Luminescent platinum complexes containing phosphorus-linked silole ligands

Article abstract of DOI:10.1039/c0dt00259c

A series of Pt(II) complexes containing silole-based ligands with diphenylphosphino groups terminally bound to a conjugated organic linker unit coordinated to the silole ring in the 2- or 2,5-positions, 1,1-dimethyl-2- (5′-diphenylphosphino-2′-thienyl)-3,4-diphenylsilole (4), 1,1-dimethyl-2,5-bis(5′-diphenylphosphino-2′-thienyl)-3, 4-diphenylsilole (5), and 1,1-dimethyl-2,5-bis(4′-diphenylphosphinophenyl) -3,4-diphenylsilole (8), have been prepared from (cod)PtX₂ (X = Cl, Me, C₂Ph) precursors. Mononuclear, cis-P₂PtX₂ (P = 4) complexes 6-7 were produced from silole 4 whereas dinuclear macrocyclic, cis-cis-X₂Pt(P-P)₂PtX₂ (P-P = 5 or 8) complexes 9-13 were produced from siloles 5 and 8. The solid state structure of the dinuclear complex 13 obtained from reaction of (cod)Pt(C₂Ph) ₂ with silole 8, was confirmed by X-ray crystallography. The optical properties of the siloles and the platinum complexes were studied by UV-vis and fluorescence spectroscopy in solution and were found to exhibit long wavelength absorption and emission bands attributed to the π-π* transitions of the silole core. The Royal Society of Chemistry.

Full text of DOI:10.1039/c0dt00259c

View Article Online / Journal Homepage / Table of Contents for this issue
This article is published as part of the Dalton Transactions themed issue entitled:
New Horizon of Organosilicon Chemistry
Guest Editor: Professor Mitsuo Kira
Tohoku University, Japan
Published in issue 39, 2010 of Dalton Transactions
Image reproduced with the permission of Akira Sekiguchi
Articles in the issue include:
PERSPECTIVES:
Silylium ions in catalysis
Hendrik F. T. Klare and Martin Oestreich
Dalton Trans., 2010, DOI: 10.1039/C003097J
Kinetic studies of reactions of organosilylenes: what have they taught us?
Rosa Becerra and Robin Walsh
Dalton Trans., 2010, DOI: 10.1039/C0DT00198H
π-Conjugated disilenes stabilized by fused-ring bulky “Rind” groups
Tsukasa Matsuo, Megumi Kobayashi and Kohei Tamao
Dalton Trans., 2010, DOI: 10.1039/C0DT00287A
Organosilicon compounds meet subatomic physics: Muon spin resonance
Robert West and Paul W. Percival
Dalton Trans., 2010, DOI: 10.1039/C0DT00188K
HOT ARTICLE:
Novel neutral hexacoordinate silicon(IV) complexes with two bidentate monoanionic benzamidinato
ligands
Konstantin Junold, Christian Burschka, Rüdiger Bertermann and Reinhold Tacke
Dalton Trans., 2010, DOI: 10.1039/C0DT00391C
Visit the Dalton Transactions website for more cutting-edge inorganic and organometallic research
www.rsc.org/dalton

PAPER
www.rsc.org/dalton | Dalton Transactions
Luminescent platinum complexes containing phosphorus-linked silole ligands†
Janet Braddock-Wilking,* Li-Bin Gao and Nigam P. Rath
Received 5th April 2010, Accepted 14th June 2010
DOI: 10.1039/c0dt00259c
A series of Pt(II) complexes containing silole-based ligands with diphenylphosphino groups terminally
bound to a conjugated organic linker unit coordinated to the silole ring in the 2- or 2,5-positions,
1,1-dimethyl-2-(5¢-diphenylphosphino-2¢-thienyl)-3,4-diphenylsilole (4), 1,1-dimethyl-2,5-bis(5¢-
diphenylphosphino-2¢-thienyl)-3,4-diphenylsilole (5), and 1,1-dimethyl-2,5-bis(4¢-
diphenylphosphinophenyl)-3,4-diphenylsilole (8), have been prepared from (cod)PtX2 (X = Cl, Me,
C2Ph) precursors. Mononuclear, cis-P2PtX2 (P = 4) complexes 6–7 were produced from silole 4 whereas
dinuclear macrocyclic, cis-cis-X2Pt(P–P)2PtX2 (P–P = 5 or 8) complexes 9–13 were produced from
siloles 5 and 8. The solid state structure of the dinuclear complex 13 obtained from reaction of
(cod)Pt(C2Ph)2 with silole 8, was confirmed by X-ray crystallography. The optical properties of the
siloles and the platinum complexes were studied by UV-vis and fluorescence spectroscopy in solution
and were found to exhibit long wavelength absorption and emission bands attributed to the p–p*
transitions of the silole core.
A common method employed for the preparation of 2,5-
disubstituted-3,4-diphenylsiloles has been the reductive cycliza-
tion of bis(phenylethynyl)silanes with lithium naphthalenide fol-
Introduction
Silole-based p-conjugated systems have received considerable
attention in the past two decades due to their distinctive electronic
lowed by subsequent reactions to introduce the functional groups
and photophysical properties arising from a low LUMO energy
at the 2,5-positions of the ring.12 Studies have shown that the
level due to s*–p* conjugation between the exocyclic bonds at
nature of the exocyclic substituents at the silicon center has a
silicon and the p* orbital of the butadiene unit.1 Siloles have
primarily inductive effect whereas the choice of groups at the 2,5-
exhibited high electron mobility2 and affinity,3 strong photolumi-
positions of the silole ring can dramatically alter the electronic
nescence especially in the solid state4 and thus have shown promise
properties of siloles through strong p-interactions.13 With an
in applications in organic light emitting diodes (OLEDs),5,6,7
interest in further exploring the electronic properties of silole-
organic field-effect transistors (OFETs),8 chemical sensors,7,9 and
based compounds with respect to the nature of the groups bound
photovoltaic devices.10 A number of reviews on the preparation,
to the silole ring, our research group has been investigating the
characterization, and reactivity of siloles and related systems are
available.11
The design of new organic photovoltaics has witnessed tremen-
incorporation of terminal phosphino and phosphine oxide units
linked through p-conjugated organic groups bound to the 2,5-
positions of the silole ring. The phosphine groups can be used as
dous development in the past few years due to the intense interest
donor ligands to a range of transition metal centers and allow
in energy and environmental concerns and the need to find
for development of a variety of conjugated materials with unique
inexpensive alternatives to traditional silicon-based solar cells.
interactions and architectures.
