Thermolysis of bis(pentacoordinate) silicon compound bearing two 1-fluorodisilanyl units at 4- and 8-positions on 1,5-bis(dimethylamino) naphthalene ring: Construction of disilapyrene skeleton and cyclophane-shaped siloxane dimer

Article abstract of DOI:10.1016/S0022-328X(03)00376-0

The thermolysis of a bis(pentacoordinate) silicon compound having two pentacoordinate silicon units at the 4- and 8-positions on the 1,5-bis(dimethylamino)naphthalene ring in the presence of diphenylacetylene affords a 1,6-dihydro-1,6-disilapyrene derivative. This reaction might proceed through a two-site silylene trapping with two acetylene molecules accompanied by an amino group migration from the naphthyl carbon atom to the silicon atom. The dimethylamino group on each silicon atom can easily be converted into a variety of functional groups. One of the disilapyrene derivatives, bis(silanol), dimerizes by a dehydrocondensation reaction using dicyclohexylcarbodiimide to form a cyclophane-shaped molecule in 76% yield. The cyclic dimer showing a greenish yellow luminescence exhibits the UV-absorption and emission spectra characteristic of a transannular interaction between two proximal chromophores in cyclophane-shaped molecules.

Full text of DOI:10.1016/S0022-328X(03)00376-0

Journal of Organometallic Chemistry 686 (2003) 215ꢁ222
/
www.elsevier.com/locate/jorganchem
Thermolysis of bis(pentacoordinate) silicon compound bearing two 1-
fluorodisilanyl units at 4- and 8-positions on 1,5-
bis(dimethylamino)naphthalene ring: construction of disilapyrene
skeleton and cyclophane-shaped siloxane dimer
Tomoyuki Saeki, Akio Toshimitsu, Kohei Tamao *
Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
Received 4 April 2003; received in revised form 17 April 2003; accepted 17 April 2003
Abstract
The thermolysis of a bis(pentacoordinate) silicon compound having two pentacoordinate silicon units at the 4- and 8-positions on
the 1,5-bis(dimethylamino)naphthalene ring in the presence of diphenylacetylene affords a 1,6-dihydro-1,6-disilapyrene derivative.
This reaction might proceed through a two-site silylene trapping with two acetylene molecules accompanied by an amino group
migration from the naphthyl carbon atom to the silicon atom. The dimethylamino group on each silicon atom can easily be
converted into a variety of functional groups. One of the disilapyrene derivatives, bis(silanol), dimerizes by a dehydrocondensation
reaction using dicyclohexylcarbodiimide to form a cyclophane-shaped molecule in 76% yield. The cyclic dimer showing a greenish
yellow luminescence exhibits the UV-absorption and emission spectra characteristic of a transannular interaction between two
proximal chromophores in cyclophane-shaped molecules.
# 2003 Elsevier Science B.V. All rights reserved.
Keywords: Bis(pentacoordinate) silicon compound; Base-coordinated silylene; Diphenylacetylene; 1,6-Dihydro-1,6-disilapyrene; Cyclophane;
Transannular interaction
1. Introduction
and that the sila-ylide character is definitely reflected
upon the reaction product. During this reaction, the
diphenylacetylene molecule is incorporated between the
silicon atom and the naphthyl carbon atom to form a
silicon-containing six-membered ring. Such a ring form-
ing reaction providing a fused ring system is very
attractive for synthetic organic chemistry.
In this paper, we describe a synthetic application of
this key reaction to construct a novel polycyclic
disilapyrene derivative, that is, the thermal degradation
of the bis(pentacoordinate) silicon compound 3 having
two pentacoordinate fluorodisilane units at the 4- and 8-
positions on the 1,5-diaminonaphthalene ring in the
presence of diphenylacetylene. The synthesis and photo-
physical properties of a cyclophane-shaped cyclic silox-
ane dimer are also described.
The reaction of pentacoordinate fluorodisilane 1 with
diphenylacetylene affords the 1-silaphenalene product 2
under thermal conditions as described in a previous
paper (Scheme 1) [1]. This reaction proceeds through an
a-elimination of fluorosilane from the pentacoordinate
disilane to generate a nitrogen-coordinated silylene
which is trapped with the acetylene molecule. The
mechanistic study of this reaction has clearly demon-
strated that the base-coordinated silylene shows an
enhanced nucleophilic character toward electrophiles
* Corresponding author. Tel.: ꢀ
3186.
E-mail address: tamao@scl.kyoto-u.ac.jp (K. Tamao).
