A new colorimetric and fluorescent ratiometric sensor for Hg2+ based on 4-pyren-1-yl-pyrimidine

Article abstract of DOI:10.1016/j.tet.2011.12.071

A novel fluorescent ratiometric chemosensor based on 4-pyren-1-yl- pyrimidine (PPM) has been designed and prepared for the detection of Hg ²⁺ in the presence of other competing metal ions in acetonitrile. The photo exhibits fluorescence color change of PPM from blue to green without and with Hg²⁺, which red shift of wavelength about 105 nm in fluorescence emission spectra. It can serve as a highly selective chemodosimeter for Hg ²⁺ with ratiometric and naked-eye detection. The photophysical properties of PPM confirmed a 2:1 (PPM-Hg²⁺) binding model and the spectral response toward Hg²⁺ was proved to be reversible.

Full text of DOI:10.1016/j.tet.2011.12.071

Tetrahedron 68 (2012) 3129e3134
Contents lists available at SciVerse ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
A new colorimetric and fluorescent ratiometric sensor for Hg2þ based
on 4-pyren-1-yl-pyrimidine
*
*
Jiena Weng, Qunbo Mei , Qidan Ling, Quli Fan, Wei Huang
Key Laboratory for Organic Electronics and Information Displays (KLOEID), Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications,
Nanjing 210046, China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 24 October 2011
Received in revised form 15 December 2011
Accepted 23 December 2011
Available online 28 December 2011
A novel fluorescent ratiometric chemosensor based on 4-pyren-1-yl-pyrimidine (PPM) has been de-
signed and prepared for the detection of Hg2þ in the presence of other competing metal ions in ace-
tonitrile. The photo exhibits fluorescence color change of PPM from blue to green without and with Hg2þ
,
which red shift of wavelength about 105 nm in fluorescence emission spectra. It can serve as a highly
selective chemodosimeter for Hg2þ with ratiometric and naked-eye detection. The photophysical
properties of PPM confirmed a 2:1 (PPMeHg2þ) binding model and the spectral response toward Hg2þ
was proved to be reversible.
Keywords:
Chemosensor
Hg2þ
Ó 2012 Elsevier Ltd. All rights reserved.
Pyrene
Pyrimidine
1. Introduction
moiety of monomer versus excimer.7 However, as far as we know,
only a few ratiometric fluorescent probes with one pyrene moiety
Currently, there is great interest in the development of highly se-
lective and sensitive fluorescent sensors for quantifying and exploring
the heavy and transition metal ions in biology and in the environ-
ment.1 Among these metal ions, mercury(II) has attracted consider-
able attention due to its toxicity to environment and biological
systems.2 For the past few years, many studies have been reported on
for metal ions have been found in the literature until now.8
Theoretically, fluorescent chemosensors consist of ion recogni-
tion unit attached with a fluorogenic unit. The recognition unit is
responsible for the selectivity and binding efficiency of the che-
mosensor.9 As a result, while designing sensors the recognition unit
linked to fluorophore should be carefully examined. Many hetero-
cycle, such as pyridine, quinoline, triazole, thiazole, pyrrole, or
imidazole etc., and their derivatives are utilized as recognition
unit.10 Pyrimidine is one of the important heterocycle with a variety
of biological and medicinal activities,11 and some of pyrimidine
derivatives are applied as photoelectric materials recently.12 How-
ever, the research using pyrimidine as recognition unit in chemo-
sensor has not yet been reported. Herein, we describe a new
ratiometric fluorescent probe with one pyrene moiety for metal
ions, using pyrimidine as recognition unit. The new pyr-
imidineepyrene derivative chemosensor PPM (Scheme 1) shows
a selective, sensitive, and reversible fluorescence change response
the design and synthesis of chemosensors for detecting Hg2þ 3
.
However, most of these chemosensors molecular to monitor metal
ions are often structurally complicated and require sophisticated
synthetic process. As a result, considerable efforts have been devoted
to design new and practical chemosensors for Hg2þ detection.
As fluorophores, pyrene moiety is one of the most useful scaf-
folds for the construction of fluorogenic chemosensors for a variety
of important chemical species.4 Depending on the relative prox-
imity between pyrene moieties, efficient, and sensitive monomer
emission at 370e430 nm and excimer emission around 480 nm are
observed.5 Upon coordination with a specific guest ion, the host
molecule could be fine-tuned to yield monomer and/or excimer
emissions depending on the orientation of the two pyrene moie-
ties.6 Many investigations have been conducted to fabricate ratio-
metric fluorescent sensors for Hg2þ, Cu2þ, Zn2þ, Cd2þ, and Agþ etc.,
by introducing two pyrene moieties and utilizing the pyrene
to the Hg2þ
.
