Functionalization of hexa-peri-hexabenzocoronenes: Investigation of the substituent effects on a superbenzene

Article abstract of DOI:10.1002/asia.201200723

We have demonstrated that the iridium-catalyzed direct borylation of hexa-peri-hexabenzocoronene (HBC) enables regioselective introduction of boryl groups to the para-, ortho-, and meta-substituted HBCs in high yields. The boryl groups have been transformed into various functionalities such as hydroxy, cyano, ethynyl, and amino groups. We have elucidated that the substituents significantly influence the photophysical properties of HBCs to enhance fluorescence quantum yields. DFT calculations revealed that the origin of the substituent effect is the lift in degeneracy in the frontier orbitals by an interaction with electron-donating and electron-withdrawing substituents at the para- and ortho-positions. The change in molecular orbitals results in an increase of the transition probability from the S₀→S₁ states. In addition, the two-photon absorption cross-section values of para-substituted HBCs are significantly larger than those of ortho- and meta-substituted HBCs. Copyright

Full text of DOI:10.1002/asia.201200723

FULL PAPER
DOI: 10.1002/asia.201200723
Functionalization of Hexa-peri-hexabenzocoronenes: Investigation of the
Substituent Effects on a Superbenzene
Ryuichi Yamaguchi,[a] Satoru Ito,[a] Byung Sun Lee,[b] Satoru Hiroto,[a]
Dongho Kim,*[b] and Hiroshi Shinokubo*[a]
Abstract: We have demonstrated that
the iridium-catalyzed direct borylation
of HBCs to enhance fluorescence
quantum yields. DFT calculations re-
vealed that the origin of the substituent
effect is the lift in degeneracy in the
frontier orbitals by an interaction with
electron-donating and electron-with-
drawing substituents at the para- and
ortho-positions. The change in molecu-
lar orbitals results in an increase of the
transition probability from the S0!S1
states. In addition, the two-photon ab-
sorption cross-section values of para-
substituted HBCs are significantly
larger than those of ortho- and meta-
substituted HBCs.
of
hexa-peri-hexabenzocoronene
(HBC) enables regioselective introduc-
tion of boryl groups to the para-,
ortho-, and meta-substituted HBCs in
high yields. The boryl groups have
been transformed into various func-
tionalities such as hydroxy, cyano, eth-
ynyl, and amino groups. We have eluci-
dated that the substituents significantly
influence the photophysical properties
Keywords: aromatic substitution ·
density functional calculations
hexa-peri-hexabenzocoronene
·
·
substituent effects
absorption
· two-photon
Introduction
ents.[7] Mꢀllen and co-workers have reported trimethoxy-
substituted HBCs, which form a helical packing layer in
liquid crystalline mesophases.[7a] Recently, they have also re-
ported HBCs with a large dipole moment induced by intro-
ducing cyano- and amino groups to the HBC core.[7c] On the
other hand, the properties of non-aggregated HBC deriva-
tives have remained unexplored. Although a number of
functionalized HBCs have been synthesized, the dependence
of the optical properties on the functional groups and their
location has not been systematically investigated. As the
HBC core can be regarded as a p-extended benzene, a so-
called “superbenzene”, studies on the substituent effects on
a superbenzene should be important to understand the
properties of HBCs at the molecular level.
We have investigated the substituent effects on the optical
properties of functionalized HBCs. We anticipated that com-
parison of the optical properties of various substituted
HBCs would reveal the substituent effects on the HBC core.
To conduct this investigation, there were several structural
considerations. To increase solubility and gain liquid crystal-
line mesophases, HBCs often possess long alkyl chains to
induce facile aggregation,[8] which prevents thorough studies
on the properties of the isolated HBC molecule. According-
ly, we anticipated that bulky substituents would be prefera-
ble for investigating the optical properties of HBCs.[9] Al-
though tert-butyl-substituted HBCs have been synthesized,
their solubility was very limited.[10] We have recently report-
ed the synthesis of mesityl-substituted HBCs through
Kumada–Tamao–Corriu cross-coupling reactions.[11] These
compounds were fairly soluble in common organic solvents
and seemed to be optimal substrates for investigations on
HBCs in the non-aggregated state.
Polycyclic aromatic hydrocarbons (PAHs) have been exten-
sively investigated for their applications in electronic and
optical molecular devices.[1–3] Their large p-conjugated
planes not only enable efficient absorption of visible and
near-infrared light but also facilitate the construction of
a p–p stacking layer to allow significant intermolecular in-
teractions, which are important in solid-state properties.[4]
Among a large number of PAHs, hexa-peri-hexabenzocoro-
nenes (HBCs) have been developed rapidly owing to the es-
tablishment of facile synthetic methods reported by Mꢀllen
and co-workers.[5]
Owing to the D6h disk-like shape and the large p-conju-
gated plane, the HBC unit has often been employed as
a building block for discotic liquid crystals.[6] However, with
HBC molecules, the attention has been mainly focused on
their properties in the aggregated state. A variety of HBCs
have been synthesized to investigate their aggregation struc-
tures, which are deeply affected by the peripheral substitu-
[a] R. Yamaguchi, S. Ito, Dr. S. Hiroto, Prof. Dr. H. Shinokubo
Department of Applied Chemistry, Graduate School of Engineering,
Nagoya University, Aichi, 464-8603 (Japan)
Fax : (+81)52-789-3188
E-mail: hshino@apchem.nagoya-u.ac.jp
[b] B. S. Lee, Prof. Dr. D. Kim
Department of Chemistry, Yonsei University
Seoul 120-749 (Korea)
Fax : (+82)2-2123-2434
E-mail: dongho@yonsei.ac.kr
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/asia.201200273.
Chem. Asian J. 2013, 8, 178 – 190
178
ꢁ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemasianj.org
Hiroshi Shinokubo, Dongho Kim et al.
To install various functionalities to HBCs, we employed
Results and Discussion
ꢀ
the direct C H borylation, which has proven to be a reliable
Iridium-Catalyzed Direct Borylation of HBCs and
Oxidation
tool for introduction of boryl groups to functionalized p-sys-
tems.[12] A couple of examples of iridium-catalyzed boryla-
tion reactions toward PAHs have been reported.[13] For ex-
ample, Marder and co-workers have reported that direct
borylation of pyrenes occurs at the 2,7-positions, thereby en-
abling facile preparation of 2,7-substituted pyrenes, which
are not easily accessible by conventional electrophilic substi-
tution reactions.[13f] We have also developed an iridium-cata-
lyzed direct borylation of perylene bisimides and mesityl-
substituted HBCs.[11] The resulting borylated products are
useful intermediates for further transformations such as
Suzuki–Miyaura coupling and oxidation reactions. After
construction of the HBC core, it can be functionalized to
synthesize various HBC derivatives by using the rich
chemistry of organoboron reagents.
Iridium-catalyzed direct borylation of 1a and 1c has already
been reported in our previous study.[11] The direct borylation
of 1b was performed with [{IrACHTUNTRGNEN(UG OMe)ACHTUTGNREN(NUGN cod)}2] (cod=cyclooc-
ta-l,5-diene), 4,4’-di-tert-butyl-2,2’-bipyridyl (dtbpy), and
4.0 equivalents of bis(pinacolate)diboron (B2pin2) in a mix-
ture of mesitylene and tert-butyl methyl ether (2:1 (v/v)) at
reflux for 36 h to provide diborylated product 2b in 88%
yield (Scheme 1). Diborylated HBCs 2a and 2c were easily
converted into their corresponding dihydroxy-substituted
HBCs 3a and 3c in high yields by using H2O2 as an oxidant.
On the other hand, ortho-substituted HBC 2b decomposed
upon oxidation under the same reaction conditions. In this
case, we found that 4.0 equivalents of Oxone oxidized 2b ef-
fectively into the dihydroxy HBC 3b in 79% yield. The
structure of 3b was unambiguously confirmed by X-ray dif-
fraction analysis.[14] As shown in Figure 1, two hydroxy
groups were placed at the ortho-position of the HBC periph-
ery. In sharp contrast to 3a and 3c, which exhibit a non-
stacked structure induced by hydrogen-bonding interactions
between hydroxy groups, 3b forms p–p stacking columnar
structures in the crystal. The distances between the two clos-
est HBC molecules are 3.35 and 3.25 ꢂ, which are much
shorter than the sum of the van der Waals radii of carbon
atoms. The HBC core was slightly distorted and the mean
plane deviation was 0.127 ꢂ. The distortion may be caused
by a crystal packing interaction. The difference in packing
among the three types of HBCs 3a, 3b, and 3c is probably
related to the presence of p–p interactions. For only ortho-
substituted HBC 3b, enough of the HBC p-surface area is
available to interact with the other molecule, thereby allow-
ing a columnar packing structure.
Herein we disclose synthetic methods for the functionali-
zation of various HBCs through borylated HBCs. In addi-
tion, the effect of the substituents on the optical proper-
ties—depending on the position of the functionality—is dis-
cussed on the basis of the DFT calculations. In this study,
we employed three types of HBCs 1a, 1b, and 1c as starting
materials. These substrates are para-, ortho-, and meta-sub-
stituted HBCs, respectively, in analogy with substituted ben-
zene derivatives.
