Luminescent metallomesogens based on platinum complex containing triphenylene unit

Article abstract of DOI:10.1016/j.tet.2014.11.070

To explore the influence of mesogenic unit on the liquid crystals and luminescence properties of metal complex, two novel triphenylene-based platinum complexes of TppyPtacac and TppyPtPhacac featuring donor-acceptor framework have been designed and synthesized, in which Tppy is triphenylene-phenylpyridine skeleton and acac/Phacac is pentane-2,4-dione derivative. Differential scanning calorimetry (DSC), polarized optical microscopy (POM) and X-ray diffraction (XRD) techniques demonstrate the complex TppyPtPhacac shows a column mesophase in the region of 55-110 °C. Both platinum complexes exhibit intense emission at about 550 nm in CH₂Cl₂ solution. Compared to the analogous platinum complexes without triphenylene unit, TppyPtacac and TppyPtPhacac display a remarkable red-shifted emission profiles (ca. 50 nm) due to strong intramolecular charge transfer. Furthermore, the hole mobilities up to 2.5×10^-4 cm² V^-1 s^-1 and 2.99×10^-5 cm² V^-1 s^-1 are achieved for the annealed film of TppyPtacac and TppyPtPhacac, respectively, which is one of the highest hole mobility with respect to cyclometalated platinum complexes.

Full text of DOI:10.1016/j.tet.2014.11.070

Tetrahedron 71 (2015) 463e469
Contents lists available at ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Luminescent metallomesogens based on platinum complex
containing triphenylene unit
*
Junwei Shi, Yafei Wang , Manjun Xiao, Ping Zhong, Yu Liu, Hua Tan, Meixiang Zhu,
*
Weiguo Zhu
College of Chemistry, Key Lab of Environment-Friendly Chemistry and Application of the Ministry of Education, Xiangtan University, Xiangtan 411105,
China
a r t i c l e i n f o
a b s t r a c t
Article history:
To explore the influence of mesogenic unit on the liquid crystals and luminescence properties of metal
complex, two novel triphenylene-based platinum complexes of TppyPtacac and TppyPtPhacac featuring
donoreacceptor framework have been designed and synthesized, in which Tppy is triphenyleneephe-
nylpyridine skeleton and acac/Phacac is pentane-2,4-dione derivative. Differential scanning calorimetry
Received 20 October 2014
Accepted 28 November 2014
Available online 3 December 2014
(
DSC), polarized optical microscopy (POM) and X-ray diffraction (XRD) techniques demonstrate the
Keywords:
ꢀ
complex TppyPtPhacac shows a column mesophase in the region of 55e110 C. Both platinum complexes
exhibit intense emission at about 550 nm in CH Cl solution. Compared to the analogous platinum
2 2
complexes without triphenylene unit, TppyPtacac and TppyPtPhacac display a remarkable red-shifted
emission profiles (ca. 50 nm) due to strong intramolecular charge transfer. Furthermore, the hole mo-
Metallomesogens
Platinum complexes
Triphenylene
Donoreacceptor framework
Luminescence
ꢂ4
2
ꢂ1 ꢂ1
ꢂ5
2
ꢂ1 ꢂ1
bilities up to 2.5ꢁ10 cm
V
s
and 2.99ꢁ10 cm
V s are achieved for the annealed film of
TppyPtacac and TppyPtPhacac, respectively, which is one of the highest hole mobility with respect to
cyclometalated platinum complexes.
Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction
knowledge, most platinum-based luminescent metallomesogens
employed
nitrogen-containing
heteroaromatic
derivatives
Over the past two decades, luminescent liquid crystals (LC)
materials have attracted much attention as charming candidates for
organic optoelectronics devices, especially for polarized organic
light-emitting diodes (OLEDs) owing to the combination of the
optoelectronic characteristics of luminescent materials with the
(2-phenylpyridine/2-phenylpyrimidines) as the cyclometalated
ligands and acetylacetonate derivatives as the ancillary
14e20
ligands.
