Preparation and properties of perarylated 3,4-disila-1,5-hexadienes. A fluorescent disilane accommodated in the crystal lattice

Article abstract of DOI:10.1021/om300551t

A dinickel complex with bridging silyl ligands, [{Ni(PCy₃)} ₂(μ-SiHPh₂)₂] (1), prepared from [Ni(cod)₂], PCy₃, and H₂SiPh₂, underwent exchange of the PCy₃ ligands with 1,2- bis(dimethylphosphino)ethane (dmpe) to yield a complex coordinated by the two bidentate ligands, [{Ni(dmpe)}₂(μ-SiHPh₂)₂]. Reactions of diarylacetylenes, ArC≡CAr (Ar = C₆H₅, C₆H₄OMe-4, C₆H₄Me-4, C ₆H₄F-4, C₆H₄CF₃-4, C ₆H₄CN-4), with 1 in a 4/1 ratio afforded 1,2-bis{(E)-1,2-diarylethenyl}-1,1,2,2-tetraphenyldisilanes via addition of the Si-H bond of the bridging silyl ligand to the alkynes and subsequent coupling of the resulted tertiary silyl ligand. X-ray crystallography of the dialkenyldisilanes resulted in three kinds of conformation of the C=C-Si-Si-C=C chain depending on the aryl group at the vinyl carbon. The disilane with phenyl substituents, 4a (Ar = C₆H₅), contained a planar C=C-Si-Si-C=C alignment with small Si-Si-C=C torsion angles (1.7(5) and 6.9(5)°). The other dialkenyldisilanes, 4b,c,e,f, had much larger torsion angles (30.9(3)-49.2(3)°), and the twisted conformation of the molecules was classified into two types. Compound 4a exhibited a fluorescence maximum at 488 nm in the solid state, while 4b-f showed peaks at 393-427 nm. The red shift in the emission of 4a is ascribed to orthogonal intramolecular charge transfer (OICT) from the electron-donating Si-Si to accepting C=C bonds.

Full text of DOI:10.1021/om300551t

Article
pubs.acs.org/Organometallics
Preparation and Properties of Perarylated 3,4-Disila-1,5-hexadienes.
A Fluorescent Disilane Accommodated in the Crystal Lattice
Makoto Tanabe, Ryouhei Yumoto, Kohtaro Osakada,* Takanobu Sanji, and Masato Tanaka
Chemical Resources Laboratory, Tokyo Institute of Technology, 4259-R1-3 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
S
* Supporting Information
ABSTRACT: A dinickel complex with bridging silyl ligands, [{Ni-
(PCy3)}2(μ-SiHPh2)2] (1), prepared from [Ni(cod)2], PCy3, and H2SiPh2,
underwent exchange of the PCy3 ligands with 1,2-bis(dimethylphosphino)-
ethane (dmpe) to yield a complex coordinated by the two bidentate ligands,
[{Ni(dmpe)}2(μ-SiHPh2)2]. Reactions of diarylacetylenes, ArCCAr (Ar =
C6H5, C6H4OMe-4, C6H4Me-4, C6H4F-4, C6H4CF3-4, C6H4CN-4), with 1 in
a 4/1 ratio afforded 1,2-bis{(E)-1,2-diarylethenyl}-1,1,2,2-tetraphenyldisi-
lanes via addition of the Si−H bond of the bridging silyl ligand to the alkynes
and subsequent coupling of the resulted tertiary silyl ligand. X-ray
crystallography of the dialkenyldisilanes resulted in three kinds of
conformation of the CC−Si−Si−CC chain depending on the aryl
group at the vinyl carbon. The disilane with phenyl substituents, 4a (Ar =
C6H5), contained a planar CC−Si−Si−CC alignment with small Si−
Si−CC torsion angles (1.7(5) and 6.9(5)°). The other dialkenyldisilanes,
4b,c,e,f, had much larger torsion angles (30.9(3)−49.2(3)°), and the twisted conformation of the molecules was classified into
two types. Compound 4a exhibited a fluorescence maximum at 488 nm in the solid state, while 4b−f showed peaks at 393−427
nm. The red shift in the emission of 4a is ascribed to orthogonal intramolecular charge transfer (OICT) from the electron-
donating Si−Si to accepting CC bonds.
preparation of the related disilanes and details of the structures
and properties in the solid state.
INTRODUCTION
■
Cyclic π-conjugated compounds having an Si atom in the ring
system, such as silacyclopentadienes (siloles),1 9-silafluorenes,2
and dithienosiloles,3 have been investigated as the materials for
organic light-emitting devices. The siloles have small HOMO−
LUMO gaps suited for emissive organic materials, but their
molecular aggregation in solution often causes concentration
quenching. In the solid state, perarylated siloles exhibit high
luminescent properties owing to restricted rotation of the
aromatic rings.4 The luminescent properties of the siloles were
attributed to their low LUMO level caused by conjugation of
σ*(Si) and π*(diene) orbitals.1c,d 1,2-Disilacyclohexadienes
with a six-membered ring composed of two CC bonds and
an Si−Si bond were reported to possess nonplanar ring
structures.3b,5 Marder et al. compared the electronic state and
luminescent behavior of the siloles and 1,1,2,2-tetramethyl-
3,4,5,6-tetraphenyl-1,2-disila-3,5-cyclohexadiene.6 Acyclic disi-
lanes with π-conjugated substituents also show unique
luminescent properties based on the intramolecular charge-
transfer mechanism between the Si−Si σ bonds and π orbitals
of CC bonds7 or aromatic rings.8−10 Similar intramolecular
charge transfer from the disilanylene unit was also proposed for
disilanylene-bridged silafluorene with a rigid planar structure,
which emitted at a longer wavelength in the solid state.11
Recently, we found a new method to prepare a dialkenyldisilane
from alkyne and dinickel complexes with bridging silyl ligands
and their emission in the solid state.12 This paper presents the
RESULTS AND DISCUSSION
■
The reaction of [Ni(cod)2] (cod = 1,5-cyclooctadiene),
H2SiPh2, and PCy3 in a 1/1/1 ratio at room temperature
produced a dinickel(I) complex with bridging diphenylsilyl
ligands, [{Ni(PCy3)}2(μ-SiHPh2)2] (1), as an orange powder
in 97% yield (Scheme 1). Complex 1 reacted with bidentate
phosphines to undergo ligand exchange of the PCy3 to yield
[(NiL)2(μ-SiHPh2)2] (2, L = 1,2-bis(dimethylphosphino)-
ethane (dmpe), 3, L = 1,2-bis(diethylphosphino)ethane
(depe)), in 90 and 42% yields, respectively. The direct
preparation of 2 was achieved in 40% yield by starting from
[Ni(cod)2], H2SiPh2, and dmpe. Complex 1 is extremely air-
sensitive, while 2 and 3 with 18-electron Ni centers are stable
toward air in the solid state.
Exchange of PCy3 ligands of 1 with dmpe caused quantitative
formation of 2 at room temperature, whereas addition of depe
to the solution of 1 at the same temperature produced a
mixture of 3 and a dinickel intermediate having PCy3 and depe
ligands, [{Ni(PCy3)}(μ-SiHPh2)2{Ni(depe)}]. The unsym-
metrical complex in the reaction mixture exhibits two
31P{1H} NMR peaks: a pair of doublets at δ 32.6 and triplet
Received: June 21, 2012
Published: September 26, 2012
© 2012 American Chemical Society
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Scheme 1
3
signals at δ 44.4 with a JP−P value of 27 Hz. Heating of the
reaction mixture for 3 h at 60 °C converted the intermediate to
product 3. Many dipalladium(I) and diplatinum(I) complexes
with two bridging SiHR2 ligands and two or three phosphine
ligands have been reported,13−15 while the dinuclear complexes
of these metals with four phosphine ligands are not known.
Similar ligand exchange of [{Pt(PCy3)}2(μ-SiHPh2)2] with
dmpe afforded a stable Pt(II) complex with a bridging silylene
ligand, [{Pt(dmpe)}2(μ-SiPh2)2].14e,16 Thus, dinickel(I) com-
plexes with 18 electrons and bridging silyl ligands are obtained
as the first examples of such complexes containing group 10
transition metals.
