Metal chelates of benzeneazo-N-tosyl-2-naphthylamine

Article abstract of DOI:10.1134/S1070328408120063

New Cu(II), Co(II), and Pd(II) complexes with benzeneazo-N-tosyl-2- naphthylamine are synthesized by chemical and electrochemical methods and characterized by IR, ¹H NMR, and XRD. XRD was used to determine that two six-membered metal rings are

Full text of DOI:10.1134/S1070328408120063

ISSN 1070-3284, Russian Journal of Coordination Chemistry, 2008, Vol. 34, No. 12, pp. 904–910. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © A.S. Burlov, A.I. Uraev, P.V. Matuev, K.A. Lysenko, N.N. Kamkin, D.A. Garnovskii, S.A. Nikolaevskii, V.A. Kogan, A.D. Garnovskii, 2008, published in
Koordinatsionnaya Khimiya, 2008, Vol. 34, No. 12, pp. 916–922.
Metal Chelates of Benzeneazo-N-Tosyl-2-Naphthylamine
a
b
a
b
b
c
A. S. Burlov , A. I. Uraev , P. V. Matuev , K. A. Lysenko , N. N. Kamkin , D. A. Garnovskii ,
a
d
a
S. A. Nikolaevskii , V. A. Kogan , and A. D. Garnovskii
a
b
Institute of Physical and Organic Chemistry, Southern Federal University, pr. Stachki 194/3, Rostov-on-Don, 344104 Russia
Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, ul. Vavilova 28, Moscow, 117813 Russia
c
Southern Scientific Center, Russian Academy of Sciences, Rostov-on-Don, Russia
d
Southern Federal University, Rostov-on-Don, Russia
E-mail: garn@ipoc.rsu.ru
Received October 26, 2007
Abstract—New Cu(II), Co(II), and Pd(II) complexes with benzeneazo-N-tosyl-2-naphthylamine are synthe-
1
sized by chemical and electrochemical methods and characterized by IR, H NMR, and XRD. XRD was used
to determine that two six-membered metal rings are formed in transplanar Ni(II) and Pd(II) complexes.
DOI: 10.1134/S1070328408120063
The persistent interest in the complexes of azo tion between the components. A solution of the hydrate
ligands is due to the fact that they served as the base for of the corresponding metal acetate (Cu, Ni, Co)
formulation and development of the views on chelate (1 mmol) in methanol (20 ml) was added to a solution
isomerism, i.e., the possibility of formation of metal of LH (2 mmol) in methanol (50 ml). Palladium acetate
rings with different size in one chelate molecule [1–11]. was dissolved in acetone (10 ml). The mixture was
As shown by X-ray diffraction [12], the replacement of refluxed on a water bath for 1 h. The complexes that
phenylamino or hydroxy groups in the ortho-position to precipitated on cooling of the solutions were filtered
the azo group by a tosylamino group gives rise to a off, washed with methanol (2 × 5 ml), and dried in a
structure with different (five- and six-membered) metal drying oven at 100°ë. The crystals for X-ray diffraction
rings. It was of interest to consider how the replacement were grown from a chloroform–methanol mixture (1 : 2).
of the benzene ring in azo compounds by a naphthalene Yield 60–65%.
ring would influence the structure.
The electrochemical synthesis (ES) of complexes I
This communication presents the results of chemi- was carried out, taking into account published data [14,
cal and electrochemical syntheses and X-ray diffraction 15], by the reaction of LH with cations formed from a
analysis of benzeneazo-N-tosyl-2-naphthylamine (LH) sacrificial anode made of the required metal (Cu, Ni,
and metal chelates (ML , I) based on it:
Co). The electrochemical cell may be represented as
follows:
2
Ts
Ts
Pt(–)/MeCN//LH (I)/M(+).
NH
N M/2
A solution of LH (1 mmol) in acetonitrile (25 ml)
N
N
contained (Et N)ClO (0.01 g) as a conducting additive.
4
4
N
N
Electrosynthesis was carried out at a constant current
40 mA) and a voltage of 15 V for 2 h. The precipitates
(
were filtered off, washed with hot methanol (3 × 10 ml),
and recrystallized from a methanol–chloroform mix-
ture (2 : 1). Yield 65–70%.
The results of elemental analysis and characteristics
of compounds I are given in Table 1.
ML2: M2+ = Cu (Ia), Ni (Ib),
Co (In), Pd (Id).
