Quinoline-substituted zinc(II) phthalocyanine for the dual detection of ferric and zinc ions

Article abstract of DOI:10.1002/bkcs.10402

Here we present the synthesis and properties of quinoline-substituted zinc(II) phthalocyanine, Zn[Pc(O-QN)₄]. Zn[Pc(O-QN)₄] can function as a highly selective chemosensor against Fe³⁺ and Zn²⁺ ions, exhibiting e

Full text of DOI:10.1002/bkcs.10402

Article
DOI: 10.1002/bkcs.10402
BULLETIN OF THE
A. Gupta et al.
KOREAN CHEMICAL SOCIETY
Quinoline-substituted Zinc(II) Phthalocyanine for the Dual Detection
of Ferric and Zinc Ions
Ankush Gupta,† A-Rong Kim,‡ Kyung-Sub Kim,§ Kun Na,§ Myung-Seok Choi,¶ and Jong S. Parkk,
*
†Department of Applied Sciences, Lyallpur Khalsa College of Engineering, Jalandhar 144001, India
‡Department of Organic Material and Polymer Engineering, Dong-A University, Busan 49315, Korea
§Department of Biotechnology, The Catholic University, Seoul 14647, Korea
¶Department of Materials Chemistry and Engineering, Konkuk University, Seoul 05030, Korea
kDepartment of Organic Material Science and Engineering, Pusan National University, Busan 46241, Korea.
*E-mail: jongpark@pusan.ac.kr
Received February 17, 2015, Accepted April 23, 2015, Published online August 10, 2015
Herewepresentthesynthesisandpropertiesofquinoline-substitutedzinc(II)phthalocyanine,Zn[Pc(O-QN)4]. Zn
[Pc(O-QN)4] can function as a highly selective chemosensor against Fe3+ and Zn2+ ions, exhibiting efficient
fluorescencequenchingandenhancement, respectively. Variouscharacterizationtechniqueswereemployedto
investigate the intermolecular interactions of Zn[Pc(O-QN)4] with metal ions. A double-electron exchange and
a forbidden photoinduced electron transfer behavior in Zn[Pc(O-QN)4] were attributed to such opposite
responses. Furthermore, by taking advantage of selectivity, we successfully employed Zn[Pc(O-QN)4] to stain
and record confocal fluorescence microscopy images of Chang liver cells in the presence of metal ions.
Keywords: Phthalocyanine, Stern–Volmer constant, Quinolone-substituted, Fluorescence quenching,
Dual detection
Introduction
was found to be effective for the dual detection of Fe3+ and
Zn2+ in mixed aqueous media. We chose phthalocyanine as
a core moiety as it exhibits a high degree of thermal and
photostability,12 with a quinoline moiety as the binding sites
for the metal ions. The strong absorption and emission in
the far-visible region by Zn[Pc(O-QN)4] makes it suitable
for practical metal ion detections. When the binding behavior
of the phthalocyanine derivative was examined, Zn[Pc(O-
QN)4] exhibited selective and discriminatory responses
toward Fe3+ and Zn2+ ions. There have been few reports thus
far in the literature aboutapplications in which phthalocyanine
derivatives are shown to be feasible for detecting these
metal ions.
The development of chemosensors for the selective and sensi-
tive detection of metal ions is an important research area.1–3
Among various physiologically relevant metal ions, Fe3+
plays a crucial role in many biochemical processes, such as
the oxygen uptake of heme and oxygen metabolism, and
serves as a cofactor in many enzymatic reactions.4,5 In addi-
tion, the concentration of Fe3+ should be moderate, as both
insufficiency and excess can lead to a variety of diseases, such
as anemia, hepatic cirrhosis, and hereditary hemochromato-
sis.6 Meanwhile, Zn2+ is the second most abundant
transition-metal ion, next to iron, present in the human body.
Itisamongthemost importantmetalsinthecatalytic andstruc-
tural cofactors of Zn2+-containing enzymes and DNA-binding
proteins.7 Further, zinc is involved in various biological pro-
cesses, such as brain functions and related pathology, gene
transcription, immune function, and mammalian reproduc-
tion.8 Given the importance of Fe3+ and Zn2+ ions in daily life,
diverse efforts have been made to develop chemosensors for
the detection of Fe3+ and Zn2+ ions.9,10 However, the detection
of these ions in aqueous/mixed aqueous media remains a chal-
lenge since most sensors reported thus far worked well in an
organic solvent medium and were subjected to interference
from other metal ions. In light of this, fluorescent molecules
soluble in aqueous/mixed aqueous media need to be devel-
oped, as they can be adopted for sensitive and efficient ana-
lyses in living cells.11
Experimental
Materials. The chemicals used in the synthesis, such as
4-nitro-phthalonitrile, 8-hydroxyquinoline, zinc(II) acetate
Zn(CH3CO2)2, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU),
dimethylformamide (DMF), and K2CO3, were purchased from
Sigma-Aldrich (Seoul, Korea) and were used as received.
