Hydrogen-bonding 3D networks by polyhedral organosilanols: Selective inclusion of hydrocarbons in open frameworks

Article abstract of DOI:10.1021/om901120m

Tetrahedral organosilanols E[C₆H₄Si(i-Pr) ₂OH]₄ (E = C, 2a; E = Si, 2b) as well as octahedral organosilanols Si₈O₁₂(CH=CHC₆H ₄SiR₂OH)₈ (R = i-Pr, 5a; R = Ph, 5b) have been derived from tetraphenylmethane and -silane (1a,b) and octavinyloctasilsesquioxane (3) designed for self-assembly of 3D hydrogen-bonding networks possessing large porosity. X-ray analyses following crystallization of 2a,b from THF/benzene and either hexane or heptane revealed adamantane-type networks with hydrogen bonds between the silanols of four separate molecules and selective inclusion of hexane or heptane, respectively. Upon changing the mixed solvent to THF/benzene/cyclohexane, X-ray analysis of 2a showed an inclusion compound of composition 2a·1.5benzene. TOPOS analyses of 2a·1.5benzene demonstrated a non-adamantane-type framework with sra network topology. Crystallization of 5a,b from acetone/benzene followed by X-ray analyses confirmed the production of the inclusion compounds 5a·18benzene and 5b·23benzene. The open frameworks of 5a·18benzene and 5b·23benzene are constructed with zeolitic or fluorite cages, and ast or flu network topology results, based on the TOPOS program. The packing of benzene molecules in 5a·18benzene and 5b·23benzene was found to be similar to that of crystals of pure benzene in edge-to-face arrangements. Thus, hydrogen-bonding networks of polyhedral organosilanols have shown selective inclusion of hydrocarbons into large cavities with adjustable porosity and without interpenetration of one network into another.

Full text of DOI:10.1021/om901120m

Organometallics 2010, 29, 3281–3288 3281
DOI: 10.1021/om901120m
Hydrogen-Bonding 3D Networks by Polyhedral Organosilanols: Selective
Inclusion of Hydrocarbons in Open Frameworks
Yoshiteru Kawakami, Yoshinobu Sakuma, Takashi Wakuda, Tatsuya Nakai,
Masayoshi Shirasaka, and Yoshio Kabe*
Department of Chemistry, Faculty of Science, Kanagawa University, 2946 Tsuchiya,
Hiratsuka 259-1293, Japan
Received December 25, 2009
Tetrahedral organosilanols E[C6H4Si(i-Pr)2OH]4 (E = C, 2a; E = Si, 2b) as well as octahedral
organosilanols Si8O12(CHdCHC6H4SiR2OH)8 (R = i-Pr, 5a; R = Ph, 5b) have been derived from
tetraphenylmethane and -silane (1a,b) and octavinyloctasilsesquioxane (3) designed for self-assembly
of 3D hydrogen-bonding networks possessing large porosity. X-ray analyses following crystal-
lization of 2a,b from THF/benzene and either hexane or heptane revealed adamantane-type networks
with hydrogen bonds between the silanols of four separate molecules and selective inclusion of
hexane or heptane, respectively. Upon changing the mixed solvent to THF/benzene/cyclohexane,
X-ray analysis of 2a showed an inclusion compound of composition 2a 1.5benzene. TOPOS analyses
3
of 2a 1.5benzene demonstrated a non-adamantane-type framework with sra network topology.
3
Crystallization of 5a,b from acetone/benzene followed by X-ray analyses confirmed the production
of the inclusion compounds 5a 18benzene and 5b 23benzene. The open frameworks of 5a
18benzene and 5b 23benzene are constructed with zeolitic or fluorite cages, and ast or flu network
3
3
3
3
topology results, based on the TOPOS program. The packing of benzene molecules in 5a 18benzene
and 5b 23benzene was found to be similar to that of crystals of pure benzene in edge-to-face
arrangements. Thus, hydrogen-bonding networks of polyhedral organosilanols have shown selective
inclusion of hydrocarbons into large cavities with adjustable porosity and without inter-
penetration of one network into another.
3
3
Introduction
on tetraphenylmethane (2a) and -silane (2b), as well as octas-
tyryloctasilsesquioxane (5a,b), are used as Td and Oh symme-
trical organic building blocks, designed for 3D hydrogen-
bonding networks. Hydrogen-bonding networks tend to form
entangled structures in which two or more independent infinite
networks interpenetrate each other.1d However, these silanol
networks selectively include hydrocarbons in their open frame-
works without interpenetration.
Self-assembly directed by hydrogen bonding and metal-
ligand binding has became a powerful tool for the construct-
ion of porous solids, with a three-dimensional (3D) network.1
Traditionally, self-assembly of well-defined 3D networks with
regular porosity has been achieved by connecting the vertices of
polyhedral organic building blocks. Derivatives of tetraphenyl-
methane,2a-g -silane,2h-j and -adamantane2e,g,k-m are useful
organic building blocks for production of an adamantane-type
network structure. Many examples of such adamantane-type
networks exist involving a strongly hydrogen-bonded group
such as a carboxylic acid,2k borol,2d pyridone,2b or metal com-
plex.2a,e Although silanols are known to form strong hydrogen
bonds, there are few networks involving 3D hydrogen-bonded
networks of silanols.3 Herein, polyhedral organosilanols based
(2) Polyhedral organic building blocks, tetraphenylmethane: (a) Hoskins,
B. F.; Robson, R. J. Am. Chem. Soc. 1989, 111, 5962; 1990, 112, 1546.
(b) Simard, M.; Su, D.; Wuest, J. D. J. Am. Chem. Soc. 1991, 113, 4696.
(c) Brunet, P.; Simard, M.; Wuest, J. D. J. Am. Chem. Soc. 1997, 119, 2737.
(d) Fournier, J.-H.; Maris, T.; Wuest, J. D.; Guo, W.; Galoppini, E. J. Am.
Chem. Soc. 2003, 125, 1002. (e) Kim, J.; Chen, B.; Reineke, T. M.; Li, H.;
Eddaoudi, M.; Moler, D. B.; O'Keeffe, M.; Yaghi, O. M. J. Am. Chem. Soc.
2001, 123, 8239. (f) Cheon, Y. E.; Suh, M. P. Chem.;Eur. J. 2008, 14, 3961.
(g) Galoppini, E.; Gilardi, R. Chem. Commun. 1999, 173. Tetraphenylsilane:
(h) Saied, O.; Maris, T.; Wang, X.; Simard, M.; Wuest, J. D. J. Am. Chem.
Soc. 2005, 127, 10008. (i) Lambert, J. B.; Liu, Z.; Liu, C. Organometallics
2008, 27, 1464. (j) Liu, Z.; Stern, C. L.; Lambert, J. B. Organometallics
2009, 28, 84. Adamantane: (k) Ermer, O. J. Am. Chem. Soc. 1988, 110,
3747, also see 2e and 2g. Tetraphenyladamantane: (l) Men, Y.-B.; Sun, J.;
Huang, Z.-T.; Zheng, Q.-Y. Angew. Chem., Int. Ed. 2009, 48, 2873.
