Phosphole-based π-conjugated electroluminescent materials for OLEDs

Article abstract of DOI:10.1039/c0nj00122h

Novel mixed phosphole-fluorene π-conjugated systems have been prepared using the Fagan-Nugent route. Their optical (UV-visible absorption, fluorescence spectra) and electrochemical properties have been systematically evaluated. The variation of the substitution pattern of phosphole derivatives and chemical modification of their P atoms afford thermally stable derivatives which are photoluminescent. The use of these derivatives as emitters in OLEDs strongly depends on the substituent linked on the P-atom. The gold complexes are not stable electroluminescent materials since they decompose rapidly when the devices are operating. In contrast, the thiooxophospholes are stable electroluminescent materials, and the OLEDs incorporating these derivatives as emitters display very high performances.

Full text of DOI:10.1039/c0nj00122h

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PAPER
www.rsc.org/njc | New Journal of Chemistry
Phosphole-based p-conjugated electroluminescent materials for OLEDswz
a
b
a
b
´
Damien Joly, Denis Tondelier, Valerie Deborde, Bernard Geffroy,*
a
a
´ ´
Muriel Hissler* and Regis Reau*
Received (in Montpellier, France) 15th February 2010, Accepted 18th March 2010
DOI: 10.1039/c0nj00122h
Novel mixed phosphole–fluorene p-conjugated systems have been prepared using the
Fagan–Nugent route. Their optical (UV-visible absorption, fluorescence spectra) and
electrochemical properties have been systematically evaluated. The variation of the
substitution pattern of phosphole derivatives and chemical modification of their P atoms
afford thermally stable derivatives which are photoluminescent. The use of these derivatives
as emitters in OLEDs strongly depends on the substituent linked on the P-atom. The gold
complexes are not stable electroluminescent materials since they decompose rapidly when
the devices are operating. In contrast, the thiooxophospholes are stable electroluminescent
materials, and the OLEDs incorporating these derivatives as emitters display very high
performances.
the optical and the electrochemical properties of phosphole-
Introduction
based conjugated oligomers and polymers was conducted with
2,5-diarylphosphole derivatives A (Fig. 1).5 A variety of other
small molecules, including for example linear oligo(phosphole)
The synthesis of new p-conjugated materials with specific
electronic and photophysical properties continues to attract
considerable attention due to their use as materials for
opto-electronic applications such as organic light-emitting
diodes (OLEDs) or photovoltaic cells.1 With this aim, various
heterocyclopentadienes (thiophene, pyrrole, silole, etc.) have
been incorporated into the backbone of p-conjugated systems,
since their electronic properties are dependent on the nature of
the heteroatom.1b,2,3 In the last decade, phospholes have
emerged as appealing building blocks for the tailoring of
p-conjugated systems, since they display electronic properties
that are markedly different from those of the widely used
highly aromatic thiophene and pyrrole rings.3 The key
property of these P-rings for the molecular engineering of
p-conjugated systems is the presence of a reactive phosphorus
centre due to the low aromatic character of this P-heterole. In
fact, delocalization within the phosphole ring arises from a
hyperconjugation involving the exocyclic P–R s-bond and the
p-system of the dienic moiety, leading to s–p hyperconjugation
phenomenon.4 This specific feature allows straightforward
access to a wide range of novel derivatives with diverse
optical and electrochemical properties by simple P-chemical
modifications. This property of the phosphole ring has been
fully exploited by several groups for the tailoring of
p-conjugated systems. The first systematic investigation of
B
1,2,6 mixed phosphole–thiophene oligomers C7 or dendritric
structures D,8 have been studied by different groups (Fig. 1).
Well-defined emissive linear p-conjugated polymers
E
(Fig. 1) incorporating phosphole rings have also been recently
reported.9 Ring-fused p-systems incorporating phosphorus
atoms (benzophospholes, dithienophospholes) are not strictly
speaking ‘‘phosphole’’ derivatives, since the fused benzene or
the thiophene ring remain aromatic to the detriment of the
phosphole cycle. These compounds have to be regarded as
P-bridged bi(p-systems). However, it is worth noting that
these rigid derivatives are generally highly emissive, as
illustrated with bisphosphoryl-bridge stilbenes F,10 dithieno-
[b,d]phosphole-based compounds G11 or bithiophene-fused
benzo[c]phospholes H3a,12 (Fig. 1). As observed for related
a
´
Sciences Chimiques de Rennes, UMR 6226 CNRS-Universite de
Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex, France.
E-mail: rreau@univ-rennes1.fr, mhissler@univ-rennes1.fr;
Fax: +33 (0)2 23 23 69 39; Tel: +33 (0)2 23 23 57 83
b CEA/LITEN & LPICM, Ecole Polytechnique, 91128 Palaiseau,
France
w A Pascal. This article is part of a themed issue on Main Group
chemistry.
z Electronic supplementary information (ESI) available: Other experi-
mental details concerning the new compounds and their related
diodes. CCDC reference number 765609. For ESI and crystallographic
data in CIF or other electronic format see DOI: 10.1039/c0nj00122h
Fig. 1 Representative examples of P-based p-conjugated systems
based on phospholes (A–E) and fused phospholes (F–J).
ꢀc
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phosphole-containing materials, their optical and electro-
chemical properties can be properly tuned by P-chemical
modifications.
The study of the derivatives depicted in Fig. 1 has enabled a
deep understanding of the fundamental structure–property
relationships of phosphole-based p-conjugated systems.
The next challenge is clearly to exploit these novel organic
materials for the fabrication of optoelectronic devices.
Basically, almost all the described P-containing oligomers or
polymers (Fig. 1) are potentially suitable materials for OLED
applications since (i) they are fluorescent, (ii) their redox
potentials are low enough to allow charges to be injected,
and (iii) they are thermally stable enough to envisage deposition
via sublimation. However, there is a gap between having a
material exhibiting the expected properties to be used
in OLEDs and having a material that can effectively be
used in a device. This is due to the fact that light-emission in
OLEDs is a consequence of radiative decay of excitons
generated by the combination of electrons and holes injection
from both electrodes.13 Therefore, a material has to satisfy a
large number of technical requirements to be really efficient
as an electroluminescent layer in OLEDs. For example,
the conjugated material has (i) to give pinhole free homo-
geneous layer via vacuum deposition or spin coating, (ii) to
be stable under an electric field, (iii) to undergo balanced
charge carrier injection from both electrodes, (iv) to exhibit
comparable charge-transporting properties of both electrons
and holes to favor exciton formation, and (v) to keep its
emission behavior in the solid state.13 Indeed, a compound
with high quantum yields and reversible redox processes in
solution can be an inefficient material for optoelectronic
applications.
