Bis(1,1,1,3,5,5,5-heptafluoro-4-iminopent-2-ene-2-aminato)copper(ii) - A new metal-containing matrix in the design of heterospin systems

Article abstract of DOI:10.1007/s11172-011-0130-y

The first heterospin compounds based on bis(1,1,1,3,5,5,5-heptafluoro-4- iminopent-2-ene-2-aminato)copper(ii) (CuL₂) and nitronyl nitroxide radicals, 2-R-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyls (NIT-R, where R = H, Me, Ph, and 1-methylpyrazol-4-yl), were synthesized and structurally characterized. An important peculiarity of the structure of synthesized solid phases is the formation of a supramolecular structure due to hydrogen bonds between the oxygen atoms of the nitronyl nitroxide fragments of NIT-R and the hydrogen atoms of the NH groups of CuL₂.

Full text of DOI:10.1007/s11172-011-0130-y

Russian Chemical Bulletin, International Edition, Vol. 60, No. 5, pp. 816—823, May, 2011
816
Bis(1,1,1,3,5,5,5ꢀheptafluoroꢀ4ꢀiminopentꢀ2ꢀeneꢀ2ꢀaminato)copper(II) —
a new metalꢀcontaining matrix in the design of heterospin systems
S. V. Fokin,a V. I. Ovcharenko,a G. V. Romanenko,a E. V. Tretyakov,a A. S. Bogomyakov,a
L. V. Saloutina,b T. I. Filyakova,b V. I. Saloutin,b V. N. Charushin,b and O. N. Chupakhinb
bInternational Tomography Center, Siberian Branch of the Russian Academy of Sciences,
3a ul. Institutskaya, 630090 Novosibirsk, Russian Federation.
Fax: +7 (383) 333 1399. Eꢀmail: Victor.Ovcharenko@tomo.nsc.ru
aI. Ya. Postovsky Institute of Organic Synthesis, Ural Branch of the Russian Academy of Sciences,
22/20 ul. S. Kovalevskoi, 620219 Ekaterinburg, Russian Federation.
Fax: : +7 (343) 374 1189. Eꢀmail: charushin@prm.uran.ru
The first heterospin compounds based on bis(1,1,1,3,5,5,5ꢀheptafluoroꢀ4ꢀiminopentꢀ2ꢀ
eneꢀ2ꢀaminato)copper(II) (CuL2) and nitronyl nitroxide radicals, 2ꢀRꢀ4,4,5,5ꢀtetramethylꢀ
4,5ꢀdihydroꢀ1Hꢀimidazoleꢀ3ꢀoxideꢀ1ꢀoxyls (NITꢀR, where R = H, Me, Ph, and 1ꢀmethylꢀ
pyrazolꢀ4ꢀyl), were synthesized and structurally characterized. An important peculiarity of the
structure of synthesized solid phases is the formation of a supramolecular structure due to
hydrogen bonds between the oxygen atoms of the nitronyl nitroxide fragments of NITꢀR and
the hydrogen atoms of the NH groups of CuL2.
Key words: copper(II), copper(II) bischelates, nitroxides, Xꢀray diffraction analysis,
magnetic properties.
Fluorinated metalꢀcontaining matrices are widely used
Results and Discussion
in the design of heterospin systems due to the high accepꢀ
tor properties of the central atom favoring the coordinaꢀ
tion of weak donors, groups >N—O of nitroxyl radicals.1,2
However, the scope of these acceptor matrices is restricted:
metal hexafluoroacetylacetonates3 and perfluorocarbꢀ
oxylates3,4 usually act as such matrices. Therefore, the
introduction of new metalꢀcontaining acceptors into the
design of molecular magnetics is a topical problem. It has
recently been shown that bis(μ2ꢀ1,1,2,2,8,8,9,9ꢀoctafluoꢀ
rononaneꢀ3,5,7ꢀtrionato)dicopper(II) ([Cu2L´2]) and bisꢀ
(1,1,1,5,5,5ꢀhexafluoroꢀ4ꢀiminopentꢀ2ꢀenꢀ2ꢀolato)copꢀ
per(II) can be used as acceptor matrices in the reactions
with nitroxyl radicals.5,6 In the present work, we synꢀ
thesized the first heterospin compounds based on bisꢀ
(1,1,1,3,5,5,5ꢀheptafluoroꢀ4ꢀiminopentꢀ2ꢀeneꢀ2ꢀaminꢀ
ato)copper(II) (CuL2) and nitroxyl radicals NITꢀR (R = H,
Me, Ph, and 1ꢀmethylpyrazolꢀ4ꢀyl (MePz)) and studied
their structures and magnetic properties.
