Unprecedented Ultralow Detection Limit of Amines using a Thiadiazole-Functionalized Zr(IV)-Based Metal-Organic Framework

Article abstract of DOI:10.1021/jacs.9b01839

A luminescent Zr(IV)-based metal-organic framework (MOF), with the underlying fcu topology, encompassing a ?-conjugated organic ligand with a thiadiazole functionality, exhibits an unprecedented low detection limit of 66 nM for amines in aqueous solution.

Full text of DOI:10.1021/jacs.9b01839

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Communication
Unprecedented ultralow detection limit of amines using a
thiadiazole-functionalized Zr(IV)-based metal-organic framework
Arijit Mallick, Ahmed M. El-Zohry, Osama Shekhah, Jun Yin, jiangtao jia, Himanshu
Aggarwal, Abdul-Hamid Emwas, Omar F. Mohammed, and Mohamed Eddaoudi
J. Am. Chem. Soc., Just Accepted Manuscript • DOI: 10.1021/jacs.9b01839 • Publication Date (Web): 15 Apr 2019
Downloaded from http://pubs.acs.org on April 15, 2019
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Unprecedented Ultralow Detection Limit of Amines Using a
Thiadiazole-Functionalized Zr(IV)-Based Metal-Organic
Framework
Arijit Mallicka, Ahmed M. El- Zohryb, Osama Shekhaha, Jun Yinb, Jiangtao Jiaa, Himanshu Aggarwala,
Abdul-Hamid Emwas,c Omar F. Mohammed,b,* and Mohamed Eddaoudia,*
9
a King Abdullah University of Science and Technology (KAUST), Functional Materials Design, Discovery and Development
Research Group (FMD3), Advanced Membranes and Porous Materials Center (AMPMC), Division of Physical Sciences and
Engineering (PSE), Thuwal 23955-6900, Saudi Arabia.
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b King Abdullah University of Science and Technology (KAUST), Division of Physical Sciences and Engineering (PSE),
Thuwal 23955-6900, Saudi Arabia.
c King Abdullah University of Science and Technology (KAUST), Core Labs, Thuwal 23955-6900, Saudi Arabia.
Supporting Information Placeholder
Recently, metal-organic frameworks (MOFs) have been widely
ABSTRACT: A luminescent Zr(IV)-based MOF, with the
explored as sensors as a result of their fast, reversible, and durable
sensing features.13,17−19 MOFs, which are inorganic-organic hybrid
crystalline materials, offer diverse structural features with tunable
pore shape, dimensions and functionalities.20−25 The modularity of
the MOF pore system offers the ability to decoarate the pores with
a periodic array of chemical functionalities, governing molecular-
level interactions between the framework and probe analytes and
affording the selective sensing toward certain analytes.13,17
Strategically, it is very thrilling to design and synthesize MOFs
for discriminative “turn on” recognition of amines through
interactions between an electron-deficient ligand and electron-rich
amines, which can perturb the MOF photoluminescence (PL).
Different from recent reports on MOFs used to sense organic
amines,7,8 we investigated an interesting MOF that offers a turn-on
sensing behavior for aliphatic amine.
underlying fcu topology, encompassing a π-conjugated organic
ligand with a thiadiazole functionality exhibits an unprecedented
low detection limit of 66 nM for amines in aqueous solution.
Markedly, this ultralow detection is driven by hydrogen bonding
interactions between the linker and the hosted amines. This
observation is supported by Density Functional Theory (DFT)
calculations which clearly corroborate the suppression of the
twisting motion of thiadiazole core in the presence of amine,
reducing significantly the non-radiative recombination pathways
and subsequently enhancing the emission intensity. Credibly,
nicotine regarded as a harmful chemical and bearing an amine
pending group is also detected with high sensitivity, positioning
this MOF as a potential sensor for practical environmental
applications. This finding serves also as a benchmark to
understand the sensing mechanism in MOFs.
