Metal ion sensing soluble α or β tetrasubstituted gallium and indium phthalocyanines: Synthesis, characterization, photochemistry and aggregation behaviors

Article abstract of DOI:10.1016/j.poly.2015.07.035

Abstract This paper reports on the synthesis and characterization of peripherally and non-peripherally tetra-substituted gallium and indium phthalocyanines (3, 4, 5 and 6) containing 6-hydroxyhexylthio group. Synthesized compounds have been characterized

Full text of DOI:10.1016/j.poly.2015.07.035

Polyhedron 100 (2015) 1–9
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Polyhedron
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Metal ion sensing soluble
a or b tetrasubstituted gallium and indium
phthalocyanines: Synthesis, characterization, photochemistry and
aggregation behaviors
a,
Ahmet T. Bilgiçli a, Merve Durdaßsoglu a, Erkan Kırbaç b, M. Nilüfer Yarasir a, , Mehmet Kandaz
⇑
⇑
a Department of Chemistry, Sakarya University, TR54187 Serdivan, Sakarya, Turkey
b Department of Chemistry, Yildiz Technical University, 34210 Istanbul, Turkey
a r t i c l e i n f o
a b s t r a c t
Article history:
This paper reports on the synthesis and characterization of peripherally and non-peripherally tetra-
substituted gallium and indium phthalocyanines (3, 4, 5 and 6) containing 6-hydroxyhexylthio group.
Synthesized compounds have been characterized by elemental analysis, FT-IR, 1H NMR, 13C NMR,
MALDI-TOF and UV–Vis spectral data. Atomic force microscopy was also used as complementary tech-
niques to investigate the morphology. Absorption spectral changes of the functional MPcs during addition
of Ag(I) and Pd(II) soft-metal ions were evaluated by UV–Vis spectroscopy with monomer–dimer forma-
tion. All the same, photochemical properties and photophysical properties (Fluorescence quantum yields
and flouresans behavior) of these phthalocyanines were performed. General trends focus on fluorescence,
photodegradation and singlet oxygen quantum yields of these compounds in dimethylformamide. The
nature of the substituent and solvent effect on the photophysical and photochemical parameters of the
substituted phthalocyanines (3, 4, 5 and 6) are also reported.
Received 10 May 2015
Accepted 13 July 2015
Available online 22 July 2015
Keywords:
Phthalocyanine
Metal sensor
Gallium and indium
Photochemistry
Photophysical
Ó 2015 Elsevier Ltd. All rights reserved.
1. Introduction
resulting photodynamic reactions give rise to singlet oxygen (1O2)
and to other active oxygen species that lead to tumor destruction.
Phthalocyanines are planar aromatic macrocycles consisting of
four isoindole units [1]. Due to their excellent stability in a wide
variety of chemical environments chemical and thermal stability
and flexible preparation methods, substituted phthalocyanines
(Pcs) has been studied for especially recent years [2].
Metalphthalocyanines (MPcs) have received a great deal of atten-
tion due to their interesting electrical, optical and structural prop-
erties, followed by numerous application for example chemical
sensors [3,4], photoconductors [5], electrochromic display [6],
catalysis [7], liquid crystal [8], nanotechnology [9] and especially,
photosensitizers for photodynamic cancer therapy (PDT) [10,11].
Phthalocyanines (Pc) have been proved as highly promising photo-
sensitizers for PDT (photodynamic therapy) due to their intense
absorption in the red region of the visible light [12]. PDT technique
based on the administration of a photosensitiser that must be con-
dense more tumor tissues than regular tissues. This is followed by
illumination of the tumor with visible light in a wavelength range
matching the absorption spectrum of the photosensitizer [13]. The
The PDT efficiency can be improved with the use of photosensitiz-
ers that absorb strongly red light above 700 nm, where tissue exhi-
bits optimal transparency. Up to now, several new generation of
potential sensitisers for PDT have been developed and investi-
gated; among these phthalocyanines have been found to be as
highly promising due to high absorbance coefficient in the region
of 650–680 nm [10].
Unsubstituted phthalocyanines are insoluble and tend to aggre-
gate (p–p stacking interactions) in common organic solvents. this
insolubility is restricted its very well research. Nevertheless,
phthalocyanines can be modified in a number of ways by incorpo-
ration of substituents in their peripheral (b) and non-peripheral (
positions and solubility of phthalocyanines can be improved. This
modification increases the -electron density and makes solvation
a)
p
easier [14]. Due to low solubility of unsubstituted phthalocyanines
are not investigated in chemical and physical properties very well,
Therefore, the solubility of Pcs is very important and soluble
phthalocyanine synthesis are main purpose [15]. These type
approaches to increase solubility, reduce aggregation, increasing
its excited state lifetimes and improving its cellular uptake in
aqueous media are of extremely importance in PTD studies [16].
Tetra substituted phthalocyanines are usually more soluble than
⇑
Corresponding authors. Tel./fax: +90 (264) 295 60 42, +90 (264) 295 59 50.
E-mail addresses: nyarasir@sakarya.edu.tr (M.N. Yarasir), mkandaz@sakarya.
edu.tr (M. Kandaz).
http://dx.doi.org/10.1016/j.poly.2015.07.035
0277-5387/Ó 2015 Elsevier Ltd. All rights reserved.

2
A.T. Bilgiçli et al. / Polyhedron 100 (2015) 1–9
octa-substituted phthalocyanines because of the formation of con-
stitutional isomers and the high dipole moment that results from
the unsymmetrical arrangement of the substituents at the periph-
ery [17].
where samples were dispersed in KBr. Chromatography was per-
formed with silica gel (Merck grade 60) from Aldrich. All reactions
were carried out under a dry N2 atmosphere. Elemental analysis (C,
H and N) was performed at the instrumental analysis laboratory of
Marmara University. Time- and applied-resolved UV–Vis array
spectrophotometer. 1H NMR and 13C NMR spectra were recorded
on a Bruker 300 spectrometer instruments. Matrix-assisted laser
desorption/ionization time-of-flight (MALDI-TOF) mass spectra
(MS) were measured using a Bruker Autoflex III mass spectrometer
equipped with a nitrogen UV-Laser operating at 337 nm. The
Phthalocyanines have a high trend to aggregate in aqueous
solutions particularly [18]. The peripheral and/or nonperipheral
substituted phthalocyanines could be form two types of aggrega-
tions which affect on electronic and optical properties. One type
is face-to-face H-aggregation [19] and other type is side-to-side
J-aggregation [20]. Generally, phthalocyanine aggregation results
in a decrease in intensity of the Q-band corresponding to the
monomeric species, simultaneously a new, broader and blueshifted
or red-shifted band is seen to increase in intensity. This shift to
lower wavelengths indicates to H-type aggregation among the
phthalocyanine molecules. In rare cases, red-shifted bands have
been observed corresponding to J-type aggregation of the phthalo-
cyanine molecules [20].
