Synthesis and structure of a difunctional siloxane endron

Article abstract of DOI:10.1007/s11172-010-0089-0

A difunctional dendron composed of three spiro-linked cyclosiloxane fragments was synthesized by a convergent way. This is of interest for the preparation of cylindrical and spherical dendritic molecules with the inorganic siloxane core and peripheral org

Full text of DOI:10.1007/s11172-010-0089-0

Russian Chemical Bulletin, International Edition, Vol. 59, No. 2, pp. 374—381, February, 2010
374
Synthesis and structure of a difunctional siloxane dendron
A. B. Zachernyuk,a A. P. Pleshkova,b K. A. Lyssenko,b M. V. Nevezhin,a and A. M. Muzafarova
aN. S. Enikolopov Institute of Synthetic Polymer Materials, Russian Academy of Sciences,
70 ul. Profsoyuznaya, 117393 Moscow, Russian Federation.
Fax: +7 (495) 335 9000. Eꢀmail: a_zacher@mail.ru
bA. N. Nesmeyanov Institue of Organoelement Compounds, Russian Academy of Sciences,
28 ul. Vavilova, 119991 Moscow, Russian Federation
A difunctional dendron composed of three spiroꢀlinked cyclosiloxane fragments was synꢀ
thesized by a convergent way. This is of interest for the preparation of cylindrical and spherical
dendritic molecules with the inorganic siloxane core and peripheral organic layer. The strucꢀ
tures of the dendron synthesized and intermediates containing the Si—Cl, Si—H, Si—OH
groups were confirmed by data from massꢀspectrometry and Xꢀray diffraction.
Key words: organospirocyclosiloxanes, polysiloxane dendrimer, difunctional dendron, conꢀ
vergent scheme, bis(2ꢀchloroꢀ4,4,6,6ꢀtetraphenylcyclosiloxanꢀ2ꢀyl) oxide, bis(2ꢀhydroxyꢀ
4,4,6,6ꢀtetraphenylcyclotrisiloxanꢀ2ꢀyl) oxide.
Organocardocyclosiloxane compounds1,2 contain cycloꢀ
a difunctional organocyclosiloxane as a starting building
block. This route implies stepwise formation of a dispiroꢀ
siloxane structure (Scheme 1).
triꢀ (Q3) or cyclotetrasiloxane (Q4) cores devoid of orꢀ
ganic margins and connected by spiroꢀbonds with other
QD2 fragments bearing organic substituents at the silicon
atoms (Q = SiX4/2, D = RR´SiX, where X = O or NH; the
nomenclature of the structure fragments of the siloxane
molecules is given in Ref. 3). The inorganic part of such
compounds are presented by cyclosiloxane backbone, which
accounts for their thermostability and acid resistance. Due
to the presence of hydrocarbon marginal groups, organoꢀ
spirocyclosiloxanes have molecular structures and are
soluble in many organic solvents. They are crystalline subꢀ
stances with increased heat resistance and thermal stabilꢀ
ity compared to the linear organosiloxanes. These strucꢀ
tures can be regarded as the firstꢀgeneration organosilicon
dendrimeric molecules built of selfꢀsimilar cyclic strucꢀ
tural fragments of silicon dioxide containing organic subꢀ
stituents at the periphery.4
The framework for the formation of the nextꢀgeneraꢀ
tion polysiloxane dendritic molecules is a difunctional denꢀ
dron built of spiroꢀlinked siloxane rings and incorporating
the Dꢀ and Qꢀsiloxane fragments.
Such type of structure with the hard molecular backꢀ
bone and spaceꢀseparated organic (polyorganosiloxane)
and inorganic functional parts contains
Scheme 1
In studies of compounds of such a structure, it should
be taken into account that the flexibility inherent in
organocyclosiloxanes was also characteristic of the molꢀ
ecules of the compoundsꢀprecursors and manifested itself
in the violation of their ideal symmetry and deformation
of the rings. The crystal lattices of cardocyclosiloxanes with
diphenyl margins possessed holes (up to 150 Å3 in volume)
filled with disordered solvent molecules that has not been
removed by evacuation,6 which distorts the results of the
elemental analysis. The IR spectra provided only a tool for
qualitative establishing the presence of the cyclotrisiloxane
fragments in the products and the NMR spectra were
poorly informative (except for the specially synthesized
trimethylsilyl derivatives). Since the inorganic constituent
of such siloxane decreases their volatility, the convenꢀ
tional electronꢀimpact ionization massꢀspectrometry does
not offer adequate information on the molecular weights
and chemical structures of these derivatives.7 The moꢀ
lecular weights and compositions of the target products
were confirmed by the MALDIꢀTOF mass spectra where
the peaks of singleꢀcharged ions related to clusters of the
all the prerequisites for the synthesis of
the wellꢀordered hybrid organicꢀinorganic
systems.
The aim of the present work is the preparation of a diꢀ
functional siloxane dendron as a functional structural unit
capable of selfꢀorganization according to a convergent
scheme that have been suggested by us previously5 from
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 367—374, February, 2010.
1066ꢀ5285/10/5902ꢀ0374 © 2010 Springer Science+Business Media, Inc.

Difunctional organocyclosiloxane dendron
Russ.Chem.Bull., Int.Ed., Vol. 59, No. 2, February, 2010
375
Scheme 3
molecules containing the alkali metal cations, as well as to
the protonated and solvated species, were observed. The
measured isotopic distributions and the m/z values are in
good agreement with the theoretical ones.
