Synthesis and spectral-kinetic investigation of fulgimide-based photochromic autocomplexes of the dinitroquinoline series

Article abstract of DOI:10.1007/s11172-008-0187-4

Two new hybrid compounds, which belong to autocomplexes of the dinitroquinoline series and contain an NH spacer and fragments of photochromic fulgimides as donor components, were synthesized. These autocomplexes were used as ligands in the synthesis of cobalt-containing metal chelates. The spectral-kinetic study revealed that these compounds exhibit photochromism. The introduction of photochromic fulgimide moieties into the autocomplexes has no substantial effect on the spectral properties of the latter but influences the kinetics of photochromic transformations by decreasing their efficiency. Chelate complexes of the hybrid compounds with cobalt ions are characterized by the lowest efficiency of photochromic transformations due to a decrease in the intensity of activating radiation as a result of its absorption by the dinitroquinoline moieties, which are not conjugated with fragments of photochromic compounds.

Full text of DOI:10.1007/s11172-008-0187-4

Russian Chemical Bulletin, International Edition, Vol. 57, No. 7, pp. 1444—1450, July, 2008
1444
Synthesis and spectralꢀkinetic investigation of fulgimideꢀbased
photochromic autocomplexes of the dinitroquinoline series
I. G. Ilyina,a V. V. Mel´nikov,a S. I. Luyksaar,b M. M. Krayushkin,b
Yu. A. P´yankov,c V. A. Barachevsky,c and I. V. Fedyanind
aDepartment of Chemistry, M. V. Lomonosov Moscow State University,
1 Leninskie Gory, 119992 Moscow, Russian Federation.
Fax: +7 (495) 939 0290. Еꢀmail: igi@org.chem.msu.ru
bN. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences,
47 Leninsky prosp., 119991 Moscow, Russian Federation.
Fax: +7 (495) 137 6939. Еꢀmail: mkray@ioc.ac.ru
cPhotochemistry Center, Russian Academy of Sciences,
7a ul. Novatorov, 119421 Moscow, Russian Federation.
Fax: +7 (495) 936 1255. Eꢀmail: barva@photonics.ru
dA. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences,
28 ul. Vavilova, 119991 Moscow, Russian Federation.
Fax: +7 (499) 135 5085
Two new hybrid compounds, which belong to autocomplexes of the dinitroquinoline series and
contain an NH spacer and fragments of photochromic fulgimides as donor components, were
synthesized. These autocomplexes were used as ligands in the synthesis of cobaltꢀcontaining metal
chelates. The spectralꢀkinetic study revealed that these compounds exhibit photochromism.
The introduction of photochromic fulgimide moieties into the autocomplexes has no substantial
effect on the spectral properties of the latter but influences the kinetics of photochromic transformaꢀ
tions by decreasing their efficiency. Chelate complexes of the hybrid compounds with cobalt ions are
characterized by the lowest efficiency of photochromic transformations due to a decrease in
the intensity of activating radiation as a result of its absorption by the dinitroquinoline moieties, which
are not conjugated with fragments of photochromic compounds.
Key words: synthesis, photochromism, autocomplexes, photochromic fulgimides, dinitroquinoꢀ
line, metal chelates, cobalt, electronic spectroscopy, Xꢀray diffraction study.
Scheme 1
Organic photochromic compounds have found inꢀ
creasing use due primarily to their interesting properꢀ
ties.1 In recent years, particular attention has been given
to the synthesis and investigation of the properties of
thermally irreversible photochromic compounds, in parꢀ
ticular, of fulgimides, which undergo reversible valence
photoisomerization resulting in the transformation of the
open form A into the cyclic form B (Scheme 1).2—4
The colorless open form A is transformed into the
colored cyclic form B under UV irradiation (hν). The
latter form is again transformed into the starting colorless
state under visible light irradiation (hν1).
A
Due to thermal stability of the forms A and B, fulgimꢀ
ides are of particular interest for the design of different
types of photoswitches, including recording media for
optical memory.3,4
In the present study, we investigated the spectralꢀ
kinetic properties of the newly synthesized hybrid comꢀ
B
pounds, which can be assigned, according to the accepted
classification,5 to organic intramolecular chargeꢀtransfer
compounds or autocomplexes. Molecules of these comꢀ
pounds are characterized by the simultaneous presence
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1417—1423, July, 2008.
1066ꢀ5285/08/5707ꢀ1444 © 2008 Springer Science+Business Media, Inc.

Fulgimideꢀbased photochromic autocomplexes
Russ.Chem.Bull., Int.Ed., Vol. 57, No. 7, July, 2008
1445
Scheme 2
of electronꢀwithdrawing and electronꢀreleasing fragments
separated by a spacer. Such structures can be considered
as convenient model systems, in which the targeted change
in the degree of intramolecular charge transfer is one of
the possible ways of controlling the electronic properties
of these compounds.