/
81-774-38-3180; fax: ꢀ81-774-38-
/
0022-328X/03/$ - see front matter # 2003 Elsevier Science B.V. All rights reserved.
doi:10.1016/S0022-328X(03)00376-0

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dihydro-1,6-disilapyrene derivative 6 as a mixture of cis
and trans stereoisomers (ca. 1:1) in the total yield of 71%
(Scheme 3) [4]. It is postulated that this reaction
proceeds in a pathway similar to that previously
presented for the reaction of mono(pentacoordinate)
counterpart 1 with diphenylacetylene affording the
silaphenalene 2 [1b]. Thus, the generation of silylene
species (or sila-ylide) by the a-elimination of fluorosi-
lane from the pentacoordinate silicon center and the
trapping with diphenylacetylene occur at two sites
during the reaction course, resulting in the fused ring
formation.
Scheme 1.
2. Results and discussion
2.1. Preparation and structure
The bis(pentacoordinate) silicon compound 3 was
prepared in one-pot starting from 1,5-bis(dimethylami-
no)naphthalene 4 as shown in Scheme 2. Thus the bis-
metallated intermediate 5 [2] was trapped with two
molar amounts of 1,1-difluorodisilane to afford 3 as a
mixture of two isomers (ca. 1:1) in the total yield of 38%.
The X-ray crystallographic analysis of one isomer,
meso-3, revealed the bis(pentacoordinate) structure as
shown in Fig. 1, and the structural parameters were
compared with the reported values for the pentacoordi-
nate fluorodisilane 1 [1b] as summarized in Table 1. The
interatomic distances between the nitrogen atom and the
pentacoordinate silicon atom are 2.770(1) and 2.728(1)
The disilapyrene compound has not yet been re-
ported, while some 1,6-disubstituted pyrene derivatives
are known [5]. The structure of this disilapyrene skeleton
was confirmed by the X-ray crystallographic analysis of
a methyl-substituted derivative, 1,1,6,6-tetramethyl-1,6-
disilapyrene 8, which was prepared from 6 in two steps,
as shown in Scheme 4. Thus, the treatment of a solution
of 6 in benzene with 47% HF almost quantitatively
afforded the bis-fluorinated compound 7 and the sub-
sequent methyl substitution reaction using an excess
amount of methyllithium gave 8 in 66% yield. The single
crystal of 8 suitable for X-ray crystallographic analysis
was obtained by recrystallization from a mixed solvent
of benzene/ethanol and the ORTEP drawing revealed a
silicon containing polycyclic structure with Ci symmetry
as shown in Fig. 2. The silicon containing six-membered
rings are slightly distorted with a deviation of Si1 from
˚
A which are somewhat shorter than that of 1.
The bond lengths and angles around the pentacoor-
dinate silicon center(s) as well as their %TBP characters
[3] are comparable to that of the thermally labile
mono(pentacoordinate) counterpart 1, indicating that
the bis(pentacoordinate) silicon compound 3 has a
suitable structure for the a-elimination of fluorosilane
under thermal conditions, thus generating the silylene
species. The 29Si-NMR chemical shift of the pentacoor-
the mean plane defined by C1Ã
/
C2Ã
/
C3Ã
/
C4Ã
/
C5 of
˚
0.2223 A.
2.3. Synthesis of cyclophane-shaped dimer
dinate silicon atoms of 3 is ꢂ
which is also comparable to that of 1 (ꢂ
/
3.8 ppm in benzene-d6
Since the disilapyrene mentioned above have an
unusual p-electron system and a functional group on
each silicon atom, we examined a possibility of utilizing
such compounds as a building-block for functional
polymers. One of the derivatives, 1,6-dihydroxy-1,6-
disilapyrene 9, prepared from 6 with 5% HCl in 90%
yield, was used in a dehydro-condensation reaction
using dicyclohexylcarbodiimide (DCC) as a dehydrating
agent (Scheme 5) [6,7]. Thus, the dehydration reaction
of 9 at 160 8C for 12 h resulted in the formation of a
mixture of oligomerized products. Separation of the
mixture preformed by gel permeation chromatography
(GPC) afforded a cyclic dimer 10 as the main fraction in
76% yield, along with a small amount of linear
oligomers.
/3.6 ppm).
2.2. Thermal degradation
A solution of the bis(pentacoordinate) silicon com-
pound 3 and 2 mol amounts of diphenylacetylene in o-
xylene was heated at 145 8C for 12 h to afford the 1,6-
The cyclic dimer 10 was obtained as a yellow powder,
which emits a yellow-green luminescence in solution.