N
N
O
CH3
Acetyl chloride
Dichloromethane
Triethyl orthoformate
Ammonium acetate
ZnCl2
Toluene
AlCl3 RT
100oC
* Corresponding authors. Tel.: þ86 25 8586 6008; fax: þ86 25 8586 6999;
e-mail addresses: iamqbmei@njupt.edu.cn (Q. Mei), iamwhuang@njupt.edu.cn,
iamdirector@fudan.edu.cn (W. Huang).
AP
PPM
Scheme 1. Synthetic route for PPM.
0040-4020/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2011.12.071

3130
J. Weng et al. / Tetrahedron 68 (2012) 3129e3134
0.8
0.7
700
600
500
400
300
200
100
0
2. Results and discussion
The synthetic route for PPM is shown in Scheme 1. The in-
termediate compound AP was synthesized from pyrene by classical
FriedeleCrafts reaction in 62% yield. PPM was synthesized by
ZnCl2-catalyzed three-component coupling reaction in 21% yield.13
0.6
0.5
0.4
0.3
0.2
0.1
0.0
The structure of the products was identified by using 1H NMR, 13
NMR, and GCeMS.
C
The chemosensor PPM displayed sensitive fluorescence change
via pyrimidine ring chelating with Hg2þ. Addition of 2 equiv of
various alkali, alkaline earth, and transition metal ions (Naþ, Kþ,
Mg2þ, Agþ, Cd2þ, Co2þ, Cr3þ, Cu2þ, Fe3þ, Hg2þ, Ni2þ, Pb2þ, Zn2þ) to
a solution of PPM (c¼1.25ꢀ10ꢁ4 M) in acetonitrile showed a selec-
tive fluorescence change from blue to green only in case of Hg2þ
(Fig. 1). This selective fluorescence change with PPM can be used
for the fluorescence detection of Hg2þ in solution (Fig. 1). Similar
fluorescence change was also observed with Hg2þ in the presence
of other ions in this study.
250
300
350
400
450
500
550
600
Wavelength (nm)
Fig. 2. UVevis and fluorescence spectra
(c¼5.0ꢀ10ꢁ5 M).
(
lex¼370 nm) of PPM in acetonitrile
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
Detailed optical studies were carried out to establish the se-
lective sensing between Hg2þ and PPM in acetonitrile. Because this
small organic molecule displayed not only absorption but also
emission variations depending on the metal ion present, so UVevis
and fluorescence measurements were investigated.
The absorption spectra of PPM in acetonitrile was typical of
those for other N-heterocycles with covalently bound pyrenyl
groups.14 As showed in Fig. 2, a long-wavelength absorption for
Ag+, Cd2+, Co2+, Cu2+, K+, Mg2+,
Na+, Ni2+, Pb2+, Zn2+ and blank
Hg2+
a pyrenyl-based
while the heterocyclic (pyrimidine)-based
centered at 279 nm. The chemosensor behavior in the presence
of 2 equiv of different metal ions (Naþ, Kþ, Mg2þ, Agþ, Cd2þ
p
e
p
* transition was found centered at 350 nm,
pep
* transition was
Fe3+
Cr3+
,
Co2þ, Cr3þ, Cu2þ, Fe3þ, Hg2þ, Ni2þ, Pb2þ, Zn2þ) indicated that
only Hg2þ promoted a notable response in its absorption spectra
(Fig. 3). Upon addition of Cr3þ and Fe3þ, although a weak new
peak at 430 nm was observed, the typical absorption of PPM at
244 nm, 279 nm, and 350 nm showed slight change in UVevis
spectra.
250
300
350
400
450
500
550
600
Wavelength (nm)
Fig. 3. UVevis spectra of PPM (c¼5.0ꢀ10ꢁ5 M) in the presence of metal ions in ace-
tonitrile. Agþ, Cd2þ, Co2þ, Cr3þ, Cu2þ, Fe3þ, Hg2þ, Mg2þ, Ni2þ, Naþ, Pb2þ, and Zn2þ ions
(2.0 equiv) were added, respectively.
Upon addition of Hg2þ, two strong new peaks at 300 nm and
415 nm were observed, with the peaks at 279 nm and 350 nm
disappeared. The peak at 415 nm in the case of Hg2þ could be at-
tributed to the formation of PPMeHg2þ chelating complex. The
Job’s plot (Fig. 4) for PPM titrated with Hg2þ revealed a 2:1 stoi-
chiometry of the complexation species.