Preparation of para-, meta-, and ortho-Substituted HBCs
with Electron-Donating and Electron-Withdrawing Groups
Scheme 2 describes various functionalizations of para-substi-
tuted HBC 3a. Methoxy-substituted HBC 5a was readily
prepared in 89% yield upon treatment of 3a with an excess
amount of methyl iodide under basic conditions in a mixture
of refluxing tetrahydrofuran (THF)/acetone (3:1, v/v).[15]
Other substituents were introduced through transition-metal
catalyzed processes. As halogenation of borylated HBCs
with CuBr2 or NaI and chloramine-T gave poor results,[16]
we prepared the triflate 4a from 3a for palladium-catalyzed
reactions. Bistriflate 4a was obtained in 86% yield in one
step by using 4.0 equivalents of Tf2O and pyridine. Sonoga-
shira coupling of 4a with 3,3-dimethyl-1-propyne afforded
Abstract in Japanese:
6a in 97% yield in the presence of [PdCl
2ACHTUNGTRENNUNG(PPh3)2]
(3 mol%), CuI (6 mol%), and 1,8-diazabicyclo[5.4.0]undec-
AHCTUNGTRENNUNG
7-ene (DBU; 6.0 equiv). Under the same reaction condi-
tions, alkynyl-substituted HBCs 6b and 6c were prepared in
85% and 97% yield, respectively. Introduction of amino
groups was achieved through a Buchwald–Hartwig amina-
Chem. Asian J. 2013, 8, 178 – 190
179
ꢁ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemasianj.org
Hiroshi Shinokubo, Dongho Kim et al.
of the cyanation products and
no reaction occurred in the ab-
sence of zinc. Unfortunately,
trimethoxy- and triamino-sub-
stituted products from the
meta-substituted HBC could
not be isolated owing to their
instability under aerobic condi-
tions. All of the obtained prod-
ucts were fully characterized
by NMR and mass spectro-
scopic analysis.
Photophysical Properties
Although a number of func-
tionalized HBCs have been re-
ported, there have been rather
few studies on their photophys-
ical properties, in particular,
fluorescence spectra of HBCs
in the non-aggregated state.
Owing to the bulky mesityl
Scheme 1. Iridium-catalyzed borylation of 1b and oxidation of 2b.
groups that avoid formation of the excimer, the present
HBC derivatives are suitable to investigate their unimolecu-
lar photophysical properties. Figure 2a shows the UV/Vis
absorption spectra of the series of para-substituted HBCs in
CH2Cl2. Mꢀllen and co-workers have reported that an elec-
tronic absorption spectrum of HBC derivatives usually con-
sists of three representative absorption bands, a-, b-, and p-
bands.[19] The a-band is the lowest energy band, which has
usually low intensity owing to its forbidden nature of the
S0!S1 transition. As shown in Figure 2a, the a-band is
strongly affected by the substituents. In comparison to 1a,
all para-substituted HBCs showed bathochromic shifts of
the a-bands, thus indicating their narrower HOMO–LUMO
gaps. In particular, 7a showed the longest bathochromic
shift of the a-band at 491 nm. In addition, intense a-bands
were observed for 6a, 7a, and 8a. Among them, the amino-
substituted HBC 7a shows the largest a-band (e=
14000 cmꢀ1 mꢀ1), and this implies that the p-donating nature
of amino groups significantly influences the transition prob-
ability of the a-band. Figure 2b shows UV/Vis absorption
spectra of ortho-substituted HBCs in CH2Cl2. A similar
trend of the substituent effect on the a-bands was observed.
As compared to para-substituted HBCs, broadened spectra
were observed because of their less symmetrical nature. The
degree of the bathochromic shift and enhancement in the a-
bands was smaller than that for para-substituted HBCs.
Only 7b exhibited an intense a-band at 486 nm with an ex-
tinction coefficient of e=7900 cmꢀ1 mꢀ1. This result indicates
that the substituent effects at the ortho-position of the HBC
core are weaker than those at the para-position. Figure 2c
shows UV/Vis absorption spectra of meta-substituted HBCs
1c, 6c, and 8c in CH2Cl2. Although meta-substituted HBCs
have an additional substituent on the HBC core, compared
to para- and ortho-substituted HBC, the spectra of all the
Figure 1. X-ray structure of 3b. a) Top view, b) side view, and c) crystal
packing. The thermal ellipsoids are scaled at 50% probability level. Mesi-
tyl groups are omitted for clarity.
tion.[17] In our first trial, however, the reaction of 4a with
mesitylamine in the presence of [Pd2ACTHNUTRGEN(UNG dba)3]·CHCl3, tri(tert-
butyl)phosphine, and sodium tert-butoxide provided only
the hydrolyzed product 3a in 82% yield. After several trials,
1,1’-diphenylphosphinoferrocene (DPPF) was found to be
effective to afford diamino HBC 7a in 16% yield. By using
Cs2CO3 as a base greatly improved the yield of 7a to 86%
yield. By following the same procedure, ortho-diamino HBC
7b was also synthesized in 86% yield (Scheme 3). Introduc-
tion of cyano substituents was carried out by using Takagiꢃs
cyanation protocol with 8.0 equivalents of KCN in the pres-
ence of zinc powder and a catalytic amount of [Pd2
ACHTUNGTRENNUNG
(dba)3]·CHCl3 and DPPF.[18] Owing to the low solubility of
4a in N-methylpyrollidone (NMP), the reaction was per-
formed in a mixed solvent system. The reaction in toluene/
NMP produced dicyano-substituted 8a in 72% yield. Under
the same reaction conditions, cyano-substituted HBCs 8b
and 8c were also prepared in 72% and 52% yield, respec-
tively (see Schemes 3 and 4). Notably, the addition of a cata-
lytic amount of zinc powder dramatically improved the yield
Chem. Asian J. 2013, 8, 178 – 190
180
ꢁ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemasianj.org
Hiroshi Shinokubo, Dongho Kim et al.
meta-substituted HBCs did not
show any changes. In particu-
lar, the a-bands appeared with
quite low intensity, thus sug-
gesting that the substituents at
the meta-positions have a negli-
gible effect on the electronic
structure of the HBC core.
Figure 3 shows emission
spectra of para-, ortho-, and
meta-substituted
HBCs
in
CH2Cl2. The shape of the fluo-
rescence spectra of 5a is simi-
lar to that of 1a; this displays
fine vibronic structures. For
either electron-donating or
electron-withdrawing substitu-
ents, the vibronic structures
became broadened to show
three obvious bands that are
attributed to (0-0), (0-1), and
(0-2) vibronic transitions for
para-, ortho-, and meta-substi-
tuted HBCs, respectively. The
substituents also influence the
fluorescence quantum yields.
HBC 1a exhibited fluores-
Scheme 2. Introduction of various functionalities to para-substituted HBC 1a. Reagents and conditions:
(i) Tf2O (4.0 equiv), pyridine (8.0 equiv), CH2Cl2, rt, 3 h; (ii) MeI (excess), K2CO3 (8.0 equiv), THF/acetone=
3:1, reflux, 24 h; (iii) 3,3-dimethyl-1-butyne (4.0 equiv), [PdCl2ACTHNUTRGEN(UNG PPh3)2] (3 mol%), CuI (6 mol%), DBU
(6.0 equiv), THF, rt, 18 h; (iv) 2,4,6-trimethylaniline (8.0 equiv), [Pd2dba3]·CHCl3 (5 mol%), DPPF (10 mol%),
Cs2CO3 (6.0 equiv), toluene, reflux, 30 h; (v) KCN (8.0 equiv), [Pd2dba3]·CHCl3 (5 mol%), DPPF (10 mol%),
Zn (6 mol%), toluene/NMP=1:1, 608C, 24 h.
cence with
a low quantum
yield (F=0.028). Introduction
of alkynyl substituents does
not have much influence on
the quantum yield (F=0.033).
On the other hand, both elec-
tron-donating and electron-
withdrawing substituents en-
hance the quantum yields to
above 0.10. Amino-substituted
HBC 7a showed the highest
quantum
yield
(F=0.33)
among the HBCs that we have
prepared. These observed
quantum yields seem to be re-
lated with the intensity of the
a-bands. Namely, HBCs with
a more allowed S0!S1 transi-
tion have higher fluorescence
quantum yields.
A
similar
trend was also observed for
ortho-substituted HBCs, but
ortho-substituted HBCs show
a smaller enhancement in the
fluorescence quantum yields
than those of para-substituted
HBCs: The quantum yield of
7b is only F=0.20, which is
about a half the value of 7a.
For meta-substituted HBCs, an
Scheme 3. Introduction of various functionalities to ortho-disubstituted HBC 1b. Reagents and conditions:
(i) Tf2O (4.0 equiv), pyridine (8.0 equiv), CH2Cl2, rt, 3 h; (ii) MeI (excess), K2CO3 (6.0 equiv), THF/acetone=
3:1, reflux, 24 h; (iii) 3,3-dimethyl-1-butyne (4.0 equiv), [PdCl2ACTHNUTRGEN(UNG PPh3)2] (3 mol%), CuI (6 mol%), DBU
(6.0 equiv), THF, rt, 18 h; (iv) 2,4,6-trimethylaniline (8.0 equiv), [Pd2dba3]·CHCl3 (5 mol%), BINAP
(10 mol%), Cs2CO3 (6.0 equiv), toluene, reflux, 24 h; (v) KCN (8.0 equiv), [Pd2dba3]·CHCl3 (3 mol%), DPPF
(6 mol%), Zn (6 mol%), toluene/NMP=1:1, 1008C, 24 h.
