Bifunctional octasubstituted phthalocyanines. Synthesis and properties

Article abstract of DOI:10.1134/S1070363207010215

Data on the synthesis of bifunctional octasubstituted phthalocyanines are reported. Some specificities of their electronic absorption spectra, thermal stability, and other properties, depending on the substituent nature and central metal ion, are revealed

Full text of DOI:10.1134/S1070363207010215

ISSN 1070-3632, Russian Journal of General Chemistry, 2007, Vol. 77, No. 1, pp. 138 146.
Pleiades Publishing, Ltd., 2007.
Original Russian Text
G.P. Shaposhnikov, V.E. Maizlish, V.P. Kulinich, 2007, published in Zhurnal Obshchei Khimii, 2007, Vol. 77, No. 1,
pp. 148 156.
Bifunctional Octasubstituted Phthalocyanines.
Synthesis and Properties
G. P. Shaposhnikov, V. E. Maizlish, and V. P. Kulinich
Ivanovo State University of Chemical Technology,
pr. F. Engel’sa 7, Ivanovo, 153000, Russia
e-mail: ttoc@isuct.ru
Received December 9, 2005
Abstract Data on the synthesis of bifunctional octasubstituted phthalocyanines are reported. Some
specificities of their electronic absorption spectra, thermal stability, and other properties, depending on the
substituent nature and central metal ion, are revealed.
DOI: 10.1134/S1070363207010215
Octasubstituted derivatives occupy a specific place
among phthalocyanines (Pc); they are used as dyes,
catalysts, materials for data storage devices, reagents
for photodynamic therapy of cancer, chemical sensors,
etc. [1]. Most known compounds of this series contain
similar substituents [1, 2]. Prior to our studies, only a
few data were available on octasubstituted phthalo-
cyanines having different functionalities [3, 4]; the
reason is that the number of initial compounds ne-
cessary for their synthesis was strongly limited.
However, bifunctional phthalocyanines attract interest
from the viewpoint of studying joint effect of different
groups on their properties, as well as from the applied
viewpoint as compounds that should combine positive
properties arising from the introduction of such
substituents.
In the present article we summarize our previous
data on the synthesis and properties of bifunctional
octasubstituted phthalocyanines which were prepared
from disubstituted phthalonitriles [5] or phthalic acids
[6].
R1
R2
R2
R1
N
M
N
R1
N
N
N
N
CN
CN
MXn
N
N
4
R2
R1
R2
R2
R1
1
2
MPc(4-R ) (5-R )
4
4
1
2
1
2
R = Cl, R = NO (I); R = Br, R = NO (II), NHCOCH (III), NHCOC H (IV), NHCOC6H4OC11H23 (V), NH2 (VI);
2
2
3
6 5
2
1
R = NO , R = OH (VII), OC H (VIII), OC H (IX), OC H N C H (X), OC H -Bu-t (XI), OC H NO (XII),
2
6
5
10
7
6
4
2
6
5
6
4
6
4
2
OC H CO H (XXIII), NH (XIV), NHCOCH (XV), NHCOC H (XVI), NHCOC H (XVII), NHCOC H (XVIII),
6
4
2
2
3
7
15
11 23
17 35
1
2
NHCOC H (XIX), NHCOC H OC H (XX), OCOC H OC H (XXI); R = SC H , R = NO (XXII), OC H
6
5
6
4
11 23
6
4
11 23
6
5
2
1
6
2
5
(
XXIII), OC H CO H (XXIV), OC H -Bu-t (XXV), NHCOCH (XXVI), NHCOC H (XXVII); R = OC H , R =
NHCOCH (XXVIII), NHCOC H (XXIX), NHCOC H OC H (XXX); R = OC H NO , R = OC H (CH ) (XXXI);
R = SO H, R = Cl (XXXII), Br (XXXIII); M = HH (II, III, VIII, X, XI), Cu (I XIII, XX XXX, XXXII, XXXIII), Co
6
4
2
6
4
3
7
15
6 5
1
2
3
7
15
6
4
11 23
6
4
2
6
3
3 2
2
1
3
(
I V, VII XX, XXII XXV, XXXII, XXXIII), ClIn (I, II, VII X), OH(Cl)Al (I, II, VII IX); OHCr (II, VII).
138

BIFUNCTIONAL OCTASUBSTITUTED PHTHALOCYANINES
Synthesis. Phthalocyanine metal complexes I
139
XXXI were synthesized from disubstituted phthalonit-
riles [7 19]. Sulfo-and-halo-substituted derivatives
XXXII and XXXIII were obtained following the
urea procedure from the corresponding phthalic acids
[20]. According to the first procedure, a disubstituted
phthalonitrile was thoroughly ground with a metal salt,
and the mixture was heated at 200 210 C. In the
synthesis of aluminum complexes, readily hydrolyzable
aluminum chloride was added to a fused phthalodi-
nitrile. Metal-free compounds (H -II, H -III, H -
0
4
8
12
16 , min
Fig. 1. Chromatogram of complex Cu-VIII (HPLC,
Silasorb 600, hexane toluene, 40:60).
2
2
2
VIII, H -X, and H -XI) were prepared by reprecipita-
tion of the corresponding magnesium complexes.
2
2
The structure of the isolated compounds was con-
firmed by analytical data, HPLC, and vibrational and
electronic spectroscopy. The IR spectra of complexes
were essentially similar to those of the free ligands
[22]. Absorption bands typical of the phthalocyanine
framework were observed at 724 734, 1300
Phthalocyanines H -VIII, H -X, and H -XI were
2
2
2
precipitated below 10 C to avoid their sulfonation
which occurs at elevated temperature, as shown with
CoPc( -OC H ) (5-NO ) as an example].
