Synthesis of metal-free and metallophthalocyanines containing 18- and 21-membered macrocycles with mixed donor atoms and their metal-ion binding properties

Article abstract of DOI:10.3906/kim-1501-54

This paper describes the synthesis of a series of metal-free phthalocyanines and metallophthalocyanines peripherally substituted by macrocycles of different ring sizes with the same donor atom sets. The effects of varying ring size of the macrocycle on the spectroscopic and metal ion binding properties of phthalocyanines were examined. For these purposes, electronic absorption properties for metal-free phthalocyanines and metallophthalocyanines were studied in dimethylformamide and tetrahydrofuran. The liquid-liquid extraction of metal picrates such as Ag(I), Hg(II), Cd(II), Zn(II), Cu(II), Ni(II), Pb(II), and Co(II) from the aqueous phase to the organic phase was carried out using metallophthalocyanines. All new compounds were characterized using several spectroscopic techniques.

Full text of DOI:10.3906/kim-1501-54

Turk J Chem
2015) 39: 750 – 763
Turkish Journal of Chemistry
(
http://journals.tubitak.gov.tr/chem/
¨
˙
⃝
c TUBITAK
Research Article
doi:10.3906/kim-1501-54
Synthesis of metal-free and metallophthalocyanines containing 18- and
1-membered macrocycles with mixed donor atoms and their metal-ion binding
properties
2
∗
¨
Halil Zeki GOK
Department of Chemistry, Faculty of Arts and Sciences, Osmaniye Korkut Ata University, Osmaniye, Turkey
Received: 20.01.2015
•
Accepted/Published Online: 16.04.2015
•
Printed: 28.08.2015
Abstract: This paper describes the synthesis of a series of metal-free phthalocyanines and metallophthalocyanines
peripherally substituted by macrocycles of different ring sizes with the same donor atom sets. The effects of varying
ring size of the macrocycle on the spectroscopic and metal ion binding properties of phthalocyanines were examined.
For these purposes, electronic absorption properties for metal-free phthalocyanines and metallophthalocyanines were
studied in dimethylformamide and tetrahydrofuran. The liquid–liquid extraction of metal picrates such as Ag(I), Hg(II),
Cd(II), Zn(II), Cu(II), Ni(II), Pb(II), and Co(II) from the aqueous phase to the organic phase was carried out using
metallophthalocyanines. All new compounds were characterized using several spectroscopic techniques.
Key words: Mixed-donor macrocycle, metal-free phthalocyanine, metallophthalocyanine, solvent extraction
1
. Introduction
Phthalocyanines and their metal complexes are one of the most attractive functional molecular materials in
the literature. They have been studied in detail for many years and are still receiving much attention because
of their extraordinary properties. These compounds have found application as dyes and pigments1,2 and have
potential as catalysts in Li-air batteries,3 in oxidation of aromatic compounds,4 as gas sensors,5 as Langmuir–
Blodgett films,6 and as photosensitizers in photodynamic cancer therapy7 due to their unique properties
such as high molar absorption coefficients, electron transfer abilities, and thermal and chemical stability.8
Factors such as the central metal and the nature and position of the substituents have an influence on their
spectroscopic properties.9
−12
Metallophthalocyanines containing diamagnetic metals such as zinc and silicon
as central metal are well known in photodynamic therapy due to their high triplet state quantum yields.11
Metallophthalocyanines with a redox active metal center such as cobalt, manganese, and titanium are used for
the design of electrochemical sensors due to their electrocatalytic properties toward many analytes.11,13
The usage of the phthalocyanine in applications is closely related to its molecular composition, stability,
and solubility. The limited solubility of the phthalocyanine in common organic solvents is the major problem con-
cerning its application capabilities. It is known that unsubstituted phthalocyanines are less soluble in common
organic solvents than substituted phthalocyanines are.14 In order to improve the solubility of phthalocyanine
in various solvents, many modifications to the peripheral or nonperipheral position of the phthalocyanines have
been reported.1
5−20
∗
Correspondence: zekigok@osmaniye.edu.tr
750

¨
GOK/Turk J Chem
One of these modifications is preparing phthalocyanines starting from a phthalonitrile precursor con-
taining a macrocyclic unit. Incorporation of a macrocycle into the phthalocyanine ring affects the optical and
electrochemical properties of phthalocyanines.21,22 A significant advantage of the attachment of a macrocycle
with mixed donor atoms to the phthalocyanine ring, according to the HSAB concept, is that selectivity increases
towards soft transition metal cations.23 A series of closely related macrocyclic and macrobicyclic systems and
their extractant properties were reported by Ocak and co-workers. They demonstrated that the presence of soft
donor atoms in the macrocyclic system enhanced the selective extraction for soft metal ions such as silver(I)
and mercury(II).2
4−26
Several papers related to the synthesis of phthalocyanines containing macrocycles with
different types of donor atoms were reported by Kantekin et al.2
7−30
One of those studies reported new soluble
phthalocyanines containing a macrocyclic unit and investigation of their extraction properties towards metal
ions.27 They obtained the highest extraction values for silver(I), mercury(II), and cadmium (II) in the extrac-
tion experiments. They concluded that this was because sulfur containing ligands are especially appropriate for
complexation with heavy metal cations such as silver(I), mercury(II), and cadmium (II) due to the softness of
sulfur, which is in agreement with the HSAB concept. The synthesis of macrocycles of different ring sizes with
different types of donor atoms and their extractant properties have been well studied.2
4−26,31−33
In contrast,
mixed donor macrocycles substituted phthalocyanines and their metal-ion binding properties have been studied
less.
Our studies focused on selective and effective extraction of heavy metals and precious metals from solu-
tion and determining the extraction behavior of macrocycles in liquid–liquid medium. For these purposes, we
have previously reported a series of synthesis of macrocycles and their metal ion binding properties in solvent
extraction.31,34 The present study, as our ongoing research in this area, describes the synthesis and character-
ization of a series of metal-free phthalocyanines and metallophthalocyanines containing 18- and 21-membered
macrocycles with mixed donor atoms. The effects of varying ring sizes of the macrocycle on the spectroscopic
properties of phthalocyanines were examined. Cation extraction studies with synthesized phthalocyanines were
performed using solvent extraction to evaluate the metal ion binding properties of phthalocyanines.
2
2
. Results and discussion
.1. Synthesis and characterization
Metal-free phthalocyanines 2b−3b and metallophthalocyanines 2c−3c and 2d−3d were prepared by the route
shown in Scheme 1. The structures of the novel compounds were characterized by a combination of elemental
1
analysis and H NMR, IR, UV-Vis, and MS spectral data. N,N’-(2,2’-(4,5-dicyano-1,2-phenylene)bis(sulfanediyl)
bis(2,1-phenylene))bis(2-chloroacet-amide) 1 was employed as the starting material for the synthesis of ph-
thalonitriles 2a and 3a.
The synthesıs of metal-free phthalocyanines 2b and 3b from corresponding phthalonitriles 2a and 3a was
accomplished in dry n-pentanol at reflux temperature for 24 h under argon in a Schlenk tube to afford 2b and 3b
as dark green amorphous solids after purification by silica gel chromatography. The metal-free phthalocyanines
were soluble in DMF and DMSO. The synthesis of metallophthalocyanines 2c−3c and 2d−3d with four
macrocycles was achieved by treating the corresponding phthalonitrile precursors 2a and 3a with anhydrous
Co(CH3 CO2)2 in quinoline for cobalt phthalocyanine complexes 2c−3c and anhydrous Zn(CH3 CO2)2 in the
same solvent for zinc phthalocyanine complexes 2d−3d. All synthesized phthalocyanine derivatives were first
treated with ethanol for 4 h under reflux temperature in a Soxhlet extractor, and then purified by silica gel
chromatography using CH2 Cl2 :CH3 OH (95:5). The complexes were soluble in solvents such as DCM, DMF,
and DMSO.
7
51

