Synthesis of Nanostructured Organosilicon Luminophores Based on Phenyloxazoles

Article abstract of DOI:10.1134/S1070428019010056

A series of nanostructured organosilicon luminophores (NOLs) composed of a central 1,4-bis(5-phenyl-1,3-oxazol-2-yl)benzene (POPOP) acceptor chromophore and various peripheral p-terphenyl and 2,5-diphenyl-1,3-oxazole donor fragments have been synthesized for the first time using van Leusen reaction and direct palladium-catalyzed C-arylation of oxazole ring. Due to different functionalities of the silicon branching centers, NOLs with different donor-acceptor ratios have been obtained. The synthesized structures are expected to possess good optical characteristics for use in photonics and optoelectronics.

Full text of DOI:10.1134/S1070428019010056

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2019, Vol. 55, No. 1, pp. 25–41. © Pleiades Publishing, Ltd., 2019.
Russian Text © M.S. Skorotetcky, O.V. Borshchev, G.V. Cherkaev, S.A. Ponomarenko, 2019, published in Zhurnal Organicheskoi Khimii, 2019, Vol. 55,
No. 1, pp. 40–59.
Synthesis of Nanostructured Organosilicon Luminophores
Based on Phenyloxazoles
M. S. Skorotetckya, O. V. Borshcheva, G. V. Cherkaeva, and S. A. Ponomarenkoa, b*
a Enikolopov Institute of Synthetic Polymeric Materials, Russian Academy of Sciences,
ul. Profsoyuznaya 70, Moscow, 117393 Russia
*e-mail: ponomarenko@ispm.ru
b Faculty of Chemistry, Moscow State University, Leninskie gory 1, Moscow, 119991 Russia
Received October 29, 2018; revised November 5, 2018; accepted November 11, 2018
Abstract—A series of nanostructured organosilicon luminophores (NOLs) composed of a central 1,4-bis(5-
phenyl-1,3-oxazol-2-yl)benzene (POPOP) acceptor chromophore and various peripheral p-terphenyl and 2,5-di-
phenyl-1,3-oxazole donor fragments have been synthesized for the first time using van Leusen reaction and
direct palladium-catalyzed C-arylation of oxazole ring. Due to different functionalities of the silicon branching
centers, NOLs with different donor–acceptor ratios have been obtained. The synthesized structures are expected
to possess good optical characteristics for use in photonics and optoelectronics.
Keywords: direct C-arylation, van Leusen reaction, phenyloxazole, arylsilane, luminophore, terphenyl,
POPOP.
DOI: 10.1134/S1070428019010056
Design of “molecular antennas” or “light-harvest-
ing complexes” is an extremely difficult problem of
synthetic chemistry. The term “light-harvesting
antennas” was introduced for the first time by Balzani
and Lehn [1–3]. By developing synthetic approaches
and molecular design they succeeded in obtaining
a number of high-molecular-weight dendritic struc-
tures based on metal complexes, which were capable
of intramolecular energy transfer. Due to their strong
ability to absorb visible light, the obtained materials
could be used as antennas for harvesting solar light. In
fact, this idea is not new, and it is widely utilized in
living organisms where photoinduced energy transfer
is necessary for efficient absorption of solar energy
and its transport to a reaction center which transforms
it into a chemical potential [4]. At present, just bio-
organisms possess the most complicated and perfect
energy transfer system operating like a molecular
antenna. Studies in this field offer a great potential for
the development of new ways of solar energy con-
version and storage [5–8]. Therefore, in recent time
efforts of many researchers were focused on the
synthesis and study of unique optical properties of
branched, hyperbranched, and dendritic luminescent
macromolecules [9–12] organized as light-harvesting
antennas.
A new class of organosilicon luminophores with
efficient intramolecular energy transfer has recently
been designed at the Institute of Synthetic Polymeric
Materials of the Russian Academy of Sciences [13].
These luminophores are branched or dendritic com-
pounds in which several organic luminophore frag-
ments of two types are covalently linked to each other
through silicon atoms, so that they are arranged at
a short distance and at a fixed angle with respect to
each other. One of these fragments can act as donor,
and the other, as acceptor of electronic excitation
energy. Furthermore, proper selection of luminophores
with certain characteristics could give rise to not only
efficient intramolecular energy transfer but also high
luminescence quantum yield. This makes it possible to
create so-called “nanostructured organosilicon lumino-
phores” (NOLs) [14] which are advantageous due to
a large absorption cross section and enormous pseudo-
Stokes shift.1 The latter allows the self-absorption
1
The Stokes shift is the difference between the absorption and
luminescence maxima of a chromophore; however, the absorp-
tion maximum of NOLs does not correspond to a vibrational
level from which a photon is emitted. In fact, the Stokes shift of
NOLs is the difference between the absorption maximum of the
donor fragment and luminescence maximum of the acceptor
fragment.
25

SKOROTETCKY et al.
26
I
II
III
NOL
Fig. 1. Scheme of synthesis of NOLs; R is a solubilizing alkyl substituent, and D and A are donor and acceptor fragments,
respectively.
effect to be minimized not only in concentrated solu-
tions but also in thin films and provides the possibility
of tuning such important optical characteristics as
absorption and luminescence to a required spectral
range.
in acidic medium. We previously developed a new
method for the synthesis of organosilicon phenyl-
oxazole derivatives via stepwise appending a phenyl-
oxazole fragment to obtain a structure identical to
POPOP [18, 19]. The proposed method is based on the
van Leusen synthesis of 5-substituted oxazoles from
aldehyde and subsequent palladium-catalyzed direct
arylation. As shown below, this approach turned out
to be not only applicable but fairly effective for the
synthesis of NOLs.
Phenyloxazoles and lower oligophenylenes are
promising luminophores for NOL structures. At
present, 1,4-bis(5-phenyl-1,3-oxazol-2-yl)benzene
(POPOP), p-terphenyl, and 2,5-diphenyl-1,3-oxazole
(PPO) exhibiting a high luminescence quantum yield
(Qlum) have found wide application in industry as
activators (p-terphenyl, PPO) and wavelength shifter
(POPOP) for plastic scintillators, as well as in laser
optics and high-energy physics [15, 16]. Owing to the
universal structure of NOLs, the above luminophores
can be combined in a single NOL molecule to obtain
new compounds with unique optical characteristics.
These new compounds are expected to efficiently
absorb light in the ultraviolet region corresponding to
absorption of the donor fragments and show lumines-
cence with a high quantum yield at longer wavelengths
corresponding to POPOP (λ ~420 nm). Taking the
above stated into account, the present work was aimed
at developing conditions for the synthesis of NOLs
with a central acceptor POPOP luminophore fragment
and donor p-terphenyl or PPO fragments.
The strategy of synthesis of phenyloxazole-based
NOLs can be divided into several main stages (Fig. 1).
In the first stage, functional precursor I containing
a solubilizing group R was prepared. This precursor is
a finished donor fragment (D) or it will be further
included into the donor moiety of NOL. For this
purpose, it is convenient to use various bromo or
organolithium derivatives. The next stage is the syn-
thesis of a mutlifunctional branching organosilicon
center II which can react with precursor I to give
functional monodendron III. Depending on the
number of reactive groups in the branching center,
organosilicon compounds with different numbers of
donor fragments can be obtained. From the viewpoint
of molecular design, the optimal structure is a mono-
dendron containing two donor fragment, from which
NOL with four peripheral donor fragments and one
central acceptor fragment (A) can be obtained in the
next stage. In this case, an optimal combination of the
simplicity of synthesis, good yields, and desired
optical properties is achieved. Though the synthesis of
a monodendron containing three donor fragments is
advantageous from the viewpoint of increased molar
Synthetic approaches to phenyloxazoles are well
known. Since the first synthesis of 2,5-diphenyl-
oxazole by Fischer in 1896, a vast number of its
derivatives and methods of synthesis have been
reported [17]. However, most of these methods are
unsuitable for the preparation of organosilicon deriva-
tives, as well as of other compounds that are unstable
Me
N
O
Me
3Ph
3Ph-Me2
PPO
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 55 No. 1 2019

SYNTHESIS OF NANOSTRUCTURED ORGANOSILICON LUMINOPHORES
27
absorption coefficient, it is characterized by a lower
yield, which therefore complicates the synthesis. In the
last stage, the obtained functional monodendron after
several transformations is brought into reaction with
difunctional precursor B to afford the target NOL
structure.
4-bromo-4″-(2-ethylhexyl)-1,1′:4′,1″-terphenyl (3)
was initially synthesized (Scheme 1) for the prepara-
tion of luminophores containing 3Ph donor fragments.
For this purpose, 2-ethylhexyl bromide (1) was con-
verted to the corresponding Grignard reagent by treat-
ment with magnesium in diethyl ether. The reaction
mixture was cooled to room temperature and added
dropwise to a solution of 0.82 equiv of 1,4-dibromo-
benzene and palladium catalyst, maintaining the tem-
perature below 5°C. Pure cross-coupling product 2 was
isolated by vacuum distillation in 86% yield. 1,4-Di-
bromobenzene was taken in an amount lesser than
equimolar to minimize side Wurtz reaction and sub-
stitution of the second bromine atom by 2-ethylhexyl
group. Otherwise, a large amount of residual 1,4-di-
bromobenzene could strongly complicate purification
of the product by vacuum distillation. Compound 3
was synthesized in a similar way (yield 70%). In this
case, the contribution of side double substitution was
statistical, and similar solubilities of compound 3
and disubstitution product, 4,4′′′-bis(2-ethylhexyl)-
1,1′:4′,1″:4″,1′′′-quaterphenyl, strongly complicated
the purification process. According to the GPC data,
the purity of 3 after repeated extraction from alcohol
and/or acetone was 85%. However, the remaining 15%
of non-functional quaterphenyl 3a is incapable of
being involved in further reactions, and it can be
readily separated in the next stage from monodendron
p-Terphenyl (3Ph), 2′,5′-dimethyl-1,1′:4′,1″-ter-
phenyl (3Ph-Me2), and PPO possess an attractive com-
bination of physicochemical properties from the view-
point of their use as donor fragments of NOLs. These
properties include absorption in the UV region with
a high molar absorption coefficient, high luminescence
quantum yield, and good photochemical stability.
Their absorption and emission ranges are well suited
for intramolecular energy transfer to the central ac-
ceptor fragment, which is a necessary condition for the
design of light-harvesting NOLs. Unlike PPO and
3Ph-Me2, the main drawback of 3Ph is its low solu-
bility in most organic solvents and in a polymer
matrix. Therefore, particular attention was given to the
improvement of solubility of prospective luminophores
containing p-terphenyl fragments. To solve this prob-
lem, a branched 2-ethylhexyl substituent was intro-
duced into the 3Ph fragments. The benzene rings in
PPO and 3Ph-Me2 contained short methyl groups to
simplify signal assignment in the NMR spectra.
In keeping with the proposed strategy for the
synthesis of NOLs, a soluble functional precursor,
Scheme 1.
