Tetrasubstituted Phthalocyanines with Benzoic Acids Moieties

Article abstract of DOI:10.1134/S1070363219060264

Phthalonitriles substituted with o-hydroxybenzoic, o-aminobenzoic, and o-mercaptobenzoic acids moieties were synthesized by nucleophilic substitution of bromine in 4-bromophthalonitrile and of nitro group in 4-nitrophthalonitrile. Template condensation of

Full text of DOI:10.1134/S1070363219060264

ISSN 1070-3632, Russian Journal of General Chemistry, 2019, Vol. 89, No. 6, pp. 1297–1306. © Pleiades Publishing, Ltd., 2019.
Russian Text © The Author(s), 2017, published in Rossiiskii Khimicheskii Zhurnal, 2017, Vol. 61, No. 1, pp. 67–76.
Tetrasubstituted Phthalocyanines with Benzoic Acids Moieties
D. A. Kuznetsovaa*, T. V. Tikhomirovaa**, V. E. Maizlisha***, and G. P. Shaposhnikova****
a Research Institute of Macroheterocycles, Ivanovo State University of Chemical Technology,
Sheremetevskii pr. 7, Ivanovo, 153000 Russia
e-mail: *dashaf305@mail.ru; **tararjkina@mail.ru; ***maizlish@isuct.ru; ****ttoc@isuct.ru
Received January 1, 2017; revised June 19, 2019; accepted June 20, 2019
Abstract—Phthalonitriles substituted with o-hydroxybenzoic, o-aminobenzoic, and o-mercaptobenzoic acids
moieties were synthesized by nucleophilic substitution of bromine in 4-bromophthalonitrile and of nitro group
in 4-nitrophthalonitrile. Template condensation of these phthalonitriles with metal acetates gave the
corresponding phthalocyanines. Metal-free phthalocyanines were synthesized by dissociation of the magnesium
complexes of the substituted phthalocyanines in a sulfuric acid medium. Treatment of the resultant phthalo-
cyanines with sodium ethoxide in ethanol yielded sodium salts of the carboxylic acids. The spectral properties
of the compounds synthesized were examined.
Keywords: nitrile, phthalocyanine, metal complexes, electronic absorption spectra
DOI: 10.1134/S1070363219060264
Phthalocyanine (H2Pc) and its metal complexes
have been attracting steady interest over the years due
to their unique structure and physicochemical properties
[1, 2]. A special place among substituted phthalo-
cyanines belongs to carboxyl-containing compounds
which, in the form of alkali metal salts, are perfectly
soluble in water. Moreover, carboxyl substituents in
the phthalocyanine molecule provide a convenient
opportunity for its further functionalization, e.g., via
esterification reaction.
influence of the nature of carboxyl-containing peripheral
substituents on the properties of phthalocyanine series
compounds, we synthesized herein substituted phthalo-
cyanines containing o-aminobenzoic, o-hydroxy-
benzoic, and o-mercaptobenzoic acids moieties.
Synthesis of the starting phthalonitriles constituted
an integral part of this study, since the nitrile method
for the preparation of phthalocyanines is the most
effective [1].
The initial substances for the synthesis of
substituted nitriles were 4-nitrophthalonitrile 1 [7] and
4-bromophthalononitrile [8], which are currently the
most popular substrates for nucleophilic substitution
reactions [9]. The electron-withdrawing substituents
(C≡N groups) in the benzene nuclei of compounds 1,
4, as well as polarization of the C–Br or C–NO2 bonds,
are responsible for the appearance of an effective
positive charge on the carbon atom with a bromine
(nitro group) attached, which facilitates substitution of
the halogen atoms or nitro groups. We used nucleo-
philes of different nature, specifically, commercially
available o-aminobenzoic, o-mercaptobenzoic, and
o-hydroxybenzoic acids. The electron-withdrawing
carboxy group in the ortho position accounts for
decreased reactivity of the nucleophile. Reactions of
nucleophilic substitution are carried out in the presence
of an alkaline agent (triethylamine, potassium carbonate).
The currently available literature describes applica-
tions of carboxyl-containing phthalocyanines in various
fields of science and technology. For example,
aluminum and zinc complexes of 2,3,9,10,16,17,23,24-
octacarboxyphthalocyanines, which are highly soluble
in aqueous media (in the form of alkali metal salts),
particularly at physiological pH, are promising
photosensitizers for photodynamic therapy due to
effective generation of reactive oxygen species [3].