Solutions of the studied compounds are kinetically
rather stable; unlike similar solutions of CuII hexafluoroꢀ
acetylacetonate, no formation of decomposition products
is detected in these solutions on storage under normal
conditions for several days. The ratio CuL2 : NITꢀR
(R = Me, Ph, MePz) in the isolated solid phases coincides
with the ratio of reactants introduced into the synthesis
(1 : 1). However, in the case of NITꢀH, CuL2(NITꢀH)2 is
isolated from an ether—hexane mixture at ratios of both
1 : 1 and 1 : 2. Only the recrystallization of this compound
from toluene gave CuL2(NITꢀH).
The choice of a mixture of solvents for the synthesis of
heterospin compounds was determined by the solubility of
the reactants and products formed. For instance, the use
of hexane and toluene turned out inefficient because of the
very low solubility of the starting CuL2 in these solvents.
At the same time, the use of pure ether gave no satisfactory
results because of the high solubility of the products.
The procedures of synthesis proposed by us (see Expeꢀ
rimental) make it possible to obtain heterospin comꢀ
pounds of CuL2 with NITꢀR as qualitative single crystals
in good yield.
The Xꢀray diffraction study of CuL2(NITꢀR) (R = Me,
Ph, MePz) showed that hydrogen bonds of the NH groups
with the NO groups of NITꢀR play the determining role in
R = H, Me, Ph, MePz
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 798—804, May, 2011.
1066ꢀ5285/11/6005ꢀ816 © 2011 Springer Science+Business Media, Inc.

Heterospin copper(II) bischelates
Russ.Chem.Bull., Int.Ed., Vol. 60, No. 5, May, 2011
817
structure formation. In bischelate CuL2, the environment
of the central atom is close to square, and the distances
Cu—N in all the structures range from 1.920(9) to 1.981(9)
Å. Molecules of the bischelates linked by hydrogen bonds
N—H...ONO with NITꢀR are bound into chains in the
structures CuL2(NITꢀMe) and CuL2(NITꢀPh) (Fig. 1).
In the case of NITꢀMePz, on of the NO groups of
nitroxide and the N atom of the pyrazole cycle are involved
in hydrogen bonding, i.e., NITꢀMePz performs the bridging
function and forms a chain with the motif "headꢀtoꢀtail"
(Fig. 2). In the structure CuL2(NITꢀMe)•C6H14, the chains
almost linear: the Cu atoms lie on the same straight line
and hexane molecules are arranged between them perpendiꢀ
cularly to the axis of the chain (see Fig. 1, c). The chain is bent
in structure CuL2(NITꢀPh) with the larger bridge NITꢀR
(see Fig. 1, b and d). The structure reaches the maximum
zigzag character in CuL2(NITꢀMePz)•C7H8; in this case,
toluene molecules are located in the loops of the structure.
A specific feature of structure CuL2(NITꢀMePz)•C7H8 is
that the O atoms of the uncoordinated group NO form
short contacts O...F (3.162(6) and 3.327(6) Å) with the
atoms F of the fragments F—C< of the adjacent chains.
a
Cu
N
C
O
F
b
c
d
Fig. 1. Structure of chains (a, b) and their packing (c, d) in CuL2(NITꢀMe)•C6H14 (a, c) and CuL2(NITꢀPh) (b, d).
Note. Fig. 1 is available in full color in the onꢀline version of the journal (http://www.springerlink.com/issn/1573ꢀ9171/current) and
on the webꢀsite of the journal (http://russchembull.ru).

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Russ.Chem.Bull., Int.Ed., Vol. 60, No. 5, May, 2011
Fokin et al.