The dinickel complex 1 reacted with ArCCAr (Ar = C6H5,
C6H4OMe-4, C6H4Me-4, C6H4F-4, C6H4CF3-4, C6H4CN-4) in
a 1/4 molar ratio at 60 °C to produce 1,2-bis{(E)-1,2-
diarylethenyl}-1,1,2,2-tetraphenyldisilane (4a−f) in 10−45%
isolated yields, together with alkyne-coordinated Ni complexes
[Ni(η2-ArCCAr)(dmpe)]18 (5a−f) in 70−96% NMR yields,
as shown in eq 1. The isolated yields, melting points, and
selected NMR data of 4a−f are summarized in Table 1.
Compound 4f was obtained in an extremely low yield due to
loss during purification. The NMR spectroscopic data of the
reaction mixtures indicated no formation of the geometrical
isomers of 4a−f. The addition of an excess amount of PhC
CPh to the solution of 2 did not change the reaction products.
Although Ni complexes with PCy3 ligands such as 1 catalyzed
the cyclotrimerization of PhCCPh at 60 °C to give
hexaphenylbenzene in 96% yield,19 the above reactions do
not form hexaarylbenzene derivatives at all. Heating of H2SiPh2
and PhCCPh in the presence of a catalytic amount of 2 at 60
°C formed a hydrosilylation product as a mixture of two
stereoisomers, (E)- and (Z)-1-diphenylsilyl-1,2-diphenylethene,
in 43% yields (E/Z = 49/51). Heating of the isolated E
compound20,21 in the presence of 2 or [Ni(dmpe)2] at 60 °C
for 35 h did not afford any disilanes, due to the low reactivity of
the tertiary Si−H bond. These results suggested that formation
of 4a−f in eq 1 involved addition of the Si−H bonds of the
bridging silyl ligands to the CC bond and successive
intramolecular Si−Si coupling of the formed silyl ligands.
Similar Si−Si bond-forming reactions of the bridging silylene
and silyl ligands in the dinuclear nickel(III) complexes were
proposed.22
The X-ray crystallographic results of 1 and 2 have already
been reported in a preliminary communication.12 Dinuclear Ni
complexes 1−3 were characterized by NMR spectroscopy in
solution. The 1H NMR signals of the bridging Si−H groups of
1−3 appear at δ −2.04, −4.02, and −6.04, which are at higher
magnetic field than the corresponding peaks of the dipalladium
and diplatinum analogues [{M(PCy3)}2(μ-SiHPh2)2] (M = Pd,
δ 2.07; M = Pt, δ 2.47).15a The 1H NMR peaks of the Ni−H−
Si 3c-2e bond at high magnetic field positions were reported for
the mononuclear Ni complexes [(dtbpe)Ni(μ-H)SiMePh2] (δ
−6.49)17a and [(dtbpe)Ni(μ-H)SiMes2][B(C6H3(CF3)2-3,5)4]
(δ −8.64)17b (dtbpe = PtBu2(CH2)2PtBu2). Complexes 1 and 2
exhibit single 29Si{1H} NMR signals at δ 121.8 (JP−Si = 25 Hz)
and 113.6 (JP−Si = 20 Hz), respectively. The 13C{1H} NMR
spectrum of 2 displays two CH3 carbon signals of the dmpe
ligands at δ 20.0 and 17.0, indicating the presence of
inequivalent CH3 groups on different sides of the NiPP
plane. Complex 3, on the other hand, shows single 13C NMR
signals of CH2 and CH3 carbons at δ 21.7 and 8.45,
respectively, probably because of fluxional behavior of the
depe ligand such as those involving its partial dissociation.
Figure 1a−e summarizes the molecular structures of 4a−c,e,f,
which were determined by X-ray crystallography, and selected
bond distances and angles of 4a−c,e,f are given in Table 2.
Table 1. Yields, Melting Points, and Selected NMR Spectroscopic Data of 4a−f
b
c
d
1H NMR
13C{1H} NMR
29Si{1H} NMR
a
compd
yield /%
mp/°C
CH
CH CSi
e
f
4a
24
34
28
42
45
10
171−173
240−242
245−247
234−236
278−280
281−283
7.17
145.2
144.7
144.5
144.3
144.2
144.2
142.0
138.7
140.8
140.8
140.9
141.4
−20.3
−19.0
−20.0
−20.9
−20.5
−18.8
4b
4c
4d
4e
4f
7.06
7.08
7.08
7.18
7.11
a
b
c
d
e
Isolated yields before recrystallization. In ppm, 400 MHz in THF-d8. In ppm, 101 MHz in THF-d8. In ppm, 79 or 99 MHz in THF-d8. Taken
f
from ref 12. The CH hydrogen signal is overlapped with the SiC6H5 signals.
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Figure 1. Thermal ellipsoid diagrams of (a) 4a (probability 30%) taken from ref 12, (b) 4b (50%), (c) 4c (50%), (d) 4e (50%), (e) 4f (50%), (f) the
Si−Si plane of 4a (torsion angles 1.7(5) and 6.9(5)°), and (g) the Si−Si plane of 4e (torsion angle 49.2(3)°). The dotted lines show close contacts
between a CH hydrogen and an aromatic carbon due to C−H/π interaction.
Table 2. Selected Bond Distances (Å) and Angles (deg) of 4a−c,e,f
a
compd
Si−Si bond
Si−C bond
CC bond
CH···Ph distance
Si−Si−C angle
Si−Si−CC torsion angle
b
4a
2.402(3)
1.903(6)
1.910(6)
1.903(4)
1.888(5)
1.895(3)
1.903(4)
1.888(4)
1.899(3)
1.336(8)
1.365(8)
1.353(5)
1.361(7)
1.352(3)
1.345(7)
1.353(5)
1.351(5)
109.2(3)
110.1(2)
112.0(1)
108.5(1)
109.76(8)
108.2(2)
108.7(1)
1.7(5)
6.9(5)
cd
,
4b
2.375(1)
2.369(2)
2.374(2)
2.362(2)
2.365(2)
2.395(1)
2.670
2.635
2.709
2.642
2.659
36.8(2)
47.8(3)
30.9(3)
48.0(4)
49.2(3)
34.8(2)
d
4c
4e
cd
,
d
4f
2.640
111.53(9)
a
b
c
Distances between the vinyl hydrogens and the ipso carbon atoms of the Ph ring. Taken from ref 12. There are two independent molecules in the
d
unit cell. The molecules have a crystallographic symmetry center at the midpoint between Si and Si*.
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Compound 4a has remarkably small Si−Si−CC torsion
angles (1.7(5) and 6.9(5)°), and its CC−Si−Si−CC chain
is included in the same plane (Figure 1a,f). On the other hand,
the Si−Si and CC bonds of 4b,c,e,f are twisted with larger
torsion angles (30.9(3)−49.2(3)°), as shown in Figure 1g. The
crystal structures of diaryldisilanes prefer a perpendicular
conformation of the Si−Si bond to the attached aromatic
rings, which favors overlap of the Si−Si σ orbitals and CC π
orbitals (σ−π conjugation).23 The Si−Si bond distance of 4a
(2.402(3) Å) is longer than those of 4b,c,e,f (2.362(2)−
2.395(1) Å) regardless of the electronic effects of the
substituents and is longer than normal Si−Si bond distances
(2.33−2.37 Å).24 The elongated Si−Si bond distance and small
Si−Si−CC dihedral angle of 4a induce facile intramolecular
charge transfer from the Si−Si to the CC bonds. Such a
conformation leads to the significant bathochromic shift of 4a.
The molecular conformations of 4b,c,e,f in the crystalline
state are classified into two types, as illustrated in Chart 1.
Figure 2. UV−vis absorption spectra of 4a−e in the solid state.
Table 3. Photophysical Data of 4a−f in the Solid State and in
Solution
Chart 1
a
solid state
solution
b
b
absorption
(λabs/nm)
fluorescence
(λem/nm)
absorption
(λabs/nm)
fluorescence
(λem/nm)
compd
4a
4b
4c
4d
4e
4f
258, 270, 294
277, 310
488
427
417
404
393
419
257, 295
271, 309
265, 300
254, 295
246, 299
323
338
329
323
328
332
264, 296
257, 270, 291
249, 272, 291
257, 314
254, 306
a
b
Casted film prepared from a toluene solution. Excited at the longest
absorption wavelengths.
