Sandwich complexes of lutetium with tetraanthraquinoneporphyrazine and asymmetric alkoxy-substituted phthalocyanines. Preparation and spectral properties

Article abstract of DOI:10.1134/S1070363214050284

Interaction of 3,6-di(hexadecyloxy)phthalonitrile with tetrachlorophthalonitrile and lutetium chloride in alcoholic medium yields lutetium complexes with asymmetric phthalocyanines. Their heating with dinitrile of anthraquinone-2,3-dicarboxylic acid gives

Full text of DOI:10.1134/S1070363214050284

ISSN 1070-3632, Russian Journal of General Chemistry, 2014, Vol. 84, No. 5, pp. 953–959. © Pleiades Publishing, Ltd., 2014.
Original Russian Text © A.V. Borisov, M.V. Korel’chuk, N.E. Galanin, G.P. Shaposhnikov, 2014, published in Zhurnal Obshchei Khimii, 2014, Vol. 84,
No. 5, pp. 862–867.
Sandwich Complexes of Lutetium
with Tetraanthraquinoneporphyrazine
and Asymmetric Alkoxy-substituted Phthalocyanines.
Preparation and Spectral Properties
A. V. Borisov, M. V. Korel’chuk, N. E. Galanin, and G. P. Shaposhnikov
Scientific-Research Institute of Macroheterocycles, Ivanovo State Chemistry-Engineering University,
pr. F. Engelsa 7, Ivanovo, 153000 Russia
e-mail: nik-galanin@yandex.ru
Received July 29, 2013
Abstract—Interaction of 3,6-di(hexadecyloxy)phthalonitrile with tetrachlorophthalonitrile and lutetium
chloride in alcoholic medium yields lutetium complexes with asymmetric phthalocyanines. Their heating with
dinitrile of anthraquinone-2,3-dicarboxylic acid gives the sandwich complexes containing fragments of
tetraanthraquinoneporphyrazine and asymmetric phthalocyanines; their spectral properties has been studied.
Keywords: phthalocyanine, chromophore, anthraquinone, lutetium complex, porphyrazine
DOI: 10.1134/S1070363214050284
Sandwich complexes of rare earth metals with
tetrapyrrole ligands are stable compound with unique
structure, being of fundamental as well as applied
interest. They can be used as sensor materials [1, 2],
optical limiters [3] as well as electrochromic [4] or
liquid-crystalline [5] materials.
Herein, we report on preparation and spectral
properties of lutetium complexes with asymmetric
alkoxy-substituted phthalocyanines of the ААВВ and
АВАВ types as well as of the related sandwich
complexes, containing fragments of tetraanthraquino-
neporphyrazine.
So far the homoligand sandwich complexes of
lanthanides have been studied in detail, including these
based on phthalocyanines or naphthocyanines [6, 7].
Similar heteroligand complexes, for example, com-bining
phthalo-cyanines and porphyrins as ligands [8–11],
have been scarcely studied. To the best of our
knowledge, information about compounds containing
fragments of tetraanthraquinoneporphyrazine and asym-
metric phthalocyanine has not been reported in the
literature.
Asymmetric phthalocyanines were prepared from
3,6-di(hexadecyloxy)phthalonitrile I (component A)
and tetrachlorophthalonitrile II (component B). In turn,
compound I was synthesized by alkylation of 2,3-
dicyanohydroquinone with n-hexadecylbromide in the
presence of K2CO3 in DMF.
Compound I was light-yellow powder, readily
soluble in benzene and chloroform, and poorly soluble
in DMF and acetone. Its composition and structure
Scheme 1.
OC16H33
CN
OH
CN
K2CO3
+
H33C16Br
CN
OC16H33
CN
OH
I
953

954
BORISOV et al.
Scheme 2.
·
C6H33O
OC6H
OC6H33
OC6H33
CN
Cl
Cl
33 N
N
N
Lu
N
(1) H13C6OLi, H13C6OH
Cl
Cl
CN
CN
Cl
Cl
OH
.
