Anthradithiophene derivatives substituted at the 2,8-positions by formyl and triphenylamine units: Synthesis, optical, and electrochemical properties

Article abstract of DOI:10.1002/ejoc.201100401

The synthesis and characterization of two new anthradithiophene (ADT) derivatives substituted by thiophenyl or 2-octylthiophenyl units at the 5,11-positions and donor (triphenylamine) or acceptor (aldehyde functions) moieties at the 2,8-positions of their backbone are described. Optical measurements were performed to evaluate the effect of electron-rich/-poor substituents on their stability towards photo-oxidation and were supported by quantum chemical calculations and cyclic voltammetry experiments. Copyright

Full text of DOI:10.1002/ejoc.201100401

FULL PAPER
DOI: 10.1002/ejoc.201100401
Anthradithiophene Derivatives Substituted at the 2,8-Positions by Formyl and
Triphenylamine Units: Synthesis, Optical, and Electrochemical Properties
Jean-Yves Balandier,[a] Noham Sebaihi,[b] Pol Boudard,[b] Vincent Lemaur,[b]
Florence Quist,[a] Claude Niebel,[a] Sara Stas,[a] Benoît Tylleman,[a] Roberto Lazzaroni,[b]
Jérôme Cornil,[b] and Yves Henri Geerts*[a]
Keywords: Sulfur heterocycles / Donor–acceptor systems / Cyclic voltammetry / Stability studies / Molecular electronics
The synthesis and characterization of two new anthradithio-
phene (ADT) derivatives substituted by thiophenyl or 2-oc-
tylthiophenyl units at the 5,11-positions and donor (tri-
phenylamine) or acceptor (aldehyde functions) moieties at
the 2,8-positions of their backbone are described. Optical
measurements were performed to evaluate the effect of elec-
tron-rich/-poor substituents on their stability towards photo-
oxidation and were supported by quantum chemical calcula-
tions and cyclic voltammetry experiments.
electron-donating groups on its stability towards photoin-
duced degradation. We describe the synthesis and the char-
acterization of new anthradithiophene derivatives bearing
triphenylamine as an electron donor (TPAADT) and formyl
groups (FADT) as electron-acceptor moieties. 2-Octylthio-
phenyl units were attached at the 5,11-positions of the
FADT backbone to fulfill solubility requirements and to
selectively perform nBuLi-mediated metalations at the 2,8-
positions of precursor ADT 1. In the case of TPAADT,
thiophenyl groups were also substituted at the 5,11-posi-
tions of the aromatic system to improve its solubility. The
spectroscopic and electrochemical properties of these syn-
thesized semiconductors were evaluated and interpreted
with the help of quantum chemical calculations.
Introduction
Fused (hetero)acenes,[1] which represent one of the most-
studied categories of organic semiconductors, have been
used in diverse applications such as organic field-effect
transistors (OFET),[2] light-emitting diodes (OLED),[3] or
photovoltaic cells.[4] Over the past 10 years, many synthetic
efforts have been carried out by the chemical community to
improve the solubility of these semiconductors to produce
organic electronic devices by solution processes. For exam-
ple, recent publications described the functionalization of
pentacene, anthradithiophene (ADT), or longer (hetero)ac-
enes cores by several units, including silyl,[2j,2k,3,4a,4c,5] thio-
phenyl,[3,4b,6] or phenyl derivatives.[3,7] Additionally, it has
been demonstrated that the presence of such substituents
enhances the stability of these derivatives towards photo-
oxidation, especially in solution.[5a,5c,6a,8] With this syn-
thetic strategy, chemical reactions involving these com-
pounds were also rendered feasible and were engaged in
oligomerization and/or polymerization reactions.[6b,9] The
synthetic work reported in the literature to increase the sta-
bility of this class of semiconductors mainly focuses on the
functionalization of the center of their aromatic cores (5,11-
positions of pentacene and ADT cores for instance). Here,
we investigate the influence of substitution at the 2,8-posi-
tions of the ADT backbone by electron-withdrawing or
Results and Discussion
FADT and TPAADT were prepared as presented in
Scheme 1. FADT (purple solid) was obtained in 72% yield
by metalation of ADT 1[6b] using nBuLi, followed by reac-
tion of the corresponding dilithiated species with DMF.