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
-0.05
Systematic spectrophotometric titration with increasing [Hg2þ
]
revealed a gradual decrease of absorption band centered at 350 nm
with the concomitant increase in a new low-energy band centered
at 415 nm (Fig. 5). The spectra remained constant after adding
approximately 3 equiv of Hg2þ. The well-defined isosbestic points
at 322 nm and 369 nm clearly indicated the presence of a unique
complex in equilibrium with the free ligand. The new low-energy
band, which was red-shifted 65 nm, was responsible for the
change of color from colorless to yellow (inset of Fig. 5). In order to
confirm the stoichiometry of the formed complex, another titration
was carried out with increasing PPM (Fig. S2). From the analysis of
the absorption spectral data (Fig. 6), the binding of Hg2þ also
confirmed the formation of 2:1 (PPMeHg2þ) chelating complex,
and occurred in a ratiometric manner through a weakened PPM
0.0
0.2
0.4
0.6
0.8
1.0
[PPM]/[PPM]+[Hg2+]
Fig. 4. Job’s plot for evaluation of the 2:1 binding stoichiometry between PPM and
Hg(ClO4)2 in acetonitrile medium; the total [PPM]þ[Hg2þ]¼5.0ꢀ10ꢁ5 M.
Fig. 1. Changes in the color of PPM (c¼5.0ꢀ10ꢁ5 M) with 2 equiv of various metal ions in acetonitrile. Top: color changes by exciting at 360 nm; bottom: color changes for ‘naked-eye’.

J. Weng et al. / Tetrahedron 68 (2012) 3129e3134
3131
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
at 440 nm with a high quantum yield (V¼1.00). It was interesting
that the emission spectrum of PPM recorded at different concen-
tration in acetonitrile did not show any red-shifted emission
(Fig. S3). Sharp concentration quenching of emission at high con-
centration (c¼1.0ꢀ10ꢁ3 M) for PPM but with no concomitant red
shift in emission spectra, which indicated that PPM was mono-
meric in dilute acetonitrile solution rather than being associated via
blank
0.50eq
1.00eq
3.00eq
(a)
(b)
inter-molecular p-stacking interactions.
The fluorescence behavior of PPM in the presence of the Hg2þ
was examined. Upon gradual addition of Hg2þ (0e0.5 equiv) to the
solution of PPM in acetonitrile (c¼5.0ꢀ10ꢁ5 M), the intensity of the
emission band centered at 440 nm decreased gradually and that of
a new fluorescent band centered at 545 nm increased gradually,
which was attributed to the formation of PPMeHg2þ complex
(Fig. 7). As a result, an obvious change in fluorescent color from blue
to green was observed (inset of Fig. 7). The more addition of Hg2þ
(0.6e3.0 equiv), caused fluorescent quenching and showed a steady
and smooth decrease both at 410 nm and 545 nm (inset of Fig. 7).
Fitting of the titration curve also suggested a 2:1 stoichiometry
PPMeHg2þ complexation species. According to the literature,15 the
detection limit was also estimated from the titration results and
was 4.69ꢀ10ꢁ6 M.
250
300
350
400
450
500
550
600
650
Wavelength (nm)
Fig. 5. UVevis spectra of PPM in acetonitrile (c¼5.0ꢀ10ꢁ5 M) in the presence of in-
creasing amount of Hg(ClO4)2 (0e3.0 equiv) predissolved in acetonitrile. Arrows in-
dicate the absorptions that increase (up) and decrease (down) during the titration
experiments. Inset: change in the color of PPM after addition of 2 equiv of Hg(ClO4)2,
PPM in acetonitrile (a) and PPM plus 2 equiv of Hg(ClO4)2 in acetonitrile (b).
and ascending complex emission, which made it possible to ratio-
metrically detect Hg2þ
.
400
350
Hg
700
600
500
400
300
200
100
0
blank
Hg2+
0eq
PPM showed very strong fluorescence in acetonitrile (Fig. 1).
The emission spectrum displayed typical emission bands centered
0.50eq
300
250
200
150
100
50
0.50eq
3.00eq
(a)
0.50eq
700
0
400
450
500
550
600
650
700
600
500
400
300
200
100
0
Wavelength (nm)
(a)
(b)
400
450
500
550
600
650
700
750
Wavelength (nm)
Fig. 7. Fluorescence spectra of PPM in acetonitrile (5.0ꢀ10ꢁ5 M, lex¼400 nm) in the
presence of increasing amount of Hg(ClO4)2 (0e0.5 equiv) predissolved in acetonitrile.
Insets: (a) fluorescence spectra of PPM in the presence of increasing amount of
Hg(ClO4)2 (0.5e3.0 equiv). (b) Change in the fluorescence of PPM after addition of
2 equiv of Hg(ClO4)2. From left to right, PPM in acetonitrile and PPM plus 2 equiv of
Hg(ClO4)2 in acetonitrile.
