Isomerically pure anthra[2,3-b:6,7-b']-difuran (anti-ADF), -dithiophene (anti-ADT), and -diselenophene (anti-ADS): Selective synthesis, electronic structures, and application to organic field-effect transistors

Article abstract of DOI:10.1021/jo301438t

A new straightforward synthesis of isomerically pure anthra[2,3-b:6,7-b'] -difuran (anti-ADF), -dithiophene (anti-ADT), and -diselenophene (anti-ADS) from readily available 2,6- dimethoxyanthracene is described. The present successful synthesis makes it p

Full text of DOI:10.1021/jo301438t

Article
pubs.acs.org/joc
Isomerically Pure Anthra[2,3‑b:6,7‑b′]-difuran (anti-ADF),
-dithiophene (anti-ADT), and -diselenophene (anti-ADS): Selective
Synthesis, Electronic Structures, and Application to Organic Field-
Effect Transistors
Masahiro Nakano,†,‡ Kazuki Niimi,†,‡ Eigo Miyazaki,‡ Itaru Osaka,‡ and Kazuo Takimiya*,‡,§
‡Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan
§Emergent Molecular Function Research Team, RIKEN Advanced Science Institute, Wako, Saitama 351-0198, Japan
S
* Supporting Information
ABSTRACT: A new straightforward synthesis of isomerically pure
anthra[2,3-b:6,7-b′] -difuran (anti-ADF), -dithiophene (anti-ADT),
and -diselenophene (anti-ADS) from readily available 2,6-
dimethoxyanthracene is described. The present successful synthesis
makes it possible to overview the linear-shaped anti-acenedichalco-
genophene compounds, that is, benzo[1,2-b:4,5-b′]-, naphtho[2,3-
b:6,7-b′]-, and anthra[2,3-b:6,7-b′]- difuran, -dithiophene, and
-diselenophene. By comparing their electrochemical and photo-
chemical properties, the electronic structures of acenedichalcoge-
nophenes can be expressed as the outcome of balance between the
central acene core and the outermost chalcogenophene rings.
Among isomerically pure parent anti-anthradichalcogenophenes,
anti-ADT and anti-ADS can afford crystalline thin films by vapor
deposition, which acted as active layer in organic field-effect transistors with mobility as high as 0.3 cm2 V−1 s−1 for ADT and 0.7
cm2 V−1 s−1 for ADS. The mobility of isomerically pure anti-ADT is higher by several times than those reported for isomercally
mixed ADT, implying that the isomeric purity could be beneficial for realizing the better FET mobility. We also tested the
diphenyl derivatives of anti-ADF, -ADT, and -ADS as the active material for OFET devices, which showed high mobility of up to
1.3 cm2 V−1 s−1.
positions by fractional recrystallization from the syn and anti
isomeric mixture.8 Furthermore, Geerts and co-workers have
recently reported the first selective synthesis of isomerically
pure anti-ADTs with π-alkyl substitutents via a multistep
synthetic protocol.9 Also, the isomerically pure syn-ADT
derivatives10 and its related molecules, anthra[2,3-b:7,6-b′]bis-
[1]benzothiophenes (syn-ABBTs), have been successfully
synthesized.11 In addition to these recent synthetic develop-
ments, Mamada and co-workers have just published synthesis,
characterization, and FET characteristics of isomerically pure
syn- and anti-dimethyl-ADTs.12 However, the selective syn-
thesis of isomerically pure parent anti-ADT, one of the most
basic compounds in this class, has remain unattained.
We were interested in the synthesis and application of
benzo[b]thiophene-based π-extended materials and developed
several practical methods for the synthesis of compounds of this
class.13 Among the methods, the thiophene-annulation reaction
of o-halogen substituted ethynylbenzene substructure effected
by sodium sulfide is a very useful reaction that allows efficient
and scalable synthesis of not only benzo[b]thiophenes13h and
INRODUCTION
■
Acenedithiophenes (AcDTs), where two thiophene rings fused
at both ends of acene cores, have been the representative
thienoacene structures and widely utilized as key building
blocks in the development of superior organic semiconductors1
applicable to organic electronic devices such as organic field-
effect transistors (OFETs)2−4 and organic photovoltaics
(OPVs).5−8 Large numbers of materials based on benzo[1,2-
b:4,5-b′]dithiophene (BDT),2,5 isomeric naphthodithiophenes
(NDTs),3,6 and anthra[2,3-b:6,7(7,6)-b′]dithiophene
(ADT)4,7,8 have been developed and enriched the material
diversity of this class, which has indeed contributed to recent
progress in the field of π-functional materials and organic
electronics (Chart 1).
From the viewpoint of synthetic organic chemistry, there had
remained several challenges in the acenedithiophene chemistry,
one of which is the synthesis of linear-shaped NDTs and the
other is a selective synthesis of isomerically pure syn- and anti-
ADT. The former has been addressed recently by two research
groups developing the new methods for the efficient synthesis
of NDTs.3,6 For the latter issue, on the other hand, Anthony
and co-workers have successfully isolated pure syn- and anti-
ADT derivatives with amide substituents at the thiophene π-
Received: July 13, 2012
Published: August 13, 2012
© 2012 American Chemical Society
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Chart 1. Molecular Structures of Representative Linear-shaped Acenedithiophenes
Scheme 1. Attempted Synthesis of anti-ADT from 2,6-Dimethoxyanthracene (1)
anthra[2,3-b]thiophene13l (one-fold cyclization) but also
BDTs13h and NDTs3a,b (2-fold cyclization), and furthermore,
benzo[1,2-b:3,4-b′:5,6-b″]trithiophenes (BTTs, 3-fold cycliza-
tion).13h We therefore attempted to employ this reaction for
the synthesis of anti-ADT, starting from 2,6-dimethoxyanthra-
cene,14 where 2- and 6- methoxyl groups can act as a strong o-
directing group in lithiation reaction to give the corresponding
3,7-dilithiated intermediate.13k,15 Although, as will be discussed
later, the first attempt to synthesize anti-ADT using the
thiophene-annulation reaction failed, the selective functionali-
zation on 3- and 7-positions on 2,6-dimethoxyanthracene
turned out to pave the way to the efficient synthesis of not just
isomerically pure parent anti-ADT but also anthra[2,3-b:6,7-
b′]-difuran (anti-ADF) and -diselenophene (anti-ADS). The
successful synthesis also provides an opportunity to compare a
range of linear-shaped acenedichalcogenophenes with benzene,
naphthalene, and anthracene as the central acene and furan,
thiophene, and selenophene as the outermost chalcogenophene
rings. We here first report the synthesis and characterization of
anti-anthradichalcogenophenes and then discuss their elec-
tronic properties in comparison with their lower homologues,
benzo[1,2-b:4,5-b′]- and naphtho[2,3-b:6,7-b′]- dichalcogeno-
phenes. Then, the parent and diphenyl derivatives of these anti-
anthradichalcogenophenes were examined as the active layer in
OFETs, showing mobility of up to 1.3 cm2 V−1 s−1.
quantitative yield. Demethylation with BBr3 gave the
corresponding dihydroxyanthracene (3) quantitatively, which
was then converted into the corresponding triflate (4). The
chemoselective Sonogashira coupling reaction with trimethyl-
silyl acetylene at the triflate site gave the potential precursor (5)
for parent anti-ADT in 56% isolated yield. The thiophene
annulation reaction promoted by the sodium sulfide reagent,
however, gave a complex mixture as a black solid, which
afforded a trace amount of ADT after gradient sublimation in
vacuum. The failure in the synthesis of ADT could be
attributed to undesired reactions of the reagent with the
substrate (5) at the 9- and 10-positions of anthracene or with in
situ generated ADT at the most reactive 5- and 11-positions
under the harsh reaction conditions, that is, high temperature
and the highly reactive and basic sodium sulfide reagent.
Considering the successful synthesis of anthra[2,3-b]thiophene
from 2-bromo-3-[2-(trimethylsilyl)ethyn-1-yl]anthracene with
sodium sulfide,13l it is most likely that the reaction itself
afforded ADT, but it reacted with the reagent to result in a
complex mixture. In fact, we confirmed that treatment of anti-
ADT, synthesized by another route (vide infra), under the same
reaction condition forms a similar mixture. It is thus concluded
that this is the limitation of the sodium sulfide-induced
thiophene annulation reaction in the synthesis of π-extended
acenedithiophene compounds.
On the other hand, 2,6-dibromo-3,7-dihydroxyanthracene
(3) seemed to be an ideal intermediate for the synthesis of
isomerically pure anthra[2,3-b:6,7-b′]difuran (anti-ADF) and
its derivatives, since the corresponding naphthalene analogue,
2,6-dibromo-3,7-dihydroxynaphthalene can be readily con-
verted into naphtho[2,3-b:6,7-b′]difuran (anti-NDF) deriva-
RESULTS AND DISCUSSION
■
Synthesis and Characterizations. As depicted in Scheme
1, lithiation of 2,6-dimethoxyanthracene (1) with excess BuLi
followed by the reaction with dibromotetrachloroethane
selectively gave 3,7-dibromo-2,6-dimethoxyanthracene (2) in a
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tives.16 As in the synthesis of anti-NDFs, the bromine atoms
were first replaced with acetylene moieties by the Sonogashira
reaction after acetylation on the hydroxyl groups. Then, the
subsequent base-promoted furan formation17 at the acetyl-
protected o-ethynylphenol substructures readily gave anti-ADF
in acceptable yield (Scheme 2). Parent anti-ADF after
isolated yield. After selective demethylation of the methoxy
groups and subsequent triflation to give 10, the Sonogashira
coupling reaction with trimethylsilylacetylene afforded the
corresponding di(ethynyl) derivative (11) in an excellent
yield, which was then treated with iodine in dichloromethane at
r.t. to give 2,8-bis(trimethylsilyl)-3,9-diiodo-ADT (12) in a
good yield. The structure of 12 was determined by
spectroscopic analyses, among which 13C NMR, in particular,
gave the vital spectroscopic evidence for the selective formation
of anti-ADT substructure as in the case of ADF (see Supporting
Information). Furthermore, single crystal X-ray analysis of 12
gave the concrete structural determination of the anti-ADT
framework (Figure 1). 12 was then proven to be the direct
Scheme 2. Synthesis of anti-ADF from 2,6-Dibromo-3,7-
dihydroxyanthracene (3)
purification by repetitive sublimations was well characterized
by spectroscopic and combustion analysis (see Experimental
section), and the selective formation of anti-ADF core was
confirmed by 13C NMR spectra, in which nine peaks assignable
to aromatic carbons were clearly observed, indicating that the
product has the centrosymmetric C2h structure, not the C2v
(syn-ADF) structure consisting of 10 nonequivalent carbons or
their mixture (see Supporting Information).