(m) Taylor, J. M.; Mahmoudkhani, A. H.; Shimizu, G. K. H. Angew. Chem.,
Int. Ed. 2007, 46, 795.
*To whom correspondence should be addressed. E-mail: kabe@
kanagawa-u.ac.jp. Fax: (þ81) 463-58-9684.
(1) Review on MOFs and hydrogen-bonding networks: (a) Zawor-
otko, M. J. Chem. Soc. Rev. 1994, 23, 283. (b) Desiraju, G. R. Angew.
Chem., Int. Ed. Engl. 1995, 34, 2311. (c) Desiraju, G. R. Chem. Commun.
1997, 1475. (d) Batten, S. R.; Robson, R. Angew. Chem., Int. Ed. 1998, 37,
1460. (e) Robson, R. J. Chem. Soc., Dalton Trans. 2000, 21, 3735. (f) Yaghi,
O. M.; Li, H.; Davis, C.; Richardson, D.; Groy, T. L. Acc. Chem. Res. 1998,
31, 474. (g) Eddaoudi, M.; Moler, D. B.; Li, H.; Chen, B.; Reineke, T. M.;
O'Keeffe, M.; Yaghi, O. M. Acc. Chem. Res. 2001, 34, 319. (h) Yaghi, O. M.;
O'Keeffe, M.; Ockwig, N. W.; Chae, H. K.; Eddaoudi, M.; Kim, J. Nature
2003, 423, 705. (i) Wuest, J. D. Chem. Commun. 2005, 5830.
(3) Review of organosilanols: (a) Lickiss, P. D. Adv. Inorg. Chem.
1995, 42, 147. Recent 3D hydrogen-bonding network of organosilanols:
(b) Beckmann, J.; Duthie, A.; Reeske, G.; Sch€urmann, M. Organometallics
€
2004, 23, 4630. (c) Beckmann, J.; Janicke, S. L. Eur. J. Inorg. Chem. 2006,
17, 3351.
r
2010 American Chemical Society
Published on Web 07/07/2010
pubs.acs.org/Organometallics

3282 Organometallics, Vol. 29, No. 15, 2010
Kawakami et al.
Scheme 1
Table 1. Crystal Data and Data Collection Parameters for 2a Hexane, 2b Heptane, and 2a 1.5Benzene
3
3
3
2a hexane
3
2b heptane
3
2a 1.5benzene
3
empirical formula
fw
cryst syst
C
927.63
monoclinic
Pn
12.591(2)
13.083(3)
17.732(3)
90.00
90.47(1)
90.00
2920.9(10)
2
1.055
0.141
3.11 to 27.69
55H90O4Si4
C55H92O4Si5
957.74
monoclinic
Pn
12.700(2)
13.154(2)
17.541(3)
90.0
93.05(0)
90.0
2926.2(8)
2
1.087
0.156
2.23 to 30.67
C58H85O4Si4
958.61
monoclinic
P21/n
12.791(2)
26.646(5)
17.054(4)
90.0
90.61(1)
90.0
5812.2(20)
4
1.094
0.144
3.03 to 27.48
space group
˚
a (A)
˚
b (A)
˚
c (A)
R (deg)
β (deg)
γ (deg)
3
˚
volume (A )
Z
density (calcd) (Mg/cm3)
absorp coeff (mm-1
θ range for data
collection (deg)
reflns collected
)
25 779
12 431 (0.0574)
1.027
32 296
13 835 (0.0388)
1.114
54 122
13 231 (0.1126)
1.035
indep reflns (Rint
goodness of fit
indicator
)
final R indices
[I> 2σ(I)]
R indices (all data)
R1 = 0.0672, wR2 = 0.1770
R1 = 0.0707, wR2 = 0.1653
R1 = 0.0809, wR2 = 0.2001
R1 = 0.0910, wR2 = 0.2018
0.778 and -0.268
R1 = 0.0775, wR2 = 0.1735
0.349 and -0.380
R1 = 0.1223, wR2 = 0.2284
0.581 and -0.478
largest diff peak
˚
and hole (e A
-3
)
Results and Discussion
dimethyldioxirane (DMD) gave the tetrahedral organosila-
nol derivatives (2a,b) in 66.7% and 53.3% total yield, re-
spectively, as shown in Scheme 1. For the Oh symmetrical
organic building blocks, octavinyloctasilsesquioxane (3), a
cubic molecule with a cage-like Si8O12 core and vinyl groups
at each vertex, was employed as the starting compound. A
Ru-catalyzed silylative coupling reaction4d of 3 with 4-(met-
hoxysilyl)styrenes (4a,b) followed by hydrolysis with HCl
afforded the octahedral organosilanol derivatives (5a,b) in
69.4% and 63.5% total yields, respectively (Scheme 1).
Formation of Hydrogen-Bonding Networks by Tetrahedral
Organosilanols (2a,b). Crystallization of the tetrahedral orga-
nosilanols from THF/benzene/hexane and THF/benzene/hep-
tane (for details see Experimental Section) provided plates of
compounds 2a and 2b. X-ray crystallography established that
2a and 2b are isomorphous (Table 1) and crystallize with
composition 2a hexane and 2b heptane, respectively.
Syntheses of Td and Oh Symmetrical Organosilanols (2a,b
and 5a,b). Introduction of silanol into the Td symmetrical
organic building blocks was accomplished as follows: Tetrakis-
(4-bromophenyl)methane (1a, E = C) and -silane (1b, E = Si)
were synthesized according to the literature methods,4 treated
with n-BuLi or t-BuLi, and reacted with diisopropylchlorosi-
lane. Subsequent neutral oxidation of the hydrosilyl groups by
(4) (a) Hoskins, B. F.; Robson, R. J. Am. Chem. Soc. 1990, 112, 1546.
(b) Galoppini, E.; Gilardi, R. Chem. Commun. 1999, 173. (c) Fournier, J.-H.;
Wang, X.; Wuest, J. D. Can. J. Chem. 2003, 81, 376. (d) Itami, Y.; Marciniec,
B.; Kubicki, M. Chem.;Eur. J. 2004, 10, 1239. (e) Murray, R. W.; Singh,
M. Org. Synth. 1997, 74, 91. (f) Voronkov, M. G.; Martynova, T. N.;
Mirskov, R. G.; Belyi, V. I. Zh. Obshch. Khim. 1979, 49, 1522. (g) Overberger,
C. G.; Saunders, J. H. Org. Synth. 1948, 28, 31. (h) Yi, C. S.; Lee, D. W.;
Chen, Y. Organometallics 1999, 18, 2043. (i) Sellmann, D.; Ruf, R.; Knoch,
F.; Moll, M. Inorg. Chem. 1995, 34, 4745.
