Synthesis, X-ray spectral, and magnetochemical study of copper complexes based on tridentate azomethines of 3-allylsalicylaldehyde

Article abstract of DOI:10.1134/S1070328413040039

Tridentate azomethine ligands (H₂L) based on 3-allylsalicylaldehyde and o-aminophenol, o-aminothiophenol, or 2-ethylamino-5-nitroaniline were synthesized and identified by IR and ¹H NMR spectroscopies. The structure of complexes (Ia-

Full text of DOI:10.1134/S1070328413040039

ISSN 1070ꢀ3284, Russian Journal of Coordination Chemistry, 2013, Vol. 39, No. 4, pp. 347–352. © Pleiades Publishing, Ltd., 2013.
Original Russian Text © A.S. Burlov, V.G. Vlasenko, Ya.V. Zubavichus, S.I. Levchenkov, Yu.V. Koshchienko, A.S. Bogomyakov, S.A. Nikolaevskii, D.A. Garnovskii, A.I. Uraev,
T.V. Lifintseva, E.V. Korshunova, 2013, published in Koordinatsionnaya Khimiya, 2013, Vol. 39, No. 4, pp. 238–243.
Synthesis, XꢀRay Spectral, and Magnetochemical Study
of Copper Complexes Based on Tridentate Azomethines
of 3ꢀAllylsalicylaldehyde
A. S. Burlova, V. G. Vlasenkob, Ya. V. Zubavichusc, S. I. Levchenkovd, Yu. V. Koshchienkoa,
A. S. Bogomyakove, S. A. Nikolaevskiia, D. A. Garnovskiid,
*
, A. I. Uraeva,
T. V. Lifintsevaf, and E. V. Korshunovaa
a Institute of Physical and Organic Chemistry, Rostov State University, pr. Stachki 194/3, RostovꢀonꢀDon, 344104 Russia
b Research Institute of Physics, Southern Federal University, RostovꢀonꢀDon, 344104 Russia
c Kurchatov Institute Russian Research Center, pl. Kurchatova 1, Moscow, 123182 Russia
d Southern Research Center of the Russian Academy of Sciences, RostovꢀonꢀDon, Russia
e International Tomography Center, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
f Pedagogical Institute, Southern Federal University, RostovꢀonꢀDon, Russia
*eꢀmail: garn@ipoc.rsu.ru
Received August 20, 2012
Abstract—Tridentate azomethine ligands (H2L) based on 3ꢀallylsalicylaldehyde and
oꢀaminophenol,
o
ꢀaminothiophenol, or 2ꢀethylaminoꢀ5ꢀnitroaniline were synthesized and identified by IR and 1H NMR
spectroscopies. The structure of complexes (Ia–Ic) was studied by magnetochemistry and EXAFS specꢀ
troscopy. Complexes Ia and Ib (X = O, S) are binuclear and exhibit antiferromagnetic exchange interacꢀ
tion: 2
J
=
⎯
36.5 and –950 cm–1, respectively. Complex Ic (X = NC2H5) is mononuclear (
µ
eff = 1.75 µB at
275 K and does not change as temperature decreases).
DOI: 10.1134/S1070328413040039
The synthesis of binuclear metal complexes based groups in position 5 of the aldehyde moiety enhance
on tridentate Schiff bases is closely connected with
the possibility of varying the fine structure of
the azomethine ligand system, which affects the strucꢀ
ture and physicochemical properties of the complexes
[1–7]. These binuclear complexes play an important
role in the development of modern magnetochemistry
and can serve as promising materials for the design of
molecular magnets [8–14].
the antiferromagnetic interaction, while those in posiꢀ
tion 5 of the amine fragment reduce this interaction.
The replacement of the 2ꢀhydroxy group in the
aldehyde moiety by 2ꢀtosylamino group not only
increases the antiferromagnetic exchange in the
dimeric molecule but, in some cases, alter the antiferꢀ
romagnetic to ferromagnetic exchange type [15–23].
The key factors affecting the nature of magnetic
exchange interactions in the dimeric complexes based
on tridentate Schiff bases include the nature of the
metal center, the type of bridging atoms and the nature
of substituents in the amine and aldehyde moieties of
Schiff bases.