Synthesis
Intermediate 2. 4-Nitro-phthalonitrile (1.00 g, 5.77 mmol),
8-hydroxyquinoline (1.0 g, 6.93 mmol), and K2CO3 (3.18,
23.08 mmol) were heated to 60 ꢀC in dimethylformamide
(DMF) (20 mL) with stirring overnight. After the reaction
was complete, the mixture was cooled to room temperature.
Excess DMF was removed under reduced pressure. The crude
product was dissolved in 250 mL of CHCl3 and washed with a
large amount of water. After the removal of the CHCl3, the
In this paper, we report the synthesis of a quinoline-
substituted zinc(II) phthalocyanine, Zn[Pc(O-QN)4], which
Correction added on 01 October 2015, after first online publication: ISSN (Print) has been corrected.
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crude product was purified by silica gel column chromatogra-
CO2 at 37 ꢀC. Chang liver cells (1 × 106 cell/well) were seeded
in a 35-mm dish and cultured in 5% CO2 for 24 h. The medium
was replaced by a serum-free medium containing different
concentrations of Fe3+ (5, 15 μM) and Zn2+ (5, 15 μM). After
6 h, the medium was removed completely. The cells were then
rinsed twice with Bulbecco's phosphate buffered saline
(DPBS) and incubated with a serum-free medium containing
5 μM Zn[Pc(O-QN)4]. After incubation for 12 h, confocal
laser scanning microscopy images were analyzed using an
LSM 510 Meta instrument (Zeiss, Germany). The fluores-
cence images were analyzed using LSM Image Browser soft-
ware (Zeiss).
phy using hexane/CHCl3 as eluent, and compound 2 was
1
obtained as a white powder. H-NMR (400 MHz, CDCl3):
δ = 7.19 [s, 1H, ArH], 7.25–7.28 [m, 1H, ArH], 7.49–7.53
[m, 2H, ArH], 7.63 [t, 1H, J = 8 Hz, ArH], 7.70 [d, 1H, J = 8
Hz, ArH], 7.84 [q, 1H, J = 4 Hz, ArH], 8.28 [q, 1H, J = 8 Hz,
ArH], 8.84–7.86 [m, 1H, ArH]; 13C-NMR (400 MHz, CDCl3):
δ = 162.61, 151.05, 149.27, 141.00, 136.59, 135.35, 130.39,
126.92, 126.70, 122.49, 121.44, 121.35, 121.13, 117.51,
115.68, 115.25, 108.69 ppm; ESI-Mass: 272.08 (M + 1)+; Ele-
mental analysis (for C17H9N3O): C 75.27, H 3.34, N 15.49
(Calcd.); C 75.62, H 3.45, N 15.56 (measured).
Zn[Pc(O-QN)4]. Intermediate 2 (0.2 g, 0.737 mmol) and
Zn(OAc)2 (0.041 g, 0.184 mmol) were dissolved in 3 mL of
DMF. After DBU (1,8-diazabicyclo[5.4.0]undec-7-ene, 0.2
mL, catalyst) was added to the reaction mixture, the mixture
was stirred and heated to 145 ꢀC and then refluxed for 15 h.
After the reaction was complete, the mixture was cooled to
room temperature. Excess DMF was removed under reduced
pressure. The crude product was dissolved in 250 mL of
CHCl3 and washed with a large amount of water. After the
removal of the CHCl3, the crude product was purified by silica
gel column chromatography using CHCl3/MeOH as eluent,
and the compound was obtained as a deep greenish powder.