Cu
N
C
O
F
Fig. 2. Structure of the chain in CuL2(NITꢀMePz)•C7H8.*
Only one NO group participates in hydrogen bonding
in the solid phase of CuL2(NITꢀH)2, whereas the second
group "supplements" the environment of the copper atom
to squareꢀpyramidal (Fig. 3, a) at a considerable Cu—O
distance of 2.657(2) Å. This results in the formation of
ribbons. In addition, the formation of hydrogen bonds of
the C—H...O type between the molecules NITꢀH was obꢀ
served inside the ribbons. Similar hydrogen bonds in the
a
Cu
N
C
O
F
b
Fig. 3. Structures of the chain in CuL2(NITꢀH)2 (a) and the layer in CuL2(NITꢀH) (b).*
* Figs 2 and 3 are available in full color in the onꢀline version of the journal (http://www.springerlink.com/issn/1573ꢀ9171/current)
and on the webꢀsite of the journal (http://russchembull.ru).

Heterospin copper(II) bischelates
Russ.Chem.Bull., Int.Ed., Vol. 60, No. 5, May, 2011
819
solid phase of CuL2(NITꢀH) result in joining of the chains
into layers (Fig. 3, b).
similar to CuL2(NITꢀMe) in which molecules of bischeꢀ
late and nitronyl nitroxide connected by hydrogen bonds
alternate. However, an analysis of the magnetic properties
using the model for uniform chain of antiferromagneticalꢀ
ly bound paramagnetic centers with the spins S = 1/2 gave
no satisfactory results (see Fig. 5). The best agreement
with the experimental data was achieved using the model
for alternant chains (H = –2JΣ(SiSi+1 + αSiSi+1))8;
the approximation of the experimental data gave the folꢀ
lowing optimal parameters: g = 2.137 ( 0.002), J/k =
= –36.2 ( 0.2) K, α = 0.892 ( 0.002). Note that this
description better corresponds to the Xꢀray diffraction data
as well. In structure CuL2(NITꢀPh) slight differences in
lengths of the hydrogen bonds and in the angles between
molecules CuL2 and linked molecules NITꢀPh were obꢀ
tained (Table 1).
For CuL2(NITꢀMePz)•C7H8, the highꢀtemperature
value of μeff (Fig. 6) equal to 2.57 μB is also well consistent
with the theoretical purely spin value of 2.45 μB. Structure
CuL2(NITꢀMePz)•C7H8 is formed by chains with the
motif "headꢀtoꢀtail" in which the fragments CuL2 alterꢀ
nate, being linked by hydrogen bonds to the NO group
of the paramagnetic ligand from one side, and from anꢀ
other side they are linked with the imine N atom of
the pyrazole cycle, i.e., only one of the NO groups particꢀ
ipates in hydrogen bonding. Taking into account the
short contacts O...F, for the description of the system
of exchange channels we chose the model of alternant
chain {Cu—N—H...ONO...F...Cu—N—H...ONO...F…}
H = –2JΣ(SiSi+1 + αSiSi+1).8 The following optimal
values of the parameters were obtained by the approximaꢀ
tion of the experimental data: g = 2.20 ( 0.01), J/k =
= –44.2 ( 0.5) K, α = 0.73 ( 0.01).
Thus, four variants of hydrogen bonds between CuL2
and NITꢀR caused by the functions of nitroxyl groups are
observed in the structures studied: (a) only one NO group
of NITꢀR acts as an acceptor of the H atoms of two NH
groups; (b) each nitroxyl groups form hydrogen bonds with
two NH groups from different molecules CuL2; (c) one
NO group of NITꢀR serves as an acceptor of H atoms of
two NH groups, and another group participates in suppleꢀ
menting of the environment of the copper atom; and
(d) one NO group of NITꢀR acts simultaneously as an
acceptor of hydrogen atoms of two NH groups and the
C—H group of the nitroxyl.
The temperature plots of the effective magnetic moment
(μeff) and magnetic susceptibility (χ) for CuL2(NITꢀMe)
are presented in Fig. 4. The highꢀtemperature value of μeff
equal to 2.49 μB (μB is Bohr magneton) for CuL2(NITꢀ
Me)•C6H14 (see Fig. 4) agrees well with the theoretical
purely spin value of 2.45 μB for two nonꢀinteracting paraꢀ
magnetic centers with spins S = 1/2 at g = 2. A decrease
in μeff with the temperature decrease indicates exchange
interactions of the antiferromagnetic character. The
approximation of the experimental data by the model
of uniform chain, whose choice was based on the Xꢀray
diffraction results (see Fig. 1), gave the following optimal
values of the parameters for the antiferromagnetically
bound paramagnetic centers with the spins S = 1/2
(H = –2JΣSiSi+1)7: g = 2.17 ( 0.01), J/k = –45.8 ( 0.5) K.
