Solid-state structure and condensation reaction of (triphenylmethyl) silanetriol

Article abstract of DOI:10.1016/j.jorganchem.2004.12.012

(Triphenylmethyl)silanetriol [1, (Ph₃C)Si(OH)₃] was obtained in 98% yield by the hydrolysis of (triphenylmethyl)trichlorosilane with ice-water in diethyl ether. Single crystal of [1 ? acetone] for X-ray crystallographic determination was grown from a saturated acetone solution. In the single crystal X-ray structure analysis, the silanetriol 1 crystallizes in the centrosymmetric triclinic space group with two independent molecules in the asymmetric unit. Two independent molecules of the silanetriols 1 interact with each other and with acetones by intermolecular hydrogen bondings. Such hydrogen-bonding interactions lead to a one-dimensional columnar polymeric tube. Finally, this tube interacts with others to make sheets alternating hydrophobic organic part and hydrophilic hydroxy groups of the molecules 1 and the oxygen of acetones arranged regularly. The silanetriol 1 is very stable compound in solution and in solid states at room temperature, but decomposed in the presence of KOH, and undergoes a condensation reaction with dicyclohexylcarbodiimide (DCC) as strong dehydrating agent to give polysiloxane. The silanetriol 1 reacts with trimethylchlorosilane to give three type siloxane products (Ph ₃C)Si(OH)_3-n(OSiMe₃)_n (n = 1, 2, 3). The number (n) of silylation of hydroxy groups on the silanetriol 1 increase with increasing the mol ratio of trimethylchlorosilane used.

Full text of DOI:10.1016/j.jorganchem.2004.12.012

Journal of Organometallic Chemistry 690 (2005) 1372–1378
www.elsevier.com/locate/jorganchem
Solid-state structure and condensation reaction
of (triphenylmethyl)silanetriol
a
b
c
Jeong Hyun Kim a,b, Joon Soo Han , Myong Euy Lee , Do Hyun Moon ,
c
Myoung Soo Lah , Bok Ryul Yoo
a,
*
a
Organosilicon Chemistry Laboratory, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 130-650, Republic of Korea
b
Department of Chemistry, Graduate School, Yonsei University, Seoul 120-749, Republic of Korea
c
Department of Chemistry, Hanyang University, Ansan, Kyunggi-do 425-791, Republic of Korea
Received 8 September 2004; accepted 2 December 2004
Available online 7 February 2005
Abstract
(Triphenylmethyl)silanetriol [1, (Ph3C)Si(OH)3] was obtained in 98% yield by the hydrolysis of (triphenylmethyl)trichlorosilane
with ice-water in diethyl ether. Single crystal of [1 Æ acetone] for X-ray crystallographic determination was grown from a saturated
acetone solution. In the single crystal X-ray structure analysis, the silanetriol 1 crystallizes in the centrosymmetric triclinic space
group with two independent molecules in the asymmetric unit. Two independent molecules of the silanetriols 1 interact with each
other and with acetones by intermolecular hydrogen bondings. Such hydrogen-bonding interactions lead to a one-dimensional
columnar polymeric tube. Finally, this tube interacts with others to make sheets alternating hydrophobic organic part and hydro-
philic hydroxy groups of the molecules 1 and the oxygen of acetones arranged regularly. The silanetriol 1 is very stable compound in
solution and in solid states at room temperature, but decomposed in the presence of KOH, and undergoes a condensation reaction
with dicyclohexylcarbodiimide (DCC) as strong dehydrating agent to give polysiloxane. The silanetriol 1 reacts with trimethylchlo-
rosilane to give three type siloxane products (Ph3C)Si(OH)3ꢀn(OSiMe3)n (n = 1, 2, 3). The number (n) of silylation of hydroxy
groups on the silanetriol 1 increase with increasing the mol ratio of trimethylchlorosilane used.
ꢀ 2004 Elsevier B.V. All rights reserved.
