ISSN 1070-4272, Russian Journal of Applied Chemistry, 2015, Vol. 88, No. 4, pp. 657−660. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © V.N. Postnov, E.B. Naumysheva, A.S. Litvinov, O.A. Krokhina, 2015, published in Zhurnal Prikladnoi Khimii, 2015, Vol. 88, No. 4,
AND ION EXCHANGE PROCESSES
At present fullerenes are among the most demanded
products of carbon nanotechnologies. They serve to create
composite materials, diamond ﬁ lms, polymer coatings
and are also used in biology, medicine, and pharmacy.
New stationary phases for gas chromatography and
chemical sensors have been developed on their basis
. However, an important factor restricting the wide
practical application of fullerenes is the high cost resulting
from speciﬁ c features of their synthesis, puriﬁ cation, and
Fullerenes are separated by liquid chromatography, with
silicas modiﬁ ed by various organic (pentabromobenzyl,
pyrenyl) groups used as sorbents. The high cost of
these sorbents is due to their difﬁ cult preparation and
expenditure for synthesis of the modiﬁ ers being used.
Therefore, development of new, simpler methods for
obtaining sorbents having pyrenyl groups in their
structure is a topical task. Of interest in this regard is the
chemical assembly technique successfully employed both
to synthesize multicomponent layers on the silica surface
[2, 3] and to obtain grafted organic surface compounds
[4–9]. In contrast to the immobilization method, this
synthetic approach makes it possible to use simpler
modiﬁ ers and is based on performing a sequence of
chemical reactions involving grafted functional groups.
The goal of our study was to develop a procedure for
synthesis of a sorbent containing pyrenyl groups by the
chemical assembly method and to examine this sorbent
in the course of a chromatic separation of C
The sorbent was synthesized from KSK-G silica gel
= 350 m
, pore radius 14 nm, 0.2–0.3 mm fraction).
To achieve a high density of grafting of organic radicals
in syntheses of sorbents intended for a chromatographic
separation of fullerenes, the silica gel surface was
hydroxylated by acid treatment with hydrochloric acid.
According to the results of a gravimetric analysis,
the concentration of hydroxy groups increased upon
hydroxylation from 5.6 to 8.2 μmol m
, in agreement
Chemical Assembly of Pyrenyl Groups on Silica
Surface and Application of a Modiﬁ ed Sorbent
for Chromatographic Separation
of Light Fullerenes
V. N. Postnov, E. B. Naumysheva, A. S. Litvinov, and O. A. Krokhina
Institute of Chemistry, St. Petersburg State University,
Universitetskii pr. 26, Petrodvorets, St. Petersburg, 198504 Russia
Received December 15, 2014
Abstract—Procedure for modifying the silica gel surface with pyrenyl groups, based on a chemical assembly of
surface compounds, was developed. The procedure includes successive treatments of silica with (2-phenylethyl)
trichlorosilane, water, chloromethyl methyl ether, and pyrene. The reaction conditions providing the maximum
content of grafted pyrenyl groups were determined. The possibility of using the resulting modiﬁ ed silica gel as a
sorbent in chromatographic separation of C
fullerenes was examined and its high efﬁ ciency in obtaining
fullerenes was demonstrated.