Going back to the synthesis of anti-ADT, it is important to
circumvent the problems associated with sodium sulfide-
induced thiophene annulation reaction, that is, high temper-
ature and the highly reactive reagent. We thus examined an
alternative route to ADT by employing the Larock thiophene
annulation reaction on the o-ethynyl-methylmercaptobenzene
substructure (Scheme 3).18 Dilithiated 2,6-dimethoxyanthra-
cene was first reacted with dimethyldisulfide to give 2,6-
dimethoxy-3,7-bis(methylthio)anthracene (8) in quantitative
Figure 1. Single crystal X-ray structural analysis of 12 clearly shows the
anti-ADT substructure.
precursor for parent anti-ADT via a hydride-promoted
reductive desilylation/deiodonation (Scheme 3). In addition,
the iodine atoms in 12 can be useful handles for
functionalization; for example, the Suzuki-Miyaura coupling
reaction between 12 and phenyl boronic acid gave the
corresponding 3,9-diphenyl-ADT (13) in a moderate yield.19
Scheme 3. Synthesis of anti-ADT via 2,8-Substituted-3,9-diiodo-anti-ADT (12)
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Scheme 4. Synthesis of anti-ADS
Figure 2. Cyclic voltammograms (a), absorption spectra in dichloromethane (b), and photoelectron yield spectroscopy in air (PESA) (c) of anti-
ADF, ADT, and ADS.
Table 1. Electronic Properties of Benzo-, Naphtho-, and Anthra-dichalcogenophenes
a
b
c
d
e
compd
Eox/V
EHOMO/eV
IP/eV
λmax (λedge)/nm
Eg/eV
ELUMO/eV
−2.5
ADF
+0.79 (0.86)
+0.71 (0.77)
+0.71 (0.77)
+1.13
−5.1
−5.0
−5.0
−5.5
−5.3
−5.3
−5.7
−5.6
−5.5
5.2
5.1
5.1
5.5
5.4
5.4
5.8
5.7
5.6
453 (468)
489 (506)
481 (501)
364 (375)
401 (412)
401 (415)
277 (308)
335 (342)
350 (359)
2.6
2.4
2.4
3.3
3.0
3.0
4.0
3.6
3.5
ADT4a
ADS
−2.6
−2.6
f
f
NDF14
NDT3b,15
NDS15
−2.2
−2.3
−2.3
−1.8
−2.0
−2.0
+0.95 (1.01)
+0.95 (1.01)
+1.40
BDF17b 22
,
BDT13c
BDS13c
+1.31
+1.19
a
V vs Ag/AgCl in benzonitrile containing tetrabutylammonium hexafluorophosphate (Bu4NPF6, 0.1 M) as supporting electrolyte at a scan rate of
100 mV/s. Counter and working electrodes were made of Pt. Oxidation onsets (Eox) are reported for all the compounds, whereas for compounds
giving reversible oxidation waves, half-wave oxidation potentials (E1/2ox) are given in the parentheses. All the potentials were calibrated with the Fc/
b
Fc+ (E1/2 = +0.46 V measured under identical conditions). Determined by a photoelectron yield spectroscopy in air (PESA, a Riken AC-2 model)
c
d
e
using the powder samples. Estimated with a following equation: EHOMO (eV) = −4.4 − Eonset. Calculated from λedge. Estimated with a following
f
equation: ELUMO (eV) = EHOMO + Eg. Electrochemical reduction potential was observed at Ered (onset)= −1.65 V for ADT and Ered (onset) = −1.70
V for ADS, both of which correspond to ELUMO = −2.7 eV.
The synthesis of anti-ADS was similarly done as in the case
of anti-ADT with several modifications (Scheme 4). The first
introduction of methylseleno groups with elemental selenium
and methyl iodide proceeded smoothly, but was slightly less
effective than the synthesis of the sulfur counterpart with
dimethyl disulfide. On the other hand, the Sonogashira
coupling of 16 with trimethylsilylacetylene did not take place,
owing to steric or electronic effect of the adjacent bulky
methylseleno group. Alternatively the Stille coupling with 1-
tributylstannyl-2-trimethylsilylacetylene did work quite well to
afford 17, the precursor for the anti-ADS framework. The
subsequent Larock selenophene annulation reaction gave 18 in
an excellent yield, and the final reductive desilylation/
deiodination effected by lithium aluminum hydride gave anti-
ADS (Scheme 4).18b
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Molecular Electronic Properties. The molecular elec-
tronic properties of anti -ADF, -ADT, and -ADS were
investigated by cyclic voltammetry (CV, Figure 2a), absorption
spectra in solution (Figure 2b), and photoelectron yield
spectroscopy in air (PESA, Figure 2c) using their powder
samples. Summarized in Table 1 are the oxidation potentials
(Eox), estimated HOMO energy levels (EHOMO), ionization
potentials (IP), absorption peaks and edges (λmax, λedge),
HOMO−LUMO energy gaps (Eg) estimated from the
absorption edges, and estimated LUMO energy levels, together
with their benzo- and naphtho- counterparts (For CV, PESA,
and absorption spectra, see Figure S1, Supporting Information).
In general, for all the chalcogenophene series, extension of
the acene core gave higher-lying EHOMO and smaller Eg as in the
case for oligoacene series (e.g., anthracene, tetracene, and
pentacene),20 which can be well represented by the schematic
energy diagram (Figure 3). On the other hand, the furan
counterparts and quite similar EHOMOs for the thiophene or
selenophene compounds are generally seen in BDX and NDX
series (Table 1, Figure 3), the difference of EHOMO (ΔEHOMO
=
0.1 eV) in the ADX series is rather smaller than those in the
BDX and NDX series (ΔEHOMO = 0.2 eV), indicating that the
perturbation from the outermost chalcogenophene rings to the
whole electronic structure is attenuated with the extension of
the central acene system. Similar π-extension effects are also
observed in Egs estimated from the absorption edges; in the
ADX series, the difference between ADF and ADT/ADS (ΔEg)
is 0.2 eV, whereas ΔEgs for the BDX and NDX series are >0.4
and 0.3 eV, respectively. This can be also understood by
considering the “dilution” effect of the perturbation from the
outermost chalcogenophene rings by extending the central
acene core. As a result, the ADF core turned out to be an
interesting π-extended core that has the suitable HOMO
energy level (−5.1 eV) as p-channel organic semiconductor
both for good stability in ambient conditions and facile hole
injection from metal electrode often used in OFETs such as
gold.
FET Characteristics of anti-ADT and ADS. One of the
primary objectives for the synthesis of isomerically pure anti-
ADT is to elucidate the isomer effects on the device
characteristics, especially field-effect mobility. In the Katz’s
pioneering works on ADTs, OFETs with the vapor deposited
thin film of isomerically mixed ADT as the active channel
showed the mobility of up to 0.09 cm2 V−1 s−1 at the substrate
temperature (Tsub) of 85 °C during vapor deposition.4a We
fabricated anti-ADT-based vapor-processed OFETs at Tsub = 85
°C together with slightly lower Tsub (60 °C). As depicted in
Figure 4a, the devices show typical FET responses, and the
extracted mobility from the saturation regime are 0.3 cm2 V−1
s−1 for both Tsub = 60 and 85 °C.
The mobility we obtained using the vapor deposited thin
films, 0.3 cm2 V−1 s−1, is in fact ca. three times higher than the
value reported for the isomerically mixed ADT. In general, the
device characteristics and extracted mobility largely depend on
many factors, such as device structure, surface treatment,
deposition rate, etc., it is hard to conclude with just the present
experimental results that the devices based on isomerically pure
anti-ADT is far superior than those with the isomerically mixed
ADT. In the case of diphenyl derivatives of linear-shaped
BDSs2b,22 and NDTs,3c the device characteristics based on
isomerically pure syn and anti compounds were compared
under identical experimental conditions and device config-
urations, and the differences between the isomers were much
pronounced; in both cases, anti derivatives gave higher mobility
in the devices by ca. 1 order of magnitude. With these previous
and present experimental results, we can say that isomerically
pure anti-ADT tends to afford better mobility in OFETs than
the isomerically mixed ADT does, but the difference is not very
large. The smaller difference than those in the NDT and BDS
cases could be interpreted by the π-extension effect in the ADT
case; largely π-extended ADT tends to have small electrical and
structural perturbation from the outermost thiophene rings
than those in the case of the BDS and NDT derivatives. These
speculations are also supported by recent results on isomeri-
cally pure syn- and anti- dimethyl-ADT derivatives.12
Figure 3. Schematic energy diagram of the linear-shaped acenedichal-
cogenophenes.
homologues in all the benzo-, naphtho-, and anthra-
dichalcogenophene series tend to have lower-lying EHOMO
and larger Eg than those of the thiophene and selenophene
counterparts. This can be explained by lower aromaticity of
furan than those of thiophene/selenophene, limiting, as a result,
the effective π-delocalization over the whole π-framework.16,21
It is interesting to note that all anthradichalcogenophenes
(ADXs) show reversible oxidation peaks (Figure 2a). This is in
sharp contrast to benzodichalcogenophenes (BDXs) and
naphthodichalcogenophenes (NDXs), the former of which
shows irreversible oxidation waves regardless of the chalcoge-
nophene rings whereas the latter shows clear dependence on
the chalcogenophene rings; only NDF shows irreversible
oxidation wave (Figure S1, Supporting Information). The
irreversibility of BDF and NDF was due to instability of the
oxidized species, not polymerization on the working
electrode,16 and we thus concluded that the low aromaticity
of the furan ring can not stabilize the cationic state of these
lower homologues. On the other hand, the reversible oxidation
wave of ADF indicates that the oxidized species (radical cation)
can be stabilized by delocalization over the anthracene core,
which is quite characteristic for ADF.