¨
GOK/Turk J Chem
O
NC
NC
S
S
N
H
Cl
Cl
SH
SH
SH
SH
H
N
O
(1)
O
O
NC
NC
S
S
N
H
S
S
NC
NC
S
S
N
H
S
S
H
N
H
N
O
O
(
3a)
(
2a)
S
S
S
O
O
O
O
S
S
S
S
S
HN
NH
N
H
HN
NH
NH
HN
S
S
HN
S
S
O
O
O
O
S
S
S
S
N
N
N
N
N
N
N
N
N
N
M
N
N
N
M
N
N
N
S
S
S
S
O
O
O
O
NH
HN
S
S
HN
NH
NH
S
S
HN
HN
N
H
S
S
S
S
O
O
O
O
S
S
S
S
2b M=2H
2c M=Co
2d M=Zn
3b M=2H
3c M=Co
3d M=Zn
Scheme 1. The synthetic route of metal-free phthalocyanines 2b–3b and metallophthalocyanines 2c–3c and 2d–3d.
Comparison of the 1 H NMR, IR, UV-Vis, and MS spectral data at each step gave some evidence of the
formation of the target products. The IR spectra of the synthesized phthalocyanines are very similar. After
conversion of the dinitrile precursors 2a and 3a to the phthalocyanines, the sharp C≡N vibration around 2230
−
1
cm
in the IR spectra of phthalonitriles 2a and 3a disappeared in the IR spectra of the phthalocyanine
752

¨
GOK/Turk J Chem
derivatives. IR spectra of all phthalocyanines are very similar and indicated the aromatic groups at around
− −1 −1
1
3
050 cm , the aliphatic groups at around 2900 cm , the C=O group at around 1680 cm , and the NH
−
1
groups in the macrocyclic rings at around 3280 cm
by intense bands. The only difference in the IR spectra
of the metal-free phthalocyanines and metallophthalocyanines is a NH stretching band peak at around 3300
1
−
cm
due to the inner core of all metal-free phthalocyanines. The inner core –NH protons of the metal-free
phthalocyanines are expected to be observed upfield around δ –3.00 to –6.00 ppm in the 1 H NMR spectra.35
The –NH protons of the metal-free phthalocyanines 2b and 3b were observed at around δ = –3.00 ppm in their
1
H NMR spectra.
1
The H NMR spectra of 2b−3b and 2d−3d exhibited aromatic protons at 9.14 (m, 8H, ArH), 7.50–6.85
m, 32H, ArH) for 2b, 9.01 (m, 8H, ArH), 7.63–6.86 (m, 32H, ArH) for 3b, 8.70 (m, 8H, ArH), 8.04–6.93 (m,
(
32H, ArH) for 2d and 8.58 (m, 8H, ArH), 7.55 (m, 32H, ArH) for 3d. The resonance of the NH protons of the
1
amide group in 2b−3b and 2d−3d appeared at around δ = 10.00 ppm as a singlet in their H NMR spectra.
The 1 H NMR spectra of phthalocyanine derivatives 2b−3b and 2d−3d displayed broad peaks. It has been
shown before that the extensive overlapping of the numerous protons in large phthalocyanine causes the broad
peaks.36 The 1 H NMR spectra of symmetric metal-free phthalocyanines 2b−3b and metallophthalocyanines
2
d−3d in DMSO-d6 exhibit the characteristic resonances of the macrocyclic and phthalocyanine moieties. All
1
signals in the H NMR spectra of metal-free phthalocyanines 2b−3b and metallophthalocyanines 2d−3d are
identical to those of the corresponding phthalonitriles 2a and 3a.
The results of elemental analysis were in good agreement with the proposed structures of metallophthalo-
cyanine derivatives 2c−3c and 2d−3d, but some of the metal-free phthalocyanines failed to afford satisfactory
elemental analysis. On the other hand, elemental analyses of large Pc molecules sometimes give unsatisfactory
results.3
6−38
Acquired MALDI-TOF spectra of the phthalocyanine derivatives allowed us to record molecular
ion peaks at 2252.70 [M + H]+ (2c), 2257.70 [M + H]+ (2d), 2420.53 [M + H]+ (3c), and 2425.09 [M +
H]+ (3d), confirming the proposed structures (Figure 1). All attempts to obtain molecular ion peaks for the
metal-free phthalocyanines 2b and 3b using different matrixes (2,5-dihydroxybenzoic acid (DHB) or dithranol)
in MALDI-TOF and different technique such as LC-MS failed. However, the UV-Vis, IR, and 1 H NMR spec-
troscopies for these two metal-free phthalocyanines 2b and 3b gave reasonable results confirming the identities
of the structures.
2
.2. Absorption properties
The UV-Vis absorption spectra of metal-free phthalocyanines 2b−3b in DMF and THF are shown in Figures
a and 2b. The Q band of the metal-free phthalocyanines splits into two bands in the visible region as a
result of D2h symmetry.39,40 The resolution of the split of the Q band decreases with increasing wavelength
2
and the presence of aggregated phthalocyanine species in solution.4
of metal-free phthalocyanines 2b–3b recorded in DMF, the Q band was observed without splitting at 740 and
44 nm, respectively. The large red shift or presence of aggregated species must have resulted in an unsplit
1−44
In the case of the UV-Vis spectrum
7
Q band.41,45,46 In the case of the UV-Vis spectra of metal-free phthalocyanines 2b−3b recorded in THF, the
UV-Vis spectra of metal-free phthalocyanines 2b−3b gave unclear split Q bands in the visible region at around
7
19−741 nm as expected. Attempts to record UV-Vis spectra with clear split Q bands for the metal-free
phthalocyanines 2b−3b failed due to the insolubility of metal-free phthalocyanines 2b−3b in other common
organic solvents.
7
53

