Synthesis and coordinating properties of 5-phenyl- and 5- pyridylmethylidene-substituted 2-selenohydantoines and 2-selenoimidazol-4-ones

Article abstract of DOI:10.1007/s11172-012-0161-z

2-Selenoimidazolidin-4-ones and 2-selenoimidazol-4-ones containing phenylor pyridylmethylidene substituent at position 5 were synthesized. The structure of 3-benzyl-2-selenohydantoine was confirmed by X-ray crystallography. A series of 2-(methylseleno)imi

Full text of DOI:10.1007/s11172-012-0161-z

Russian Chemical Bulletin, International Edition, Vol. 61, No. 6, pp. 1182—1192, June, 2012
1182
Synthesis and coordinating properties of
5ꢀphenylꢀ and 5ꢀpyridylmethylideneꢀsubstituted 2ꢀselenohydantoines
and 2ꢀselenoimidazolꢀ4ꢀones
M. Yu. Steklov, A. N. Chernysheva, R. L. Antipin, A. G. Majouga, E. K. Beloglazkina,
A. A. Moiseeva, E. D. Strel´tsova, and N. V. Zyk
Department of Chemistry, M. V. Lomonosov Moscow State University,
Build. 3, 1 Leninskie Gory, 119991 Moscow, Russian Federation.
Eꢀmail: bel@org.chem.msu.ru
2ꢀSelenoimidazolidinꢀ4ꢀones and 2ꢀselenoimidazolꢀ4ꢀones containing phenylꢀ or pyridylꢀ
methylidene substituent at position 5 were synthesized. The structure of 3ꢀbenzylꢀ2ꢀselenoꢀ
hydantoine was confirmed by Xꢀray crystallography. A series of 2ꢀ(methylseleno)imidazolꢀ4ꢀ
ones was obtained by alkylation of 3,5ꢀdisubstituted selenohydantoines with methyl iodide. The
synthesized selenohydantoines and 3ꢀbenzylꢀ5ꢀpyridylmethylideneꢀ2ꢀ(methylseleno)imidazolꢀ
4ꢀones were examined in the complexation reactions with CoCl2, NiCl2, CuCl2, and
CuI(CH3CN)4ClO4; electrochemical investigations showed that reduced forms of the copperꢀ
containing complexes were stable
Key words: 2ꢀselenohydantoines substituted at position 5, 2ꢀselenoimidazolꢀ4ꢀones substiꢀ
tuted at position 5, N,Seꢀcontaining ligands, transition metal complexes, electrochemistry.
Organoselenium compounds are important intermediꢀ
nitrogen atoms are of special interest, since the presence
of a powerful electronꢀdonating nitrogen atom and weakly
donating selenium atom gives them a possibility to coorꢀ
dinate metals of various nature and oxidation state or to
accomplish competing coordination of a certain metal
atom. Such complexes can be used as cytostatic agents.4
The latest studies on intramolecular stabilization of orgaꢀ
noselenium compounds showed that the intramolecular
ates in organic synthesis and convenient models for the
investigation of reaction mechanisms in organic and bioꢀ
organic chemistry. A wide application of organoselenium
compounds in the synthesis is determined by their easy
incorporation into organic molecules and subsequent reꢀ
moval after performing all the necessary synthetic transꢀ
formations, which was used in the preparation of a numꢀ
ber of complicated natural compounds.1
High biological activity of organoselenium compounds
is yet another reason for their active studies. Selenium
deficiency in human body was found to increase the probꢀ
ability of cardioꢀvascular pathologies, cancer, and arthriꢀ
tis. It is known that the process of peroxide oxidation of
lipids is one of the main reasons of human organism ageꢀ
ing. A seleniumꢀcontaining enzyme glutathioneperoxidase
catalyzing reactions of peroxides with mercapto groups of
glutathione can inhibit this process in the organism.2
Development of chemistry of seleniumꢀcontaining
compounds received a powerful impulse by the studies
directed on the preparation of conducting materials based
on the chargeꢀtransfer seleniumꢀcontaining complexes and
radical ion salts. An important field of their practical apꢀ
plication is the preparation of semiconductor materials,
films, and coatings.3
…
interactions Se N play an important role in the antioxiꢀ
dant activity of these compounds.5
The Ni atom in the active site of the [FeNiSe] hydroꢀ
genase enzyme is coordinated with the selenium atom of
selenocysteine.6 The catalytic properties of this enzyme
considerably differ from the properties of the sulfurꢀconꢀ
taining analog, [FeNi] hydrogenase.7 The molybdenumꢀ
containing enzyme formate dehydrogenase H, besides
the molybdenum—sulfur bonds, contains the molybdeꢀ
num—selenium bond (selenocysteine), which is required
for the catalytic activity.8 Comparison of complex comꢀ
pounds simulating these active centers and containing S
and Se atoms allows one to better understand the nature of
the catalytic activity of these enzymes.
The present work was devoted to the development of
methods for the preparation of new Se,Nꢀcontaining
ligands of the 2ꢀselenoimidazolidinꢀ4ꢀone and 2ꢀseꢀ
lenoimidazolꢀ4ꢀone series, including those containing
donating pyridylmethylene substituents at position 5
of the fiveꢀmembered heterocycle and studies of a posꢀ
As to the present moment, coordination compounds
of metals with seleniumꢀcontaining ligands are studied
poorly. Organic ligands containing both selenium and
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1170—1180, June, 2012.
1066ꢀ5285/12/6106ꢀ1182 © 2012 Springer Science+Business Media, Inc.

2ꢀSelenohydantoines and 2ꢀselenoimidazolꢀ4ꢀones
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 6, June, 2012
1183
sibility of their complexation with CuII, CoII, NiII, and
CuI salts.
Scheme 2
Results and Discussion
A twoꢀstep procedure for the preparation of seleniumꢀ
containing analog from the corresponding thiohydantoine
described in the literature9 (Scheme 1) turned out to be
applicable only to the synthesis of 5ꢀphenylmethylideneꢀ
substituted selenohydantoine 3 in a moderate yield; the
preparation of 5ꢀpyridylmethylideneꢀsubstituted selenoꢀ
hydantoines by this method failed.
Scheme 1
i. 1) Et3N/THF, 2) PhCH2NCSe (20%), ; ii. 1) KOH/H2O,
2) PhCH2NCSe/EtOH, 3) HCl; iii. HCl/EtOH (45%), .
Scheme 3
5ꢀPyridylmethylideneꢀsubstituted selenohydantoines
were synthesized by an alternative procedure starting from
3ꢀNꢀbenzylꢀsubstituted selenohydantoine 4. Compound 4
was obtained using two methods: the reaction of benzyl
isoselenocyanate with ethyl glycinate10 or with the potasꢀ
sium salt of the same amino acid with subsequent acidifyꢀ
ing of the reaction mixture and cyclization of the thus
formed selenourea according to the modified by us literaꢀ
ture procedure by reflux in a mixture of HCl/EtOH
(Scheme 2). The latter method allowed us to achieve
a 45% yield of the target product, while in the first method
it did not exceed 20%.
The structure of compound 4 was confirmed by Xꢀray
crystallography (Fig. 1). The crystallographic data, experꢀ
imental details and refinement parameters of the structure
are given in Table 1. All the nitrogen and carbon atoms
of the fiveꢀmembered heterocycle lie in one plane; the
exocyclic oxygen and selenium atoms are in the same
plane. The dihedral angle C(1)—N(1)—C(4)—C(5) is
equal to ~84.
5: R = Ph (a), 2ꢀPy (b), 3ꢀPy (c), 4ꢀPy (d)
the corresponding aldehyde in AcOH in the presence of
the equimolar amount of AcONa (method A) and a twoꢀ
step oneꢀpot synthesis from the same starting compounds
(method B).