(1) Mg, Et2O
(2) 7, Pd(dppf)Cl2
(1) Mg, THF
(2) 11, Pd(dppf)Cl2
Et
Et
Br
Br
86%
70%
Bu
Bu
Bu
Br
Et
1
2
3
Me
Br
Me
(1) Mg, THF
(2) 12, Pd(dppf)Cl2
(1) Mg, THF
Me
(2) 7, Pd(dppf)Cl2
Me
Br
Me
63%
87%
Br
Me
Me
4
5
6
(1) n-BuLi, THF, –78°C
(2) MgBr2, Et2O
Br
MgBr
SiMen(OEt)3–n
MenSi(OEt)4–n, 0–20°C
Br
Br
Br
7
8
9a (n = 1, 58%)
9b (n = 0, 46%)
SiMenCl3–n
Me
Br
(1) SOCl2; (2) DMF, 60°C
9a, 9b
Br
Br
Br
Br
Me
10a (n = 1, 95%)
10b (n = 0, 91%)
11
12
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 55 No. 1 2019

SKOROTETCKY et al.
28
reagent was added to 3 equiv of triethoxy(methyl)-
silane at –15°C. Silane 9a was isolated in 58% yield by
fractional distillation under reduced pressure. It was
then treated with excess thionyl chloride in the pres-
ence of a catalytic amount of DMF. The progress of
13 (Scheme 2) which is much more soluble in organic
solvents. Therefore, to avoid large losses of the prod-
uct on further extractions, functional precursor 3 was
used without additional purification. If necessary, pure
compound 3 can be isolated by vacuum sublimation.
1
the reaction was monitored by H NMR spectroscopy,
The progress of reactions and the purity of final and
intermediate products were monitored by gel-permea-
tion chromatography in the linear mode (molecular
weight range 100–15000, pore diameter 500 Å) with
a diode array detector. This method turned out to be
very informative, and it allowed even small molecules
with different conjugation chain lengths to be distin-
guished due to simultaneous recording of electronic
absorption spectra of all components in the range
λ 200–800 nm. As a result, we were able to determine
the optimal reaction time (reactions times of organo-
metallic reactions are often overestimated because of
the lack of appropriate monitoring) and ensure high
purity of the isolated compounds due to high sensi-
tivity of the diode array detector which is two orders
of magnitude more sensitive than the refractive index
detector.
which clearly showed disappearance of signals of
ethoxy groups in the region δ 1–4 ppm. Vacuum
distillation gave 95% of 10a with a purity of 98%
(GLC). (4-Bromophenyl)trichlorosilane (10b) was
synthesized in a similar way in an overall yield of
33.5% (over two stages) with a purity of 97%.
Functional monodendrons with 3Ph and 3Ph-Me2
donor fragments were synthesized according to a spe-
cially developed three-step procedure (Scheme 2).
Treatment of 3 and 6 with tert-butyllithium at low
temperature, followed by reaction with chlorosilane
10a or 10b gave compounds 13a–13c in 62–83% yield
(after purification by silica gel column chromatog-
raphy). In the next stage, compounds 13a–13c were
lithiated with butyllithium at –78°C in THF, and the
subsequent reaction with DMF and treatment with
1M aqueous HCl afforded benzaldehyde derivatives
14a–14c. Their yields were determined from the
1H NMR data by the appearance of a singlet at about
δ 10 ppm typical of the aldehyde proton. Compounds
14a–14c without additional purification were convert-
ed to 5-substituted oxazoles 15a–15c via van Leusen
reaction with tosylmethyl isocyanide (TosMIC). After
purification by column chromatography on silica gel
with toluene as eluent, compounds 15a–15c were
isolated in 68–88% yield.
Functional precursor with donor 3Ph-Me2 frag-
ments, 4-bromo-2′,4″,5′-trimethyl-1,1′:4′,1″-terphenyl
(6), was synthesized in a way similar to the synthesis
of 3 (Scheme 1). The Grignard compound derived
from p-bromotoluene reacted with excess 1,4-dibromo-
2,5-dimethylbenzene to obtain 4-bromo-2,4′,5-tri-
methylbiphenyl (5) which was isolated in 63% yield by
vacuum distillation. Compound 6 was prepared by the
Kumada reaction of p-dibromobenzene with the
Grignard reagent derived from 5. Pure compound 6
was isolated in 87% yield after recrystallization from
ethanol.
Taking into account that oxazole derivatives are
capable of being involved in various side reactions
under lithiation conditions, functional monodendrons
with PPO donor fragments were synthesized according
to a different procedure. In this case, the organosilicon
branching centers were tris(4-bromophenyl)methyl-
silane (16a) and tetrakis(4-bromophenyl)silane (16b)
which were obtained by monolithiation of 1,4-di-
bromobenzene, followed by treatment with trichloro-
(methyl)- or tetrachlorosilane (Scheme 3). According
to the GPC data, the yields of 16a and 16b were almost
quantitative provided that the temperature conditions
were strictly met, so that compounds 16a and 16b
could be used without additional purification. Mono-
lithiation of 16a and 16b and subsequent reaction with
DMF gave aldehydes 17a and 17b which were isolated
in 68 and 73% yield, respectively, by silica gel column
chromatography with toluene as eluent. In the next
stage, the aldehyde group in 17a and 17b was pro-
An appropriate branching center was necessary to
combine functional precursors 3 and 6 to a target
organosilicon light-harvesting antenna. As such
branching centers we used (4-bromophenyl)(dichloro)-
(methyl)silane (10a) and (4-bromophenyl)trichloro-
silane (10b). Compounds 10a and 10b were prepared
through the corresponding ethoxysilanes, (4-bromo-
phenyl)(diethoxy)(methyl)silane (9a) and (4-bromo-
phenyl)(triethoxy)silane (9b). Due to simple isolation
of ethoxysilanes and high yields, this approach turned
out to be more convenient and effective than the direct
synthesis of chlorosilanes.
Compound 9a was synthesized by lithiation of
1,4-dibromobenzene (7) with butyllithium in THF at
–78°C, followed by treatment with anhydrous magne-
sium dibromide. The resulting solution of Grignard
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 55 No. 1 2019

SYNTHESIS OF NANOSTRUCTURED ORGANOSILICON LUMINOPHORES
29
Scheme 2.
R
(1) t-BuLi, THF, –78°C
(2) 10a, 10b
3, 6
Alk
SiMen
Br
62–83%
R
3–n
13a–13c
R
(1) n-BuLi, THF, –78°C
(2) DMF, 1 M HCl
Alk
SiMen
CHO
82–91%
R
3–n
14a–14c
R
TosMIC, MeOH/THF
K2CO3, reflux
O
Alk
SiMen
68–88%
N
R
3–n
15a–15c
n = 1 (a, c), 0 (b); R = H, Alk = 2-ethylhexyl (a, b); R = Alk = Me (c); TosMIC is 4-methylbenzenesulfonylmethyl isocyanide.
Scheme 3.
(1) n-BuLi, THF, –78°C
(2) MenSiCl4–n
(1) n-BuLi, THF, –78°C
(2) DMF, 1 M HCl
7
Br
SiMen
Br
Br
SiMen
CHO
90–96%
68–73%
3–n
3–n
16a, 16b
OH
17a, 17b
Me
Me
OH
O
O
Me
Me
TsOH, PhH, reflux
Br
SiMen
93–98%
3–n
18a, 18b
n = 1 (a), 0 (b).
tected by acetalization with 2,2-dimethylpropane-1,3-
diol in boiling benzene in the presence of p-toluene-
sulfonic acid with simultaneous removal of liberated
water by azeotropic distillation. The choice of 5,5-di-
methyl-1,3-dioxane protecting group was dictated by
its higher stability in comparison to 1,3-dioxolane
protection (with the use of ethylene glycol) which may
be partially removed during chromatographic purifica-
tion on silica gel.
a result, compounds 21a–21c with protected aldehyde
group were obtained (Scheme 4). Particular attention
was given to the purification of these compounds,
since the presence of incompletely substituted products
or initial reactants could give rise to by-products in the
next stages, which could complicate purification of the
target products. The dioxane protecting group was
removed in aqueous acetone under acidic conditions.
The progress of the reaction was monitored by TLC
1
on silica gel, as well as by H NMR spectroscopy,
Compounds 18a and 18b were subjected to direct
arylation with functional precursors 20a and 20b
which were prepared previously by the van Leusen
reaction from the corresponding benzaldehydes. As
following the appearance of a characteristic signal at
δ ~10 ppm due to the aldehyde proton. Since the reac-
tion is reversible, in no case complete removal of the
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 55 No. 1 2019

SKOROTETCKY et al.
30
protecting group was achieved. On the other hand, the
dioxane protecting group prevents compounds 21a–
21c from reacting in the next stage, so that they can be
isolated in the pure state. Aldehydes 22a–22c were
converted to oxazoles 23a–23c according to van
Leusen. Compounds 23a–23c were isolated in 75–97%
yield after purification by silica gel column chro-
matography.
thoroughly purified by recrystallization from dioxane
(compounds 25 and 27 with 3Ph donor fragments) or
silica gel chromatography (compounds 24, 26, 28, and
29 with 3Ph-Me2 and PPO donor fragments); after
purification, the yields of 24–28 were 58‒88%, while
NOL 29 was isolated in 17% yield. The low isolated
yield of the latter may be due to complex purification
procedure which we failed to optimize, whereas the
reaction yield was no less than 86%. Unlike the other
NOLs that are readily soluble in such organic solvents
as toluene, THF, and chloroform, compound 28 was
appreciably soluble (>5 wt %) only in chloroform. Its
solubility in THF was as low as 1.9 g/L, and it was
even less soluble in toluene. Therefore, it was purified
Thus, we have successfully synthesized unsym-
metrical functional monodendrons 15a–15c and 23a–
23c with an oxazole fragment in the focal point. In the
final stage, compounds 15a–15c and 23a–23c were
subjected to palladium-catalyzed cross-coupling with
1,4-dibromobenzene (Scheme 5). The products were
Scheme 4.
(1) n-BuLi, THF, –78°C
(2) DMF, 1 M HCl
Br
CHO
Et
Et
74%
Bu
Bu
19
TosMIC, MeOH/THF
K2CO3, reflux
CHO
N
Alk
79–91%
O
Alk
20a, 20b
20, Alk = 2-ethylhexyl (a), Me (b).
Me
Me
O
20a, 20b, t-BuOLi
Pd(PPh3)4, dioxane
reflux
O
N
18a, 18b
O
82–92%
Alk
SiMen
3–n
21a–21c
CHO
N
HCl, acetone, reflux
89–90%
O
Alk
SiMen
3–n
22a–22c
N
TosMIC, MeOH/THF
K2CO3, reflux
O
N
75–97%
O
Alk
SiMen
3–n
23a–23c
21–23, n = 1 (a), 0 (b, c); Alk = Me (a, b), 2-ethylhexyl (c).