The molecular structure of such a dimeric product was
confirmed by NMR, IR, and MS spectroscopies, and X-
ray crystallographic analysis of a butyl-substituted
analogue 10? which was obtained in a similar sequence
using bis(4-butylphenyl)acetylene in place of diphenyla-
Scheme 2.

T. Saeki et al. / Journal of Organometallic Chemistry 686 (2003) 215ꢁ
/222
217
˚
Fig. 1. X-ray structure of meso-3 in stereo view at 60% probability level. All hydrogen atoms are omitted for clarity. Selected bond lengths (A) and
angles (8): Si1ÃSi2 2.3649(5), Si1ÃC13 1.882(2), Si1ÃC1 1.885(2), Si1ÃF1 1.6415(9), N1Á Á ÁSi1 2.770(1), Si3ÃSi4 2.3878(6), Si3ÃC29 1.873(2), Si3ÃC5
1.888(2), Si3ÃF2 1.646(1), N2Á Á ÁSi3 2.728(1), N1Á Á ÁSi1ÃF1 168.67(5), N2Á Á ÁSi3ÃF2 168.50(5).
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
Table 1
˚
Selected interatomic distances (A), angles (8) and dihedral angles (8),
and %TBP meso-3 and 1
meso-3
1
Interatomic distances
N1 Si1 (N2Á Á ÁSi3)
Á Á Á
F1ÃSi1 (F2ÃSi3)
Si1ÃSi2 (Si3ÃSi4)
/
/
/
/
2.770(1) 2.728(1)
1.6415(9) 1.646(1)
2.852(2)
1.637(2)
/
/
/
/
2.3649(5) 2.3878(6) 2.3711(9)
Angles
N1 Si1Ã
Á Á Á
F1ÃSi1ÃSi2 (F2Ã
/
/
/
F1 (N2
/
Á Á Á
/
Si3Ã
/
F2)
168.67(5) 168.50(5) 166.10(9)
101.38(4) 95.59(7)
/
/
/
Si3Ã
/
Si4)
98.21(4)
Dihedral angles
C1ÃC2ÃC3/C6Ã
(C5ÃC6ÃC7/C2Ã
Si1ÃC1ÃC8/N1ÃC8Ã
(Si3ÃC5ÃC4/N2ÃC4Ã
/
/
/
C7Ã
C3Ã
C1
C5)
/
C8
12.38
22.92
5.09
12.80
29.94
Scheme 4.
/
/
/
/C4)
/
/
/
/
23.11
/
/
/
/
Pentacoordination characters
%TBPa
%TBPe
52
76
51
74
57
80
Ref. [1b].
Scheme 3.
Fig. 2. X-ray structure of 8 at 60% probability level. All hydrogen
˚
atoms are omitted for clarity. Selected bond lengths (A): Si1Ã
1.827(3), Si1ÃC7 1.822(3), Si1ÃC5 1.852(2), C4ÃC5 1.352(3), Si1Ã
1.856(2).
/C6
/
/
/
/C1
cetylene as the trapping agent. The ORTEP drawing of
10? shown in Fig. 3 reveals a cyclophane-shaped
structure, in which two disilapyrene rings are accumu-
lated and connected by two siloxane bridges. Fig. 4
shows the space-filling model of the core structure of
10?. The inter-atomic distance between C13 and C14*,
that is nearly the gap between the two disilapyrene units,
˚
is 3.768(3) A, which is somewhat longer than the sum of
˚
the van der Waals radii of two carbon atoms (3.40 A)
[8].

218
T. Saeki et al. / Journal of Organometallic Chemistry 686 (2003) 215ꢁ222
/
acteristic of layered cyclophane molecules, could explain
˚
these results even though the distance of 3.77 A is longer
˚
3.3 A)
than the estimated value for such interactions (Â
/
[9].
3. Conclusion
The unique reaction mode of a nitrogen-coordinated
silylene toward diphenylacetylene has been applied to
construct the novel polycyclic 1,6-dihydro-1,6-disilapyr-
ene skeleton. The cyclophane-shaped dimer with two
siloxane bridges, selectively prepared in the dehydro-
condensation reaction using DCC, shows a red-shifted
UVꢁvis absorption spectrum and an emission spectrum
/
of increased intensity, characteristic of the molecules in
which two aromatic planes are facing each other.
Although the origin of the somewhat long-distance
transannular interaction remains to be clarified, these
observations may provide a new model of hetero-
cyclophanes containing a silicon-substituted fused ring
system.
Scheme 5.
4. Experimental
Fig. 4. Space-filling model of the core of 10?.