We also fabricated ADF- and ADS-based OFETs. The vapor
deposited thin films of ADF, however, readily resublimed
during the deposition of gold source and drain electrode, and
thus evaluation of ADF thin film as an active layer in OFETs
were failed in our device configuration with the bottom-gate
E
HOMOs estimated from the oxidation onsets are −5.1 eV for
ADF and −5.0 eV for ADT/ADS. Although lower lying EHOMOs
of the furan compounds than the thiophene or selenophene
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Figure 4. Output and transfer characteristics of (a) anti-ADT-based and (b) anti-ADS-based OFETs fabricated on octadecyltrichlorosilane (ODTS)-
SAM modified Si/SiO2 substrates at Tsub = 85 °C.
and top contact source and drain electrodes. This is attributed
to a lower sublimation point of ADF than that of ADT, which
means that the packing energy of the ADXs is affected by the
chalcogen atoms, suggesting that the packing effectiveness and
intermolecular interactions in the solid state are also affected by
the chalcogen atoms. On the other hand, anti-ADS behaved as a
good organic semiconductor similar to its sulfur counterpart:
typical FET responses were observed for anti-ADS-based
OFETs with extracted mobility of up to 0.7 cm2 V−1 s−1 at
Tsub = 85 °C (Figure 4b). These FET results indicate that the
present anti-anthradichalcogenophenes are quite promising π-
extended core for organic semiconductors, though the high
volatility of parent ADF unfortunately prevent its evaluation as
an organic semiconductor. Several furan-based π-extended
materials have recently been investigated as promising organic
semiconductors,23,24 and in this regard, anti-ADF framework
should also be interesting, provided that appropriate molecular
modification is done. For this reason, we then synthesized and
evaluated diphenyl derivative of ADF together with the
counterparts of ADT and ADS.
All anti-DPh-ADXs are poorly soluble compounds and were
purified by repeated vacuum sublimation. Their vapor-
processed OFET devices including DPh-ADF-based ones
showed typical OFET characteristics under ambient conditions
(Figure 5). The best mobilities obtained were 0.6 cm2 V−1 s−1
for DPh-ADF, 1.3 cm2 V−1 s−1 for DPh-ADT, and 0.5 cm2 V−1
s−1 for DPh-ADS. Compared to the mobility of the parent ones,
DPh-ADT gave better mobility than the parent by several
times, whereas the DPh-ADS-based device showed slightly
lower mobility.
It is also interesting to note that these mobility values are
similar to those of DPh-NDX series, but fairly higher than those
of DPh-BDX series, implying that saturation of mobility with
extension of acenedichalcogenophene cores is observed in the
thin film transistor setting (Figure 6).2b,16,25
CONCLUSION
■
We have successfully established selective synthetic routes to
anthra[2,3-b:6,7-b′] -difuran (anti-ADF), -dithiophene (anti-
ADT), and -diselenophene (anti-ADS) from readily available
2,6-dimethoxyanthracene via selective functionalization at 3-
and 7-positions as a key step. Although the synthesis of ADFs
went straightforward as its lower analogue, NDFs, the syntheses
of ADT and ADS via heteroannulation reactions using sodium
chalcogenide reagents did not work, and thus alternative
approach consisting of the Larock’s thiophene or selenophene
formation followed by reductive deiodination and desilylation
was developed for the reproducible syntheses of anti-ADT and
Diphenyl Anthradichalcogenophenes (DPh-ADXs) for
OFETs. The synthesis of DPh-ADXs are shown in Scheme 5,
which is basically the same as for the synthesis of the parent
systems: introduction of the phenyl substituents at the ADX
precursor stage readily afford corresponding DPh-ADXs in
acceptable yields, which means that the present synthetic routes
to ADX derivatives are versatile for further development of
ADX-based organic semiconductors.
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high mobilities of up to 1.3 cm2 V−1 s−1. These mobilities
observed for DPh-ADX-based OFETs were almost similar to
those for DPh-NDX-based OFETs, implying that there could
be a certain upper limit of the mobility with extension of the
acenedichalcogenophene cores. With all these studies on anti-
anthradichalcogenophene from their synthetic chemistry to
OFET applications, we would like to place an emphasis on the
potential of isomerically pure anti-anthradichalcogenophenes as
a key component of organic electronics in future.
Scheme 5. Synthesis of anti-DPh-ADXs
EXPERIMENTAL SECTION
■
Synthesis General. All chemicals and solvents are of reagent grade
unless otherwise indicated. Triethylamine, ethanol, tetrahydrofuran
(THF), N,N-dimethylformamide (DMF), and N,N-dimethylacetamide
(DMA) were purified with standard distillation procedures prior to
use. 2,6-Dimethoxyanthracene14 was prepared according to the
reported procedure. All reactions were carried out under nitrogen
atmosphere. Melting points were uncorrected. Nuclear magnetic
resonance spectra were obtained in deuterated chloroform (CDCl3) or
deuterated dimethylsulfoxide (DMSO-d6) with teteramethylsilane
(TMS) as internal reference; chemical shifts (δ) are reported in
parts per million. EI-MS spectra were obtained using an electron
impact ionization procedure (70 eV). The molecular ion peaks of the
bromine, sulfur, or selenium containing compounds showed a typical
isotopic pattern, and all the mass peaks are reported based on 79Br, 32S,
or 80Se, respectively. All reported HRMS were obtained using an
atmospheric pressure chemical ionization (APCI, vaporizer temper-
ature: 400 °C) with a linear quadrupole ion trap (LTQ) or orbitrap
method, except for 6, where an electrospray ionization (ESI) with was
used.
2,6-Dibromo-3,7-dimethoxyanthracene (2). To a suspension
of 2,6-dimethoxyanthracene 1 (12 g, 50 mmol) in THF (2.0 L) was
added 1.67 M hexane solution of n-BuLi (140 mL, 234 mmol) at 0 °C.
After the mixture was stirred for 1 h at room temperature, 1,2-
dibromo-1,1,2,2,-trichloroethane (100 g, 307 mmol) was added to the
solution at 0 °C, and the resulting mixture was stirred for 12 h at room
temperature. The mixture was poured into a saturated aqueous
ammonium chloride solution (200 mL), and the organic solvent was
removed by evaporation. The resulting precipitate was collected by
filtration, washed with water, methanol and a small amount of
chloroform, then dried in vacuo to give 2,6-dibromo-3,7-dimethox-
yanthracene 2 (20.0 g, quantitative yield) as a pale-green solid. Mp
ADS. The selective formation of the anti-isomer by the routes
was confirmed by 13C NMR spectra as well as single crystal X-
ray analysis. The physicochemical properties of parent anti-
ADXs investigated by cyclic voltammograms, UV−vis absorp-
tion spectra, and PESA, clearly indicated that anti-ADXs have
relatively high-lying HOMO energy levels (∼−5.0 eV) and
small HOMO−LUMO energy gap (∼2.4 eV). Comparison of
these electronic properties with those of the lower analogues,
BDXs and NDXs, can give insight into the electronic structure
trend of acenedichalocogenophenes as the balance between the
central acene core and the outermost chalcogenophene rings.
Among isomerically pure parent anti-anthradichalcogeno-
phenes, anti-ADT and anti-ADS can afford crystalline thin
films by vapor deposition, which acted as active layer in organic
field-effect transistors with mobility as high as 0.3 cm2 V−1 s−1
for ADT and 0.7 cm2 V−1 s−1 for ADS, respectively. The
mobility of isomerically pure anti-ADT is higher by several
times than those reported for isomercally mixed ADT, implying
that there could exist an isomer effect on the field-effect
mobility, but not significant. Considering the large syn/anti
isomer effects on FET characteristics previously reported for
DPh-BDS and DPh-NDT, the present small influence can be
understood by the dilution effect of the central acene part;
largely π-extended ADT tends to have small electrical and
structural perturbation from the outermost thiophene rings
than those in the case of the BDS and NDT derivatives. We
then tested the diphenyl derivatives of anti-ADF, -ADT, and
-ADS as the active material for OFET devices, which showed
1
282−283 °C; H NMR (400 MHz, CDCl3) δ 8.18 (s, 2H), 8.12 (s,
2H), 7.21 (s, 2H), 4.04 (s, 6H); 13C NMR (100 MHz, CDCl3) δ
176.0, 132.7, 124.0, 120.9, 115.0, 105.8, 90.1, 56.9; EI-MS (70 eV) m/z
= 394 (M+); HRMS (APCI): Calcd for C16H12Br2O2 394.92768
[MH+], found 394.92789.
3,7-Dibromoanthracene-2,6-diol (3). To a solution of 2,6-
dibromo-3,7-dimethoxyanthracene 2 (25 g, 63 mmol) in dichloro-
methane (700 mL) was added dropwise a dichloromethane solution of
BBr3 (ca. 4 M, 50 mL, 100 mmol) at 0 °C. After refluxing for 12 h,
crashed ice (ca. 100 g) was added to the mixture at 0 °C. The organic
solvent was removed by evaporation, and the resulting precipitate was
collected by filtration, washed with water and methanol, dried in vacuo
to give 3,7-dibromoanthracene-2,6-diol 3 (23.2 g, quantitative yield) as
1
a pale-green solid. Mp >300 °C; H NMR (400 MHz, DMSO-d6) δ
10.61 (s, 2H), 8.27 (s, 2H), 8.20 (s, 2H), 7.31 (s, 2H); 13C NMR (100
MHz, DMSO-d6) δ 150.2, 131.4, 129.9, 128.2, 122.3, 114.8, 107.8; IR
(KBr) ν = 3359 cm−1 (OH); EI-MS (70 eV) m/z = 366 (M+); HRMS
(APCI): Calcd for C14H9Br2O2 366.89638 [MH+], found 366.89654.
2,6-Dibromo-3,7-bis(trifluoromethanesulfonyloxy)-
anthracene (4). To a solution of 3,7-dibromoanthracene-2,6-diol 3
(5.0 g, 14 mmol) and triethylamine (10.0 mL, 71.4 mmol) in
dichloromethane (400 mL) was added trifluoromethanesulfonic
anhydride (7.0 mL, 42 mmol) at 0 °C. After stirring for 19 h at
room temperature, the mixture was diluted with water (50 mL) and
hydrochloric acid (4 M, 100 mL). The resulting mixture was extracted
with dichloromethane (150 mL × 3). The combined organic layer was
washed with brine (100 mL × 3), dried (MgSO4), and purified by flash
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Figure 5. Output and transfer characteristics of (a) DPh-ADF-based, (b) DPh-ADT-based OFETs, (c) DPh-ADS-based OFETs fabricated on
octadecyltrichlorosilane (ODTS)-SAM modified Si/SiO2 substrates at Tsub = 150 °C.
column chromatography on silica gel (Rf = 0.5, dichloromethane/
hexane, 1:1 v/v) to give 2,6-dibromo-3,7-bis(trifluoromethane-
sulfonyloxy)anthracene 4 (8.6 g, quantitative yield) as a yellow solid.
mmol), Pd(PPh3)2Cl2 (56.2 mg, 0.080 mmol, 5 mol %) and CuI (30.5
mg, 0.16 mmol, 10 mol %). After stirring for 12 h at room
temperature, the mixture was diluted with water (50 mL) and
hydrochloric acid (4 M, 10 mL). The resulting precipitate was
collected by filtration and washed with water. The solid was purified by
flash column chromatography on silica-gel (Rf = 0.6, dichloromethane/
hexane, 1:1 v/v) to gave 2,6-dibromo-3,7-bis(trimethylsilylethynyl)-
anthracene 5 (437 mg, 56%) as a pale-yellow solid. Mp 281−282 °C;
1H NMR (400 MHz, CDCl3) δ 8.22 (s, 2H), 8.19 (s, 2H), 8.17 (s,
2H), 0.32 (s, 18H); 13C NMR (100 MHz, CDCl3) δ 134.3, 134.0,
131.8, 131.2, 125.6, 123.2, 122.0, 103.3, 100.8, 0.14; EI-MS (70 eV)
1
Mp 232−233 °C; H NMR (400 MHz, CDCl3) δ 8.42 (s, 2H), 8.37
(s, 2H), 8.01 (s, 2H); 13C NMR (100 MHz, CDCl3) δ 145.2, 134.5,
131.8, 131.8, 131.2, 121.4, 117.8, 115.5; IR (KBr) ν = 1417, 1212 cm−1
(-O−SO2-); EI-MS (70 eV) m/z = 630 (M+); HRMS (APCI): Calcd
for C16H6F6O6S2Br2 629.78713 [M+], found 629.78632.