Good performance in catalytic therapy is shown by
cobalt complex (Teraphthal®) which, in the presence
of ascorbic acid, catalyzes the formation of reactive
oxygen species under no-light conditions [4]. Also,
carboxyl-containing phthalocyanines exhibit dyeing,
catalytic, and liquid-crystal properties [1, 5, 6].
With the view of expanding the range of carboxyl-
substituted phthalocyanines and elucidating the
1297

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KUZNETSOVA et al.
Scheme 1.
HOOC
X
7
5
COOH
XH
1
3
(1) DMF, Et3N
(2) HCl
6
NC
NC
NO2
NC
NC
+
4
2
1
2, 3
X = NH (2), S (3).
An important role in nucleophilic substitution
reactions is played by the solvent. In this study, DMF
was the solvent of choice, because in aprotic solvents
nucleophilic substitution reactions are accelerated by
3–5 orders of magnitude compared to those conducted
in aprotic nonpolar solvents [10].
yield. The end product was a viscous brown mass,
consisting mainly of pitchwood and 4-
nitrophthalonitrile, as proven by IR spectroscopy. In
this situation, we changed the substrate from 4-
nitrophthalonitrile 1 to 4-bromophthalonitrile 4, and
carried out the reactions in the presence of potassium
carbonate rather than of triethylamine (Scheme 2).
The time of the reaction between the starting
compounds used for the synthesis of phthalonitriles 2,
3, 5 was determined from the absence of unreacted
starting phthalonitrile 1, 4 in the reaction mixture
sample, almost completely dissolved in water.
According to existing views on the role of
potassium carbonate, nucleophilic substitution
reactions between halogen-substituted substrates and
aryloxy compounds in the presence of K2CO3 proceed
by the following scheme [9]. The aryloxy compound is
initially chemisorbed on the K2CO3 surface, and this is
accompanied by its deprotonation with formation of a
reactive six-membered complex. The latter sub-
sequently reacts with the carbon atom in position (4) of
the starting nitrile 4, giving a sigma complex which
undergoes the loss of bromine and decomposition. The
reaction product is desorbed from the interface into the
DMF solution, thereby enabling further ArOH
deprotonation events on the K2CO3 surface. Thus, the
role of potassium carbonate eventually consists in
conversion of ArOH to ArO– anion which is more
reactive towards nucleophilic substitution than ArOH.
The reactions of 4-nitrophthalonitrile with o-amino-
benzoic and o-mercaptobenzoic acids in the presence
of triethylamine in DMF yielded 4-(2-carboxy-
phenylamino)- (2) and 4-(2-carboxyphenylthio)
phthalonitriles (3) (Scheme 1). Isolation of the target
phthalonitriles is based on the directly opposite
characteristics of the water solubility of carboxylic
acids and their alkali metal salts. The synthesis
procedure yields phthalonitriles in the form of
potassium salts of the corresponding carboxylic acids,
occurring in solution due to their good solubility.
Accordingly, the reaction mixture was poured into 2 M
solution of hydrochloric acid, and a precipitate was
formed due to conversion of the potassium salts of
phthalonitriles to the corresponding carboxylic acids 2,
3, which are insoluble in water.
The phthalonitriles 2, 3, 5 synthesized appeared as
beige powders, well-soluble in acetone, DMF, and
DMSO.
As to reaction of 4-nitrophthalonitrile with o-hyd-
roxybenzoic acid under conditions similar to those in
Scheme 1, it did not give the target product in a good
The nature of the bridging group in the molecules
of phthalonitriles affects their melting points. For
example, phthalonitrile containing an o-mercapto-
Scheme 2.
HOOC
O
7
5
COOH
1
3
(1) DMF, K2CO3
(2) HCl
6
NC
NC
Br
NC
NC
+
OH
4
2
4
5
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TETRASUBSTITUTED PHTHALOCYANINES WITH BENZOIC ACIDS MOIETIES
δ, ppm
Fig. 1. 1H NMR spectrum of compound 3 in CDCl3.
benzoic acid residue melts at 141°C; the melting point
of the phthalonitrile with the bridging sulfur atom
replaced by oxygen is 146°C; and in the presence of
the NH group the melting point increases to 161°C.
vibration of the C–S bond, and that of compound 5,
absorption of Ar–O–Ar at 1251 cm–1 [11].