Compounds 4c,e are included in type A, while 4f has a
conformation of type B. Crystals of 4b contain both structures
as the crystallographically independent molecules in the unit
cell (Figure 1b). Molecules of type A have a C−H/π
interaction between the vinylic C−H groups and the aryl
group attached to the different Si atom.25 The conformation of
type B has a C−H/π interaction between the vinylic C−H
bond and the aryl group attached to the same Si atom and an
intramolecular π−π stacking interaction between one aryl
group of the CC bond and the Ph ring bonded to Si atoms.26
Less bulky and electron-withdrawing CN substituents of the
aryl groups are suggested to favor π stacking interactions
between two aromatic rings.
Figure 2 shows the absorption spectra of 4a−e in the solid
state, and the photophysical properties in the solid state are
summarized in Table 3. The absorption spectra of 4a−e are
similar in shape and exhibit two or three shoulders in the range
between 249 and 310 nm, which are at significantly longer
wavelengths in comparison to that of divinyldislane (CH2
CHSiMe2)2 (λmax 227 nm).27 The bathochromic shifts of 4a−e
are attributed to the extension of σ−π conjugation between the
Si−Si bond and the aromatic rings. Solid disilanes 4a−e show
blue or blue-green emission upon irradiation. The emission of
4a is observed as a widely broadening peak at a maximum (λem)
of 488 nm, which is significantly red-shifted relative to those of
4b−e (λem 393−427 nm), as shown in Figure 3. Emission at
longer wavelength of 4a and the conformation of the molecule
in the solid state are consistent with emission via orthogonal
intramolecular charge transfer (OICT) from electron-donating
σ(Si−Si) bonds to electron-accepting π*(CC) bonds. Kira,
Figure 3. Fluorescence spectra of 4a−e in the solid state.
Sakurai, and Ishikawa9,10 reported luminescent properties of
aryldisilanes and attributed them to the OICT mechanism. The
molecule prefers a conformation having the Si−Si bond in a
plane at the photoexcited state by rotation of the Si−C(aryl)
bonds, giving low-lying charge-transfer states in comparison to
the normal excited state. The conformation with a planar
orientation between the Si−Si and the CC bonds of 4a (Si−
Si−CC torsion angles 1.7(5) and 6.9(5)°) is suited for the
OICT, whereas 4b−e with twisted geometries (30.9(3)−
49.2(3)°) show luminescence due to σ−π conjugation. An
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electron-withdrawing cyano substituent at the aryl groups
appears to induce the OICT.10 The absorption spectrum of 4f
in the solid state, however, is similar in shape to those of 4a−e,
while the emission peak of 4f (419 nm) appears within the
range of 393−427 nm of 4b−e (Figure 4). The electronic effect
Figure 6. Fluorescence spectra of 4a−f in THF solution (0.001 mM).
range 323−338 nm in comparison to those of 4b−f in the solid
state (393−427 nm). Blue-shifted emission in solution can be
attributed to free rotation of the Si−Si or Si−C bonds and lack
of σ−π conjugation of the Si−Si−CC chain. The
fluorescence spectrum of 4f displays a regular emission at
332 nm and a shoulder peak at 354 nm. The latter red-shifted
emission is ascribed to the OICT induced by the strongly
electron accepting cyano group.10
Figure 4. UV−vis absorption spectrum (solid line) and fluorescence
spectrum (hashed line) of 4f in the solid state.
of the cyano group does not influence the absorption and
emission peaks. Thus, the fluorescent properties of the
dialkenyldisilanes 4 and their steric effect, the planarity of the
CC−Si−Si−CC skeletons in particular, have significant
relevance.
UV irradiation of 4a−f in organic solvents led to the
formation of complicated compound mixtures, probably due to
photochemical Si−Si bond cleavage of the vinyldisilanes.28 The
photochemical decomposition of 4a−f is observed even within
the time of the fluorescent measurements. Therefore, Figures 5
and 6 display absorption and emission spectra which are
obtained with the first scanning of each sample. The UV−vis
absorption spectra of 4a−f are similar to those in the solid state
and exhibit two shoulder peaks in the range 246−309 nm. The
fluorescent spectra of 4a−f in solution display the peaks in the
CONCLUSIONS
■
We prepared dinickel complexes with bridging secondary silyl
ligands and found a new route to synthesize dialkenyldisilanes
from their reactions with alkynes. The reactions of the dinuclear
complexes with bridging silyl ligands toward alkynes are much
rarer than those using mononuclear transition-metal complexes
with the silyl ligands.29 The reactions of alkynes with 2 produce
dialkenyldisilanes 4, which are suggested to involve consecutive
Si−C and Si−Si bond-making processes on the dinickel
structure. It should be noted that the C6H5-substituted disilane
4a possesses a planar CC−Si−Si−CC chain with a small
dihedral angle and shows strong blue-green emission in the
solid state because of the conformation.
EXPERIMENTAL SECTION
■
General Procedures. All manipulations of the complexes were
carried out using standard Schlenk techniques under an argon or
nitrogen atmosphere or in a nitrogen-filled glovebox (Miwa MFG).
Hexane, toluene, and THF were purified by using a Grubbs-type
solvent purification system (Glass Contour).30 Dehydrated CH2Cl2
(Kanto Chemical) for purification was used as received. H, 13C{1H},
1
29Si{1H}, and 31P{1H} NMR spectra were recorded on JEOL JNM-
500 MHz and Bruker Biospin Avance III 400 MHz NMR
spectrometers. Chemical shifts in 1H and 13C{1H} NMR spectra
were referenced to the residual peaks of the solvents used.31 The peak
positions of the 19F{1H}, 29Si{1H}, and 31P{1H} NMR spectra were
referenced to external CF3COOH (δ −76.5), SiMe4 (δ 0), and 85%
H3PO4 (δ 0), respectively, in C6D6 or THF-d8. All signals of 4a−f in
the 1H and 13C{1H} NMR spectra were assigned by 2D NMR
experiments. IR spectra were recorded on a JASCO FTIR-4100
spectrometer. High-resolution FAB (matrix nitrobenzyl alcohol, NBA)
mass spectra were performed using a JEOL JMS-700 mass
spectrometer. UV−vis spectra of 4a−e in the solid state were
recorded using an Agilent 8453 spectrometer. Fluorescence spectra of
4a−e in the solid state were recorded using a Hitachi F 4500
Figure 5. UV−vis absorption spectra of 4a−f in THF solution (0.01
mM).
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spectrometer. UV−vis spectra of 4f in the solid state and 4a−f in
solution were recorded using a JASCO V-530 spectrometer.
Fluorescence spectra of 4f in the solid state and 4a−f in solution
were recorded using a JASCO FP-3600 spectrometer. Melting points
were measured using a Yanaco MP-J3 apparatus and were uncorrected.
Elemental analyses were performed using a LECO CHNS-932 or
Yanaco MT-5 CHN autorecorder at the Center for Advanced
Materials Analysis, Technical Department, Tokyo Institute of
Technology. [Ni(cod)2], tricyclohexylphosphine, 1,2-bis-
(dimethylphosphino)ethane (dmpe), and bis(diethylphosphino)-
ethane (depe) (Sigma-Aldrich) and H2SiPh2 and PhCCPh
(Tokyo Chemical Industry) were purchased and used as received. 4-
Me-, 4-MeO-, 4-F-, 4-F3C-, and 4-NC-substituted diarylacetylenes
were prepared according to the reported procedure.32
(m, 2H, NiHSi, JP−H = 6.0 Hz). 13C{1H} NMR (101 MHz, THF-d8,
room temperature): δ 150.6 (C6H5 ipso), 136.9 (C6H5 ortho), 127.1
(C6H5 para), 126.7 (C6H5 meta), 21.7 (PCH2CH3), 8.45 (PCH2CH3).
The P(CH2)2 carbon signal is overlapped with solvent signals. 31P{1H}
NMR (162 MHz, C6D6, room temperature): δ 21.6. IR (KBr): 1538
(νSi−H) cm−1. A suitable 29Si NMR signal was not observed due to
decomposition during the measurement. HRMS (FAB): calcd for
C44H70Ni2P4Si2 [M]+ 894.2673, found m/z 894.2585. The 31P{1H}
NMR spectra of the reaction mixture at room temperature in C6D6
displayed two signals at δ 32.6 and 44.4 with the same 3JP−P values (27
Hz), which were assigned to the dinickel intermediate [{Ni(depe)}(μ-
SiHPh2)2{Ni(PCy3)}]. After heating at 60 °C for 3 h, these signals
became negligible and the signal of product 3 (δ 21.6) increased.