3
3

Article
Organometallics, Vol. 29, No. 15, 2010 3283
are constructed from tetraphenylmethane (1) and -silane (2),
several minor differences are noteworthy. In particular, the
C-C-C bond angles at the core of the tetraphenylmethane
(1) in 2a hexane have values between 108.2(3)° and 111.4(3)°,
3
whereas the C-Si-C angles at the core of tetraphenylsilane
(2) in 2b heptane varies more widely (107.2(1)-114.8(1)°),
3
because of the greater flexibility of the four-coordinated sili-
con atom in 2 as compared to the carbon atom in 1, as shown
in Table 3.
This pattern of hydrogen bonding is often found in mono-
silanols3 and can be regarded as a bonding motif similar to
carboxylic acid dimers1b,c and borol dimers.2d Assuming the
four hydrogen-bonded silanols (synthon R(4)(4) H-bond)5c-f
and tetraphenylmethane or -silane building blocks (tecton)
to be four-connected nodes, the adamantane-type or dia-
mond-type (i.e., dia) net6 is represented as shown in Figure 2c
based on the X-ray crystallographic data of 2a hexane using
3
the TOPOS program.5g It is well known that an adamantane-
type network readily enables interpenetration to fill potential
cavity space. The adamantane frameworks of 2a hexane and
Figure 1. Crystal structures as viewed along the a-axis: (a) 2a
hexane, (b) 2b heptane, and (c) 2a 1.5benzene. Guest hydro-
carbons in a cavity are drawn as green molecules. (d) Geometry
of hydrogen-bonded silanol tetramer. All ellipsoids are shown at
the 30% probability level.
3
3
3
3
2b heptane contain only four molecules instead of the 10
3
molecules observed in the corresponding borol derivatives.2d
Undoubtedly, the smaller size of the adamantane framework
and the steric requirements of the bulky substituents on the
silicon atoms prevent interpenetration in these networks. In
fact, the framework without hexane or heptane is composed
of 18% and 22% guest-accessible cavities in the unit cells on
the basis of PLATON calculations.7
Use of cyclohexane in THF/benzene (for details see Ex-
perimental Section) unexpectedly produced needles of
2a 1.5benzene. The X-ray structure of 2a 1.5benzene is
3
3
shown in Figure 1c. The selected bond and hydrogen bond
parameters of the tetraphenylmethane core and the silanol
tetramer are also collected in Tables 2 and 3. The X-ray
crystal structure of 2a 1.5benzene revealed a four-connected
3
non-adamantane framework possessing two distinct one-
dimensional (1D) channels with differing pore sizes, as shown
(5) TOPOS is a program package for multipurpose geometrical and
topological analysis of crystal structures. It works with crystal structure
details and provides automatic determination of network topology and
degree of interpenetration. (a) Blatov, V. A.; Carlucci, L.; Ciani, G.;
Proserpio, D. M. Cryst.EngComm 2004, 6, 378. (b) Baburin, I. A.; Blatov,
V. A.; Carlucci, L.; Ciani, G.; Proserpio, D. M. J. Solid State Chem. 2005,
178, 2452. (c) Baburin, I. A.; Blatov, V. A.; Carlucci, L.; Ciani, G.; Proserpio,
D. M. Cryst. Growth Des. 2008, 8, 519. (d) Baburin, I. A.; Blatov, V. A.;
Carlucci, L.; Ciani, G.; Proserpio, D. M. CrystEngComm 2008, 10, 1822.
(e) Baburin, I. A.; Blatov, V. A. Acta Crystallogr. 2007, B63, 791. (f) Baburin,
I. A. Z. Kristallogr. 2008, 223, 371. (g) http://www.topos.ssu.samara.ru.
(6) For the taxonomy of zeolites as well as inorganic, organic, and
metal-organic networks, three-letter designations are widely accepted.
(a) Ockwig, N. W.; Delgado-Friedrichs, O.; O’Keeffe, M.; Yaghi, O. M.
Acc. Chem. Res. 2005, 38, 176. (b) O'Keeffe, M.; Peskov, M. A.; Ramsden,
S. J.; Yaghi, O. M. Acc. Chem. Res. 2008, 41, 1782. (c) Delgado-Friedrichs,
O.; Foster, M. D.; O'Keeffe, M.; Proserpio, D. M.; Treacy, M. M. J.; Yaghi,
O. M. J. Solid State Chem. 2005, 178, 2533. (d) http://rcsr.anu.edu.au/
Figure 2. Partial views of the 3D network present in the crystals:
(a) 2a hexane and (b) 2b heptane. Both views have four net-
work units containing hydrocarbons as guests (green). All sub-
3
3
stituents on the Si atom are omitted for clarity. (c) dia network of
2a hexane based on TOPOS analysis. The tetrahedral units of
3
four hydrogen-bonded silanols and tetraphenylmethane are
viewed as four-connected nodes.
€
home. The proceeding Schlafli symbols are also used in mathematical senses
such as in 66-dia, 42.63.8-sra, (43.63)4(66)-ast, and (412.612.84)(46)2-flu. In the
text, networks are simply denoted by the three-letter symbols. In those
networks, dia is the most common network with a tetrahedral 4-connected
node. For example, it is found in the diamond framework. sra is a non-
diamondoid 4-connected network. ast is a 4-connected zeolitic network with
both tetrahedral and cubic parts, such as AlPO4-16 or octadecasil zeolite. flu
is a 4- and 8-connected network found in fluorite, CaF2.
(7) PLATON is a versatile program package for multipurpose crys-
tallography. Other than automatic structure solution, refinement, and
geometrical calculations, it calculates the accessible volume (Vg). If V is
the volume of the unit cell, then the porosity in % is given by 100 Vg/V.
(a) Spek, A. L. PLATON, A Multipurpose Crystallographic Tool; Utrecht
University: Utrecht, The Netherlands, 2001. (b) van der Sluis, P.; Spek, A. L.
Acta Crystallogr. 1990, A46, 194. (c) http://www.cryst.chem.uu.nl/platon.
Even though crystallization occurred in a mixed solvent,
the open cavities selectively enclathrated only hexane in 2a
and heptane in 2b, respectively, as shown in Figure 1a and b.
These crystals formed open frameworks, based on four hydrogen-
bonded silanols, as shown in Figure 2a and b.
The hydrogen-bonded silanols in 2a hexane and 2b
3
3
heptane give rise to cyclic tetramers with distorted tetrahe-
dral geometries, shown in Figure 1d. Hydrogen-bond para-
meters are also collected in Table 2. The O-O distances
˚
(between 2.730(4) and 2.833(4) A) are indicative of weak to
medium strength hydrogen bonding. Although the networks

3284 Organometallics, Vol. 29, No. 15, 2010
Kawakami et al.
