123, 10696–10707; Angew. Chem. Int. Ed. 2011, 50, 10510–10520.
[18] a) S. R. Halper, L. Do, J. R. Stork, S. M. Cohen, J. Am. Chem. Soc.
2006, 128, 15255–15268; b) D. W. Smithenry, S. R. Wilson, K. S. Sus-
lick, Inorg. Chem. 2003, 42, 7719–7721; c) K. S. Suslick, P. Bhyrappa,
J. H. Chou, M. E. Kosal, S. Nakagaki, D. W. Smithenry, S. R. Wilson,
Acc. Chem. Res. 2005, 38, 283–291; d) R. Kitaura, G. Onoyama, H.
Sakamoto, R. Matsuda, S. Noro, S. Kitagawa, Angew. Chem. 2004,
116, 2738–2741; Angew. Chem. Int. Ed. 2004, 43, 2684–2687.
[19] a) H. S. Liu, Y. Q. Lan, S. L. Li, Cryst. Growth Des. 2010, 10, 5221–
5226; b) D. Y. Du, J. S. Qin, C. X. Sun, X. L. Wang, S. R. Zhang, P.
Shen, S. L. Li, Z. M. Su, Y. Q. Lan, J. Mater. Chem. 2012, 22, 19673–
19678.
[20] a) P. Benndorf, S. Schmitt, R. Kçppe, P. OÇa-Burgos, A. Scheurer,
K. Meyer, P. W. Roesky, Angew. Chem. 2012, 124, 5091–5095;
Angew. Chem. Int. Ed. 2012, 51, 5006–5010; b) H. L. Jiang, N. Tsu-
mori, Q. Xu, Inorg. Chem. 2010, 49, 10001–10006; c) H. Wang, S. J.
Liu, D. Tian, J. M. Jia, T. L. Hu, Cryst. Growth Des. 2012, 12, 3263–
3270; d) D. Y. Du, J. S. Qin, S. L. Li, Y. Q. Lan, X. L. Wang, Z. M.
Su, Aust. J. Chem. 2010, 63, 1389–1395.
[11] T. Gadzikwa, G. Lu, C. L. Stern, S. R. Wilson, J. T. Hupp, S. T.
Nguyen, Chem. Commun. 2008, 5493–5495.
[12] A. C. Sudik, A. P. Cꢋtꢆ, A. G. Wong-Foy, M. OꢄKeeffe, O. M. Yaghi,
Angew. Chem. 2006, 118, 2590–2595; Angew. Chem. Int. Ed. 2006,
45, 2528–2533.
[13] a) P. Thanasekaran, C. C. Lee, K. L. Lu, Acc. Chem. Res. 2012, 45,
1403–1418; b) B. J. Burnett, P. M. Barron, C. Hu, W. Choe, J. Am.
Chem. Soc. 2011, 133, 9984–9987; c) Z. Zhang, S. Xiang, Y. S. Chen,
S. Ma, Y. Lee, T. Phely-Bobin, B. Chen, Inorg. Chem. 2010, 49,
8444–8448.
[14] a) Y. Q. Lan, S. L. Li, H. L. Jiang, Q. Xu, Chem. Eur. J. 2012, 18,
8076–8083; b) X. L. Wang, C. Qin, S. X. Wu, K. Z. Shao, Y. Q. Lan,
S. Wang, D. X. Zhu, Z. M. Su, E. B. Wang, Angew. Chem. 2009, 121,
[21] a) S. Dang, J. H. Zhang, Z. M. Sun, H. J. Zhang, Chem. Commun.
2012, 48, 11139–11141; b) X. Ma, X. Li, Y. E. Cha, L. P. Jin, Cryst.
Growth Des. 2012, 12, 5227–5232.
[22] a) Y. Q. Sun, J. Zhang, Y. M. Chen, G. Y. Yang, Angew. Chem. 2005,
117, 5964–5967; Angew. Chem. Int. Ed. 2005, 44, 5814–5817;
b) J. W. Cheng, S. T. Zheng, G. Y. Yang, Dalton Trans. 2007, 4059–
4066.
[23] T. Gunnlaugsson, J. P. Leonard, Chem. Commun. 2005, 3114–3131.
[24] a) F. S. Richardson, Chem. Rev. 1982, 82, 541–552; b) J. S. Qin, D. Y.
Du, L. Chen, X. Y. Sun, Y. Q. Lan, Z. M. Su, J. Solid State Chem.
2011, 184, 373–378.
Received: April 22, 2013
Published online: July 12, 2013
11286
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Chem. Eur. J. 2013, 19, 11279 – 11286