Good solubility in organic solvents, including
chloroform, allowed 1H NMR spectroscopic
examination of the phthalonitriles synthesized. In the
spectra recorded in deuterated chloroform the signals
were observed at low fields, as characteristic of
protons from the benzene rings of the substituted
benzoic acid residues and of phthalonitrile. The
absence of a proton signal from hydroxy groups can be
explained by deuterium exchange [12].
Phthalonitriles 2, 3, 5 were identified using
elemental analysis, IR and 1H NMR spectroscopy, and
MALDI-TOF spectrometry.
Comparison of the IR spectra of the starting (1, 4)
and target (2, 3, 5) phthalonitriles reveals that the
bands attributable to the stretching vibrations of the
nitrile group at 2230–2240 cm–1 are preserved, and
those characteristic of vibrations of the NO2 group
(1531 and 1355 cm–1) and of the C–Br bond (598 cm–1)
disappeared [11]. In the spectra of compounds 3, 5, an
absorption band appears in the 1729–1738 cm–1 range
as characteristic of the stretching vibrations of the
C=O bond of carboxylic acids. For compound 2, the
C=O vibration is observed at 1672 cm–1, probably due
to the secondary amino group in the ortho position
with respect to the carboxyl substituent, enabling
intramolecular hydrogen bonding [11]. The IR
spectrum of nitrile 2 reveals absorption at 1593 cm–1
associated with bending, and that at 3367 cm–1, with
stretching, vibrations of the N–H bonds of the
secondary amino group. Also, there is a band at
1307 cm–1, corresponding to vibrations of the C–N
bond, and absorption attributable to hydrogen bonds is
observed at 3367 cm–1. The IR spectrum of nitrile 3
exhibits absorption at 996 cm–1 corresponding to the
For example, the 1H NMR spectrum of compound 3
(Fig. 1), recorded in deuterated chloroform, exhibits a
low-field multiplet at 7.49–7.46 ppm due to resonance
of proton (4) from the mercaptobenzoic acid residue,
substituted at ortho position with respect to the C–S
bond, and also a multiplet at 7.57–7.54 ppm, arising
from proton (6) in the para position with respect to the
sulfur atom. A multiplet at 7.83–7.81 ppm corresponds
to the resonance of proton (5) from the mercapto-
benzoic acid residue at the para position with respect
to the carboxy group, and a doublet at 7.87 ppm, to the
signal from proton (2) of the phthalonitrile residue.
The signals from protons (7) and (1) appeared as
doublets at 7.93 and 7.95 ppm, respectively. The
resonance of proton (3) from the phthalonitrile residue
was observed as a multiplet at the lowest field (8.05–
8.03 ppm).
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KUZNETSOVA et al.
Scheme 3.
HOOC
NC
X
NC
2, 3, 5
M(CH3COO)2·xH2O
urea
H2NOC
X
HOOC
X
X
X
H2NOC
HOOC
N
N
N
N
N
N
N
N
N
H2SO4
M
N
M
N
N
N
N
N
N
CONH2
COOH
X
X
X
X
CONH2
COOH
6−8
M = Co (a), Cu (b); x = 0 (a), 2 (b); X = NH (2, 6), S (3, 7), O (5, 8).
Having identified the phthalonitriles 2, 3, 5 syn-
thesized, we proceeded to the next stage of the study,
consisting of synthesis and examination of the physico-
chemical properties of the corresponding phthalo-
cyanines. Metal phthalocyanines 6–8 were synthesized
by the “nitrile” method (Scheme 3).
indicated the formation of phthalocyanines containing
carbamoyl groups (–CONH2). The products were
reprecipitated from concentrated sulfuric acid, which
led to acid hydrolysis of the carbamoyl groups with
conversion of the phthalocyanines to the corresponding
carboxylic acids.
To this end, substituted phthalonitriles 2, 3, 5 were
carefully triturated with cobalt or copper acetate, and
the resulting mixture was heated at 180–190°C in the
presence of urea. The complexes synthesized were
purified by reprecipitation from concentrated sulfuric
acid.
The phthalocyanines 6–8 synthesized were blue-
green powdered substances soluble in DMF and
aqueous alkali solutions.