Table 2. Selected Hydrogen Bond Parameters of 2a Hexane, 2b Heptane, 2a 1.5Benzene, 5a 18Benzene, and 5b 23Benzene
3
3
3
3
3
O-H
H
O
O
O
O-H
3 3 3
O
3 3 3
3 3 3
2a hexane
3
0.73(4)-0.75(5)
0.71(4)-0.76(4)
0.71(4)-0.76(3)
0.74(4)-0.75(3)
0.74(4)-0.75(3)
2.02(5)-2.12(5)
2.09(4)-2.16(4)
1.96(3)-2.12(4)
2.03(3)-2.10(5)
1.95(4)-1.98(2)
2.741(5)-2.828(5)
2.730(4)-2.833(4)
2.689(4)-2.795(4)
2.758(4)-2.795(4)
2.669(3)-2.702(2)
155(5)-165(4)
146(4)-155(4)
156(4)-167(4)
157(5)-164(4)
161(4)-162(4)
2b heptane
3
2a 1.5benzene
3
5a 18benzene
3
5b 23benzene
3
Table 3. Selected Bond Lengths and Angles of Tetrahedral
Organic Frameworks in the Crystals of 2a Hexane, 2b Heptane,
and 2a 1.5Benzene
3
3
3
network
type
E-C
C-E-C
2a hexane (E = C)
3
3
3
dia
dia
sra
1.551(5)-1.575(5) 108.2(3)-111.4(3)
1.868(4)-1.874(3) 107.2(1)-114.8(1)
1.540(4)-1.545(4) 101.7(2)-113.5(2)
2b heptane (E = Si)
2a 1.5benzene (E = C)
Figure 3. (a) Partial view of the 3D network present in 2a
Figure 4. Cage units of (a) to and (b) trd structures. The linkage
of (c) to and (d) trd cages in zeolite A and octadecasil zeolite.
Each cage is linked at the square faces of the to or trd structures
together through cubic prisms (yellow).
3
1.5benzene. The view has four network units containing hydro-
carbons as guests (green). All substituents on the Si atom are
omitted for clarity. (b) sra network of 2a 1.5benzene based on
3
TOPOS analysis.
introducing octasilsesquioxane, having a cubic cage, into the
silanol 3D network seems to allow for the expansion of the
pore structure in the network and produces zeolite-like
frameworks.
in Figure 1c. The larger channel is occupied by three benz-
enes, while the smaller channel is completely empty, with a
total of 20% guest-accessible volume.
To simplify the framework connectivity, a topological
analysis of 2a 1.5benzene was performed using the TOPOS
Crystallization of octahedral organosilanol derivatives
(5a,b) with cubic cages from acetone/benzene (for details
see Experimental Section) provided prisms of 5a and 5b,
whose X-ray crystallographic analysis confirmed a composi-
tion of 5a 18benzene and 5b 23benzene, respectively (Table 4).
3
program. The four-connected node of tetraphenylmethane
and the synthon R(4)(4) H-bond by four silanols revealed an
sra network,6 as shown in Figure 3b. An analogous topology
has been found in metallic and binary inorganic solids such
as SrAl2, andPBr5.5a,b Thus fitting the large cyclohexane into the
cavities of the adamantane network seems to allow the frame-
work to be changed with inclusion of benzenes.
3
3
The X-ray structures of 5a 18benzene and 5b 23benzene are
3
3
shown in Figure 5.
In the crystal structures, each octasilsesquioxane cube forms
silanol hydrogen bonds with 12 neighboring cubes, resulting in
a large cavity where either 18 or 23 benzene molecules were
located, as shown in Figure 6a and b. Selected hydrogen bond
parameters of the silanol tetramer are listed in Table 2. There
is a surprisingly large guest-accessible volume for 5a and 5b
of 50.9% and 51.0% of the unit cell volume, respectively.
TOPOS analyses of 5a 18benzene and 5b 23benzene
Formation of Zeolite-Type Hydrogen-Bonding Networks
by Octahedral Organosilanols (5a,b). In microporous silic-
ates and zeolites, a number of structures can be built from
truncated octahedral (to) or truncated rhombic dodecahe-
dral (trd) cages of silicates and aluminosilicates, commonly
referred to as sodalite and octadecasil cages, as shown in
Figure 4a and b.8 These cages have both square and hexagonal
faces in their structures. Connecting the square faces of the to
structures yields zeolite A, while connecting the hexagonal
faces of the to structures yields faujasite zeolite.8 The trd
structures also yield octadecasil zeolite and aluminophosphate
molecular sieve AlPO4-16 by linking the square faces.8 The
prisms that connect the square faces of to and trd are
obviously cubes, as shown in Figure 4c and d. Therefore,
3
3
showed an eight-connected cube with the synthon R(4)(4)
H-bond resulting in ast networks6 without interpenetration,
as shown in Figure 6c. This network is exhibited by zeolites
such as octadodecasil and the ALPO4-16 frameworks.8 If
the whole silsesquioxane cube is considered to be an eight-
connected node, the network can be further simplified to flu6
or a fluorite-type of network (Figure 6d). In any case, both
the ast and flu networks are very rare even in metal organic
frameworks (MOFs).10 To the best of our knowledge, these
3D networks are the first hydrogen-bonded replicas of
zeolite or fluorite.
(8) (a) Baerlocher, Ch.; Meier, W. M.; Olson, D. H. Atlas of Zeolite
Framework Types, 5th ed.; Elsevier: Amsterdam, 2001. (b) The original date
available at http://www.iza-structure.org/databases/.

Article
Table 4. Crystal Data and Data Collection Parameters of
5a 18Benzene and 5b 23Benzene
Organometallics, Vol. 29, No. 15, 2010 3285
3
3
5a 18benzene
5b 23benzene
3
3
empirical formula
fw
cryst syst
C
220H276O20Si16
C149H137O10Si8
4624.61
monoclinic
C2/m
26.089(3)
29.765(3)
20.783(2)
90.0
127.19(0)
90.0
12857(2)
2
1.195
3689.85
monoclinic
C2/m
22.911(3)
30.535(3)
18.608(3)
90.00
124.05(0)
90.00
10786(2)
2
1.136
space group
˚
a (A)
˚
b (A)
˚
c (A)
R (deg)
β (deg)
γ (deg)
volume (A )
Z
3
˚
density (calcd)
(Mg/cm3)
absorp coeff
0.154
0.143
(mm-1
)
θ range for data
collection (deg)
reflns collected
3.21 to 27.48
3.00 to 27.48
12 450
12 450 (0.0000)
1.206
66 958
14 838 (0.0394)
1.195
indep reflns (Rint
goodness of
fit indicator
final R indices
[I> 2σ(I)]
)
Figure 6. Partial view of the 3D networks present in the crys-
tals: (a) 5a 18benzene and (b) 5b 23benzene. Both views have
four network units containing hydrocarbons as guests (green).