Results and Discussion
The synthesis of a dendron by a convergent scheme
implied dimerization of the cyclosiloxane fragments folꢀ
lowed by condensation of the resulting difunctional bisꢀ
(cyclotrisiloxanyl) oxide with tetrachlorosilane.5 The diꢀ
functional organocyclotrisiloxanes with the phenyl subꢀ
stituents at the silicon atoms, viz., 2,2ꢀdichloroꢀ4,4,6,6ꢀ
tetraphenylcyclotrisiloxane (1) and 2ꢀchloroꢀ4,4,6,6ꢀ
tetraphenylcyclotrisiloxane (2), were used as the starting
compounds for the preparation of bis(cyclotrisiloxanyl)
oxides.
n = 1—5
ner that would provide the preferential formation of
We expected that the synthesis of the hydroxylꢀconꢀ
taining bis(cyclotrisiloxanyl) oxide would be carried out
by hydrolytic condensation (Scheme 2) of dichloroꢀ
trisiloxane 1. According to the GPC data, at the ratio of 1
and H2O of 1:3, hydrolysis results in the formation of
oligomers containing from 3 to 5 rings in the chain.
bis(hydroxycyclotrisiloxanyl) oxide 4 was unsuccessful.
Scheme 2
According to the Xꢀray diffraction data, compound 3
crystallizes in the form of solvate with THF. There are
four independent molecules of 3 and four THF molecules
in the unit cell. The principal geometric parameters of the
independent molecules in the crystal, except for turn of
the phenyl rings, do not differ (Table 1).
The sixꢀmembered rings are characterized by the flatꢀ
tened conformation with maximum deviation of the silicon
atoms from 0.07 to 0.24 Å. The Si—O bond lengths in the
ring are in the range from 1.614(3) to 1.655(3) Å and the
Si(1)—O(H) bond lengths are in the range from 1.578(3) to
1.622(3) Å. The analysis of the crystal packing in 3 showed
that one of the hydroxyl groups in each of the independent
molecules forms strong Нꢀbond with the hydroxyl group
of the other molecule assembling the molecules into dimers
(Fig. 1). The distances О...О characterizing the Нꢀbond
strengths are in the range of 2.672(5)—2.719(4) Å. In turn,
the other ОН group in the molecule forms an Нꢀbond
with the solvate molecule of THF (the distances О...О are
in the range of 2.582(4)—2.665(4) Å). It should be noted
that although the formation of the Нꢀbonds with THF
molecules is generally not characteristic (the analysis of
the Cambridge Structural Database revealed only 39 such
structures), but, if present, such Нꢀbonds are always strong
(the average distance О...О is 2.683 Å). Thus, the major
structural unit in the crystal of 3 is the Нꢀbonded dimer
with two solvate molecules of THF, which probably reꢀ
sults in the sufficiently high stability of 3.
n = 1—5
The IR spectrum of the reaction product, besides a douꢀ
blet in the region of 1025 and 1040 cm–1 typical of the
starting cyclosiloxane 1, contains
1080—1090 cm–1 indicating the presence of unstrained
siloxane bonds between the cyclic fragments.8 Blocking
the hydroxy groups with chlorotrimethylsilane (Scheme 3)
allowed determination of the intensity ratio of the
HMe : HPh signals in the H NMR spectrum of the reacꢀ
tion products of 2 : 7, which corresponds on average to
three siloxane fragments in the molecule.
The formation of a set of the condensation products is
apparently due to the lability of the intermediates, which
can be explained by the presence of functional groups in
the "inorganic" part of the molecule, as well as by the
features of the hydrolytic condensation, which is mainly
a heterofunctional process in the neutral medium.9 Synꢀ
thesis of monocyclic diol 3 was carried out by hydrolysis
of compound 1 in the presence of ammonium carbonate;
virtually no formation of oligomeric products was observed.
Performing the hydrolysis of dichloride 1 in a such manꢀ
a
band at
1
The formation of dicyclic compound 4 by homoꢀ
functional condensation of monocyclic diol 3 was doꢀ

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Russ.Chem.Bull., Int.Ed., Vol. 59, No. 2, February, 2010
Zachernyuk et al.
Table 1. Selected bond lengths (d) and bond angles (ω) in the structure of 3
Parameter
Bond
Value
Parameter
Bond
Value
Parameter
Angle
Value
d/Å
d/Å
ω/deg
Si(1A)—O(5A)
Si(1A)—O(4A)
Si(1A)—O(1A)
Si(1A)—O(3A)
Si(2A)—O(1A)
Si(2A)—O(2A)
Si(2A)—C(1A)