The plots μeff(T) and χ(T) for CuL2(NITꢀPh) are preꢀ
sented in Fig. 5. The highꢀtemperature value of μeff equal
to 2.50 μB is close to the theoretical value of 2.45 μB for
two nonꢀinteracting paramagnetic centers with the spins
S = 1/2 at g = 2. The value of μeff decreases with the
temperature decrease, indicating exchange interactions of
the antiferromagnetic character. The chain structure is
The temperature plots of μeff and inverse magnetic susꢀ
ceptibility 1/χ for CuL2(NITꢀH)2 are presented in Fig. 7.
χ/cm3 mol–1
μeff/μ
B
μ
eff/μ
χ/cm3 mol–1
B
0.0075
0.0060
0.0045
0.0030
1
2
2.5
2.0
1.5
1.0
0.5
0
0.006
2
1
2.5
2.0
1.5
1.0
0.5
0
0.005
0.004
0.003
100
200
T/K
Fig. 5. Temperature plots of the effective magnetic moment (1)
and magnetic susceptibility (2) for CuL2(NITꢀPh). Points are
experimental data, and lines are theoretical curves (solid line is
the model of alternant chain, and dotted line is the model of
uniform chain).
100
200
T/K
Fig. 4. Temperature plots of the effective magnetic moment (1) and
magnetic susceptibility (2) for CuL2(NITꢀMe)•C6H14. Points
are experimental data, and solid lines are theoretical curves.

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Russ.Chem.Bull., Int.Ed., Vol. 60, No. 5, May, 2011
Fokin et al.
Table 1. Hydrogen bond lengths (d) and the corresponding bond angles (ϕ) in the structures of the synthesized complexes
Compound (T/K)
Bond
d(N—H),
d(H...ONO)/Å
d(N...ONO),
ϕ(N—H...ONO),
d(С—H)/Å
d(C...ONO)/Å
ϕ(C—H...ONO)/deg
CuL2(NITꢀMe)•C6H14
N(1)—H(1A)...O(02´)
N(2)—H(2A)...O(01)
N(3)—H(3A)...O(02´)
N(4)—H(4A)...O(01)
N(1)—H(1A)...O(02´)
N(2)—H(2A)...O(01)
N(3)—H(3A)...O(01)
N(4)—H(4A)...O(02´)
N(1)—H(1A)...N(3R´)
N(2)—H(2A)...O(1R
N(3)—H(3A)...N(3R´)
N(4)—H(4A)...O(1R)
N(1)—H(1A)...O(01´)
N(2)—H(2A)...O(01´)
C(07)—H(07A)...O(01´)
N(1)—H(1A)...O(01´)
N(2)—H(2A)...O(01´)
C(07)—H(07A)...O(01´)
N(1)—H(1A)...O(01´)
N(2)—H(2A)...O(01´)
C(07)—H(07A)...O(01´)
N(1)—H(12)...O(2R)
N(2)—H(22)...O(2S)
N(4)—H(42)...O(2R)
N(6)—H(62)...O(1S´)
N(7)—H(72)...O(1S´)
N(8)—H(82)...O(1R´)
C(7R)—H(7R)...O(1R´)
C(7S)—H(7S)...O(2S´)
0.88
0.88
0.88
0.88
0.79(2)
0.76(2)
0.77(2)
0.74(2)
0.86
0.86
0.86
0.86
0.88
0.88
0.95
0.88
0.88
0.95
0.88
0.88
0.95
0.87
0.87
2.17
2.05
2.06
2.15
2.27(2)
2.28(2)
2.28(2)
2.20(2)
2.28
2.10
2.27
2.08
2.07
2.15
2.39
2.08
2.15
2.43
2.12
2.19
2.56
2.25
2.32
2.25
2.12
2.16
2.25
2.45
2.27
2.938(12)
2.911(10)
2.916(12)
3.004(11)
3.023(2)
3.011(3)
3.004(3)
2.927(3)
3.130(7)
2.932(6)
3.120(7)
2.917(7)
2.931(3)
2.974(3)
3.289(3)
2.945(2)
2.990(2)
3.330(3)
2.962(3)
3.015(3)
3.435(3)
3.086(4)
3.169(4)
3.071(4)
2.981(4)
3.016(4)
3.117(5)
3.022(6)
3.199(5)
145.2
166.6
163.2
165.3
161(2)
161(2)
157(2)
169(2)
169.6
163.0
169.4
165.1
166.6
156.7
157.6
167.2
158.4