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2
[Hg2+]/[PPM]
(b)
1.4
To explore practical applicability of PPM as a Hg2þ selective
chemosensor, a competition experiment was done. As showed in
Fig. 8, under the same condition slight fluorescence changes of PPM
were observed in the presence of 2 equiv of different metal ions
(Naþ, Kþ, Mg2þ, Agþ, Cd2þ, Co2þ, Ni2þ, and Pb2þ). By addition of
transition metal ions (Cu2þ, Cr3þ, Fe3þ), the fluorescent intensity of
PPM decreased to varying degrees, especially the addition of
2 equiv of Cr3þ or Fe3þ caused about 43% or 53% fluorescence de-
crease of PPM, respectively, but no any new emission band was
observed. And the addition of 2 equiv of Zn2þ caused a shoulder
band centered at 491 nm (Fig. S4); however, the intensity of the
peak at 440 nm decreased only 3%. A great difference between
addition of 2 equiv of Hg2þ and other metal ions was not only the
emission band centered at 440 nm disappeared almost, but also
a new band centered at 545 nm appeared. Thus PPM was more
sensitively to detect Hg2þ than other metal ions mentioned above.
Further more, upon addition of 2 equiv of Hg2þ to the solution,
which containing PPM and 2 equiv of competing metal ion, the
change of the emission was similar to that only 2 equiv of Hg2þ was
1.2
1.0
0.8
0.6
0.4
[PPM]/[Hg2+] = 1.89
0.2
0.0
0
1
2
3
4
5
[PPM]/[Hg2+]
Fig. 6. (a): The ratios of absorption at 350 nm to those at 415 nm (A350nm/A415nm) de-
pended on the ratios of [Hg2þ]/[PPM] upon addition Hg(ClO4)2 into a solution of PPM
(c¼5.0ꢀ10ꢁ5 M); (b): The variation of absorption at 415 nm depended on the ratios of
[PPM]/[Hg2þ] upon addition PPM into a solution of Hg(ClO4)2 (c¼5.0ꢀ10ꢁ5 M).

3132
J. Weng et al. / Tetrahedron 68 (2012) 3129e3134
PPM+Mn+
PPM+Mn++Hg2+
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
Blank Ag+ Cd2+ Co2+ Cr3+ Cu2+ Fe3+ K+ Mg2+ Na+ Ni2+ Pb2+ Zn2+ Hg2+
Fig. 8. Fluorescence responses of PPM in acetonitrile (5.0ꢀ10ꢁ5 M, lex¼400 nm) to
various 2 equiv of metal ions. Bars represent the final (I(440nm)) over the initial
(I0(440nm)) emission intensity. The black bars represent the addition of the competing
metal ion to the solution of PPM. The red bars represent the change of the emission
that occurs upon the subsequent addition of 2 equiv of Hg2þ to the above solution.
added to the PPM solution. As a result, PPM displayed selectivity to
detect Hg2þ
.
Reversibility and regeneration are important factors for che-
mosensor in practical applications.16 Because Iꢁ has strong binding
ability toward Hg2þ, KI was added to the solution of PPMeHg2þ
species to test whether the proposed complex could be reversed.
The introduction of KI (2 equiv to Hg2þ) could immediately restore
the initial fluorescence of PPM. When Hg2þ (1 equiv to PPM) was
added to system again, the fluorescence of PPM was quenched
(Fig. S6eS8). The regeneration indicated that the chemosensor
PPM could be revived with proper treatment. This process could be
repeated at least ten times (Fig. 9), which signified that PPM can
function as a fluorescent switch modulated by Hg2þ/KI (Fig. 9).
For our system, there were two potential binding sites in the
pyrimidine ring, however, all the analysis mentioned-above con-
firmed a 2:1 (PPMeHg2þ) binding model, thus it might be sug-
gested that only one of the nitrogen atoms in PPM operated. In
order to study the complexation mode of Hg2þ with PPM, a com-
parison of 1H NMR experiments of PPM with those of TPAPM
(diphenyl-(4-pyrimidin-4-yl-phenyl)-amine)17 and PPy (2-phenyl-
pyridine) were carried out. We performed 1H NMR experiments in
(DMSO-d6), which were shown in Fig. 10 and Fig. S9. Upon addition
of excessive Hg2þ, considerable change was noted in the chemical
shift of Hc in the pyrimidine group of PPM, which shifted to
downfield by 0.19 ppm. The proton signal of Hd in the pyrene ring
Fig. 10. (a) Molecular structure formulas of PPM, TPAPM, and PPy; (b) The 1H NMR
spectra of (1) PPM in DMSO-d6; (2)e(6) upon gradual addition of solid Hg(ClO4)2 to the
solution of PPM in DMSO-d6; (c) The 1H NMR spectra of (1) PPy in DMSO-d6; (2)e(3)
upon gradual addition of solid Hg(ClO4)2 to the solution of PPy in DMSO-d6.
was also shifted to downfield slightly. In the case of TPAPM, the
changes of chemical shift were almost the same as those of PPM.
