Synthesis, structure and catalytic properties of bis[2-(trifluoromethyl)phenyl]silanediol

Article abstract of DOI:10.1002/aoc.4427

A novel trifluoromethylaryl-substituted disilanol, bis[(2-trifluoromethyl)phenyl] silanediol, was prepared by hydrolysis of the precursor dichloride and fully characterized. Single-crystal X-ray diffraction indicates doubly linked hydrogen bonded dimers a

Full text of DOI:10.1002/aoc.4427

Received: 16 March 2018
DOI: 10.1002/aoc.4427
Revised: 27 April 2018
Accepted: 27 April 2018
F U L L P A P E R
Synthesis, structure and catalytic properties of bis[2‐
(trifluoromethyl)phenyl]silanediol†
Natascha Hurkes1 | Ferdinand Belaj2
| Julian R. Koe3 | Rudolf Pietschnig1
1 Institute of Chemistry and Center for
A novel trifluoromethylaryl‐substituted disilanol, bis[(2‐trifluoromethyl)phe-
nyl] silanediol, was prepared by hydrolysis of the precursor dichloride and fully
characterized. Single‐crystal X‐ray diffraction indicates doubly linked hydrogen
bonded dimers and also hydrogen bonding to tetrahydrofuran solvent. The
acidity of the silanol functions is enhanced by the presence of the
trifluoromethyl groups and the compound is found to be active in promoting
a standard Diels–Alder reaction, increasing yields by a factor of three.
Interdisciplinary Nanostructure Science
and Technology (CINSaT), University of
Kassel, Heinrich‐Plett‐Straße 40, 34132
Kassel, Germany
2 Institute of Chemistry, Karl‐Franzens‐
University, Schubertstraße 1, 8010 Graz,
Austria
3 Department of Natural Sciences,
International Christian University, 3‐10‐2
Osawa, Mitaka, Tokyo 181‐8585, Japan
KEYWORDS
catalysis, Diels–Alder, hydrogen bond, silanediol, trifluoromethyl
Correspondence
Julian R. Koe, Department of Natural
Sciences, International Christian
University, 3‐10‐2 Osawa, Mitaka, Tokyo
181‐8585 Japan.
Email: koe@icu.ac.jp
Rudolf Pietschnig, Institute of Chemistry
and Center for Interdisciplinary
Nanostructure Science and Technology
(CINSaT), University of Kassel, Heinrich‐
Plett‐Straße 40, 34132 Kassel, Germany.
Email: pietschnig@uni‐kassel.de
Funding information
Deutsche Forschungsgemeinschaft,
Grant/Award Number: CRC 1319;
European Union, Grant/Award Number:
ITN SHINE
1 | INTRODUCTION
silanol, which can be increased by the presence of one
electron‐withdrawing group at silicon.[2c] Here we report
Silanols are the silicon analogues of alcohols and there-
fore are of fundamental importance.[1] Due to their
relative acidity compared to their carbon analogues, the
binding interactions of organosilanols have been
employed for catalytic purposes quite recently.[2]
Silanediols acting as hydrogen‐bonding organocatalysts
in Diels–Alder reactions were first reported by Franz
and co‐workers.[2b] The activity of the silanediol catalyst
in such reactions is correlated with the acidity of the
the synthesis of a novel silanediol bearing two electron‐
withdrawing 2‐(trifluoromethyl)phenyl units at silicon
and its catalytic properties with respect to a standard
Diels–Alder reaction.
2 | RESULTS AND DISCUSSION
We anticipated that bis[(2‐trifluoromethyl)phenyl]
dichlorosilane (1) should be a reasonable precursor for
the preparation of the corresponding silanediol (3).
†Dedicated to Prof. Bob West on the occasion of his 90th birthday
Appl Organometal Chem. 2018;e4427.
wileyonlinelibrary.com/journal/aoc
Copyright © 2018 John Wiley & Sons, Ltd.
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https://doi.org/10.1002/aoc.4427

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HURKES ET AL.
Starting from 1‐bromo‐2‐(trifluoromethyl) benzene,
dichlorosilane
1
was obtained via metal–halogen
exchange with n‐BuLi and subsequent twofold salt
metathesis with SiCl4 (Scheme 1). In addition to the
envisaged
dichlorosilane,
the
corresponding
trichlorosilane 2 was formed which could be separated
by distillation. Dichlorosilane 1 was isolated in moderate
yield as a colourless and sublimable solid.