Note that FADT is produced as a mixture of isomers, as its
preparation was made starting from a mixture of syn/anti
isomers of ADT 1. Synthesis of TPAADT was performed
in three steps starting from thiophene derivative 2,[10] with
an overall yield of 35%. 4-Bromo-N,N-diphenylaniline and
compound 2 were first engaged in a Stille coupling, and
deprotection of the aldehyde functions, using 6 m HCl, af-
forded product 3 in 60% yield. Diquinone 4 was obtained
as an inseparable mixture of syn/anti isomers in 72% yield
by reaction of dialdehyde 3 with cyclohexane-1,4-dione in
the presence of 5% KOH. Finally, TPAADT (mixture of
syn/anti isomers) was synthesized by reaction of 4 with the
corresponding lithium intermediate of thiophene, followed
[a] Laboratoire Chimie des Polymères, Université Libre de
Bruxelles (ULB), Faculté des Sciences,
CP 206/1 Boulevard du Triomphe, 1050 Bruxelles, Belgique
Fax: +32-2-650-5410
E-mail: ygeerts@ulb.ac.be
[b] Service de Chimie des Matériaux Nouveaux,
Université de Mons (UMONS),
Place du Parc 20, 7000 Mons, Belgique
Supporting information for this article is available on the
WWW under http://dx.doi.org/10.1002/ejoc.201100401.
Eur. J. Org. Chem. 2011, 3131–3136
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Y. H. Geerts et al.
FULL PAPER
Scheme 1. Synthesis of FADT and TPAADT.
by reduction/deoxygenation using SnCl2 in 6 m HCl. octylthiophenyl groups (in 1 and FADT) were replaced by
TPAADT was obtained as a pure dark red solid in 80% methyl groups in the geometry optimizations to reduce the
yield by precipitation from the reaction mixture using meth- computational costs (those substituents do not contribute
anol. Several trials were attempted to prepare compound 5 to the description of the frontier electronic levels and the
bearing 2-octylthiophenyl moieties at the 5,11-positions of first absorption peaks). The thiophene (TPAADT) and 2-
the ADT core. The same procedure used for the synthesis octylthiophene (1 and FADT) units are found to be perpen-
of TPAADT was applied using 2-octylthiophene instead of dicular to the conjugated cores in the optimized geometry,
thiophene. ADT 5 appeared to be impossible to isolate. In- which reduces the steric hindrance with the hydrogen atoms
deed, several purification techniques (all performed under at the 4,6,10,12-positions. The vertical transition energies to
light exclusion), such as recrystallization and chromatog- the lowest excited states of the isolated compounds were
raphy on silica gel, alumina (neutral and basic), or Celite, computed from the optimized geometries with the time-de-
were tried without any success. In each case, degradation of pendent density functional theory (TD-DFT) formalism,[12]
product 5 was observed, which is certainly due to its poor using the same functional and basis set. The Gaussian 03
stability in solution. All ADT derivatives possess reasonable package was used for all calculations.[13]
solubilities in common organic solvents and were charac-
Bathochromic shifts of the absorption maxima of,
terized by NMR and UV/Vis spectroscopy, cyclic voltam- respectively, 28 nm (0.12 eV) and 71 nm (0.29 eV) are ob-
metry, and mass spectrometry (see Supporting Infor- served going from 1 to TPAADT and from 1 to FADT
mation).
(Figure 1). These redshifts are due to the substitution of the
The absorption and emission spectra of 1, FADT, and ADT core at the 2,8-positions by triphenylamine units,
TPAADT were measured in 10–5 m chloroform solutions which extend the π conjugated system,[14] or by the meso-
and were compared to theoretical simulations. To do so, meric effects induced by the formyl groups.[15] The calcu-
geometry optimizations were performed at the density func- lated transition energies follow the same behavior going
tional theory (DFT) level, using the B3LYP functional[11] from 1 to TPAADT [43 nm (0.18 eV)] and from 1 to FADT
and the 6-31G(d,p) basis set. The octyl chains of the 2- [95 nm (0.36 eV)]. TPAADT also presents molar extinction
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Formyl- and Triphenylamine-Substituted Anthradithiophene Derivatives
coefficients (ε) higher than those of ADT 1 and FADT, by
about a factor of two; this increase is also consistent with
the quantum chemical calculations (Supporting Infor-
mation, Figure S15).
Figure 2. Emission spectra of 1 (λexcitation = 516 nm), FADT
(λexcitation = 587 nm), and TPAADT (λexcitation = 544 nm) in CHCl3
(10–5 m).
Figure 1. UV/Vis spectra of 1, FADT, and TPAADT in CHCl3
(10–5 m).