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 55 No. 1 2019

SYNTHESIS OF NANOSTRUCTURED ORGANOSILICON LUMINOPHORES
31
Scheme 5.
7, t-BuOLi, Pd(PPh3)4
dioxane, reflux
C6H4-p
O
15a–15c, 23a–23c
Alk
X
SiMen
17–88%
N
3–n
2
24–29
n = 1 (24–26), 0 (27–29); Alk = Me (24, 26, 28), 2-ethylhexyl (25, 27, 29);
Me
N
X =
(24);
(25, 27);
(26, 28, 29).
O
Me
by extraction first from toluene and then from
chloroform.
EXPERIMENTAL
Commercial 2.5 M and 1.6 M solutions of butyl-
lithium in hexane, a 1.6 M solution of tert-butyllithium
in pentane, thionyl chloride, (4-bromophenyl)tri-
methylsilane, tosylmethyl isocyanide (TosMIC), anhy-
drous potassium carbonate, 4-methylbenzaldehyde,
1,2-dibromoethane, 4,4′-dibromobiphenyl, 1-bromo-2-
ethylhexane, 1,4-dibromobenzene (Acros Organics),
tetrakis(triphenylphosphine)palladium(0), magnesium,
1,4-dibromo-2,5-dimethylbenzene, [1,1′-bis(diphenyl-
phosphanyl)ferrocene]dichloropalladium(II)
[Pd(dppf)Cl2], and 2,2-dimethylpropane-1,3-diol
(Sigma–Aldrich) were used without additional purifi-
cation. Ethoxysilanes manufactured by Penta Ltd. were
purified by distillation just before use. Lithium tert-
butoxide was prepared by reacting a 2.5 M solution of
butyllithium with tert-butyl alcohol in anhydrous THF,
followed by evaporation of volatile components. Tetra-
hydrofuran, dioxane, and other solvents were dried and
purified according to known procedures and were
stored over 3-Å zeolite. Compounds 5, 6, and 13c were
synthesized as described in [14].
All NOLs 24–29 are individual compounds with
a branched structure consisting of two types of
chromophores linked through silicon atoms to the
central POPOP acceptor fragment. The donor frag-
ments are different 3Ph, 3Ph-Me2, and PPO derivatives
with methyl and solubilizing 2-ethylhexyl groups. It
should be noted that the synthesized NOLs with
similar chromophore fragments are characterized by
different donor–acceptor ratios, 4:1 for 25 and 26 and
6:1 for 27 and 28.
In summary, we have successfully synthesized
a series of new nanostructured organosilicon lumino-
phores with the same central acceptor fragment
(POPOP) and different peripheral donor fragments
(p-terphenyl or PPO). The synthetic strategy included
reactions of chlorosilanes with organolithium or
organomagnesium reagents, van Leusen oxazole syn-
thesis, and palladium-catalyzed cross-coupling, which
ensured high selectivity and good reaction yields. It
should be noted that we were the first to utilize direct
CH arylation in the synthesis of NOLs. The target
conjugated structures were selected taking into account
their unique optical characteristics and appropriate
spectral range for efficient intramolecular photoin-
duced energy transfer. Compounds with different
ratios of donor p-terphenyl and 2,5-diphenyloxazole
and acceptor fragments have been obtained. The struc-
ture of intermediate and final products was confirmed
by modern physicochemical analysis methods, includ-
Silica gel with a grain size of 40–60 μm and a pore
diameter of 60 Å (Merck) was used for column chro-
matography. Thin-layer chromatography was per-
formed on Sorbfil plates (Sorbpolimer) with a lumino-
phore layer. All reactions were carried out in anhy-
drous solvents under argon unless otherwise stated.
1
The H NMR spectra were measured on a Bruker
AC-250 spectrometer at 250 MHz. The 13C and
29Si NMR spectra were recorded on a Bruker AVII-
300 spectrometer at 75.5 and 59.6 MHz, respectively.
The chemical shifts were determined relative to the
residual solvent signal. The spectra were processed by
ACDLabs software. The mass spectra (MALDI) were
obtained on a Bruker Autoflex II instrument (resolu-
tion FWHM 18000; nitrogen laser, λ 337 nm; time-of-
flight detector, reflectron mode). The final spectrum
was the sum of 300 spectra recorded for different parts
1
ing gel permeation chromatography, H, 13C, and 29Si
NMR, elemental analysis, and MALDI-TOF mass
spectrometry. The use of GPC with a sensitive diode
array detector ensured control of high purity of the
synthesized compounds. The obtained NOLs can find
application in organic photonic materials and devices
where a large absorption cross section in the UV
region (270–330 nm) and bright luminescence in the
region λ 420 nm are required [20, 21].
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SKOROTETCKY et al.
32
Me
Me
Me
Me
Me
Me
N
Si
Me
O
Me
O
Si
N
Me
Me
Me
Me
Me
Me
24
Et
Et
Bu
Bu
N
Si
Me
O
Me
O
Si
N
Bu
Et
Bu
Et
25
Me
Me
N
N
O
O
N
Si
Me
O
Me
O
Si
N
O
O
N
N
Me
Me
26
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SYNTHESIS OF NANOSTRUCTURED ORGANOSILICON LUMINOPHORES
33
Et
Et
Bu
Bu
Bu
Et
N
Si
O
O
Si
N
Et
Bu
Bu
Et
Bu
Et
27
R
R
N
R
O
N
O
N
O
Si
O
O
N
N
O
Si
O
N
N
O
R
N
R
R
28, 29
28, R = Me; 29, R = 2-ethylhexyl.
of a sample. 2,5-Dihydroxybenzoic acid (Acros, 99%)
or α-cyano-4-hydroxycinnamic acid (Acros, 99%) was
used as matrix. Gel permeation chromatography was
performed on a Shimadzu instrument (Japan) equipped
with RID-10A refractive index and SPD-M10AVP
diode array detectors and a Phenomenex column
(USA), 7.8×300 mm, packed with Phenogel (pore size
500 Å); column temperature 40°C; eluent THF, flow
rate 1 mL/min. GLC analyses were obtained on
a Khromatek Kristall 5000.2 chromatograph (Russia)
equipped with a thermal conductivity detector and
a 2-m×3-mm column packed with 5% SE-30 on
Chromaton-N-AW; carrier gas helium, flow rate
30 mL/min. The elemental compositions (C, H, N)
were determined with an accuracy of 0.3–0.5% on
a Carlo Erba 1106 automated CHN analyzer; samples
were burnt in a Schöninger flask, and an alkaline
solution of hydrogen peroxide was used as sorbent.
Silicon was determined by spectrophotometry.
1-Bromo-4-(2-ethylhexyl)benzene (2). A solution
of 60 mL (0,336 mol) of 1-bromo-2-ethylhexane (1) in
500 mL of THF was added dropwise to a suspension of
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SKOROTETCKY et al.
34
9.8 g (0.403 mol) of magnesium in 50 mL of diethyl
ether. The mixture was refluxed for 1.5 h with stirring
and added dropwise to a solution of 65 g (0.276 mol)
of 1,4-dibromobenzene and 0.58 g (2 mmol) of
Pd(dppf)Cl2 in 100 mL of diethyl ether, cooled to 0°C,
maintaining the temperature not higher than 5°C. The
cooling bath was removed, and the mixture was stirred
for 20 h and poured into a mixture of 400 mL of ice
water and 200 mL of diethyl ether. The organic phase
was separated, washed with distilled water (3×
300 mL), dried over sodium sulfate, and evaporated on
a rotary evaporator under reduced pressure. The resi-
due was purified by vacuum distillation. Yield 63.6 g
(86%), purity 98% (GLC), bp 128–130°C (6.3×
cooled to room temperature, and added to the mixture
containing lithium derivative of p-dibromobenzene.
The mixture was stirred for 30 min, allowed to warm
up to room temperature (20°C), and added dropwise to
a solution of 158 g (0.89 mol) of triethoxy(methyl)-
silane in 100 mL of THF, maintaining the temperature
not higher than 5°C. The mixture was then stirred at
room temperature, 800 mL of distilled water was
added, the organic phase was separated, and the
aqueous phase was extracted with diethyl ether (2×
800 mL). The combined extracts were washed with
water until neutral washings, dried over Na2SO4, and
evaporated on a rotary evaporator. Vacuum distillation
of the residue gave 24.12 g (58%) of 9a with a purity
1
1
10–4 bar). H NMR spectrum (CDCl3), δ, ppm (J, Hz):
of 97%, bp 71–78°C [(3–4)×10–4 bar]. H NMR spec-
0.87 m (6H), 1.26 m (8H), 1.54 m (1H), 2.49 d (2H,
J = 7.0), 7.02 m (2H, J = 8.5), 7.38 m (2H, J = 8.2).
13C NMR spectrum (CDCl3), δC, ppm: 10.73, 14.12,
22.99, 26.28, 28.77, 32.19, 39.46, 40.99, 119.19,
130.91, 131.08, 140.81. Mass spectrum: m/z 268.19
[M]+; calculated: M 268.08.
trum (CDCl3), δ, ppm (J, Hz): 0.34 s (3H), 1.23 t (6H),
3.79 m (4H, J = 7.33), 7.51 s (4H).
(4-Bromophenyl)triethoxysilane (9b) was synthe-
sized as described above for 9a using 30 g (0.127 mol)
of p-dibromobenzene, 51 mL (0.127 mol) of 2.5 M
n-BuLi in hexane, 3.36 g (0.14 mol) of magnesium,
11.76 mL (0.136 mol) of 1,2-dibromoethane, and
125 mL (0.76 mol) of tetraethoxysilane. After evapora-
tion of the solvent and other volatile components, the
residue was purified by vacuum distillation. Yield
18.67 g (46%), bp 92–97°C (3.7×10–4 bar); published
4-Bromo-4″-(2-ethylhexyl)-1,1′:4′,1″-terphenyl
(3) was synthesized as described above for compound
2 using 1.68 g (70 mmol) of magnesium, 20 g
(66.8 mmol) of 1-bromo-4-(2-ethylhexyl)benzene (2),
41.7 g (133.7 mmol) of 4,4′-dibromobiphenyl, and
0.2 g (0.3 mmol) Pd(dppf)Cl2. The product was
purified by repeated extraction from alcohol and/or
acetone. Yield 23.1 g (70%), purity ≥85% (GPC). The
product was used without additional purification.
An analytical sample of 3 was obtained by vacuum
1
data [22]: bp 104±1°C (0.64–0.65 mbar). H NMR
spectrum (CDCl3), δ, ppm (J, Hz): 1.24 t (9H, J =
7.33), 3.36 m (6H, J = 7.33), 7.54 s (4H).
(4-Bromophenyl)(dichloro)(methyl)silane (10a).
A mixture of 10 g (34.6 mmol) of compound 9a and
100 μL of DMF was heated to 60°C, and 13.6 mL
(0.188 mol) of thionyl chloride was added dropwise.