Scheme 1 Synthesis of mixed fluorene–phosphole derivatives.
Synthesis and characterization of mixed
fluorene–phosphole derivatives
We have investigated the Fagan–Nugent method,17 which is a
versatile route to 2,5-diarylphospholes A (Fig. 1), for the
preparation of the target mixed linear fluorene–phosphole
derivatives. The diynes 1a,b were obtained in medium yields
(ca. 80–60%) via Sonogashira coupling of 9,90-dimethyl-2-
bromofluorene with 1-phenyl-octa-1,7-diyne or octa-1,7-diyne,
respectively (Scheme 1). Their treatment with ‘‘zirconocene’’,
generated in situ from Cp2ZrCl2 and BuLi (2 equiv.), followed
by addition of PhPBr2, afforded the target mixed fluorene–
phospholes 2a,b (Scheme 1). These compounds give usual
31P{1H} NMR spectrum (d (CD2Cl2): 2a, +11.5; 2b,
+12.4).4,5 They were not isolated since s3,l3-phosphole
derivatives are generally not thermally stable enough to be
used as materials for OLEDs.5e
Up to now, applications to organic semiconductor devices
of P-based materials have remained underdeveloped. It has
been recently shown that benzophosphole sulfide I14 (Fig. 1) is
an efficient electron-transporting material in OLED, and
that copolymers J15 (Fig. 1) incorporating dibenzophosphole
subunits are solution-processable materials for single-layer
OLEDs. Beside these examples involving fused-derivatives,
only phosphole-based oligomers A (Fig. 1) have proven
to be suitable electroluminescent materials for OLEDs.5b,e
They have been used in single-layer devices, showing that
they can act both as emissive and charge-transporting
materials, and also as dopants for the fabrication of efficient
white-emitting OLEDs.5b,e,16 Therefore, there is still a need
to really show that phosphole-based p-conjugated systems can
satisfy all the diverse criteria to be suitable materials
for OLEDs.
Phospholes 2a,b were transformed into gold complexes 3a,b
and thiooxophospholes 4a,b by treatment with (tetrahydro-
thiophene)AuCl and elemental sulfur, respectively (Scheme 1).5a,e
They were readily purified by column chromatography and
isolated as air-stable compounds in good yields (60%–70%,
Table 1). They exhibit expected NMR data, and their structures
were supported by high-resolution mass spectrometry and
elemental analysis. The structure of the gold complex 3b was
determined unambiguously by X-ray crystallography (Fig. 2).
The metric data of the phosphole–AuCl subunit compare well
with those of other related complexes.5e,11c For example, the
phosphorus center adopts a distorted tetrahedral geometry
(Table 1) with typical P–Au (2.2287(15) A) and P–C (1.815(6)
A–1.824(7) A) bond lengths (Table 2). The metal atom
displays an almost linear geometry (P–Au–Cl, 175.241). The
angles between the central P-ring and the two fluorenyl
substituents are relatively high (56.61 and 56.01). These twist
angles are comparable (43.51 and 54.51) to those observed for
the 2,5-biphenylphosphole complex RAuCl (Scheme 1).5e The
shortest distance between two Au-centers is 7.90 A, indicating
In this paper, we describe the synthesis and elucidation of
electronic properties following experimental results (UV-vis
spectroscopy, electrochemical behavior) of novel mixed
phosphole–fluorene p-conjugated systems (Scheme 1). Multi-
layer OLEDs based on these materials will be described. A
comparative study on the influence of the substitution pattern
of the 2,5-substituent (fluorenyl versus phenyl) and of the
phosphorus atom (sulfur versus gold) on their electronic
property and OLED performances is provided. OLEDs
exhibiting the highest external quantum efficiency values ever
reached for P-based materials are reported.
ꢀc
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Fig. 2 Molecular structure of phospholes 3b in the solid state and a perspective view of the packing of gold complex 3b in the crystalline phase.
H atoms are omitted for clarity.
the absence of aurophilic interactions. The intermolecular
solid-state organization of the molecule 3b shows several
intermolecular interactions. Firstly, two P-phenyl rings of
neighboring molecules p-stacked (3.7 A) with a parallel-
displaced arrangement (Fig. 2). Secondly, T-shape CHꢁ ꢁ ꢁp
interactions (ca. 2.95 A) take place between fluorenyl
substituents (Fig. 2).
Table 2 Selected bond lengths (A) and twist angles (1) between the
phosphole ring and its 2- and 5-substituents for the gold complex 3b
Bond length
Angle
P–(C1)
1.824(7)
1.351(8)
1.472(9)
1.369(9)
1.815(6)
2.2287(15)
2.2934(15)
56.6/56.0
(C1)–P–(C8)
(C1)–P–(C39)
C(1)–P–Au
(C8)–P–(C39)
C(8)–P–Au
C(39)–P–Au
P–Au–Cl
93.2(3)
(C1)–C2)
(C2)–(C7)
(C7)–(C8)
(C8)–P
P–Au
Au–Cl
Twist angles
108.6(3)
117.9(2)
106.6(3)
118.11(19)
110.8(2)
175.27(5)
Optical and electrochemical studies
To get an insight into the substitution effect on the optical
properties of these novel phosphole-based conjugated systems,
their UV-vis absorption and fluorescence spectra were measured
in CH2Cl2. All phosphole derivatives exhibit an intense
absorption band in the UV-visible region attributed to the
p–p* transitions of the conjugated system.5 The values of lmax
and the optical end absorption lonset (the solution optical
‘‘HOMO–LUMO’’ gap) become red-shifted on replacing one
or two phenyl groups by fluorenyl substituents (Table 1).