Si(2A)—C(7A)
Si(3A)—O(3A)
Si(3A)—O(2A)
Si(3A)—C(13A)
Si(3A)—C(19A)
Si(1B)—O(5B)
Si(1B)—O(3B)
Si(1B)—O(1B)
Si(1B)—O(4B)
Si(2B)—O(2B)
Si(2B)—O(1B)
Si(2B)—C(7B)
Si(2B)—C(1B)
Si(3B)—O(3B)
Si(3B)—O(2B)
Si(3B)—C(19B)
Si(3B)—C(13B)
Si(1C)—O(4C)
Si(1C)—O(5C)
Si(1C)—O(1C)
Si(1C)—O(3C)
Si(2C)—O(1C)
Si(2C)—O(2C)
Si(2C)—C(1C)
Si(2C)—C(7C)
Si(3C)—O(3C)
Si(3C)—O(2C)
Si(3C)—C(14C)
Si(3C)—C(20C)
Si(1D)—O(5D)
Si(1D)—O(1D)
Si(1D)—O(4D)
Si(1D)—O(3D)
Si(2D)—O(2D)
Si(2D)—O(1D)
Si(2D)—C(7D)
Si(2D)—C(1D)
Si(3D)—O(2D)
1.614(3)
1.605(3)
1.624(3)
1.641(3)
1.632(3)
1.650(3)
1.807(5)
1.860(4)
1.622(3)
1.648(3)
1.803(5)
1.856(4)
1.586(3)
1.614(3)
1.621(3)
1.622(2)
1.625(3)
1.645(2)
1.857(3)
1.876(3)
1.637(3)
1.645(3)
1.853(4)
1.864(4)
1.602(3)
1.605(3)
1.627(3)
1.635(3)
1.622(3)
1.649(3)
1.819(4)
1.860(4)
1.616(3)
1.655(3)
1.831(4)
1.878(4)
1.578(3)
1.614(3)
1.619(2)
1.621(2)
1.650(3)
1.652(3)
1.849(4)
1.858(4)
1.618(3)
Si(3D)—O(3D)
Si(3D)—C(19D)
Si(3D)—C(13D)
1.644(2)
1.855(4)
1.860(3)
Si(2B)—O(2B)—Si(3B)
Si(1B)—O(3B)—Si(3B)
O(4C)—Si(1C)—O(5C)
O(4C)—Si(1C)—O(1C)
O(5C)—Si(1C)—O(1C)
O(4C)—Si(1C)—O(3C)
O(5C)—Si(1C)—O(3C)
O(1C)—Si(1C)—O(3C)
O(1C)—Si(2C)—O(2C)
O(1C)—Si(2C)—C(1C)
O(2C)—Si(2C)—C(1C)
O(1C)—Si(2C)—C(7C)
O(2C)—Si(2C)—C(7C)
C(1C)—Si(2C)—C(7C)
O(3C)—Si(3C)—O(2C)
O(3C)—Si(3C)—C(14C)
O(2C)—Si(3C)—C(14C)
O(3C)—Si(3C)—C(20C)
O(2C)—Si(3C)—C(20C)
C(14C)—Si(3C)—C(20C)
Si(2C)—O(1C)—Si(1C)
Si(2C)—O(2C)—Si(3C)
Si(3C)—O(3C)—Si(1C)
O(5D)—Si(1D)—O(1D)
O(5D)—Si(1D)—O(4D)
O(1D)—Si(1D)—O(4D)
O(5D)—Si(1D)—O(3D)
O(1D)—Si(1D)—O(3D)
O(4D)—Si(1D)—O(3D)
O(2D)—Si(2D)—O(1D)
O(2D)—Si(2D)—C(7D)
O(1D)—Si(2D)—C(7D)
O(2D)—Si(2D)—C(1D)
O(1D)—Si(2D)—C(1D)
C(7D)—Si(2D)—C(1D)
O(2D)—Si(3D)—O(3D)
O(2D)—Si(3D)—C(19D)
O(3D)—Si(3D)—C(19D)
O(2D)—Si(3D)—C(13D)
O(3D)—Si(3D)—C(13D)
C(19D)—Si(3D)—C(13D)
Si(1D)—O(1D)—Si(2D)
Si(1D)—O(3D)—Si(3D)
Si(3D)—O(2D)—Si(2D)
130.82(16)
133.81(17)
110.13(15)
111.45(17)
109.06(17)
109.94(16)
109.56(15)
106.63(15)
106.95(16)
109.80(16)
108.83(16)
110.20(18)
108.57(15)
112.3(2)
108.14(14)
108.96(18)
109.2(2)
109.40(17)
110.10(18)
110.99(18)
133.32(17)
130.11(16)
132.9(2)
108.93(15)
108.45(13)
111.14(14)
111.07(14)
106.66(14)
110.59(14)
107.11(15)
109.37(14)
108.88(15)
110.46(14)
109.87(14)
111.05(18)
107.93(14)
108.16(18)
111.34(17)
109.36(16)
107.63(14)
112.32(16)
131.04(16)
133.1(2)
Angle
ω/deg
O(5A)—Si(1A)—O(4A)
O(5A)—Si(1A)—O(1A)
O(4A)—Si(1A)—O(1A)
O(5A)—Si(1A)—O(3A)
O(4A)—Si(1A)—O(3A)
O(1A)—Si(1A)—O(3A)
O(1A)—Si(2A)—O(2A)
O(1A)—Si(2A)—C(1A)
O(2A)—Si(2A)—C(1A)
O(1A)—Si(2A)—C(7A)
O(2A)—Si(2A)—C(7A)
C(1A)—Si(2A)—C(7A)
O(3A)—Si(3A)—O(2A)
O(3A)—Si(3A)—C(13A)
O(2A)—Si(3A)—C(13A)
O(3A)—Si(3A)—C(19A)
O(2A)—Si(3A)—C(19A)
C(13A)—Si(3A)—C(19A)
Si(1A)—O(1A)—Si(2A)
Si(2A)—O(2A)—Si(3A)
Si(3A)—O(3A)—Si(1A)
O(5B)—Si(1B)—O(3B)
O(5B)—Si(1B)—O(1B)
O(3B)—Si(1B)—O(1B)
O(5B)—Si(1B)—O(4B)
O(3B)—Si(1B)—O(4B)
O(1B)—Si(1B)—O(4B)
O(2B)—Si(2B)—O(1B)
O(2B)—Si(2B)—C(7B)
O(1B)—Si(2B)—C(7B)
O(2B)—Si(2B)—C(1B)
O(1B)—Si(2B)—C(1B)
C(7B)—Si(2B)—C(1B)
O(3B)—Si(3B)—O(2B)
O(3B)—Si(3B)—C(19B)
O(2B)—Si(3B)—C(19B)
O(3B)—Si(3B)—C(13B)
O(2B)—Si(3B)—C(13B)
C(19B)—Si(3B)—C(13B)
Si(1B)—O(1B)—Si(2B)
110.76(15)
108.88(17)
110.98(16)
109.91(16)
109.43(15)
106.81(15)
108.22(16)
109.48(17)
109.06(17)
109.35(16)
108.81(16)
111.8(2)
108.08(15)
108.85(19)
110.2(2)
109.38(18)
109.9(2)
110.4(2)
132.24(17)
130.28(17)
133.0(2)
108.25(16)
111.28(15)
106.39(14)
108.61(13)
111.68(14)
110.62(14)
108.16(14)
110.11(16)
108.19(16)
108.70(17)
110.23(14)
111.41(16)
107.48(15)
107.14(17)
109.48(14)
108.96(15)
111.53(14)
112.1(2)
130.47(16)
132.7(2)
cumented.10 However, no evidence for its structure was
presented. The attempts to carry out condensation of
monocycle 3 were undertaken, viz., heating in bulk
to 250 °С, in a solvent (THF), and in trifluoroacetic
acid. In all cases, mixtures of oligomeric products with
a higher degree of polymerization (according to the
GPC data) were produced, no cardocyclic compounds
were isolated. Thus, we did not succeed in terminating
the condensation process at the step of the formation
of dimer 4. For the preparation of 4 as an individual
compound, we developed another synthetic approach inꢀ
cluding two steps.