Organic photovoltaics typically contain a donor–acceptor func-
We recently reported the preparation and characterization
tionality consisting of a polymer such as poly(3-hexylthiophene)
of a series of 1,1-dimethyl-2,5-disubstituted-3,4-diphenylsiloles
and a soluble fullerene derivative, respectively, which facilitate the
containing diphenylphosphino or diphenylphosphine oxide
separation of the photogenerated excitons.10 Siloles combined with
groups bound directly to or linked to the terminal positions of a
thiophene units, such as in polymers containing dithienosilole and
conjugated organic group bound to the 2,5-positions of the silole
poly(thienylsilole), show great promise for donor–acceptor mate-
rials for photovoltaic applications.10 Our interest in the unique
properties and potential applications of silole-thiophene based
molecules and materials for potential applications in OLEDs,
OFETs, and photovoltaics led us to study the new phosphine-
linked silole-thiophene systems described herein.
ring. A luminescent di(gold) complex, 1,1-dimethyl-2,5-bis(4-
diphenylphosphino(chlorogold)phenyl)-3,4-diphenylsilole
was
produced.14 The coordination chemistry of related phosphine-
substituted oligothiophenes with metals such as platinum,15,16
palladium,15, 16, 17 and gold,18 through coordination of the
phosphorus centers resulted in the formation of a number
of novel phosphino(oligothiophene)metal complexes. Related
2,5-disubstituted siloles containing 7-azaindolylaryl or 2,2¢-
dipyridylamino groups containing coordinated zinc centers at the
open nitrogen sites have also been reported.19
Department of Chemistry and Biochemistry and Center for Nanoscience,
University of Missouri-St. Louis, St. Louis, Missouri, 63121, USA. E-mail:
wilkingj@umsl.edu
† Electronic supplementary information (ESI) available: Complete list-
ings of geometrical parameters, positional and isotropic displacement
coefficients for hydrogen atoms and anisotropic displacement coefficients
for the non-hydrogen atoms for complex 13. CCDC 772326. For ESI
and crystallographic data in CIF or other electronic format see DOI:
10.1039/c0dt00259c
Here we report the preparation, spectroscopic characterization,
and coordination chemistry of 1,1-dimethyl-2-(5¢-diphenylpho-
sphino-2¢-thienyl)-3,4-diphenylsilole (4) and 1,1-dimethyl-2,5-
bis(5¢-diphenylphosphino-2¢-thienyl)-3,4-diphenylsilole (5). The
This journal is
The Royal Society of Chemistry 2010
Dalton Trans., 2010, 39, 9321–9328 | 9321
©

coordination chemistry of these siloles as well as 1,1-dimethyl-
2,5-bis(4-diphenylphosphinophenyl)-3,4-diphenylsilole (8) with a
series of (cod)PtX2 (X = Cl, Me, C2Ph) complexes produced either
mononuclear, cis-P2PtX2 (P = 4) or dinuclear macrocyclic, cis-cis-
X2Pt(P–P)2PtX2 (P–P = 5 or 8) complexes depending upon the
silole precursor employed.
complexes. In all cases, the bimetallic macrocyclic complexes 9–13
were produced as yellow solids in 59–78% yields.
(2)
Results and discussion
Treatment of 2,5-bis(2¢-thienyl)-3,4-diphenylsilole (1)20 with NBS
produced a mixture of the mono- and dibromo-substituted
thienyl-linked siloles, 1,1-dimethyl-2-(5¢-bromo-2¢-thienyl)-3,4-
diphenylsilole (2) and 1,1-dimethyl-2,5-bis(5-bromo-2¢-thienyl)-
3,4-diphenylsilole (3),21 respectively along with unreacted 1. Sub-
sequent reaction of the mixture with TMEDA and nBuLi followed
by diphenylchlorophosphine produced the new silole-thiophene-
based phosphine ligands 4 (24% yield) and 5 (17% yield),
respectively (Scheme 1). The new complexes described herein were
characterized by multinuclear NMR, UV-vis and fluorescence
spectroscopy, elemental analysis and X-ray crystallography (13).
1
Complexes 6–7 and 9–13 exhibited 31P{ H} NMR resonances
with platinum satellites between 4–18 ppm, with the farthest
downfield shifts detected for the complexes containing methyl
groups bound to the platinum center. Large phosphorus–platinum
coupling values were observed for complexes 6, 9, and 10 (1JPtP
=
3672–3702 Hz); these values are similar to those observed for the
23
related complexes, cis-(Ph3P)2PtCl2 and cis-Pt(PTn)2Cl2 (n = 1–
3).15,16 These larger coupling values are generally due to the weak
trans influence of the chloride ligand trans to the phosphorus
center. As expected, the stronger trans influence ligands, CH3 and
C
CPh, weaken the phosphorus–platinum coupling in 7 and 11
(1JPtP = 1858 Hz), as well as 12 and 13 (1JPtP = 2326–2331 Hz),
respectively. The latter coupling values are similar to the values
24
reported for the related complexes, cis-(Ph3P)2PtMe2 and cis-
1
(Ph3P)2Pt(C2Ph)2,25 respectively. The 29Si{ H} NMR spectra for
the complexes 6–7 and 9–13 exhibit resonances between 8–9 ppm.
UV-vis and emission studies
UV-vis absorption spectra (in CH2Cl2 as solutions) for the free
ligands (4, 5, and 8) and the complexes (6–7, and 9–13) are shown
in Fig. 1–3. Fig. 1 provides a comparison of the absorption spectra
of 4 with the corresponding platinum complexes 6–7, whereas
Fig. 2 shows the absorption spectrum of 5 compared with those of
platinum complexes 9, 11, and 12. Fig. 3 provides a comparison of
the absorption spectra of 8 with the platinum complexes 10 and 13.
Scheme 1
The 13C{ H} NMR spectra for 4 and 5 exhibited resonances for
1
the silole and thienyl ring carbon atoms between 133–154 ppm.
The 29Si{ H} NMR resonances for 4 and 5 were observed at ca.
1
9 ppm and the 31P{ H} signals were found upfield of PPh3 at
1
22
-18 ppm.
The coordination chemistry of 4 and 5 was investigated using
the platinum(II) cyclooctadiene complexes, cis-(cod)PtX2 (X = Cl,
Me). Reaction of two equivalents of 4 with cis-(cod)PtX2 produced
the mononuclear complexes 6 (X = Cl) and 7 (X = Me) as yellow
solids in 69 and 73% yields, respectively, as shown in eqn (1).
(1)
Eqn (2) summarizes the reactions of 5 and the related silole 8
(containing a C6H4 group linking the silole to the terminal PPh2
unit), with the corresponding, cis-(cod)PtX2 (X = Cl, Me, C CPh)
Fig. 1 Electronic absorption spectra of 4, 6, and 7 in CH2Cl2 at room
temperature.
9322 | Dalton Trans., 2010, 39, 9321–9328
This journal is The Royal Society of Chemistry 2010
©

of the ring. The unique electronic properties of thiophene-silole
basedsystems have beenattributedtothe presence of conjugated p-
donor thienyl groups in conjunction with electron-accepting silole
rings.29
Incorporation of thienyl groups in the 2,5-positions of the
silole ring in 1,1-dimethyl-3,4-diphenyl-2,5-bis(2-thienyl)silole
A, resulted in a red-shift of the absorption maximum (418 nm)
compared to 1,1-dimethyl-2,3,4,5-tetra(phenyl)silole B (359 nm),20
whereas terthiophene30 with no silole core exhibits a significant
blue-shift in the absorption maximum (353 nm) compared to
A and B. A related bis(diphenylphosphino)dithienosilole, 1,1¢-
(4,4-diphenyl-4H-silolo[3,2-b:4,5-b¢]dithiophene-2,6-diyl)bis[1,1-
diphenylphosphine] (C) exhibited an absorption maximum
at 380 nm and was red-shifted by 35 nm compared to the
unsubstituted dithienosilole, further demonstrating the enhanced
conjugation effects of the phosphine substituent.31 Lowering of
the LUMO energy levels, as well as red-shifting of the absorption
bands in related mono- and diphosphino-substituted thienyl
systems relative to the unsubstituted thiophene monomers and
oligomers, has also been reported and is due to a bonding
interaction between the p-orbitals on the thienyl unit with the
phosphorus centers.32
Fig. 2 Electronic absorption spectra of 5, 9, 11 and 12 in CH2Cl2 at room
temperature.