These data show an effective p-extension in the present
phosphole–fluorene hybrids. It is worth noting that the values
of lmax and lem recorded for 3b,4b are considerably more
red-shifted than that of the related tert-fluorene (lmax = 348 nm,
lem = 394, 415 nm).19 This observation is in agreement with
theoretical studies predicting that heterocyclopentadienes with
a low aromatic character are optimal building blocks for the
synthesis of extended p-conjugated systems with a low HOMO–
LUMO gap.2e,3f–h,4c,d As observed with 2,5-diphenylphosphole
derivatives RAuCl, RS (Scheme 1), the nature of the P-substituent
(sulfur atom or AuCl fragment) has little impact on the
maximum of absorption (3a/4a, 3b/4b, Table 1). s4-Phospholes
3a,b and 4a,b are fluorophores with broad emissions and their
emission maxima depend mainly on the nature of the
2,5-substituents. A yellow–green emission is observed for the
2,5-di(9,90-dimethylfluorenyl)phospholes 3b,4b (lem
560–565 nm), whereas the emission of 2-(9,90-dimethylfluor-
enyl)-5-(phenyl)phospholes 3a,4a are blue-shifted (Dlem
=
=
40 nm) (Table 1, Fig. 3). The Stokes shifts of the mono-
(fluorenyl)phospholes 3a,4a (ca. 7578 cmꢂ1) are smaller than
those of the bis(fluorenyl)phospholes 3b,4b (ca. 7850 cmꢂ1
)
(Table 1). These Stokes shifts are relatively important (Fig. 3,
Table 1), suggesting an important rearrangement of these
molecules upon photoexcitation. Remarkably, the nature of
Table 1 Optical and electrochemical data for derivatives 3a,b, 4a,b and reference compounds RAuCl/RS
a
b
b
c
e
f
g
g
d
31P{1H}/ppm
Yield/%
labs/nm
lonset/nm
e
max/Mꢂ1 cmꢂ1
lem/nm
ff ꢃ 100d
lem/nm
Ff ꢃ 100 Epa/V
Epc/V
3a
3b
4a
4b
RAuCl
RS
41.0
41.2
54.0
54.9
41.7
55.3
70
70
60
64
77
87
373
387
373
392
358
380
447
460
450
470
413
440
11 700
18 200
15 000
11 600
6300
520
560
520
565
506
516
3
518
550
520
552
12
26
13
40
+0.97h ꢂ2.05
+0.87h ꢂ2.08
+0.88 ꢂ2.10h
+0.82 ꢂ2.06h
+1.45 ꢂ2.14
+1.12 ꢂ2.08h
70
0.7
3
7.3
0.05
5e
505/630 11.2
517 0.5
5e
13 500
a
b
c
d
Measured in CD2Cl2. Measured in CH2Cl2 (5 ꢃ 10ꢂ5 M). Measured in CH2Cl2 (5 ꢃ 10ꢂ6 M). Measured relative to quinine sulfate (H2SO4,
0.1 M). In neat film. Measured in integrating sphere.18 g All potentials were obtained during cyclic voltametric investigations in 0.2 M
e
f
Bu4NPF6 in CH2Cl2. Platinum electrode diameter 1 mm, sweep rate: 200 mV sꢂ1. All reported potentials are referenced to the reversible formal
h
potential of the ferrocene/ferrocenium couple. Reversible process.
ꢀc
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derivative 4b exhibits the highest PL quantum efficiency in thin
films (Table 1).
In order to estimate the electrochemical properties of these
novel phosphole-based conjugated systems, their redox
potentials were determined by cyclic voltammetry (CV). The
measurement conditions are summarized in the caption of
Table 1. The gold complexes and sulfur derivatives exhibit
very different electrochemical behaviour. Reversible oxidation
processes take place for the gold complexes 3a,b only, whereas
reversible reduction processes are recorded for the thio-
oxophospholes 4a,b only. These data illustrate the dramatic
impact of the nature of the P-chemical modification on the
electrochemical properties of phosphole-based p-conjugated
systems. Replacing the phenyl rings by fluorenyl substituents
at the 2,5-positions of the phosphole ring does not affect the
reduction potentials but results in a shift of the oxidation
potentials to the negative direction (RAuCl/3a/4a and RS/3b/4b
series, Table 1). In line with the conclusions drawn from the
UV-vis measurement (vide supra) these electrochemical data
indicate that the HOMO–LUMO gaps of 3b,4b (3b,
DE = 2.65 V; 4b, DE = 2.64 V) are smaller than those of
3a,4a (3a, DE = 2.73 V; 4a, DE = 2.79 V) and RAuCl/RS
(RAuCl, DE = 3.0 V; RS, DE = 2.98 V).
Fig. 3 Absorption spectra and emission spectra of RAuCl (dotted
line), 3a (dashed line), 3b (continous line) in CH2Cl2.
the P-chemical modification (S/AuCl) has a deep impact on
their photoluminescence (PL) quantum yield.
The quantum yields (Ff) of the gold complexes are higher
than those of the corresponding sulfur derivatives (3a/4a,
3b/4b, Table 1). In fact the thioxophosphole 4a is only weakly
fluorescent (Ff = 0.7%), whereas the emission efficiency of
complex 3b (Ff = 70%) is the highest ever recorded for a
non-rigidified (i.e. ‘‘non-fused phospholes’’, Fig. 1) phosphole
derivative. These data recorded in solution suggest that the
gold complexes 3a,b are the most promising materials for the
fabrication of OLEDs among the newly prepared mixed
phosphole–fluorene derivatives (Scheme 1).
OLEDs based on electroluminescent mixed
fluorene–phosphole derivatives
Following the study of their optical and electrochemical
properties, phosphole derivatives 3a,b and 4a,b (Scheme 1)
were investigated as organic materials in OLEDs having an tin
indium oxide (ITO) anode and an aluminium cathode (Fig. 4,
left). The HOMO and LUMO energies for 3a,b and 4a,b,
estimated from the redox data using a SCE energy level of
4.4 V relative to vacuum,5e,21 showed rather large barriers for
electron injection for phosphole-based materials (Fc (4.10) ꢂ
EA E 1.3–1.1 eV). The barriers for hole injection are lower
(Fa (5.10) ꢂ IP E 0.4–0.6 eV), indicating an unbalanced
carrier injection. Therefore, it was necessary to employ a
multilayer OLED structure in order to reduce barriers for
carrier injection. For such purpose, a series of electron- (Alq3/
BCP/DPVBi) and hole- (CuPc/a-NPB) transport materials
were used (Fig. 4, right; Fig. 5). BCP also acts as a
hole-blocking layer to avoid emission from Alq3. Indeed,
the investigated OLEDs I–VI (Table 3) have an (ITO)/
CuPc(10 nm)/a-NPB(50 nm)/organic layer(15 nm)/DPVBi
(35 nm)/BCP(10 nm)/Alq3(10 nm)/LiF(1.2 nm)/Al(100 nm)
configuration (Fig. 4 and 5).
The gold complexes 3a,b and the thiooxophospholes 4a,b
are thermally stable enough to give thin films upon vacuum
sublimation. The absorption and emission spectra recorded in
thin films are essentially comparable to those obtained in
CH2Cl2 solution (Table 1, Fig. 3). It is noteworthy that the
gold complexes 3a,b display one single emission band only in
the solid state. This behavior is different from that of the
corresponding complex RAuCl that exhibit dual emission in
thin film arising from aggregate formation due to p–p stacking
and/or Au–Au interactions. It is very likely that the bulkiness
of the fluorene substituents of complexes 3a,b, and especially
the presence of two methyl groups at the 9,90-positions,
prevents the formation of strong aggregates in the solid state.