Keywords: Silanetriol; Siloxane; Silanol; Silylation
1. Introduction
stituent have been isolated and studied for their struc-
tures and properties [7–18]. A bulky substituent on the
silicon of silanetriol makes OH groups on the silicon
stabilized for self-condensation reaction. Recently (tri-
phenylmethyl)trichlorosilane containing a bulky substi-
tuent on the silicon was synthesized from the Friedel–
Crafts reaction of (trichloromethyl)trichlorosilane with
excess benzene [19] and hydrolyzed with water in organic
solvent to give (triphenylmethyl)silanetriol (1) [8] in
good yield. As a continuing study on the chemistry of
silanetriol 1, we conducted the systemic studies on its so-
lid-state structure, thermal properties, and condensation
reactions. In this paper, we wish to report these results
in details.
Much attention has been paid to synthetic ap-
proaches to silanepolyols, which can be used as models
for studies on the building block of silica [1,2]. Espe-
cially silanetriols, which are unstable compounds, can
be useful precursors for the synthesis of silsesquioxanes,
ladder polymers, and metallosilsesquioxanes [2a,3–5].
Since stable c-hexylsilanetriol was first isolated and
characterized by single crystal X-ray structure analysis
in 1982 [6], some stable silanetriols bearing a bulky sub-
*
Corresponding author. Tel.: +82 2 958 5087; fax: +82 2 958 5089.
E-mail address: bryoo@kist.re.kr (B.R. Yoo).
0022-328X/$ - see front matter ꢀ 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2004.12.012

J.H. Kim et al. / Journal of Organometallic Chemistry 690 (2005) 1372–1378
1373
2. Results and discussion
2.1. Solid-state structure and thermal property of
(triphenylmethyl)silanetriol
(Triphenylmethyl)trichlorosilane was hydrolyzed
with crash ice-water in diethyl ether to give the stable
silanetriol 1 in 98% yield (Eq. (1)). The silanetriol 1
was obtained in higher yield in diethyl ether solvent than
that in THF [8].
Ph OH
Ph
C
Cl
ice-water
Ph
C
Si OH
OH
Ph
Si Cl
Cl
in diethyl ether
ð1Þ
Ph
Ph
Fig. 1. Molecular structure of the two crystallographically indepen-
dent molecules of the silanetriol 1 and acetone (thermal ellipsoids
˚
shown at 50% probability level). Selected bond lengths (A) and angles
1 (98%)
The silanetriol 1 was purely isolated as colorless crys-
(deg): Si(1)–O(1) 1.627(6); Si(1)–O(2) 1.621(6); Si(1)–O(3) 1.613(6);
Si(1)–C(1) 1.946(7); Si(2)–O(4) 1.617(6); Si(2)–O(5) 1.634(6); Si(2)–
O(6) 1.632(7); Si(2)–C(20) 1.900(8); O(7)–C(39) 1.27(5); O(8)–C(42)
1.110(12); O(1)–Si(1)–O(2) 108.8(3); O(1)–Si(1)–O(3) 108.9(4); O(2)–
Si(1)–O(3) 109.5(3); O(1)–Si(1)–C(1) 110.6(3); O(2)–Si(1)–C(1)
109.8(3); O(3)–Si(1)–C(1) 109.2(3); O(4)–Si(2)–O(5) 109.0(3); O(4)–
Si(2)–O(6) 109.4(3); O(5)–Si(2)–O(6) 108.3(4); O(4)–Si(2)–C(20)
111.4(4); O(5)–Si(2)–C(20) 109.0(3); O(6)–Si(2)–C(20) 109.6(4).
tals by cooling a concentrated diethyl ether solution.
Single crystals of the compound 1 suitable for X-ray
crystallographic determination could be obtained from
a concentrated THF solution [8] and an acetone at
ꢀ20 ꢁC, respectively. The crystallographic data of com-
pound 1 and acetone are summarized in Table 1.
The ORTEP plot of [1 Æ acetone] determined by the
single crystal X-ray structure analysis and the selected
bond lengths and bond angles for the silanetriol 1 is de-
picted in Fig. 1.