The reaction of phthalonitriles 3, 5 with magnesium
acetate in the presence of urea at 180–190°C gave the
corresponding magnesium phthalocyanines from
which ligands 9, 10 were isolated by reprecipitation
from concentrated sulfuric acid (Scheme 4).
The resulting phthalocyanines were soluble in DMF
though insoluble in water and alkaline solutions, which
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TETRASUBSTITUTED PHTHALOCYANINES WITH BENZOIC ACIDS MOIETIES
Scheme 4.
HOOC
X
X
HOOC
N
(1) Mg(CH3COO)2·xH2O
urea
(2) H2SO4
HOOC
X
HN
N
N
N
N
NC
NC
NH
N
COOH
3, 5
X
X
COOH
9, 10
X = S (3, 9), O (5, 10).
The phthalocyanine ligands 9, 10 synthesized were
green and blue-green powdered substances, soluble in
DMF and aqueous alkaline solutions. Attempts to carry
out synthesis with 4-(2-carboxyphenylamino)phthalo-
nitrile under identical conditions were unsuccessful.
Carboxyphthalocyanine sodium salts are well-
soluble in water, which is essential from the viewpoint
of their useful applications [1–4]. Accordingly, the
synthesized phthalocyanines 9, 10 were treated with a
solution of sodium ethoxide in ethanol to obtain the
Electronic absorption spectra of phthalocyanines 6–13
λ
max, nm (D/Dmax)
Comp. no.
Compound
DMF
H2O
–
H2SO4
6a
CoPc(4-NH-C6H4-COOH)4
CuPc(4-NH-C6H4-COOH)4
CoPc(4-S-C6H4-COOH)4
CuPc(4-S-C6H4-COOH)4
CoPc(4-O-C6H4-COOH)4
CuPc(4-O-C6H4-COOH)4
H2Pc(4-S-C6H4-COOH)4
H2Pc(4-O-C6H4-COOH)4
CoPc(4-NH-C6H4-COONa)4
CuPc(4-NH-C6H4-COONa)4
CoPc(4-S-C6H4-COONa)4
CuPc(4-S-C6H4-COONa)4
H2Pc(4-S-C6H4-COONa)4
CoPc(4-O-C6H4-COONa)4
CuPc(4-O-C6H4-COONa)4
668
762
6b
642, 682 (0.76, 1.00)
–
818
7a
668
–
766
7b
636, 682 (0.66, 1.00)
–
748, 775 (0.88, 1.00)
8a
669
–
702, 786 (0.27, 1.00)
8b
640, 682 (0.66, 1.00)
–
702, 790 (0.19, 1.00)
9
617, 683 (0.38, 1.00)
–
800
10
658, 691 (0.98, 1.00)
–
777, 838 (0.91, 1.00)
11a
11b
12a
12b
12c
13a
13b
–
–
–
–
–
–
–
631
757
640, 690 (1.00, 0.84)
818
633, 675 (1.00, 0.94)
759
640
775
647, 681 (1.00, 0.86)
742, 782 (0.80, 1.00)
634
643
785
790
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KUZNETSOVA et al.
Scheme 5.
HOOC
X
X
HOOC
N
N
HN
N
N
N
N
NH
COOH
X
X
COOH
9, 10
C2H5ONa
NaOOC
X
HOOC
X
X
X
NaOOC
HOOC
N
N
N
N
N
N
N
N
N
C2H5ONa
M
N
N
M
N
N
N
N
N
COONa
COOH
X
X
X
X
COONa
COOH
6−8
X = S (7, 9, 12), O (8, 10, 13), NH (6, 11); M = Co (a), Cu (b), 2Na (c).
sodium salts of the corresponding phthalocyanines
(Scheme 5).
cyanines there is an absorption band at 1012–1013 cm–1
characteristic for metal-free phthalocyanines [13].
The resulting phthalocyanines were characterized by
elemental analysis, electronic spectroscopy, and
MALDI-TOF spectrometry.
The positions of the absorption bands of the syn-
thesized phthalocyanines in the electronic absorption
spectra are presented in table.