Here, we successfully synthesized a luminescent Zr(IV)-based
MOF, Zr-BTDB-fcu-MOF (1), with the underlying fcu topology,
by incorporating a π-conjugated, electron-deficient, thiadiazole-
functionalized ligand H2BTDB {H2BTDB
=
4,4 ′ -
The need to sense dangerous small molecules at a very low
detection limit is of great importance, since their leakage or loss
of control, even at a very low concentration, may lead to extensive
hazards to human health.1−3. Furthermore, there is a pressing need
for detection of amines in our daily life, like assessment of food
quality, pollution control, and management of some diseases.4
Recently, various techniques were developed and applied for the
detection of hazardous amines. Partciularly, luminescence-based
sensing approaches gained substantial attention due to their
simple handling procedures, high sensitivity, and fast response
time.5,6 While different groups have reported the sensing of
amines, their discriminative sensing within a vast group of
chemicals remains scarce due to challenges associated with the
molecular identification of amines.7,8 Accordingly, the amines’
structural, chemical and physical characteristics must be
considered, like their molecular size, shapes, hydrogen bond
formation capability and electronic properties.9-12
Chemical sensors are designed to identify a probe-analyte via a
change in their properties, e.g., their conductivity, color,
luminescence, or capacitance.13 Most of the sensing of such
analytes is based on fluorescence quenching.14−15 Examples of
fluorescence-intensity enhancement, i.e., a “turn-on” behavior for
sensing of amines, are scarce; although, they are more desirable
for use in sensing devices.16 Notably, the ability to construct a
sensor with a “turn-on” feature is still a challenge, due to many
characteristics that confine and obstruct with fluorescence
phenomena in general.
(benzoic]i1,2,5]thiadiazole-4,7-diyl) dibenzoic acid} (see Figure
1a and Figures S1-S5 in the Supporting Information ).26 Notably,
few Zr(IV)-based MOF materials containing a benzothiadiazole
moiety with excellent PL properties have been demonstrated in
the literature.27-29 The synthesized (1) structure was confirmed
using powder X-ray diffraction (PXRD) (Figure S6).28 The
synthesized (1) is a UiO-68 type and has two type of cages, a big
one (∼25 Å) and smal one (∼15 Å ) in pore diameter that are
connected via triangular window with diameter ∼10 Å. N2
sorption measurements at 77 K of (1) revealed a type (I)
reversible isotherm and an apparent BET surface area of 2380 m2
g−1 (Figure S8). The chemical stability of (1) in various solvents
was confirmed by PXRD and adsorption (Figure S6).
Thermogravimetric analysis showed that (1) is stable up to 350 °C
in nitrogen atmosphere (Figure S9).
Appropriately, (1) displayed strong absorption band at 385 nm
in aqueous medium (Figure S10). Luminescence of (1) and free
ligand, has been thoroughly examined upon excitation at 385 nm
as shown in Figure 1b. In water, (1) unveils a broad emission
band with a λmax at 501 nm, which is redshifted by 20 nm
compared to free H2BTDB. This emission band was ascribed to
π–π* transition of organic ligand in (1).31
The luminescence-sensing studies were carried on the
following VOAs: methylamine (MA), ethylamine (EA),
triethylamine (TEA), aniline (A), and para-phenylenediamine
(PDA) (Figure 2, Figure S11–S17 in SI). In order to gain better
insights on structure-property relationship, we deployed
a
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Figure. 1. (a) Schematic representation of the synthesis of Zr-BTDB-fcu-MOF (1), (inset) optical images of (1) single crystals. (b) PL
spectra for (1) (red) and linker (black). (Inset) Optical images of luminescence for MOF and linker solutions under 365 nm UV
radiation.
systematic protocol for all sensing experiments. From each
aqueous solution of VOAs, portions of a 3 M were added in an
incremental manner to an aqueous well-dispersed suspension of
(1). Subsequently, fluorescence intensity of (1) was recorded after
each incremental addition.
ns. In contrast to earlier literature reports, (1) is one of the
exceptional examples that can discriminately sense aliphatic
amines in a “turn-on” process. In order to gain insight on the
sensing mechanism governing the turn-on behavior of (1) in
response to aliphatic amines, we elaborated on our examination
study. In this case, if our assumption is correct, then this increase
in fluorescence intensity is directly related to basicity of amines.