[
4
6
5 4
2 4
As shown in [21], the reaction of 4-aminophthalo-
nitrile with metal salts does not give the correspond-
ing metal phthalocyanines. Likewise, we failed to
obtain the desired products from such substituted
aminophthalonitriles as 5-amino-4-bromo-, 4-amino-
1
600 cm 1 (C N and C=C stretching vibrations,
respectively). As might be expected, absorption bands
typical of substituents were present (as in the spectra
of the parent phthalonitriles [5]).
5
-nitro-,
and
5-amino-4-phenoxyphthalonitriles.
Template syntheses of both tetra- and octasubsti-
tuted metal phthalocyanines leads to the formation of
mixtures of randomers [23] which are difficult or even
impossible to isolate as individual substances. In
collaboration with the Analytical Chemistry De-
partment, Moscow State University, we made an
attempt to separate randomers of complexes soluble
in organic solvents, in particular of CuPc(4-OC H )
Therefore, the complex Cu-VI was synthesized by
alkaline hydrolysis of the corresponding acetyl deri-
vative on heating in 10% aqueous sodium hydroxide
at 80 C; following an analogous procedure,
CoPc(4-NH ) (5-NO ) was obtained from CoPc
2
4
2 4
(4-NHCOCH ) (5-NO ) .
3 4 2 4
Halo-and-sulfo-substituted phthalocyanine metal
6
5 4
complexes XXXII and XXXIII were synthesized by
heating a mixture of the corresponding phthalic acid,
copper or cobalt salt, urea, and a catalytic amount of
ammonium molybdate. The optimal reaction condi-
tions (temperature and reaction time) were developed
to ensure maximal yields of the target products [20].
(5-NO ) , by high-performance liquid chromatography
2 4
(HPLC) which is known to be the most efficient for
this purpose. Both normal- and reversed-phase tech-
niques were applied with variation of eluents and
stationary phases. The most appropriate was to use
normal-phase chromatography with toluene or hexane
toluene (20:80 and 40:60) as eluent. As a result, we
obtained 4 fractions (Fig. 1). The compounds isolated
therefrom had similar elemental compositions and
almost identical electronic absorption spectra.
The resulting compounds were purified in different
ways, depending on their specific properties. Com-
pounds that are sparingly soluble in organic solvents
were reprecipitated from concentrated sulfuric acid [in
the case of aluminum and chromium complexes, the
process was accompanied by replacement of the extra
ligand (Cl) by hydroxy group], followed by Soxhlet
extraction with organic solvents to remove soluble
impurities. Indium complexes ClIn-I, ClIn-II, ClIn-
Physical properties of the prepared phthalocyanines
are largely determined by the nature of substituents.
Compounds containing bromine atoms and amino or
nitro groups are poorly soluble in organic solvents.
The presence of hydroxy, sulfo, or carboxy groups
endows them with solubility in aqueous alkali, while
aryloxy, acyloxy, tert-butyl, phenylsulfanyl, and some
acylamino groups provide improved solubility in
organic solvents. All the phthalocyanines prepared are
soluble in concentrated sulfuric acid.
2
VII were not subjected to reprecipitation from H SO4
due to their lability under these conditions. Com-
pounds XIII, XXIV, XXXII, and XXXIII that are
soluble in aqueous alkalis were converted into water-
soluble sodium salts, and the solutions were acidified.
Complexes IV, VIII XI, and XX XXXI were pre-
liminarily extracted with organic solvents (benzene,
chloroform) and were then purified by liquid
chromatography.
Thermal stability on exposure to air. With a
view to elucidate mutual effect of ortho-substituents
in the benzene rings of phthalocyanine ligand on the
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 77 No. 1 2007

1
40
Table 1. Differential thermal analysis data for octasubstituted phthalocyanine cobalt complexes
Temperature,
maximal exothermic maximal weight
SHAPOSHNIKOV et al.
C
Compound
start of weight loss,
Tst
effect
loss
CoPc[4-Br] [5-NHCOCH ] (Co-III)
285
278
260
240
235
215
210
220
600 650
494
700
580
605
680
612
625
590
630
4
3 4
CoPc[4-OC H C(CH ) ] [5-NO ] (Co-XI)
6
4
3 3 4
2 4
CoPc[4-OC H NO ] [5-NO ] (Co-XII)
532
550
562
485
485
625
6
4
2 4
2 4
CoPc[4-OC H ] [5-NHCOCH ] (Co-XXVIII)
6
5 4
3 4
CoPc[4-OC H COOH] [5-NO ] (Co-XIII)
6
4
4
2 4
CoPc[4-Br] [5-NHCOC H ] (Co-IV)
4
6 5 4
CoPc(4-Cl) (5-SO H) (Co-XXXII)
4
3
4
CoPc(4-Br) (5-SO H) (Co-XXXIII)
4
3
4
stability of complexes to thermally induced oxidation,
we examined the behavior of Cu-II Co-IV, Co-VII,
Co-XI Co-XIII, Co-XXXII, and Co-XXXIII
served at 600 650 C. Replacement of the acetylamino
group by a bulkier benzoylamino group leads to
decrease of Tst to 215 C (Table 1). An analogous
pattern is observed upon replacement of the bromine
atoms in Co-III by bulky phenoxy groups. Depending
on the nature of the substituent in the ortho position
with respect to the nitro group, the thermal stability
changes according to the following series: Cu-II >
Co-VII > Co-XI > Co-XII > Co-XIII.