¨
GOK/Turk J Chem
(
2d)
(
2c)
(
3c)
(
3d)
Figure 1. The MALDI-TOF spectra of metallophthalocyanines.
.4
1.2
.0
0.8
1
a)
b)
0
0
0
0
.6
.4
.2
.0
(
(
(
(
(
(
2b) (DMF)
2c) (DMF)
2d) (DMF)
2b) (THF)
2c) (THF)
2d) (THF)
(3b) (DMF)
(3c) (DMF)
(3d) (DMF)
(3b) (THF)
(3c) (THF)
(3d) (THF)
(3c) (DCM)
(3d) (DCM)
1
(2c) (DCM)
(
(
2d) (DCM)
2d) (CHCl
)
(3d) (CHCl
3c) (CHCl
3
)
)
3
(
3
0
.6
0.4
.2
0
0.0
300
3
00
400
500
600
700
800
400
500
600
700
800
Wavelength (nm)
Wavelength (nm)
Figure 2. Absorption spectra of phthalocyanines 2b–2d (a) and 3b–3d (b) in different solvents.
Figures 2a and 2b also show the electronic spectra of metallophthalocyanines 2c−3c and 2d−3d in DMF,
CH2 Cl2 , and THF. Deprotonation of metal-free phthalocyanines and binding metal ion to inner core forms
metallophthalocyanines with D4h symmetry. Metal complexes of substituted and unsubstituted phthalocyanines
with D4h symmetry show an intense single Q band in the visible region.36,47 In the electronic spectra of
cobalt(II) phthalocyanines 2c−3c in DMF and THF, intense Q band absorptions were observed at around 692
754

¨
GOK/Turk J Chem
nm with a weaker absorption at around 627 nm. The electronic spectra of zinc(II) phthalocyanines 2d−3d
display intense Q bands in the visible region at around 710 nm in DMF and THF with a weaker absorptions
at around 640 nm. B band absorptions were observed at around 335 nm for cobalt(II) phthalocyanines 2c−3c
and 370 nm for zinc phthalocyanines 2d−3d in DMF and THF. The values of Q and B band absorptions with
molar absorption coefficients for all phthalocyanines are given in Table 1.
Table 1. Location of the Q bands and B bands (in nm) of metal-free phthalocyanines 2b–6b and metallophthalocyanines
2
c–6c and 2d–6d in DMF and THF.
Q band,
λmax, (nm) Log ε
DMF)
B band,
λmax, (nm) Log ε
(DMF)
Q band,
λmax, (nm) Log ε
(THF)
B band,
λmax, (nm) Log ε
(THF)
Pcs
(
2
3
4
5
6
2
3
4
5
6
2
3
4
5
6
b
b
b
b
b
c
740
744
743
743
4.87
5.15
5.10
5.06
4.71
4.75, 4.27 317
5.16, 4.67 340
5.19, 4.74 336
5.17, 4.70 338
4.98, 4.58 335
5.35, 4.76 368
5.01, 4.29 368
5.24, 4.54 369
5.44, 4.80 372
4.94, 4.33 376
365, 319
366, 329
366, 330
364, 324
367, 327
5.13, 5.18 741, 718
4.62, 4.58 312, 360
5.05, 4.95
5.07, 5.01
5.22, 5.22
5.23, 5.19
4.82, 4.81
4.88
4.95
4.94
5.00
4.88
5.24, 5.21 741, 718
5.20, 5.18 741, 720
5.21, 5.23 741, 718
4.98, 5.02 741, 719
4.96, 4.90 332, 364
4.88, 4.82 332, 364
5.02, 4.96 320, 362
4.59, 4.57 328, 360
4.64, 4.40 325
4.96, 4.46 336
4.91, 4.44 333
4.99, 4.50 335
4.86, 4.38 335
4.67, 4.06 366
4.53, 3.85 366
4.65, 3.96 365
4.92, 4.22 369
4.85, 4.20 368
5
5
5
5
3
4
745
697, 629
691, 626
692, 625
694, 629
695, 634
712, 640
711, 637
711, 637
711, 637
713, 639
5.07
5.15
5.19
5.17
5.05
5.24
4.72
4.95
5.15
4.82
696, 631
692, 627
692, 627
692, 627
692, 628
710, 638
709, 636
708, 636
709, 636
709, 637
c
5
5
c
c
c
5
5
3
4
d
d
d
d
d
4.61
4.42
4.51
4.65
5
5
3
4
5
5
4.72
The UV-Vis spectra of metallophthalocyanines 2c−3c and 2d−3d displayed a similar-shaped Q band,
but with a small shift in the wavelength (Figure 2). This can be attributed to the molecular structure of
metallophthalocyanines, which share a macrocycle peripherally substituted on the phthalocyanine ring but
have different central metal ions such as zinc and cobalt for 2c−3c and 2d−3d, respectively. This structural
similarity leads to the similar shapes of their Q-bands.48
The Q band wavelength of the metallophthalocyanines 2c−3c and 2d−3d varies as the solvent is
changed. The effects of solvents on the state of aggregation of soluble phthalocyanines have been studied by
several groups and reported in numerous papers.4
9−52
The position of the Q band is affected by the polar solvents
clearly shown by the shift of the Q band to shorter wavelengths and by a decrease in their molar absorptivity.49,50
Small shifts to shorter wavelength in the position of Q bands in the UV-Vis spectra of metallophthalocyanines
were observed with increasing solvent polarity (Figure 2).
The effects of varying ring sizes of the macrocycle on the spectroscopic properties of phthalocyanines
peripherally substituted by macrocycles were investigated. In the case of phthalocyanine derivatives 2b–
2
d and 3b–3d, which are substituted by four 18- and 21-membered macrocycles with N2 S4 donor atoms,
respectively (Scheme 1), it was observed that the Q band position for the metal-free phthalocyanines 2b–3b
and metallophthalocyanines 2c–3c and 2d–3d was constant at around 740, 690, and 710 nm, respectively. A
series of structurally similar phthalocyanines 5b–5d and 6b–6d bearing 21-membered macrocycles peripherally
with different types of donor atoms reported before by our group showed similar results for the Q band
7
55