The solid-state PL quantum efficiencies were measured with a
calibrated integration sphere system.18 They vary from 12%
(3a) to 46% (4b) and are notably higher than those of their
corresponding all phenyl analogues RAuCl, RS (Table 1). Note
that the quantum efficiencies are higher in thin film than in
dilute solution except for 3b (Table 1). This behavior is quite
rare, because organic fluorophores are generally less emissive
in the solid state than in solution due to the formation of less
emissive aggregates such as excimers. However, this behavior,
which has already been observed for other silole- and phosphole-
based p-conjugated systems, is probably due to the steric
protection provided by the tetrahedral Si- or P-centers, which
precludes the p-stacking of these heavy heteroatom-based
chromophores.8,20 The most important piece of information
is that all newly prepared derivatives display good photo-
luminescence efficiency in the solid state and thus appear to be
good candidates as materials for OLEDs. Note that, in
contrast to what is observed in solution, the thiooxophosphole
The electroluminescence (EL) spectra of the devices resemble
the solution and thin-film PL of the mixed fluorene–phosphole
derivatives, showing that the EL emission bands are from
these P-luminophores. As expected from the thin film study,
no low-energy emission arising from excimers is observed. The
turn-on voltages required to obtain EL with the gold
complexes 3a,b are relatively high (10.0–11.3 V). The brightness
and maximum external quantum efficiency (EQE, Z) are
superior to those recorded using the reference complex RAuCl
(Devices I,II/V, Table 3). However, these performances are
very modest compared to the state of the art. For example,
EQEs of 2–4% can be attained with fluorescent materials
ꢀc
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Fig. 4 Structure of the multi-layer OLEDs using fluorene–phosphole
derivatives as emissive layer (EML) and energy level HOMO and
LUMO diagram.
Fig. 6 Emission spectra of the diode II depending on applied current.
Fig. 7 Luminance–current density characteristics of the diodes III
(K) and IV (’).
Fig. 5 Chemical structures of the OLED components.
Moreover, the brightness of these OLEDs increases linearly
with the current density, showing the operational stability of
these devices (Fig. 7). The relatively high value of brightness
reached with bis(fluorene)phosphole derivative 4b (device IV,
Table 3) is noteworthy. This device is the most efficient OLED
based on phosphole-based EL materials reported to date. The
EQE and power efficiency are good for such a simple device
structure and compare well with those recorded with other
optimized emissive materials. This result is of particular
interest to show that phospholes are useful synthons for the
tailoring of EL materials.
(5% is generally accepted as the upper value that can be
reached using electrofluorescent materials). Furthermore, the
lifetime of these devices is extremely short. After few seconds,
a new red-shifted emission is observed. The intensity of this
band increases much faster than the original emission of the
gold complex (Fig. 6), modifying strongly the emission of
diode. It is very likely that this behavior is due to a fast
decomposition of the phosphole gold complexes when an
electric field is applied. Indeed, although complexes 3a,b
display high PL efficiency both in solution and thin film
(Table 1), they appear not to be valuable EL materials for
the fabrication of OLEDs.
The devices III and IV fabricated with the thioxophosphole
derivatives 4a,b (Table 3) exhibit improved performances. The
operating voltages are quite low (4.3–6.3 V) and the brightness
is much higher than those observed with the gold complexes
(Table 3). As observed for the optical properties in solution
Conclusions
In conclusion, we have prepared a novel series of phosphole-
based p-conjugated systems bearing fluorenyl substituents.
Their electronic properties have been studied both in solution
and in the solid state. These new P-derivatives have been used
as electroluminescent materials in OLEDs. The gold complexes,
and in thin films, the nature of 2,5-substituents modifies the
EL
l
and the CIE coordinates (Table 1 and 2) of the OLED.
max
Table 3 EL performance of the multi-layer OLED devices incorporating fluorine–phosphole derivative as emissive layer (se Fig. 4)
CIE coordinates
b
a
b
b
ꢂ1 b
Power efficiency/lm W20
lEmLax/nm
Von/V
V20/V
B20/cd mꢂ2 b
Z20/%
x
y
Diode
Sample
c
I
3a
3b
4a
4b
RAuCl
RS
660
730
524
560
637
567
10.0
11.3
6.3
4.3
9.0
16.9
16.5
11.7
10.7
12.0
9.2
16.8
4.9
167
1000
0.5
0.1
0.1
0.3
1.8
0.04
0.05
0.02
0.01
0.49
0.42
0.31
0.43
—
0.37
0.41
0.48
0.53
—
c
II
III
IV
V
VI
c
0.2
1.4
c
7.5 ꢃ 10ꢂ3
d
d
3.2
26.6
0.05
—
—
a
b
c
Turn-on voltage at which emission becomes detectable (0.1 cd mꢂ2). Mesured at 20 mA cmꢂ2
.
Device configurations (thickness): (ITO)/
d
CuPc(10 nm)/a-NPB(50 nm)/organic layer(15 nm)/DPVBi(35 nm)/BCP(10 nm)/Alq3(10 nm)/LiF(1.2 nm)/Al(100 nm). Device configurations
(thickness): ITO/PEDOT:PSS(25 nm)/organic layer(20 nm)/Mg:Ag(80 nm)/Ag(150 nm).5e
ꢀc
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although they display high fluorescence efficiency, are not
interesting materials since they decompose rapidly when the
devices are operating. In contrast, thiooxophospholes are
stable electroluminescent materials, and the performance of
the OLED IV fabricated with the bis(fluorenyl)phosphole
derivative 4b is the best ever reported for devices using EL
phosphorus-based materials.
5016A, 150 mesh, 58 A) or silica gel (Merck Geduran 60,
0.063–0.200 mm) in 3.5–20 cm columns. 1H, 13C, and
31P NMR spectra were recorded on Bruker AM300 or
1
DPX200. H and 13C NMR chemical shifts were reported in
parts per million (ppm) relative to Si(CH3)4 as external
standard. 31P NMR downfield chemical shifts were expressed
with a positive sign, in ppm, relative to external 85% H3PO4.
Assignment of proton atoms is based on COSY experiment.
Assignment of carbon atoms is based on HMBC, HMQC and
DEPT-135 experiments. High-resolution mass spectra were
obtained on a Varian MAT 311, Waters Q-TOF 2 or a
ZabSpec TOF Micromass instrument at CRMPO, University
of Rennes 1. Elemental analyses were performed by the
CRMPO, University of Rennes 1.