Phthalocyanines bearing thia-oxo functionalities show optical
changes when they bind Ag (I) and Pd (II) ions, while crown-
attached phthalocyanines are well suited to bind alkaline and
alkaline earth metal ions [21].
Substitution at non-peripheral positions gives rise to red shift-
ing of the Q-band of MPcs according to the substitution at the
peripheral positions [22,23] and the presence of electron donating
sulfur groups on Pc leads to the red shifting of the Q-band to more
longer wavelengths as a result of the electron-donating thioether
substituents when compared with those of unsubstituted and
alklyl or O-substituted derivatives [24].
Due to their heavy diamagnetic nature and axially substituted
capacity Ga(III) and In(III) metals have been chosen as central
atoms. It is known that axial substitution can introduce a dipole
moment perpendicular to macrocycle, and via steric effect it can
alter the spatial relationship between neighboring molecules
[25]. Also are known that photophysical properties of the phthalo-
cyanine are influenced by the presence and nature of the central
metal ion. Phthalocyanine complexes with diamagnetic ions, such
as Zn2+, Al3+, and Ga3+, both high triplet yields and long lifetimes
have [26].
MALDI matrice,
a-cyano-4-hydroxy-cinnamic acid (CHCA) was
chosen as the best one.
2.2. Synthesis
2.2.1. 4-(6-hydroxyhexylthio)-phthalonitrile (1)
The compound was prepared according to the procedure
reported in the literature [22].
2.2.2. 3-(6-hydroxyhexylthio)-phthalonitrile (2)
The compound was prepared according to the procedure
reported in the literature [28].
2.2.3. [Ga] 2(3),9(10),16(17),23(24)-tetrakis-(6-hydroxyhexylthio)
phthalocyanine (3)
A well-powdered mixture of compound 1 (0.5 g, 1.92 mmol),
and GaCI3 (0.08 g, 0.44 mmol) were refluxed in 1-hexanol (1 cm3)
and 1,8-diazabicyclo [5.4.0.] undec-7-ene (DBU, 0.05 ml)
(0.05 cm3) under argon sealed glass tube. The temperature of the
reaction mixture was raised to 150–160 °C and kept for 8 h. The
deep green-blue product was cooled tort, and the solid was washed
successively with hot-heptane, copious of the mixture of iso-
propanol and water, and cold acetonitrile to remove impurities
until the filtrate was clear. The green–blue product was isolated
by silica gel column chromatography with THF-MeOH (50/2 v/v)
and then dried in vacuum. The complex 3 is highly soluble in
CHCl3, CH2Cl2, THF, i-PrOH, MeOH, EtOH, DMF, DMSO, DMAA,
and pyridine. Yield 0.174 g (34.80%), mp > 200 °C. Anal. Calc. for
First of all this paper is concerned with the synthesis of
ligand 4-(6-hydroxyhexylthio)-phthalonitrile and 3-(6-hydroxy-
hexylthio)-phthalonitrile were prepared according to the proce-
dure reported in the literatüre [27,28] and then, its peripherally
C
56H64N8O4S4GaCI (1145.2 g/mol): C, 58.66; H, 5.63; N, 9.77.
Found: C, 59.12; H, 5.75; N, 9.58%. FT-IR (KBr):
m
, cmꢀ1 3350 (br,
OH), 3040 (Ar–H), 2952, 2873 (Aliph–H), 1726 (w, H–O. . .H, weak),
1660, 1599, 1584, 1465, 1433, 1338, 1255, 1214, 1068, 912, 870,
835, 745. 1H NMR (DMSO-d6): d, ppm 8.13–7.75 (m, br, 12H, phe-
nyl H3, H5, H6), 5.08 (s, t, br, 4H, –CH2–OH, D2O exchangeable),
3.48 (t, br, 8H, CH2OH), 3.30 (DMSO), 2.80 (m, 8H, CH2CH2-S–),
1.62 (m, 8H,CH2CH2–S–Ar), 1.46 (m, 8H, CH2CH2CH2–OH), 1.35
(m,8H, CH2CH2CH2–OH) 13C NMR (300 MHz, DMSO-d6): d, ppm
148.25 (S–Ar–C4), 132.75 (Ar–C6), 129.80 (Ar–C5), 128.16 (Ar–
C3), 115.11 (Ar–C2), 114.10 (Ar–C1), 144.98(Ar–CN), 144.01 (Ar–
CN), 67.31 (–CH2OH), 40.85 (DMSO), 36.98 (S–CH–),
37.56(CH2CH2OH), 35.26 (–SCH2CH2CH2–), 22.30 (–CH2CH2–),
and nonperipherally b-
a-substituted MPcs, M[Pc(b-SC6H12OH)4]
{M = Ga(III)(3), In(III)(4)}, M[Pc(a-SC6H12OH)4] {M = Ga(III)(5),
In(III)(6)} are described, and also their soft metal ions (Ag(I) and
(Pd(II)) binding properties are investigated and evaluated. In addi-
tion, Surface morphologies of novel type phthalocyanines were
performed by AFM without interaction and after interaction with
soft metal ions (Ag(I) and (Pd(II). Finally, photochemical properties
(Singlet oxygen quantum yields and photodegradation quantum
yields) and photophysical properties (Fluorescence quantum yields
and flouresans behavior) of
nes were investigated.
a
or b tetra-substituted phthalocyani-
14.08 (–CH2CH2–).UV–Vis (THF): kmax, nm 704 (Q), 632 (n–p⁄
sh), 331 (B). MS (MALDI-TOF-MS, -cyano-4-hydroxycinnamic acid
(CHCA) as matrix): 1146.8 [M+H]+.