2,6-Dibromo-3,7-bis(trimethylsilylethynyl)anthracene (5).
To a deaerated solution of 2,6-dibromo-3,7-bis(trifluoromethane-
sulfonyloxy)anthracene 4 (1.0 g, 1.6 mmol) in triethylamine (10 mL)
and DMF (10 mL) was added trimethylsilylacetylene (0.32 mL, 3.2
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2,6-Dimethoxy-3,7-bis(methylthio)anthracene (8). To a
suspension of 2,6-dimethoxyanthracene 1 (16.5 g, 69 mmol) in
THF (2.0 L) was added 1.62 M hexane solution of n-BuLi (175 mL,
276 mmol) at 0 °C. After the mixture was stirred for 1 h at room
temperature, dimethyldisulfide (31 mL, 345 mmol) was added to the
mixture at 0 °C, and the resulting mixture was stirred for 9 h at room
temperature. The mixture was poured into a saturated aqueous
ammonium chloride solution (500 mL), and the organic solvent was
removed by evaporation. The resulting precipitate was collected by
filtration, washed with water, and then dissolved in chloroform. The
solution was dried (MgSO4), and concentrated in vacuo. The residue
was then purified by flash column chromatography on silica gel (Rf =
0.7, dichloromethane/hexane, 1:1 v/v) to give analytically pure 2,6-
dimethoxy-3,7-bis(methylthio)anthracene 8 (22.7 g, quantitative yield)
as a pale-yellow solid. Mp 253−255 °C; 1H NMR (400 MHz, CDCl3)
δ 8.08 (s, 2H), 7.50 (s, 2H), 7.12 (s, 2H), 4.03 (s, 6H), 2.58 (s, 6H);
13C NMR (100 MHz, CDCl3) δ 153.8, 130.7, 129.5, 128.3, 122.4,
122.0, 103.3, 55.9, 14.5; EI-MS (70 eV) m/z = 330 (M+). Anal. Calcd
for C18H18O2S2: C, 65.42; H, 5.49%. Found: C, 65.47; H, 5.34%.
3,7-Bis(methylthio)anthracene-2,6-diol (9). To a solution of
2,6-dimethoxy-3,7-bis(methylthio)anthracene 8 (14 g, 42 mmol) in
dichloromethane (2 L) was added dropwise a dichloromethane
solution of BBr3 (ca. 4 M, 40 mL, 160 mmol) at 0 °C. After the
mixture was stirred for 18 h at room temperature, crashed ice (ca. 100
g) was added to the mixture at 0 °C. The organic solvent was removed
by evaporation and the resulting precipitate was collected by filtration,
washed with water, and dried in vacuo to give practically pure 3,7-
bis(methylthio)anthracene-2,6-diol 9 (12.7 g, quantitative yield) as a
Figure 6. Mobility dependence on the chalcogenophene rings and
central acene cores in diphenyl-acenedichalcogenophene series.
m/z = 526 (M+). HRMS (APCI): Calcd for C24H24Br2Si2 525.97778
[M+], found 525.97723.
2,6-Diacetoxy-3,7-dibromoanthracene (6). To a suspension of
3,7-dibromoanthracene-2,6-diol 3 (5.0 g, 14 mmol) and triethylamine
(15 mL, 107 mmol) in dichloromethane (400 mL) was added acetic
anhydride (3.4 mL, 36 mmol) at 0 °C. After the mixture was stirred for
7 h at room temperature, the mixture was diluted with water (100 mL)
and hydrochloric acid (4 M, 100 mL). The organic solvent was
removed by evaporation, and the resulting precipitate was collected by
filtration, washed with water and small amount of chloroform, and
then dried in vacuo to give 2,6-diacetoxy-3,7-dibromoanthracene 6 as a
white solid (2.7 g, 43%). Mp >300 °C; 1H NMR (400 MHz, CDCl3) δ
8.26 (s, 2H), 8.25 (s, 2H), 7.75 (s, 2H), 2.45 (s, 2H); 13C NMR (100
MHz, CDCl3) δ 168.6 145.6, 132.6, 131.0, 130.9, 125.5, 120.6, 116.7,
20.8; IR (KBr) ν = 1763 cm−1 (CO); EI-MS (70 eV) m/z = 450
(M+). HRMS (ESI): Calcd for C18H12Br2O4 472.89946 [MNa+],
found 472.89948.
1
pale-green solid. Mp 252−255 °C; H NMR (400 MHz, CDCl3) δ
8.10 (s, 2H), 8.05 (s, 2H), 7.36 (s, 2H), 6.37 (s, 2H), 2.48 (s, 6H); 13C
NMR (100 MHz, CDCl3) δ 151.1, 132.9, 131.6, 129.2, 127.3, 123.7,
107.8, 19.4; IR (KBr) ν = 3396 cm−1 (OH); EI-MS (70 eV) m/z =
302 (M+). Anal. Calcd for C16H14O2S2: C, 63.55; H, 4.67%. Found: C,
63.32; H, 4.42%.
2,6-Bis(methylthio)-3,7-bis(trifluoromethanesulfonyloxy)-
anthracene (10). To a suspension of 3,7-bis(methylthio)anthracene-
2,6-diol 9 (10 g, 33 mmol) and triethylamine (30 mL, 214 mmol) in
dichloromethane (500 mL) was added trifluoromethanesulfonic
anhydride (15 mL, 89 mmol) at 0 °C. After stirring for 20 h at
room temperature, the mixture was diluted with water (100 mL) and
hydrochloric acid (4 M, 100 mL). Evaporation of the organic solvent
in vacuo gave a precipitate, which was collected by filtration, washed
with water and small amount of chloroform, them dried in vacuo to
give 2,6-bis(trifluoromethanesulfonyloxy)-3,7-bis(methylthio)-
2,6-Diacetoxy-3,7-bis(trimethylsilylethynyl)anthracene (7).
To a deaerated solution of 2,6-deacetoxy-3,7-dibromoanthracene 6
(1.8 g, 4.0 mmol) in triethylamine (20 mL) and DMF (20 mL) was
added trimethylsilylacetylene (1.2 mL, 9.6 mmol), Pd(PPh3)2Cl2 (140
mg, 0.2 mmol, 5.0 mol %) and CuI (76.2 mg, 0.4 mmol, 10 mol %).
After stirring for 12 h at 60 °C, the mixture was diluted with water (10
mL) and hydrochloric acid (4 M, 20 mL). The resulting precipitate
was collected by filtration and washed with water, which was further
purified by flash column chromatography on silica-gel (Rf = 0.3,
dichloromethane/hexane, 1:1 v/v) to give 2,6-diacetoxy-3,7-bis-
(trimethylsilylethynyl)anthracene 7 (1.6 g, 84%) as a yellow solid.
1
anthracene 10 (10.5 g, 56%) as a yellow solid. Mp 212−213 °C; H
NMR (400 MHz, CDCl3) δ 8.28 (s, 2H), 7.86 (s, 2H), 7.73 (s, 2H),
2.63 (s, 6H); 13C NMR (100 MHz, CDCl3) δ 145.9, 132.2, 130.6,
130.0, 125.9, 125.6, 120.5, 119.1, 117.3, 15.6; IR (KBr) ν = 1429, 1222
cm−1 (-O−SO2-); EI-MS (70 eV) m/z = 566 (M+). Anal. Calcd for
C18H12F6O6S4: C, 38.16; H, 2.13%. Found C, 38.37; H, 1.83%.
2,6-Bis(methylthio)-3,7-bis(trimethylsilylethynyl)anthracene
(11). To a deaerated solution of 2,6-bis(trifluoromethanesulfonyloxy)-
3,7-bis(methylthio)anthracene 10 (283 mg, 0.5 mmol) in triethyl-
amine (5.0 mL) and DMF (5.0 mL) was added trimethylsilylacetylene
(0.17 mL, 1.2 mmol), Pd(PPh3)2Cl2 (17.6 mg, 0.025 mmol, 5 mol %)
and CuI (9.5 mg, 0.05 mmol, 10 mol %). After stirring for 12 h at 60
°C, the mixture was diluted with water (10 mL) and hydrochloric acid
(4 M, 2.0 mL). The resulting precipitate was collected by filtration and
washed with water. The solid was purified by flash column
chromatography on silica-gel (Rf = 0.5, dichloromethane/hexane, 1:1
v/v) to give 2,6-bis(methylthio)-3,7-bis(trimethylsilylethynyl)-
anthracene 11 (230 mg, quantitative yield) as a pale yellow solid
1
Mp 232−233 °C; H NMR (400 MHz, CDCl3) δ 8.26 (s, 2H), 8.18
(s, 2H), 7.65 (s, 2H), 2.40 (s, 6H), 0.30 (s, 18H); 13C NMR (100
MHz, CDCl3) δ 169.5, 147.9, 134.6, 131.4, 130.4, 126.5, 119.4, 117.8,
100.8, 100.4, 21.2, 0.24; IR (KBr) ν = 1774 cm−1 (CO); EI-MS (70
eV) m/z = 486 (M+). HRMS (APCI): Calcd for C28H30O4Si2
487.17554 [MH+], found 487.17480.