Experimental section
General
Details of the X-ray crystallography study. Single crystals
suitable for X-ray crystal analysis were obtained by slow
evaporation of a dichloromethane solution of 3b. Single-
crystal data collection were performed at 100 K with an APEX
Determination of optical data. UV-Visible spectra were
recorded at room temperature on a UVIKON 942 spectro-
photometer and luminescence spectra were recorded in freshly
distilled solvents at room temperature with a PTI spectro-
fluorimeter (PTI-814 PDS, MD 5020, LPS 220B) using a
xenon lamp. Quantum yields were calculated relative to
quinine sulfate (F = 0.546 in 1 N H2SO4).30
II Bruker-AXS (Centre de Diffractometrie, Universite de
´ ´
Rennes 1, France) with Mo-Ka radiation (l = 0.71073 A).z
Reflections were indexed, Lorentz-polarization-corrected
and integrated by the DENZO program of the KappaCCD
software package. The data merging process was performed
using the SCALEPACK program.22 Structure determinations
were performed by direct methods with the solving program
SIR97,23 which revealed all the non-hydrogen atoms. The
SHELXL program24 was used to refine the structures by
full-matrix least-squares based on F2. All non-hydrogen atoms
were refined with anisotropic displacement parameters.
Hydrogen atoms were included in idealized positions and
refined with isotropic displacement parameters. Atomic
scattering factors for all atoms were taken from International
Tables for X-ray Crystallography.25 In the case of the derivative
3b a CH2Cl2 molecule was found highly disordered in an
asymmetric unit. A modelling of its disorder was not possible,
and so the protons of this CH2Cl2 molecule were not
modelled, and we used a ‘squeeze’ treatment in order to
remove the scattering contribution of these molecules which
cannot be satisfactorily modelled after this ‘squeeze’ treatment.
Anisotropic displacement parameters associated to the atoms
of the derivative 3b are always satisfactory, and lends
confidence to the treatment of the structural resolution of this
derivative. Table S1z gives the crystallographic data for the
derivative 3b after this ‘squeeze’ treatment. Table S2z gives the
crystallographic data for the derivative 3b before the ‘squeeze’
treatment. Details of crystal data and structural refinements
are given in Table 2.
Cyclic voltammetry measurements. The electrochemical
studies were carried out under argon using an Eco Chemie
Autolab PGSTAT 30 potentiostat for cyclic voltammetry with
the three-electrode configuration: the working electrode was a
platinum disk, the reference electrode was a saturated calomel
electrode and the counter-electrode a platinum wire. All
potential were internally referenced to the ferrocene/
ferrocenium couple. For the measurements, concentrations
of 10ꢂ3 M of the electroactive species were used in freshly
distilled and degassed dichloromethane (Lichrosolv, Merck)
and 0.2
M
tetrabutylammonium hexafluorophosphate
(TBAHFP, Fluka) which was twice recrystallized from ethanol
and dried in vacuo prior to use.
Device fabrication and characterization. EL devices based on
a multilayer structure were fabricated onto patterned ITO-
coated glass substrates from Asahi (sheet resistance 10 O mꢂ1
)
or PGO CEC020S (thickness: 100 nm and sheet resistance: less
of 20 O mꢂ1). The organic materials (from Aldrich and Syntec)
were deposited onto the ITO anode by sublimation under high
vacuum (o10ꢂ6 Torr) at a rate of 0.2–0.3 nm sꢂ1. The
common structure of all the devices is the following: a thin
layer (10 nm thick) of copper phtalocyanine (CuPc) is used as
the hole-injection layer (HIL) and 50 nm of N,N0-diphenyl-
N,N0-bis(1-naphthylphenyl)-1,10-biphenyl-4,40-diamine (a-NPB)
as hole-transporting layer (HTL). The emitting layer consists
of phosphole derivatives (15 nm). A thin layer of 4,40-bis(2,20-
diphenylvinyl)biphenyl (DPVBi) (35 nm), a commercially
available molecule (from Syntec) is used as electron-transporting
layer (ETL). A thin layer of bathocuproine (BCP) (10 nm)
is used as hole-blocking layer. Alq3 (10 nm) is used as electron-
transporting layer (ETL). Finally, a cathode consisting of
1.2 nm of LiF capped with 100 nm of Al is deposited onto
the organic stack. The entire device is fabricated in the
same run without breaking the vacuum. In this study, the
thicknesses of the different organic layers were kept constant
Syntheses. All experiments were performed under an
atmosphere of dry argon using standard Schlenk techniques.
Column chromatography was performed in air, unless stated
in the text. Solvents were freshly distilled under argon from
sodium/benzophenone (tetrahydrofuran, diethyl ether) or
from phosphorus pentoxide (pentane, dichloromethane).
Cp2ZrCl2 was obtained from Alfa Aesar Chem. Co.
[PdCl2(PPh3)2], CuI, octa-1,7-diyne, n-BuLi, diisopropyl-
amine, and S8 were obtained from Acros Chem. Co. All
compounds were used as received without further purification.
PPhBr2,26 9,90-dimethyl-2-bromofluorene,27 AuCl(tht)28 and
1-phenyl-octa-1,7-diyne29 were prepared as described in the
literature. Preparative separations were performed by gravity
column chromatography on basic alumina (Aldrich, Type
ꢀc
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1608 | New J. Chem., 2010, 34, 1603–1611

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for all the devices. The active area of the devices defined by the
overlap of the ITO anode and the metallic cathode was 0.3 cm2.
The current–voltage–luminance (I–V–L) characteristics of
the devices were measured with a regulated power supply
(ACT100 Fontaine) combined with a multimeter and a
1 cm2 area silicon calibrated photodiode (Hamamatsu). The
spectral emission was recorded with a SpectraScan PR650
spectrophotometer. All the measurements were performed at
room temperature and at ambient atmosphere with no further
encapsulation of devices.
127.0 (s, CHfluorenyl), 125.8 (s, CHfluorenyl), 122.6 (s, CHfluorenyl),
122.6 (s, C2fluorenyl), 120.1 (s, CHfluorenyl), 119.8 (s, CHfluorenyl),
89.9 (s, CfluorenylCRC), 81.4 (s, CfluorenylCR), 46.8 (s,
C
9-fluorenyl), 28.1 (s, RCCH2), 26.8 (s, CH3), 19.0 (s, CH2).
MS (LSIMS): m/z 490.2634 (calculated: 490.26605, M+ꢄ).).