To ensure complete metallation of the aryl precursor,
an excess of n‐BuLi (2 eq.) was used in agreement with
published procedures for related compounds.[3] We did
not isolate the lithiated intermediate and reacted further
in situ with SiCl4. Again 2 eq. of SiCl4 was used to ensure
that all metallated species were quenched prior to the
distillation step. Heating of metallated organofluorine com-
pounds or mixtures of organofluorine and organolithium
compounds might cause potential hazards. Since the reac-
tivity of the Si─Cl functionalities in 1 and 2 precludes stan-
dard quenching procedures with protic reagents, we have
chosen this counterintuitive approach. In synthetic proce-
dures for the related 2‐(trifluoromethyl)phenylphosphanes,
this issue has been circumvented via either complete substi-
tution or the use of protecting groups.[4]
FIGURE 1 ORTEP plot of the crystal structure of 1 with
ellipsoids drawn at 30% probability level (hydrogen atoms omitted
for clarity)
these. As in other CF3‐substituted aryldichlorosilanes,[6a]
the Si─Cl bond lengths of 2.0483(8) and 2.0536(8) Å are
slightly shorter than those in non‐perfluoro‐substituted
aryldichlorosilanes.[6a,8]
Controlled hydrolysis of dichlorosilane 1 in the pres-
ence of two equivalents of NEt3 in Et2O affords bis[(2‐
trifluoromethyl)phenyl] silanediol (3) in moderate yield
as a crystalline solid after workup (Scheme 2). The 29Si
NMR chemical shift of ‐38.2 ppm is within the expected
range for diarylsilanediols.[5b] The 19F NMR chemical shift
of the o‐CF3 unit in 3 (‐56.93 ppm) is comparable to that in
the recently reported silanediol [2,5‐(CF3)2C6H3]2Si
(OH)2.[6b] The infrared (IR) spectrum of 3 show a vibra-
tional band at 3326 cm−1 characteristic for the Si─OH unit.
Recrystallization of 3 from tetrahydrofuran (THF) afforded
single crystals suitable for X‐ray diffraction. Silanediol 3
crystallizes as a dimeric 1:1 THF adduct in triclinic space
group P‐1 (Figure 2). In addition to the hydrogen bonding
towards the THF molecule, dimer formation by two
silanediols takes place via two intermolecular hydrogen
bonding interactions resulting in discrete units of the type
[3⋅THF]2 (Figure 3).
The O─H bond lengths were fixed at 0.84 Å and the
hydrogen atoms were refined without any constraints to
the bond angles. The OH⋅⋅⋅O distances range between
1.839(3) and 1.9112 (13) Å. The O⋅⋅⋅O (THF) distances are
2.6454 (13)–2.6843 (12) Å, which are shorter than the
O⋅⋅⋅O distances resulting from the intermolecular interac-
tion between two silanediol molecules (2.7479 (12)–
2.7483 (12) Å). The O─H⋅⋅⋅O (THF) angles are smaller than
the remaining O─H⋅⋅⋅O angles (160.3(9)–160.8(13)° versus
173.9(6)–176.8(7)°). A survey of all hydrogen bonding
interactions in 3 is summarized in Table 1.
29Si NMR chemical shifts are 4.4 ppm for 1 and
‐2.7 ppm for 2 which are comparable to those for
other aryl‐substituted di‐ and trichlorosilanes.[5] The 19F
NMR chemical shifts, −56.76 ppm for 1 and ‐56.60 ppm
1
for 2, as well as the JCF coupling constant of 31.9 Hz,
are in the expected range for o‐CF3‐substituted
arylchlorosilanes.[6] In contrast to the observations of
Batsanov et al. who encountered Cl/F exchange in the
reactions of 2,4,6‐tris‐trifluoromethylphenyllithium and
2,6‐bis‐trifluoromethylphenyllithium with SiCl4, no such
exchange was observed in the preparation of 1 and 2.[6a]
Recrystallization of 1 from benzene afforded single
crystals suitable for X‐ray diffraction. Compound 1 crys-
tallizes in the monoclinic space group Pc (Figure 1).