Chem. Asian J. 2013, 8, 178 – 190
181
ꢁ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemasianj.org
Hiroshi Shinokubo, Dongho Kim et al.
sulting in splitting of the de-
generated orbitals. The remov-
al of degeneracy can be ex-
plained by the interaction of
two HOMOs of the parent
HBC with the amino groups.
One HOMO interacts signifi-
cantly with the electron-donat-
ing amino groups to destabilize
the energy level, while the
other stays at almost the same
energy level owing to the lack
of an interaction at the nodal
plane position of the molecular
orbital. As a result, the two or-
bitals have different energies.
This situation can be con-
firmed from the molecular or-
bitals of diamino HBCs.
Figure 5 illustrates the HOMO
and HOMO-1 of para-diamino
Scheme 4. Introduction of various functionalities to meta-substituted HBC 1c. Reagents and conditions:
(i) Tf2O (6.0 equiv), pyridine (8.0 equiv), CH2Cl2, rt, 16 h; (ii) 3,3-dimethyl-1-butyne (6.0 equiv), [PdCl2ACHTNUGTRNEG(UN PPh3)2]
(5 mol%), CuI (10 mol%), DBU (6.0 equiv), THF, rt, 24 h; (iii) KCN (12.0 equiv), [Pd2dba3]·CHCl3 (5 mol%),
DPPF (10 mol%), Zn (6 mol%), toluene/NMP=1:1, 608C, 24 h.
HBC II-a, in which the
HOMO has a substantial con-
tribution from the amino
groups, while the HOMO-
enhancement in the fluorescence quantum yields with sub-
stituents was not observed. A fine vibronic structure was ob-
served for cyano-substituted 8c, while both 8a and 8b
showed a rather broad spectrum. These spectroscopic stud-
ies clearly demonstrate that the substituent effect on the
HBC core increases in the order of meta-, ortho-, and para-
substituted HBCs.
1 has no molecular orbital coefficient on the nitrogen atoms.
The splitting of HOMO and HOMO-1 weakened the con-
figuration interaction to enhance the oscillator strengths of
the a-bands (Table 1, entries 2 and 3). The higher oscillator
strength would lead to the higher radiative rate constant be-
cause of the rigid structure of the HBC unit. The observed
fluorescence quantum yield of the amino-substituted HBCs
was substantially higher than the unsubstituted HBC. Ac-
cordingly, the splitting of HOMO and HOMO-1 should be
related to the enhancement in emission efficiency in amino-
substituted HBCs 8a and 8b.
Figure 4c shows the energy diagrams of cyano HBCs III-
a, III-b, and III-c. In comparison to unsubstituted HBCs, di-
cyano HBCs III-a and III-b have LUMO and LUMO+1 of
different energies, while HOMO and HOMO-1 are almost
degenerate. For tricyano HBC III-c, both HOMOs and
LUMOs are almost degenerate as well as the parent HBC.
In the case of para-dicyano-substituted HBC III-a, the
substituent interacts with the LUMO but not with LUMO+
1 (Figure 6). One of the two degenerate LUMOs is stabi-
lized by effective hybridization with the electron-withdraw-
ing cyano groups, thereby resulting in the splitting of
LUMO and LUMO+1.
Theoretical Investigations
We then performed theoretical calculations on several
HBCs to elucidate the substituent effect on the optical prop-
erties of HBCs. Peripheral mesityl and N-mesityl groups
were replaced with hydrogen atoms and methyl groups, re-
spectively, to reduce the calculation cost. The molecular ge-
ometries were fully optimized by the density-functional
theory (DFT) based on B3LYP hybrid functional with the
6–31G(d) basis set.[20] Oscillator strengths were calculated
by the time-dependent DFT (TD-DFT) method.
Figure 4 displays the calculated frontier orbitals and
energy diagrams. Unsubstituted HBC I has two sets of de-
generate frontier orbitals, HOMO and HOMO-1 as well as
LUMO and LUMO+1 (Figure 4a). As reported by Mꢀllen
and co-workers, both the a-band and b-band result from the
transitions between these two degenerated HOMOs and
LUMOs. The forbidden feature of the a-band is due to the
configuration interaction of these degenerate transitions
(Table 1, entry 1).[21]
Compared to the amino-substituted HBCs, the oscillator
strengths of the a-band for the cyano-substituted HBCs are
relatively small (Table 1, entry 4–6). In addition, the oscilla-
tor strengths decrease in the order of para, ortho, and meta.
This order is the same as that of the energy gaps between
LUMO and LUMO+1. This result suggests that the degree
of the splitting in the LUMOs is responsible for the oscilla-
tor strength of the a-band of cyano HBCs. In meta-cyano
substituted HBC III-c, which has almost degenerate
Figure 4b shows the energy diagrams of para- and ortho-
diamino HBCs II-a and II-b as well as the parent HBC I.
For both diamino-substituted HBCs, the introduction of
amino groups destabilizes one of two HOMOs, thereby re-
Chem. Asian J. 2013, 8, 178 – 190
182
ꢁ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemasianj.org
Hiroshi Shinokubo, Dongho Kim et al.
Figure 3. Emission spectra of a) para-disubstituted HBCs 1a, 3a, 5a, 6a,
7a, and 8a, b) ortho-disubstituted HBCs 1b, 3b, 5b, 6b, 7b, and 8b, and
c) meta-disubstituted HBCs 1c, 3c, 6c, and 8c. All spectra were recorded
at 2.0ꢄ10ꢀ6 m in dichloromethane with excitation at 400 nm.
Figure 2. UV/Vis absorption spectra of a) para-disubstituted HBCs 1a,
5a, 6a, 7a, and 8a, b) ortho-disubstituted HBCs 1b, 5b, 6b, 7b, and 8b,
and c) meta-disubstituted HBCs 1c, 6c, and 8c. All spectra were record-
ed at 3.0ꢄ10ꢀ6 m in dichloromethane.
Non-Linear Optical Studies
LUMOs, transition of the lowest energy band is completely
forbidden.
As HBCs have rigid and large p-conjugated planes, they
have been attractive targets for materials with large two-
photon absorption (TPA) cross-section values. Recently, Wu
and co-workers synthesized octupolar HBCs that bear
donors and acceptors at the HBC periphery, thus exhibiting
large TPA cross sections.[22] Encouraged by this result, we in-
vestigated the TPA cross-section of three-types of substitut-
ed HBCs to clarify the regiochemical dependence of the
non-linear optical (NLO) properties. The results are sum-
marized in Table 2 and Figure S43 (see the Supporting Infor-
mation). The TPA cross-section values were measured at
800 nm in toluene. Among three alkynyl-substituted HBCs,
6a had the largest TPA cross-section value (700 GM), while
6b and 6c showed lower values (400 and 480 GM, respec-
tively). The larger value for para-substituted HBC 6a is
The oscillator strengths of the a-band by TD-DFT calcu-
lations and observed fluorescence quantum yields of substi-
tuted HBCs are plotted in Figure 7. Interestingly, an almost
linear and positive correlation was obtained. This result indi-
cates that the oscillator strength of the a-band is critical to
the fluorescence quantum yield of substituted HBCs. The
substituents at the para- and ortho-positions effectively lift
the degeneracy of the HOMOs or LUMOs to enhance the
oscillator strengths of the lowest energy band, thus affording
higher fluorescence quantum yields.
Chem. Asian J. 2013, 8, 178 – 190
183
ꢁ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemasianj.org
Hiroshi Shinokubo, Dongho Kim et al.
fluorescence quantum yields of
HBCs. Importantly, the effect
of the substituents significantly
depends on their location:
para-disubstituted HBCs expe-
rience the largest substituent
effects than other HBCs. Ac-
cording to the theoretical anal-
ysis, the enhanced a-bands can
be accounted for by the split-
ting of degenerate HOMOs
with electron-donating sub-
stituents or LUMOs with elec-
tron-accepting groups. Interest-
ingly, the fluorescence quan-
tum yields show a linear corre-
lation with oscillator strengths
of the a-bands. These results
demonstrate that the emission
properties of HBCs can be ma-
nipulated by electron-donating
and electron-accepting groups
probably due to effective conjugation over the HBC plane
compared to ortho- and meta-substituted HBCs. This result
is consistent with those obtained by single-photon optical
analysis. The same trend was also observed for another
series of HBCs. para-Substituted HBC 7a had a larger TPA
cross-section value of 910 GM than that of ortho-substituted
HBC 7b (440 GM). Due to the instability of the meta-
amino-substituted HBC under aerobic conditions, we could
not measure its TPA cross-section value. With regard to the
NLO properties, large molecular polarizability is an impor-
tant factor to contribute to a large TPA cross-section value.
Many efforts have been directed for enhancing the TPA
cross-section value by using a donor (D)/acceptor (A)-type
chromophoric system, introducing additional groups to per-
turb the charge redistribution. In terms of the effect of vari-
ous functional groups on NLO properties, the introduction
of amino groups (D) to HBCs is more effective than those
of cyano groups (A). We can conclude that the NLO proper-
ties of HBCs were dependent on the introduction of func-
tional groups and their locations.
at the appropriate positions. The present strategy for func-
tionalization of HBCs should be useful for development in
the field of PAHs. The potential application of the present
substituted HBCs for electronic devices is currently under
investigation.
