Reactions of silicon hydrides catalyzed by rhodium(III) sulfoxide complexes

Article abstract of DOI:10.1134/S1070363217080400

Dehydrocondensation reactions of silicon hydrides catalyzed by the rhodium(III) complex [RhCl₃(Me₂SO)₃] in the absence of the second substrate were studied. It was found that the complex [RhCl₃(Me₂SO)₃] catalyzed the dehydrocondensation reaction with the formation of compounds containing siloxane bonds. Analysis of NMR spectra has shown that the reaction of [RhCl₃(Me₂SO)₃] with silicon hydride includes sequential desoxygenation of sulfoxide ligands to sulfide ligands with the complex [RhCl₃(Me₂S)₃] formation.

Full text of DOI:10.1134/S1070363217080400

ISSN 1070-3632, Russian Journal of General Chemistry, 2017, Vol. 87, No. 8, pp. 1884–1886. © Pleiades Publishing, Ltd., 2017.
Original Russian Text © A.A. Eliseeva, E.G. Prudnikova, T.L. Panikorovskii, N.K. Skvortsov, 2017, published in Zhurnal Obshchei Khimii, 2017, Vol. 87,
No. 8, pp. 1398–1400.
LETTERS
TO THE EDITOR
Reactions of Silicon Hydrides Catalyzed
by Rhodium(III) Sulfoxide Complexes
a
a
b
a
A. A. Eliseeva *, E. G. Prudnikova , T. L. Panikorovskii , and N. K. Skvortsov
a
St. Petersburg State Institute of Technology (Technical University), Moskovskii pr. 26, St. Petersburg, 190013 Russia
e-mail: nastya.shkinder@gmail.com
*
b
St. Petersburg State University, St. Petersburg, Russia
Received April 27, 2017
Abstract—Dehydrocondensation reactions of silicon hydrides catalyzed by the rhodium(III) complex
[
[
RhCl
RhCl
3
(Me
(Me
2
SO)
SO)
3
] in the absence of the second substrate were studied. It was found that the complex
] catalyzed the dehydrocondensation reaction with the formation of compounds containing
3
2
3
3 2 3
siloxane bonds. Analysis of NMR spectra has shown that the reaction of [RhCl (Me SO) ] with silicon hydride
includes sequential desoxygenation of sulfoxide ligands to sulfide ligands with the complex [RhCl
3 2 3
(Me S) ]
formation.
Keywords: dehydrocondensation, silicon hydride, rhodium(III) complex, desoxygenation of ligands
DOI: 10.1134/S1070363217080400
Rhodium complexes are widely used as catalysts
for hydrosilylation and dehydrocondensation reactions
of silicon hydrides. Coordination-unsaturated rhodium(I)
complexes with phosphorus-containing ligands are
prevailingly used for these purposes, whereas data on
the catalytic activity of rhodium complexes in higher
oxidation states are limited to singular examples [1, 2].
and to the elucidation of the possibility of the prepara-
tion of compounds with Si–Si bonds. It has been found
that the complex [RhCl (Me SO) ] catalyzes the
3
2
3
reaction of diphenylsilane dehydrocondensation in the
absence of an alcohol at higher temperatures (40–50°C,
–3
the catalyst concentration 10 mol/mol of diphenyl-
silane) with the hydrogen evolution and the formation
of a solid reaction product (Scheme 1).
Recently we have shown that rhodium(III) sul-
foxide complexes [RhCl (R SO) ], in spite of coordina-
Bands of stretching Si–H vibrations in the region of
3
2
3
–
1
2
8
100 cm and of bending vibrations in the region of
tion saturation, are effective catalysts for reactions of
diphenylsilane methanolysis [3] and styrene methyl-
dichlorosilane hydrosilylation [4], being no worse than
the traditional Wilkinson's catalyst [RhCl(Ph P) ] and
–
1
60 cm are absent from the IR spectrum of the
resulting compound, but strong absorption bands in the
–
1
range of 1000–1100 cm characteristic of the Si–O–Si
3
3
1
bond appear. In the H NMR spectrum resonance
sometimes surpassing it in activity and selectivity.
signals of Si–H protons in the region of 5 ppm also are
not observed, which points to the complete consump-
tion of silylhydride hydrogen atoms.
This paper is devoted to the catalytic silicon
hydride reactions in the absence of a second substrate
Scheme 1.
C H )
(
(C H )
6 5 2
6
5 2
O
C H
Si
Si
6
5
H
Si
H
O
O
+
H2
Si
Si
C H
6
5
O
(
C H )
(C H )
6 5 2
6
5 2
1
884