In the present study, we investigated autocomplexes
of the dinitroquinoline series containing an NH spacer
and fragments of photochroꢀ
mic fulgimides as donor
components. Earlier,6 we
have reported the synthesis
and investigation of the charꢀ
acteristic features of the doꢀ
norꢀacceptor interactions in
numerous autocomplexes of
this series containing donor moieties of different nature
and strength. Based on the results of the detailed spectroꢀ
scopic study, it was established that the charge transfer in
these compounds can occur both via the direct polar
conjugation through the bridging nitrogen atom and
through space between the closely spaced fragments of
the autocomplexes.
In the present study, we used the fulgides, 3ꢀ(Z)ꢀ[αꢀ
(2,5ꢀdimethylꢀ3ꢀthienyl)ethylidene]ꢀ4ꢀisopropylideneꢀ
tetrahydrofuranꢀ2,5ꢀdione (1a) and its benzothiophene
analog 1b, as the starting compounds (Scheme 2). The
reactions of these compounds with Bocꢀphenylenediꢀ
amine 2 were carried out under reflux in benzene for
20 h. Then the reaction mixture was concentrated, the
residue was dissolved in a mixture of dichloromethane
and ethanol and filtered through silica gel, and the solꢀ
vent was distilled off. The resulting mixture of amido
acids was dissolved in THF, 1.1 equiv. of N,N´ꢀcarbonylꢀ
diimidazole (CDI) was added, and the reaction mixture
was allowed to stand at room temperature for 24 h.
The product was isolated by silica gel flash chromatoꢀ
graphy. This method was used to synthesize Bocꢀamiꢀ
nophenylfulgimides 3a,b in 80—85% yields. In the fiꢀ
nal step of the synthesis of aminophenylfulgimides,
the Boc protection was removed by the reaction with
a 5 M ethanolic HCl solution followed by the treatꢀ
ment of the resulting hydrochlorides with a methanoꢀ
lic ammonia solution. Amines 4a,b were obtained in
80—90% yields.
1, 3, 4: R1 = Me, R2 = H (a); R1R2 = —(CH=CH)2— (b)
Boc = ButOCO
Scheme 3
Then 8ꢀchloroꢀ5,7ꢀdinitroquinoline (7) was syntheꢀ
sized starting from 8ꢀhydroxyquinoline (5) by successive
transformations through 8ꢀhydroxyꢀ5,7ꢀdinitroquinoline
(6) according to known procedures7—9 (Scheme 3). The
reaction of compound 7 with amines 4a,b was carried out
by refluxing equimolar amounts of the starting reagents
in a mixture of acetone and ethanol. After partial evapoꢀ
ration of the reaction mixture, the colored precipitates of
autocomplexes 8a,b were filtered off and crystallized from
an appropriate solvent.
We also used autocomplex 9 as a model compound
(its synthesis and spectral properties have been described
in our earlier study6) and chelate CoII complexes (8a•Co,
8b•Co, and 9•Co), which were synthesized by the reacꢀ
tions of autocomplexes 8a,b and 9 as ligands with cobalt
acetate in an appropriate organic solvent.

1446
Russ.Chem.Bull., Int.Ed., Vol. 57, No. 7, July, 2008
Ilyina et al.
Results and Discussion
bands of this autocomplex and compounds 8a,b are virtuꢀ
ally identical (see Table 1). The UV irradiation of comꢀ
Compound 4a is characterized by the most intense
absorption band with a maximum at 250 nm and two
longerꢀwavelength bands at 280 (sh) and 340 nm (sh) in
the UVꢀspectral region for the open form A and an abꢀ
sorption band with a maximum at 520 nm in the visible
spectral region for the cyclic form B (Fig. 1). The reꢀ
placement of the thiophene fragment (compound 4a) with
the benzothiophene fragment (compound 4b) leads to
a slight hypsochromic shift of the absorption band of
the cyclic form (Table 1).
The absorption spectra of the open form of autocomꢀ
plexes 8a,b, which were synthesized based on compounds
4a,b, respectively, show a new absorption band in the
visible region at 425 nm (Fig. 2, curve 1), which coinꢀ
cides with the absorption band of model autocomplex 9
(see Table 1). In the UVꢀspectral region, the absorption
A
0.6
0.4
1
0.2
2
300
400
500
600
700
λ/nm
Fig. 1. Spectra of the starting (1) and colored (2) forms of amine 4a
in MeCN (1•10–4 mol L–1). The cell path length was 2 mm.