Experimental Section
Instrumentation and Materials
1H NMR (500 MHz) and 13C NMR (126 MHz) spectra were recorded on
a Varian INOVA-500 spectrometer, and chemical shifts were reported in
ppm relative to CHCl3 (d=7.260 ppm) for 1H NMR and CDCl3 (d=
77.0 ppm) for 13C NMR. UV/Vis absorption spectra were recorded on
a Shimadzu UV-2550 or JASCO V670 spectrometer. Emission spectra
were recorded on a JASCO FP-6500 spectrometer and absolute fluores-
cence quantum yields were measured by a photon-counting method using
an integration sphere. Mass spectra were recorded on a Bruker micro-
TOF using a ESI-TOF method in the positive and negative mode for ace-
tonitrile solutions. X-ray data were recorded on a Bruker SMART
APEX X-Ray diffractometer equipped with a large area CCD detector.
Unless otherwise noted, materials obtained from commercial suppliers
were used without further purification.
5,8,14,17-Tetramesitylhexabenzo[bc,ef,hi,kl,no,qr]coronene-2,11-diyl
Conclusions
bis(trifluoromethanesulfonate) (4a)
A flask containing 3a (616 mg, 0.6 mmol) was purged with N2, and then
charged with anhydrous and degassed CH2Cl2 (8 mL) and pyridine
(0.39 mL, 8.0 equiv). Then the mixture was stirred for 1 min. Trifluorome-
thanesulfonic anhydride (0.41 mL, 4.0 equiv) was added to this mixture
dropwise at room temperature. The mixture was then stirred at room
temperature for 3 h, quenched with aqueous HCl (1m), extracted with
CH2Cl2, and then dried over Na2SO4. The solvents were removed under
vacuum, and the crude product was purified by silica-gel column chroma-
tography (CH2Cl2/n-hexane=1:2) and recrystallized from CH2Cl2/MeOH
In conclusion, we have demonstrated the introduction of
various functional groups after construction of the HBC
ꢀ
skeleton through iridium-catalyzed C H borylation. Three
types of HBCs, para-, meta-, and ortho-substituted HBCs,
could be readily prepared in high yields through transition-
metal catalyzed transformation of HBC bistriflates. The
electron-donating and electron-accepting groups substantial-
ly alter electronic structures of HBCs, thus showing batho-
chromic shifts in their absorption and emission spectra. In
particular, introduction of amino and cyano groups intensi-
fied the a-bands of the absorption spectra and enhanced
to afford 4a (667 mg, 0.52 mmol) in 86% yield as
a yellow solid.
1H NMR (CDCl3, 500 MHz): d=9.11 (s, 4H), 9.03 (s, 4H), 9.02 (s, 4H),
7.16 (s, 8H), 2.47 (s, 12H), 2.25 ppm (s, 24H); 13C NMR (CDCl3,
126 MHz): d=148.9, 140.8, 138.5, 137.7, 136.2, 133.4, 130.9, 129.8, 128.6,
125.1, 124.9, 124.9, 124.6, 124.0, 121.5, 120.9, 114.7, 21.3, 21.2 ppm; UV/
Chem. Asian J. 2013, 8, 178 – 190
184
ꢁ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemasianj.org
Hiroshi Shinokubo, Dongho Kim et al.
Table 1. Calculated wavelengths and oscillator strengths of a-bands of
HBC derivatives by the TD-DFT method.
Entry Compounds Excitation
Excited
state
CI coeffi- Oscillator
wavelength
[nm]
cient
strength, f
1
2
3
4
5
6
I
428
HOMO-
0.50537
0
1!LUMO 0.50532
HOMO!
LUMO+1
409
HOMO-
1!
-0.49275
0.49464
0
LUMO+1
HOMO!
LUMO
II-a
II-b
III-a
III-b
III-c
454
HOMO-
1!
0.32398
0.61536
0.0580
LUMO+1
HOMO!
LUMO
435
447
HOMO-
-0.32185
0.0923
0.0267
1!LUMO 0.61147
HOMO!
LUMO+1
HOMO-
1!
-0.39932
0.58068
LUMO+1
HOMO!
LUMO
432
440
424
HOMO-
0.37928
0.0467
0.0055
0.0584
1!LUMO 0.58068
HOMO!
LUMO+1
HOMO! 0.54725
LUMO
-0.44042
HOMO!
LUMO+1
HOMO-
1!
0.37462
0.59718
LUMO+1
HOMO!
LUMO
442
HOMO-
1!
-0.4718
0.52311
0.0022
LUMO+1
HOMO!
LUMO
426
441
422
HOMO-
0.50797
0.0066
1!LUMO 0.48404
HOMO!
LUMO+1
HOMO-
0.49753
0
0
1!LUMO 0.49627
HOMO!
LUMO+1
HOMO-
-0.49602
1!LUMO 0.50115
HOMO!
LUMO+1
Figure 4. Energy diagrams of the HBC derivatives. a) Unsubstituted
HBC, b) para- and ortho-diamino HBCs, and c) para-dicyano, ortho-di-
cyano, and meta-tricyano HBCs.
2,5,11,14-Tetramesityl-8,17-dimethoxyhexabenzo[bc,ef,hi,kl,no,qr]coronene
(5a)
A flask containing 3a (20.5 mg, 0.02 mmol) and potassium carbonate
(22.1 mg, 8.0 equiv) was purged with N2, and then charged with an anhy-
drous and degassed mixture of THF/acetone=3:1 (4 mL). Iodomethane
(0.4 mL, excess) was added dropwise to this mixture at room tempera-
ture. The mixture was then stirred under reflux for 24 h, quenched with
aqueous HCl (1m), extracted with CH2Cl2, and then dried over Na2SO4.
Vis (CH2Cl2): lmax (e [mꢀ1 cmꢀ1])=347 (93000), 363 (220000), 393 nm
(75000); HR-MS (ESI-MS): m/z=1291.3446, calcd for (C80H56F6O6S2)+
1291.3495 [(M+H)+].
=
Chem. Asian J. 2013, 8, 178 – 190
185
ꢁ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemasianj.org
Hiroshi Shinokubo, Dongho Kim et al.
Table 2. Two-photon absorption cross-sections of 6, 7, and 8 in toluene.
Type
Compound
Functionality
s [GM]
ortho
6b
7b
8b
6c
7c
6a
7a
8a
tBu-ethynyl
CN
NMes
tBu-ethynyl
CN
tBu-ethynyl
CN
400
420
440
480
690
700
790
910
meta
para
NMes
and then charged with anhydrous and degassed THF (5 mL). Then, 1,8-
diazabicyclo[5.4.0]undec-7-ene (91.3 mg, 6.0 equiv), pure water (2 drops),
Figure 5. Removal of the degeneracy of HOMOs with amino groups.
AHCTUNGTRENNUNG
and 3,3-dimethylbut-1-yne (32.9 mg, 4.0 equiv) were added to this mix-
ture at room temperature. The mixture was then stirred under room tem-
perature for 18 h, quenched with aqueous HCl (1m), extracted with
CH2Cl2, and then dried over Na2SO4. The solvents were removed under
vacuum, and the crude product was purified by silica-gel column chroma-
tography (CH2Cl2/n-hexane=1:2) and recrystallized from CHCl3/MeOH
to afford 6a (113 mg, 0.097 mmol) in 97% yield as a yellow solid.
1H NMR (CDCl3, 500 MHz): d=9.21 (s, 4H), 9.06 (s, 4H), 9.01 (s, 4H),
7.13 (s, 8H), 2.46 (s, 12H), 2.24 (s, 24H), 1.47 ppm (s, 18H); 13C NMR
(CDCl3, 126 MHz): d=140.2, 139.1, 137.3, 136.3, 130.9, 130.7, 130.4,
128.4, 125.4, 124.9, 124.5, 123.6, 123.5, 122.9, 121.4, 121.2, 99.9, 79.7, 31.2,
28.2, 21.3, 21.2 ppm; UV/Vis (Toluene): lmax (e [mꢀ1 cmꢀ1])=352
(110000), 372 (260000), 399 (98000), 416 nm (32000); HR-MS (ESI-MS):
m/z=1155.5855, calcd for (C90H74)+ =1155.5863 [(M+H)+].
Figure 6. Splitting of LUMOs of unsubstituted HBC by cyano groups
N2,N11,5,8,14,17-Hexamesitylhexabenzo[bc,ef,hi,kl,no,qr]coronene-2,11-
diamine (7a)
A flask containing 4a (258 mg, 0.2 mmol), [Pd2ACTHNUTRGNEG(UN dba)3]·CHCl3 (10.4 mg,
5 mol%), 1,1’-bis(diphenylphosphino)ferrocene (11.1 mg, 10 mol%), and
cesium carbonate (391 mg, 6.0 equiv) was purged with N2, and then
charged with anhydrous and degassed toluene (15 mL). 2,4,6-Trimethyla-
niline (216 mg, 8.0 equiv) was added to this mixture dropwise at room
temperature. The mixture was then stirred under reflux for 24 h,
quenched with CH2Cl2, and then the solvent was removed under vacuum.