Anal. calc. for C38H34 (490.691): C, 93.02; H, 6.98; Found C,
93.36; H, 7.21
1-Phenyl-2-(9,90-dimethylfluorene-2-yl)-5-(phenyl)phosphole
AuCl 3a
To a THF solution (10 mL) of Cp2ZrCl2 (286 mg, 1.00 mmol)
and 1,8-bis(9,90-di(methyl)fluorene-2-yl)-octa-1,7-diyne 1a
(366 mg, 1.00 mmol) was added dropwise (ca. 1 min), at
ꢂ78 1C, a hexane solution of n-BuLi (2.5 M, 0.8 ml,
2.05 mmol). The solution was warmed to room temperature,
and stirred overnight. To this solution was added, at ꢂ78 1C,
freshly distilled PhPBr2 (0.22 mL, 1.05 mmol). The solution
was allowed to warm to room temperature and stirred for
30 h. The solution was filtered on basic alumina (THF) and
the volatile materials were removed in vacuo. The yellow
precipitate of phosphole 2a (31P{1H} NMR (80 MHz, CDCl3):
d = +11.5) was dissolved in THF (20 mL) and AuCl(tht)
(320 mg, 1.00 mmol) was added to the THF solution and
stirred at room temperature overnight. The solvent was
removed in vacuo. After purification by column chromatography
on silica gel (n-heptane–ethyl acetate, 6:4, Rf = 0.3) the
compound 3a was obtained as a yellow solid (yield 70%,
500 mg, 0.7 mmol). 1H NMR (300 MHz, CDCl3): d =
1-(9,9-Dimethylfluoren-2-yl)-8-phenyl-octa-1,7-diyne 1a
Catalytic amounts of [PdCl2(PPh3)2] (99 mg, 0.14 mmol) and
CuI (27 mg, 0.14 mmol) were added to a solution of 1-phenyl-
octa-1,7-diyne (519 mg, 2.8 mmol) and 9,90-dimethyl-2-
bromofluorene (786 mg, 2.9 mmol) in THF (30 mL) and
diisopropylamine (30 mL) at 55 1C. The heterogeneous brown
mixture was stirred for 1 day at 55 1C. All volatile materials
were removed in vacuo and the residue was extracted with
diethyl ether (3 ꢃ 20 mL). After purification by column
chromatography on silica gel (heptane–ethyl acetate, 95:5,
v/v, Rf = 0.1) the product 1a was obtained as a yellow oil
(yield 68%, 750 mg, 2.00 mmol). 1H NMR (300 MHz, CDCl3):
d = 7.74 (m, 1H, CHfluorenyl), 7.68 (m, 1H, CHfluorenyl),
7.56 (m, 1H, CHfluorenyl), 7.50–7.40 (m, 4H, 2 CHphenyl
,
2 CHfluorenyl), 7.40–7.30 (m, 5H, 3 CHphenyl, 2 CHfluorenyl),
2.57 (m, 4H, RCCH2), 1.89 (m, 4H, CH2), 1.53 (s, 6H, CH3).
13C NMR (75 MHz, CDCl3): d = 153.9 (s, Cfluorenyl), 153.5
(s, Cfluorenyl), 138.8 (s, Cfluorenyl), 138.7 (s, Cfluorenyl), 131.6
(s, CHortho-phenyl), 130.7 (s, CHfluorenyl), 128.2 (s, CHmeta-phenyl),
127.6 (s, CHfluorenyl), 127.5 (s, CHfluorenyl), 127.1 (s, CHfluorenyl),
125.9 (s, CHpara-phenyl), 124.0 (s, Cipso phenyl), 122.6 (s, CHfluorenyl),
122.5 (s, C2-fluorenyl), 120.2 (s, CHfluorenyl), 119.9 (s, CHfluorenyl),
89.9 (s, CRCCphenyl), 89.8 (s, CRCCfluorenyl), 81.7
(s, CRCCfluorenyl), 81.0 (s, RCCphenyl), 46.8 (s, C9fluorenyl),
28.1 (s, RCCH2), 28.0 (s, RCCH2), 27.1 (s, CH3), 19.2
(s, CH2), 19.1 (s, CH2). Anal. calc. for C29H26 (374.527): C,
93.00; H, 7.00; Found: C, 93.23; H, 7.15.
7.76–7.30 (m, 17H, 7 CHfluorenyl, 2 CHortho-phenyl, 2 CHmeta-phenyl
,
CH , 5 CHphenyl), 3.10–2.75 (m, 4H, CbCH2), 1.95–1.75
para-phenyl
(m, 4H, CH2), 1.49 (s, 3H, CH3), 1.45 (s, 3H, CH3). 13C NMR
(50 MHz, CDCl3): d = 154.0 (s, Cfluorenyl), 153.9 (s, Cfluorenyl),
151.1 (d, 2J(P,C) = 17.4 Hz, Cb), 150.0 (d, 2J(P,C) = 17.8 Hz,
Cb), 139.1 (s, Cfluorenyl), 138.4 (s, Cfluorenyl), 134.6 (d, 1J(P,C) =
58.6 Hz, Ca), 134.0 (d, 3J(P,C) = 13.8 Hz, CHortho-phenyl),
2
1
132.9 (d, J(P,C) = 13.7 Hz, Cfluorenyl), 131.7 (d, J(P,C) =
2
2.7 Hz, CHpara-phenyl), 131.6 (d, J(P,C) = 13.7 Hz, Cphenyl),
3
129.4 (d, J(P,C) = 6.2 Hz, CHfluorenyl), 129.3 (d, J(P,C) =
2
12.2 Hz, CHmeta-phenyl), 128.3 (s, CHphenyl), 128.3 (d, J(P,C) =
3
1,8-Bis(9,90-di(methyl)fluoren-2-yl)octa-1,7-diyne 1b
6.4 Hz, CHphenyl), 128.0 (s, CHphenyl), 127.7 (s, CHfluorenyl),
127.1 (s, CHfluorenyl), 125.1 (d, 1J(P,C) = 58.3 Hz, Cipso), 123.8
Catalytic amounts of [PdCl2(PPh3)2] (0.35 g, 0.50 mmol) and
CuI (0.10 g, 0.50 mmol) were added to a solution of
1,7-octadiyne (0.64 mL, 5.00 mmol) and 9,90-dimethyl-2-
bromofluorene (2.63 g, 10.00 mmol) in THF (20 mL) and
diisopropylamine (50 mL) at 55 1C. The heterogeneous brown
mixture was stirred for a week at 55 1C. All volatile materials
were removed in vacuo and the residue was extracted with
diethyl ether (3 ꢃ 20 mL). After purification by column
chromatography on silica gel (heptane–ether, 99:1, v/v, Rf
0.50) the product 1b was obtained as a pale yellow solid (yield
80%, 3.70 g, 4.00 mmol). 1H NMR (200 MHz, CD2Cl2): d =
7.77–7.72 (m, 2H, CHfluorenyl), 7.72–7.66 (m, 2H, CHfluorenyl),
7.55–7.51 (m, 2H, CHfluorenyl), 7.51–7.46 (m, 2H, CHfluorenyl),
7.46–7.39 (m, 2H, CHfluorenyl), 7.39–7.32 (m, 4H, CHfluorenyl),
2.58 (s, 4H, RCCH2), 1.88 (s, 4H, RCCH2CH2), 1.50
(s, 12H, CH3). 13C–{1H} NMR (50 MHz, CD2Cl2): d =
153.9 (Cfluorenyl), 153.6 (s, Cfluorenyl), 138.7 (s, Cfluorenyl),
138.5 (s, Cfluorenyl), 130.5 (s, CHfluorenyl), 127.5 (s, CHfluorenyl),
3
(d, J(P,C) = 6.4 Hz, CHfluorenyl), 122.7 (s, CHfluorenyl), 120.2
(s, CHfluorenyl), 120.0 (s, CHfluorenyl), 46.8 (s, C9-fluorenyl), 28.5
(d, 3J(P,C) = 6.6 Hz, CbCH2), 28.3 (d, 3J(P,C) = 6.6 Hz,
CbCH2), 26.8 (s, 2 CH3), 22.6 (s, CH2), 22.5 (s, CH2). 31P{1H}
NMR (121 MHz, CD2Cl2): d = 41.00 ppm. MS (ESI): m/z
737.14152 (calculated 737.1422 [M + Na]+). Anal. calc. for
C35H31PAuCl (715.027): C, 58.79; H, 4.37; P, 4.33; Found: C,
58.86; H, 4.59; P, 4.68.