157.0
168.0
161.5
156.9
162.6
166.6
157.9
169.8
167.5
171.2
119.6
170.0
CuL2(NITꢀPh)
CuL2(NITꢀMePz)•C7H8
CuL2(NITꢀH)2 (70)
CuL2(NITꢀH)2 (150)
CuL2(NITꢀH)2 (290)
CuL2(NITꢀH)
0.87
0.87
0.87
0.87
0.94
0.94
The highꢀtemperature value of μeff for CuL2(NITꢀH)2
equal to 3.12 μB agrees well with the theoretical purely
spin value of 3.0 μB for three nonꢀinteracting paramagnetꢀ
ic centers with the spins S = 1/2 at g = 2. The complicated
system of exchange channels in the chain CuL2(NITꢀH)2
has no appropriate models for the description of the magꢀ
(1/χ)/mol cm–3
χ/cm3 mol–1
μeff/μ
B
μeff/μ
B
250
1
2
1
2
2.5
2.0
1.5
1.0
0.5
0
3.0
2.5
2.0
1.5
1.0
0.0060
0.0045
0.0030
0.0015
200
150
100
50
100
200
T/K
100
200
T/K
Fig. 6. Temperature plots of the effective magnetic moment (1)
and magnetic susceptibility (2) for CuL2(NITꢀMePz)•C7H8.
Points are experimental data, and solid lines are theoretical
curves.
Fig. 7. Temperature plots of the effective magnetic moment (1)
and inverse magnetic susceptibility (2) for CuL2(NITꢀH)2. Points
are experimental data, and solid line is the theoretical curve.

Heterospin copper(II) bischelates
Russ.Chem.Bull., Int.Ed., Vol. 60, No. 5, May, 2011
821
μ
eff/μ
(1/χ)/mol cm–3
spins S = 1/2 at g = 2. The decrease in μeff below 100 K is
caused by the antiferromagnetic exchange interactions beꢀ
tween unpaired electrons of the paramagnetic centers,
which is indicated by the negative value of the Weiss conꢀ
stant θ. At temperatures above 50 K, the temperature
dependence of the inverse magnetic susceptibility is deꢀ
scribed by the Curie—Weiss equation with the parameters
C = 0.776 cm3 K mol–1 and θ = –20 K.
Thus, we synthesized and structurally characterized
the first heterospin compounds based on bis(1,1,1,3,5,5,5ꢀ
heptafluoroꢀ4ꢀiminopentꢀ2ꢀeneꢀ2ꢀaminato)copper(II) and
stable nitronyl nitroxide radicals of the 2ꢀimidazoline
series. According to the Xꢀray diffraction data, hydrogen
bonds of the NH groups with the NO groups of NITꢀR
play the determining role in the formation of the supramoꢀ
lecular structure of these compounds.
B
1
2
2.4
2.0
1.6
1.2
0.8
400
300
200
100
100
200
T/K
Fig. 8. Temperature plots of the effective magnetic moment (1)
and inverse magnetic susceptibility (2) for CuL2(NITꢀH). Points
are experimental data, and solid line is the theoretical curve.
Experimental
Nitroxyl radicals were synthesized according to the known
procedures.9,10 Bis(4ꢀiminoꢀ1,1,1,3,5,5,5ꢀheptafluoropentꢀ2ꢀ
eneꢀ2ꢀaminato)copper(II) (CuL2) was synthesized according to
a procedure described previously.11 Microanalyses of the comꢀ
pounds were carried out on a Carlo Erba 1106 analyzer at the
N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry
(Siberian Branch of the Russian Academy of Sciences).