The crude product was purified by silica-gel column chromatography
(CHCl3/n-hexane=1:3) and recrystallized from CH2Cl2/MeOH to afford
1
7a (216 mg, 0.17 mmol) in 86% yield as a yellow solid. H NMR (CDCl3,
500 MHz): d=8.92 (s, 4H), 8.81 (s, 4H), 8.28 (s, 4H), 7.10 (s, 8H), 7.04
(s, 4H), 5.73 (s, 2H, NH), 2.44 (s, 12H), 2.38 (s, 6H), 2.34 (s, 12H),
2.22 ppm (s, 24H); 13C NMR (CDCl3, 126 MHz): d=145.6, 139.4, 139.2,
137.0, 136.4, 135.8, 135.6, 134.9, 132.1, 130.8, 130.6, 129.8, 128.4, 124.8,
123.4, 123.2, 120.7, 120.0, 119.3, 107.5, 21.3, 21.1, 18.6 ppm; UV/Vis
(CH2Cl2): lmax (e [mꢀ1 cmꢀ1])=327 (68000), 359 (72000), 377 (150000),
433 (24000), 459 (13000), 491 nm (14000); HR-MS (ESI-MS): m/z=
1260.6331, calcd for (C96H80N2)+ =1260.6316 [(M)+].
Figure 7. Correlation of the calculated oscillator strengths and observed
fluorescence quantum yields of the a-band of various HBCs.
5,8,14,17-Tetramesitylhexabenzo[bc,ef,hi,kl,no,qr]coronene-2,11-
dicarbonitrile (8a)
The solvents were removed under vacuum, and the crude product was
purified by silica-gel column chromatography (CH2Cl2/n-hexane=1:2)
and recrystallized from CH2Cl2/MeOH to afford 5a (18.7 mg,
A flask containing 4a (64.6 mg, 0.05 mmol), [Pd2ACTHNUTRGNEG(UN dba)3]·CHCl3 (2.59 mg,
1
5 mol%), 1,1’-bis(diphenylphosphino)ferrocene (2.77 mg, 10 mol%),
KCN (26.0 mg, 8.0 equiv), and zinc powder (0.19 mg, 6 mol%) was
purged with N2, and then charged with an anhydrous and degassed mix-
ture of toluene/NMP=1:1 (4 mL). The mixture was then stirred at 608C
for 24 h, quenched with aqueous HCl (1m), extracted with CH2Cl2, and
then dried over Na2SO4. The solvents were removed under vacuum, and
the crude product was purified by silica-gel column chromatography
(CH2Cl2/n-hexane=2:1) and recrystallized from CH2Cl2/MeOH to afford
8a (37.5 mg, 0.036 mmol) in 72% yield as a yellow solid. 1H NMR
(CDCl3, 500 MHz): d=9.44 (s, 4H), 9.11 (s, 4H), 9.08 (s, 4H), 7.14 (s,
8H), 2.46 (s, 12H), 2.24 ppm (s, 24H); 13C NMR (CDCl3, 126 MHz): d=
141.1, 138.3, 137.6, 136.0, 131.8, 130.8, 129.5, 128.6, 127.9, 125.2, 124.9,
124.3, 124.0, 122.2, 121.2, 119.4, 111.2, 21.3, 21.2 ppm; UV/Vis (CH2Cl2):
lmax (e [mꢀ1 cmꢀ1])=353 (73000), 371 (180000), 402 (51000), 421 (20000),
0.018 mmol) in 89% yield as a yellow solid. H NMR (CDCl3, 500 MHz):
d=9.02 (s, 4H), 9.00 (s, 4H), 8.71 (s, 4H), 7.14 (s, 8H), 4.24 (s, 6H), 2.46
(s, 12H), 2.25 ppm (s, 24H); 13C NMR (CDCl3, 126 MHz): d=158.8,
139.8, 139.2, 137.3, 136.4, 132.4, 131.0, 130.7, 128.4, 124.8, 123.6, 123.4,
120.8, 120.5, 108.2, 56.0, 21.3, 21.2 ppm; UV/Vis (CH2Cl2): lmax (e
[mꢀ1 cmꢀ1])=349 (82000), 365 (200000), 396 (58000), 444 (6500), 472 nm
(10000); HR-MS (ESI-MS): m/z=1055.4775, calcd for (C80H62O2)+
1055.4823 [(M+H)+].
=
2,11-Bis(3,3-dimethylbut-1-yn-1-yl)-5,8,14,17-
tetramesitylhexabenzo[bc,ef,hi,kl,no,qr]coronene (6a)
A
flask containing 4a (129 mg, 0.1 mmol), [PdCl2ACHTUNGTRENNU(G PPh3)2] (2.11 mg,
3 mol%), and copper(I) iodide (1.14 mg, 6 mol%) was purged with N2,
Chem. Asian J. 2013, 8, 178 – 190
186
ꢁ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemasianj.org
Hiroshi Shinokubo, Dongho Kim et al.
449 (4900), 478 nm (5600); HR-MS (ESI-MS): m/z=1044.4451, calcd for
(C78H70)+ =1044.4438 [(M)+].
product was purified by silica-gel column chromatography (CH2Cl2/n-
hexane=1:2) and recrystallized from CH2Cl2/MeOH to afford 2b (1.32 g,
1.06 mmol) in 88% yield as a yellow solid. 1H NMR (CDCl3, 500 MHz):
d=9.84 (s, 2H), 9.69 (s, 2H), 9.24 (s, 2H), 9.01 (s, 2H), 9.00 (s, 2H), 8.99
(s, 2H), 7.16 (s, 4H), 7.08 (s, 4H), 2.48 (s, 6H), 2.42 (s, 6H), 2.25 (s,
12H), 2.23 (s, 12H), 1.57 ppm (s, 24H); 13C NMR (CDCl3, 126 MHz): d=
140.1, 140.0, 139.4, 139.0, 137.3, 137.1, 136.5, 136.1, 131.2, 131.0, 130.98,
130.86, 130.1, 129.6, 128.9, 128.8, 127.7, 124.42, 124.38, 123.52, 123.48,
123.1, 121.8, 121.7, 121.6, 84.4, 25.1, 21.31, 21.29, 21.19, 21.14 ppm; UV/
Vis (CH2Cl2): lmax (e [mꢀ1 cmꢀ1])=349 (100000), 366 (240000), 396 nm
1,2,3,4-Tetra(4-bromophenyl)-5,6-diphenylbenzene
A
mixture of 2,3,4,5-tetrakis(4-bromophenyl)cyclopenta-2,4-dienone
(3.10 g, 4.39 mmol) and 1,2-diphenylethyne (1.25 g, 1.6 equiv) in diphenyl
ether (8 mL) was heated at 2008C under N2 for 36 h. The resulting mix-
ture was cooled to room temperature and then diluted with diethyl ether.
The precipitate was collected by filtration, washed with methanol and n-
hexane, and dried to give 1,2,3,4-tetra(4-bromophenyl)-5,6-diphenylben-
zene (3.47 g, 4.08 mmol) in 93% yield as a white solid. 1H NMR (CDCl3,
500 MHz): d=7.06 (d, J=8.5 Hz, 4H), 7.02 (d, J=8.5 Hz, 4H), 6.85–6.90
(m, 6H), 6.72–6.78 (m, 4H), 6.66 (d, J=2.5 Hz, 4H), 6.64 ppm (d, J=
2.0 Hz, 4H); 13C NMR (CDCl3, 126 MHz): d=141.0, 139.7, 139.4, 138.94,
138.91, 138.8, 132.7, 131.1, 130.3, 130.1, 126.9, 125.7, 120.1, 119.9 ppm;
HR-MS (ESI-MS): m/z=884.8457, calcd for (C42H26Br4)ꢀ =884.8425
[(M+Cl)ꢀ].
(83000); HR-MS (ESI-MS): m/z=1247.6294, calcd for (C90H80B2O4)+
1247.6341 [(M+H)+].
=
8,11,14,17-Tetramesitylhexabenzo[bc,ef,hi,kl,no,qr]coronene-2,5-diol (3b)
A flask containing 2b (624 mg, 0.5 mmol) was purged with N2, and then
charged
with
a
degassed
mixture
of
THF/acetone/H2O
(30 mL:4 mL:2 mL). Oxone (1.23 g, 4.0 equiv) was then added to this
mixture, which was then stirred at room temperature for 3 h. The flask
was cooled to 08C (ice/water) and saturated aqueous sodium thiosulfate
was added dropwise. The reaction mixture was diluted with CH2Cl2 and
the organic layers were separated. The aqueous layer was extracted with
CH2Cl2. The combined organic layers were dried over Na2SO4, and con-
centrated with a rotary evaporator. The crude product was purified by
silica-gel column chromatography (CH2Cl2/ethyl acetate=1:1) and re-
crystallized from CH2Cl2/n-hexane to afford 3b (405 mg, 0.40 mmol) in
79% yield as a yellow solid. 1H NMR (CDCl3, 500 MHz): d=9.04 (s,
2H), 9.01 (s, 2H), 8.99 (s, 2H), 8.78 (s, 2H), 8.31 (s, 2H), 8.01 (s, 2H),
7.10 (s, 8H), 5.27 (s, 2H, OH), 2.46 (s, 6H), 2.43 (s, 6H), 2.27 (s, 12H),
2.23 ppm (s, 12H); 13C NMR (CDCl3, 126 MHz): d=154.22, 154.15,
139.7, 139.6, 139.0, 137.11, 137.08, 136.17, 136.09, 132.3. 132.2, 131.48,
131.38, 130.9, 130.7, 124.6, 124.5, 123.6, 123.4, 123.3, 120.5, 120.3, 120.2,
120.1, 120.0, 109.3, 109.0, 21.4, 21.3, 21.18, 21.15 ppm; UV/Vis (CH2Cl2):
lmax (e [mꢀ1 cmꢀ1])=348 (86000), 364 (210000), 395 nm (62000); HR-MS
(ESI-MS): m/z=1027.4488, calcd for (C78H58O2)+ =1027.4510 [(M+H)+
].
