A luminescent dye@MOF platform: Emission fingerprint relationships of volatile organic molecules

Article abstract of DOI:10.1002/anie.201307331

Self-assembly of luminescent moieties into porous metal-organic frameworks (MOFs) has generated many luminescent platforms for probing volatile organic molecules (VOMs). However, most of those explored thus far have only been based on the luminescence intensity of one transition, which is not efficient for probing different VOMs. We have synthesized a luminescent MOF material containing 1D nanotube channels, and further developed a luminescent dye@MOF platform to realize the probing of different VOMs by tuning the energy transfer efficiency between two different emissions. The dye@MOF platform exhibits excellent fingerprint correlation between the VOM and the emission peak-height ratio of ligand to dye moieties. The dye@MOF sensor is self-calibrating, stable, and instantaneous, thus the approach should be a very promising strategy to develop luminescent materials with unprecedented practical applications. Got the glow: A 3D coordination network with large hexagonal nanotube channels based on 1D infinite rod-shaped metal-carboxylate chains is reported. This material can absorb Rhodamine B dye into its pores to form a luminescent platform for visually probing different small molecules. Copyright

Full text of DOI:10.1002/anie.201307331

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DOI: 10.1002/anie.201307331
Luminescent Metal–Organic Sensors
A Luminescent Dye@MOF Platform: Emission Fingerprint
Relationships of Volatile Organic Molecules**
Ming-Jie Dong, Min Zhao, Sha Ou, Chao Zou, and Chuan-De Wu*
Abstract: Self-assembly of luminescent moieties into porous
metal–organic frameworks (MOFs) has generated many
luminescent platforms for probing volatile organic molecules
(VOMs). However, most of those explored thus far have only
been based on the luminescence intensity of one transition,
which is not efficient for probing different VOMs. We have
synthesized a luminescent MOF material containing 1D
nanotube channels, and further developed a luminescent
dye@MOF platform to realize the probing of different VOMs
by tuning the energy transfer efficiency between two different
emissions. The dye@MOF platform exhibits excellent finger-
print correlation between the VOM and the emission peak-
height ratio of ligand to dye moieties. The dye@MOF sensor is
self-calibrating, stable, and instantaneous, thus the approach
should be a very promising strategy to develop luminescent
materials with unprecedented practical applications.
volatile organic molecules (VOMs) with clearly differentiable
and unique readouts based on a host MOF sensor is still
a challenge, because most of this class of small molecules have
similar chemical and physical properties.[9]
It has been well established that some metal ions, such as
lanthanide(III) and cadmium(II) ions, can be bridged by
carboxylate groups to form infinite rod-shaped metal–car-
boxylate secondary building units (SBUs), which have
provided an effective route to construct novel MOFs with
large nanotube channels.[10,11] To enhance the luminescent
emission of such MOFs, we have designed and synthesized
a rigid, acentric linear carboxylic ligand, (E)-4-(2-carboxyvi-
nyl)benzoic acid (H2L), with two chromophoric centers as
a linker (Scheme 1). The solvothermal reaction of H2L and
Cd(NO3)2·4H2O in acidified DMF solvent yielded colorless
rod-like crystals of [CdL(H2O)]·4DMF·2H2O (CZJ-3; CZJ =
As an emerging type of porous materials, metal–organic
frameworks (MOFs) have the advantages over conventional
inorganic porous materials in that their structures and
functions are systematically and predictably designable and
readily modulated.[1,2] Such unique characteristics allow for
the use of MOF materials in various disciplines to realize
applications in the fields of gas storage, separation, hetero-
geneous catalysis, photonics, and drug delivery.[3–7] Moreover,
self-assembly of inorganic and organic luminescent moieties
into porous MOFs has allowed us to generate unique
luminescent platforms for chemical sensing, light-emitting,
biotechnology, and environmental monitoring.[8] Guest-de-
pendent luminescence sensors based on molecular coordina-
tion compounds have the distinct advantages of fast response,
high sensitivity, and noninvasive operation. Although
a number of luminescent MOFs have been shown to have
guest-dependent optical properties, most luminescent sensors
explored thus far are only based on the guest-dependent
luminescence intensity of one transition, which is not accurate
enough because the absolute luminescent intensity in the
solid state is variable. Moreover, the probing of different
Scheme 1. (E)-4-(2-carboxyvinyl)benzoic acid (H2L) ligand.