,
a
2. Experimental
2.2.4. [In] 2(3),9(10),16(17),23(24)-tetrakis-(6-hydroxyhexylthio)
phthalocyanine (4)
2.1. Materials and methods
A well-powdered mixture of compound 1 (0.5 g, 1.92 mmol),
and anhydrous InCI3 (0.06 g, 0.26 mmol) were refluxed in 1-hex-
anol (1 cm3) and 1,8-diazabicyclo [5.4.0.] undec-7-ene (DBU,
0.05 ml) (0.05 cm3) under argon sealed glass tube. The temperature
of the reaction mixture was raised to 150–160 °C and kept for 8 h.
After cooling to room temperature and diluting with 2-propanol, it
was filtered. The dark green–blue crude product formed during the
reaction was treated with 2-propanol several times and filtered off.
It was then successively washed with CH3CN, and dried. Further
Chloroform (CHCl3), tetrahydrofuran (THF), 4-nitrophthaloni-
trile, 3-nitrophthalonitrile, GaCI3, InCI3 were purchased from
Merck and Alfa Aesar and used as received. All other reagents were
obtained from Fluka, Aldrich and Alfa Aesar Chemical Co. and used
without purification. The purity of the products was tested in each
step by TLC(SiO2, CHCl3/MeOH and THF/MeOH). FT-IR spectropho-
tometer recorded on Perkin Elmer Two FT-IR spectrophotometer

A.T. Bilgiçli et al. / Polyhedron 100 (2015) 1–9
3
purification by silica gel chromatography (CHCl3/MeOH as a eluent
(5/100%) and dried in vacuo. Blue phthalocyanine 4 is soluble in
THF, MeOH, EtOH, DMF, DMSO. Yield 0.14 g (27.30%),
mp > 200 °C. Anal. Calc. for C56H64N8O4S4InCI (1190.6 g/mol): C,
56.44; H, 5.41; N, 9.40; Found: C, 57.12; H, 5.63; N, 9.61%. FT-IR
to remove impurities. Finally, the product was further purified by
silica gel chromatography CHCl3/MeOH (20:1 v/v). After washing
the resulting oily product with copious amounts of hexane, diethy-
lether and i-PrOH, finally it was dried in vacuum. This product is
soluble in MeOH, THF, DMF, DMSO, pyridine and insoluble in
diethylether.
(KBr):
m
, cmꢀ1 3227 (H-bonded, OH), 2958 (Ar–H), 2950, 2851
(Aliph–H), 1645, 1573, 1463, 1364, 1261, 1109, 1025, 984, 798,
720, 615. 1H NMR (DMSO-d6): d, ppm 8.11–7.76 (m, br, 12H, phe-
nyl H3, H5, H6), 4.80 (s, t, br, 4H, –CH2–OH, D2O exchangeable),
3.42 (t, br, 8H, CH2OH), 3.30 (DMSO), 2.82 (m, 8H, CH2CH2-S–),
1.65 (m, 8H,CH2CH2–S–Ar), 1.47 (m, 8H, CH2CH2CH2–OH), 1.30
(m,8H, CH2CH2CH2–OH) 13C NMR (300 MHz, DMSO-d6): d, ppm
146.25 (S–Ar–C4), 135.78 (Ar–C6), 130.80 (Ar–C5), 128.16
(Ar–C3), 116.78 (Ar–C2), 114.10 (Ar–C1), 144.98 (Ar–CN), 144.01
(Ar–CN), 68.31 (–CH2OH), 40.80 (DMSO), 36.90 (S–CH–), 36.56
(CH2CH2OH), 35.12 (–SCH2CH2CH2–), 21.40 (–CH2CH2–), 14.12
(–CH2CH2–). UV–vis (THF): kmax, nm 710(Q), 636(n–p⁄, sh), 341
Yield 0.12 g (23.40%), mp > 200 °C. Anal. Calc. for
C
56H64N8O4S4InCI (1190.6 g/mol): C, 56.44; H, 5.41; N, 9.40;
Found: C, 56.10; H, 5.78; N, 9.48%. FT-IR (KBr):
m
, cmꢀ1 3355 (br,
OH), 3043 (Ar–H), 2950, 2872 (Aliph–H), 1726 (w, H–O. . .H, weak),
1663, 1599, 1587, 1462, 1435, 1338, 1252, 1214, 1070, 912, 876,
837, 745. 1H NMR (DMSO-d6): d, ppm 8.30–7.75 (m, br, 12H, phe-
nyl H4, H5, H6), 4.18 (s, t, br, 4H, –CH2–OH, D2O exchangeable),
3.38 (t, br, 8H, CH2OH), 3.32 (DMSO), 2.80 (m, 8H, CH2CH2-S–),
1.64 (m, 8H,CH2CH2–S–Ar), 1.32 (m, 8H, CH2CH2CH2–OH), 1.29
(m,8H, CH2CH2CH2–OH) 13C–NMR (300 MHz, DMSO-d6): d, ppm
146.20 (S–Ar–C3), 135.18 (Ar–C6), 130.16 (Ar–C5), 125.10
(Ar–C4), 118.32 (Ar–C2), 115.28 (Ar–C1), 145.10 (Ar–CN), 145.12
(Ar–CN), 67.32 (–CH2OH), 40.05 (DMSO), 38.75 (S–CH–), 37.65
(CH2CH2OH), 36.24 (–SCH2CH2CH2–), 20.80 (–CH2CH2–), 12.96
(–CH2CH2–). UV–vis (THF): kmax, nm 740 (Q), 660 (n–p⁄, sh), 345
(B). MS (MALDI-TOF-MS,
a-cyano-4-hydroxycinnamic acid
(CHCA) as matrix): 1191.5 [M+H]+.