1,2,3,4-Tetra(4-mesitylphenyl)-5,6-diphenylbenzene
A
flask containing 1,2,3,4-tetra(4-bromophenyl)-5,6-diphenylbenzene
(2.56 g, 3.0 mmol), [Pd2A(dba)3]·CHCl3 (82.4 mg, 3 mol%), and di-tert-bu-
CHTUNGTRENNUNG
tylphosphine oxide (29.2 mg, 6 mol%) was purged with N2, and then
charged with anhydrous and degassed THF (10 mL) and the mixture was
stirred for 15 min. To this mixture was added dropwise a solution of mesi-
tylmagnesium bromide prepared previously from mesityl bromide
(4.78 g, 8.0 equiv) and magnesium (0.874 g, 12.0 equiv) in anhydrous de-
gassed THF (30 mL) at room temperature. The mixture was then stirred
at 608C for 48 h, quenched with aqueous HCl (1m), extracted with
CH2Cl2, and then dried over Na2SO4. The solvents were removed under
vacuum, and the crude product was purified by silica-gel column chroma-
tography (CHCl3) and recrystallized from diethyl ether to afford
2
(2.83 g, 2.82 mmol) in 94% yield as a white solid. 1H NMR (CDCl3,
500 MHz): d=7.02 (d, J=8.5 Hz, 4H), 6.82–6.96 (m, 22H), 6.69 (d, J=
8 Hz, 4H), 6.64 (d, J=8.5 Hz, 4H), 2.291 (s, 6H), 2.286 (s, 6H), 2.286 (s,
6H), 1.81 (s, 6H), 1.80 (s, 6H), 1.78 (s, 6H), 1.76 ppm (s, 6H); 13C NMR
(CDCl3, 126 MHz): d=140.8, 140.6, 140.5, 140.1, 139.2, 139.13, 139.06,
139.0, 137.9, 137.8, 136.23, 136.16, 135.95, 135.89, 135.6, 131.9, 131.7,
131.6, 127.75, 127.69, 127.5, 126.6, 125.1, 21.0, 20.4, 20.3 ppm; HR-MS
(ESI-MS): m/z=1006.5502, calcd for (C78H70)+ =1006.5472 [(M)+].
8,11,14,17-Tetramesitylhexabenzo[bc,ef,hi,kl,no,qr]coronene-2,5-diyl
bis(trifluoromethanesulfonate) (4b)
A flask containing 3b (103 mg, 0.1 mmol) was purged with N2, and then
charged with anhydrous and degassed CH2Cl2 (5 mL) and pyridine
(0.062 mL, 8.0 equiv), then the mixture was stirred for 1 min. Trifluoro-
methanesulfonic anhydride (0.017 mL, 4.0 equiv) was added dropwise to
this mixture at room temperature. The mixture was then stirred at room
temperature for 3 h, quenched with aqueous HCl (1m), extracted with
CH2Cl2, and then dried over Na2SO4. The solvents were removed under
vacuum, and the crude product was purified by silica-gel column chroma-
tography (CH2Cl2/n-hexane=1:2) and recrystallized from CH2Cl2/MeOH
to afford 4b (105 mg, 0.081 mmol) in 81% yield as a yellow solid.
1H NMR (CDCl3, 500 MHz): d=9.12 (s, 2H), 9.08 (s, 2H), 9.07 (s, 2H),
8.99 (s, 2H), 8.96 (s, 2H), 8.78 (s, 2H), 7.17 (s, 4H), 7.11 (s, 4H), 2.49 (s,
6H), 2.44 (s, 6H), 2.26 (s, 12H), 2.25 ppm (s, 12H); 13C NMR (CDCl3,
126 MHz): d=148.5, 140.9, 140.7, 138.7, 138.4, 137.6, 137.4, 136.2, 136.0,
133.4, 131.6, 131.2, 131.1, 130.8, 129.4, 128.6, 128.5, 125.2, 125.1, 124.4,
124.1, 123.9, 123.8, 122.1, 121.4, 120.3, 120.0, 117.7, 115.4, 114.5, 21.30,
21.28, 21.17 ppm; UV/Vis (CH2Cl2): lmax (e [mꢀ1 cmꢀ1])=344 (110000),
360 (280000), 381 nm (87000); HR-MS (ESI-MS): m/z=1291.3526, calcd
for (C80H56F6O6S2)+ =1291.3495 [(M+H)+].
2,5,8,11-Tetramesitylhexabenzo[bc,ef,hi,kl,no,qr]coronene (1b)
A solution of FeCl3 (4.87 g, 20.0 equiv) in CH3NO2 (8 mL) was added to
a stirred solution of 1,2,3,4-tetra(4-mesitylphenyl)-5,6-diphenylbenzene
(1.51 g, 1.50 mmol) in anhydrous CH2Cl2/EtOH (150 mL:0.075 mL). The
reaction mixture was stirred for 1 h with continuous N2 bubbling through
the reaction mixture. The mixture was poured into MeOH (100 mL) and
concentrated with a rotary evaporator. The crude product was purified
by silica-gel column chromatography (CH2Cl2/n-hexane=1:2) and recrys-
tallized from CH2Cl2/MeOH to afford 1b (1.42 g, 1.43 mmol) in 95%
yield as a yellow solid. This product was soluble enough in organic sol-
vents such as CH2Cl2, CHCl3, and toluene. 1H NMR (CDCl3, 500 MHz):
d=9.06 (s, 2H), 9.03 (s, 2H), 8.99 (s, 2H), 8.93 (s, 2H), 8.91 (d, J=8 Hz,
2H), 8.77 (d, J=8 Hz, 2H), 7.87 (t, J=8 Hz, 2H), 7.13 (s, 4H), 7.12 (s,
4H), 2.48 (s, 6H), 2.45 (s, 6H), 2.29 (s, 12H), 2.25 ppm (s, 12H);
13C NMR (CDCl3, 500 MHz): d=139.9, 139.7, 139.2, 139.1, 137.1, 136.3,
136.1, 131.0, 130.9, 130.8, 130.7, 130.2, 130.1, 128.42, 128.39, 126.6, 125.2,
124.5, 124.2, 123.5, 123.4, 123.3, 123.2, 121.9, 121.7, 121.1, 121.0, 21.35,
21.29, 21.19, 21.17 ppm; UV/Vis (CH2Cl2): lmax (e [mꢀ1 cmꢀ1])=345
(90000), 361 (210000), 391 nm (71000); HR-MS (ESI-MS): m/z=
995.4634, calcd for (C78H58)+ =995.4611 [(M+H)+].
2,5,8,11-Tetramesityl-14,17-dimethoxyhexabenzo[bc,ef,hi,kl,no,qr]coronene
(5b)
A
flask containing 3b (103 mg, 0.1 mmol) and potassium carbonate
2,5-Diboryl-8,11,14,17-tetramesitylhexabenzo[bc,ef,hi,kl,no,qr]coronene
(83 mg, 6.0 equiv) was purged with N2, and then charged with an anhy-
drous and degassed mixture of THF/acetone=3:1 (4 mL). Then, iodome-
thane (0.3 mL, excess) was added dropwise to this reaction mixture at
room temperature. The mixture was then stirred at 608C for 24 h,
quenched with aqueous HCl (1m), extracted with CH2Cl2, and then dried
over Na2SO4. The solvents were removed under vacuum, and the crude
product was purified by silica-gel column chromatography (CH2Cl2/n-
(2b)
A flask containing 1b (1.19 g, 1.20 mmol), bis(pinacolato)diboron (1.22 g,
4.0 equiv), 4,4’-di-tert-butyl-2,2’-bipyridyl (19.3 mg, 6 mol%), and [{Ir-
N
ACHTUNGTRENNUNG
(20 mL:10 mL). The mixture was then stirred at 808C for 36 h. The crude
Chem. Asian J. 2013, 8, 178 – 190
187
ꢁ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemasianj.org
Hiroshi Shinokubo, Dongho Kim et al.
hexane=1:2) and recrystallized from CH2Cl2/MeOH to afford 5b
(79.5 mg, 0.075 mmol) in 75% yield as a yellow solid. 1H NMR (CDCl3,
500 MHz): d=9.00 (s, 6H), 8.94 (s, 2H), 8.55 (s, 2H), 8.39 (s, 2H), 7.14
(s, 4H), 7.09 (s, 4H), 4.13 (s, 6H), 2.47 (s, 6H), 2.42 (s, 6H), 2.25 (s,
12H), 2.24 ppm (s, 12H); 13C NMR (CDCl3, 126 MHz): d=158.5, 139.7,
139.6, 139.3, 139.1, 137.2, 137.1, 136.4, 136.1, 132.3, 131.9, 131.0, 130.81,
130.77, 130.6, 128.4, 124.7, 124.6, 123.5, 123.4, 123.2, 120.7, 120.5, 120.3,
108.6, 107.3, 55.8, 21.3, 21.2 ppm; UV/Vis (CH2Cl2): lmax (e [mꢀ1 cmꢀ1])=
349 (91000), 366 (220000), 396 nm (64000); HR-MS (ESI-MS): m/z=
1055.4817, calcd for (C80H62O2)+ =1055.4823 [(M+H)+].
