Expanded π-electron systems, tri(phenanthro)hexaazatriphenylenes and tri(phenanthrolino)hexaazatriphenylenes, that are self-assembled to form one-dimensional aggregates

Article abstract of DOI:10.1021/jo101212d

This paper reports the self-assembling and electrochemical nature of hexaazatriphenylene-based electron-deficient heteroaromatics with an expanded π-electron system. The tri(phenanthro)hexaazatriphenylenes (TPHAT-Cs) and tri(phenanthrolino)hexaazatriphenylenes (TPHAT-Ns) were prepared by condensation reactions of the corresponding phenanthrenequinones and phenanthrolinediones, respectively, with hexaaminobenzene. Their electron affinity was indicated from cyclic voltammetry measurements, in which the first reduction potentials were evaluated at around -1.7 V (vs Fc/Fc⁺) in dichloromethane. In nonpolar and polar solvents and in the film state, the TPHAT-Cs and TPHAT-Ns formed one-dimensional aggregates with an H-type parallel stacking mode. In the MALDI-TOF mass spectra, significant peaks were seen at several multiples of the parent ion up to tetramer aggregates. The ¹H NMR spectra indicated a line-broadening effect due to the aggregation. The UV-vis and fluorescence spectra showed a concentration dependence, which is attributed to a dynamic exchange between the monomer and aggregate species. The order of the aggregative nature was estimated from the concentration dependence and the fluorescence quantum yield. By replacement of the peripheral aromatic moieties instead of the phenanthrene (TPHAT-Cs) with the phenanthroline (TPHAT-Ns), the aggregative nature was enhanced.

Full text of DOI:10.1021/jo101212d

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Expanded π-Electron Systems, Tri(phenanthro)hexaazatriphenylenes
and Tri(phenanthrolino)hexaazatriphenylenes, That Are Self-Assembled
To Form One-Dimensional Aggregates
Tsutomu Ishi-i,*,†,§ Ryoichi Hirashima,† Naotaka Tsutsumi,† Shogo Amemori,†
Shigeki Matsuki,† Yuuki Teshima,† Rempei Kuwahara,‡ and Shuntaro Mataka§
†Department of Biochemistry and Applied Chemistry, Kurume National College of Technology,
1-1-1 Komorino, Kurume 830-8555, Japan, ‡Interdisciplinary Graduate School of Engineering Sciences, and
§Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasuga-koh-en,
Kasuga 816-8580, Japan
ishi-i@kurume-nct.ac.jp
Received July 7, 2010
This paper reports the self-assembling and electrochemical nature of hexaazatriphenylene-based
electron-deficient heteroaromatics with an expanded π-electron system. The tri(phenanthro)-
hexaazatriphenylenes (TPHAT-Cs) and tri(phenanthrolino)hexaazatriphenylenes (TPHAT-Ns)
were prepared by condensation reactions of the corresponding phenanthrenequinones and phenan-
throlinediones, respectively, with hexaaminobenzene. Their electron affinity was indicated from
cyclic voltammetry measurements, in which the first reduction potentials were evaluated at around
-1.7 V (vs Fc/Fcþ) in dichloromethane. In nonpolar and polar solvents and in the film state, the
TPHAT-Cs and TPHAT-Ns formed one-dimensional aggregates with an H-type parallel stacking
mode. In the MALDI-TOF mass spectra, significant peaks were seen at several multiples of the
parent ion up to tetramer aggregates. The 1H NMR spectra indicated a line-broadening effect due to
the aggregation. The UV-vis and fluorescence spectra showed a concentration dependence, which is
attributed to a dynamic exchange between the monomer and aggregate species. The order of the
aggregative nature was estimated from the concentration dependence and the fluorescence quantum
yield. By replacement of the peripheral aromatic moieties instead of the phenanthrene (TPHAT-Cs)
with the phenanthroline (TPHAT-Ns), the aggregative nature was enhanced.
Introduction
semiconductors with a hole-transporting ability and n-type
ones with an electron-transporting ability. The former has
been extensively studied and has excellent characteristics,
whereas the latter is relatively rare and has unsatisfactory
performance. One of the desired performances of the organic
semiconductors is a high carrier-drift mobility compa-
rable to inorganic silicon materials. Recently, a π-stacked
Semiconducting organic compounds1 have been very
interesting in recent years in view of their application to
carrier-transporting materials in organic light-emitting
diodes,2 field-effect transistors,3 and photovoltaics.3d,4
These semiconductors are classified into two groups: p-type
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Published on Web 09/23/2010
DOI: 10.1021/jo101212d
r
2010 American Chemical Society

Ishi-i et al.
JOCArticle
one-dimensional structure created from the self-assembly of
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Recently, we have studied electron-deficient heteroaro-
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conductors based on their high electron affinity. In these studies,
we found that the n-type semiconducting hexaazatriphenylenes
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SCHEME 1. Preparation of TPHAT-Cs 6a-d
(HATs)14,15 can be self-assembled both in solution and bulk
state to form π-stacked one-dimensional aggregates.16 The self-
assembling HAT molecule is one of the new candidates as
parent of a large-sized n-type semiconductor.17 Our strategy is
based on the combination of the HAT core with other aromatics
to improve both its self-assembled aggregative nature and
electron affinity. In this strategy, we selected the phenanthrene
and phenanthroline rings as the fused aromatics, because the
corresponding diketone derivatives can be obtained and reacted
with hexaaminobenzene16 to produce the desired large-
sized n-type semiconductors. Combinations of the HAT
core with the three phenanthrene and phenanthroline rings
result in tri(phenanthro)hexaazatriphenylene (TPHAT-C)
and tri(phenanthrolino)hexaazatriphenylene (TPHAT-N),
respectively, which are composed of 13 fused six-membered
rings similar to that of hexabenzocoronene.9,10 In this
paper, we report that the TPHAT-C and TPHAT-N deriv-
atives provide a high electron affinity as n-type semicon-
ductors, as well as a strong self-assembling nature to form
one-dimensional aggregates.
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Chem. Soc. 2002, 124, 3486–3487. (b) Zhang, Q.; Prins, P.; Jones, S. C.;
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2005, 7, 5019–5022. (c) Kikuzawa, Y.; Mori, T.; Takeuchi, H. Org. Lett.
2007, 9, 4817–4820.
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Results and Discussion
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S. C.; Barlow, S.; Domercq, B.; Amy, F.; Kahn, A.; Bredas, J.-L.; Kippelen,
B.; Marder, S. R. J. Am. Chem. Soc. 2005, 127, 16358–16359.
Preparation. TPHAT-Cs 6a-d were prepared by conden-
sation reactions of the corresponding 3,4-disubsituted-9,10-
phenanthrenequinones 4a-d with hexaaminobenzene 516
in ethanol/THF in the presence of potassium carbonate
(Scheme 1). The key synthetic intermediates 4a-d were
obtained from 9,10-phenanthrenequinone (1) in two steps.
The radical-initiated bromination of 1 gave the dibromide
2,18 which was converted into 4a-d by the coupling reaction
with the corresponding boronic acid 3a and boronate esters
3b-d in the presence of a palladium (0) catalyst.