R1 = 0.0937,
wR2 = 0.2552
R1 = 0.1020,
wR2 = 0.2628
0.851 and -0.514
R1 = 0.0668,
wR2 = 0.1562
R1 = 0.0739,
wR2 = 0.1605
0.353 and -0.308
3
3
R indices (all data)
All substituents on the Si atom are omitted for clarity. (c) ast
network and (d) flu network of 5b 23benzene based on TOPOS
largest diff peak and
)
3
-3
˚
hole (e A
analyses. The octahedral units of the silsesquioxane core are
viewed as cubes or eight-connected nodes.
molecule perpendicular to the other two parallel molecules
(Figure 7a). However, the perpendicular and parallel ben-
zenes are not overlapped enough to provide optimal edge-to-
face or face-to-face interactions. In contrast, all 18 benzenes
in the 5a 18benzene network are perpendicularly associated
3
in a cavity to provide optimal edge-to-face interactions similar
to that found in pure crystalline benzene (Figure 7b). The
larger size of the organosilanol in the network of 5b
3
23benzene enables the accommodation of 23 benzenes in a
cavity. Some excess benzenes in the unit cell are not perpen-
dicularly associated with neighboring benzenes (Figure 7c).
Thus, the surprisingly large cavities of 5a and 5b are
supported not only by three-dimensional silanol hydrogen
bonding but also by benzene clathrates with edge-to-face
interactions.
Figure 5. Crystal structures as viewed along the a-axis: (a) 5a
18benzene and (b) 5b 23benzene. Guest hydrocarbons in a cav-
ity are drawn as green molecules. All ellipsoids are shown at the
30% probability level.
3
3
Packing of Benzene Molecules in Hydrogen-Bonding Net-
works by Polyhedral Organosilanols. A very interesting part
of the crystal structures is the arrangement of the benzene
molecules inside the cavities of the hydrogen-bonding net-
works in these polyhedral organosilanols. Space-filling mod-
els of the benzenes within the network structures are shown
in Figure 7 to give an open view of the arrangement of the
benzene molecules in the unit cell. For comparison, a pack-
ing analysis of pure crystalline benzene molecules reveals
edge-to-face packing in herringbone layers (Figure 7d).9
Conclusions
In summary, the crystal structures of 2a,b and 5a,b with
hydrocarbons are the first examples of adamantane-type,
SrAl2-type, zeolite-type, and fluorite-type packing motifs
formed by silanol hydrogen bonding. Depending on the pore
size, hydrocarbons were included in the open frameworks
without interpenetration of the networks. Furthermore, as a
guest hydrocarbon perpendicular stacking of the benzene
cluster is found in the pores of 5a and 5b. Having established
this silanol hydrogen-bonded framework, we are currently
investigating covalent organic frameworks (COFs) as well as
MOFs based on polyhedral organosilanols with the aim of
achieving structural integrity during removal of the guest
molcules.11
In the network of 2a 1.5benzene, three benzenes repeat
within the cavity by translation along the a-axis, with one
3
(9) Crystal structures of pure benzene: (a) Cox, E. G.; Cruickshank,
D. W. J.; Smith, J. A. S. Proc. R. Soc. London 1958, A247, 1. (b) Bacon,
G. E.; Curry, N. A.; Wilson, S. A. Proc. R. Soc. London 1964, A279, 98.
(c) Jeffrey, G. A.; Ruble, J. R.; McMullan, R. K.; Pople, J. A. Proc. R. Soc.
London 1987, A414, 47.
(10) Metal organic frameworks (MOFs) with octadecasil network:
€
€
€
(a) Gadara, F.; Gomez-Lor, B.; Iglesias, M.; Snejko, N.; Gutierrez-
Puebla, E.; Monge, A. Chem. Commun. 2009, 2393. MOF with fluorite
network: (b) Chun, H.; Kim, D.; Dybtsev, D. N.; Kim, K. Angew. Chem., Int.
Ed. 2004, 43, 971.
(11) Preliminary experiments show that the adamantane-type net-
work of 2b does not remain ordered under cryogenic (77 K) nitrogen
adsorption conditions.

3286 Organometallics, Vol. 29, No. 15, 2010
Kawakami et al.
Synthesis of Diisopropylchlorosilane. Magnesium turnings
(12.2 g, 500 mmol) were added to anhydrous Et2O (50 mL),
and a few drops of 1,2-dibromoethane was added for activat-
ion of the magnesium surface. A solution of 2-chloropropane
(47.6 mL, 520 mmol) in Et2O (250 mL) was added dropwise over
2 h at 0 °C. After complete addition, the reaction mixture was
stirred for 2 h at room temperature. To this Grignard reagent
was added dropwise trichlorosilane (25.2 mL, 250 mmol) in
200 mL of Et2O over 2 h and stirred overnight using a dry ice/
methanol trap over the reaction vessel. The reaction mixture was
Schlenk filtered with a glass filter, and the solvent was removed
in vacuo. The resulting mixture was fractionally distilled to give
16.7 g (111 mmol) of diisopropylchlorosilane (44.2%): bp 136-
8 °C; 1H NMR (500 MHz, CDCl3) δ 4.47 (t, J = 1.8 Hz, 1H),
1.12-1.03 (m, 2H), 0.97 (d, J = 7.3 Hz, 6H), 0.92 (d, J = 7.3 Hz,
6H); 13C NMR (125 MHz, CDCl3) δ 17.31, 16.97, 13.81; MS
(EI) m/z calcd for C6H15ClSi (M)þ 150, found 150.
Synthesis of Diphenylchlorosilane. Magnesium turnings (5.35 g,
220 mmol) were added to anhydrous THF (10 mL), and a few
drops of 1,2-dibromoethane was added for activation of the magnes-
ium surface. A solution of chlorobenzene (20.3 mL, 200 mmol) in
THF(100 mL) was addeddropwiseover1 h. Aftercomplete addi-
tion, the reaction mixture was refluxed overnight. This Grignard
reagent was added dropwise to a solution of trichlorosilane (10.2 mL,
100 mmol) in 100 mL of THF over 3 h and stirred overnight using
a dry ice/methanol trap over the reaction vessel. The solvent was
removed in vacuo and redissolved in 100 mL of hexane. The react-
ion mixture was Schlenk filtered with a glass filter, and the solvent
was removed under reduced pressure. The resulting mixture was
fractionally distilled to give 18.0 g (82.4 mmol) of diphenylchloro-
1
silane (82.4%): bp 96-8 °C/0.4 mmHg; H NMR (500 MHz,
CDCl3) δ 7.79 (d, J = 7.9 Hz, 4H), 7.58 (t, J = 7.5 Hz, 2H), 7.53
(t, J = 7.5 Hz, 4H), 5.88 (s, 1H); 13C NMR (125 MHz, CDCl3) δ
134.49, 131.90, 131.05, 128.28; MS (EI) m/z calcd for C12H11ClSi
(M)þ 218, found 218.
Synthesis of Tetrakis[4-(diisopropylhydrosilyl)phenyl]methane.
