A two-photon fluorescent probe for colorimetric and ratiometric monitoring of mercury in live cells and tissues

Article abstract of DOI:10.1039/c8cc08608g

Owing to the extreme toxicity of mercury, methods for its selective and sensitive sensing in solutions, and in live cells and tissues are in great demand. In this study, we developed a naphthalimide-based diphenylphosphinothioyl group-containing fluorescent and colorimetric probe that selectively detects mercury (Hg²⁺). Upon addition of mercury (Hg²⁺) to a solution of the probe, both a colorimetric change from colorless to yellow and a fluorescence change from blue to green (under a 365 nm hand-held UV lamp) occur, both of which can be observed using the "naked-eye". Furthermore, the probe possesses the capability of sensing intracellular mercury in both live cells and tissues using dual-emission channels and two-photon microscopy.

Full text of DOI:10.1039/c8cc08608g

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A two-photon fluorescence probe for colorimetric and ratiometric
monitoring of mercury in live cells and tissues
Liyan Chen,†a Sang Jun Park,†b Di Wu,c* Hwan Myung Kimb* and Juyoung Yoona*
Received 00th January 20xx,
Accepted 00th January 20xx
DOI: 10.1039/x0xx00000x
www.rsc.org/
mediated chemical processes such as cyclization,3 desulfurization,4
Owing to the extreme toxicity of mercury, methods for its
selective and sensitive sensing in solutions, and in live cells and
tissues are in great demand. In this study, we developed a
naphthalimide-based, diphenylphosphinothioyl group containing
fluorescence and colorimetric probe that selectively detected
mercury (Hg2+). Upon addition of mercury (Hg2+) to a solution of
the probe, both a colorimetric change from colorless to yellow and
a fluorescence change from blue to green (under 365 nm hand-
held UV lamp) occur, both of which can be observed using the
"naked-eye". Furthermore, the probe possesses the capability of
sensing intracellular mercury in both live cells and tissues using
dual-emission channels and two-photon microscopy.
oxymercuration5 and others6. Though effective, these detection
methods have important drawbacks. For example, most detect
mercury in an "off-on" manner. In contrast, because changes in
interconnected fluorescent signals are monitored, ratiometric
fluorescence probes are capable of detecting analytes with high
accuracies because interference arising from instrumental issues,
probe concentrations and ambient environmental changes are
minimized.7 Notably, Coskun and co-workers reported
a
significantly ratiometric fluorescence probe by the advantage of
internal charge transfer mechanism utilizing boradiazaindacene
dyads.6j The probe efficiently detect mercury with larger intensity
ratio changes and excellent selectivity. Regrettably, the applications
in live cells are lack of explorations. Besides that, though some
fluorescent probes have been successfully applied to monitor
mercury in vivo. However, the majority of them developed to date
employ one-photon microscopy to detect mercury inside the cells
or tissues. In contrast, two-photon microscopy (TPM), in which two
near-infrared (NIR) photons serve as the excitation source,
possesses significant advantages including reduced photodamage
and greater tissue imaging depths.8
Owing to its wide use in the chemical industrial and its extreme
toxicity, mercury is a hazardous threat to both human health and
the environment.1 The toxicity of mercuric ion is caused by its
strong binding affinity to thiols in enzymes and proteins, which
results in severe and irreversible damage to physiological processes.
Consequently, novel strategies for selective and sensitive detection
of mercury in the environment and living systems are in great
demand. In contrast to several traditional methods that have been
developed for this purpose thus far, including those that rely on
absorption spectroscopy, gas chromatography-mass spectrometry,
voltammetry and atomic absorption/emission spectrometry, those
that utilize fluorescence methods possess significant advantages,
including instantaneous response, operational simplicity, high
selectivity and sensitivity, and real-time detection capability.2 Thus,
a considerable effort has been given to the development of
fluorescence probes for monitoring mercury in aqueous solution
and in biological samples. These studies have led to a number of
fluorescent chemosensor systems that utilize various mercury
Thus, in the investigation described below, we developed a
new colorimetric and ratiometric fluorescence probe, which
contains a naphthalimide fluorophore and which can be utilized to
monitor mercury in both live cells and tissues using two-photon
microscopy.