Anthra[2,3-b:6,7-b′]difuran (anti-ADF). To a suspension of
cesium carbonate (6.0 g, 18 mmol) in DMA (50 mL) and water (6
mL) was added 2,6-diacetoxy-3,7-bis(trimethylsilylethynyl)anthracene
7 (1.0 g, 2.1 mmol), and the resulting mixture was then stirred at 80
°C for 4 h. The mixture was poured into 200 mL of saturated aqueous
ammonium chloride solution, and the resulting precipitate was
collected by filtration and washed with water to give anthra[2,3-
b:6,7-b′]difuran (0.33 g, 63%) as a yellow solid. Analytical sample was
obtained by repetitive gradient sublimation in vacuo (ca. 240 °C at
<10−2 Pa under nitrogen atmosphere) and solvent washing (chloro-
form). Mp >300 °C; 1H NMR (400 MHz, DMSO-d6) δ 8.83 (s, 2H),
8.35 (s, 2H), 8.17 (s, 2H), 8.03 (d, J = 8.0 Hz, 2H), 7.07(d, J = 8.0 Hz,
2H); 13C NMR (100 MHz, DMSO-d6) δ 153.5, 149.1, 129.7, 129.1,
129.0, 125.5, 118.2, 106.3, 105.0; EI-MS (70 eV) m/z = 258 (M+).
Anal. Calcd for C18H10O2: C, 83.71; H, 3.90%. Found C, 83.77; H,
4.11%; HRMS (APCI): Calcd for C18H10O2 259.07536 [MH+], found
259.07547.
1
Mp 210−213 °C; H NMR (400 MHz, CDCl3) δ 8.08 (s, 2H), 8.05
(s, 2H), 7.47 (s, 2H), 2.60 (s, 6H), 0.33 (s, 18H); 13C NMR (100
MHz, CDCl3) δ 137.9, 133.5, 131.5, 130.4, 124.9, 121.4, 120.7, 102.7,
102.1, 15.8, 0.51; EI-MS (70 eV) m/z = 462 (M+). Anal. Calcd for
C26H30S2Si2: C, 67.47; H, 6.53%. Found: C, 67.32; H, 6.40%.
3,9-Diiodo-2,8-bis(trimethylsilyl)anthra[2,3-b:6,7-b′]-
dithiophene (12). To a solution of 2,6-bis(methylthio)-3,7-bis-
(trimethylsilylethynyl)anthracene 11 (2.9 g, 6.3 mmol) in dichloro-
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methane (200 mL) was added iodine (8.0 g, 31 mmol) at 0 °C. After
stirring for 3 h at room temperature, the mixture was poured into a
vigorously stirred aqueous solution of sodium hydrogen sulfite (50
mL). The resulting precipitate was collected by filtration, washed
successively with water (100 mL) and ethanol (100 mL), and dried in
vacuo to give crude 3,9-diiodo-2,8-bis(trimethylsilylethynyl)anthra-
[2,3-b:6,7-b′]dithiophene 12 (4.1 g, 88%) as a dark reddish solid. Mp
250 °C (Decomp.); 1H NMR (400 MHz, CDCl3) δ 8.84 (s, 2H), 8.52
(s, 2H), 8.51 (s, 2H), 0.56 (s, 18H); 13C NMR (100 MHz, CDCl3) δ
144.6, 142.4, 137.6, 129.8, 129.6, 126.1, 124.1, 119.9, 86.9, 0.8; EI-MS
(70 eV) m/z = 686 (M+). Anal. Calcd for C24H24I2S2Si2: C, 41.99; H,
3.52%. Found: C, 42.00; H, 3.22%.
the mixture was stirred for 12 h at room temperature, crashed ice (ca.
100 g) was added to the mixture at 0 °C. The organic solvent was
removed by evaporation and the resulting precipitate was collected by
filtration. The crude product was washed successively with water and
small amount of ethanol and chloroform, and dried in vacuo to give
sufficiently pure 3,7-bis(methylseleno)anthracene-2,6-diol 15 (13.0 g,
quantitative yield) as a pale-green solid. Mp 272−273 °C (Decomp.);
1H NMR (400 MHz, CDCl3) δ 8.21 (s, 2H), 8.13 (s, 2H), 7.36 (s,
2H), 2.32 (s, 6H); 13C NMR (100 MHz, CDCl3) δ 151.2, 135.5,
131.8, 129.1, 123.6, 122.9, 107.1, 9.7; IR (KBr) ν = 3404 cm−1 (OH);
EI-MS (70 eV) m/z = 398 (M+); HRMS (APCI): Calcd for
C16H14O2Se2 398.93970 [MH+], found 398.93930.
Anthra[2,3-b:6,7-b′]dithiophene (anti-ADT). To a suspension
of 3,9-diiodo-2,8-bis(trimethylsilyl)anthra[2,3-b:6,7-b′]dithiophene 12
(2.0 g, 2.9 mmol) in ethanol (200 mL) was added sodium borohydride
(8.0 g, 31 mmol). The mixture was then reflux for 24 h. After cooling
to 0 °C, hydrochloric acid (4M, 50 mL) was added to the mixture with
stirring (ca. 10 min) to precipitate a dark-red solid. The solid was
collected by filtration, washed successively with water (100 mL) and
ethanol (100 mL), and dried in vacuo to give crude anthra[2,3-b:6,7-
b′]dithiophene (4.1 g, 88%) as an orange solid. Analytical sample was
obtained by repetitive gradient sublimation in vacuo (ca. 290 °C at
<10−2 Pa under nitrogen atmosphere) and solvent washing (chloro-
form). Mp >300 °C; 1H NMR (400 MHz, DMSO-d6) δ 8.84 (s, 2H),
8.69 (s, 2H), 8.63 (s, 2H), 7.75 (d, J = 5.2 Hz, 2H), 7.51 (d, J = 5.2
Hz, 2H); EI-MS (70 eV) m/z = 290 (M+). Anal. Calcd for C18H10S2:
C, 74.45; H, 3.47%. Found: C, 74.18; H, 3.22%; HRMS (APCI):
Calcd for C18H10S2 291.02967 [MH+], found 291.02991. The
solubility of anti-ADT was not sufficient for measuring 13C NMR
spectra.
2,6-Bis(methylseleno)-3,7-bis(trifluoromethanesulfonyloxy)-
anthracene (16). To a suspension of 3,7-bis(methylseleno)-
anthracene-2,6-diol 15 (12 g, 30 mmol) and triethylamine (40.0 mL,
285 mmol) in dichloromethane (700 mL) was added trifluorometha-
nesulfonic anhydride (15 mL, 89 mmol) at 0 °C. After the mixture was
stirred for 3 h at room temperature, the mixture was diluted with water
(100 mL) and hydrochloric acid (4 M, 100 mL). The resulting mixture
was extracted with dichloromethane (400 mL × 3). The combined
organic layers were washed with brine (400 mL × 3), dried (MgSO4)
and purified by flash column chromatography on silica-gel (Rf = 0.3,
dichloromethane/hexane, 1:1 v/v) to give 2,6-bis(methylseleno)-3,7-
bis(trifluoromethanesulfonyloxy)anthracene 16 (7.5 g, 38%) as a
yellow solid. Mp 223−224 °C; 1H NMR (400 MHz, CDCl3) δ 8.31 (s,
2H), 7.90 (s, 2H), 7.88 (s, 2H), 2.51 (s, 6H); 13C NMR (100 MHz,
CDCl3) δ 146.9 130.8, 130.4, 129.8, 126.1, 125,7, 118.7, 7.2; IR (KBr)
ν = 1425, 1222 cm−1 (-O−SO2-); EI-MS (70 eV) m/z = 662 (M+);
HRMS (APCI): Calcd for C18H12O6F6S2Se2 661.83044 [M+], found
661.82971.
3,9-Diphenylanthra[2,3-b:6,7-b′]dithiophene (13). To a de-
gassed suspension of 3,9-diiodo-2,8-bis(trimethylsilyl)anthra[2,3-b:6,7-
b′]dithiophene 12 (69 mg, 0.1 mmol), phenylboronic acid (36.6 mg,
0.3 mmol) and K3PO4·nH2O (200 mg) in DMF (3.0 mL) was added
Pd(PPh3)4 (11.6 mg, 0.01 mmol, 10 mol %) at 90 °C. After stirring for
15 h, the resulting mixture was poured into a saturated aqueous
sodium hydrogen sulfite solution (50 mL) with stirring (ca. 10 min).
The resulting precipitate was collected by filtration, washed
successively with water (100 mL) and ethanol (100 mL), and
recrystallization from CHCl3 to give 3,9-dipheynyl-anthra[2,3-b:6,7-
b′]dithiophene 13 (30 mg, 68%) as a dark-red solid. Mp >300 °C; 1H
NMR (400 MHz, CDCl3) δ 8.71 (s, 2H), 8.60 (s, 2H), 8.56 (s, 2H),
7.72 (d, J = 8.0 Hz, 4H), 7.59 − 7.49 (m, 6H), 7.43 (s, 2H); 13C NMR
(100 MHz, CDCl3) δ138.5, 137.8, 137.2, 135.9, 129.4, 129.1, 128.9,
128.8, 127.9, 125.9, 125.7, 121.3, 120.8; EI-MS (70 eV) m/z = 442
(M+); HRMS (APCI): Calcd for C30H18S2 442.08444 [M+], found
442.08450.
2,6-Bis(methylseleno)-3,7-bis[(trimethylsilyl)ethynyl]-
anthracene (17). To a deaerated solution of 2,6-bis(methylseleno)-
3,7-bis(trifluoromethanesulfonyloxy)anthracene 16 (1.50 g, 2.27
mmol) in DMF (40 mL) were added trimethyl[(tributylstannyl)-
ethynyl]silane (2.2 g, 5.68 mmol) and Pd(PPh3)2Cl2 (79.7 mg, 0.114
mmol, 5 mol %). After stirring for 2 h at 60 °C, the mixture was
diluted with water (10 mL) and hydrochloric acid (4 M, 2.0 mL). The
resulting precipitate was collected by filtration and washed with water.
The solid was purified by flash column chromatography on silica-gel
(Rf = 0.3, dichloromethane/hexane, 1:1 v/v) to give 2,6-bis-
(methylthio)-3,7-bis[(trimethylsilyl)ethynyl]anthracene 17 (1.02 g,
1
81%) as a pale-yellow solid. Mp 227−228 °C; H NMR (400 MHz,
CDCl3) δ 8.11 (s, 2H), 8.05 (s, 2H), 7.67 (s, 2H), 2.46 (s, 6H), 0.33
(s, 18H); 13C NMR (100 MHz, CDCl3) δ 132.8, 132.7, 131.6, 130.6,
125.3, 124.9, 122.2, 103.4, 101.3, 6.84, 0.25; EI-MS (70 eV) m/z = 558
(M+); HRMS (APCI): Calcd for C26H30Se2Si2 558.02110 [M+], found
558.02063.