(Table 1) on heating in air. The results showed that
complex Cu-II is quite thermally stable. Its decom-
position begins above 300 C and is accompanied by
exothermic effect which attains its maximum value at
7
00 C. On the whole, the decomposition process
follows a complicated pattern: The DTA curve shows
several diffuse maxima.
The electronic absorption spectra of the compounds
under study in organic solvents are typical of phthalo-
cyanine, its metal complexes, and their substituted
derivatives [25]; they are characterized by strong
absorption bands in the short- ( 320 366 nm) and
long-wave regions ( 630 766 nm) (Table 2). In all
cases, the Q band is displaced to longer wavelengths
relative to its position in the spectra of unsubstituted
Cobalt complex Co-VII is considerably less stable.
A relatively large weight loss and a strong exothermic
effect are observed at 283 C. It is known than nitro
compounds are explosive, i.e., they are capable of
undergoing instantaneous decomposition with forma-
tion of gaseous products and heat evolution upon
absorption of a small amount of energy [24]. The
energy capacity of such compounds increases as the
concentration of oxygen therein rises, i.e., as the
number of oxygen-containing groups (such as nitro,
hydroxy, etc.) increases; as a result, more complete
combustion can be achieved. A relatively large weight
loss observed for CoPc(4-OH) (5-NO ) is likely to
phthalocyanines. The difference
in a series of
max
complexes formed by the same metal depends on the
substituent nature (Table 2). Detailed interpretation of
the effect of molecular structure of substituted
phthalocyanines on their electronic absorption spectra
may be difficult, for not only mutual electronic effects
of substituents but also geometric structure of mole-
cule should be taken into account. For example,
molecular-mechanics calculations revealed that the
nitro groups in MPc(4-Br)4(5-NO2)4 are turned
through an angle of 80 with respect to the macroring
plane; the nitro groups in MPc(4-OC H ) (5-NO ) lie
4
2 4
originate from its decomposition accompanied by
vigorous gas evolution and liberation of a lot of
energy; this follows from the strong intensity of the
exothermic peak. Further heating leads to increase in
the weight loss, the process is accompanied by the
second exothermic effect, and the decomposition is
complete at 535 C with formation of cobalt oxide.
6
5 4
2 4
in the macroring plane, but the phenyl groups with
that plane form a dihedral angle of 71 .
Decomposition of the other complexes begins in
the temperature range from 215 to 285 C (Table 1).
The complexes are less thermally stable than the
corresponding unsubstituted phthalocyanines for
The spectra of metal-free compounds II, III, VIII,
X, and XI in DMF displayed a strong narrow peak
instead of a characteristic doublet in the region 670
720 nm [26] (Fig. 2). The same pattern (i.e., dis-
appearance of the doublet) was observed previously
which T is equal 400 C. The most stable is Co-III.
st
Its decomposition starts at 285 C and is accompanied
by exothermic effect whose maximal value is ob-
in the spectra of some octasubstituted H Pc in DMF
2
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 77 No. 1 2007

BIFUNCTIONAL OCTASUBSTITUTED PHTHALOCYANINES
141
Table 2. Electronic absorption spectra of octasubstituted phthalocyanines
max, nm (log )
CHCl3
Compound
DMF
H SO
2 4
CuPc(4-Cl) ( -NO )
683, 640
680
780, 755
763
5
2 4
4
CoPc(4-Cl) (5-NO )
4
2 4
H2Pc(4-Br) (5-NO )
683, 630
680, 640
680
805, 760, 720
783, 758
773
4
2 4
CuPc(4-Br) (5-NO )
4
2 4
CoPc(4-Br) (5-NO )
4
2 4
ClInPc(4-Br) (5-NO )
700
4
2 4
OHAlPc(4-Br) (5-NO )
690
688
696
800, 758, 730
800, 767, 730
845
4
2 4
OHCrPc(4-Br) (5-NO )
4
2 4
CuPc(4-OH) (5-NO )
4
2 4
CoPc(4-OH) (5-NO )
716
833
4
2 4
ClInPc(4-OH) (5-NO )
729
4
2 4