The target products were obtained by both methods,
but method A gave higher yields for benzaldehyde and all
three pyridinecarbaldehydes (Table 2). In addition, the
workꢀup and the isolation of the final product in this case
is experimentally considerably easier.
Note that our attempts to involve benzyl isoselenoꢀ
cyanate into the threeꢀcomponent reaction with glycine
and ꢀ, ꢀ, and ꢀpyridinecarbaldehydes in glacial acetic
acid, analogous to the known procedure for thiohydantoꢀ
ines,11 did not lead to the formation of products 5a—d.
Each of the compounds 3, 5a—d was isolated as a single
geometric isomer. We assign them the Zꢀconfiguration
based on the 1H NMR data for Eꢀ and Zꢀisomers of
For the introduction of a substituent into position 5 of
the selenohydantoine ring, we used two alternative proceꢀ
dures (Scheme 3): a reaction of 2ꢀselenohydantoine 4 and

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Steklov et al.
Table 1. Crystallographic data, experimental details and paramꢀ
eters of refinement for the structure of compound 4
C(9)
Parameter
Value
C(10)
C(8)
Molecular formula
Molecular weight
C10H10N2ОSе
253.16
C(5)
C(7)
T/K
Wavelength/Å
120(2)
0.71073
C(4)
Crystal form
Crystal size/mm
Crystal system
Space group
Colorless prisms
0.25×0.15×0.10
Monoclinic
P21/с
C(6)
N(1)
O(1)
Se(1)
a/Å
b/Å
c/Å
/deg
13.0120(8)
5.6521(4)
13.3908(8)
90
94.1460(10)
90
982.25(11)
4
1.712
C(2)
C(3)
C(1)
N(2)
/deg
/deg
V/Å3
Z
Fig. 1. Molecular structure of compound 4 (the ellipsoids of
atomic displacements are shown with 50% probability). Selected
bond distances (Å) and bond angles (deg): Se(1)—C(1)
1.8305(16), N(1)—C(1) 1.380(2), N(1)—C(2) 1.393(2), N(2)—C(1)
1.327(2), N(2)—C(3) 1.455(2); the angle C(1)—N(1)—C(2)
111.42(13), C(1)—N(2)—C(3) 112.63(13), N(2)—C(1)—Se(1)
127.24(12), N(1)—C(1)—Se(1) 124.57(12).
dcalc/g cm–3
Absorption coefficient/mm–1
F(000)
3.788
504
Range of /deg
Range of reflection indices
1.57—29.0
–17 < h < 17,
–7 < k < 7,
–18 < l < 18
11147/2623
(Rint = 0.0324)
1.004
Number of measured/independent
reflections
QꢀFactor on F2
RꢀFactors (I > 2(I))
R1
wR2
2ꢀthiohydantoine derivatives containing a pyridylmethylꢀ
idene fragment at position 5, according to which the shifts
of the vinylic protons in the spectra of Zꢀ or Eꢀ isomers are
found in the range of  6.40—6.85 and 6.10—6.35, respecꢀ
tively.11
0.0206
0.0479
RꢀFactors (on all the data)
Alkylation of 3,5ꢀdisubstituted selenohydantoines 3
and 5b—d with methyl iodide gives rise to 2ꢀ(methylꢀ
seleno)imidazolones 6 and 7a—c (Scheme 4). Alkylation
with 1,2ꢀdibromoethane and 1,3ꢀdibromopropane leads
to the derivatives 8a,b (see Scheme 4), each of which conꢀ
tains two chelating fragments connected by the polyꢀ
methylene chain with different number of carbon atoms.
The potassium salts of selenohydantoines 3, 5 and
3ꢀbenzylꢀ2ꢀmethylselenoꢀ5ꢀ(pyridylmethylene)imidazolꢀ
R1
wR2
0.0276
0.0488
4ꢀones 7 were studied in the complexation reactions with
transition metal salts.
The reaction of the potassium salt of selenohydantoine
3 with copper(II) chloride in ethanol unexpectedly led to
the isolation of a coordination compound 9 of the compoꢀ
Scheme 4
Comꢀ
pound
6
R
R´
Comꢀ
pound
7b
R
R´
Comꢀ
pound
8a
R
R´
n
Ph
2ꢀPy
Ph
Bn
3ꢀPy
4ꢀPy
Bn
Bn
2ꢀPy
2ꢀPy
Bn
Bn
2
3
7a
7c
8b

2ꢀSelenohydantoines and 2ꢀselenoimidazolꢀ4ꢀones
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 6, June, 2012
1185
Table 2. Yields of selenohydantoines 5a—d
obtained by methods A and B
tron spectroscopy, the results of electrochemical studies
also give evidences in favor of the indicated structure (for
the details, see below): the presence on the CVA curve of
two peaks of the reduction CuI  Cu0 at different potenꢀ
tials confirms the presence of two attached to each other
copper atoms.
Comꢀ
pound
Yield (%)
A
B
5a
5b
5c
5d
74
91
83
77
19
53
57
59
The potassium salts of pyridylmethylideneꢀsubstituted
selenohydantoines 5b—d were examined in the complexꢀ
ation reactions with nickel, cobalt, and copper(II) chloꢀ
rides, as well as with CuI(MeCN)4ClO4. The complex
compounds of the composition LM or L2M were isolated
as the reaction products (Scheme 6).
sition Cu2L2 (Scheme 5), i.e. in the course of the reaction
copper(II) was reduced to copper(I). We suggested that
this reduction can be caused by the solvent (EtOH). To
check this hypothesis, the reaction was reproduced in
MeCN. In fact, the complex compound 10 of the compoꢀ
sition CuL2 was the product in this case. Thus, coordinaꢀ
tion compounds of different composition can be obtained
by varying solvent in the reaction of ligand 3 with CuCl2.
Scheme 6
Scheme 5
5: R = 2ꢀPy (b´), 3ꢀPy (c´), 4ꢀPy (d´)
Comꢀ
pound
11
12a
12b
R
M
Comꢀ
pound
12c
12d
12c
R
M
4ꢀPy
2ꢀPy
2ꢀPy
Cu
Co
Ni
2ꢀPy
4ꢀPy
4ꢀPy
Cu
Co
Cu
The structures of complexes 11 and 12e with the deproꢀ
tonated 4ꢀPyꢀcontaining ligand 8, suggested based on the
results of elemental analysis and spectroscopic data, are
shown below.
Extremely low solubility of the complexes in all the
solvents tried and the electrochemical data evidence in
favor of their polymeric structure. The region of the reꢀ
duction potentials CuI  CuII for compounds 11 and 12e
and the region of the reduction potentials CuII  CuI for
compound 12e have a single peak each, which indicates
the absence of the interaction between the copper atoms
According to the electron spectroscopic data,12 the
copper atoms in the coordination compound 9 are in the
trigonal environment. The electron spectroscopy data did
not allow us to unambiguously determine coordination
environment of the copper atom in compound 10; howevꢀ
er, the IR spectra of the complex compounds 9 and 10
exhibit displacement of the vibration bands of the C=N
group to the shortꢀwave region of the spectrum as comꢀ
pared to the spectrum of the starting ligand by 9 and 7 cm–1
,
respectively, which confirms the coordination of the copꢀ
per ion with the nitrogen atom. A suggested structure of
complex 9 is shown below. In addition to the data of elecꢀ

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Steklov et al.
cases containing additional water molecules. Based on the
data of electron and IR spectroscopy, as well as on the
results of electrochemical studies, it can be suggested
that the structure of these complexes is similar to the strucꢀ
ture of the sulfurꢀcontaining analogs described in the
works.11,15 The coordination of the metal ions is effected
by the pyridine nitrogen atom and the nitrogen atom of
the C=N bond, compounds 13a,b with the 2ꢀpyridylꢀconꢀ
taining ligand 7a have a sixꢀmembered metallacycle in
the composition, whereas complexes 13c—f with 3ꢀ
and 4ꢀpyridylꢀcontaining ligands 7b,c have a polymeric
structure.