The IR spectra of compounds 6–13 show absorp-
tion bands characteristic of phthalocyanines [13], with
bands characteristic for the introduced substituents and
observed for the corresponding phthalonitriles pre-
served. Also, in the IR spectra of the substituted phthalo-
The electronic absorption spectra of cobalt
complexes 6a, 7a, 8a, which were recorded in DMF,
reveal intense absorption in the long-wavelength
region at 668 and 669 nm (Fig. 2, table). It should be
noted that the absorption band position is un-
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TETRASUBSTITUTED PHTHALOCYANINES WITH BENZOIC ACIDS MOIETIES
Fig. 3. Electronic absorption spectra of the complexes in
DMF: (1) 7a, (2) 6b, and (3) 7b.
Fig. 2. Electronic absorption spectra of the cobalt
complexes in DMF: (1) 8a, (2) 6a, and (3) 7а.
Fig. 4. Electronic absorption spectra of the copper
complexes in concentrated H2SO4: (1) 6b, (2) 8b, and (3) 7b.
Fig. 5. Electronic absorption spectrum of compound 10 in
DMF.
affected by the nature of the heteroatom in the spacer
group.
increases as S→O→NH, and for the cobalt complexes,
as NH→S→O.
In going from the metal complexes of the
phthalocyanines to the corresponding ligands, the Q-
band in the spectra splits into two equally intense
components. This is attributable to reduction in the
molecular symmetry from D4h to D2h and is charac-
teristic of phthalocyanine ligands [15] (Fig. 5, table).
In going from cobalt complex 7a to copper
complexes 6b, 7b the Q-band in the electronic
absorption spectrum recorded in DMF experiences a
slight bathochromic shift. Also, broadening of the
absorption bands of the copper complexes is observed,
indicating their greater tendency to associate (Fig. 3).
The electronic absorption spectra of the sodium
salts of the phthalocyanines synthesized, which were
recorded in water (Fig. 6, table), demonstrate
broadening and hypsochromic shifts of the absorption
bands relative to those in the spectra recorded in DMF.
These spectral patterns are indicative of strong
molecular association in solution.
A change of solvent from DMF to concentrated
sulfuric acid (Fig. 4, table) alters the spectral pattern.
For all the phthalocyanines synthesized the Q-band
experiences a significant bathochromic shift caused by
protonation of the phthalocyanine macrocycle at meso
nitrogen atoms [14]. The magnitude of the shift
substantially depends on the nature of the spacer group
and on the metal-complexing agent. For example, in
the case of the copper phthalocyanines the shift
After changing the solvent from DMF and water to
concentrated sulfuric acid the spectra of all the
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KUZNETSOVA et al.
[7] and [8], respectively. Their physicochemical charac-
teristics agreed well with those given in literature.
Synthesis of phthalonitriles 2, 3, 5 containing o-
benzoic acids residues. A round-bottomed flask
equipped with a reflux condenser and a thermometer
was charged with 1 g (0.0058 mol) of 4-nitro-
phthalonitrile, 0.0060 mol of o-amino or o-mer-
captobenzoic acid, 1.5 mL of triethylamine, and 40 mL
of DMF. The resulting mixture was heated in an air
bath to 130°C with stirring and kept at this temperature
for 2 h. Next, the reaction mixture was poured into
2 M hydrochloric acid solution. The resulting
precipitate was filtered off, rinsed with water until the
washing water became neutral, and dried.
Fig. 6. Electronic absorption spectra in water: (1) 11a, (2)
12c, and (3) 11b.
4-(2-Carboxyphenylamino)phthalonitrile (2). Yield
0.719 g (47.14%). mp 161°C. Found, %: C 67.95; H
4.06; N 15.32. C15H9N3O2. Calculated, %: C 68.44; H
synthesized phthalocyanines exhibit a significant batho-
chromic shift of the Q-band due to protonation of the
phthalocyanine macrocycle at meso nitrogen atoms
(see the table) [14].
1
3.45; N 15.96. H NMR spectrum (CDCl3), δ, ppm:
8.69 m (OH, 1H), 8.63–8.61 d.d (H3, 1H), 8.10 d (H1,
1H); 8.04 m (H7, 1H); 7.95–7.73 m (H2, 1H); 7.62–7.43
m (H2, 1H); 6.93 d (H6, 1H); 6.69–6.66 m (H4, 1H). IR
spectrum, ν, cm–1: 3367 (N–H stretch); 1593 (NH
bend); 1672 (C=O); 2228 (C≡N).
EXPERIMENTAL
All studies were carried out using the equipment of
the Center for Collective Use, Ivanovo State University
of Chemical Technology.