However, treatment of excessive Hg2þ, the proton signal of Hb in
the pyridine group of PPy has nearly no change. Another difference
between PPy and PPM in the 1H NMR experiments was that the
proton signal of Hc in the phenyl of PPy shifted to upfield obviously.
These spectral changes might be suggested that Hg2þ was bound to
the 1-position nitrogen atom rather than the 3-position nitrogen
atom. Based on the result of the 1H NMR experiments, the possible
binding mechanism of PPM with Hg2þ was schematically depicted
in Scheme 2. Moreover, the formation of new chelating complex
between PPM and Hg2þ can be proved by the appearance of new
absorption band as well as red-shift emission band in UVevis
spectra and fluorescence emission spectra, respectively.
700
600
500
400
300
200
100
N
N
Hg2+
N
N
N
N
0
MeCN
blankHg1 KI1 Hg2 KI2 Hg3 KI3 Hg4 KI4 Hg5 KI5 Hg6 KI6 Hg7 KI7 Hg8 KI8 Hg9 KI9Hg10KI10
Fig. 9. Fluorescence intensity changes of PPM in acetonitrile (5.0ꢀ10ꢁ5 M, lex
¼
Scheme 2. The possible binding mechanism of PPM with Hg2þ
.
400 nm) upon alternate addition of Hg(ClO4)2 and KI.

J. Weng et al. / Tetrahedron 68 (2012) 3129e3134
3133
3. Conclusion
(100 mL) at 0 ꢂC. The mixture was stirred at room temperature over
night. The mixture was poured into 1 L deionized water slowly and
stirred for 2 h. And then, the mixture was separated, the organic
layer was collected, dried over anhydrous MgSO4, filtrated, and
concentrated. The residue was purified by silica gel column chro-
matography to give the compound AP (3.02 g, 62%) as light yellow
In summary, we have developed a novel fluorescent sensor for
Hg2þ based on the 4-pyren-1-yl-pyrimidine (PPM) with high sen-
sitivity and selectivity. This chemosensor was easily prepared and
found to be possible to detect the Hg2þ ratiometrically. The re-
markable photophysical properties of PPM confirmed
a
2:1
solid. 1H NMR (400 MHz, CDCl3):
d 9.08e9.05 (1H, d, ArH),
(PPMeHg2þ) binding model and the spectral response toward Hg2þ
was established to be reversible. More interestingly, the Hg2þ was
bound to the 1-position nitrogen atom of PPM, which has been
proposed on the basis of 1H NMR experiments. This work opens up
the possibility of a family of highly sensitive chemosensors for Hg2þ
based on 4-aryl-pyrimidine.
8.39e8.37 (1H, d, ArH), 8.26e8.21 (3H, m, ArH), 8.17e8.14 (2H, m,
ArH), 8.07e8.03 (2H, m, ArH), 2.91 (3H, s, CH3); 13C NMR (100 MHz,
CDCl3):
d 202.13, 133.99, 131.89, 131.87, 131.05, 130.49, 129.72,
129.61, 129.47, 127.11, 127.05, 126.38, 126.32, 126.08, 124.98, 124.26,
123.96, 30.46. GCeMS: M, found 244. C18H12O requires 244.29.
4.4.2. 4-Pyren-1-yl-pyrimidine (PPM). To a toluene (20 mL) solu-
tion of ZnCl2 (0.14 g, 1 mmol), and triethyl ortho-formate (5 mL,
30 mmol) were added AP (2.44 g, 10 mmol), and ammonium ace-
tate (1.54 g, 20 mmol). The mixture was heated at 100 ꢂC under
a nitrogen atmosphere for 48 h. A saturated aqueous solution of
NaHCO3 (100 mL) was added to the mixture to quench the reaction.