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R. A. J.; Meijer, E. W. Chem. Mater. 2001, 13, 2675–2679. (c) Ong, C. W.;
Liao, S.-C.; Chang, T. H.; Hsu, H.-F. Tetrahedron Lett. 2003, 44, 1477–1480.
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Chem. Soc. 2006, 128, 13042–13043. (e) Barlow, S.; Zhang, Q.; Kaafarani,
B. R.; Risko, C.; Amy, F.; Chan, C. K.; Domercq, B.; Starikova, Z. A.;
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Antipin, M. Yu.; Timofeeva, T. V.; Kippelen, B.; Bredas, J.-L.; Kahn, A.;
Marder, S. R. Chem.;Eur. J. 2007, 13, 3537–3547. (f) Gao, B.; Liu, Y.;
Geng, Y.; Cheng, Y.; Wang, L.; Jing, X.; Wang, F. Tetrahedron Lett. 2009,
50, 1649–1652.
TPHAT-Ns 14a-c were obtained from 1,10-phenanthro-
line (7) in 7 steps (Scheme 2). 2,9-Dichloro-1,10-phenanthro-
line (10) was prepared according to a reported method19 and
(16) (a) Ishi-i, T.; Hirayama, T.; Murakami, K.; Tashiro, H.; Thiemann,
T.; Kubo, K.; Mori, A.; Yamasaki, S.; Akao, T.; Tsuboyama, A.; Mukaide,
T.; Ueno, K.; Mataka, S. Langmuir 2005, 21, 1261–1268. (b) Ishi-i, T.;
Murakami, K.; Imai, Y.; Mataka, S. Org. Lett. 2005, 7, 3175–3178. (c) Ishi-i,
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(18) Bhatt, M. V. Tetrahedron 1964, 20, 803–821.
(19) Yamada, M.; Tanaka, Y.; Yoshimoto, Y. Bull. Chem. Soc. Jpn. 1992,
65, 1006–1011.
(17) Ishi-i, T.; Yaguma, K.; Kuwahara, R.; Taguri, Y.; Mataka, S. Org.
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SCHEME 2. Preparation of TPHAT-Ns 14a-c
was converted into the corresponding dibromide 11 by
treatment with phosphorus tribromide. The 5 and 6 positions
in 11 were oxidized by the treatment with nitric acid/sulfuric
acid/KBr to give 12.20 The coupling reactions of 12 with
boronic acid 3a and boronate esters 3c,d gave the corre-
sponding 2,9-disubstituted-1,10-phenanthroline-5,6-dione
13a-c in moderate yields. Finally, the TPHAT-Ns 14a-c
were obtained by the condensation reactions of 13a-c with
hexaaminobenzene 5.16 In 14a with 4-butylphenyl groups
and 14b with 4-octylphenyl groups, the preparation reaction
was performed in ethanol/THF in the presence of potassium
carbonate (condition A), as used in 6a-d. Condition A was
not suitable for the preparation of 14c with 4-octyloxyphenyl
groups, whereas 14c was obtained in acetic acid at the
refluxing temperature (condition B). The low isolated yield
(6%) in 14a is attributed to its poor solubility.
dissociation. The resulting spectra provided four aromatic
proton signals (Ha, Hb, Hc, and Hd shown in Scheme 2),
from which the structures of 14a-c could be assigned
(Supporting Information). In contrast, the broad peaks in
the phenanthrene-fused system 6a-d still appeared even in
the presence of trifluoroacetic acid-d1. These results indi-
cated that in 14a-c the protonation occurs at the nitrogen
atoms on the peripheral phenanthroline rings to dissociate
the aggregates but not on the central HAT ring. The struc-
tural assignment in 6a-d can be performed at high tempera-
ture. At 120 °C, the five aromatic proton signals (Ha, Hb,
Hc, Hd, and He shown in Scheme 1) became sharp peaks
suitable for detection in 1,1,2,2-tetrachloroethane-d2 solu-
tions (Supporting Information).
The TPHAT-Cs 6a-c and TPHAT-N 14b can dissolve
in various solvents from polar to nonpolar ones, such as
cyclohexane, toluene, dichloromethane, chloroform, 1,1,2,2-
tetrachloroethane, and THF. Compared to 6c bearing the
octyl groups, 6d bearing the octyloxy groups showed a poor
solubility in cyclohexane. Similarly, 14c bearing the octyloxy
groups cannot dissolve in cyclohexane. For 14a, the short
alkyl chain (butyl group) significantly lowered the solubility
in cyclohexane and toluene. In addition, 14a can dissolve
in 1,1,2,2-tetrachloroethane at the low concentration of
<0.1 mM. Thus, a detailed analysis of the aggregation ability
was performed in the polar 1,1,2,2-tetrachloroethane for
6a-d and 14a-c and in the nonpolar cyclohexane for
6a-c and 14b.
The TPHATs 6a-d and 14a-c were identified using
1
spectroscopic methods.21 In particular, H NMR spectros-
copy is effective for assigning the structure. In halogenated
solvents, such as chloroform-d1, dichloromethane-d2, and
1,1,2,2-tetrachloroethane-d2, a line-broadening effect arising
from the aggregation was observed. By the addition of
trifluoroacetic acid-d1, the broad peaks in the phenanthro-
line-fused system 14a-c became sharp due to aggregate
(20) Margiotta, N.; Bertolasi, V.; Capitelli, F.; Maresca, L.; Moliterni,
A. G. G.; Vizza, F.; Natile, G. Inorg. Chem. Acta 2004, 357, 149–158.
(21) The TPHAT-C 6c with octyl groups shows mesophase. The details of
the mesophase formation will be reported elsewhere.
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FIGURE 1. Cyclic voltammograms of 6c, 14b, 14c, and HAT-Ph in
dichloromethane (0.5 mM) in the presence of tetrabutylammonium
hexafluoroborate (0.1 M). The current intensity for 6c was indicated
by three times to precisely compare.
TABLE 1. Half-Wave Reduction Potentials (E1/2red) of 6c, 14b, 14c,
and HAT-Pha
E1/2red (V, vs Fc/Fcþ)
compound
first
second
third
6c
14b
14c
HAT-Ph
-1.73
-1.66
-1.70
-1.86
-1.86
-1.79
-1.81
-2.11
-2.25
-2.02
-2.21
-2.31
aDetermined by cyclic voltammetry using a cell equipped with glassy
carbon as the working electrode, a platinum wire as the counter
electrodes, and Ag/AgNO3 as the reference electrode. All electrochemi-
cal measurements were performed in a dichloromethane solution
(0.5 mM) containing 0.1 M tetrabutylammonium hexafluorophosphate.
FIGURE 2. MALDI-TOF mass spectra of (a) 6c and (b) 14b, which
indicate multiples of the parent ion up to tetramer.
UV-vis Spectroscopy. The one-dimensional π-stacking of
the TPHAT molecules is indicated in the UV-vis spectra.