4-(2-Carboxyphenylthio)phthalonitrile (3). Yield
1.39 g (86%). mp 141°C. Found, %: C 63.85; H 3.42;
N 9.27; S, 11.03. C15H8N2O2S. Calculated, %: C 64.28;
H 2.88; N 9.99; S, 11.44. Mass spectrum, m/z: 279.31
[M]+; calculated M 280.30. 1H NMR spectrum
(CDCl3), δ, ppm: 8.04 m (H3, 1H); 7.95 d (H1, 1H);
7.93 d (H7, 1H); 7.88 d (H2, 1H); 7.82 m (H5, 1H);
7.56 t (H6, 1H); 7.48 m (H4, 1H). IR spectrum, ν, cm–1:
2230 (C≡N); 1729 (C=O); 996 (C–S).
Elemental analysis of the compounds synthesized
was performed on a CHNS-O FlashEA 1112 series
elemental analyzer.
Electronic absorption spectra were recorded in organic
solvents (DMF and chloroform) on a HITACHI
U-2001 spectrophotometer at room temperature in the
wavelength range of 400–900 nm. IR spectra were
measured on an Avatar 360 FT-IR ESP instrument in
the range of 400–4000 cm–1 from thin films (acetone)
and KBr pellets.
4-(2-Carboxyphenyloxy)phthalonitrile (5). A round-
bottomed flask equipped with a reflux condenser and a
thermometer was charged with 1 g (0.0048 mol) of
4-bromophthalonitrile, 0.663 g (0.0048 mol) of
o-hydroxybenzoic acid, 1.52 g (0.0110 mol) of K2CO3,
and 30 mL of DMF. The resulting mixture was heated
in an air bath to 120–130°C with stirring and kept at
this temperature for 2 h. Next, the reaction mixture
was acidified with hydrochloric acid until the solution
became neutral, whereupon it was evaporated. The
target product was extracted with acetone. Water was
added dropwise to the acetone solution until a
precipitate was formed, and the resulting precipitate
was filtered off and dried. Yield 0.8128 g (64%). mp
46°C. Found, %: C 67.49; H 3.73; N 9.86. C115H8N2O3.
Calculated, %: C 68.18; H 3.05; N 10.60. H NMR
spectrum (CDCl3), δ, ppm: 8.03 m (H3, 1H); 7.94 m
1
The H NMR spectra of the phthalonitriles were
recorded on a Bruker DRX-500 instrument in CDCl3
with tetramethylsilane as internal reference.
MALDI-TOF mass spectra were obtained on a
Shimadzu Biotech Axima Confidence mass
spectrometer in the positive ion mode with 2,5-dihyd-
roxybenzoic acid used as a matrix. Samples were
prepared by dissolution either in acetone (C = 10–4–
10–5 M) or in DMF and mixed in a 1 : 1 ratio with a
solution of the matrix (30 mg/mL) in THF.
4-Nitrophthalonitrile (1) and 4-bromophthalo-
nitrile (4) were synthesized by the known procedures
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TETRASUBSTITUTED PHTHALOCYANINES WITH BENZOIC ACIDS MOIETIES
(H4, 1H); 7.77 d (H1, 1H); 7.57 d (H2, 1H); 7.02 d (H6,
1H); 6.94 m (H5, 1H); 6.82 m (H7, 1H). IR spectrum
(film), ν, cm–1: 2233 (C≡N); 1738 (C=O); 1251 (Ar–O–Ar).
Synthesis of tetra-4 (2-carboxyphenylthio/oxy)-
phthalocyanines (9, 10) (general procedure). A tube
was charged with 1 mmol of substituted phthalonitrile
(3, 5), 0.3 mmol of magnesium acetate, and 0.18 g
(3 mmol) of urea, heated to 180–190°C, and kept at
this temperature until the reaction mixture hardened.
After cooling it was crushed and dissolved in
concentrated sulfuric acid. The resulting solution was
poured onto ice. The precipitate formed was filtered
off on a glass filter and rinsed with water until the
washing water became neutral.
Synthesis of cobalt/copper tetra-4-(2-carboxy-
phenylthio/amino/oxy)phthalocyanines (6–8) (general
procedure). A mixture of 1 mmol of substituted
phthalonitrile (2, 3, 5), 0.3 mmol of cobalt or copper
acetate, and 0.18 g (3 mmol) of urea was thoroughly
triturated, heated to 180–190°C, and kept at this
temperature until the mass hardened. After cooling the
reaction mixture was crushed and dissolved in
concentrated sulfuric acid. The resulting solution was
poured onto ice. The precipitate was filtered off on a
glass filter and rinsed with water until the washing
water became neutral.