Tschierske and co-workers prepared a series of
platinum-based luminescent metallomesogens containing rod-like
2-phenylpyrimidines/2-phenylpyridines ligand. The effect of the
molecular structure on the mesogens (lamellar, nematic and co-
1
e3
unique properties of anisotropic fluids.
To date, numerous efforts
have been devoted to design luminescent LC materials based on
lumnar phase) and luminescence properties were systemically in-
small molecules,4 polymers
,5
6,7
and metal complexes.
8,9
Among
vestigated.
14,15
Subsequently, the functionalized bidentate and
these materials, the luminescent LC materials with metal ions (lu-
minescent metallomesogens) are a particularly enticing family due
to their outstanding optoelectrical and magnetic characteristics
combined with the properties of anisotropic fluids.
terdentate platinum complexes have received considerable atten-
tion in luminescent metallomesogens. Bruce et al. reported the
half-disc N,C,N-Pt(II) complexes possessing a column mesogen and
16
phase state-dependent emission spectra. The rod-like, ortho-
To this end, platinum complexes are one of the most attractive
candidates for luminescent metallomesogens due to the possibility
of nearly 100% internal quantum efficiency, square-planar geome-
try, strong intermolecular Pt/Pt interaction and diverse charge
transfer transition (e.g., metal-metal-to-ligand charge transfer,
platinated complexes bearing 2,5-diphenylpyrimidines and
b
-diketonate ligands showed a smectic phase and strong lumi-
17,18
nescence (
F
em>50%), reported by the same group.
Recently, we
also presented the luminescent metallomesogens based on
19,20
mononuclear and dinuclear platinum complexes.
Both of the
10e13
excimeric ligand-to-ligand charge transfer).
To the best of our
mono-/dinuclear platinum complexes possessed green emission in
the smectic phase. However, all of these platinum-based lumines-
cent metallomesogens are comprised of rigid cyclometalated ligand
and peripheral flexible chains. Few investigations in the platinum
*
Corresponding authors. Tel.: þ86 731 58293377; fax: þ86 731 58292251; e-mail
21
addresses: wangyf_miracle@hotmail.com (Y. Wang), zhuwg18@126.com (W. Zhu).
complex with a pendant mesogens unit have been explored.
http://dx.doi.org/10.1016/j.tet.2014.11.070
0
040-4020/Ó 2014 Elsevier Ltd. All rights reserved.

464
J. Shi et al. / Tetrahedron 71 (2015) 463e469
With this in mind, we focus our attention on the structur-
2.2. Liquid crystalline properties
eeproperty relationship in mesogenic unit and luminescent met-
allomesogens. Inspired by a wide application of triphenylene unit
The thermal stability of these platinum complexes was evalu-
ated by thermal gravity analysis (TGA). The decomposition tem-
peratures with 5% weight loss are observed at 162 C and 192 C for
TppyPtacac and TppyPtPhacac, respectively (Fig. S1). It is noted that
TppyPtPhacac exhibits a better thermal stability owing to the ad-
ditional phenyl units in the ancillary ligand.
21,22
in discotic liquid crystals and emission materials,
it could be
ꢀ
ꢀ
available to favour the liquid crystal and charge mobility by in-
troducing the triphenylene derivative into luminescent metal-
lomesogens. Furthermore, encouraged by our previous work on
19,20
platinum-based metallomesogens,
we designed and synthe-
sized two novel triphenylene-based platinum complexes featuring
donoreacceptor (DeA) framework, so-called TppyPtPhacac and
TppyPtacac, in which the Tppy is the triphenylene-phenylpyridine
skeleton and Phacac/acac is the pentane-2,4-dione derivative
On the other hand, the phase transition properties of TppyPtacac
and TppyPtPhacac were characterized by DSC and POM. As shown
in Fig. S2, only one endothermic peak at 152 C is observed between
ꢀ
the solid and isotropic phase while one exothermic transition at
ꢀ
(Chart 1). In these molecules, the triphenylene derivative acts as the
118 C is detected on the cooling circle. On contrary, the DSC curve
ꢀ
ꢀ
donor (D) unit while the platinum segment is considered as the
acceptor group (A). Both DeA platinum complexes are expected to
promote the mesogens and tuning the emission via intramolecular
interaction.
of TppyPtPhacac shows two endothermic peaks at 55 C and 110 C,
which are corresponding to the melting and clearing transitions.