LH
1
Id: H NMR (300 MHz, CDCl ), δ, ppm: 1.09 (6H,
3
EXPERIMENTAL
s, 2CH ), 6.61–8.06 (28 H m, C –H), 8.46 (2 H, d,
3
Ar
3
LH was synthesized by a reported procedure [13].
J = 8.0, C –H ).
Ar
8
1
H NMR (300 MHz, CDCl ) δ, ppm: 2.30 (3 H, s,
1
3
The H NMR spectra were recorded on a Varian
CH ), 7.14–8.01 (14 H, m, C –H), 8.86 (1 H, d, C –H ,
3
Ar
Ar
8
Unity 300 (300 MHz) instrument in the internal stabili-
3
J = 8.5 Hz), 13.38 (1 H, s, NH).
2
zation mode of H resonance line in CDCl . The IR
3
The chemical synthesis (CS) of complexes I was spectra were recorded on a Nicolet Impact 400 instru-
carried out as reported previously [6, 7] by direct reac- ment (mineral oil mulls). The magnetochemical mea-
9
04

METAL CHELATES OF BENZENEAZO-N-TOSYL-2-NAPHTHYLAMINE
Table 1. Elemental analysis data and physical properties of LH and Ia–Id
905
Contents (found/calculated), %
Com-
pound
T , °C
Color
Molecular formula
mp
C
H
N
M
LH
Ia
186–187 Red
C H N O S
68.70/68.81 4.52/4.77 10.42/10.47
2
3
19
3
2
200–201 Brown
C H N O S Cu CS 63.56/63.91
4.37/4.20 9.32/9.72
4.28/4.20
7.01/7.35
7.45/7.35
4
6
36
6
4 2
ES 63.62/63.91
9
.82/9.72
Ib
Ic
Id
277–278 Dark green
271–272 Dark violet
263–264 Green
C H N O S Ni CS 64.01/64.27
4.40/4.22 9.85/9.78
4.31/4.22
6.92/6.83
6.75/6.83
4
6
36
6
4 2
ES 64.25/64.27
9
.84/9.78
C H N O S Co CS 64.99/64.25
4.55/4.22 9.77/9.26
7.01/6.85
6.76/6.85
4
6
36
6
4 2
ES 64.12/64.257 4.35/4.22
9
.32/9.26
C H N O S Pd CS 60.56/60.89
4.22/4.37 9.32/9.26 11.71/11.73
4
6
36
6
4 2
surements were carried out by the Faraday method on a
Table 3 presents the stretching frequencies for LH
setup constructed at the Department of Chemistry of and for complexes ML (Ia–Id) and their effective mag-
2
Rostov State University [16].
netic moments (µ ). On going from azo compounds to
ef
complexes Ia, Id, ν(NH) bands disappear from the IR
spectra, which is indicative of replacement of the pro-
ton in the ligand amino group by a metal ion. This is
X-Ray diffraction study of LH, Ib, and Id was car-
ried out on a SMART APEX II CCD diffractometer
(
MoKα radiation, graphite monochromator, ω scan
1
1
confirmed by H NMR data. The H NMR spectrum of
LH exhibits a singlet from the NH group proton at
mode, í = 100 K). The experimental data were pro-
cessed and averaged using the SAINT-Plus program
package [17]; absorption correction was applied
semiempirically using equivalent reflections [18].
1
3.88 ppm, which disappears for complex Id, while the
signals of the aromatic protons shift upfield. These
spectral characteristics of complexes attest to their che-
late structure.
The structures were solved by the direct method and
refined by least squares in the anisotropic full-matrix
Copper (Ia) and cobalt (Ic) complexes are paramag-
2
netic (Table 3). The µ value (4.21 µ ) of the cobalt
ef
B
approximation on F . The positions of hydrogen
hkl
complex attests to a tetrahedral structure of the coordi-
atoms (except for H(1N) in the ligand) were calculated
geometrically and refined in the isotropic approxima-
tion. The main crystal data and refinement parameters
are summarized in Table 2. All calculations were car-
ried out by the SHELXTL-Plus program package [19].
nation unit. The nickel complex (Ic) is diamagnetic,
which may imply its planar structure. The value µ =
ef
2
.0 µ for Ia corresponds to the effective magnetic
B
moment of one unpaired electron including the orbital
contribution.
The complexes obtained by electrosynthesis have
similar magnetic and spectral characteristics.
The X-ray diffraction data of nickel (Ib) and palla-
dium (Id) complexes (Figs. 1, 2) confirmed the conclu-
sions based on spectroscopic data.