Fulgimideꢀbased photochromic autocomplexes
Russ.Chem.Bull., Int.Ed., Vol. 57, No. 7, July, 2008
1447
Table 1. Spectralꢀkinetic characteristics of the compounds
max
max
Comꢀ
pound
Solvent
λ
λ
kAB
kBA
kpd
A
B
nm
s–1
4а
4b
8а
8а•Co
8b
8b•Co
9
9•Co
MeCN
MeCN
MeCN
MeCN
MeCN
MeCN
Toluene
Toluene
250, 280 sh, 340 sh
220, 290 sh, 335 sh
<300, 340 sh, 425
<300, 350, 490
220, 260, 340 sh, 420
330, 420, 480
522
480
0.010
0.001
0.006
0.030
0.010
0.040
—
0.0020
0.0002
0.0300
0.0200
0.0200
0.0200
—
0.0060
0.0003
0.0020
0.0020
0.0004
0.0004
—
~460—600
~490—540
~450—550
~490—540
—
300 sh, 380 sh, 420
370, 440, 500
—
—
—
—
Note. λ max and λ max are the absorption maxima of the starting (A) and photoinduced (B) forms; kAB, kBA, and kpd are
A
B
the rate constants of photocoloration, photobleaching, and photodegradation, respectively.
pounds 8a,b in solution through an UFSꢀ2 light filter
causes a weak absorption in the 460—600 nm region
(see Fig. 2, curve 2, Table 1).
8b•Co in solution under visible light irradiation in the
region of photoinduced absorption of these compounds
(through a ZhSꢀ12 light filter) is substantially higher (the
rate constants differ by one—two orders of magnitude)
than that of photochromic fulgimides 4a,b (see Table 1).
The study of photodegradation of the reaction prodꢀ
ucts showed that the stability of photochromic benꢀ
zothiopheneꢀcontaining compounds 4b and 8b to photoꢀ
degradation is an order of magnitude higher than that of
the corresponding thiopheneꢀsubstituted compounds 4a
and 8a (see Table 1). The efficiency of photodegradation
of chelate complexes 8a•Co and 8b•Co is virtually idenꢀ
tical to that of compounds 8a,b (see Table 1), which
indicates that metal has no effect on the mechanism of
phototransformations of these compounds.
An analysis of the spectralꢀkinetic data suggested the
absence of conjugation between two fragments of the
hybrid photochromic compounds due to the presence of
the phenyl spacer between the photochromic electronꢀ
releasing fragment and the electronꢀwithdrawing dinitroꢀ
quinoline moiety. In this case, the low efficiency of phoꢀ
tochromic transformations of the hybrid compounds and
their chelates can be attributed to intense absorption of
The corresponding chelates 8a•Co and 8b•Co are
also characterized by insignificant photoinduced spectral
changes in the visible spectral region (Fig. 3). As can be
seen from a comparison of the absorption spectra preꢀ
sented in Fig. 3, the absorption spectrum of the starting
form of the chelates is determined primarily by the abꢀ
sorption identical to the absorption spectrum of comꢀ
pound 9•Co (see Fig. 3, curve 3).
It was found that the slight photoinduced change in
the absorbance in the visible spectral region of solutions
of both hybrid compounds 8a,b and their chelate comꢀ
plexes 8a•Co and 8b•Co is reversible. This follows from
the results of investigation of the coloration kinetics of
solutions under UV irradiation and the bleaching kinetꢀ
ics under visible light irradiation, as evidenced by the
measured rate constants of these phototransformations
(see Table 1). Solutions of the chelate complexes are
characterized by the highest photocoloration rates (see
Table 1). The rate of photoinduced bleaching of comꢀ
pounds 8a,b and their chelate complexes 8a•Co and
A
A
2.5
2.0
2.5
2.0
1.5
1.0
0.5
1.5
2
1.0
0.5
1
3
1
2
300
400
500
600
700
λ/nm
300
400
500
600
700
λ/nm
Fig. 2. Absorption spectra of the starting (1) and colored (2) forms of
a solution of autocomplex 8a in MeCN (1•10–4 mol L–1). The cell
path length was 10 mm.
Fig. 3. Absorption spectra of the starting (1) and colored (2) forms
of a solution of complex 8a•Co and a solution of complex 9•Co (3)
in MeCN (1•10–4 mol L–1). The cell path length was 10 mm.

1448
Russ.Chem.Bull., Int.Ed., Vol. 57, No. 7, July, 2008
Ilyina et al.
Table 2. Selected bond lengths (d) and bond angles (ω) in comꢀ
pound 8a
activating radiation by the dinitroquinoline fragments
showing absorption in the same UVꢀspectral region as the
fulgimide fragments, which are not conjugated with the
dinitroquinoline fragments. The intermolecular excitaꢀ
tion energy transfer between the unconjugated but closely
spaced fragments cannot be ruled out.