The molecule 1 crystallizes in the centrosymmetric tri-
clinic space group with two independent molecules in
the asymmetric unit. In Fig. 1, the lengths of Si–O bonds
Table 1
Crystallographic data for the silanetriol 1
˚
in the two molecules range from 1.613 to 1.634 A. The
bond lengths of Si(1)–C(1) and Si(2)–C(20) are 1.946
Compound
(1 Æ acetone) · 2
44H48O8Si2
761.00
Empirical formula
Formula weight
Temperature (K)
C
˚
and 1.900 A, respectively. The bond angles for O–Si–O
and O–Si–C in the two molecules range from 108.3 to
109.5ꢁ and from 109.0 to 111.4ꢁ, respectively. These
are comparable to those found in t-BuSi(OH)3 [15]
and (Me3)3CSi(OH)3 [18]. The solid-state packing dia-
gram and hydrogen-bonded network structure of the
silanetriol 1 and acetone are predicted in Fig. 2. Two
independent molecules of the silanetriol 1 interact each
other by the intermolecular hydrogen bondings to form
a dimeric-unit as shown in a circle of Fig. 2. Such a di-
meric-unit interacts with two acetones by the intermo-
lecular hydrogen bondings. Such hydrogen-bonding
interactions lead to a one-dimensional columnar poly-
meric tube. Finally, such a tube interacts with others
to make sheets alternating hydrophobic organic part
and hydrophilic hydroxy groups of the molecules 1
and oxygens of acetones arranged regularly as shown
in Fig. 2. The distances of O(1)–O(4) and O(2)–O(5)
bonds of the dimeric unit formed by the hydrogen bon-
dings between two independent molecules are 2.865 and
293(2)
0.71073
Triclinic
˚
Wave length (A)
Crystal system
Space group
Unit cell dimensions
ꢀ
P1
˚
a (A)
8.850(2)
9.654(2)
˚
b (A)
˚
c (A)
12.662(2)
86.51(2)
a (ꢁ)
b (ꢁ)
c (ꢁ)
86.730(10)
70.93(2)
1019.8(4)
3
˚
Volume (A )
Z
1
1.239
Density, calcd. (g/cm3)
Absorption coefficient (mm)
F(000)
0.139
404
Crystal size (mm)
h range for data collection (deg)
Index ranges
0.2 · 0.2 · 0.3
1.61–24.97
0< = h< = 10
ꢀ10< = k< = 11
ꢀ14< = l< = 15
3082/2870 [Rint = 0.0132]
80.1
Full-matrix least-squares on F2
3082/15/499
1.145
Reflections collected/unique
Completeness to 2h (%)
Refinement method
˚
2.870 A, respectively, which are within the normal O–O
˚
bond distances for the hydrogen bondings (2.70–3.16 A)
of the silanetriols [2b]. The O(1)–O(7), O(3)–O(8), O(5)–
O(8), and O(6)–O(7) bond distances of the intermolecu-
lar hydrogen-bondings formed between the dimeric
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2r(I)]
R indices (all data)
R1 = 0.0540, wR2 = 0.1478
R1 = 0.0545, wR2 = 0.1489

1374
J.H. Kim et al. / Journal of Organometallic Chemistry 690 (2005) 1372–1378
1
In the H NMR spectra of solution of the silanetriol
1, the proton resonance of OH on the silanetriol 1 was
shifted from 6.45 in DMSO-d6 to 5.63 in acetone-d6 to
4.38 ppm in acetonitril-d3 solvent, indicating that the
chemical shift of OH on the silanetriol 1 depends on or-
ganic solvents used in NMR studies. These results are
consistent with the basicity of solvent, making stronger
hydrogen bonding with the OH group of 1 at stronger
basicity [20,21]. The proton resonance of OH on the sila-
netriol 1 in DMSO-d6 appeared at lower field than that
of t-BuSi(OH)3 (5.50 ppm [15]), (1-trimethylsilyl)cyclo-
penta-2,4-dienylsilanetriol (5.76 ppm [12]), pentamethyl-
cyclopenta-2,4-dienylsilanetriol (5.67 ppm [13]), and
9-methylfluoren-9-yl)silanetriol (6.12 ppm [9]).