(s, 2H), 7.12 (s, 8H), 2.50 (s, 6H), 2.45 (s, 6H), 2.31 (s, 12H), 2.26 ppm (s,
12H); 13C NMR (CDCl3, 126 MHz): d=141.5, 140.9, 138.6, 138.1, 137.5,
137.4, 136.1, 135.8, 131.0, 130.9, 130.8, 130.5, 128.6, 128.5, 126.8, 125.3,
124.9, 124.40, 124.37, 123.64, 123.57, 123.4, 123.3, 121.4, 119.6, 118.4,
110.1, 21.4, 21.3 ppm; UV/Vis (CH2Cl2): lmax (e [mꢀ1 cmꢀ1])=352 (73000),
370 (150000), 410 (40000), 448 nm (3000); HR-MS (ESI-MS): m/z=
1045.4489, calcd for (C78H70)+ =1045.4516 [(M+H)+].
5,11,17-Trimesitylhexabenzo[bc,ef,hi,kl,no,qr]coronene-2,8,14-triyl
tris(trifluoromethanesulfonate) (4c)
A flask containing 3c (92.5 mg, 0.1 mmol) was purged with N2, and then
charged with anhydrous and degassed CH2Cl2 (5 mL) and pyridine
(0.064 mL, 8.0 equiv). Then, trifluoromethanesulfonic anhydride
(0.11 mL, 6.0 equiv) was added dropwise to this mixture at room temper-
ature. The mixture was then stirred at room temperature for 16 h,
quenched with aqueous HCl (1m), extracted with CH2Cl2, and then dried
over Na2SO4. The solvents were removed under vacuum, and the crude
product was purified by silica-gel column chromatography (CH2Cl2/n-
hexane=1:2) and recrystallized from CH2Cl2/MeOH to afford 4c
(94.5 mg, 0.072 mmol) in 72% yield as a yellow solid. 1H NMR (CDCl3,
500 MHz): d=9.08 (s, 6H), 9.06 (s, 6H), 7.24 (s, 6H), 2.53 (s, 9H),
2.29 ppm (s, 18H); 13C NMR (CDCl3, 126 MHz): d=148.9, 141.2, 138.2,
138.1, 136.4, 133.1, 130.0, 128.7, 125.1, 125.0, 124.6, 121.9, 120.8, 120.3,
117.7, 115.0, 21.3, 21.2 ppm; UV/Vis (CH2Cl2): lmax (e [dꢀ1 cmꢀ1])=329
(30000), 344 (80000), 361 (190000), 391 nm (64000); HR-MS (ESI-MS):
m/z=1321.2186, calcd for (C72H45F9O9S3)+ =1321.2155 [(M+H)+].
2,5-Bis(3,3-dimethylbut-1-yn-1-yl)-8,11,14,17-
tetramesitylhexabenzo[bc,ef,hi,kl,no,qr]coronene (6b)
A
flask containing 4b (129 mg, 0.1 mmol), [PdCl2ACTHUNGTERNU(NG PPh)2] (2.11 mg,
3 mol%), and copper(I) iodide (1.14 mg, 6 mol%) was purged with N2,
and then charged with anhydrous and degassed THF (5 mL). 1,8-
DiazabicycloACHTUNGTRENNUNG[5.4.0]undec-7-ene (91.3 mg, 6.0 equiv), distilled water
(3 drops), and 3,3-dimethylbut-1-yne (32.9 mg, 4.0 equiv) were added to
this mixture at room temperature. The mixture was then stirred under
room temperature for 18 h, quenched with aqueous HCl (1m), extracted
with CH2Cl2, and then dried over Na2SO4. The solvents were removed
under vacuum, and the crude product was purified by silica-gel column
chromatography (CH2Cl2/n-hexane=1:2) and recrystallized from CH2Cl2/
MeOH to afford 6b (106 mg, 0.091 mmol) in 91% yield as a yellow solid.
1H NMR (CDCl3, 500 MHz): d=9.27 (s, 2H), 9.23 (s, 2H), 9.05 (s, 2H),
8.99 (s, 6H), 7.13 (s, 4H), 7.05 (s, 4H), 2.46 (s, 6H), 2.42 (s, 6H), 2.23 (s,
12H), 2.21 (s, 12H), 1.52 ppm (s, 18H); 13C NMR (CDCl3, 126 MHz): d=
140.1, 139.1, 137.1, 136.3, 136.1, 130.9, 128.4, 125.7, 125.2, 124.3, 123.6,
121.4, 31.2, 28.2, 21.24, 21.17 ppm; UV/Vis (toluene): lmax (e [dꢀ1 cmꢀ1])=
336 (40000), 352 (120000), 370 (290000), 399 nm (120000); HR-MS
(ESI-MS): m/z=1155.5813, calcd for (C90H74)+ =1155.5863 [(M+H)+].
2,8,14-Tris(3,3-dimethylbut-1-yn-1-yl)-5,11,17-
trimesitylhexabenzo[bc,ef,hi,kl,no,qr]coronene (6c)
A
flask containing 4c (132 mg, 0.1 mmol), [PdCl2ACHTNGUTERNU(NG PPh)2] (3.5 mg,
5 mol%), and copper(I) iodide (1.9 mg, 10 mol%) was purged with N2,
and then charged with anhydrous and degassed THF (10 mL). 1,8-
N2,N5,8,11,14,17-Hexamesitylhexabenzo[bc,ef,hi,kl,no,qr]coronene-2,5-
DiazabicycloACTHNUTRGNEUG[N 5.4.0]undec-7-ene (91.3 mg, 6.0 equiv), distilled water
diamine (7b)
(2 drops), and 3,3-dimethylbut-1-yne (49.3 mg, 6.0 equiv) were added to
this mixture at room temperature. The mixture was then stirred at room
temperature for 24 h, quenched with aqueous HCl (1m), extracted with
CH2Cl2, and then dried over Na2SO4. The solvents were removed under
vacuum, and the crude product was purified by silica-gel column chroma-
tography (toluene/n-hexane=1:8) and recrystallized from CH2Cl2/MeOH
to afford 6c (95.0 mg, 0.085 mmol) in 85% yield as a yellow solid.
1H NMR (CDCl3, 500 MHz): d=9.19 (s, 6H), 9.05 (s, 6H), 7.18 (s, 6H),
2.49 (s, 9H), 2.26 (s, 18H), 1.47 ppm (s, 27H); 13C NMR (CDCl3,
126 MHz): d=140.4, 139.5, 137.7, 136.7, 130.8, 130.7, 128.7, 125.6, 125.0,
124.7, 123.8, 123.1, 121.9, 121.3, 100.1, 80.0, 31.5, 31.4, 28.5, 21.5 ppm;
UV/Vis (CH2Cl2); lmax (e [mꢀ1 cmꢀ1])=354 (100000), 372 (270000),
401 nm (120000); HR-MS (ESI-MS): m/z=1117.5751, calcd for
(C87H72)+ =1117.5707 [(M+H)+].
A flask containing 4b (129 mg, 0.1 mmol), [Pd2ACHTNUTRGNE(UGN dba)3]·CHCl3 (3.1 mg,
3 mol%), 2,2’-bis(diphenylphosphino)-1,1’-binaphthyl (3.7 mg, 6 mol%),
and cesium carbonate (195 mg, 6.0 equiv) was purged with N2, and then
charged with anhydrous and degassed toluene (12 mL). 2,4,6-Trimethyla-
niline (108 mg, 8.0 equiv) was added dropwise to this mixture at room
temperature. The mixture was then stirred under reflux for 24 h,
quenched with CH2Cl2, and then the solvents were removed under
vacuum. The crude product was purified by silica-gel column chromatog-
raphy (CHCl3/n-hexane=1:3) and recrystallization from CH2Cl2/MeOH
to afford 7b (108 mg, 0.086 mmol) in 86% yield as a yellow solid.
1H NMR (CDCl3, 500 MHz): d=8.978 (s, 2H), 8.974 (s, 2H), 8.965 (s,
2H), 8.89 (s, 2H), 8.39 (s, 2H), 7.88 (s, 2H), 7.12 (s, 4H), 7.09 (s, 2H),
7.01 (s, 4H), 5.69 (s, 2H, NH), 2.46 (s, 4H), 2.43 (s, 12H), 2.30 (s, 12H),
2.25 (s, 12H), 2.24 ppm (s, 12H); 13C NMR (CDCl3, 126 MHz): d=145.5,
139.4, 139.30, 139.27, 139.20, 137.05, 136.95, 136.4, 136.1, 135.6, 135.4,
135.1, 132.2, 132.0, 130.9, 130.7, 130.6, 129.5, 128.35, 128.33, 124.83,
124.75, 123.4, 123.29, 123.27, 123.18, 120.5, 120.1, 119.9, 119.3, 108.1,
106.8, 21.31, 21.29, 21.1, 18.5 ppm; UV/Vis (CH2Cl2): lmax (e [mꢀ1 cmꢀ1])=
330 (47000), 382 (140000), 455 (8700), 486 nm (7900); HR-MS (ESI-MS):
m/z=1260.6293, calcd for (C96H80N2)+ =1260.6316 [(M+H)+].