It was of interest to study the effect of the allyl
group in position 3 of the aldehyde moiety on the
strength and type of the exchange.
As a continuation of the synthesis and structure
investigations of dimeric complexes based on tridenꢀ
tate azomethine ligands [15–23], we obtained
new azomethine ligands (Н2L) based on 3ꢀallylsalicylꢀ
In reviews [6, 7], it was shown that the substituꢀ
ents in the aldehyde and amine fragments of tridenꢀ
tate azomethines considerably affect the value and
the nature of exchange interaction in the dimeric
aldehyde and
oꢀaminophenol, oꢀaminothiophenol,
and 2ꢀethylaminoꢀ5ꢀnitroaniline and their copper(II)
complexes. For example, the electronꢀwithdrawing complexes (Ia–Ic).
347

348
BURLOV et al.
R
CH2
CH2
CH2
Cu
H2
C C
H2
C C
H2
C
C
H
H
H
CH3
OH
H
C
OH
O
N
O
X
N
O
Cu
Cu
C N
XH
C
C N
X
N C2H5
H
H
H
H
C
C
H2
H2C
R
R
R
(
(H2La–в): X = O, R = H (
а
);
(Ia
,
Ib
)
Ic)
X = S, R = H (
b
);
X = NC2H5, R = NO2 (c)
EXPERIMENTAL
For C18H19N3O3
calculated (%): C, 66.45;
H, 5.89;
H, 5.92;
N, 12.91.
N, 12.89.
Commercially available (Alfa Aesar) 3ꢀallylsalicylꢀ
aldehyde, ꢀaminophenol, and ꢀaminothiophenol
Found (%):
C, 66.48;
o
o
and 2ꢀethylaminoꢀ5ꢀnitroaniline prepared by a
reported procedure [17] were used.
1H NMR (CDCl3;
δ
, ppm): 1.35 (3H, t,
J
= 7.2 Hz,
Synthesis of azomethines.
oꢀAminophenol (1.03 g,
0.01 mol), or ꢀaminothiophenol (1.25 g, 0.01 mol),
⎯
CH2–CH3), 3.36 (2H, q,
3.49 (2H, d, = 6.5 Hz, –CH2–CH=CH2), 510–5.16
(3H, m, –CH2–CH=CH2, NH), 6.01–6.09 (1H, m,
–CH2–CH=CH2), 6.63 (1H, d, = 9.1 Hz, CAr–H),
6.97 (1H, t, = 7.6 Hz, CAr–H), 7.26–7.36 (2H, m,
CAr–H), 7.92 (1H, d, = 2.5 Hz, CAr–H), 8.12 (1H,
dd, = 9.1 Hz, = 2.4 Hz, CAr–H), 8.70 (1H, s,
CH=N), 12.55 (1H, s, OH). IR (
, cm–1): 3402 s
(NH), 3083 s (OH), 1610 s (C=N), 1293
(Ph O)
J = 4.2 Hz, –CH2–CH3),
o
J
or 2ꢀethylaminoꢀ5ꢀnitroaniline (1.81 g, 0.01 mol) in
anhydrous toluene (10 mL) was added to a solution of
3ꢀallylsalicylaldehyde (1.62 g, 0.01 mol) in anhydrous
toluene (20 mL). The resulting mixture was heated
with a Dean–Stark trap under argon until the calcuꢀ
lated amount of water fully separated. After compleꢀ
tion of the reaction, 2/3 of toluene was distilled off
under vacuum, and boiling methanol (30 mL) was
added. The precipitate was filtered off, washed with
J
J
J
J
J
ν
ν
ν
ν
w
ν
⎯
.
methanol (2 5 mL), and recrystallized from a methꢀ
×
Synthesis of metal complexes. Acetate monohyꢀ
anol–toluene mixture (1 : 1).
3ꢀAllylsalicylalꢀ2'ꢀhydroxyaniline Н2La (orange
crystals, mp = 103–104°C). Yield 87%.
drate in anhydrous methanol (10 mL) was added to a
solution of 1 mmol of Ia (0.25 g), or Ib (0.27 g), or Ic
(0.33 g) in anhydrous methanol (20 mL). The resulting
mixture was refluxed on a water bath under argon for
2 h. The precipitated complexes were filtered off,
For C16H15NO2
washed with methanol (3
vacuum drying oven at 150°С.