2,6-Dimethoxy-3,7-bis(methylseleno)anthracene (14). To a
suspension of 2,6-dimethoxyanthracene 1 (12 g, 50 mmol) in THF
(2.0 L) was added 1.67 M hexane solution of n-BuLi (140 mL, 234
mmol) at 0 °C. After the mixture was stirred for 1 h at room
temperature, selenium powder (16.6 g, 210 mmol) was added to the
solution at 0 °C, and the resulting mixture was stirred for 30 min at
room temperature to give a clear solution of corresponding selenoate.
Iodomethane (15 mL, 243 mmol) was then added to the solution at 0
°C and the mixture was stirred for 12 h. The mixture was poured into
a saturated aqueous ammonium chloride solution (500 mL), and
evaporation of the organic solvent in vacuo gave a precipitate, which
was collected by filtration, washed with water and methanol, then dried
in vacuo to give 2,6-dimethoxy-3,7-bis(methylseleno)anthracene 14
(16.0 g, 76%) as a white solid. Mp 267−268 °C (Decomp.); 1H NMR
(400 MHz, CDCl3) δ 8.08 (s, 2H), 7.62 (s, 2H), 7.11 (s, 2H), 4.02 (s,
6H), 2.42 (s, 6H); 13C NMR (100 MHz, CDCl3) δ 154.6, 130.1,
128.8, 125.9, 125.4, 122.5, 103.1, 55.9, 5.0; EI-MS (70 eV) m/z = 426
(M+). HRMS (APCI): Calcd for C18H18O2Se2 426.97100 [MH+],
found 426.97018.
3,9-Diiodo-2,8-bis(trimethylsilyl)anthra[2,3-b:6,7-b′]-
diselenophene (18). To a solution of 2,6-bis(methylseleno)-3,7-
bis[(trimethylsilyl)ethynyl]anthracene 17 (0.557 g, 1.0 mmol) in
dichloromethane (60 mL) was added iodine (1.01 g, 4 mmol) at 0 °C.
After stirring for 3 h at room temperature, the mixture was poured into
a saturated aqueous sodium hydrogen sulfite solution (5 mL) with
stirring (ca. 10 min). The resulting precipitate was collected by
filtration, washed successively with water (100 mL) and ethanol (100
mL), and dried in vacuo to give 3,9-diiodo-2,8-bis(trimethylsilyl)-
anthra[2,3-b:7,8-b′] diselenophene 18 (0.694 g, 89%) as a dark-
1
reddish solid. Mp >300 °C; H NMR (400 MHz, CDCl3) δ 8.76 (s,
2H), 8.59 (s, 2H), 8.54 (s, 2H), 0.55 (s, 18H); 13C NMR (100 MHz,
CDCl3) δ 164.6, 137.7, 130.7, 127.9, 126.7, 124.0, 114.4, 99.8, 98.6,
0.28; EI-MS (70 eV) m/z = 782 (M+). HRMS (APCI): Calcd for
C24H24I2Se2Si2 781.78302 [M+], found 781.78308.
Anthra[2,3-b:6,7-b′]diselenophene (anti-ADS). To a suspen-
sion of 3,9-diiodo-2,8-bis(trimethylsilyl)anthra[2,3-b:6,7-b′]-
diselenophene 18 (0.50 g, 0.64 mmol) in 1,4-dioxane (100 mL) was
added LiAlH4 (0.5 g, 13.2 mmol), and the mixture was refluxed for 24
h; ethyl acetate (50 mL) was then added to the mixture at 0 °C with
stirring (ca. 10 min). The resulting precipitate was collected by
filtration, washed successively with water (100 mL) and ethanol (100
mL), and dried in vacuo to give anthra[2,3-b:6,7-b′]diselenophene
3,7-Bis(methylseleno)anthracene-2,6-diol (15). To a solution
of 2,6-dimethoxy-3,7-bis(methylseleno)anthracene 14 (14 g, 33
mmol) in dichloromethane (2 L) was added dropwise a dichloro-
methane solution of BBr3 (ca. 4 M, 50 mL, 200 mmol) at 0 °C. After
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(0.21 g, 86%) as an orange solid. The solid was purified by repetitive
gradient sublimation in vacuo (ca. 310 °C at <10−2 Pa under nitrogen
atmosphere) and solvent washing (chloroform). Mp >300 °C; 1H
NMR (400 MHz, DMSO-d6) δ 8.76 (s, 2H), 8.74 (s, 2H), 8.61 (s,
2H), 8.17 (d, J = 5.2 Hz, 2H), 7.71 (d, J = 5.2 Hz, 2H); EI-MS (70 eV)
m/z = 386 (M+); HRMS (APCI): Calcd for C18H10Se2 385.91075
[M+], found 385.91040. The solubility of anti-ADS was not sufficient
for measuring 13C NMR spectra.
2,6-Diacetoxy-3,7-bis(phenylethynyl)anthracene (19). To a
deaerated solution of 2,6-diacetoxy-3,7-dibromoanthracene 6 (1.8 g,
4.0 mmol) in triethylamine (20 mL) and DMF (20 mL) were added
phenylacetylene (0.98 g, 9.6 mmol), Pd(PPh3)2Cl2 (140 mg, 0.2
mmol, 5 mo l%), and CuI (76.2 mg, 0.4 mmol, 10 mol %). After
stirring for 12 h at 60 °C, the mixture was diluted with water (10 mL)
and hydrochloric acid (4 M, 20 mL). The resulting precipitate was
collected by filtration and washed with water, methanol, and
dichloromethane to give 2,6-diacetoxy-3,7-bis(phenylethynyl)-
anthracene 19 (1.6 g, 81%) as a yellow solid. Mp >300 °C; 1H
NMR (400 MHz, CDCl3) δ 8.34 (s, 2H), 8.26 (s, 2H), 7.73 (s, 2H),
7.56−7.55 (m, 4H), 7.40−7.39 (m, 6H), 2.46 (s, 6H); 13C NMR (100
MHz, CDCl3) δ 186.7,146.3,140.4, 139.1, 133.7, 133.3, 130.3, 129.9,
12.7, 122.5, 118.8, 144.0,93.9, 23.3; IR (KBr) ν = 1752.36 cm−1 (C
O); EI-MS (70 eV) m/z = 494 (M+). HRMS (APCI): Calcd for
C34H22O4 494.15126 [M+], found 494.15195.
2,8-Diphenylanthra[2,3-b:6,7-b′]dithiophene (DPh-ADT). To
a suspension of 3,9-diiodo-2,8-diphenylanthra[2,3-b:6,7-b′]-
dithiophene 21 (2.17 g, 2.9 mmol) in ethanol (200 mL) was added
sodium borohydride (8.0 g, 31 mmol). The mixture was then reflux for
24 h. After cooling to 0 °C, hydrochloric acid (4M, 50 mL) was added
to the mixture with stirring (ca. 10 min) to precipitate a dark red solid.
The solid was collected by filtration, washed successively with water
(100 mL) and ethanol (100 mL), and dried in vacuo to give crude 2,8-
diphenylanthra[2,3-b:6,7-b′]dithiophene (DPh-ADT, 1.28 g, quantita-
tive yield) as a dark-reddish solid. The solid was purified by repetitive
gradient sublimation in vacuo (ca. 320 °C at <10−2 Pa under nitrogen
atmosphere) and solvent washing (chloroform) for device fabrication.
Mp > 300 °C; EI-MS (70 eV) m/z = 442 (M+). Anal. Calcd for
C30H18S2: C, 81.41; H, 4.10%. Found: C, 81.49; H, 4.11%. The
solubility of DPh-ADT was too low to obtain 1H and 13C NMR
spectra for structural characterization.
2,6-Bis(methylseleno)-3,7-bis(phenylethynyl)anthracene
(22). To a deaerated solution of 2,6-bis(trifluoromethanesulfonyloxy)-
3,7-bis(methylseleno)anthracene 16 (1.50 g, 2.27 mmol) in DMF (40
mL) was added tributyl(phenylethynyl)tin (2.22 g, 5.68 mmol),
Pd(PPh3)2Cl2 (79.7 mg, 0.11 mmol, 5 mol %). After stirring for 2 h at
60 °C, the mixture was diluted with water (10 mL) and hydrochloric
acid (4 M, 2.0 mL). The resulting precipitate was collected by filtration
and washed with water. The solid was purified by flash column
chromatography on silica-gel (Rf = 0.6, dichloromethane/hexane, 1:1
v/v) to give 2,6-bis(methylseleno)-3,7-bis(phenylethynyl)anthracene
2,8-Diphenylanthra[2,3-b:6,7-b′]difuran (DPh-ADF). To a
suspension of cesium carbonate (6.0 g, 18 mmol) in DMA (200
mL) and water (24 mL) were added 2,6-diacetoxy-3,7-bis-
(phenylethynyl)anthracene 19 (1.04 g, 2.1 mmol), and the resulting
mixture was then stirred at 100 °C for 24 h. After poured into 200 mL
of saturated aqueous ammonium chloride solution, the precipitate was
collected by filtration and washed with water to give 2,8-
diphenylanthra[2,3-b:6,7-b′]difuran (0.740 g, 86%) as an orange
solid. The solid was purified by repetitive gradient sublimation in
vacuo (ca. 280 °C at <10−2 Pa under nitrogen atmosphere) and
solvent washing (chloroform). Mp >300 °C; EI-MS (70 eV) m/z =
410 (M+). HRMS (APCI): Calcd for C30H18O2 410.13013 [M+],
found 410.13120. The solubility of DPh-ADF was not sufficient to
1
22 (0.91 g, 71%) as a pale-yellow solid. Mp 227−228 °C; H NMR
(400 MHz, CDCl3) δ 8.18 (s, 2H), 8.13 (s, 2H), 7.74 (s, 2H), 7.66−
7.64 (m, 4H), 7.40−7.38 (m, 6H), 2.51 (s, 6H); 13C NMR (100 MHz,
CDCl3) δ 131.2, 132.5, 132.3, 131.9, 130.9, 129.2, 129.0, 125.6, 125.2,
123.5, 122.6, 95.6, 88.6, 7.06; EI-MS (70 eV) m/z = 564 (M+); HRMS
(APCI): Calcd for C32H22Se2 566.00465 [M+], found 566.00598.
3,9-Diiodo-2,8-diphenylanthra[2,3-b:6,7-b′]diselenophene
(23). To a solution of 2,6-bis(methylseleno)-3,7-bis(phenylethynyl)-
anthracene 22 (0.566 g, 1.0 mmol) in dichloromethane (60 mL) was
added iodine (1.01 g, 4 mmol) at 0 °C. After stirring for 3 h at room
temperature, the mixture was poured into a saturated aqueous sodium
hydrogen sulfite solution (5 mL) with stirring (ca. 10 min). The
resulting precipitate was collected by filtration, washed successively
with water (100 mL) and ethanol (100 mL), and dried in vacuo to give
3,9-diiodo-2,8-bis(trimethylsilylethynyl)anthra[2,3-b:6,7-b′]-
diselenophene 23 (0.788 g, quant) as a dark-reddish solid, which was
sufficiently pure for the characterization and next reaction. Mp >300
°C; EI-MS (70 eV) m/z = 788 (M+). HRMS (APCI): Calcd for
C30H16I2Se2 789.76663 [M+], found 789.76819. The solubility of
compound 23 was not sufficient for measuring 1H and 13C NMR
spectra.