1ꢀMethylꢀ4ꢀ(4,4,5,5ꢀtetramethylꢀ3ꢀoxideꢀ1ꢀoxylꢀ4,5ꢀdiꢀ
hydroꢀ1Hꢀimidazolꢀ2ꢀyl)ꢀ1Hꢀpyrazolebis(4ꢀiminoꢀ1,1,1,3,5,5,5ꢀ
heptafluoropentꢀ2ꢀeneꢀ2ꢀaminato)copper(II) toluene solvate,
CuL2(NITꢀMePz)•C7H8. A solution of NITꢀMePz (0.0233 g,
0.1 mmol) in toluene (4 mL) was added to a solution of CuL2
(0.0500 g, 0.1 mmol) in ether (3 mL). The solution volume
was decreased to ~3 mL by passing a weak argon flow above
the surface of the reaction mixture. After 1 h dark blue crystals
were formed, filtered off, washed with cold toluene, and dried
in air. The yield was 75%. Found (%): C, 33.3; H, 2.4; N, 15.1;
netic properties. At temperatures higher 50 K, the temperꢀ
ature dependence of the inverse magnetic susceptibility is
well described by the Curie—Weiss equation with the paꢀ
rameters C = 1.3 cm3 mol–1 and θ = –25 K. The negative
value of the Weiss constant indicates the presence of antiꢀ
ferromagnetic interactions comparable in value with the
exchange interactions in the compounds described above.
The temperature plots of μeff and inverse magnetic susꢀ
ceptibility 1/χ for CuL2(NITꢀH) are presented in Fig. 8.
The value of μeff at 300 K is equal to 2.40 μB and remains
almost unchanged with the temperature increase to 100 K,
after which it decreases smoothly reaching 0.67 μB at 5 K.
The value of μeff in the temperature region 100—300 K
agrees well with the theoretical purely spin value of 2.45 μB
for two nonꢀinteracting paramagnetic centers with the
Table 2. Selected bond lengths (d) in the structures of the synthesized complexes
Bond
d/Å
CuL2(NITꢀMe)•C6H14 CuL2(NITꢀPh) CuL2(NITꢀMePz)•C7H8
CuL2(NITꢀH)2
150 K
CuL2(NITꢀH)
70 K
290 K
Cu—N
1.920(9),
1.938(9),
1.968(10),
1.981(9)
1.932(2),
1.933(2),
1.940(2),
1.945(2)
1.946(5),
1.952(5),
1.955(5),
1.963(5)
1.978(2), 1.976(2), 1.973(2),
1.981(2) 1.976(2) 1.973(2)
1.940(3),
1.941(3),
1.946(3),
1.949(3),
1.934(3),
1.938(3),
1.941(3),
1.941(3).
Cu—O
O—N
—
.—
.—
2.637(2) 2.657(2) 2.710(2)
—
1.302(10),
1.241(10)
1.281(2),
1.281(2)
1.268(5),
1.294(5)
1.294(2), 1.285(2), 1.290(3),
1.284(3) 1.280(2) 1.281(3)
1.275(4),
1.278(4),
1.281(4),
1.270(4).

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Fokin et al.
Table 3. Crystallographic characteristics of the compounds and details of Xꢀray diffraction experiments
Parameter
CuL2(NITꢀMePz)• CuL2(NITꢀPh)
•C7H8
CuL2(NITꢀMe)•
•C6H14
CuL2(NITꢀH)2
CuL2(NITꢀH)
Empirical
formula
Molecular weight
Space group
Z
C28H29CuF14N8O2 C23H21CuF14N6O2 C24H33CuF14N6O2
C24H30CuF14N8O4
C17H17CuF14N6O2
839.13
P21/c
743.00
P21/n
767.10
P21/n
824.10
C2/c
4
666.91
P1
4
4
4
4
T/K
293
240
173
70
150
290
245
a/Å
b/Å
c/Å
α/deg
15.357(5)
17.452(6)
13.189(5)
—
90.032(7)
—
3535(2)
1.577
0.731
12.6561(11)
16.1375(14)
15.0469(13)
—
106.789(5)
—
2942.2(4)
1.677
0.865
12.078(3)
15.992(4)
17.155(5)
—
90.289(9)
—
3313.5(16)
1.538
0.770
17.7807(12) 17.8435(9) 18.0736(11) 10.253(3)
9.1354(9) 9.1348(5) 9.1338(4) 10.780(4)
20.7911(19) 20.9440(12) 21.2430(12) 23.395(6)
90.437(18)
105.441(6) 105.689(2) 106.072(7) 98.468(16)
—
—
—
β/deg
γ/deg
—
—
—
103.80(2)
V/Å3
3255.3(5)
1.682
0.797
3255.3(5)
1.665
0.789
3369.7(3) 2481.3(13)
dcalc/g cm–3
μ/mm–1
θ Range/deg
Ihkl, measured/
independent
(Ihkl > 2σ(I))/N*
1.624
0.769
1.785
1.014
1.17—26.50
23041/7299
1.86—28.27
23671/7190
1.19—25.00
18303/5821
4.76—28.02 2.02—26.37 2.02—28.27 1.76—28.18
9583/
3829
10807/
3366
11235/
4085
40884/
11629
3652/503
3610/487
0.0381/0.0680
4801/425
0.0959/0.2494
3043/232
0.0390/
0.1004
2542/232
0.0350/
0.0787
2145/232
0.0451/
0.0886
4915/722
0.0529/
0.1350
R1/wR2 (I > 2σ(I)) 0.0652/0.1040
* Number of refined parameters.