The thermal property of the silanetriol 1 was studied
by a TGA and DSC techniques. The powders of 1 were
dried at 30 ꢁC for 24 h under vacuum and then applied
for the studies of TGA and DSC under the condition of
flowing air and nitrogen (44 mL/min), respectively. In
both cases, the data of TGA and DSC were very similar
each other. TGA data of 1 was disclosed to be stable up
to 180 ꢁC without the loss of mass, then the decomposi-
tion rapidly preceded above 180 ꢁC in the nitrogen
atmosphere as shown in Fig. 4. About 600 ꢁC, 81.1%
of weight loss reached, 18.9% of residue was remained
until up to 1000 ꢁC. It means that silica (SiO2) was
formed by decomposing all organic part of 1 off. Endo-
thermic phenomena was maximized at 192 ꢁC in DSC.
Fig. 2. Packing diagram of the silanetriol 1 and acetone (H-bonded
network structure in a circle). For clarity, all carbon and hydrogen
atoms are not shown in the circle.
˚
units and acetones are 2.796, 3.145, 2.824, and 2.938 A,
˚
respectively. The average O–O bond distance (2.8675 A)
of the former (the dimeric unit) is stronger than that
˚
(2.9258 A) of the latter (between 1 and acetones).
The packing diagram of [1 Æ acetone] is different to
that of [1 Æ THF] as shown in Fig. 3 [8]. The packing dia-
gram of 1 containing THF shows that the molecule 1
interacts with other two molecules and an acetone by
the intermolecular hydrogen bondings as shown in a
box. The O(1)–O(2) and O(2)–O(1) distances of the
intermolecular hydrogen bondings formed between the
two hydroxy-groups on the silanetriols are the same
2.2. Polymerization reaction of silanetriol 1
Generally, it is well-known that simple silanetriols are
easily polymerized by self-condensation to give poly-
siloxanes. Thus the self-condensation reaction of 1 was
carried out by varying reaction conditions such as reac-
tion catalyst, solvent, and temperature. Among some
reactions, the silanetriol 1 was polymerized to give
poly(triphenylmethyl)siloxane when 1,3-dicyclohexyl-
carbodiimide (DCC) was used as a dehydrate agent to
(Eq. (2)). The results are summarized in Table 2.
˚
2.898 A and the distance of O(3)–O(3) is relatively long
˚
3.083 A. The distances of O(2)–O(4) and O(4)–O(3) of
the intermolecular hydrogen bondings formed between
˚
a THF and the two silanetriols are 2.772 and 3.052 A,
respectively. Hydrogen-bonding networks of the silanet-
riols formed in an up and down fashion lead to one-
dimensional wires. Such wires make sheets alternating
hydrophobic organic part and hydrophilic hydroxy-
groups on the silicon and oxygen at THF. The sheets
are regularly arranged as shown in Fig. 3. Earlier known
silanetriols showed a variety type of network structures:
(a) a double-sheet structure in C6H11Si(OH)3 [6] and t-
BuSi(OH)3 [15] where the molecules arrange in a head-
to-head with hydrophobic alkyl groups and tail-to-tail
fashion with hydrophilic OH groups alternating sheets,
(b) a discrete hexameric cage structure with hydrogen-
bonded silanetriols such as (Me3)3SiSi(OH)3 [16] and
(Me3)3CSi(OH)3 [18], (c) a discrete tetrameric cage struc-
ture with hydrogen-bonded silanetriols as [C5H4(Si-
Me3)]Si(OH)3 [12], and etc. [8].
reflux
!