1
obtain H and 13C NMR spectra useful for structural characterization.
2,6-Bis(methylthio)-3,7-bis(phenylethynyl)anthracene (20).
To
a deaerated solution of 2,6-bis(methylthio)-3,7-bis-
(trifluoromethanesulfonyloxy)anthracene 10 (283 mg, 0.5 mmol) in
triethylamine (5.0 mL) and DMF (5.0 mL) were added phenyl-
acetylene (1.23 g, 1.2 mmol), Pd(PPh3)2Cl2 (17.6 mg, 0.025 mmol, 5
mol %), and CuI (9.5 mg, 0.05 mmol, 10 mol %). After stirring for 12
h at 60 °C, the mixture was diluted with water (10 mL) and
hydrochloric acid (4 M, 2.0 mL). The resulting precipitate was
collected by filtration and washed with water. The solid was purified by
flash column chromatography on silica-gel (Rf = 0.6, dichloromethane/
hexane, 1:1 v/v) to give 2,6-bis(methylthio)-3,7-bis(phenylethynyl)-
anthracene 20 (234 mg, quantitative yield) as a pale-yellow solid. Mp
2,8-Diphenylanthra[2,3-b:6,7-b′]diselenophene (DPh-ADS).
To a suspension of 3,9-diiodo-2,8-diphenylanthra[2,3-b:6,7-b′]-
diselenophene 23 (0.504 g, 0.64 mmol) in THF (100 mL) was
added LiAlH4 (0.5 g, 13.2 mmol), and the mixture was refluxed for 24
h. After cooling, ethyl acetate (50 mL) was added to the mixture at 0
°C with stirring (ca. 10 min). The resulting precipitate was collected
by filtration, washed successively with water (100 mL) and ethanol
(100 mL), and dried in vacuo to give 2,8-diphenylanthra[2,3-b:6,7-
b′]diselenophene (0.343 g, quantitative yield) as a dark-reddish solid.
The solid was purified by repetitive gradient sublimation in vacuo (ca.
360 °C at <10−2 Pa under nitrogen atmosphere) and solvent washing
(chloroform) for device fabrication. Mp >300 °C; EI-MS (70 eV) m/z
= 536 (M+); HRMS (APCI): Calcd for C30H19Se2 538.98117 [MH+],
found 538.98096. The solubility of DPh-ADS was not sufficient for
1
222−223 °C; H NMR (400 MHz, CDCl3) δ 8.12 (s, 2H), 8.10 (s,
2H), 7.66−7.64 (m, 4H), 7.52 (s, 2H), 7.40−7.38 (m, 6H), 2.63 (s,
6H); 13C NMR (100 MHz, CDCl3) δ138.1, 132.8, 132.3, 131.6, 130.5,
129.2, 129.0, 124.9, 123.6, 121.6, 120.9, 96.4, 87.8, 15.9; EI-MS (70
eV) m/z = 470 (M+). Anal. Calcd for C32H22S2: C, 81.66; H, 4.71%.
Found C, 81.56; H, 4.69%.
3,9-Diiodo-2,8-diphenylanthra[2,3-b:6,7-b′]dithiophene
(21). To a solution of 2,6-bis(methylthio)-3,7-bis(phenylethynyl)-
anthracene 20 (2.96 g, 6.3 mmol) in dichloromethane (200 mL) was
added iodine (8.0 g, 31 mmol) at 0 °C. After stirring for 3 h at room
temperature, the mixture was poured into a vigorously stirred aqueous
solution of sodium hydrogen sulfite (50 mL). The resulting precipitate
was collected by filtration, washed successively with water (100 mL)
and ethanol (100 mL), and dried in vacuo to give crude 3,9-diiodo-2,8-
diphenylanthra[2,3-b:6,7-b′]dithiophene 21 (4.71 g, quantitative yield)
as a dark-reddish solid. Analytical sample was obtained by
recrystallization from chlorobenzene. Mp >300 °C; EI-MS (70 eV)
m/z = 694 (M+). Anal. Calcd for C30H16I2S2: C, 51.89; H, 2.32%.
Found: C, 52.11; H, 2.42%. Poor solubility of 21 did not allow its
1
measuring H and 13C NMR spectra.
Device Fabrication. Si/SiO2 substrates were exposed to ODTS
(octadecyltrichlorosilane) vapor at room temperature in a closed
desiccator under nitrogen overnight. OFETs were fabricated in a “top-
contact” configuration on a heavily doped n+-Si (100) wafer with a 200
nm thermally grown SiO2 (Ci = 17.3 nF cm−2). Thin film (50 nm
thick) of ADX derivatives as an active layer was vacuum-deposited on
the Si/SiO2 substrate maintained at various temperatures (Tsub) at a
deposition rate of ca. 1 Å s−1 under a pressure of ∼10−3 Pa. On top of
1
characterization by means of H and 13C NMR spectra.
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the organic thin film, gold films (80 nm) as drain and source
electrodes were deposited through a shadow mask. For a typical
device, the drain-source channel length (L) and width (W) are 40 μm
and 3.0 mm, respectively. Characteristics of the OFET devices were
measured at room temperature in the air with a Keithley 4200
semiconducting parameter analyzer. Field-effect mobility (μFET) was
calculated in the saturation regime (Vd = −60 V) of the Id using the
following equation,
2008, 37, 284−285. (e) Kashiki, T.; Miyazaki, E.; Takimiya, K. Chem.
Lett. 2009, 38, 568−569. (f) Pan, H.; Li, Y.; Wu, Y.; Liu, P.; Ong, B. S.;
Zhu, S.; Xu, G. Chem. Mater. 2006, 18, 3237−3241. (g) Pan, H.; Li, Y.;
Wu, Y.; Liu, P.; Ong, B. S.; Zhu, S.; Xu, G. J. Am. Chem. Soc. 2007, 129,
4112−4113. (h) Pan, H.; Wu, Y.; Li, Y.; Liu, P.; Ong, B. S.; Zhu, S.;
Xu, G. Adv. Funct. Mater. 2007, 17, 3574−3579.
(3) (a) Shinamura, S.; Miyazaki, E.; Takimiya, K. J. Org. Chem. 2010,
75, 1228−1234. (b) Shinamura, S.; Osaka, I.; Miyazaki, E.; Nakao, A.;
Yamagishi, M.; Takeya, J.; Takimiya, K. J. Am. Chem. Soc. 2011, 133,
5024−5035. (c) Osaka, I.; Abe, T.; Shinamura, S.; Miyazaki, E.;
Takimiya, K. J. Am. Chem. Soc. 2010, 132, 5000−5001. (d) Osaka, I.;
Abe, T.; Shinamura, S.; Takimiya, K. J. Am. Chem. Soc. 2011, 133,
6852−6860.
Id = (WCi/2L)mFET(V − V )2
g
th
where Ci is the capacitance of the SiO2 insulator, and Vg and Vth are
the gate and threshold voltages, respectively. Current on/off ratio (Ion/
Ioff) was determined from the Id at Vg = 0 V (Ioff) and Vg = −60 V
(Ion). The μFET data reported in Table S1 (Supporting Information)
are typical values from more than five different devices.
(4) (a) Laquindanum, J. G.; Katz, H. E.; Lovinger, A. J. J. Am. Chem.
Soc. 1998, 120, 664−672. (b) Payne, M. M.; Parkin, S. R.; Anthony, J.
E.; Kuo, C.-C.; Jackson, T. N. J. Am. Chem. Soc. 2005, 127, 4986−
4987. (c) Dickey, K. C.; Anthony, J. E.; Loo, Y. L. Adv. Mater. 2006,
18, 1721−1726. (d) Chen, M.-C.; Kim, C.; Chen, S.-Y.; Chiang, Y.-J.;
Chung, M.-C.; Facchetti, A.; Marks, T. J. J. Mater. Chem. 2008, 18,
1029−1036. (e) Coropceanu, V.; Kwon, O.; Wex, B.; Kaafarani, B. R.;
Physicochemical Studies. UV−vis spectra were measured in
dichloromethane or chloroform solution (concentration: 10−5∼10−6
M). Cyclic voltammograms (CVs) were recorded in benzonitrile
containing tetrabutylammonium hexafluorophosphate (Bu4NPF6, 0.1
M) as supporting electrolyte at a scan rate of 100 mV/s. Counter and
working electrodes were made of Pt, and the reference electrode was
Ag/AgCl. All the potentials were calibrated with the standard
ferrocene/ferrocenium redox couple (Fc/Fc+: E1/2 = +0.46 V
measured under identical conditions). X-Ray diffractions of thin
films deposited on the Si/SiO2 substrate were obtained with a CuKα
source (λ = 1.541 Å) in the air. Ionization potentials (IPs) were
determined with photoemission yield spectroscopy in air. AFM images
of thin films on Si/SiO2 were obtained with a tapping mode in air.
Gruhn, N. E.; Durivage, J. C.; Neckers, D. C.; Bred
Eur. J. 2006, 12, 2073−2080.
́
as, J.-L. Chem.
(5) (a) Liang, Y.; Wu, Y.; Feng, D.; Tsai, S.-T.; Son, H.-J.; Li, G.; Yu,
L. J. Am. Chem. Soc. 2009, 131, 56−57. (b) Liang, Y.; Feng, D.; Wu, Y.;
Tsai, S.-T.; Li, G.; Ray, C.; Yu, L. J. Am. Chem. Soc. 2009, 131, 7792−
7799. (c) Huo, L.; Hou, J.; Zhang, S.; Chen, H. Y.; Yang, Y. Angew.
Chem. Inter. Ed. 2010, 49, 1500−1503. (d) Liang, Y.; Xu, Z.; Xia, J.;
Tsai, S.-T.; Wu, Y.; Li, G.; Ray, C.; Yu, L. Adv. Mater. 2010, 22, E135−
E138. (e) Piliego, C.; Holcombe, T. W.; Douglas, J. D.; Woo, C. H.;
́
Beaujuge, P. M.; Frechet, J. M. J. Am. Chem. Soc. 2010, 132, 7595−
ASSOCIATED CONTENT
* Supporting Information
■
7597. (f) Zhang, Y.; Hau, S. K.; Yip, H.-L.; Sun, Y.; Acton, O.; Jen, A.