In the solid state the molecules of 1 show a low
symmetry owing to the orientations of the phenyl rings
which are non‐coplanar with an interplanar angle of
79.71 (11)° giving rise to axial chirality. Similar to [2,4‐
[6a]
(CF3)2C6H3]2SiCl2
the Si⋅⋅⋅F distances in 1 are rather
short: Si(1)⋅⋅⋅F(13) = 2.863(2) Å; Si(1)⋅⋅⋅F(23) = 3.086(2)
Å. The C─Si─C and C─Si─Cl bond angles in 1 are com-
parable with those in other dichlorosilanes,[6,7] while the
Cl─Si─Cl bond angle of 105.74(3)° is the smallest of
SCHEME 1 Preparation of 1 and 2
SCHEME 2 Hydrolytic formation of 3 from 1

HURKES ET AL.
3 of 6
FIGURE 2 ORTEP plot of the crystal structure of 3 with ellipsoids drawn at 30% probability level (aryl and THF hydrogen atoms omitted
for clarity)
FIGURE 3 Hydrogen bonded dimers in the crystal structure of 3 with ellipsoids drawn at 30% probability level (aryl and THF hydrogen
atoms omitted for clarity)
TABLE 1 Survey of hydrogen bonding interactions in 3
D─ H⋅⋅⋅Aa
d (D─ H) (Å)
d (H⋅⋅⋅A) (Å)
d (D⋅⋅⋅A) (Å)
∠(DHA) (°)
O(1)─H(1)⋅⋅⋅O(2)(i)
O(2)─H(2)···O(51)
O(3)─H(3)⋅⋅⋅O(4)(ii)
O(4)─H(4)⋅⋅⋅O(61)
0.84
0.84
0.84
0.84
1.9092 (12)
1.877(4)
2.7483 (12)
2.6843 (12)
2.7479 (12)
2.6454 (13)
176.8(7)
160.8(13)
173.9(6)
160.3(9)°
1.9112 (13)
1.839(3)
aSymmetry transformations used to generate equivalent atoms: (i) 1 − x, 1 − y, 2 − z; (ii) 2 − x, 1 − y, 1 − z.
The Si─O bond lengths range between 1.6229(9) and
1.6411(9) Å and the Si─Cl‐bond lengths between 1.8817
(12) and 1.8882 (12) Å. The Si─O distances of the OH
groups coordinated to the THF molecules (1.6407(9),
1.6411(9) Å) are significantly longer than the other two
Si─O bonds (1.6229(9), 1.6232(9) Å) which form the
dimers. This is closely related to the situations in other
adducts between silanols and solvents.[9] In general, bond
distances and angles are comparable to those for (2,5‐
(CF3)2C6H3)2Si(OH)2.[6b]

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HURKES ET AL.
This model reaction is based on carbonyl activation in
the Diels–Alder reaction of methacrolein and Rawal's
diene at −70 °C in a non‐polar solvent such as toluene,
so the acidity of the silanol is not levelled by the basicity
of a donor solvent. In the presence of 3, the yield of the
model reaction increases by a factor of three compared
with the reaction under identical conditions without
the silanol. Interestingly this moderate increase is in
the average range of that of silanediol catalysts for this
reaction but inferior to that of BINOL, which is a supe-
rior catalyst for this reaction under otherwise identical
conditions, but has no silanol functionalities at all.[2c]
Although a mechanism similar to that proposed by
Franz and co‐workers,[2b] via hydrogen‐bonding‐based
activation of the carbonyl oxygen, seems likely, a disad-
vantage of increasing the acidity via incorporation
of trifluoromethyl units is reduced π‐stacking ability of
the aryl groups in 3.
SCHEME 3 Diels–Alder model reaction to assess the activation
of carbonyl compounds by silanediol 3
Dimeric association via hydrogen bonding has been
identified as a potential aspect in the preorganization of
substrate and catalyst in silanol‐mediated reactions along
with the acidity of the catalytic silanol.[10] As an indica-
tion of the acidity, the proton resonance of silanediol 3
in THF‐d8 is clearly deshielded (6.37 ppm) compared
with the resonance of its non‐fluorinated analogue Ph2Si
(OH)2 in the same solvent (5.95 ppm). The catalytic
activity of silanediol 3 concerning Diels–Alder reactions
was therefore explored for a model reaction which has
been used before to assess silanol catalysts (Scheme 3).[2b]
TABLE 2 Crystal data and structure refinement for 1 and 3
3 | CONCLUSIONS
1
3
In summary, we prepared and fully characterized a
fluoro‐substituted silanediol, bis[2‐(trifluoromethyl)phe-
nyl]silanediol. X‐ray diffraction studies revealed that
hydrogen bonding occurs between pairs of adjacent
molecules resulting in the formation of doubly linked
dimers in the solid state. According to our findings,
this compound is active in catalysing Diels–Alder
reactions.