The progress of the reaction was monitored by
1H NMR, following the disappearance of signals of
ethoxy groups. The product was isolated by vacuum
distillation. Yield 8.87 g (95%), purity 98% (GLC),
bp 55–57°C (3×10-4 bar); published data [23]: bp 57°C
1
sublimation. H NMR spectrum (CDCl3), δ, ppm
(J, Hz): 0.91 m (6H), 1.24–1.44 m (8H), 1.62 m (1H,
J = 5.5), 2.60 d (2H, J = 6.7), 7.26 m (2H, J = 8.6),
7.49–7.71 m (10H). 13C NMR spectrum (CDCl3), δC,
ppm: 10.81, 14.16, 23.07, 25.45, 28.88, 32.38, 39.77,
41.09, 76.70, 77.01, 77.33, 121.51, 126.70, 127.20,
127.00, 128.60, 129.70, 131.90, 137.70, 138.50, 139.70,
140.50, 141.40. Found, %: C 74.30; H 7.08; Br 18.74.
C26H29Br. Calculated, %: C 74.10; H 6.94; Br 18.96.
1
(0.12 mbar). H NMR spectrum (CDCl3), δ, ppm:
1.02 s (3H), 7.59 m (4H).
(4-Bromophenyl)(diethoxy)(methyl)silane (9a).
A solution of 35 g (0.148 mol) of p-dibromobenzene
in 650 mL of anhydrous THF was cooled to –78°C,
60 mL (0.148 mol) of a 2.5 M solution of n-BuLi in
hexane was added dropwise at such a rate that the
temperature did not exceed –70°C, and the mixture
was stirred for 1 h at that temperature. A solution of
13.7 mL (0.159 mol) of 1,2-dibromoethane in 90 mL
of diethyl ether was added to a suspension of 3.92 g
(0.1632 mol) of magnesium in 20 mL of diethyl ether,
and the mixture was refluxed for 30 min with stirring,
(4-Bromophenyl)trichlorosilane (10b) was syn-
thesized as described above for 10a from 10 g
(31.3 mmol) of 9b. Yield 8.8 g (91%), purity 97%
1
(GLC), bp 62–64°C (4.2×10–4 bar). H NMR spec-
trum (CDCl3): δ 7.67 ppm, s (4H).
(4-Bromophenyl)bis[4″-(2-ethylhexyl)-1,1′:4′,1″-
terphenyl-4-yl](methyl)silane (13a). Compound 3,
12.79 g (25.8 mmol), was dissolved in 500 mL of
THF, and 30.7 mL (51.6 mmol) of a 1.7 M solution of
t-BuLi in pentane was added dropwise, maintaining the
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SYNTHESIS OF NANOSTRUCTURED ORGANOSILICON LUMINOPHORES
35
temperature not higher than –25°C. The mixture was
allowed to warm up to room temperature and cooled to
–78°C, and 3.137 g (11.6 mmol) of chlorosilane 10a
was added in one portion. The progress of the reaction
was monitored by GPC and TLC. After 40 min, the
cooling bath was removed, and the mixture was
allowed to warm up to room temperature, poured into
500 mL of ice water, and extracted with diethyl ether
(2×400 mL). The combined extracts were washed with
water until neutral washings, dried over Na2SO4, and
evaporated, and the residue was kept under reduced
pressure (1 mbar). The crude product, 11.49 g, was
purified by silica gel column chromatography
133.7, 135.8, 135.9, 137.00, 137.80, 139.00, 140.50,
141.30, 142.10, 145.00, 193.00. Found, %: C 86.45;
H 8.15; Si 3.24. C60H66OSi. Calculated, %: C 86.69;
H 8.00; Si 3.38.
5-(4-{[Bis(4″-(2-ethylhexyl)-1,1′:4′,1″-terphenyl-
4-yl)](methyl)silyl}phenyl)-1,3-oxazole (15a). Potas-
sium carbonate, 0.858 g (6.2 mmol), was added to
a solution of 2.58 g (3.1 mmol) of compound 14a and
0.636 g (3.2 mmol) of TosMIC in a mixture of 40 mL
of methanol and 15 mL of THF. The mixture was
refluxed for 2 h with stirring (TLC), poured into
100 mL of ice water, and extracted with diethyl ether
(2×200 mL). The combined extracts were washed with
water until neutral washings, dried over Na2SO4, and
evaporated, and the residue was purified by silica gel
column chromatography using toluene as eluent. Yield
1
(hexane–toluene, 5:1). Yield 8.0 g (80%). H NMR
spectrum (CDCl3), δ, ppm (J, Hz): 0.90–0.95 m (15H),
1.28–1.40 m (16H), 1.64 m (2H, J = 5.9), 2.61 m (4H,
J = 6.6), 7.26 m (4H, J = 8.1), 7.47 m (2H, J = 8.1),
7.55–7.62 m (6H), 7.65 m (4H, J = 8.1), 7.89 m (4H,
1
2.38 g (88%). H NMR spectrum (CDCl3), δ, ppm
(J, Hz): 0.92–0.97 m (12H), 0.98 s (3H), 1.29–1.42 m
(16H), 1.66 m (2H, J = 5.9), 2.63 d (4H, J = 6.6),
7.28 m (4H, J = 8.1), 7.45 s (1H), 7.59 m (4H, J = 8.1),
7.67–7.75 m (20H), 7.97 s (1H). 13C NMR spectrum
(CDCl3), δC, ppm: –3.29, 10.83, 14.18, 23.08, 25.48,
28.9, 32.40, 39.80, 41.11, 76.72, 77.04, 77.35, 122.09,
123.8, 126.57, 126.68, 127.35, 127.46, 128.24, 128.64,
129.05, 129.70, 134.37, 135.80, 135.90, 137.20,
137.80, 139.00, 140.00, 141.00, 141.90, 150.60,
150.60, 151.50, 151.50. Found, %: C 85.69; H 7.68;
N 1.61; Si 3.31. C62H67NOSi. Calculated, %: C 85.57;
H 7.76; N 1.61; Si 3.23.
13
J = 8.1), 7.71 s (8H). C NMR spectrum (CDCl3), δC,
ppm: –3.29, 10.84, 14.18, 21.48, 23.08, 25.48, 28.90,
32.41, 39.80, 41.12, 76.71, 77.03, 77.35, 124.55,
125.32, 126.57, 126.69, 127.35, 127.46, 128.24,
129.10, 129.70, 131.20, 134.20, 135.00, 135.80,
137.00, 137.80, 137.90, 139.40, 140.40, 141.30,
141.90. Found, %: C 80.07; H 7.65; Br 9.00; Si 2.98.
C59H65BrSi. Calculated, %: C 80.33; H 7.43; Br 9.06;
Si 3.18.
4-{[Bis(4″-(2-ethylhexyl)-1,1′:4′,1″-terphenyl-4-
yl)](methyl)silyl}benzaldehyde (14a). A solution of
1.05 g (1.2 mmol) of 13a in 20 mL of THF was cooled
to –78°C, and 0.9 mL (1.4 mmol) of a 2.5 M solution
of n-BuLi in hexane was added dropwise, maintaining
the temperature not higher than –70°C. The mixture
was stirred for 1 h at that temperature, and 0.18 mL
(2.3 mmol) of DMF was added. The mixture was
allowed to warm up to room temperature, acidified
with 1 M aqueous HCl, poured into 100 mL of ice
water, and extracted with diethyl ether (2×150 mL).
The combined extracts were washed with water until
neutral washings, dried over Na2SO4, and evaporated,
and the residue was purified by silica gel column
chromatography using toluene as eluent. Yield 0.9 g
2,2′-(Benzene-1,4-diyl)bis[5-(4-{bis[4″-(2-ethyl-
hexyl)-1,1′:4′,1″-terphenyl-4-yl](methyl)silyl}-
phenyl)-1,3-oxazole] (25). A degassed solution of
1.5 g (1.63 mmol) of compound 15a, 0.327 g
(4.1 mmol) of lithium tert-butoxide, 47 mg
(0.04 mmol) of Pd(PPh3)4, and 0.193 g (0.8 mmol) of
1,4-dibromobenzene in 20 mL of anhydrous dioxane
was refluxed for 1.5 h until complete disappearance of
the initial compound (TLC, GPC). The mixture was
poured into 200 mL of distilled water and extracted
twice with diethyl ether. The combined extracts were
washed with water until neutral washings, dried over
Na2SO4, and evaporated, and the residue was passed
through a layer of silica gel using toluene–ethyl acetate
(20:1) as eluent to remove traces of the catalyst. The
product was purified by recrystallization from dioxane.
1
(91%). H NMR spectrum (CDCl3), δ, ppm (J, Hz):
0.92–0.97 m (12H), 0.97 s (3H), 1.30–1.43 m (16H),
1.66 m (2H, J = 5.9), 2.63 m (4H, J = 6.6), 7.28 m
(4H, J = 8.1), 7.60 d (4H, J = 8.1), 7.67 m (4H, J =
8.1), 7.69–7.75 m (12H), 7.82 m (2H, J = 8.1), 7.92 m
(2H, J = 8.1), 10.1 s (1H). 13C NMR spectrum
(CDCl3), δC, ppm: –3.40, 10.84, 14.18, 23.08, 25.48,
28.90, 32.41, 39.80, 41.12, 76.72, 77.04, 77.35,
126.47, 126.66, 126.69, 127.37, 127.46, 128.77, 129.7,
1
Yield 0.91 g (61%). H NMR spectrum (CDCl3), δ,
ppm (J, Hz): 0.90–0.96 m (24H), 0.99 s (6H), 1.29–
1.42 m (32H), 1.66 m (4H, J = 5.9), 2.62 m (8H, J =
6.6), 7.28 m (8H, J = 8.8), 7.56–7.61 m (10H), 7.69–
7.75 m (36H), 7.81 m (4H, J = 8.1), 8.27 s (4H).
13C NMR spectrum (CDCl3), δC, ppm: –3.27, 10.83,
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SKOROTETCKY et al.
36
14.17, 23.07, 25.47, 28.89, 32.40, 39.79, 41.11, 76.71,
77.03, 77.35, 123.66, 124.46, 126.58, 126.68, 126.72,
127.35, 127.46, 128.68, 128.79, 129.70, 134.40,
135.80, 136.00, 137.20, 138.00, 139.40, 140.40,
141.30, 141.90, 151.70, 160.70. Found, %: C 85.81;
H 7.63; N 1.45; Si 2.93. C130H136N2O2Si2. Calculated,
%: C 86.04; H 7.55; N 1.54; Si 3.10. Mass spectrum
(MALDI-TOF): m/z 1814.69 [M]+; calculated:
M 1813.01.
7.97 s (1H). 13C NMR spectrum (CDCl3), δC, ppm:
10.78, 14.15, 23.04, 25.4, 28.84, 32.33, 39.74, 41.06,
122.14, 123.75, 126.57, 126.65, 127.33, 127.44,
128.77, 129.67, 132.47, 135.28, 136.89, 136.98,
137.73, 139.27, 140.39, 141.26, 142.04. 29Si NMR
spectrum (CDCl3): δSi –14.39 ppm. Found, %:
C 87.44; H 7.87; N 1.14; Si 2.53. C87H93NOSi. Cal-
culated, %: C 87.31; H 7.83; N 1.17; Si 2.35.