2.2.5. [Ga] 1(4),8(11),15(18),22(25)-tetrakis-(6-hydroxyhexylthio)
phthalocyanine (5)
(B). MS (MALDI-TOF-MS,
a-cyano-4-hydroxycinnamic acid
A well-powdered mixture of compound 2 (0.25 g, 0.96 mmol),
and anhydrous GaCI3 (0.02 g, 0.22 mmol) were refluxed in 1-hex-
anol (1 cm3) and 1,8-diazabicyclo [5.4.0.] undec-7-ene (DBU,
0.05 ml) (0.05 cm3) under argon sealed glass tube. The temperature
of the reaction mixture was raised to 150–160 °C and kept for 5 h.
The color of the mixture turned green–blue over this time. After
heating for an additional 3 h, the green–blue product was cooled
to room temperature. The crude product formed was washed sev-
eral times, successively with hexane, i-PrOH and then cold CH3CN,
to remove impurities. Finally, the product was further purified by
silica gel chromatography CHCl3/MeOH (100:4 v/v). After washing
the resulting oily product with copious amounts of hexane, diethy-
lether and i-PrOH, finally it was dried in vacuum. This product is
soluble in MeOH, THF, DMF, DMSO, pyridine and insoluble in
diethylether.
(CHCA) as matrix): 1191.5 [M+H]+.
2.3. Photophysical and photochemical studies
2.3.1. Fluorescence quantum yields
Fluorescence quantum yields (UF) were determined by the
comparative method (Eq. (1)) [29],
F:AStd:n2
UF
¼
U
ð1Þ
FðStdÞ FStd:A:n2
Std
where F and FStd are the areas under the fluorescence emission
curves of the samples (3, 4, 5 and 6) and the standard, respectively.
A and AStd are the respective absorbances of the samples and stan-
dard at the excitation wavelengths, respectively. n2 and nS2td are the
refractive indices of solvents used for the sample and standard,
respectively. Unsubstituted ZnPc (in DMF) (UF = 0.17) [30], was
employed as the standard. Both the samples and standard were
excited at the same wavelength. The absorbance of the solutions
at the excitation wavelength ranged between 703 and 732.
Yield 0.087 g (32.80%), mp > 200 °C. Anal. Calc. for
C
56H64N8O4S4GaCI (1145.2 g/mol): C, 58.66; H, 5.63; N, 9.77.
Found: C, 59.85; H, 5.69; N, 9.82%. FT-IR (KBr):
m
, cmꢀ1 3358 (br,
OH), 3042 (Ar–H), 2950, 2870(Aliph-H), 1725 (w, H–O. . .H, weak),
1660, 1599, 1586, 1460, 1430, 1335, 1252, 1213, 1070, 913, 875,
837, 742. 1H NMR (DMSO-d6): d, ppm 8.10–7.70 (m, br, 12H, phe-
nyl H4, H5, H6), 5.12 (s, t, br, 4H, –CH2–OH, D2O exchangeable),
3.42 (t, br, 8H, CH2OH), 3.30 (DMSO), 2.79 (m, 8H, CH2CH2-S–),
1.65 (m, 8H,CH2CH2–S–Ar), 1.38 (m, 8H, CH2CH2CH2–OH), 1.32
(m,8H, CH2CH2CH2–OH) 13C NMR (300 MHz, DMSO-d6): d, ppm
147.15 (S–Ar–C3), 133.16 (Ar–C6), 130.20 (Ar–C5), 126.16
(Ar–C4), 118.20 (Ar–C2), 115.30 (Ar–C1), 145.78(Ar–CN), 145.01
(Ar–CN), 68.20 (–CH2OH), 40.80 (DMSO), 38.70 (S–CH–),
37.15(CH2CH2OH), 36.26 (–SCH2CH2CH2–), 21.42 (–CH2CH2–),
2.3.2. Singlet oxygen quantum yields
Singlet oxygen quantum yield (UD) determinations were car-
ried out using the experimental set-up described in literature
[31–33]. Quantum yields of singlet oxygen photogeneration were
determined in air (no oxygen bubbled) using the relative method
with ZnPc as reference and DPBF as chemical quencher for singlet
oxygen, using formula (2),
Std
R:I
13.76 (–CH2CH2–). UV–vis (THF): kmax, nm 734 (Q), 658 (n–p⁄
sh), 346 (B). MS (MALDI-TOF-MS, -cyano-4-hydroxycinnamic acid
(CHCA) as matrix): 1146.5 [M+H]+.
,
USDtd
ð2Þ
abs
UD
¼
RStd:Iabs
a
where USDtd is the singlet oxygen quantum yields for the standard
ZnPc (USDtd ¼ 0:56) for ZnPc in DMF [34]. R and RStd are the DPBF
2.2.6. [In] 1(4),8(11),15(18),22(25)-tetrakis-(6-hydroxyhexylthio)
phthalocyanine (6)
photobleaching rates in the presence of the respective samples (3,
Std
abs
4, 5 and 6) and standard, respectively. Iabs and I are the rates of
A well-powdered mixture of compound 1 (0.5 g, 1.92 mmol),
and anhydrous InCI3 (0.06 g, 0.26 mmol) were refluxed in 1-hex-
anol (1 cm3) and 1,8-diazabicyclo [5.4.0.] undec-7-ene (DBU,
0.05 ml) (0.05 cm3) under argon sealed glass tube. The temperature
of the reaction mixture was raised to 150–160 °C and kept for 5 h.
The color of the mixture turned green–blue over this time. After
heating for an additional 3 h, the green–blue product was cooled
to room temperature. The crude product formed was washed sev-
eral times, successively with hexane, i-PrOH and then cold CH3CN,
light absorption by the samples (3, 4, 5 and 6) and standard, respec-
tively. To avoid chain reactions induced by DPBF in the presence of
singlet oxygen [35], the concentration of quencher (DPBF) was low-
ered to ꢁ3 ꢂ 10ꢀ5 mol dmꢀ3 Solutions of sensitizer (containing
DPBF) were prepared in the dark and irradiated in the Q band region
using the setup described above. DPBF degradation at 417 nm (in
DMSO) were monitored. The light intensity of 7.05 ꢂ 1015
photons sꢀ1 cmꢀ2 was used for UD determinations.