We tried to understand whether the sensitivity of (1) was due to
amine structure or to a change in pH of the media caused by the
addition of amine. Therefore, we collected PL spectra of (1) in
buffer solutions with different pH values (pH 2, pH 3, pH 7, pH 8,
pH 9, and pH 10). Interestingly, only a negligible enhancement in
fluorescence intensity was observed (Figure S20 in SI),
corroborating that the change in sensitivity was not related to a
change in pH. Here, we assume that the selected VOAs can easily
diffuse in (1), due to its relatively larger pore-aperture size,
affording the hosted VOA molecules to interact with exposed
surface of (1) pore system. It should be noted that the diameters of
tested VOAs are smaller than the pore-aperture size of the
triangular sole entrance (~10 Å) to octahedral and tetrahedral
cages of (1). 33
Perceptibly, we designed a series of additional experiments to
support these facts and to understand the plausible interactions
between the analyte and the thiadiazole core of the linker. We
performed similar experiments with an isoreticular MOF (2)
(Figures 3a and S7), bearing an anthracene core instead of
thiadiazole (Figure 3b and Figure S21). Distinctively, no
significant change in fluorescence intensity was observed when
MA was added to solution containing (2), confirming that
aliphatic amines had strong interaction with the thiadiazole core.
Therefore, we tried to understand the mode of interaction between
aliphatic amine and thiadiazole core. In general, aliphatic amines
are prone to protonation in water due to their high pka values (e.g.,
pka MAH+=10.6, pka TEAH+= 11.1).34 Note, aromatic amines are
Notably, increased concentrations of aromatic amines, like
aniline and phenylenediamine, led to a drastic decrease in
fluorescence intensity of (1) (Figure 2b and S16), suggesting an
electron transfer process that can also quench fluorescence.
However, due to the absence of spectral overlap between emission
of the linker and absorption of aniline, the energy transfer can be
discarded here. Alternatively, in case of aliphatic amines like MA,
the fluorescence intensity was enhanced. Whereas in the case of
pyridine (pka = 3.2), no change in the fluorescence intensity was
observed (Figure S18). Among all VOAs tested, MA displayed
the highest turn-on efficiency. These observations suggest that (1)
can discriminately sense aliphatic amines via
a “turn-on”
fluorescence behavior (Figure 2a). Furthermore, the detection
limit of (1) towards MA was determined to be 66.2 nM according
to the equation 3σ/k.31,32 These results indicate that (1) is more
sensitive toward MA than other tested amines. Interestingly, we
observed that turn-on detection only occurred in aqueous media;
i.e. when we carried out same set of experiments in anhydrous
acetonitrile and absolute ethanol, no change was observed upon
addition of MA (Figure S19 in SI), signifying the importance of
protonation for sensing.
Figure 2c shows time-resolved PL lifetime (TRPL)
measurements. Linker emission in (1) shows a bi-exponential
decay with lifetimes of 1.8 ns (62%) and 8.9 ns (38%). When
aniline was added, the lifetimes became shorter, reaching 1 ns
(80%) and 6.5 ns (20%), consistent with the emission quenching
observed in steady-state measurements. In contrast, when MA
was added, emissions showed a single exponential decay of 11.5
Figure 2. Fluorescence intensity of (1) aqueous suspension upon addition of 3 M of MA (a), aniline (b) (λmax = 515 nm). c)
Fluorescence lifetime decay profile of (1) before and after addition of 225 μL MA (λex = 400 nm).
