ISSN 1070-3632, Russian Journal of General Chemistry, 2016, Vol. 86, No. 2, pp. 291–295. © Pleiades Publishing, Ltd., 2016.
Original Russian Text © A.V. Okhlobystina, А.О. Okhlobystin, N.N. Letichevskaya, V.F. Abdulaeva, N.О. Movchan, N.Т. Berberova, 2016, published in
Zhurnal Obshchei Khimii, 2016, Vol. 86, No. 2, pp. 263–267.
Electrochemical Synthesis of Aromatic Sulfur Compounds
in Ionic Liquids
А. V. Okhlobystinaa, А. О. Okhlobystina, N. N. Letichevskayaa,
V. F. Abdulaevaa, N. О. Movchanb, and N. Т. Berberovaa
a Astrakhan State Tecnhical University, ul. Tatishcheva 16, Astrakhan, 414025 Russia
e-mail: ionradical@gmail.com
b Southern Scientific Center, Russian Academy of Sciences, Rostov-on-Don, Russia
Received June 26, 2015
Abstract—Electrochemical properties of ionic liquids (pyridinium and imidazolium salts) and the effect of
additives of organic solvents on the electrochemical determination of organic compounds in ionic liquids have
been studied. Transformations of aromatic and aliphatic sulfur compounds in ionic liquids in the presence of
aromatic substrates are discussed. A new method has been proposed for identification of organic sulfur
compounds – gas chromatography on columns with ionic liquid as the active phase.
Keywords: ionic liquid, aromatic sulfur compound, electrochemical synthesis, extraction
DOI: 10.1134/S1070363216020146
Nowadays, the interest to ionic liquids has rapidly
emerged. Ionic liquids have been recognized for a
number of attractive advantages: they are practically
non-volatile, non-flammable, readily dissolve many
inorganic, organic, and organometallic compounds
(involving gases), they have been used as efficient
extracting agent that can be easily regenerated and
reused [1]. The ionic liquids with imidazolium
[R1R2Im]+ and pyridinium [R1R2Py]+ cations are
widely used. Most of them are highly stable and possess
lyophilic properties over a wide range of temperatures.
The possibility to vary cations and anions allows
designing of ionic liquids for specific tasks. Methyl
and n-butyl groups are most often used as the
hydrocarbon substituents R1 and R2. The anionic part
can contain different anions: Cl–, Br–, I–, PF6–, BF4–, etc.
studies. Investigation of the process of electrochemical
decomposition of [1-Bu-3-MeR1Im]+Х– (Х = PF6, BF4)
has shown that these ionic liquids are not always inert
at a carbon glass electrode, but the use of tungsten
electrode improves their stability [3].
The topicality of the search for novel methods of
synthesis of aromatic sulfur compounds (thiophenols,
thiocresols, aromatic sulfides, disulfides, etc.) is
mainly due to their valuable properties. These com-
pounds, possess antioxidant properties; on top of that,
they are precursors in the synthesis of organometallic
compounds exhibiting proliferative properties [4].
Aromatic sulfur compounds have been used for metal
protection against corrosion, as antimicrobial drugs,
photosensibilizers in color and IR photography,
accelerators of vulcanization, and inhibitors of rubber
aging [5, 6]. Among the studies on transformations of
sulfur compounds in the pyridinium and imidazolium
ionic liquids medium, the report [7] on transformation
of benzylthiol catalyzed by cobalt phthalocyanine in
the medium of imidazolium ionic liquid, leading to the
corresponding disulfide in 95% yield, is remarkable.
The use of ecologically friendly reagents is one of
the basic principles of “green” chemistry [2]. The
electrochemical synthesis is practically impossible in
the absence of solvent; ionic liquids can be used as the
alternative reaction medium, since they are electric
conductors. Being electrochemically stable, they allow
performing of electrochemical experiments over a
wide range of potentials. Physico-chemical properties
of ionic liquids and the nature of the used electrodes
are important points to be considered in electrochemical
In this work we studied the transformations of
aliphatic and aromatic sulfur compounds in the medium
of ionic liquids in order to prepare sulfur compounds
valuable for medicine.
291