OHAlPc(4-OH) (5-NO )
751
750
828
850
4
2 4
OHCrPc(4-OH) (5-NO )
4
2 4
H Pc(4-OC H ) (5-NO )
676(4.83), 610(4.18), 361(4.66)
688(4.70), 610(4.23), 340(4.58)
678(4.79), 610(4.25), 334(4.62)
687(4.69), 612(4.24), 344(4.61)
678(4.80), 618(4.18), 346(4.61)
702(4.79), 629(4.27)
687(4.87), 625(4.31)
685(4.81), 631(4.22)
686(4.87), 622(4.33), 335(4.84)
677(4.88), 621(4.35), 334(4.83)
694(4.88), 625(4.32), 336(4.82)
686(4.85), 625(4.32), 334(4.83)
676(4.84), 621(4.31), 332(4.81)
688(4.83), 622(4.30), 335(4.81)
676(4.85), 621(4.32), 332(4.81)
700
702, 678
691
681
693
681
714, 683
694
695
874, 814
796
786
801
807
813, 772
791
774
808
784
817, 789
794
772
774
768
2
6
5 4
2 4
CuPc(4-OC H ) (5-NO )
6
5 4
2 4
CoPc(4-OC H ) (5-NO )
6
5 4
2 4
CuPc(4-OC H ) (5-NO )
1
0
7 4
2 4
CoPc(4-OC H ) (5-NO )
1
0
7 4
2 4
H Pc(4-OC H N C H ) (5-NO )
2
6
4
2
6
5 4
2 4
CuPc(4-OC H N C H ) (5-NO )
6
4
2
6
5 4
2 4
CoPc(4-OC H N C H ) (5-NO )
6
4
2
6
5 4
2 4
CuPc(4-OC H -Bu-t) (5-NO )
698, 627, 334
686, 626, 332
714, 683, 624, 335
6
4
4
2 4
CoPc(4-OC H -Bu-t) (5-NO )
6
4
4
2 4
H2Pc(4-OC H -Bu-t) (5-NO )
6
4
4
2 4
CuPc(4-OC H NO ) (5-NO )
6
4
2 4
2 4
CoPc(4-OC H NO ) (5-NO )
6
4
2 4
2 4
CuPc(4-OC H COOH) (5-NO )
6
4
4
2 4
CoPc(4-OC H COOH) (5-NO )
6
4
4
2 4
CuPc(4-OCOC H OC H ) (5-NO )
678
718, 342
704, 327
716
6
4
11 23 4
2 4
CuPc(4-SC H ) (5-NO )
710(4.86), 632(4.18), 34(4.81)
694(4.52), 628(4.12), 34(4.48)
712
846
844
6
5 4
2 4
CoPc(4-SC H ) (5-NO )
6
5 4
2 4
CuPc(4-SC H ) (5-NHCOCH )
6
5 4
3 4
CuPc(4-SC H ) (5-NHCOC H )
718
722
6
5 4
7 15 4
CuPc(4-SC H ) (5-OC H )
696
694
6
5 4
6 5 4
CuPc(4-SC H ) (5-OC H COOH)
709
697
6
5 4
6
4
4
4
CoPc(4-SC H ) (5-OC H COOH)
6
5 4
6 4
CuPc(4-SC H ) (5-OC H -t-Bu)
700
688
708
699
6
5 4
6
4
4
4
CoPc(4-SC H ) (5-OC H -t-Bu)
6
5 4
6 4
a
CoPc(4-NH ) (5-NO )
766, 694
722
725
725
725
725
2
4
2 4
CoPc(4-NHCOCH ) (5-NO )
705, 641a
706, 643a
3
4
2 4
CoPc(4-NHCOC H ) (5-NO )
6
5 4
2 4
CuPc(4-NHCOC H OC H ) (5-NO )
700, 629a
695, 628a
6
4
11 23 4
2 4
CoPc(4-NHCOC H OC H ) (5-NO )
6
4
11 23 4
2 4
CuPc(4-OC H ) (5-NHCOCH )
687(4.89), 623(4.35), 333(4.82)
682(4.87), 621(4.34), 331(4.82)
687(4.86), 625(4.32), 336(4.81)
681(4.89), 624(4.33), 332(4.85)
689(4.88), 629(4.34), 338(4.83)
690, 625, 335
688, 623, 334
689, 633, 335
690, 625, 333
688, 635, 336
825
822
776, 757
760
817
6
5 4
3 4
CoPc(4-OC H ) (5-NHCOCH )
6
5 4
3 4
CuPc(4-OC H ) (5-NHCOC H )
6
5 4
7 15 4
CoPc(4-OC H ) (5-NHCOC H )
6
5 4
7 15 4
CuPc(4-OC H ) (5-NHCOC H OC H )
6
5 4
6
4
11 23 4
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 77 No. 1 2007

142
SHAPOSHNIKOV et al.
Table 2. (Contd.)
max, nm (log )
Compound
DMF
CHCl3
H SO
2
4
CoPc([4-OC H ) (5-NHCOC H OC H )
11 23 4
681(4.89), 627(4.35), 335(4.86)
678, 634, 333
794
778
781, 756
776
799, 760
776, 750
789
774, 752
772
6
5 4
6
4
a
CuPc(4-Br) (5-NH )
714, 646, 325
4
2 4
a
CuPc(4-Br) (5-NHCOCH )
680, 631, 321
4
3 4
CoPc(4-Br) (5-NHCOCH )
679(4.85), 617(4.32), 322(4.81)
685(4.86), 618(4.33), 320(4.82)
4
3 4
H Pc(4-Br) (5-NHCOCH )
2
4
3 4
a
CuPc(4-Br) (5-NHCOC H )
688, 639, 323
4
6 5 4
CoPc(4-Br) (5-NHCOC H )
687(4.84), 624(4.31), 324(4.82)
4
6 5 4
CuPc(4-Br) (5-NHCOC H OC H )
705, 630a
695, 634a
809
4
6
4
11 23 4
CoPc(4-Br) (5-NHCOC H OC H )
4
6
4
11 23 4
CoPc(4,5-NHCOC H )
708
6
5 8
CuPc(4-OC H NO ) [5-OC H (CH ) ]
682, 631
682, 631
6
4
2 4
6
3
3 2 4
H O/NaOH(0.5%)
2
CuPc(4-Cl) (SO H)
676, 610a
666, 606a
676, 602
670, 606
a
793, 430a
781, 417a
791, 430a
791, 417
4
3
4
4
CoPc(4-Cl) (SO H)
4
3
a
a
CuPc(4-Br) (SO H)
678, 611
667, 611
4
3
4
4
CoPc(4-Br) (SO H)
664, 606a
674, 613
4
3
a
Inflection point.
[
27, 28] and was explained by the formation of Pc2
and shortening of the distance between the com-
ponents of the doublet (as compared to unsubstituted
dianion and change of the molecular symmetry from
D2h to D . The solvent polarizes the N H bond in
H Pc) are observed.