5,11,17-Trimesitylhexabenzo[bc,ef,hi,kl,no,qr]coronene-2,8,14-
tricarbonitrile (8c)
A flask containing 4c (26.4 mg, 0.02 mmol), [Pd2ACTHNUTRGNEG(UN dba)3]·CHCl3 (1.04 mg,
5 mol%), 1,1’-bis(diphenylphosphino)ferrocene (1.11 mg, 10 mol%),
KCN (15.6 mg, 12.0 equiv), and zinc powder (0.078 mg, 6 mol%) was
purged with N2, and then charged with anhydrous and degassed toluene/
NMP=1:1 (2 mL). The mixture was then stirred at 608C for 24 h,
quenched with aqueous HCl (1m), extracted with CH2Cl2, and then dried
over Na2SO4. The solvents were removed under vacuum, and the crude
product was purified by silica-gel column chromatography (CH2Cl2/n-
hexane=1:1) and recrystallized from CH2Cl2/MeOH to afford 8c
(10.6 mg, 0.011 mmol) in 56% yield as a yellow solid. 1H NMR (CDCl3,
500 MHz): d=9.46 (s, 6H), 9.15 (s, 6H), 7.19 (s, 6H), 2.49 (s, 9H),
2.26 ppm; 13C NMR (CDCl3, 126 MHz): d=142.0, 138.0, 137.9, 136.0,
131.3, 129.8, 128.7, 127.6, 125.5, 125.0, 124.3, 123.8, 120.4, 119.2, 111.5,
21.3, 21.2 ppm; UV/Vis (CH2Cl2): lmax (e [mꢀ1 cmꢀ1])=329 (30000), 344
(80000), 368 (190000), 391 nm (64000); HR-MS (ESI-MS): m/z=
952.3667, calcd for (C72H45N3)+ =952.3686 [(M+H)+].
8,11,14,17-Tetramesitylhexabenzo[bc,ef,hi,kl,no,qr]coronene-2,5-
dicarbonitrile (8b)
A flask containing 4b (129 mg, 0.1 mmol), [Pd2ACHTNUTRGNE(UGN dba)3]·CHCl3 (3.1 mg,
3 mol%), 1,1’-bis(diphenylphosphino)ferrocene (3.3 mg, 6 mol%), KCN
(52.0 mg, 8.0 equiv), and zinc powder (0.39 mg, 6 mol%) was purged with
N2, and then charged with an anhydrous and degassed mixture of tolu-
ene/NMP=1:1 (5 mL). The mixture was then stirred at 1008C for 24 h,
quenched with aqueous HCl (1m), extracted with CH2Cl2, and then dried
over Na2SO4. The solvents were removed under vacuum, and the crude
product was purified by silica-gel column chromatography (CHCl3/n-
hexane=2:1) and recrystallized from CHCl3/n-hexane to afford 8b
(75.1 mg, 0.072 mmol) in 72% yield as a yellow solid. 1H NMR (CDCl3,
500 MHz): d=9.17 (s, 2H), 9.13 (s, 4H), 8.73 (s, 2H), 8.69 (s, 2H), 8.22
Chem. Asian J. 2013, 8, 178 – 190
188
ꢁ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemasianj.org
Hiroshi Shinokubo, Dongho Kim et al.
Two-Photon Absorption Experiments
Bruzek, S. R. Parkin, A.-F. Miller, J. E. Anthony, Angew. Chem.
2011, 123, 7151; Angew. Chem. Int. Ed. 2011, 50, 7013.
The two-photon absorption (TPA) spectrum was measured in the NIR
region using the open-aperture Z-scan method with 130 fs pulses from an
optical parametric amplifier (Light Conversion, TOPAS) operating at
a repetition rate of 2 kHz generated from a Ti:sapphire regenerative am-
plifier system (Spectra-Physics, Hurricane). After passing through
a 10 cm focal length lens, the laser beam was focused and passed through
a 1 mm quartz cell. As the position of the sample cell could be controlled
along the laser beam direction (z axis) using the motorcontrolled delay
stage, the local power density within the sample cell could be simply con-
trolled under constant laser intensity. The transmitted laser beam from
the sample cell was then detected by the same photodiode as used for
reference monitoring. The on-axis peak intensity of the incident pulses at
the focal point, I0, ranged from 40 to 60 GWcmꢀ2. For a Gaussian beam
profile, the nonlinear absorption coefficient can be obtained by curve fit-
ting of the observed open-aperture traces T(z), as shown by Equa-
tion (1):
[4] a) J. P. Hill, W. Jin, A. Kosaka, T. Fukushima, H. Ichihara, T. Shimo-
mura, K. Ito, T. Hashizume, N. Ishii, T. Aida, Science 2004, 304,
1481; b) S. Xiao, M. Myers, Q. Miao, S. Sanaur, K. Pang, M. L. Stei-
gerwald, C. Nuckolls, Angew. Chem. 2005, 117, 7556; Angew. Chem.
Int. Ed. 2005, 44, 7390.
[5] a) X. Yang, X. Dou, K. Mꢀllen, Chem. Asian J. 2008, 3, 759; b) J.
Wu, M. D. Watson, K. Mꢀllen, Angew. Chem. 2003, 115, 5487;
Angew. Chem. Int. Ed. 2003, 42, 5329; c) S. Ito, M. Wehmeier, J. D.
Brand, C. Kꢀbel, R. Epsch, J. P. Rabe, K. Mꢀllen, Chem. Eur. J.
2000, 6, 4327.
[6] a) W. Pisula, X. Feng, K. Mꢀllen, Adv. Mater. 2010, 22, 3634; b) J.
Wu, W. Pisula, K. Mꢀllen, Chem. Rev. 2007, 107, 718.
[7] a) X. Feng, W. Pisula, M. Takase, X. Dou, V. Enkelmann, M.
Wagner, N. Ding, K. Mꢀllen, Chem. Mater. 2008, 20, 2872; b) J. Wu,
M. Baumgarten, M. G. Debije, J. M. Warman, K. Mꢀllen, Angew.
Chem. 2004, 116, 5445; Angew. Chem. Int. Ed. 2004, 43, 5331; c) L.
Chen, X. Dou, W. Pisula, X. Yang, D. Wu, G. Floudas, X. Feng, K.
Mꢀllen, Chem. Commun. 2012, 48, 702.
0l
bI0ð1 ꢀ eꢀa
Þ
2
ð1Þ
TðzÞ ¼ 1 ꢀ
2a0½1 þ ðz=z0Þ ꢁ
[8] M. Kastler, W. Pisula, D. Wasserfallen, T. Pakula, K. Mꢀllen, J. Am.
Chem. Soc. 2005, 127, 4286.
where a0 is the linear absorption coefficient, l the sample length, and z0
the diffraction length of the incident beam. After the nonlinear absorp-
tion coefficient has been obtained, the TPA cross section s(2) of one
[9] a) W. W. H. Wong, D. Vak, Th. B. Singh, S. Ren, C. Yan, D. J. Jones,
I. I. Liaw, R. N. Lamb, A. B. Holmes, Org. Lett. 2010, 12, 5000;
b) W. W. H. Wong, T. B. Singh, D. Vak, W. Pisula, C. Yan, X. Feng,
E. L. Williams, K. L. Chan, Q. Mao, D. J. Jones, C.-Q. Ma, K.
Mꢀllen, P. Bꢅuerle, A. B. Holmes, Adv. Funct. Mater. 2010, 20, 927.
[10] a) S. K. Sadhukhan, C. Viala, A. Gourdon, Synthesis 2003, 1521;
b) P. T. Herwig, V. Enkelmann, O. Schmelz, K. Mꢀllen, Chem. Eur.
J. 2000, 6, 1834.
solute
molecule
(in
units
of
GM,
where
1 GM=
10ꢀ50 cm4 sphotonꢀ1 moleculeꢀ1) can be determined by using the following
relationship, as shown in Equation (2):
10ꢀ3
s
ð2ÞNAd
hn
ð2Þ
b ¼
[11] a) T. Teraoka, S. Hiroto, H. Shinokubo, Org. Lett. 2011, 13, 2532;
b) R. Yamaguchi, S. Hiroto, H. Shinokubo, Org. Lett. 2012, 14, 2472.
[12] a) I. A. I. Mkhalid, J. H. Barnard, T. D. Marder, J. M. Mulphy, J. F.
Hartwig, Chem. Rev. 2010, 110, 890; b) N. Miyaura, Bull. Chem. Soc.
Jpn. 2008, 81, 1535; c) T. Ishiyama, N. Miyaura, J. Organomet.
Chem. 2003, 680, 3.
where NA is the Avogadro constant, d is the concentration of the com-
pound in solution, h is the Planck constant, and n is the frequency of the
incident laser beam.
[13] a) D. N. Coventry, A. S. Basanov, A. E. Goeta, J. A. K. Howard,
T. B. Marder, R. N. Perutz, Chem. Commun. 2005, 2172; b) H. Hata,
H. Shinokubo, A. Osuka, J. Am. Chem. Soc. 2005, 127, 8264; c) S.
Hiroto, I. Hisaki, H. Shinokubo, A. Osuka, Angew. Chem. 2005, 117,
6921; Angew. Chem. Int. