Synthesis of palladium and nickel complexes with octaphenyltetraazaporphyrins

Article abstract of DOI:10.1023/B:RUGC.0000016039.52090.d2

Palladium(II) and nickel(II) complexes with octaphenyltetraazaporphyrin, octakis(4-bromophenyl)tetraazaporphyrin, and octakis(4-nitrophenyl) tetraazaporphyrin were obtained by reactions of octaphenyltetraazaporphyrin, Mg octaphenyltetraazaporphyrin, octak

Full text of DOI:10.1023/B:RUGC.0000016039.52090.d2

Russian Journal of General Chemistry, Vol. 73, No. 10, 2003, pp. 1645 1647. Translated from Zhurnal Obshchei Khimii, Vol. 73, No. 10, 2003,
pp. 1738 1741.
Original Russian Text Copyright
2003 by Chizhova, Khelevina, Berezin.
Synthesis of Palladium and Nickel Complexes
with Octaphenyltetraazaporphyrins
N. V. Chizhova, O. G. Khelevina, and B. D. Berezin
Institute of Solution Chemistry, Russian Academy of Sciences, Ivanovo, Russia
Ivanovo State University of Chemical Technology, Ivanovo, Russia
Received December 3, 2001
Abstract Palladium(II) and nickel(II) complexes with octaphenyltetraazaporphyrin, octakis(4-bromo-
phenyl)tetraazaporphyrin, and octakis(4-nitrophenyl)tetraazaporphyrin were obtained by reactions of octa-
phenyltetraazaporphyrin, Mg octaphenyltetraazaporphyrin, octakis(4-bromophenyl)tetraazaporphyrin, and
octakis(4-nitrophenyl)tetraazaporphyrin with palladium(II) and nickel(II) chlorides in DMF.
At present palladium(II) complexes with por-
phyrins and phthalocyanines have found use as
catalysts and highly effective sensors [1].
DMF within 10 min (reagent molar ratio 1:20), and
compound VII, within 20 s (reagent molar ratio 1:10).
R
R
There are no published data on palladium(II) com-
plexes with octaphenyltetraazaporphyrins. A nickel(II)
complex with octaphenyltetraazaporphyrin was ob-
tained earlier [2] from the ligand and nickel(II) acetate
in pyridine. Nickel(II) complexes with octakis(4-
bromophenyl)tetraazaporphyrin and octakis(4-nitro-
phenyl)tetraazaporphyrin have not been described.
N
N
R
R
N
X
N
N
X
N
N
N
The aim of the present work was to develop con-
venient methods of synthesis of palladium and nickel
complexes of phenyl-substituted tetraazaporphyrins.
We studied the coordination reactions of octaphenyl-
tetraazaporphyrin (I) and its magnesium complex (II),
octakis(4-bromophenyl)tetraazaporphyrin (III), and
octakis(4-nitrophenyl)tetraazaporphyrin (IV) with
palladium(II) and nickel(II) chlorides in DMF, follow-
ing reaction progress by spectrophotometry.
R
R
R
R
I IV
R
R
Our studies showed that palladium(II) chloride
reacts with octakis(4-nitrophenyl)tetraazaporphyrin
(IV) in DMF for 2 days at room temperature, and the
reaction time with octakis(4-bromophenyl)tetraaza-
porphyrin (III) increases to 80 days. For faster
complex formation of octaphenyltetraazaporphyrins
with PdCl2, the reactions were performed in boiling
DMF.
N
R
R
N
N
N
M
PdCl2, NiCl2
DMF
N
N
N
R
N
R
Complex V of palladium with octaphenyltetraaza-
porphyrin is formed in boiling DMF within 1 h (por-
phyrazine:metal salt molar ratio 1:20). Introduction
of bromine atoms and electron-acceptor nitro groups
into benzene rings accelerates coordination with PdCl2
in DMF. Thus, compound VI is formed in boiling
R
R
V X
I IV, X = H, R = H (I), Br (III), NO2 (IV); X, X = Mg,
R = H (II). V X, M = Pd, R = H (V), Br (VI), NO2 (VII);
M = Ni, R = H (VIII), Br (IX), NO2 (X).