4
A.T. Bilgiçli et al. / Polyhedron 100 (2015) 1–9
2.3.3. Photodegradation quantum yields
phthalocyanines can be synthesized from b-substituted phthaloni-
The study of degradation of the molecules intended for use as
photo catalysts is especially important. Thus, Photodegradation
quantum yield (Ud) determinations were carried out by the exper-
imental set-up described in literature [35–37]. Photodegradation
quantum yields were determined using formula (3),
triles on the other hand 1(4),8(11),15(18),22(25)-tetra-substituted
phthalocyanines are synthesized from
[27,28].
a-substituted analogues
In this study, ligands, 4-(6-hydroxyhexylthio)-phthalonitrile (1)
and 3-(6-hydroxyhexylthio)-phthalonitrile (2), their metal ion
sensor gallium(III) and indium(III) phthalocyanines, 3, 4 5 and 6,
were prepared. Related Pcs, 3–6, were accomplished by heating a
pulverized mixture of 4-(6-hydroxyhexylthio)-phthalonitrile and
3-(6-hydroxyhexylthio)-phthalonitrile with anhydrous GaCI3,
InCI3 metal salt at ca. 150–160 °C under N2 atmosphere in the
presence of 1-hexanol and 1,8-diazabicyclo[5.4.0]undec-7-ene
(DBU) for 8 h (Scheme 1).
ðC0 ꢀ CtÞ:V:NA
Ud
¼
ð3Þ
I
abs:S:t
where ‘‘C0’’ and ‘‘Ct’’ are the sample (3, 4, 5 and 6) concentrations
before and after irradiation respectively, ‘‘V’’ is the reaction volume,
‘‘NA’’ the Avogadro’s constant, ‘‘S’’ the irradiated cell area and ‘‘t’’ the
irradiation time, ‘‘Iabs’’ is the overlap integral of the radiation source
light intensity and the absorption of the samples (3, 4, 5 and 6). A
light intensity of 2.50 ꢂ 1016 photons sꢀ1 cmꢀ2 was employed for
Ud determinations.
Generally, phthalocyanine complexes are insoluble in general
organic solvents. If you are added suitable functional group on
the ring from
be increased. All of newly synthesized
a
or b positions, solubility of phthalocyanines can
or b substituted metal-
a
lophthalocyanines 3–6 have excellent solubility in CHCl3, MeOH,
THF, DMF, DMSO.
3. Results and discussion
The structure of phthalocyanines (3–6) were verified by
standard method elemental analysis, FT-IR, 1H NMR, 13C NMR,
MALDI-TOF, UV–Vis, fluorescence spectral data and AFM as
complementary techniques. All the analytical spectral data are
consistent with the predicted structures.
3.1. Synthesis and characterization
In common, substituted phthalocyanines are prepared by
cyclotetramerization of
a or b substituted 1,3-diimino-1H-isoin-
doles or phthalonitriles. 2(3),9(10),16(17),23(24)-Tetra-substituted
Scheme 1. Synthetic route of 2(3), 9(10), 16(17), 23(24)-tetrakis-(6-hydroxyhexylthio) phthalocyanine M{Pc[S-C6H12OH)]4} (M = Ga(III) (3), In(III) (4)} and Synthetic route of
1(4),8(11),15(18),22(25)-Tetrakis-(6-hydroxyhexylthio) phthalocyanine M{Pc[SC6H12OH)]4} (M = Ga(III) (5), In(III) (6) (i and ii) K2CO3, 6-mercapto-1-hexanol, DMF, 40 °C,
2 days. (iii and iv) anhydrous GaCI3, InCI3, 160–170 °C, for 8 h, DBU.

A.T. Bilgiçli et al. / Polyhedron 100 (2015) 1–9
5
Fig. 1. UV–Vis spectra of 3, 4, 5 and 6 in THF.
Fig. 3. UV–Vis spectra of 5 in THF during titration with Pd(II) (A) ions and UV–Vis
spectra of 3 in THF during titration with Pd(II) (B) ions in THF.
–C„N vibration at 2223 cmꢀ1. The FT-IR spectra of phthalocyani-
nes (3–6) are very similar with the exception of small stretching
shifts.
1H NMR investigations of compounds 3–6 provide the charac-
teristic chemical shifts for the structures as expected. The 1H
NMR spectra of 3, 4, 5 and 6 are broader than the corresponding
signals in the starting 4-(6-hydroxyhexylthio)-phthalonitrile (1)
and 3-(6-hydroxyhexylthio)-phthalonitrile (2) derivative. This
broadening is likely due to chemical exchange caused by aggrega-
tion-disaggregation equilibria and the fact that the product
obtained in these reactions is a mixture of positional isomers
which are expected to show chemical shifts that differ slightly
from each other. The peripheral –OH proton at 4.50–4.70 ppm in
3–6 were easily identified in the 1H NMR spectrum with a broad
chemical shift especially in the case of 3–6 and this signal
disappears on deuterium oxide, D2O exchange [27,28]. The other
resonances related to OCH2, CH2, SCH2 and Ar–H protons in
the 1H NMR spectra of 3–6 are very similar to that of
4-(6-hydroxyhexylthio)-phthalonitrile (1) and 3-(6-hydroxy-
hexylthio)-phthalonitrile (2).
Fig. 2. UV–Vis spectra of 6 in THF during titration with Ag(I) (A) ions and UV–Vis
spectra of 4 in THF during titration with Ag(I) (B) ions in THF.
UV/Vis spectra of the phthalocyanine complexes (3–6) exhib-
ited characteristic absorptions in the Q-band region at around
650–700 nm, attributed to the
Cyclotetramerization of 4-(6-hydroxyhexylthio)-phthalonitrile
(1) and 3-(6-hydroxyhexylthio)-phthalonitrile (2) to the phthalo-
cyanines (3–6) were confirmed by the disappearance of the sharp
p–
p⁄ transition from the HOMO

6
A.T. Bilgiçli et al. / Polyhedron 100 (2015) 1–9
Fig. 4. Absorption spectra of 5 (A) and 3 (B) in THF at different concentrations (inset: plot of absorbance versus concentration).