Guided by the results of previous studies,9 we designed the
naphthalimide containing fluorescence probe, NAP-PS, for
detection of mercury. We anticpated that NAP-PS would possess
several beneficial features, including high stability and cell-
permeability (Scheme
1 and Scheme S1). Moreover, the
diphenylphosphinothioyl moiety was incorporated into a familiar 4-
hydroxy-1,8-naphthalimide fluorophore in order to achieve
ratiometric detection of mercury. It was envisaged that mercury
would promote cleavage of the thiophosphinate ester P-O bond in
NAP-PS to produce NAP-O-, which is an intramolecular charge
transfer (ICT) system that displays long emission wavelength owing
to the strong electron-donating oxy-anion site and strong electron-
withdrawing naphthalimide group (Scheme 1).10 To assess the
validity of the expectations stated above, we prepared NAP-PS by
using a four-step sequence, starting with commercially available 4-
bromo-1,8-naphthalic anhydride and butylamine (Scheme S1).
a. Department of Chemistry and Nano Science, Ewha Womans University, Seoul,
120-750, Korea
b. Department of Chemistry and Energy Systems Research, Ajou University, Suwon,
Korea
c. School of Chemistry, Chemical Engineering and Life Science,
Wuhan University of Technology, No. 122 Luoshi Road, Wuhan 430070, China
†Contributed equally to this work
*Correspondence: E-mail: jyoon@ewha.ac.kr; kimhm@ajou.ac.kr；
wudi19871208@163.com
Electronic Supplementary Information (ESI) available: Experiment section and
additional table and figures. See DOI: 10.1039/x0xx00000x
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 1
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C4H9
N
the addition of mercury(II) perchlorate (30 μM) uVniedwerArt3ic6le5Onnlinme
C4H9
N
O
O
C4H9
O
O
hand-held UV lamp.
DOI: 10.1039/C8CC08608G
Et3N, S
THF, reflux
O
N
O
O
Hg2+
-HgS
+
HO
P
Ph
Cl
P
Ph
The excellent selectivity of NAP-PS for sensing mercury was
demonstrated by the observation that no fluorescence responses
are induced by other metal ions including Zn2+, Cu2+, Mn2+, Pb2+, Al3+,
Ca2+, Cr3+, K+, Fe3+, Fe2+, Cs+, Na+, Ni2+, Mg2+, Sr2+, Cd2+ and Ag+. As
the results in Figure 2 show, only the addition of mercury leads to a
significant ratiometric response of the fluorescence intensities at
450 nm to 550 nm. Moreover, other metal ions do not interfere
with detection of mercury by NAP-PS.
O
Ph
Ph
O
Ph
P
S
OH
Ph
NAP-PS
DPA
NAP-OH
Scheme 1. Synthesis of probe NAP-PS.
By viewing the absorption spectra shown in Figure 1A, NAP-PS
(10 μM) in HEPES buffer (1.0 mM, pH = 7.4) has an absorption band
centered at 370 nm. Upon addition of various amounts of mercury
(Hg2+) to the solution of NAP-PS, the absorption peak shifts in a
continuous fashion to 450 nm, associated with a color change from
colorless to yellow (Figure 1A insert). Moreover, NAP-PS emits
strong blue fluorescence with a maximum at 450 nm. Addition of
mercury causes a significant decrease in the intensity of the
emission band at 450 nm and a concurrent increase in the intensity
of a peak at 560 nm. Also, the gradual change occurring in emission
can be observed as a blue to green color change using the naked
eye under a hand-held UV lamp (365 nm) (Figure 1B inset). At
mercury concentrations above 60 μM, the ratio of the fluorescence
intensity at 550 and 450 nm (F550/F450) reaches a maximum (Figure
S1). Moreover, the F550/F450 ratio is linearly dependent on the
mercury concentration in the range of 0-12 μM (Figure S2). Based
on the 3δ/k criterion, the detection limit of the probe for mercury is
43 nM.
350
A)
300
Probe and other metal
250
200
Hg2+
150
100
50
0
400
450
500
550
600
650
Wavelength / nm
16
14
12
10
8
B)
0.20
A)
0.16
0.12
0.08
0.04
6
4
2
0
300
350
400
450
500
550
Wavelength / nm
Figure 2. A) Fluorescence spectra of probe NAP-PS (10 μM) before
and after addition of 200 μM different metal ions in HEPES buffer
(1.0 mM, pH = 7.4), λex = 380 nm, Slits: 3/5 nm; B) Fluorescence
intensity ratios (F550/F450) of probe NAP-PS (10 μM) before and after
addition of 200 μM different metal ions in HEPES buffer (1.0 mM,
pH = 7.4).