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facilitating the extended  conjugation, thus resulting in the turn-
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on fluorescence behavior (Figure 3). This turn-on sensing of an
aliphatic amine by (1) is also transferable to other materials, such
as nicotine. Nicotine is an extremely harmful compound present
in tobacco products, which make it very attractive to detect even
at low concentrations in aqueous (or biological) medium. Nicotine
contains an aliphatic amine functionality with a pka of 7.9.
Therefore, a low concentration could be detected in an aqueous
medium with
a similar turn-on fluorescence sensing. The
detection limit of (1) for nicotine was calculated to be around 280
nM (Figure 4 and S24).
8
9
In conclusion, we have successfully explored the sensing
properties of a highly luminescent Zr(IV)-based MOF material
(1), towards aliphatic amines. Delightfully, (1) exhibits a selective
detection behavior towards aliphatic amines (via fluorescence
turn-on behavior), as established from PL titration measurements.
The mechanism of sensing via hydrogen bonding was validated
experimentally and supported by DFT calculations. (1) exhibited a
detection limit of 66.2 nM for MA, which is considered superior
to some previously reported MOF-based sensors. Given its
excellent detection performance as well as its high thermal and
chemical stability, Zr-BTDB-fcu-MOF (1) offers great prospects
as a sensor for environmental applications.
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Figure 3. (a) Fluorescence intensity of (2) water suspension
upon addition of 3 M MA (λmax = 447 nm). (b) The increase
in Fluorescent of (1) upon addition of 3 M nicotine and its
chemical structure.
ASSOCIATED CONTENT
Supporting Information
The Supporting Information is available free of charge on the
ACS Publications website. Synthesis, experimental data and
not protonated in water at pH = 7.0. We also conducted control
experiment with the linker alone, and the results indicate less
sensitivity compared with (1) (Figure 25). To understand the
effect of protonated MA on PL enhancement of H2BTDB, we
performed density functional theory (DFT) calculations, as
illustrated in Figure 4. For H2BTDB alone, the dihedral angle
between benzene and thiadiazole unit changes significantly from
ground to excited state (Δ = 22°), increasing the
non-radiative channels. While once two or four MA molecules
are attached to H2BTDB, the change of dihedral angle becomes
considerably smaller (Δ = 12°), due to the strong hydrogen
bonding (dH = 1.9 Å) between protonated MA and N atoms on
thiadiazole unit. This demonstrates clearly that the H-bonding
interaction restricts the rotation of the thiadiazole core, reducing
non-radiative recombination pathways and subsequently
enhancing emission intensity. Considerately, we calculated the
ratio between MA and thiadiazole linker (L) in (1). The ratio of
2:1 (MA: L) was found; and reaches almost saturation upon
addition of 12 µM. For instance, increasing the concentration to
21 mM, which is still below the ratio 4:1, does not change the
fluorescence enhancement, which is in excellent agreement with
DFT calculations.35
procedures,
X-ray
diffraction,
sorption
data
and
photoluminescence measurements
AUTHOR INFORMATION
Corresponding Author
Mohamed Eddaoudi: omar.abdelsaboor@kaust.edu.sa
Additionally, we measured the solid-state NMR of (1) and the
linker (Figure S26) where a chemical shift for the –COOH proton
at ~15 ppm (in linker) was missing from the MOF due to
coordination with Zr(IV), and no additional N-H protons were
observed. These results confirm that the thiadiazole core was not
protonated during the synthesis and that it can easily participate in
formation of a hydrogen bond with incoming protonated amines.
Furthermore, we collected PL spectra from (1) in presence of
NH4Cl. The PL spectra showed a turn-on fluorescence in aqueous
Figure 4. (a) Molecular structures of H2BTDB, H2BTDB
with two and four MA molecules. Red arrows represent the
dihedral angles between benzene and thiadiazole-based units
and red dashed lines indicate the hydrogen bond lengths (dH)
formed by H of MA and N of thiadiazole; (b) Dihedral angles
between benzene and thiadiazole units for ground and excited
states of H2BTDB, H2BTDB with two and four MA
molecules. Δ represents the dihedral angle change from
ground to excited state. The calculations are performed in
water using CAM-B3LYP/6-31(d,p) method.