¨
GOK/Turk J Chem
positions (Scheme 2).53,54 When comparing the phthalocyanines 5b–5d and 6b–6d with the phthalocyanines
3
b–3d, phthalocyanine derivatives 5b–5d and 6b–6d contain one more oxygen and sulfur donor atoms,
respectively, instead of one carbon atom in the phthalocyanines 3b–3d. In the case of phthalocyanine derivatives
b–2d, 3b–3d, and 4b–4d, which are substituted by four 18-, 19-, and 21-membered macrocycles with
2
N2 S4 donor atoms, respectively (Scheme 3), they all have the same phthalocyanine skeleton substituted
different ring-sized macrocycles at peripheral positions.55 The Q band position for these structurally related
phthalocyanine derivatives was observed at around 740 nm for metal-free phthalocyanines, 690 nm for cobalt(II)
phthalocyanines, and 710 nm for zinc(II) phthalocyanines (Table 1). These results imply that changing one
atom in the same macrocycle or varying ring sizes of the macrocycle containing the same number and type of
donor atoms do not significantly affect the Q band position in these phthalocyanine derivatives.
S
S
O
O
S
S
S
S
O
O
S
S
O
O
O
O
S
S
S
S
HN
NH
S
S
HN
NH
NH
HN
NH
HN
HN
NH
NH
HN
S
S
S
S
O
S
S
O
O
O
O
O
S
S
S
S
S
S
N
N
M
N
N
M
N
N
N
N
N
N
N
N
N
N
N
N
N
N
M
N
N
N
N
N
N
N
S
S
S
S
S
S
O
O
O
O
NH
S
S
HN
NH
O
O
NH
S
S
HN
NH
NH
S
S
HN
NH
HN
HN
HN
S
S
S
S
S
S
O
O
O
O
S
S
O
O
S
S
S
S
S
O
S
O
6
b, 6c, 6d containing four 21-membered macrocycles
5
b, 5c, 5d containing four 21-membered macrocycles
3
b, 3c, 3d containing four 21-membered macrocycles
with N2S4 donor atoms
with N S donor atoms
2
5
with N2S4O donor atoms
Scheme 2. Phthalocyanine derivatives 3b–3d, 5b–5d, and 6b–6d containing four 21-membered macrocycles.
S
S
S
O
O
S
S
S
O
O
O
O
S
S
S
S
S
S
HN
NH
NH
HN
HN
NH
NH
HN
HN
NH
NH
HN
S
S
O
O
S
S
S
S
O
O
O
O
S
S
N
M
N
S
S
S
S
N
M
N
N
M
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
S
S
S
S
S
S
O
O
O
O
NH
HN
S
S
HN
NH
O
O
HN
NH
NH
S
S
HN
NH
NH
HN
S
S
S
S
HN
S
S
S
S
O
O
S
S
O
O
O
S
O
S
S
S
4
b, 4c, 4d containing four 19-membered macrocycles
with N donor atoms
2
b, 2c, 2d containing four 18-membered macrocycles
3b, 3c, 3d containing four 21-membered macrocycles
with N donor atoms
2 4
S
with N donor atoms
2
S
4
2 4
S
Scheme 3. Phthalocyanine derivatives containing four macrocycles of different ring sizes: 2b–2d with 18-membered
macrocycle, 3b–3d with 21-membered macrocycle, and 4b–4d with 19-membered macrocycle.
756

¨
GOK/Turk J Chem
2
.3. Extraction of metal picrates
The metal ion binding properties of N,N’-(2,2’-(4,5-dicyano-1,2-phenylene)bis(sulfanediyl)bis(2,1-phenylene))bis(2-
chloroacet-amide) 1, cobalt(II) phthalocyanines 2c–3c, and zinc(II) phthalocyanines 2d–3d were determined by
+
2+
using solvent extraction experiments in order to estimate the extractability of metal ions such as Ag , Hg
,
Cd2+ , Zn2+ , Cu2+ , Ni2+ , Pb2+ , and Co2+ from the aqueous phase to the organic phase. The metal ion-
binding properties of phthalonitriles 2a and 3a were reported before.31 Chloroform was tested as the organic
solvent to reveal extraction efficiency. The results related to the extractability of the above metal picrates from
aqueous phase to organic phase are given in Table 2 and illustrated in Figure 3.
Figure 3. The extractability of aqueous metal picrates for 1, 2a, 2c, 2d (a) and 1, 3a, 3c, 3d (b) into the chloroform
phase.
Table 2. The extractability of aqueous metal picrates for all compounds into the chloroform phase.
a
Metal ion Extractability (%)
(
< 1
< 1
1)
(2a)
14.5 ꢀ 0.2 < 1
4.6 ꢀ 0.6
(3a)
(2c)
(2d)
< 1
(3c)
< 1
(3d)
< 1
10.7 ꢀ 1.0
Ni2
Cu
+
6.4 ꢀ 0.4
2
+
0
20.9 ꢀ 1.3 27.6 ꢀ 0.9 8.7 ꢀ 0.7
2
+
Hg
16.0 ꢀ 2.2 11.5 ꢀ 0.3 38.8 ꢀ 1.7 80.5 ꢀ 1.5 81.9 ꢀ 2.9 78.3 ꢀ 1.7 81.7 ꢀ 0.3
2
+
Zn
Ag
Cd
Pb
Co
0
0
0
9.3 ꢀ 1.4
11.3 ꢀ 1.9 1.5 ꢀ 0.5
15.0 ꢀ 1.8
+
3.9 ꢀ 0.5
9.1 ꢀ 0.6
16.1 ꢀ 0.9 94.8 ꢀ 1.5 91.2 ꢀ 1.6 91.7 ꢀ 0.3 93.3 ꢀ 0.7
2
+
+
+
< 1
< 1
< 1
0
8.2 ꢀ 1.6
1.7 ꢀ 0.1
1.3 ꢀ 0.3
< 1
2
< 1
< 1
1.5 ꢀ 0.3
0
22.0 ꢀ 0.3 11.2 ꢀ 0.3 3.5 ꢀ 0.3
7.5 ꢀ 0.3
2
< 1
5.8 ꢀ 1.4
< 1
< 1
< 1
a
Temperature: 20.0 ꢀ 0.1 C; aqueous phase (10 mL); [Pic ] = 1.25 × 10−5 M, organic phase (10 mL); [L] = 1.25 ×
◦
−
−4
1
0
M; the values calculated from three independent extraction experiments.
As seen from Table 2, precursor acetamide compound 1 with an open ring exhibited the lowest extraction
efficiency for all the metal ions in chloroform. The best extractability belongs to the Hg2+ ion in chloroform
by 16.0%. The reaction of precursor acetamide compound 1 with appropriate dithiol afforded phthalonitriles
2
a and 3a, which are 18- and 21-membered macrocycles with N2 S4 donor atoms, respectively. Both of the
macrocycles possess the same number and type of donor atoms in the macrocyclic ring but have different cavity
size. The 18-membered macrocycle with nitrogen sulfur donor atoms 2a extracted Ag+ and Hg2+ ions to the
organic phase with 9.1% and 11.5%, respectively. The extraction values obtained in the presence of phthalonitrile
7
57