REACTIONS OF SILICON HYDRIDES
To determine the compound structure, we have
1885
isolated its single crystals and studied them using
X-ray diffraction analysis. According to the X-ray
data, the compound is octaphenyltetracyclosiloxane
(
see the figure). Crystal structure of the siloxane is a
triclinic modification previously described in [5, 6].
The independent part consists of two halves of
siloxane molecules differing by the slope angles of the
phenyl groups with respect to the siloxane ring
(
1
112.5°, 112.3° for the first molecule and 110.6°,
09.5° for the second molecule, respectively). The
lengths of the Si–C bonds vary within the limits of
.849–1.864 Å. The conformation of the siloxane ring
1
General view of the octaphenyltetracyclosiloxane molecule
in a crystal.
is close to flat, the deviation of atoms from the ring
plane for the both molecules not exceeding 0.08 Å.
The Si–O bond lengths are within the limits of 1.617–
1
1
.627 Å and are consistent with the average length of
,630 Å for Si–O bonds in siloxanes.
4
0°C in the presence of [RhCl (Me SO) ] gives
3
2
3
two products: methyldiphenylsilanol and 1,1,3,3-tetra-
phenyl-1,3-dimethyldisiloxane in the ratio 25 : 75
(Scheme 2).
According to the chromato-mass-spectrometry data,
the dehydrocondensation of diphenylmethylsilane at
Scheme 2.
C H
C H
C H
C H
6 5
6
5
6
5
6
5
H
Si CH3
C H
H C Si
O
Si CH3 + H C Si OH
3
3
C H
C H
C H
6 5
6
5
6
5
6
5
The complex [RhCl (Me SO) ] also catalyzes the
to chlorine, δ = 3.46 ppm, and in the trans-position to
the ligand bound through oxygen, δ = 3.65 ppm).
Signals of methyl protons of sulfoxides bound through
sulfur, which were previously identified as singlets [9],
3
2
3
reaction of 1,1,3,3-tetramethyldisiloxane with the
formation of a mixture of cyclic and linear oligomeric
siloxanes.
are doublets with a constant J
= of 0.5 Hz of
RhH
We have studied [RhCl (Me SO) ] transformations
3
2
3
103
splitting by the
Rh atom, as we have shown by
on its reaction with silicon hydride by the NMR
method. According to the X-ray data, the complex has
the structure of mer,cis-[RhCl (Me SO) ], in which
applying algorithms of narrowing lines. The presence
of these signals can be used as indicators for studying
transformations of the initial metal complex.
3
2
3
two sulfoxides are coordinated through the sulfur atom
and one through the oxygen atom [7, 8].
The analysis of the NMR spectra has shown that the
reactions of [RhCl (Me SO) ] with silicon hydrides
3
2
3
Cl
include sequential deoxygenation of sulfoxide ligands
to sulfide ligands with the final formation of a complex
with three dimethylsulfide ligands (Scheme 3).
Me
S
O
Cl
Me
Rh
O
Cl
Me
S
Me
The product of full deoxygenation to the sulfide
complex was obtained with a high yield by the reaction
of [RhCl (Me SO) ] with a tetramethyldisiloxane
S
Me
O
Me
3
2
3
1
In the H NMR spectrum of [RhCl (Me SO) ] three
3
2
3
signals are clearly observed, which correspond to three
ligands: dimethylsulfoxide molecule bound through
oxygen (δ = 2.88 ppm) and two dimethylsulfoxide
molecules bound through sulfur (in the trans-position
Scheme 3.
] → [RhCl (Me
S) ] → [RhCl
[
RhCl
3
(Me
2
SO)
3
3
2
SO)
2
(Me
2
S)]
→
[RhCl
3
(Me
2
SO)(Me
2
2
3
(Me
2
3
S) ].
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 87 No. 8 2017