The emission spectra recorded for CH2Cl2 solutions of com-
pounds 4 and 6–7 are shown in Fig. 4, emission spectra of
compounds 5, 9, 11, and 12 in Fig. 5, and emission spectra for
compounds 8, 10, and 13 in Fig. 6, respectively. The position and
intensity of the emission maxima change slightly for the related
compounds within each figure, but the most significant difference
is in the emission maxima for the different types of silole systems.
The shorter wavelength emission maxima are found in Fig. 6 for
the siloles containing the –(C6H4)PPh2 units bound to the 2,5-
positions of the ring and upon replacement of the aryl linker unit
with one or two thiophene groups bound to the silole ring, a
significant shift to longer wavelength emission is observed. Similar
differences were reported for compounds A and B where the
emission maximum for A was 515 nm and for B the maximum was
significantly blue-shifted and observed at 467 nm.20 The related
bis(diphenylphosphino)dithienosilole C exhibited a lower energy
Fig. 3 Electronic absorption spectra of 8, 10 and 13 in CH2Cl2 at room
temperature.
All of the spectra in Fig. 1–3 exhibit little change for wavelengths
below 350 nm for the free ligands compared to the platinum
complexes, except for the bis(phenylethynyl)platinum-containing
complexes which show slightly more resolved absorption bands
in this region. The prominent long wavelength absorption regions
above 350 nm remain essentially unchanged in position but show
moderate changes in the intensity of the maxima as displayed
in Fig. 1–3. These long wavelength absorption bands near 430,
445, and 375 nm, as observed in Fig. 1, 2, and 3, respectively, are
attributed to the p–p* transitions of the silole ring.26 The shorter
wavelength absorption bands observed between 311–316 nm in
Fig. 2–3 for complexes 12 and 13 are assigned to the p–p*
transitions of the alkyne units.27 The absorption maximum for cis-
Pt(PPh3)2(C CPh)2 was reported as 314 nm in CHCl3 solution.28
A bathochromic shift was observed in the long wavelength
absorption bands of the free siloles (4 and 5) and the platinum
complexes containing one or two thiophene groups (6–7, 9, 11–12)
compared to the silole (8) and platinum complexes incorporating
the –(C6H4)PPh2 units (10 and 13) bound to the 2,5-positions
Fig. 4 Emission spectra of 4, 6, and 7 in CH2Cl2 at room temperature.
Excitation wavelengths (nm): 4 (460), 6 (483), 7 (483).
This journal is
The Royal Society of Chemistry 2010
Dalton Trans., 2010, 39, 9321–9328 | 9323
©

Table 1 Photoluminescent data for compounds 4–13
Absorptiona Emissionb
c
Compound
l
abs /nm em/nm
log(e)
l
fF
4
430
444
430
430
374
449
373
445
444
377
4.68
4.63
4.78
4.80
4.18
4.71
4.46
4.75
4.63
4.73
536
548
557
538
503
550
500
550
549
507
0.41 ¥ 10-2
1.42 ¥ 10-2
0.30 ¥ 10-2
0.61 ¥ 10-2
0.69 ¥ 10-2
3.35 ¥ 10-2
1.28 ¥ 10-2
4.54 ¥ 10-2
3.77 ¥ 10-2
1.24 ¥ 10-2
5
6
7
d
d
8
9
10
11
12
13
d
a Concentration: [M] = 1 ¥ 10-5 M in CH2Cl2 at 298 K. b Concentration:
[M] = 1 ¥ 10-4 M in CH2Cl2 at 298 K. c Determined with reference to
fluorescein. d Determined with reference to 9,10-diphenylanthracene.
phosphine units, a hypsochromic shift is observed compared to
the free ligand.33 In addition, these phosphino(oligothiophene)
ligands, upon coordination to gold centers, exhibit blue shifts in
the emission maxima compared to the free ligand.32,33 Recently, we
prepared a di(gold) complex with the gold centers coordinated to
the terminal phosphine sites of ligand 8 and observed a significant
blue shift in the emission maximum (416 nm) for the complex
compared to the free ligand.14
Fig. 5 Emission spectra of 5, 9, 11 and 12 in CH2Cl2 at room temperature.
Excitation wavelengths (nm): 5 (452), 9 (502), 11 (504), 12 (497).
Table 1 summarizes the photoluminescent data for compounds
4–13. The moderate photoluminescent quantum efficiencies de-
termined at room temperature in CH2Cl2 solution (Table 1)
are similar to values reported for other siloles in solution.20,34
Solid state absorption and emission studies of these and related
silole-based ligands and the corresponding platinum complexes
described herein are planned.
X-Ray crystallography
The molecular structure of complex 13 was confirmed by X-
ray crystallography. Fig. 7 shows the structure of 13 along with
selected bond distances and angles. The platinum center adopts a
slightly distorted square planar geometry with the two phosphines
and the two alkynyl groups in a mutual cis-arrangement to
each other. The mean plane containing the two phosphorus
and two carbon centers bound to platinum exhibits a mean
Fig. 6 Emission spectra of 8, 10 and 13 in CH2Cl2 at room temperature.
Excitation wavelengths (nm): 8 (429), 10 (427), 13 (435).
emission maximum (465 nm) compared to the unsubstituted
dithienosilole (420 nm). Molecular orbital calculations on the
model compound D containing only hydrogen substituents at
both phosphorus and silicon indicated a lower energy LUMO
compared to the unsubstituted dithienosilole model complex and
the optimized geometry had the phosphine lone pair orbital lying
in the same plane as the thiophene unit.31
The coordination of the phosphorus centers in 4, 5, and 8 to
platinum does not significantly change the energy of the absorption
and emission maxima as observed in Fig. 1–6. A similar trend
was observed for a series of cis-Pt(PTn)2Cl2 complexes (P = 2-
PPh2, T = thienyl; n = 1–3) where the absorption spectra were
dominated by the p–p* transitions for the oligothiophene units
and little change in the spectra was observed for the free
ligands compared to the platinum complexes, suggesting a minor
influence of coordination to the metal center.15 In contrast,
related phosphino(oligothiophene) ligands show an expected
bathochromic shift for the p–p* transitions of the thiophene units
with chain length, but upon coordination of gold centers to the
˚
deviation of 0.12 A from planarity, with the platinum center lying
˚
above the plane by 0.048 A. The P1–Pt–P2 bond angle for the
mutually cis-phosphines is 99.19(9)◦, whereas the angle for the cis-
phenylethynyl groups, C1–Pt1–C9, is 87.6(4)◦. The cis-C–Pt–P an-
gles of 84.6(3)–89.2(3)◦ and the trans-P–Pt–C angles of 170.5(3)–
171.1(3)◦ provide further indication of a distorted square planar
environment at the metal center. The Pt–C C bond angles at
the platinum-alkynyl groups are nonlinear at 168.5(8)–170.9(10)◦.