¨
GOK/Turk J Chem
3
a for Ag+ and Hg2+ in chloroform were relatively high when compared to those of compounds 1 and 2a. It
extracted Ag+ and Hg2+ ions to the chloroform phase with 16.1% and 38.8%, respectively. Cation binding
properties depend upon different factors such as macrocyclic effect, cavity size, and the type and number of
donor atoms.56,57 The high extraction efficiency in the presence of macrocycles compared to the results in the
case of precursor acetamide 1 with an open ring can be interpreted as the result of the macrocyclic effect and
the increment in the size of the macrocycles.
As seen from Scheme 1, all phthalocyanine derivatives contain either four 18-membered macrocycles (2b,
2
c, 2d) or four 21-membered macrocycles (3b, 3c, 3d). The E% values obtained for metal cation extraction
with all phthalocyanines were higher than those of phthalonitriles 2a and 3a in organic solvent. The highest
extractability belongs to Hg2+ and Ag+ cations with all phthalocyanines (2c, 2d, 3c, 3d) in organic solvent.
The values of extractability belonging to Hg2+ and Ag+ are in the range of 91.2%−94.8% and 78%−81%,
respectively. This showed that the extraction capabilities of the phthalocyanine containing macrocycles increase
compared to those of corresponding macrocycles.
The systematic changes in macrocyclic ligands’ structures such as variation in donor atom sets and the
macrocyclic cavity size have certain effects on macrocycle selectivity towards metal ions.58 Table 3 contains a
comparison of the results of the current study with those of previous studies for cation-macrocycle interaction
for Ag(I) and Hg(II) metal ions with a series of closely structures containing macrocycles.27,59,60 The extraction
values given in Table 3 referred to the conditions when the macrocycles were attached to either a phthalocyanine
or porphyrazine skeleton. As seen clearly from Table 3, the extraction results for Ag(I) and Hg(II) metal ions
obtained from different studies with a series of closely structures showed similar behavior. It can be concluded
that the increasing extraction capability is due to the planarity of phthalocyanines and porphyrazines skeleton
and increasing number of the macrocyclic unit in phthalocyanines and porphyrazines.
+
2+
Table 3. The extractability values of Ag and Hg
ions with a series of closely related ligands.
Donor atom % Extractability
sets Ag(I) Hg(II)
9-membered N2S4
1-membered N2S4
6-membered NS5
4-membered S2O2
4-membered S4
Ring size
Reference
1
2
1
1
1
1
91%
92%
93%
95%
94%
94%
81%
80%
65%
89%
86%
81%
This study
This study
[27]
[59]
[59]
8-membered S2O4
[60]
Consequently, new metal-free phthalocyanines and metallophthalocyanines containing macrocycles in
different ring sizes were synthesized and characterized. Comparison of the λmax of the phthalocyanine derivatives
2
b−3b, 2c−3c, and 2d−3d in different solvents such as DMF and THF illustrated no sensitivity of the Q
band to varying ring size of macrocycle substituted phthalocyanines. From the experimental results of the
solvent extraction, all phthalocyanines showed high extraction efficiency towards Hg2+ and Ag+ cations. They
are all excellent extractors for those cations and have the potential to be used in the efficient extraction of Ag+
and Hg2+ ions from aqueous solutions.
758

¨
GOK/Turk J Chem
3
3
. Experimental
.1. Materials
N,N’-(2,2’-(4,5-dicyano-1,2-phenylene)bis(sulfanediyl)bis(2,1-phenylene))bis(2-chloroacetamide) 1 and phthaloni-
triles 2a and 3a were prepared according to the literature.31,53 All reagents and solvents were reagent grade
quality and were obtained from commercial suppliers. All solvents were dried and purified as described by
Perrin and Armarego.61
Chloroform, dichloromethane, picric acid, Pb(NO3)2 , Co(NO3)2 .6H2 O, Cu(NO3)2 .3H2 O, Zn(NO3)2 .6H2
O, Ni(NO3)2 .6H2 O, Cd(NO3)2 .4H2 O, AgNO3 , and Hg(NO3)2 .H2 O were reagent grade quality and were pur-
chased from Merck. Demineralized water was used in the extraction experiments. The solvents were saturated
with each other before use in order to prevent volume changes of the phases during extraction.
3
.2. Equipment
FTIR spectra were measured on a PerkinElmer Spectrum 65 spectrometer in KBr pellets. 1 H and 13 C NMR
spectra were recorded on a Varian Mercury 400 MHz spectrometer in CDCl3 and DMSO-d6 (99.9%). Mass
spectra were measured on a Micromass Quatro LC/ULTIMA LC-MS/MS and a Bruker Daltonics MALDI-TOF
spectrometer. Optical spectra were recorded in the UV-Vis region with a PG T80+ spectrophotometer in 1 cm
path length cuvettes at room temperature. The elemental analyses were conducted with a LECO Elemental
Analyzer (CHNS 0932) spectrophotometer. The melting points were determined with an electrothermal appa-
ratus and are reported without correction. In the solvent extraction experiment, a Selecta type shaker with a
thermostat was used.
3
3
.3. Synthesis
.3.1. General procedure for the syntheses of metal-free phthalocyanines (2b, 3b)
A mixture of an appropriate phthalonitrile [2a (0.250 g, 0.455 mmol) and 3a (0.3 g, 0.505 mmol)] and a few
drops of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in dry n-pentanol (1.5 mL) was placed under a nitrogen
atmosphere in a standard Schlenk tube. The reaction mixture was heated and was stirred under nitrogen at
◦
1
45 C for 24 h. After cooling to room temperature, the mixture was diluted with ethanol (10 mL) until the
product precipitated. The precipitated crude product was filtered and then treated with ethanol for 4 h in a
Soxhlet extractor. It was then filtered and washed with ethanol, diethyl ether, and CH2 Cl2 and was dried
under a vacuum. Finally, pure metal-free phthalocyanines were obtained by silica gel chromatography using
CH2 Cl2 :CH3 OH (95:5).
3
.3.2. Metal-free phthalocyanine (2b)
◦
The yield was 32% (0.082 g). mp > 300 C. Anal. calcd. for C104 H82 N16 O8 S16 : C, 56.86; H, 3.76; N,
−
1
1
2
1
1
0.20%. Found: C, 55.59; H, 3.84; N, 10.13. IR (KBr disc) νmax /cm : 3381 (NH), 3284 (NH), 3051 (CHAr),
924 (CH), 1642 (C=O), 1575, 1510, 1467, 1338, 1302, 1259, 1106, 1021, 871, 742, 678. 1 H NMR (DMSO-d6)δ:
0.11 (br, s, 8H, NH), 9.14 (m, 8H, ArH), 7.50–6.85 (m, 32H, ArH), 3.53 (br, s, 16H, O=C–CH2), 2.63 (br, s,
6H, SCH2), –2.97 (br, s, 2H, NH). UV-Vis (DMF): λmax , nm (log ε): 740 (4.87), 589 (4.81), 365 (5.13), 319
(
5.18).
7
59