1
886
ELISEEVA et al.
Scheme 4.
] → [PtCl (Et
(Et S) ] → Pt colloid.
filtered off on a glass filter. The reaction product was
washed with hexane and dried at 80°C. Yield 0.45 g
[
PtCl
2
(Et
2
SO)
2
2
2
SO)(Et
2
S)]
–1
(
91%). IR spectrum ν, cm : 1416 s (SC–H), 683 w
1
→
[PtCl
2
2
2
(S–C). H NMR spectrum (CDCl ), δ, ppm: 2.54 d
(
1
3
3
3
6H, SCH , J
= 0.7 Hz), 2.31 d (3H, SCH , J
.0 Hz). C NMR spectrum (CDCl ), δ , ppm: 21.03
=
3
RhH
3
RhH
1
3
excess. The structure of the complex was confirmed by
the elemental analysis and also by NMR and IR
spectroscopy. It should be noted that the oxidation
state of the metal remains unchanged in this case. It
3 p
(
CH ) 21.93 (2CH ). Found, %: C 18.88; N 4.15; S
3 3
2
4.67. C H Cl RhS . Calculated, %: C 18.21; H 4.59;
6
18
3
3
S 24.31.
1
13
follows from the analysis of the H and C NMR
spectra of the resulting sulfide compound that in its
structure two sulfide molecules are located in the trans-
position to each other [δ , ppm: 2.54 d (6H, SCH ); δ ,
REFERENCES
1
2
3
. Reznikov, A.N., Lobadyuk, V.I., Spevak, V.N., and
Skvortsov, N.K., Russ. J. Gen. Chem., 1998, vol. 68,
no. 6, p. 910.
H
3
p
ppm: 21.93 (2CH )], and the third molecule,in the
3
trans-position to Cl [δ , ppm: 2.31 d (3H, SCH ); δ ,
H
3
C
. Voinova, T.V., Spevak, V.N., and Skvortsov, N.K., Izv.
St. Petersburg State Techn. Inst. (Techn. Univer.), 2012,
no. 16 (42), p.8.
ppm: 21.03 (CH )]. The structure of such octahedral
complex obtained in a different way was studied
earlier by the X-ray diffraction analysis [10].
3
. Eliseeva, A.A., Prudnikova, E.G., Khokhryakov, K.A.,
Spevak, V.N., and Skvortsov, N.K., Izv. St. Petersburg
State Techn. Inst. (Techn. Univer.), 2015, no. 32(58),
p. 85.
Cl
Cl
S(Me)2
Rh
(
Me)2S
S(Me)2
4. Eliseeva, A.A., Spevak, V.N., Kalinin, A.V., and
Cl
Skvortsov, N.K., Izv. St. Petersburg State Techn. Inst.
Similar processes of deoxygenation of sulfoxide
ligands by silicon hydrides were observed previously
for platinum(II) complexes [11]. However, in the case
of platinum complexes the reaction with tetramethyl-
disiloxane proceeds deeper to reduce a metal complex
to a platinum colloid (Scheme 4).
(
Techn. Univer.), 2014, no. 1(4), p. 48.
5
. Ovchinnikov, Yu.N., Shklover, V.E., Struchkov, Yu.T.,
Dement’ev, V.V., and Frunze, T.M., Metalloorg.
Chem., 1988, vol. 1, no. 5, p. 1117.
6
. Hensen, K., Gebhardt, F., Kettner, M., Pickner, P., and
Bolte, M., Acta Cryst. (C), 1997, vol. 53, no. 12,
p. 1867. doi 10.1107/S0108270197010068
Thus, the complex [RhCl (Me SO) ] catalyzes
3
2
3
reactions of silicon hydrides with the formation of
compounds containing siloxane bonds. No formation
of products containing Si–Si bonds was not found.
7
. Sokol, V.I. and Porai-Koshits, M.A., Koord. Khim.,
1
975, vol. 1, no. 4, p. 577.
8
. Harlos, M., Ott, I., Gust, R., Alborzinia, H., Wolf, S.,
Kromm, А., and Sheldrick, W., J. Med. Chem., 2008,
vol. 51, no. 13, p. 3924. doi 10.1021/jm800173s
Synthesis
of
[RhCl (Me S) ].
Complex
3
2
3
[
Rh(Me SO) Cl ], 0.5 g (0.0011 mol), was partially
2
3
3
dissolved in methylene chloride. 1,1,3,3-Tetramethyl-
disiloxane, 1 mL (0.0076 mol), was added to the
solution. During stirring hydrogen was liberated and
the reaction mixture self-heated; the solution turned
dark cherry. The resulting solution was left for a day to
complete the reaction. After 24 h a crystalline mass of
cherry color and a viscous liquid were formed. To the
mixture 20 mL of hexane was added, a precipitate was
9. James, B.R. and Morris, R.H., Can. J. Chem., 1980,
vol. 58, no. 4, p. 399. doi 10.1139/v80-064
10. Abassi, A., Habibian M., and Sandström, M., Acta
Cryst. (E), 2007, vol. 63, p. m1094. doi 10.1107/
S1600536807027912
11. Skvortsov, N.K., Spevak, V.N., Lobadyuk, V.I., Titov, K.E.,
Konovalov, V.E., and Bel’skii, V.K., Zh. Obshch.
Khim., 1994, vol. 64, no. 10, p. 1663.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 87 No. 8 2017