Ph3C ꢀ SiðOHÞ þ DCC
Polysiloxane
ð2Þ
3
in benzene
As shown in Table 2, the compound 1 is stable up to
the reflux temperature of acetone or benzene. Unreacted
silanetriol 1 was recovered without self-condensation
when an acetone and a benzene solution of the silanet-
riol 1 were refluxed for 24 h, respectively. When NaOH
was used a catalyst for a self-condensation, triphenyl-
methane was obtained in 96% yield as a decomposed
compound along with insoluble silicate, suggesting that
the cleavage reaction of Si–C bond in the presence of
strong base catalyst occurred. When DCC, which is
known as a good dehydrating agent, was used, the sila-
netriol 1 was polymerized to give only polysiloxanes
through condensation reaction. These results showed

J.H. Kim et al. / Journal of Organometallic Chemistry 690 (2005) 1372–1378
1375
Fig. 3. Packing diagram of 1 Æ THF and H-bonded network structure in a box (indicating O1–O3 for three oxygens of 1 and O4 for the oxygen of
THF). For clarity, all carbon and hydrogen atoms are not shown in the box.
that the silanetriol 1 is very stable in neutral medium,
but undergo self-condensation in the presence of strong
dehydrating agent.
methyl-3,3,3-trimethyldisiloxane (2c). The higher sily-
lated products increase with increasing the ratio of
(CH3)3SiCl and 1 in the reaction. These results are sum-
marized in Table 3.
2.3. Reaction of 1 with trimethylchlorosilane
As shown in Table 3, the ratio of three products 2a–c
obtained from the silylation of the silanetriol 1 with
trimethylchlorosilane depends on the mol ratio of both
1 and trimethylchlorosilane. In a 24 h reaction of 1:1
mixture of 1 with trimethylchlorosilane, the monosily-
lated and disilylated products were obtained in 69%
and 14% yields with an 83% consumption of 1. When
1 reacted with 2 equiv of trimethylchlorosilane for 48
h to give the three products 2a, 2b, and 2c in 52%,
46%, and 2% yields. The compound 1 reacted with 3.3
equiv of trimethylchlorosilane to afford the three prod-
ucts 2a, 2b, and 2c in 1%, 81%, and 19%. The results
suggest that the reactivity of 1 is not good due to the
In order to test the reactivity of the hydroxy-groups
on the silanetriol 1, the reaction with trimethylchlorosi-
lane, which is known as a good silylating agent, was car-
ried in the presence of pyridine as a HCl scavenger out at
the reflux temperature of ethyl ether. The silanetriol 1
reacts slowly with trimethylchlorosilane to give three
kinds of silylated products: monosilylated product, 1,1-
dihydroxy-1-(triphenylmethyl)-3,3,3-trimethyldisiloxane
(2a); disilylated product, 1-hydroxy-1-trimethylsiloxy-1-
triphenylmethyl-3,3,3-trimethyldisiloxane (2b); three
silylated product, 1,1-bis(trimethylsiloxy)-1-triphenyl-

1376
J.H. Kim et al. / Journal of Organometallic Chemistry 690 (2005) 1372–1378
Table 3
Reaction of 1 with trimethylchlorosilanea
Mol ratio of
reactants
Reaction time (h)
Products (%)
2a
2b
2c
1.0 (17)b
2.0 (ꢀ)
3.3 (ꢀ)
a
24
48
48
69
52
1
14
46
81
–
2
19
Reaction of the silanetriol 1 with (CH3)3SiCl was carried out at
the refluxing temperature of diethyl ether.
b
Unreacted 1 remained.
creases from 2a, 2b, to 2c. In the 29Si NMR spectra of
the compound 2a–c, two kinds of silicon-resonance sig-
nals appeared at ꢀ5.63 and ꢀ63.36 ppm for SiMe3 and
SiCPh3 of 2a; at 4.40 and ꢀ73.39 ppm for those of 2b;
3.17 and ꢀ84.14 ppm for those of 2c, respectively.
In conclusion, the silanetriol 1 is very stable com-
pound in solution and in solid states at room tempera-
ture, decomposed in the presence of KOH, and but
undergoes condensation reaction in the presence of
DCC as strong dehydrating agent to give polysiloxane.
The compound 1 reacts with trimethylchlorosilane to
give three type siloxane products (Ph3C)Si(OH)3ꢀn(OSi-
Me3)n (n = 1, 2, 3). The number (n) of silylation of hy-
Fig. 4. Thermogram of TGA and DSC for the silanetriol 1 in the
nitrogen atmosphere.
steric hindrance of bulky triphenylmethyl-substituent on
the silicon.