Notably, the melting point decreases with the increasing number of
ꢀ
peripheral chains. However, only one peak at 50 C is detected for
TppyPtPhacac during the cooling scan, implying that an undetect-
21
able transition from isotropic to liquid crystal phase has occurred.
The POM study revealed that TppyPtacac presents a spherulitic
texture (Fig. 1a) and no fluidity upon cooling circle, indicating that
TppyPtacac could be a crystal. The complex of TppyPtPhacac ex-
hibits a birefringent texture along with good fluidity during heating
and cooling process. Even though no characteristic texture was
observed, a distinct colour change from yellow to green is observed
on heating process for TppyPtPhacac (Fig. 1b and c). According to
these results, complex TppyPtPhacac is tentatively proved to be
theomorphic LC property.
To further confirm the LC property, X-ray diffraction (XRD) was
carried out for both platinum complexes. As in the case of TppyP-
tacac, the XRD diffraction pattern reveals a crystal packing with
ꢀ
a disorder structure at 100 C (Fig. S3). For TppyPtPhacac, as shown
ꢀ
in Fig. 2, a distinct reflection peak at 17.9 A and one weak peak at
ꢀ
1/2
1
5.7 A, with a d-spacing ratio of 1/3 :2, are obtained, which
demonstrates it is a column LC phase. Additionally, a diffuse peak in
ꢀ
wide angle region (ca. 4.3 A) is assigned to the loose ordering of the
2
5,26
19
molten peripheral chains.
Compared to the previous work, it
Chart 1. Structural evolution of platinum-based metallomesogens.
is noted that the LC phase was changed from smectic to column via
introducing the triphenylene derivative into platinum complex.
Herein, the preparation, liquid crystal and optophysical prop-
erties of both platinum complexes are discussed in detail. Complex
TppyPtPhacac shows a column mesophase characterized by dif-
ferential scanning calorimetry (DSC), polarized optical microscopy
2
.3. Optophysical properties
The UVevis absorption and photoluminescent (PL) spectra of
(
POM) and X-ray diffraction (XRD) techniques. The hole mobilities
both platinum complexes were measured in CH
2
Cl
2
solution
ꢂ4
2
ꢂ1 ꢂ1
ꢂ5
2
ꢂ1 ꢂ1
up to 2.5ꢁ10 cm
V
s
and 2.99ꢁ10 cm
V s are ach-
ꢂ5
(10 M) and as a thin film at rt. As depicted in Fig. 3, similar ab-
ieved for the annealed film of TppyPtacac and TppyPtPhacac,
sorption spectra are observed for both platinum complexes in the
solution. The intense absorption bands in the region of
respectively.
1
263e350 nm are attributed to the ligand centred
(
pe
p
*
) transi-
2
7
tions. The weak absorption bands from 360 nm to 474 nm are
assigned to the metal-to-ligand charge transfer (MLCT) transition.
Compared to the reported platinum complexes, it implies that
introducing the triphenylene unit into cyclometalated ligand has
a strong effect on the absorption of platinum complexes.