1-Phenyl-2,5-bis(9,90-di(methyl)fluoren-2-yl)phosphole)AuCl 3b
To a THF solution (10 mL) of Cp2ZrCl2 (155 mg, 0.53 mmol)
and 1,8-bis(9,90-di(methyl)fluorene-2-yl)1,7-octadiyne 1b (469 mg,
0.53 mmol) was added dropwise (ca. 1 min), at ꢂ78 1C, a
hexane solution of n-BuLi (2.5 M, 0.42 mL, 1.06 mmol). The
solution was warmed to room temperature, and stirred
overnight. To this solution was added, at ꢂ78 1C, freshly
distilled PhPBr2 (110 mL, 0.53 mmol). The solution was
ꢀc
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2010 New J. Chem., 2010, 34, 1603–1611 | 1609

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allowed to warm to room temperature and stirred for 30 h.
The solution was filtered on basic alumina (THF) and the
volatile materials were removed in vacuo. The yellow precipitate
of phosphole 2b (31P{1H} NMR (80 MHz, CDCl3):
d = +12.4) was dissolved in THF (20 mL) and AuCl(tht)
(169.9 mg, 0.53 mmol) was added to the THF solution and
stirred at room temperature overnight. The solvent was
removed in vacuo. After purification by column chromato-
graphy on silica gel (pentane–ether, 1:1) the compound 3b was
obtained as a yellow solid (yield 64%, 280 mg, 0.3 mmol).
1H NMR (200 MHz, CD2Cl2): d = 7.80–7.61 (m, 8 H,
(d, 3J(P,C) = 11.4 Hz, CHortho-phenyl), 129.1 (d, 3J(P,C) =
5.0 Hz, CHfluorenyl), 128.8 (d, 3J(P,C)
= 12.2 Hz,
CHmeta-phenyl), 128.6 (d, 1J(P,C) = 72.5 Hz, Cipso), 128.2
(s, CHphenyl), 127.9 (d, 2J(P,C) = 5.5 Hz, CHphenyl), 127.8
(s, CHphenyl), 127.5 (s, CHfluorenyl), 127.0 (s, CHfluorenyl), 123.3
3
(d, J(P,C) = 5.3 Hz, CHfluorenyl), 122.6 (s, CHfluorenyl), 120.1
(s, CHfluorenyl), 119.7 (s, CHfluorenyl), 46.7 (s, C9-fluorenyl), 28.9
(s, CH2), 28.8 (s, CH2), 26.8 (s, CH3), 26.7 (s, CH3), 22.8
(s, CbCH2), 22.7 (s, CbCH2).31P{1H} NMR(121 MHz,
CD2Cl2): d = 54.01 ppm, MS (ESI): m/z 537.17818 (calculated
537.1785 [M +Na]+), m/z 515.19624 (515.1979 [M + H]+).
Anal. calc. for C44H39PS (514.672): C, 81.68; H, 6.07; P, 6.02;
Found: C, 81.51; H, 6.26; P, 6.32.
6 CHfluorenyl, 2 CHortho-phenyl), 7.60–7.30 (m, 11 H, 8 CHfluorenyl
,
3 CHmeta-phenyl, CHpara-phenyl), 2.96 (m, 4H, CbCH2), 1.86
(m, 4H, CH2), 1.49 (s, 6H, CH3), 1.46 (s, 6H, CH3).
13C NMR (50 MHz, CDCl3): d = 154.0 (s, Cfluorenyl), 153.9
(s, Cfluorenyl), 150.3 (d, 2J(P,C) = 17.8 Hz, Cb), 139.1
1-Phenyl-2,5-bis(9,90-di(methyl)fluoren-2-yl)thiooxophosphole
4b
(s,
C =
fluorenyl), 138.4 (s, Cfluorenyl), 134.1 (d, 1J(P,C)
A hexane solution of n-BuLi (2.5 M, 0.42 mL, 1.06 mmol) was
added dropwise (ca. 1 min), at ꢂ78 1C, to a THF solution
(10 mL) of Cp2ZrCl2 (155 mg, 0.53 mmol) and 1,8-bis(9,90-
di(methyl)fluorene-2-yl)-1,7-octadiyne (469 mg, 0.53 mmol).
The solution was warmed to room temperature, and stirred
overnight. To this solution was added, at ꢂ78 1C, freshly
distilled PhPBr2 (110 mL, 0.53 mmol). The solution was
allowed to warm to room temperature and stirred for 30 h.
The solution was filtered on basic alumina (THF) and the
volatile materials were removed in vacuo. The yellow precipitate
containing phosphole 2a (31P{1H} NMR (80 MHz, CDCl3):
d = 14.37) was dissolved in CH2Cl2 (20 mL), and elemental
sulfur (17 mg, 0.07 mmol) was added to this solution. The
reaction mixture was stirred for four days, filtered and the
solvent was removed in vacuo. After purification on silica gel
(pentane–CH2Cl2, 9:1, v/v, Rf 0.3), 4b was obtained as a
yellow–orange solid (yield = 60%, 200 mg, 0.32 mmol).
1H NMR (300 MHz, CD2Cl2): d = 7.90 (m, 2H, CHortho-phenyl),
59.1 Hz, Ca), 134.0 (d, 2J(P,C) = 13.7 Hz, CHortho-phenyl),
132.3 (d, 4J(P,C) = 2.7 Hz, CHpara-phenyl), 131.9 (d, 2J(P,C) =
13.6 Hz, Cfluorenyl), 129.3 (d, 3J(P,C) = 12.1 Hz, CHmeta-phenyl),
3
128.3 (d, J(P,C) = 6.5 Hz, CHfluorenyl), 127.6 (s, CHfluorenyl),
127.1 (s, CHfluorenyl), 125.4 (d, 1J(P,C) = 58.0 Hz, Cipso), 123.8
3
(d, J(P,C) = 6.5 Hz, CHfluorenyl), 122.6 (s, CHfluorenyl), 120.1
(s, CHfluorenyl), 120.0 (s, CHfluorenyl), 46.8 (s, Cfluorenyl), 28.6
(s, CbCH2), 28.4 (s, CbCH2), 26.8 (s, CH3), 22.6 (s, CH2).