2,2′-(Benzene-1,4-diyl)bis[5-(4-{tris[4″-(2-ethyl-
hexyl)-1,1′:4′,1″-terphenyl-4-yl]silyl}phenyl)-1,3-
oxazole] (27) was synthesized as described above for
compound 25 using 3.9 g (3.19 mmol) of 15b, 0.64 g
(7.98 mmol) of lithium tert-butoxide, 62 mg
(0.05 mmol) of Pd(PPh3)4, and 0.376 g (1.59 mmol) of
1,4-dibromobenzene. The mixture was refluxed for 2 h
and evaporated, and the residue was passed through
a layer of silica gel using toluene–ethyl acetate (20:1) to
remove traces of the catalyst. The product was purified
by recrystallization from dioxane. Yield 2.41 g (68%).
1H NMR spectrum (CDCl3), δ, ppm (J, Hz): 0.86–
0.95 m (36H), 1.25–1.40 m (48H), 1.63 m (6H J =
5.9), 2.59 d (12H, J = 6.4), 7.26 m (12H, J = 7.9),
7.55–7.61 m (14H), 7.69–7.84 m (56H), 8.25 s (4H).
13C NMR spectrum (CDCl3), δC, ppm: 10.83, 14.05,
23.04, 25.66, 28.98, 32.57, 39.93, 41.18, 123.78,
126.63, 126.70, 126.80, 127.37, 127.48, 128.95,
129.69, 132.69, 135.5, 136.96, 137.11, 137.90, 139.42,
140.54, 141.30, 142.19, 151.82, 160.82. 29Si NMR
spectrum (CDCl3): δ –14.47 ppm. Found, %: C 87.93;
H 7.92; N 1.16; Si 2.14. C180H188N2O2Si2. Calculated,
%: C 87.61; H 7.68; N 1.14; Si 2.28.
(4-Bromophenyl){tris[4″-(2-ethylhexyl)-
1,1′:4′,1″-terphenyl-4-yl]}silane (13b) was synthe-
sized as described above for 13a using 24 mL
(38.4 mmol) of 1.6 M t-BuLi in pentane, 9.32 g
(18.83 mmol) of 3, and 1.65 g (5.7 mmol) of 10b. The
product was purified by silica gel column chromatog-
raphy (hexane–toluene, 5:1). Yield 5.73 g (83%).
1H NMR spectrum (CDCl3), δ, ppm (J, Hz): 0.87–
0.95 m (18H), 1.25–1.38 m (24H), 1.63 m (3H, J =
5.9), 2.59 d (6H, J = 6.7), 7.25 d (6H, J = 7.6), 7.55‒
7.61 m (10H), 7.72 m (24H). 13C NMR spectrum
(CDCl3), δC, ppm: 0.75, 14.11, 23.01, 25.38, 28.82,
32.31, 39.71, 41.03, 124.84, 126.54, 126.62, 127.3,
127.41, 129.64, 131.18, 132.27, 133.23, 136.81, 137.7,
137.93, 139.22, 140.37, 141.23, 142.04. 29Si NMR
spectrum (CDCl3): δSi –14.16 ppm. Found, %:
C 83.63; H 7.71; Br 6.41; Si 2.22. C84H91BrSi. Cal-
culated, %: C 83.48; H 7.59; Br 6.61; Si 2.32.
4-{Tris[4″-(2-ethylhexyl)-1,1′:4′,1″-terphenyl-4-
yl]silyl}benzaldehyde (14b) was synthesized as
described above for compound 14a using 5.7 g
(4.8 mmol) of 13b, 3.45 mL (5,52 mmol) of 1.6 M
n-BuLi in hexane, and 0.85 mL (10 mmol) of DMF.
4-{Methyl[bis(2′,4″,5′-trimethyl-1,1′:4′,1″-ter-
phenyl-4-yl)]silyl}benzaldehyde (14c) was synthe-
sized as described above for compound 14a using 4 g
(5.4 mmol) of 13c, 3.9 mL (6.2 mmol) of 1.6 M
n-BuLi in hexane, and 0.84 mL (10 mmol) of DMF.
According to the NMR data, the conversion was 87%.
The product was used in further synthesis without
additional purification. 1H NMR spectrum (DMSO-d6),
δ, ppm (J, Hz): 0.96 s (3H), 2.23 s (6H), 2.27 s (6H),
2.38 s (6H), 7.1 m (4H, J = 7.9), 7.22 s (8H), 7.39 m
(4H, J = 7.9), 7.59 m (4H, J = 8.2), 7.78 m (2H, J =
7.9), 7.93 m (2H, J = 7.9), 10.05 s (1H).
1
According to the H NMR data, the conversion was
83%. The product was used in further synthesis
1
without additional purification. H NMR spectrum
(CDCl3), δ, ppm (J, Hz): 0.87–0.96 m (18H), 1.24–
1.40 m (24H), 1.63 m (3H, J = 5.9), 2.60 d (6H, J =
6.7), 7.26 m (6H, J = 7.9), 7.58 m (6H, J = 8.2), 7.67‒
7.79 m (25H), 7.93 m (3H), 10.11 s (1H).
5-(4-{Tris[4″-(2-ethylhexyl)-1,1′:4′,1″-terphenyl-
4-yl]silyl}phenyl)-1,3-oxazole (15b) was synthesized
as described above for compound 15a using 5.27 g
(4.6 mmol) of aldehyde 14b, 0.93 g (4.8 mmol) of
TosMIC, and 1.25 g (9.1 mmol) of potassium car-
bonate. The reaction mixture was refluxed for 2 h with
stirring. The product was purified by silica gel column
chromatography using toluene as eluent. Yield 3.71 g
5-(4-{Methyl[bis(2′,4″,5′-trimethyl-1,1′:4′,1″-
terphenyl-4-yl)]silyl}phenyl)-1,3-oxazole (15c) was
synthesized as described above for compound 15a
using 3.7 g (5.3 mmol) of 14c, 1.09 g (5.6 mmol) of
TosMIC, and 1.48 g (10.7 mmol) of potassium car-
bonate. The reaction mixture was refluxed for 2 h with
stirring. The product was purified by silica gel column
chromatography using toluene as eluent. Yield 3.39 g
1
(68%). H NMR spectrum (CDCl3), δ, ppm (J, Hz):
0.87–0.95 m (18H), 1.26–1.40 m (24H), 1.63 m (3H,
J = 5.9), 2.59 d (6H, J = 6.7), 7.26 m (6H J = 7.94),
7.44 s (1H), 7.57 m (6H, J = 8.2), 7.69–7.78 m (28H),
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SYNTHESIS OF NANOSTRUCTURED ORGANOSILICON LUMINOPHORES
37
(86%). 1H NMR spectrum (DMSO-d6), δ, ppm (J, Hz):
0.94 s (3H), 2.23 s (6H), 2.27 s (6H), 2.38 s (6H),
7.09 m (4H, J = 8.8), 7.22 s (8H), 7.39 m (4H, J = 7.9),
7.58–7.67 m (7H), 7.75 m (2H, J = 8.2), 8.36 s (1H).
of DMF. After evaporation of the solvent, the residue
was purified by silica gel column chromatography
using toluene as eluent. Yield 3.06 g (68%). H NMR
1
spectrum (CDCl3), δ, ppm (J, Hz): 0.86 s (3H), 7.33 m
(4H, J = 8.2), 7.53 m (4H, J = 8.2), 7.64 m (4H, J =
7.9), 7.86 m (4H, J = 7.9), 10.05 s (1H). 13C NMR
spectrum (CDCl3), δC, ppm: ‒3.73, 125.05, 128.82,
131.37, 133.24, 135.61, 136.63, 137.04, 143.44,
192.43. 29Si NMR spectrum (CDCl3): δSi ‒9.95 ppm.
Found, %: C 51.98; H 3.59; Br 34.42; Si 6.11.
C20H16Br2OSi. Calculated, %: C 52.19; H 3.50;
Br 34.72; Si 6.10.
2,2′-(Benzene-1,4-diyl)bis[5-(4-{methyl[bis-
(2′,4″,5′-trimethyl-1,1′:4′,1″-terphenyl-4-yl)]silyl}-
phenyl)-1,3-oxazole] (24) was synthesized as
described above for compound 25 using 3.8 g
(5.2 mmol) of 15c, 1.04 g (13 mmol) of lithium
tert-butoxide, 60 mg (0.05 mmol) of Pd(PPh3)4, and
0.585 g (2.47 mmol) of 1,4-dibromobenzene. The
reaction mixture was refluxed for 4 h. After evapora-
tion of the solvent, the product was purified by column
chromatography on silica gel using toluene–ethyl
4-[Tris(4-bromophenyl)silyl]benzaldehyde (17b)
was synthesized as described above for compound 14a
using 11,6 g (17.8 mmol) of 16b, 11,68 mL
(18.7 mmol) of 1.6 M n-BuLi, and 2.07 mL
(35.6 mmol) of DMF. The product was purified by
silica gel column chromatography using toluene as
eluent. Yield 7.8 g (73%). 1H NMR spectrum (CDCl3),
δ, ppm (J, Hz): 7.36 m (6H, J = 8.2), 7.56 m (6H,
J =8.5), 7.68 m (2H, J = 8.2), 7,89 m (2H, J = 8.2),
10.07 s (1H).
1
acetate (20:1) as eluent. Yield 2.7 g (71%). H NMR
spectrum (CDCl3), δ, ppm (J, Hz): 0.98 s (6H), 2.31 s
(12H), 2.33 s (12H), 2.43 s (12H), 7.19 m (8H, J =
5.8), 7.23–7.31 m (16H), 7.43 d (8H, J = 7.9), 7.56 s
(2H), 7.65 m (8H, J = 7.9), 7.74 m (4H, J = 7.9),
13
7.80 m (4H, J = 8.2), 8.25 s (4H). C NMR spectrum
(CDCl3), δC, ppm: –3.23, 19.97, 20.00, 21.18, 123.61,
124.38, 126.69, 128.58, 128.76, 128.80, 128.85,
129.09, 131.82, 131.97, 132.54, 132.69, 133.77,
135.04, 135.97, 136.41, 137.39, 138.67, 140.37,
140.91, 142.97, 151.75, 160.61. 29Si NMR spectrum
(CDCl3): δSi –10.96 ppm. Found, %: C 85.84; H 6.21;
N 1.70; Si 3.42. C110H96N2O2Si2. Calculated, %:
C 86.12; H 6.31; N 1.83; Si 3.66.