Scheme 7
Comꢀ
pound
13a
13b
13c
R
M
Comꢀ
pound
13d
13e
13f
R
M
and allows us to rule out a binuclear structure with the
Cu—Cu bond analogous to that suggested above for
the complex 9. Such a polymeric structure has been deꢀ
scribed earlier for the structurally similar coordination
compounds with the ligands of ꢀpyridylmethylidenethioꢀ
hydantoine series.11
According to the electron spectroscopic data,13 the coꢀ
ordination polyhedrons of the metal atoms in complexes
12a and 12d are the tetrahedrons. The IR spectra of the
complex compounds exhibit a displacement of the vibration
band of the C=N group toward the shortꢀwave region of the
spectrum by 7—16 cm–1 as compared to the position of
this band in the IR spectra of the ligands, which indicates
that the metal atoms are bonded to the nitrogen atom.
For compound 12a, the structure shown below seems
the most probable. Earlier, such a structure has been
suggested for the analogous coordination compound with
the pyridylmethylideneꢀsubstituted thiohydantoine (comꢀ
pound A).14 Their structural resemblance also is confirmed
by their very close redox characteristics (see below).
2ꢀPy
2ꢀPy
3ꢀPy
Co
Cu
Co
3ꢀPy
3ꢀPy
4ꢀPy
Cu
Ni
Cu
Electrochemical studies of ligands and complexes. Elecꢀ
trochemical investigation of seleniumꢀcontaining ligands
and their coordination compounds was carried out in DMF
solutions in the presence of 0.1 M Bu4NClO4 as an indifꢀ
ferent electrolyte on a glassꢀcarbon (GC) disk electrode
by cyclic voltammetry (CVA) and rotating disk electrode
(RDE). The results obtained are summarized in Table 3.
Figure 2 shows the CVA curves of 2ꢀpyridylmethylideneꢀ
selenohydantoine ligand 5b and its complex compound
with CoII 12a. The CVA curve of the ligand 5b has three
I/A
–16
–8
0
8
16
1.0
0
–1.0
–2.0 E/V
3ꢀBenzylꢀ5ꢀpyridylmethylideneꢀ2ꢀ(methylseleno)imidꢀ
azolꢀ4ꢀones 7a—c react with cobalt(II), nickel(II), and
copper(II) chlorides (Scheme 7) to form coordination comꢀ
pounds 13a—f of the composition L2MCl2, in a number of
Fig. 2. Cyclic voltammograms (DMF, the concentration of
10–3 mol L–1, 0.1 M Bu4NClO4) of ligand 5b (the dashed line)
and its coordination compound with CoII 12a (the solid line).

2ꢀSelenohydantoines and 2ꢀselenoimidazolꢀ4ꢀones
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 6, June, 2012
1187
Table 3. Electrochemical reduction (ERed) and oxidation (EOx) potentials of ligands and complexes measured relative
to Ag|AgCl|KCl(sat.) using CVA (Ep is the peak potential) and RDE (E1/2 is the halfꢀwave potential) methods on
a GC electrode (DMF, 0.1 M Bu4NClO4, CVA 200 mV s–1, RDE 20 mV s–1, 2800 min–1), the number of electrons
(in parentheses) transferred in a given step and determined on the RDE by comparison with the wave of the oneꢀ
electron oxidation of ferrocene, as well as peak potentials on the inverse scans of the CVA curves (after the slash)
Red
Red
Ox
Ox
Compound
Ep
E1/2
Ep
E1/2
V
Ligand 5b
1) –0.94
3) –1.70
4) –2.07
1) –0.87
2) –1.42
3) –1.63
4) –2.03
1) 1.12
2) 1.46
1) 1.01 (2)
2) 1.22 (2)
Ligand 5c
(potassium salt)
1) –1.81
2) –1.90
3) –2.23
—
1) 0.36
2) 1.02
3) 1.49
—
Ligand 7a
Ligand7b
Complex 9
1) –1.17/–1.08
2) –1.57
3) –2.03
1) –1.14 (1)
2) –1.51 (1)
3) –2.26
1) 1.52
1) 1.52
1) 1.42 (2)
1) –1.30/–1.24
2) –1.88/–1.79
3) –2.26
1) –1.20 (1)
2) –1.83 (1)
1) 1.43
1) –0.39
2) –0.64
3) –1.87/–1.81
4) –2.24
1) –0.55
2) –0.84
2) –1.23
3) –1.84
4) –2.30
1) 0.33/0.31
2) 1.02/0.02
3) 1.46
1) 0.39 (1)
1) 0.97
2) 1.43
(3ꢀH)2СuI
2
Complex 11
[(5cꢀH)СuI]n
1) –0.60
2) –1.13
3) –1.59
4) –1.93
1) 0.49
1) 0.37/0.47
2) 1.32
1) 1.16
2) –1.51
3) –1.70
4) –1.89
Complex 12a
(5aꢀH)2СоII
1) –0.96/–0.91
2) –1.16/–1.11
3) –1.71/1.60
1) –0.92 (1)
2) –1.13 (1)
3) –1.65 (2)
1) 0.84
2) 1.00
1) 0.90 (2)
1) 1.20
Complex 12e
[(5cꢀH)2СuII]n
1) 0.38/0.49
2) –0.16/0.23
3) –1.16
1) 0.50
1) 1.23
2) –1.23
3) –1.46
4) –1.73
4) –1.52
5) –1.85
Complex 13b
(6)2СuIICl2
1) 0.37/0.56
2) 0.09/0.14
3) –0.29/0.21
4) –1.38/–1.34
5) –2.26
1) 0.52 (1)
2) 0.10 (1)
3) 0.17 (1)
4) –1.32 (2)
1) 1.02
2) 1.38
1) 1.12 (2)
2) 1.40 (2)
Complex 13c
(7a)2СoIICl2
1) –1.30/–1.25
2) –1.83
3) –1.92
1) –0.78
1) 1.18
1) 1.30
1) 1.01
4) –2.28
Complex 13d
(7a)2СuIICl2
1) 0.40/0.46
1) 0.45 (1)
2) –1.24 (2)
1) 1.14 (2)
2) –1.31/–1.25
3) –1.85/–1.76
4) –1.88/–1.74
5) –2.22
Complex 13e
(7a)2NiIICl2
1) –1.26/–1.18
2) –1.85
3) –2.19
1) –1.24
2) –1.61
3) –2.05
1) 1.14
1) 1.01
4) –2.23

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Steklov et al.
irreversible cathode peaks at –0.94, –1.70, and –2.07 V
and two irreversible anode peaks at 1.12 and 1.46 V. Earliꢀ
er, we have shown that the first steps of both reduction and
oxidation of the structurally close 3ꢀphenylꢀ5ꢀpyridylmeꢀ
thylideneꢀ2ꢀthiohydantoines15 proceed irreversibly with
respect to the C=S bond at the potentials ~–1.1 V (oneꢀ
electron process) and 1.1—1.5 V (twoꢀelectron process),
respectively. Comparing these data with the results obꢀ
tained in the studies of selenohydantoine 5b, it can be
suggested that the oxidation and reduction of the latter
proceeds similarly at the C=Se bond (Scheme 8).
an organic radical anion, if the reduction occurs "at the
ligand") is stable in solution.
The complex compounds of copper(I) 11 and copper(II)
12e with the anionic 4ꢀpyridylmethylideneselenohydanꢀ
toine ligand 5c are reversibly reduced in the first step "at
the metal" (see Table 3 and Fig. 3). Note that for comꢀ
plex 11 after scanning the potential into the anode region,
the reꢀregistrated CVA acquired the form very similar to
the CVA curve for complex 12e (see Fig. 3). Apparently,
the oxidation of CuI in complex 11 to CuII leads to the
formation of a coordination compound structurally simiꢀ
lar to 12e.