4h
2
H Pc molecule, thus favoring its subsequent dissocia-
tion.
2
The complexes of tetra-4-nitro-, tetra-4-halo-, and
tetra-4-halo-tetra-5-nitrophthalocyanines with the
same metal rank as follows with respect to the red
shift of the Q band in the electronic absorption spectra:
MPc(4-Hlg) > MPc(4-Hlg)4(5-NO ) > MPc(4-NO ) .
In going to 1-chloronaphthalene (complexes II,
VIII, and X), chloroform (III, XI), or concentrated
sulfuric acid, the spectrum becomes typical of the free
ligand: It contains a doublet in the long-wave region
4
2 4
2 4
It is known that introduction of a nitro group exerts a
considerably stronger effect on the position of the
long-wave absorption band than does introduction of
a halogen atom [26]. The nitro group in the examined
octasubstituted phthalocyanine complexes is forced
out from the macroring plane, and its effect on the
electron density distribution over the macroring is
clearly reduced; therefore, the red shift of the Q
band is smaller as compared to MPc(4-NO ) .
(
Fig. 2). As in the spectra of known nitro-substituted
phthalocyanines [26], red shift of the absorption bands
A
1
.1
0
0
0
.8
.6
.4
1
2
4
Complex Cu-VI and known tetra-4-bromo- and
tetra-4-aminophthalocyanine copper complexes give
the following series according to the position of their
2
long-wave absorption band: CuPc(4-Br) < CuPc
4
(
4-Br)4(5-NH ) < CuPc(4-NH ) . Introduction of a
2 4 2 4
0
.2
0
strong electron-donor amino group into the ortho posi-
tion with respect to the bromine atom leads to a
considerable red shift of the absorption maximum
400
500
600 700 , nm
(44 nm), while the blue shift relative to CuPc(4-NH2)4
is insignificant ( = 2 nm) [26]; these findings are
consistent with a weak effect of halogen substituents
in Pc molecules on the electronic absorption spectra.
Fig. 2. Electronic absorption spectra of H -VIII in
2
(
1) DMF and (2) H SO .
2 4
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 77 No. 1 2007

BIFUNCTIONAL OCTASUBSTITUTED PHTHALOCYANINES
143
A
1
A
2
1
0.9
.2
1
2
3
0
.9
4
3
0
.6
0
.6
0
.3
0
0
.3
600 700 800 600 700 800 , nm
Fig. 3. Electronic absorption spectra of (1 3) Cu-III and
4) Co-III in DMF: (1) initial solution, (2) twofold
(
diluted solution, and (3) fourfold diluted solution.
5
00
600
700 800 900
The dependence of the Q band position on the nature
of the central ion in the series MPc-I and MPc-II is
analogous to that known for unsubstituted complexes
,
nm
Fig. 4. Electronic absorption spectra of CuPc(4-Br)
4
[
2].
As might be expected, replacement of the amino
groups in CuPc(4-Br) (5-NH ) by acylamino groups
(5-NO ) in (1) DMF, (2) H SO , and (3) 1-chloro-
naphthalene.
2 4 2 4
4
2 4
the benzene ring of Pc molecules by bromine almost
does not affect the position of the Q band (Table 2).
(compounds III V) is accompanied by a considerable
blue shift of the Q band (Table 2) due to reduced
donor effect of the amino group. Extension of the
length of the acyl residue produces an insignificant
red shift of the long-wave maximum. It should be
noted that the spectra of tetra-5-acylamino-tetra-4-
bromophthalocyanine copper complexes in DMF
contain two absorption bands in the regions 631 646
and 679 681 nm, the former being more diffuse
Analysis of the electronic absorption spectra of
octasubstituted metal phthalocyanines containing nitro
groups and other substituents in the ortho position
with respect to the former revealed the following
specific features.
The red shift of the long-wave absorption band in
the spectra of cobalt complexes increases in the fol-
lowing series (Table 2): CoPc(4-OC H NO )
(
Table 2, Fig. 3). The intensity ratio of these bands
depends on the concentration. Dilution of the initial
solution leads to increase in the intensity of the long-
wave band, while the intensity of the short-wave band
decreases. Taking into account published and our
experimental data, we can conclude that the absorp-
tion at 631 646 nm originates from the presence of
associates in solution and that the absorption at 679
6
4
2 4
(
(
(
(
5-NO2)4 CoPc(4-OC H COOH) (5-NO )
CoPc
6
4
4
2 4
4-OC H -Bu-t)4(5-NO )
CoPc(4-OC H )
6
4
2 4
6 5 4
5-NO2)4 CoPc(4-OC H ) (5-NO ) CoPc(4-Cl)4
10 7 4 2 4
5-NO2)4 CoPc(4-Br) (5-NO ) < CoPc(4-OC H N=
4 2 4 6 4
NC H ) (5-NO )
<
CoPc(4-SC H ) (5-NO )
2 4
<
6
5 4
2 4
6
5 4
CoPc(4-NHCOCH ) (5-NO )
CoPc(4-NHCO
C H ) (5-NO ) < CoPc(4-OH) (5-NO ) . A conclu-
3
4
2 4
6
81 nm belongs to monomeric species. By contrast,
6
5 4
2 4
4
2 4
the cobalt complex shows in the spectra a clearly
sion may be drawn that increase in the donor power of
the ortho substituent is accompanied by a red shift of
the Q band due to enhanced polarization of the mo-
lecule [26]. An analogous pattern is typical of tetra-
bromophthalocyanines II VI (Table 2). In the elec-
tronic spectra of hydroxy-and-nitro-substituted com-
plexes VII in DMF, the Q band is broadened due to
association via intra- and intermolecular hydrogen
bonding [29].
defined Q band and its vibrational satellite.