Bis(4-bromophenyl)[4-(5,5-dimethyl-1,3-dioxan-
2-yl)phenyl](methyl)silane (18a). A solution of
3.95 g (8.58 mmol) of compound 17a, 3.577 g
(34.3 mmol) of 2,2-dimethylpropane-1,3-diol, and
0.32 g (1.7 mmol) of p-toluenesulfonic acid in benzene
was refluxed in a flask equipped with a Dean–Stark
trap until water no longer separated (17 h). Triethyl-
amine, 1 mL, was added, and the mixture was poured
into 200 mL of distilled water and extracted with
diethyl ether (2×150 mL). The combined extracts were
washed with water until neutral washings, dried over
Na2SO4, and evaporated. Yield 4.32 g (93%), purity
Tris(4-bromophenyl)(methyl)silane (16a) was
synthesized as described in [24] using 34.62 g
(0.146 mol) of p-dibromobenzene, 59 mL (0.146 mol)
of 2.5 M n-BuLi in hexane, and 5.74 mL (0.0489 mol)
of trichloro(methyl)silane. Yield 24.1 g (96%), purity
97% (GPC). The product was used in further synthesis
1
1
without additional purification. H NMR spectrum
99% (GPC). H NMR spectrum (CDCl3), δ, ppm
(CDCl3), δ, ppm (J, Hz): 0.81 s (3H), 7.33 m (6H, J =
7.9), 7.52 m (6H, J = 8.2).
(J, Hz): 0.79 s (3H), 0.81 s (3H), 1.30 s (3H), 3.66 d
(2H, J = 10.4), 3.79 d (2H, J = 11.3), 5.41 s (1H),
7.31 m (4H, J = 8.5), 7.46–7.55 m (8H). 13C NMR
spectrum (CDCl3), δC, ppm: –3.55, 21.85, 22.99,
30.23, 77.64, 101.45, 124.62, 125.74, 131.10, 134.26,
135.19, 135.54, 136.71, 139.93. 29Si NMR spectrum
(CDCl3): δSi –10.25 ppm. Found, %: C 54.85; H 4.69;
Br 29.06; Si 5.25. C25H26Br2O2Si. Calculated, %:
C 54.96; H 4.80; Br 29.25; Si 5.14.
Tetrakis(4-bromophenyl)silane (16b) was synthe-
sized as described in [25] using 36.18 g (0.1563 mol)
of p-dibromobenzene, 60 mL (0.15 mol) of 2.5 M
n-BuLi in hexane, and 4,32 mL (0.0376 mol) of tri-
chloro(methyl)silane. Yield 22.5 g (90%), purity 97%
(GPC). The product was used in further synthesis
1
without additional purification. H NMR spectrum
(CDCl3), δ, ppm (J, Hz): 7.36 m (8H, J = 8.5), 7.54 m
(8H, J = 8.5).
Tris(4-bromophenyl)[4-(5,5-dimethyl-1,3-di-
oxan-2-yl)phenyl]silane (18b) was synthesized as
described above for compound 18a using 7.33 g
(12.2 mmol) of 17b, 11.68 g (48.7 mmol) of 2,2-di-
methylpropane-1,3-diol, and 0.46 g (2.4 mmol) of
p-toluenesulfonic acid. The mixture was refluxed for
4-[Bis(4-bromophenyl)(methyl)silyl]benzalde-
hyde (17a) was synthesized as described above for
compound 14a using 5 g (9.8 mmol) of 16a, 6.42 mL
of 1.6 M n-BuLi in hexane, and 1,51 mL (19.6 mmol)
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SKOROTETCKY et al.
38
12 h. Yield 8.28 g (98%), purity 99% (GPC). The
product was not subjected to additional purification.
1H NMR spectrum (CDCl3), δ, ppm (J, Hz): 0.72 s
(3H), 1.31 s (3H), 3.73 d (2H, J = 10.7), 3.79 s (2H,
J = 11.3), 5.43 s (1H), 7.35 m (6H, J = 8.2), 7.49–
7.57 m (10H). 13C NMR spectrum (CDCl3), δC, ppm:
21.83, 22.98, 30.23, 77.66, 101.40, 125.17, 125.91,
131.28, 131.87, 133.16, 136.23, 137.66, 140.31.
29Si NMR spectrum (CDCl3): δSi –13.80 ppm. Found,
%: C 52.74; H 4.00; Br 34.49; Si 4.25. C30H27Br3O2Si.
Calculated, %: C 52.42; H 3.96; Br 34.88; Si 4.09.
5,5′-({[4-(5,5-Dimethyl-1,3-dioxan-2-yl)phenyl]-
(methyl)silanediyl}dibenzene-4,1-diyl)bis-
[2-(4-methylphenyl)-1,3-oxazole] (21a). A solution of
4.14 g (7.5 mmol) of 18a, 2.65 g (16.68 mmol) of 20b,
3.33 g (41.7 mmol) of lithium tert-butoxide, and
192 mg (0.16 mmol) of Pd(PPh3)4 in 100 mL of
dioxane was refluxed for 2 h with stirring. The mixture
was poured into 200 mL of distilled water and ex-
tracted twice with diethyl ether. The combined extracts
were washed with water until neutral washings, dried
over Na2SO4, and evaporated, and the residue was
purified by silica gel column chromatography using
toluene–ethyl acetate (20:1) as eluent. Yield 4.36 g
4-(2-Ethylhexyl)benzaldehyde (19) was synthe-
sized as described above for compound 14a using
25.5 g (94.7 mmol) of 2, 39.8 mL (99.5 mmol) of
2.5 M n-BuLi in hexane, and 8 mL (0.1 mol) of DMF.
The product was purified by silica gel column
chromatography using toluene as eluent. Yield 27.31 g
1
(82%). H NMR spectrum (CDCl3), δ, ppm (J, Hz):
0.82 s (3H), 0.90 s (3H), 1.31 s (3H), 2.41 s (6H),
3.70 d (2H, J = 10.4), 3.79 d (2H, J = 11.0), 5.43 s
(1H), 7.26 m (4H, J = 8.5), 7.42 s (2H), 7.56 s (4H),
13
1
7.63 m (8H, J = 7.9), 8.08 m (4H, J = 8.2). C NMR
(74%). H NMR spectrum (CDCl3), δ, ppm (J, Hz):
spectrum (CDCl3), δC, ppm: –3.54, 21.36, 21.85,
23.00, 30.23, 77.64, 101.51, 122.82, 124.16, 125.10,
125.41, 125.75, 128.29, 129.59, 135.34, 135.64,
135.78, 138.33, 138.56, 139.87, 151.58, 160.63.
29Si NMR spectrum (CDCl3): δSi –10.58 ppm. Found,
%: C 76.63; H 6.15; N 4.10; Si 3.87. C45H42N2O4Si.
Calculated, %: C 76.89; H 6.02; N 3.99; Si 4.00.
0.80–0.97 m (6H), 1.17–1.36 m (8H), 1,62 m (1H, J =
6.4), 2.61 d (2H, J = 7.3), 7.32 m (2H, J = 8.2), 7.81 m
(2H, J = 7.9), 9.98 s (1H).
5-[4-(2-Ethylhexyl)phenyl]-1,3-oxazole (20a) was
synthesized as described above for compound 15a
using 20.5 g (94.0 mmol) of 19, 19.27 g (98.7 mmol)
of TosMIC, and 25.99 g (0.188 mol) of anhydrous
potassium carbonate. The reaction mixture was
refluxed for 1.5 h with stirring, and the product was
purified by silica gel column chromatography using
toluene as eluent. Yield 19.03 g (79%). 1H NMR spec-
trum (CDCl3), δ, ppm (J, Hz): 0.89 t (6H, J = 7.32),
1.23–1.36 m (8H), 1.58 m (1H, J = 5.4), 2.56 d (2H,
J = 7.0), 7.22 m (2H, J = 8.2), 7.32 s (1H), 7.57 m (2H,
2,2′,2″-({[4-(5,5-Dimethyl-1,3-dioxan-2-yl)-
phenyl]silanetriyl}tribenzene-4,1-diyl)tris[5-(4-
methylphenyl)-1,3-oxazole] (21b) was synthesized
as described above for compound 21a using 8.17 g
(11.9 mmol) of 18b, 6.24 g (39.2 mmol) of 20b, 6.27 g
(78.5 mmol) of lithium tert-butoxide, and 453 mg
(0.39 mmol) of Pd(PPh3)4. The product was purified by
silica gel column chromatography using toluene–ethyl
acetate (20 : 1) as eluent. Yield 10.08 g (92%).
1H NMR spectrum (CDCl3), δ, ppm (J, Hz): 0.83 s
(3H), 1.32 s (3H), 2.41 s (9H), 3.69 d (2H, J = 11.0),
3.81 d (2H, J = 10.7), 5.47 s (1H), 7.27 m (6H, J =
8.2), 7.44 s (3H), 7.59–7.67 m (10H), 7.71 m (6H, J =
8.2), 8.14 m (6H, J = 8.2). 13C NMR spectrum
(CDCl3), δC, ppm: 21.35, 21.84, 23.01, 30.25, 77.67,
101.49, 122.97, 124.17, 125.10, 125.52, 125.93,
128.17, 128.72, 128.98, 129.59, 133.51, 135.88,
136.46, 136.71, 138.58, 140.24, 151.68, 160.51.
29Si NMR spectrum (CDCl3): δSi –14.30 ppm. Found,
%: C 77.96; H 5.68; N 4.45 Si 2.98. C60H51N3O5Si.
Calculated, %: C 78.15; H 5.57; N 4.56; Si 3.05.
13
J = 8.2), 7.91 s (1H). C NMR spectrum (CDCl3), δC,
ppm: 10.74. 14.10. 22.98. 25.36. 28.77. 32.25. 39.89.
41.02. 120.80. 124.17. 125.13. 129.69. 142.75. 150.10.
151.75. Found, %: C 79.51; H 9.15; N 5.29.
C17H23NO. Calculated, %: C 79.33; H 9.01; N 5.44.
5-(4-Methylphenyl)-1,3-oxazole (20b) was synthe-
sized as described in [26] using 5 g (41.6 mmol) of
4-methylbenzaldehyde, 8.53 g (43.7 mmol) of
TosMIC, and 11.5 g (83.2 mmol) of anhydrous potas-
sium carbonate. The product was purified by silica gel
column chromatography using toluene–ethyl acetate
1
(20:1) as eluent. Yield 6.01 g (91%). H NMR spec-
trum (CDCl3), δ, ppm (J, Hz): 2.39 s (3H), 7.24 m (2H,
J = 7.9), 7.31 s (1H), 7.55 m (2H, J = 8.2), 7.90 s (1H).
13C NMR spectrum (CDCl3), δC, ppm: 21.33, 120.81,
124.32, 129.57, 138.66, 150.11, 151.69. Found, %:
C 75.39; H 5.59; N 8.84. C10H9NO. Calculated, %:
C 75.45; H 5.70; N 8.80.