The mixture was extracted with CHCl3, and the organic extracts
were dried over anhydrous MgSO4, filtrated, and concentrated. The
crude product was purified by silica gel column chromatography to
give the compound PPM (0.59 g, 21%) as light yellow powder. 1H
4. Experimental
4.1. Materials and instrumentations
Acetonitrile was of high performance liquid chromatography
purity and used without further treatment. All other solvents and
reagents were of analytical purity and used without further
purification. The salts solutions of metal ions were NaNO3,
KNO3, Mg(ClO4)2, AgNO3, Cd(NO3)2$4H2O, Co(NO3)2$6H2O,
Cr(NO3)3$9H2O, Cu(NO3)2$3H2O, Fe(NO3)3$9H2O, Hg(ClO4)2$3H2O,
Ni(NO3)2$6H2O, Pb(NO3)2, Zn(NO3)2$6H2O. 1H NMR and 13C NMR
were measured on a Bruker Ultra Shield Plus 400 MHz spectrom-
eter with TMS as an internal standard and CDCl3/DMSO-d6 as sol-
vent. Mass spectrometric data were obtained with a Shimadzu GC-
MS-QP 2010 Plus spectrometry. UVevis spectra were recorded on
a Shimadzu UV-3600 UVevis-NIR spectrophotometer. Fluores-
cence spectra were determined with Shimadzu RF-5301PC lumi-
nescence spectrometer.
NMR (400 MHz, CDCl3):
d 9.49 (1H, s, pyrimidineeH), 8.93e8.92
(1H, d, pyrimidineeH), 8.51e8.49 (1H, d, pyreneeH), 8.21e8.04
(8H, m, pyreneeH), 7.80e7.79 (1H, d, pyrimidineeH); 13C NMR
(100 MHz, CDCl3):
d 166.84, 159.09, 157.04, 132.49, 132.46, 131.30,
130.74, 128.87, 128.77, 128.64, 127.51, 127.30, 126.34, 125.95, 125.63,
125.05, 124.91, 124.64, 123.95, 122.76; GCeMS: M, found 281.
C20H12N2 requires 280.32.
Acknowledgements
4.2. General procedures of spectra detection
This work was financially supported by the National Basic Re-
search Program of China (973 Program, 2009CB930601), the Na-
tional Natural Science Foundation of China (Project No. 50803027,
No. 50903001, No. 20905038), and the Natural Science Fund for
Colleges and Universities in Jiangsu Province (Grant No.
08KJD430020).
Solutions of Fe3þ, Cr3þ, Pb2þ were prepared in mixed solvent of
acetonitrile and deionized water (Vacetonitrile/Vdeionized
¼9:1).
water
Solutions of all other metal ions were prepared in acetonitrile. The
solutions of PPM and KI were also prepared in acetonitrile. In ti-
tration experiments, each time a 3 mL solution of PPM was filled in
a quartz optical cell of 1 cm optical path length, and the Hg2þ so-
lution was added into quartz optical cell gradually by using a micro-
pipette. Spectral data were recorded at 3 min after the addition.
Supplementary data
Supplementary data related to this article can be found online at
doi:10.1016/j.tet.2011.12.071.
4.3. Quantum yield measurement
References and notes
Fluorescence quantum yield was determined using optically
matching solutions of 9,10-diphenylanthracene (Ff¼0.9 in cyclo-
hexane) as standards at an excitation wavelength of 360 nm and
the quantum yield is calculated using Eq. 1.18
1. (a) Schrader, T.; Hamilton, A. Functional Synthetic Receptors; John Wiley: New
York, NY, 2005; (b) Anslyn, E. V. J. Org. Chem. 2007, 72, 687e699; (c) de Silva, R.
A. P.; Gunnlaugsson, T.; McCoy, C. P. J. Chem. Educ. 1997, 74, 53e58; (d) Bod-
enant, B.; Weil, T.; Businelli-Pourcel, M.; Fages, F.; Barbe, B.; Pianet, I.; Laguerre,
M. J. Org. Chem. 1999, 64, 7034e7039.
2. (a) Nadal, M.; Schuhmacher, M.; Domingo, J. L. Sci. Total Environ. 2004, 321,
59e69; (b) Fitzgerald, W. F.; Lamgorg, C. H.; Hammerschmidt, C. R. Chem. Rev.
2007, 107, 641e662; (c) Koester, C. J. Anal. Chem. 2005, 77, 3737e3754; (d) Ri-
chardson, S. D.; Ternes, T. A. Anal. Chem. 2005, 77, 3807e3838.
3. (a) Chen, P.; He, C. J. Am. Chem. Soc. 2004, 126, 728e729; (b) Ono, A.; Togashi, H.
Angew. Chem., Int. Ed. 2004, 43, 4300e4302; (c) Liu, B.; Tian, H. Chem. Commun.
2005, 3156e3158; (d) Wu, J. S.; Hwang, I. C.; Kim, K. S.; Kim, J. S. Org. Lett. 2007,
9, 907e910; (e) Nolan, E. M.; Lippard, S. J. Chem. Rev. 2008, 108, 3443e3480; (f)
Chen, X.; Baek, K. H.; Kim, Y.; Kim, S. J.; Shin, I.; Yoon, J. Tetrahedron 2010, 66,
4016e4021; (g) Mahato, P.; Ghosh, A.; Saha, S.; Mishra, S.; Mishra, S. K.; Das, A.
