Multi-purpose barbituric acid derivatives with aggregation induced emission

Article abstract of DOI:10.1016/j.saa.2019.117320

Three D-π-A barbituric acid derivatives with simple structure and intramolecular charge transfer (ICT) mechanisms were synthesized. Molecular dynamics simulations have successfully explained that CB-1 exhibits the best aggregate induced emission (AIE) act

Full text of DOI:10.1016/j.saa.2019.117320

Accepted Manuscript
Multi-purpose barbituric acid derivatives with aggregation
induced emission
Hanjun Zhang, Yuezhi Cui, Furong Tao, Datong Zhang, Zhen Xu,
Li Guo
PII:
S1386-1425(19)30710-3
DOI:
https://doi.org/10.1016/j.saa.2019.117320
Article
Number:
Reference:
117320
SAA 117320
Spectrochimica Acta Part A: Molecular and Biomolecular
Spectroscopy
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Revised date:
Accepted date:
20 April 2019
13 June 2019
25 June 2019
Please cite this article as: H. Zhang, Y. Cui, F. Tao, et al., Multi-purpose barbituric acid
derivatives with aggregation induced emission, Spectrochimica Acta Part A: Molecular
and Biomolecular Spectroscopy, https://doi.org/10.1016/j.saa.2019.117320
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ACCEPTED MANUSCRIPT
Multi-purpose Barbituric Acid Derivatives with Aggregation Induced
Emission
Hanjun Zhang, Yuezhi Cui*, Furong Tao, Datong Zhang, Zhen Xu*, Li Guo
School of Chemical and Pharmaceutical Engineering, Qilu University of Technology
(Shandong Academy of Sciences), Jinan 250353, P. R. China
Tel: +86 531 89631208; Fax: +86 531 89631760;
E-mail address: yuezhicui@163.com, xuzhen123@126.com
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Abstract
Three D-π-A barbituric acid derivatives with simple structure and intramolecular
charge transfer (ICT) mechanisms were synthesized. Molecular dynamics simulations
have successfully explained that CB-1 exhibits the best Aggregate induced emission
(AIE) activity due to the electron-deficient barbituric acid and the electron-rich
carbazole exhibit a conformation which similar to π-π stacking, resulting in a strong
electrostatic attraction between the molecules, meanwhile the N-atom substituent of
the carbazole is n-propane plays a hydrophobic role. At the same time, barbituric acid
derivatives also have mechanochromic fluorescent properties. In addition, CB-1 and
CB-3 exhibited outstanding fluorescence stability than CB-2 in aggregation state which
can be used to detect nitroaromatic explosives in aqueous media. The Stern–Volmer
quenching constant (Ksv) of CB-1 and CB-3 is 6.6×104, 1×105 M-1, respectively.
Key words: Aggregation induced emission (AIE); Intramolecular charge transfer (ICT);
mechanochromic fluorescence (MCF); Fluorescent sensor;
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Introduction
As is known to all, the disadvantages of explosives are not only harmful to humans,
but also extremely destructive to the environment [1-5]. Therefore, the detection of
explosives has attracted wide attention as a hot issue at present [6-13]. But wars and
terrorist attacks are not limited to land, but they also spread to the ocean. However,
most nitroaromatic detection are currently limited to organic reagents because of the
very low solubility of explosives in water and the fluidity of water, which makes testing
difficult. However, the problem is solved by compounds having the characteristics of
AIE [14, 15].
Up to now, there have been a lot of studies to detect nitroaromatics based on AIE
properties [16]. Conjugated polymers are selected for most sensors due to that they
not only have high molecular weight and a high degree of electron cloud delocalization,
but also due to longer conjugated chains, when contact with nitroaromatics, a point of
contact can be formed with multiple points of response. Hence, conjugated polymers
are more efficient in detecting nitroaromatics, but due to their large molecular weight,
not only solubility is lowered, but also difficult to synthesize [17]. In practical
applications, we must consider not only the sensitivity of the sensor but also the cost.
In contrast, small molecule compounds with AIE properties, although having lower
fluorescence quantum yields, or less sensitive than polymers, have some advantages
in considering solubility and cost [18].
In this paper, three small-molecular barbituric acid derivatives with AIE properties
were designed. All of the three compounds contain electron-rich carbazole groups, in
which barbituric acids and carbazole groups are linked by a single double bond, and
the molecules are a twisted conformation. Hence, the barbituric acid derivatives are
not only mechanochromic fluorescent, but also can promote the interaction with
electron-deficient nitroaromatics.