Note that compounds 9 and 11, having the similar
simple molecular formula (LH)CuI, very strongly differ
electrochemically: the CVA curve for the first of these
complexes has two reduction peaks CuI  Cu0, which
proves the presence in its composition of two copper
atoms bonded to each other, whereas for the second comꢀ
plex, the curve contains only one such a peak; therefore,
the copper atoms in the composition of the complex do
not interact.
Scheme 8
Ligands 7a,b are reduced in three sequential steps, the
first and the second of which are oneꢀelectron; the oxidaꢀ
tion of the ligands proceeds in one step by a twoꢀelectron
process (see Table 3, Fig. 2). Their coordination comꢀ
pounds 13b—e have additional peaks on the cathode
branch of the CVA curve (see Fig. 2), with the potentials
of the first reduction peak of the cobaltꢀ and nickelꢀconꢀ
taining complexes 13c and 13e being very close to the
reduction potential of the free ligand. The oxidation poꢀ
tentials of complexes 13b—e correspond to the oxidation
of coordinated chloride anions.15
Note that both the oxidation and the reduction of seleꢀ
nohydantoine proceed easier than the oxidation and the
reduction of its sulfurꢀcontaining analog. A comparable
easiness of oxidation of compound 5b can be explained by
the greater electronꢀdonating power of the benzyl substitꢀ
uent on the N(3) nitrogen atom in this ligand as compared
to the phenyl substituent of the sulfur analog studied earliꢀ
er,15 as well as by the lower electronegativity of the Se
atom as compared to the S atom. In addition, according
to theory of hardꢀsoft acids and bases, a selenium atom is
"softer" as compared to a sulfur atom, which from the
point of view of molecular orbitals theory means a smaller
gap between the HOMO and the LUMO of selenohydanꢀ
toine than in the case of the sulfur analog.
For the cobalt complex of ligand 5b, i.e., compound
12a, the cathode branch of the CVA curve has three reꢀ
versible peaks (see Fig. 2 and Table 3), of which the first
(E1/2 –0.96 V) and the second (E1/2 –1.16 V) are the oneꢀ
electron ones. The third wave (E1/2 –1.71 V) is the twoꢀ
electron. The anode region has two irreversible peaks
with Ep 0.84 and 1.00 V. Very similar pattern has been
observed by us earlier during electrochemical studies of
the structurally close cobalt thiohydantoine complex
(compound A).14 Such similarities of the redox characterꢀ
istics of compounds 12a and A confirm the structure sugꢀ
gested for compound 12a. In addition, the electrochemiꢀ
cal reversibility of the first reduction wave of complex 12a
shows that the reduced form of the complex (containing
either CoI, if the reduction takes place at the Co atom, or
I/A
–40
–20
0
20
40
1.0
0
–1.0
–2.0 E/V
Fig. 3. Cyclic voltammograms (DMF, the concentration of
10–3 mol L–1, 0.1 M Bu4NClO4) of complex 12e (the solid line)
and complex 11 immediately after the dissolution (the dashed
line), as well as after the scanning the potential into the oxidaꢀ
tion region (the dashedꢀandꢀdotted line).

2ꢀSelenohydantoines and 2ꢀselenoimidazolꢀ4ꢀones
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 6, June, 2012
1189
I/A
Experimental
–16
1
H NMR spectra were recorded on a BruckerꢀAvance specꢀ
trometer (400 MHz). IR spectra were recorded on a TermoNꢀ
icolet IR200 infraꢀred Fourier transform spectrometer (USA),
UV spectra were recorded on a Hitachi Uꢀ2900 spectrometer.
Elemental analysis was performed on a Perkin—Elmer CHNꢀ
analyzer (model 2400). In order to trap selenium oxide, the tail
part of the oxidation and reduction reactor additionally was
equipped with a ~3 cm long silver net rolled as a stopper. Mass
spectra MALD were recorded on a Bruker Autoflex II instruꢀ
ment (the FWHM resolution of 18000) equipped with a nitrogen
laser with an operational wavelength of 337 nm and timeꢀofꢀ
flight mass analyzer, accelerating voltage of 20 kV; the samples
were deposited on a support made of polished steel; the spectra
were recorded in the positive ions mode; the resulting spectrum
was a sum of 300 spectra obtained in the different sites of the
sample. 2,5ꢀDihydroxybenzoic acid (DHB) (Acros, 99%) and
ꢀcyanoꢀ4ꢀhydroxycinnamic acid (HCCA) (Acros, 99%) were
used as matrices. For all the indicated massꢀspectral peaks, the
isotopic distribution corresponded to the calculated data.
–8
0
8
16
1.0
0
–1.0
–2.0
E/V
Fig. 4. Cyclic voltammograms (DMF, the concentration of
10–3 mol L–1, 0.1 M Bu4NClO4) of ligand 7b (the dashed line)
and its coordination compound with CuII 13d (the solid line).
Xꢀray diffraction studies were performed on a Bruker Smart
APEX2 CCD Area Detector singleꢀcrystal automatic diffractoꢀ
meter (graphite monochromator, (MoꢀK) = 0.71073 Å, ꢀ and
ꢀscan technique). The structure was solved using the SHELXTL
ver. 5.1 program package.16 Positions of hydrogen atoms were
calculated in isotropic approximation using the riding model.
For electrochemical studies we used a PIꢀ50ꢀ1.1 potentiomꢀ
eter connected to a PRꢀ8 program block. A glass carbon disk
(d = 2 mm) served as a reference electrode, 0.1 M solution
of Bu4NClO4 in DMF was used as a supporting electrolyte,
Ag/AgCl/KCl(sat.) was used as a comparison electrode, a platiꢀ
num plate was used as an auxilary electrode. In the CVA studies,
the potential sweep speed was 200 mV s–1, in the RDE studies,
20 mV s–1. The potentials are given with allowance for the
iRꢀcompensation. The number of transferred electrons in the
redox processes was determined by comparison of the wave limit
current in the experiments on RDE with the current of the oneꢀ
electron oxidation of ferrocene taken in the equal concentraꢀ
tion. All the measurements were carried out under dry argon;
The samples were dissolved in a preꢀdegassed solvent. DMF
(pure grade) was purified by stirring for 4 days over freshly calꢀ
cined K2CO3 with subsequent distillation in vacuo over CaH2.
3ꢀPhenylꢀ5ꢀphenylmethylideneꢀ2ꢀthioimidazolidinꢀ4ꢀone (1)
and 3ꢀphenylꢀ5ꢀphenylmethylideneꢀ2ꢀ(methylthio)imidazolꢀ4ꢀ
one (2) were obtained according to the procedures described
earlier.17,18 Benzyl isoselenocyanate was synthesized according
to the known procedure19 from benzyl isocyanate; the converꢀ
sion of the starting compound in the latter reaction was moniꢀ
tored by 13C NMR spectroscopy: the spectrum of isocyanate has
a signal for the isonitrile carbon atom at  165, while in the
spectrum of isoselenocyanate has a signal for the carbon atom of
the isoselenocyanate group (—N=C=Se) at  132.
The copperꢀcontaining complexes 13b,d undergo a reꢀ
versible redox transition at the potential of 0.30—0.40 V.
From this it follows that the reduction of these complexes,
unlike of Niꢀ and Coꢀcontaining analogs, proceeds "at the
metal" (CuII  CuI). It should be especially noted that
even when the potential reaches the level of –2.3 V during
an inverse potential scanning, no decomposition of the
complex with the isolation of metallic copper is observed.
This means that a zeroꢀvalence copper is held exclusively
strong by the complexes of such a structural type. After the
copper in the complexes 13b,d is reduced to Cu0, its presꢀ
ence in the coordination compound does not cause any
noticeable shift of the ligand reduction wave potentials
(see Table 3, Fig. 4).