×
5 mL), and dried in a
calculated (%): C, 75.87;
Found (%): C, 75.90;
H, 5.97;
H, 6.01;
N, 5.53.
N, 5.58.
Bis(3ꢀallylsalicylalꢀ2'ꢀhydroxyanilinato)dicopper(II)
(
Ia, X = O, R = H). Dark green powder. mp > 260°C.
1H NMR (CDCl3;
6.6 Hz, CH2–CH=CH2), 5.09–5.16 (2H, m,
CH2–CH=CH2), 5.82 (1H, s, OH), 6.01–6.10 (1H,
δ
, ppm): 3.49 (2H, d, J =
Yield 80%.
⎯
⎯
m,
⎯CH2–CH=CH2), 6.92–7.26 (5H, m, CAr–H),
For C32H26N2O4Cu2
7
.29–7.30 (2H, m, CAr–H), 8.69 (1H, s, CH=N),
12.55 (1H, s, OH). IR ( (OH), 1626 s
, cm–1): 3051 s
(C=N), 1282 (Ph–O)
calculated (%): C, 61.04; H, 4.16; N, 4.45; Cu, 20.19.
ν
ν
Found (%):
C, 61.15; H, 4.05; N, 4.32; Cu, 20.21.
ν
w
ν
.
After evaporation of toluene, 3ꢀallylsalicylalꢀ2'ꢀ
mercaptoaniline Н2Lb was used for the synthesis of Ib
IR (
ν
, cm–1): 1602 s
ν
(C=N), 1327
w ν(Ph–O).
without isolation.
3ꢀAllylsalicylalꢀ2'ꢀethylaminoꢀ5'ꢀnitroaniline Н2Lc
(yellow crystals, mp = 174–175°C). Yield 55%.
Bis(3ꢀallylsalicylalꢀ2'ꢀmercaptoanilinato)dicopꢀ
per(II) (Ib, X = S, R = H). Dark brown powder. mp =
255–256°C. Yield 75%.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 39
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SYNTHESIS, XꢀRAY SPECTRAL, AND MAGNETOCHEMICAL STUDY
349
Xꢀray diffraction data available from the Cambridge
Crystallographic Data Centre (CCDC) were used
[27].
For C32H26N2O2S2Cu2
calculated (%): C, 58.07; H, 3.96; N, 4.23; Cu, 19.20.
Found (%):
C, 58.17; H, 3.89; N, 4.32; Cu, 19.34.
The goodnessꢀofꢀfit function Q, which was miniꢀ
mized during determination of the structure parameꢀ
ters of the local environment, was calculated by the
formula (1)
IR (
ν
, cm–1): 1601 vs
(C=N), 1341 w (Ph–O).
ν
[(Methanol)ꢀ3ꢀallylsalicylalꢀ2'ꢀethylaminoꢀ5ꢀnitroꢀ
anilinato]copper(II) (Ic, X = NC2H5, R = NO2).
Brown powder. mp = 255–256°C. Yield 56%.
2
kχ (k) − kχ (k)
[
]
exp
th
∑
(1)
Q =
×100%.
2
kχ (k)
[
]
exp
∑
For C19H21N3O4Cu
The magnetic properties of polycrystalline samples
were studied on a Quantum Design MPMSꢀXL
SQUID magnetometer in the temperature range of 2–
300 K in a 5 kOe magnetic field. The calculated molar
magnetic susceptibility was corrected for atom diaꢀ
magnetism according to the Pascal additive method
[11].
calculated (%): C, 54.47; H, 5.05; N, 10.03; Cu, 15.17.
Found (%):
C, 54.52; H, 5.05; N, 10.15; Cu, 15.37.
IR (
ν
, cm–1): 1602 vs
ν(C=N), 1341
w ν(Ph–O).
IR spectra were recorded on a Varian 3100ꢀFTIR
Excalibur instrument for powders using the frustrated
1
total internal reflection technique. H NMR spectra
were run on a Varian Unityꢀ300 spectrometer
(300 MHz) in the mode of internal stabilization of the
RESULTS AND DISCUSSION
2H polar resonance line in CDCl3
.