The silylated products in the solution were character-
1
ized by NMR techniques. In H NMR spectra, the pro-
ton-resonance signals of trimethylsilyl-group at the
silylated products is shifted to up-filed with increasing
the numbers of silylation of the hydroxy groups on the
silanetriol 1 with trimethylchlorosilane due to an in-
crease of steric repulsion between a trimethylsilyl- and
a bulky Ph3C-group on the silicon atom. The typical
protons resonances of the aromatic rings for the com-
pounds 2a–c are between 7.17 and 7.32 ppm. The mono-
silylated compound 2a appeared at 0.00 ppm with a
singlet for the resonance of methyl-protons and at 2.89
ppm with a broad singlet for that of Si–OH, the disily-
lated compound 2b at ꢀ0.02 and 2.56 ppm, respectively,
the trisilylated compound 2c at ꢀ0.04 ppm for the reso-
nance of methyl-protons. In 13C NMR spectra, the res-
onance signals of aliphatic-carbons for the compounds
2a, 2b, and 2c appear at ꢀ1.27, ꢀ1.32, and ꢀ1.37 ppm
for methyl-substituent and 53.94, 53.89, and 53.66
ppm for benzylic-carbon, suggesting that the chemical
shifts are moved to up-filed as their steric hindrance in-
droxy groups on the silanetriol 1 increase with
increasing the mol ratio of trimethylchlorosilane used.
3. Experimental section
Trimethylchlorosilane and DCC were purchased
from Gelest. Inc. and used without purification. TLC
plate sheets coated with silica gel 60 F254 from Merck.
NMR spectra were recorded on a Varian Unity Plus
1
600 (FT, 600 MHz, H; 150 MHz for 13C) spectrometer
1
or Bruker Avance 300 spectrometer (300 MHz for H;
75 MHz for 13C, for 29Si) in acetone-d6 and chloro-
form-d1 solvents. The chemical shifts are given in ppm
relative to the residual proton signal of the solvents.
Melting points (uncorrected) were measured with a
Mel-Temp II melting point apparatus using sealed cap-
illary tubes. Thermogravimetric analysis was measured
with a Universal V1 8M form TA Instruments. The
Table 2
Self–condensation reaction of 1
Reactant 1
Reaction conditionsa
Products (%)
Cat.
Solvent
Time (h)
Polymerb (average molecular weights)
Other
100
100
–
Acetone
Benzene
Benzene
Benzene
Acetone
24
24
72
72
72
–
–
–
–
–
96c
NaOH
DCC
DCC
–
–
99 (5500)
99 (12,400)
–
a
Reaction was carried out at the reflux temperature of solvent.
Percentage of polymer indicates the mol% of Ph3CSiO3/2 unit converted from 1.
Triphenylmethane.
b
c

J.H. Kim et al. / Journal of Organometallic Chemistry 690 (2005) 1372–1378
1377
powder of the silanetriol 1 was dried at 30 ꢁC for 24 h
under vacuum and then applied for the studies of
TGA and DSC. Temperature was increased to 1000
ꢁC from the initial equilibrium temperature of 30 ꢁC in
the heating rate of 10 ꢁC/min under the condition of
flowing air and nitrogen (44 mL/min), respectively. Gel
permeation chromatography (GPC) was carried out on
a Waters Millipore gel permeation chromatograph with
Ultrastyragel GPC column series (in sequence, 100, 500,
1089 cmꢀ1 (strong band, Si–O–Si), 1H NMR d 6.50–7.50
(broad, Ph-H); 13C NMR d 56.8 (broad, Si-C), 125.9,
128.3, 130.1, 143.3 (broad, phenyl-C). 28Si NMR d
ꢀ82 (broad). The same reaction was carried out using
acetone solvent (50 mL) at 50 ꢁC for 72 h. This reaction
gave poly(phenylsilsesquioxane)s with higher molecular
weight (Mw = 12,400; Mw/Mn = 1.38).