To confirm the threeꢀdimensional structure and its
influence on the photochromic properties, we studied
compound 8a by Xꢀray diffraction. The principal geoꢀ
metric parameters of the dinitroquinoline, Nꢀphenylꢀ
substituted maleinimide, and dimethylthiophene fragꢀ
ments are similar to those expected for related comꢀ
pounds (Fig. 4, Table 2). The conjugation between the
maleinimide and phenyl substituents is absent because
the rings are twisted with respect to one another by 53.4°,
like in most of analogous compounds (information from
the Cambridge Structural Database10). The conjugation
between the phenyl and quinoline fragments through the
N(4) atoms is also weak, if presents at all. The rings are
twisted with respect to one another by 43.9°.
The observed conformation of the molecule is staꢀ
bilized mainly by the following intramolecular inꢀ
teractions: the moderateꢀstrength hydrogen bond
N(4)—H(4N)...N(1) (N...N, 2.576(4) Å) and the shortꢀ
ened O(4)...C(10) and O(5)...C(23) intramolecular
contacts (2.738 and 2.945 Å, respectively). There is
also the shortened C(21)...C(29) distance (smaller
than the sum of the van der Waals radii of the carbon
atoms; 3.42 Å) between the methyl substituents of
the thiophene fragment. The disordered ethanol solvent
molecule is not involved in hydrogen bonding. Weak
Bond
d/Å
Bond
d/Å
N(1)—C(1)
1.321(4)
1.337(4)
1.457(4)
1.350(4)
1.439(4)
1.367(4)
1.396(4)
1.375(4)
1.441(4)
1.408(4)
N(5)—C(19)
C(16)—O(5)
C(19)—O(6)
C(17)—C(20)
C(20)—C(23)
C(22)—C(23)
C(22)—S(1)
S(1)—C(25)
C(18)—C(28)
1.400(4)
1.195(4)
1.207(4)
1.357(4)
1.483(5)
1.364(5)
1.715(3)
1.723(4)
1.339(4)
N(1)—C(9)
C(9)—C(8)
C(8)—N(4)
N(4)—C(10)
C(10)—C(11)
C(11)—C(12)
C(12)—C(13)
C(13)—N(5)
N(5)—C(16)
Angle
ω/deg
Angle
ω/deg
C(7)—C(8)—N(4)
128.4(3) N(5)—C(19)—C(18) 106.1(3)
C(8)—N(4)—C(10) 131.0(3) C(16)—C(17)—C(20) 122.6(3)
N(4)—C(10)—C(11) 122.5(3) C(17)—C(20)—C(23) 122.1(3)
C(12)—C(13)—N(5) 120.3(3) C(23)—C(22)—S(1)
C(13)—N(5)—C(16) 122.7(3) C(22)—S(1)—C(25)
111.3(3)
92.1(2)
C(19)—N(5)—C(16) 113.3(2) C(19)—C(18)—C(28) 122.8(3)
N(5)—C(16)—C(17) 105.5(3)
O...π and C—H...O interactions are the major intermoꢀ
lecular contacts.
To conclude, we synthesized four new hybrid comꢀ
pounds, including chelate complexes containing the diniꢀ
troquinoline and photochromic fulgimide fragments.
C(30)
O(6)
O(3)
O(4)
C(28)
C(19)
C(29)
C(21)
N(3)
C(7)
C(6)
C(15) C(14)
C(13)
O(2)
O(1)
C(18)
C(17)
N(5)
N(4) C(10)
C(5)
C(4)
N(2)
C(8)
C(9)
H(4N)
C(11) C(12)
C(3)
C(16)
C(26)
N(1)
C(20)
C(23)
C(24)
C(1)
C(2)
O(5)
C(22)
C(25)
S(1)
C(27)
Fig. 4. General view of the Xꢀray diffraction structure of molecule 8a. The hydrogen atoms (except for H(4N)) are omitted.

Fulgimideꢀbased photochromic autocomplexes
Russ.Chem.Bull., Int.Ed., Vol. 57, No. 7, July, 2008
1449
one (3a). A mixture of fulgide 1a (2 g, 7.2 mmol) and pꢀ(tertꢀ
butoxycarbonylamino)aniline (2) (1.57 g, 7.54 mmol) was refluxed
in benzene (50 mL) for 20 h. Then benzene was distilled off on
a rotary evaporator. The residue was dissolved in dichloromethane,
SiO2 (15 g) was added, and dichloromethane was distilled off on
a rotary evaporator. The reaction mixture immobilized on silica gel
was transferred onto a 8ꢀcm glass filter, which was packed with silica
gel (40—63 μm) to a height of 4 cm and placed into a roundꢀbottom
flask connected to a waterꢀjet vacuum pump through a pipe.