Preparation of 1,2-Bis{(E)-1,2-diphenylethenyl}-1,1,2,2-tetra-
phenyldisilane (4a). The experimental procedure was modified
simply from that of the previous report.12 To a toluene solution (10
mL) of 2 (198 mg, 0.25 mmol) was added PhCCPh (196 mg, 1.10
mmol), followed by stirring at 60 °C for 15 h. The reaction solution
was diluted in CH2Cl2 (30 mL) and filtered through Florisil to remove
the Ni complex. The solvent was evaporated under reduced pressure
to give a yellow oil. The crude product was washed with hexane (3 mL
× 2) and dried in vacuo to give 4a (43 mg, 24%) as a white solid.
Recrystallization with toluene/hexane (1/7) afforded colorless crystals
of 4a suitable for X-ray crystallography. The 1H NMR spectrum of the
reaction mixture before purification displayed the complete conversion
of 2 into 4a and [Ni(η2-PhCCPh)(dmpe)]18 (5a; 94% NMR yield).
Data for 4a are as follows. 1H NMR (400 MHz, THF-d8, room
Preparation of [{Ni(PCy3)}2(μ-SiHPh2)2] (1). To a hexane
solution (30 mL) of [Ni(cod)2] (1.74 g, 6.33 mmol) and PCy3
(2.53 g, 9.02 mmol) was added H2SiPh2 (1.60 mL, 8.62 mmol). The
reaction mixture was stirred at room temperature for 20 h, giving an
orange precipitate from the red solution. The precipitate was collected
by filtration, washed with hexane (20 mL × 2), and dried under
1
vacuum to give 1 (3.20 g, 97%) as an orange solid. H NMR (400
3
MHz, C6D6, room temperature): δ 8.11 (d, 8H, C6H5 ortho, JH−H
=
3
7.4 Hz), 7.34 (t, 8H, C6H5 meta, JH−H = 7.4 Hz), 7.22 (t, 4H, C6H5
3
para, JH−H = 7.4 Hz), 1.86−1.76 (m, 18H, PC6H11), 1.51 (br, 18H,
PC6H11), 1.30 (m, 12H, PC6H11), 0.99 (m, 18H, PC6H11), −2.04 (m,
2H, NiHSi, JP−H = 15 Hz). 13C{1H} NMR (126 MHz, C6D6, room
temperature): δ 144.7 (C6H5 ipso), 136.8 (C6H5 ortho), 128.3 (C6H5
3
4
meta), 127.6 (C6H5 para), 36.8 (apparent triplet, PCH, |1JP−C + JP−C
|
temperature): δ 7.44 (d, 8H, SiC6H5 ortho, JH−H = 7.0 Hz), 7.29 (t,
3
4H, SiC6H5 para, JH−H = 7.1 Hz), 7.17 (apparent triplet, 10H, C6H5
= 8.3 Hz), 30.7 (PCHCH2), 27.8 (apparent triplet, PCHCH2CH2, JP−C
3
= 5.1 Hz), 26.6 (PCHCH2CH2CH2). 29Si{1H} NMR (99 MHz, C6D6,
meta and CH, JH−H = 6.9 Hz), 7.01 (m, 6H, CC6H5 para and
room temperature): δ 121.8 (m, JP−Si = 25 Hz). 31P{1H} NMR (162
meta), 6.91 (br, 6H, =CC6H5 para and meta), 6.78 (m, 8H, CC6H5
ortho). 13C{1H} NMR (101 MHz, THF-d8, room temperature): δ
145.2 (CH), 142.5 (CC6H5 ipso), 142.0 (CSi), 138.0 (
CC6H5 ipso), 137.5 (SiC6H5 ortho), 135.6 (SiC6H5 ipso), 130.2 (
CC6H5 ortho), 129.7 (SiC6H5 para), 129.1 (CC6H5 ortho), 128.7
(CC6H5 meta), 128.4 (CC6H5 meta), 128.2 (SiC6H5 meta), 127.9
(CC6H5 para), 126.3 (CC6H5 para). 29Si{1H} NMR (99 MHz,
C6D6, room temperature): δ −20.3. Anal. Calcd for C52H42Si2: C,
86.38; H, 5.85. Found: C, 86.34; H, 5.79. To isolate the Ni complex
from the mixture, the solvent was removed under reduced pressure.
The crude product was washed with hexane (2 mL × 2) and purified
repeatedly with toluene/hexane (10/3) to give 5a as a pale yellow
2
MHz, C6D6, room temperature): δ 45.9. IR (KBr): 1590 (νSi−H) cm−1.
Anal. Calcd for C60H88Ni2P2Si2: C, 68.97; H, 8.49. Found: C, 66.86; H,
8.68. It was difficult to obtain satisfactory data for the elemental
analysis and HRMS due to the severe air sensitivity of 1.
Preparation of [{Ni(dmpe)}2(μ-SiHPh2)2] (2). To a toluene
solution (20 mL) of 1 (1.21 g, 1.16 mmol) was added dmpe (390 μL,
2.34 mmol), and then the mixture was stirred at room temperature for
16 h. The solution was evaporated under reduced pressure to give an
orange residue, which was washed with hexane (9 mL × 3) and dried
1
under vacuum to give 2 (815 mg, 90%) as a red solid. H NMR (400
3
MHz, C6D6, room temperature): δ 7.84 (d, 8H, C6H5 ortho, JH−H
=
1
6.0 Hz), 7.27−7.21 (m, 12H, C6H5 meta and para), 1.23 (br, 8H,
PCH2), 0.83−0.88 (br, 24H, PCH3), −4.02 (br m, 2H, NiHSi).
13C{1H} NMR (101 MHz, THF-d8, room temperature): δ 148.7
solid (2.9 mg, 6%). Data for 5a are as follows. H NMR (400 MHz,
3
THF-d8, room temperature): δ 7.48 (d, 4H, C6H5 ortho, JH−H = 6.8
Hz), 7.21 (t, 4H, C6H5 meta, 3JH−H = 7.6 Hz), 7.04 (t, 2H, C6H5 para,
3JH−H = 7.4 Hz), 1.64 (m, 4H, PCH2, JP−H = 13 Hz), 1.42 (apparent
3
(apparent quintet, C6H5 ipso, JP−C = 4.0 Hz), 134.3 (C6H5 ortho),
4
triplet, 12H, PCH3, |2JP−C + JP−C| = 3.2 Hz). 13C{1H} NMR (101
126.2 (C6H5 para), 126.0 (C6H5 meta), 32.2 (m, PCH2), 20.0 (br,
PCH3), 17.0 (br, PCH3). 29Si{1H} NMR (99 MHz, THF-d8, room
MHz, THF-d8, room temperature): δ 138.2 (apparent triplet, C6H5
ipso, 3JP−C = 8.9 Hz), 137.6 (d, CC6H5, 2JP−C = 13 Hz), 129.3 (C6H5
ortho), 128.3 (C6H5 mata), 125.2 (C6H5 para), 30.3 (apparent triplet,
2
temperature): δ 113.6 (apparent quintet, JP−Si = 20 Hz). 31P{1H}
NMR (162 MHz, C6D6, room temperature): δ 8.31. IR (KBr): 1579
(νSi−H) cm−1. Anal. Calcd for C36H54Ni2P4Si2: C, 55.13; H, 6.94.
Found: C, 54.55; H, 6.82. HRMS (FAB): calcd for C36H54Ni2P4Si2
[M]+ 782.1422, found m/z 782.1440. The direct preparation of 2 was
performed from the reaction of [Ni(cod)2] (172 mg, 0.63 mmol),
dmpe (120 μL, 0.72 mmol), and H2SiPh2 (130 μL, 0.70 mmol) in
toluene (15 mL). The reaction mixture was stirred for 45 h at room
temperature, resulting in the formation of an orange slurry. The
precipitate was collected by filtration, washed with hexane (5 mL × 3),
and dried under vacuum to give 2 (97 mg, 40%).
PCH2, |1JP−C + 2JP−C| = 22 Hz), 15.6 (apparent triplet, PCH3, |1JP−C
+
3JP−C| = 11 Hz). 31P{1H} NMR (162 MHz, THF-d8, room
temperature): δ 22.5.