RESULTS AND DISCUSSION
Metal chelates were prepared by direct reaction of
components (chemical synthesis) and by electrochemi-
cal synthesis according to the following scheme
According to X-ray diffraction, complexes Ib and
Id have similar structures with trans-planar N coordi-
4
MeOH
CH3CN
electrochemical
synthesis
0
nation with trans-arrangement of donor nitrogen
atoms. Two benzeneazo-N-tosyl-2-naphthylamine mol-
ecules function as monodeprotonated bidentate
I + MAc ⋅ nH O
II
I + M .
2
2
chemical
synthesis
According to elemental analysis data, complexes I N,N-ligands forming two identical six-membered
2
+
2+
have the composition ML2.
metal rings with Ni and Pd ions. In the crystal both
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 34 No. 12 2008

9
06
BURLOV et al.
Table 2. Selected crystal data and X-ray experiment details for LH, Ib, and Id
Value
Parameter
LH
Ib
C H N NiO S
Id
Molecular formula
C H N O S
C H Cl N O PdS
2
23
19
3
2
46 36
6
4
2
48 38
6
6
4
M
401.47
859.64
1146.06
System
Monoclinic
Monoclinic
Triclinic
Space group
P2 /c
P2 /n
ê1
1
1
Z(Z')
a, Å
b, Å
4(1)
7.8815(4)
20.8055(11)
12.1553(7)
90.00
100.769(5)
90.00
1958.1(4)
1.362
2(0.5)
11.2230(8)
16.3089(12)
11.7940(8)
90.00
106.343(2)
90.00
2071.5(3)
1.378
1(0.5)
9.9859(4)
11.5365(5)
12.1976(5)
98.4210(10)
104.0800(10)
111.2540(10)
1226.73(9)
1.551
c, Å
α, deg
β, deg
γ, deg
3
V, Å
–
3
ρ(calcd), g cm
–1
µ, cm
F(000)
θmax, deg
1.9
840
58
6.21
892
59.2
8.41
580
60
2
The number of measured reflections
23714
25943
32252
The number of independent reflections
5213
5819
7157
The number of reflections with I > 2σ(I)
4091
3958
6794
The number of refined parameters
267
268
308
R1
wR2
GOOF
0.0423
0.1162
0.979
0.0461
0.1173
0.989
0.0236
0.0651
1.052
0.890/–0.745
∆
ρmax/∆ρmin, e Å–3
0.514/–0.429
0.533/–0.528
–
1
Table 3. Stretching frequencies (ν, cm ) and effective magnetic moment (µ ) of benzeneazo-N-tosyl-2-naphthylamine and
ef
its complexes Ia–Id
ν, cm–1
Compound
M
H
µef, µB
ν(N–H)
ν (SO )
ν (SO )
ν(N=N)
as
2
s
2
LH
Ia
3100–3240
1308 w
1290 s
1291 s
1290 s
1291 s
1306 w
1130 m
1090 s
1090 s
1092 s
1092 s
1090 s
1090 s
1092 s
1421 w
Cu
Cu
Ni
Ni
Co
Co
Pd
1410 w
1410 w
1421 w
1421 w
1400 w
1400 w
1420 w
2.00
2.00
Ia*
Ib
Diamagnetic
"
Ib*
Ic
4.21
1
283 m
1306 w
283 m
1290 m
Ic*
Id
4.21
1
Diamagnetic
"
*
Obtained by electrochemical method.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 34 No. 12 2008

METAL CHELATES OF BENZENEAZO-N-TOSYL-2-NAPHTHYLAMINE
907
C(22)
C(17)
C(21)
C(15)
C(14)
C(23)
C(16)
O(1)
C(18)
C(20)
C(13)
S(1)
C(11)
C(19)
Ni(1)
C(12)
N(3)
N(1A)
O(2)
N(1)
C(1)
N(3A)
N(2)
C(2)
C(10)
C(3)
C(4)
C(9)
C(8)
C(5)
C(7)
C(6)
Fig. 1. Structure of complex Ib (thermal ellipsoids are given with 50% probability; the same is in Figs. 2 and 3). The hydrogen atoms are omitted.