A mixture of amido acids was washed from silica gel in vacuo, and
a mixture of dichloromethane and ethanol (40 : 1) was poured
portionwise (100 mL) onto a filter. The fractions were collected in
individual flasks. The fractions containing amido acids were comꢀ
bined (TLC monitoring; a dichloromethane—ethanol mixture, 40 : 1,
as the eluent; Rf for amide acids was ~0.3), and the eluent was
distilled off on a rotary evaporator. The residue was dissolved in
THF (50 mL), and CDI (1.28 g, 7.9 mmol) was added. The reaction
mixture was stirred at room temperature for 24 h, and THF was
distilled off on a rotary evaporator. After silica gel flash chromatogꢀ
raphy (hexane—ethyl acetate mixture, 5 : 1, as the eluent), fulgimide
3a was obtained in a yield of 2.87 g (85%) as paleꢀyellow crystals,
m.p. 208—211 °C. 1H NMR, δ: 1.49 (s, 9 H, C(CH3)3); 2.02, 2.12,
2.33, 2.39, and 2.47 (all s, 3 H each, CH3); 6.48 (s, 1 H, NH); 6.54
The Xꢀray diffraction study revealed that there is no conꢀ
jugation between the fragments separated by the phenyl
spacers. The spectralꢀkinetic data show that solutions of
these compounds in acetonitrile are characterized by
a substantially lower efficiency of photochromic transꢀ
formations compared to the starting fulgimides. This fact
can be responsible for a decrease in the intensity of radiꢀ
ation activating photochromic transformations due to
radiation absorption by the dinitroquinoline fragments.
The influence of the structures of the photochromic comꢀ
pounds under consideration on their spectralꢀkinetic
properties was established.
Experimental
The absorption spectra were measured on a Cary 50 spectroꢀ
photometer (Varian) in 1.0ꢀcm cells at room temperature. Toluene
and acetonitrile (Aldrich) were used as the solvents. The concentraꢀ
tions of the solutions used for measuring the absorption spectra were
1•10–4 mol L–1. The solutions were irradiated with filtered radiaꢀ
tion from a DRShꢀ250 mercury gasꢀdischarge lamp. The light filters
for isolation of mercury lines were chosen based on the positions of
the absorption bands of the compounds under study.
(s, 1 H, HAr); 6.97 (d, 1 H, HAr, J = 6.8 Hz); 7.24 (d, 1 H, HAr
,
J = 7.5 Hz); 7.30 (t, 1 H, HAr, J = 8.3 Hz); 7.41 (s, 1 H, HAr). MS,
m/z (Irel (%)): 467 [M + 1]+ (3), 466 [M]+ (18), 411 (9), 307 (22),
306 (100), 224 (12). Found (%): C, 67.04; H, 6.55; N, 6.04.
C26H30N2O4S. Calculated (%): C, 66.93; H, 6.48; N, 6.00.
1ꢀ(4ꢀAminophenyl)ꢀ3ꢀ[(Z)ꢀ1ꢀ(2,5ꢀdimethylꢀ3ꢀthienyl)ethylꢀ
idene]ꢀ4ꢀisopropylidenepyrrolidineꢀ2,5ꢀdione (4a). Fulgimide 3a
(1 g, 2.14 mmol) was dissolved with stirring in a 5 M ethanolic HCl
solution (75 mL) and kept at room temperature for 12 h. Then the
reaction mixture was concentrated to dryness on a rotary evaporator,
the residue was dissolved in methanol (30 mL), and a 5 M methanꢀ
olic NH3 solution (10 mL) was added. The mixture was concentratꢀ
ed to dryness on a rotary evaporator, diethyl ether (30 mL) was
added to the residue, and the precipitate was filtered off and washed
on a filter with diethyl ether (2×20 mL). The filtrate was concentratꢀ
ed on a rotary evaporator. Fulgimide 4a was obtained in a yield of
The IR spectra were measured on an IR 200 Fourierꢀtransꢀ
form spectrophotometer (ThermoNikolet, USA) in KBr pellets
at 2 cm–1 resolution; the number of scans was 64.
1
The H NMR spectra were recorded on a Bruker WMꢀ250
radiospectrometer (250 MHz) in CDCl3. The EI mass spectra were
obtained on a Kratos MSꢀ30 instrument using a direct inlet system;
the ionizing voltage was 70 eV; the emission current was 0.1 mA;
the ionization chamber temperature was 250 °C. The melting
points were measured on a Boetius hotꢀstage apparatus and are
uncorrected.
The reaction mixtures were analyzed and the purity of
the reaction products was checked by TLC on Silufol UVꢀ254 plates.
3ꢀ(Z)ꢀ[1ꢀ(2,5ꢀDimethylꢀ3ꢀthienyl)ethylidene]ꢀ4ꢀisopropylꢀ
idenetetrahydrofuranꢀ2,5ꢀdione (1a) was synthesized according
to a known procedure.11 The yield was 28%, paleꢀyellow crystals,
m.p. 154—156 °C (chloroform—hexane) (cf. lit. data11: m.p.
155—156 °C).