Preparation of 1,2-Bis{(E)-1,2-bis(4-methoxyphenyl)-
ethenyl}-1,1,2,2-tetraphenyldisilane (4b). The procedure was
similar to the preparation of 4a. To a toluene solution (10 mL) of
2 (193 mg, 0.25 mmol) was added ArCCAr (Ar = C6H4OMe-4; 252
mg, 1.06 mmol), followed by stirring at 60 °C for 44 h to produce 4b
(71.7 mg, 34%) as a white solid. Vapor diffusion crystallization with
CH2Cl2/toluene afforded colorless crystals of 4b suitable for X-ray
Preparation of [{Ni(depe)}2(μ-SiHPh2)2] (3). To a toluene
solution (10 mL) of 1 (213 mg, 0.20 mmol) was added depe (100
μL, 0.43 mmol), and then the mixture was stirred at 60 °C for 6 h. The
solution was evaporated under reduced pressure to give an orange
residue, which was washed with hexane (3 mL × 2) and dried under
vacuum to give 3 (77 mg, 42%) as a brown solid. The product 3 in
solution was partially decomposed during the 13C{1H} NMR
measurement. 1H NMR (400 MHz, C6D6, room temperature): δ
1
crystallography. The H and 31P{1H} NMR spectra of the reaction
mixture displayed signals of [Ni(η2-ArCCAr)(dmpe)] (5b; 86%
1
NMR yield, δp 23.2 in C6D6). H NMR (400 MHz, THF-d8, room
3
temperature): δ 7.42 (d, 8H, SiC6H5 ortho, JH−H = 6.8 Hz), 7.27 (t,
3
3
4H, SiC6H5 para, JH−H = 7.2 Hz), 7.16 (t, 8H, SiC6H5 meta, JH−H
=
7.4 Hz), 7.06 (s, 2H, CH), 6.74 (d, 4H, =CC6H4 ortho, 3JH−H = 8.8
3
Hz), 6.71 (d, 4H, =CC6H4 ortho, JH−H = 8.8 Hz), 6.58 (d, 4H,
3
3
3
7.93 (d, 8H, C6H5 ortho, JH−H = 6.6 Hz), 7.28 (t, 8H, C6H5 meta,
=CC6H4 meta, JH−H = 8.8 Hz), 6.47 (d, 4H, =CC6H4 meta, JH−H
=
3
3JH−H = 7.2 Hz), 7.22 (t, 4H, C6H5 para, JH−H = 7.0 Hz), 1.39−1.26
8.8 Hz), 3.66 (s, 6H, OCH3), 3.59 (s, 6H, OCH3). 13C{1H} NMR
(101 MHz, THF-d8, room temperature): δ 159.9 (CC6H4 para),
(m, 24H, P(CH2)2 + PCH2CH3), 0.75 (m, 24H, PCH2CH3), −6.04
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158.8 (CC6H4 para), 144.7 (CH), 138.7 (CSi), 137.5 (SiC6H5
ortho), 136.3 (SiC6H5 ipso), 134.7 (CC6H4 ipso), 131.6 (CC6H4
ortho), 130.8 (CC6H4 ipso), 130.3 (CC6H4 ortho), 129.4 (SiC6H5
para), 128.1 (SiC6H5 meta), 114.2 (CC6H4 meta), 113.8 (CC6H4
meta), 55.1 (OCH3), 54.9 (OCH3). 29Si{1H} NMR (99 MHz, THF-d8,
(CSi), 137.4 (SiC6H5 ortho), 134.3 (SiC6H5 ipso), 130.4 (CC6H4
2
ortho and SiC6H5 para), 130.0 (q, CC6H4 para, JF−C = 32 Hz),
2
129.5 (CC6H4 ortho), 129.2 (q, CC6H4 para, JF−C = 32 Hz),
3
128.7 (SiC6H5 meta), 125.8 (q, CC6H4 meta, JF−C = 4 Hz), 125.7
3
(q, CC6H4 meta, JF−C = 4 Hz), 125.0 (q, CF3, JF−C = 272 Hz),
124.9 (q, CF3, JF−C = 272 Hz). 19F{1H} NMR (376 MHz, THF-d8,
room temperature): δ −70.1, −70.4. 29Si{1H} NMR (99 MHz, THF-
d8, room temperature): δ −20.5. Anal. Calcd for C52H38F4Si2: C,
67.59; H, 3.85; F, 22.91. Found: C, 67.38; H, 3.71; F, 22.80.
r o o m t e m p e r a t u r e ) :
C56H50O4Si2·C7H8·CH2Cl2: C, 75.34; H, 5.93. Found: C, 75.31; H,
5.68.
δ
− 1 9 . 0 . A n a l . C a l c d f o r
Preparation of 1,2-Bis{(E)-1,2-bis(4-tolyl)ethenyl}-1,1,2,2-tet-
raphenyldisilane (4c). The procedure was similar to the preparation
of 4a. To a toluene solution (10 mL) of 2 (85.3 mg, 0.11 mmol) was
added ArCCAr (Ar = C6H4Me-4; 96.3 mg, 0.47 mmol), followed by
stirring at 60 °C for 10 h to produce 4c (23.8 mg, 28%) as a white
solid. Vapor diffusion crystallization with CH2Cl2/toluene afforded
Preparation of 1,2-Bis{(E)-1,2-bis(4-cyanophenyl)ethenyl}-
1,1,2,2-tetraphenyldisilane (4f). The procedure was similar to the
preparation of 4a. To a toluene solution (10 mL) of 2 (115 mg, 0.15
mmol) was added ArCCAr (Ar = C6H4CN-4; 132 mg, 0.58 mmol),
followed by stirring at 60 °C for 24 h to give 4f (11.6 mg, 10%) as a
white solid. Vapor diffusion crystallization with CH2Cl2/toluene
afforded colorless crystals of 4f suitable for X-ray crystallography.
1
colorless crystals of 4c suitable for X-ray crystallography. The H and
31P{1H} NMR spectra of the reaction mixture displayed signals of
[Ni(η2-ArCCAr)(dmpe)] (5c; 88% NMR yield, δp 23.3 in C6D6).
1H NMR (400 MHz, THF-d8, room temperature): δ 7.41 (d, 8H,
1
The H and 31P{1H} NMR spectra of the reaction mixture displayed
signals of [Ni(η2-ArCCAr)(dmpe)] (5f, 70% NMR yield, δp 25.5 in
1
3
3
THF-d8). H NMR (400 MHz, THF-d8, room temperature): δ 7.46−
SiC6H5 ortho, JH−H = 6.8 Hz), 7.27 (t, 4H, SiC6H5 para, JH−H = 7.4
3
7.42 (m, 12H, SiC6H5 ortho + CC6H4 meta), 7.41 (t, 4H, SiC6H5
para, 3JH−H = 7.6 Hz), 7.28 (t, 8H, SiC6H5 meta, 3JH−H = 7.6 Hz), 7.24
(d, 4H, CC6H4 ortho, 3JH−H = 8.4 Hz), 7.11 (s, 2H, CH), 6.87 (d,
Hz), 7.15 (t, 8H, SiC6H5 meta, JH−H = 7.4 Hz), 7.08 (s, 2H, CH),
6.82 (d, 4H, CC6H4 ortho, 3JH−H = 7.2 Hz), 6.69 (m, 12H, CC6H4
ortho and meta), 2.18 (s, 6H, C6H4CH3), 2.11 (s, 6H, C6H4CH3).
13C{1H} NMR (101 MHz, THF-d8, room temperature): δ 144.5 (
3
4H, CC6H5 ortho, JH−H = 7.6 Hz), 6.85 (d, 4H, CC6H5 ortho,
3JH−H = 8.4 Hz). 13C{1H} NMR (101 MHz, THF-d8, room
temperature): δ 146.4 (CC6H4 ipso), 144.8 (CC6H4 ipso), 144.2
(CH), 141.4 (CSi), 137.3 (SiC6H5 ortho), 133.9 (SiC6H5 ipso),
132.7 (CC6H4 meta), 132.6 (CC6H4 meta), 130.6 (SiC6H5 para +
CC6H4 ortho), 129.8 (CC6H4 ortho), 128.9 (SiC6H5 meta), 118.7
(CN), 118.5 (CN), 112.4 (CC6H5 para), 111.3 (CC6H5 para).