F, 35.3. C21H21N8O2F14Cu. Calculated (%): C, 33.8; H, 2.8;
N, 15.0; F, 35.6.
at ~5 °C for 48 h. The brown crystals that formed were filtered
off, washed with hexane, and dried in air. The yield was 31%.
Found (%): C, 30.9; H, 2.7; N, 12.5; F, 39.7. C17H17N6O2F14Cu.
Calculated (%): C, 30.6; H, 2.6; N, 12.6; F, 39.9.
2ꢀPhenylꢀ4,4,5,5ꢀtetramethylꢀ4,5ꢀdihydroꢀ1Hꢀimidazoleꢀ3ꢀ
oxideꢀ1ꢀoxylbis(4ꢀiminoꢀ1,1,1,3,5,5,5ꢀheptafluoropentꢀ2ꢀeneꢀ2ꢀ
aminato)copper(II), CuL2(NITꢀPh). A solution of NITꢀPh (0.0229 g,
0.1 mmol) in ether (3 mL) and hexane (5 mL) were added to
a solution of CuL2 (0.0500 g, 0.1 mmol) in ether (3 mL). The
obtained reaction mixture was stored in the open flask at ~5 °C.
After 24 h large dark blue prismatic crystals were formed, filtered off,
washed with cold hexane, and dried in air. The yield was 80%.
Found (%): C, 37.7; H, 3.0; N, 10.9; F, 35.0. C23H21N6O2F14Cu.
Calculated (%): C, 37.2; H, 2.9; N, 11.3; F, 35.8.
2,4,4,5,5ꢀPentamethylꢀ4,5ꢀdihydroꢀ1Hꢀimidazoleꢀ3ꢀoxideꢀ
1ꢀoctylbis(4ꢀiminoꢀ1,1,1,3,5,5,5ꢀheptafluoropentꢀ2ꢀeneꢀ2ꢀaminꢀ
ato)copper(II) hexane solvate, CuL2(NITꢀMe)•C6H14. A mixꢀ
ture of CuL2 (0.0500 g, 0.1 mmol) and NITꢀMe (0.0168 g,
0.1 mmol) was dissolved in ether (5 mL), hexane (5 mL) was
added, and the solution was stored in the open flask at ~5 °C.
After 10 h large brown crystals that formed were filtered off,
washed with a cold ether—hexane (1 : 5) mixture, and dried in air
within 1 min. The yield was 35%. Found (%): C, 31.9; H, 3.3;
N, 12.2; F, 39.3. C18H19N6O2F14Cu. Calculated (%): C, 31.8;
H, 2.8; N, 12.3; F, 39.1. A similar procedure was used to synthesize
bis(4,4,5,5ꢀtetramethylꢀ4,5ꢀdihydroꢀ1Hꢀimidazoleꢀ3ꢀoxideꢀ1ꢀoxyl)ꢀ
bis(4ꢀiminoꢀ1,1,1,3,5,5,5ꢀheptafluoropentꢀ2ꢀeneꢀ2ꢀaminato)ꢀ
copper(II), CuL2(NITꢀH)2, which was isolated as large brown crysꢀ
tals. The yield was 45%. Found (%): C, 34.4; H, 3.8; N, 13.2; F, 32.1.
C24H30N8O4F14Cu. Calculated (%): C, 35.0; H, 3.7; N, 13.6; F, 32.3.