(25 s). The higher stability of FADT towards photodegrad-
ation, by about a factor of two compared to those of 1 and
The emission maximum also displays a redshift in agree- TPAADT, is attributed to the substitution of the ADT core
ment with the observations made in the UV/Vis spectra. periphery by strong electron-withdrawing formyl groups,
Bathochromic shifts of 21 nm (0.08 eV) and of 91 nm which make the central backbone electron deficient. On the
(0.33 eV) are measured between 1 and TPAADT and be- contrary, TPAADT is less stable than 1 due to the electron-
tween 1 and FADT, respectively (Figure 2). The optical donating triphenylamine units introduced at the 2,8-posi-
band gaps, collected in Table 1, were determined from the tions of the ADT skeleton. The stability order observed can
intersection of the normalized absorption and emission be rationalized from the calculated energy of the HOMO
spectra of all ADT derivatives. The band gap value de- levels among the three ADT molecules (Table 1). FADT in-
creases from 2.35 eV for 1 to 2.25 eV for TPAADT and to deed possesses the lowest HOMO level (–5.23 eV),
2.04 eV for FADT.
TPAADT the highest one (–4.58 eV), whereas the HOMO
It was previously demonstrated that the reaction involved level of ADT 1 (–4.77 eV) is between the two. In addition,
in the photoinduced degradation of fused linear (hetero)- upon irradiation of TPAADT, a new broadband located
acenes can be compared to a Diels–Alder cycloaddition be- around 790 nm is also observed (Supporting Information,
tween the most reactive central ring of the (hetero)acenes Figure S3) and is assigned to the formation of a radical–
and the O2 singlet formed upon UV/Vis irradiation, which cation by oxidation of the molecule.[16] Furthermore, sev-
leads to the formation of an endoperoxide bridge.[8] eral isosbestic points were noted in the UV/Vis spectra of 1
Thereby, the stability of 1, FADT, and TPAADT towards and FADT (Supporting Information, Figures S1 and S2),
photo-oxidation was investigated by monitoring the ab- thus indicating the coexistence in solution of two species:
sorbance decay of 10–5 m chloroform solutions stored in the the starting derivatives and their corresponding photo-oxid-
dark at room temperature, under ambient atmosphere and ized species. Such a phenomenon is however not observed
exposed to 10 cm of an 8-W UV/Vis lamp (λ1 = 244 nm, λ2 for TPAADT. This might imply that the degradation of the
= 366 nm; Figure 3; Supporting Information, Figures S1– latter occurs following a more complex mechanism that cer-
S3). Considering an absorbance decay of 50% of the lower tainly involves the radical–cation formed under UV/Vis ir-
energy bands of all ADT compounds, the stability order radiation. Throughout all these experiments, it was also
observed is as follows: FADT (55 s) Ͼ 1 (33 s) Ͼ TPAADT found that freshly prepared solutions of all products stored
Table 1. Experimental optical data and calculated vertical transition energies (ΔEvert.) to the lowest excited state as well as calculated
HOMO (H) and LUMO (L) values of 1, FADT, and TPAADT in the gas phase.
Product
Experimental
Theory
[a]
[b]
λabs.
λem
Eg
ΔEvert.
H
L
[nm] (eV)
[nm] (eV)
[eV]
[nm] (eV)
[eV]
[eV]
1
516 (2.40)
587 (2.11)
544 (2.28)
538 (2.30)
629 (1.97)
559 (2.22)
2.35
2.04
2.25
525 (2.36)
620 (2.00)
568 (2.18)
–4.77
–5.23
–4.58
–2.10
–2.94
–2.12
FADT
TPAADT
[a] λexcitation = λabs. of the lower energy band. [b] Optical band gaps determined from the intersection between normalized absorption and
emission spectra.
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Y. H. Geerts et al.
FULL PAPER
in the dark remain stable for at least 36 h. As a conse- ments confirm the stability order observed in the photo-
quence, this observation shows that light irradiation acts as oxidation studies and predicted by theoretical calculation
the agent responsible for the degradation of the ADTs.
of HOMO levels, because Eox1-FADT
Eox1-TPAADT. ADT 1 and TPAADT present one reduction
wave at similar potentials: Ered1-1 –1.89 V and
Ͼ
Eox1-1
Ͼ
=
Ered1-TPAADT = –1.81 V, which is in agreement with the
quantum chemical calculations (Table 1). On the contrary,
FADT shows three successive quasireversible reductions lo-
cated at –1.40, –1.66, and –1.85 V. The first reduction po-
tential of FADT is higher than that of 1 and TPAADT,
consistent with the increase in its electron affinity due to the
presence of strong electron-accepting functions (aldehyde),
thus leading to the stabilization of the FADT LUMO en-
ergy level (Table 2).