The UV-vis spectra of 6a-d changed depending on the
concentration and temperature of the 1,1,2,2-tetrachloro-
ethane solutions. The spectral change is attributed to a
dynamic exchange between the monomer and aggregate
species (Figure 3 and Supporting Information). The UV-vis
spectra of 6a in 1,1,2,2-tetrachloroethane showed three
bands around 460, 440, and 370 nm (Figure 3a). The former
two bands can be assigned to the transition from the highest
ground state to the ν = 0 level of the lowest excited state
(0-0 transition) and to the ν = 1 level (0-1 transition). The
absorbance ratio (abs0-0/abs0-1) of the 0-0 and 0-1 transi-
tions decreased with the increase of concentration and with
the decrease of temperature, leading to the facilitated aggre-
gation. The foregoing trend is very similar to those of the
π-stacked aggregates with an H-type parallel stacking mode,16b,22
which is rationalized by the molecular exciton model.23 The
TPHAT-Cs 6a-d provided almost the same spectral change
versus the concentration to each other (Figure 3a and b, and
Supporting Information). At 1.0 mM, the abs0-0/abs0-1 values of
0.93 for 6a, 0.94 for 6b, 0.95 for 6c, and 1.00 for 6d are almost the
same, indicating the side chain groups (butyl in 6a, hexyl in 6b,
octyl in 6c, and octyloxy in 6d) only slightly affect the aggregation
in the TPHAT-C system.
Electrochemical Properties. The high electron affinity and
electrochemical stability were studied by cyclic voltammetry
(Figure 1, Table 1, and Supporting Information). In 6c, 14b,
and 14c, three quasi-reversible reduction potentials were
observed around -1.7 to -2.2 V (vs Fc/Fcþ). The first
reduction potentials (-1.66 to -1.73 V) in 6c, 14b, and 14c
shift more positively compared to the reduction potential
(-1.86 V) of the 2,3,6,7,10,11-hexaphenyl-1,4,5,8,9,12-
hexaazatriphenylene (HAT-Ph).16a These results indicated
an enhancement of the electron affinity by the combination
of the central HAT ring with the peripheral phenanthrene/
phenanthroline rings. Compared to the phenanthrene-fused
6c, the phenanthroline-fused 14b showed a higher electron
affinity due to the electron-deficient phenanthroline ring. By
replacement of the octyl group (14b) with the octyloxy group
(14c), the electron affinity decreased. No oxidation potential
was observed in the cyclic voltammogram (∼1.5 V), indicat-
ing the n-type semiconducting nature of the TPHATs.
MALDI-TOF Mass Spectrometry. Direct evidence for
the aggregation of 6a-d and 14a-c was obtained from
the MALDI-TOF mass spectrometry, in which aggregate
species can be detected up to the tetramer (Figure 2 and
Supporting Information). For example, in addition to the
parent ions of 6c (m/z 1813) and 14b (m/z 1819), significant
peaks are seen at several multiples of the parent ion up to
7252 for 6c and 7276 for 14b, which are assemblies of four
molecules (Figure 1).
(22) (a) van der Boom, T.; Hayes, R. T.; Patrick, Y. Z.; Bushard, J.; Weiss,
E. A.; Wasielewski, M. R. J. Am .Chem. Soc. 2002, 124, 9582–9590. (b)
Wang, W.; Han, J. J.; Wang, L.-Q.; Li, L.-S.; Shaw, W. J.; Li, A. D. Q. Nano
Lett. 2004, 3, 455–458.
(23) Kasha, M.; Rawls, H. R.; El-Bayoumi, M. A. Pure Appl. Chem. 1965,
11, 371–392.
6862 J. Org. Chem. Vol. 75, No. 20, 2010

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FIGURE 3. UV-vis spectra of (a) 6a, (b) 6c, (c) 14a, (d) 14b, and (e) 14c at 20 °C in 1,1,2,2-tetrachloroethane (at 0.001, 0.01, 0.1, and 1.0 mM).
By replacement of the peripheral aromatic moieties
instead of the phenanthrene (TPHAT-C system) with the
phenanthroline (TPHAT-N system), the aggregative nature
is significantly enhanced, and the effect of the side-chain
group is clearly observed. The concentration- and temperature-
dependencies in TPHAT-N 14b bearing the octyl groups
were lower than that in TPHAT-C 6c bearing the octyl
groups. At 20 °C, the abs0-0/abs0-1 value in 6c signif-
icantly changed from 0.95 (1.0 mM) to 1.28 (0.001 mM),
whereas the value in 14b only slightly changed from 0.93
(1.0 mM) to 1.01 (0.001 mM) (Figure 3b and d). These
results indicate the superior aggregative nature of the
TPHAT-N system.
Compared to TPHAT-N 14b bearing the alkyl chains,
TPHAT-N 14c bearing the alkoxy chains provides very slight
concentration- and temperature-dependencies in the
UV-vis spectra. The abs0-0/abs0-1 values in 14c seldom
changed with the concentration from 0.88 (1.0 mM) to 0.89
(0.001 mM) at 20 °C, indicating the high aggregation stabil-
ity (Figure 3e). The enhanced aggregation in 14c would be
attributed to the expansion of the π-electron system includ-
ing the oxygen atoms. Furthermore, the most significant
J. Org. Chem. Vol. 75, No. 20, 2010 6863

Ishi-i et al.
JOCArticle
stability is increased as 14a > 14c > 14b > 6a-d (6a >
6b > 6c > 6d).
In a nonpolar solvent, such as cyclohexane, the UV-vis
spectra of 6a-c and 14b seldom changed with the concentra-
tion and temperature, indicating the high stability of the
aggregates in the cyclohexane solution (Figure 4 and Support-
ing Information). Compared to the polar 1,1,2,2-terrachloro-
ethane system, the TPHAT-N and TPHAT-C molecules are
more tightly stacked in the nonpolar cyclohexane system.
The UV-vis spectra of the spin-coated films prepared
from the cyclohexane solutions of 6a-c and 14b are similar
to those of the solutions (Figure 4 and Supporting
Information). These results showed that in the film state,
the 6a-c and 14b molecules are self-assembled with a
H-aggregate stacking mode similar to the one created in
the solution state. The H-type aggregate with a wide π-face
overlap is very suitable for electron-carrier transport along
the π-stacked aggregate structure. The self-assembled film
formation can be applied to the organic devices prepared by
a wet process such as spin-coating.
Fluorescence Spectroscopy. The aggregation of the
TPHATs is reflected in the fluorescence spectra. In 1,1,2,2-
tetrachloroethane, a significant concentration dependence
was observed due to the dynamic exchange between the
monomer and aggregates species, as found in the UV-vis
spectra. In the TPHAT-C 6c, around 560 nm an excimer-like
emission arising from the aggregate species can be detected in
addition to the monomer emission around 490 nm. The
FIGURE 4. UV-vis spectra of 6a at 20 °C in cyclohexane (at 0.001
and 1.0 mM) and in the spin-coated film.
enhancement in the aggregation was achieved in TPHAT-N
14a bearing the short alkyl chains. The UV-vis spectra
of 14a indicated a significantly weak 0-0 transition band
as a shoulder around 450 nm (Figure 3c). The reduction in
the alkyl chain length from octyl (14b) to butyl (14a)
significantly facilitated the aggregation. Compared to 14b
bearing the long alkyl chains, 14a bearing the short alkyl
chains seems to show less favorable solvation to increase
the aggregative nature. As a summary of the foregoing
results, one can conclude that the order of aggregation
FIGURE 5. Fluorescence spectra of (a) 6c, (b) 14a, and (c) 14b in 1,1,2,2-tetrachloroethane and (d) 6c in cyclohexane at 0.001, 0.01, 0.01, and
1.0 mM (at 20 °C).