A solution of tetrakis(4-bromophenyl)methane (1a) (3.60 g,
5.66 mmol) in anhydrous THF (250 mL) was added to n-BuLi
in hexanes (19.2 mL, 1.60 M, 31.7 mmol) at -78 °C and stirred
for 1 h. Then diisopropylchlorosilane (6.20 mL, 35.8 mmol) was
added dropwise over 1 h and then warmed to ambient tempera-
ture overnight. The solvent was removed in vacuo, and the
residue was redissolved in chloroform. The resulting salt was filte-
red, and the filtrate was evaporated to afford the crude product.
The crude product was purified by gel permeation chromato-
graphy to give 2.34 g (3.02 mmol) of tetrakis[4-(diisopropylhy-
drosilyl)phenyl]methane (53.3%): 1H NMR (500 MHz, CDCl3)
δ 7.43 (d, J = 8.1 Hz, 8H), 7.18 (d, J = 8.1 Hz, 8H), 3.97 (t, J =
3.0 Hz, 4H), 1.28-1.22 (m, 8H), 1.11 (d, J = 7.3 Hz, 24H), 1.03
(d, J = 7.3 Hz, 24H); 13C NMR (125 MHz, CDCl3) δ 147.39,
134.53, 131.53, 130.53, 65.15, 18.76, 18.64, 10.78; MS (MALDI-
TOF, matrix: DHB) calcd for C49H76Si4Na (M þ Naþ) 799,
found 799.
Figure 7. Crystal structures as viewed along the b-axis (left)
and c-axis or ac-plane (right): (a) 2a 1.5benzene, (b) 5a
3
3
18benzene, (c) 5b 23benzene, and (d) pure benzene.9a Benzene
3
molecules are shown as space-filling models for clarity of the
stacking.
Experimental Section
General Information. 1H NMR, 13C NMR, and 29Si NMR
spectra were recorded at room temperature using JEOL JNM-ECP
500 or JNM-EX 400 spectrometers. Low-resolution EI mass
spectra were recorded on a JEOL JMS-AX505H mass spectro-
meter, and MALDI-TOF mass spectra were measured on a
Shimadzu AXIMA-CFR mass spectrometer using angiotensin
II and insulin β for accurate mass calibration. High-resolution
mass spectra (ESI) were recorded on a JEOL JMS-T100LC mass
spectrometer. The standard substance Yokudelna (purchased
from JEOL) was used for calibration. HPLC (GPC) purification
was performed using a Japan Analytical Industry LC-908. Start-
ing materials and reagents were purchased from Sigma-Aldrich,
Wako, TCI, and Kanto. Tetrahydrofuran (THF), hexane, and
benzene were distilled from sodium benzophenone ketyl. Met-
hanol was distilled from magnesium methoxide, and toluene was
distilled from lithium aluminum hydride (LAH). Tetrakis-
(4-bromophenyl)methane,4a tetrakis(4-bromophenyl)silane,4c
Synthesis of Tetrakis[4-(diisopropylhydrosilyl)phenyl]silane. The
reaction of tetrakis(4-bromophenyl)silane (1b) (2.00 g, 3.06 mmol),
t-BuLi in pentanes (22.5 mL, 1.60 M, 37.1 mmol), and diisopropyl-
chlorosilane (3.60 mL, 21.3 mmol) was performed in a similar man-
ner to that described above and gave 1.62 g (2.04 mmol) of tet-
rakis[4-(diisopropylhydrosilyl)phenyl]silane (66.7%): 1H NMR
(500 MHz, CDCl3) δ 7.54-7.52 (br, 16H), 3.94 (t, J = 3.0 Hz,
4H), 1.26-1.21 (m, 8H), 1.08 (d, J = 7.3 Hz, 24H), 1.01 (d, J = 7.3
Hz, 24H); 13C NMR (125 MHz, CDCl3) δ 135.76, 135.43, 134.82,
134.78, 18.70, 18.60, 10.71; MS (MALDI-TOF, matrix: DHB)
calcd for C48H76Si5Na (M þ Naþ) 815, found 815.
Synthesis of Tetrakis[4-(diisopropylhydroxysilyl)phenyl]methane
(2a). To a solution of tetrakis[4-(diisopropylhydrosilyl)phenyl]-
methane (0.290 g, 0.366 mmol) in anhydrous carbon tetrachloride
(20 mL) was added dimethyldioxirane in acetone solution (30.0 mL,
0.300 M, 9.00 mmol). The resulting mixture was stirred for 1 h and
then evaporated to afford 0.321 g (0.366 mmol) of 2a (99.9%):
dimethyldioxirane (DMD),4e octavinyloctasilsesquioxane,4f
4h,i
4-chlorostyrene,4g and RuH(CO)(PCy3)2
cording to literature methods.
were prepared ac-

Article
Organometallics, Vol. 29, No. 15, 2010 3287
1H NMR (500 MHz, THF-d8) δ 7.46 (d, J = 8.1 Hz, 8H), 7.16
(d, J = 8.1 Hz, 8H), 4.87 (s, 4H,), 1.14-1.07 (m, 8H), 1.03 (d,
J = 7.1 Hz, 24H), 0.95 (d, J = 7.1 Hz, 24H); 13C NMR
(125 MHz, THF-d8) δ 148.40, 134.28, 134.23, 131.30, 66.22,
17.95, 17.65, 13.81; HRMS (ESI) calcd for C49H76O4Si4Na
(M - Naþ) 863.4718, found 863.4674.
Synthesis of Tetrakis[4-(diisopropylhydroxysilyl)phenyl]silane
(2b). The reaction of tetrakis[4-(diisopropylhydrosilyl)phenyl]-
silane (0.590 g, 0.738 mmol) and dimethyldioxirane (DMD) in
acetone (30.0mL, 0.300 M, 9.00 mmol) was performed ina similar
manner to that described above and gave 0.663 g (0.737 mmol) of
2b (99.9%): 1H NMR (500 MHz, THF-d8) δ 7.60 (d, J = 7.8 Hz,
8H), 7.55 (d, J = 7.8 Hz, 8H), 5.04 (s, 4H), 1.18-1.11 (m, 4H),
1.01 (d, J = 7.2 Hz, 24H), 0.93 (d, J = 7.2 Hz, 24H); 13C NMR
(125 MHz, THF-d8) δ 139.39, 136.04, 135.76, 134.41, 17.80,
13.68; HRMS (ESI) calcd for C48H76O4Si5Na (M þ Naþ)
879.4488, found, 879.4467.