0.71 g (91%) as colorless crystals, m.p. 150—151 °C. IR, ν/cm–1
:
3369 (NH2), 3056 (CH arom.), 2984—2856 (CH3), 1695 (CO of
1
amide). H NMR, δ: 2.01, 2.10, 2.31, 2.38, and 2.44 (all s, 3 H
4ꢀIsopropylideneꢀ3ꢀ(Z)ꢀ[1ꢀ(2ꢀmethylꢀ3ꢀbenzothienyl)ethylꢀ
idene]tetrahydrofuranꢀ2,5ꢀdione (1b) was synthesized according to
a known procedure.12 The yield was 20%, white crystals, m.p.
174—176 °C (cf. lit. data12: m.p. 173—176 °C).
NꢀBocꢀpꢀPhenylenediamine (2) was synthesized according to
a known procedure.13 The yield was 72%, white powder, m.p.
113—114 °C (cf. lit. data13: m.p. 114—115 °C).
each, CH3); 3.70 (s, 2 H, NH2); 6.52 (s, 1 H, HAr); 6.76 (d, 2 H,
HAr, J = 7.4 Hz); 7.10 (d, 2 H, HAr, J = 8.0 Hz). MS, m/z (Irel (%)):
367 [M + 1]+ (11), 366 [M]+ (24), 351 (83), 217 (90), 189 (100).
Found (%): C, 69.14; H, 6.22; N, 7.57. C21H22N2O2S. Calculatꢀ
ed (%): C, 68.83; H, 6.05; N, 7.64.
1ꢀ{4ꢀ[(tertꢀButoxycarbonyl)amino]phenyl}ꢀ4ꢀisopropylideneꢀ
3ꢀ[(Z)ꢀ1ꢀ(2ꢀmethylꢀ3ꢀbenzothienyl)ethylidene]pyrrolidineꢀ2,5ꢀdiꢀ
one (3b). A mixture of (2.26 g, 7.2 mmol) fulgide 1b and pꢀ(tertꢀ
butoxycarbonylamino)aniline (2) (1.57 g, 7.54 mmol) was refluxed
in benzene (50 mL) for 20 h and then worked up as described above
to prepare compound 3a. After silica gel flash chromatography
(hexane—ethyl acetate mixture, 5 : 1, as the eluent), fulgimide 3b
was obtained in a yield of 2.90 g (80%), m.p. 219—220 °C.
1H NMR, δ: 1.52 (s, 9 H, C(CH3)3); 2.16, 2.24, 2.46, and 2.53
8ꢀHydroxyꢀ5,7ꢀdinitroquinoline (6) was synthesized according
to a known procedure.7 The yield was 64%, yellowꢀgreen powder,
m.p. 276—277 °C (with decomp.) (cf. lit. data8: m.p. 276—279 °C).
8ꢀChloroꢀ5,7ꢀdinitroquinoline (7) was synthesized according
to a known procedure.9 The yield was 87%, large transparent
crystals, m.p. 157 °C (cf. lit. data8: m.p. 158 °C; cf. lit. data9: m.p.
154 °C). 1H NMR (DMSOꢀd6), δ:9 9.27 (dd, 1 H, H(2), J2,3 = 4.0 Hz,
J2,4 = 1.5 Hz); 9.03 (s, 1 H, H(6)); 8.93 (d, 1 H, H(4), J3,4 = 8.9 Hz);
8.02 (d, 1 H, H(3), J3,4 = 8.9 Hz).
(all s, 3 H each, CH3); 6.51 (s, 1 H, NH); 6.59 (d, 2 H, HAr
,
J = 7.5 Hz); 7.00 (d, 2 H, HAr, J = 7.8 Hz); 7.12—7.48 (m, 3 H,
HAr); 7.75 (d, 1 H, HAr, J = 9.1 Hz). MS, m/z: 502 [M]+.
Found (%): C, 69.54; H, 6.03; N, 5.81. C29H30N2O4S. Calculatꢀ
ed (%): C, 69.30; H, 6.02; N, 5.57.
Compound 9 has been described in our earlier study.6
1ꢀ{4ꢀ[(tertꢀButoxycarbonyl)amino]phenyl}ꢀ3ꢀ[(Z)ꢀ1ꢀ(2,5ꢀdiꢀ
methylꢀ3ꢀthienyl)ethylidene]ꢀ4ꢀisopropylidenepyrrolidineꢀ2,5ꢀdiꢀ

1450
Russ.Chem.Bull., Int.Ed., Vol. 57, No. 7, July, 2008
Ilyina et al.
1ꢀ(4ꢀAminophenyl)ꢀ3ꢀisopropylideneꢀ4ꢀ[(Z)ꢀ1ꢀ(2ꢀmethylꢀ3ꢀ
benzothienyl)ethylidene]pyrrolidineꢀ2,5ꢀdione (4b). Compound 3b
(1 g, 2 mmol) was worked up as described above in the synthesis of
compound 4a. Fulgimide 4b was obtained in a yield of 0.65 g (82%)
as colorless crystals, m.p. 239—241 °C. IR, ν/cm–1: 3374 (NH2),
3057 (CH arom.), 2990—2852 (CH3), 1703 (CO of amide).