The composition and structure of azomethines
Н2Lа, в were determined by elemental analysis, and
1H NMR and IR spectroscopy.
Cu
Kꢀedge Xꢀray absorption spectra were meaꢀ
sured in the transmission mode on the EXAFS specꢀ
trometer of the station K1.3b “Structural material sciꢀ
ence” of the Kurchatov Synchrotron Center (Mosꢀ
cow). The energy of the electron beam used as the
source of Xꢀray synchrotron radiation was 2.5 GeV at
an average current of 60–80 mA. A Si(111) double
crystal monochromator was utilized for energy selecꢀ
The 1H NMR spectrum of the ligand Н2Lа exhibits
OH proton signals for the 3ꢀallylsalicylaldehyde fragꢀ
ment at 12.55 ppm and for the oꢀaminophenol moiety
at 5.82 ppm and CH=N signals at 8.69 ppm. The IR
spectrum of Н2Lа shows a broadened stretching vibraꢀ
tion band at 3051 cm–1
bands at 1626
ν
(OH) and stretching vibration
tion at the CuKꢀedge. The incident and transmitted
ν
(C=N) and 1282 cm–1
ν
(Ph–O)
.
Xꢀray radiation intensities were measured by airꢀfilled
ionization chambers connected to Keithleyꢀ6487
picoamperemeters.
The samples for recording the EXAFS spectra were
thoroughly mixed with Apiezon and placed between
thin polyester films. The sample thickness was so
adjusted as to reduce the transmitted Xꢀray intensity
by a factor of 2.5–3.0. After standard procedures for
The 1H NMR spectrum of the ligand Н2Lb exhibits
OH proton signals for the aldehyde moiety at
12.55 ppm and the CH=N group protons at 8.70 ppm.
The amine (NH) and allyl (CH2–CH=CH2) protons
are responsible for a multiplet at 5.10–5.16 ppm. The
IR spectra of Н2Lb show
ν
(OH) and
tion bands at 3402–3083 cm–1, a strong bands typical
of the azomethine bond
(C=N) at 1610 cm–1, and a
(Ph–O) band at 1293 cm–1.
This spectral behavior in combination with the data
of elemental analysis confirm the formation of imine
structures for Н2Lа–c
ν
(NH) absorpꢀ
ν
background subtraction, normalization to the
step, and subtraction of atomic absorption μ0 [24], the
resulting EXAFS ( )ꢀspectra were Fourier transꢀ
formed in the photoelectron wave vector range from
2.5–3.5 to 12.5–15 Å–1 with the weighting function k3
The threshold ionization energy E0 was chosen as the
maximum of the ꢀedge first derivative and was subseꢀ
Кꢀedge
ν
χ
k
.
.
According to elemental analysis data, the composiꢀ
tion of chelates Ia and Ib is (ML)2. The changes in the
IR spectra of these complexes compared to the spectra
of ligands are typical for metalꢀchelates; in particular,
K
quently varied during fitting. The exact values for the
structure parameters of metal atom local environment
were determined by nonꢀlinear fitting of the coordinaꢀ
tion sphere (CS) parameters. This was done by comꢀ
paring the calculated EXAFS signal with the signal
isolated from the full EXAFS spectrum by Fourier filꢀ
tration of the Fourier transforms (FT). The nonꢀlinꢀ
the bands due to
frequency decreases by 10 cm–1 and the
quency increases being manifested at 1327 (Ia) and
1341 cm–1
Ib).
According to published data [15–23],
ν
(OH) disappear, while the
ν
(C=N)
ν
(Ph–O) freꢀ
(
ear fitting was done using the IFFEFITꢀ1.2.10 proꢀ complexes Ia and Ib may exist as dimers. A study of the
gram package [25]. The photoelectron wave scattering temperature dependences of the magnetic susceptibilꢀ
phases and amplitudes needed to construct the theoꢀ ity of Ia (Fig. 1) and Ib showed that their effective
retical spectrum were calculated using the FEFF7 magnetic moments considerably decrease on cooling,
program [26]. As model compounds, complexes of that testify the antiferromagnetic exchange interaction
the same metals with similar local structures and with between the copper(II) ions in these compounds.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 39
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350
BURLOV et al.