6864 J. Org. Chem. Vol. 75, No. 20, 2010

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TABLE 2. Fluorescence Quantum Yields (ΦFL) for 6a-d and 14a-ca
b
ΦFL
compound
cyclohexane
1,1,2,2-tetrachloroethane
6a
6b
6c
6d
14a
14b
14c
0.03
0.04
0.04
0.30
0.39
0.45
0.59
0.07
0.28
0.18
0.03c
aMeasured at 0.001 mM and excited at 420 nm. bRelative to fluo-
rescein (ΦFL 0.97 in ethanol, excited at 450 nm). cExcited at 380 nm.
FIGURE 6. Fluorescence images of 6c in 1,1,2,2-tetrachloroethane
at 0.001, 0.01, and 0.1 mM (from left to right) under UV light (365
nm).
population of the aggregate emission increased with the
increase of concentration together with the decrease of
monomer emission population (Figure 5a). The aggregation
dynamics can be visualized by changing the emission color
from blue (0.001 mM) to green (0.1 mM) (Figure 6).24
A
similar concentration dependence was observed in TPHAT-Cs
6a, 6b, and 6d. Compared to the TPHAT-Cs, the TPHAT-Ns
mainly provide an aggregate emission because of their facili-
tated aggregation (Figures 5b and 5c). The formed aggregate
emits a weak fluorescence that decreases the fluorescence
quantum yield (ΦFL). The ΦFL values of the TPHAT-Ns are
lower than those of the TPHAT-Cs: 0.30 in 6a vs 0.07 in 14a,
0.45 in 6c vs 0.28 in 14b, and 0.59 in 6d vs 0.18 in 14c. The
order of the aggregative nature is estimated from the ΦFL
values (Table 2). The estimated order is 14a>14c>14b>6a>
6b>6c > 6d, which is in agreement with that estimated from
the UV-vis spectroscopy.
The cyclohexane solutions of 6a-c and 14b provided only
weak aggregate emissions at the longer wavelength around
550-600 nm for all the concentrations. At the dilute con-
centration of 0.001 mM, the emission band (around 550 nm)
in the cyclohexane solution of 6c is observed at a longer
wavelength than that (around 490 nm) in the 1,1,2,2-
tetrachloroethane solution; nevertheless, the polarity of the
cyclohexane is lower than that of 1,1,2,2-tetrachloroethane
(Figure 5a and d). The bathochromic shift observed in
cyclohexane would be attributed to a stabilization effect on
the excited state in the aggregate.25 The stabilization effect
should be ascribed to the excimer formation in the aggregate
structure or the migration of the photogenerated exciton.26
A similar bathochromic shift was observed in 6a, 6b, and 14b
as described above. In the 1,1,2,2-tetrachloroethane solu-
tions, 6a-c and 14b provide moderate ΦFL values of
0.28-0.45. The ΦFL values are reduced in the nonpolar
cyclohexane solutions to 0.03-0.04 (Table 2). The lowering
emission ability also supports the enhanced aggregation of
FIGURE 7. AFM image of 6a. The sample was prepared by drop
casting from a 0.01 mM cyclohexane solution on freshly cleaved
mica.
6a-c and 14b in the nonpolar solvent. In the film state of
6a-c and 14c prepared from cyclohexane solutions, the
emission is too weak to be detected, indicating the enhanced
aggregation in the film state.
AFM Observation. The π-stacked one-dimensional
aggregate structure of the TPHATs can be visualized by
atomic force microscopy (AFM) observations (Figure 7
and Supporting Information). The cyclohexane solutions
of 6a-c and 14b, in which the TPHAT molecules are
significantly self-assembled to form the one-dimensional
aggregates, were casted on freshly cleaved mica. The AFM
images indicate a nanoscale fibrous structure with a height
of ca. 2.8-3.5 nm, which is comparable to the molecular
size of the TPHATs (the extended molecular size is of
ca. 3.2-4.2 nm, whereas the aromatic core size is of ca.
2.5 nm).27 In 6a-c, the height increased with the increase
€
(24) Wurthner, F.; Chen, Z.; Dehm, V.; Stepanenko, V. Chem. Commun.
2006, 1188–1190.
(25) Ikeda, M.; Takeuchi, M.; Shinkai, S. Chem. Commun. 2003, 1354–
(27) The π-stacked one-dimensional aggregate is also supported by X-ray
diffraction patterns of 6a, 6b, 6c, and 14b (Supporting Information). A weak
reflection around 26° would be attributed to the intracolumnar π-stacking
distance of ca. 0.34 nm. In contrast, a strongly sharp reflection around
2.9-3.7° (2.38 nm for 6a, 2.69 nm for 6b, 3.03 nm for 6c, and 2.85 nm for14b)
would be due to the intercolumnar packing.
1355.
€
(26) Wu, J.; Fechtenkotter, A.; Gauss, J.; Watson, M. D.; Kastler, M.;
Fechtenkotter, C.; Wagner, M.; Mullen, K. J. Am. Chem. Soc. 2004, 126,
€
€
11311–11321.
J. Org. Chem. Vol. 75, No. 20, 2010 6865

Ishi-i et al.
JOCArticle
of alkyl chain length: ca. 2.8-2.9 nm in 6a, ca. 3.0-3.1 nm
in 6b, and ca. 3.4-3.5 nm in 6c.
Anal. Calcd for C34H32O2 (472.62): C, 86.40; H, 6.82. Found: C,
86.21; H, 6.81.
3,6-Bis(4-hexylphenyl)-9,10-phenanthrenequinone (4b). Yellow
powder; mp 156-158 °C; IR (KBr, cm-1) 3023, 2954, 2925,
2854, 1671 (νCdO), 1593, 1394, 1316, 1296, 1237, 1188, 927, 842,
812; 1H NMR (CDCl3) δ 0.90 (t, J = 6.8 Hz, 6 H), 1.23-1.46 (m,
12 H), 1.68 (quint, J = 7.8 Hz, 4 H), 2.70 (t, J = 7.8 Hz, 4 H),
7.34 (d, J = 8.3 Hz, 4 H), 7.62 (d, J = 8.3 Hz, 4 H), 7.67 (dd, J =
1.5, 8.3 Hz, 2 H), 8.26 (d, J = 1.5 Hz, 2 H), 8.27 (d, J = 8.3 Hz, 2
H); 13C NMR (CDCl3) δ 14.1, 20.6, 29.0, 31.4, 31.7, 35.7, 122.4,
127.2, 128.1, 129.2, 129.7, 131.2, 136.2, 136.8, 144.3, 148.8,
180.1; FAB-MS (positive, NBA) m/z 529 [(M þ 1)þ]. Anal.