Formula
C14H8Cl2F6Si C14H10F6O2Si
⋅C4H8O
Formula weight
Temperature (K)
Wavelength (Å)
Crystal system
Space group
Unit cell dimensions
a (Å)
389.19
100
424.41
100
0.71073
Monoclinic
Pc
0.71073
Triclinic
P‐1
7.9481(2)
7.9115(2)
12.2892(3)
9.0357(3)
4 | EXPERIMENTAL
b (Å)
13.6360(6)
16.0306(6)
105.6495 (18)
c (Å)
Unless otherwise noted, all manipulations were carried
out under strict exclusion of moisture and air in an inert
argon atmosphere using standard Schlenk techniques
α (°)
β (°)
104.1011(8) 90.2620 (15)
105.2280 (15)
1
where appropriate. H NMR, 13C NMR and 29Si NMR
γ (°)
Volume (Å3)
749.48(3)
2
1829.09 (12)
4
spectra were recorded with a Bruker Avance III at a
Larmor frequency of 300 MHz for 1H using
tetramethylsilane as reference and C6D6 as solvent (dried
over potassium and distilled prior to use). 1‐Bromo‐2‐
(trifluoromethyl)benzene was purchased from ABCR
while other reagents were obtained from Sigma‐Aldrich.
Mass spectra were recorded with an Agilent 5975C using
direct insertion of the sample into the ionization source
(EI) or with a micrOTOF (Bruker Daltonics) using an
Apollo™Ion Funnel electrospray ionization (ESI) source.
Combustion analyses were performed with a HEKAtech
Euro EA. Attenuated internal reflectance IR spectra were
recorded with a Bruker Alpha Platinum ATR‐IR spectro-
photometer using neat samples.
Z
Density (calcd) (Mg m−3
)
1.725
1.541
μ(mm−1
)
0.571
0.204
θrange for data collection
(°)
2.57–30.00
2.34–30.00
Goodness‐of‐fit on F 2
1.040
1.060
Data/parameters
3496/210
0.0245
10623/533
0.0368
Final R indices R1
[I > 2σ(I)]
R indices wR2 (all data)
0.0573
0.1009
CCDC number
1826249
1826250

HURKES ET AL.
5 of 6
added to a cooled solution (0 °C) of NEt3 (0.32 g,
3.2 mmol, 2 eq.) and water (0.06 g, 3.2 mmol, 2 eq.) in
30 ml of Et2O. Stirring was continued for 12 h while
slowly warming to room temperature. Eliminated salts
were removed by filtration and extracted with further
portions of Et2O. From the combined extracts the solvent
was evaporated under reduced pressure. The colourless
solid product, 3, was washed several times with pentane
and dried to constant weight.
4.1 | Synthesis of Bis[2‐(trifluoromethyl)
phenyl] dichlorosilane (1) and [(2‐
Trifluoromethyl)phenyl] trichlorosilane (2)
1‐Bromo‐2‐(trifluoromethyl)benzene (14.41 g, 64 mmol,
1 eq.) dissolved in 60 ml of Et2O was cooled to −90 °C and
slowly treated with 51 ml of n‐BuLi (2.5 M in hexane,
128 mmol, 2 eq.). Upon addition the reaction mixture was
slowly warmed to room temperature and further stirred
for 2 h. The mixture was then cooled to −80 °C and SiCl4
(15 ml, 21.74 g, 128 mmol, 2 eq.) was added. Stirring was
continued for 12 h while slowly warming to room tempera-
ture. The solvent was evaporated under reduced pressure
and the residue extracted with pentane. Eliminated salts
were removed by filtration and the pentane was evaporated
under reduced pressure. The product mixture was sepa-
rated by fractional distillation affording 1 and 2.