2 Experimental section
2.1 Materials
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1-Bromopropane (Energy, 98%), carbazole (Energy, 98%), dimethylformamide (DMF)
(Aladdin, 99%), 1,3-dimethyl-barbituric acid (Aladdin, 99%), diphenylurea (Jiuding
Chemical, 99%), malonyl chloride (Aladdin, 99%) were used without further
purification. DMF is usually dried sequentially by molecular sieves (4 Å), CaH2 and
sodium sand successively, and distilled prior to use.
2.2 Characterizations
UV-vis spectra were measured by UV-2500 spectrometer. Emission spectra were
measured on an F-4600 fluorescence spectrophotometer. 1H NMR (600 MHz) spectra
were measured on AVANCE II 400 spectrometer.
2.3 Synthesis of compounds
The synthetic routes of barbituric acid derivatives which including
1,3-dimethyl-5-((9-propyl-9H-carbazol-3-yl)methylene)pyrimidine-2,4,6-trione (CB-1),
1,3-diphenyl-5-((9-propyl-9H-carbazol-3-yl)methylene)pyrimidine-2,4,6-trione (CB-2),
1,3-dimethyl-5-((9-phenyl-9H-carbazol-3-yl)methylene)pyrimidine-2,4,6-trione (CB-3)
are illustrated in Scheme 1. In addition, the synthesis step of 9-propyl
carbazole-3-carbaldehyde (2) is available in the previous works [19, 20], and the
synthesis step of 9-phenyl carbazole-3-carbaldehyde (3) is also available in the
previous work [21].
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Scheme 1. Synthetic routes to CB-1, -2 and -3.
2.3.1. Synthesis of 1,3-diphenyl barbituronic acid (1)
1,3-dimethyl-barbituric acid (2 mmol) was added to N, N-diphenyl urea (424.5 mg, 2
mmol) with 6 ml CHCl3, and the mixture was heated to 80oC for 4 h. Then the mixture
was extracted with dichloromethane, the combined organic phases dried over Na2SO4.
After filtration, the filtrate was concentrated under reduced pressure and further
1
purified by column chromatography. Yield: 343.1 mg (75%). H NMR (400 MHz,
DMSO-d6): δ 7.45 (d, J = 7.5 Hz, 3H), 7.41 (d, J = 7.5 Hz, 1H), 7.28 (d, J = 7.4 Hz, 3H),
4.01 (s, 1H) (Fig. S1).
2.3.2.
Synthesis
of
1,3-dimethyl-5-((9-propyl-9H-carbazol-3
yl)methylene)pyrimidine-2,4,6-trione (CB-1);
1,3-dimethyl-barbituric acid (2 mmol) was added to ethanol (5ml) with 9-propyl
carbazole-3-carbaldehyde (2 mmol), and the mixture was heated to 90oC for 4 h. Then
the mixture was extracted with dichloromethane, the combined organic phases dried
over Na2SO4, and the product was purified by silica gel column chromatography (ethyl
acetate: petroleum ether 2:1). Dry overnight in a vacuum oven at 50 oC. Yield: 90%. 1H
NMR (400 MHz, Chloroform-d) δ 9.29 (s, 1H), 8.81 (s, 1H), 8.54 (d, J = 8.9 Hz, 1H), 8.22
(d, J = 7.7 Hz, 1H), 7.54 (t, J = 7.7 Hz, 1H), 7.47 (d, J = 8.6, 3.3 Hz, 2H), 7.35 (t, J = 7.5 Hz,
1H), 4.33 (t, J = 7.1 Hz, 2H), 3.47 (s, 6H), 1.96 (p, J = 7.4 Hz, 2H), 1.01 (t, J = 7.4 Hz, 3H)
(Fig. S2). FT-IR (KBr, cm-1): 1718 (C=O) (Fig. S3).
2.3.3.
Synthesis
of
1,3-diphenyl-5-((9-propyl-9H-carbazol-3-yl)methylene)pyrimidine-2,4,6-trione
(CB-2);
1 (2 mmol) was added to ethanol (5ml) with 9-propyl carbazole-3-carbaldehyde (2
mmol), and the mixture was heated to 90oC for 4 h. Then the reaction mixture was
extracted with dichloromethane and dried over Na2SO4. Then the mixture was
extracted with dichloromethane, the combined organic phases dried over Na2SO4, and
the product was purified by silica gel column chromatography (ethyl acetate:
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o
1
petroleum ether 2:1). Dry overnight in a vacuum oven at 50 C. Yield: 90%. CB-2: H
NMR (400 MHz, Chloroform-d) δ 9.23 (s, 1H), 8.94 (s, 1H), 7.53 (d, J = 14.3 Hz, 5H), 7.46
(s, 4H), 7.44 – 7.36 (m, 5H), 4.31 (s, 2H), 3.76 (s, 2H), 1.87 (s, 2H), 0.99 (t, J = 7.3 Hz, 3H)
(Fig. S4). FT-IR (KBr, cm-1): 1731 (C=O) (Fig. S5).
2.3.3.
Synthesis
of
1,3-dimethyl-5-((9-phenyl-9H-carbazol-3-yl)methylene)pyrimidine-2,4,6-trione
(CB-3).
1,3-dimethyl-barbituric acid (2 mmol) was added to ethanol (5 ml) with 9-phenyl
carbazole-3-carbaldehyde (2 mmol), and the mixture was heated to 90oC for 4 h. Then
the reaction mixture was extracted with dichloromethane and dried over Na2SO4. Then
the mixture was extracted with dichloromethane, the combined organic phases dried
over Na2SO4, and the product was purified by silica gel column chromatography (ethyl
o
acetate: petroleum ether 2:1). Dry overnight in a vacuum oven at 50 C. Yield: 90%.
CB-3: 1H NMR (400 MHz, Chloroform-d) δ 9.34 (d, J = 1.7 Hz, 1H), 8.81 (s, 1H), 8.40 (d, J
= 8.9, 1.8 Hz, 1H), 8.26 (d, J = 7.7 Hz, 1H), 7.66 (t, J = 7.7 Hz, 2H), 7.60 – 7.53 (m, 3H),
7.51 – 7.46 (m, 1H), 76.41 (t, J = 5.4 Hz, 3H), 3.46 (d, J = 1.5 Hz, 6H) (Fig. S6). FT-IR (KBr,
cm-1): 1722 (C=O) (Fig. S7).
3 Results and discussion
3.1 Optical properties
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Fig. 1. UV-visible absorption spectra of CB-1, -2 and -3 in tetrahydrofuran (THF)
solution (10-4M).
It is obvious that there are two types of absorption peaks in Figure 1, in which the
peaks at the absorption wavelengths of 430, 445 and 425 nm (CB-1, CB-2 and CB-3,
respectively.) are designated as the intramolecular charge transfer (ICT) peak of the
carbazole unit to the barbituric acid unit [22]. Another peak is the π-π* electronic
transition of the corresponding benzene ring unit, ranging from 250 to 350 nm. We
also found that the absorption wavelength of CB-2 has a larger red shift than CB-1 and
CB-3, the reason maybe is that when the substituent on the N atom of barbituric acid
is benzene ring which expands degree of the conjugation. In addition, compared with
CB-1 and CB-2, the absorption wavelength of CB-3 shows blue shift. This is because
when the substituent of N atom of carbazole is benzene ring, the molecular structure
of CB-3 is three-dimensional and the planarity is poor. Molecular dynamics simulation
confirms this possibility.
As can be seen from Fig. 2 and Fig 3, CB-1, -2 and -3 have strong fluorescence in the
solid state, which exhibits non-emission in well dissolved of pure THF solution,
however, fluorescence intensity changes with the increase of water fractions.
Fig. 2. Photographs of CB-1, -2 and -3 in solid and pure THF.
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Fig. 3. Fluorescent photographs of CB-1, -2 and -3 in THF/H2O solution of different fw
by a 365 nm ultraviolet lamp.
When the fw increases from 0% to 90%, the emission intensities of CB-2, and -3
increased by 12-fold, 14-fold, respectively under similar conditions. CB-1 shows a more
complex trend than other compounds, when fw increases from 0% to 80% whose
intensity increased by 47-fold, meanwhile when fw was increased to 90%, the reason
for the sudden drop of fluorescence intensity is the formation of precipitates when
fw=90% (Fig. 4). The coumarin 307 is selected as the reference standard material to
study the fluorescence quantum yield (ΦF) change of AIE active molecules [23, 24].
The ΦF of CB-1, CB-2 and CB-3 in nano-aggregate states is 10%, 4.0% and 3.3%,
respectively.
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Fig. 4. Left: The fluorescence intensity change of CB-1, -2 and -3 in THF with increasing
water volume content. Right: emission intensity (red) and emission peak (blue) relative
to the water fraction in the mixture.
3.2 Molecular dynamics simulations
As we all know, there are two factors that affect the properties of AIE: i) property of
the compound itself; ii) method of aggregation induction of compound; To better
explain the AIE properties of the three compounds, molecular dynamics simulations
were performed for 3 different systems in BIOVIA Materials Studio 2017 Forcite
package. Eight molecules of each compound (CB-1, CB-2, CB-3) were randomly
dissolved in 400 water molecules, respectively, to form 4 different initial systems with
the same cubic simulation lattice (X = 26.49 Å, Y= 26.49 Å, and Z= 26.49 Å). Their
simple point charge (SPC) model [25, 26], which can accurately describe the water
solution environment [27], is adopted for all water molecules.
The MD simulation was performed using the COMPASS force field [28, 29], which is
a force field for atomistic simulation of common organic molecules based on the
state-of-the-art ab initio and empirical parametrization techniques. All simulations
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were equilibrated at constant temperature (298.15 K) and the Normal Pressure and
Temperature Ensemble (NPT) for 30 ns. Atomic coordinates were saved for every
200ps.
Fig. 5. Molecular dynamics simulations were performed for CB-1, -2 and -3.
It is known from the above that the AIE index (Im/I0) (Im is the maximum
fluorescence intensity of the aggregation solution (0<fw<100%), and I0 is the
fluorescence intensity when fw=0%) of these compounds decreases in turn:
CB-1 >CB-3~CB-2. As shown in Fig. 5, the electron-deficient barbituric acid and the
electron-rich carbazole exhibit a conformation which similar to π-π stacking, resulting
in a strong electrostatic attraction between the molecules, meanwhile the N-atom
substituent of the carbazole is n-propane plays a hydrophobic role. Hence, both of
hydrophobic interaction of the alkyl chain and the intermolecular electrostatic
attraction work together to cause the CB-1 molecules to closely accumulate in the
aqueous medium. Not only that, we also calculated the torsion distributions of planar
A and B (Fig. 6) for the 3 compound during simulations (Fig. S8). As shown below, the
torsion of Planar A and B is quite different for the three systems: the corresponding
dihedral angles of these three compounds are 51o for CB-1, 62ο for CB-2, 60ο for CB-3,
respectively. It notes that the dihedral angle of plane A and plane B of CB-1 is 51o,
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which the smallest dihedral angle and most beneficial to intramolecular charge
transfer, thus facilitating the generation of fluorescence. Obviously, compound CB-1
has the strongest AIE activity.
Fig. 6. Planes A and B of the three compounds
However, for CB-3 and CB-2 which three-dimensional structure is large and the
combination is relatively loose. In addition two-sided angle of plane A and plane B of
CB-2 and CB-3 are large, which easily leads to the occurrence of TICT, resulting in a
decrease in fluorescence.
We calculated the binding energy for each system after self-assembled through the
equation below (Table 1):

Ebinding = Etotal – (Esolution + 8Ecompound
)
(1)

Where the 8 represents the number of each compound molecules, Ebinding is the
binding energy of each system after simulation, Etotal is the potential energy of each
energy-minimized system in equilibrium, and Esolution is the potential energy of the
individual aqueous solution without any compounds, Ecompound is the potential energy
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
of each single compound. Etol is the total enthalpy of each system after 30ns
simulation.
Table 1：The binding energy of compounds
system
CB-1
CB-2
CB-3

214.074
148.138 112.943
Ebindin（g kcal/mol）
As we all known, the binding energy is the energy released when several particles
combine from a free state into a composite particle and the larger the binding energy
value, the more stable the structure of the molecule and the closer the compound
aggregates.
3.2 Mechanochromic fluorescence properties
Based on their AIE properties, the MCF properties of CB-1, -2 and -3 were explored.