31P-{1H} NMR (80 MHz, CD2Cl2): d = 41.16. Anal. calc. for
C44H39PAuCl (831.190): C, 63.58; H, 4.73; P, 3.73; Found: C,
63.92; H, 6.54; P, 4.89.
1-Phenyl-2-(9,90-dimethylfluorene-2-yl)-5-
(phenyl)thiooxophosphole 4a
To a THF solution (10 mL) of Cp2ZrCl2 (286 mg, 1.00 mmol)
1-(9,90-dimethylfluorene-2-yl)-8-(phenyl)-1,7-octadiyne
and
(366 mg, 1.00 mmol) was added dropwise (ca. 1 min), at
ꢂ78 1C, a hexane solution of n-BuLi (2.5 M, 0.8 mL,
2.05 mmol). The solution was warmed to room temperature,
and stirred overnight. To this solution was added, at ꢂ78 1C,
freshly distilled PhPBr2 (0.22 mL, 1.05 mmol). The solution
was allowed to warm to room temperature and stirred for
30 h. The solution was filtered on basic alumina (THF) and the
volatile materials were removed in vacuo. The yellow
precipitate containing phosphole 2a (31P{1H} NMR
(80 MHz, CDCl3): d = +11.5) was dissolved in CH2Cl2
(20 mL), and elemental sulfur (32 mg, 0.12 mmol) was added
to this solution. The reaction mixture was stirred for four
days, filtered and the solvent was removed in vacuo. After
purification on silica gel (n-heptane–ethyl acetate, 8:2, v/v, Rf
0.3), 4a was obtained as a yellow–orange solid (yield = 70%,
7.72–7.62 (m, 4H, CH
), 7.50–7.40 (m, 4H, CHfluorenyl),
fluorenyl
7.43–7.34 (m, 9H, 6 CHfluorenyl, 2 CHmeta-phenyl, CHpara-phenyl),
2.92 (s, 4H, RCCH2), 1.84 (s, 4H, RCCH2CH2), 1.43
(s, 12H, CH3). 13C NMR (75 MHz, CD2Cl2): d = 153.1
(s, Cfluorenyl), 152.8 (s, Cfluorenyl), 147.5 (d, 2J(P, C) = 23.4
Hz, Cb), 138.0 (s, Cfluorenyl), 137.9 (s, Cfluorenyl), 133.4 (d,
1J(P, C) = 80 Hz, Ca), 131.0 (d, 4J(P,C) = 3.0 Hz,
CHpara-phenyl), 130.9 (d, 2J(P,C) = 11.9 Hz, C2-fluorenyl),
130.0 (d, 3J(P, C)
= 11.3 Hz, CHortho-phenyl), 128.3
1
(d, J(P, C) = 72.2 Hz, Cipso), 128.0 (d, J(P,C) = 12.2 Hz,
2
3
CHmeta-phenyl), 127.2 (d, J(P,C) = 5.6 Hz, CHfluorenyl), 126.7
(s, CHfluorenyl), 126.2 (s, CHfluorenyl), 122.6 (d, 3J(P, C) =
5.4 Hz, CHfluorenyl) 121.8 (s, CHfluorenyl), 119.3 (s, CHfluorenyl),
118.6 (s, CHfluorenyl), 46.0 (s, C9-fluorenyl), 27.6 (s, CH2), 27.4
(s, CH2), 26.1 (s, CH3), 26.0 (s, CH3), 22.0 (s, CbCH2). 31P{1H}
NMR NMR (120 MHz, CD2Cl2): d = 54.88. MS (ESI): m/z
631.2604 (calculated 631.2588, [M + H]+), m/z 653.3406 (calcu-
lated 653.2408, [M + Na]+). Anal. calc. for C44H39PS (630.835):
C, 83.78; H, 6.23; P, 4.91; Found: C, 83.92; H, 6.54; P, 4.89.
1
0.7 mmol, 360 mg). H NMR (300 MHz, CD2Cl2): d = 7.90
(m, 2H, CHortho-phenyl), 7.72–7.62 (m, 2H, CHfluorenyl),
7.55–7.30 (m, 13H, 5 CHfluorenyl, 2 CHmeta-phenyl, CHpara-phenyl
,
5 CH ), 2.90 (m, 4H, QCCH2), 1.84 (s, 4H, QCCH2CH2),
phenyl
1.44 (s, 6H, CH3), 13C NMR (75 MHz, CD2Cl2): d = 153.9
(s, Cfluorenyl), 153.5 (s, Cfluorenyl), 148.9 (d, 2J(P,C) = 23.1 Hz,
Cb), 147.9 (d, 2J(P,C) = 23.5 Hz, Cb), 138.8 (s, Cfluorenyl),
138.6 (s, Cfluorenyl), 134.6 (d, 1J(P,C) = 80.1 Hz, Ca), 132.9
Acknowledgements
This work is supported by the Ministere de la Recherche et de
2
(d, J(P,C) = 12.9 Hz, Cfluorenyl), 131.7 (d, 1J(P,C) = 2.7 Hz,
l’Enseignement Supe
´
rieur, the Institut Universitaire de
gion Bretagne, and the project
CHpara-phenyl), 131.6 (d, 2J(P,C) = 11.3 Hz, Cphenyl), 130.7
France, the CNRS, the Re
´
ꢀc
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1610 | New J. Chem., 2010, 34, 1603–1611

View Article Online
ANR PSICO. Thanks are due to Dr Christophe Lescop
and Dr Dimitri Aldakov for X-ray diffraction studies and
fluorescence measurements of PMMA films, respectively.
11 (a) Y. Dienes, S. Durben, T. Karpati, T. Neumann, U. Englert,
L. Nyulaszi and T. Baumgartner, Chem.–Eur. J., 2007, 13, 7487;
(b) T. Baumgartner, T. Neumann and B. Wirges, Angew. Chem.,
Int. Ed., 2004, 43, 6197; (c) Y. Dienes, U. Englert and
T. Baumgartner, Z. Anorg. Allg. Chem., 2009, 635, 238;
(d) C. R. Nieto, S. Durben, I. M. Kormos and T. Baumgartner,
Adv. Funct. Mater., 2009, 19, 3625.
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