(2) LuCl3 6H2O
+
N
N
CN
OC6H33
N
N
Cl
OC6H33
Cl
I
II
Cl
Cl
Cl
Cl
III
C6H33O
OC6H33
OC6H
33 N
OC6H33
N
N
Lu
N
OH
N
N
+
N
N
OC6H33
OC6H33
Cl
Cl
Cl
Cl
IV
1
were confirmed by elemental analysis, IR, and Н
NMR spectroscopy data (Scheme 1).
hexanolate-1 with subsequent addition of excess of
lutetium chloride led to formation of a mixture of
phthalocyanines (Scheme 2).
Heating of the mixture of nitriles I and II (1 : 6
ratio) in boiling hexanol-1 in the presence of lithium
By column chromatography, the following products
were isolated: hydroxylutetium 1,4,8,11-tetra(hexa-
decyloxy)-15,16,17,18,22,23,24,25-octachlorophthalo-
cyaninate III (ААВВ) and hydroxylutetium 1,4,15,18-
tetra(hexadecyloxy)-8,9,10,11,22,23,24,25-octachloro-
phthalocyaninate IV (АВАВ).
D
Composition and structure of compounds III and
1
IV were confirmed by elemental analysis, Н NMR,
1
and electronic spectroscopy data. In the Н spectra of
the products, broadened and poorly resolved signals of
benzene rings and alkoxy substituents were observed.
That could point at association of phthalocyanines in
the solution. Indeed, the spectra quality was improved
upon dilution of the solutions. Noteworthily, signals of
protons of the hydroxyl groups bound to lutetium were
not observed in the spectra, likely, due to deuterium
exchange.
λ, nm
Fig. 1. Electronic absorption spectra of solutions in
CH2Cl2: compounds III (1) and IV (2).
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SANDWICH COMPLEXES OF LUTETIUM WITH TETRAANTHRAQUINONEPORPHYRAZINE
955
Scheme 3.
O
N
O
O
O
O
O
O
N
N
N
N
N
N
H33C16
O
OC16H33
N
Cl
OC16H33
N
N
N
Lu
N
OH
Cl
Cl
Lu
O
N
Cl
Cl
N
N
Cl
Cl
Cl
Cl
N
N
N
Cl
OC16H33
N
N
N
N
Cl
OC16H33
Cl
H33C16
N
Cl
Cl
O
VII, OC(NH2)2
VII, urea
N
Cl
Cl
OC16H33 H33C16
O
III
III
V
V
O
N
O
O
H33C16
O
OC16H33
O
O
O
N
N
N
N
Cl
Cl
N
N
N
N
N
Lu
N
OH
Cl
Cl
Cl
Cl
N
O
N
N
Lu
O
N
N
Cl
Cl
Cl
Cl
OC16H33
Cl
N
H33C16O
OC16H33
OC16H33
Cl
N
N
N
Cl
H33C16
N
N
N
O
IV
IV
N
Cl
OC16H33
Cl
Cl
VI
VI
Scheme 4.
Under the reaction conditions, the phthalocyanine
А4 was not formed; compound of the А3В type was
found in trace amounts; the АВ3 and В4 type
complexes were poorly soluble in organic solvents and
could not be isolated by chromatography. Hyd-
roxylutetium complexes were formed, evidently, due
to partial alkaline hydrolysis.
O
CO2H
CO2H
O
VIII
In the long-wave range of electronic absorption
spectrum of compound III (Fig. 1, curve 1), the Q
band was observed, split into two components with
(1) NH4OAc, AcOH
(2) NH3
(3) SOCl2, DMF
O
CN
CN
λmax of 704 and 646 nm and the intensity ratio of 0.71 : 1;
in the short-wave range, the B band was found (λmax
349 nm). In the spectrum of compound IV (Fig. 1,
curve 2), the Q band was split into two components as
well (λmax 709 and 647 nm), their intensities ratio being
O
VII
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956
BORISOV et al.
D
D
λ, nm
λ, nm
Fig. 3. Electronic absorption spectra of solution of
compound VI in CH2Cl2 (1) and in DMF (2).
Fig. 2. Electronic absorption spectra of solution of
compound V in CH2Cl2 (1) and in DMF (2).
of 1 : 0.58. The B band maximum was found at λmax
351 nm in the case of complex IV.
Heteroligand complexes V and VI were extracted
from the reaction mixtures with dichloromethane and
purified via column chromatography. They were dark-
green compounds, readily soluble in benzene, chloro-
form, and dichloromethane, and poorly soluble in
acetone and DMF. Their composition and structure
The observed splitting of the long-wave band is
typical of the АВАВ-type phthalocyanines and can be
explained by the four-orbital Gouterman’s model [12].
In particular, the long-wave maxima in absorption
spectra of symmetric phthalocyanines are assigned to
electronic transition from the а1u orbital to two
perpendicular degenerate orbitals eg*. In the case of
asymmetric phthalocyanines, the degeneration was
removed, and the Q was split into several components.
The splitting then should be the highest in the case of
the АВАВ-type compounds, being in agreement with
the experiment.
1
were confirmed by elemental analysis, Н NMR, and
electronic spectroscopy data.
Electronic absorption spectrum of complex V in
dichloromethane (Fig. 2, curve 1) contained the Q
band split into two components in the long-wave
range, λmax of 707 and 653 nm (Δλ 54 nm), intensity
ratio of 0.79 : 1. It is known that in the absence of
reducing agents phthalocyanine complexes of
lanthanides exist in the neutral-radical “green” form in
the solutions [19]. Presence of weak absorption band at
λmax 549 nm, typical of transition of the unpaired
electron confirmed that complex V in dichloromethane
also existed in the “green” form. Probably, the
unpaired electron was majorly localized at the more
electron-acceptor fragment of tetraanthraquinone-
porphyrazine. Furthermore, the B band was found in
the spectrum (λmax 339 nm).
The heteroligand sandwich compounds, the second
chromophore being tetraanthraquinoneporphyrazine,
could be prepared via template interaction of the
heteroligand complex with phthalonitrile [13–19] or its
derivative. In this work, the heteroligand sandwich
complexes of lutetium with phthalocyanines AABB
(V) and ABAB (VI) were prepared via heating of
phthalocyanines III or IV, respectively, with excess of
dinitrile of anthraquinone-2,3-dicarboxylic acid (VII)
in urea melt (Scheme 3).
As compared with the above-described spectrum, in
the case of solution of V in DMF (Fig. 2, curve 2)
splitting of the Q band decreased (Δλ 46 nm), the ratio
of intensity of the components with λmax 698 and
652 nm being changed to 1:0.88. The band at λmax
549 nm disappeared, and the B band was shifted (λmax
The dinitrile VII was in turn prepared from anthra-
quinone-2,3-dicarboxylic acid VIII via sequential treat-
ment with ammonium acetate in acetic acid, ammonia
solution, and thionyl chloride in DMF (Scheme 4).
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SANDWICH COMPLEXES OF LUTETIUM WITH TETRAANTHRAQUINONEPORPHYRAZINE
957
348 nm). The described featured pointed at transition
Complexes III and IV. 1.00 g (1.6 mmol) of com-
pound I was added to the boiling solution of lithium
hexanolate-1 (prepared by dissolution of 0.1 g of
lithium in 30 mL of hexanol-1), the mixture was
incubated during 10 min, and then 2.53 g (9.6 mmol)
of compound II was added. The mixture was incubated
during 2 h, then 2.38 g (6.0 mmol) of lutetium(III)
chloride hexahydrate was added, and the mixture was
further incubated during 2 h. 20 mL of the alcohol was
distilled off the mixture, the residue was cooled down,
suspended in 40 mL of acetone, and 5 mL of acetic
acid was added. After 5 min of incubation, the formed
precipitate was filtered off, washed with 50 mL of
acetone, and dried. The product was suspended in
30 mL of dichloromethane and filtered. The filtrate
was subject to column chromatography (Kieselgel 60
silica gel, Merck; dichloromethane–THF 50 : 1 as
eluent). From the eluted fractions, individual com-
plexes III and IV were isolated in the form of green
waxy substances.
of complex V into its reduced “blue” form.
In the absorption spectrum of the “green” form of
complex VI (solution in dichloromethane, Fig. 3, curve 1),
the Q band was split into two components as well, λmax
of 702 and 656 nm, the intensities ratio being of
1 : 0.91. In the spectrum of the “blue” form (solution
in DMF), Δλ was down to 30 nm, the intensities ratio
being of 0.99 : 1. The B band maximum in the spectra
of the both forms of complex VI was found at 350 nm.