400
B)
300
200
100
0
The time dependence of the fluorescence response of NAP-PS
was measured in order to determine the observed rate constant of
its reaction with mercury. As the results in Figure 3 show, a HEPES
buffer (1.0 mM, pH = 7.4) solution of NAP-PS (10 μM) displays very
faint fluorescence at 550 nm and a high overall photostability.
Following addition of 2 equivalents of mercury, the intensity of the
emission band of NAP-PS at 550 nm increases with time and
reaches a maximum after 20 min. Pseudo first order kinetic analysis
400
450
500
550
600
650
Wavelength / nm
Figure 1. A) Fluorescence spectra of NAP-PS (10 μM), obtained
upon addition of mercury(II) perchlorate (0−30 μM) in HEPES buffer
(1.0 mM, pH = 7.4); B) UV−vis spectra of NAP-PS (10 μM) obtained
upon addition of mercury(II) perchlorate (0−30 μM) in HEPES buffer
(1.0 mM, pH = 7.4); All spectra were recorded after incubation with
o
of the time course data leads to an observed rate constant (25 C)
of 9.9 × 10-1 min-1 for the reaction of mercury with NAP-PS (Figure
S3).
different concentrations of mercury(II) perchlorate for 40 min; λex
=
As suggested previously,9a,11 the chemical process responsible
for the absorption and emission spectroscopic changes of NAP-PS
involves mercury promoted cleavage of the P-O bond, which
generates the strongly fluorescent NAP-O- anion. To confirm the
380 nm, λem1 = 450 nm, λem2 = 550, slits: 3/5 nm; Figure 1A inset:
photograph of solutions of probe NAP-PS (10 μM) before and after
addition of mercury(II) perchlorate (30 μM); Figure 1B inset:
photograph of solutions of probe NAP-PS (10 μM) before and after
2 | J. Name., 2012, 00, 1-3
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occurrence of this process, a solution of NAP-PS (10 μM) and = 10-50 cm4/photon) for NAP-PS and NAP-OH in HEPESVbieuwffAertric(leFOignulirnee
mercuric perchlorate (20 μM) in HEPES was monitored using high- S9). Analysis of the results form the TPEF spectroscopy experiments
DOI: 10.1039/C8CC08608G
resolution mass spectrometry (HRMS) (Figure S4). The observed with NAP-PS and NAP-OH containing HeLa cells demonstrated that
formation of peaks at m/z 268.0952 and 217.0399 in the HRMS the detection windows of 400-450 nm (Fblue) and 500-600 nm
spectrum is consistent with formation of NAP-OH (calcd. m/z (Fyellow), and excitation at 740 nm are optimal for determining
268.0979 for C16H14NO3) and diphenylphosphinic acid (DPA) (calcd. Fyellow/Fblue ratios (Figure S12). Additionally, fluorescence of NAP-PS
m/z 217.0424 for C12H10PO2), respectively. Moreover, both the in HeLa cells is maintained over 1 h with 2-sec laser pulse intervals,
fluorescence and absorption spectra of NAP-OH and the mixture indicating that it has the level of robust photostability needed for
following reaction of NAP-PS with mercuric perchlorate are cell imaging experiments (Figure S13).
identical (Figure S5 and Figure S6).
To show that NAP-PS can be employed to detect mercury in live
cells, average emission intensity Fyellow/Fblue ratios were determined
using Hg(ClO4)2 treated HeLa cells. Cell calibration test indicated
that the Fyellow/Fblue ratio of NAP-PS was linearly increased by
treatment with various concentrations of Hg(ClO4)2 (Figure S14).
Upon excitation at 740 nm, the respective Fyellow/Fblue values of
untreated HeLa cells labeled with probe NAP-PS and NAP-OH were
found to be 0.39 and 4.01 (Figure 4a and d). Treatment NAP-PS
labeled HeLa cells with Hg(ClO4)2 (25 μM) for 30 min leads to an
increase in the Fyellow/Fblue ratio to 1.40, which corresponds to a 3.6-
fold enhancement (Figure 4b). Finally, incorporation of the known
500
400
300
200
100
mercury
chelator
N,N,N,N-tetrakis(2-
10 M Probe
10 M Probe + 20 M Mercury
pyridylmethyl)ethylenediamine (TPEN,
Fyellow/Fblue value to 0.43 (Figure 4c).