In the first step (Scheme 4), bis(2ꢀchloroꢀ4,4,6,6ꢀ
tetraphenylcyclotrisiloxanꢀ2ꢀyl) oxide (5) was synthesized
by partial hydrolysis of dichloride 1 at a ratio 1 : H2O of
2 : 1. In this case, hydrolysis was also accompanied by

Difunctional organocyclosiloxane dendron
Russ.Chem.Bull., Int.Ed., Vol. 59, No. 2, February, 2010
377
O(3S)
H(4OA)
O(4A)
O(5B)
Si(2B)
O(1B)
O(2B)
H(5OB)
Si(1B)
O(4B)
O(1A)
Si(2A)
Si(3B)
Si(1A)
O(3B)
O(3A)
O(5A)
O(2A)
Si(3A)
H(5OA)
H(4OB)
O(1S)
Fig. 1. General view of Нꢀbonded dimer 3.
condensation, but dichloride 5 was readily isolated from
Scheme 5
the reaction mixture by recrystallization.
Scheme 4
the siloxane bond that links the cyclic fragments (a maxiꢀ
mum at 1080 cm–1). Its position corresponds to the asymꢀ
metric stretching vibrations of the group Si—O—Si in linꢀ
ear siloxanes. The IR spectral data confirm that cycloꢀ
siloxane fragments are not split during condensation. Diol
4 undergoes spontaneous selfꢀdimerization, which is conꢀ
firmed by mass spectral data, the IR spectrum being virtuꢀ
ally unchanged.
For additional confirmation of the structure of diol 4,
we prepared its bis(trimethylsilyl) derivative 6 (Scheme 6).
In the second step (Scheme 5), hydrolysis of dichloꢀ
ride 5 was carried out in neutral medium. The yield of diol
4 was 75—82%. The data from elemental analysis, IR
spectroscopy, and mass spectrometry confirm the compoꢀ
sition and structure of compound 4.
Scheme 6
The IRꢀspectra of 4 and 5 display the intense absorpꢀ
tion band consisting of two maxima at 1025 and 1040 cm–1
,
the former corresponding to the asymmetric stretching
vibrations of the Si—O bond in the strained siloxane rings
and the latter being typical of the rings containing funcꢀ
tional groups.8 In addition, there is an absorption band of
In the IR spectrum of compound 6, the position of the
absorption band of the newly formed bond Si—O—Si coꢀ

378
Russ.Chem.Bull., Int.Ed., Vol. 59, No. 2, February, 2010
Zachernyuk et al.
Table 2. Dependence of the yield of dendron 8 on the reaction
conditions
incides with that of the siloxane bond between the cyclic
fragments, which is in agreement with the data in Ref. 8.
The ratio of the integral intensities of the signals for the
1
Solvent
HCl acceptor
t*/h
The yield of 8 (%)
protons HMe : HPh in the H NMR spectrum is 1 : 2.2,
which corresponds to two cyclosiloxane fragments in the
molecule.
THF
THF
THF
Diethyl ether
—
Aniline
mꢀNitroaniline
The same
170
5
5
43
12
61
14
As an alternative route for the preparation of diol 4, we
considered oxidation of the hydride groups in bis(4,4,6,6ꢀ
tetraphenylcyclotrisiloxanꢀ2ꢀyl) oxide (7), which was synꢀ
thesized by hydrolytic condensation of 2ꢀchloroꢀ4,4,6,6ꢀ
tetraphenylcyclotrisiloxane (2) (Scheme 7).
5
* Reaction time.
corresponding monocycles, which is probably explained
by greater lability of compound 4 compared to the linear
siloxanes and by the easiness of its condensation in the
acidic medium.
Scheme 7
The maximum yield of the dendron (61%) was obꢀ
tained in the reaction in THF using mꢀnitroaniline as the
acceptor of HCl.
The structure of dendron 8 studied by the Xꢀray difꢀ
fraction analysis is shown in Fig. 2. Compound 8 crystalꢀ
lizes in the form of a solvate with one molecule of ССl4.
Compound 8 occupies special position in the crystal, the
symmetry plane passes through the atoms Сl(1), Cl(2),
Si(1), and О(2). The principal geometric parameters of 8
are close to those of compound 3. For example, the siliꢀ
conꢀcontaining rings in the molecule are planar with the
maximal deviation of the spiro atom Si(2) from the
plane of the tetraphenylcyclotrisiloxane fragment equal to
0.07 Å. The Si—O bond lengths vary in the range of
1.604(2)—1.647(4) Å. The analysis of crystal packing
showed that all intermolecular contacts in 8 correspond to
the usual van der Waals interactions. The geometric paꢀ
rameters of 8 are presented in Table 3.
The ratio of the integral intensities of the signals for
the protons at the silicon atoms and for the phenyl protons
in the Н NMR spectrum is equal to 1 : 20, which conꢀ
1
firms its structure.
The attempt to oxidize compound 7 in the presence of
Pd/C according to a known procedure11 was not successꢀ
ful. Thus, only the method for preparation of diol 4 by
hydrolysis of its dichloride precursor 5 makes it possible to
synthesize compound 4 on a preparative scale.
Using heterofunctional condensation of diol 4 with
tetrachlorosilane (Scheme 8) in THF or diethyl ether both
in the presence of acceptor of HCl, viz., aniline or mꢀnitroꢀ
aniline, and in the absence of an acceptor, 15,15ꢀdichloroꢀ
2,2,4,4,10,10,12,12ꢀoctaphenyldispiro[5.1.5.3]heptasilꢀ
oxane (dendron) (8) was prepared (Table 2).
With the aim of preparing a hydroxylꢀcontaining anaꢀ
log of dendron 8, we carried out its hydrolysis under the
conditions similar to those used for the hydrolysis of
ring 1, i.e., in excess of water in the presence of (NH4)2CO3
to keep the medium neutral (Scheme 9).
