Synthesis of an arylbromosilylene-platinum complex by using a 1,2-dibromodisilene as a silylene source

Article abstract of DOI:10.1021/om201227p

Kinetically stabilized 1,2-dibromodisilene, Bbt(Br)Si=Si(Br)Bbt (Bbt = 2,6-bis[bis(trimethylsilyl)methyl]-4-[tris(trimethylsilyl)methyl]phenyl) (2), was treated with [Pt(PCy₃)₂] to afford the corresponding arylbromosilylene-Pt complex, Bbt(Br)Si=Pt(PCy₃)₂ (1), as stable orange crystals. The molecular structure of 1 was elucidated by spectroscopic and X-ray crystallographic analyses. The nature of the Si-Pt bond in 1 was investigated with the aid of DFT calcualtions.

Full text of DOI:10.1021/om201227p

Article
pubs.acs.org/Organometallics
Synthesis of an Arylbromosilylene−Platinum Complex by Using a
1
,2-Dibromodisilene As a Silylene Source
†
,‡
,†
,†
Tomohiro Agou, Takahiro Sasamori,* and Norihiro Tokitoh*
†
Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
‡
Kyoto University Pioneering Research Unit for Next Generation, Gokasho, Uji, Kyoto 611-0011, Japan
*
S Supporting Information
ABSTRACT: Kinetically stabilized 1,2-dibromodisilene, Bbt(Br)SiSi(Br)Bbt
(
(
Bbt = 2,6-bis[bis(trimethylsilyl)methyl]-4-[tris(trimethylsilyl)methyl]phenyl)
2), was treated with [Pt(PCy ) ] to afford the corresponding arylbromosily-
3
2
lene−Pt complex, Bbt(Br)SiPt(PCy ) (1), as stable orange crystals. The
3
2
molecular structure of 1 was elucidated by spectroscopic and X-ray crystallo-
graphic analyses. The nature of the Si−Pt bond in 1 was investigated with the aid of DFT calcualtions.
1
2
ilylene−transition metal complexes have been postulated as
(trimethylsilyl)methyl]phenyl). During the course of our
study on its reactivity, 1,2-dibromodisilene 2 was found to
exhibit reactivity as a bromosilylene toward ketones, alcohols,
alkenes, alkynes, and a diene, playing a role as a bottleable
S
key intermediates in transition metal-catalyzed trans-
formations of organosilicon compounds, and thus their
synthesis as stable species had been attempted since the middle
1
of the last century. Since the seminal work on the synthesis of
source of arylbromosilylene Bbt(Br)Si: by proper choice of the
reaction conditions and partners.
us to examine the reaction of 2 with a low-valent transition
metal complex in the expectation of obtaining the correspond-
ing bromosilylene complex, demonstraiting a new synthetic
method of silylene complexes bearing a reactive functional
2
3
12,13
base-stabilized and base-free silylene complexes two decades
ago, a number of stable silylene complexes have been
synthesized and isolated by incorporating various transition
metals and silylene ligands, allowing us to understand not only
fundamental characteristics but also the unsual reactivity of
These results prompted
4
silylene−transition metal complexes. The present synthetic
group on the low-coordianted silicon (i.e., 2 + 2 ML → 2
n
methodology of silylene complexes can be classified into several
Bbt(Br)SiML ). Here, we report the synthesis of a
n
5
categories, including (i) anion abstraction from silyl complexes
bromosilylene−Pt complex, Bbt(Br)SiPt(PCy ) (1), by
3
2
+
−
−
(
R XSi−ML → [R SiML ] + X , X = halide and
the reaction of disilene 2 with [Pt(PCy ) ], and the structure
2
n
2
n
3 2
pseudohalide), (ii) direct coordination of free silylenes to
and properties of 1 were investigated experimentally and
theoretically.