Splitting of the Q band into a doublet (Fig. 4) is
observed only in the spectra of copper tetrahalotetra-
nitrophthalocyanine complexes in DMF; the same was
also noted previously for other nitro-substituted
phthalocyanine copper complexes [2]. In going from
DMF to 1-chloronaphthalene, the spectrum is con-
verted into single-band. Replacement of chlorine in
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 77 No. 1 2007

144
SHAPOSHNIKOV et al.
tively) owing to association of their molecules in
(
a)
(b)
DMF. The Bouguer Lambert Beer law is violated at
a concentration exceeding 10 6 M, which supports the
above stated. The first absorption band in the elec-
tronic spectra of other phenylsulfanyl-substituted
complexes (XXIII and XXV) is narrow, indicating
the absence of association in solution.
D
0
.75
1
1
0
.50
2
Complexes XXXII and XXXIII in DMF display
an intense Q band. Halogen atoms and sulfo group
weakly affect the position of the Q band. The presence
of sulfo groups in complexes XXXII and XXXIII
makes them soluble in aqueous medium, so that their
absorption spectra in water can be examined. The
spectrum of Co-XXXIII in aqueous alkali contains
two strong peaks in the visible region. One of these,
2
0
.25
5
00
600 700 800
600 700 800
nm
,
674 nm, is more intense, and the other, less
max
Fig. 5. Electronic absorption spectra of (a) Co-XXXIII
and (b) Cu-XXXIII in (1) DMF and (2) 0.5% NaOH.
intense maximum is located at 613 nm. By contrast,
in the spectrum of copper complex Cu-XXXIII, the
more intense maximum is located at shorter wave-
Comparison of the spectra of tetra-4-aryloxy-tetra-
-nitrophthalocyanines VIII and XI XIII shows that
lengths,
611 nm, while the other maximum
max
5
appears as a shoulder on the long-wave slope of the
short-wave band (Fig. 5).
substituent in the para position of the benzene ring
almost does not affect the position of the absorption
maximum. The spectra of tetra(phenylsulfanyl)tetra-
nitrophthalocyanine complexes MPc-XXII show a red
shift of the long-wave absorption band relative to the
corresponding bands in the spectra of tetraphenoxy-
tetranitrophthalocyanines MPc-VIII. An analogous
pattern was observed previously for tetra-4-phenyl-
sulfanyl- and tetra-4-phenoxyphthalocyanine metal
complexes [30].
Replacement of organic solvents by concentrated
sulfuric acid leads to the expected [25, 26] consi-
derable red shift of absorption maxima due to protona-
tion of the porphyrazine macroring at the meso-nitro-
gen atoms. The Q band in the spectra of metal-free
compounds in concentrated sulfuric acid is split into
two components, which is typical of H Pc (Table 2,
2
Fig. 3). Metal complexes I and II display the long-
wave absorption band in the region 763 783 nm.
Electron-acceptor nitro groups reduce the basicity
of the exocyclic nitrogen atoms, leading to blue shift
of the Q band relative to its position in the spectra of
unsubstituted and tetrahalo-substituted phthalocyanine
metal complexes [26]. Splitting of the Q band is ob-
served for the copper complexes in both concentrated
sulfuric acid and DMF (Fig. 4). Unlike complexes
with bivalent metals, the spectral curves of com-
pounds containing tervalent metal ions are similar in
the shape and position of the long-wave absorption
bands.
Some specificity of the electronic absorption spec-
tra is also inherent to phenylsulfanyl-substituted com-
plexes MPc-XXII. The red shift of the Q band in the
spectra of phenylsulfanyl-substituted copper com-
plexes in DMF changes as follows: CuPc(4-SPh)4
5-OPh) > CuPc(4-SPh) (5-OC H -Bu-t)4 > CuPc
(
(
(
(
4
4
6
>
4
4-SPh) (5-OC H COOH)
CuPc(4-SPh)4
4
6
4
4
5-NO ) > CuPc(4-SPh) (5-NHCOCH ) > CuPc
4-SPh) (5-NHCOC H ) . Replacement of the nitro
groups in MPc(4-SC H ) (5-NO ) (XXII) by bulky
substituents (complexes XXIII XXV) induces a blue
shift up to 24 nm, presumably due to distortion of the
planar structure of the molecule (steric hindrances are
created by two phenyl groups in the ortho position
with respect to each other). A small red shift of the Q
2
4
4
3 4
4
7
15 4
6
5 4
2 4
Introduction of hydroxy, aryloxy, or phenylsulfanyl
groups instead of halogen atoms induces an ap-
preciable red shift of the Q band, as compared to the
corresponding complexes I and II. Tetraaminotetra-
bromo- and tetraaminotetranitrophthalocyanine com-
plexes Cu-VI and Co-XIV in concentrated sulfuric
acid are protonated first at the amino groups; therefore,
the difference between the absorption maxima in
H SO and DMF is smaller than that observed for the
band (
= 2 8 nm) is observed in going from nitro-
to acylamino-substituted compounds XXVI and
XXVII; the red shift increases with extension of the
alkyl chain in the acyl group (Table 2). Phenylsulfanyl-
substituted phthalocyanine metal complexes XXIV,
XXVI, and XXVII containing carboxyphenyloxy and
acylamino groups give rise to broadened Q bands with
diffuse maxima ( max 709, 712, and 718 nm, respec-
2
4
other complexes (Tabe. 2). Copper complexes of tetra-
5-acylamino-tetra-4-bromophthalocyanines are also
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 77 No. 1 2007

BIFUNCTIONAL OCTASUBSTITUTED PHTHALOCYANINES
characterized by splitting of the long-wave absorption REFERENCES
145
band into two components, as is observed for bromo-
nitro derivatives (Table 2).