Table 1
Spectral parameters of 3, 4, 5 and 6 in DMF.
Comp. in Q band
log
Excitation
Emission
Stokes Shift
DMF
kmax (nm)
e
kEx (nm)
kEm (nm)
DStokes (nm)
3
4
5
6
704
706
733
704
4.09 705
4.49 690
4.06 732
4.47 706
722
733
754
728
17
43
22
22
phthalocyanines (3–6) in THF were observed as a single band of
high intensity at 704 nm for 3, 710 nm for 4, 734 nm for 5,
740 nm for 6. There was also a shoulder at the slightly higher
energy side of the Q band for each phthalocyanine. B band absorp-
tions of the metallophthalocyanines 3–6 were observed at 331,
341, 346, 345 nm respectively (Fig. 1).
3.2. Metal ion binding titration studies
Fig. 5. Absorption
(
), excitation
(
)
and emission
(
) spectra of the
compound 6 in DMF.
Sulfur atoms on the periphery of the metallophthalocyanine
complexes (MPcs) are know that optically sensitive to soft metal
ions, such as Ag(I) and Pd(II). Thus, The metal binding properties
(highest occupied molecular orbital) to the LUMO (lowest unoccu-
pied molecular orbital) of the Pc2ꢀ ring, and in the B band region
(UV region) at around 300–400 nm, arising from the deeper
p–
p⁄
of
a or b tetrasubstituted phthalocyanines were investigated. In
transitions. The Q-band absorptions of
p–
p⁄ transition for all
order to show metalion binding capability of the MPcs was used

A.T. Bilgiçli et al. / Polyhedron 100 (2015) 1–9
7
between 320–360 nm increased and somewhat shifts to shorter
wavelengths (the CT region). These figures show that the binding
of Ag(I) or Pd(II) to the donor atoms of 3–6 results in pronounced
effects on the B- and especially Q-bands and on the n–p⁄ transi-
tions in the UV/Vis spectrum. Also binding ratios (Insets in
Figs. 2 and 3) of 4, 6 to Ag (I) and 3, 5 Pd(II) ions were found to
be 3:1, 1:1, 3:1 respectively.
In this study, the aggregation behavior of synthesized
a or b
tetrasubstituted phthalocyanine complex (3–6) were investigated
at different concentrations and solvent. Because aggregation
behavior of phthalocyanines are important both investigation of
photophysical and photochemical and to perform of sensor proper-
ties (as a example 5 (Fig 4A) and 3 (Fig 4B) were given in THF). As
shown in the figure, the Q band increases in intensity with increas-
ing in the concentration of 3 and 5 any new band were observed
due to the aggregated species.
Fig. 6. A typical spectrum for the determination of singlet oxygen quantum yield
for complex 3 in DMF at a concentration 6 ꢂ 10ꢀ6 mol dmꢀ3
.
3.3. Fluorescence spectra and quantum yields
In this study, fluorescence properties of synthesized
a or b
tetrasubstituted phthalocyanine were investigated the effect of
solvent used (DMF). Fig. 5 shows the absorption, fluorescence exci-
tation and emission spectra of 3, 4, 5 and 6 in DMF. Fluorescence
emission peaks were observed at: 754 nm for 5, 728 nm for 6,
723 nm for 3, 734 nm for 4 in DMF (Table 1). The Stokes’s shifts
range from 5 to 15 nm in DMF, which is usual for ZnPc derivatives
[38]. The observed Stokes shifts were typical of MPc complexes. As
has been observed before, there is a increase UF on going from
ZnPc (UF = 0.17 [39], in DMF) to derivatives UF = 0.2295 (5),
0.0692 (6), 0.2666 (3) and 0.0551 (4). The fluorescence quantum
yields were more observed in gallium metallophthalocyanines (3
and 5) than typical of MPc complexes, although indium metalloph-
thalocyanines (4 and 6) were lower observed, Because of indium is
a very heavy metal.
3.4. Photochemical properties
Fig. 7. A typical spectrum for the determination of photodegradation for complex 3
in DMF.
3.4.1. Singlet oxygen quantum yields
Singlet oxygen generation is very importance in PDT and the
singlet oxygen quantum yield (UD) gives an indication of how well
a photosensitizer is able to generate it. Thus, Singlet oxygen quan-
tum yields of the substituted Pcs in DMF solution were determined
by using 1,3-diphenylisobenzofuran (DPBF) as a quencher. The UD
values were obtained using Eq. (2). Fig. 6 shows spectral changes
observed during photolysis of complex 3 in DMF the presence of
DPBF. The disappearance of DPBF was monitored using UV–Vis
spectroscopy. The rate at which the DPBF degrades is related to
the production of singlet oxygen. There were no changes in the Q
band intensities during the UD determinations, confirming that
complexes are not degraded during singlet oxygen studies [38].
The UD values for 3, 4, 5 and 6 (UD = 0.4287, 0.1323, 0.4214,
0.1355, in DMF). This results consistent with literature [40,41].
UV–Vis spectroscopy. Each titration experiment was carried out
using a MeOH/THF solution of the MPcs (10/90, v/v) to ensure com-
plete dissolution of the analyte salt in MeOH. The concentration of
the metal salt (ca. 10ꢀ3 mol cmꢀ3) was kept higher than those of
the MPc (ca. 10ꢀ5 mol cmꢀ3) to diminish the absorption decreases
of the bands due to dilution. Gradual addition of Ag(I) to the solu-
tions of 3–6 at room temperature caused a gradual color change,
from green to blue, which suggests that the complexes coordinate
with Ag(I) to form aggregated species Interaction of Ag(I) with
these complexes decreases the solubility of the dimer, trimer, tet-
ramer complexes formed, which results in the little observation of
an intractable little product at the end of the titration due to poly-
mer. As shown in Fig 2A (6) and Fig 2B (4) Ag(I) binding to the
donor atoms of the complexes results in pronounced effects on
the Q-, B- and shoulder band absorptions (n–p⁄ transitions: attrib-
uted to the non-bonding sulfur electron (n) to the p⁄ phthalocya-
nine orbital [24]. During the titration of 3, 4, 5 and 6 with Ag(I)
the intensity of the Q and B-bands decreases and increase in the
intensity of the dimeric H-type aggregates.