1070-3632/03/7310-1645$25.00 2003 MAIK Nauka/Interperiodica

1646
CHIZHOVA et al.
Electronic absorption spectra of palladium(II), nickel(II),
and magnesium complexes of phenyl-substituted tetra-
azaporphyrins in chloroform, , nm (log )
bonds (for all the porphyrazines presented) and also
of the M N back dative bond [for nickel(II) and
palladium(II) complexes]. The electronic absorption
spectra of nickel(II) and palladium(II) complexes with
bromo- and nitro-substituted porphyrazines are bato-
chromically shifted by as little as 1 4 nm with respect
to the spectra of nickel(II) and palladium(II) octa-
phenyltetraazaporphyrins, and bands are stronger.
Complex
Band I
Band II
Soret band
I Pd2+
616 (4.28) 560 (3.83)
619 (4.92) 565 (4.35)
620 (4.92) 565 (4.40)
633 (4.32) 583 (3.75)
630 (4.38) 580 (3.80)
633 (4.95) 580 (4.28)
634 (4.96) 585 (4.30)
639 (4.91) 595 (4.30)
350 (4.26)
350 (4.87)
354 (4.86)
377 (4.25)
370 (4.37)
375 (4.90)
375 (4.92)
379 (4.86)
III Pd2+
IV Pd2+
a
I Ni2+
Solutions of palladium complexes with bromo and
nitro derivatives of octaphenyltetraazaporphyrin in
benzene and chloroform fluoresce in light (the color
changes from bluish green to dark red).
I Ni2+
III Ni2+
IV Ni2+
a
I Mg2+
Nitro substitution in porphyrin molecules is known
[7] to increase their resistance to oxidation, whereas
bromine substitution in tetraazaporphyrin molecules
increases their photochemical stability [8].
a
Data of [2].
The effect of electron-acceptor substituents on the
Complex VII of palladium(II) with octakis(4-nitro-
phenyl)tetraazaporphyrin appeared to be highly re-
sistant to sulfuric acid. A solution of complex VII in
100% H2SO4 did not decompose within 1 year at
room temperature (the electronic absorption spectrum
remained unchanged). The half-life of nickel complex
X in 100% H2SO4 was 3 months at room temperature.
rate of tetraazaporphyrin coordination with metal salts
in strongly coordinating basic solvents was studied
earlier [3 5]. The rate of complex formation of bromo
and nitro derivatives of porphyrazines increases as the
result of enhanced polarization of N H bonds in the
reaction center [4, 5].
Nickel(II) chloride, having a smaller molecular
radius compared to PdCl2, readily coordinates with
nitro- and bromo-substituted octaphenyltetraazapor-
phyrins in DMF at room temperature. Thus, nitro
derivative X is formed at 20 C within 20 min (reagent
molar ratio 1:10) and compound IX, within 20 h
(reagent molar ratio 1:20). Nickel(II) chloride reacts
with octaphenyltetraazaporphyrin (I) in DMF at room
temperature for 5 days, and the reaction time de-
creases to 1 min on boiling (reagent molar ratio 1:10).
EXPERIMENTAL
The electronic absorption spectra were recorded on
a Specord M-40 instrument. Thin-layer chromato-
graphy was carried out on Silufol plates.
Magnesium octaphenyltetraazaporphyrin complex
(II) was synthesized by the procedure in [9].
Octaphenyltetraazaporphyrin (I). A solution of
0.1 g of complex II in 50 ml of trifluoroacetic acid,
was allowed to stand at room temperature for 2 h.
Dimethylformamide, 40 ml, was then added, and the
mixture was poured into cold distilled water, the
precipitate was filtered off and washed with a solution
of NaHCO3 (to neutral reaction), water, and ethanol,
and dried. Yield 0.07 g (70%).
It was found that palladium(II) and nickel(II)
complexes with octaphenyltetraazaporphyrins can be
obtained from magnesium(II) complex and metal
chlorides in boiling DMF by metal exchange. In this
case, the procedures of synthesis of compounds V and
VIII are simplified (complex II obtained by Linstead’s
procedure is used, the amount of the solvent is de-
reased).