˚
˚
The Pt–P (2.311(3)–2.318(2) A) and Pt–C (2.0006(10)–2.013(9) A)
distances of 13 are within the expected range and are similar
35
to the bond distances observed for cis-(Ph3P)2Pt(C CPh)2 and
cis-[Pt{C CC(OH)Me2}2(PPh3)2].H2O.28 The bond angles at the
platinum centers in the latter two complexes are quite similar,
however, some variations are observed for the corresponding
angles in 13 but these values are expected based on the constrained
geometry of the macrocycle in 13.28, 35 The bimetallic platinum
˚
centers of 13 exhibit a large Pt ◊ ◊ ◊ Pt separation of 16.0 A
˚
and a shorter Si ◊ ◊ ◊ Si separation of 5.2 A. A related bimetallic
9324 | Dalton Trans., 2010, 39, 9321–9328
This journal is
The Royal Society of Chemistry 2010
©

3,4-diphenylsilole (8b) which exhibited dihedral angles of 41.9–
41.6◦.14 The silicon center adopts a distorted tetrahedral geometry
with C–Si–C angles of 92.0(4)–116.0(4)◦, where the smallest of
these angles is found for the endocyclic ring angle, C35–Si–C38.
˚
The endo- and exocyclic Si–C distances (1.859(11)–1.883(9) A) of
˚
13 are similar to those observed for 8b (1.84–1.87 A) and other
related 1,1-dimethyl-2,3,4,5-tetra(aryl)siloles.20,37
Conclusion
The coordination chemistry of 1,1-dimethyl-3,4-diphenylsilole
based ligands containing [(5¢-diphenylphosphino)-2¢-thienyl] units
in the 2- or 2,5-positions of the silole ring or (4¢-
diphenylphosphino) groups in the 2,5-positions of the silole ring
has been investigated with (cod)PtX2 (X = Cl, Me, or C2Ph)
precursors to produce either mononuclear cis-P2PtX2 complexes
or macrocyclic dinuclear complexes, cis-cis-X2Pt(P–P)2PtX2. The
macrocyclic framework was confirmed for complex 13 by X-ray
crystallography. The ligands and the platinum complexes exhibited
long wavelength absorption in the region of 350–500 nm and
emission maxima near 500–550 nm. The platinum complexes
showed little change in the absorption and emission maxima
compared to the free ligands, indicating little perturbation in
the electronic environment of the ligand with the coordination
of the metal center to phosphorus. However, a large difference
in the absorption and emission maxima was observed for the
[(5¢-diphenylphosphino-2¢-thienyl)]-based ligands and complexes
compared to the (4¢-diphenylphosphino)phenyl-based ligands
and complexes, where the latter systems were blue shifted by
nearly 60 nm and approximately 40 nm, respectively. Future
studies involving variations of the choice of the linker groups
in the 2,5-positions of the silole ring, the nature of the terminal
phosphine units, as well as the metal center and co-ligands should
enable us to vary the electronic and structural properties of these
unique complexes.
Fig. 7 Molecular structure of complex 13 (with thermal ellipsoids
shown at 50% probability level). The H atoms, solvent molecules and
disorder atoms are omitted from the figure. Selected bond distances
(A) and angles ( ): Pt ◊ ◊ ◊ Pt = 16.0, Si ◊ ◊ ◊ Si = 5.2, Pt1–P1 = 2.318(2),
Pt1–P2 = 2.311(3), Pt1–C1 = 2.006(10), Pt1–C9 = 2.013(9), P1–C17 =
1.825(10), P1–C23 = 1.832(10), P1–C29 = 1.826(8), P2–C56A = 1.844(9),
P2–C59 = 1.820(11), P2–C65 = 1.818(11), Si1–C35 = 1.883(9), Si1–C38 =
1.884(9), Si1–C39 = 1.859(11), Si1–C40 = 1.867(10), C1–C2 = 1.219(14),
◦
˚
C2–C3
= 1.441(15), C9–C10 = 1.194(13), C10–C11 = 1.441(14),
C35–C36 = 1.353(13), C36–C37 = 1.492(13), C37–C38 = 1.340(14);
C1–Pt1–C9 = 87.6(4), P2–Pt1–P1 = 99.19(9), C1–Pt1–P2 = 89.2(3),
C9–Pt1–P2 = 170.5(3), C1–Pt1–P1 = 171.1(3), C9–Pt1–P1 = 84.6(3),
C17–P1–C29 = 105.2(4), C17–P1–C23 = 101.4(4), C29–P1–C23 = 104.0(4),
C17–P1–Pt1 = 111.2(3), C29–P1–Pt1 = 113.3(3), C23–P1–Pt1 = 120.2(3),
C65–P2–C59 = 100.4(5), C65–P2–C56A = 103.9(5), C59–P2–C56A =
110.0(5), C65–P2–Pt1 = 116.1(4), C59–P2–Pt1 = 116.2(4), C56A–P2–Pt1 =
Experimental section
General procedures
109.3(3), C39–Si1–C40
=
110.1(5), C39–Si1–C35
=
113.0(5),
C40–Si1–C35 = 113.1(4), C39–Si1–C38 = 111.7(5), C40–Si1–C38 =
116.0(4), C35–Si1–C38 = 92.0(4), C2–C1–Pt1 = 170.9(10), C1–C2–C3 =
177.0(10), C10–C9–Pt1 = 168.5(8), C9–C10–C11 = 176.1(11).
Unless otherwise noted, all reactions were carried out under
an inert atmosphere of argon or nitrogen using standard
Schlenk techniques or a drybox using solvents dried by standard
procedures. The following commercially available reagents were
purchased from Aldrich and used as received, chlorodiphenyl-
phosphine, n-butyllithium, (2.5 M in hexanes), 2-bromothiophene,
TMEDA, and anhydrous ZnCl2. Phenylacetylene, Pt(cod)Cl2 and
Pt(cod)Me2 were purchased from Acros Organics. Chloroform-
d1 was purchased from Cambridge Isotopes, Inc., and
degassed and dried over activated molecular sieves before
use. The following compounds were prepared by literature
methods, 1,1-dimethyl-2,5-bis(2¢-thienyl)-3,4-diphenylsilole (1,
TST),20 dimethylbis(phenylethynyl)silane,38 1,1-dimethyl-2,5-
bis(5¢-bromo-2¢-thienyl)-3,4-diphenylsilole (3),39 1,1-dimethyl-
macrocycle containing PdCl2 units linked in
a
trans-
arrangement by two 5,5¢¢-bis(diphenylphosphino)-2,2¢:5¢,2¢¢-
terthiophene groups has been recently characterized by X-ray
crystallography and was found to exhibit an interplanar separation
˚
of approximately 6.3 A between the nearly parallel terthio-
phene units.36 The angles at the palladium center were distorted
somewhat from a square planar environment, probably due to ring
strain in the macrocycle.
The five-membered silole ring of 13 is essentially planar with a
˚
mean deviation of 0.029 A. The four aryl substituents at the 2, 3, 4,
and 5 positions of the silole ring exhibit a non-coplanar propeller
type arrangement. The dihedral angles between the aryl groups in
the 2,5-substituents and the silole ring in 13 are 21.0 and 32.0◦,
respectively and are considerably smaller compared to the related
complex, 1,1-dimethyl-2,5-bis(4¢diphenylphosphinophenyloxide)-
2,5-bis(4¢-diphenylphosphinophenyl)-3,4-diphenylsilole
(8),14
1
1
1
1
Pt(cod)(C C–Ph)2.40 The H, 13C{ H}, 29Si{ H}, and 31P{ H}
NMR spectra were recorded on a Bruker ARX-500 MHz
spectrometer in CDCl3 at room temperature. Proton and
carbon NMR chemical shifts (d) were referenced to the residual
This journal is
The Royal Society of Chemistry 2010
Dalton Trans., 2010, 39, 9321–9328 | 9325
©

peaks of the solvent chloroform-d1. Silicon NMR chemical
shifts were referenced to external SiMe4. Phosphorus NMR
chemical shifts are referenced relative to external H3PO4. Mass
spectral data were obtained in EI mode on a JEOL M Station-
JMS700. Infrared spectra were recorded on a Thermo-Nicolet
Avatar 360 ESP FT-IR spectrometer. UV-vis and fluorescence
spectra were recorded on Cary 50 Bio UV-Visible and Cary
Eclipse Fluorescence spectrophotometers, respectively. Emission
spectra were measured using the lmax value for each compound
obtained from the absorption spectra and also by the computer
optimized excitation energy resulting in spectra of identical shape
and position but with differing intensity. Elemental analysis
determinations were obtained from Atlantic Microlabs, Inc.,
Norcross, GA. X-Ray crystallographic determinations were
performed on a Bruker Apex II diffractometer equipped with a
CCD area detector.