Synthesis of 4-(Diisopropylhydrosilyl)styrene. Magnesium turn-
ings (1.46 g, 60.0 mmol) were added to anhydrous THF (5 mL),
and a few drops of 1,2-dibromoethane was added to activate the
magnesium surface. A solution of 4-chlorostyrene (6.00 mL,
50.0 mmol) in THF (45 mL) was added dropwise over 1 h. The re-
action mixturewas stirredfor 2 h at 60 °C and then cooled to room
temperature. A solution of diisopropylchlorosilane (10.4 mL,
60.0 mmol) in 20 mL of THF was added, and the mixture stirred
for 1 h. The solvent was removed in vacuo, and the residue redis-
solved in 50 mL of hexane. The reaction mixture was washed with
100 mL of water, and the organic layer was dried over magnesium
sulfate. The solution of crude product was concentrated and puri-
fied on a silica gel short column with hexane as the eluent to give
7.91 g (36.2 mmol) of 4-(diisopropylhydrosilyl)styrene (72.4%):
1H NMR (500 MHz, CDCl3) δ 7.60 (d, J = 7.9 Hz, 2H), 7.49 (d,
J = 7.9 Hz, 2H), 6.81 (dd, J = 17.6, 10.9 Hz, 1H), 5.89 (d, J =
17.6 Hz, 1H), 5.35 (d, J = 10.9 Hz, 1H), 4.08 (t, J = 3.1 Hz, 1H),
1.40-1.30 (m, 2H), 1.19 (d, J = 7.3 Hz, 6H), 1.12 (d, J = 7.3 Hz,
6H); 13C NMR (125 MHz, CDCl3) δ 138.25, 136.94, 135.74,
133.80, 125.48, 114.06, 18.67, 18.48, 10.75; MS (EI) m/z calcd for
C14H22Si (M)þ 218, found 218.
Synthesis of 4-(Dipenylhydrosilyl)styrene. The reaction of mag-
nesium (2.19 g, 90.0 mmol), 4-chlorostyrene (9.60 mL, 80.0 mmol),
and diphenylchlorosilane (15.7 mL, 80.0 mmol) was performed in
a similar manner to that described above and gave 20.5 g (71.6 mmol)
of 4-(dipenylhydrosilyl)styrene (89.5%): 1H NMR (500 MHz,
CDCl3) δ 7.57 (d, J = 7.3 Hz, 4H), 7.54 (d, J = 8.0 Hz, 2H), 7.41-
7.37 (m, 4H), 7.35 (t, J = 7.3 Hz, 4H), 6.70 (dd, J = 17.6, 10.9 Hz,
1H), 5.77 (d, J = 17.6 Hz, 1H), 5.47 (s, 1H), 5.26 (d, J = 10.9 Hz,
1H); 13C NMR (125 MHz, CDCl3) δ 138.90, 136.69, 136.06,
135.77, 133.27, 132.83, 129.81, 128.05, 125.82, 114.73; MS (EI)
m/z calcd for C20H18Si (M)þ 286, found 286.
4-(diphenylhydrosilyl)styrene (17.2 g, 60.0 mmol) was per-
formed in a similar manner to that described above and gave
18.5 g (58.5 mmol) of 4b (97.5%): 1H NMR (500 MHz, C6D6) δ
7.74 (d, J = 7.6 Hz, 4H), 7.68 (d, J = 8.0 Hz, 2H), 7.25 (d, J =
8.0 Hz, 2H), 7.22-7.17 (m, 6H), 6.55 (dd, J = 17.5, 10.9 Hz,
1H), 5.63 (d, J = 17.5 Hz, 1H), 5.08 (d, J = 10.9 Hz, 1H), 3.50 (s,
3H); 13C NMR (125 MHz, C6D6) δ 139.50, 137.16, 136.11,
135.80, 134.62, 134.10, 130.29, 128.23, 126.12, 114.66, 51.58; MS
(EI) m/z calcd for C21H20OSi (M)þ 316, found 316.
Synthesis of Octakis[4-(diisopropylmethoxysilyl)styryl]octasil-
sesquioxane. Octavinyloctasilsesquioxane (3) (0.252 g, 0.399 mmol)
and RuHCl(CO)(PCy3)2 (36.3 mg, 50.0 μmol) were added to an
anhydrous toluene solution (6.4 mL) of 4-(diisopropylmethoxy-
silyl)styrene (4a) (1.58 g, 6.38 mmol) under an N2 atmosphere and
stirred for 72 h at 80 °C. The solvent was evaporated and the crude
product purified by gel permeation chromatography to give 0.663 g
(0.277 mmol) of octakis[4-(diisopropylmethoxysilyl)styryl]octasil-
sesquioxane (69.4%): 1H NMR (500 MHz, C6D6) δ 7.66 (d, J =
19.2 Hz, 8H), 7.36 (d, J = 7.8 Hz, 16H), 7.29 (d, J = 7.8 Hz, 16H),
6.57 (d, J = 19.2 Hz, 8H), 3.30 (s, 24H), 1.05 (sept, J = 7.3 Hz,
16H), 0.96 (d, J = 7.3 Hz, 48H), 0.89 (d, J = 7.3 Hz, 48H); 13
C
NMR (125 MHz, C6D6) δ 150.29, 138.45, 135.93, 135.29, 126.65,
118.29, 51.81, 17.64, 17.44, 12.33; MS (MALDI-TOF, matrix:
3-aminoquinoline) m/z calcd for C129H193N2O20Si16 (M þ
C9H9N2)þ 2538, found 2538.
Synthesis of Octakis[4-(diphenylmethoxysilyl)styryl]octasil-
sesquioxane. The reaction of 4-(dipenylmethoxysilyl)styrene (4b)
(1.02 g, 3.22 mmol) and octavinyloctasilsesquioxane (3) (0.128 g,
0.202 mmol) in the presence of RuHCl(CO)(PCy3)2 (23.4 mg,
32.2 μmol) was performed in a similar manner to that described
above and gave 0.376 g (0.128 mmol) of octakis[4-(diphenyl-
methoxysilyl)styryl]octasilsesquioxane (63.5%): 1H NMR (500
MHz, C6D6) δ 7.60 (d, J = 19.2 Hz, 8H), 7.56 (d, J = 6.5 Hz,
32H), 7.49 (d, J = 7.8 Hz, 16H), 7.24 (d, J = 7.8 Hz, 16H),
7.13-7.04 (m, 48H), 6.52 (d, J = 19.2 Hz, 8H), 3.34 (s, 24H); 13
C
NMR (125 MHz, C6D6) δ 150.07, 139.01, 136.19, 135.74, 134.38,
130.32, 129.27, 128.22, 126.77, 118.73, 51.58; MS (MALDI-
TOF, matrix: 3-aminoquinoline) m/z calcd for C177H161N2O20-
Si16 (M þ C9H9N2)þ 3082, found 3082.
Synthesis of Octakis[4-(diisopropylhydroxysilyl)styryl]octasil-
sesquioxane (5a). Octakis[4-(diisopropylmethoxysilyl)styryl]oct-
asilsesquioxane (0.240 g, 0.100 mmol) was stirred at room
temperature for 2 h in a 1:9 mixture of 1 M HCl/THF (5 mL).