Tetra-4-(2-carboxyphenylthio)phthalocyanine (9).
Yield 0.1068 g (38.14%). Found, %: C 63.86; H 3.78;
N 9.63. C60H34N8O8S4. Calculated, %: C 64.16; H
3.05; N 9.98. IR spectrum, ν, cm–1: 1013 (H2Pc); 1718
(C=O); 997 (C–S).
Cobalt tetra-4-(2-carboxyphenylamino)phthalo-
cyanine (6a). Yield 0.1025 g (36.88%). Found, %: C
64.71; H 3.91; N 14.52. C60H36CoN12O8. Calculated,
%: C 64.81; H 3.26; N 15.12. IR spectrum, ν, cm–1:
1717 (C=O); 1605 (N–H bend); 3329 (N–H stertch).
Tetra-4-(2-carboxyphenyloxy)phthalocyanine (10).
Yield 0.1083 g (40.95%). Found, %: C 67.82; H 3.89;
N 10.17. C60H34N8O12. Calculated, %: C 68.05; H
3.24; N 10.58. IR spectrum, ν, cm–1: 1012 (H2Pc);
1727 (C=O); 1251 (Ar–O–Ar).
Cobalt
tetra-4-(2-carboxyphenylthio)phthalo-
Synthesis of sodium salts of cobalt/copper tetra-
4-(2-carboxyphenylthio/amino/oxy)phthalocyanines
(11–13) (general procedure). A round-bottomed flask
equipped with a reflux condenser and a magnetic
stirrer was charged with 40 mg of the substituted
phthalocyanine and a solution of sodium ethoxide in
ethanol. The reaction mixture was refluxed for 3 h; the
resulting precipitate was filtered off on a paper filter
and washed free from sodium ethoxide excess with
isopropanol. The target product was extracted with
water, which was subsequently evaporated.
cyanine (7a). Yield 0.1196 g (40.54%). Found, %: C
60.74; H 3.08; N 8.93; S, 10.04. C60H32CoN8O8S4.
Calculated, %: C 61.07; H 2.73; N 9.49; S, 10.87.
Mass spectrum, m/z: 1233.07 [M + K + 2Li]+; cal-
culated M 1180.14. IR spectrum, ν, cm–1: 1726 (C=O);
1003 (C–S).
Cobalt
tetra-4-(2-carboxyphenyloxy)phthalo-
cyanine (8a). Yield 0.1179 g (42.30%). Found, %: C
64.12; H 3.09; N 9.97. C60H32CoN8O12. Calculated, %:
C 64.58; H 2.89; N 10.04. IR spectrum, ν, cm–1: 1731
(C=O); 1250 (Ar–O–Ar).
Sodium salt of cobalt tetra-4-(2-carboxyphenyl-
thio)phthalocyanine (12a). Yield 0.0332 g (80.4%).
Found, %: C 56.11; H 2.95; N 8.14; S, 9.96.
C60H28CoN8Na4O8S4. Calculated, %: C 56.83; H 2.23;
S, 10.11; N 8.84. IR spectrum, ν, cm–1: 1601 (C=O);
1106 (C–S).
Copper tetra-4-(2-carboxyphenylamino)phthalo-
cyanine (6b). Yield 0.1013 g (36.31%). Found, %: C
64.11; H 4.23; N 14.52. C60H36CuN12O8. Calculated,
%: C 64.54; H 3.25; N 15.05. IR spectrum, ν, cm–1:
1715 (C=O); 1603 (N–H bend); 3332 (N–H).
Copper tetra-4-(2-carboxyphenylthio)phthalo-
cyanine (7b). Yield 0.1838 g (34.22%). Found, %: C
60.25; H 3.02; N 9.10; S, 9.99. C60H32CuN8O8S4.
Calculated, %: C 60.83; H 2.72; N 9.46; S, 10.82. IR
spectrum, ν, cm–1: 1730 (C=O); 1006 (C–S).