chemistry department of Zhejiang University). The formula
of CZJ-3 was established based on the single-crystal X-ray
structure, elemental analysis, and thermogravimetric analysis
(Supporting Information, Figure S3). CZJ-3 can absorb
Rhodamine B molecules into its pores to form the lumines-
cent material Rho@CZJ-3 by taking advantage of the nano-
tube channels. The emission peak height of Rhodamine B in
Rho@CZJ-3 can be utilized as a reference to that of the
original CZJ-3 for probing small molecules. We have found
that each VOM has a unique characteristic readout of the
luminescent peak-height ratio between two luminescent
centers in the visible light region; hence, probing different
VOMs is simply realized by monitoring the relative lumines-
cent readouts of Rho@CZJ-3.
Single-crystal X-ray diffraction analysis revealed that
CZJ-3 crystallizes in the chiral hexagonal space group
P6522.[12] The fundamental building unit of CZJ-3 contains
one cadmium(II) cation, one L ligand and one coordinated
water molecule. As shown in Figure 1, the two carboxylate
groups of the L ligand comprise of two different coordination
modes: the first carboxylate bridges two CdII ions in
a bidentate fashion, whereas the second carboxylate chelates
and bridges three Cd centers (Figure S1). The Cd cation is
coordinating to six carboxyl oxygen atoms from five L ligands
and one water molecule. The hepta-coordinated CdII ions are
further bridged by carboxylate groups to form infinite 1D rod-
shaped metal-carboxylate SBUs running along the c axis
[*] M.-J. Dong, M. Zhao, S. Ou, Dr. C. Zou, Prof. Dr. C.-D. Wu
Center for Chemistry of High-Performance and Novel Materials,
Department of Chemistry, Zhejiang University
Hangzhou, 310027 (P. R. China)
E-mail: cdwu@zju.edu.cn
[**] We are grateful for the financial support of the NSF of China
(21073158 and J1210042), Zhejiang Provincial Natural Science
Foundation of China (Z4100038) and the Fundamental Research
Funds for the Central Universities (2013FZA3006).
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/anie.201307331.
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times at room temperature, a dye-uptake assay was employed
to quantify the access to the pores in CZJ-3. By soaking an
activated sample of CZJ-3 in an acetone solution of Rhoda-
mine B (Figure S20; cross dimensions of ca. 6.43 ꢁ 12.7 ꢁ
15.5 ꢀ3) for 24 h at room temperature, the dye was almost
fully absorbed by CZJ-3, as determined by UV/Vis absorption
spectroscopy, and the dye-uptake was 0.19 wt% (Figure S6).
The PXRD pattern of Rho@CZJ-3, a sample embedded with
Rhodamine B, suggests that the framework structure remains
intact. We have also further studied the sorption abilities of
CZJ-3 and Rho@CZJ-3 for different VOMs, by immersing
the acetone-exchanged samples of CZJ-3 and Rho@CZJ-3 in
chlorobenzene and nitrobenzene solvents for 12 h at room
temperature to study their guest inclusion properties. UV/Vis
analysis indicates that the activated ones readily take up 2.1
and 1.5 molecules of chlorobenzene, and 1.2 and 0.8
molecules of nitrobenzene per formula unit of CZJ-3 and
Rho@CZJ-3, respectively. Rho@CZJ-3 is very stable, and the
included Rhodamine B molecules cannot leak into solution
during the absorption of different small solvent molecules, as
determined by UV/Vis absorption spectroscopy. The above
properties of Rho@CZJ-3 are beneficial for its application in
sensing small molecules. To encapsulate Rhodamine B into
the pores of CZJ-3, the second luminescent transition from
the dye can be readily generated, in addition to the original
one of the CZJ-3, whereaas the luminescent intensity ratios
can be further tuned by additional solvent molecules.