Scheme 9
Scheme 8
n = 1 (9), 2 (10), 3 (11), 4 (12)
The synthesis of 8 in THF without an acceptor was
analogous to that of cyclosiloxanes 1 and 2. The yield of
the dendron in this case was lower (43%) than those of the
However, in this case, a mixture of hydroxylꢀcontainꢀ
ing dendron coupling products is produced. The presence
of four oligomeric products with the terminal hydroxyl

Difunctional organocyclosiloxane dendron
Russ.Chem.Bull., Int.Ed., Vol. 59, No. 2, February, 2010
379
Cl(1)
C(13A)
C(19A)
C(13)
C(19)
O(5)
O(1)
Si(4A)
Si(4)
Si(1)
O(1A)
O(5A)
Si(2A)
Si(2)
O(4A)
O(4)
O(2)
Si(3A)
C(7A)
Si(3)
C(7)
O(3A)
O(3)
C(1)
Cl(2)
C(1A)
Fig. 2. General view of dendron 8. The second positions of the chlorine atoms are not shown.
Table 3. Selected bond lengths (d) and bond angles (ω) in the structure of 8
Bond
d/Å
Angle
ω/deg
Angle
ω/deg
Si(1)—O(1)
Si(1)—Cl(2)
Si(1)—Cl(1)
Si(1)—Cl(1´)*
Si(1)—Cl(2´)*
Si(2)—O(3)
Si(2)—O(5)
Si(2)—O(2)
Si(2)—O(1)
Si(3)—O(4)
Si(3)—O(3)
Si(3)—C(1)
Si(3)—C(7)
Si(4)—O(4)
Si(4)—O(5)
Si(4)—C(13)
Si(4)—C(19)
1.611(2)
2.016(2)
2.016(2)
2.018(2)
2.012(2)
1.604(2)
1.609(2)
1.619(2)
1.632(2)
1.633(2)
1.647(2)
1.847(3)
1.850(3)
1.628(2)
1.643(2)
1.848(3)
1.851(3)
O(1)—Si(1)—O(1А)
O(1)—Si(1)—Cl(2´)
O(1)—Si(1)—Cl(2´)
O(1)—Si(1)—Cl(2)
O(1А)—Si(1)—Cl(2)
O(1)—Si(1)—Cl(1)
O(1А)—Si(1)—Cl(1)
Cl(2)—Si(1)—Cl(1)
O(1)—Si(1)—Cl(1´)
O(1А)—Si(1)—Cl(1´)
Cl(2´)—Si(1)—Cl(1´)
O(3)—Si(2)—O(5)
O(3)—Si(2)—O(2)
O(5)—Si(2)—O(2)
O(3)—Si(2)—O(1)
O(5)—Si(2)—O(1)
O(2)—Si(2)—O(1)
109.0(1)
113.12(8)
113.12(8)
103.51(9)
103.51(9)
113.86(9)
113.86(9)
112.1(1)
106.96(9)
106.96(9)
107.28(11)
108.83(9)
110.9(1)
110.2(1)
109.6(1)
110.0(1)
107.3(1)
O(4)—Si(3)—O(3)
O(4)—Si(3)—C(1)
O(3)—Si(3)—C(1)
O(4)—Si(3)—C(7)
O(3)—Si(3)—C(7)
C(1)—Si(3)—C(7)
O(4)—Si(4)—O(5)
O(4)—Si(4)—C(13)
O(5)—Si(4)—C(13)
O(4)—Si(4)—C(19)
O(5)—Si(4)—C(19)
C(13)—Si(4)—C(19)
Si(1)—O(1)—Si(2)
Si(2)—O(2)—Si(2А)
Si(2)—O(3)—Si(3)
Si(4)—O(4)—Si(3)
Si(2)—O(5)—Si(4)
106.59(9)
108.2(1)
111.3(1)
109.9(1)
107.3(1)
113.35(12)
106.22(9)
110.56(11)
108.65(11)
108.91(10)
110.94(11)
111.44(12)
131.49(12)
133.17(18)
131.93(11)
133.72(11)
132.41(12)
* The Сl(1´) and Сl(2´) atoms relate to the second position of the disordered SiCl2 group.
LiAlH4), CCl4, diethyl ether, and hexane (dried and distilled
over CaH2).
groups was established by mass spectrometry. The isolaꢀ
tion of 15,15ꢀdihydroxyꢀ2,2,4,4,10,10,12,12ꢀoctaphenylꢀ
dispiro[5.1.5.3]ꢀheptasiloxane (9, n = 1) from the reacꢀ
tion mixture by reprecipitation or recrystallization failed.
Difunctional tetraphenylcyclotrisiloxanes 1 and 2 were synꢀ
thesized according to a known procedure8 by the reactions of
1,3ꢀdihydroxytetraphenyldisiloxane with tetrachloroꢀ and triꢀ
chlorosilane in the presence and in the absence of an HCl acꢀ
ceptor. THF was used as a solvent. Ammonium carbonate (anaꢀ
lytically pure grade) as the hydrogen chloride acceptor was used
without additional purification.
The 1H NMR spectra were recorded on a Bruker WPꢀ200
SY (200.13 MHz) instrument. CDCl3 was used as the solvent
and the internal standard.
Experimental
The starting silicon tetrachloride, trichlorosilane, dichloroꢀ
diphenylsilane, pyridine, and trimethylchlorosilane were freshly
distilled in an inert atmosphere prior to use. The solvents used
were THF (successively dried and distilled over CaH2 and

380
Russ.Chem.Bull., Int.Ed., Vol. 59, No. 2, February, 2010
Zachernyuk et al.
Gas chromatographic analysis was carried out on a Model
Table 4. Crystallographic data and main details of structure reꢀ
finement for compounds 3 and 8
3700 (Russia) chromatograph (catharometer as the detector; heꢀ
lium as the carrier gas; columns 2 m × 3 mm with SEꢀ30 (5%) on
ChromatonꢀNꢀAW). Integration of chromatograms was carried
out with an Interchrom integrator (Bulgaria).