Disilene 2 was treated with 2 equiv of [M(PCy ) ] (M = Pd,
14
low-valent transion metals (R Si: + ML → R SiML ), (iii)
2
n
2
n
[
1,2]-migration of a substituent from silicon to transition metal
3
2
centers in silyl complexes (R XSi−ML → R SiM(L )X),
Pt) in C D at 25 °C, and the reactions were monitored by
2
n
2
n
6 6
(
iv) salt elimination from 1,1-dimetallosilanes (or their
equivalents) and transition metal dihalides (R SiM′ + L MX
2
multinuclear NMR spectroscopy. In the case of the reaction
15
with [Pd(PCy3)2], the color of the reaction mixture turned
from yellow to black within minuites, and then intractable
mixtures containing palladium black were obtained. Conversely,
2
2
n
→
R SiML + M′X , M′ = Li, etc., X = halogen), and (v)
2
n
2
−
addition of an anion to silylidyne complexes (X + RSiML
n
−
6
→
[R(X)SiML ] ). Method (ii) was employed in the
the reaction of 2 with [Pt(PCy ) ] afforded bromosilylene−Pt
n
3 2
1
31
synthesis of the first neutral silylene complexes, Mes Si
complex 1 as the sole product, judging from the H and
P
2
7
Pt(PR ) (I: R = Cy, II: R = i-Pr), and it was recently found to
NMR spectra of the reaction mixture. Complex 1 was isolated
in 56% yield as orange-colored, air- and moisture-sensitive
crystals by the careful recrystallization from the reaction
mixture (Scheme 1). Although the formation mechanism of
complex 1 is still unclear, the reaction was clean and did not
contain any intermediates detectable by means of multinuclear
3
2
be applicable to the synthesis of dialkylsilylene−transition metal
8
9
complexes. Method (iv) has been recently developed and
applied to synthesize the first example of Schrock-type silylene
1
0
complexes. Although these methodologies have their own
advantages and are complementary to each other, there are still
limitations in the availability of stable silylene−transition metal
complexes. Especially, introduction of a functional group such
as a halogen to the silylene center of the silylene−transition
metal complex is not straightforward yet due to the difficulty of
16
29
NMR spectroscopy. The Si NMR spectrum of 1 in C D
6
6
shows a triplet signal with a set of satellite signals in
2
characteristic low-field region (δ 298.11, J = 137 Hz,
Si
SiP
1
JSiPt = 3660 Hz), revealing the low-coordinated silicon
11
preparation of an appropriate silylene ligand source.
character of 1. Compared to the previously reported
We have recently reported the synthesis and properties of
kinetically stabilized 1,2-dibromodisilene Bbt(Br)SiSi(Br)Bbt
Received: December 10, 2011
Published: January 25, 2012
(
2) (Bbt = 2,6-bis[bis(trimethylsilyl)methyl]-4-[tris-
©
2012 American Chemical Society
1150
dx.doi.org/10.1021/om201227p | Organometallics 2012, 31, 1150−1154

Organometallics
Article
4,7
Scheme 1. Reactions of Disilene 2 with [M(PCy ) ] (M = Pt,
Pt)
the reported SiPt double-bond lengths (2.21−2.27 Å),
3
2
revealing the SiPt double-bond character of 1 in the solid
state. The Si1−Br1 bond of 1 (2.3143(15) Å) is elongated from
those of 1,2-dibromodisilene 2 (2.243(3), 2.254(3) Å),
probably because of the 5d(Pt1)→π*(Si1−Br1) electronic
interaction. The presence of such a donor/acceptor-type
interaction was indicated by the DFT calculations (vide
infra). Both the Si1 and Pt1 atoms of 1 show planar
geometries, as shown by the summations of the bond angles
around them. The angle between the least-squares plane of the
silylene ligand (defined by the Si1, Pt1, Br1, and C(Bbt)
atoms) and the platinum coordination plane (defined by the