2
2
. Results and discussion
19
.1. Synthesis
The synthetic routes of platinum complexes are shown in
Excitation with 450 nm at rt, both platinum complexes exhibit
a maximum emission peak at about 550 nm (ꢃ2 nm) and a shoul-
der at about 592 nm. Compared to the reported 2-phenylpyridine-
Scheme 1. The key precursor triphenylene derivative 5 was pre-
24
pared via a four-step reaction starting from pyrocatechol. Then,
2
0
19
compound 5 was reacted with 6 to give the cyclometalated ligand
via Suzuki Coupling reaction in a moderate yield of 54.9%.
based metallomesogens, TppyPtacac and TppyPtPhacac present
7
a red-shifted emission (ca. 50 nm) in solution owing to an effective
intramolecular charge transfer transition. The neat film of both
platinum complexes display a remarkable bathochromic shifts (ca.
70 nm) with a maximum peak located at about 620 nm due to the
Chloride-bridged dimer was obtained according to the previous
procedure and used to the next step without any further purifica-
19
tion. Finally, cleavage reaction between chloride-bridged dimer
2
0
21
and ancillary ligand (acac or 8 ) was carried out to afford the
platinum complexes in 41e50% yield. The cyclometalated ligand
formation of nonemission excimer or excimer-like adducts.
However, a monomer emission from TppyPtacac is observed in
the neat film, which implies that the TppyPtPhacac has a more
tendency to aggregation in the film.
1
13
and platinum complexes were characterized by H NMR, C NMR
TOF-MS and elemental analysis.

J. Shi et al. / Tetrahedron 71 (2015) 463e469
465
Scheme 1. The synthetic route of platinum complexes.
Fig. 1. POM (100ꢁ) images: (a) TppyPtacac at 120 ꢀC on cooling circle; (b) TppyPtPhacac at room temperature; (c) TppyPtPhacac at 70 C on heating circle.
ꢀ
To gain insight into the influence of morphologies on PL emis-
sion, the temperature-dependent PL spectra of TppyPtPhacac were
studied (Fig. 4a). A broad emission band at about 620 nm is pre-
sented. The emission peak and shape show a tiny change at dif-
ferent temperatures. It is noted that the emission intensity
Fig. 4b, a dramatic decrease in emission intensity is presented in the
crystal state, whereas the emission intensity displays the trend of
stability in liquid crystal phase due to the well-organized structure.
2.4. Hole mobilities
ꢀ
gradually decreases with increasing the temperature from 28 C to
ꢀ
7
0
C, which is attributed to the larger extent of self-quenching
Charge mobility plays a vital role in organic optoelectronic
materials. However, few investigations on the charge mobility of
platinum complexes have been explored. Herein, the hole
aggregates and increased thermally activated non-radioactive de-
2
6,28
cay processes with increased temperature.
As described in

466
J. Shi et al. / Tetrahedron 71 (2015) 463e469
mobilities of TppyPtacac and TppyPtPhacac were measured using
space charge limited current (SCLC) model. The pristine films of
TppyPtacac and TppyPtPhacac exhibit the hole mobilities of
ꢂ5
2
ꢂ1 ꢂ1
ꢂ6
2
ꢂ1 ꢂ1
1
.43ꢁ10 cm
V
s
and 3.12ꢁ10 cm
V s , respectively.
ꢀ
Upon thermal treatment at 100 C for 30 min, the hole mobilities of
ꢂ4
2
ꢂ1 ꢂ1
s and
TppyPtacac and TppyPtPhacac are 2.5ꢁ10
cm
V
ꢂ5
2
ꢂ1 ꢂ1
2
.99ꢁ10 cm V
s , respectively, which are higher than those of
2
3,29
analogous platinum complexes.
Moreover, the hole mobilities
of the annealed film are an order of magnitude higher than that of
the pristine film. To further evaluate the affect of morphology on
the hole mobility, the annealed film surface morphology of both
platinum complexes was investigated by atomic force microscopic
(
AFM, Fig. 5). The AFM images reveal that the annealed neat films of
TppyPtacac and TppyPtPhacac display small root-mean-square
rms) roughness of 1.45 nm and 0.50 nm, respectively. Obviously,
(
the smooth surface of annealed film is responsible for an improved
hole mobility.