In complex Ib, the antiferromagnetic exchange
χ
'M, cm3 mol–1
μeff
,
μB
interaction between the copper(II) ions is so strong
that at temperatures below 200 K, the paramagnetism
is caused by the presence of a minor paramagnetic
0.003
0.002
0.001
1.2
1.0
0.8
0.6
0.4
0.2
0
impurity (
f
≈
0.05). The difference between the magꢀ
netic properties of complexes Ia and Ib is caused by
the difference in the nature of bridging atoms; the
replacement of the bridging oxygen atoms by the sulfur
atoms significantly increases the antiferromagnetic
exchange in all known cases [6, 7, 16].
According to elemental analysis data, complex Ic
has the composition CuL
⋅
CH3OH. The effective
magnetic moment of complex Ic does not depends on
the temperature, being 1.75 μB at 2 K, which is practiꢀ
cally equal to the purely spin value. These data may
imply that complex Ic is mononuclear. In view of this
conclusion, the model structure of complex Ic can be
constructed considering two approximations: dimerꢀ
ization through the phenoxide oxygen atom is preꢀ
vented by the ortho allyl substituent; dimerization
through the nitrogen atom bonded to ethyl is unlikely.
0
50 100 150 200 250 300
, K
T
Fig. 1. Temperature dependence of (
ᮀ)
μ
per copper(II)
eff
atom and ( ) χ'M for complex Ia (the continuous line is
°
the theoretical dependence).
The temperature dependence of the magnetic susꢀ
In order to establish the local atomic structure of
ceptibility of complexes is well interpreted within the
framework of the Heisenberg–Dirac–Van Vleck isoꢀ
tropic model [11]. The exchange interaction parameꢀ
ters in complexes Ia and Ib were calculated by the
Bleaney–Bowers equation [28].
complexes Ia–Ic, copper
Kꢀedge Xꢀray absorption
spectra (EXAFS) of these compounds were measured.
Figure 2 shows the FT of EXAFS absorption for comꢀ
plexes Ia–Ic
.
The FT for complexes Ia–Ic are substantially disꢀ
The best agreement between the theory and experꢀ similar. Whereas the FT of Ia and Ic exhibits one major
iment for complex Ia was observed for the following peak (
= 1.56–1.59 Å) corresponding to the first CS,
model parameters: = 0.0045, = 1.51
= –365 cm–1
360
10–6 cm3/mol.
r
2J
,
f
N
=
the FT of Ib shows two clearly resolved peaks (r
and 1.92 Å) of approximately equal amplitudes. Howꢀ
α
×
FT, arb. units. O/N
15
S
Cu
3
10
5
2
1
L
0
1
2
3
4
5
6
r
,
Å
Fig. 2. FT for the best fit of complexes (
1
)
Ic, (
2
)
Ia, (
3
)
Ib. (–) is experimental curve, (
᭺
) is theoretical FT.
No. 4
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 39
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SYNTHESIS, XꢀRAY SPECTRAL, AND MAGNETOCHEMICAL STUDY
351
Structural data for the local atomic environment of the copꢀ
per atom obtained by multisphere fitting of EXAFS data*
ever, all FT have one feature in common, namely, a
peak at = 2.48–2.62 Å, which may reflect the
r
Cu⋅⋅⋅Cu distance in the FT. By varying the lower and
upper EXAFS integration parameters during Fourier
transformation, it is possible to distinguish (against the
CS containing light O and N atoms) CS with heavier
Cu atoms due to different scattering amplitudes of
photoelectrons by these atoms. Thus, it can be reliably
stated that these peaks in the FT of complexes Ia and
Ib correspond to the CS containing Cu atoms, indicatꢀ
ing the dimeric structure of the molecules of these
compounds. In the FT of complex Ic, the peak at r =
2.48 Å, conversely, corresponds to the CS consisting of
light atoms and does not contain metal atoms. Note
also the peak at r = 1.95 Å in the FT of Ic, which is
absent in the other two FT. This peak was interpreted
as being due to the solvent molecule coordinated to
copper. Considering these FT features, the models
of the dimeric complexes Ia and Ib were constructed
where two copper ions are connected by two
oxygen (Ia) or sulfur (Ib) bridges to each other and are
bonded to two ligands (Cu–O and/or Cu–N bonds).
Complex Ic is monomeric and has a coordinated solꢀ
vent molecule.
Comꢀ
pound
C.N.
R
, Å
σ
2, Å2
Atom
Q
, %**
9.9
Ia
1
3
1
1
1
2
0.75
2
2
1.86
1.94
3.02
1.90
1.96
2.28
2.96
1.95
1.99
2.27
0.0030
0.0030
0.0066
0.0027
0.0030
0.0062
0.0082
0.0040
0.0040
0.0040
2
N
O
Cu
O/N
O/N
S
Cu
O/N
O/N
L
Ib
11.4
6.4
Ic
1
Notes: *
R
are interatomic distances,
tor, is the goodnessꢀofꢀfit function.
** The fitting was performed for = 0.998–2.860 Å.
C.N. is the coordination number.
σ
is the Debye–Waller facꢀ
Q
R
N, no.
By nonꢀlinear multisphere approximation of the
calculated EXAFS to the experimental spectrum,
quantitative CS parameters were found (table). For
complexes Ia and Ib, the Cu⋅⋅⋅Cu distances are 3.02
0.03 and 2.96 0.03 Å, respectively. These distances
are typical of dimeric compounds with similar ligands
[7, 15, 16, 22, 23]. Statistical analysis of the correꢀ
sponding Cu⋅⋅⋅Cu distances for more than 100 crystꢀ
sallographically characterized copper complex dimers
from the CCDC also demonstrated that these disꢀ
tances for complexes Ia and Ib are close to the statistiꢀ
cally mean values for complexes with sulfur (2.92 Å)
and oxygen (3.0 Å) bridges (Fig. 3). The Cu⋅⋅⋅Cu disꢀ
tances in dimers with different bridges are different
because the bond angle at a bridging sulfur atom is
28
24
20
16
12
8
2
4
0
2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3
R, Å
N, no.
most often much smaller (<90
oxygen atom (>100 ). This is caused by the fact that
sulfur provides almost nonꢀhybridized orbitals for
°
) than that at a bridging
10
°
p
the overlap with metal atoms, whereas oxygen atoms
tend to bind to metal atoms with pronounced sp
hybridization.
8
6
The CS of complex Ic has a radius of 2.27 Å and
contains atoms present in the coordinated solvent
molecule. Note that for complex Ib, a satisfactory
4
agreement of the Q factor was obtained only for the CS
2
(C.N. 0.75) corresponding to the Cu⋅⋅⋅Cu distance at a
constant typical value of the Debye–Waller factor.
This may be indicative of either variability of Cu⋅⋅⋅Cu
distances in this compound or a small monomer impuꢀ
rity.
1
0
2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3
R, Å
Thus, by magnetochemical and Xꢀray spectral
measurements, we found that, depending on the type
of bridging X atom in the ligand molecule, copper
binuclear complexes with strong antiferromagnetic
Fig. 3. Column diagram of the Cu⋅⋅⋅Cu distances in copper
complex dimers with (1) S and (2) O bridges according to
CCDC data. The dashed line shows the values for the
Cu⋅⋅⋅Cu distances in Ia and Ib
.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 39
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352
BURLOV et al.
12. Magnetism: Molecules to Material, Miller, J.S. and Drilꢀ
lon, V., Eds., Berlin: VerlagꢀChem., 2001–2004,
vols. 1–5.
exchange interaction (X = O, S) or mononuclear
complexes (X = NC2H5) are formed.
13. Chaudhury, P., Coord. Chem. Rev., 2003, vol. 243, no. 1,
ACKNOWLEDGMENTS
p. 143.
This work was supported by the Basic Research
Program of Presidium of the Russian Academy of Sciꢀ
ences no. 8 “Development of Methods for the Prepaꢀ
ration of Chemical Compounds and Design of New
Materials”, RF President (grant NShꢀ927.2012.3),
and the Russian Foundation for Basic Research
(projects nos. 12ꢀ03ꢀ00462ꢀa, 12ꢀ03ꢀ31285 mol_a,
11ꢀ03ꢀ00475ꢀa, and 10ꢀ03ꢀ00434ꢀa).
14. Kahn, O., Galy, J., Journaux, Y., et al., J. Am. Chem.
Soc., 1982, vol. 104, no. 8, p. 2165.