As shown in Fig.7 and 8, CB-1, -2 and -3 are yellow powder with yellow fluorescence
(λmax=546, 559, 578, respectively) under 365 nm UV light. After grinding, the colour of
CB-1 and CB-3 change a little (λmax=552, 562, respectively), however, the colour of
CB-2 and (λmax=570) is an orange power with red fluorescence. To further understand
the reversibility of the MCF effect of CB-1, -2, -3 powders, when exposure of the
ground powder to ethanol vapour, the colour and emission was restored (Fig. 8).
Fig.7. Normalized fluorescence spectra of CB-1, -2 and -3 after different treatments.
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Fig.8. Fluorescence photographs of colour changes of CB-1,-2 and -3 under grinding
and fuming.
In order to further investigate the mechanism of the MCF phenomenon of CB-1, -2,
-3 powders, powder X-ray diffraction (XRD) studies were carried out. As shown in Fig. 9,
the XRD curves of all the three compounds in original showed strong and sharp
diffraction peaks, indicating that the compounds were in an ordered arrangement of
crystalline states. After grinding, the diffraction peak of CB-2 shows a relatively weak
intensity or even disappears which meaning that the order of the molecules is changed
from a crystalline states form to an amorphous structure [30-32], however, the
difference of diffraction peaks between CB-1 and CB-3 is smaller compared. After
fumed by ethanol, the diffraction peak of all the compounds reappeared which mean
that the compounds restore to crystalline state. These results indicate that CB-2 have
relatively good MCF properties of which the mechanism is that the mutual
transformation of the crystalline state and the amorphous state.
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Fig.9. XRD patterns of the corresponding samples.
3.5 Detection of nitroaromatic explosives
As a potential explosive sensing material, it requires not only fast response to
analyses and high sensitivity, but also relatively stable fluorescence performance. As
show in Fig.10, the fluorescence intensity of CB-1 and CB-3 remained unchanged
within 900 s in nano-aggregates state, but the fluorescence intensity of CB-2
decreased by 30% within 1000 s, respectively. Therefore, CB-1 and CB-3 have better
fluorescence stability in nano-aggregates state and have potential explosive sensing
material.
Fig. 10. CB-1,-2 and -3light stability in nano-aggregates state.
The electron-deficient nitroaromatic explosives of PA, TNT, and DNT interact readily
with electron-rich-carbazole group in CB-1 and CB-3 molecules. The quenching
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efficiency ((1-I/I0) ×100%) of aggregates CB-1 (fw = 80%) and CB-3 (fw = 90%) towards
PA, TNT and DNT are shown in Fig. 11. With the increase of nitroaromatic
concentration, the fluorescence of the two compounds are remarkably quenched. In
the presence of PA, the fluorescence intensities of CB-1 and CB-3 were quenched up to
95% and 97%, respectively, however, the quenching efficiency are relatively low in the
presence of DNT and TNT. In order to more intuitively compare the quenching effect
of two compounds on three nitroaromatics which can use the Stern-Volmer equation
to explain. As shown in Fig. 12, the I0/I-1 as the ordinate and the concentration (Q) of
the nitroaromatics as the abscissa, then Stern-Volmer curve was obtained according to
quenching equation 3.1 [33].
I0 / I = 1+K [Q]
(3.1)
In equation 3.1, I0 represent the fluorescence intensity of the compound without
the nitroaromatic explosives; Q represent the concentration of the added
nitroaromatic explosives; I represent the fluorescence intensity of the compound after
the addition of the nitroaromatic explosives at a concentration of Q; K represent the
maximum Stern–Volmer quenching constant (Ksv).
When the concentration range of nitroaromatics is 0-4×10-4M. For CB-1, the values
of KSV of PA, TNT and DNT are 6.6×104, 3×104 and 2.1×104 M-1, respectively. For CB-3,
the values of KSV of PA, TNT and DNT are 1×105, 3.5×104 and 1.47×104 M-1, respectively.
These results indicate that PA, TNT and DNT have significant quenching effect on CB-1
and CB-3, and PA has the highest quenching efficiency.
At the same time, according to the formula LOD = 3S / Ksv [34, 35], the limit of
detection (LOD) of CB-1 and CB-3 in fw=90% mixture solution for PA is 0.015 μM and
0.010 μM, respectively. LOD of CB-1 and CB-3 in fw=90% mixture solution for TNT is 3.4
μM and 2.42 μM, respectively. LOD of CB-1 and CB-3 in fw=90% mixture solution for
DNT is 4.85μM and 0.3nM, respectively.