Inorg. Chem. 2010, 49, 11485e11492; (h) Lohani, C. R.; Kim, J. M.; Lee, K. H.
Tetrahedron 2011, 67, 4130e4136.
ꢀ
ꢁ
2
ðIunk=Aunk
Þ
hunk
hstd
Funk
¼
Fstd
(1)
ðIstd=Astd
Þ
Where Funk and Fstd are the fluorescence quantum yields of the
sample and the standard, respectively. Iunk and Istd are the in-
tegrated emission intensities of the sample and the standard, re-
spectively. Aunk and Astd are the absorbance of the sample and the
standard, respectively. And hunk and hstd are the refractive indexes
of the corresponding solutions.
4. (a) Winnik, F. M. Chem. Rev. 1993, 93, 587e614; (b) Nishzawa, S.; Kato, Y.; Ter-
amae, N. J. Am. Chem. Soc. 1999, 121, 9463e9464; (c) Sahoo, D.; Narayanaswami,
V.; Kay, C. M.; Ryan, R. O. Biochemistry 2000, 39, 6594e6601; (d) Kim, S. J.; Noh, K.
H.; Lee, S. H.; Kim, S. K.; Kim, S. K.; Yoon, J. J. Org. Chem. 2003, 68, 597e600; (e)
Yuasa, H.; Miyagawa, N.; Izumi, T.; Nakatani, M.; Izumi, M.; Hashimoto, H. Org.
Lett. 2004, 6,1489e1492; (f) Moon, S. Y.; Youn, N. J.; Park, S. M.; Chang, S. K. J. Org.
Chem. 2005, 70, 2394e2397; (g) Jun, E. J.; Won, H. N.; Kim, J. S.; Lee, K. H.; Yoon, J.
4.4. Synthesis
4.4.1. 1-Pyren-1-yl-ethanone (AP). A mixture of AlCl3 (2.95 g,
22 mmol), acetyl chloride (1.6 mL, 22 mmol) in CH2Cl2 (50 mL) was
added dropwise to a solution of pyrene (4.04 g, 20 mmol) in CH2Cl2

3134
J. Weng et al. / Tetrahedron 68 (2012) 3129e3134
Tetrahedron Lett. 2006, 47, 4577e4580; (h) Park, S. M.; Kim, M. H.; Choe, J. I.; No,
K. T.; Chang, S. K. J. Org. Chem. 2007, 72, 3550e3553.
607e609; (d) Liu, L.; Zhang, G.; Xiang, J.; Zhang, D.; Zhu, D. Org. Lett. 2008, 10,
4581e4584; (e) Li, Z.; Lou, X.; Yu, H.; Li, Z.; Qin, J. Macromolecules 2008, 41,
7433e7439; (f) Wan, Y.; Niu, W.; Behof, W. J.; Wang, Y.; Boyle, P.; Gorman, C. B.
Tetrahedron 2009, 65, 4293e4297; (g) Suresh, M.; Mandal, A. K.; Saha, S.;
Suresh, E.; Mandoli, A.; Liddo, R. D.; Parnigotto, P. P.; Das, A. Org. Lett. 2010, 12,
5406e5409.
5. (a) Fabbrizzi, L.; Poggi, A. Chem. Soc. Rev. 1995, 24, 197e202; (b) Birks, J. B.
Photophysics of Aromatic Molecules; Wiley Inter-Science: London, 1970.
6. (a) Shiraishi, Y.; Tokitoh, Y.; Hirai, T. Org. Lett. 2006, 8, 3841e3844; (b) Kim, H. J.;
Hong, J.; Hong, A.; Ham, S.; Lee, J. H.; Kim, J. S. Org. Lett. 2008, 10, 1963e1966;
(c) Jung, H. S.; Park, M.; Han, D. Y.; Kim, E.; Lee, C.; Ham, S.; Kim, J. S. Org. Lett.
2009, 11, 3378e3381.
11. Jain, K. S.; Chitre, T. S.; Miniyar, P. B.; Kathiravan, M. K.; Bendre, V. S.; Veer, V. S.;
Shahane, S. R.; Shishoo, C. J. Curr. Sci. 2006, 90, 793e803.
7. (a) Kim, J. S.; Choi, M. G.; Song, K. C.; No, K. T.; Ahn, S.; Chang, S. K. Org. Lett.