Calcd for C38H40O2 (528.72): C, 86.32; H, 7.63. Found: C, 86.11;
H, 7.59.
3,6-Bis(4-octylphenyl)-9,10-phenanthrenequinone (4c). Yellow
powder: mp 157-158 °C; IR (KBr, cm-1) 3023, 2956, 2925,
2853, 1671 (νCdO), 1593, 1391, 1316, 1297, 1237, 1188, 927, 841,
811; 1H NMR (CDCl3) δ 0.90 (t, J = 6.8 Hz, 6 H), 1.23-1.42 (m,
20 H), 1.67 (quint, J = 7.8 Hz, 4 H), 2.67 (t, J = 7.8 Hz, 4 H),
7.35 (d, J = 8.3 Hz, 4 H), 7.63 (d, J = 8.3 Hz, 4 H), 7.69 (dd, J =
1.5, 8.3 Hz, 2 H), 8.26 (d, J = 1.5 Hz, 2 H), 8.28 (d, J = 8.3 Hz,
2 H); 13C NMR (CDCl3) δ 14.1, 22.7, 29.2, 29.3, 29.5, 31.4, 31.9,
35.7, 122.4, 127.7, 128.1, 129.3, 129.7, 131.2, 136.2, 136.8, 144.3,
148.8, 180.1; FAB-MS (positive, NBA) m/z 585 [(M þ 1)þ].
Anal. Calcd for C42H48O2 (584.83): C, 86.26; H, 8.27. Found: C,
85.88; H, 8.22.
3,6-Bis(4-octyloxylphenyl)-9,10-phenanthrenequinone (4d).
Yellow powder; mp 110-112 °C; IR (KBr, cm-1) 3069, 3054,
2954, 2922, 2851, 1659 (νCdO), 1591, 1519, 1309, 1244, 1185, 824;
1H NMR (CDCl3) δ 0.90 (t, J = 6.8 Hz, 6 H), 1.25-1.43 (m, 16
H), 1.49 (quint, J = 6.8 Hz, 4 H), 1.83 (quint, J = 6.8 Hz, 4 H),
4.04 (t, J = 6.8 Hz, 4 H), 7.05 (d, J = 8.8 Hz, 4 H), 7.65 (dd, J =
1.5, 8.3 Hz, 2 H), 7.65 (d, J = 8.8 Hz, 4 H), 8.22 (d, J = 1.5 Hz,
2 H), 8.25 (d, J = 8.3 Hz, 2 H); 13C NMR (CDCl3) δ 14.1, 22.7,
26.0, 29.22, 29.24, 29.4, 31.8, 68.3, 115.2, 121.9, 127.7, 128.6,
129.4, 131.2, 131.6, 136.2, 148.4, 160.2, 180.1; FAB-MS (positive,
NBA) m/z 617 [(M þ 1)þ]. Anal. Calcd for C42H48O4 (616.83): C,
81.78; H, 7.84. Found: C, 81.78; H, 7.82.
Conclusion
In conclusion, we have demonstrated that the electron-
deficient tri(phenanthro)- and tri(phenanthrolino)hexaazatri-
phenylenes with an expanded π-electron system can be self-
assembled to form one-dimensional aggregates. The electron
affinity is enhanced by the expansion of the electron-deficient
aromatic system, which is created by a combination of the
central hexaazatriphenylene core with the three peripheral
phenanthrene/phenanthroline rings. The extended aggregates
of the π-stacked aromatic moieties would provide an efficient
path for the electron-carrier transport within the one-
dimensional aggregate structures. It is convinced that the
present study provide new valuable information for creat-
ing as an electron-carrier transporting material in the
organic devices such as an organic field effect transistor
and photovoltaic cell. We are currently in the process of
obtaining electron-mobility measurements.
Experimental Section
Spectroscopic Measurements. UV-vis spectra were measured
in a 0.01 cm width quartz cell (1.0 mM), a 0.1 cm cell (0.1 mM), a
1.0 cm cell (0.01 mM), and a 10.0 cm cell (0.001 mM). Fluores-
cence spectra were measured in a 1.0 cm width quartz cell.
Preparation of Spin-Coated Films. Film samples for UV-vis
and fluorescence spectroscopy were prepared by drop-casting
and subsequent spin-coating (2000 rpm, 30 s) from 1.0 mM
cyclohexane solutions (100 μL ꢀ 3) on quartz cell (12.5 ꢀ 12.5 ꢀ
45 mm).
Electrochemical Measurement. Cyclic voltammetry measure-
ments were measured in deaerated dichloromethane solution
(0.5 mM) containing tetrabutylammonium hexafluoroborate
(0.1 M) as a supporting electrolyte at 298 K at scan rate
of 10-100 mV s-1 (10 mV s-1 for 14b and 100 mV s-1 for 6c,
14c, and HAT-Ph). The glassy carbon working electrode was
polished with BAS polishing alumina suspension and rinsed
with acetone before use. The counter electrode was a platinum
wire. The measured potentials were recorded with respect to an
Ag/AgCl (saturated KCl) reference electrode.
General Procedure for Preparation of 3,6-Bis(4-butylphenyl)-
9,10-phenanthrenequinone (4a). A mixture of 2 (831 mg, 2.27
mmol) and tetrakis(triphenylphosphine)palladium(0) (552 mg,
0.455 mmol) in deaerated DME (45 mL) was heated at 60 °C for
5 min under an argon atmosphere. To the mixture were added
4-butylphenylboronic acid (3a) (890 mg, 5.0 mmol) and deaer-
ated aqueous 2 M sodium carbonate solution (22.5 mL) at 60 °C,
and the mixture was heated at 85 °C for 18 h. The reaction
mixture was poured into water and extracted with dichloro-
methane. The organic layer was washed with brine and water,
dried over anhydrous magnesium sulfate, and evaporated in
vacuo to dryness. The residue (1.31 g) was purified by silica gel
column chromatography (WAKO C300) eluting with hexane/
dichloromethane (1:4, v/v) and by recrystallization from hexane/
dichloromethane to give 4a in 63% yield (677 mg, 1.43 mmol)
as yellow powder: mp 211-213 °C; IR (KBr, cm-1) 3023,
2955, 2927, 2856, 1671 (νCdO), 1594, 1393, 1316, 1236, 1188,
926, 840, 824; 1H NMR (CDCl3) δ 0.96 (t, J = 7.3 Hz, 6 H), 1.41
(sept, J = 7.3 Hz, 4 H), 1.66 (quint, J = 7.3 Hz, 4 H), 2.71 (t, J =
7.3 Hz, 4 H), 7.35 (d, J = 8.3 Hz, 4 H), 7.63 (d, J = 8.3 Hz, 4 H),
7.69 (dd, J = 1.5, 8.3 Hz, 2 H), 8.26 (d, J = 1.5 Hz, 2H), 8.28 (d,
J = 8.3 Hz, 2 H); 13C NMR (CDCl3) δ 13.9, 22.3, 33.5, 35.4,
122.4, 127.2, 128.1, 129.2, 129.7, 131.1, 136.1, 136.8, 144.3,
148.8, 180.0; FAB-MS (positive, NBA) m/z 473 [(M þ 1)þ].
