Synthesis and structures of bi(1,1-stannole)s

Article abstract of DOI:10.1002/ejic.200500274

The synthesis and structures of bi(1,1-stannole)s are described. Treatment of 1-bromo-4-(dibromophenylstannyl)-1,3-butadiene with tert-butyllithium gives the bi(1,1-stannole) having a phenyl group on each tin atom, whereas treatment of 1-bromo-4-(tribromostannyl)-1,3-butadiene with phenyl- or bulky alkyllithiums gives the bi(1,1-stannole) having a phenyl or an alkyl group on each tin atom. The X-ray analysis of the tert-butyl-substituted bi(1,1-stannole) is also described. All bi(1,1-stannole)s display two shoulder absorption bands due to π-π* and σ-π* transitions. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.

Full text of DOI:10.1002/ejic.200500274

FULL PAPER
Synthesis and Structures of Bi(1,1-stannole)s
Masaichi Saito,*[a] Ryuta Haga,[a] and Michikazu Yoshioka[a]
Keywords: Metallacycles / Tin / UV/Vis spectroscopy
The synthesis and structures of bi(1,1-stannole)s are de-
scribed. Treatment of 1-bromo-4-(dibromophenylstannyl)-
1,3-butadiene with tert-butyllithium gives the bi(1,1-stan-
nole) having a phenyl group on each tin atom, whereas treat-
ment of 1-bromo-4-(tribromostannyl)-1,3-butadiene with
ing a phenyl or an alkyl group on each tin atom. The X-ray
analysis of the tert-butyl-substituted bi(1,1-stannole) is also
described. All bi(1,1-stannole)s display two shoulder absorp-
tion bands due to π–π* and σ–π* transitions.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
phenyl- or bulky alkyllithiums gives the bi(1,1-stannole) hav- Germany, 2005)
Introduction
Results and Discussion
Group 14 metalloles,[1] or metallacyclopentadienes, have
attracted much attention because of interest in them as a
possible precursor for the preparation of conjugated poly-
mers having unique electronic structures[2,3] as well as the
potential aromaticity of their anions.[4] Since the successful
synthesis of some oligo(1,1-silole)s[5,6] and poly(1,1-silole)s,
they have been applied to organic electroluminescent (EL)
devices.[7,8] Most recently, poly(1,1-germole) has also been
reported.[9] In contrast to the silicon and germanium ana-
logs, however, attempts to prepare oligo- and poly(1,1-stan-
nole)s are still unknown. Although the synthesis and some
simple reactions of stannoles have been reviewed,[1] even the
synthesis of bi(1,1-stannole) has not yet been successful.
In the course of our studies on organotin compounds,[10]
we have already reported that bromination of hexaphen-
ylstannole (1) gives the ring-opened halogenated product 2
(Scheme 1).[11,12] We have also preliminarily reported that
debrominative cyclization of 2 affords the bi(1,1-stan-
nole).[13] We report herein the synthesis, structures, and
physical properties of some bi(1,1-stannole)s.
Synthesis of Bi(1,1-stannole) 3
Treatment of 2 with two equivalents of tert-butyllithium
in THF at –100 °C gave a yellow solution. After usual
workup, the mixture was chromatographed to give bi(1,1-
stannole) 3 as yellow crystals in 58% yield together with
stannole 4 (7%) (Scheme 2). To the best of our knowledge,
compound 3 is the first example of bi(1,1-stannole). Two
possible mechanisms for the formation of 3 are shown in
Scheme 2. The initial step of the reaction is the formation
of 1-bromo-1-phenylstannole (5), which reacts further with
tert-butyllithium to give the stannole anion 6 or the stan-
nole radical 7. The stannole anion 6 then reacts with 5 to
give 3, while the stannole radical 7 couples to itself to also
give 3. Product 4 is formed by nucleophilic substitution at
the tin atom of 5 by tert-butyllithium. Trapping of the inter-
mediary ionic species 6 by addition of methyl iodide or
chlorotrimethylstannane, expecting to obtain a methylated
or a stannylated product, failed and the bi(1,1-stannole) 3
was obtained in 71 or 77% yield, respectively. Therefore, a
radical mechanism for the formation of 3 is more likely,
although the ionic mechanism cannot be ruled out entirely.