2,2′,2″-({[4-(5,5-Dimethyl-1,3-dioxan-2-yl)-
phenyl]silanetriyl}tribenzene-4,1-diyl)tris-
{5-[4-(2-ethylhexyl)phenyl]-1,3-oxazole} (21c) was
synthesized as described above for compound 21a
using 2.5 g (3.6 mmol) of 18b, 3.37 g (13.1 mmol) of
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SYNTHESIS OF NANOSTRUCTURED ORGANOSILICON LUMINOPHORES
39
20a, 2.62 g (32.7 mmol) of lithium tert-butoxide, and
150 mg (0.13 mmol) of Pd(PPh3)4. The product was
purified by silica gel column chromatography using
toluene–ethyl acetate (20:1) as eluent. Yield 3.78 g
124.22, 125.08, 125.74, 128.90, 129.10, 129.63,
134.87, 136.68, 136.84, 137.30, 138.70, 141.43,
151.84, 160.35, 192.39. Si NMR spectrum (CDCl3):
δSi –14.28 ppm. Found, %: C 79.17; H 5.05; N 5.20;
Si 3.28. C55H41N3O4Si. Calculated, %: C 79.02;
H 4.94; N 5.03; Si 3.36.
29
1
(85%). H NMR spectrum (CDCl3), δ, ppm (J, Hz):
0.82 s (3H), 0.89 m (18H), 1.24–1.37 m (27H), 1.61 m
(3H), 2.57 d (6H, J = 7.0), 3.69 d (2H, J = 11.0),
3.81 d (2H, J = 11.3), 5.46 s (1H), 7.24 m (6H, J =
8.2), 7.44 s (3H), 7.60–7.74 m (16H), 8.14 m (6H, J =
8.5). 13C NMR spectrum (CDCl3), δC, ppm: 10.75,
14.09, 21.85, 22.98, 23.02, 25.40, 28.79, 30.25, 32.29,
39.96, 41.05, 77.70, 101.53, 123.00, 124.08, 125.28,
125.54, 125.95, 128.75, 129.73, 133.54, 135.93,
136.46, 136.73, 140.28, 142.72, 151.79, 160.56.
29Si NMR spectrum (CDCl3): δSi –14.32 ppm. Found,
%: C 80.03; H 7.84; N 3.39; Si 2.18. C81H93N3O5Si.
Calculated, %: C 79.96; H 7.70; N 3.45; Si 2.31.
4-[Tris(4-{5-[4-(2-ethylhexyl)phenyl]-1,3-oxazol-
2-yl}phenyl)silyl]benzaldehyde (22c) was synthe-
sized as described above for compound 22a from
3.38 g (2.78 mmol) of 21c using 10 mL of 1 M
aqueous HCl. The product was purified by silica gel
column chromatography using toluene–ethyl acetate
1
(3:1) as eluent. Yield 2.79 g (89%). H NMR spectrum
(CDCl3), δ, ppm (J, Hz): 0.85–0.93 m (18H), 1.24–
1.33 m (24H), 1.61 m (3H), 2.57 d (6H, J = 7.0),
7.24 m (6H, J = 8.5), 7.45 s (3H), 7.61–7.74 m (12H),
7.82 m (2H, J = 7.9), 7.95 d (2H, J = 8.2), 8.18 m (6H,
J = 8.5), 10.11 s (1H). 13C NMR spectrum (CDCl3), δC,
ppm: 10.75, 14.08, 22.98, 25.39, 28.79, 32.28, 39.96,
41.05, 123.04, 124.09, 125.20, 125.73, 128.90, 129.09,
129.20, 129.76, 134.87, 136.62, 136.69, 136.84,
137.30, 141.43, 142.83, 151.91, 160.36, 192.39.
29Si NMR spectrum (CDCl3): δSi –14.28. Found, %:
C 80.55; H 7.55; N 3.64; Si 2.48. C76H83N3O4Si. Cal-
culated, %: C 80.74; H 7.40; N 3.72; Si 2.48.
4-[(Bis{4-[2-(4-methylphenyl)-1,3-oxazol-5-yl]-
phenyl})(methyl)silyl]benzaldehyde (22a). A solu-
tion of 5.23 g (7.44 mmol) of compound 21a in
a mixture of 70 mL of acetone and 10 mL of 1 M
aqueous HCl was refluxed for 27 h (TLC). The mix-
ture was poured into 200 mL of distilled water and
extracted twice with diethyl ether. The combined ex-
tracts were washed with water until neutral washings,
dried over Na2SO4, and evaporated, and the residue
was purified by silica gel column chromatography
using toluene–ethyl acetate (3:1) as eluent. Yield
5,5′-({Methyl[4-(1,3-oxazol-5-yl)phenyl]silane-
diyl}dibenzene-4,1-diyl)bis[2-(4-methylphenyl)-1,3-
oxazole] (23a). Potassium carbonate, 2.02 g
(14.6 mmol), was added to a solution of 4.5 g
(7.3 mmol) of compound 22a and 1.5 g (7.6 mmol) of
TosMIC in a mixture of 150 mL of methanol and
10 mL of THF. The mixture was refluxed for 2 h with
stirring (TLC), poured into 200 mL of ice water, and
extracted twice with diethyl ether. The combined ex-
tracts were washed with water until neutral washings,
dried over Na2SO4, and evaporated, and the residue
was purified by silica gel column chromatography
using toluene–ethyl acetate (3:1) as eluent. Yield 4.4 g
1
4.12 g (90%). H NMR spectrum (CDCl3), δ, ppm
(J, Hz): 0.97 s (3H), 2.41 s (6H), 7.26 m (4H, J = 7.9),
7.43 s (2H), 7.61–7.66 m (8H), 7.73 m (2H, J = 7.9),
7.90 m (2H, J = 7.9), 8.13 m (4H, J = 8.2), 10.07 s
(1H). 13C NMR spectrum (CDCl3), δC, ppm: –3.75,
21.35, 122.90, 124.16, 125.05, 125.58, 128.68, 128.82,
129.60, 135.57, 135.73, 137.01, 137.13, 138.64,
143.73, 151.69, 160.41, 192.47. 29Si NMR spectrum
(CDCl3): δSi –10.31 ppm. Found, %: C 78.16; H 5.38;
N 4.27; Si 4.31. C40H32N2O3Si. Calculated, %:
C 77.89; H 5.23; N 4.54; Si 4.55.
1
(92%). H NMR spectrum (CDCl3), δ, ppm (J, Hz):
0.95 s (3H), 2.41 s (6H), 7.26 m (4H, J = 7.9), 7.43 s
(3H), 7.61–7.71 m (12H), 7.95 s (1H), 8.12 m (4H, J =
8.2). 13C NMR spectrum (CDCl3), δC, ppm: –3.65,
21.35, 122.15, 122.81, 123.78, 124.16, 125.06, 125.52,
128.44, 128.82, 129.60, 135.59, 135.76, 135.93,
137.92, 138.62, 150.67, 151.27, 151.65, 160.52.
29Si NMR spectrum (CDCl3): δSi –10.58 ppm. Found,
%: C 76.74; H 5.21; N 6.25; Si 4.08. C42H33N3O3Si.
Calculated, %: C 76.92; H 5.07; N 6.41; Si 4.28.
4-(Tris{4-[5-(4-methylphenyl)-1,3-oxazol-2-yl]-
phenyl}silyl)benzaldehyde (22b) was synthesized as
described above for compound 22a using 10.05 g
(10.13 mmol) of 21b and 20.3 mL of 1M aqueous HCl.
The product was purified by silica gel column
chromatography using toluene–ethyl acetate (3:1) as
1
eluent. Yield 7.53 g (89%). H NMR spectrum
(CDCl3), δ, ppm (J, Hz): 2.41 s (9H), 7.27 m (6H, J =
7.9), 7.44 s (3H), 7.63 m (6H, J = 8.2), 7.71 m (6H, J =
8.2), 7.82 m (2H, J = 7.9), 7.95 m (2H, J = 8.2),
8.17 m (6H, J = 8.5), 10.11 s (1H). 13C NMR spectrum
(CDCl3), δC, ppm: 21.35, 76.57, 76.99, 77.42, 123.04,
2,2′,2″-({[4-(1,3-Oxazol-5-yl)phenyl]silanetriyl}-
tribenzene-4,1-diyl)tris[5-(4-methylphenyl)-1,3-ox-
azole] (23b) was synthesized as described above for
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SKOROTETCKY et al.
40
23a from 8.4 g (10.0 mmol) of 22b and 2.05 g
(10.5 mmol) of TosMIC in the presence of 2.77 g
(20.1 mmol) of potassium carbonate. The product was
purified by silica gel column chromatography using
toluene–ethyl acetate (3:1) as eluent. Yield 6.55 g
125.23, 125.61, 126.75, 128.67, 128.79, 128.98,
129.67, 135.68, 135.90, 136.08, 137.97, 138.66,
151.57, 151.74, 160.64, 160.73. 29Si NMR spectrum
(CDCl3): δSi –10.57 ppm. Found, %: C 77.83; H 5.10;
N 5.83; Si 4.44. C90H68N6O6Si2. Calculated, %:
C 78.01; H 4.95; N 6.06; Si 4.05.
1
(75%). H NMR spectrum (CDCl3), δ, ppm (J, Hz):
2.41 s (9H), 7.27 m (6H, J = 7.6), 7.44 s (4H), 7.61–
7.76 m (16H), 7.97 s (6H), 7.71 m (6H, J = 8.2).
13C NMR spectrum (CDCl3), δC, ppm: 21.35, 122.39,
122.99, 123.90, 124.17, 125.06, 125.62, 128.87,
129.18, 129.61, 133.63, 135.52, 136.67, 136.86,
138.64, 150.76, 151.17, 151.74, 160.42. 29Si NMR
spectrum (CDCl3): δSi –14.34. Found, %: C 78.12;
H 4.92; N 6.10; Si 3.04. C57H42N4O4Si. Calculated, %:
C 78.24; H 4.84; N 6.40; Si 3.21.
2,2′,2″,2′′′,2′′′′,2′′′′′-[Benzene-1,4-diylbis(1,3-ox-
azole-2,5-diylbenzene-4,1-diylsilanetetrayltriben-
zene-4,1-diyl)]hexakis[5-(4-methylphenyl)-1,3-oxa-
zole] (28) was synthesized as described above for
compound 25 using 6.3 g (7.2 mmol) of 23b, 1.44 g
(18.0 mmol) of lithium tert-butoxide, 83 mg
(0.07 mmol) of Pd(PPh3)4, and 0.809 g (3.4 mmol) of
1,4-dibromobenzene. The reaction mixture was
refluxed for 1.5 h. The product was purified by
extraction from toluene and chloroform. Yield 5.6 g
2,2′,2″-({[4-(1,3-Oxazol-5-yl)phenyl]silanetriyl}-
tribenzene-4,1-diyl)tris{5-[4-(2-ethylhexyl)phenyl]-
1,3-oxazole} (23c) was synthesized as described above
for 23a from 3.37 g (2,98 mmol) of 22c and 0.611 g
(3.1 mmol) of TosMIC in the presence of 0.824 g
(5.96 mmol) of potassium carbonate. The product was
purified by silica gel column chromatography using
toluene–ethyl acetate (3:1) as eluent. Yield 3.38 g
1
(59%). H NMR spectrum (CDCl3), δ, ppm (J, Hz):
2.40 s (18H), 7.27 m (12H, J = 7.9), 7.44 s (6H), 7.59–
7.85 m (34H), 8.17 m (12H, J = 8.2), 8.25 s (4H).