The excitation and emission spectra of H2L, CZJ-3 and
Rho@CZJ-3 were examined at room temperature in the solid
state. The free H2L ligand displays an intense and broad band
with a maximum at 430 nm in the emission spectrum under
310 nm UV excitation, which is attributed to the p–p*
electron transition of the H2L ligand, which involves
a ligand-centered excited state (Figure S10). The light emis-
sion peak of CZJ-3 shifts to 420 nm upon excitation at 340 nm
(Figure S11). The blue-shift of the emission of L in CZJ-3
should be attributed to the deprotonation and coordination of
L to Cd2+ ions.[14]
As expected, the dye encapsulated Rho@CZJ-3 simulta-
neously shows both the characteristic emissions of the dye and
L moieties upon excitation at 340 nm in the solid state at room
temperature. Rhodamine B and L within Rho@CZJ-3 emit
different colors, red around 595 nm and blue around 420 nm,
respectively. To make comparisons, we measured the emission
spectra of Rhodamine B and a thoroughly ground mixture of
Rhodamine B and CZJ-3 under the same conditions. Rhoda-
mine B does not display any emission, whereas the mechan-
ically ground mixture only presents the emission band of CZJ-
3 excited at 340 nm in the solid-state (Figure S12). These
results demonstrate that the dye molecules were encapsulated
in the nanotube channels of CZJ-3, and isolation of the dye
molecules by the pores of CZJ-3 can restrain the nonradiative
energy transfer process, which would otherwise quench the
photoluminescence.
Figure 1. A) A side-view of the partial nanotube wall in CZJ-3, showing
the coordination mode of L, the coordination environments of CdII
ions, and the connection between the 1D rod-shaped CdII-carboxylate
SBUs and L ligands. B) A perspective view of the 3D framework
structure of CZJ-3 with open-ended 1D hollow chiral nanotube
channels of 2 nm in diameter, as viewed along the c axis.
(Figure S2). Each Cd-carboxylate infinite SBU is connected
with six other chains through L linkers to generate an
interesting 3D coordination network with hexagonal nano-
tube channels propagated along the c axis. The diameter of
the 1D nanotube channels is about 2.0 nm (opposite Cd···Cd
distance), taking into account the van der Waals radii, in
which the vacancies are filled with DMF and water molecules.
PLATON calculations indicate that the vacant space in CZJ-3
is about 67.3% of the crystal volume (2679.4 ꢀ3 of the
3982.8 ꢀ3 unit cell volume).[13]
After the as-synthesized CZJ-3 was heated at 808C under
vacuum for 6 h, PXRD analysis of the sample showed that the
sharp diffraction peaks almost disappear (Figure S4). This
result suggests that CZJ-3 lost its long-range order upon
removal of the included solvent molecules. However, the
sharp diffraction peaks of PXRD can be restored by exposing
the evacuated sample to the vapor of DMF at 808C for 12 h.
These results suggest that the structure of CZJ-3 is flexible
and reversible depending upon the solvent guests. However,
such properties prevent the evaporated CZJ-3 from taking up
gas molecule as confirmed by the gas adsorption experiments.
Since the framework of CZJ-3 easily collapses after removal
of guest solvents, we have therefore activated CZJ-3 by
a solvent-exchange method (Figure S5). After the as-synthe-
sized sample was solvent-exchanged with dry acetone several
It is interesting that such a Rho@CZJ-3 platform has
allowed us to systematically tune the emissive light colors by
modulating the amounts of encapsulated Rhodamine B in
Rho@CZJ-3. The contents of absorbed Rhodamine B in
different Rho@CZJ-3 samples were determined by UV/Vis
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The above results
clearly demonstrate
that the photolumines-
cent properties of
Rho@CZJ-3 are varia-
ble, depending on the
amounts of included
Rhodamine B and the
excitation
energy.
Additionally, as shown
in Figure S21, the pho-
toluminescence
of
Rho@CZJ-3 is also
sensitive to the size of
the MOF crystals and
the homogeneity of
Rhodamine B in the
pores. We have used
the ground samples to
probe different VOMs.
Because Rhodamine B
is bulky, there remains
enough vacant space to
accommodate
small
solvent molecule, as
demonstrated above.