The yield of 3 was improved (82%) when the reaction was
carried out in diethyl ether, although the reason for the sol-
vent-dependent product yield is not clear.
Synthesis of Bi(1,1-Stannole)s Having Various Substituents
on the Tin Atom
Scheme 1.
The synthesis of other bi(1,1-stannole)s having various
substituents on the tin atom was achieved by the reaction of
1-bromo-4-(tribromostannyl)-1,3-butadiene (8) with lithium
reagents.
[a] Department of Chemistry, Faculty of Science, Saitama Univer-
sity,
Shimo-okubo, Saitama-city, Saitama, 338-8570, Japan
E-mail: masaichi@chem.saitama-u.ac.jp
3750
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
DOI: 10.1002/ejic.200500274
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Synthesis and Structures of Bi(1,1-stannole)s
FULL PAPER
Scheme 2.
Synthesis of 1-Bromo-4-(tribromostannyl)-1,3-butadiene
(8)
Scheme 4). The preferential formation of 1 to 3 may be as-
cribed to the size of the lithium reagent. In fact, the reaction
of 8 with bulkier tert-butyllithium (2 equiv.) rather than
phenyllithium gave bi(1,1-stannole) 10 having a tert-butyl
group on each tin atom as the sole product in 55% yield
(Scheme 4). Reaction of 7 with sec-butyllithium (2 equiv.),
a moderately bulky reagent, gave a bi(1,1-stannole) 11 hav-
ing a sec-butyl group on each tin atom as a 1:1 dia-
stereomeric mixture[17] in a relatively good yield (40%;
Scheme 4). The diastereomeric ratio was estimated by signal
intensities (δ = –60.59 and –60.57 ppm) in the 119Sn NMR
spectrum. Contrary to the bulky lithium reagent, the reac-
tion of less bulky methyllithium (1 equiv.) with 8 gave 4-
bromo-1,2,3,4-tetraphenyl-1-(trimethylstannyl)-1,3-butadi-
ene (12) in 15% yield. Methyllithium would directly attack
the tin to afford trimethyl derivative 12 (Scheme 4). Reac-
tion of 8 with methyllithium (3 equiv.) gave 12 (62%) and
1,1-dimethylstannole 13 (27%; Scheme 4).
We attempted to synthesize 8 by the reaction of 1 or 2
with bromine. However, the reaction of 2 with bromine gave
a complex mixture. Reaction of hexaphenylstannole (1)
with excess bromine also gave a complex mixture contain-
ing 1,4-dibromo-1,2,3,4-tetraphenylbutadiene.[14]
Since the p-methoxyphenyl group on the tin atom is
known to be easily removed by halogenation,[15] the reac-
tion of 1,1-di(p-methoxyphenyl)stannole (9) with bromine
was examined. Compound 9 was prepared by the reaction
of 1,4-dilithio-1,2,3,4-tetraphenylbutadiene with dichloro-
di(p-methoxyphenyl)stannane[16] in 58% yield (Scheme 3).
Reaction of 9 with bromine (1 equiv.) at –40 °C gave a com-
plex mixture, and treatment of 9 with bromine (2 equiv.)
at –20 °C afforded 1,4-dibromo-1,2,3,4-tetraphenylbutadi-
ene (41%).[14] However, the reaction of 9 with excess bro-
mine (10 equiv.) at room temperature gave 8 (96%). The
structure of 8 was determined by NMR spectroscopy and
elemental analysis (Scheme 3).
Scheme 3.
Reaction of 8 with Lithium Reagents: Synthesis of Bi(1,1-
stannole)s
Treatment of 8 with phenyllithium (2 equiv.) afforded
bi(1,1-stannole) 3 (12%) and hexaphenylstannole 1 (33%; Scheme 4.
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M. Saito, R. Haga, M. Yoshioka
FULL PAPER
Structures of 3 and 10
angle between the stannole plane and the Sn–Sn bond is
67° for 10 (74° for 3).