Conclusions
Two new anthradithiophene derivatives bearing electron-
donating (triphenylamine) and withdrawing (formyl) groups
at the 2,8-positions of the ADT core have been successfully
synthesized and characterized. It has been proven by optical
experiments that the ADT skeleton is more resistant
towards photo-oxidation by about a factor of two when the
latter is substituted on its periphery by electron-accepting
units. This observation is fully supported by quantum
chemical calculations as well as by cyclic voltammetry ex-
periments.
Figure 3. Evolution of the absorbance of the lower energy band of
1 (516 nm), FADT (587 nm), and TPAADT (544 nm) (10–5 m) in
CHCl3, under exposure to UV/Vis light (λ1 = 244 nm, λ2 = 366 nm)
at room temperature and under ambient atmosphere.
The electrochemical properties of all ADT derivatives
were studied by cyclic voltammetry (Supporting Infor-
mation, Figures S16–21) and are listed in Table 2. Oxi-
dation processes were measured in dichloromethane and re-
duction ones in N,N-dimethylformamide vs. the Fc+/Fc
couple. All measurements were also performed under light
exclusion in degassed solutions of the products to avoid the
presence in solution of their photo-oxidized corresponding
species. ADT 1 presents two quasireversible oxidations at
Eox1-1 = 0.35 V and Eox2-1 = 0.61 V. These two waves are
ascribed to the successive oxidations of 1 into its corre-
sponding radical–cation and dication species. FADT shows
Experimental Section
General: All chemicals and solvents were purchased from Acros
and Aldrich and were used without further purification unless
otherwise stated. THF was dried by a conventional method (Na/
benzophenone distillation under an atmosphere of argon) and col-
lected with glass syringes. TLC was performed with SiO2 Silica gel
60F254 on aluminum sheets (Merck). Column chromatography was
performed with silica gel 60 (particle size 0.063–0.200 mm, Merck).
1H NMR (300 MHz) and 13C NMR (75 MHz) were recorded with
a Bruker Advance 300 spectrometer. The residual signal of the sol-
vent was taken as internal reference standard. HRMS (EI) and
MALDI-ToF measurements were made with a Waters AutoSpec 6
and with a Waters QToF Premier apparatus, respectively. Absorp-
tion spectra were recorded in CHCl3 with an Agilent 8453 spectro-
photometer. Emission spectra were measured with an Aminco
Bowman series 2 luminescence spectrophotometer. Melting points
were observed by microscopy using a Mettler FP 82 hot stage. Cy-
clic voltammetry measurements were performed with a Princeton
Applied research Parstat 2273 potentiostat equipped with Electro-
chemistry Powersuite 2.58 software. Measurements were carried
out at room temperature in a three-electrode single-compartment
a single quasireversible oxidative process (Eox1-FADT
=
0.57 V), which appears positively shifted compared to that
of compound 1. This is due to the presence of electron-
accepting formyl groups, which render FADT more difficult
to oxidize than 1. TPAADT exhibits multiple oxidative
waves with the first quasireversible one (Eox1-TPAADT
=
0.28 V) shifted to negative potentials, which is caused by
the substitution of the ADT backbone with electron-rich
triphenylamine groups. These electrochemical measure-
Table 2. Experimental potential values E = (Epc + Epa)/2 in V (vs.
Fc+/Fc couple) of ADT derivatives 1, FADT, and TPAADT in
CH2Cl2 (oxidation) or DMF (reduction) solution containing 0.1 m
of TBAPF6 at a scan rate of 100 mV·s–1 and their estimated
HOMO and LUMO energy levels (eV).
cell (5 mL), at a scan rate of 100 mVs–1. Concentrations of 10–3
m
in CH2Cl2 or DMF solutions containing TBAPF6 (0.1 m) as sup-
porting electrolyte were prepared. Before each measurement, solu-
tions were degassed for 10 min by bubbling nitrogen. A platinum
disc (Ø = 1.6 mm, ALS Japan) was used as a working electrode. A
platinum wire (Ø = 0.5 mm, ALS Japan) was employed as counter
electrode, and an Ag/AgCl/NaCl(sat) electrode (ALS Japan) was
used as reference. The Ag/AgCl electrode was checked against the
ferrocene/ferrocenium (Fc+/Fc) couple before and after each ex-
periment. All potentials are reported vs. Fc+/Fc couple.
Product
Eox1
[V]
Ered1
[V]
HOMO[a]
[eV]
LUMO[a]
[eV]
1
0.35
0.57
0.28
–1.89
–1.40
–1.81
–5.15
–5.37
–5.08
–2.91
–3.40
–2.99
FADT
TPAADT
[a] HOMO and LUMO energy levels are estimated from the first
oxidation and reduction potential waves according to HOMO =
–(4.8 + Eox1) and LUMO = –(4.8 + Ered1).[17]
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Formyl- and Triphenylamine-Substituted Anthradithiophene Derivatives
5,11-Bis(5-octylthiophen-2-yl)anthradithiophene (1, syn/anti iso-
mers): Identical procedure described in literature.[6b]
125.0, 123.7, 122.8, 119.8, 119.7, 118.7, 118.6, 117.5 ppm. HRMS
(MALDI): calcd. for C62H40N2S4 [M]+.940.2074; found 940.2054.