The induced-fit-type
Figure 2. The emission spectra (A), emission peak-height ratios of L to dye moieties (B), CIE chromaticity
coordinates (C), and photographs (D) with different amounts of encapsulated Rhodamine B (a=0.02 wt%,
b=0.04 wt%, c=0.06 wt%, d=0.08 wt%, e=0.1 wt%, f=0.12 wt%, g=0.16 wt%, and h=0.19 wt%), for
Rho@CZJ-3 excited at 340 nm in the solid-state at room temperature.
interaction
between
Rho@CZJ-3 and guest
molecules will subse-
quently
tune
the
spectroscopy. As shown in Figure 2, upon increasing the
Rhodamine B included in CZJ-3 (excited at 340 nm),
Rho@CZJ-3 exhibits tunable emissive light colors that are
controlled by decreasing the emission intensity ratio between
L and the dye transitions. The observed emission colors of
Rho@CZJ-3 match well with the calculated chromaticity
coordinates, according to the 1931 Commission Internatio-
nale de LꢂEclairage (CIE) chromaticity diagram, which can
be clearly and directly observed with the naked eye.
The emission of the dye in Rho@CZJ-3 is mainly
sensitized by the L moiety within the same framework. Such
ligand-to-dye energy transfer behaviors have been confirmed
by the emission spectra (excited at 420 nm) of the transition
from the L moieties at room temperature (Figure S13).
Moreover, the luminescence colors of Rho@CZJ-3 can be
systematically modulated by tuning the excitation energy.
Upon increasing the excitation wavelength, the emission
intensities of L and dye gradually changed in the lumines-
cence spectra of Rho@CZJ-3. These results demonstrate that
the emission energy of the ligand matches well with the
excitation energy of the dye. Moreover, the quantum yields of
29.5, 28.9, 28.7, 27.6, 25.4, 25.4, 23.8, and 24.3% for
Rho@CZJ-3 (a–h, respectively) are higher than that of CZJ-
3 (12.5%; excited at 340 nm). These values indicate that the
light absorption and energy transfer balance well, which
results in the enhanced luminescence of Rho@CZJ-3 from
efficient ligand-to-dye energy transfer by effectively prevent-
ing the nonradiative decay.
energy transfer efficiency between the excited state of L
and Rhodamine B, as the emission of the dye in Rho@CZJ-3
is mainly sensitized by the L moiety within the same
framework excited at 340 nm. Considering that the emission
peak heights of L and dye in Rho@CZJ-3-f are comparable,
we explored its sensing capability for various VOMs by self-
referencing the emission peak heights of L to dye moieties in
the photoluminescent spectra of Rho@CZJ-3-f.
After the acetone-activated samples of Rho@CZJ-3-f
were exposed to different solvents, such as 4-methylphenol,
acetophenone, phenol, benzyl alcohol, and pyridine for
10 min, as shown in Figure 3 (see also Figure S14), the
included solvent can be readily correlated to the emission
peak heights around the 420 and 595 nm transitions in the
photoluminescence spectra of Rho@CZJ-3-f. Although the
emissive intensity of a single transition of L or dye is
nonspecific to some solvents, such as acetophenone vs.
phenol, these solvent molecules are easily distinguished by
monitoring the emission peak-height ratios of L to dye
moieties. Moreover, the luminescent intensities of Rho@CZJ-
3 are also highly responsive to different concentrations of the
mixed VOMs (Figure S22–S24). These results clearly indicate
that Rho@CZJ-3 is an excellent sensor for probing different
VOMs. The unique solvent-dependent emission of
Rho@CZJ-3 can be rationalized by the guest-dependent
energy transfer from L to dye moieties. Such a luminescent
sensor for probing a range of solvent molecules is remarkable,
because it did not require any additional calibration.
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Moreover, probing VOMs through relative emission
intensity is more reliable than with absolute single-emission
intensity, because the single-emission intensity is variable
depending on many uncontrollable factors, whereas the peak-
height ratio is almost a constant for each VOM, as observed in
the luminescence spectra of Rho@CZJ-3. The sensing stabil-
ity of the luminescent Rho@CZJ-3 has been shown by
recycling experiments (Figure S19). Remarkably, the relative
emission intensity between L and dye moieties in the
luminescence spectra of Rho@CZJ-3-f is almost a constant
for 15 cycles in sensing benzene molecules.