1. Phthalocyanines: Properties and Applications, Lez-
noff, C.C. and Lever, A.B.P., Eds., New York: VCH,
Thus analysis of the electronic absorption spectra
shows that introduction of peripheral substituents into
phthalocyanine molecule strongly affects the absorp-
tion pattern.
1
989 1996, vols. 1 4.
2
3
. Uspekhi khimii porfirinov (Advances in the Porphyrin
Chemistry), Golubchikov, O.A., Ed., St. Petersburg:
Nauch.-Issled. Inst. Khim., S.-Peterb. Gos. Univ.,
Prospects in practical applications. We examined
liquid crystalline, catalytic, and other properties of
substituted phthalocyanines with a view to define
possible fields of their applications in practice. It is
known that some substituted phthalocyanines behave
as liquid crystals [31]. Using polarized microscopy,
it was found that copper complexes XXXII and
XXXIII form mesophases upon contact with binary
1
999, vol. 2.
. Simonov, A.D., Kundo, N.N., Mamaeva, E.K., and
Akimova, L.A., Zh. Prikl. Khim., 1977, vol. 50, no. 2,
p. 307.
4. Mikhalenko, S.A. and Luk’yanets, E.A., Anilinokras.
promst., Moscow: NIITEKhim, 1975, no. 3, p. 3.
5
6
7
. Shaposhnikov, G.P. and Maizlish, V.E., Izv. Vyssh.
Uchebn. Zaved., Ser. Khim. Khim. Tekhnol., 2004,
vol. 47, no. 5, p. 26.
systems water NH OH and water NaOH. The texture
4
was identified as grain-like nongeometric, which cor-
responds to a chromonic mesophase [32]. The unde-
cyloxybenzoylamino groups in combination with the
nitro groups endow copper complex Cu-XX with the
ability to produce lyotropic mesophase in binary
systems containing some organic solvents (chloroform,
benzene, toluene). Replacement of the nitro groups
by bromine gives compounds V which exhibit meso-
morphic properties in binary systems with toluene
. Kulinich, V.P., Maizlish, V.E., Shaposhnikov, G.P.,
and Lutsenko, O.G., RU Patent 2161151, Byull.
Izobret., 2000, no. 36.
. Shishkina, O.V., Maizlish, V.E., Shaposhnikov, G.P.,
and Smirnov, R.P., Russ. J. Gen. Chem., 1998, vol. 68,
no. 5, p. 813.
8. Shishkina, O.V., Maizlish, V.E., Shaposhnikov, G.P.,
and Smirnov, R.P., Russ. J. Gen. Chem., 2000, vol. 70,
no. 1, p. 130.
(
copper complex) and chloroform (cobalt complex). It
should be noted that the above phthalocyanines also
form thermotropic mesophase, i.e., they are ampho-
tropic [18].
9
. Balakirev, A.E., Maizlish, V.E., Shaposhnikov, G.P.,
and Smirnov, R.P., Russ. J. Gen. Chem., 2000, vol. 70,
no. 4, p. 623.
Substituted phthalocyanine cobalt complexes ef-
fectively catalyze a number of redox processes [33].
We showed that Co-XXXII and Co-XXXIII are
active as catalysts in the oxidation of hydrogen sulfide
and that their activity is comparable with the activity
of cobalt disulfophthalocyanine which is well known
desulfurization catalyst [34]. Some of the examined
cobalt complexes are active electrochemical reduction
of oxygen. Tetrahydroxytetranitro- and tetrabromo-
tetranitrophthalocyanine cobalt complexes showed the
highest electrocatalytic activity [35, 36]. Our results
allowed us to class these complexes with efficient
oxygen (air) electrode catalysts.
1
1
1
0. Shishkina, O.V., Maizlish, V.E., Shaposhnikov, G.P.,
and Smirnov, R.P., Russ. J. Gen. Chem., 2000, vol. 70,
no. 6, p. 937.
1. Shishkina, O.V., Maizlish, V.E., and Shaposhni-
kov, G.P., Russ. J. Gen. Chem., 2001, vol. 71, no. 2,
p. 243.
2. Maizlish, V.E., Balakirev, A.E., Shishkina, O.V., and
Shaposhnikov, G.P., Russ. J. Gen. Chem., 2001,
vol. 71, no. 2, p. 246.
13. Balakirev, A.E., Maizlish, V.E., and Shaposhni-
kov, G.P., Russ. J. Gen. Chem., 2002, vol. 72, no. 2,
p. 307.
Tetra-4-bromo-tetra-5-(4-undecyloxybenzoylami-
no)- and tetra-4-phenoxy-tetra-5-(4-undecyloxyben-
zoylamino)phthalocyanine complexes of cobalt turned
out to be light-sensitive substances which may be
used as materials for optical recording devices, includ-
ing those operating in the IR region [19]. Bromo- and
sulfo-substituted phthalocyanine copper complex was
tested as direct dye. The complex is greenish blue,
and its technical parameters are comparable with those
of known copper(II) phthalocyaninetetrasulfonic acid
tetrasodium salt [37].