Cl(3)
Cl(1)
Cl(2)
C(1S)
C(17)
C(15)
C(14)
C(16)
H(1S)
C(13)
C(11)
O(1)
O(2)
C(12)
C(22)
S(1)
C(23)
C(21)
N(1)
C(18)
N(3)
C(20)
C(19)
Pd(1)
N(2)
N(3A)
C(1)
N(1A)
C(10)
C(2)
C(3)
C(4)
C(9)
C(8)
C(5)
C(7)
C(6)
Fig. 2. Structure of complex Id. The hydrogen atoms are omitted.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 34 No. 12 2008

9
08
BURLOV et al.
Table 4. Selected bond lengths and bond angles in structures The six-membered metal rings MN C are nonplanar
3
2
LH, Ib, and Id
having a twist-boat conformation. Slight deviations
from the ring plane are observed in both complexes for
the metal atom (1.02 Å for Ni(1) and 1.04 Å for Pd(1))
and for the N(2) atom (0.24 and 0.23 Å, respectively)
which deviate from the mean planes (the mean root-
square deviations are 0.02 and 0.01 Å) to the opposite
directions. The folding angle along the N(1)–N(3) line
is 45.9° for Ib and 48.4° for Id. In both complexes, the
phenyl group is not conjugated with the lone pair of
N(3) (the C(19)C(18)N(3)N(2) torsion angles are 29.8°
and 33.6°, respectively), which is apparently due to
d, Å
Bond
LH
Ib
Id
M–N(1)
1.882(2)
1.895(2)
1.435(2)
1.436(2)
1.628(2)
1.764(2)
1.385(3)
1.268(2)
1.382(3)
1.441(3)
1.404(3)
2.013(1)
2.022(1)
1.443(1)
1.445(1)
1.629(1)
1.763(1)
1.384(1)
1.266(1)
1.381(1)
1.434(1)
1.414(2)
M–N(3)
S(1)–O(2)
S(1)–O(1)
S(1)–N(1)
S(1)–C(11)
N(1)–C(1)
N(2)–N(3)
N(2)–C(2)
N(3)–C(18)
C(1)–C(2)
1.434(1)
1.436(1)
1.628(1)
1.757(1)
1.392(2)
1.268(2)
1.402(2)
1.423(2)
1.409(2)
steric repulsion between the SO group and the neigh-
2
boring ligand.
The insignificant elongation of the S–O bonds in Id
is obviously related to the presence of ë–ç···O interac-
tions with a solvation CHCl molecule. The hydrogen
3
atom H(1S) is involved in the formation of bifurcated
unsymmetrical H-bond with the O(1) and O(2) oxygen
atoms (H(1S)···O(1) 2.19 Å, C(1S)H(1S)O(1) 134°,
H(1S)···O(2) 2.56 Å, C(1S)H(1S)O(1) 149°) (Fig. 2).
Note that the naphthalene fragment in Ib is some-
what distorted. The deviations of C(1) and C(10) atoms
from the plane through the other ring atoms are 0.107
and 0.08 Å, whereas in complex Id the maximum devi-
ation observed for C(1) is only 0.04 Å. The ring distor-
tion and, as a result, some shortening of the C(1)–C(2)
bond in Ib (Table 4) is apparently caused by steric
repulsion of the substituents at N(1) and N(3A) atoms
in both complexes, the repulsion being stronger for
shorter M–N bonds.
Angle
ω, deg
N(1)MN(3A)*
N(1)MN(3)
94.52(8)
85.48(8)
117.74(9)
112.71(9)
104.88(9)
107.6(1)
108.8(1)
104.3(1)
97.11(4)
82.89(4)
O(2)S(1)O(1)
O(2)S(1)N(1)
O(1)S(1)N(1)
119.71(7)
110.61(7)
103.39(7)
116.89(6)
113.35(6)
104.90(5)
107.81(6)
108.97(6)
104.16(6)
121.36(8)
118.79(8)
119.63(6)
121.7(1)
To analyze how the metal coordination affects the
bond length distribution in the ligand, X-ray diffraction
of LH was carried out. The structure is shown in Fig. 3.
O(2)S(1)C(11) 108.41(7)
O(1)S(1)C(11) 108.36(7)
N(1)S(1)C(11) 105.42(7)
An
abnormally
strong
intramolecular
H-bond N(1)−H(1N)···N(3) (N(1)···N(3) 2.559(1) Å;
N(1)H(1N)···N(3) 139°) is formed in the ligand with
closure of a six-membered ring. According to the Cam-
bridge Crystallographic Data Centre, the distance
between the hydrogen donor and acceptor in six-mem-
bered H-bonded rings in structures of this type usually
exceeds 2.6 Å. Only the structure of 2,4-bis(pheny-
lazo)aniline [20] with N···N distance shorter (2.532 Å)
than that in LH is known.