In summary, we have synthesized a luminescent MOF
material containing 1D nanotube channels, for the first time,
and developed a luminescent dye@MOF approach to realize
the first dye@MOF sensor based on two emissions of host and
guest for probing different VOMs. The luminescent
dye@MOF platform represents a significant step forward in
small molecular sensors, owing to the excellent fingerprint
correlation between the solvent and emission peak-height
ratio of ligand to dye moieties. Additionally, because the
richness of organic linkers and dyes can be used to tune their
different excited state energy in the dye@MOF platform, this
very promising luminescent dye@MOFapproach should be of
practical use for sensitizing and probing different substrate
molecules/ions by tuning the energy transfer efficiency. Such
a Rho@CZJ-3 sensor is not only more stable and reliable, but
also exhibits higher sensitivity than Rho@CZJ-3, based on the
single-emission intensity of L or dye moiety. The power to
unambiguously recognize VOMs highlights this approach as
a very promising strategy to develop luminescent dye@MOFs
with unprecedented potential applications.
Figure 3. A) Emission peak heights of L (dark bars) and dye (light
bars) moieties. B) The emission peak-height ratios between L and dye
moieties in Rho@CZJ-3-f after adsorption of 4-methylphenol, acetophe-
none, phenol, benzyl alcohol, and pyridine molecules excited at
340 nm in the solid state at room temperature.
Above results indicate that the emission intensities of
Rho@CZJ-3 are very sensitive to the included solvent
molecules by tuning the energy transfer from L to dye
moieties. The relative emission intensity of L versus dye
moieties is almost a constant, and is unique for each guest and
variable to different solvent molecules in the luminescence
spectra of Rho@CZJ-3. Such characteristics can be used to
draw an emission-fingerprint map of VOMs, based on the
photoluminescence of Rho@CZJ-3. This internal-reference
strategy should be able to overcome the drawback of variable
solid-state emission intensities encountered when probing
VOMs by a single emissive transition. As shown in Figure 4,
even small molecules that have very similar structural motifs
are unambiguously differentiable, such as isomers of o-, m-,
and p-xylene, homologues of benzene, toluene, and ethyl-
benzene, and halobenzenes, including fluoro-, chloro- and
bromobenzene (Figures S15–17). Although nitrobenzene and
Received: August 20, 2013
Revised: October 30, 2013
Published online: January 13, 2014
Keywords: fingerprint relationships · luminescence ·
.
metal-organic frameworks · relative emission · sensors
[1] For a themed issue on metal – organic frameworks, see: (Eds.:
J. R. Long, O. M. Yaghi), Chem. Soc. Rev. 2009, 38, 1213.
[2] For a special issue on metal – organic frameworks, see: (Eds.: H.-
C. Zhou, J. R. Long, O. M. Yaghi), Chem. Rev. 2012, 112, 673.
[3] a) G. Fꢃrey, C. Serre, T. Devic, G. Maurin, H. Jobic, P. L.
Llewellyn, G. De Weireld, A. Vimont, M. Daturi, J.-S. Chang,
Chem. Soc. Rev. 2011, 40, 550; b) S.-T. Zheng, T. Wu, C. Chou, A.
Fuhr, P. Feng, X. Bu, J. Am. Chem. Soc. 2012, 134, 4517; c) T. A.
Makal, J.-R. Li, W. Lu, H.-C. Zhou, Chem. Soc. Rev. 2012, 41,
7761; d) K. C. Stylianou, J. Rabone, S. Y. Chong, R. Heck, J.
Armstrong, P. V. Wiper, K. E. Jelfs, S. Zlatogorsky, J. Bacsa,
A. G. McLennan, C. P. Ireland, Y. Z. Khimyak, K. M. Thomas,
D. Bradshaw, M. J. Rosseinsky, J. Am. Chem. Soc. 2012, 134,
20466.
Figure 4. The solvent-dependent emission peak-height ratios of L to
dye moieties in the luminescence spectra of Rho@CZJ-3-f excited at
340 nm in the solid state at room temperature.
[4] a) H. Wu, Q. Gong, D. H. Olson, J. Li, Chem. Rev. 2012, 112, 836;
b) H. Deng, C. J. Doonan, H. Furukawa, R. B. Ferreira, J.
Towne, C. B. Knobler, B. Wang, O. M. Yaghi, Science 2010, 327,
846; c) P. Nugent, Y. Belmabkhout, S. D. Burd, A. J. Cairns, R.