1H-NMR (400 MHz, CDCl3): δ = 7.47–7.77 [m, 24H, ArH],
Results and Discussion
The intermediate 2 was prepared via the reaction of
4-nitrophthalonitrile with 8-hydroxyquinoline in the presence
of K2CO3 and DMF, which was confirmed by 1H-NMR mea-
surements (Figure S1). Further, the cyclotetramerization with
zinc acetate in the presence of DBU as a strong base resulted in
the formation of the quinoline-substituted zinc
(II) phthalocyanine, Zn[Pc(O-QN)4] (Scheme 1). The struc-
ture of Zn[Pc(O-QN)4] was confirmed by 1H-NMR and
MALDI-MS measurements (Figures S2 and S3).
Zn[Pc(O-QN)4] showed well-defined UV–vis spectra, with
sharp Q-bands in the 590–710 nm region, indicating mono-
meric species in solution (Figure 1(a)). While no significant
features were observed in the B-bands, the Q-band of Zn[Pc
(O-QN)4] showed maximum absorption at 680 nm with a
shoulder at 615 nm. According to aprevious report,13 thesplit-
ting of the Q-band was attributed to extended π-conjugation as
a consequence of intramolecular electronic coupling between
the phthalocyanine subunits. In the fluorescence emission
spectrum collected with excitation at 350 nm, Zn[Pc(O-
QN)4] exhibited a mirroring of the Q-band, with a strong fluo-
rescence emission band at 694 nm.
1
8.24 [s, 6H, ArH], 8.89 [s, 6H, ArH]; H-NMR (400 MHz,
CDCl3): δ = 7.47–7.77 [m, 24H, ArH], 8.24 [s, 6H, ArH],
8.89 [s, 6H, ArH]; MALDI: 1151.286 (M + 1)+; Elemental
analysis (for C68H36N12O4Zn ꢁ 4H2O): C 66.80, H 3.63, N
13.75 (Calcd.); C 66.69, H 3.45, N 13.09 (measured).
Property Investigation. The UV–vis and photolumines-
cence emission spectra were obtained from a Lambda 7 spec-
trometer (Perkin Elmer, Waltham, MA, USA) and an LS-45
spectrofluorophotometer (Perkin Elmer), respectively. Scan-
ning electron microscopy (SEM) images were obtained
using an FE-SEM apparatus (JSM 6700F, JEOL, Tokyo,
Japan). The Fourier transform infrared (FT-IR) spectra were
collected by an Avatar 370 FT-IR spectrometer, and the
Raman spectra were measured using a confocal Raman spec-
trometer with a laser excited at 532 nm (NTEGRA Spectra,
NT-MDT, Moscow, Russia). X-ray photoelectron spectros-
copy (XPS) measurements were performed on an ESCALAB
250 XPS system (Thermo Fisher Scientific/UK, Korea Basic
Science Institute, KBSI) with Al Kα radiation (1486.6 eV) as
the X-ray source. Matrix-assisted laser desorption/ionization
mass spectrometry (MALDI-MS) measurements were carried
out by employing α-cyano-4-hydroxy cinnamic acid as matrix
(KBSI). Electrospray ionization mass spectrometry (ESI-MS)
measurements were carried out using a Synapt G2 spectrom-
eter equipped with a time-of-flight (TOF) analyzer (Waters/
UK, KBSI).
The attachment of the quinoline moiety, a well-known
metal capture agent, in the phthalocyanine core encouraged
us to determine its sensing behavior toward different metal
ions. The binding behavior of Zn[Pc(O-QN)4] was investi-
gated toward various cations. In H2O/THF (1:1) mixtures,
Zn[Pc(O-QN)4] showed increased absorbance after adding
N
O
CN
CN
O
N
N
O
CN
CN
N
Zn
N
O2N
K2CO3
DMF
Zn(OAc)2
N
N
N
N
O
N
N
OH2
N
DMF
DBU,
N
2
O
N
Cell Culture and Fluorescence Imaging. Chang liver cells
were acquired from American Type Culture Collection
(ATCC CCL 13, USA) and cultured in Eagle's Medium with
Earle's BSS and 2 mM L-glutamine (EMEM) containing 10%
fetal bovine serum and 1% streptomycin–ampicillin under 5%
Zn[Pc(O-QN)4]
Scheme 1. Synthesis of an intermediate 2 and a quinoline-substituted
phthalocyanine Zn[Pc(O-QN)4], using a Synapt G2 spectrometer
equipped with a time-of-flight (TOF) analyzer (Waters/UK, KBSI).
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Quinoline-substituted Zinc(II) Phthalocyanine
KOREAN CHEMICAL SOCIETY
Fe3+, with a small leveled-off tail, which suggested that
phthalocyanine interacting with ferric ions formed larger
aggregates, leading to a scattering phenomenon.14,15 Fluores-
cence with various metals revealed that Zn[Pc(O-QN)4]
responded selectively for Fe3+ and Zn2+ but in opposite direc-
tions (Figure 1(b)). The emission band at 694 nm decreased
with increasing amounts of Fe3+ ions but increased with the
amount of Zn2+ ions. These optical changes could be observed
easily by the naked eye under UV illumination at 365 nm
(Figure 1(b, inset)). The interaction between Zn[Pc(O-
QN)4] and Fe3+ ions was quantitated by a Stern–Volmer plot
(Figure 1(c)), which shows a linear curve of the fluorescence
intensity ratio (Io/I) at low concentrations of the Fe3+ ions. The
plots bend upward at highers concentration of Fe3+ ions, as the
mechanism involved in the quenching of the emission of
Zn[Pc(O-QN)4] by Fe3+ ions is complexation rather than col-
lisional deactivation.16 From the linear part of the slope at low
concentrations, the Stern–Volmer constant KSV was found to
be 4.2 × 103 M−1 from the equation I0/I = KSV[A] + 1, where I0
and I, are respectively, the fluorescence intensity levels before
and after the addition of Fe3+ ions, [A] is the molar concentra-
tion of Fe3+ ions, and KSV is the quenching constant. In con-
trast, the addition of Zn2+ ions to the solution of Zn[Pc(O-
QN)4] resulted in an enhancement of the emission (Figure 1
(d)). No noticeable change in the fluorescence emission
of Zn[Pc(O-QN)4] was observed with ions other than Fe3+
and Zn2+.
The FT-IRspectra of Zn[Pc(O-QN)4]afterbeing exposedto
Fe3+ and Zn2+ ions showed significant changes compared to
pristine phthalocyanine (Figure 2(a)). The absorption band
at 1609 cm−1 was attributed to the C N/C C stretching of
the quinoline fragment, which suggests that the quinoline moi-
ety was successfully embedded into the phthalocyanine core.
The intermolecular interaction was supported by the shifting
of the IR absorption band at 1609 cm−1 to a higher frequency
at 1616 cm−1 upon complexation with Fe3+ ions. A similar
shift was observed after exposure to Zn2+ ions. Meanwhile,
distinct transitions were observed at 1088, 1128, 1217,
1340, 1433, and 1516 cm−1 in the Raman spectrum of Zn
[Pc(O-QN)4] (Figure 2(b)). These transitions were assigned
to the phthalocyanine skeletal modes that may involve the
Zn–N and C–H vibrational motion of zinc phthalocyanine
andpendant tetraannulenes, as well as C–H vibrational motion
of the quinoline moiety. In the presence of Fe3+ and Zn2+ ions,
while these skeletal modes were still observable, the peaks at
1433and1516 cm−1 shiftedtohighervalues of1439and1521
cm−1, respectively. This indicates that, as a consequence of the
complex formations between Zn[Pc(O-QN)4] and metal ions,
conjugation is considerably reduced, leading to a shifting of
the peaks toward higher wavenumbers. Further, the binding
of Fe3+ and Zn2+ ions with the Pc derivative was also proved
by ESI-MS (Figure 2(c)). The mass spectrum of Zn[Pc(O-
QN)4] with the Fe3+ and Zn2+ ions showed peaks at m/z
114.99 and 176.91, corresponding to the [Pc-4Fe]12+ and
[Pc-4Zn]8+complexes, which confirms the binding of Fe3+
and Zn2+ ions with Zn[Pc(O-QN)4] and shows the 1:4 stoichi-
ometry of the host and guest species.