29Si{1H} NMR (79 MHz, THF-d8, room temperature): δ −18.8. It was
difficult to obtain the satisfactory data for the elemental analysis.
Cyclotrimerization of PhCCPh Catalyzed by 1. To a toluene
solution (5 mL) of PhCCPh (56.3 mg, 0.32 mmol) was added a
catalytic amount of 1 (16.5 mg, 16 μmol). The reaction mixture was
then stirred at 60 °C for 16 h. The reaction solution was diluted in
CH2Cl2 (20 mL) and filtered through Florisil to remove
decomposition products. The solvent was removed under vacuum to
give pure hexaphenylbenzene (54.2 mg, 96%). The NMR spectra of
the product were identified on the basis of literature data.19
CH), 140.8 (CSi), 139.6 (CC6H4 ipso), 137.6 (CC6H4 ipso),
137.5 (SiC6H5 ortho), 136.0 (SiC6H5 ipso), 135.6 (CC6H4 para),
135.4 (CC6H4 para), 130.2 (CC6H4 ortho), 129.5 (SiC6H5 para),
129.3 (CC6H4 ortho), 129.1 (CC6H4 meta), 129.0 (CC6H4
meta), 128.1 (SiC6H5 meta), 21.0 (CH3), 20.9 (CH3). 29Si{1H} NMR
(79 MHz, THF-d8, room temperature): δ −20.0. Anal. Calcd for
C56H50Si2: C, 86.32; H, 6.47. Found: C, 86.15; H, 6.33.
Preparation of 1,2-Bis{(E)-1,2-bis(4-fluorophenyl)ethenyl}-
1,1,2,2-tetraphenyldisilane (4d). The procedure was similar to
the preparation of 4a. To a toluene solution (15 mL) of 2 (258 mg,
0.33 mmol) was added ArCCAr (Ar = C6H4F-4; 304 mg, 1.42
mmol), followed by stirring at 60 °C for 18 h to give 4d (110 mg,
42%) as a pale yellow solid. The 1H and 31P{1H} NMR spectra of the
reaction mixture displayed signals of [Ni(η2-ArCCAr)(dmpe)] (5d;
1
96% NMR yield, δp 23.5 in C6D6). H NMR (400 MHz, THF-d8,
room temperature): δ 7.43 (d, 8H, SiC6H5 ortho, 3JH−H = 7.6 Hz), 7.33
(t, 4H, SiC6H5 para, 3JH−H = 7.4 Hz), 7.22 (t, 8H, SiC6H5 meta, 3JH−H
= 7.4 Hz), 7.08 (s, 2H, CH), 6.72−6.82 (m, 12H, =CC6H4 ortho
and meta), 6.65 (apparent triplet, 4H, =CC6H4 meta, |3JF−H + 3JH−H| =
8.8 Hz). 13C{1H} NMR (101 MHz, THF-d8, room temperature): δ
162.8 (d, CC6H4 para, JF−C = 249 Hz), 162.1 (d, CC6H4 para,
JF−C = 245 Hz), 144.3 (CH), 140.8 (CSi), 138.0 (d, CC6H4
Hydrosilylation of PhCCPh with H2SiPh2 Catalyzed by 1.
To a mixture of PhCCPh (130 mg, 0.73 mmol) and H2SiPh2 (168
μL, 0.91 mmol) in THF (5 mL) was added complex 1 (37.6 mg, 36
μmol), followed by stirring at 60 °C for 9 h. The reaction solution was
diluted in CH2Cl2 (20 mL) and filtered through Florisil to remove
decomposition products. The solvent was evaporated under reduced
pressure to give a colorless oil. The crude product was purified by
column chromatography on silica gel (eluent CH2Cl2/hexane 1/10, Rf
= 0.54) and dried under vacuum to give (E)-1-diphenylsilyl-1,2-
diphenylethene as a white solid (198 mg, 75% based on PhCCPh).
The NMR spectra of the product were identified on the basis of
literature data.20
Hydrosilylation of PhCCPh with H2SiPh2 Catalyzed by 2.
The procedure was similar to the above reaction. To a mixture of
PhCCPh (183 mg, 1.03 mmol) and H2SiPh2 (184 μL, 0.99 mmol)
in toluene (5 mL) was added complex 2 (38.4 mg, 49 μmol), followed
by stirring at 60 °C for 24 h. After purification by column
chromatography, the product contained a mixture of (E)- and (Z)-
1-diphenylsilyl-1,2-diphenylethene as a colorless oil (159 mg, 43%
based on PhCCPh, E/Z = 49/51). The Z isomer of the mixtures
was identified by comparison to the data of the E isomer. Data for the
Z isomer are as follows. 1H NMR (400 MHz, CDCl3, room
temperature): δ 7.62 (s, 1H, CH), 7.48 (d, 4H, SiC6H5 ortho,
3JH−H = 6.8 Hz), 6.98−7.39 (CC6H5 ortho, meta, para, and SiC6H5
meta, para, overlapped with the signals of E isomer), 5.34 (s, 1H, SiH,
JSi−H = 204 Hz). 13C{1H} NMR (101 MHz, CDCl3, room
temperature): δ 148.5 (CH), 145.5 (CC6H5 ipso), 139.7 (
CSi), 138.5 (CC6H5 ipso), 136.1 (SiC6H5 ortho), 133.7 (SiC6H5
ipso), 129.7, 129.1, 128.0 (SiC6H5 meta), 127.7 (CC6H5 para), 126.5
(CC6H5 para). Three signals were overlapped with those of the E
isomer. The ortho and meta carbons of the CC6H5 groups and the
4
ipso, JF−C = 3 Hz), 137.4 (SiC6H5 ortho), 135.2 (SiC6H5 ipso), 134.0
4
3
(d, CC6H4 ipso, JF−C = 3 Hz), 132.0 (d, CC6H4 ortho, JF−C = 8
3
Hz), 130.8 (d, CC6H4 ortho, JF−C = 8 Hz), 130.0 (SiC6H5 para),
2
128.5 (SiC6H5 meta), 115.7 (d, CC6H4 meta, JF−C = 21 Hz), 115.5
(d, CC6H4 meta, JF−C = 21 Hz). 19F{1H} NMR (376 MHz, THF-
2
d8, room temperature): δ −121.4, −124.4. 29Si{1H} NMR (79 MHz,
THF-d8, room temperature): δ −20.9. Anal. Calcd for C52H38F4Si2 +
C4H8O: C, 77.57; H, 5.35; F, 8.76. Found: C, 77.77; H, 5.06; F, 8.48.
Preparation of 1,2-Bis{(E)-1,2-bis(p-trifluoromethylphenyl)-
ethenyl}-1,1,2,2-tetraphenyldisilane (4e). The procedure was
similar to the preparation of 4a. To a toluene solution (10 mL) of
2 (293 mg, 0.37 mmol) was added ArCCAr (Ar = C6H4CF3-4; 494
mg, 1.57 mmol), followed by stirring at 60 °C for 17 h to give 4e (167
mg, 45%) as a white solid. Vapor diffusion crystallization with
CH2Cl2/toluene afforded colorless crystals of 4e suitable for X-ray
crystallography. The H and 31P{1H} NMR spectra of the reaction
1
mixture displayed signals of [Ni(η2-ArCCAr)(dmpe)] (5e; 80%
1
NMR yield, δp 24.2 in C6D6). H NMR (400 MHz, THF-d8, room
3
temperature): δ 7.46 (d, 8H, SiC6H5 ortho, JH−H = 8.0 Hz), 7.41 (d,
3
3
4H, CC6H4 meta, JH−H = 8.4 Hz), 7.38 (t, 4H, SiC6H5 para, JH−H
= 7.2 Hz), 7.26 (t, 8H, SiC6H5 meta, 3JH−H = 7.6 Hz), 7.23 (d, 4H, 
CC6H4 meta, partly overlapped), 7.18 (s, 2H, CH), 6.92 (d, 4H, 
3
3
CC6H5 ortho, JH−H = 8.4 Hz), 6.91 (d, 4H, CC6H5 ortho, JH−H
=
8.0 Hz). 13C{1H} NMR (101 MHz, THF-d8, room temperature): δ
145.9 (CC6H4 ipso), 144.2 (CH), 144.1 (CC6H4 ipso), 140.9
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para carbons of the SiC6H5 group were not assigned. 29Si{1H} NMR
(99 MHz, CDCl3, room temperature): δ −25.1.