Luebke, K. Forrest, T. Pham, S. Ma, B. Space, L. Wojtas, E.
Mohamed, M. J. Zaworotko, Nature 2013, 495, 80; d) S. Kim,
K. W. Dawson, B. S. Gelfand, J. M. Taylor, G. K. H. Shimizu, J.
Am. Chem. Soc. 2013, 135, 963.
aniline both exhibit significant quenching effects for the
emission of Rho@CZJ-3, because of their different effects on
the energy transfer from L to dye moieties, they are easily
read-out by monitoring the relative emission peak heights of
L to dye moieties (Figure S18).
1578
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[5] a) L. Ma, C. Abney, W. Lin, Chem. Soc. Rev. 2009, 38, 1248; b) J.
Lee, O. K. Farha, J. Roberts, K. A. Scheidt, S. T. Nguyen, J. T.
Hupp, Chem. Soc. Rev. 2009, 38, 1450; c) A. Corma, L. I. Garcia,
H. F. X. Xamena, Chem. Rev. 2010, 110, 4606; d) P. Wu, C. He, J.
Wang, X. Peng, X. Li, Y. An, C. Duan, J. Am. Chem. Soc. 2012,
134, 14991; e) G.-Q. Kong, S. Ou, C. Zou, C.-D. Wu, J. Am.
Chem. Soc. 2012, 134, 19851; f) A. Aijaz, A. Karkamkar, Y. J.
Choi, N. Tsumori, E. Rçnnebro, T. Autrey, H. Shioyama, Q. Xu,
J. Am. Chem. Soc. 2012, 134, 13926; g) S. Horike, S. Shimomura,
S. Kitagawa, Nat. Chem. 2009, 1, 695; h) C. Zou, Z. Zhang, X.
Xu, Q. Gong, J. Li, C.-D. Wu, J. Am. Chem. Soc. 2012, 134, 87;
i) X.-L. Yang, M.-H. Xie, C. Zou, Y. He, B. Chen, M. OꢂKeeffe,
C.-D. Wu, J. Am. Chem. Soc. 2012, 134, 10638.
Rosseinsky, J. Am. Chem. Soc. 2010, 132, 4119; j) Z. Xie, L.
Ma, K. E. deKrafft, A. Jin, W. Lin, J. Am. Chem. Soc. 2010, 132,
922; k) H.-L. Jiang, Y. Tatsu, Z.-H. Lu, Q. Xu, J. Am. Chem. Soc.
2010, 132, 5586; l) N. B. Shustova, B. D. McCarthy, M. Dinca, J.
Am. Chem. Soc. 2011, 133, 20126; m) Y. Cui, H. Xu, Y. Yue, Z.
Guo, J. Yu, Z. Chen, J. Gao, Y. Yang, G. Qian, B. Chen, J. Am.
Chem. Soc. 2012, 134, 3979; n) X.-L. Qi, R.-B. Lin, Q. Chen, J.-B.
Lin, J.-P. Zhang, X.-M. Chen, Chem. Sci. 2011, 2, 2214.
[9] Y. Takashima, V. M. Martꢄnez, S. Furukawa, M. Kondo, S.
Shimomura, H. Uehara, M. Nakahama, K. Sugimoto, S. Kita-
gawa, Nat. Commun. 2011, 2, 168.
[10] P. Thanasekaran, T.-T. Luo, C.-H. Lee, K.-L. Lu, J. Mater. Chem.
2011, 21, 13140.
[6] a) Y.-Q. Lan, H.-L. Jiang, S.-L. Li, Q. Xu, Adv. Mater. 2011, 23,
5015; b) Y. Ikezoe, G. Washino, T. Uemura, S. Kitagawa, H.
Matsui, Nat. Mater. 2012, 11, 1081; c) X. Kong, E. Scott, W. Ding,
J. A. Mason, J. R. Long, J. A. Reimer, J. Am. Chem. Soc. 2012,
134, 14341.
[7] a) R. Vaidhyanathan, S. S. Iremonger, G. K. H. Shimizu, P. G.
Boyd, S. Alavi, T. K. Woo, Science 2010, 330, 650; b) J. An, S. J.