4.1. General
2.4. Photophysical properties
Fig. 5 shows the UVꢁvis absorption and emission
All reactions were performed under nitrogen, unless
stated otherwise. The solvents were purified and dried
by standard techniques. The 1H (300 MHz) NMR
spectra were recorded by Varian Mercury 300 spectro-
meter. The 13C (67.9 MHz), 19F (254 MHz), 29Si (53.7
MHz) NMR spectra were recorded by JEOL JNM-EX
/
spectra of 10 together with those of the reference
monomer 8 in benzene, and the photophysical data are
summarized in Table 2. The transformation into the
cyclized structure apparently gives rise to a remarkable
change in spectra as follows. (1) The longest wavelength
absorption band of the cyclophane 10 appears at 412
nm, which is ca. 20 nm red-shifted compared with that
of the monomer 8. (2) The emission spectra show a red-
shifted band at 488 nm and a 10-fold increase in the
fluorescence intensity for 10 in comparison with 8
[quantum yield, F: 0.00810 (8) and 0.0825 (10)]. A
transannular p-electron interaction and an excimer
formation between two proximal chromophores, char-
270 spectrometer. The H and 13C chemical shifts are
1
referenced to internal benzene-d6 (1H, d 7.200 and 13C,
d 128.00 ppm) or THF-d8 (13C, d 25.20 ppm). The 19F
and 29Si chemical shifts are referenced to external CFCl3
(0 ppm) and Me4Si (0 ppm), respectively. Column
chromatography was performed using Kieselgel (70ꢁ
/
230 mesh) (Merck). Recycling preparative GPC was
performed by using JAIGEL 1H, 2H (Japan Analytical
Industry, Co., Ltd). IR spectra were recorded by IR-810
Fig. 3. X-ray structure of 10? in stereo view at 50% probability level. All hydrogen atoms, butyl group on each phenyl ring, and solvent molecules are
˚
omitted for clarity. Selected bond lengths (A) and angles (8): Si1Ã
/
C1 1.860(3), Si1Ã
O1ÃSi2* 147.0(1).
/
C12 1.839(2), Si1Ã
/
C15 1.875(3), Si1Ã
/
O1 1.636(2), Si2ÃC5
/
1.859(2), Si2ÃC10 1.846(2), Si2ÃC16 1.842(3), Si2ÃO1* 1.662(2), Si1Ã
/
/
/
/
/

T. Saeki et al. / Journal of Organometallic Chemistry 686 (2003) 215ꢁ
/222
219
Fig. 5. (a) UV absorption and (b) emission spectra of 8 (/
Á Á Á) and 10 (*
/
) in benzene.
was evaporated and the crude product was recrystallized
from hexane to afford 3 (11.0 g, 15.0 mmol; 38%) as
colorless solids (a mixture of meso and rac isomers (ca.
1:1)). One of the isomers, meso-3, was separated by the
repeated recrystallization from hexane. meso-3 M.p.:
Table 2
Photophysical data of 8 and 10 in benzene
Compound
UVꢁ/vis
FL
b
labs (nm) a
440
Ff
1
labs (nm)
o
143 8C (dec.) (from benzene). H-NMR (C6D6) d 0.71
(S, 6H), 0.77 (d, Jꢃ
6H), 6.79 (d, Jꢃ7.6 Hz, 2H), 7.14ꢁ
7.62 (m, 8H), 8.35 (d, Jꢃ
6.8 Hz, 2H); 13C-NMR (C6D6)
d ꢂ2.16, 2.71 (d, Jꢃ18 Hz), 47.11, 47.62, 115.71,
/9.2 Hz, 6H), 2.06 (s, 6H), 2.14 (s,
8
358
374
394
15 200
22 200
19 200
0.00810
0.0825
/
/
7.20 (m, 12H), 7.55ꢁ
/
/
/
/
10
366
379
412
27 700
29 500
9880
488
128.07, 128.12, 129.07, 130.28, 130.46, 135.50, 135.56,
135.67, 136.77, 137.72, 137.79, 154.00; 29Si-NMR
a
(C6D6) d ꢂ
/
21.42 (d, Jꢃ
/
38 Hz), ꢂ
/
3.54 (d, Jꢃ296
/
Excited at 366 nm.
Determined with reference to anthracene.