Si1, Pt1, P1, and P2 atoms) is 72° (Figure 1b), which is close to
the value reported for complex I (69°). One noticeable
structural feature of 1 is that the geometry around the Si1 atom
substantially deviates from trigonal-planar one and approaches
a T-shaped geometry (Pt1−Si1−C(Bbt) angle: 151.86(17)°,
Pt1−Si1−Br1 angle: 109.88(6)°). In contrast, previously
reported silylene−Pt complexes exhibit trigonal or Y-shaped
geometries around the silylene ligands (e.g., Pt−Si−C(Mes)
angles of complex I: 123.8(2)°, 130.6(2)°). Such a structural
anomaly in 1 would be due to the steric repulsion between the
Bbt and cyclohexyl groups, judging from the results of DFT
calculations on less hindered model complexes as shown in
Table 1. The optimized geometries of model complex 6 bearing
a Bbt′ group, where the C(SiMe ) group at the para-position
2
9
silylene−Pt complexes (δ 309−394), the Si resonance of 1 is
Si
2
slightly high-field shifted. The J value of 1 is ranked between
SiP
2
those of the neutral silylene−Pt complexes ( J 107−118 Hz)
SiP
and that of cationic silylene−Pt complex {Mes SiPt(H)[(i-
2
2
17
Pr) PCH CH P(i-Pr) ]}[MeB(C F ) ] ( J = 188 Hz).
2
2
2
2
6
5 3
SiP(trans)
1
Meanwhile, the JSiPt coupling constant of 1 (3660 Hz) is much
larger than those of the previously reported silylene−Pt(0)
complexes (e.g., II: J = 2973 Hz), suggesting the enhanced
1
SiPt
s-character of the Si−Pt bond in 1 as compared with those of
1
the previously reported silylene−Pt(0) complexes. The J
PPt
coupling constant of 1 (3300 Hz) also increased compared to
1
those of the other silylene−Pt(0) complexes (e.g., I: J
068 Hz; II: J = 3119 Hz). These NMR spectroscopic
features of 1 indicate the arylbromosilylene ligand Bbt(Br)Si:
should exhibit larger π-accepting ability than carbon-substituted
=
PPt
1
3
PPt
silylene ligands such as Mes Si:.
2
3
3
The solid-state structure of 1 was determined by the X-ray
crystallographic analysis (Figure 1). The Si1−Pt1 bond length
of Bbt group was replaced by a H atom, well reproduced the
experimentally observed structure of 1. Therefore, the
subsequent calculations were carried out by using the optimized
structure of 6.
The UV−vis spectra of complex 1 in THF and benzene are
almost identical, both of which exhibit two strong absorption
bands at λmax = 382 and 312 nm, respectively (Figure 2). In
addition to these distinct absorption bands, complex 1 exhibits
a weak, shoulder-like absorption extended to 560 nm, resulting
in the orange-red color of 1. The negligible solvent effect in the
UV−vis absorption spectra indicates no apparent coordination
of a THF molecule to complex 1 under these conditions. The
origins of these absorptions were investigated by using TDDFT
calculations on model complex 6, and the simulated spectra are
shown by vertical green lines in Figure 2, exhibiting a good
agreement between the simulated and experimental absorption
spectra. The simulated spectrum contains two intense
absorption peaks at 397 nm (f = 0.1200, HOMO−1 →
LUMO) and 321 nm (f = 0.1121, HOMO−5 → LUMO) and a
red-shifted weak transition at 518 nm (f = 0.0092, HOMO →
LUMO), well reproducing the experimentally observed
absorption peaks of 1.
The electronic character of the Si−Pt bond of model
complex 6 was investigated by using DFT calculations, and the
selected Kohn−Sham molecular orbitals of 6 are shown in
Figure 3. The HOMO and HOMO−1 of 6 correspond to the
σ- and π-type bonding orbitals of the Si−Pt bond, respectively.