3.3. Condensation reaction of 1 with trimethylchlorosilane
3
4
˚
10 , and 10 A columns) using THF solvent as an eluant.
Molecular weights were calibrated by polystyrene stan-
dards. HRMS (high-resolution mass (70 eV, EI) spectra)
were performed by Korea Basic Science Institute, Seoul,
Korea. (Triphenylmethyl)trichlorosilane was obtained
by the reaction of benzene with (trichloromethyl)trichlo-
rosilane in the presence of aluminum chloride [19].
Into a solution of 1 (200 mg, 0.62 mmol) in diethyl
ether (10 mL) in the presence of pyridine (50 mL (49
mg), 0.62 mmol) as a HCl scavenger was added drop-
wise trimethylchlorosilane (67 mg, 0.62 mmol). A mild
exothermic reaction accompanied by the formation of
triethylamine Æ hydrochloride salt occurred. The reac-
tion mixture was allowed to warm up to reflux temper-
ature and stirred for one day. The insoluble salt, which
had formed, was filtered off. The filtrate was concen-
trated by evaporation under vacuum to give 250 mg
of reaction mixture, consisted of a mixture of 1,1-dihy-
droxy-1-triphenylmethyl-3,3,3-trimethyldisiloxane (2a),
1-dihydroxy-1-trimethylmethyl-1-triphenylmethyl-3,3,3-
trimethyldisiloxane (2b) in 69% and 14% yields. The 1:2
and 1:3.3 reactions of 1 and trimethylchlorosilane were
carried out under the same reaction condition above,
respectively. These results are summarized in Table 2.
3.1. Synthesis of (triphenylmethyl)silantriol 1
Into a stirring crush ice (50 g, 360 mmol) in diethyl
ether (500 mL) in ice-water bath was added dropwise (tri-
phenylmethyl)trichlorosilane (5.0 g, 13.2 mmol) in diethyl
ether (100 mL) for 1 h. The reaction mixture was stirred at
0 ꢁC for another 1 h and warmed upto room temperature.
Then organic layer was separated, washed three times
with distilled water (30 mL), concentrated, and crystal-
lized to give (triphenylmethyl)silanetriol (1; 4.2 g, 98%)
as crystalline solids. A single crystal [0.2 · 0.2 · 0.3 mm]
of 1:1 mixture of two compounds 1 and acetone suitable
for X-ray crystallographic determination was obtained
from a solution of acetone at ꢀ30 ꢁC.
1
Data for 2a, H NMR (300 MHz, CDCl3) d 0.00 (s,
9H, SiCH3), 2.89 (br. s, 2H, Si–OH), 7.17–7.32 (m,
15H, phenyl-H). 13C NMR (75 MHz, CDCl3) d
ꢀ1.27 (SiC3), 53.94 (benzylic–C), 125.99, 128.19,
130.20, 145.34 (phenyl–C). 29Si NMR (60 MHz,
CDCl3) d 5.63 (SiMe3), ꢀ63.36 (SiCPh3). HRMS (EI,
70 eV) Calc. for C22H26O3Si2 (M+) m/z 394.1420,
Found m/z 394.1423. Data for 2b, 1H NMR (300
MHz, CDCl3) d ꢀ0.02 (s, 18H, Si–CH3), 2.56 (br. s,
2H, Si–OH), 7.17–7.32 (m, 15H, phenyl-H). 13C
NMR (75 MHz, CDCl3) d ꢀ1.32 (SiC3), 53.89 (ben-
zylic-C), 125.80, 127.94, 130.37, 145.72 (phenyl-C).
29Si NMR (60 MHz, CDCl3) d 4.40 (Si Me3), ꢀ73.39
(SiCPh3). HRMS (EI, 70 eV) Calc. for C25H34O3Si3
(M+) m/z 466.1816, Found m/z 466.1814. Data for 2c,
1H NMR (300 MHz, CDCl3) d ꢀ0.04 (s, 27H, SiCH3),
7.18–7.29 (m, 15H, phenyl–H). 13C NMR (75 MHz,
CDCl3) d ꢀ1.37 (SiC3), 53.66 (benzylic-C), 125.52,
127.72, 130.54, 146.00 (phenyl-C). 29Si NMR (60
MHz, CDCl3) d 3.17 (SiMe3), ꢀ84.14 (SiCPh3). HRMS
(EI, 70 eV) Calc. for C28H42O3Si4 (M+) m/z 538.2211,
Found m/z 538.2210.