Octakis(4-bromophenyl)tetraazaporphyrin (III) and
octakis(4-nitrophenyl)tetraazaporphyrin (IV) were
synthesized by the procedures in [10, 11].
The electronic absorption spectra of the synthesized
palladium(II) and nickel(II) complexes with octa-
phenyltetraazaporphyrins I, III, and IV in chloroform
are given in the table, together with the spectra of the
nickel(II) and magnesium complexes obtained earlier.
Palladium(II) octaphenyltetraazaporphyrin
(V). a. A solution of 0.1 g of compound I and 0.19 g
of PdCl2 (molar ratio 1:10) in 40 ml of DMF was
heated under reflux for 30 min, 0.19 g of PdCl2 was
then added and refluxing was continued for an
additional 30 min. After cooling, the mixture was
poured into water, the precipitate was filtered off,
washed with water, dried in air, and subjected to
chromatography on alumina (eluent pyridine diethyl
When passing from magnesium to nickel(II) and
palladium(II) octaphenyltetraazaporphyrins, a hypso-
chromic shift of bands is observed in the electronic
absorption spectra (spectral criterion of bond strength)
[6]. This shift is indicative of strengthening of M
N
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 10 2003

SYNTHESIS OF PALLADIUM AND NICKEL COMPLEXES
1647
ether, 1:4). Yield 0.073 g (66%), Rf 0.67 (CHCl3
CCl4, 1:1).
Nickel(II) octakis(4-bromophenyl)tetraazapor-
phyrin (IX). A solution of 0.1 g of compound III and
0.17 g of NiCl2 (molar ratio 1:20) in 20 ml of DMF
was allowed to stand at 20 C for 20 h, after which it
was poured into water, the precipitate was filtered off,
washed with water, dried in air, subjected to chro-
matography on silica gel (chloroform), and repreci-
pitated from methanol. Yield 0.096 g (92%), Rf 0.78
(CHCl3 CCL4, 1:4). Found, %: C 47.68; H 1.92; Br
39.70; N 6.88; Ni 3.58. C64H32Br8N8Ni. Calculated,
%: C 47.72; H 2.00; Br 39.68; N 6.96; Ni 3.64.
b. A solution of 0.1 g of compound II and 0.19 g
of PdCl2 (molar ratio 1:10) in 20 ml of DMF was re-
fluxed for 30 min, 0.19 g of PdCl2 was then added
and refluxing was continued for an additional 30 min.
After cooling, the mixture was poured into water, the
precipitate was filtered off, washed with water, dried
in air, and subjected to chromatography on alumina
(eluent pyridine diethyl ether, 1:4). Yield 0.087 g
(80%), Rf 0.67 (CHCl3 CCl4, 1:1). Found, %:
C 75.38; H 3.08; N 10.87; Pd 10.36. C64H40N8Pd.
Calculated, %: C 75.44; H 3.14; N 10.87; Pd 10.44.
Nickel(II) octakis(4-nitrophenyl)tetraazapor-
phyrin complex (X). A solution of 0.1 g of com-
pound IV and 0.101 g of NiCl2 (molar ratio 1:10) in
15 ml of DMF was allowed to stand at 20 C for
20 min, after which it was poured into water, the
precipitate was filtered off, washed with water, dried
in air, subjected to chromatography on silica gel
(acetone), and reprecipitated from methanol. Yield
0.098 g (93%), Rf 0.75 (CHCl3). Found, %: C 57.26;
H 2.35; N 16.66; Ni 4.33. C64H32N16NiO16. Calcu-
lated, %: C 57.38; H 2.41; N 16.73; Ni 4.38.
Palladium(II) octakis(4-bromophenyl)tetraaza-
porphyrin (VI). A solution of 0.1 g of compound III
and 0.23 g of PdCl2 (molar ratio 1:20) in 20 ml of
DMF was refluxed for 10 min, cooled, poured into
water, the precipitate was filtered off, washed with
water, dried in air, subjected to chromatography on
silica gel (chloroform), and reprecipitated from m
ethanol. Yield 0.1 g (90%), Rf 0.41 (CCl4), 0.77
(CHCl3 CCl4, 1:4). Found, %: C 46.38; H 1.88; Br
38.44; N 6.69; Pd 6.36. C64H32Br8N8Pd. Calculated,
%: C 46.35; H 1.93; Br 38.54; N 6.76; Pd 6.42.