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Fig. 11. Fluorescence spectra of CB-1 and CB-3 in aggregates state containing
different amounts of PA, TNT, DNT.
Fig. 12. KSV of CB-1 and CB-3 in aggregates state containing different amounts of PA,
TNT, DNT.
In order to explore its quenching mechanism, we tested the absorption spectra of
nitroaromatics and the emission spectra of the compounds. As show in Fig. 13, there
not overlap of the emission spectra and the absorption spectra, therefore, Förster
resonance energy transfer (FRET) is impossible. Therefore, photoinduced electron
transfer (PET) is the only possibility of CB-1 and CB-3 quenching mechanism [36-38].
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Fig. 13. Absorption spectra of TNT, DNT, PA and CB-1 and CB-3 emission spectrum.
The reason PA has better quenching effect than TNT and DNT for both CB-1 and
CB-3 is that PA has the most significant driving forces in PET mechanism [39] (Fig. 14).
All optimizations and electronic structurecalcul ation were done at B3LYP/ 6-311g (d,
p) level for the three systems. Solvation effects were incorporated by SMD [40]
solvation model with water as solvent. The dispersion correction was conducted by
Grimme's D3 version with BJ damping function [41]. All quantum calculations were
done with Gaussian09 software.
Fig. 14. Energy levels, energy gaps and electron cloud distributions of the HOMO
and LUMO of PA, TNT, DNT and PB-3 calculated by the B3LYP/6-325 31G (d) program.
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4 Conclusion
In summary, we have synthesized three barbituric derivatives with AIE properties.
Molecular dynamics simulations show that CB-1 has the best fluorescence activity and
CB-2 have relatively good MCF properties. Meanwhile, CB-1 and CB-3 have better
fluorescence stability in nano-aggregates state which have electron-rich carbazole
group can interact with electron-deficient nitroaromatic explosives and the maximum
Stern–Volmer quenching constant (Ksv) of PA is 6.6×104, 1×105 M-1, respectively.
Acknowledgements
This work was financially supported by the Natural Science Foundation of Shandong
province (ZR2018MB025), Key R&D Program Projects of Shandong province
(2017GGX202001) and the Funds for Research Leader in Jinan （2018GXRC028）.
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References
[1] Germain M E, Knapp M J. Optical explosives detection: from color changes to
fluorescence turn-on. [J]. Cheminform, 2009, 38(9):2543-2555.
[2] Gole B, Song W, Lackinger M, et al. Explosives sensing by using electron-rich
supramolecular polymers: role of intermolecular hydrogen bonding in significant
enhancement of sensitivity. [J]. Chemistry - A European Journal, 2015,
20(42):13662-13680.
[3] Pon S N, Venugopalan S, Senthilkumar N, et al. Voltammetric determination of
nitroaromatic and nitramine explosives contamination in soil [J]. Talanta, 2006,
69(3):656-662.
[4] Salinas Y, MartãNez-Mã Ã R, Marcos M D, et al. Optical chemosensors and reagents
to detect explosives [J]. Chemical Society Reviews, 2012, 41(3):1261-1296.
[5] Wang D.H, CuiYZ, Tao F.R. et al. A novel film of conjugated polymer grafted onto
gelatin for detectingnitroaromatics vapor with excellent inhibiting
photobleaching.Sensors and Actuators B, 2016, 225,319-326.
[6] Zhang Z, Ai X, Obolda A, et al. A rapid-response fluorescent film probe to DNT
based on novel AIE materials [J]. Sensors and Actuators B: Chemical, 2019, 281:
971-976.
[7] Adil L R, Gopikrishna P, Krishnan Iyer P. Receptor-free detection of picric acid: a
new structural approach for designing aggregation-induced emission probes [J].
ACS applied materials & interfaces, 2018, 10(32): 27260-27268.
[8] Özcan Ç, Üzer A, Durmazel S, et al. Colorimetric Sensing of Nitroaromatic Energetic
Materials Using Surfactant-Stabilized and Dithiocarbamate-Functionalized Gold
Nanoparticles[J]. Analytical Letters, 2019: 1-15.
[9] Ahamad M N, Shahid M, Ahmad M, et al. Cu (II) MOFs Based on Bipyridyls:
Topology, Magnetism, and Exploring Sensing Ability toward Multiple
Nitroaromatic Explosives [J]. ACS Omega, 2019, 4(4): 7738-7749.