Geib, N. L. Rosi, J. Am. Chem. Soc. 2010, 132, 38; c) Y.-S. Bae,
R. Q. Snurr, Angew. Chem. 2011, 123, 11790; Angew. Chem. Int.
Ed. 2011, 50, 11586.
[8] a) B. Chen, S.-C. Xiang, G.-D. Qian, Acc. Chem. Res. 2010, 43,
1115; b) Y. Cui, Y. Yue, G. Qian, B. Chen, Chem. Rev. 2012, 112,
1126; c) M. D. Allendorf, C. A. Bauer, R. K. Bhakta, R. J. T.
Houk, Chem. Soc. Rev. 2009, 38, 1330; d) L. E. Kreno, K. Leong,
O. K. Farha, M. Allendorf, R. P. Van Duyne, J. T. Hupp, Chem.
Rev. 2012, 112, 1105; e) A. Lan, K. Li, H. Wu, D. H. Olson, T. J.
Emge, W. Ki, M. Hong, J. Li, Angew. Chem. 2009, 121, 2370;
Angew. Chem. Int. Ed. 2009, 48, 2334; f) S. Pramanik, C. Zheng,
X. Zhang, T. J. Emge, J. Li, J. Am. Chem. Soc. 2011, 133, 4153;
g) N. Yanai, K. Kitayama, Y. Hijikata, H. Sato, R. Matsuda, Y.
Kubota, M. Takata, M. Mizuno, T. Uemura, S. Kitagawa, Nat.
Mater. 2011, 10, 787; h) K. A. White, D. A. Chengelis, K. A.
Gogick, J. Stehman, N. L. Rosi, S. Petoud, J. Am. Chem. Soc.
2009, 131, 18069; i) K. C. Stylianou, R. Heck, S. Y. Chong, J.
Bacsa, J. T. A. Jones, Y. Z. Khimyak, D. Bradshaw, M. J.
[11] a) Q.-R. Fang, G.-S. Zhu, Z. Jin, Y.-Y. Ji, J.-W. Ye, M. Xue, H.
Yang, Y. Wang, S.-L. Qiu, Angew. Chem. 2007, 119, 6758; Angew.
Chem. Int. Ed. 2007, 46, 6638; b) T.-T. Luo, H.-C. Wu, Y.-C. Jao,
S.-M. Huang, T.-W. Tseng, Y.-S. Wen, G.-H. Lee, S.-M. Peng, K.-
L. Lu, Angew. Chem. 2009, 121, 9625; Angew. Chem. Int. Ed.
2009, 48, 9461; c) K. Barthelet, J. Marrot, D. Riou, G. Fꢃrey,
Angew. Chem. 2002, 114, 291; Angew. Chem. Int. Ed. 2002, 41,
281; d) N. L. Rosi, J. Kim, M. Eddaoudi, B. Chen, M. OꢂKeeffe,
O. M. Yaghi, J. Am. Chem. Soc. 2005, 127, 1504; e) T. Devic, C.
Serre, N. Audebrand, J. Marrot, G. Fꢃrey, J. Am. Chem. Soc.
2005, 127, 12788.
[12] Crystal data for CZJ-3: C10H8CdO5, Mw = 320.56, Hexagonal,
space group P6522, a = 22.4022(6) ꢀ, c = 9.1637(3) ꢀ, V=
3982.7(2) ꢀ3, Z = 6, T= 293 K, 1calcd = 0.802 gcmÀ3
,
m =
6.617 mmÀ1, F(000) = 936, 8451 reflections, 2365 independent
reflections, int = 0.0617, R1[I>2s(I)] = 0.0381, wR2 = 0.0938,
R
GOF = 1.137, Flack parameter= 0.03(3). CCDC 956106 (CZJ-
3) contains the supplementary crystallographic data for this
paper. These data can be obtained free of charge from The
Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.
uk/data_request/cif.
[13] A. L. Spek, PLATON, a multipurpose crystallographic tool,
Utrecht University, Utrecht, The Netherlands, 2008.
[14] J. R. Lakowicz, Principles of Fluorescence Spectroscopy, 3rd ed.,
Springer, Berlin, 2006.
Angew. Chem. Int. Ed. 2014, 53, 1575 –1579
ꢀ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
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