As expected, electronic absorption bands of compound
VI, containing the АВАВ-type phthalocyanine, were
significantly broadened as compared with those of
complex V, containing the ААВВ-type ligand.
EXPERIMENTAL
Electronic absorption spectra of the solutions were
recorded using the Helios Zeta spectrophotometer. IR
spectra of thin films on thallium iodide crystal were
recorded with the Avatar 360 FT-IR spectrometer
(400–4000 cm–1). 1Н NMR spectra in CDCl3 or
DMSO-d6 (TMS as internal reference) were recorded
using the Bruker Avance-500 spectrometer. Elemental
analysis was performed using the FlashEA 1112
CHNS–O Analyzer instrument.
Hydroxylutetium 1,4,8,11-tetra(hexadecyloxy)-
15,16,17,18,22,23,24,25-octachlorophthalocyaninate
(III) (ААВВ). Yield 0.32 g (10%), readily soluble in
benzene, dichloromethane, and chloroform, poorly
1
soluble in acetone. Н NMR spectrum (CDCl3), δ,
ppm: 7.18–7.12 m (4Н, Ar), 4.30 t (4Н, J 6.5 Hz, Alk),
4.14 t (4Н), 1.89–1.82 m (8Н), 1.30–1.21 m (104Н),
0.88 t (12Н, J 7.2 Hz). Electronic absorption spectrum
(CH2Cl2), λmax, nm (D/Dmax): 704 (0.44), 646 (0.62),
349 (1.00). Found, %: С 60.01; Н 7.93; N 5.38.
С96H137Cl8LuN8О5. Calculated, %: С 59.38; Н 7.11; N
5.77.
Commercial 2,3-dicyanohydroquinone (98%) and
tetrachlorophthalonitrile II (98%) (Aldrich) were used.
Anthraquinone-2,3-dicarboxylic acid was prepared as
described elsewhere [20].
3,6-Di(hexadecyloxy)phthalonitrile (I). A mixture
of 2.0 g (12.5 mmol) of compound II, 8.4 g
(27.5 mmol) of 1-bromohexadecane, 6.9 g (50 mmol)
of K2CO3, and 30 mL of DMF was stirred at 150°С
during 5 h, and then cooled down and diluted with
100 mL of water. The formed precipitate was filtered
off, washed successively with 50 mL of HCl solution
(10%), 100 mL of water, and 400 mL of acetone, and
then dried. Yield 7.5 g (98%), light-yellow powder,
readily soluble in benzene, chloroform, poorly soluble
in acetone. IR spectrum, ν, cm–1: 3085 (С–Н, Ar),
2921 (С–Н, Alk), 2223 (C≡N), 1498, 1461, 1281;
Hydroxylutetium 1,4,15,18-tetra(hexadecyloxy)-
8,9,10,11,22,23,24,25-octachlorophthalocyaninate
(IV) (АВАВ). Yield 0.58 g (18%), readily soluble in
benzene, dichloromethane, and chloroform, poorly
1
soluble in acetone. Н NMR spectrum (CDCl3), δ,
ppm: 7.16–7.10 m (4Н, Ar), 4.20 t (8Н, J 7.2 Hz),
1.88–1.83 m (8Н), 1.31–1.25 m (104Н), 0.89 t (12Н,
J 6.6 Hz). Electronic absorption spectrum (СH2Cl2),
λ
max, nm (D/Dmax): 800 (sh), 709 (0.79), 647 (0.46),
351 (1.00). Found, %: С 60.33; Н 7.56; N 5.27.
С96H137Cl8LuN8О5. Calculated, %: С 59.38; Н 7.11; N
5.77.
1
1192, 1071 (С–О–С); 836, 477. Н NMR spectrum
(CDCl3), δ, ppm: 7.17 s (2Н, Ar), 4.08 t (4Н, J 6.5 Hz,
Alk), 1.86 t (4Н, J 6.6 Hz, Alk), 1.49 t (4Н, J 6.4 Hz,
Alk), 1.30–1.25 m (48Н, J 6.9 Hz, CH2), 0.86 t (6Н, J
6.6 Hz, CH3). Found, %: С 78.91; H 11.32; N 4.47.
C40H68N2O2. Calculated, %: C 78.89; H 11.25; N 4.60.