¨
GOK/Turk J Chem
3
.3.3. Metal-free phthalocyanine (3b)
◦
The yield was 22% (0.066 g). mp > 300 C. Anal. calcd. for C116 H106 N16 O8 S16 : C, 58.91; H, 4.52; N,
−
1
9
2
.48%. Found: C, 54.36; H, 3.68; N, 10.51. IR (KBr disc) νmax /cm : 3385 (NH), 3285 (NH), 3047 (CHAr),
907 (CH), 1671 (C=O), 1606, 1575, 1508, 1477, 1437, 1378, 1302, 1259, 1106, 1019, 871, 737, 677. 1 H NMR
(
DMSO-d6)δ: 10.01 (br, s, 8H, NH), 9.01 (m, 8H, ArH), 7.63–6.86 (m, 32H, ArH), 3.58 (br, s, 16H, O=C–CH2),
2
7
.74 (m, 16H, SCH2), 1.75–1.60 (m, 24H, SCH2), –3.55 (br, s, 2H, NH). UV-Vis (DMF): λmax , nm (log ε):
44 (5.15), 589 (4.86), 366 (5.24), 329 (5.21).
3
.3.4. General procedure for the syntheses of metallophthalocyanines (2c–3c, 2d–3d)
Phthalonitrile [2a (0.3 g, 0.546 mmol) and 3a (0.3 g, 0.505 mmol)] was reacted with anhydrous Co(CH3 CO2)2
◦
and Zn(CH3 CO2)2 in quinoline (2 mL) at 190 C for 7 h in a Schlenk tube under nitrogen in order to obtain
cobalt(II) phthalocyanines 2c–3c and zinc(II) phthalocyanines 2d–3d, respectively. At the end of this period,
the reaction mixture was cooled to room temperature. The product was precipitated by the addition of ethanol
(
10 mL) and the product was filtered. The crude product was treated with ethanol for 4 h in a Soxhlet extractor.
The green product was then filtered and washed with ethyl acetate, acetone, and diethyl ether. Finally, pure
phthalocyanines were obtained by silica gel column chromatography using CH2 Cl2 :CH3 OH (95:5).
3
.3.5. Cobalt(II) phthalocyanine (2c)
◦
The yield was 40% (0.133 g). mp > 300 C. Anal. calcd. for C104 H80 N16 O8 S16 Co: C, 55.42; H, 3.58; N,
−
1
9
1
6
.94%. Found: C, 54.68; H, 3.85; N, 9.63. IR (KBr disc) νmax /cm : 3290 (NH), 3051 (CHAr), 2914 (CH3),
681 (C=O), 1578, 1515, 1435, 1409, 1380, 1297, 1122, 1064, 958, 755. 1 H UV-Vis (DMF): λmax , nm (log ε):
97 (4.75), 629 (4.27), 317 (5.07). MS (MALDI-TOF) m/z: 2252.70 [M + H]+ .
3
.3.6. Cobalt(II) phthalocyanine (3c)
◦
The yield was 63% (0.190 g). mp > 300 C. Anal. calcd. for C116 H104 N16 O8 S16 Co: C, 57.27; H, 4.33; N,
−
1
9
2
.25%. Found: C, 57.65; H, 4.78; N, 8.84. IR (KBr disc) νmax /cm : 3279 (NH), 3058 (CHAr), 2924 (CH3),
861, 1683 (C=O), 1578, 1514, 1435, 1408, 1379, 1298, 1118, 1070, 959, 755. UV-Vis (DMF): λmax , nm (log
+
+
ε): 691 (5.16), 626 (4.67), 340 (5.15). MS (MALDI-TOF) m/z: 2420.53 [M + H] , 2514.91 [M + 4Na] .
3
.3.7. Zinc(II) phthalocyanine (2d)
◦
The yield was 20% (0.060 g). mp > 300 C. Anal. calcd. for C104 H80 N16 O8 S16 Zn: C, 55.26; H, 3.57; N,
−
1
9
.91%. Found: C, 54.58; H, 3.70; N, 9.54. IR (KBr disc) νmax /cm : 3270 (NH), 3055 (CHAr), 2918 (CH3),
665 (C=O), 1577, 1512, 1434, 1370, 1296, 1111, 1062, 938, 756. 1H NMR (DMSO-d6): δ 10.17 (br, s, 8H,
1
NH), 8.70 (m, 8H, ArH), 8.04–6.93 (m, 32H, ArH), 3.51 (br, s, 16H, O=C–CH2), 3.11 (br, s, 16H, SCH2).
UV-Vis (DMF): λmax , nm (log ε): 712 (5.35), 640 (4.76), 368 (5.24). MS (MALDI-TOF) m/z: 2257.70 [M +
+
H] .
760