Gel permeation chromatography was carried out on Waters
μꢀStyragel columns (the pore sizes were 105, 104, 103, and 106 Å)
and Silasorb 600 silylated with hexamethyldisilazane (the parꢀ
ticle size was 7.5 μm) using toluene as the eluent and a Waters
410 or RIDK 102 differential refractometer as the detector.
The IR spectra were registered on a URꢀ10 instrument in
KBr pellets.
Parameter
Compound
3
8
Molecular formula
Molecular weight
Crystal system
Space group
T/K
C28H30O6Si3
546.79
C49H40Cl6O9Si7
1182.24
Orthorhombic
Pnma
Triclinic
Р–1
120
120
Z(Z´)
8(4)
4(0.5)
The Xꢀray diffraction studies for compounds 3 and 8 were perꢀ
formed on a Bruker AXS SMART 1000 diffractometer equipped
with a CCD detector (λ(MoꢀKα) = 0.71073 Å, graphite monoꢀ
chromator, ω−scanning technique). The processing and averaging
of experimental data were performed using a SAINT Plus12 softꢀ
ware with the semiempirical allowance for absorption.13
The structures of compound 3 and 8 were solved by direct
methods and refined by the fullꢀmatrix leastꢀsquares method in
a/Å
b/Å
c/Å
α/deg
18.182(5)
18.403(5)
20.760(5)
64.379(6)
64.432(5)
73.872(5)
5615(2)
1.294
18.337(3)
28.187(4)
10.952(2)
90.00
β/deg
γ/deg
90.00
5660.9(14)
1.347
V/Å3
dcalc/g cm–3
Absorption
coefficient μ/mm–1
F(000)
the isotropic appoximation based on F2 with the successive
hkl
2.09
4.55
syntheses of electron density. The analysis of the differential
Fourier syntheses showed that the phenyl rings, the carbon
atoms of THF in 3 and chlorine atoms of the SiCl2 and ССl4
groups in 8 are disordered with the equal values of populations.
The positions of the hydrogen atoms, except for the atoms of the
hydroxyl groups, were calculated from the geometry, whereas
the latter was localized from the Fourier syntheses. The strucꢀ
ture refinements were performed using the SHELX TL 5.10 proꢀ
gram package (see Ref. 14). Principal crystallographic and strucꢀ
ture refinement parameters for compounds 3 and 8 are summaꢀ
rized in Table 4.
2304
52
33501 (0.0456)
2360
54.0
37980 (0.0798)
2θmax/deg
Number of reflections
measured
added with stirring to a solution of 1 (6.2 g, 12.1 mmol) in THF
(10 mL) for 1.3 h. The reaction mixture was stirred for additional
3 h. Then THF was completely removed, the product was reꢀ
crystallized from dry CCl4. Needleꢀlike crystals of 5 (4.9 g, 84%)
were obtained. M.p. 132—134 °C. Found (%): С, 59.27; H, 4.18;
Si, 16.82; Cl, 7.21. C48H40Cl2O7Si6. Calculated (%): C, 59.51;
H, 4.13; Si, 17.37; Cl, 7.23. MALDIꢀTOF MS, found: m/z 989.08
[M + Na]+. C48H40Cl2O7Si6Na; calculated: m/z 989.05. Found:
m/z 1005.05 [M + K]+. C48H40Cl2O7Si6K; calculated: m/z
1005.03. IR (CCl4), ν/cm–1: 1025, 1040 (SiOSi cyclic); 1080
(SiOSi linear); 704, 726, 1128, 1602 (SiCPh).
Bis(2ꢀhydroxyꢀ4,4,6,6ꢀtetraphenylcyclotrisiloxanꢀ2ꢀyl) oxide
(4). To a cooled (–3 °C) solution of water (0.4 g, 22 mmol) and
(NH4)2CO3 (1 g, 10.4 mmol) in dry THF (20 mL), a solution of 5
(1.09 g, 1.12 mmol) in THF (16 mL) was added for 1.5 h. The mixꢀ
ture was stirred for additional 1 h at room temperature. The
precipitate that formed was filtered off, 70% of the solvent was
removed and hexane (10 mL) was added. Colorless crystals of 4
(0.85 g, 82%) were obtained by recrystallization. M.p. 93—95 °C.
Found (%): C, 61.48; H, 4.64; Si, 17.63. C48H42O9Si6. Calcuꢀ
lated (%): C, 61.93; H, 4.52; Si, 18.06. MALDIꢀTOF MS, found:
m/z 953.14 [M + Na]+. C48H42O9Si6Na; calculated: m/z 953.13.
Found: m/z 969.12 [M + K]+. C48H42O9Si6K; calculated: m/z
969.10. IR (CCl4), ν/cm–1: 1025, 1040 (SiOSi cyclic); 1080
(SiOSi linear); 704, 726, 1128, 1602 (SiCPh); 3383, 3568,
3619 (SiOH).
The MALDIꢀTOF mass spectra were recorded on a Bruker
Reflex IY instrument in the linear mode. 2,5ꢀDihydroxybenzoic
acid was used as a matrix. The m/z measurement accuracy
was <35 ppm.
Hydrolytic condensation of 2,2ꢀdichloroꢀ4,4,6,6ꢀtetraphenylꢀ
cyclotrisiloxane (1). A solution of 1 (12.4 g, 24.2 mmol) in THF
(25 mL) was added with stirring to a cooled (0—1 °C) solution of
water (1.31 g, 72.6 mmol) in THF (125 mL) for 2.5 h and 60% of
THF was distilled off. Then hexane (20 mL) was added, the preꢀ
cipitate that formed was filtered off and dried in vacuo. According
to GPC data, the crystals (6.8 g) obtained were a mixture of oliꢀ
gomers. IR (CCl4), ν/cm–1: 1025, 1040 (SiOSi cyclic); 1080—1090
(SiOSi linear); 704, 726, 1128, 1595 (SiCPh). After treatment of
the obtained crystals with Me3SiCl and Py (a 1% solution in
THF), a mixture of trimethylsilyl derivatives was obtained.
1Н NMR (CDCl3), δ: 0.18 (s, 18 НMe); 7.05—7.77 (m, 63 НPh).