Hz; 19F-NMR (C6D6) d ꢂ
C42H48N2SI4F2: C, 68.99; H, 6.62; N, 3.83. Found: C,
/144.86. Anal. Calc. for
b
1
69.01; H, 6.64; N, 3.88. rac-3; H-NMR (C6D6) d 0.62
Infrared spectrophotometer as KBr plate. UVꢁvis
/
(S, 6H), 0.79 (d, Jꢃ
6H), 6.79 (d, Jꢃ7.5 Hz, 2H), 7.14ꢁ
7.63 (m, 8H), 8.38 (d, Jꢃ
6.9 Hz, 2H); 13C-NMR (C6D6)
d ꢂ2.61, 2.78 (d, Jꢃ18 Hz), 45.23, 49.71, 115.82,
/9.0 Hz, 6H), 2.05 (s, 6H), 2.11 (s,
absorption spectra were recorded by Shimadzu UV-
3100PC spectrometer. Fluorescence spectra were re-
corded by a Perkin Elmer LS50B. Melting points were
determined with Yanaco MP-S3 instrument and are
uncorrected. Mass spectra and elemental analyses were
performed at the Mass Spectrum and Microanalysis
Division of Institute for Chemical Research, Kyoto
University.
/
/
7.18 (m, 12H), 7.59ꢁ
/
/
/
/
128.15, 129.04, 129.94, 130.13, 135.50, 135.57, 135.81,
136.69, 136.84, 137.76, 137.87, 154.16; 29Si-NMR
(C6D6) d ꢂ
/
21.85 (d, Jꢃ
/
37 Hz), ꢂ
/
2.96 (d, Jꢃ298
/
Hz); 19F-NMR (C6D6) d ꢂ
/146.12.
4.2. Bis(pentacoordinate) silicon compound (3)
4.3. 1,6-Dimethyl-1,6-bis(dimethylamino)-2,3,7,8-
tetraphenyl-1,6-dihydro-1,6-dihydro-1,6-disilapyrene (6)
To a solution of 1,5-bis(dimethylamino)naphthalene 4
(8.57 g, 40.0 mmol) in hexane (40 ml) was added n-BuLi
(1.63 mol lꢂ1 hexane sol., 73.6 ml, 120 mmol) at room
temperature. After refluxing for 3 days, the resulting
A solution of 3 (3.66 g, 5.0 mmol) and diphenylacet-
ylene (1.78 g, 10.0 mmol) in o-xylene (2.5 ml) was heated
under reflux for 12 h. The standing of this reaction
mixture at room temperature afforded 6 (2.34 g, 3.57
mmol; 71%) as yellow solids (a mixture of cis and trans
4,8-dilithio-1,5-bis(dimethylamino)naphthalene
5
formed as a cream-color precipitate was washed with
hexane several times under nitrogen. To a suspension of
5 in THF (120 ml) was added 1,1-difluoro-1,2-dimethyl-
2,2-diphenyldisilane [1b] (32.1 g, 115 mmol) at 0 8C. The
reaction mixture was allowed to warm up to room
temperature and stirred at that temperature for 5 h.
After removal of lithium salt by filtration, the filtrate
isomers (ca. 1:1)). The following data are for the
1
mixture; H-NMR (C6D6) d 0.45ꢁ
/
0.46 (s, 6H), 2.46ꢁ
7.02 (m, 4H), 7.06ꢁ7.18 (m, 16H),
7.5 Hz, 2H), 7.68 (d, Jꢃ
7.2 Hz, 2H); 13C-
NMR (C6D6) d ꢂ2.44, ꢂ2.19, 38.35, 38.39, 125.23,
126.42, 127.82, 127.91, 128.56, 130.80, 130.95, 131.07,
/
2.48 (s, 12H) 6.89ꢁ
/
/
7.59 (d, Jꢃ
/
/
/
/

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T. Saeki et al. / Journal of Organometallic Chemistry 686 (2003) 215ꢁ222
/
131.13, 134.25, 134.29, 134.51, 134.58, 134.95, 137.63,
142.65, 143.74, 143.92, 143.96, 153.95; 29Si-NMR
mixture was treated with a saturated aqueous solution
of NaHCO3, extracted with benzene, and dried over
Na2SO4. After filtration and evaporation of solvent, the
crude product was suspended in hexane to afford 9 (163
mg, 0.27 mmol; 90%) as yellow solids (a mixture of cis
and trans isomers (ca. 1:1)). The following data are for
(C6D6)
C44H42N2Si2: C, 80.68; H, 6.46; N, 4.28. Found: C,
d
ꢂ
/
21.22,
ꢂ21.12. Anal. Calc. for
/
80.58; H, 6.38; N, 4.31.