Then 5 mL of chloroform was added, and the organic layer
was washed 5 mL of water. Evaporation of the solvent from
the mixture gave 0.228 g (0.100 mmol) of 5a in quantitative
yield: 1H NMR (500 MHz, acetone-d6) δ 7.64 (d, J = 8.3 Hz,
16H), 7.61 (d, J = 8.3 Hz, 16H), 7.53 (d, J = 19.2 Hz, 8H),
6.55 (d, J = 19.2 Hz, 8H), 4.90 (br, 8H), 1.19 (sept, J = 7.3 Hz,
Synthesis of 4-(Diisopropylmethoxysilyl)styrene (4a). To an-
hydrous methanol (20 mL) at -78 °C was added sodium metal
(0.920 g, 40.0 mmol), and the solution was warmed to ambient
temperature over 1 h. Stirring was continued for an additional
2 h until the sodium is fully dissolved. 4-(Diisopropylhydro-
silyl)styrene (4.37 g, 20.0 mmol) in THF (40 mL) was added
dropwise and stirred for 18 h at 40 °C. Trimethylchlorosilane
(6.35 mL, 50 mmol) in THF (10 mL) was added to the reaction
mixture and stirred for an additional hour. The solvent and
volatiles were removed in vacuo and redissolved in 40 mL of hex-
ane. The resulting salt was filtered, and the filtrate was evapo-
16H), 1.05 (d, J = 7.3 Hz, 48H), 0.96 (d, J = 7.3 Hz, 48H); 13
C
NMR (125 MHz, acetone-d6) δ 150.39, 138.96, 138.41, 135.37,
126.70, 118.02, 17.63, 17.31, 13.29; 29Si NMR (100 MHz, acetone-
d6) δ 3.91, -77.68; HRMS (ESI) m/z calcd for C112H168NaO20Si16
(M þ Na)þ 2303.8335, found 2303.8367.
Synthesis of Octakis[4-(diphenylhydroxysilyl)styryl]octasil-
sesquioxane (5b). The reaction of octakis[4-(diphenylmethoxy-
silyl)styryl)octasilsesquioxane (0.147 g, 50.0 μmol) in a 1:9 mix-
ture of 1 M HCl/THF (5 mL) was performed in a similar manner
to that described above and gave 0.141 g (50.0 μmol) of 5b in
quantitative yield: 1H NMR (500 MHz, acetone-d6) δ 7.67-7.58
(m, 64H), 7.50 (d, J = 19.3 Hz, 8H), 7.43 (t, J = 7.3 Hz, 16H),
7.37 (t, J = 7.3 Hz, 32H), 6.54 (d, J = 19.3 Hz, 8H), 6.06 (br,
8H); 13C NMR (125 MHz, acetone-d6) δ 150.25, 139.12, 138.83,
137.15, 136.08, 135.59, 130.55, 128.55, 127.04, 118.66; 29Si
NMR (100 MHz, acetone-d6) δ -16.37, -77.83; HRMS (ESI)
m/z calcd for C160H136Na2O20Si16 (M þ 2Na)2þ 2870.5729,
found 2870.5708.
1
rated to afford 4.43 g (17.8 mmol) of 4a (89.2%): H NMR
(500 MHz, C6D6) δ 7.54 (d, J = 7.8 Hz, 2H), 7.31 (d, J = 7.8 Hz,
2H), 6.60 (dd, J = 17.9, 11.0 Hz, 1H), 5.67 (d, J = 17.9 Hz, 1H),
5.10 (d, J = 11.0 Hz, 1H), 3.45 (s, 3H), 1.21 (sept, J = 7.3 Hz,
2H), 1.11 (d, J = 7.3 Hz, 6H), 1.05 (d, J = 7.3 Hz, 6H); 13C
NMR (125 MHz, C6D6) δ 138.83, 137.36, 135.21, 134.22,
125.93, 114.16, 51.82, 17.67, 17.46, 12.37; MS (EI) m/z calcd
for C15H24OSi (M)þ 248, found 248.
X-ray Crystal Structure Determination for All Crystals. The
recrystallization procedures for 2a hexane, 2b heptane, 2a
1.5benzene, 5a 18benzene, and 5b 23benzene were performed
Synthesis of 4-(Diphenylmethoxysilyl)styrene (4b). The reac-
tion of methanol (40 mL), sodium metal (2.76 g, 120 mmol), and
3
3
3
3
3

3288 Organometallics, Vol. 29, No. 15, 2010
Kawakami et al.
P
P
as follows: Single crystals suitable for X-ray crystallography
were obtained from THF/benzene/hexane or cyclohexane (2a)
or THF/benzene/heptane (2b) in 1:1:1 ratios, and acetone/ben-
zene (5a,b) in 1:10 ratios. The “THF/benzene/hexane” notation
signifies that the compound was dissolved in the first solvent and
then precipitated with successive addition of the second and
third solvents. The “acetone/benzene” notation indicates that
the compound was dissolved in the first solvent and then pre-
cipitated with addition of the second solvent.
All reflections were measured on a Rigaku Mercury diffract-
ometer using a CCD camera. The structures were solved by
direct methods (SHELXS-9712 and SIR 200413) using WinGX
v1.70.01 as an interface.14 The non-hydrogen atoms were refi-
ned anisotropically by the full-matrix least-squares method
(SHELXL-97).12 Hydrogen atoms were placed at calculated
The agreement indices are defined as R1 = ( Fo| - |Fc )/ |Fo|
P
P
and wR2 = [ (Fo2 - Fc ) / (wFo4)]1/2. Crystal data and data
2 2
collection parameters are listed in Tables 1 and 4.
The kind and quantity of guest solvent molecules were
roughly estimated by 1H NMR spectroscopy of dissolved
samples. Their location within the cavity was easily determined
by normal difference Fourier synthesis. The small size of the
cavities in 2a,b and the perpendicular packing of benzenes in 5a,
b sufficiently ordered the guest solvent molecules. Nevertheless,
some of the disordered benzenes were restrained to be regular
and planar by fixing their bond lengths, and the sums of the
population parameters of the disordered benzenes were con-
strained to P1 þ P2 = 1.
Acknowledgment. This work was supported by a
Grant-in-Aid for Research Center Project from the Min-
istry of Education, Culture, Sports, Science and Technol-
ogy of Japan. The authors are grateful to the Shin-Etsu
Chemical Co., Ltd., for providing the chlorosilanes.
positions and kept fixed. In subsequent refinement, the function
P
w(Fo2 - Fc ) was minimized, where |Fo| and |Fc| are the obs-
2 2
erved and calculated structure factor amplitudes, respectively.
(12) Sheldrick, G. M. SHELXS-97, Program for the Solution of
€
Crystal Structures; University of Gottingen: Germany.
(13) Burla, M. C.; Caliandro, R.; Camalli, M.; Carrozzini, B.;
Cascarano, G. L.; De Caro, L.; Giacovazzo, C.; Polidori, G.; Spagna,
R. J. Appl. Crystallogr. 2005, 38, 381.
Supporting Information Available: X-ray data for all crystals
are available as CIF files. This material is available free of charge
via the Internet at http://pubs.acs.org.
(14) Farrugia, L. J. J. Appl. Crystallogr. 1999, 32, 837.