1
4. Zharnikova, M.A., Balakirev, A.E., Maizlish, V.E.,
and Shaposhnikov, G.P., Russ. J. Gen. Chem., 2002,
vol. 72, no. 1, p. 131.
1
5. Maizlish, V.E., Ivanovskii, S.A., Shaposhnikov, G.P.,
Abramov, I.G., Smirnov, A.V., Bykova, V.V., and
Usol’tseva, N.V., Russ. J. Gen. Chem., 2002, vol. 72,
no. 9, p. 1463.
16. Balakirev, A.E., Maizlish, V.E., and Shaposhni-
kov, G.P., Russ. J. Gen. Chem., 2002, vol. 72, no. 10,
p. 1633.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 77 No. 1 2007

146
SHAPOSHNIKOV et al.
1
7. Balakireva, O.V., Maizlish, V.E., and Shaposhni-
kov, G.P., Russ. J. Gen. Chem., 2003, vol. 73, no. 2,
p. 292.
29. Becker, H., Einfuhrung in die Elektronentheorie
organisch chemischer Reaktionen, Berlin: Wissen-
schaften, 1974, 3rd ed.
1
1
8. Balakirev, A.E., Maizlish, V.E., Balakireva, O.V.,
Shaposhnikov, G.P., Bykova, V.V., and Usol’tse-
va, N.V., Russ. J. Gen. Chem., 2004, vol. 74, no. 2,
p. 395.
3
0. Derkacheva, V.M. and Lu’kyanets, E.A., Zh. Obshch.
Khim., 1980, vol. 50, no. 10, p. 2313.
3
1. Usol’tseva, N.V., Akopova, O.B., Bykova, V.V.,
Smirnova, A.I., and Pikin, S.A., Zhidkie kristally:
diskoticheskie mezogeny (Liquid Crystals: Discotic
Mesogens), Usol’tseva, N.V., Ed., Ivanovo: Ivanov.
Gos. Univ., 2004.
9. Balakirev, A.E., Maizlish, V.E., Shaposhnikov, G.P.,
Gribova, L.K., Savchenko, V.E., Bykova, V.V., and
Usol’tseva, N.V., RU 2210572, Byull. Izobret., 2003,
no. 23.
3
2. Bykova, V.V., Usol’tseva, N.V., Zharova, M.A., Lu-
tsenko, O.G., Kulinich, V.P., and Shaposhnikov, G.P.,
Zhidkie kristally i ikh prakticheskoe primenenie (Li-
quid Crystals and Their Practical Application), 2003,
no. 1, p. 7.
2
2
0. Lutsenko, O.G., Kulinich, V.P., and Shaposhni-
kov, G.P., Russ. J. Gen. Chem., 2003, vol. 73, no. 9,
p. 1463.
1. Mikhalenko, S.A., Solov’eva, L.I., Ivanova, T.M., and
Luk’yanets, E.A., Zh. Obshch. Khim., 1985, vol. 55,
no. 5, p. 1106.
33. Uspekhi khimii porfirinov (Advances in the Porphyrin
Chemistry), Golubchikov, O.A., Ed., St. Petersburg:
Nauch.-Issled. Inst. Khim., S.-Peterb. Gos. Univ.,
2
2
2
2
2. Sidorov, A.N. and Kotlyar, I.P., Opt. Spektrosk., 1961,
vol. 11, no. 2, p. 175.
2
004, vol. 4.
3. Torres, T., J. Porphyrins Phthalocyanines, 2000,
vol. 4, no. 3, p. 325.
34. Shaposhnikov, G.P., Kulinich, V.P., and Mai-
zlish, V.E., Uspekhi v neftekhimicheskom sinteze
4. Kast, H., Spreng- und Zondstoffe, Braunschweig:
polifunktsional’nykh
Advances in Petrochemical Synthesis of Polyfunc-
tional Aromatic Compounds), Moscow: Khimiya,
005, p. 109.
aromaticheskikh
soedinenii
F. Vieweg & Sohn, 1921.
(
5. Berezin, B.D., Koordinatsionnye soedineniya porfiri-
nov i ftalotsianina (Coordination Compounds of
Porphyrins and Phthalocyanine), Moscow: Nauka,
2
1
978.
35. Bazanov, M.I., Shishkina, O.V., Maizlish, V.E., Pet-
rov, A.V., Shaposhnikov, G.P., Smirnov, R.P., and
Gzheisyak, A., Elektrokhimiya, 1998, vol. 34, no. 8,
p. 912.
2
6. Elektronnye spektry pogloshcheniya ftalotsianinov i
rodstvennykh soedinenii. Katalog (Catalog of Elec-
tronic Absorptin Spectra of Phthalocyanines and
Related Compounds), Luk’yanets, E.A., Ed., Cher-
kassy: NIITEKhim, 1989.
3
6. Bazanov, M.I., Balakireva, O.V., Balakirev, A.E.,
Kurach, M.V., Maizlish, V.E., and Shaposhnikov, G.P.,
Elektrokhimiya, 2002, vol. 38, no. 9, p. 1113.
2
2
7. Wohrle, D., Meyer, G., and Wahe, B., Macromol.
Chem., 1980, vol. 181, no. 10, p. 2127.
3
7. Lutsenko, O.G., Kulinich, V.P., Shaposhnikov, G.P.,
and Arakcheeva, A.A., RU Patent 2233281, Byull.
Izobret., 2004, no. 21.
8. Wohrle, D. and Hudolf, U., Macromol. Chem., 1985,
vol. 186, no. 10, p. 2177.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 77 No. 1 2007