4.4. 1,6-Difluoro-1,6-dimethyl-2,3,7,8-tetraphenyl-1,6-
dihydro-1,6-disilapyrene (7)
the mixture; 1H-NMR (C6D6) d 0.43ꢁ
1.41ꢁ1.42 (s, 2H), 6.90ꢁ7.16 (m, 20H), 7.58ꢁ
Jꢃ7.5 Hz, 2H), 7.71ꢁ7.74 (d, Jꢃ
7.5 Hz, 2H); 13C-
NMR (C4D8O) d ꢂ0.96, ꢂ0.85, 125.28, 126.65, 127.85,
128.14, 129.10, 130.63, 130.66, 131.06, 131.44, 133.99,
137.98, 142.81, 143.20; 29Si-NMR (C4D8O) d ꢂ
19.09.
/
0.43 (s, 6H),
7.62 (d,
/
/
/
/
/
/
To a solution of 6 (328 mg, 0.50 mmol) in benzene
(2.5 ml) was added a 47% aqueous solution of HF (2.5
ml) at room temperature and stirred for 5 min. The
organic layer separated, washed with water several times
and dried over Na2SO4. After evaporation of solvent,
the crude product was suspended in hexane to afford 7
/
/
/
Anal. Calc. for C40H32O2Si2: C, 79.96; H, 5.37. Found:
C, 80.03; H, 5.31.
(304 mg, 0.50 mmol; Â
/
100%) as yellow solids (a
4.7. Dehydro-condensation of 9? with DCC
mixture of cis and trans isomers (ca. 1:1)). The following
1
data are for the mixture; H-NMR (C6D6) d 0.47ꢁ
(d, Jꢃ6.3ꢁ6.6 Hz, 6H), 6.89ꢁ6.94 (t, Jꢃ7.5 Hz, 2H),
7.00ꢁ7.17 (m, 18H), 7.49ꢁ7.52 (d, Jꢃ7.5 Hz, 2H),
7.60ꢁ7.64 (dd, Jꢃ
7.5, 1.2 Hz, 2H); 13C-NMR (C6D6) d
3.18, ꢂ3.09, ꢂ2.85, ꢂ2.74, 126.04, 126.94, 127.34,
/0.49
A solution of 9 (60 mg, 0.10 mmol) and DCC (103
mg, 0.50 mmol) in DMSO (2.0 ml) was warmed up to
160 8C and stirred for 12 h. The reaction mixture was
treated with water, extracted with chloroform, and dried
over Na2SO4. The crude product was subjected to GPC
with CHCl3 as eluent to afford 10 (44 mg, 0.038 mmol;
/
/
/
/
/
/
/
/
/
ꢂ
/
/
/
/
127.84, 128.54, 128.74, 130.61, 130.75, 130.86, 130.91,
131.15, 131.18, 131.88, 133.97, 134.04, 135.15, 138.35,
140.70, 140.90, 141.42, 141.48, 156.21; 29Si-NMR
76%) as light yellow solids. M.p.: 281 8C (dec.) (from
1
benzene). H-NMR (C6D6) d 0.55 (s, 12H), 6.94ꢁ
/
7.25
7.5 Hz, 4H): 13C-NMR (C6D6) d
0.84, 125.55, 126.42, 127.77, 128.13, 128.72, 130.50,
130.55, 131.24, 132.82, 133.36, 133.99, 137.43, 142.15,
143.14, 153.54; 29Si-NMR (C6D6) d ꢂ
23.42. Anal. Calc.
(C6D6) d ꢂ
/
9.32, ꢂ
/
9.17, ꢂ
/
3.93, ꢂ
/
3.81; 19F-NMR
(m, 44H), 7.80 (d, Jꢃ
/
(C6D6)
C40H30Si2F2; C, 79.43; H, 5.00. Found: C, 79.14; H,
d
ꢂ
/
149.73,
ꢂ
/
149.30. Anal. Calc. for
ꢂ
/
5.13.
/
for C80H60O2Si4; C, 82.43; H, 5.19. Found; C, 82.22; H,
5.09.
4.5. 1,1,6,6-Tetramethyl-2,3,7,8-tetraphenyl-1,6-dihydro-
1,6-disilapyrene (8)
To a solution of 7 (60 mg, 0.10 mmol) in benzene (5.0
ml) was added a 1.14 mol lꢂ1 Et2O solution of MeLi
(0.88 ml, 1.0 mmol) at 0 8C. The mixture was allowed to
warm up to room temperature and stirred for 1 h. The
reaction mixture was treated with a saturated aqueous
solution of NH4Cl, extracted with benzene, and dried
over Na2SO4. After evaporation of solvent, the crude
product was suspended in hexane to afford 8 (38 mg,
4.8. 2,3,7,8-Tetrakis(4-butylphenyl)-1,6-dihydroxy-1,6-
dimethyl-1,6-dihydro-1,6-disilapyrene (9?)