[10] Khezri B, Mousavi S M B, Sofer Z, et al. Recyclable nanographene-based
micromachines for the on-the-fly capture of nitroaromatic explosives [J].
Nanoscale, 2019.
19

ACCEPTED MANUSCRIPT
[11] Ghasemi F, Hormozi-Nezhad M R. Determination and identification of
nitroaromatic explosives by a double-emitter sensor array [J]. Talanta, 2019, 201:
230-236.
[12] Wang X Q, Feng D D, Zhao Y D, et al. A Multifunctional 1D Cd-based Metal-Organic
Complex for the Highly Luminescent Sensitive Detection of Fe3+, CrO42-/Cr2O72-,
and Nitroaromatic Explosives [J]. Journal of Solid State Chemistry, 2019.
[13] Kose M, Kırpık H, Kose A. Fluorimetric detections of nitroaromatic explosives by
polyaromatic imine conjugates [J]. Journal of Molecular Structure, 2019.
[14] Luo J, Xie Z, Lam J W Y, et al. Aggregation-induced emission of
1-methyl-1,2,3,4,5-pentaphenylsilole[J].
2001(18):1740-1741.
Chemical
Communications,
[15] Zhao Z, He B, Tang B Z. ChemInform Abstract: Aggregation‐Induced Emission of
Siloles [J]. Cheminform, 2015, 46(45).
[16] Xiang S, Ying W and Yu L. Fluorescence based explosive detection: from
mechanisms to sensory materials [J]. Chem. Soc. Rev. 2015,
44(22):10.1039.C5CS00496A.
[17] S. J. Toal, D. Magde and W. C. Trogler, Chem. Commun, 2005, 5465–5467.
[18] X. Wang, Y. Guo, D. Li, H. Chen and R.-C. Sun, Chem. Commun., 2012, 48,
5569–5571.
[19] Yang M, Dong Y, Fei S, et al. Hydrogenation of N-propylcarbazole over supported
ruthenium as a new prototype of liquid organic hydrogen carriers (LOHC) [J]. RSC
Advances, 2013, 3(47):24877.
[20] S. J, G. P, S. T, et al. Synthesis, optical and electrochemical properties of carbazole
sensitizers and their interaction with TiO2 [J]. Journal of Molecular Structure,
2014, 1060:191-196.
[21] Xue S, Liu W, Qiu X, et al. Remarkable Isomeric Effects on Optical and
Optoelectronic
Properties
of\r,
N\r,
-Phenylcarbazole-Capped
9,10-Divinylanthracenes[J]. The Journal of Physical Chemistry C, 2014,
118(32):18668-18675.
20

ACCEPTED MANUSCRIPT
[22] NakamaruKatsumi. Synthesis, Luminescence Quantum Yields, and Lifetimes of
Trischelated Ruthenium (II) Mixed-ligand Complexes Including 3, 3′-Dimethyl-2,
2′-bipyridyl [J]. Bulletin of the Chemical Society of Japan, 1982, 55(9):2697-2705.
[23] J. N. Demasa, G. A. Crosby. Measurement of Photoluminescence Quantum Yields
[J]. Chemistry International, 2015, 37(5-6).
[24] Li K, Zhang Y, Qiao B, et al. Facile fabrication of AIE/AIEE-active fluorescent
nanoparticles based on barbituric for cell imaging applications[J]. Rsc Advances,
2017, 7(48):30229-30241.
[25] H. J. C. Berendsen, J. P. M. Postma, W. F. van Gunsterenand J. Hermans, in
Intermolecular Forces, ed. B. Pullman,Reidel Publ., Dordrecht, 1981, pp. 331–342.
[26] H. J. C. Berendsen, J. R. Grigera and T. P. Straatsma,J. Phys. Chem., 1987, 91(24),
6269–6271.
[27] Wiedemair, Martin J; Hofer, Thomas S. Towards a dissociative SPC-like water
model-probing the impact of intramolecular Coulombic contributions, Physical
Chemistry Chemical Physics., 2017 19(47) 31910-31920.
[28] H.Sun, P.Ren, J.R.A. libai and JG simmons. The compassforce field:
parameterization and validation for phosphazenes, Comput. Theor. Polym. Sci. 8
(1998) 229-246.