M.p. 248–254 °C.
5-Tributylstannyl-2,3-bis(1,3-dioxolan-2-yl)thiophene (2): Identical
procedure previously reported in literature.[10]
5,11-Bis(5-octylthiophen-2-yl)anthra[2,3-b]dithiophene-2,8-dicarbal-
dehyde (syn/anti isomers): To a solution of compound 1 (0.24 g,
0.36 mmol) in dry THF (20 mL) cooled to –80 °C under an atmo-
sphere of argon was added dropwise nBuLi (2.5 m in hexane,
0.32 mL, 0.79 mmol), and the mixture was stirred for 10–15 min.
Then, anhydrous DMF (0.07 g, 0.08 mL, 1.00 mmol) was added in
one portion. After 10 min, the cooling bath was removed, and the
mixture was stirred for 2 h at room temperature. The reaction was
then quenched by addition of water (30 mL), and the mixture was
extracted with dichloromethane (2ϫ). The combined organic layers
were dried with magnesium sulfate, filtered, and concentrated. The
residue was purified by column chromatography on silica gel
(CH2Cl2) to afford dialdehyde derivative FADT (0.19 g, 0.26 mmol)
as a purple solid. Yield: 72%. 1H NMR (300 MHz, CDCl3, 25 °C):
δ = 10.12 (m, 2 H, CHO), 8.65 (m, 2 H, HADT), 8.46 (m, 2 H,
HADT), 8.05 (s, 2 H, H3, H9), 7.12 (m, 4 H, Hthio), 3.04 (t, J =
7.7 Hz, 4 H, Ha), 1.89 (m, 4 H, Hb), 1.36 (m, 20 H, Hc–g), 0.91 (t,
J = 6.7 Hz, 6 H, Hh) ppm. 13C NMR (75 MHz, CDCl3, 25 °C): δ
= 185.0, 148.7, 146.1, 145.9, 139.0, 138.6, 138.4, 138.1, 135.6, 135.4,
133.7, 131.5, 131.3, 130.6, 130.4, 130.3, 130.2, 129.5, 126.1, 126.0,
124.5, 120.7, 120.6, 32.1, 31.8, 30.5, 29.6, 29.5, 22.9, 14.3 ppm. Rf
0.87 (dichloromethane). HRMS (MALDI): calcd. for
C44H46O2S4 [M]+ 734.2381; found 734.2380. M.p. 267–271 °C.
5-[4-(Diphenylamino)phenyl]thiophene-2,3-dicarbaldehyde (3): Un-
der an atmosphere of argon, a mixture of 5-tributylstannyl-2,3-
bis(1,3-dioxolan-2-yl)thiophene (2; 2.54 g, 4.91 mmol), 4-bromo-
N,N-diphenylaniline (1.34 g, 4.1 mmol), and Pd(PPh3)4 (208 mg) in
toluene (30 mL) was heated at reflux for 1.5 h. The medium was
then concentrated and passed through silica gel (CH2Cl2 + 1%
Et3N) to remove the catalyst residues. Fractions containing the blue
fluorescent spot (Rf = 0.5) were combined, and the solvent was
evaporated. The residue was dissolved in THF (80 mL) and HClaq
(6 m, 50 mL) was added. The mixture was stirred at room tempera-
ture for 20 min. The mixture was extracted with CH2Cl2 (2ϫ) and
the combined organic layers were washed with KOHaq (1 m) and
water. The organic layer was dried with magnesium sulfate, filtered,
and concentrated. The residue was then purified by chromatog-
raphy on silica gel (CH2Cl2) to afford 3 (0.94 g, 2.46 mmol) as a
shining red orange solid. Yield: 60%. 1H NMR (300 MHz, CDCl3,
25 °C): δ = 10.43 (s, 1 H, CHO), 10.38 (s, 1 H, CHO), 7.68 (s, 1 H,
H4), 7.51 (d, J = 8.8 Hz, 2 H, HTPA), 7.31 (m, 4 H, HTPA), 7.19–
7.03 (m, 8 H, HTPA) ppm. 13C NMR (75 MHz, CDCl3, 25 °C): δ
= 185.0, 182.2, 153.6, 149.9, 146.9, 144.8, 144.2, 129.7, 127.4, 125.6,
=
124.9, 124.3, 123.7, 122.1 ppm. Rf = 0.60 (dichloromethane).