It should be noted that the electrochemical behavior of
the complexes depends on the electrode material. Thus,
when complex 13e was studied on an Au electrode, an
additional peak appeared on the CVA curve in the reducꢀ
tion region at –0.76 V. Apparently, the complexes under
study can be adsorbed on the surface of the metallic elecꢀ
trode. Moreover, the first reduction peak of complex 13d
loses its reversibility on metallic (Au and Pt) electrodes,
probably, as a result of disproportionation of the copper(I)
complex to CuII and Cu0.
In conclusion, we have developed approaches to the
preparation of 3ꢀphenylꢀ and 3ꢀbenzylꢀsubstituted 2ꢀseleꢀ
noimidazolidinꢀ4ꢀones and 2ꢀselenoimidazolꢀ4ꢀones conꢀ
taining phenylꢀ or pyridylmethylidene group at position 5.
Their coordination compounds with CoII, NiII, CuII, and
CuI were obtained. Electrochemical data showed that the
reduced forms of the copperꢀcontaining complexes of these
ligands are stable, that makes them promising subjects for
further studies as catalysts of redox reactions including
electrochemically induced.
3ꢀPhenylꢀ5ꢀphenylmethylideneꢀ2ꢀselenoimidazolidinꢀ4ꢀone (3).
Selenium (0.16 g, 2 mmol) was added to anhydrous EtOH (15 mL)
with stirring under argon. The mixture was cooled to 0 C, folꢀ
lowed by addition of NaBH4 (0.182 g, 4 mmol). After the reacꢀ
tion mixture became colorless, 3ꢀphenylꢀ5ꢀphenylmethylideneꢀ
2ꢀ(methylthio)imidazolꢀ4ꢀone (2) (0.28 g, 1 mmol) was added
and this was refluxed for 40 min. Then, the reaction mixture was
cooled to ~20 C and acidified to pH 5, which was accompanied

1190
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 6, June, 2012
Steklov et al.
by formation of a brickꢀred precipitate. The reaction mixture
was stirred for another 20 min to remove residual hydrogen seꢀ
lenide, which was absorbed in a washer filled with an alkaline
solution and attached to the reaction flask. A precipitate formed
was filtered off, the mother liquor was diluted with water (20 mL),
the thus formed precipitate was filtered off on a glass filter and
dried in air. Compound 3 (0.079 g, 25%) was obtained as an
orange powder. M.p. 120 C. 1H NMR (DMSOꢀd6), : 6.82 (s, 1 H,
=CH); 7.50 (m, 8 H, Ph); 7.92 (s, 2 H, Ph); 13.14 (s, 1 H, NH).
IR, /cm–1: 3164 (NH), 1714 (C=O), 1643 (C=N), 1590 (C=C).
3ꢀBenzylꢀ2ꢀselenoimidazolidinꢀ4ꢀone (4). An ethanolic soluꢀ
tion of benzyl isoselenocyanate (3 g, 15.3 mmol) was added dropꢀ
wise under argon to an equal volume of a solution of glycine
(1.147 g, 15.3 mmol) and KOH (0.857 g, 15.3 mmol) in miniꢀ
mum water placed in a twoꢀnecked flask. The reaction mixture
was acidified to pH 4, a light orange precipitate formed was
filtered off, washed with water, and refluxed for 4 h in a mixture
of HCl—EtOH (1 : 1). A precipitate formed on cooling was filꢀ
tered off and dried in air. The yield was 1.7 g (45%). M.p..
202—204 C. 1H NMR (DMSOꢀd6), : 4.12 (s, 2 H, CH2); 4.93
(s, 2 H, CH2); 7.35 (m, 5 H, Ph); 10.95 (br.s, 1 H, NH).
5ꢀPhenyl(pyridyl)methylideneꢀ2ꢀselenoimidazolidinꢀ4ꢀones 5a—d.
Method A. Glacial acetic acid (8 mL) AcONa (2 equiv.), and
3ꢀbenzylꢀ2ꢀselenoimidazolidinꢀ4ꢀone (4) (1 equiv.) were placed
into a roundꢀbottom flask, followed by a dropwise addition of an
aldehyde (1 equiv.) with stirring. The reaction mixture was reꢀ
fluxed for 4 h, cooled to ~20 C, and poured onto ice. A precipiꢀ
tate obtained was filtered off, sequentially washed with EtOH
and diethyl ether, and dried in air.
190—194 C. 1H NMR (DMSOꢀd6), : 5.12 (s, 2 H, CH2);
6.80 (s, 1 H, =CH); 7.35 (m, 5 H, HPh); 7.48 (dd, 1 H, HPy,
J1 = 4.7 Hz, J2 = 8.1 Hz); 8.28 (d, 1 H, HPy, J = 8.0 Hz); 8.61
(d, 1 H, HPy, J = 4.7 Hz); 8.94 (d, 1 H, HPy, J = 1.76 Hz);
13.15 (s, 1 H, NH). MS (MALDI), m/z (Irel (%)): 343 [M]+ (100).
3ꢀBenzylꢀ5ꢀ(4ꢀpyridylmethylidene)ꢀ2ꢀselenoimidazolidinꢀ4ꢀone
(5d). Compound 5d (0.515 g, 77%) was obtained from comꢀ
pound 4 (0.5 g, 2 mmol), AcONa (0.324 g, 4 mmol), and 4ꢀpyrꢀ
idinecarbaldehyde (0.186 mL, 0.002 mol) as a red powder. M.p.
242—244 C. 1H NMR (DMSOꢀd6), : 5.15 (s, 2 H, CH2); 6.74
(s, 1 H, =CH); 7.30 (m, 5 H, HPh); 7.78 (d, 2 H, HPy, J = 6.1 Hz);
8.64 (d, 2 H, HPy, J = 6.3 Hz); 13.20 (s, 1 H, NH). IR, /cm–1
:
3320 (NH), 1748 (C=O), 1625 (C=N), 1599 (C=C). MS
(MALDI), m/z (Irel (%)): 343 [M]+ (100).
5ꢀArylmethylideneꢀ3ꢀbenzyl(phenyl)ꢀ2ꢀ(methylseleno)imidazolꢀ
4ꢀones 6 and 7a—c (general procedure). 5ꢀArylmethylideneꢀ2ꢀ
selenoimidazolidinꢀ4ꢀone (1 equiv.) and KOH (1 equiv.) were
added to a mixture of H2O—EtOH (1 : 1, 10 mL). Methyl iodide
(1 equiv.) was added dropwise after the complete dissolution
of the reactants. A precipitate formed was filtered off and dried
in air.
3ꢀPhenylꢀ5ꢀphenylmethylideneꢀ2ꢀ(methylseleno)imidazolꢀ4ꢀ
one (6). Compound 6 (0.207 g, 81%) was obtained from comꢀ
pound 3 (0.27 g, 0.75 mmol), KOH (0.042 g, 0.75 mmol), and
methyl iodide (0.125 mL, 0.75 mmol) as a light yellow powder.
M.p. 158—160 C. 1H NMR (CDCl3), : 2.60 (s, 3 H, Me); 7.10
(s, 1 H, =CH); 7.50 (m, 8 H, Ph); 8.22 (d, 2 H, Ph, J = 7.0 Hz).
MS (MALDI), m/z (Irel (%)): 342 [M]+ (100).
3ꢀBenzylꢀ5ꢀ(2ꢀpyridylmethylidene)ꢀ2ꢀ(methylseleno)imidazolꢀ
4ꢀone (7a). Compound 7a (0.567 g, 88%) was obtained from
compound 5b (0.616 g, 2 mmol), KOH (0.1 g, 2 mmol), and
methyl iodide (0.27 mL, 2 mmol) as a light brown powder. M.p.