4,4,5,5ꢀTetramethylꢀ4,5ꢀdihydroꢀ1Hꢀimidazoleꢀ3ꢀoxideꢀ1ꢀ
oxylbis(4ꢀiminoꢀ1,1,1,3,5,5,5ꢀheptafluoropentꢀ2ꢀeneꢀ2ꢀaminꢀ
ato)copper(II), CuL2(NITꢀH). CuL2(NITꢀH)2 (0.081 g, 0.1 mmol)
was dissolved in toluene (5 mL), and the solution was left to stay
Xꢀray diffraction study. Xꢀray diffraction experiments were
carried out on a SMART APEX CCD diffractometer (Bruker
AXS) (MoꢀKα radiation, λ = 0.71073 Å, T = 295 K, an absorpꢀ
tion correction was applied by the Bruker SADABS program,
version 2.10). The structures were solved by direct methods and
refined by fullꢀmatrix least squares in the anisotropic approxiꢀ
mation for nonꢀhydrogen atoms. In most cases, the positions of
H atoms were calculated theoretically. The H atoms of the methyl
groups were refined isotropically in the rigid group approximaꢀ
tion. All calculations on structure determination and refinement
were performed using the Bruker Shelxtl Version 6.14 program
package. Selected bond lengths in the structures are listed
in Table 2, and hydrogen bonding parameters are given in Table 1.
The crystallographic characteristics of the compounds and exꢀ
perimental details are presented in Table 3.
The magnetic properties of the complexes were measured on
a SQUID magnetometer in the temperature range 2—300 K in
a magnetic field of 5 kOe. The paramagnetic components of
magnetic susceptibility (χ) were determined with allowance for
the diamagnetic contribution estimated from Pascal´s constants
and temperatureꢀindependent paramagnetism for Cu2+ ions,
which was accepted to be 60•10–6 cm3 mol–1. The effective
magnetic moment was calculated by the formula
2
μ
eff = [3k/(NAβ )•χT]1/2 ≈ (8χT)1/2
,
where NA, β, and k are Avogadro´s number, Bohr magneton,
and the Boltzmann constant, respectively.

Heterospin copper(II) bischelates
Russ.Chem.Bull., Int.Ed., Vol. 60, No. 5, May, 2011
823
rushin, Izv. Akad. Nauk, Ser. Khim., 2006, 2043 [Russ. Chem.
Bull., Int. Ed., 2006, 55, 2122].
6. V. I. Ovcharenko, S. V. Fokin, G. V. Romanenko, V. N.
Ikorskii, D. S. Yachevskii, D. L. Chizhov, V. N. Charushin,
Izv. Akad. Nauk, Ser. Khim., 2006, 1836 [Russ. Chem. Bull.,
Int. Ed., 2006, 55, 1904].
7. W. E. Estes, D. P. Gavel, W. E. Hatfield, D. Hodgson, Inorg.
Chem., 1978, 17, 1415.
8. J. W. Hall, W. E. Marsh, R. R. Weller, W. E. Hatfield, Inorg.
Chem., 1981, 20, 1033.
This work was financially supported by the Russian
Foundation for Basic Research (Project Nos 08ꢀ03ꢀ00025,
09ꢀ03ꢀ00091, and 09ꢀ03ꢀ12108), the Division of Inorganꢀ
ic Materials Chemistry of the Russian Academy of Sciꢀ
ences (Program "Chemistry and Physical Chemistry of
Supramolecular Systems and Atomic Clusters," No. 5.7.2),
the Ural Branch of the Russian Academy of Sciences
(Project Nos 09ꢀMꢀ23ꢀ2006 and 09ꢀPꢀ3ꢀ1013), and the
Joint Project of the Ural Branch and Siberian Branch of
the Russian Academy of Sciences (Project No. 47).
9. E. F. Ullman, J. H. Osiecki, D. G. B. Boocock, R. Darcy,
J. Am. Chem. Soc., 1972, 94, 7049.
10. V. I. Ovcharenko, S. V. Fokin, G. V. Romanenko, Yu. G.
Shvedenkov, V. N. Ikorskii, E. V. Tretyakov, S. F. Vasiꢀ
levskii, Zh. Strukt. Khim., 2002, 43, No. 1, 163 [Russ. J.
Struct. Chem., 2002, 43, No. 1, 153].
11. M. A. Kurykin, L. S. German, I. L. Knunyants, Izv. Akad.
Nauk SSSR, Ser. Khim., 1980, 2827 [Bull. Acad. Sci. USSR,
Div. Chem. Sci. (Engl. Transl.), 1980, 29].
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Received May 7, 2010;
in revised form December 23, 2010