ꢀ
Fig. 2. XRD pattern of complex TppyPtPhacac at 80 C.
3. Conclusions
Two novel DeA platinum-based luminescent metallomesogens
bearing triphenylene unit were prepared and characterized. The
TppyPtPhacac exhibited liquid crystal with column mesomorphism
characterized by DSC, POM and XRD. Both platinum complexes
revealed PL emission in the region of 500e600 nm. As expected,
integrating the triphenylene derivative linkage together in plati-
num complex plays a positive role in favour of the liquid crystals
property and effective intramolecular charge transfer. In addition,
ꢂ5
ꢂ4
hole mobilities with the order of 10 e10 were achieved for the
annealed films of platinum complexes. This research could provide
a novel strategy for design the luminescent metallomesogens with
DeA framework.
4
4
. Experimental
.1. Materials and instrumentation
All reagents were purchased from Aldrich, J&K Chemical and
Aladdin companies. All reactions were carried out under N
2
at-
mosphere. H NMR and C NMR spectra were acquired using
a Bruker Dex-400 NMR instrument using CDCl as a solvent. Mass
Fig. 3. Absorption spectra and PL spectra of platinum complexes in CH
film at room temperature.
2
Cl
2
and neat
1
13
3
spectra (MS) were recorded on a Bruker Autoflex MALDITOF in-
strument using dithranol as a matrix. The UVevis absorption and
photoluminescence spectra were measured with a Varian Cray 50
ꢀ
ꢀ
Fig. 4. (a) Temperature-dependence PL emission spectra of TppyPtPhacac complexes in thin film from 28 C to 70 C; (b) emission intensity of maximum wavelength versus
temperature for TppyPtPhacac.

J. Shi et al. / Tetrahedron 71 (2015) 463e469
467
4.3. 1,2-Bis(octyloxy)benzene (1)
A mixture of pyrocatechol (5.0 g, 45.5 mmol), 1-bromooctane
(18.5 g, 96.0 mmol), potassium carbonate (25.0 g, 181.2 mmol),
potassium iodide (0.5 g, 2.9 mmol) and tetrabutylammonium
bromide (0.53 g, 1.64 mmol) was dissolved in ethanol (130 mL) and
refluxed for 24 h under nitrogen atmosphere. After cooling to room
temperature (rt), the reaction mixture was filtered and the solvent
was removed by rotary evaporation. The residue was purified by
silica gel column chromatography using petroleum ether (PE) as
1
eluent to obtain oily liquid 1 (12.8 g, 84%). H NMR (CDCl
3
, 400 MHz,
TMS),
d
(ppm): 6.88 (s, 4H), 4.0 (t, J¼6.0 Hz, 4H), 1.84e1.77 (m, 4H),
1.46 (d, J¼4.0 Hz, 4H), 1.31e1.28 (m, 16H), 0.88 (t, J¼8.0 Hz, 6H).
4.4. 4-Bromine-1,2-bis(octyloxy)benzene (2)
To a stirred solution of compound 1 (1.0 g, 3.0 mmol) in THF
(
(
40 mL) was slowly added the mixture of N-bromosuccinimide
ꢀ
0.65 g, 3.7 mmol) and THF (10 mL) at 0 C. The reaction mixture
ꢀ
was stirred for 8 h at 0 C in dark. Then the solvent was removed by
rotary evaporation. The residue was purified by silica gel column
chromatography using PE as eluent to give a yellow solid 2 (0.94 g,
1
7
2
(
8.3%). H NMR (CDCl
3
, 400 MHz, TMS),
d
(ppm): 6.98 (d, J¼4.0 Hz,
H), 6.73 (s, 1H), 3.95 (t, J¼6.0 Hz, 4H), 1.82e1.77 (m, 4H), 1.30e1.28
m, 20H), 0.88e0.86 (m, 6H).