These orbitals also contain small contributions of the Si−Br
antibonding interactions. The LUMO of 6 corresponds to the
Si−Pt π-antibonding orbital and mainly consists of the vacant
Figure 1. Molecular structure of 1. (a) Thermal ellipsoids are drawn at
the 30% probability level, and only the major parts of the disorderd
molecules are shown. Hydrogen atoms are omitted for clarity. Selected
bond lengths (Å) and angles (deg): Si1−Pt1 2.2076(15), Si1−C(Bbt)
1
2
9
.916(5), Si1−Br1 2.3143(15), Pt1−P1 2.3170(13), Pt1−P2
.3289(14), Pt1−Si1−C(Bbt) 151.86(17), C(Bbt)−Si1−Br1
8.16(16), Br1−Si1−Pt1 109.88(6), Si1−Pt1−P1 120.85(5), Si1−
3
p(Si) orbital on the bromosilylene ligand. Meanwhile, the
Pt1−P2 124.36(5), P1−Pt1−P2 113.98(5). (b) Ball-and-stick
representation of the core structure of 1 showing the angle between
the coordination planes of Si1 and Pt1 atoms.
LUMO+1 of 6 could be described as a mixture of an in-plane
Si−Pt π-bonding orbital and the Si−Br σ* orbital.
The interactions between the bromosilylene ligand and the
Pt center in model complex 6 were further analyzed on the
basis of NBO calculations. The calculated natural bonding
orbital corresponding to the Si−Pt bonding interaction is
of 1 (2.2076(15) Å) is shorter than the shortest end of the Si−
18
Pt single bond lengths (2.224−2.451 Å) and comparable to
1
151
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Organometallics
Article
Table 1. Selected Bond Lengths (Å) and Angles (deg) around the Silylene Ligands in 1 and Model Complexes 3−6
1
1
1
a
Si−Pt/Å
Si−Br/Å
Si−C(R )/Å
Pt−Si−C(R )/deg
C(R )−Si−Br/deg
Br−Si−Pt/deg
θ/deg
b
c
c
c
c
1
3
4
5
6
2.2076(15)
2.21660
2.21665
2.22571
2.24376
2.3143(15)
2.29392
2.25851
2.31782
2.34099
1.916(5)
1.89861
1.89527
1.90797
1.93727
151.86(17)
133.536
135.735
145.848
151.288
98.16(16)
100.148
109.88(6)
126.316
123.081
113.452
106.878
72
89
90
90
64
101.170
100.700
94.994
a
1
Angles between the coordination planes of the low-coordinated silicon (defined by Si, Pt, C(R ), and Br atoms) and platinum (Pt, Si, and the two P
b
c
atoms) atoms (θ/deg). Experimental values obtained by X-ray diffraction analysis. Optimized geometry calculated at the B3PW91/
LanL2DZ[Pt]:6-31G(d)[C,H,Br,P,Si] level of theory.
constants of 1 in the NMR spectra (vide supra). On the other
hand, the Si−Pt π-back-bonding was evaluated as a relatively
strong donor/acceptor interaction rather than a distinct
covalent bond, and the stabilization energy by the 5d(Pt)→
p*(Si) interaction was estimated to be 20.89 kcal·mol− by the
1
3
second-order perturbation theory. These calculational results
showed that the Si−Pt bond in 1 is mainly composed of the
Si−Pt σ bond, and the contribution of the π-back-donation
interaction is much smaller compared to the σ bond. Therefore,
the Si−Pt bond in the bromosilylene−Pt complex would be
best described as a single bond rather than a genuine double
bond. Such description was further confirmed by the Wiberg
bond index of the Si−Pt bond in 6 (0.9924).
SUMMARY
■
In conclusion, bromosilylene−Pt complex 1 was successfully
synthesized by the reaction of stable 1,2-dibromodisilene 2 with
[
Pt(PCy ) ]. The structure of 1 was unambiguously confirmed
3 2
on the basis of multinuclear NMR spectra and single-crystal X-
ray diffraction analysis. Compared to the previously reported
silylene−Pt complexes, 1 exhibited increased J
Figure 2. UV−vis absorption spectra of 1 in THF (blue line) or
benzene (red line) and TDDFT-simulated spectra (vertical green
lines).