When compared to UD of ZnPc to
a or b tetrasubstituted phthalo-
cyanine complex (3–6) were found lower than expect in 0.56 for
ZnPc in DMF. The results of gallium metallophthalocyanines were
observed as close to zinc phthalocyanines but, the results of
indium metallophthalocyanines were lower observed.
Table 2
The gradual addition of Na2PdCl4 in MeOH (in ll portions) to 3,
Photophysical and photochemical properties of 3, 4, 5 and 6 in DMF.
4, 5 and 6 in THF at room temperature caused a similar gradual
color change {Fig. 3A (5), Fig. 3B (3)}, suggesting H-type complex
formation in the case compound 3–6. These distinctive changes
could be attributed to the increase in the intensity of the dimeric
H-type aggregates and a decrease in the intensity of the monomers
in 3–6. During the titration, the intensity of the B-bands in 3–6
Comp.
Solvent
UF
Ud
UD
3
4
5
6
DMF
DMF
DMF
DMF
0.2666
0.0551
0.2295
0.0692
0.0036
0.0031
0.003
0.428
0.132
0.421
0.135
0.0022

8
A.T. Bilgiçli et al. / Polyhedron 100 (2015) 1–9
Fig. 8. (A) AFM images of 6, (B) AFM images of 4, (C) AFM images of 6+Ag(I), (D) AFM images of 4+Ag(I) were prepared from THF.
Fig. 9. (A) AFM images of 5, (B) AFM images of 3, (C) AFM images of 5+Pd(II), (D) AFM images of 3+Pd(II) were prepared from THF.

A.T. Bilgiçli et al. / Polyhedron 100 (2015) 1–9
9
3.4.2. Photodegradation (photobleaching) quantum yields
(3 and 5) can exhibit Type II photosensitizer properties on PDT
applications. The novel type indium metallophthalocyanines (4
and 6) cannot exhibit Type II photosensitizer properties on PDT
applications.
Photobleaching is a process where phthalocyanine as photosen-
sitizer is degraded under light irradiation owing to singlet oxygen
attack which also import for photocatalytic studies in PDT. MPcs
stability is especially important in the bod at a suitable under light.
The photobleaching stabilities of complexes 3, 4, 5 and 6 were
determined in DMF by monitoring the decrease in the intensity
of the Q band under irradiation with increasing time (Fig 7 as a
example of 3). The photodegradation quantum yield (Ud) values
for the complexes are listed in Table 2 are of the order of 10ꢀ4.
Stable ZnPc molecules show values as low as 10ꢀ6 and for unstable
molecules, values of the order 10ꢀ3 have been reported [42].
Acknowledgment
We thanks, The Research Fund of Sakarya University (Project
_
no: 2013-02-04-049 and 2014-02-04-011) and TUBITAK (Project
no: 114Z448).
References
[1] N.B. McKeown, Phthalocyanine Materials: Synthesis, Structure and Function
Cambridge University Press, Cambridge, 1998.
3.5. Morphology of the phthalocyanines
[2] C.C. Leznoff, A.B.P. Lever, Phthalocyanines Properties and Applications, vols. 1–
4, VCH, Weinheim, 1996.
[3] W. Wu, S. Ji, H. Guo, X. Wang, J. Zhao, Dyes Pigm. 89 (2011) 199.
[4] M. Brumbach, D. Placencia, N.R. Armstrong, J. Phys. Chem. C 112 (2008) 3142.
[5] F. Yakuphanoglu, M. Kandaz, M.N. Yarasir, F.B. Sßenkal, Physica B 393 (2007)
235.
[6] Y.S. Krasnov, G.Y. Kolbasov, I.N. Tretyakova, L.A. Tomachynska, V.Y. Chernii,
S.V. Volkov, Solid State Ionics 180 (2009) 928.
[7] A. Kalilur Rahiman, K. Rajesh, K. Shanmuga Bharathi, S. Sreedaran, V.
Narayanan, Inorg. Chim. Acta 362 (2009) 1491.
[8] T.V. Basova, R.G. Parkhomenko, I.K. Igumenov, A. Hassan, M. Durmus, A.G.
Gürek, V. Ahsen, Dyes Pigm. 111 (2014) 58.
[9] M. Durmußs, T. Nyokong, Inorg. Chem. Commun. 10 (2007) 332.
[10] K.L. Dao, R.N. Hanson, Bioconjugate Chem. 23 (2012) 2139.
[11] K. Ishii, M. Shiine, Y. Shimizu, S. Hoshino, H. Abe, K. Sogawa, N. Kobayashi, J.
Phys. Chem. B 112 (2008) 3138.
[12] E. Kirbaç, G.Y. Atmaca, A. Erdog˘musß, J. Organomet. Chem. 752 (2014) 115.
[13] M.N. Sibata, A.C. Tedesco, J.M. Marchetti, Eur. J. Pharma. Sci. 23 (2004) 131.
[14] E.N. Kaya, M. Durmus, M. Bulut, J. Organomet. Chem. 774 (2014) 94.
[15] A. Günsel, M.N. Yarasßır, M. Kandaz, A. Koca, Synthesis, Polyhedron 29 (2010)
3394.
[16] N. Saydan, M. Durmus, M.G. Dizge, H. Yaman, A.G. Gürek, E. Antunes, et al., J.
Porphyrins Phthalocyanines 13 (2009) 681.
[17] Z. Biyiklioglu, Synth. Met. 196 (2014) 48.
[18] H. Li, N. Nguyen, F.R. Fronczek, M.G.H. Vincente, Tetrahedron 65 (2009) 3357.
[19] M. Sevim, M.N. Yarasßır, M. Kandaz, A. Koca, Dyes Pigm. 111 (2014) 190.
[20] A.T. Bilgiçli, A. Günsel, M. Kandaz, A.R. Özkaya, Dalton Trans. 41 (2012) 7047.
[21] M. Kandaz, I. Yılmaz, O. Bekaroglu, Polyhedron 19 (2000) 115.