4.5. 2-(3,4-Bis(octyloxy)benzene)-4,4,5,5-tetramethyl-1,3,2-
dioxaborolane (3)
A mixture of compound 2 (4.0 g, 9.68 mmol), bis(pinacolato)
diboron (3,68 g, 15.4 mmol), potassium acetate (2.89 g, 29.0 mmol),
0
and [1,1 -bis(diphenyl-phosphino)ferrocene]dichloropalladium(II)
(
8
163 mg, 0.19 mmol) in 1,4-dioxane (120 mL) was reacted for 24 h at
ꢀ
0
C in nitrogen atmosphere. After cooling to rt, the reaction
Cl
3ꢁ30 mL). The combined organic layer was washed with water
3ꢁ50 mL) and dried with Na SO . The solvent was removed by
mixture was poured into water (50 mL) and extracted with CH
(
(
2
2
2
4
Fig. 5. AFM images of spin-coated films of (a) TppyPtacac, (b) TppyPtPhacac. The
scanning area is 5ꢁ5 m for all images.
rotary evaporation. Then, the crude product was purified by silica
gel column chromatography using PE/CH Cl (v/v, 5:1) as eluent to
give as oily solid 3 (2.13 g, 71%). H NMR (CDCl , 400 MHz, TMS),
(ppm): 7.39 (d, J¼4.0 Hz, 2H), 7.29 (s, 1H), 4.04e3.99 (m, 4H),
m
2
2
1
3
and PerkineElmer LS50B luminescence spectrometer, respectively.
d
ꢀ
ꢀ
TGA was carried out with an NETZSCH STA449 from 25 C to 600 C
1
.83e1.78 (m, 4H), 1.55e1.37 (m, 32H). 0.91e0.88 (m, 6H).
ꢀ
at a 20 C/min heating rate under N
2
atmosphere. Differential
scanning calorimetry (DSC) was measured the phase transition
4.6. 1,2-Bis(octyloxy)-4(bromophenyl)benzene (4)
ꢀ
temperature with a rate of 10 C/min heating rate under N
2
at-
mosphere. X-ray diffraction (XRD) with Cu
K
a
radiation
A mixture of compound 3 (5.0 g,10.8 mmol), 4-bromoiodobenzene
ꢀ
(
l
¼1.5418 A) was measured the liquid crystal structure, and the
(
0
4.6 g,16.3 mmol), tetrakis(triphenylphosphine)palladiun(0) (374 mg,
.324 mmol), and potassium carbonate (2 M, 20 mL) in THF (150 mL)
was refluxed for 24 h under N . Aftercoolingtort, the reactionmixture
was poured into water (50 mL) and extracted with CH Cl
(3ꢁ30 mL).
The combined organic layer was washed with water (3ꢁ50 mL) and
dried with Na SO . The solvent was removed by rotary evaporation
and the residue was purified by silica gel column chromatography
using PE/CH Cl (v/v, 10:1) as eluent to give as a white solid 4 (2.8 g,
53.8%). H NMR (CDCl , 400 MHz, TMS),
ꢀ
ꢀ
scans were performed in continuous mode from 1.5 to 35 (2
q
angle).
2
2
2
4
.2. Devices fabrication
2
4
The hole mobility was measured using the space charge limited
current (SCLC) model with devices configuration of ITO/
PEDOT:PSS (40 nm)/Active Layer (100 nm)/MoO (10 nm)/Ag
100 nm). The active layer is the pristine film (or annealed film at
a
2
2
1
3
3
d
(ppm): 7.52 (d, J¼8.36 Hz,
(
1
2H), 7.40 (d, J¼9.57 Hz, 2H), 7.07 (d, J¼6.69 Hz, 2H), 6.88 (s,1H), 4.03 (t,
J¼6.7 Hz, 4H), 1.85 (t, J¼6.89 Hz, 4H), 1.25e0.88 (m, 20H), 0.88e0.87
(m, 6H).