Data for 1: m.p. 192–3 ꢁC dec.; 1H NMR (300 MHz,
acetonitril-d3) d 4.38 (s, OH, 3H), 7.14–7.30 (m, 15H,
Ph-H); 1H NMR (300 MHz, acetone-d6) d 5.63 (s,
OH, 3H), 7.12–7.27 (m, 15H, Ph-H); 1H NMR (300
MHz, DMSO-d6) d 6.45 (s, OH, 3H), 7.10–7.27 (m,
15H, Ph-H); 13C NMR (75 MHz, acetone-d6) d 55.16,
126.25, 128.70, 131.63, 147.92; 29Si NMR (60 MHz,
DMSO-d6) d ꢀ53.19; HRMS (EI, 70 eV) Calc. for
C19H18O3Si (M+) m/z 322.1025, Found m/z 322.1029;
IR (KBr pellet): 3336 (s, OH), 1595, 1481, 1442, 947,
898, 811, 745, 705, 507 cmꢀ1
.
3.2. Self-condensation reaction of silanetriol 1
A solution of 1 (1.0 g, 3.1 mmol) and DCC (2.1 g,
10.2 mmol) in benzene (50 mL) was stirred at reflux tem-
perature for 72 h. Then benzene was removed from a
reaction mixture. Poly(phenylsiloxane) was extracted
with n-hexane (20 mL · 3) from the reaction mixture.
Then, 1,3-dicyclohexylurea was precipitated off in hex-
ane solution. Poly(phenylsilsesquioxane)s (0.91 g) was
obtained after hexane was removed. Data for
poly(phenylsilsesquioxane)s: white solid, Rf = 0.55
(TLC, a 3:7 mixture of methylene chloride and hexane
as eluant), Mw = 5,500, Mw/Mn = 1.30; IR (KBr pellet):
3.4. X-ray crystallography
All X-ray data were collected on a Siemens SMART
CCD area detector with graphite monochromated Mo
˚
K radiation (0.71073 A) source at ambient temperature
or at ꢀ100 ꢁC.

1378
J.H. Kim et al. / Journal of Organometallic Chemistry 690 (2005) 1372–1378
[3] R. Murugavel, V. Chandrasekhar, H.W. Roesky, Acc. Chem.
Res. 29 (1996) 183.
Unit cell dimensions were based on 25 well-centered
reflections by using a least-squares procedure. During
the data collection, three standard reflections moni-
tored after every hour did not reveal any systematic
variation in intensity. The structures were solved by
the SHELXS-97 [22], followed by successive difference
Fourier synthesis. The non-hydrogen atoms were re-
fined anisotropically and hydrogen atoms were placed
in calculated positions and refined only for the isotropic
thermal factors. All calculations were carried out on a
personal computer with use of SHELXS-97 and
SHELXL-97. Crystal parameters and procedural infor-
mation corresponding to data collection and structure
refinement were given in Table 1.
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Crystallographic data for the structural analyses have
been deposited with the Cambridge Crystallographic
Data Centre, CCDC No. 249439 for compound 1. Copies
of this information may be obtained free of charge from
the Director, CCDC, 12 Union Road Cambridge, CB2
1EZ, UK (fax: +44-1223-336033; e-mail: deposit@ccdc.
cam.ac.uk or www: http://www.ccdc.cam. ac.uk).
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Acknowledgement
This research was supported financially by the Minis-
try of Science and Technology.
(b) B.R. Yoo, J.H. Kim, B.G. Cho, I.N. Jung, J. Organomet.
Chem. 631 (2001) 36;
(c) B.R. Yoo, J.H. Kim, H.-J. Lee, K.-B. Lee, I.N. Jung, J.
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