Synthesis and photochromic properties of thiosemicarbazide and thiocarbazate derivatives of dithienylperfluorocyclopentene

Article abstract of DOI:10.1007/s11172-010-0203-3

A number of new thiosemicarbazide and thiocarbazate derivatives of dithienylperfluorocyclopentene have been synthesized. Spectral-kinetic study of photochemical transformations of these compounds was performed. All the compounds obtained exhibit photochromic properties. Dependencies of spectral characteristics of two thermally stable forms and kinetic properties of photocoloration and photodegradation processes from the nature of substituents affecting the conjugated bonds length in the molecules were found.

Full text of DOI:10.1007/s11172-010-0203-3

Russian Chemical Bulletin, International Edition, Vol. 59, No. 5, pp. 1047—1050, May, 2010
1047
Synthesis and photochromic properties of thiosemicarbazide
and thiocarbazate derivatives of dithienylperfluorocyclopentene
M. M. Krayushkin,a B. V. Lichitskii,a A. A. Dudinov,a O. Yu. Kuznetsova,a
O. I. Kobeleva,b T. M. Valova,b and V. A. Barachevskiib
aN. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences,
47 Leninsky prosp., 119991 Moscow, Russian Federation.
Fax: +7 (499) 135 5328. Eꢀmail: mkray@ioc.ac.ru
bPhotochemistry Center, Russian Academy of Sciences,
7a ul. Novatorov, 119421 Moscow, Russian Federation.
Fax: +7 (495) 936 1255. Eꢀmail: barva@photonics.ru
A number of new thiosemicarbazide and thiocarbazate derivatives of dithienylperfluoroꢀ
cyclopentene have been synthesized. Spectralꢀkinetic study of photochemical transformations
of these compounds was performed. All the compounds obtained exhibit photochromic propꢀ
erties. Dependencies of spectral characteristics of two thermally stable forms and kinetic
properties of photocoloration and photodegradation processes from the nature of substituents
affecting the conjugated bonds length in the molecules were found.
Key words: synthesis, photochromism, sulfurꢀcontaining diarylethenes, photocoloration,
photobleaching, photodegradation.
Thermally irreversible photochromic compounds from
the class of diarylethenes (DAE) possessing unique therꢀ
mal stability of the photoinduced form remain the most
promising for the use in various fields of photonics,1 in
particular, for development of registration media for optiꢀ
cal memory with superhigh information capacity,2 photoꢀ
switches of various types.3 Development of photoactive
coordination compounds is one of important problems in
the creation of optoelectronic devices.4 Photocontrolled
systems of this type with the use of photochromic organic
compounds and nanoparticles of noble metals are of speꢀ
cial interest. For accomplishing efficient molecular interꢀ
action of photochromic compounds with nanoparticles of
noble metals, as a rule, derivatives of photochromic comꢀ
pounds with thiol groups are used, that creates certain
difficulties in accomplishing their synthesis.5—7
Diarylethenes 1—7 were obtained from dithienylperfluoroꢀ
cyclopentene 8 and different thiosemicarbazide derivatives or
methyl dithiocarbazate (Scheme 1). Aldehyde 8 was obtained
according to the procedure described earlier.8
A mixture of aldehyde 8 (0.06 g, 0.14 mmol) and the
corresponding thiosemicarbazide or methyl dithiocarbazate
Scheme 1
In the present work, results of spectralꢀkinetic study of
photochromic transformations in the series of sulfurꢀconꢀ
taining DAE without thiol substituents are represented
for the first time.
Experimental
1H NMR spectra were recorded on a Bruker AMꢀ300
spectrometer (300 MHz) in DMSOꢀd6. Melting points were
measured on a Boetius heating stage and uncorrected. Reaction
course and purity of compounds obtained were monitored by TLC
(Merck Silica gel 60 F254 plates, eluent: ethyl acetate—hexane).
R = NH2 (1), NHPh (2), 4ꢀMeC6H4NH (3), 2ꢀMeC6H4NH (4),
4ꢀFC6H4NH (5), 2ꢀFC6H4NH (6), SMe (7)
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1023—1025, May, 2010.
1066ꢀ5285/10/5905ꢀ1047 © 2010 Springer Science+Business Media, Inc.

1048
Russ.Chem.Bull., Int.Ed., Vol. 59, No. 5, May, 2010
Krayushkin et al.
Table 1. Yields, melting points, 1H NMR spectroscopic (DMSOꢀd6) and elemental analysis data for compounds 1—7
Comꢀ Yield
pound (%)
M.p.
/°С
Found
Calculated
Molecular
formula
1H NMR
(δ, J/Hz)
(%)
С
H
N
1
2
68
62
254—256
>300
40.12
39.99
51.70
51.51
2.94
2.83
3.41
3.35
14.86
14.73
11.80
11.63
C19H16F6N6S4
C31H24F6N6S4
1.98 (s, 6 Н, 2 СН3); 7.57 (s, 2 H, СННеt);
8.34 (s, 2 H, CH); 13.32 (s, 2 H, NH2)
1.98 (s, 6 Н, 2 СН3); 7.15 (m, 2 Н, arom.);
7.39 (m, 4 Н, arom.); 7.57 (m, 4 Н, arom.,
2 Н, СННеt); 8.28 (s, 2 Н, СН); 9.80
(s, 2 Н, NH); 11.89 (s, 2 Н, NH)
3
4
54
56
>300
>300
52.85
52.79
3.89
3.76
11.24
11.19
C33H28F6N6S4
1.92 (s, 6 Н, 2 СН3); 2.29 (s, 6 Н, 2 СН3);
7.12 (d, 4 H, arom., J = 7.2); 7.42 (d, 4 H,
arom., J = 7.2); 7.54 (s, 2 H, СННеt); 8.28
(s, 2 H, CH); 9.72 (s, 2 H, NH); 11.87 (s,
2 H, NH)
1.98 (s, 6 Н, 2 СН3); 2.21 (s, 6 Н, 2 СН3);
7.12—7.38 (m, 8 H, arom.); 7.52 (s, 2 H, СННеt);
8.28 (s, 2 H, CH); 9.68 (s, 2 H, NH); 11.86
(s, 2 H, NH)
52.96
52.79
3.87
3.76
11.32
11.19
C33H28F6N6S4
5
6
66
60
>300
>300
49.28
49.07
3.15
2.92
11.39
11.08
C31H22F8N6S4
C31H22F8N6S4
1.92 (s, 6 Н, 2 СН3); 7.18 (m, 4 H, arom.); 7.51
(m, 4 H, arom.); 7.54 (s, 2 H, СННеt); 8.28 (s,
2 H, CH); 9.81 (s, 2 H, NH); 11.90 (s, 2 H, NH)
1.92 (s, 6 Н, 2 СН3); 7.13—7.30 (m, 6 H, arom.);
7.54 (s, 2 H, СННеt); 7.58—7.64 (m, 2 H, arom.);
8.28 (s, 2 H, CH); 9.72 (s, 2 H, NH); 12.05 (s,
2 H, NH)
49.19
49.07
3.22
2.92
11.27
11.08
7
64
>300
40.13
39.86
2.99
2.87
8.94
8.85
C21H18F6N4S6
1.92 (s, 6 Н, 2 СН3); 2.48 (s, 6 Н, 2 СН3); 7.58
(s, 2 H, СННеt); 8.36 (s, 2 H, CH); 13.32 (s, 2 H,NH)
Scheme 2
(0.29 mmol) in ethanol (3 mL) was refluxed for 4 h. Then the
reaction mixture was cooled, a precipitate formed was filtered
off. Basic physicoꢀchemical characteristics of compounds 1—7
obtained are given in Table 1.
Dimethyl sulfoxide (DMSO) was used for obtaining solutions
of photochromic DAE. A working concentration of these
solutions was 2•10–4 mol L–1
.
Spectralꢀkinetic studies of the processes of DAE photoꢀ
coloration, photobleaching, and photodegradation in solution
were performed using Varian Cary 50 bio spectrophotometer in
0.2ꢀcm quartz cuvettes. Irradiation was made by filtered and
nonfiltered light of the Hamamatsu LCꢀ4 lamp.
A
2.0
1.5
1.0
0.5
Results and Discussion
1
It is known that photochromic DAE perfluorocycloꢀ
pentеne derivatives undergo reversible isomerization
between two thermally stable forms:1 open (A) and cyclic
(В) (Scheme 2).
Results of comparative spectralꢀkinetic studies of phoꢀ
tochromic transformations of DAE in DMSO at the same
concentration of compounds in solution (2•10–4 mol L–1
are given in Figs 1—3, as well as in Table 2.
2
300
400
500
600
700
λ/nm
)
Fig. 1. Absorption spectra for compound 1 in DMSO before (1)
and after irradiation by the UV light through a light filter
UFSꢀ1 (2).
Typical absorption spectra of the starting open and
photoinduced cyclic forms are shown in Fig. 1, whereas

Synthesis and photochromic properties of diarylethenes Russ.Chem.Bull., Int.Ed., Vol. 59, No. 5, May, 2010
1049
A
kinetics of the reversible photoinduced transformations
between these forms, in Fig. 2.
0.8
0.6
0.4
0.2
From Table 2, it follows that introduction of an aryl
fragment onto amino derivative 1 in all the cases leads
(compounds 2—6) to a bathochromic shift of the absorpꢀ
tion bands of both the open and cyclic forms, which is
due to the increase of conjugation in the DAE molecules
containing the aryl substituent. Introduction of a methyl
group at different positions of the benzene ring (comꢀ
pounds 3 and 4) results in the hypsochromic shift of the
absorption band of the cyclic form, which apparently is
due to the lowering conjugation because of electronꢀ
donating effect of the methyl substituent. Replacement of
the methyl groups with the fluorine atoms (compounds 5
and 6) leads to the opposite effect, which confirms influꢀ
ence of the electronic factor.
1
2
25 50
0
500
1000 1500 2000
t/s
Fig. 2. Kinetics of the photocoloration under influence of the
UV light through a light filter UFSꢀ1 (1) and photobleaching
under influence of the visible light through a light filter
OSꢀ12 (2) for the solution of compound 1 on the wavelength
660 nm in DMSO.
A/Amax
The largest bathochromic shift of the absorption band
of the open form is found for compound 7, in which
the amino group was exchanged for the methylsulfanyl
group.
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
All the compounds studied possess comparable light
sensitivity to the UV irradiation, which is indicated by the
phot
close to each other ΔAВ
values. For the most comꢀ
pounds, the phototransformation process of the open form
to cyclic is described by the exponential curve. Aminoꢀ
substituted DAE 1, apparently possessing the lowest steric
hindrance in photoisomerization, is characterized by the
highest rate constant.
200
400
600
800
t/s
Attention should be paid to a decrease in the effiꢀ
ciency of DAE photodegradation after introduction of
methyl substituents onto the aryl fragment. Fluorination,
as well as replacement of the amino group with the
methylsulfanyl group, on the contrary, reduce stability of
compounds to the irreversible photochemical transforꢀ
mations (see Fig. 2). oꢀMethylphenylꢀsubstituted DAE 4
possesses the highest stability to the photodegradation
(see Fig. 3).
Fig. 3. The A/Amax value versus irradiation time with nonfiltered
light for the DAE derivatives studied in DMSO solution.
Table 2. Spectralꢀkinetic characteristics of photochromic transꢀ
formations of DAE in DMSO
max
max
phot
Comꢀ
pound
λ
λ
ΔAВ
kA—B/s–1
τ
photodeg/s
1/2
А
В
nm
In conclusion, the synthetic and spectralꢀkinetic
studies performed resulted in the first synthesis of seven
new sulfurꢀcontaining DAE, which undergo photochroꢀ
mic transformations in DMSO solution. Spectralꢀkinetic
characteristics of photochromic transformations depend
on the structures of the sulfurꢀcontaining substituents.
1
2
3
4
5
6
7
340
350
350
347
345
345
360
648
660
650
650
655
660
657
0.8
0.82
0.47
0.39
0.47
0.47
*
570
760
985
1015
590
890
550
0.6
1.0
0.8
0.7
0.9
0.6
0.29
This work was financially supported by the Russian
Foundation for Basic Research (Project No. 08ꢀ03ꢀ00660).
max
max
Note: λ
and λ
are the wavelengths of the absorption
A
В
phot
band maxima for the open (A) and cyclic (В) forms; ΔAВ
is
the maximum change of the photoinduced optical density in the
absorption band maximum of the cyclic form (В) under influꢀ
ence of the UV irradiation in the photoequilibrium state; kA—B is
the rate constant of phototransformation of the open form (A) to
References
1. M. Irie, Chem. Rev., 2000, 100, 1685.
the cyclic form (В) under influence of the UV irradiation; τ
2. В. A. Barachevskii, M. M. Krayushkin, Izv. Akad. Nauk, Ser.
Khim., 2008, 853 [Russ. Chem. Bull., Int. Ed., 2008, 57, 867].
3. M. Heilemann, P. Dedecker, J. Hofkens, M. Sauer, Laser
Photon. Rev., 2009, 3, 180.
1/
photodeg is the time for the ΔAВphot value to decrease by a factor of
2
2 under influence of the nonfiltered irradiation.
* k1 = 0.72, k2 = 0.17.

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Krayushkin et al.
4. Y. Jin, N. Friedman, J. Am. Chem. Soc., 2005, 127, 11902.
5. H. Nishi, S. Kobatake, Macromolecules, 2008, 41, 3995.
6. R. A. Pala, K. T. Shimizu, N. A. Melosh, M. L. Brongersma,
Nano Lett., 2008, 8, 1506.
8. A. Osuka, D. Fujikane, H. Shinmori, S. Kobatake, M. Irie, J.
Org. Chem., 2001, 66, 3913.
7. S. J. van der Molen, J. Liao, T. Kudernac, J. S. Agustsson, L.
Bernard, M. Calame, B. J. van Wees, B. L. Feringa, C.
Schnenberger, Nano Lett., 2009, 9, 76.
Received November 30, 2009;
in revised form February 27, 2010