HRMS (EI): calcd. for C24H17NO2S [M]+ 383.0980; found
383.0980. M.p. 143–148 °C.
Supporting Information (see footnote on the first page of this arti-
cle): Optical and cyclic voltammetry data; NMR, mass, and theo-
retical absorption spectra.
2,8-[4-(Diphenylamino)phenyl]anthradithiophene-5,11-dione
syn/anti isomers): To a mixture of 3 (1.60 g, 4.17 mmol) and 1,4-
cyclohexanedione (0.23 g, 2.09 mmol) in mixture of THF
(4,
a
(140 mL) and absolute ethanol (50 mL) was slowly added 5% KOH
(6 mL). The mixture was then stirred for 20 min. The red precipi-
tate formed was isolated by filtration, washed with ethanol and
methanol, and dried. Diquinone 4 (1.21 g, 1.50 mmol) was used
without further purification. Yield: 72%. 1H NMR (300 MHz,
CDCl3, 40 °C): δ = 8.76 (s, 2 H, HADT), 8.65 (s, 2 H, HADT), 7.59
Acknowledgments
The authors would like to thank Pascal Gerbaux (UMONS) for
MS measurements. The collaboration between Brussels and Mons
is supported by Région Wallonne (Mirage project) jointly with the
European Commission, Fonds Européen de Développement
(m, 6 H, H3, H9, HTPA), 7.36–7.26 (m, 8 H, HTPA), 7.21–7.04 (m, Régional (FEDER) (Smartfilm RF project) and the Belgian Fed-
16 H, HTPA
)
ppm. 13C NMR: Solubility too low. HRMS
eral Office of Science Policy (PAI 6/27). Research in Mons is also
(MALDI): calcd. for C54H34N2O2S2 [M]+ 806.2062; found supported by the OPTI2MAT Excellence Program and by Belgian
806.2036. M.p. Ͼ300 °C.
National Fund for Scientific Research – Fonds de la Recherche
Collective (FRFC). B. T. and N. S. are Fonds pour la Formation à
la Recherche dans l’Industrie et dans l’Agriculture (FRIA) research
fellows. J. C. is a senior research fellow of the FNRS.
2,8-[4-(Diphenylamino)phenyl]-5,11-bis(thiophen-2-yl)anthra[2,3-b]-
dithiophene (TPAADT, syn/anti isomers): To a solution of thiophene
(0.125 g, 0.120 mL, 1.49 mmol) in dry THF (20 mL) cooled to
–80 °C under an atmosphere of argon was added dropwise nBuLi
(2.5 m in hexane, 0.60 mL, 1.49 mmol), and the mixture was stirred
for 10–15 min. Then, diquinone 4 (0.200 g, 0.25 mmol) was added
in one portion. After 10 min, the cooling bath was removed, and
the mixture was stirred until complete dissolution of the diquinone
(≈30 min). Finally, the reaction was protected from the light and a
solution of SnCl2 (1.125 g) in HClaq (6 m, 2.70 mL) was slowly
added. The reaction was stirred (still protected from the light) for
an additional 20 min, and then the mixture was poured into meth-
anol (150 mL). The precipitate formed was then isolated by fil-
tration, washed with 6 m HClaq, H2O, and MeOH, and dried. Prod-
uct TPAADT was obtained (0.191 g, 0.20 mmol) as a dark red so-
[1] J. E. Anthony, Chem. Rev. 2006, 106, 5028.
[2] a) J. G. Laquindanum, H. E. Katz, A. J. Lovinger, A. Dodabal-
apur, Adv. Mater. 1997, 9, 36; b) C. X. Li, H. Sirringhaus, F.
Garnier, A. B. Holmes, S. C. Moratti, N. Feeder, W. Clegg, S. J.
Teat, R. H. Friend, J. Am. Chem. Soc. 1998, 120, 2206; c) J. G.
Laquindanum, H. E. Katz, A. J. Lovinger, J. Am. Chem. Soc.
1998, 120, 664; d) K. Ito, T. Suzuki, Y. Sakamoto, D. Kubota,
Y. Inoue, F. Sato, S. Tokito, Angew. Chem. 2003, 115, 1191;
Angew. Chem. Int. Ed. 2003, 42, 1159; e) J. A. Merlo, C. R.