¨
GOK/Turk J Chem
3
.3.8. Zinc(II) phthalocyanine (3d)
◦
The yield was 16% (0.048 g). mp > 300 C. Anal. calcd. for C116 H104 N16 O8 S16 Zn: C, 57.37; H, 4.32; N,
−
1
9
2
.23%. Found: C, 53.44, H, 4.70; N, 8.45. IR (KBr disc) νmax /cm : 3278 (NH), 3058 (CHAr), 2924 (CH3),
1
852, 1660 (C=O), 1578, 1512, 1434, 1372, 1298, 1110, 1062, 939, 756. H NMR (DMSO-d6): δ 10.06 (br,
s, 8H, NH), 8.58 (m, 8H, ArH), 7.55 (m, 32H, ArH), 3.33 (br, s, O=CH2 Cl), 2.66 (m, 16H, SCH2), 1.65 (m,
2
2
4H, SCH2). UV-Vis (DMF): λmax , nm (log ε): 711 (5.01), 637 (4.29), 368 (4.72). MS (MALDI-TOF) m/z:
425.09 [M + H]+ .
3
.4. Extraction method
The metal ion binding properties of N,N’-(2,2’-(4,5-dicyano-1,2-phenylene)bis(sulfanediyl)bis(2,1-phenylene))bis(2-
chloroacet-amide) 1, cobalt(II) phthalocyanines 2c−3c, and zinc(II) phthalocyanines 2d−3d were investi-
gated by liquid–liquid solvent extraction. Picrate extraction experiments were performed following published
procedures.3
1−34,62
Solvent extraction experiments were carried out using aqueous metal picrate solutions,
which were prepared from a mixture of the metal nitrates (Pb(NO3)2 , Co(NO3)2 .6H2 O, Cu(NO3)2 .3H2 O,
Zn(NO3)2 .6H2 O, Ni(NO3)2 .6H2 O, Cd(NO3)2 .4H2 O, AgNO3 , Hg(NO3)2 .H2 O) and picric acid in deionized
water. Chloroform was tested as organic solvent in extraction experiments. An organic solution (10 mL) of
−
4
−5
−2
ligand (1.25 × 10
M) and an aqueous solution (10 mL) containing 1.25 × 10
M picric acid and 1 × 10
◦
M metal nitrate were placed in stoppered flask and shaken for 2 h at 20 ꢀ 0.1 C. Then the resulting mixtures
were allowed to stand for least 2 h at that temperature in order to complete the phase separation. The concen-
tration of the picrate ion remaining in the aqueous phase was then determined by UV-Vis spectrophotometer
at 355 nm. A blank experiment was performed in the absence of host and showed that no picrate extraction
occurred.
The extractability (E %) was determined as the absorbance of picrate in aqueous solutions. The
extractability was calculated from the following equation:
[
A0 − A]
A0
E(%) =
× 100,
(1)
where A0 is the absorbance in the absence of ligand and A the absorbance in the aqueous phase after extraction.
Acknowledgments
¨
˙
This study was supported in part by the Scientific and Technological Research Council of Turkey (TUBITAK)
(
Project No: TBAG-109T806). Dr Hasan Demir from the Department of Chemical Engineering at Osmaniye
¨
Korkut Ata University and Ozg u¨ r Do ˘g an are gratefully acknowledged for their assistance.
References
1
.
Erk, P.; Hengelsberg, H. In The Porphyrin Handbook: Applications of Phthalocyanines; Kadish, K. M.; Smith, K.
M.; Guilard, R., Eds. Elsevier: San Diego, CA, USA; 2003.
¨
2
3
4
.
.
.
Topuz, B. B.; G u¨ nd u¨ z, G.; Mavis, B.; C¸ olak, U. Dyes Pigments 2013, 96, 31–37.
Yoo, E.; Zhou, H. J. Power Source 2013, 244, 429–434.
Sorokin, A. B. Chem. Rev. 2013, 113, 8152–8191.
7
61