15. Garnovskii, A.D., Burlov, A.S., Garnovskii, D.A.,
et al., Polyhedron, 1999, vol. 18, p. 863.
16. Uraev, A.I., Vasilchenko, I.S., Ikorskii, V.N., et al.,
Mendeleev Commun., 2005, vol. 15, no. 4, p. 133.
17. Burlov, A.S., Koshchienko, Yu.V., Ikorskii, V.N., et al.,
Russ. J. Inorg. Chem., 2006, vol. 51, no. 7, p. 1065.
18. Garnovskii, A.D., Ikorskii, V.N., Uraev, A.I., et al.,
J. Coord. Chem., 2007, vol. 60, no. 14, p. 1493.
19. Burlov, A.S., Koshchienko, Yu.V., Lyssenko, K.A.,
et al., J. Coord. Chem., 2008, vol. 61, no. 1, p. 85.
20. Burlov, A.S., Nikolaevskii, S.A., Bogomyakov, A.S.,
et al., Russ. J. Coord. Chem., 2009, vol. 35, no. 7, p. 486.
21. Garnovskii, A.D., Burlov, A.S., Vasil’chenko, I.S.,
et al., Russ. J. Coord. Chem., 2010, vol. 36, no. 2, p. 81.
22. Shmakova, T.O., Garnovskii, D.A., Lysenko, K.A.,
REFERENCES
1. Holm, R.H. and O’Connor, M.J., Prog. Inorg. Chem.
1966, vol. 7, p. 83.
2. Vigato, P.A., Peruzzo, V., and Tamburini, S., Coord.
Chem. Rev., 2012, vol. 256, p. 953.
3. Vigato, P.A., Peruzzo, V., and Tamburini, S., Coord.
Chem. Rev., 2004, vol. 248, p. 1717.
4. Vigato, P.A., Peruzzo, V., Tamburini, S., et al., Coord.
Chem. Rev., 2007, vol. 251, p. 1331.
,
et al., Russ. J. Coord. Chem., 2009, vol. 35, no. 9, p. 657.
23. Shmakova, T.O., Garnovskii, D.A., Lysenko, K.A.,
et al., Izv. Ross. Akad. Nauk., Ser. Khim., 2009, no. 7,
p. 1344.
24. Kochubei, D.I., Babanov, Yu.A., Zamaraev, K.I., et al.,
Rentgenospektral’nyi metod izucheniya struktury amorꢀ
fnykh tel: EXAFSꢀspektroskopiya (XꢀRay Spectral
Investigation of Solids: EXAFS Spectroscopy),
Novosibirsk: Nauka, 1988.
25. Newville, M., J. Synchrotron Rad., 2001, vol. 8, p. 322.
26. Zabinski, S.I., Rehr, J.J., Ankudinov, A., and
Alber, R.C., Phys. Rev., B, 1995, vol. 52, p. 2995.
27. Allen, F.H., Acta Crystallogr., Sect. B: Struct. Sci., 2002,
5. Vigato, P.A., Peruzzo, V., and Tamburini, S., Coord.
Chem. Rev., 2008, vol. 252, p. 1871.
6. Kogan, V.A., Zelentsov, V.V., Osipov, O.A., et al., Usp.
Khim., 1979, vol. 48, no. 7, p. 1208.
7. Kogan, V.A., Lukov, V.V., and Shcherbakov, I.N., Russ.
J. Coord. Chem., 2010, vol. 36, no. 6, p. 401.
8. Ovcharenko, V.I. and Sagdeev, R.Z., Usp. Khim., 1999,
vol. 68, no. 5, p. 381.
9. Kalinnikov, V.T., Rakitin, Yu.V., and Novotortsev, V.M.,
Usp. Khim., 2003, vol. 72, no. 12, p. 1123.
10. Magnetic Molecular Magnetism, Gatteshi, D., Kahn, O.,
Miller, J.S., and Palacio, F., Eds., Dordrecht: Kluwer
Acad., 1985.
vol. 58, p. 380.
11. Kahn, O., Molecular Magnetism, New York: Verlagꢀ 28. Bleaney, B. and Bowers, K.D., Proc. R. Soc. London A
,
Chem., 1993.
1952, vol. 214, p. 451.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 39
No. 4
2013