A solution of 3 (366 mg, 0.50 mmol) and bis(4-
butylphenyl)acetylene (290 mg, 1.0 mmol) in o-xylene
(2.5 ml) was heated under reflux for 12 h. The reaction
mixture was treated with 5% HCl (2.5 ml), extracted
with Et2O, and dried over Na2SO4. After usual work-up,
the crude product was suspended in hexane to afford 9?
(252 mg, 0.31 mmol; 62%) as yellow solids (a mixture of
cis and trans isomers (ca. 2:1); stereochemistries were
not assigned). The following data are for the mixture;
0.064 mmol; 64%) as pale yellow solids. M.p.: ꢀ
(from benzene). The following data are for the mixture;
1H-NMR (C6D6) d 0.39 (s, 12H), 6.86ꢁ
7.15 (m, 20H),
7.48 (d, Jꢃ 0.15,
3.5 Hz, 4H). 13C-NMR (C6D6) d ꢂ
/
300 8C
/
/
/
125.35, 126.44, 128.48, 128.53, 128.63, 128.86, 130.63,
130.88, 133.88, 135.41, 137.91, 142.65, 143.27, 143.37,
1H-NMR (C6D6) d 0.48ꢁ
Hz, 6H), 0.93 (t, Jꢃ7.2 Hz, 6H), 1.17ꢁ
1.42ꢁ1.59 (m, 8H), 2.42 (t, Jꢃ7.8 Hz, 4H), 2.48 (t, Jꢃ
6.9 Hz, 4H), 7.00ꢁ7.09 (m, 12H), 7.71ꢁ7.78 (m, 4H);
13C-NMR (C6D6) d ꢂ
0.84, ꢂ0.75, 14.33, 14.36, 22.69,
/
0.50 (s, 6H), 0.87 (t, Jꢃ
/7.5
/
/
1.34 (m, 8H),
153.14; 29Si-NMR (C6D6) d ꢂ
C42H36Si2: C, 84.51; H, 6.08. Found: C, 84.47; H, 6.14.
/21.64. Anal. Calc. for
/
/
/
/
/
/
/
4.6. 1,6-Dihydroxy-1,6-dimethly-2,3,7,8-tetraphenyl-1,6-
dihydro-1,6-disilapyrene (9?)
22.77, 33.84, 33.98, 35.69, 35.75, 127.78, 128.17, 128.89,
130.91, 131.00, 131.11, 134.19, 134.42, 134.44, 134.52,
138.33, 139.70, 139.90, 140.00, 140.95, 143.42, 154.03;
To a solution of 6 (197 mg, 0.30 mmol) in benzene (12
ml) was added 5% HCl (6.0 ml) at room temperature
and the mixture was stirred for 5 min. The reaction
29Si-NMR (C6D6) d ꢂ
/
17.46 (major isomer), ꢂ17.41
/
(minor isomer). Anal. Calc. for C56H64O2Si2: C, 81.50;
H, 7.82. Found: C, 81.43; H, 7.91.

T. Saeki et al. / Journal of Organometallic Chemistry 686 (2003) 215ꢁ
/222
221
Table 3
Experimental details for X-ray structural analysis of meso-3, 8 and 10?
meso-3
8
10? (C6H6)3
Molecular formula
Formula weight
Crystal system
Space group
C42H48N2Si4F2
731.19
Triclinic
C42H36Si2
596.92
C130H136Si4O2
1842.85
Monoclinic
P21/n(#14)
9.7620(6)
10.8526(6)
15.2383(8)
Monoclinic
P21/n(#14)
13.0172(3)
17.1908(6)
23.8745(6)
¯
P/1(#2)
/
˚
a (A)
12.5966(5)
14.9337(4)
11.5433(4)
106.838(2)
101.594(2)
71.360(2)
˚
b (A)
˚
c (A)
a (8)
b (8)
96.212(3)
90.791(2)
g (8)
3
V (A )
˚
1955.2100
2
Colorless, prismatic
1604.9(1)
2
Colorless, prismatic
5342.0(2)
2
Yellow, prismatic
Z
Crystal description
Crystal size (mm)
Temperature (8C)
Radiation
0.30ꢄ
100
MoꢁKa (lꢃ
/
0.30ꢄ
/
0.20
0.30ꢄ/0.25ꢄ
/0.15
0.40ꢄ
/
0.15ꢄ0.15
/
ꢂ
/
ꢂ
/
100
ꢂ
/
100
˚
0.71070 A) graphite monochromated
/
/
m (Moꢁ
2umax (8)
No. of collected reflections
No. of observations (I ꢀ3s(I))
No. of variables
/
Ka) (cmꢂ1
)
1.94
55.1
1.40
55.1
1.08
55.8
7834
6467
643
3454
2731
200
10 049
7395
632
/
Reflection/parameter ratio
R
10.06
0.038
0.058
1.35
13.65
0.060
0.083
1.12
11.70
0.056
0.083
1.09
Rw
Goodness-of-fit
4.9. Dehydro-condensation of 9? with DCC
tion. The data were corrected for Lorentz and polariza-
tion effects and secondary extinction. The crystal
structures were resolved by direct methods in SIR92
and a full-matrix least-squares refinement was carried
out for all non-hydrogen atoms. Hydrogen atoms were
included but not refined. All the calculations were
performed using the TEXSAN crystallographic package
from Molecular Structure Corp. The crystal data and
analytical conditions are listed in Table 3.
