Synthesis and spectral properties of isomers of cobalt tetrakis(dicyanophenoxy)phthalocyaninate

Article abstract of DOI:10.1007/s11172-018-2364-4

4,4′-[1,3-Phenylenebis(oxy)]- and 4,4′-(1,4-phenylenebis(oxy)]diphthalonitriles and the corresponding tetrasubstituted cobalt phthalocyaninates were synthesized. The spectral properties of the synthesized complexes in various organic solvents were studied

Full text of DOI:10.1007/s11172-018-2364-4

Russian Chemical Bulletin, International Edition, Vol. 67, No. 12, pp. 2250—2252, December, 2018
2250
Synthesis and spectral properties of isomers
of cobalt tetrakis(dicyanophenoxy)phthalocyaninate*
D. A. Erzunov, A. S. Vashurin, and O. I. Koifman
Ivanovo State University of Chemistry and Technology,
7 Sheremetevsky prosp., 153000 Ivanovo, Russian Federation.
E-mail: asvashurin@mail.ru
4,4´-[1,3-Phenylenebis(oxy)]- and 4,4´-(1,4-phenylenebis(oxy)]diphthalonitriles and the
corresponding tetrasubstituted cobalt phthalocyaninates were synthesized. The spectral proper-
ties of the synthesized complexes in various organic solvents were studied.
Key words: diphthalonitriles, cobalt phthalocyaninates, template fusion, dicyanophenoxy
groups.
Cobalt phthalocyaninates have already recommended
containing extended fragments with terminal cyano groups
at the periphery is very promising for the further template
fusion, for example, for the synthesis of the bimetallic
complexes.
The purpose of this work is to synthesize isomeric
cobalt 3-(3,4-dicyanophenoxy)- and 4-(3,4-dicyanophen-
oxy)phenoxyphthalocyaninates.
themselves as efficient catalysts, for example, in such
processes as demercaptanization of oil.1 This application
is caused by high selectivity of the catalyzed oxidation
processes2 and relatively mild conditions of their occur-
rence,3 which, in turn, exerts a positive effect on the qual-
ity of the target reaction products.
The homogeneous catalysts based on water-soluble
cobalt phthalocyaninates are most popular in the present
time.4 However, along with significant advantages of their
use, there is a number of substantial drawbacks, such as
the isolation of the catalyst from the reaction mixture fol-
lowed by regeneration and occurrence of aggregation
processes in aqueous media.5 Therefore, the preparation
and study of the physicochemical properties of the hetero-
geneous catalysts based on metal phthalocyaninates evoke
special attention. Among these catalysts, phenyl-substi-
tuted cobalt phthalocyaninates6 in which the peripheral
fragments are directly linked to each other7 exhibited high
activity. At the same time, similar compounds are fairly
rigid,8 because the aromatic fragments in the structure of
the peripheral substituent are restricted in the possibility
of turning relative to each other and, as a consequence, in
adopting a more favorable position in the space. To en-
hance the catalytic activity of compounds of the phthalo-
cyanine class, it is necessary to vary the macrocycle
structure and increase the number of coordination sites
of the substrate—catalyst—oxidant interaction.
Results and Discussion
Cobalt phthalocyaninates were synthesized by template
fusion from the corresponding phthalodinitriles. At the
Scheme 1
The last problem can be solved by various methods,
for example, by the preparation of polymer-like phthalo-
cyanine structures containing several metals. From this
point of view, the synthesis of phthalocyanine precursors
* Based on the materials of the VII International Conference on
Physical Chemistry of Crown Compounds, Porphyrins, and
Phthalocyanines (September 9—14, 2018, Tuapse, Russia).
Conditions: i. DMF, K2CO3, 48 h, 25 °C.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2250—2252, December, 2018.
1066-5285/18/6712-2250 © 2018 Springer Science+Business Media, Inc.