General Procedure for Preparation of 3,6,13,16,23,26-
Hexakis(4-butylphenyl)-triphenanthro[9,10-b:90,100-h:900,1000-n]-
1,4,5,8,9,12-hexaazatriphenylene (6a). To a solution of 4a (473
mg, 1.0 mmol) and crushed potassium carbonate (140 mg,
1.0 mmol) in dry ethanol (7.5 mL) and dry THF (15 mL) was
added hexaaminobenzene trihydrochloride (5) (97 mg, 0.35
mmol), and the mixture was heated at the refluxing temperature
for 19 h under an argon atmosphere. The reaction mixture was
poured into water and extracted with chloroform. The organic
layers was washed with brine and water, dried over anhydrous
magnesium sulfate, and evaporated in vacuo to dryness. The
residue (631 mg) was subjected to silica gel column chromatog-
raphy (WAKO C300) eluting with chloroform to give crude
product (285 mg). The crude product was purified by GPC
eluting with chloroform to give 6a in 12% yield (59 mg, 0.0399
mmol): viscous dark brown solid; mp >350 °C; IR (KBr, cm-1
)
3022, 2953, 2925, 2854, 1609, 1498, 1458, 1437, 1398, 1366, 1300,
1247, 1184, 1155, 823; 1H NMR (CDCl2CDCl2, 120 °C) δ 1.19
(t, J = 7.3 Hz, 18 H), 1.65 (sept, J = 7.3 Hz, 12 H), 1.90 (quint,
J = 7.3 Hz, 12 H), 2.88 (t, J = 7.3 Hz, 12 H), 7.37 (d, J = 6.8 Hz,
12 H), 7.66 (d, J = 6.8 Hz, 12 H), 7.83 (br-d, 6 H), 8.36 (br-s, 6
H), 9.26 (br-d, 6 H); 13C NMR (CDCl2CDCl2, 120 °C) δ 14.1,
22.8, 33.9, 35.6, 120.5, 126.0, 127.0, 127.5, 129.0, 129.1, 131.9,
138.6, 140.6, 141.2, 141.4, 142.3; MALDI-TOF-MS (positive,
dithranol) m/z 1476.90 (Mþ, calcd for C108H96N6, 1476.77).
Anal. Calcd for C108H96N6 0.2CHCl3 (1477.96): C, 86.53; H,
3
6.46; N, 5.60. Found: C, 86.46; H, 6.55; N, 5.72.
3,6,13,16,23,26-Hexakis(4-hexylphenyl)triphenanthro[9,10-
b:90,100-h:900,1000-n]-1,4,5,8,9,12-hexaazatriphenylene (6b). Vis-
cous dark brown solid; mp >350 °C; IR (KBr, cm-1) 3022,
6866 J. Org. Chem. Vol. 75, No. 20, 2010

Ishi-i et al.
JOCArticle
2954, 2925, 2853, 1609, 1498, 1457, 1436, 1397, 1366, 1301, 1249,
1184, 1155, 817; 1H NMR (CDCl2CDCl2, 120 °C) δ 1.11 (t, J =
7.3 Hz, 18 H), 1.35-1.72 (m, 36 H), 1.92 (quint, J = 7.3 Hz,
12 H), 2.86 (t, J = 7.3 Hz, 12 H), 7.35 (d, J = 7.3 Hz, 12 H), 7.62
(d, J = 7.3 Hz, 12 H), 7.77 (br-d, 6 H), 8.28 (br-s, 6 H), 9.15 (br-d,
6 H); 13C NMR (CDCl2CDCl2, 120 °C) δ 14.2, 22.9, 29.5,
31.4, 32.1, 36.0, 120.5, 126.0, 127.1, 127.5, 128.9, 129.1, 132.0,
138.5, 140.8, 141.3, 141.5, 142.4; MALDI-TOF-MS (positive,
dithranol) m/z 1645.08 (Mþ, calcd for C120H120N6, 1644.96).
1012, 922, 856, 842, 745, 566; 1H NMR (CDCl3,) δ 7.79 (d, J =
8.3 Hz, 2 H), 8.30 (d, J = 8.3 Hz, 2 H); 13C NMR (CDCl3) δ
127.1. 131.1, 138.9, 150.7, 152.2, 177.5; FAB-MS (positive,
NBA) m/z 367, 369, 371 [1:2:1, (M þ 1)þ]. Anal. Calcd for
C12H4Br2N2O2 (365.86): C, 39.17; H, 1.10; N, 7.61. Found: C,
38.91; H, 1.18; N, 7.43.
2,9-Bis(4-butylphenyl)-1,10-phenanthroline-5,6-dione (13a).
Pale orange solid; mp 186-188 °C; IR (KBr, cm-1) 3060,
3029, 2956, 2927, 2857, 1675 (νC=O), 1571, 1515, 1462, 1442,
1371, 1325, 1181, 924, 829, 768; 1H NMR (400 MHz) δ 0.97 (t,
J = 7.3 Hz, 6 H), 1.41 (sext, J = 7.3 Hz, 4 H), 1.68 (quint, J =
7.3 Hz, 4 H), 2.74 (t, J = 7.3 Hz, 4 H), 7.42 (d, J = 8.3 Hz, 4 H),
8.00 (d, J = 8.3 Hz, 2 H), 8.31 (d, J = 8.3 Hz, 4 H), 8.53 (d, J =
8.3 Hz, 2 H); 13C NMR (CDCl3) δ 14.0, 22.3, 33.4, 35.6, 121.0,
126.5, 127.9, 129.3, 135.1, 137.9, 146.6, 153.1, 162.9, 178.9;
FAB-MS (positive, NBA) m/z 475 [(M þ 1)þ]. Anal. Calcd for
Anal. Calcd for C120H120N6 0.1CHCl3 (1646.28): C, 86.99; H,
3
7.30; N, 5.07. Found: C, 87.02; H, 7.28; N, 5.09.
3,6,13,16,23,26-Hexakis(4-octylphenyl)triphenanthro[9,10-
b:90,100-h:900,1000-n]-1,4,5,8,9,12-hexaazatriphenylene (6c). Vis-
cous dark brown solid; mp >350 °C; IR (KBr, cm-1) 3023,
2955, 2925, 2853, 1610, 1514, 1499, 1466, 1437, 1400, 1368, 1302,
1250, 1185, 1156, 824; 1H NMR (CDCl2CDCl2, 120 °C) δ 1.07
(t, J = 6.3 Hz, 18 H), 1.34-1.77 (m, 60 H), 1.90 (quint, J = 7.8
Hz, 12 H), 2.85 (t, J = 7.8 Hz, 12 H), 7.33 (br-d, 12 H), 7.59 (br-
C
32H30N2O2 (474.23): C, 80.98; H, 6.37; N, 5.90; Found: C,
80.68; H, 6.34; N, 5.85.
d, 12 H), 7.74 (br-d, 6 H), 8.23 (br-s, 6 H), 9.09 (br-d, 6 H); 13
C
2,9-Bis(4-octylphenyl)-1,10-phenanthroline-5,6-dione (13b).