ꢀ
00 C for 30 min) of TppyPtacac and TppyPtPhacac. Indium tin
2
3
oxide (ITO) was cleaned with the general procedures.
The
PEDOT:PSS was spin-coated onto the ITO glass at 4000 rpm and
ꢀ
then baked at 160 C for 15 min in air. The active layer was spin-cast
4.7. 10-Bromine-2,3,6,7-tetra(octyloxy)-benzophenanthrene (5)
from chloroform (20 mg/mL) at 1000 rpm for TppyPtacac and
2
000 rpm for TppyPtPhacac. A MoO
3
and Ag cathode was then
To a stirred solution of compound 1 (1.4 g, 4.08 mmol) and
compound 4 (1.0 g, 2.04 mmol) in CH Cl (50 mL) was added
2 2
iron(III) chloride anhydrous (991 mg, 6.12 mmol). The reaction
mixture was stirred for 0.5 h at rt and quenched with methanol. The
2 2
mixture was poured into water (50 mL) was extracted with CH Cl .
ꢂ7
thermally evaporated under vacuum (w10
Torr) through
2
a shadow mask defining an active device area of w0.03 cm . The
hole mobilities were calculated according to the relative
literature.23

468
J. Shi et al. / Tetrahedron 71 (2015) 463e469
The combined organic layer was washed with water and dried with
Na SO . Then, the solvent was removed by rotary evaporator and
the residue was purified by silica gel column chromatography using
PE/CH Cl (v/v, 10:3) as eluent to give compound 5 as a solid
730 mg, 43.5%). H NMR (CDCl
4.10. Synthesis of the complex TppyPtPhacac
2
4
Complex TppyPtPhacac was prepared similarly to complexes
TppyPtacac, using di-m-chloro dimer (312 mg, 0.123 mmol), com-
pound 8 (180 mg, 0.308 mmol), sodium carbonate (130 mg,
2
2
1
(
3
, 400 MHz, TMS),
d
(ppm): 8.56 (s,
1
1
0
H), 8.31 (d, J¼8.68 Hz, 1H), 7.93e7.81 (m, 4H), 7.64 (d, J¼8.64 Hz,
H), 4.24 (t, J¼6.4 Hz, 8H), 1.94e1.88 (m, 8H), 1.40e1.31 (m, 40H),
.88e0.90 (m, 12H).
1.23 mmol) and dry 2-ethoxyethanol (20 mL). TppyPtPhacac was
1
obtained as a yellow solid (90 mg, yield 37.6%). H NMR (CDCl
3
,
400 MHz, TMS),
d
(ppm): 9.25 (s, 1H), 8.95 (s, 1H), 8.61 (d, J¼4.3 Hz,
1
H), 8.37 (s, 1H), 8.17 (d, J¼4.59 Hz, 3H), 8.11 (d, J¼4.40 Hz, 2H),
7
.96e7.82 (m, 5H), 7.73 (d, J¼8.0 Hz, 1H), 7.64 (d, J¼8.1 Hz 1H), 7.61
4
5
.8. 2-(4-(2,3,6,7-Tetraoctyloxybenzophenanthrene)phenyl)-
-((octyloxy)methyl)pyridine (7)
(
(
d, J¼7.8 Hz,1H), 7.01 (d, J¼4.34 Hz, 2H), 6.82 (t, J¼8.75 Hz, 2H), 6.79
s, 1H), 4.66 (s, 2H), 4.33e4.26 (s, 6H), 4.06 (t, J¼6.4 Hz, 2H), 3.9 (t,
J¼2.96 Hz, 2H), 3.80 (t, J¼3.0 Hz, 2H), 3.63 (t, J¼6.5 Hz, 2H), 2.0 (t,
J¼3.45 Hz, 7H), 1.86 (t, J¼3.4 Hz, 3H). 1.74 (t, J¼3.42 Hz, 8H),
A mixture of compound 5 (678 mg, 0.827 mmol), compound 6
(
(
350 mg, 0.827 mmol), tetrakis(triphenylphosphine)palladiun(0)