127.7 (d, JPC = 7 Hz), 127.4 (d, JPC = 10 Hz), 127.2, 126.4, 126.1,
1 1
-1.7. 29Si{ H} NMR (99 MHz, DEPT): d 9.1. 31P{ H} NMR
(202 MHz): d -18.8. HRMS (EI): m/z calcd for C38H31PS2Si,
610.1374; found, 610.1381. Anal. Calcd for C38H31PS2Si: C, 74.72;
H, 5.12. Found: C, 74.52; H, 5.04.
Compound 5. Mp: 188–190 ◦C; 1H NMR (500 MHz): d 7.37–
7.22 (m, 25H, ArH), 7.10–7.04 (m, 7H, ArH), 7.02–6.93 (m, 2H,
thienyl H), 6.93–6.88 (m, 4H, ArH), 6.85–6.82 (m, 2H, thienyl H),
1
0.67 (s, 6H, SiMe). 13C{ H} NMR (125 MHz): d 153.9, 149.4,
138.8, 137.96 (d, JPC = 9 Hz), 137.89 (d, JPC = 26 Hz), 135.5 (d,
JPC = 23 Hz), 133.3 (d, JPC = 19 Hz), 132.1, 129.4, 128.8, 128.6,
1
128.5 (d, JPC = 7 Hz), 127.9 (d, JPC = 6 Hz), 127.5, -1.7. 29Si{ H}
1
NMR (99 MHz, DEPT): d 8.9. 31P{ H} NMR (202 MHz): d
-18.8. HRMS (EI): m/z calcd for C50H40P2S2Si, 794.1815; found,
794.1831. Anal. Calcd for C50H40P2S2Si: C, 75.54; H, 5.07. Found:
C, 75.07; H, 5.09.
General procedures for the synthesis of complexes (6–7; 9–13).
(1,1-Dimethyl-5-thienyl-2-(5¢-bromo-2¢-thienyl)-3,4-diphenylsilole
(TSTBr, 2) and 1,1-dimethyl-2,5-bis(5¢-bromo-2¢-thienyl)-3,4-
diphenylsilole (BrTSTBr, 3)39
The appropriate phosphine ligands, dissolved in CH2Cl2 (5 mL)
were added to a solution of Pt(cod)X2 in CH2Cl2 (5 mL). The
reaction mixture was stirred overnight at room temperature and
the solvent then removed under vacuum. The resulting solid
residue was dissolved in a minimum amount of CH2Cl2, and
precipitated with 20 mL of hexanes. The precipitate was collected
by filtration, washed with hexanes (3 ¥ 15 mL) and dried under
vacuum.
To a solution of 1,1-dimethyl-2,5-bis(2¢-thienyl)-3,4-diphenylsilole
(1, 1.6 g, 3.7 mmol) in THF (15 mL) was added dropwise a solution
of NBS (0.73 g, 4.1 mmol) in 5 mL of anhydrous DMF. The
mixture was stirred at room temperature for 15 min in the dark
then poured into 100 mL of water. The organic material was
extracted with CH2Cl2 (2 ¥ 100 mL), washed with water (3 ¥
50 mL) and brine (50 mL) then the organic layer was dried over
anhydrous MgSO4. After filtration and evaporation of the solvents,
the crude product mixture was subjected to silica gel column
chromatography (hexane–CH2Cl2 = 5 : 1) to give a mixture of 1, 2
and 3.
Preparation of compound 6. Compound 6 was prepared by the
general procedure described above using 4 (100 mg, 0.16 mmol)
and Pt(cod)Cl2 (30.6 mg, 0.08 mmol). After purification, 82.1 mg
(0.055 mmol) of 6 obtained in 69% yield as a yellow solid. 1H NMR
(500 MHz): d 7.47–7.42 (m, 2H, thienyl H), 7.18–7.02 (m, 25H,
ArH), 6.98–6.90 (m, 19H, ArH), 6.89–6.84 (m, 5H, ArH), 6.81–
6.74 (m, 9H, ArH/thienyl H), 6.58 (m, 2H, thienyl H), 0.57 (s,
1,1-Dimethyl-5-thienyl-2-(5¢-diphenylphosphino-2¢-thienyl)-3,4-
diphenylsilole (4) and 1,1-dimethyl-2,5-bis(5¢-diphenylphosphino-
2¢-thienyl)-3,4-diphenylsilole (5)
1
1
12H, SiMe). 29Si{ H} NMR (99 MHz, DEPT): d 9.3. 31P{ H}
NMR (202 MHz): d 4.7 (s, JPtP = 3696 Hz). Anal. Calcd for
C76H62Cl2P2PtS4Si2: C, 61.36; H, 4.20. Found: C, 61.36; H, 4.24.
To the solution mixture of 1, 2 and 3 from above in diethyl
ether (100 mL) was added TMEDA (1.2 mL, 7.8 mmol). The
mixture was cooled to -78 ◦C and a solution of n-butyllithium
(2.5 M in hexanes, 2.9 mL, 7.4 mmol) was then added dropwise.
The mixture was stirred for 90 min and then warmed to 0 ◦C,
Preparation of compound 7. Compound 7 was prepared by the
general procedure described above using 4 (100 mg, 0.16 mmol)
and Pt(cod)Me2 (26.6 mg, 0.08 mmol). After purification, 84.5 mg
(0.058 mmol) of 7 was obtained in 73% yield as a yellow solid. 1H
NMR (500 MHz): d 7.37–7.30 (m, 2H, thienyl H), 7.22–7.13 (m,
24H, ArH), 7.11–7.07 (m, 6H, ArH), 7.06–6.89 (m, 17H, thienyl
H/ArH), 6.95–6.85 (m, 11H, ArH), 6.65 (m, 2H, thienyl H), 0.69
◦
stirred for 1 h, then recooled to -78 C. A diethyl ether (5 mL)
solution of chlorodiphenylphosphine (1.6 g, 5.2 mmol) was added
dropwise, and stirred at -78 ◦C for 1 h. The mixture was allowed
to warm to rt and stirred overnight. The solvent was removed
under vacuum and the residue mixture was subjected to silica gel
column chromatography with neat hexane to remove 1, followed
by hexane–dichloromethane (5 : 1) to provide 4 as a yellow powder
(0.56 g, 24% based on TST), followed by hexane–dichloromethane
(3 : 1) to provide 5 as a yellow powder (0.5 g, 17% based on TST).
Compound 4. Mp: 190–191 ◦C; 1H NMR (500 MHz): d 7.28–
7.19 (m, 14H, ArH), 7.16–7.09 (m, 4H, ArH), 7.04–6.99 (m, 4H,
ArH), 6.98–6.97 (m, 1H, thienyl H), 6.96–6.92 (m, 3H, thienyl H),
6.88–6.85 (m, 2H, ArH), 6.84–6.82 (m, 2H, ArH), 6.79–6.77 (m,
1
(s, 12H, SiMe), 0.37 (t, 6H, JPtH = 70 Hz, JPH = 15, PtMe). 29Si{ H}
1
NMR (99 MHz, DEPT): d 9.0. 31P{ H} NMR (202 MHz): d 18.1
(s, JPtP = 1858 Hz). Anal. Calcd for C78H68P2PtS4Si2: C, 64.75; H,
4.74. Found: C, 64.83; H, 4.89.
Preparation of compound 9. Compound 9 was prepared by the
general procedure described above using 5 (100 mg, 0.12 mmol)
and Pt(cod)Cl2 (47.8 mg, 0.12 mmol). After purification, 84.7 mg
(0.04 mmol) of 9 was isolated as a yellow solid in 68% yield.
1H NMR (500 MHz): d 7.65–7.52 (m, 4H, thienyl H), 7.37–7.18
(m, 26H, overlapping with solvent), 7.14–7.00 (m, 36H, ArH),
6.90–6.81 (m, 10H, ArH), 6.73–6.67 (m, 4H, thienyl H), 0.65 (s,
1
1H, thienyl H), 0.63 (s, 6H, SiMe). 13C{ H} NMR (125 MHz):
1
1
d 154.0, 152.7, 149.5, 142.9, 139.2, 138.8, 138.0 (d, JPC = 8 Hz),
137.6, 137.4, 135.6, 135.5, 133.3 (d, JPC = 19 Hz), 132.3, 131.5,
129.7, 129.4, 128.8, 128.6 (d, JPC = 10 Hz), 128.5 (d, JPC = 7 Hz),
12H, SiMe). 29Si{ H} NMR (99 MHz, DEPT): d 9.3. 31P{ H}
NMR (202 MHz): d 4.8 (s, JPtP = 3702 Hz). Anal. Calcd for
C100H80Cl4P4Pt2S4Si2: C, 56.60; H, 3.80. Found: C, 56.37; H, 4.39.
9326 | Dalton Trans., 2010, 39, 9321–9328
This journal is
The Royal Society of Chemistry 2010
©

Table 2 Crystallographic data and structure refinement for 13
Preparation of compound 10. Compound 10 was prepared by
the general procedure described above using 8 (100 mg, 0.12 mmol)
and Pt(cod)Cl2 (47.8 mg, 0.12 mmol). After purification, 95.6 mg
(0.045 mmol) of 10 was obtained as a yellow solid in 76% yield.
1H NMR (500 MHz): d 7.40–7.22 (m, 32H, ArH overlapping with
solvent), 7.19–6.91 (m, 30H, ArH), 6.84–6.70 (m, 14H, ArH), 0.43
Formula
C146H118Cl18O2P4Pt2Si2
FW
3112.74
Cryst. size/mm
Cryst. syst.
Space group
0.51 ¥ 0.30 ¥ 0.11
Monoclinic
P21/c
22.261(4)
14.057(3)
22.741(4)
90
98.290(7)
90
7042(2)
1.468
2
2.439
2.59 to 27.60
157483/16137
[R(int) = 0.1008]
Numerical
0.7752 and 0.3704
0.0761
1
1
(s, 12H, SiMe). 29Si{ H} NMR (99 MHz, DEPT): d 8.6. 31P{ H}
NMR (202 MHz): d 13.8 (s, JPtP = 3672 Hz). Anal. Calcd for
C108H88Cl4P4Pt2Si2: C, 61.83; H, 4.23. Found: C, 61.65; H, 4.64.
˚
a/A
˚
b/A
˚
c/A
a/◦
b/◦
g /◦
Preparation of compound 11. Compound 11 was prepared by
the general procedure described above using 5 (100 mg, 0.12 mmol)
and Pt(cod)Me2 (40.0 mg, 0.12 mmol). After purification, 79.5 mg
(0.039 mmol) of 11 was obtained as a yellow solid in 65% yield. 1H
NMR (500 MHz): d 7.59–7.25 (m, 8H, thienyl H/ArH overlapping
with solvent), 7.14–6.90 (m, 68H, ArH), 6.72–6.63 (m, 4H, thienyl
3
˚
V/A
Dc/g cm-3
Z
m/mm-1
q range/◦
Reflns collected/indep. reflns
1
H), 0.64 (s, 12H, SiMe), 0.36 (s, 12H, JPtH = 70 Hz, PtMe). 29Si{ H}
1
NMR (99 MHz, DEPT): d 8.6. 31P{ H} NMR (202 MHz): d 18.1
Abs. correct
Max. and min. transm.
Final R indices [I > 2s(I)]
R indices wR2 (all data)
(s, JPtP = 1858 Hz). Anal. Calcd for C104H92P4Pt2S4Si2: C, 61.22; H,
4.54. Found: C, 61.50; H, 4.67.
0.2280
3.332 and -3.139
-3
˚
Largest diff. peak and hole/e A
Preparation of compound 12. Compound 12 was prepared by
the general procedure described above using 5 (100 mg, 0.12 mmol)
and Pt(cod)(C2Ph)2 (60.6 mg, 0.12 mmol). After purification,
84.4 mg (0.035 mmol) of 12 was obtained as a yellow solid in
59% yield. 1H NMR (500 MHz): d 7.41 (m, 4H, thienyl H), 7.38–
7.16 (m, 16H, ArH), 7.12–6.94 (m, 24H, ArH), 6.88–6.76 (m, 18H,
determined by global refinement of reflections from the complete
data set. Collected data were corrected for systematic errors
using SADABS41 based on the Laue symmetry using equivalent
reflections.
Crystal data and intensity data collection parameters are listed
in Table 2.
Structure solution and refinement were carried out using the
SHELXTL-PLUS software package.42 The structure was solved
by direct methods in monoclinic space groups P21/c and refined
1
ArH), 6.63–6.56 (m, 4H, thienyl H), 0.55 (s, 12H, SiMe). 29Si{ H}
1
NMR (99 MHz, DEPT): d 8.6. 31P{ H} NMR (202 MHz): d 7.8
(s, JPtP = 2326 Hz). IR (NaCl, cm-1): 2120 n(C C). Anal. Calcd
for C132H100P4Pt2S4Si2: C, 66.48; H, 4.23. Found: C, 66.93; H, 5.03.
Preparation of compound 13. Compound 13 was prepared by
the general procedure described above using 8 (100 mg, 0.12 mmol)
and Pt(cod)(C2Ph)2 (60.6 mg, 0.12 mmol). After purification,
110.4 mg (0.046 mmol) of 13 was obtained as a yellow solid in
2
with full matrix least-squares refinement by minimizing Rw(Fo
2
- Fc )2. All non-hydrogen atoms were refined anisotropically to
convergence. One of the phenyl rings is disordered over two
positions. This disorder was resolved with 50% occupancy atoms.
Several solvent molecules were found in the lattice. The solvents
were modeled as 2.5 CHCl3 and 3.25 H2O molecules and were
resolved with two orientations of 50% occupancy models. All H
atoms were added in the calculated position and were refined using
appropriate riding models (AFIX m3). The model was refined to
convergence to the final residual values of R1 = 7.1% and wR2 =
22.2%.
Complete listings of geometrical parameters, positional and
isotropic displacement coefficients for hydrogen atoms, and
anisotropic displacement coefficients for the non-hydrogen atoms
are submitted as ESI (Tables S1–S5†). A table of calculated and
observed structure factors is available in electronic format.
1
78% yield. H NMR (500 MHz): d 7.40–7.29 (m, 20H, ArH),
7.25–7.17 (m, 10H, ArH), 7.13–6.90 (m, 36H, ArH), 6.85–6.68 (m,
1
20H, ArH), 0.38 (s, 12H, SiMe). 29Si{ H} NMR (99 MHz, DEPT):
1
d 8.3. 31P{ H} NMR (202 MHz): d 16.0 (s, JPtP = 2331 Hz). IR
(NaCl, cm-1): 2121 n(C C). Anal. Calcd for C140H108P4Pt2Si2: C,
71.23; H, 4.61. Found: C, 71.00; H, 4.65.
X-Ray experimental for 13. X-Ray diffraction quality crystals
of 13 were obtained by slow evaporation from a solution of
CH2Cl2. A crystal with approximate dimensions of 0.51 ¥ 0.30 ¥
0.1 mm3 was mounted on a Mitgen loop in a random orientation.
Preliminary examination and data collection were performed
using a Bruker Kappa Apex II charge coupled device (CCD)
detector system single crystal X-ray diffractometer equipped with
an Oxford Cryostream LT device. Data were collected using
Acknowledgements
˚
graphite monochromated Mo-Ka radiation (l = 0.71073 A) from a
fine focus sealed tube X-ray source. Preliminary unit cell constants
were determined with a set of 36 narrow frame scans. Typical
data sets consist of combinations of v and f scan frames with
typical scan width of 0.5◦ and counting time of 15–30 s/frame
at a crystal to detector distance of 4.0 cm. The collected frames
were integrated using an orientation matrix determined from the
narrow frame scans. Apex II and SAINT software packages were
used for data collection and data integration.41 Analysis of the
integrated data did not show any decay. Final cell constants were
Funding from the National Science Foundation is greatly ac-
knowledged (CHE-0719380 and MRI, CHE-0420497 for the
purchase of the Apex II diffractometer).
References
1 S. Yamaguchi and K. Tamao, Bull. Chem. Soc. Jpn., 1996, 69, 2327.
2 H. Murata, G. G. Malliaras, M. Uchida, Y. Shen and Z. H. Kafafi,
Chem. Phys. Lett., 2001, 339, 161.
This journal is
The Royal Society of Chemistry 2010
Dalton Trans., 2010, 39, 9321–9328 | 9327
©

3 X. Zhan, C. Risko, F. Amy, C. Chan, W. Zhao, S. Barlow, A. Kahn,
J.-L. Bre´das and S. Marder, J. Am. Chem. Soc., 2005, 127, 9021.
4 (a) H. Murata, Z. H. Kafafi and M. Uchida, Appl. Phys. Lett., 2002,
80, 189; (b) J. Luo, Z. Xie, J. W. Y. Lam, L. Cheng, H. Chen, C. Qui,
H. S. Kwok, X. Zhan, Y. Liu, D. Zhu and B. Z. Tang, Chem. Commun.,
2001, 1740; (c) J. Chen, C. C. W. Law, J. W. Y. Lam, Y. Dong, S. M. F.
Lo, I. D. Williams, D. Zhu and B. Z. Tang, Chem. Mater., 2003, 15,
1535.
and R. Reau, Coord. Chem. Rev., 2003, 244, 1; (f) S. Yamaguchi and K.
Tamao, Chem. Lett., 2005, 34, 2; (g) J. Chen and Y. Cao, Macromol.
Rapid Commun., 2007, 28, 1714; (h) V. Y. Lee and A. Sekiguchi, Angew.
Chem., Int. Ed., 2007, 46, 6596.
12 (a) K. Tamao, S. Yamaguchi and M. Shiro, J. Am. Chem. Soc., 1994,
116, 11715; (b) S. Yamaguchi and K. Tamao, J. Organomet. Chem.,
2002, 653, 223.
13 X. Zhan, S. Barlow and S. Marder, Chem. Commun., 2009, 1948.
14 J. Braddock-Wilking, L.-B. Gao and N. P. Rath, Organometallics, 2010,
29, 1612.
15 T. L. Stott, M. O. Wolf and B. O. Patrick, Can. J. Chem., 2007, 85, 383.
16 R. D. Myrex, G. M. Gray, A. G. VanEngen Spivey and C. M. Lawson,
Organometallics, 2006, 25, 5045.
17 T. L. Stott, M. O. Wolf and A. Lam, Dalton Trans., 2005, 652.
18 T. L. Stott, M. O. Wolf and B. O. Patrick, Inorg. Chem., 2005, 44, 620.
19 J. Lee, Q.-D. Liu, M. Motala, J. Dane, J. Gao, Y. Kang and S. Wang,
Chem. Mater., 2004, 16, 1869.
20 S. Yamaguchi, T. Endo, M. Uchida, T. Izumizawa, K. Furukawa and
K. Tamao, Chem.–Eur. J., 2000, 6, 1683.
21 F. Wang, J. Luo, K. Yang, J. Chen, F. Huang and Y. Cao, Macro-
molecules, 2005, 38, 2253.
22 A. Sen and J. Halpern, Inorg. Chem., 1980, 19, 1073.
23 (a) J. A. Rahn, L. Baltusis and J. H. Nelson, Inorg. Chem., 1990, 29, 750;
(b) L. Bemi, H. C. Clark, J. A. Davies, C. A. Fyfe and R. E. Wasylishen,
J. Am. Chem. Soc., 1982, 104, 438.
24 (a) C. M. Haar, S. P. Nolan, W. J. Marshall, K. G. Moloy, A. Prock
and W. P. Giering, Organometallics, 1999, 18, 474; (b) R. Romeo and
G. Alibrandi, Inorg. Chem., 1997, 36, 4822.
5 Y. Shirota and H. Kageyama, Chem. Rev., 2007, 107, 953.
6 (a) K. Tamao, M. Uchida, T. Izumizawa, K. Furukawa and S.
Yamaguchi, J. Am. Chem. Soc., 1996, 118, 11974; (b) J. Ohshita, M.
Nodono, H. Kai, T. Watanabe, A. Kunai, K. Komaguchi, M. Shiotani,
A. Adachi, K. Okita, Y. Harima, K. Yamashita and M. Ishikawa,
Organometallics, 1999, 18, 1453; (c) H. Y. Chen, W. Y. Lam, J. D. Luo,
Y. L. Ho, B. Z. Tang, D. B. Zhu and H. S. Kwok, Appl. Phys. Lett.,
2002, 81, 574; (d) L. C. Palilis, A. J. Makinen, M. Uchida and Z. H.
Kafafi, Appl. Phys. Lett., 2003, 82, 2209; (e) M. S. Liu, J. D. Luo and
A. K. Y. Jen, Chem. Mater., 2003, 15, 3496; (f) W. Kim, L. C. Palilis,
M. Uchida and Z. H. Kafafi, Chem. Mater., 2004, 16, 4681; (g) L. Lee,
Q.-D. Liu, D.-R. Bai, Y. Kang, Y. Tao and S. Wang, Organometallics,
2004, 23, 6205; (h) K. L. Chan, M. J. McKiernan, C. R. Towns and
A. B. Holmes, J. Am. Chem. Soc., 2005, 127, 7662; (i) K. Geramita,
J. McBee, Y. Shen, N. Radu and T. D. Tilley, Chem. Mater., 2006, 18,
3261; (j) J. Lee, Y.-Y. Yuan, Y. Kang, W.-L. Jia, Z.-H. Lu and S. Wang,
Adv. Funct. Mater., 2006, 16, 681; (k) H.-J. Son, W.-S. Han, J.-Y. Chun,
C.-J. Lee, J.-I. Han, J. Ko and S. O. Kang, Organometallics, 2007, 26,
519.
7 Z. Li, Y. Q. Dong, J. W. Y. Lam, J. Sun, A. Qin, M. Haussler, Y. P.
Dong, H. H. Y. Sung, I. D. Williams, H. S. Kwok and B. Z. Tang, Adv.
Funct. Mater., 2009, 19, 905.
25 R. J. Cross and M. F. Davidson, J. Chem. Soc., Dalton Trans., 1986,
1987.
8 (a) J. Ohshita, K.-H. Lee, D. Hamamoto, Y. Kunugi, J. Ikadai, Y.-W.
Kwak and A. Kunai, Chem. Lett., 2004, 33, 892; (b) Y. Wang, L. Hou, K.
Yang, J. Chen, F. Wang and Y. Cao, Macromol. Chem. Phys., 2005, 206,
2190; (c) D.-H. Kim, J. Ohshita, K.-H. Lee, Y. Kunugi and A. Kunai,
Organometallics, 2006, 25, 1511; (d) H. Usta, G. Lu, A. Facchetti and
T. J. Marks, J. Am. Chem. Soc., 2006, 128, 9034; (e) G. Lu, H. Usta, C.
Risko, L. Wang, A. Facchetti, M. A. Ratner and T. J. Marks, J. Am.
Chem. Soc., 2008, 130, 7670.
9 See for example: (a) J. C. Sanchez, S. A. Urbas, S. J. Toal, A. G.
DiPasquale, A. L. Rheingold and W. C. Trogler, Macromolecules, 2008,
41, 1237; (b) J. C. Sanchez, A. G. DiPasquale, A. L. Rheingold and W. C.
Trogler, Chem. Mater., 2007, 19, 6459; (c) S. J. Toal, J. C. Sanchez, R. E.
Dugan and W. C. Trogler, J. Forensic Sci., 2007, 52, 79.
10 (a) W. Zeng, Y. Cao, Y. Bai, Y. Wang, Y. Shi, M. Zhang, F. Wang, C.
Pan and P. Wang, Chem. Mater., 2010, 22, 1915; (b) J. Chen and Y.
Cao, Acc. Chem. Res., 2009, 42, 1709; (c) J. C. Byers, P. M. DiCarmine,
M. M. Abd Rabo Moustafa, X. Wang, B. L. Pagenkopf and O. A.
Semenikhin, J. Phys. Chem. B, 2009, 113, 15715; (d) L. Huo, H.-Y.
Chen, J. Hou, T. L. Chen and Y. Yang, Chem. Commun., 2009, 5570;
(e) P. M. DiCarmine, X. Wang, B. L. Pagenkopf and O. A. Semenikhin,
Electrochem. Commun., 2008, 10, 229; (f) J. Hou, H.-Y. Chen, S. Zhang,
G. Li and Y. Yang, J. Am. Chem. Soc., 2008, 130, 16144; (g) L. Liao, L.
Dai, A. Smith, M. Durstock, J. Lu, J. Ding and T. Tao, Macromolecules,
2007, 40, 9406; (h) B. Mi, Y. Dong, Z. Li, J. W. Y. Lam, M. Ha¨ubler,
H. H. Y. Sung, H. S. Kwok, Y. Dong, I. D. Williams, Y. Liu, Y. Luo, Z.
Shuai, D. Zhu and B. Zhong Tang, Chem. Commun., 2005, 3583.
11 (a) J. Dubac, A. Laporterie and G. Manuel, Chem. Rev., 1990, 90, 215;
(b) E. Colomer, R. J. P. Corriu and M. Lheureux, Chem. Rev., 1990,
90, 265; (c) B. Wrackmeyer, Coord. Chem. Rev., 1995, 145, 125; (d) J.
Dubac, C. Gue´rin, and P. Meunier, in The Chemistry of Organic Silicon
Compounds, ed. Z. Rappoport and Y. Apeloig, John Wiley & Sons,
New York, 1998, vol. 2 (pt. 3), ch. 34, p. 1961; (e) M. Hissler, P. W. Dyer
26 S. Yamaguchi, R.-Z. Jin and K. Tamao, J. Organomet. Chem., 1998,
559, 73.
27 G. T. Crisp and P. D. Turner, Tetrahedron, 2000, 56, 8335.
28 (a) A. Furlani, S. Licoccia, M. V. Russio, A. C. Villa and C. Guastini,
J. Chem. Soc., Dalton Trans., 1984, 2197; (b) I. Collamati and A.
Furlani, J. Organomet. Chem., 1969, 17, 457.
29 S. Yamaguchi and K. Tamao, J. Chem. Soc., Dalton Trans., 1998,
3693.
30 R. S. Becker, J. Sexias de Melo, A. L. Macanita and F. Elisei, J. Phys.
Chem., 1996, 100, 18683.
31 J. Ohshita, K. Kurushima, K.-H. Lee, A. Kunai, Y. Ooyama and Y.
Harima, Organometallics, 2007, 26, 6591.
32 T. L. Stott and M. O. Wolf, J. Phys. Chem. B, 2004, 108, 18815.
33 T. L. Stott, M. O. Wolf and B. O. Patrick, Inorg. Chem., 2005, 44, 620.
34 A. J. Boydston, Y. Yin and B. L. Pagenkopf, J. Am. Chem. Soc., 2004,
126, 10350.
35 M. Bonamico, G. Dessy, V. Fares, M. V. Russo and L. Scaramuzza,
Cryst. Struct. Commun., 1977, 6, 39.
36 T. L. Stott, M. O. Wolf and A. Lam, Dalton Trans., 2005, 652.
37 (a) L. Parkanyi, J. Organomet. Chem., 1981, 216, 9; (b) G. Yu, S. Yin,
Y. Liu, J. Chen, X. Zu, X. Sun, D. Ma, X. Zhan, Q. Peng, Z. Shuai,
B. Tang, D. Zhu, W. Gang and Y. Luo, J. Am. Chem. Soc., 2005, 127,
6335.
38 H. Son, W. Han, H. Kim, C. Kim, J. Ko, C. Lee and S. Kang,
Organometallics, 2006, 25, 766.
39 F. Wang, J. Luo, K. Yang, J. Chen, F. Huang and Y. Cao, Macro-
molecules, 2005, 38, 2253.
40 M. Herberhold, T. Schmalz, W. Milius and B. Wrackmeyer,
J. Organomet. Chem., 2002, 64, 1173.
41 Bruker Analytical X-Ray, Madison, WI, 2008.
42 G. M. Sheldrick, Bruker-SHELXTL, Acta Crystallogr., Sect. A: Found.
Crystallogr., 2008, 64, 112–122.
9328 | Dalton Trans., 2010, 39, 9321–9328
This journal is
The Royal Society of Chemistry 2010
©