Yellow needles; mp 134-135 °C; IR (KBr, cm-1) 3061, 3029,
2956, 2925, 2852, 1671 (νCdO), 1570, 1462, 1442, 1374, 1325,
1181, 1094, 925, 829, 768; 1H NMR (CDCl3) δ 0.91 (t, J = 6.8
Hz, 6 H), 1.21-1.39 (m, 10 H), 1.69 (quint, J = 7.3 Hz, 4 H),
2.71 (t, J = 7.3 Hz, 4 H), 7.38 (d, J = 8.4 Hz, 4 H), 8.01 (d, J =
8.1 Hz, 2 H), 8.32 (d, J = 8.4 Hz, 4 H), 8.54 (d, J = 8.1 Hz,
2 H); 13C NMR (CDCl3) δ 14.1, 22.7, 29.25, 29.29, 29.5, 31.2,
31.9, 35.9, 120.9, 126.4, 127.9, 129.2, 135.1, 137.8, 146.6,
153.0, 162.9, 178.9; FAB-MS (positive, NBA) m/z 587 [(M þ
1)þ]. Anal. Calcd for C40H46N2O2 (586.81): C, 81.87; H, 7.90;
N, 4.77. Found: C, 81.78; H, 7.86 ; N, 4.74.
2,9-Bis(4-octyloxyphenyl)-1,10-phenanthroline-5,6-dione (13c).
Pale orange solid; mp 143-144 °C; IR (KBr, cm-1) 3020, 2922,
2852, 1671 (νCdO), 1605, 1571, 1511, 1467, 1445, 1373, 1328,
1251, 1173, 826; 1H NMR (CDCl3) δ 0.90 (t, J = 6.8 Hz, 6 H),
1.27-1.42 (m, 12 H), 1.47-1.60 (m, 8 H), 1.85 (quint, J = 6.8 Hz,
4 H), 4.09 (t, J = 6.8 Hz, 4 H), 7.10 (d, J = 9.0 Hz, 4 H), 7.95 (d,
J = 8.3 Hz, 2 H), 8.36 (d, J = 9.0 Hz, 4 H), 8.50 (d, J = 8.3 Hz,
2 H); 13C NMR (CDCl3) δ 14.1, 22.7, 22.0, 29.22, 29.24, 29.4,
31.8, 68.3, 115.0, 120.2, 126.0, 129.5, 130.0, 137.7, 153.0, 161.9,
162.3, 178.8; FAB-MS (positive, NBA) m/z 619 [ (M þ 1)þ ].
Anal. Calcd for C40H46N2O4 (618.35): C, 77.64; H, 7.49; N, 4.53;
Found: C, 77.28; H, 7.38; N, 4.50.
3,6,13,16,23,26-Hexakis(4-butylphenyl)tri-1,10-phenanthrolino-
[5,6-b:50,60-h:500,600-n]-1,4,5,8,9,12-hexaazatriphenylene (14a).
Dark brown solid; mp >350 °C; IR (KBr, cm-1) 3061, 3025,
2954, 2926, 2856, 1582, 1568, 1490, 1369, 1282, 1219, 1180,
1158, 1017, 829, 769; 1H NMR (CD2Cl2:CF3COOD, 9:1 (v/v))
δ 1.04 (t, J = 7.8 Hz, 18 H), 1.49 (sext, J = 7.8 Hz, 12 H), 1.79
(quint, J = 7.8 Hz, 12 H), 2.90 (t, J = 7.8 Hz, 12 H), 7.72 (d,
J = 7.3 Hz, 12 H), 8.35 (d, J = 7.3 Hz, 12 H), 8.94 (br-d, 6 H),
10.59 (br-d, 6 H); 13C NMR (CD2Cl2/CF3COOD, 9:1 (v/v)) δ
14.1, 22.8, 33.7, 36.1, 126.0, 127.8, 128.6, 130.7, 131.0, 139.8,
141.0, 141.4, 144.2, 150.6, 158.7; MALDI-TOF-MS (positive,
dithranol) m/z 1482.20 (Mþ, calcd for C102H90N12, 1482.74).
NMR (CDCl2CDCl2, 120 °C) δ 14.1, 22.8, 29.5, 29.8, 29.9,
31.5, 32.2, 36.0, 120.7, 126.3, 127.2, 127.6, 129.0, 129.7, 132.2,
138.5, 141.0, 141.6, 142.1, 142.5; MALDI-TOF-MS (positive,
dithranol) m/z 1813.53 (Mþ, calcd for C132H144N6, 1813.15).
Anal. Calcd for C132H144N6 (1814.60): C, 87.37; H, 8.00; N,
4.63. Found: C, 87.15; H, 8.00; N, 4.67.
3,6,13,16,23,26-Hexakis(4-octyloxyphenyl)triphenanthro-
[9,10-b:90,100-h:900,1000-n]-1,4,5,8,9,12-hexaazatriphenylene (6d).
Viscous dark brown solid; mp >350 °C; IR (KBr, cm-1) 3036,
2952, 2925, 2854, 1606, 1514, 1499, 1472, 1367, 1246, 1179, 823;
1H NMR (CDCl2CDCl2, 120 °C) δ 1.07 (t, J = 6.8 Hz, 18 H),
1.40-1.63 (m, 48 H), 1.71 (quint, J = 6.8 Hz, 12 H), 2.01 (quint,
J = 6.8 Hz, 12 H), 4.17 (t, J = 6.8 Hz, 12 H), 7.08 (d, J = 8.3 Hz,
12 H), 7.63 (d, J = 8.3 Hz, 12 H), 7.77 (br-d, 6 H), 8.28 (br-s, 6 H),
9.17 (br-d, 6 H); 13C NMR (CDCl2CDCl2, 120 °C) δ 14.1, 22.8,
26.5, 29.5, 29.7, 29.9, 32.1, 68.9, 115.5, 120.0, 125.9, 127.1, 128.6,
128.9, 132.0, 133.6, 141.0, 141.3, 141.4, 159.5; MALDI-TOF-MS
(positive, dithranol) m/z 1909.31 (Mþ, calcd for C132H144N6O6,
1909.11). Anal. Calcd for C132H144N6O6 0.1CHCl3 (1910.59): C,
3
82.53; H, 7.55; N, 4.37. Found: C, 82.40; H, 7.63; N, 4.32.
2,9-Dibromo-1,10-phenanthroline (11). A mixtureof 10(2.38 g,
9.55 mmol) in phosphorus tribromide (14.5 mL, 154 mmol)
was heated at 170 °C for 5.5 h under an argon atmosphere. After
the reaction mixture was cooled to room temperature, it was
quenched by addition of cold water and neutralized with sodium
hydrogencarbonate. The formed solid was collected by filtration
and washed with water and methanol. The solid (2.63 g) was
purified by recrystallization from chloroform to give 11 in 74%
yield (2.40 g, 7.09 mmol) as white powder: mp 225-227 °C; IR
(KBr, cm-1) 3041, 1588, 1573, 1546, 1471, 1439, 1408, 1343, 1243,
1123, 1112, 1063, 878, 849, 786, 726, 621, 601, 573, 548; 1H NMR
(CDCl3) δ 7.80 (d, J = 8.3 Hz, 2 H), 7.83 (s, 2 H), 8.09 (d, J =
8.3 Hz, 2 H); 13C NMR (CDCl3) δ 126.5, 127.9, 128.5, 138.2,
143.1, 145.5; FAB-MS (positive, NBA) m/z 337, 339, 341 [1:2:1,
(M þ 1)þ ]. Anal. Calcd for C12H6Br2N2 (335.89): C, 42.64; H,
1.79; N, 8.29. Found: C, 42.71; H, 1.87; N, 8.34.