Method B. 3ꢀBenzylꢀ2ꢀselenoimidazolidinꢀ4ꢀone (4) (1 equiv.)
was dissolved in 2% ethanolic KOH (14 mL) with vigorous stirꢀ
ring, an aldehyde (1 equiv.) was added dropwise. The reaction
mixture was stirred for 12 h. A precipitate was filtered off and
dissolved in water. The solution, with vigorous stirring, was neuꢀ
tralized with dilute hydrochloric acid to pH = 7. A precipitate
formed was filtered off and recrystallized from a mixture of
EtOH—DMF (3 : 1).
1
160 C. H NMR (CDCl3), : 2.05 (s, 3 H, Me); 4.45 (s, 2 H,
CH2); 6.65 (s, 1 H, =CH); 7.25 (m, 6 H, HPy, HPh); 7.86 (m, 1 H,
HPy); 8.61 (m, 1 H, HPy); 9.05 (d, 1 H, HPy, J = 4.9 Hz). IR,
/cm–1: 1717 (C=O), 1635 (C=N), 1562 (C=C). Found (%):
C, 58.09; H, 3.94; N, 12.59. C17H15N3OSe. Calculated (%):
C, 57.30; H, 4.21; N, 11.80.
3ꢀBenzylꢀ5ꢀ(3ꢀpyridylmethylidene)ꢀ2ꢀ(methylseleno)imidazolꢀ
4ꢀone (7b). Compound 7b (0.459 g, 88%) was obtained from
compound 5c (0.5 g, 14.6 mmol), KOH (0.082 g, 14.6 mmol),
and methyl iodide (0.22 mL, 14.6 mmol) as a light green powder.
M.p. 152—154 C. 1H NMR (CDCl3), : 2.59 (s, 3 H, Me); 4.80
(s, 2 H, CH2); 6.95 (s, 1 H, =CH); 7.35 (m, 5 H, HPh); 7.50
(dd, 1 H, HPy, J1 = 5.2 Hz, J2 = 8.1 Hz); 8.59 (d, 1 H, HPy,
J = 8.1 Hz); 8.71 (d, 1 H, HPy, J = 5.2 Hz); 9.25 (d, 1 H, HPy,
J = 1.8 Hz). IR, /cm–1: 1708 (C=O), 1634 (C=N), 1582 (C=C).
MS (MALDI), m/z (Irel (%)): 357 [M]+ (100).
The yields of compounds 5a—d and amounts of the starting
reactants are given in the description of method A.
3ꢀBenzylꢀ5ꢀ(phenylmethylidene)ꢀ2ꢀselenoimidazolidinꢀ4ꢀone
(5a). Compound 5a (0.2 g, 74%) was obtained from compound 4
(0.2 g, 0.8 mmol), AcONa (0.13 g, 0.16 mmol), and benzaldeꢀ
hyde (0.081 mL, 0.8 mmol) as a brown powder. M.p. 231 C.
1H NMR (DMSOꢀd6), : 5.13 (s, 2 H, CH2); 6.79 (s, 1 H, =CH);
7.35 (m, 5 H, HPh); 7.45 (m, 3 H, HPh); 7.85 (m, 2 H, HPh);
13.03 (s, 1 H, NH). IR, /cm–1: 3250 (NH), 1740 (C=O),
1650 (C=N), 1600 (C=C). MS (MALDI), m/z (Irel (%)): 342
[M]+ (100).
3ꢀBenzylꢀ5ꢀ(2ꢀpyridylmethylidene)ꢀ2ꢀselenoimidazolidinꢀ4ꢀone
(5b). Compound 5b (0.616 g, 91%) was obtained from comꢀ
pound 4 (0.5 g, 2 mmol), AcONa (0.324 g, 4 mmol), and 2ꢀpyrꢀ
idinecarbaldehyde (0.19 mL, 2 mmol) as a dark brown powder.
M.p. 228—230 C. 1H NMR (DMSOꢀd6), : 5.24 (s, 2 H, CH2);
6.65 (s, 1 H, =CH); 7.45 (m, 7 H, HPy, HPh); 7.75 (m, 1 H,
HPy); 8.69 (d, 1 H, HPy, J = 4.9 Hz); 11.9 (s, 1 H, NH). IR,
/cm–1: 3330 (NH), 1717 (C=O), 1620 (C=N), 1584 (C=C).
MS (MALDI), m/z (Irel (%)): 343 [M]+ (100).
3ꢀBenzylꢀ5ꢀ(4ꢀpyridylmethylidene)ꢀ2ꢀ(methylseleno)imidazolꢀ
4ꢀone (7c). Compound 7c (0.439 g, 84%) was obtained from
compound 5d (0.5 g, 14.6 mmol), KOH (0.082 g, 14.6 mmol),
and methyl iodide (0.22 mL, 14.6 mmol) as a black powder.
1H NMR (CDCl3), : 2.60 (s, 3 H, Me); 4.80 (s, 2 H, CH2); 6.90
(s, 1 H, =CH); 7.35 (m, 5 H, HPh); 8.12 (d, 2 H, HPy, J = 6.1 Hz);
8.65 (d, 2 H, HPy, J = 6.1 Hz). IR, /cm–1: 1717 (C=O),
1637 (C=N), 1562 (C=C). MS (MALDI), m/z (Irel (%)): 357
[M]+ (100).
3ꢀBenzylꢀ5ꢀ(3ꢀpyridylmethylidene)ꢀ2ꢀselenoimidazolidinꢀ4ꢀone
(5c). Compound 5c (0.56 g, 83%) was obtained from compound
4 (0.5 g, 2 mmol), AcONa (0.324 g, 4 mmol), and 3ꢀpyridineꢀ
carbaldehyde (0.1852 mL, 2 mmol) as a black powder. M.p.
2,2´ꢀ(Alkaneꢀ,ꢀdiyldiselenyldiyl)bis[3ꢀbenzylꢀ5ꢀ(2ꢀpyrꢀ
idylmethylidene)ꢀ3,5ꢀdihydroꢀ4Hꢀimidazolꢀ4ꢀones] 8a,b (general
procedure). Dibromoalkane (0.028 g, 0.15 mmol) was added
dropwise into a flatꢀbottom flask containing DMF (20 mL), comꢀ

2ꢀSelenohydantoines and 2ꢀselenoimidazolꢀ4ꢀones
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 6, June, 2012
1191
pound 7a (0.1 g, 0.3 mmol), and K2CO3 (0.06 g, 0.4 mol). The
reaction mixture was stirred for 8 h at ~20 C, followed by addiꢀ
tion of water (50 mL). A precipitate formed was filtered off and
dried in air.
2,2´ꢀ(Ethaneꢀ1,2ꢀdiyldiselenyldiyl)bis[3ꢀbenzylꢀ5ꢀ(2ꢀpyridylꢀ
methylidene)ꢀ3,5ꢀdihydroꢀ4Hꢀimidazolꢀ4ꢀone] (8a). The yield
was 0.093 g (90%), a violet powder. M.p. 190—192 C. 1H NMR
(CDCl3), : 3.89 (s, 4 H, CH2); 4.82 (s, 4 H, CH2); 7.12 (s, 2 H,
=CH); 7.20 (m, 2 H, HPy); 7.35 (m, 12 H, HPy, HPh); 7.52
(m, 2 H, HPy); 8.65 (d, 2 H, HPy, J = 8.0 Hz). IR, /cm–1: 1710
(C=O), 1633 (C=N), 1581 (C=C). Found (%): C, 57.83; H, 4.17;
N, 12.15. C34H28N6O2Se2. Calculated (%): C, 57.46; H, 3.94;
N, 11.83.