Newman, C. P. Gerlach, T. W. Kelley, D. V. Muyres, S. E. Fritz,
M. F. Toney, C. D. Frisbie, J. Am. Chem. Soc. 2005, 127, 3997;
f) M. L. Tang, T. Okamoto, Z. Bao, J. Am. Chem. Soc. 2006,
128, 16002; g) F. Valiyev, W. S. Hu, H. Y. Chen, M. Y. Kuo, I.
Chao, Y. T. Tao, Chem. Mater. 2007, 19, 3018; h) T. Yamam-
oto, K. Takimiya, J. Am. Chem. Soc. 2007, 129, 2224; i) D.
Kumaki, T. Umeda, T. Suzuki, S. Tokito, Org. Electron. 2008,
9, 921; j) M. L. Tang, A. D. Reichardt, T. Siegrist, S. C. B.
Mannsfeld, Z. Bao, Chem. Mater. 2008, 20, 4669; k) M. L.
Tang, J. H. Oh, A. D. Reichardt, Z. Bao, J. Am. Chem. Soc.
2009, 131, 3733; l) P. Gao, D. Beckmann, H. N. Tsao, X. Feng,
1
lid. Yield: 80%. H NMR (300 MHz, CDCl3, 25 °C): δ = 8.24 (s,
2 H, HADT), 8.17 (s, 2 H, HADT), 7.72 (dd, J = 5.0, 0.8 Hz, 2 H,
Hthio), 7.54 (d, J = 8.7 Hz, 4 H, HTPA), 7.41 (m, 4 H, Hthio, H3,
H9), 7.30 (m, 10 H, Hthio, HTPA), 7.19–7.03 (m, 16 H, HTPA) ppm.
13C NMR (75 MHz, CDCl3, 25 °C): δ = 148.7, 147.3, 146.32,
146.27, 140.8, 140.7, 139.9, 139.8, 139.6, 138.4, 138.3, 129.92,
129.85, 129.6, 129.4, 129.3, 129.1, 128.6, 127.6, 127.5, 127.1, 125.2,
Eur. J. Org. Chem. 2011, 3131–3136
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
3135

Y. H. Geerts et al.
FULL PAPER
V. Enkelmann, M. Baumgarten, W. Pisula, K. Müllen, Adv.
Mater. 2009, 21, 213–216; m) K. Park, S. H. Park, E. Kim,
J. D. Kim, S. Y. An, H. S. Lim, H. H. Lee, D. H. Kim, D. Y.
Ryu, D. R. Lee, J. H. Cho, Chem. Mater. 2010, 22, 5377; n) J.
Smith, R. Hamilton, Y. Qi, A. Kahn, D. D. C. Bradley, M.
Heeney, I. McCulloch, T. D. Anthopoulos, Adv. Funct. Mater.
2010, 20, 2330; o) J. Smith, A. Bashir, G. Adamopoulos, J. E.
Anthony, D. D. C. Bradley, R. Hamilton, M. Heeney, I.
McCulloch, T. D. Anthopoulos, Adv. Mater. 2010, 22, 3598; p)
P. Gao, D. Cho, X. Yang, V. Enkelmann, M. Baumgarten, K.
Müllen, Chem. Eur. J. 2010, 16, 5119.
ecules 2008, 41, 6977; d) D. Lehnherr, J. Gao, F. A. Hegmann,
R. R. Tykwinski, J. Org. Chem. 2009, 74, 5017; e) R. Rieger, D.
Beckmann, W. Pisula, M. Kastler, K. Müllen, Macromolecules
2010, 43, 6264.
M. C. Chen, C. Kim, S. Y. Chen, Y. J. Chiang, M. C. Chung,
A. Facchetti, T. J. Marks, J. Mater. Chem. 2008, 18, 1029.
a) A. D. Becke, J. Chem. Phys. 1993, 98, 5648; b) C. Lee, W.
Yang, R. G. Parr, Phys. Rev. B 1988, 37, 785.
a) R. E. Stratmann, G. E. Scuseria, M. J. Frisch, J. Chem. Phys.
1998, 109, 8218; b) R. Bauernschmitt, R. Ahlrichs, Chem. Phys.
Lett. 1996, 256, 454; c) M. E. Casida, C. Jamorski, K. C. Cas-
ida, D. R. Salahub, J. Chem. Phys. 1998, 108, 4439.
M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E. Scuseria,
M. A. Robb, J. R. Cheeseman, J. A. J. Montgomery, T. Vreven,
K. N. Kudin, J. C. Burant, J. M. Millam, S. S. Iyengar, J. Tom-
asi, V. Barone, B. Mennucci, M. Cossi, G. Scalmani, N. Rega,
G. A. Petersson, H. Nakatsuji, M. Hada, M. Ehara, K. Toyota,
R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda,
O. Kitao, H. Nakai, M. Klene, X. Li, J. E. Knox, H. P. Hratch-
ian, J. B. Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gom-
perts, R. E. Stratmann, O. Yazyev, A. J. Austin, R. Cammi, C.