[29] H. Sun, COMPASS: an ab initio force-field optimized for condensed-phase
applicationsoverview with details on alkane and benzene compounds, J. Phys.
Chem. B 102 (1998) 7338-7364.
[30] Z. G. Chi, X. Q. Zhang, B. J. Xu, X. Zhou, C. P. Ma, Y. Zhang, S. W. Liu and J. R. Xu,
Chem. Soc. Rev., 2012, 41, 3878;
[31] X. Q. Zhang, Z. G. Chi, H. Y. Li, B. J. Xu, X. F. Li, W. Zhou, S. W. Liu, Y. Zhang and J. R.
Xu, Chem. – Asian J., 2011, 6, 808;
[32] H. Y. Li, X. Q. Zhang, Z. G. Chi, B. J. Xu, W. Zhou, S. W. Liu, Y. Zhang and J. R. Xu, Org.
Lett., 2011, 13, 556.
[33] Mirco Natali, Sebastiano Campagna and Franco Scandola Photoinduced electron
transfer across molecular bridges: Electron- and hole-transfer superexchange
pathways, Chem. Soc. Rev. 43 (12) (2014) 4005–4018.
21

ACCEPTED MANUSCRIPT
[34] Ma X, Tao F, Zhang Y, et al. Detection of nitroaromatic explosives by a 3D
hyperbranched σ–π conjugated polymer based on a POSS scaffold [J]. Journal of
Materials Chemistry A, 2017, 5(27).
[35] H. Zhou, J.S. Li, M. H. Chua, H. Yan, B.Z. Tang and J.W. Xu. Poly (acrylate) with a
tetraphenylethene pendant with aggregation-induced emission (AIE)
characteristics: highly stable AIE-active polymer nanoparticles for effective
detection of nitro compounds. Polym. Chem., 5 (2014) 5628-5637.
[36] S. Chemate, Y. Erande, D. Mohbiya and N. Sekar. Acridine derivative as a “turn on”
probe for selective detection of picric acid via PET deterrence. RSC Adv., 6 (2016),
84319-84325.
[37] Kaur M, Mehta S K, Kansal S K. A fluorescent probe based on nitrogen doped
graphene quantum dots for turn off sensing of explosive and detrimental water
pollutant, TNP in aqueous medium[J]. Spectrochim Acta A Mol Biomol Spectrosc,
2017, 180:37-43.
[38] Yuan L, Lin W, Zheng K, et al. FRET-based small-molecule fluorescent probes:
rational design and bioimaging applications [J]. Acc Chem Res, 2013,
46(7):1462-1473.
[39] Zhang H J, Tian Y, Tao F, et al. Detection of nitroaromatics based on aggregation
induced emission of barbituric acid derivatives [J]. Spectrochimica Acta Part A:
Molecular and Biomolecular Spectroscopy, 2019: 117168.
[40] Marenich,A. V.; C ramer, C. J.; Truhlar, D. G. Universal Solvation Model Based on
Solute Electron Density and on a Continuum Model of the Solvent Defined by the
Bulk Dielectric Constant and Atomic Surface Tensions. The Journal of Physical
Chemistry B 2009, 113 (18), 6378–6396.
[41] Grimme, S., Ehrlich, S. & Goerigk, L. Effect of the damping function in dispersion
corrected density functional theory. Journal of Computational Chemistry 32, 1456
–1465 (2011).
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Graphical Abstract
Barbituric acid derivatives have mechanochromic fluorescent properties which also
can be used to detect nitroaromatic explosives in aqueous media.
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Multi-purpose Barbituric Acid Derivatives with Aggregation Induced
Emission
Hanjun Zhang, Yuezhi Cui*, Furong Tao, Datong Zhang, Zhen Xu, Li Guo
School of Chemical and Pharmaceutical Engineering, Qilu University of Technology
(Shandong Academy of Sciences), Jinan 250353, P. R. China
Tel: +86 531 89631208; Fax: +86 531 89631760;
E-mail address: yuezhicui@163.com
Highlights:

We founded that the alkyl substituents play important role in forming aggregates
of the CB-1.

We founded that the CB-2 have relatively good MCF properties of which the
mechanism is that the mutual transformation of the crystalline state and the
amorphous state.

We designed and synthesized barbituric derivative fluorescence sensors, which
can generate aggregates in high water content and can thus be used for the
detection of nitroaromatics in aqueous media.
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