1
mM)12 reduces the
The liver is an important organ for carrying out metabolic and
detoxification functions of humans. It has been reported that
accumulation of mercury leads to liver dys function and related
diseases.13 In order to further explore the biological value of NAP-
PS, fluorescence imaging of mercury in live tissues was carried out
using TPM. The Fyellow/Fblue ratio of TPM images of liver tissues
stained with NAP-PS (50 μM) for 1 h was found to be 0.77 (Figure
5a). When liver tissues are pretreated with Hg(ClO4)2, the
Fyellow/Fblue ratio value increases to 1.70 (Figure 5b). These results
show that NAP-PS along with TPM can be employed to directly and
quantitatively determine the presence of mercury in both live cells
and tissues.
0
5
10
15
20
25
30
Time / mins
Figure 3. Time-dependentchanges in F550/F450 nm for solutions of
NAP-PS (10 μM) upon addition of mercuric perchlorate (20 μM), λex
= 380 nm, Slits: 3/5 nm.
The ability to utilize NAP-PS to monitor mercury in the solid
state was assessed. The initially white NAP-PS solid was mixed with
solid mercuric perchlorate. Grinding of this solid mixture gradually
promotes a color change to yellow (Figure S7). The emission color
change caused by grinding this solid mixture was examined using a
hand-held UV lamp (365 nm). As shown by viewing Figure S8, upon
grinding the strong blue emission of solid NAP-PS undergoes a
change to green-emission.
4.0
(a)
(b)
(c)
3.0
2.0
1.0
0.0
Encouraged by the excellent performance by NAP-PS in sensing
mercury in the solution and solid states, we explored the use of the
probe for fluorescence imaging in the live cells. MTT assay showed
that NAP-PS and NAP-OH have negligible cytotoxicity under the
imaging condition (Figure S10). In order to avoid limitations
associated with photodamage and autofluorescence caused by
using a short excitation wavelength (λex = 380 nm), we first assessed
the use of two-photon microscopy (TPM) for determining mercury
concentrations. To evaluate the permeability of NAP-PS into the
cells, real-time images were performed at intervals of 5-sec (Figure
S11). No signal was observed in the cells before treatment with
NAP-PS, however, the fluorescence intensities of the cells began to
increase after loaded with the probe, and the signal was saturated
within 1 min. Thus, NAP-PS has the high cell permeability, and the
fluorescence observed in the cell can be confirmed to be the
fluorescence caused by the probe, not the auto-fluorescence of the
cell. To find appropriate two-photon excitation wavelengths, TPEF
intensities were assessed by incorporating NAP-PS and NAP-OH in
HeLa cells (Figure S12). Cells containing NAP-OH display bright
emission when exposed to two-photon excitation wavelengths in
the 740-800 nm range, while those containing NAP-PS display
bright fluorescence when exposed to wavelengths of light below
740 nm (Figure S12a-c). The degree of two-photon absorption
cross-section was calculated to be 15 and 42 GM respectively (1 GM
(d)
(e)
4
3
2
1
0
F
F
Hg2+
Hg2+
Control
Dye
+ TPEN
Figure 4. Pseudo colored ratiometric TPM images of HeLa cells
incubated with (a) Probe NAP-PS (5 μM) and (d) Dye (NAP-OH, 5
μM) for 30 min; HeLa cells were pretreated with (b) Hg(ClO4)2 (25
μM) for 30 min and (c) Hg(ClO4)2 and then TPEN (1 mM) for 30 min
additionally before labeling with probe NAP-PS; (e) Average
Fyellow/Fblue ratios in the TPM images. Images were acquired using
740 nm excitation and emission windows of 400-450 nm (blue) and
500-600 nm (yellow); Scale bars = 20 μM.
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(c) J. Jiang, W. Liu, J. Cheng, L. Yang, H. Jiang, D. Bai and W.
2.0
1.5
1.0
0.5
0.0
Liu, Chem. Commun., 2012, 48, 8371; (d) B. GuV, ieLw. HAruticalenOgn,liNne.
2.0
1.5
1.0
0.5
0.0
(a)
(b)
(c)
DOI: 10.1039/C8CC08608G
Mi, P. Yin, Y. Zhang, X. Tu, X. Luo, S. Luo and S. Yao, Analyst,
2015, 140, 2778.
F
6
(a) E. M. Nolan and S. J. Lippard, J. Am. Chem. Soc., 2007,
129, 5910; (b) H. Y. Lee, K. M. K. Swamy, J. Y. Jung, G. Kim
and J. Yoon, Sensor Actuat. B-Chem. 2013, 182, 530; (c) X.