CoII tetrakis(dicyanophenoxy)phthalocyanines
Russ. Chem. Bull., Int. Ed., Vol. 67, No. 12, December, 2018
2251
Table 1. Spectral properties of complexes 4 and 5 in organic
first stage, the initial 4,4´-[1,3-phenylenebis(oxy)]- (2)
and 4,4´-[1,4-phenylenebis(oxy)]diphthalonitriles (3)
were synthesized by the nucleophilic substitution of the
nitro group in 4-nitrophthalonitrile (1) (Scheme 1).
The reaction was carried out in DMF for 48 h at room
temperature. In both cases, the final product was purified
by recrystallization from ethanol. The purity control was
detected by thin-layer chromatography. The structures of
the obtained compounds were confirmed by MALDI-TOF
spectrometry and NMR spectroscopy.
solvents
CoPc
λ/nm (logε)
DMSO
Py
Acetone Chloroform
DMF
4
5
662
(4.03)
663
662
(3.99)
664
664
(4.42)
665
673
(4.34)
675
675
(4.48)
677
(3.61)
(3.55)
(3.67)
(3.81)
(3.63)
The corresponding cobalt phthalocyaninates were
synthesized by the reactions of phthalonitriles 2 and 3 with
cobalt(II) acetate. The reaction was conducted in a ceramic
crucible at 190—195 °С (Scheme 2). The synthesized
complexes were identified by the data of MALDI-TOF
spectrometry.
It follows from analysis of the electronic absorption
spectra of solutions of the synthesized metal complexes
that the bathochromic shift of the long-wavelength absorp-
tion band of the studied compounds occurs upon the re-
placement of the solvent in the series DMSO — pyrid-
ine — acetone — chloroform — DMF. It is found that the
absorption Q band undergoes an insignificant bathochro-
mic shift in all solvents used on going from the meta-
substituted metal complexes to the corresponding para-
substituted analogs (Table 1).
Experimental
Electronic absorption spectra were recorded on a UNICO
2800 spectrophotometer in a range of 300—1100 nm in quartz
cells with an optical layer thickness of 1 cm. The solvents used
were DMSO, pyridine, acetone, chloroform, and DMF. 1Н and
13С NMR spectra were recorded on a Bruker AVANCE 500
spectrometer (TMS as an internal standard) with working fre-
quencies of 500 and 125 MHz, respectively. Mass spectra were
measured on a Simadzu Axima Confidence time-of-flight mass
spectrometer (MALDI-TOF MS) on the CHCA (α-cyano-4-
hydroxycinnamic acid) matrix. Silica gel Silica L 100/250
(NevaKhim, Russia) was used as a sorbent in column chrom-
atography. Thin-layer chromatograms were obtained on the
POLYGRAM SIL G/UV strips with ethanol (in the case of
phthalonitriles) and chloroform (in the case of the metal phtha-
locyanine complexes) as eluents. The subsequent development
of the chromatographic pattern was performed by the UV irra-
diation of the strips with a wavelength of 230 nm.
Thus, we synthesized, purified, and identified the
isomeric complexes of cobalt tetrakis(dicyanophenoxy)
phthalocyaninate and studied their spectral properties.
Scheme 2
R =
(4),
(5)
Conditions: i. 190—195 °C, ~30 min.