S
K. Y. Chem. Mater. 2010, 22, 2696−2698. (g) Zou, Y.; Najari, A.;
Instrumentation for the characterization of compounds, AFM
images of vapor deposited thin films of anti-ADF, anti-ADT,
anti-ADS, DPh-ADF, DPh-ADT, and DPh-ADS on Si/SiO2
substrates, absorption spectra and cyclic voltammograms of
anti-BDF/BDT/BDS and NDF/NDT/NDS, NMR spectra of
compounds. This material is available free of charge via the
Internet at http://pubs.acs.org.
́
Berrouard, P.; Beaupre, S.; Aïch, B. R.; Tao, Y.; Leclerc, M. J., M. J. Am.
Chem. Soc. 2010, 132, 5330−5331. (h) Boudreault, P.-L. T.; Najari, A.;
Leclerc, M. Chem. Mater. 2011, 23, 456−469.
(6) (a) Loser, S.; Bruns, C. J.; Miyauchi, H.; Ortiz, R. P.; Facchetti,
A.; Stupp, S. I.; Marks, T. J. J. Am. Chem. Soc. 2011, 133, 8142−8145.
(b) Dutta, P.; Yang, W.; Eom, S. H.; Lee, W.-H.; Kang, I. N.; Lee, S.-H.
Chem. Commun. 2012, 48, 573−575. (c) Osaka, I.; Abe, T.; Shimawaki,
M.; Koganezawa, T.; Takimiya, K. ACS Macro Lett. 2012, 1, 437−440.
(d) Dutta, P.; Yang, W.; Lee, W.-H.; Kang, I. N.; Lee, S.-H. J. Mater.
Chem. 2012, 22, 10840−10851.
AUTHOR INFORMATION
Corresponding Author
*ktakimi@hiroshima-u.ac.jp
■
(7) Lloyd, M. T.; Mayer, A. C.; Subramanian, S.; Mourey, D. A.;
Herman, D. J.; Bapat, A. V.; Anthony, J. E.; Malliaras, G. G. J. Am.
Chem. Soc. 2007, 129, 9144−9149.
Author Contributions
†These authors contributed equally to this work.
(8) Li, Z.; Lim, Y.-F.; Kim, J. B.; Parkin, S. R.; Loo, Y.-L.; Malliaras,
G. G.; Anthony, J. E. Chem. Commun. 2011, 47, 7617−7619.
(9) Tylleman, B.; Vande Velde, C. M. L.; Balandier, J.-Y.; Stas, S.;
Sergeyev, S.; Geerts, Y. H. Org. Lett. 2011, 13, 5208−5211.
(10) During the preparation of this manuscript, synthesis and
characterization of isomerically pure syn-ADT derivatives were
reported: Lehnherr, D.; Waterloo, A. R.; Goetz, K. P.; Payne, M.
M.; Hampel, F.; Anthony, J. E.; Jurchescu, O. D.; Tykwinski, R. R. Org.
Lett. 2012, 14, 3660−3663.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
This work was financially supported by Grants-in-Aid for
Scientific Research (No. 23245041) from MEXT, Japan, by a
Founding Program for World-Leading R&D on Science and
Technology (FIRST), Japan, and by Japan Advanced Printed
Electronics Technology Research Association (JAPERA),
Japan.
(11) Lehnherr, D.; Hallani, R.; McDonald, R.; Anthony, J. E.;
Tykwinski, R. R. Org. Lett. 2012, 14, 62−65.
(12) After submission of this manuscript, synthesis, characterization,
and FET device characteristics of isomerically pure syn and anti-
dimethyl-ADTs were reported: Mamada, M.; Minamiki, T.; Katagiri,
H.; Tokito, S. Org. Lett. 2012, 14, 4062−4065.
(13) (a) Shinamura, S.; Osaka, I.; Miyazaki, E.; Takimiya, K.
Heterocycles 2011, 83, 1187−1204. (b) Takimiya, K.; Kunugi, Y.;
Konda, Y.; Niihara, N.; Otsubo, T. J. Am. Chem. Soc. 2004, 126, 5084−
5085. (c) Takimiya, K.; Konda, Y.; Ebata, H.; Niihara, N.; Otsubo, T. J.
Org. Chem. 2005, 70, 10569−10571. (d) Takimiya, K.; Kunugi, Y.;
Toyoshima, Y.; Otsubo, T. J. Am. Chem. Soc. 2005, 127, 3605−3612.
(e) Takimiya, K.; Kunugi, Y.; Konda, Y.; Ebata, H.; Toyoshima, Y.;
Otsubo, T. J. Am. Chem. Soc. 2006, 128, 3044−3050. (f) Yamamoto,
T.; Takimiya, K. J. Am. Chem. Soc. 2007, 129, 2224−2225. (g) Izawa,
REFERENCES
■
(1) (a) Anthony, J. E. Chem. Rev. 2006, 106, 5028−5048.
(b) Anthony, J. E. Angew. Chem., Int. Ed. 2008, 47, 452−483.
(c) Takimiya, K.; Shinamura, S.; Osaka, I.; Miyazaki, E. Adv. Mater.
2011, 23, 4347−4370.
(2) (a) Laquindanum, J. G.; Katz, H. E.; Lovinger, A. J.; Dodabalapur,
A. Adv. Mater. 1997, 8, 36−39. (b) Takimiya, K.; Kunugi, Y.; Konda,
Y.; Niihara, N.; Otsubo, T. J. Am. Chem. Soc. 2004, 126, 5084−5085.
(c) Takimiya, K.; Kunugi, Y.; Ebata, H.; Otsubo, T. Chem. Lett. 2006,
35, 1200−1201. (d) Kashiki, T.; Miyazaki, E.; Takimiya, K. Chem. Lett.
8110
dx.doi.org/10.1021/jo301438t | J. Org. Chem. 2012, 77, 8099−8111

The Journal of Organic Chemistry
Article
T.; Miyazaki, E.; Takimiya, K. Chem. Mater. 2009, 21, 903−912.
(h) Kashiki, T.; Shinamura, S.; Kohara, M.; Miyazaki, E.; Takimiya, K.;
Ikeda, M.; Kuwabara, H. Org. Lett. 2009, 11, 2473−2475. (i) Saito, M.;
Yamamoto, T.; Osaka, I.; Miyazaki, E.; Takimiya, K.; Kuwabara, H.;
Ikeda, M. Tetrahedron Lett. 2010, 51, 5277−5280. (j) Saito, M.; Osaka,
I.; Miyazaki, E.; Takimiya, K.; Kuwabara, H.; Ikeda, M. Tetrahedron
Lett. 2011, 52, 285−288. (k) Niimi, K.; Kang, M. J.; Miyazaki, E.;
Osaka, I.; Takimiya, K. Org. Lett. 2011, 13, 3430−3433. (l) Niimi, K.;
Miyazaki, E.; Osaka, I.; Takimiya, K. Synthesis 2012, 44, 2102−2106.
(14) Mery, S.; Haristoy, D.; Nicoud, J.-F.; Guillon, D.; Monobe, H.;
Shimizu, Y. J. Mater. Chem. 2003, 13, 1622−1630.
(15) Niimi, K.; Shinamura, S.; Osaka, I.; Miyazaki, E.; Takimiya, K. J.
Am. Chem. Soc. 2011, 133, 8732−8739.
(16) Nakano, M.; Mori, H.; Shinamura, S.; Takimiya, K. Chem. Mater.
2012, 24, 190−198.
(17) (a) Dai, W.-M.; Lai, K. W. Tetrahedron Lett. 2002, 43, 9377−
9380. (b) Hayashi, N.; Saito, Y.; Higuchi, H.; Suzuki, K. J. Phys. Chem.
A 2009, 113, 5342−5347. (c) Yue, D.; Yao, T.; Larock, R. C. J. Org.
Chem. 2005, 70, 10292−10296.
(18) (a) Yue, D.; Larock, R. C. J. Org. Chem. 2002, 67, 1905−1909.
(b) Kesharwani, T.; Worlikar, S. A.; Larock, R. C. J. Org. Chem. 2006,
71, 2307−2312.
(19) Miyaura, N.; Suzuki, A. Chem. Rev. 1995, 95, 2457−2483.
(20) Takimiya, K.; Konda, Y.; Ebata, H.; Otsubo, T.; Kunugi, Y. Mol.
Cryst. Liq. Cryst. 2006, 455, 361−365.
(21) Takimiya, K.; Yamamoto, T.; Ebata, H.; Izawa, T. Sci. Tech. Adv.
Mater. 2007, 8, 273−276.
(22) Nakano, M.; Shinamura, S.; Houchin, Y.; Osaka, I.; Miyazaki, E.;
Takimiya, K. Chem. Commun. 2012, 48, 5671−5673.
(23) Tsuji, H.; Mitsui, C.; Ilies, L.; Sato, Y.; Nakamura, E. J. Am.
Chem. Soc. 2007, 129, 11902−11903.
(24) (a) Miyata, Y.; Terayama, M.; Minari, T.; Nishinaga, T.;
Nemoto, T.; Isoda, S.; Komatsu, K. Chem.−Asian J 2007, 2, 1492−
1504. (b) Bijleveld, J. C.; Karsten, B. P.; Mathijssen, S. G. J.; Wienk, M.
M.; de Leeuw, D. M.; Janssen, R. A. J. J. Mater. Chem. 2011, 21, 1600−
1606. (c) Li, Y.; Sonar, P.; Singh, S. P.; Zeng, W.; Soh, M. S. J. Mater.
Chem. 2011, 21, 10829−10835. (d) Gidron, O.; Diskin-Posner, Y.;
Bendikov, M. J. Am. Chem. Soc. 2010, 132, 2148−2150. (e) Gidron,
O.; Dadvand, A.; Sheynin, Y.; Bendikov, M.; Perepichka, D. F. Chem.
Commun. 2011, 47, 1976−1978. (f) Mitsui, C.; Soeda, J.; Miwa, K.;
Tsuji, H.; Takeya, J.; Nakamura, E. J. Am. Chem. Soc. 2012, 134, 5448−
5451. (g) Huo, L.; Huang, Y.; Fan, B.; Guo, X.; Jing, Y.; Zhang, M.; Li,
Y.; Hou, J. Chem. Commun. 2012, 48, 3318−3320. (h) Niimi, K.; Mori,
H.; Miyazaki, E.; Osaka, I.; Kakizoe, H.; Takimiya, K.; Adachi, C.
Chem. Commun. 2012, 48, 5892−5894.
(25) Although DPh-BDF was reported by Tsuji et al. (ref 23), no
OFET devices and performances were mentioned.
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