[22] X.A. Micó, S.I. Vagin, L.R. Subramanian, T. Ziegler, M. Hanack, Eur. J. Org. Chem.
(2005) 4328.
As known, the investigation of surface areas of thin films are
especially important for high technological applications. The thin
films that have nanostructure and regular morphology are also
important [43–45]. Atomic force microscopy (AFM) was also used
to investigate the nano morphology of 3–6 in THF. The samples
were prepared by drop-casting a concentrated solution of 3–6 in
THF (6 mg/mL) onto a SiO2 substrate. In the AFM images, was
observed uniform particle structures between 10 and 20 nm (Fig
8 and Fig 9) In addition, thin films have regular morphology.
AFM imafes of 6 and 4 without interaction with Ag(I) ions were
given in Fig 8A and B, respectively. In addition, AFM imafes of 5
and
3 without interaction with Pd (II) ions were given in
Fig 9A and B, respectively.
AFM morphologies of 3–6 in the case of Ag(I) and Pd(II) were
given [6-Ag(I) (Fig 8C), 4-Ag(I) (Fig 8D) and 5-Pd(II) (Fig 9C),
3-Pd(II) (Fig 9D)]. Morphologies formed from soft acid (Ag(I) or
Pd(II)) soft base (Pcs) interactions also clearly reflect in the
self-assembly processes of 3–6 including molecular packing
conformations and morphologies.
4. Conclusion
[23] D. Arican, M. Arici, A.L. Ugur, A. Erdogmus, A. Koca, Electrochim. Acta 106
(2013) 541.
[24] M.N. Yarasir, M. Kandaz, B.F. Senkal, A. Koca, B. Salih, Polyhedron 26 (2007)
5235.
We have presented the synthesis and characterization of
peripherally or nonperipherally (b- or
a-) substituted M[Pc(b-
SC6H12OH)4] {M = Ga(III)(3), In(III)(4)}, M[Pc(a-SC6H12OH)4]
{M = Ga(III)(5), In(III)(6)} metallopthalocyanines. Structures of the
new compounds were characterized by elemental analysis, FT-IR,
1H NMR, 13C NMR, MALDI-TOF, UV–Vis spectral data as standart
method and also AFM was used as complementary techniques to
investigate of surface morphology. The soft metal ions (Ag(I) and
[25] M. Hanack, T. Schneider, M. Barthel, J.S. Shirk, S.R. Flom, R.G.S. Pong, Coord.
Chem. Rev. 219 (2008) 235.
[26] H. Ali, J.E. van Lier, Chem. Rev. 99 (1999) 2379.
[27] M.N. Yarasir, M. Kandaz, A. Koca, B. Salih, Polyhedron 26 (2007) 1139.
[28] M. Kandaz, M.N. Yarasir, A. Koca, Polyhedron 28 (2009) 257.
[29] S. Frey-Forgues, D. Lavabre, J. Chem. Edu. 76 (1999) 1260.
[30] A. Ogunsipe, J.Y. Chen, T. Nyokong, New J. Chem. 28 (2004) 822.
[31] J.H. Brannon, D. Madge, J. Am. Chem. Soc. 102 (1980) 62.
[32] A. Ogunsipe, T. Nyokong, J. Photochem. Photobiol. A: Chem 173 (2005) 211.
[33] I. Seotsanyana-Mokhosi, N. Kuznetsova, T. Nyokong, Photochem. Photobiol. A:
Chem 140 (2001) 215.
(Pd(II)) binding properties and binding ratios of
a- b- or substi-
tuted metallophtalocyanines are investigated and evaluated by
UV–Vis spectroscopy. In the same time, photochemical and photo-
physical properties of novel type phthalocyanines have been deter-
mined. According to photochemical and photophysical results,
Singlet oxygen quantum yields of gallium metallophthalocyanines
(3 and 5) were found to be about 4 times more than indium met-
allophthalocyanines (4 and 6). Similar results were obtained to flu-
orescence and quantum yields. Fluorescence and quantum yields
of gallium metallophthalocyanines (3 and 5) were found higher
than indium metal phthalocyanines (4 and 6).
[34] W. Spiller, H. Kliesch, D. Wohrle, S. Hackbarth, B. Roder, G. Schnurpfeil, J. Porp,
Phthalocyan 2 (1998) 145.
[35] D. Çakır, M. Göksel, V. Çakır, M. Durmusß, Z. Biyiklioglu, H. Kantekin, Dalton
Trans. (2015), http://dx.doi.org/10.1039/C5DT00747J.
[36] A. Ogunsipe, T. Nyokong, J. Photochem. Photobiol. A: Chem 173 (2005) 211.
[37] A. Ogunsipe, D. Maree, T. Nyokong, J. Mol. Struct. 650 (2003) 131.
[38] M.O. Senge, M.W. Renner, W.W. Kalisch, J. Fajer, Dalton Trans. (2000) 381.
[39] M. Durmus, T. Nyokong, Spectrochim. Acta A 69 (2008) 1170.
[40] M. Durmus, T. Nyokong, Tetrahedron 63 (2007) 1385.
[41] M. Durmus, T. Nyokong, Photochem. Photobiol. Sci. 6 (2007) 659.
[42] S. Maree, T. Nyokong, J. Porphyrins Phthalocyanines 5 (2001) 782.
[43] N. Akkaya, A.T. Bilgiçli, A. Aytekin, M.N. Yarasir, M. Kandaz, Polyhedron 85
(2015) 857.
[44] A. Günsel, M. Kandaz, F. Yakuphanoglu, W.A. Farooq, Synth. Met. 161 (2011)
1477.
[45] A.T. Bilgiçli, A. Günsel, M. Kandaz, A. Altindal, H. Cömert, J. Org. Chem. 785
(2015) 112.
Photodegradation (photobleaching) quantum yields of
a- b-
substituted phthalocyanines were investigated due to required to
be stable to UV light of complexes. The singlet oxygen quantum
efficiency gives indication of the potential of the complexes as pho-
tosensitizers in applications where singlet oxygen is required
(Type II mechanism). Although the novel gallium phthalocyanines