2,2´ꢀ(Propaneꢀ1,3ꢀdiyldiselenyldiyl)bis[3ꢀbenzylꢀ5ꢀ(2ꢀpyrꢀ
idylmethylidene)ꢀ3,5ꢀdihydroꢀ4Hꢀimidazolꢀ4ꢀone] (8b). The yield
was 0.057 g (54%), a light beige powder. M.p. 150 C. 1H NMR
(CDCl3), : 2.78 (quint, 2 H, CH2, J = 6.9 Hz); 3.74 (t, 4 H,
CH2, J = 6.9 Hz); 5.05 (s, 4 H, CH2); 7.42 (s, 2 H, =CH); 7.55
(m, 12 H, HPy, HPh); 7.84 (m, 2 H, HPy); 8.92 (d, 2 H, HPy,
J = 4.82 Hz); 8.98 (d, 2 H, HPy, J = 8.0 Hz). IR, /cm–1: 1716
(C=O), 1637 (C=N), 1580 (C=C). Found (%): C, 57.72; H, 4.20;
N, 11.35. C35H30N6O2Se2. Calculated (%): C, 58.01; H, 4.14;
N, 11.60.
Bis(3ꢀphenylꢀ5ꢀphenylmethylideneꢀ2ꢀselenoimidazolidinꢀ4ꢀone)ꢀ
dicopper(I) (9). A solution of CuCl2•2H2O (0.015 g, 0.09 mmol)
in EtOH (5 mL) was added to a solution of compound 3 (0.061 g,
0.18 mmol) and KOH (0.01 g, 0.18 mmol) in EtOH (5 mL) and
the mixture was stirred for 2 h. A precipitate formed was filtered
off, washed with water and EtOH and dried in air to obtain
compound 9 (0.052 g, 88%) as an orange powder. M.p. 260 C.
IR, /cm–1: 1729 (C=O), 1634 (C=N), 1597 (C=C). EAS, /nm
(/L mol–1 cm–1): 427 (800). Found (%): C, 50.33; H, 2.89;
N, 7.43. C32H22Cu2N4O2Se2. Calculated (%): C, 49.29; H, 2.82;
N, 7.19.
Bis(3ꢀphenylꢀ5ꢀphenylmethylideneꢀ2ꢀselenoimidazolidinꢀ4ꢀone)ꢀ
copper(II) (10). Potassium hydroxide (0.017 g, 0.3 mmol) was
added to a solution of compound 3 (0.1 g, 0.3 mmol) in MeCN
(5 mL). After KOH dissolved, a solution of CuCl2•2H2O (0.026 g,
0.15 mmol) in MeCN (5 mL) was added and the reaction mixꢀ
ture was stirred for 2 h. A precipitate formed was filtered off and
dried in air to obtain compound 10 (0.1 g, 79%) as a light brown
powder. M.p. 254 C. IR, /cm–1: 1728 (C=O), 1636 (C=N),
1597 (C=C). MS (MALDI), m/z (Irel (%)): 717 [M]+ (100).
[3ꢀBenzylꢀ5ꢀ(4ꢀpyridylmethylidene)ꢀ2ꢀselenoimidazolidinꢀ4ꢀ
one]copper(I) (11). A solution of CuI(MeCN)4ClO4 (0.06 g,
0.18 mmol) in MeCN (5 mL) was added to a solution of comꢀ
pound 5d (0.125 g, 0.37 mmol) and KOH (0.02 g, 0.37 mmol) in
EtOH (5 mL). The reaction mixture was refluxed until a preꢀ
cipitate was formed. The precipitate was filtered off and dried
in air to obtain compound 11 (0.057 g, 41%) as a dark brown
powder. M.p. 296—300 C. IR, /cm–1: 3050—3650 (OH), 1727
(C=O), 1637 (C=N), 1588 (C=C). EAS, /nm (/L mol–1 cm–1):
615.5 (670). Found (%): C, 46.83; H, 2.37; N, 9.81.
C32H24Cu2N6O2Se2•H2O. Calculated (%): C, 46.36; H, 3.14;
N, 10.15.
tion mixture. A precipitate formed was filtered off and dried
in air.
Bis[3ꢀbenzylꢀ5ꢀ(2ꢀpyridylmethylidene)ꢀ2ꢀselenoimidazolidinꢀ4ꢀ
one]cobalt(II) (12a). Compound 12a (0.091 g, 43%) was obtained
from compound 5b (0.1 g, 0.3 mmol), KOH (0.017 g, 0.3 mmol),
and CoCl2•6H2O (0.03 g, 0.5 mmol) as a brown powder. M.p..
305 C. IR, /cm–1: 1720 (C=O), 1640 (C=N), 1600 (C=C).
EAS, /nm (/L mol–1 cm–1): 711 (350), 653 (400). MS (MALDI),
m/z (Irel (%)): 743 [M]+ (100).
Bis[3ꢀbenzylꢀ5ꢀ(2ꢀpyridylmethylidene)ꢀ2ꢀselenoimidazolidinꢀ4ꢀ
one]nickel(II) (12b). Compound 12b (0.09 g, 43%) was obtained
from compound 5b (0.1 g, 0.3 mmol), KOH (0.017 g, 0.3 mmol),
and NiCl2•6H2O (0.03 g, 0.5 mmol) as a red powder. M.p.
292 C. IR, /cm–1: 3050—3650 (OH), 1721 (C=O), 1637
(C=N), 1597 (C=C). Found (%): C, 51.25; H, 3.47; N, 11.08.
C32H24N6NiO2Se2•H2O. Calculated (%): C, 50.59; H, 3.42;
N, 11.06.
Bis[3ꢀbenzylꢀ5ꢀ(2ꢀpyridylmethylidene)ꢀ2ꢀselenoimidazolidinꢀ4ꢀ
one]copper(II) (12c). Compound 12c (0.078 g, 37%) was obꢀ
tained from compound 5b (0.1 g, 0.3 mmol), KOH (0.017 g,
0.3 mmol), and CuCl2•2H2O (0.03 g, 0.5 mmol) as a brown
powder. M.p. 282 C. IR, /cm–1: 3000—3600 (OH), 1714
(C=O), 1637 (C=N), 1587 (C=C). MS (MALDI), m/z (Irel (%)):
747 [M]+ (100).
Bis[3ꢀbenzylꢀ5ꢀ(4ꢀpyridylmethylidene)ꢀ2ꢀselenoimidazolidinꢀ4ꢀ
one]cobalt(II) (12d). Compound 12d (0.074 g, 54%) was obtained
from compound 5d (0.125 g, 0.37 mmol), KOH (0.02 g, 0.37 mmol),
and CoCl2•6H2O (0.043 g, 0.18 mmol) as a dark brown powder.
M.p. >350 C. IR, /cm–1: 1717 (C=O), 1630 (C=N), 1606
(C=C). EAS, /nm (/L mol–1 cm–1): 435.5 (4800), 595.5 (470),
621 (430), 660 (370). MS, m/z: 744 [M + H]+. Found (%):
C, 52.07; H, 3.63; N, 10.76. C32H24CoN6O2Se2. Calculated (%):
C, 51.82; H, 3.24; N, 11.34.
Bis[3ꢀbenzylꢀ5ꢀ(4ꢀpyridylmethylidene)ꢀ2ꢀselenoimidazolidinꢀ4ꢀ
one]copper(II) (12e). Compound 12e (0.128 g, 93%) was obꢀ
tained from compound 5d (0.125 g, 0.37 mmol), KOH (0.02 g,
0.37 mmol), and CuCl2•2H2O (0.031 g, 0.18 mmol) as a brown
powder. M.p. 284—286 C. IR, /cm–1: 1723 (C=O), 1643 (C=N),
1588 (C=C). EAS, /nm (/L mol–1 cm–1): 437.5 (1400).
Found (%): C, 52.36; H, 3.52; N, 11.16. C32H24CuN6O2Se2.
Calculated (%): C, 51.47; H, 3.22; N, 11.26.
Reaction of 3ꢀbenzylꢀ2ꢀ(methylseleno)ꢀ5ꢀpyridylmethylideneimidꢀ
azolꢀ4ꢀones 7a—c with CuCl2, CoCl2 and NiCl2 (general proceꢀ
dure). A solution of a metal salt (0.5 equiv.) in EtOH (5 mL) was
added to a solution of 3ꢀbenzylꢀ5ꢀpyridylmethyleneꢀ2ꢀ(methylꢀ
seleno)imidazolꢀ4ꢀone 7a—c (1 equiv.) in EtOH (5 mL). The
reaction mixture was refluxed until a precipitate was formed.