4.2.1 | Analytical details for 3
Yield: 0.13 g (0.4 mmol; 23%). IR (cm−1): 3326 (b); 1438
(s); 1163 (s); 1111 (s); 1050 (s); 1034 (s); 903 (s); 886 (s);
833 (s); 770 (s); 711 (s); 506 (s). MS/EI: m/z (%) = 352
(10) [M]+; 207 (70) [M
−
C7H4F3]+; 161 (100)
[C7H4F3O]; 145 (5) [C7H4F3]+; 77 (20) [C6H6]+. HRMS/
ESI(+): m/z 375.0236 [M
Na]+; calcd for
=
+
[C10H10F6O2SiNa]+ = 375.0251. Elemental analysis: calcd
for C14H10O2F6Si (%): C: 47.73; H: 2.86; found (%): C:
47.37; H: 2.87. 1H NMR (300 MHz; THF‐d8; δ, ppm):
8.24 (m; 2H; Ar─ H); 7.67 (m; 2H; Ar─ H); 7.56 (m; 4H;
Ar─ H); 6.37 (b; 2H; ─ Si─ OH). 13C NMR (100.5 MHz;
THF‐d8; δ, ppm): 138.1 (CH); 136.5 (m; Cq); 135.7 (q;
2JCF = 31 Hz, Cq─ CF3); 131.2 (CH); 130.4 (CH); 126.3
4.1.1 | Analytical details for 1
Yield: 3.41 g (8.8 mmol; 27%). Sublimation: 97 °C/
0.1 mbar. IR (cm−1): 1313 (s); 1169 (s); 1120 (s); 1049
(s); 819 (s); 769 (s); 559 (s); 537 (s); 484 (s); 434 (s). MS/
EI: m/z (%) = 388 (30) [M]+; 243 (100) [M − C7H4F3]+;
45 (15) [C7H4F3]+; 77 (20) [C6H6]+. HRMS/ESI(+) upon
quenching with methanol: m/z = 403.0559 [M + Na]+;
calcd for [C16H14F6O2SiNa]+ = 403.0565. Elemental anal-
ysis: calcd for C14H8Cl2F6Si (%): C: 43.20; H: 2.07; found
(%): C: 43.90; H: 2.29. 1H NMR (400 MHz; C6D6; δ,
ppm): 8.23 (m; 2H; Aryl─H); 7.27 (m; 2H; Aryl─H);
6.99 (m; 2H; Aryl─H); 6.85 (tm; 2H; Aryl─H). 13C NMR
(100.5 MHz; C6D6; δ, ppm): 136.7 (CH); 134.2 (q;
2JCF = 32 Hz, C─CF3); 131.9 (CH); 131.5 (CH); 130.3
(m; Cq); 127.1 (q; 3JCF = 7 Hz; CH); 125.0 (q; 1JCF = 274 Hz,
CF3). 19F NMR (376.3 MHz; C6D6; δ, ppm): −56.76. 29Si
NMR (59.6 MHz; C6D6; δ, ppm): 4.4.
3
1
(q; JCF = 5 Hz; CH);125.8 (q; JCF = 274 Hz, CF3). 19F
NMR (376.3 MHz; THF‐d8; δ, ppm): −56.93. 29Si NMR
(59.6 MHz; THF‐d8; δ, ppm): −38.2.
4.3 | Details for Catalytic Model Reaction
The procedure followed previous literature reports.[2b,11]
Catalyst
3 (42.44 mg, 0.10 mmol, 0.2 eq.) and
methacrolein (41.5 μl, 0.50 mmol, 1.0 eq.) were dissolved
in toluene (0.75 ml). The resulting solution was cooled to
−70 °C and trans‐3‐(tert‐butyldimethylsiloxy)‐N,N‐
dimethyl‐1,3‐butadien‐1‐amine (260 μl, 1.00 mmol,
2.0 eq.) was added. After stirring for 48 h at −70 °C, the
reaction was quenched with LiAlH4 (4.0 M, 0.50 ml,
2.0 mmol, 4.0 eq.) and stirred for 0.5 h at −70 °C and then
1.5 h at room temperature. Excess LiAlH4 was quenched
with water (0.5 ml) and the resulting solid was removed
by filtration and washed with Et2O (5 × 3 ml). The filtrate
was concentrated under reduced pressure to yield a pale
yellow oil, which was dissolved in acetonitrile (2.0 ml).
After cooling to 0 °C, HF (70% in pyridine, 0.27 ml) was
added and the materials were stirred for 8 h at room tem-
perature. The mixture was then treated with 1.10 g of
CaCl2, filtered and the solvent removed under reduced
pressure. The crude product was purified by column
chromatography on silica (50:50 hexanes–ethyl acetate).
Evaporation of the eluent afforded 4‐hydroxymethyl‐4‐
methylcyclohex‐2‐en‐1‐one in a yield of 30 mg. In
4.1.2 | Analytical details for 2
Yield: 2.31 g (8.3 mmol; 13%). Boiling point: 43 °C/
1
0.1 mbar. H NMR (300 MHz; C6D6; δ, ppm): 7.89 (m;
1H; Ar─H); 7.40 (m; 1H; Ar─H); 7.14 (m; 2H; Ar─H).