Dinitrile of anthraquinone-2,3-dicarboxylic acid
(VII). A mixture of 2.90 g (0.01 mol) of the acid VIII,
2.50 g (0.03 mol) of ammonium acetate, and 20 mL of
glacial acetic acid was refluxed during 2 h. 15 mL of
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958
BORISOV et al.
acetic acid was distilled off, and the residue was
diluted with 50 mL of water. The formed precipitate
was filtered off, washed with water till pH 7, and
suspended in 100 mL of ammonia (30 %) solution. The
suspension was stirred during 5 days and then filtered
off. The precipitate was washed with water till pH 7
and dried. The product was dissolved in 30 mL of
DMF, cooled down to 3°С, 8 mL of thionyl chloride
was added, and the mixture was stirred during 5 h. The
reaction mixture was diluted with 100 mL of water; the
formed precipitate was filtered off, washed with water
till pH 7, and dried. Yield 1.61 g (61%), grey powder,
soluble in DMF and DMSO, poorly soluble in acetone
and chloroform. IR spectrum, ν, cm–1: 3071, 2223,
(40%), dark-green powder, readily soluble in dichloro-
methane, chloroform, and benzene, poorly soluble in
acetone and DMF. 1Н NMR spectrum (CDCl3), δ, ppm:
7.80–7.76 m (8Н), 7.56–7.54 m (8Н), 7.25 s (8Н), 7.09
s (4Н), 4.25–4.18 m (8Н), 1.85–1.82 m (8Н), 1.32–1.19
m (104Н), 0.88 t (12Н, J 7.2 Hz). Electronic absorp-
tion spectrum, λmax, nm (D/Dmax): CH2Cl2, 702 (0.88),
656 (0.79), 350 (1.00); DMF, 685 (0.99), 655 (1.00), 351
(0.99). Found, %: С 65.17; Н 5.98; N 7.09. С160Н160Cl8·
LuN16О12. Calculated, %: С 64.97; Н 5.45; N 7.58.
ACKNOWLEDGMENTS
This work was financially supported by Russian
Foundation for Basic Research (project 13-03-
00481A).
1
1678, 1447, 897, 748. Н NMR spectrum (DMSO-d6),
δ, ppm: 8.65 s (2Н), 8.31–8.28 m (2Н), 7.95–7.90 m
(2Н). Found, %: С 74.13; Н 2.87; N 10.61.
С16Н6N2О2. Calculated, %: С 74.42; Н 2.34; N 10.85.
REFERENCES
Preparation of sandwich complexes V and VI. A
mixture of 0.20 g (0.1 mmol) of compound III or IV,
0.20 g (0.8 mmol) of compound VII, and 1.0 g of urea
was heated at 190°С during 3 h, and then cooled down.
The reaction mixture was crushed, extracted with
dichloromethane; the extract was dried and washed
with acetone. The residue was dissolved in dichloro-
methane and subject to column chromatography
(Kieselgel 60 silica gel Merck, dichloromethane–THF
mixture 10 : 1 as eluent), the major green zone was
collected. After the solvent removal, the target pro-
ducts were obtained.
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24,25-octachlorophthalocyaninato]tetraantraquino-
neporphyrazinatolutetium(III) (V). Yield 0.17 g
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1
acetone and DMF. Н NMR spectrum (CDCl3), δ,
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(8Н), 7.07 s (4Н), 4.33–4.25 m (4Н), 4.15 t (4Н, J
7.2 Hz), 1.87–1.81 m (8Н), 1.32–1.20 m (104Н), 0.88 t
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(0.22), 339 (0.98); DMF, 698 (1.00), 652 (0.88), 348
(0.91). Found, %: С 65.21; Н 5.87; N 7.13. С160Н160Cl8·
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neporphyrazinatolutetium(III) (VI). Yield 0.12 g
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SANDWICH COMPLEXES OF LUTETIUM WITH TETRAANTHRAQUINONEPORPHYRAZINE
959
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