To gain further insight into the mode of interaction, we
recorded the XPS spectra of Zn[Pc(O-QN)4] in the presence
of Fe3+ and Zn2+ ions. A strong absorption peak around
1027 eV was observed, which was attributed to the typical sig-
nals for Zn2+ 2p3/2 (Figure 2(d)). In the presence of Fe3+ ions, a
(a)
(b)
Zn[Pc(O-QN)4]
with Fe3+
Zn[Pc(O-QN)4]
with Zn2+
with Fe3+
with Zn2+
1800
1600
1400
1200
1000
800
600
300
600
900
1200
1500
1800
Wavenumber (cm-1)
m/z
Raman shift (cm-1)
110
115
120
125
130
(c)
(d)
Figure 1. (a) UV–vis (red) and PL (blue) spectra of Zn[Pc
(O-QN)4]. Both intensities are normalized. (b) Selectivity of Zn
[Pc(O-QN)4] (1 × 10−5 M) toward different metals ions. Bars repre-
sent the emission intensity ratio (I0 –I)/I0 × 100 (I0 = initial fluores-
cence intensity at 694 nm, I = final fluorescence intensity at 694
nm after the addition of subsequent addition of different metal ions
[100 equiv]). The inset shows a photograph (under 365 nm UV light)
uponthe addition of100 equiv ofvarious metal ions. (c) Fluorescence
spectra of Zn[Pc(O-QN)4] (10 μM) with the addition of Fe3+ ions
(100 equiv). The inset shows a Stern–Volmer plot in response to
Fe3+ ions. (d) The titration and Stern-Volmer plots with Zn2+
(0–100 equiv.), under identical conditions as in (c), are presented.
Zn[Pc(O-QN)4]
with Fe3+
with Zn2+
with Fe3+
O1s
Zn2+ 2p
C1s
N1s
400
with Zn2+
174 176 178 180 182 184 186 188 190
1200
1000
800
600
200
0
m/z
Binding energy (eV)
Figure 2. (a) FT-IR, (b) Raman, (c) ESI-MS, and (d) XPS spectra of
Zn[Pc(O-QN)4] in the absence (black) and presence of Fe3+ (red) and
Zn2+ (blue) ions.
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Quinoline-substituted Zinc(II) Phthalocyanine
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slight chemical shift in the signals to a higher binding energy
level was observed. In addition, peak broadening correspond-
ing to Zn2+ 2p3/2 at 1027 eV was noted, along with the disap-
pearance of the peak signal of N 1s at 403.6 eV. However, no
significant change in the O 1s peak was observed. From these
results, we can conclude that Fe3+ ions interact by masking the
nitrogen atoms of the quinoline moiety of Zn[Pc(O-
QN)4]. Meanwhile, in the presence of Zn2+ ions, compared
to pristine Zn[Pc(O-QN)4], the signals from N 1s and O 1s
were found to have shifted to a higher binding energy, from
403.6 to 404.21 eV and from 536.8 to 537.2 eV, respectively.
These shifts indicate that Zn2+ ions interact via the quinoline
nitrogen and ethereal oxygen of the phthalocyanine Zn[Pc
(O-QN)4].
occupied molecular orbital (HOMO) of the phthalocyanine
derivative. Hence, this double-electron exchange returns the
fluorophore to its ground state following a nonradiative proc-
ess, resulting in fluorescence quenching.17 Meanwhile, for
Zn2+ ions, the formation of the complex takes place via inter-
actions with a nitrogen atom of a quinoline moiety and via
ethereal oxygen, which restricts the photoinduced electron
transfer (PET) to the photoexcited phthalocyanine core; hence
theenhancementintheobservedfluorescence intensity. Based
on these findings, the complex structure of the derivative Zn
[Pc(O-QN)4] with Fe3+ and Zn2+ ions can be reasonably
deduced (Figure 5).
For comparison, we prepared a model compound Zn[Pc(t-
Bu)4] (Figure 3(a)) in which no quinoline moiety was present.
Under a condition similar to that used for Zn[Pc(O-QN)4], we
studied the sensing behavior of this derivative with Fe3+ and
Zn2+ ions. A much lower degree of quenching (only less than
40%) in the fluorescence emission of Zn[Pc(t-Bu)4] was
observed with Fe3+ ions, and no change in the emission was
observed with Zn2+ ions (Figure 3(b) and (c)). Through this
comparison, it was confirmed that Fe3+ and Zn2+ ions predom-
inantly interact with the quinoline moiety of Zn[Pc(O-QN)4].
In order to examine the morphological behaviors of the
complex, we carried out SEM studies of Zn[Pc(O-QN)4] in
a solvent mixture of H2O/THF (1:1). SEM images of Zn[Pc
(O-QN)4] in this solvent show the presence of spherical aggre-
gates (Figure 4(a)), whereas the images of Zn[Pc(O-QN)4] in
the presence of Fe3+ ions show aggregates with irregular
shapes but not spherical aggregates (Figure 4(b)). This obser-
vation clearly indicates the formation of the complex. Simi-
larly, the SEM images of Zn[Pc(O-QN)4] in the presence of
Zn2+ ions show aggregates with irregular shapes, but these
were found to differ from those of the derivative Zn[Pc(O-
QN)4] in the presence of Fe3+ ions (Figure 4(c)).
Figure 4. (a) SEM images of Zn[Pc(O-QN)4] in a solvent mixture of
H2O/THF (1:1) showing the presence of spherical aggregates. (b) Zn
[Pc(O-QN)4] in the presence of 100 equiv of Fe3+ ions and (c) Zn[Pc
(O-QN)4] in the presence of 100 equiv of Zn2+ ions show the irreg-
ularly shaped large aggregates.
In light of these results, it is envisioned that the response of
Zn[Pc(O-QN)4] involves different binding modes in the cases
of Fe3+ and Zn2+ ions. It is suggested that for Fe3+ ions, the
formation of the complex takes place via interaction only with
a nitrogen atom of a quinoline moiety, leading to a transfer of
an electron from the lowest unoccupied molecular orbital
(LUMO) of Zn[Pc(O-QN)4] to one of the d orbitals of the
Fe3+ ions. This electron is then transferred to the highest
(a)
(b)
(c)
Fe3+
tBu
tBu
N
Zn
N
N
N
N
N
N
N
tBu
tBu
600
650
700
750
800
600
650
700
750
800
Wavelength (nm)
Wavelength (nm)
Figure 3. (a) Chemical structure of the model compound Zn[Pc
(t-Bu)4]. Fluorescence spectra of Zn[Pc(t-Bu)4] (10 μM) with the
addition of (b) Fe3+ (100 equiv) and (c) Zn2+ ions (100 equiv) in
H2O/THF (1:1) mixture.
Figure 5. Proposed representation of the complex structures of Zn[Pc
(O-QN)4] with Fe3+: [Pc-4Fe]12+ (a) and Zn2+ [Pc-4Zn]8+ (b).
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Quinoline-substituted Zinc(II) Phthalocyanine
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alternativesto enzyme-based colorimetric assays in diagnostic
applications.
(a)
(b)
(d)
(f)
Acknowledgment. This work was supported by the Technol-
ogy Innovation Program (No. 10047756, Development of
tetra-pyrrole type for color, light-emitting, detecting devices)
funded by the Ministry of Trade, Industry & Energy
(MI, Korea).
20µm
(c)
(e)
Supporting Information. Additional 1H-NMR and MALDI-
Mass data are provided.
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Figure 6. Bright-field images (left) and corresponding confocal fluo-
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Inspired by the above results, we further investigated the
applicability of Zn[Pc(O-QN)4] in cell imaging. Images were
recorded after laser excitation at 488 nm and using emission
wavelengths around 655 nm for red fluorescence. As shown
in Figure 6, Zn[Pc(O-QN)4] was successfully employed in
the staining of Chang liver cells, which exhibited a red emis-
sion. After pre-incubation with Fe3+, the fluorescence inten-
sity was found to decrease and be completely quenched at
a higher concentration of 15 M. In comparison, enhanced
emission with excellent cell permeability was recorded after
pre-incubation with Zn2+. These observations clearly demon-
strated that Zn[Pc(O-QN)4] was biocompatible and useful for
detecting Fe3+ andZn2+ ionsinsidecells due tohigh selectivity
of the receptor toward metal ions.
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Conclusion
We have presented quinoline-substituted Zn(II) phthalocya-
nine, Zn[Pc(O-QN)4], which can function as a highly selective
chemosensor for Fe3+ and Zn2+. Zn[Pc(O-QN)4] showed
selective and efficient fluorescence quenching toward Fe3+
ions and fluorescence enhancement toward Zn2+ ions.
Various characterization techniques were employed to inves-
tigate the intermolecular interaction between Zn[Pc(O-QN)4]
and metal ions. Combined experimental results revealed
that the main cause of the different behaviors of Zn[Pc(O-
QN)4] in the presence of Fe3+ and Zn2+ ions is the different
modes of interaction resulting from the discriminating detec-
tions of Fe3+ and Zn2+ ions. In addition, Zn[Pc(O-QN)4] was
successfully employed to stain Chang liver cells for fluores-
cent imaging in the absence and presence of metal ions.
We believe that the approach presented here would be
useful for the development of effective chemosensor
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© 2015 Korean Chemical Society, Seoul & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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BULLETIN OF THE
Article
Quinoline-substituted Zinc(II) Phthalocyanine
KOREAN CHEMICAL SOCIETY
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www.bkcs.wiley-vch.de 2184