+
media due to hydrogen-bonding interaction with NH4 moiety
(Figure S22). By adding NH4Cl in presence of an amine into (1)
Omar F. Mohammed: mohamed.eddaoudi@kaust.edu.sa
aqueous solution, the fluorescence intensity was enhanced (Figure
+
S23), indicating that the interaction of NH4 with the framework
Notes
was stronger than its interaction with the protonated amine. It also
confirms that the formation of hydrogen bond with linker was the
key force restricting the rotation of thiadiazole group and
The authors declare no competing financial interests.
ACKNOWLEDGMENT
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(19) Asha, K. S.; Bhattacharyya, K.; Mandal, S. Discriminative
detection of nitro aromatic explosives by a luminescent metal−organic
framework. J. Mater. Chem. C 2014, 2, 10073−10081.
(20) Yaghi, O. M.; Li, H.; Eddaoudi, M.; O’ Keeffe, M. Design and
synthesis of an exceptionally stable and highly porous metal-organic
framework. Nature, 1999, 402, 276−279.
The authors gratefully acknowledge financial support from King
Abdullah University of Science and Technology (KAUST).
In the memory of Abdallah Eddaoudi
1
2
3
REFERENCES
4
5
6
7
8
9
(21) Deng, H.; Grunder, S.; Cordova, K. E.; Valente, C.; Furukawa, H.;
Hmadeh, M.; Gandara, F.; Whalley, A. C.; Liu, Z.; Asahina, S.; Kazumori,
H.; O’Keeffe, M.; Terasaki, O.; Stoddart, J. F.; Yaghi, O. M. Large-Pore
Apertures in a Series of Metal-Organic Frameworks. Science, 2012, 336,
1018−1023.
(1) Merchant, Z. M.; Cheng, S. G. G. In Characterization of Foods,
Emerging Methods ; Gaonkar, A. G., Ed.; Elsevier Science: New York,
1995; Chapter 15.
(2) Ajayakumar, M. R.; Mukhopadhyay, P. Naphthalene-bis-
hydrazimide: radical anions and ICT as new bimodal probes for
differential sensing of a library of amines. Chem. Commun. 2009, 25,
3702−3704.
(3) Bao, B.; Yuwen, L.; Zheng, X.; Weng, L.; Zhu, X.; Zhan, X.; Wang,
L. A fluorescent conjugated polymer for trace detection of diamines and
biogenic polyamines. J. Mater. Chem. 2010, 20, 9628−9634.
(4) Medina, M. Á.; Urdiales, J. L.; Rodríguez-Caso, C.; Ramírez F. J.;
Sánchez-Jiménez, F. Biogenic amines and polyamines: similar
biochemistry for different physiological missions and biomedical
applications. Crit. Rev. Biochem. Mol. Biol., 2003, 38, 23.
(5) Hinoue, T.; Miyata, M.; Hisaki, I.; Tohnai, N. Guest-Responsive
Fluorescence of Inclusion Crystals with n-Stacked Supra-molecular
Beads. Angew. Chem., Int. Ed. 2012, 51, 155−158.
(6) Stetter, J. R.; Penrose, W. R.; Yao, S. Sensors, Chemical Sensors,
Electrochemical Sensors, and ECS. J. Electrochem. Soc. 2003, 150,
S11−S16.
(7) Liu, J. J.; Shan, Y. B.; Fan, C. R.; Lin, M. J.; Huang, C. C.; Dai, W.
X. Encapsulating Naphthalene in an Electron-Deficient MOF to Enhance
Fluorescence for Organic Amines Sensing. Inorg. Chem. 2016, 55,
3680−3684.
(8) Mallick, A.; Garai, B.; Addicoat, M. A.; Petkov, P., St.; Heine, T.;
Banerjee, R. Solid state organic amine detection in a photochromic porous
metal organic framework. Chem. Sci. 2015, 6, 1420−1425.