Slow evaporation of the solvent from chloroform solu-
tions of 3 and 10 gave X-ray quality crystals. The structure
of 3 has been reported previously.[13] Because of the sym-
metrical structures of 3 and 10 with respect to the Sn–Sn
bond, only a half moiety was refined. The ORTEP drawing
of 10, with selected bond lengths and angles, is shown in
Figure 1. The length of the Sn–Sn bond is quite normal[18]
at 2.7822(7) Å [2.7844(7) Å for 3].[13] Each stannole ring has
a nearly planar structure and is oriented in an anti fashion
through the Sn–Sn bond probably due to steric reasons. The
Spectroscopic Properties
In the 119Sn NMR spectrum, each central tin atom of
the compounds with the stannole skeleton resonates in the
range from δ = –100 to –45ppm, in the same region as that
of 1,1,2,3,4,5-hexaphenylstannole (δ = –88.7 ppm).[11] The
tin atoms of alkyl-substituted bi(1,1-stannole)s 10 and 11
resonate to higher field than that of 3, as is observed in
normal distannanes (δ = –108.7 and –144.7 ppm for
[19]
Me3SnSnMe3
119Sn,117Sn
and Ph3SnSnPh3,[20] respectively). The
1J
coupling constant of 2865 Hz for 3 is a normal
value for distannanes (cf. 2748 Hz for Bu3SnSnBu3).[19] The
UV/Vis absorption spectra for 3, 10, and 11 are shown in
Figure 2. All bi(1,1-stannole)s display two shoulder absorp-
tion bands at around 320 and 370 nm. The latter band can
be assigned to the π–π* transition of the stannole ring be-
cause a similar absorption band is found in 1,1,2,3,4,5-
hexaphenylstannole (1; λmax = 355 nm).[21] The π–π* transi-
tion of group 14 metalloles is observed in the same region,
at around 360 nm, because the contributions of the diene
moiety to both HOMO and LUMO are predominant rather
than that of the metal moiety.[21] The shorter wavelength
band can be assigned to the transition from σ(Sn–Sn) to
π*(diene) because the corresponding band is absent in 1.
This absorption (320 nm) is red-shifted compared to that of
a bi(1,1-silole) (300 nm)[7] because of the higher energy level
of a σ(Sn–Sn) bond than that of a σ(Si–Si) bond.
Figure 1. ORTEP drawing of 10 with thermal ellipsoid plots (40%
probability for non-hydrogen atoms). Selected bond lengths [Å] and Conclusions
angles [°]: Sn(1)A–Sn(1)B 2.7822(7), Sn(1)A–C(1) 2.143(4), C(1)–
C(2) 1.353(5), C(2)–C(3) 1.506(5), C(3)–C(4) 1.352(5), Sn(1)A–C(4)
2.157(4); C(1)–Sn(1)A–C(4) 83.28(14).
Several bi(1,1-stannole)s combining two stannacyclopen-
tadienyl units through an Sn–Sn bond have been synthe-
Figure 2. UV/Vis spectra of bi(1,1-stannole)s 3, 10, and 11.
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Synthesis and Structures of Bi(1,1-stannole)s
FULL PAPER
by recrystallization from hexane and dichloromethane to afford 3
(1141 mg, 82%).
sized and characterized. The product yield in the formation
of bi(1,1-stannole) by the reaction of 1-bromo-4-(tribromo-
phenylstannyl)-1,3-butadiene with lithium reagent is de-
pendent on the size of the lithium reagent used. The X-ray
analysis of bi(1,1-stannole) shows a symmetrical structure
with respect to the Sn–Sn bond. All bi(1,1-stannole)s dis-
play two shoulder absorption bands due to π–π* and σ–π*
transitions.
Attempt to Trap Intermediary Ionic Species with Methyl Iodide: tert-
Butyllithium (1.48  in pentane; 0.29 mL, 0.43 mmol) was added
to a diethyl ether (4 mL) solution of 2 (114 mg, 0.14 mmol) at –
100 °C. The color of the solution immediately turned yellow.
Methyl iodide (0.05 mL, 0.80 mmol) was added to this solution.
After warming to room temperature over 7 h, the solvent was evap-
orated. Recrystallization from hexane and dichloromethane gave 3
(56 mg, 71%).