Harima, Y.; Yamashita, K.; Ishikawa, M. Organometallics 1999, 18,
1453−1459. (c) Ohshita, J.; Kai, H.; Takata, A.; Iida, T.; Kunai, A.;
Ohta, N.; Komaguchi, K.; Shiotani, M.; Adachi, A.; Sakamaki, K.;
Okita, K. Organometallics 2001, 20, 4800−4805. For reviews, see:
(d) Ohshita, J. Macromol. Chem. Phys. 2009, 210, 1360−1370.
(4) (a) Luo, J.; Xie, Z.; Lam, J. W. Y.; Cheng, L.; Chen, H.; Qiu, C.;
Kwok, H. S.; Zhan, X.; Liu, Y.; Zhu, D.; Tang, B. Z. Chem. Commun.
2001, 1740−1741. For reviews, see: (b) Liu, J.; Lam, J. W. Y.; Tang,
B. Z. J. Inorg. Organomet. Polym. 2009, 19, 249−285. (c) Hong, Y.;
Lam, J. W. Y.; Tang, B. Z. Chem. Commun. 2009, 4332−4353.
(5) (a) Hseu, T.-H.; Chi, Y.; Liu, C.-S. J. Am. Chem. Soc. 1982, 104,
1594−1598. (b) Hoshi, T.; Nakamura, T.; Suzuki, T.; Ando, M.;
Hagiwara, H. Organometallics 2000, 19, 3170−3178.
X-ray Crystal Structure Analyses. Single crystals of 4b,c,e,f
suitable for X-ray diffraction study were mounted on MicroMounts
(MiTeGen). The crystallographic data of 4b,c,e,f were collected on a
Rigaku Saturn CCD area detector equipped with monochromated Mo
Kα radiation (λ = 0.710 73 Å) at 113 K. Calculations were carried out
using the Crystal Structure program package, version 4.0, for
Windows. The positional and thermal parameters of non-hydrogen
atoms were refined anisotropically on F2 by full-matrix least-squares
methods using SHELXL-97.33 Hydrogen atoms were placed at
calculated positions and refined with a riding mode on their
corresponding carbon atoms. The overall quality of the reflection
data of 4b,e was poor. The toluene molecule of 4b as crystallization
solvent was refined without hydrogen atoms. The data of 4e resulted
in a maximum residual electron density larger than that normally
expected (Alert A by checkcif). Selected bond distances and angles of
4a−c,e,f are given in Table 2.
(6) (a) Zhan, X.; Risko, C.; Korlyukov, A.; Sena, F.; Timofeeva, T. V.;
́
Antipin, M. Y.; Barlow, S.; Bredas, J.-L.; Marder, S. R. J. Mater. Chem.
2006, 16, 3814−3822. For reviews, see: (b) Zhan, X.; Barlow, S.;
Marder, S. R. Chem. Commun. 2009, 1948−1955.
(7) (a) Ishikawa, M.; Sugisawa, H.; Fuchikami, T.; Kumada, M.;
Yamabe, T.; Kawakami, H.; Fukui, K.; Ueki, Y.; Shizuka, H. J. Am.
Chem. Soc. 1982, 104, 2872−2878. (b) Shizuka, H.; Okazaki, K.;
Tanaka, H.; Tanaka, M.; Ishikawa, M.; Sumitani, M.; Yoshihara, K. J.
Phys. Chem. 1987, 91, 2057−2062. (c) Horn, K. A.; Grossman, R. B.;
Thorne, J. R. C.; Whitenack., A. A. J. Am. Chem. Soc. 1989, 111, 4809−
4821.
(8) (a) Shizuka, H.; Obuchi, H.; Ishikawa, M.; Kumada, M. J. Chem.
Soc., Chem. Commun. 1981, 405−406. (b) Shizuka, H.; Sato, Y.; Ueki,
Y.; Ishikawa, M.; Kumada, K. J. Chem. Soc., Faraday Trans. 1 1984, 80,
341−357. (c) Shizuka, H.; Obuchi, H.; Ishikawa, M.; Kumada, M. J.
Chem. Soc., Faraday Trans. 1 1984, 80, 383−401. (d) Yamamoto, M.;
Kudo, T.; Ishikawa., M.; Tobita, S.; Shizuka, H. J. Phys. Chem. A 1999,
103, 3144−3154. For reviews, see: (e) Shizuka, H.; Hiratsuka, H. Res.
Chem. Intermed. 1992, 18, 131−182. (f) Steinmetz, M. G. Chem. Rev.
1995, 95, 1527−1588.
ASSOCIATED CONTENT
* Supporting Information
■
S
Figures, a table, and CIF files giving crystallographic data for
4b,c,e,f and NMR spectroscopic data for 1−3, 4f, 5a, and the
hydrosilylated products. This material is available free of charge
via the Internet at http://pubs.acs.org.
AUTHOR INFORMATION
Corresponding Author
*E-mail: kosakada@res.titech.ac.jp.
■
Notes
The authors declare no competing financial interest.
(9) (a) Sakurai, H.; Sugiyma, H.; Kira, M. J. Phys. Chem. 1990, 94,
1837−1843. (b) Kira, M.; Miyazawa, T.; Mikami, N.; Sakurai, H.
Organometallics 1991, 10, 3793−3795. (c) Kira, M.; Miyazawa, T.;
Sugiyama, H.; Yamaguchi, M.; Sakurai, H. J. Am. Chem. Soc. 1993, 115,
3116−3124.
ACKNOWLEDGMENTS
■
This work was financially supported by Grants-in-Aid for
Scientific Research (B) (No. 24350027) and for Young
Chemists (No. 23750059) from the Ministry of Education,
Culture, Sports, Science, and Technology of Japan. We thank
Akemi Fuchigami (Tokyo Institute of Technology) for
assistance in the measurement of absorption and fluorescence
spectra. NSK Ltd. is gratefully acknowledged for financial
support of this research.
(10) (a) Tajima, Y.; Ishikawa, H.; Miyazawa, T.; Kira, M.; Mikami, N.
J. Am. Chem. Soc. 1997, 119, 7400−7401. (b) Ishikawa, H.; Shimanuki,
Y.; Sugiyama, M.; Tajima, Y.; Kira, M.; Mikami, N. J. Am. Chem. Soc.
2002, 124, 6220−6230. (c) Ishikawa, H.; Sugiyama, M.; Shimanuki, Y.;
Tajima, Y.; Setaka, W.; Kira, M.; Mikami, N. J. Phys. Chem. A 2003,
107, 10781−10786. (d) Ishikawa, H.; Sugiyama, M.; Baba, I.; Setaka,
W.; Kira, M.; Mikami, N. J. Phys. Chem. A 2005, 109, 8959−8961.
(11) Shimizu, M.; Tatsumi, H.; Mochida, K.; Oda, K.; Hiyama, T.
Chem. Asian J. 2008, 3, 1238−1247.
REFERENCES
■
(1) (a) Braye, E. H.; Hubel, W.; Caplier, I. J. Am. Chem. Soc. 1961,
̈
83, 4406−4413. (b) Tamao, K.; Uchida, M.; Izumizawa, T.; Furukawa,
K.; Yamaguchi, S. J. Am. Chem. Soc. 1996, 118, 11974−11975.
(c) Yamaguchi, S.; Tamao, K. Bull. Chem. Soc. Jpn. 1996, 69, 2327−
2334. For reviews, see: (d) Yamaguchi, S.; Tamao, K. J. Chem. Soc.,
Dalton Trans. 1998, 3693−3702.
(12) Tanabe, M.; Yumoto, R.; Osakada, K. Chem. Commun. 2012, 48,
2125−2127.
(13) Pd2 complexes: (a) Kim, Y.-J.; Lee, S.-C.; Park, J.-I.; Osakada,
K.; Choi, J.-C.; Yamamoto, T. Organometallics 1998, 17, 4929−4931.
(b) Kim, Y.-J.; Lee, S.-C.; Park, J.-I.; Osakada, K.; Choi, J.-C.;
Yamamoto, T. J. Chem. Soc., Dalton Trans. 2000, 417−421.