C(1)N(1)S(1)
C(1)N(1)M
S(1)N(1)M
129.63(11) 121.7(2)
117.8(1)
120.2(1)
N(3)N(2)C(2)
117.51(13) 119.9(2)
N(2)N(3)C(18) 115.39(13) 114.0(2)
113.8(1)
In LH, unlike the metal rings in Ib and Id, the
H-bonded ring is planar. Moreover, the plane of the
phenyl group at N(3) is coplanar to the H-bonded ring,
which in turn decreases the N(3)–C(18) bond length to
*
The atoms were obtained from basis atoms by symmetric trans-
formations 1 – x + 1, –y + 1, –z + 1 and 1 – x, –y, –z + 1 for Ib and
Id, respectively.
1
.423(2) Å.
complexes have ë symmetry, the molecules occupy
i
However, the bond lengths and bond angles in the
specific positions with the symmetry center coinciding
N(1)C(1)C(2)N(2)N(3) fragment in LH and in com-
plexes I almost do not differ (Table 4). The greatest
change is observed for the N(2)–C(2) bond, which is
probably due to deviation of N(2) from the ring plane in
with the metal atom. Complex Id is a crystal solvate
with two CHCl molecules, whereas Ib crystallizes
3
without solvation molecules.
A comparison of the key geometric parameters of the complexes (see above). Thus, the effects of M(II)
complexes Ib and Id has shown that their structures are coordination and strong H-bond in LH on the bond
almost identical (Table 4). Thus in both Ib and Id, the length distribution in the ring are similar. Moreover, the
M–N(3) distance is somewhat shorter than M–N(1). slight variation of the bond lengths upon ring distortion
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 34 No. 12 2008

METAL CHELATES OF BENZENEAZO-N-TOSYL-2-NAPHTHYLAMINE
909
C(22)
C(21)
O(1)
C(12)
C(23)
C(13)
C(14)
C(15)
C(17)
S(1)
C(20)
H(1N)
C(11)
N(3)
C(18)
C(16)
O(2)
N(1)
C(1)
C(19)
N(2)
C(2)
C(10)
C(9)
C(3)
C(8)
C(7)
C(4)
C(5)
C(6)
Fig. 3. Structure of the ligand LH.
indicate that the geometric parameters in this system (project no. NSh 363.2008.3), inner grants of the
depend little on the degree of flattening of metal rings. Southern Federal University (program “Development
of the Network of National Universities”), the Program
As shown previously [21–23], similar tosylami-
of the Presidium of the RAS “Support of Innovations”
noazo compounds and their metal complexes are
(
Development of High-Temperature Greases Based on
effective additives to lubrication oils improving lubri-
cating properties (loading, antiwear, and antifriction
characteristics). Therefore, compounds prepared and
described in this work may prove useful for the devel-
opment of new effective lubricating compositions for
various industry branches.
Polyorganosiloxanes Modified by Azomethine Metal
Complexes).
REFERENCES
1
. Dyachenko, O.A., Atovmyan, L.O., and Aldoshin, S.M.,
J. Chem. Soc., Chem. Commun., 1975, no. 2, p. 105.
Thus, the X-ray diffraction studies of Ib and Id
showed that replacement of the benzene ring by a naph-
thalene ring in the azo compound LH results in struc-
tures with two six-membered metal rings rather than a
five- and a six-membered ring [6, 7]. We would like to
emphasize in this connection that back in 1967, Price
noted the possibility of formation of two-membered
metal rings in azoamino complexes [24]. This fact is
included in the classical handbook [25], although it was
not confirmed by X-ray diffraction either in the study
cited [24] or in other X-ray diffraction works [10, 12].
2. Kogan, V.A., Kharabaev, N.N., Osipov, O.A., and
Kochin, S.G., Zh. Strukt. Khim., 1981, vol. 22, no. 1,
p. 126.
3. Kogan, V.A., Kochin, S.G., Antsyshkina, A.S., et al.,
Mendeleev Commun., 1997, p. 239.
4
5
. Kochin, S.G., Antsyshkina, A.S., Sadikov, G.G., et al.,
Dokl. Akad. Nauk, 1997, vol. 355, no. 6, p. 777 [Dokl.
(Engl. Transl.), vol. 355, no. 6, p. 178].
. Kogan, V.A., Kochin, S.G., Antsyshkina, A.S., et al.,
Mendeleev Commun., 1999, p. 82.