Attempt to Trap Intermediary Ionic Species with Chlorotrimeth-
ylstannane: tert-Butyllithium (1.60  in pentane; 0.24 mL,
0.38 mmol) was added to a diethyl ether (4 mL) solution of 2
(98 mg, 0.12 mmol) at –100 °C and a diethyl ether (2 mL) solution
of chlorotrimethylstannane (30 mg, 0.15 mmol) was then added.
After warming to room temperature over 4 h, the solvent was evap-
orated. Recrystallization from hexane and dichloromethane gave 3
(53 mg, 77%).
Experimental Section
General Procedures: All reactions were carried out under argon.
THF and diethyl ether used in the syntheses were distilled from
sodium benzophenone ketyl under argon before use. 1H (400 MHz)
and 13C NMR (100 MHz) spectra were recorded on a Bruker AM-
400 or an ARX-400 spectrometer in CDCl3 with tetramethylsilane
as an internal standard. Although nJSn,13C couplings were observed
in the 13C NMR spectra as satellite signals, most of the J
n
119Sn-13
C
Preparation of 1,1-Di(p-methoxyphenyl)-2,3,4,5-tetraphenylstannole
(9): A suspension of diphenylacetylene (4.40 g, 24.7 mmol) and
lithium (171 mg, 24.7 mmol) in diethyl ether (17 mL) was stirred
for 4 h at room temperature. A THF (15 mL) solution of di(p-meth-
oxyphenyl)dichlorostannane[16] (4.11 g, 10.2 mmol) was added to
the resulting suspension and the mixture was refluxed for 3 h. After
removal of solvents, any material insoluble in dichloromethane was
filtered off. After evaporation, the residue was subjected to column
chromatography (hexane/ethyl acetate = 10:1) to give 9 (4.035 g,
58%). M.p. 200 °C (decomp.) (recrystallized from dichlorometh-
n
117Sn-13
C
and J
couplings could not be estimated separately because
of line broadening. The multiplicities of the signals in the 13C NMR
spectra given in parentheses were deduced from DEPT spectra.
119Sn NMR (149 MHz) spectra were recorded on a Bruker ARX-
400 spectrometer in CDCl3 with tetramethylstannane as an external
standard. Column chromatography was carried out with Merck
Kieselgel 60 (SiO2). All melting points were determined on a Mita-
mura Riken Kogyo MEL-TEMP apparatus and are uncorrected.
Electronic spectra were recorded on a JASCO V-560 UV/Vis spec-
trometer. Elemental analyses were carried out at the Microanalyti-
cal Laboratory of Molecular Analysis and Life Science Center, Sai-
tama University.
1
ane/hexane). H NMR: δ = 3.81 (s, 6 H), 6.80–6.86 (m, 4 H), 6.89
(d, J = 8 Hz, 4 H), 6.92–7.05 (m, 16 H), 7.50 (d, J = 8 Hz, 4 H)
ppm. 13C NMR: δ = 55.0 (q), 114.9 (d, JSn,C = 58 Hz), 125.3 (d),
125.8 (d), 127.3 (d), 127.8 (d), 128.3 (s), 129.3 (d, JSn,C = 22 Hz),
130.3 (d), 138.3 (d, JSn,C = 46 Hz), 140.7 (s, JSn,C = 68 Hz), 142.5
(s, JSn,C = 45 Hz), 143.0 (s), 154.4 (s, JSn,C = 89 Hz), 160.7 (s) ppm.
119Sn NMR: δ = –79.9 ppm. C40H34O2Sn (665.44): calcd. C 72.20,
H 5.15; found C 72.30, H 4.93.