(14) Pt2 complexes: (a) Auburn, M.; Ciriano, M.; Howard, J. A. K.;
Murray, M.; Pugh, N. J.; Spencer, J. L.; Stone, F. G. A.; Woodward, P.
J. Chem. Soc., Dalton Trans. 1980, 659−666. (b) Sanow, L. M.; Chai,
M.; McConnville, D. B.; Galat, K. J.; Simons, R. S.; Rinaldi, P. L.;
Youngs, W. J.; Tessier, C. A. Organometallics 2000, 19, 192−205.
(c) Braddock-Wilking, J.; Levchinsky, Y.; Rath, N. P. Organometallics
2000, 19, 5500−5510. (d) Arii, H.; Takahashi, M.; Noda, A.; Nanjo,
M.; Mochida, K. Organometallics 2008, 27, 1929−1935. (e) Tanabe,
M.; Ito, D.; Osakada, K. Organometallics 2008, 27, 2258−2267.
(15) Pd−Pt heterometallic complexes: (a) Tanabe, M.; Yamada, T.;
Osakada, K. Organometallics 2003, 22, 2190−2192. (b) Yamada, T.;
Tanabe, M.; Osakada, K.; Kim, Y.-J. Organometallics 2004, 23, 4771−
4777.
(2) (a) Gilman, H.; Gorsich, R. D. J. Am. Chem. Soc. 1955, 77, 6380−
6381. (b) Lee, S. H.; Jang, B.-B.; Kafafi, Z. H. J. Am. Chem. Soc. 2005,
127, 9071−9078. (c) Sanchez, J. C.; DiPasquale, A. G.; Rheingold, A.
L.; Trogler, W. C. Chem. Mater. 2007, 19, 6459−6470. (d) Matsuda,
T.; Kadowaki, S.; Goya, T.; Murakami, M. Org. Lett. 2007, 9, 133−136.
(e) Shimizu, M.; Mochida, K.; Hiyama, T. Angew. Chem., Int. Ed. 2008,
47, 9760−9764. (f) Tobisu, M.; Onoe, M.; Kita, Y.; Chatani, N. J. Am.
Chem. Soc. 2009, 131, 7506−7507. (g) Furukawa, S.; Kobayashi, J.;
Kawashima, T. J. Am. Chem. Soc. 2009, 131, 14192−14193.
(h) Ureshino, T.; Yoshida, T.; Kuninobu, Y.; Takai, K. J. Am. Chem.
Soc. 2010, 132, 14324−14326. (i) Yabusaki, Y.; Ohshima, N.; Kondo,
H.; Kusamoto, T.; Yamanoi, Y.; Nishihara, H. Chem. Eur. J. 2010, 16,
5581−5585.
(3) (a) Ohshita, J.; Nodono, M.; Watanabe, T.; Ueno, Y.; Kunai, A.;
Harima, Y.; Yamashita, K.; Ishikawa, M. J. Organomet. Chem. 1998,
553, 487−491. (b) Ohshita, J.; Nodono, M.; Kai, H.; Watanabe, T.;
Kuanai, A.; Komaguchi, K.; Shiotani, M.; Adachi, A.; Okita, K.;
(16) Braddock-Wilking, J.; Levchinsky, Y.; Rath, N. P. Inorg. Chim.
Acta 2002, 330, 82−88.
6794
dx.doi.org/10.1021/om300551t | Organometallics 2012, 31, 6787−6795

Organometallics
Article
(17) (a) Iluc, V. M.; Hillhouse, G. L. Tetrahedron 2006, 62, 7577−
7582. (b) Iluc, V. M.; Hillhouse, G. L. J. Am. Chem. Soc. 2010, 132,
11890−11892.
(18) Porschke, K. R.; Mynott, R.; Angermund, K.; Kruger, C. Z.
̈
̈
Naturforsch. 1985, 40b, 199−209.
(19) Muller, C.; Lachicotte, R. J.; Jones, W. D. Organometallics 2002,
21, 1975−1981.
̈
(20) Tillack, A.; Pulst, S.; Baumann, W.; Baudisch, H.; Kortus, K.;
Rosenthal, U. J. Oraganomet. Chem. 1997, 532, 117−123.
(21) (E)-1-Diphenylsilyl-1,2-diphenylethene in 75% yield was
synthesized from hydrosilylation of PhCCPh with H2SiPh2
catalyzed by complex 1.
(22) Shimada, S.; Rao, M. L. N.; Hayashi, T.; Tanaka, M. Angew.
Chem., Int. Ed. 2001, 40, 213−216.
(23) (a) Ohshita, J.; Iida, T.; Ohta, N.; Komaguchi, K.; Shiotani, M.;
Kunai, A. Org. Lett. 2002, 4, 403−406. (b) Sanji, T.; Yoshiwara, A.;
Kibe, T.; Sakurai, H. Silicon Chem. 2003, 2, 151−155. (c) Iida, T.;
Ohshita, J.; Ohta, N.; Komaguchi, K.; Itagaki, Y.; Shiotani, M.; Kunai,
A. J. Organomet. Chem. 2003, 688, 192−199.
(24) Sheldrick, W. S. In The Chemistry of Organic Silicon Compounds;
Patai, S., Rappoport, Z., Eds.; Wiley: New York, 1989; Part 1, Chapter
3.
(25) (a) Umezawa, Y.; Tsuboyama, S.; Honda, K.; Uzawa, J.; Nishio,
M. Bull. Chem. Soc. Jpn. 1998, 71, 1207−1213. (b) Suezawa, H.;
Yoshida, T.; Umezawa, Y.; Tsuboyama, S.; Nishio, M. Eur. J. Inorg.
Chem. 2002, 3148−3155.
(26) The distances (3.445(4), 3.378(3) Å) between the SiC6H5 and
Ar groups of 4b,f are shorter than the limit of distances of aromatic
π−π stacking (<3.5 Å). See also: Magistrato, A.; Pregosin, P. S.;
Albinati, A.; Rothlisberger, U. Organometallics 2001, 20, 4178−4184.
(27) Sakurai, H.; Tominaga, K.; Kumada, M. Bull. Chem. Soc. Jpn.
1966, 39, 1279−1282.
(28) (a) Sakurai, H.; Kamiyama, Y.; Nakadaira, Y. J. Am. Chem. Soc.
1976, 98, 7424−7425. (b) Ishiakwa, M.; Fuchikami, T.; Kumada, M. J.
Organomet. Chem. 1978, 149, 37−48. (c) Leigh, W. J.; Bradaric, C. J.;
Sluggett, G. W.; Venneri, P.; Conlin, R. T.; Dhurjati, M. S. K.; Ezhova,
M. B. J. Organomet. Chem. 1998, 561, 19−27.
(29) (a) Corriu, R. J. P.; Moreau, J. J. E. J. Chem. Soc., Chem.
Commun. 1980, 278−279. (b) Takao, T.; Suzuki, H.; Tanaka, M.
Organometallics 1994, 13, 2554−2556. (c) Tanabe, M.; Jiang, J.;
Yamazawa, H.; Osakada, K.; Ohmura, T.; Suginome, M. Organo-
metallics 2011, 30, 3981−3991.
(30) Pangborn, A. B.; Giardello, M. A.; Grubbs, R. H.; Rosen, R. K.;
Timmers, F. J. Organometallics 1996, 15, 1518−1520.
(31) Fulmer, G. R.; Miller, A. J. M.; Sherden, N. H.; Gottlieb, H. E.;
Nudelman, A.; Stoltz, B. M.; Bercaw, J. E.; Goldberg, K. I.
Organometallics 2010, 29, 2176−2179.
(32) (a) Mio, M. J.; Kopel, L. C.; Braun, J. B.; Gadzikwa, T. L.; Hull,
K. L.; Brisbois, R. G.; Markworth, C. J.; Grieco, P. A. Org. Lett. 2002, 4,
3199−3202. (b) Nishihara, Y.; Inoue, E.; Ogawa, D.; Okada, Y.;
Noyori, S.; Takagi, K. Tetrahedron Lett. 2009, 50, 4643−4646.
(33) Sheldrick, G. M. SHELXL-97: Program for Crystal Structures;
University of Gottingen, Gottingen, Germany, 1997.
6795
dx.doi.org/10.1021/om300551t | Organometallics 2012, 31, 6787−6795