Zhou, X. Wu and J. Yoon, Chem. Commun., 2015, 51, 111; (d)
L. Long, X. Tan, S. Luo and C. Shi, New. J. Chem., 2017, 41,
8899; (e) Y. Zhang, H. Chen, D. Chen, D. Wu, Z. Chen, J.
Zhang, X. Chen, S. Liu and J. Yin, Sensor. Actuat. B-Chem.,
2016, 224, 907; (f) S. Ma, L. Li, M. She, Y. Mo, S. Zhan, P. Liu
and J. Li, Chin. Chem. Lett., 2017, 28, 2014; (g) A.Chatterjee,
M. Banerjee, D. G. Khandare, R. U. Gawas, S. C.
Mascarenhas, A. Ganguly, R. Gupta and H. Joshi, Anal.
Chem., 2017, 89, 12698; (h) J. Sivamani, V. Sadhasivam and
A. Siva, Sensor. Actuat. B-Chem., 2017, 246, 108; (i) H. N. Kim,
W. X. Ren, J. S. Kim and J. Yoon, Chem. Soc. Rev. 2012, 41,
3210; (j) A. Coskun and E. U. Akkaya, J. Am. Chem. Soc. 2006,
128, 14474.
(a) R. Y. Tsien and M. Poenie, TIBS, 1986, 11, 450; (b) M. H.
Lee, J. S. Kim and J. L. Sessler, Chem. Soc. Rev., 2015,44,
4185; (c) M. A. Haidekker and E. A. Theodorakis, J. Mater.
Chem. C, 2016, 4, 2707.
(a) H. M. Kim and B. R. Cho, Chem. Rev., 2015, 115, 5014; (b)
Y. L. Pak, S. J. Park, D. Wu, B. Cheon, H. M. Kim, J. Bouffard,
and J. Yoon, Angew. Chem. Int. Ed., 2018, 57, 1567.
(a) B. Tang, B. Ding, K. Xu, and L. Tong, Chem. Eur. J., 2009,
15, 3147; (b) H. G. Im, H. Y. Kim and S.-K. Chang, Sensor.
Actuat. B-Chem., 2014, 191, 854.
F
Control
Hg2+
Figure 5. Pseudo colored ratiometric TPM images of rat liver tissues
incubated with NAP-PS (50 μM) for 1 h (a) before and (b) after
pretreatment with Hg(ClO4)2 (250 μM) for 1 h; (c) Average
Fyellow/Fblue ratios in the TPM images; Images were acquired using
740 nm excitation and emission windows of 400–450 nm (blue)
and 500–600 nm (yellow); Scale bars = 20 μM.
The results presented above show that NAP-PS is a highly effective
colorimetric and ratiometric fluorescence probe for monitoring
mercury. The ratiometric fluorescence response of NAP-PS is a
consequence of its reaction with mercury, which cleaves the
thiophosphinate P-O bond in the probe to form the intramolecular
charge transfer (ICT) system, NAP-O-. Importantly, the use of this
probe as a dual-channel sensor for mercury in both live cells and
tissues was demonstrated in this effort.
7
8
9
Notes and references
10 (a) B. Zhu, C. Gao, Y. Zhao, C. Liu, Y. Li, Q. Wei, Z. Ma, B. Du
and X. Zhang, Chem. Commun., 2011, 47, 8656; (b) Y. Tian, F.
Xin, C. Gao, J. Jing and X. Zhang, J. Mater. Chem. B, 2017, 5,
6890; (c) C. Liu, H. Wu, Z. Wang, C. Shao, B. Zhu and X.
Zhang, Chem. Commun., 2014, 50, 6013; (d) B. Zhu, P. Li, W.
Shu, X. Wang, C. Liu, Y. Wang, Z. Wang, Y. Wang and B. Tang,
Anal. Chem., 2016, 88, 12532; (e) Y. Hao, Y. Zhang, K. Ruan,
W. Chen, B. Zhou, X. Tan, Y. Wang, L. Zhao, G. Zhang, P. Qu,
and M. Xu, Sensor. Actuat. B-Chem., 2017, 244, 417; (f) X.
Xia, F. Zeng, P. Zhang, J. Lyu, Y. Huang and S. Wu, Sensor.
Actuat. B-Chem., 2016, 227, 411; (g) X. Wu, L. Li, W. Shi, Q.
Gong, X. Li and H. Ma, Anal. Chem., 2016, 88, 1440.