2007, 9, 1129e1132; (b) Park, S. Y.; Yoon, J. H.; Hong, C. S.; Souane, R.; Kim, J. S.;
Matthews, S. E.; Vicens, J. J. Org. Chem. 2008, 73, 8212e8218; (c) Zhou, Y.; Zhu,
C. Y.; Gao, X. S.; You, X. Y.; Yao, C. Org. Lett. 2010, 12, 2566e2569; (d) Kumar, M.;
Kumar, R.; Bhalla, V. Org. Lett. 2011, 13, 366e369; (e) Martínez, R.; Espinosa, A.;
12. (a) Wong, K. T.; Hung, T. S.; Lin, Y.; Wu, C. C.; Lee, G. H.; Peng, S. M.; Chou, C. H.;
Su, Y. O. Org. Lett. 2002, 4, 513e516; (b) Wu, C. C.; Lin, Y. T.; Chiang, H. H.; Cho, T.
Y.; Chen, C. W. Appl. Phys. Lett. 2002, 81, 577e579; (c) Hughes, G.; Wang, C.;
Batsanov, A. S.; Fern, M.; Frank, S.; Bryce, M. R.; Perepichka, I. F.; Monkman, A.
P.; Lyons, B. P. Org. Biomol. Chem. 2003, 1, 3069e3077; (d) Lin, C. F.; Huang, W.
S.; Chou, H. H.; Lin, J. T. J. Organomet. Chem. 2009, 694, 2757e2769; (e) Ge, G.;
He, J.; Guo, H.; Wang, F.; Zou, D. J. Organomet. Chem. 2009, 694, 3050e3057; (f)
Wang, Z. Q.; Xu, C.; Dong, X. M.; Zhang, Y. P.; Hao, X. Q.; Gong, J. F.; Song, M. P.;
Ji, B. M. Inorg. Chem. Commun. 2011, 14, 316e319; (g) Su, S. J.; Cai, C.; Kido, J.
Chem. Mater. 2011, 23, 274e284.
ꢀ
Tarraga, A.; Molina, P. Tetrahedron 2010, 66, 3662e3667; (f) Hou, C.; Xiong, Y.;
Fu, N.; Jacquot, C. C.; Squier, T. C.; Cao, H. Tetrahedron Lett. 2011, 52, 2692e2696;
(g) Liu, X.; Yang, X.; Fu, Y.; Zhu, C.; Cheng, Y. Tetrahedron 2011, 3181e3186.
8. (a) Caballero, A.; Martínez, R.; Lloveras, V.; Ratera, I.; Vidal-Gancedo, J.; Wurst,
ꢀ
K.; Tarraga, A.; Molina, P.; Veciana, J. J. Am. Chem. Soc. 2005, 127, 15666e15667;
ꢀ
(b) Martínez, R.; Zapata, F.; Caballero, A.; Espinosa, A.; Tarraga, A.; Molina, P.
13. Sasada, T.; Kobayashi, F.; Sakai, N.; Konakahara, T. Org. Lett. 2009, 11, 2161e2164.
14. Simon, J. A.; Curry, S. L.; Schmehl, R. H.; Schatz, T. R.; Piotrowiak, P.; Jin, X.;
Thummel, R. P. J. Am. Chem. Soc. 1997, 119, 11012e11022.
Org. Lett. 2006, 8, 3235e3238.
9. (a) Valeur, B.; Leray, I. Coord. Chem. Rev. 2000, 205, 3e40; (b) Nohta, H.; Sato-
zono, H.; Koiso, K.; Yoshida, H.; Ishida, J.; Yamaguchi, M. Anal. Chem. 2000, 72,
4199e4202; (c) Okamoto, A.; Ichiba, T.; Saito, I. J. Am. Chem. Soc. 2004, 126,
8364e8365.
10. (a) Ojida, A.; Mito-oka, Y.; Sada, K.; Humachi, I. J. Am. Chem. Soc. 2004, 126,
2454e2463; (b) Cao, Y.; Zheng, Q.; Chen, C.; Huang, Z. Tetrahedron Lett. 2003,
44, 4751e4755; (c) Coskun, A.; Yilmaz, M. D.; Akkaya, E. U. Org. Lett. 2007, 9,
15. Shortreed, M.; Kopelman, R.; Kuhn, M.; Hoyland, B. Anal. Chem. 1996, 68,
1414e1418.
16. Nolan, E. M.; Racine, M. E.; Lippard, S. J. Inorg. Chem. 2006, 45, 2742e2749.
17. TPAPM was synthesized from triphenylamine by two steps. The synthetic route
for TPAPM and characterization were shown in supplementary data.
18. Hamai, S.; Hirayama, F. J. Phys. Chem. 1983, 87, 83e89.