Sodium salt of cobalt tetra-4-(2-carboxyphenyl-
amino)phthalocyanine (11a). Yield 0.0381
g
(90.3%). Found, %: C 59.73; H 3.12; N 13.52; Co,
4.07. C60H32CoN12Na4O8. Calculated, %: C 60.06; H
2.69; Co, 4.91; N 14.01. IR spectrum, ν, cm–1: br 1449
(C=O; N–H bend), 3331 (N–H).
Copper tetra-4-(2-carboxyphenyloxy)phthalo-
cyanine (8b). Yield 0.1047 g (37.39%). Found, %: C
63.96; H 3.11; N 9.73. C60H32CuN8O12. Calculated, %:
C 64.32; H 2.88; N 10.00. IR spectrum, ν, cm–1: 1729
(C=O); 1252 (Ar–O–Ar).
Sodium salt of cobalt tetra-4-(2-carboxyphenyl-
oxy)phthalocyanine (13a). Yield 0.0379 g (87.3%).
Found, %: C 59.17; H 2.96; N 8.84; Co, 4.09.
C60H28CoN8Na4O12. Calculated, %: C 59.86; H 2.34;
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 89 No. 6 2019

1306
KUZNETSOVA et al.
Co, 4.90; N 9.31. IR spectrum, ν, cm–1: br 1565
(C=O); 1251 (Ar–O–Ar).
and Guilard, R., Eds., San Diego: Academic, Elsevier
Science (United States), 2003, vol. 15.
3. Vorozhtsov, G.N., Kazachkina, N.I., Luzhkov, Yu.M.,
Kuznetsova, N.A., Luk’yanets, E.A., Mikhalenko, S.A.,
Pecherskikh, E.V., Solov’eva, L.I., Chissov, V.I., and
Yakubovskaya, R.I., RF Patent 2193563, 2002.
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Kaliya, O.L., Kogan, B.Ya., Luzhkov, Yu.M., Pankra-
tov, A.A., Chissov, V.I., and Yakubovskaya, R.I., RF
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Zav’yalov, A.V., Maizlish, V.E., and Shaposhnikov, G.P.,
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10.1134/S1070363217120544
Sodium salt of copper tetra-4-(2-carboxyphenyl-
thio)phthalocyanine (12b). Yield 0.0387 g (92.3%).
Found, %: C 56.03; H 2.87; N 8.01; S, 9.88.
C60H28CuN8Na4O8S4. Calculated, %: C 56.63; H 2.22;
N 8.80; S, 10.08. IR spectrum, cm–1: br 1486 (C=O);
1036 (C–S).
Sodium salt of copper tetra-4-(2-carboxyphenyl-
amino)phthalocyanine (11b). Yield 0.0384
g
(91.2%). Found, %: C 59.21; H 3.15; N 13.24.
C60H32CuN12Na4O8. Calculated, %: C 59.83; H 2.68; N
13.95. IR spectrum, ν, cm–1: 1432 br (C=O; N–H
bend); 3391 (N–H stretch).
6. Maizlish, V.E., Martynyuk, T.A., and Shaposhnikov, G.P.,
Russ. J. Gen. Chem., 2014, vol. 84, no. 1, p. 131. doi
10.1134/S1070363214010204
Sodium salt of tetra-4-(2-carboxyphenylthio)-
phthalocyanine (12c). Yield 0.0375 g (85.8%).
Found, %: C 56.98; H 2.79; N 8.09; C60H28N8Na6O8.
Calculated, %: C 57.42; H 2.25; N 8.93. IR spectrum,
ν, cm–1: 1451 br (C=O); 1043 (C–S).
7. Thiel, W. and Mayer, R., J. Prakt. Chem., 1986, vol. 328,
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9. Abramov, I.G., Doctoral (Chem.) Dissertation,
Yaroslavl, 2003.
10. Shein, S.M., Doctoral (Chem.) Dissertation, Novo-
sibirsk, 1970.
11. Dyer, J.R., Applications of Absorption Spectroscopy of
Organic Compounds, New Jersey: Prentice-Hall, 1965.
12. Uspekhi khimii porfirinov (Advances in Porphyrin
Chemistry), Golubchikov, O.A., Ed., St. Petersburg:
Inst. Khimii Sankt-Petersb. Gos. Univ., 1997.
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FUNDING
This study was financially supported by the
Ministry of Education and Science of the Russian
Federation (project no. 4.1929.2017/4.6).
CONFLICT OF INTEREST
No conflict of interest was declared by the authors.
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