(9) Mertz, E.; Zimmerman, S. C. Cross-Linked Dendrimer Hosts
Containing Reporter Groups for Amine Guests. J. Am. Chem. Soc. 2003,
125, 3424−3425.
(10) Greene, N. T.; Morgan, S. L.; Shimizu, K. D. Molecularly
imprinted polymer sensor arrays. Chem. Commun. 2004, 1172−1173.
(11) Comes, M.; Marcos, M. D.; Martınez-Manez, R.; Sancenon, F.;
Soto, J.; Villaescusa, L. A.; Amoros, P.; Beltran, D. Chromogenic
Discrimination of Primary Aliphatic Amines in Water with Functionalized
Mesoporous Silica. Adv. Mater. 2004, 16, 1783−1786.
(12) Mohr, G. J. Chromo- and Fluororeactands: Indicators for Detection
of Neutral Analytes by Using Reversible Covalent-Bond Chemistry.
Chem. - Eur. J. 2004, 10, 1082−1090. (b) Chernikova, V.; Yassine, O.;
Shekhah, O.; Eddaoudi, M.; Salama, K. N. Highly Sensitive and Selective
SO2 MOF Sensor: the Integration of MFM-300 MOF as a Sensitive Layer
on a Capacitive Interdigitated Electrode. J. Mater. Chem. A, 2018, 6,
5550.
(13) Kreno, L. E.; Leong, K.; Farha, O. K.; Allendorf, M.; Van Duyne,
R. P.; Hupp, J. T. Metal−Organic Framework Materials as Chemical
Sensors. Chem. Rev. 2012, 112, 1105−1125.
(14) Che, Y.; Zang, L. Enhanced fluorescence sensing of amine vapor
based on ultrathin nanofibers. Chem. Commun. 2009, 34, 5106−5108.
(15) Takashima, Y.; Martínez, V. M.; Furukawa, S.; Kondo, M.;
Shimomura, S.; Uehara, H.; Nakahama, M.; Sugimoto, K.; Kitagawa, S.
Molecular decoding using luminescence from an entangled porous
framework. Nat. Commun. 2011, 2, 168.
(16) Kumpf, J.; Freudenberg, J.; Fletcher, K.; Dreuw, A.; Bunz, U. H.
F. Detection of Amines with Extended Distyrylbenzenes by Strip Assays.
J. Org. Chem. 2014, 79, 6634−6645.
(17) Pramanik, S.; Zheng, C.; Zhang, X.; Emge, T. J.; Li, J. New
Microporous Metal−Organic Framework Demonstrating Unique
Selectivity for Detection of High Explosives and Aromatic Compounds. J.
Am. Chem. Soc. 2011, 133, 4153−1455.
(18) (a) Gole, B.; Bar, A. K.; Mukherjee, P. S. Fluorescent
metal−organic framework for selective sensing of nitroaromatic
explosives. Chem. Commun. 2011, 47, 12137−12139. (b) Wang, J. H.; Li,
M.; Li, D. A dynamic, luminescent and entangled MOF as a qualitative
sensor for volatile organic solvents and a quantitative monitor for
acetonitrile vapour. Chem. Sci. 2013, 4, 1793−1801.
(22) Huang, R. W.; Wei, Y. S.; Dong, X. Y.; Wu, X. H.; Du, C. X.;
Zang, S. Q.; Mak, T. C. W. Hypersensitive dual-function luminescence
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
switching of
a
silver-chalcogenolate cluster-based metal−organic
framework. Nat. Chem. 2017, 9, 689−697.
(23) Bloch, W. M.; Burgun, A.; Coghlan, C. J.; Lee, R.; Coote, M. L.;
Doonan, C. J.; Sumby, C. J. Capturing snapshots of post-synthetic
metallation chemistry in metal−organic frameworks. Nat. Chem. 2014, 6,
906−912.