REFERENCES
Palladium(II) octakis(4-nitrophenyl)tetraaza-
porphyrin (VII). A solution of 0.1 g of compound
IV and 0.14 g of PdCl2 (molar ratio 1:10) in 15 ml of
DMF was refluxed for 20 s, cooled, poured into water,
the precipitate was filtered off, washed with water,
dried in air, subjected to chromatography on silica gel
(acetone), and reprecipitated from methanol. Yield
0.1 g (93%), Rf 0.73, (CHCl3). Found, %: C 55.44; H
2.28; N 16.08; Pd 7.59. C64H32 N16O16Pd. Calcu-
lated, %: C 55.42; H 2.31; N 16.15; O 18.45; Pd 7.67.
1. Porfiriny: Spektroskopiya, elektrokhimiya, primenenie
(Porphyrins: Spectroscopy, Electrochemistry, Applica-
tion), Enikolopyan, N.S., Ed., Moscow: Nauka, 1987.
2. Berezin, B.D. and Khelevina, O.G., Porfiriny: Struk-
tura, svoistva, sintez (Porphyrins: Structure, Properties,
Synthesis), Moscow: Nauka, 1985, pp. 83 113.
3. Khelevina, O.G., Chizhova, N.V., and Berezin, B.D.,
Koord. Khim., 1991, vol. 17, no. 3, p. 400.
4. Petrov,O.A., Chizhova, N.V., and Karaseva, N.A.,
Koord. Khim., 1999, vol. 25, no. 9, p. 680.
Nickel(II) octaphenyltetraazaporphyrin (VIII).
a. A solution of 0.1 g of compound I and 0.15 g
of NiCl2 (molar ratio 1:10) in 35 ml of DMF was
refluxed for 1 min, cooled, poured into water, the
precipitate was filtered off, washed with water, dried
in air, and subjected to chromatography on alumina
(eluent pyridine diethyl ether 1:4). Yield 0.83 g
(80%), Rf 0.69 (CHCl3 CCl4, 1:1).
5. Khelevina, O.G., Chizhova, N.V., and Rumyantse-
va, S.V., Koord. Khim., 1999, vol. 25, no. 9, p. 680.
6. Berezin, B.D. and Enikolopyan, N.S., Metalloporfi-
riny (Metal Porphyrins), Moscow: Nauka, 1988.
7. Kopranenkov, V.N., Makarova, E.A., and Luk’ya-
nets, E.A., Khim. Geterotsikl. Soedin., 1986, no. 9,
p. 1189.
b. A solution of 0.1 g of compound II and 0.14 g
of NiCl2 (molar ratio 1:10) in 20 ml of DMF was
refluxed for 1 min, cooled, poured into water, the
precipitate was filtered off, washed with water, dried
in air, and subjected to chromatography on alumina
(eluent pyridine diethyl ether 1:1). Yield 0.094 g
(90%), Rf 0.69 (CHCl3 CCl4, 1:1). Found, %: C
79.08; H 3.24; N 11.45; Ni 5.98. C64H40N8Ni. Cal-
culated, %: C 79.11; H 3.32; N 11.53; Ni 6.04.
8. Khelevina, O.G., Chizhova, N.V., and Berezin, B.D.,
Zh. Fiz. Khim., 1993, vol. 67, no. 9, p. 1877.
9. Gook, A H., J. Chem. Soc., 1937, p. 929.
10. Chizhova, N.V., Khelevina, O.G., and Berezin, B.D.,
Izv. Vyssh. Uchebn. Zaved., Ser. Khim. Khim. Tekhnol.,
1994, vol. 37, no. 1, p. 20.
11. Chizhova, N.V. and Berezin, B.D., Zh. Org. Khim.,
1994, vol. 30, no. 11, p. 1678.
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