2,2ꢀDihydroxyꢀ4,4,6,6ꢀtetraphenylcyclotrisiloxane (3). To
a cooled (–3 °C) solution of water (0.4 g, 22 mmol) and
(NH4)2CO3 (1 g, 10.4 mmol) in THF (20 mL), a solution of 1
(5.32 g, 10.4 mmol) in THF (16 mL) was added for 0.5 h. The
mixture was stirred for additional 1 h at room temperature. The
precipitate that formed was filtered off, 70% of the solvent was
removed and hexane (10 mL) was then added. White crystal
flakes of 3 (4.68 g, 95%) were isolated by recrystallization. M.p.
62 °C. Found (%): C, 60.98; H, 4.66; Si, 17.79. C24H22O5Si3.
Dimer of compound 4. The dimer formed when a dilute soluꢀ
tion of 4 (0.2 mol L–1) in THF was left for 4 days at 25 °C. MS
MALDIꢀTOF, found: m/z 1865.28 [M + Na]+. C96H82O17Si12Na;
calculated: m/z 1865.26. Found: m/z 1881.25 [M + K]+.
Calculated (%): C, 60.93; H, 4.52; Si. 17.76. IR (KBr), ν/cm–1
:
1028—1041 (SiOSi cyclic); 1080 (SiOSi linear); 704, 726, 1128,
1600 (SiCPh); 3383, 3568, 3619 (SiOH).
C96H82O17Si12K; calculated: m/z 1881.23. IR (KBr), ν/cm–1
:
1028—1041 (SiOSi cyclic); 1080 (SiOSi linear); 704, 726, 1128,
1600 (SiCPh); 3383, 3568, 3619 (SiOH).
Bis(2ꢀchloroꢀ4,4,6,6ꢀtetraphenylcyclotrisiloxanꢀ2ꢀyl) oxide
(5). A solution of water (0.1 g, 5.55 mmol) in THF (6 mL) was

Difunctional organocyclosiloxane dendron
Russ.Chem.Bull., Int.Ed., Vol. 59, No. 2, February, 2010
381
Bis(2ꢀtrimethylsiloxyꢀ4,4,6,6ꢀtetraphenylcyclotrisiloxanꢀ2ꢀ
yl)oxide (6). A solution of 4 (0.05 g, 0.054 mmol) in dry THF
(2 mL) was quickly added to a solution of Me3SiCl (0.06 mL,
0.27 mmol) and pyridine (0.01 mL, 0.0108 mmol) in dry THF
(2 mL). The mixture was stirred for 10 h. The precipitate that
formed was filtered off, the solvent and excess of Me3SiCl were
removed in vacuo at 35 °C for 2 h. White crystalline compound 6
(0.056 g, 97%) was obtained. M.p. 86—87 °C. Found (%):
С, 60.76; Н, 5.6; Si, 20,14. C54H58O9Si8. Calculated (%): С, 60.23;
Н, 5.4; Si, 20.85. MALDIꢀTOF MS, found: m/z 1097.23 [M + Na]+
C54H58O9Si8Na; calculated: m/z 1097.21. Found: m/z 1113.20
[M + K]+. C54H58O9Si8K; calculated: m/z: 1113.18. 1Н NMR
(CDCl3), δ: 0.18 (s, 18 Н, SiMe3); 7.05—7.77 (m, 40 Н, Ph).
IR (ССl4), ν/cm–1: 1029—1040 (SiOSi cyclic); 1090 (SiOSi linꢀ
ear); 704, 726, 1129, 1595 (SiCPh), 855, 1260 (SiCMe).
1985.19. Found: m/z 2001.19 [M + K]+. C96H82O21S14K; calcuꢀ
lated: m/z 2001.17. Found: m/z 2003.22 [M + Na + H2O]+.
C96H84O22Si14Na; calculated: m/z 2003.20. Found: m/z 2021.24
[M + Na + 2 H2O]+. C96H86O23Si14Na; calculated: m/z 2021.22.
Compound 11 (n = 3, 3.9%). MALDIꢀTOF MS, found:
m/z: 2975.32 [M + Na + H2O]+. C144H124O32Si21Na; calcuꢀ
lated: m/z 2975.30. Found: m/z 2993.33 [M + Na + 2H2O]+.
C144H126O33Si21Na; calculated: m/z 2993.31.
Compound 12 (n = 4, 7.1%). MALDIꢀTOF MS, found:
m/z: 3947.42 [M + Na + H2O]+. C192H164O42Si28Na; calcuꢀ
lated: m/z 3947.40. Found: m/z: 3965.44 [M + Na + 2 H2O]+.
C192H166O43Si28Na; calculated: m/z 3965.41.
References
Bis(4,4,6,6ꢀtetraphenylcyclotrisiloxanꢀ2ꢀyl) oxide (7). A soꢀ
lution of 2 (3.36 g, 7.05 mmol) in THF (3 mL) was added to
a cooled (0 °C) mixture of H2O (0.063 g, 3.5 mmol) and
(NH4)2CO3 (0.336 g, 3.5 mmol) in THF (3 mL) for 20 min. The
mixture was stirred at room temperature for 9.5 h and the preciꢀ
pitate that formed was filtered off. The product was isolated by
recrystallization from a mixture of THF and hexane. Colorless
needleꢀlike crystals of 7 (2.3 g, 73%) were obtained. M.p.
156—158 °C. Found (%) C, 64.20; H, 4.72; Si, 18.74. C48H42O7Si6.
Calculated (%): C, 64.07; H, 4.67; Si, 18.74. MALDIꢀTOF MS,
found: m/z: 921.16 [M + Na]+. C48H42O7Si6Na; calculated: m/z
921.14. Found: m/z 937.13 [M + K]+. C48H42O7Si6K; calculated:
m/z 937.11. 1Н NMR (CDCl3), δ: 4.59 (s, 2 H, SiH); 7.00—7.77
(m, 40 H, Ph). IR (KBr), ν/cm–1: 1030, 1040 (SiOSi cyclic);
1090 (SiOSi linear); 702, 727, 1127, 1599 (SiCPh); 2249 (SiH).