1
2
and J
SiPt
SiP
coupling constants, indicating the enhanced s-character of the
Si−Pt bond of 1. The bonding character between the
bromosilylene and Pt moieties in 1 was theoretically
investigated, revealing the high s-character of the Si−Pt bond
as predicted by the experimental data. In addition, the NBO
analysis showed that the π-back-donation from the Pt to Si
center should be much weaker than the σ-donation from the Si
to Pt. A reactivity study of 1 is currently in progress.
EXPERIMENTAL SECTION
■
General Procedures and Instrumentation. All the manipu-
lations were performed in a glovebox filled with argon. Solvents were
purified by standard methods and/or the Ultimate Solvent System,
1
9
Glass Contour Company, and the remaing trace water and oxygen
were thoroughly removed by bulb-to-bulb distillation from potassium
1
13
31
mirror prior to use. H (300 MHz), C (75 MHz), P (121 MHz),
and 29Si (59 MHz) NMR spectra were recorded on a JEOL JNM AL-
00 NMR spectrometer. H and C NMR spectra were referenced to
1
13
3
Figure 3. Kohn−Sham molecular orbitals of the model complex 6
the signals due to residual C D H (7.15 ppm) or C D (128 ppm),
6 5 6 6
respectively, while 31P and Si NMR spectra were referenced to the
29
(
isovalue = 0.03). Hydrogen atoms are not shown for clarity.
signals of 85% H PO (0 ppm) or tetramethylsilane (0 ppm),
3
4
respectively. 1 Pt (129 MHz) NMR spectra were recorded on a
Bruker AVANCE-600 spectrometer and referenced to the signal of 1.2
M Na PtCl in D O (0 ppm). UV−vis spectra were recorded on a
95
predominantly formed from the 3s(Si) and 6s(Pt) orbitals
0
.79
0.29
(
σ(Si−Pt) = 0.8844(3s3p )Si + 0.4667(6s6p )Pt), showing
2
6
2
that the main bonding interaction between the bromosilylene
and platinum moieties originates from the 3s(Si)→6s*(Pt) σ-
donation. The large s-character of the Si−Pt bond was also
JASCO Ubest V-570 spectrometer. All melting points were
determined on a Yanaco micro melting point apparatus and are
uncorrected. Elemental analyses were performed at the Microanalytical
Laboratory of the Institute for Chemical Research, Kyoto University.
1
2
suggested by the observed large
J
and
J
coupling
SiP
SiPt
1
152
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Organometallics
Article
1
2
a
20
Bbt(Br)SiSi(Br)Bbt (2)
and [Pt(PCy ) ] were synthesized
3 2
ACKNOWLEDGMENTS
■
according to the literature.
This work was financially supported by the Grants-in-Aid for
Scientific Research (B) (No. 22350017), Young Scientist (A)
(No. 23685010), Young Scientist (B) (No. 21750037), and the
Global COE Program B09 from the MEXT, Japan.
Computation time was provided by the Super Computer
System, Institute for Chemical Research, Kyoto University. The
synchrotron radiation experiments were performed at the
BL38B1 of SPring-8 with the approval of the Japan
Synchrotron Radiation Research Institute (JASRI) (Proposal
No. 2011A1409).
Synthetic Procedure for 1. In a 5 mm φ NMR tube connected to a
J.Young joint, 2 (97 mg, 0.066 mmol) and [Pt(PCy ) ] (0.10 g, 0.13
3
2
mmol) were dissolved in C D (0.5 mL), and the tube was sealed and
6
6
moderately shaken at 25 °C with a homemade shaker to afford an
orange solution and reddish-orange crystals after 10 h. The crystals
were filtered in a glovebox, washed with hexane, and dried in vacuo to
give analytically pure 1 as orange crystals (0.11 g, 0.074 mmol, 56%).
