5-acylamino-4-phenoxyphthalodinitriles and metal phthalocyanines based thereon

Article abstract of DOI:10.1023/A:1012303522618

Tetra(5-acetylamino-4-phenoxy)-, tetra(5-benzoylamino-4-phenoxy)-, and tetra(5-octanoylamino-4-phenoxy)phthalocyanines are synthesized, and their electronic absorption spectra are studied.

Full text of DOI:10.1023/A:1012303522618

Russian Journal of General Chemistry, Vol. 71, No. 2, 2001, pp. 246 249. Translated from Zhurnal Obshchei Khimii, Vol. 71, No. 2, 2001,
pp. 274 278.
Original Russian Text Copyright
2001 by Maizlish, Balakirev, Shishkina, Shaposhnikov.
5-Acylamino-4-phenoxyphthalodinitriles
and Metal Phthalocyanines Based Thereon
V. E. Maizlish, A. E. Balakirev, O. V. Shishkina, and G. P. Shaposhnikov
Ivanovo State University of Chemical Engineering, Ivanovo, Russia
Received December 17, 1999
Abstract Tetra(5-acetylamino-4-phenoxy)-, tetra(5-benzoylamino-4-phenoxy)-, and tetra(5-octanoylamino-
4-phenoxy)phthalocyanines are synthesized, and their electronic absorption spectra are studied.
There is some information in literature concerning
the synthesis and properties of hydroxy-substituted
phthalocyanines, including alkoxy-, aryloxy-, arylene-
oxy-, and other derivatives [1 5], that are soluble in
organic solvents and find application as pH-sensitive
dyes [1, 2], photosensitizers in photodynamic therapy
of cancer [3], catalysts for fuel elements, solar
batteries [4, 5], etc. They all contain from 4 to 8 iden-
tical substituents. The only reported phthalocyanines
with the benzene rings bearing both aryloxy and other
substituents are tetra(4-aryloxy-5-nitro)phthalocyani-
nes [6].
duct II lacks absorption bands characteristic of C N
stretching vibrations. The reaction performed at 60 C
(2 h) at the I:SnCl2 ratio of 1:4 gave compound II
in a fairly high yield. The product was identified by
elemental analysis, IR spectroscopy, and by a com-
parison of its physicochemical characteristics with
those of authentic samples.
5-Amino-4-phenoxyphthalodinitrile (II) is a beige-
colored powder with a well-defined melting point.
Above 80 C it darkens and above 102 C, melts with
decomposition. The presence of a primary amino
group in the phthalodinitrile was confirmed by quali-
tative reaction.
In the present paper we report the synthesis and
properties of cobalt and copper(II) tetra(5-acylamino-
4-phenoxy)phthalocyanines. The synthesis was per-
formed by the nitrile procedure from 5-acylamino-4-
phenoxyphthalodinitriles and the corresponding metal
acetates.
The IR spectra of dinitriles I and II contain a series
of common absorption bands [7]. In particular, at
1
2232 cm there is a C N absorption band [8]. A band
1
at 1256 cm is observed, belonging to the phen-
1
oxy group [8]. The band near 1544 cm due to
The starting phthalodinitriles were prepared in two
symmetrical stretching virations of the nitro group,
ways. The first started from 5-nitro-4-phenoxyphthalo- characteristic of dinitrile I, disappears from the IR
dinitrile (I) [6].
spectrum of compound II, while new bands at 1632
and 3416 cm appear, characteristic respectively of
bending and stretching vibrations of the amino group
[8].
1
PhO
PhO
H2N
CN
CN
CN
CN
SnCl2, HCl
O2N
Dinitrile II was acylated with acetic anhydride and
octanoyl chloride to obtain 5-acetylamino and 5-oc-
tanoylamino-4-phenoxyphthalodinitriles (III, IV),
respectively.
I
II
PhO
CN
CN
RCOX
RCOHN
The synthesis of compound III was performed at
100 110 C in the presence of freshly calcined sodium
acetate. In the absence of the additive and at a higher
temperature (to 150 C), the reaction mixture gets dark,
and the target reaction product is difficult to isolate.
III, IV
R = Me (III), C7H15 (IV); X = AcO, Cl.
5-Amino-4-phenoxyphthalodinitrile (II) was ob-
tained by reduction of dinitrile I with tin dichloride
in hydrochloric acid. It was found that up to 45 C
compound I undergoes no transformations, while
above 80 C it decomposes. The IR spectrum of pro-
The synthesis of compound IV was performed at
120 C using a double excess of octanoyl chloride.
After neutralization of the reaction mixture, nitrile
IV was extracted with diethyl ether.
1070-3632/01/7102-0246$25.00 2001 MAIK Nauka/Interperiodica