11 (a) M. H. Lee, J. S. Kim and J. L. Sessler, Chem. Soc. Rev.,
2015, 44, 4185; (b) M. A. Haidekker and E. A. Theodorakis, J.
Mater. Chem. C, 2016, 4, 2707; (c) B. Zhu, C.Gao, Y. Zhao, C.
Liu, Y. Li, Q. Wei,Z. Ma, B. Du and X. Zhang, Chem. Commun.,
2011, 47, 8656.
‡ This study was supported financially by a National Research
Foundation of Korea (NRF) grant funded by the Korea
government (MSIP) (No. 2012R1A3A2048814 for J. Yoon and No.
2016R1E1A1A02920873 for H. M. Kim). The Korea Basic Science
Institute (Western Seoul) is acknowledged for the LC/MS data.
FAB mass spectral data were obtained from the Korea Basic
Science Institute (Daegu) on a Jeol JMS 700 high resolution mass
spectrometer.
1
2
(a) M. Altrichter, Ambio., 2008, 37, 108; (b) K. P. Lisha and T.
Pradeep, Gold. Bulletin., 2009, 42, 144.
(a) D. Wu, A. C. Sedgwick, T. Gunnlaugsson, E. U. Akkaya, J.
Yoon and T. D. James, Chem. Soc. Rev., 2017, 46, 7105; (b) D.
Wu, L. Chen, W. Lee, G. Ko, J. Yin and J. Yoon, Coord. Chem.
Rev., 2018, 354, 74; (c) S. Lee, J. Li, X. Zhou, J. Yin and J. Yoon,
Coord. Chem. Rev., 2018, 366, 29.
12 C. S. Lim, D. W. Kang, Y. S. Tian, J. H. Han, H. L. Hwang and B.
R. Cho, Chem. Commun., 2010, 46, 2388.
13 (a) C. Y. Ung, S. H. Lam, M. M. Hlaing, C. L. Winata, S.Korzh, S.
Mathavan and Z. Gong, BMC. Genomics.,2010, 11, 212; (b)
M. R. Lee, Y. H. Lim, B. E. Lee, Y. C. Hong, Environ. Health.,
2017, 16, 17.
3
(a) Y.-K. Yang, K.-J. Yook and J. Tae, J. Am. Chem. Soc., 2005,
127, 16760; (b) S.-K. Ko, Y.-K. Yang, J. Tae and I. Shin, J. Am.
Chem. Soc., 2006, 128, 14150; (c) J.-S. Wu, I.-C. Hwang, K. S.
Kim and J. S. Kim, Org. Lett., 2007, 9, 907; (d) G.-Q. Shang, X.
Gao, M.-X. Chen, H. Zheng and J.-Z. Xu, J. Fluoresc., 2008, 18,
1187; (e) H. Lee and H.-J. Kim, Tetrahedron Lett., 2011, 52,
4775; (f) X. Zhang, Y. Xiao and X. Qian, Angew. Chem. Int. Ed.,
2008, 47, 8025; (g) A. Tantipanjaporn, S. Prabpai, K. Suksen
and P. Kongsaeree, Spectrochim. Acta. A, 2018, 192, 101; (h)
Y. Liu, X. Lv, Y. Zhao, M. Chen, J. Liu, P. Wang and W. Guo,
Dyes. Pigm.,2012, 92, 909; (i) S. Chen, W. Wang, M. Yan, Q.
Tu, S.-W. Chen and T. Li, Sensor. Actuat. B-Chem., 2018, 255,
2086; (j) M. Wang, J. Wen, Z. Qin, H. Wang, M.-S. Yuan and J.
Wang, Dyes. Pigm., 2015, 120, 208.
4
5
(a) X. Chen, K.-H. Baek, Y. Kim, S.-J. Kim, I. Shin and J. Yoon,
Tetrahedron, 2010, 66, 4016; (b) W. Xuan, C. Chen, Y. Cao,
W. He, W. Jiang, K. Liu and W. Wang, Chem. Commun., 2012,
48, 7292; (c) F. Wang, S.-W. Nam, Z. Guo, S. Park and J. Yoon,
Sensor Actuat. B-Chem., 2012, 161, 948.
(a) S. Ando and K. Koide, J. Am. Chem. Soc., 2011, 133, 2556;
(b) M. Santra, B. Roy and K. H. Ahn, Org. Lett.,2011, 13, 3422;
4 | J. Name., 2012, 00, 1-3
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ChemComm
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Journal Name
COMMUNICATION
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DOI: 10.1039/C8CC08608G
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