ACKNOWLEDGMENTS
6. Garnovskii, A.D., Vasil’chenko, I.S., and Garnovskii, D.A.,
Sovremennye Aspekty Sinteza Metallokompleksov.
Osnovnye Ligandy I Metody (Modern Aspects of the
Synthesis of Metal Complexes. Key Ligands and Meth-
ods), Rostov-on-Don: LaPO, 2000, vol. 355.
This work was supported by the Russian Foundation
for Basic Research (projects no. 07-03-00256, 07-03-
0710, 08-03-00154), Russian Federation President
0
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 34 No. 12 2008

9
10
BURLOV et al.
7
. Synthetic Coordination and Organometallic Chemistry, 17. Bruker SMART. Bruker Molecular Analysis Research
Garnovskii, A.D. and Kharisov, B.I., Eds., New York:
Marcel Dekker, 2003.
Tool. Version 5.059, Madison (WI, USA), Bruker AXS,
1998.
8
9
. Kogan, V.A. and Shcherbakov, I.N., Ross. Khim. Zh., 18. Sheldrick, G.M., SADABS. Version 2.01. Bruker/Sie-
2
004, vol. 48, no. 1, p. 69.
mens Area Detector Absorption Correction Program,
Madison (WI, USA): Bruker AXS, 1998.
. Kogan, V.A., Antsyshkina, A.S., Sadikov, G.G., et al.,
Zh. Neorg. Khim., 2004, vol. 49, no. 12, p. 1988 [Russ. J.
Inorg. Chem. (Engl. Transl.), vol. 49, no. 12, p. 1844].
1
2
2
2
2
9. Sheldrick, G., M SHELXTL Version 5.10. Structure
Determination Software Suite, Madison (WI, USA):
Bruker AXS, 1998.
1
1
0. Garnovskii, A.D. and Vasil’chenko, I.S., Usp. Khim.,
005, vol. 74, no. 3, p. 211.
1. Kogan, V.A., Lyubchenko, S.N., Shcherbakov, I.N., et al.,
Koord. Khim., 2005, vol. 31, no. 8, p. 563 [Russ. J.
Coord. Chem. (Engl. Transl.), vol. 31, no. 8, p. 533].
0. Buzykin, B.I., Sorokin, M.Yu., Fassakhov, R.Kh., et al.,
Zh. Obshch. Khim., 1998, vol. 68, no. 12, p. 1968 [Russ.
J. Gen. Chem. (Engl. Transl.), vol. 68, no. 12, p. 1885].
2
1. Barchan, G.P., Chigarenko, G.G., Kogan, V.A., et al.,
USSR Inventor’s Certificate No. 810778, Byull. Izobret.,
1
1
1
2. Aldoshin, S.M., D’yachenko, O.A., and Atovmyan, L.O.,
1
981, no. 9.
Koord. Khim., 1980, vol. 6, no. 6, p. 954.
2. Barchan, G.P., Chigarenko, G.G., Bolotnikov, V.S., et al.,
3. Witt, O.N. and Schmitt, G., Ber. Dtsch. Chem. Ges.,
USSR Inventor’s Certificate No. 910741, Byull. Izobret.,
1
894, vol. 27, no. 3, p. 2370.
1
982, no. 9.
4. Garnovskii, A.D., Antsyshkina, A.S., Sadikov, G.G., et al.,
Zh. Neorg. Khim., 1998, vol. 43, no. 11, p. 1852 [Russ. J.
Inorg. Chem. (Engl. Transl.), vol. 43, no. 11, p. 1723].
3. Burlov, A.S., Uraev, A.I., Lysenko, K.A., et al., Koord.
Khim., 2006, vol. 32, no. 9, p. 714 [Russ. J. Coord.
Chem. (Engl. Transl.), vol. 32, no. 9, p. 686].
1
1
5. Kharisov, B.I., Garnovskii, A.D., and Tsivadze, A.Yu., J. 24. Price, R., Metal Complexes of Azo-Dyestuffs, J. Chem.
Coord. Chem., 2007, vol. 60, p. 435.
Soc., A, 1967, no. 12, p. 2048.
6. Kurbatov, V.P., Khokhlov, A.V., Garnovskii, A.D., et al., 25. Price, R., The Chemistry of Synthetic Dyes, Venkatara-
Koord. Khim., 1979, vol. 5, no. 3, p. 351. man, K.M., Ed., New York: Academic, vol. 3.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 34 No. 12 2008