Essentially the same procedures as described above,
using 9? (83 mg, 0.10 mmol) and DCC (103 mg, 0.50
mmol) in DMSO (2.0 ml), followed by the purification
by GPC with CHCl3 as eluent afforded 10? (45 mg, 0.028
mmol; 56%) as light yellow solids. M.p.: 277 8C (dec.)
1
(from benzene). H-NMR (C6D6) d 0.65 (s, 12H), 0.89
(t, Jꢃ
(m, 16H), 1.45ꢁ
7.03ꢁ7.16 (m, 24H), 7.28ꢁ
Hz, 2H), 7.93 (d, Jꢃ
7.5 Hz, 2H); 13C-NMR (C6D6) d
0.58, 14.34, 14.39, 22.77, 22.87, 33.89, 34.22, 35.72,
/
7.2 Hz, 12H), 0.98 (t, Jꢃ
1.70 (m, 16H), 2.42ꢁ
7.37 (m, 12H), 7.52 (d, Jꢃ
/
7.2 Hz, 12H), 1.19ꢁ
2.59 (m, 16H),
7.8
/
1.43
/
/
/
/
/
/
5. Supplementary material
ꢂ
/
35.92, 128.77, 129.99, 130.72, 131.29, 132.92, 133.50,
134.07, 137.79, 139.57, 139.90, 140.23, 140.47, 142.99,
Crystallographic data for the structure analyses have
been deposited with the Cambridge Crystallographic
Data Centre, CCDC nos. 207079-207081 for com-
pounds meso-3, 8, and 10?, respectively. Copies of this
information may be obtained free of charge from The
Director, CCDC, 12 Union Road, Cambridge CB2
153.67; 29Si-NMR (C6D6) d ꢂ
/
23.29. Anal. Calc. for
112H124O2Si4: C, 83.32; H, 7.74. Found: C, 83.06; H,
7.81.
C
1EX, UK (fax: ꢀ44-1223-336-033; e-mail: deposit@
ccdc.cam.ac.uk).
/
4.10. X-ray structural analysis of meso-3, 8 and 10?
Single crystals of meso-3, 8 and 10? suitable for X-ray
crystallography were obtained by recrystallization from
benzene (meso-3 and 8) or from benzene/EtOH (10:1)
(10?). The unit cell of 10? contains three molecules of
benzene as crystalline solvent. Intensity data were
collected on a Rigaku RAXIS-IV imaging plate area
Acknowledgements
We thank Prof R. Corriu for the experimental details
of the lithiation of 1,5-diaminonaphthalene and the
Ministry of Education, Culture, Sports, Science and
detector with graphite monochromated MoꢁKa radia-
/

222
T. Saeki et al. / Journal of Organometallic Chemistry 686 (2003) 215ꢁ222
/
[4] The two stereoisomers cannot be separated by standard techniques.
The subsequent reactions were performed by using the mixture of
isomers.
Technology, Japan, for the Grant-in-Aid for COE
Research on Elements Science, No. 12CE2005, and T.
S. thanks the Japan Society for the Promotion of
Science for Research Fellowship for Young Chemists.
[5] 1,6-Dichacogenopyrene compounds and diazapyrene structure in
2-arylquinoline dimer have been reported: (a) Y. Morita, T.
Ohmae, J. Toyoda, S. Matsuda, F. Toda, K. Nakasuji, Chem.
Lett. 3 (1993) 443; (b) A. Herman, R. Theodore, Acta Crystallogr.,
Sect. C: Cryst. Struct. Commun. C49 (1993) 1638 and references
cited therein.
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