The precipitate was filtered off, washed with water and EtOH,
and dried in air.
Bis[3ꢀbenzylꢀ5ꢀ(2ꢀpyridylmethylidene)ꢀ2ꢀ(methylseleno)imidꢀ
azolꢀ4ꢀone]cobalt(II) dichloride (13a). Compound 13a (0.052 g,
48%) was obtained from compound 7a (0.14 g, 0.4 mmol) and
CoCl2 (0.025 g, 0.196 mmol) as a brown powder. M.p. 210 C.
IR, /cm–1: 1717 (C=O), 1664 (C=N), 1586 (C=C). Found (%):
C, 49.01; H, 3.48; N, 10.14. C34H30Cl2CoN6O2Se2. Calculatꢀ
ed (%): C, 48.46; H, 3.56; N, 9.98.
Bis[3ꢀbenzylꢀ5ꢀ(2ꢀpyridylmethylidene)ꢀ2ꢀ(methylseleno)imidꢀ
azolꢀ4ꢀone]copper(II) dichloride (13b). Compound 13b (0.06 g,
56%) was obtained from compound 7a (0.14 g, 0.4 mmol)
and CuCl2 (0.026 g, 0.2 mmol) as a light brown powder. M.p.
182 C. IR, /cm–1: 3300—3600 (OH), 1717 (C=O), 1664
Reaction of 3ꢀbenzylꢀ5ꢀpyridylmethylideneꢀ2ꢀselenoimidazolꢀ
idinꢀ4ꢀones 5b—d with CuCl2•2H2O, CoCl2•6H2O, and
NiCl2•6H2O (general procedure). Potassium hydroxide (1 equiv.)
was added to a solution of 3ꢀbenzylꢀ5ꢀpyridylmethyleneꢀ2ꢀseleꢀ
noimidazolidinꢀ4ꢀone 5b—d in EtOH. After KOH dissolved,
a metal salt (0.5 equiv.) in EtOH was added to the reacꢀ

1192
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 6, June, 2012
Steklov et al.
(C=N), 1635 (C=C). Found (%): C, 45.97; H, 3.24; N, 9.47.
C34H30Cl2CuN6O2Se2•2H2O. Calculated (%): C, 46.18;
H, 3.88; N, 9.51.
2. R. Gouriprasanna, B. K. Sarma, P. Phadnis, G. J. Mugesh,
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Moura, D. V. DerVartanian, B. H. Huynh, H. D. Peck,
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Stadtman, Biochem., 1998, 37, 3518.
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10. M. Koketsu, A. Takahashi, H. Ishihara, J. Heterocycl. Chem.,
2007, 44, 79.
11. E. K. Beloglazkina, S. Z. Vatsadze, A. G. Mazhuga, N. A.
Frolova, R. B. Romashkina, N. V. Zyk, A. A. Moiseeva,
K. P. Butin, Russ. Chem. Bull., Int. Ed., 2005, 54, 2771 [Izv.
Akad. Nauk, Ser. Khim., 2005, 2679].
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Chem., 2001, 40, 628.
Bis[3ꢀbenzylꢀ5ꢀ(3ꢀpyridylmethylidene)ꢀ2ꢀ(methylseleno)imidꢀ
azolꢀ4ꢀone]cobalt(II) dichloride (13c). Compound 13c (0.079 g,
73%) was obtained from compound 7b (0.11 g, 0.3 mmol)
and CoCl2 (0.019 g, 0.15 mmol) as a brown powder. M.p.
256 C. IR, /cm–1: 3300—3600 (OH), 1720 (C=O), 1631
(C=N), 1600 (C=C). Found (%): C, 46.16; H, 3.81; N, 9.36.
C34H30Cl2CoN6O2Se2•2H2O. Calculated (%): C, 46.49; H, 3.90;
N, 9.57.
Bis[3ꢀbenzylꢀ5ꢀ(3ꢀpyridylmethylidene)ꢀ2ꢀ(methylseleno)imidꢀ
azolꢀ4ꢀone]copper(II) dichloride (13d). Compound 13d (0.079 g,
73%) was obtained from compound 7b (0.11 g, 0.3 mmol)
and CuCl2 (0.021 g, 0.15 mmol) as a green powder. M.p.
250 C. IR, /cm–1: 3300—3600 (OH), 1720 (C=O), 1643
(C=N), 1594 (C=C). Found (%): C, 46.21; H, 3.17; N, 9.54.
C34H30Cl2CuN6O2Se2•2H2O. Calculated (%): C, 46.18; H, 3.88;
N, 9.51.
Bis[3ꢀbenzylꢀ5ꢀ(3ꢀpyridylmethylidene)ꢀ2ꢀ(methylseleno)imidꢀ
azolꢀ4ꢀone]nickel(II) dichloride (13e). Complex compound 13e
(0.057 g, 53%) was obtained from compound 7b (0.11 g, 0.3 mmol)
and NiCl2 (0.019 g, 0.15 mmol) as a light green powder. M.p.
280 C. IR, /cm–1: 3100—3600 (OH), 1714 (C=O), 1643
(C=N), 1597 (C=C). EAS, /nm (/L mol–1 cm–1): 490.5
(1200), 464 (1250). Found (%): C, 46.01; H, 3.28; N, 9.14.
C34H30Cl2N6NiO2Se2•2H2O. Calculated (%): C, 46.47; H, 3.87;
N, 9.57.
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2nd ed., John Wiley and Sons, New York—London—Sydꢀ
ney, 1966.
14. A. G. Majouga, E. K. Beloglazkina, S. Z. Vatsadze, A. A.
Moiseeva, F. S. Moiseev, K. P. Butin, N. V. Zyk, Mendeleev
Commun., 2005, 15, 48.
Bis[3ꢀbenzylꢀ5ꢀ(4ꢀpyridylmethylidene)ꢀ2ꢀ(methylseleno)imidꢀ
azolꢀ4ꢀone]copper(II) dichloride (13f). Compound 13f (0.068 g,
69%) was obtained from compound 7c (0.109 g, 0.3 mmol)
and CuCl2 (0.021 g, 0.15 mmol) as a black powder. M.p.
204 C. IR, /cm–1: 3200—3650 (OH), 1720 (C=O), 1634
(C=N), 1609 (C=C). Found (%): C, 45.66; H, 4.17; N, 9.73.
C34H30Cl2CuN6O2Se2•2H2O. Calculated (%): C, 46.18; H, 3.88;
N, 9.51.
15. E. K. Beloglazkina, A. G. Majouga, I. V. Yudin, N. A. Froꢀ
lova, N. V. Zyk, V. D. Dolzhikova, A. A. Moiseeva, R. D.
Rakhimov, K. P. Butin, Russ. Chem. Bull., Int. Ed., 2006, 55,
1015 [Izv. Akad. Nauk, Ser. Khim., 2006, 978].
16. R. HerbstꢀIrmer, G. M. Scheldrick, Acta Crystallogr., 1998,
B54, 443.
17. M. J. Korohoda, Pol. J. Chem., 1981, 55, 359.
18. A. I. Khodair, Carbohydrate Res., 2001, 331, 445.
19. L. F. Tietze, T. Eicher, Reaktionen und Synthesen im orgaꢀ
nishꢀchemischen Praktikum und Forschungslaboratorium,
Georg Thieme Verlag, Stuttgart—New York, 1991.
This work was financially supported by the Russian
Foundation for Basic Research (Project No. 10ꢀ03ꢀ00677ꢀa).
References
1. V. A. Potapov, S. V. Amosova, Zh. Org. Khim., 2003, 39,
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Received December 22, 2010;
in revised form January 20, 2012