¨
GOK/Turk J Chem
5
6
7
8
9
.
.
.
.
.
Sizun, T.; Bouvet, M.; Chen, Y.; Suisse, J. S.; Barochi, G.; Rossignol, J. Sens. Actuators B 2011, 159, 163–170.
Valli, L. Adv. Colloid Interface Sci. 2005, 116, 13–44.
Zorlu, Y.; Dumoulin, F.; Denis, B.; Ahsen, V.; Lafont, D. Tetrahedron Lett. 2010, 51, 6615–6618.
Leznoff, C. C.; Lever, A. B. P. Phthalocyanines: Properties and Applications; VCH: New York, NY, USA, 1996.
Christie, R. M. Dyes Pigments 1995, 27, 35–43.
1
1
1
1
1
1
1
1
0. Y u¨ ksel, F.; G u¨ rek, A. G.; Lebrun, C.; Ahsen, V. New J. Chem. 2005, 29, 726–732.
1. Nyokong, T. Chem. Rev. 2007, 251, 1707–1722.
2. Akinbulu, I. A.; Nyokong, T. Polyhedron 2010, 29, 1257–1270.
3. C¸ akır, D.; Bekircan, O.; Bıyıklıo ˘g lu, Z. Synthetic Metals 2015, 201, 18–24.
4. Eberhardt, W.; Hanack, M. Synthesis 1997, 95–100.
5. Bilgin, A.; Yanmaz, D.; Ya g˘ cı, C¸ . Turk. J. Chem. 2014, 38, 1135–1152.
6. W ¨o hrle, D.; Tsaryova, O.; Semioshkin, A.; Gabel, D.; Suvorova, O. J. Organomet. Chem. 2013, 747, 98–105.
7. Evren, D.; Yenilmez, H. Y.; Kalkan Burat, A. Turk. J. Chem. 2014, 38, 1174–1184.
¨
1
1
2
8. Koray, A. R.; Ahsen, V.; Bekaro g˘ lu, O. Chem. Commun. 1986, 932–933.
9. Demirayak, N.; Akku ¸s , F.; G ¨o k, Y. Inorg. Chem. Commun. 2013, 37, 97–100.
0. Bilgin, A.; Ertem, B.; G ¨o k, Y. Tetrahedron Lett. 2003, 44, 6937–6941.
˙
¨
2
2
1. Kandaz, M.; Yılmaz, I.; Bekaro ˘g lu, O. Polyhedron 2000, 19, 115–121.
2. Rosenthal, I.; Ben-Hur, E.; Greenberg, S.; Concepcion-Lam, A.; Drew, D.; Leznoff, C. C. Photochem. Photobiol.
1
987, 46, 959–963.
2
2
2
3. Hancock, R. D.; Martell, A. E. Chem. Rev., 1989, 89, 1875–1914.
¨
4. Ocak, U.; G ¨o k, Y.; S¸ ent u¨ rk, H. B. Sep. Sci. Technol. 2009, 44, 1240–1249.
¨
5. Kantekin, H.; Kılı ¸c aslan, M. B.; A ˘g ın, F.; Alp, H.; Ocak, U. J. Coord. Chem. 2010, 63, 1921–1932.
¨
2
2
2
2
6. Ocak, U.; Alp, H.; G ¨o k ¸c e, P.; Ocak, M. Sep. Sci. Technol. 2006, 41, 391–401.
7. Ertem, B.; Bilgin, A.; Kantekin, H.; G ¨o k, Y. Polyhedron 2008, 27, 2186–2192.
8. Bıyıklıo ˘g lu, Z.; Kantekin, H. J. Organomet. Chem. 2008, 693, 505–509.
9. Kantekin, H.; Dilber, G.; Nas, A. J. Organomet. Chem. 2010, 695, 1210–1214.
˙
3
3
0. Bıyıklıo ˘g lu, Z.; Acar, I., Kantekin, H. Inorg. Chem. Chem. 2008, 11, 630–632.
1. G ¨o k, H. Z.; Demir, H. J. Incl. Phenom. Macrocycl. Chem. 2015, 81, 95-104.
¨
3
2. Alp, H.; G ¨o k, H. Z.; Kantekin, H.; Ocak, U. J. Hazard. Mater. 2008, 159, 519–522.
¨
3
3
3. G ¨o k, H. Z.; Ocak, U.; Kantekin, H.; Alp, H. Transit. Met. Chem. 2007, 323, 1073–1078.
4. G ¨o k H. Z.; Demir H. Sep. Sci. Technol. 2015, DOI 10.1080/01496395.2014.983247.
¨
3
3
3
5. Oz ¸c elik, S¸ .; Koca, A.; G u¨ l, A. Polyhedron 2012, 42, 227–235.
6. Zhao, Z.; Nyokong, T.; Maree, M. D. Dalton Trans. 2005, 3732–3737.
7. Maruccio, S. M.; Svirskaya, P. I.; Greenberg, S.; Lever, A. B. P.; Leznoff, C. C.; Tomer, K. B. Can. J. Chem. 1985,
6
3, 3057–3069.
3
3
4
8. Ogunbayo, T. B.; Abimbola, O.; Nyokong, T. Dyes Pigments 2009, 82, 422–426.
9. Kabay, N.; G ¨o k, Y. Inorg. Chem. Commun. 2011, 14, 1880–1883.
0. Hanack, M.; Heckman, H.; Polley, R. In Methods of Organic Chemistry: Additional Supplementary Volume, Georg
Thieme Verlag: Stuttgart, Germany, 1998.
762

¨
GOK/Turk J Chem
4
4
4
4
4
4
4
4
1. Kobayashi, N.; Ogata, H.; Nonaka, N.; Lukyanets, E. A. Chem. Eur. J. 2003, 20, 5123–5134.
2. Ogunbayo, T.; Nyokong, T. Polyhedron 2009, 28, 2710–2718.
3. Nostrum, C. F.; Picken, S. J.; Nolte, R. J. M. Angew. Chem. Int. Ed. 1999, 33, 2173–2175.
4. Leznoff, C. C.; Suchozak, B. Can. J. Chem. 2001, 79, 878–887.
5. Engelkamp, H.; Nolte, R. J. M. J. Porphyrins. Phthalocyanines 2000, 4, 454–459.
6. Yanık, H.; Aydın, D.; Durmu ¸s , M.; Ahsen, V. J. Photochem. Photobiol. A 2009, 206, 18–26.
7. Takahashi, K.; Kawashima, M.; Tomita, Y.; Itoh, M. Inorg. Chim. Acta 1995, 232, 69–73.
8. Tian, M.; Wada, T.; Sasabe, H. J. Heterocycl. Chem. 2000, 37, 1193–1202.
¨
4
5
5
5
5
5
5
5
5
5
9. Ko ¸c ak, M.; G u¨ rek, A.; G u¨ l, A.; Bekaro g˘ lu, O. Chem. Ber. 1994, 127, 355–358.
0. Din ¸c er, H.; Gonca, E.; G u¨ l, A. Dyes Pigments 2008, 79, 166–169.
1. Ogunsipe, A.; Nyokong, T. J. Mol. Struct. 2004, 689, 89–97.
2. Durmu ¸s , M.; Ahsen, V.; Nyokong, T. J. Photochem. Photobiol. A: Chem. 2007, 186, 323–329.
3. G ¨o k, H. Z.; Farsak, B. J. Organomet. Chem. 2013, 735, 65–71.
4. G ¨o k, H. Z.; Farsak, B.; Kele ¸s , H.; Kele ¸s , M. Turk. J. Chem. 2014, 38, 1073–1082.
5. G ¨o k, H. Z.; Farsak, B. J. Mol. Struct. 2013, 1054–1055, 25–31.
6. Izatt, R. M.; Bradshaw, J. S.; Nielsen, S. A.; Lamb, J. D.; Christensen, J. J. Chem. Rev. 1985, 85, 271–339.
7. Hancock, R. D.; Martell, A. E. Chem. Rev. 1989, 89, 1875–1914.
8. Izatt, R. M.; Pawlak, K.; Bradshaw, J. S. Chem. Rev. 1995, 95, 2529–2586.
¨
5
6
6
9. Kabay, N.; Baygu, Y.; Ocak, U.; G u¨ n, S.; G ¨o k, Y. Sep. Sci. Technol. 2015, 10.1080/01496395.2014.978468.
0. Kabay, N.; Baygu, Y.; Alpoguz, H. K.; Kaya, A.; G ¨o k, Y. Dyes Pigments 2013, 96, 372–376.
1. Perrin, D. D.; Armarego, W. L. F. Purification of Laboratory Chemicals. 2nd ed., Pergamon Press: Oxford, UK,
1
989.
6
2. G ¨o k, H. Z.; G ¨o k, Y.; Eker, E. Turk. J. Chem. 2015, 39, 426–437.
7
63