Anal. Calcd for C102H90N12 0.1CHCl3 (1483.89): C, 82.27; H,
6.09; N, 11.28. Found: C, 82.02; H, 6.21; N, 11.08.
3
2,9-Dibromo-1,10-phenanthroline-5,6-dione (12). To a mix-
ture of 11 (2.34 g, 6.91 mmol) and KBr (8.29 g, 69.1 mmol)
was added dropwise concd sulfuric acid (28 mL) along the vessel
wall at 0 °C. Then concd nitric acid (14 mL) was added dropwise
along the vessel wall at 0 °C. The mixture was heated at 80 °C for
3 h. After the reaction mixture was cooled to 0 °C, it was poured
slowly into ice water and neutralized with saturated sodium
hydrogencarbonate aqueous solution. The formed precipitate
was collected by filtration and washed with water and methanol
to give 12 in 67% yield (1.71 g, 4.64 mmol) as pale yellow
powder. An analytical sample obtained by GPC eluting with
chloroform. Mp 252-254 °C; IR (KBr, cm-1) 3071, 1693
(νCdO), 1601, 1561, 1436, 1356, 1296, 1234, 1122, 1108, 1076,
3,6,13,16,23,26-Hexakis(4-octylphenyl)-tri-1,10-phenanthrolino-
[5,6-b:50,60-h:500,600-n]-1,4,5,8,9,12-hexaazatriphenylene (14b).
Brown solid; mp >350 °C; IR (KBr, cm-1) 3060, 3026, 2924,
2852, 1582, 1568, 1491, 1426, 1369, 1282, 1219, 1178, 1158,
1017, 830, 769; 1H NMR (CD2Cl2:CF3COOD, 9:1 (v/v)) δ 0.82
(t, J = 6.8 Hz, 18 H), 1.10-1.37 (m, 60 H), 1.70 (quint, J = 7.8
Hz, 12 H), 2.79 (t, J = 7.8 Hz, 12 H), 7.61 (d, J = 6.8 Hz, 12 H),
8.25 (d, J = 6.8 Hz, 12 H), 8.84 (br-d, 6 H), 10.50 (br-d, 6 H);
13C NMR (CD2Cl2/CF3COOD, 9:1 (v/v)) δ 14.2, 23.1, 29.7,
29.8, 29.9, 31.6, 32.3, 36.5, 125.9, 127.8, 128.6, 130.7, 131.1,
139.8, 141.1, 141.3, 144.2, 150.8, 158.8; MALDI-TOF-MS
(positive, dithranol) m/z 1819.13 (Mþ, calcd for C126H138N12,
J. Org. Chem. Vol. 75, No. 20, 2010 6867

Ishi-i et al.
JOCArticle
1819.12). Anal. Calcd for C126H138N12 0.1CHCl3 (1820.52):
C126H138N12O6 0.1CHCl3 (1916.52): C, 78.54; H, 7.22; N,
8.72. Found: C, 78.48; H, 7.07; N, 8.85.
3
3
C, 82.65; H, 7.60; N, 9.17. Found: C, 82.39; H, 7.43; N, 9.07.
3,6,13,16,23,26-Hexakis(4-octyloxyphenyl)-tri-1,10-
phenanthrolino[5,6-b:50,60-h:500,600-n]-1,4,5,8,9,12-hexaazatri-
phenylene (14c). To a solution of 13c (118 mg, 0.20 mmol) in
dearerated acetic acid (3 mL) was added hexaaminobenzene
trihydrochloride (5) (21 mg, 0.076 mmol), and the mixture was
heated at refluxing temperature for 12.5 h under an argon
atmosphere. The reaction mixture was poured into water and
extracted with chloroform. The organic layer was washed with
2 M sodium carbonate aqueous solution and water, dried over
anhydrous magnesium sulfate, and evaporated in vacuo to
dryness. The residue (98 mg) was subjected to silica gel column
chromatography (WAKO C300) eluting with chloroform to
give crude product (69 mg). The crude product was purified
by GPC eluting with chloroform to give 14c in 41% yield (52 mg,
0.027 mmol) as a dark brown solid: mp >350 °C; IR (KBr,
cm-1) 3066, 3040, 2924, 2853, 1607, 1571, 1510, 1491, 1472,
1370, 1307, 1285, 1250, 1217, 1172, 826, 772; 1H NMR (CD2Cl2:
CF3COOD, 9:1 (v/v)) δ 0.95 (t, J = 6.8 Hz, 18 H), 1.37-1.59 (m,
60 H), 1.95 (quint, J = 6.8 Hz, 12 H), 4.27 (t, J = 6.8 Hz, 12 H),
7.40 (d, J = 7.3 Hz, 12 H), 8.41 (d, J = 7.3 Hz, 12 H), 8.88 (br-d,
6 H), 10.54 (br-d, 6 H); 13C NMR (CD2Cl2:CF3COOD, 9:1
(v/v)) δ 14.3, 23.1, 23.4, 29.5, 29.7, 29.8, 32.3, 69.6, 116.9,
124.6, 125.0, 126.7, 130.3, 139.4, 140.5, 140.6, 143.6, 157.7,
164.7; MALDI-TOF-MS (positive, dithranol) m/z 1915.56
(Mþ, calcd for C126H138N12O6, 1915.09). Anal. Calcd for
Acknowledgment. We thank Professor Dr. Teruo
Shinmyozu, Dr. Shin-ichiro Kato, and Mr. Masaru Konno
(Kyushu University) for the CVmeasurement, Mr. Tomoyuki
Ishikawa (Fukuoka Industrial Technology Center) for the
measurement of MALDI-TOF mass spectrometry, and Dr
Masayuki Chikamtsu (AIST, Japan) and Professor Dr.
Yusuke Tsuda (Kurume National College of Technology)
for the helpful discussion. This work was partially performed
under the Cooperative Research Program of “Network Joint
Research Center for Materials and Devices (Institute for
Materials Chemistry and Engineering, Kyushu University)”.
This work was partially supported by DIC Award in the
Society of Synthetic Organic Chemistry, Iketani Science and
Technology Foundation, and Grant-in-Aid for Scientific
Research (C) from the Ministry of Education, Science, Culture,
Sports, and Technology of Japan.
Supporting Information Available: 1H NMR, UV-vis,
fluorescence, MALDI-TOF-MS, cyclic voltammograms, AFM,
X-ray diffraction, and general experimental procedures. This
material is available free of charge via Internet at http://
pubs.acs.org.
6868 J. Org. Chem. Vol. 75, No. 20, 2010