13C NMR spectrum (CDCl3), δC, ppm: 21.35, 123.00,
123.81, 124.17, 124.80, 125.06, 125.63, 126.70,
128.67, 128.88, 129.21, 129.60, 133.62, 135.53,
136.69, 136.90, 138.63, 151.36, 151.74, 160.42,
1
29
(97%). H NMR spectrum (CDCl3), δ, ppm (J, Hz):
160.72. Si NMR spectrum (CDCl3): δSi –14.33 ppm.
0.83–0.95 m (18H), 1.22–1.36 m (24H), 1.60 m (3H),
2.57 d (6H, J = 7.0), 7.24 m (6H, J = 8.2), 7.45 s (3H),
7.46 s (1H), 7.61–7.79 m (16H), 7.97 s (1H), 8.17 m
(6H, J = 8.2). 13C NMR spectrum (CDCl3), δC, ppm:
10.75, 14.07, 22.97, 25.42, 28.79, 32.30, 39.97, 41.05,
122.41, 122.94, 123.94, 124.09, 125.22, 125.67,
128.87, 129.22, 129.75, 133.68, 135.60, 136.70,
136.88, 142.82, 151.88, 160.46. 29Si NMR spectrum
(CDCl3): δSi –14.34 ppm. Found, %: C 79.81; H 7.24;
N 4.94; Si 2.27. C78H84N4O4Si. Calculated, %:
C 80.10; H 7.24; N 4.79; Si 2.40.
Found, %: C 78.80; H 4.68; N 5.97; Si 3.24.
C120H86N8O8Si2. Calculated, %: C 79.01; H 4.75;
N 6.14; Si 3.08.
2,2′,2″,2′′′,2′′′′,2′′′′′-[Benzene-1,4-diylbis(1,3-ox-
azole-2,5-diylbenzene-4,1-diylsilanetetrayltriben-
zene-4,1-diyl)]hexakis{5-[4-(2-ethylhexyl)phenyl]-
1,3-oxazole} (29) was synthesized as described above
for compound 25 using 2.6 g (2.22 mmol) of 23c,
0.44 g (5.55 mmol) of lithium tert-butoxide, 25 mg
(0.02 mmol) of Pd(PPh3)4, and 0.249 g (1.05 mmol)
of 1,4-dibromobenzene. The reaction mixture was
refluxed for 1.5 h, and the product was purified by
silica gel column chromatography using toluene–ethyl
5,5′,5″,5′′′-{Benzene-1,4-diylbis[1,3-oxazole-2,5-
diylbenzene-4,1-diyl(methylsilanetriyl)dibenzene-
4,1-diyl]}tetrakis[2-(4-methylphenyl)-1,3-oxazole]
(26) was synthesized as described above for compound
25 using 3.25 g (4.95 mmol) of 23a, 0.99 g
(12.3 mmol) of lithium tert-butoxide, 57 mg
(0.05 mmol) of Pd(PPh3)4, and 0.557 g (2.36 mmol) of
1,4-dibromobenzene. The reaction mixture was
refluxed for 60 min, and the product was purified by
silica gel column chromatography using toluene–ethyl
1
acetate (3:1) as eluent. Yield 0.45 g (17%). H NMR
spectrum (CDCl3), δ, ppm (J, Hz): 0.84–0.93 m (36H),
1.23–1.37 m (49H), 1.61 m (6H), 2.57 d (12H, J =
7.0), 7.24 m (12H, J = 8.2), 7.45 s (6H), 7.59 s (2H),
7.64 m (12H, J = 8.2), 7.71–7.85 m (20H), 7.95 m
(12H, J = 8.2), 8.25 s (4H). 13C NMR spectrum
(CDCl3), δC, ppm: 10.73, 14.08, 22.96, 25.36, 28.76,
32.25, 39.93, 41.02, 123.01, 123.82, 124.05, 125.21,
125.63, 126.72, 128.70, 128.89, 129.22, 129.73,
133.63, 135.54, 136.69, 136.91, 142.75, 151.39,
1
acetate (3:1) as eluent. Yield 2.3 g (71%). H NMR
spectrum (CDCl3), δ, ppm (J, Hz): 0.97 s (6H), 2.40 s
(12H), 7.26 m (8H, J = 8.5), 7.43 s (5H), 7.56 s (2H),
7.61–7.69 m (20H), 7.78 m (4H, J = 8.2), 8.13 m (8H,
29
151.82, 160.44, 160.75. Si NMR spectrum (CDCl3):
δSi –14.33 ppm. Found, %: C 80.40; H 7.26; N 4.45;
Si 2.20. C162H170N8O8Si2. Calculated, %: C 80.63;
H 7.10; N 4.64; Si 2.33.
13
J = 8.2), 8.24 s (4H). C NMR spectrum (CDCl3), δC,
ppm: –3.51, 21.42, 123.04, 123.79, 124.26, 124.64,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 55 No. 1 2019

SYNTHESIS OF NANOSTRUCTURED ORGANOSILICON LUMINOPHORES
41
11. Ensslen, P. and Wagenknecht, H.-A., Acc. Chem. Res.,
ACKNOWLEDGMENTS
2015, vol. 48, no. 10, p. 2724.
12. Romano, F., Yu, Y., Korgel, B.A., Bergamini, G., and
Ceroni, P., Top Curr. Chem., 2016, vol. 374, no. 4,
article no. 53.
13. Luponosov, Y.N., Ponomarenko, S.A., Surin, N.M.,
Borshchev, O.V., Shumilkina, E.A., and Muzafa-
rov, A.M., Chem. Mater., 2009, vol. 21, no. 3, p. 447.
14. Ponomarenko, S.A., Surin, N.M., Borshchev, O.V.,
Luponosov, Y.N., Akimov, D.Y., Alexandrov, I.S.,
Burenkov, A.A., Kovalenko, A.G., Stekhanov, V.N.,
Kleymyuk, E.A., Gritsenko, O.T., Cherkaev, G.V.,
Kechek’yan, A.S., Serenko, O.A., and Muzafa-
rov, A.M., Sci. Rep., 2014, vol. 4, p. 6549.
This study was performed under financial support
by the Ministry of Science and Higher Education of
the Russian Federation (state assignment, program for
support of leading scientific schools, project no. NSh-
5698.2018.3), by the Program of Fundamental
Research of the Presidium of the Russian Academy of
Sciences (project no. 32, “Nanostructures: Physics,
Chemistry, Biology, and Basics of Technology”), and
by the Russian Foundation for Basic Research (project
no. 16-03-01118).
CONFLICT OF INTERESTS
15. Grinev, B.V. and Senchishin, V.G., Plastmassovye
stsintillyatory (Plastic Scintillators), Khar’kov: Akta,
2003.
The authors declare the absence of conflict of
interests.
16. Kumari, S. and Sahare, P.D., Adv. Porous Mater., 2013,
vol. 1, p. 114.
17. Oxazoles: Synthesis, Reactions, and Spectroscopy,
REFERENCES
Palmer, D.C., Ed., Hoboken NJ: Wiley, 2003.
18. Skorotetcky, M.S., Borshchev, O.V., Surin, N.M.,
Odarchenko, Y., Pisarev, S.A., Peregudova, S.M.,
Törnroos, K.W., Chernyshov, D., Ivanov, D.A., and
Ponomarenko, S.A., Dyes Pigm., 2017, vol. 141, p. 128.
19. Skorotetcky, M.S., Surin, N.M., Borshchev, O.V., and
Ponomarenko, S.A., Mendeleev Commun., 2017,
vol. 27, p. 377.
20. Ponomarenko, S.A., Surin, N.M., Borshchev, O.V.,
Skorotetcky, M.S., and Muzafarov, A.M., Proc. SPIE,
2015, vol. 9545, no. 954509.
21. Ponomarenko, S.A., Borshchev, O.V., Surin, N.M.,
Skorotetcky, M.S., Kleymyuk, E.A., Starikova, T.Yu.,
and Tereshenko, A.S., Proc. SPIE, 2017, vol. 10344,
no. 103440N.
22. Starikova, T.Y., Surin, N.M., Borshchev, O.V.,
Pisarev, S.A., Svidchenko, E.A., Fedorov, Y.V., and
Ponomarenko, S.A., J. Mater. Chem. C, 2016, vol. 4,
p. 4699.
23. Ponomarenko, S.A., Borshchev, O.V., Lupono-
sov, Yu.N., Muzafarov, A.M., and Surin, N.M., RU
Patent no. 2396290.
1. Balzani, V., Campagna, S., Denti, G., Juris, A.,
Serroni, S., and Venturi, M., Sol. Energy Mater. Sol.
Cells, 1995, vol. 38, p. 159.
2. Alpha, B., Ballardini, R., Balzani, V., Lehn, J.M.,
Perathoner, S., and Sabbatini, N., Photochem. Photo-
biol., 1990, vol. 52, p. 299.
3. Jullien, L., Canceill, J., Valeur, B., Bardez, E.,
Lefèvre, J.-P., Lehn, J.-M., Marchi-Artzner, V., and
Pansu, R., J. Am. Chem. Soc., 1996, vol. 118, p. 5432.
4. Croce, R. and van Amerongen, H., Nat. Chem. Biol.,
2014, vol. 10, p. 492.
5. Trofymchuk, K., Reisch, A., Didier, P., Fras, F.,
Gilliot, P., Mely, Y., and Klymchenko, A.S., Nat.
Photonics, 2017, vol. 11, p. 657.
6. Arrigo, A., La Ganga, G, Nastasi, F., Serroni, S.,
Santoro, A., Santoni, M.-P., Galletta, M., Campagna, S.,
and Puntoriero, F., C. R. Chim., 2017, vol. 20, no. 3,
p. 209.
7. Frischmann, P.D., Mahata, K., and Wȕrthner, F., Chem.
Soc. Rev., 2012, vol. 42, no. 4, p. 1847.
8. He, Z., Ishizuka, T., and Jiang, D., Polym. J., 2007,
24. Wang, D., Niu, Y., Wang, Y., Han, J., and Feng, S.,
vol. 39, no. 9, p. 889.
J. Organomet. Chem., 2010, vol. 695, no. 21, p. 2329.
9. Ziessel, R. and Harriman, A., Chem. Commun., 2011,
25. Yu, H., Shen, C., Tian, M., Qu, J., and Wang, Z.,
vol. 47, p. 611.
Macromolecules, 2012, vol. 45, no. 12, p. 5140.
10. Adronov, A. and Fréchet, M.J., Chem. Commun., 2000,
26. Hachiya, H., Hirano, K., Satoh, T., and Miura, M.,
no. 18, p. 1701.
Angew. Chem. Int. Ed., 2010, vol. 49, p. 2202.
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