1H NMR, δ: 2.15, 2.21, 2.45, and 2.52 (all s, 3 H each, CH3); 3.58
a = 10.153(4) Å, b = 8.165(3) Å, c = 35.72(1) Å, β = 90.002(1)°,
3
V = 2961.3(18) Å , dcalc = 1.412 g cm–3, space group P21/c, Z = 4.
The intensities of 20017 reflections were measured on an automated
Smart 1000 CCD diffractometer at 110 K (MoꢀKα radiation, graphꢀ
ite monochromator, ωꢀscanning technique, 2θmax = 54°), of which
6447 observed reflections (Rint = 0.160) were used in the calculaꢀ
tions. The monoclinic angle β is close to 90°, but Rint for the
orthorhombic system is 0.575, which is indicative of the monoclinic
system. The refinement of the occupancies of two possible twin
components (TWIN instructions, BASF) gave 0.00 for the second
component. The structure was solved by direct methods and refined
by the fullꢀmatrix leastꢀsquares method with anisotropic and isotroꢀ
pic displacement parameters based on F2. The hydrogen atoms were
positioned geometrically. The H(4N) atom was located in a differꢀ
ence Fourier map. All hydrogen atoms were refined using a riding
model. The positions of the atoms of the disordered ethanol solvent
molecule were refined using a rigidꢀbody model with the fixed
geometric parameters determined for the crystal structure of ethanol.
The lowest reliability factors were obtained by superposing three
components with an occupancy ratio of 0.55 : 0.25 : 0.2. The final
(s, 2 H, NH2); 6.59 (d, 2 H, HAr, J = 7.5 Hz); 7.00 (d, 2 H, HAr
,
J = 7.8 Hz); 7.12—7.48 (m, 3 H, HAr); 7.75 (d, 1 H, HAr
,
J = 9.1 Hz). MS, m/z (Irel (%)): 402 [M]+. Found (%): C, 71.65;
H, 5.53; N, 6.80. C24H22N2O2S. Calculated (%): C, 71.62; H, 5.51;
N, 6.96.
Synthesis of autocomplexes 8a,b. A solution of equimolar
amounts of dinitrochloroquinoline 7and the corresponding amine 4a,b
in chloroform was heated to reflux, cooled, and concentrated by
a factor of 2—3. The colored precipitates that formed were filtered off
and crystallized from the appropriate solvent (acetonitrile or ethanol).
3ꢀ[(Z)ꢀ1ꢀ(2,5ꢀDimethylꢀ3ꢀthienyl)ethylidene]ꢀ1ꢀ{4ꢀ[(5,7ꢀ
dinitroꢀ8ꢀquinolyl)amino]phenyl}ꢀ4ꢀisopropylidenepyrrolidineꢀ2,5ꢀ
dione (8a). The yield was 80%, orange crystals, m.p. 253—255 °C
(MeCN). IR, ν/cm–1: 3242 (NH), 3110—3056 (CH arom.),
R factors were R1 = 0.0674 (based on F2 for 2531 observed
hkl
2986—2858 (CH3), 1702 (CO of amide), 1336—1315 (ν NO2),
reflections with I > 2σ(I)), wR2 = 0.1094, GOF = 0.907. All
calculations were carried out with the use of the SHELXTL PLUS
5.1 program package.14
s
1595—1542 (νas NO2). Found (%): C, 61.03; H, 4.28; N, 12.05.
C30H25N5O6S. Calculated (%): C, 61.74; H, 4.32; N, 12.00.
1ꢀ{4ꢀ[(5,7ꢀDinitroꢀ8ꢀquinolyl)amino]phenyl}ꢀ4ꢀisopropylꢀ
ideneꢀ3ꢀ[(Z)ꢀ1ꢀ(2ꢀmethylꢀ1ꢀbenzothiophenꢀ3ꢀyl)ethylidene]ꢀ
pyrrolidineꢀ2,5ꢀdione (8b). The yield was 82%, brightꢀyellow powder,
m.p. 250—253 °C. IR, ν/cm–1: 3195 (NH), 3108—3049 (CH arom.),
This study was financially supported by the Russian
Foundation for Basic Research (Project No. 04ꢀ03ꢀ32845).
2988—2839 (CH3), 1712 (CO of amide), 1330—1312 (ν NO2),
References
s
1570—1540 (νas NO2). Found (%): C, 63.93; H, 3.99; N, 10.90.
C33H25N5O6S. Calculated (%): C, 63.96; H, 4.07; N, 11.30.
Synthesis of chelate compounds (general procedure). A solution
of the corresponding autocomplex in acetone was added to a hot
methanolic solution of cobalt acetate tetrahydrate in a ratio of 1 : 2
using a small excess with respect to 8a,b or 9. The reaction mixture
was heated to reflux and then allowed to slowly cool and evaporate
in air. The crystals were filtered off and successively washed with
methanol and water.