15,15ꢀDichloroꢀ2,2,4,4,10,10,12,12ꢀoctaphenyldispiroꢀ
[5.1.5.3]heptasiloxane (8). To a solution of 4 (0.48 g, 0.516 mmol)
and mꢀnitroaniline (0.142 g, 1 mmol) in dry THF (2.5 mL) that
was cooled to –5 °C, a solution of SiCl4 (0.06 mL, 0.516 mmol)
in dry THF (1 mL) was added with stirring. The reaction mixture
was stirred for 3 h at room temperature. The precipitate that
formed was filtered off and THF was completely removed. The
product was isolated by crystallization from dry CCl4. White
crystals of 8 (0.32 g, 61%) were collected. M.p. 145—148 °C.
1. K. A. Andrianov, A. B. Zachernyuk, G. V. Solomatin,
Dokl. Akad. Nauk USSR, 1977, 236, 601 [Dokl. Chem.
(Engl. Transl.), 1977].
2. A. B. Zachernyuk, A. A. Zhdanov, V. E. Shklover, Zh.
Obshch. Khim., 1987, 57, 562 [J. Gen. Chem. USSR
(Engl. Transl.), 1987, 57].
3. G. Garzó, J. Tamá, T. Székely, K. Ujszászi, Acta Chim. Acad.
Sci. Hung, 1971, 69, 273.
4. A. B. Zachernyuk, Abstrs, Vserossiiskaya konferentsiya "Kremꢀ
niiorganicheskiye soedineniya: sintez, svoystva, primenenie"
[AllꢀRussian Conference "Organosilicon compounds: synthesis,
properties, and application"] (Moscow, February 1—4, 2000),
Moscow, 2000, p. 19.
5. M. V. Nevezhin, A. B. Zachernyuk, A. M. Muzafarov, Abstrs,
SanktꢀPeterburgskaya konferentsiya molodykh uchenykh "Sovꢀ
remennye problemy nauki o polimerakh" [StꢀPetersburg´s Conꢀ
ference of Young Scientists "Modern problems of polymer sciꢀ
ence" ] (St. Petersburg, February 1—3, 2005), St. Petersburg,
2005, p. 1—18.
6. V. E. Shklover, Yu. T. Struchkov, G. V. Solomatin, A. B.
Zachernyuk, A. A. Zhdanov, Zh. Struct. Khim, 1980, 21, 94
[J. Struct. Chem. USSR (Engl. Transl.), 1980, 21].
7. V. Yu. Orlov, A. B. Zachernyuk, K. A. Andrianov, Izv. Akad
Nauk USSR. Ser. Khim., 1974, 330 [Bull. Acad. Sci. USSR,
Div. Chem. Sci. (Engl. Transl.), 1974, 23].
MALDIꢀTOF MS, found: m/z 1029.08 [M
+
3H]+.
C48H43Cl2O9Si7, calculated: m/z 1029.06. Found: m/z 1047.09
[M + 3 H + H2O]+. C48H45Cl2O10Si7, calculated: m/z 1047.07.
Found: m/z 1065.10 [M + 3 H + 2 H2O]+. C48H47Cl2O11Si7;
calculated: m/z: 1065.08. IR (ССl4), ν/cm–1: 1022, 1042 (SiOSi
cyclic); 1129, 1486, 1599 (SiCPh).
Hydrolysis of dendron 8. To a cooled (–3 °C) solution of
water (0.4 g, 22 mmol) and (NH4)2CO3 (1 g, 10.4 mmol) in THF
(20 mL), a solution of 8 (1.15 g, 1.12 mmol) in dry THF (16 mL)
was added for 2 h. The precipitate that formed was filtered off
and the solvent was removed. A noncrystallizable mixture (1.04 g)
of oligomers (in a ratio of 14.4 : 8.4 : 1 : 1.8, according to
the GPC data) was obtained. According to the massꢀspectral
data, hydroxylꢀcontaining condensation products are present,
n = 1—4 (see Scheme 9).
8. A. B. Zachernyuk, E. A. Burlova, A. A. Zhdanov, Zh. Obshch.
Khim, 1983, 55, 1368 [J. Gen. Chem. USSR (Engl. Transl.),
1983, 55].
9. E. A. Chernyshev, P. V. Ivanov, D. N. Golubykh, Izv. Akad
Nauk. Ser. Khim., 2001, 1909 [Russ. Chem. Bull., Int. Ed.,
2001, 50, 1998].
10. K. A. Andrianov, A. B. Zachernyuk, Khimiya geterotsikl.
soedinenii, 1972, 1183 [Chem. Heterocycl. Compd. (Engl. Transl.),
1972].
11. J. K. Paulasaari, W. P. Weber, Macromolecules, 2000, 33, 2005.
12. Bruker SMART, Bruker Molecular Analysis Research Tool,
v. 5.059, Bruker AXS, Madison, Wisconsin, USA, 1998.
13. G. M. Sheldrick, SADABS, v. 2.01, Bruker/Siemens Area
Detector Absorption Correction Program, Bruker AXS, Madiꢀ
son, Wisconsin, USA, 1998.
15,15ꢀDihydroxyꢀ2,2,4,4,10,10,12,12ꢀoctaphenyldispiroꢀ
[5.1.5.3]heptasiloxane (9, n = 1, 56.3%). MALDIꢀTOF MS,
found: m/z 1013.12 [M + Na]+. C48H42O11Si7Na; calculated:
m/z 1013.10. Found: m/z 1029.09 [M + K]+. C48H42O11Si7K;
calculated: m/z 1029.07.
14. G. M Sheldrick, SHELXTL v. 5.10, Structure Determination
Software Suite, Bruker AXS, Madison, Wisconsin, USA, 1998.
Compound 10 (n = 2, 32.7%). MALDIꢀTOF MS, found:
m/z 1985.21 [M + Na]+. C96H82O21Si14Na; calculated: m/z
Received September 29, 2008;
in revised form October 26, 2009