Preparation of Bi(1,1-stannole) 3. (a) Method A (in THF): tert-Bu-
tyllithium (1.60  in pentane; 3.2 mL, 5.12 mmol) was added at –
100 °C to a THF (30 mL) solution of 1-bromo-4-(dibromophen-
ylstannyl)-1,2,3,4-tetraphenyl-1,3-butadiene
2.56 mmol). After warming to room temperature over 4 h, the sol-
vent was evaporated. The residue was subjected to column
(2;
2030 mg,
Reaction of 9 with Bromine (2 equiv.): A carbon tetrachloride
(8 mL) solution of bromine (0.02 mL, 0.39 mmol) at –20 °C was
added to a carbon tetrachloride (7 mL) solution of 9 (134 mg,
0.19 mmol). After warming to room temperature, the solvent was
evaporated. The residue was recrystallized from dichloromethane
and methanol to give 1,4-dibromo-1,2,3,4-tetraphenylbutadiene
(39 mg, 41%).[14]
chromatography (hexane/ethyl acetate
=
10:1) to afford
bis(1,2,3,4,5-pentaphenylstannacyclopentadienyl) (3; 826 mg, 58%)
and 1-tert-butyl-1,2,3,4,5-pentaphenylstannole (4; 103 mg, 7%).
3: M.p. 209 °C (decomp.) (recrystallized from dichloromethane/
1
methanol). H NMR: δ = 6.73–6.80 (m, 8 H), 6.84–6.89 (m, 8 H),
6.94–7.00 (m, 24 H), 7.13–7.20 (m, 4 H), 7.24–7.27 (m, 6 H) ppm.
13C NMR: δ = 125.4 (d), 125.9 (d), 127.3 (d), 127.9 (d), 129.0 (d,
JSn,C = 53 Hz), 129.6 (d, JSn,C = 22 Hz), 130.5 (d), 137.4 (d, JSn,C
= 10, 46 Hz), 138.7 (s), 140.5 (s, JSn,C = 61 Hz), 142.4 (s, JSn,C
47 Hz), 145.9 (s, JSn,C = 37, 334, 350 Hz), 154.3 (s, JSn,C = 22,
81 Hz) ppm. 119Sn NMR: δ = –99.3 ppm (1J
= 2865 Hz).
C68H50Sn2 (1104.6): calcd. C 73.94, H 4.56; found C 73.30, H 4.31.
4: M.p. 160–161 °C (decomp.) (recrystallized from dichlorometh-
ane/methanol). 1H NMR: δ = 1.37 (s, 9 H, JSn,H = 75, 78 Hz),
6.79–6.80 (m, 4 H), 6.89–6.97(m, 12 H), 7.03–7.06 (m, 4 H), 7.30–
7.37 (m, 3 H), 7.48–7.61 (m, 2 H) ppm. 13C NMR: δ = 31.1 (q),
32.7 (s), 125.0 (d), 125.7 (d), 127.2 (d), 127.8 (d), 128.8 (d), 129.0
(d), 129.2 (d), 130.4 (d), 137.2 (d), 139.9 (s), 140.8 (s), 143.4 (s),
144.6 (s), 155.2 (s) ppm. 119Sn NMR: δ = –59.9 ppm. C38H34Sn
(609.42): calcd. C 74.90, H 5.62; found C 74.90, H 5.58.
Reaction of 9 with Bromine (excess): A carbon tetrachloride (8 mL)
solution of bromine (0.89 mL, 17.3 mmol) was added at room tem-
perature to a dichloromethane (15 mL) solution of 9 (1200 mg,
1.74 mmol). The residue was recrystallized from dichloromethane
and methanol to give 1-bromo-1,2,3,4-tetraphenyl-4-(tribromos-
tannyl)-1,3-butadiene (8; 1328 mg, 96%). M.p. 167–168 °C (de-
=
119Sn,117Sn
1
comp.) (recrystallized from dichloromethane/hexane). H NMR: δ
= 7.06–7.16 (m, 4 H), 7.20–7.39 (m, 14 H), 7.48–7.53 (m, 2 H) ppm.
13C NMR: δ = 128.0 (d), 128.1 (d), 128.2 (d), 128.3 (d), 128.56 (d),
128.58 (d), 128.9 (d), 129.0 (d), 129.8 (d), 129.9 (d), 130.1 (d), 130.8
(d), 136.4 (s), 136.6 (s, JSn,C = 10 Hz), 136.8 (s), 138.8 (s), 141.0 (s,
JSn,C = 67 Hz), 144.1 (s), 156.69 (s, JSn,C = 61 Hz) ppm. 119Sn
NMR: δ = –285.4 ppm. C28H20Br4Sn (794.78): calcd. C 42.32, H
2.54; found C 42.65, H 2.50.