5-ACYLAMINO-4-PHENOXYPHTHALODINITRILES
247
Yields, positions of the first band in the electronic absorption spectra, and elemental analyses of copper(II) and cobalt
tetra(5-acylamino-4-phenoxy)phthalocyanines VIII XII
Electronic spectrum, max, nm
Found, %
H
Calculated, %
Comp. Yield,
Formula
no.
%
H2SO4
DMF chloroform
C
N
C
H
N
VIII
IX
X
XI
XII
44
35
37
48
46
825
794
789
687
681
685
690
685
683
66.1
71.4
71.5
70.5
70.4
3.6
3.9
3.6
6.3
6.3
14.6
11.5
11.5
11.5
11.6
C64H44CuN12O8
C84H52CuN12O8
C84H52CoN12O8
C88H92CuN12O8
C88H92CoN12O8
65.6
71.0
71.2
70.0
70.2
3.8
3.7
3.7
6.1
6.2
14.3
11.8
11.9
11.1
11.2
757, 776 687
760 681
633, 689
690
Nitriles III, IV recrystallized from benzene are
clream-colored powders with well-defined melting
points. Therewith, the melting point markedly de-
creases with increasing alkyl chain length. Thus, the
melting points of III and IV are respectively 120 122
and 74 76 C. The test for primary amino group was
negative.
and cobalt acetates at 175 180 C (30 min) to obtain
metal phthalocyanines VIII XII (see table).
Complexes VIII XII are dark green powders.
They are insoluble in water and aqueous alkalis and
readily soluble in DMF, chloroform, acetone, benzene,
pyridine, and concentrated sulfuric acid.
The solubility in organic solvents allowed the
complexes to be extracted with chloroform and then
purified by column chromatography (sorbent silica
gel, eluent chloroform benzene, 2:1).
The IR spectra of compounds III and IV preserve
most absorption bands characteristic of nitrile II,
1
including that at 2232 cm . At the same time,
1
the band at 1632 cm due to the free amino group
1
It should be noted that the elemental analyses of
the complexes synthesized from mixtures of dinitriles
III, V and VI, VII and isolated as described above
show that the products contain no admixtures of
bromides derived from V, VI. Copper tetra(5-acetyl-
mino-4-phenoxy)phthalocyanine (VIII) obtained both
from nitrile III and a mixture of nitriles III and V had
similar electronic absorption spectra.
disappers, and a band at 1724 1712 cm appears,
characteristic of acylamino carbonyl vibrations [8].
It is known that the bromine atom in bromine-sub-
stituted phthalodinitriles can be subject to nucleophilic
substitution [6, 9]. We attempted to use this reaction
for preparing acylaminophenoxyphthalodinitriles from
nitriles V, VI. The latter were obtained by the
procedure in [10].
Compounds VIII XII were identified by elemental
analysis and electronic spectroscopy.
Br
CN
CN
RCOHN
Analysis of the electronic absorption spectra in
organic solvents (see table and Figs. 1 and 2) shows
the following. The complexes all exhibit strong ab-
sorption in the range 633 690 nm. But complex XII
in chloroform gives a diffuse band with a maximum
at 690 nm and an inflection at 645 nm, whereas the
related copper complex XI, two absorption bands at
V, VI
PhO
CN
CN
PhOH, LiOH
DMSO
RCOHN
III, VII
689 and 633 nm. The same spectrum (
689 and
630 nm) is also characteristic of the lattermcaxomplex in
benzene, implying aggregation of the compounds in
organic solvents. Replacement of the acetyl residue by
octanoyl has almost no effect on the position of the Q
band. As would be expected, in going from organic
solvents to concentrated sulfuric acid the first band
undergoes a bathochromic shift. It should be noted
that the long-wave band of complex XI is split into
two bands, which is probably associated with the
presence of positional isomers (randomers).
R = Me (III), Ph (VII).
As the nucleophilic agent we used phenol in the
presence of lithium hydroxide. The synthesis was
performed in DMSO under conditions similar to those
for preparing nitrile I [6]. However, only mixtures of
the starting and target dinitriles could be isolated,
which proved impossible to separate.
Nitriles III, IV, and VII were reacted with Cu(II)
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 71 No. 2 2001