1
Mp: 146 °C (dec). H NMR (300 MHz, C D , rt): δ 0.43 (s, 27H),
6
6
0
(
.46 (s, 36H), 1.28−1.39 (m, 12H), 1.61−1.77 (m, 24H), 1.83−1.91
13 1
m, 12H), 2.22−2.35 (m, 18H), 3.13 (s, 2H); 6.89 (s, 2H). C{ H}
NMR (75 MHz, C D , rt): δ 2.94 (s, CH(SiMe ) ), 6.20 (s,
6
6
3 2
C(SiMe ) ), 22.25 (s, C(SiMe ) ), 26.94 (brs, CH ), 28.09 (brs, CH ),
3
3
3
3
2
2
3
1.27 (s, CH(SiMe ) ), 31.40 (brs, CH ), 41.07 (brs, P-CH), 127.68
3 2 2
REFERENCES
3
(
s, C3), 146.51 (s, C4), 148.30 (s, C2), 154.48 (t, J = 9.8 Hz, C1).
■
CP
2
9
1
2
Si{ H} NMR (59 MHz, C D , rt): δ 1.03 (s), 1.71 (s), 297.50 (t, J
138 Hz, J = 3660 Hz). P{ H} NMR (121 MHz, C D , rt): δ
SiPt 6 6
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6
6
31
SiP
1
1
=
1
2
54.33 ( J = 3300 Hz, J = 138 Hz). No signal was observed in
PPt
PSi
1
95
Pt NMR spectra even after long-time measurement for a few days.
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H, 9.04.
66
133
2
8
X-ray Crystallographic Analysis of 1. The intensity data of 1 were
collected on a Rigaku Saturn CCD diffractometer equipped with a
VariMax X-ray optics system using graphite-monochromated Mo Kα
radiation (λ = 0.71075 Å). Preliminary reflection data were collected
on a BL38B1 beamline in SPring-8 with the approval of the Japan
Synchrotron Radiation Research Institute (JASRI) with a diffrac-
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(
2011A1409). The structure was solved by a direct method2
(SHELXS-97) and refined by full-matrix least-squares method on F
21
for all reflections (SHELXL-97). All hydrogen atoms were placed
using AFIX instructions, while the other atoms were refined
anisotropically. The tris(trimethylsilyl)methyl group is disordered
over two positions with 58% and 42% occupancy, and one of the
trimethylsilyl groups in one bis(trimethylsilyl)methyl group is also
disordered over two positions with 62% and 38% occupancy. Crystal
data for 1: C H BrP PtSi , fw = 1488.38 g·mol , T = 123(2) K,
trigonal, space group R3
V = 37274.6(6) Å , Z = 18, D
(
(
2
(
5) Lee, V. Y.; Sekiguchi, A. In Organometallic Compounds of Low-
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Inagawa, Y.; Iwamoto, T.; Kira, M. Dalton Trans. 2010, 39, 9414.
−1
66
133
2
8
̅
(#148), a = 54.9060(5) Å, c = 14.2772(2) Å,
3
−3
= 1.194 g·cm , crystal size 0.10 ×
calcd
(
3
0
.03 × 0.01 mm , 0.74° < θ < 25.50°, independent reflections = 15287
(Rint = 0.0797), completeness = 99.2%, GOF = 1.074, R (I > 2σ(I)) =
1
(
0
.0428, wR (all data) = 0.1340, largest diffraction peak and hole 3.045
2
−3
and −1.042 e·Å (around Pt1 atom).
Theoretical Calculations for Model Complexes R(Br)SiPt-
(
PMe ) (3, R = Me; 4, R = 2,6-(i-Pr) -C H ; 5, R = Bbt′) and
3
2
2
6 3
(
9) Takanashi, K.; Lee, V. Y.; Yokoyama, T.; Sekiguchi, A. J. Am.
Chem. Soc. 2009, 131, 916.
10) Nakata, N.; Fujita, T.; Sekiguchi, A. J. Am. Chem. Soc. 2006, 128,
6024.