Method B (in Diethyl Ether): tert-Butyllithium (1.50  in pentane;
3.4 mL, 5.10 mmol) was added at –100 °C to a diethyl ether
(40 mL) solution of 2 (1999 mg, 2.52 mmol). After warming to
room temperature over 4 h, the solvent was evaporated. The residue
was subjected to column chromatography (ethyl acetate) followed
Reaction of 8 with Phenyllithium: Phenyllithium (0.88  in cyclohex-
ane; 0.20 mL, 0.18 mmol) was added at –80 °C to a THF (3 mL)
solution of 7 (70 mg, 0.09 mmol). After warming to room tempera-
ture over 3.5 h, the volatile substances were removed. After fil-
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M. Saito, R. Haga, M. Yoshioka
FULL PAPER
tration of material insoluble in dichloromethane, the filtrate was
subjected to column chromatography (hexane/ethyl acetate = 10:1)
to afford 1 (18 mg, 33%) and 3 (6 mg, 12%).
with Mo-Kα radiation (λ = 0.71073 Å). The structure was solved
by direct methods using SIR[22] and refined by full-matrix least-
squares techniques (SHELXL-97)[23] using all independent reflec-
tions (5672 reflections) for 298 parameters. The non-hydrogen
atoms were refined anisotropically and all the hydrogen atoms were
placed at calculated positions [d(C–H) = 0.96 Å]. R1 = 0.042 [I Ͼ
2σ(I), 5389 reflections], wR2 = 0.097 (for all reflections), GOF =
1.094. The crystallographic data and details associated with data
collection for 10 are given in Table 1.
Reaction of 8 with tert-Butyllithium. Formation of Bi(1,1-stannole)
10: tert-Butyllithium (1.43  in pentane; 1.1 mL, 1.57 mmol) was
added at –95 °C to a THF (10 mL) solution of 8 (408 mg,
0.51 mmol). After warming to room temperature over 3 h, the vola-
tile substances were removed. After removal of material insoluble
in dichloromethane by filtration, the filtrate was recrystallized from
dichloromethane and methanol to give bis(1-tert-butyl-2,3,4,5-tet-
raphenylstannacyclopentadienyl) (10; 150 mg, 55%). M.p. 270–
300 °C (decomp.) (recrystallized from dichloromethane). 1H NMR:
δ = 1.10 (s, 18 H, JSn,H = 85 Hz), 6.80–6.84 (m, 8 H), 6.87–7.04
(m, 32 H) ppm. 13C NMR: δ = 31.6 (q), 35.2 (s), 124.9 (d), 125.6
(d), 127.2 (d), 127.7 (d), 129.6 (d), 130.7 (d), 140.9 (s), 143.5 (s),
148.5 (s), 154.2 (s) ppm. 119Sn NMR: δ = –46.4 ppm. C64H58Sn2
(1064.6): calcd. C 72.21, H 5.49; found C 71.54, H 5.37. The JSn,Sn
and JSn,C satellites were not observed because of low solubility.
Table 1. Crystallographic data for compound 10.
Formula
Mol. mass
Color
C64H58Sn2
1064.52
yellow
Crystal size [mm]
Temperature [K]
Crystal system
Space group
a [Å]
b [Å]
c [Å]
0.3 × 0.1 × 0.1
298
triclinic
P1 (#2)
12.756(2)
11.087(3)
10.685(2)
117.650(10)
86.180(10)
99.130(10)
1321.6(4)
1
Reaction of 8 with sec-Butyllithium: sec-Butyllithium (0.96  in pen-
tane; 0.53 mL, 0.51 mmol) was added at –95 °C to a THF (3 mL)
solution of 8 (136 mg, 0.17 mmol). After warming to room tem-
perature over 7 h, the volatile substances were removed. After re-
moval of material insoluble in dichloromethane by filtration, the
filtrate was recrystallized from diethyl ether to give a 1:1 dia-
stereomeric mixture of bis(1-sec-butyl-2,3,4,5-tetraphenylstannacy-
clopentadienyl) (11; 37 mg, 40%). M.p. 230–233 °C (decomp.)