1. V. A. Barachevskii, Khim. Vysok. Energii, 2003, 37, 10 [High
Energy Chem., 2003, 37 (Engl. Transl.)].
2. B. Otto, K. RuckꢀBraun, Eur. J. Org. Chem., 2003, 2409.
3. R. Matsushima, H. Sakaguchi, J. Photochem. Photobiol. A,
1997, 108, 239.
4. Y. Yokoyama, Chem. Rev., 2000, 100, 1717.
5. Ya. F. Freimanis, Organicheskie soedineniya s vnutrimolekulꢀ
yarnym perenosom zaryada [Organic Compounds with Intramoꢀ
lecular Charge Transfer], Zinatne, Riga, 1985, 190 pp.
(in Russian).
6. I. G. Ilyina, V. V. Mel´nikov, B. N. Tarasevich, K. P. Butin,
Zh. Org. Khim., 2006, 42, 1016 [Russ. J. Org. Chem., 2006, 42,
996 (Engl. Transl.)].
7. R. P. Dikshoorn, Recl. Trav. Chim. PaysꢀBas, 1929, 48, 550.
8. H. Hennig, J. Tauchnitz, K. Schone, Z. Chem., 1971, 267.
9. N. L. Khilkova, V. N. Knyazev, N. S. Patalakha, V. N. Drozd,
Zh. Org. Khim., 1992, 28, 1048 [Russ. J. Org. Chem., 1992, 28
(Engl. Transl.)].
10. F. H. Allen, Acta Crystallogr., 2002, B58, 380.
11. A. P. Glaze, S. A. Harris, H. G. Heller, W. Johncock, S. N.
Oliver, P. J. Strydom, J. Whittall, J. Chem. Soc., Perkin Trans. 1,
1985, 957.
12. M. Kose, E. Orhan, J. Photochem. Photobiol. A, 2006, 177, 170.
13. F. Troisi, A. Russo, C. Gaeta, G. Bifulco, P. Neri, Tetrahedron
Lett., 2007, 48, 7986.
14. G. M. Sheldrick, SHELXTL v. 5.10, Structure Determination
Software Suite, Bruker AXS, Madison, Wisconsin, USA.
Bis{3ꢀ[(Z)ꢀ1ꢀ(2,5ꢀdimethylꢀ3ꢀthienyl)ethylidene]ꢀ1ꢀ{4ꢀ[(5,7ꢀ
dinitroꢀ8ꢀquinolyl)amino]phenyl}ꢀ4ꢀisopropylidenepyrrolidineꢀ2,5ꢀ
dionato}diaquacobalt(II) hexahydrate (8a•Co). The yield was 80%,
redꢀbrown powder, m.p. >300 °C (with decomp.). IR, ν/cm–1
:
3110—3070 (CH arom.), 2987—2858 (CH3), 1710 (CO of amide),
1320—1274 (ν NO2), 1597—1526 (νas NO2). Found (%): C, 52.26;
s
H, 3.97; N, 9.71. C60H64CoN10O20S2. Calculated (%): C, 52.67;
H, 4.70; N, 10.24.
Bis{1ꢀ{4ꢀ[(5,7ꢀdinitroꢀ8ꢀquinolyl)amino]phenyl}ꢀ4ꢀisopropylꢀ
ideneꢀ3ꢀ[(Z)ꢀ1ꢀ(2ꢀmethylꢀ1ꢀbenzothiophenꢀ3ꢀyl)ethylidene]ꢀ
pyrrolidineꢀ2,5ꢀdionato}diaquacobalt(II) (8b•Co). The yield was
65%, redꢀbrown powder, m.p. >300 °C (with decomp.). IR, ν/cm–1
:
3104—3064 (CH arom.), 2986—2850 (CH3), 1710 (CO of amide),
1320—1280 (ν NO2), 1596—1525 (νas NO2). Found (%): C, 60.48;
s
H, 3.86; N, 9.77. C66H52CoN10O14S2. Calculated (%): C, 59.50;
H, 3.93; N, 10.50.
Bis[5,7ꢀdinitroꢀ8ꢀ(phenyl)aminoquinolinato]cobalt(II) (9•Co).
The yield was 81%, black crystals with green luster, m.p. 239—241
°C. IR, ν/cm–1: 3117—3074 (CH arom.), 1597—1527 (νas NO2),
1320—1269 (ν NO2). Found (%): C, 53.28; H, 2.90; N, 16.40.
s
C30H18CoN8O8. Calculated (%): C, 53.19; H, 2.68; N, 16.54.
Xꢀray diffraction study of compound 8a. The crystals
(C30H25N5O6S, M = 583.636) are monoclinic, at 110 K,
Received July 20, 2007;
in revised form May 14, 2008