13C NMR (75.4 MHz; C6D6; δ, ppm): 136.7 (CH); 134.6 (q;
2JCF = 32 Hz; C─CF3); 133.0 (CH); 131.5 (CH); 128.0 (q;
3
3JCF = 2 Hz; Cq); 127.5 (q; JCF = 5 Hz; CH); 124.3 (q;
1JCF = 274 Hz; CF3). 19F NMR (282.2 MHz; C6D6; δ,
ppm): −56.60. 29Si NMR (59.6 MHz; C6D6; δ, ppm): −2.7.
4.2 | Synthesis of Bis[2‐(trifluoromethyl)
phenyl] silanediol (3)
Bis[(2‐trifluoromethyl)phenyl] dichlorosilane (0.61 g,
1.6 mmol, 1 eq.) dissolved in 10 ml of Et2O was slowly

6 of 6
HURKES ET AL.
Hoboken, NJ 2017 141. b) R. Pietschnig, S. Spirk, Coord. Chem.
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Chichester 2001 695.
contrast, only 10 mg of product was obtained following
the same procedure without addition of 3 under other-
wise identical conditions. The spectral data for the
product (4‐hydroxymethyl‐4‐methylcyclohex‐2‐en‐1‐one)
match the values reported in the literature.
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4.4 | Crystallographic Details
The crystal structures were determined using a Bruker
APEX‐II CCD diffractometer using with graphite‐
monochromated Mo Kα radiation (0.71073 Å). All struc-
tures were solved by direct methods (SHELXS‐97)[12] and
refined by full‐matrix least‐squares techniques against F2
(SHELXL‐2014/6).[12] The non‐hydrogen atoms were
refined with anisotropic displacement parameters without
any constraints. The hydrogen atoms of the phenyl rings
were put at the external bisectors of the C─C─C angles at
C─H distances of 0.95 Å and common isotropic displace-
ment parameters were refined for the hydrogen atoms of
the same ring. For 3, the positions of the hydrogen atoms
of the OH groups were taken from a difference Fourier
map, the O─H distances were fixed to 0.84 Å and the hydro-
gen atoms were refined with individual isotropic displace-
ment parameters without any constraints to the bond
angles. The hydrogen atoms of the CH2 groups of the sol-
vent co‐crystallizing with 3 were refined with common iso-
tropic displacement parameters for the hydrogen atoms of
the same group and idealized geometries with approxi-
mately tetrahedral angles and C─H distances of 0.99 Å.
Table 2 summarizes the crystal data and refinement for
the structures of 1 and 3. Crystallographic data for this
paper can be obtained free of charge quoting CCDC
1826249–1826250 from the Cambridge Crystallographic
Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
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ACKNOWLEDGEMENTS
Two of the authors (J.R.K. and R.P.) acknowledge Prof.
Robert West, for his invitations to join his laboratory at
UW in the 1990s and without whose catalytic activity
the current collaboration would not have been possible.
R.P. thanks the Deutsche Forschungsgemeinschaft (CRC
1319) for financial support.
[10] N. T. Tran, S. O. Wilson, A. K. Franz, Org. Lett. 2012, 14, 186.
[11] A. N. Thadani, A. R. Stankovic, V. H. Rawal, Proc. Natl. Acad.
Sci. U. S. A. 2004, 101, 5846.
[12] a) G. M. Sheldrick, Acta Crystallogr. 2008, A64, 112. b) G. M.
Sheldrick, SHELXS‐97. Program for the Solution of Crystal
Structures, University of Göttingen, Germany 1997.
ORCID
How to cite this article: Hurkes N, Belaj F, Koe
JR, Pietschnig R. Synthesis, structure and catalytic
properties of bis[2‐(trifluoromethyl)phenyl]
silanediol. Appl Organometal Chem. 2018;e4427.
https://doi.org/10.1002/aoc.4427
Ferdinand Belaj http://orcid.org/0000-0001-9749-2109
Rudolf Pietschnig http://orcid.org/0000-0003-0551-3633
REFERENCES
[1] a) R. Pietschnig, in Main Group Strategies towards Functional
Organic Materials, (Eds: T. Baumgartner, F. Jäkle), Wiley,