Pomelli, J. W. Ochterski, P. Y. Ayala, K. Morokuma, G. A.
Voth, P. Salvador, J. J. Dannenberg, V. G. Zakrzewski, S. Dap-
prich, A. D. Daniels, M. C. Strain, O. Farkas, D. K. Malick,
A. D. Rabuck, K. Raghavachari, J. B. Foresman, J. V. Ortiz, Q.
Cui, A. G. Baboul, S. Clifford, J. Cioslowski, B. B. Stefanov,
G. Liu, A. Liashenko, P. Piskorz, I. Komaromi, R. L. Martin,
D. J. Fox, T. Keith, M. A. Al-Laham, C. Y. Peng, A. Nanayak-
kara, M. Challacombe, P. M. W. Gill, B. Johnson, W. Chen,
M. W. Wong, C. Gonzalez, J. A. Pople, Gaussian 03, re-
vision B.03, Gaussian, Inc., Wallingford, CT, 2004.
[10]
[11]
[12]
[3] S. A. Odom, S. R. Parkin, J. E. Anthony, Org. Lett. 2003, 5,
4245.
[13]
[4] a) M. T. Lloyd, A. C. Mayer, S. Subramanian, D. A. Mourey,
D. J. Herman, A. V. Bapat, J. E. Anthony, G. G. Malliaras, J.
Am. Chem. Soc. 2007, 129, 9144; b) A. A. Gorodetsky, M. Cox,
N. J. Tremblay, I. Kymissis, C. Nuckolls, Chem. Mater. 2009,
21, 4090; c) Y. Jiang, T. Okamoto, H. A. Becerril, S. Hong,
M. L. Tang, A. C. Mayer, J. E. Parmer, M. D. McGehee, Z.
Bao, Macromolecules 2010, 43, 6361.
[5] a) J. E. Anthony, J. S. Brooks, D. L. Eaton, S. R. Parkin, J. Am.
Chem. Soc. 2001, 123, 9482; b) M. M. Payne, S. A. Odom, S. R.
Parkin, J. E. Anthony, Org. Lett. 2004, 6, 3325; c) M. M. Payne,
J. H. Delcamp, S. R. Parkin, J. E. Anthony, Org. Lett. 2004, 6,
1609.
[6] a) J. Wang, K. Liu, Y. Y. Liu, C. L. Song, Z. F. Shi, J. B. Peng,
H. L. Zhang, X. P. Cao, Org. Lett. 2009, 11, 2563; b) J. Y. Ba-
landier, F. Quist, S. Stas, B. Tylleman, C. Ragoen, A. Mayence,
S. Bouzakraoui, J. Cornil, Y. H. Geerts, Org. Lett. 2011, 13,
548.
[7] a) Q. Miao, X. Chi, X. Shengxiong, R. Zeis, M. Lefenfeld, T.
Siegrist, M. L. Steigerwald, C. Nuckolls, J. Am. Chem. Soc.
2006, 128, 1340; b) I. Kaur, M. Jazdzyk, N. N. Stein, P. Prusev-
ich, G. P. Miller, J. Am. Chem. Soc. 2010, 132, 1261.
[8] K. Ono, H. Totani, T. Hiei, A. Yoshino, K. Saito, K. Eguchi,
M. Tomura, J. I. Nishida, Y. Yamashita, Tetrahedron 2007, 63,
9699.
[14] H. Meier, U. Stalmach, H. Kolshorn, Acta Polym. 1997, 48,
379.
[15] J. Cornil, D. A. dos Santos, D. Beljonne, J. L. Brédas, J. Phys.
Chem. 1995, 99, 5604.
[16] S. S. Zade, N. Zamoshchick, M. Bendikov, Acc. Chem. Res.
2011, 44, 14.
[17] C. Chi, G. Wegner, Macromol. Rapid Commun. 2005, 26, 1532.
[9] a) D. Lehnherr, R. R. Tykwinski, Org. Lett. 2007, 9, 4583; b)
D. Lehnherr, R. McDonald, M. J. Fergusson, R. R. Tykwinski,
Tetrahedron 2008, 64, 11449; c) T. Okamoto, Y. Jiang, F. Qu,
A. C. Mayer, J. E. Parmer, M. D. McGehee, Z. Bao, Macromol-
Received: March 23, 2011
Published Online: May 2, 2011
3136
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Eur. J. Org. Chem. 2011, 3131–3136