38 mg, 0.033 mmol) and caesium carbonate (2 M, 10 mL) in tolu-
13
3
1.36e1.14 (m, 82H), 0.94e0.90 (m, 21H). C NMR (100 MHz, CDCl ),
d
(ppm): 14.09, 22.71, 26.23, 26.26, 26.27, 26.29, 29.31, 29.38, 29.47,
ꢀ
ene (40 mL) was heated to 80 C for 24 h in N
2
atmosphere. After
2
6
9.53, 29.60, 29.68, 29.72, 31.84, 31.87, 31.90, 31.95, 67.85, 68.18,
9.16, 69.57, 69.79, 69.88, 71.28, 95.27, 106.76, 107.07, 114.29, 121.63,
cooling to rt, the reaction mixture was poured into water (50 mL)
and extracted with CH Cl . The combined organic layer was washed
with water and dried with Na SO . Then, the solvent was removed
by rotary evaporator. The residue was purified by silica gel column
chromatography using CH Cl /PE (v/v, 10:1) as eluent to give
a yellow solid 10 (470 mg, 54.9%). H NMR (CDCl
(ppm): 8.68 (s, 1H), 8.55 (d, J¼8.70 Hz, 2H), 8.21 (s, 1H), 8.20e8.03
m, 4H),8.10 (d, J¼8.03 Hz, 2H), 7.90 (d, J¼7.8 Hz, 2H), 7.80 (s, 2H),
.58 (s, 2H), 4.25 (t, J¼6.31 Hz, 8H), 3.53 (t, J¼6.56 Hz, 2H), 1.95 (t,
2
2
123.31, 124.22, 124.27, 124.38, 125.40, 128.18, 128.70, 128.82, 129.42,
2
4
1
32.99, 126.87, 139.62, 146.20, 149.43, 149.58, 149.70, 161.45, 167.04,
þ
178.62. MALDI-MS (m/z): 1821.315 for [M ]. Anal. Calcd for
2
2
109 9
C H159NO Pt: C, 71.83; H, 8.79; N, 0.77. Found: C, 71.79; H, 8.83; N,
1
3
, 400 MHz, TMS),
0.72.
d
(
4
Acknowledgements
13
J¼6.60 Hz, 8H), 1.41e1.25 (m, 52H), 0.90e0.88 (m, 15H). C NMR
100 MHz, CDCl3), (ppm): 14.06, 22.65, 26.21, 29.34, 29.54, 31.84,
9.54, 69.73, 69.81, 70.12, 70.99, 107.45, 107.63, 120.29, 121.34,
23.54, 123.80, 124.39, 124.64, 125.03, 127.47, 127.77, 128.38, 129.27,
32.86, 136.68, 137.97, 142.25, 148.69, 149.27, 149.79, 149.87, 156.09.
Financial support from the National Natural Science Foundation
of China (21202139, 51273168 and 21172187), the Innovation Group
in Hunan Natural Science Foundation (12JJ7002), The Scientific
Research Fund of Hunan Provincial Education Department
(12B123), Natural Science Foundation of Hunan (12JJ4019,
(
6
1
1
d
þ
MALDI-MS (m/z): 1035.735 for [M ].
11JJ3061).
4
.9. Synthesis of the complex TppyPtacac
Supplementary data
To a mixture of K PtCl
mL) was added a solution of compound 10 (100 mg,
2
4
(18.2 mg, 0.044 mmol) and water
Supplementary data associated with this article can be found in
the online version, at http://dx.doi.org/10.1016/j.tet.2014.11.070.
(
3
0
.096 mmol) in chloroform (8 mL) and 2-ethoxyethanol (3 mL).
ꢀ
The reaction mixture was heated to 80 C for 24 h in N
2
atmo-
References and notes
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/
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3