(recrystallized from dichloromethane/methanol). 1H NMR: δ =
0.77 (t, J = 7 Hz, 6 H), 1.03–1.26 (m, 6 H), 1.47–1.58 (m, 4 H),
2.06–2.12 (m, 2 H), 6.76–6.78 (m, 8 H), 6.84–6.87 (m, 8 H), 6.91–
6.95 (m, 16 H), 6.98–7.02 (m, 4 H) ppm. 13C NMR: δ = 14.5 (q),
19.7 (q), 19.7 (q), 30.4 (t), 32.1 (d), 124.9 (d), 125.6 (d), 127.2 (d),
127.7 (d), 129.3 (d), 129.3 (d), 130.6 (d), 141.0 (s), 143.5 (s), 148.6
(s), 148.8 (s), 153.7 (s), 153.8 (s) ppm. 119Sn NMR: δ = –60.59,
–60.57 ppm. C64H58Sn2 (1064.62): calcd. C 72.21, H 5.49; found C
71.58, H 5.46.
α [°]
β [°]
γ [°]
V [Å3]
Z
Dcalcd. [gcm–3]
1.34
0.984
µ [mm–1]
Radiation
Scan type
2θmax [°]
No. of reflections
No. of parameters
R [I Ͼ 2σ(I)]
wR2 (all data)
Goodness of fit
Mo-Kα
ω-2θ
55.0
5672
298
0.042
0.097
1.094
CCDC-260657 (for 10) contains supplementary crystallographic
data. These data can be obtained free of charge from The Cam-
bridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif.
Reaction of 8 with Methyllithium (1 equiv.): Methyllithium (1.02 
in diethyl ether; 0.2 mL, 0.20 mmol) was added at –100 °C to a
THF (5 mL) solution of 8 (163 mg, 0.21 mmol). After warming to
room temperature, the volatile substances were removed. After re-
moval of material insoluble in dichloromethane by filtration, the
filtrate was subjected to column chromatography (hexane/ethyl ace-
tate = 10:1) to give 4-bromo-1,2,3,4-tetraphenyl-1-(trimethylstan-
nyl)-1,3-butadiene (12; 19 mg, 15%). M.p. 118 °C (decomp.)
Acknowledgments
This work was partially supported by Grants-in-Aid for Young Sci-
entists (B), nos. 10740288 (M. S.) and 13740349 (M. S.) from the
Ministry of Education, Culture, Sports, Science, and Technology,
Japan, and from the Japan Society for the Promotion of Science,
respectively. M. Saito acknowledges a Sasakawa Scientific Research
Grant from the Japan Science Society and a research grant from
the Toray Science Foundation. R. Haga is grateful for Research
Fellowships from the Japan Society for the Promotion of Science
for Young Scientists.
1
(recrystallized from dichloromethane/hexane). H NMR: δ = 0.13
(s, 9 H, JSn,H = 52, 54 Hz), 6.96–7.10 (m, 9 H), 7.13–7.23 (m, 9 H),
7.36–7.40 (m, 2 H) ppm. 13C NMR: δ = –7.0 (q), 124.3 (s), 124.9
(d), 126.4 (d), 127.3 (d), 127.4 (d), 127.7 (d), 127.8 (d), 127.9 (d),
128.0 (d), 128.2 (d), 130.0 (d), 130.1 (d), 130.5 (d), 138.7 (s), 139.7
(s), 140.3 (s), 144.4 (s), 145.3 (s), 148.5 (s), 152.4 (s) ppm. 119Sn
NMR: δ = –36.2 ppm. C31H29BrSn (600.20): calcd. C 62.04, H
4.87; found C 62.04, H 4.79.
Reaction of 8 with Methyllithium (3 equiv.): Methyllithium (1.02 
in diethyl ether; 0.4 mL, 0.41 mmol) was added at –90 °C to a THF
(4 mL) solution of 8 (101 mg, 0.13 mmol). After warming to room
temperature, the volatile substances and material insoluble in
dichloromethane were removed. The residue (64 mg) contained
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FULL PAPER
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Published Online: August 10, 2005
Eur. J. Inorg. Chem. 2005, 3750–3755
www.eurjic.org
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
3755