11) For the synthesisof chlorosilylene complex Mes(Cl)SiMo(η -
C Me )(Me PCH CH PMe ): Mork, B. V.; Tilley, T. D. Angew.
Bbt′(Br)SiPt(PCy ) (6) (Bbt′ = 2,6-[CH(SiMe ) ] -C H ). Geometry
3
2
3 2 2
6 3
optimizations and TD-DFT calculations were performed using the
22
(
1
(
Gaussian 03 (Rev. E.01) program package at the B3PW91 density
functional level of theory using LanL2DZ[Pt]:6-31G(d)[Br,P,Si,C,H]
mixed basis sets. The optimized geometries of these model complexes
are included in the Supporting Information. NBO calculations on 6
were carried out using the NBO program (Version 3.1) included in
the Gaussian 03 program package at the B3PW91/LanL2TZ(f)[Pt]:6-
5
5
5
2
2
2
2
23
Chem., Int. Ed. 2003, 42, 357.
(12) (a) Sasamori, T.; Hironaka, K.; Sugiyama, Y.; Takagi, N.;
Nagase, S.; Hosoi, Y.; Furukawa, Y.; Tokitoh, N. J. Am. Chem. Soc.
008, 130, 13856. (b) Han, J. S.; Sasamori, T.; Mizuhata, Y.; Tokitoh,
N. Chem. Asian J., in press (DOI: 10.1002/asia.201100833).
13) Recently, similar reactivities of other stable 1,2-dibromodisilenes
have been reported; see: Suzuki, K.; Matsuo, T.; Hashizume, D.;
Tamao, K. J. Am. Chem. Soc. 2011, 133, 19710.
311G(2df)[Br,P,Si]:6-31G(d)[C,H] level.
2
ASSOCIATED CONTENT
■
(
*
S
Supporting Information
CIF file of 1 and the optimized geometries of model complexes
3
−6. This material is available free of charge via the Internet at
(
14) A related three-coordinated carbonyl−platinum complex has
been reported recently; see: Bertsch, S.; Braunschweig, H.; Forster,
http://pubs.acs.org.
M.; Gruss, K.; Radack, K. Inorg. Chem. 2011, 50, 1816.
5
AUTHOR INFORMATION
Corresponding Author
E-mail: sasamori@boc.kuicr.kyoto-u.ac.jp; tokitoh@boc.kuicr.
kyoto-u.ac.jp.
(15) [Pd(PCy ) ] was prepared in situ by the treatment of [Pd(η -
3
2
■
*
3
C H )(η -C H )] with 2 equiv of PCy , and its generation was
checked by P NMR spectroscopy.
16) Addition of PCy to the C D solution of disilene 2 did not
5
5
3
5
3
3
1
(
3
6
6
show any detectable change in the NMR spectra, indicating that PCy3
does not participate in the generation of reactive bromosilylene
Bbt(Br)Si: from 2.
Notes
The authors declare no competing financial interest.
1
153
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Organometallics
Article
(
17) Grumbine, S. D.; Tilley, T. D.; Arnold, F. P.; Rheingold, A. L. J.
Am. Chem. Soc. 1993, 115, 7884.
18) The range ofSi−Ptsingle-bond lengths was taken from the
(
CCDC data library. Most ofSi−Pt single bond lengths are within the
range 2.30−2.40Å, while a pincer-type silyl−Pt(II) complex was
reportedto have an exceptionally short Si−Pt single bond (2.224 Å).
Sangtrirutnugl, P.; Tilley, T. D. Organometallics 2008, 27, 2223.
(
19) Pangborn, A. B.; Giardello, M. A.; Grubbs, R. H.; Rosen, R. K.;
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(
Chem. Soc. 1976, 98, 5850. (b) Tasuno, Y.; Yoshida, T.; Otsuka, S.
Inorg. Synth. 1979, 19, 220.
(
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̈
̈
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(
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(
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1
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