248
MAIZLISH et al.
D
D
1.1
1
1.1
2
1
0.9
0.6
0.9
2
0.6
0.3
0.3
500
20
600
16
700 800 909
14 12 11
, nm
500
600
16
700
14
800 909
12 11
, nm
3
1
18
10 , cm
3
1
20
18
10 , cm
Fig. 2. Electronic absorption spectra of solutions (c
5
Fig. 1. Electronic absorption spectra of solutions (c 1.1
M) of copper tetra(5-acetylamino-4-phenoxy)-
phthalocyanine (VIII) in (1) DMF and (2) H SO .
10
M) of (1) copper tetra(5-octanoylamino-4-phen-
5
10
oxy)phthalocyanine (XI) and (2) cobalt tetra(5-octano-
ylamino-4-phenoxy)phthalocyanine (XII) in DMF.
2
4
PhO
CN
CN
alkyl substituents, which, in its turn, leads to a dif-
ferent depth of protonation of the porphyrazine cycle.
4
RCOHN
EXPERIMENTAL
III, IV, VII
The IR spectra were taken on a Specord M-80
spectrophotometer in the range 400 4000 cm
in KBr.
NHCOR
OPh
PhO
1
RCOHN
N
The electronic absorption spectra were measu-
ed in DMF, chloroform, and concentrated sul-
uric acid on a Specord M-40 spectrophotometer
at room temperature in the range 500 900 nm.
N
N
N
M(OAc)2
N
M
N
N
N
5-Amino-4-phenoxyphthalodinitrile (II). 5-Nitro-
4-phenoxyphthalodinitrile, 0.3 g, was slowly added to
a solution of 0.7 g of tin(II) chloride in 2.1 ml of
conc. HCl. The reaction mixture was stirred at 60 C
for 2 h and then poured into 50 ml of ice water. The
precipitate that formed was filtered off, washed with
water to neutral washings free of chloride ions, and
dried at 60 C to obtain the reaction product as a
yellow powder soluble in acetone, chloroform, DMF
and insoluble in water and aqueous alkalis. Yield
0.2 g (79%), decomp. point 102 106 C. Found, %: C
72.1; H 4.1; N 18.1. C14H9N3O. Calculated, %: C
71.5; H 3.9; N 17.9.
PhO
RCOHN
NHCOR
OPh
VIII XII
R = Me (VIII), Ph (IX, X), C7H15 (XI, XII); M = Cu
(VIII, IX, XI), Co (X, XII).
As follows from a comparion of the electronic ab-
sorption spectra of known metal tetra(5-nitro-4-phen-
oxy)phthalocyanines and synthesized N-acylamino
derivatives VIII XII, the position of the Q band
depends the nature of alkyl in the acylamino group.
With VIII, a bathochromic shift is observed, while
with XI, XII, hypsochromic (see table). This differen-
5-Acetylamino-4-phenoxyphthalodinitrile (III).
ce is apparently explained by the different size of the a. A mixture of 0.1 g of nitrile II, 0.05 g of sodium
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 71 No. 2 2001

5-ACYLAMINO-4-PHENOXYPHTHALODINITRILES
249
acetate, and 0.1 ml of acetic anhydride was heated at
110 C for 2 h, after which it was diluted with water,
the precipitate was filtered off, washed with water to
neutral washings, and dried at 50 C. Nitrile III is a
dried at 50 C and purified first by extraction with
chloroform in a Soxhlet apparatus and then by column
chromatography on silica gel (eluent chloroform
benzene, 2:1). Phthalocyanines VIII XII are dark
cream-colored powder insoluble in water and aqueous green powders insoluble in water and aqueous alkalis
alkalis and soluble in acetone, chloroform, and DMF.
Yield 0.05 g (38 %), mp 120 122 C. Found, %: C
70.5; H 4.2; N 15.4. C16H11N3O2. Calculated, %: C
69.3; H 4.0; N 15.2.
and soluble in DMF, chloroform, benzene, pyridine,
and concentrated sulfuric acid, and compounds X XII,
in acetone.
ACKNOWLEDGMENTS
b. Phenol, 0.27 g, was added to a solution of 0.5 g
of nitrile V in 30 ml DMSO, after which 0.11 g of
lithium hydroxide was added to the mixture over the
course of 2 h. The reaction mixture was stirred for
7 days at room temperature and then poured into
300 ml of 10% aqueous sodium chloride. The preci-
pitate that formed was filtered off and washed with
5% aqueous sodium hydroxide to neutral washings
free of bromide ions. Purification was performed by
recrystallization from benzene.
The work was financially supported by the Grant
for Basic Natural Science of the Ministry for Educa-
tion of the Russian Federation (no. 97-0-9.4-381).
REFERENCES
1. Wohrle, D., Iskander, N., and Craschew, G., Photo-
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vol. 55, no. 2, pp. 2155 2159.
5-Octanoylamino-4-phenoxyphthalodinitrile
(IV). A mixture of 0.1 g of nitrile II and 0.2 ml of
octanoyl chloride was heated at 120 C for 1.5 h, after
which it was diluted with 5 ml of 10% aqueous
sodium bicarbonate, the precipitate was filtered off,
washed with water to neutral washings, dried at 50 C,
and recrystallized from benzene to obtain compound
IV as a cream-colored powder insoluble in water and
aqueous alkalis and soluble in acetone, chloroform,
and DMF. Yield 0.09 g (63%), mp 74 76 C. Found,
%: C 72.9; H 6.7; N 11.9. C22H23N3O2. Calculated,
%: C 73.1; H 6.4; N 11.6.
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5-Benzoylamino-4-phenoxyphthalodinitrile
(VII). A mixture of 0.38 g of nitrile VI, 0.16 g of
phenol, and 0.07 g of lithium hydroxide in 30 ml of
DMSO was stirred for 7 days at room temperature,
after which it was poured into 300 ml of 10% aqueous
sodium chloride. The precipitate formed was filtered
off, and washed with 5% aqueous sodium hydroxide
and then with water to neutral washings free of
bromide ions.
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p. 158.
Tetra(5-acylamino-4-phenoxy)phthalocyanines
VIII XII. Disubstituted phthalodinitrile, 0.9 mmol,
and 0.25 mmol of corresponding metal acetate were
melted in a quartz ampule at 175 180 C for 30 min.
The resulting melt was ground, washed successively
with 3% HCl to colorless filtrates and water to
remove chloride ions. The reaction products were
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and Smirnov, R.P., Zh. Obshch. Khim., 2000, vol. 70,
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