(24) Van-Humbeck, J. F.; McDonald, T. M.; Jing, X.; Wiers, B. M.;
Zhu, G.; Long, J. R. Ammonia Capture in Porous Organic Polymers
Densely Functionalized with Brønsted Acid Groups. J. Am. Chem. Soc.
2014, 136, 2432–2440.
(25) Deria, P.; Bury, W.; Hupp, J. T.; Farha, O. K. Versatile
Functionalization of the NU-1000 Platform by Solvent-assisted Ligand
Incorporation. Chem. Commun. 2014, 50, 1965−1968.
(26) Mostakim, SK.; Biswas, S. A Thiadiazole-functionalized Zr(IV)-
based Metal–Organic Framework as a Highly Fluorescent Probe for the
Selective Detection of Picric Acid. CrystEngComm, 2016, 18, 3104−3113.
(27) Zhang, X.; Gorohmaru, H.; Kadowaki, M.; Kobayashi, T. Ishi-i, T.;
Thiemann, T. Mataka, S. Benzo-2,1,3-thiadiazole-based, Highly Dichroic
Fluorescent Dyes for Fluorescent Host–Guest Liquid Crystal Displays. J.
Mater. Chem., 2004, 14, 1901−1904.
(28) Dong, Y.; Koken, B.; Ma, X.; Wang, L.; Cheng, Y.; Zhu, C.;
Polymer-based Fluorescent Sensor Incorporating 2,2′-bipyridyl and
Benzo[2,1,3]thiadiazole Moieties for Cu2+ Detection. Inorg. Chem.
Commun., 2011, 14, 1719−1722.
(29) Edelmann, M. J.; Raimundo, J.-M.; Utesch, N. F.; Diederich, F.;
Dramatically Enhanced Fluorescence of Heteroaromatic Chromophores
upon Insertion as Spacers into Oligo(triacetylne)s. Helv. Chim. Acta,
2002, 85, 2195–2213.
(30) Zhang, W.-Q.; Li, Q.-Y.; Cheng, J.-Y.; Cheng, K.; Yang, X.; Li,
Y.; Zhao, X.; Wang, X.-J. Ratiometric Luminescent Detection of Organic
Amines Due to the Induced Lactam–Lactim Tautomerization of Organic
Linker in a Metal–Organic Framework. ACS Appl. Mater. Interfaces,
2017, 9, 31352–31356.
(31) Hussain, S.; De, S.; Iyer, P. K. Thiazole-Containing Conjugated
Polymer as a Visual and Fluorometric Sensor for Iodide and Mercury.
ACS Appl. Mater. Interfaces, 2013, 5, 2234–2240.
(32) Masih, D.; Chernikova, V.; Shekhah, O.; Eddaoudi, M.;
Mohammed, O. F. Zeolite-Like Metal–Organic Framework (MOF)
Encaged Pt(II)-Porphyrin for Anion-Selective Sensing. ACS Appl. Mater.
Interfaces, 2018, 10, 11399–11405.
(33) Schaate, A.; Roy, P.; Godt, A.; Lippke, J.; Waltz, F.; Wiebcke, M.;
Behrens, P. Modulated Synthesis of Zr–Based Metal–Organic
Frameworks: From Nano to Single Crystals. Chem. Eur. J., 2011, 17,
6643–6651.
(34) Hall Jr., H.K. Sterically Hindered Phenolic Buffers. Application to
Determination of Rates of Amidation of Ethyl Chloroformate. J. A.m.
Chem. Soc. 1957, 79, 5439–5441.
(35) El-Zohry, A. M.; Alturki, A.; Yin, J.; Mallick, A.; Shekhah, O.;
Eddaoudi, M.; Ooi, B. S.; Mohammed, O. F. Tunable Twisting Motion of
Organic Linkers via Concentration and Hydrogen-Bond Formation J.
Phys. Chem. C 2019, 123, 5900-5906.
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