2252 Russ. Chem. Bull., Int. Ed., Vol. 67, No. 12, December, 2018
Erzunov et al.
Chloroform (special purity grade, 99%), DMF special purity
grade, 99%), resorcinol (reagent grade, 98%), and hydroquinone
(reagent grade, 98%, Sigma-Aldrich) were used as received. Prior
to use sodium hydroxide, potassium carbonate, and cobalt(II)
acetate were dehydrated according to known procedures.8
4-Nitrophthalonitrile (special purity grade, 99%, Sigma-Aldrich)
was used without additional purification.
obtained complex from unreacted initial reagents and resins, the
alloy was transferred onto the Schott filter, and the obtained
metal complex was washed off with chloroform. Cobalt phthalo-
cyaninate was decontaminated from residual amounts of impuri-
ties using column chromatography (sorbent silica gel, eluent
chloroform). The purity of the obtained complex was monitored
by thin-layer chromatography using chloroform as eluent. The
yield was 66%. IR, ν/cm–1: 3035.62, 2923.75 (Сar—Н), 2233.25
(C≡N), 1590.98, 1523.47, 1473.32 (Car=Car), 1245.73 (Ar—O—Ar).
MS MALDI-TOF, found: 1509.01 [M]+. CoС88Н40N16O8.
Calculated: 1508.23.
Template synthesis of cobalt tetra-4-[4-(3,4-dicyanophenoxy)]-
phthalocyanine (5) was carried out similarly to the synthesis of
compound 4. The yield was 69%. IR, ν/cm–1: 3018.26, 2923.75
(Car—H), 2233.25 (C≡N), 1562.04, 1492.61 (Car=Car), 1245.73
(Ar—O—Ar). MS MALDI-TOF, found: 1509.57 [M]+.
CoС88Н40N16O8. Calculated: 1508.23.
Synthesis of 4,4´-[1,3-phenylenebis(oxy)]diphthalonitrile (2).
4-Nitrophthalonitrile (1.00 g, 5.78 mmol), resorcinol (0.32 g,
2.89 mmol), and DMF (100 mL) were placed in a three-necked
flask equipped with a magnetic stirrer, a thermometer, and a reflux
condenser. After the substances were completely dissolved, the
reaction mixture was stirred for 1 h at 20 °С. Then potassium
carbonate (1.00 g, 7.26 mmol) was introduced by equal portions.
The mixture was stirred for 48 h at ~20 °С, after which it was
poured into 300 mL of a 0.1 М solution of NaOH and filtered
off. The obtained pale yellow precipitate was washed with water,
a 10% solution of alkali, and water again to the neutral pH, and
washed from the filter with DMF. Then DMF was distilled off
in vacuo. The subsequent purification was performed by recrystal-
lization from ethanol (65% yield). 1Н NMR (CDCl3), δ: 7.76
(dd, 2 H, H(12,18), J = 8.6 Hz); 7.55 (t, AX2 pattern, 1 H, H(6),
J = 8.3 Hz); 7.32 (d, 2 H, H(7,13), 4J = 2.5 Hz); 7.29 (dd, 2 H,
H(9,17), 4J = 2.5 Hz, 3J = 8.3 Hz); 6.99 (dd, 2 H, H(3,5), 3J =
= 8.3 Hz, 4J = 2.2 Hz); 6.82 (m, AX2 pattern, 1 H, 4J = 2.2 Hz).
13С NMR (acetone-d6), δ: 160.66 (С(8,16)); 155.52 (С(2,4));
135.65 (С(12,18)); 132.35 (С(6)); 122.03 (С(7,9,13,17); 117.91
(С(20,22); 117.66 (С(19,21)); 115.10 (С(10,14)); 114.74 (С(3,5));
112.85 (С(1)); 109.91 (С(11,15)). MS MALDI-TOF, found:
362.11 [M]+. C22H10N4O2. Calculated: M = 362.08.
Synthesis of 4,4´-[1,4-phenylenebis(oxy)]diphthalonitrile (3)
was carried out similarly to the synthesis of compound 2. The
yield was 76%. 1Н NMR (acetone-d6), δ: 8.01 (d, 2 Н, Н(12,18),
J = 8.7 Hz); 7.64 (d, 2 Н, Н(7,13), J = 2.5 Hz); 7.48 (dd, 2 Н,
Н(9,17), J = 8.7 Hz, J = 2.6 Hz); 7.35 (s, 4 Н, Н(2,3,4,5)).
13С NMR (acetone-d6), δ: 158.36 (С(8,16)); 154.87 (С(1,6));
134.99 (С(12,18)); 122.12 (С(9,17)); 120.63 (С(2,3,4,5); 120.09
(С(7,13); 116.70 (С(20,22); 116.13 (С(19,21)); 115.67 (С(10,14));
107.79 (C(11,15)). MS MALDI-TOF, found: 362.09 [M]+.
C22H10N4O2. Calculated: M = 362.08.
This work was financially supported by the Russian
Science Foundation (Project No. 17-73-20017).
References
1. P. Kumar, K. Gill, S. Kumar, S. K. Ganguly, S. L. Jain,
J. Mol. Catal. A Chem., 2015, 401, 48—54.
2. A. Vashurin, A. Filippova, S. Znoyko, A. Voronina, O. Lefe-
dova, I. Kuzmin, V. Maizlish, O. Koifman, J. Porphyr.
Phthalocyanines, 2015, 19, 983—996.
3. V. Panwar, P. Kumar, S. S. Ray, S. L. Jain, Tetrahedron Lett.,
2015, 56, 3948—3953.
4. S. Matsuda, S. Mori, Y. Kubo, K. Uosaki, K. Hashimoto,
S. Nakanishi, Chem. Phys. Lett., 2015, 620, 78—81.
5. A. S. Vashurin, Russ. Chem. Bull., 2016, 65, 2220—2228.
6. X. Zhang, Z. Wu, X. Zhang, L. Li, Y. Li, H. Xu, X. Li, X. Yu,
Z. Zhang, Y. Liang, H. Wang, Nat. Commun., 2017, 8, 1—8.
7. H. Xu, J. Xiao, B. Liu, S. Griveau, F. Bedioui, Biosens.
Bioelectron., 2015, 66, 438—444.
8. Z. H. Yang, Y. Zhuo, R. Yuan, Y. Q. Chai, Sensors Actuators
B: Chem., 2016, 227, 212—219.
Synthesis of cobalt tetra-4-[3-(3,4-dicyanophenoxy)phenoxy]-
phthalocyaninate (4). 4,4´-[1,3-Phenylenebis(oxy)]diphthalo-
nitrile (0.25 g, 0.69 mmol) and cobalt(II) acetate (0.03 g,
0.17 mmol) were placed in a ceramic crucible. Fusion was con-
ducted at 190—200 °С for 30 min to the complete solidification
of the reaction mixture. For the primary decontamination of the
Received September 17, 2018;
in revised form October 25, 2018;
accepted October 30, 2018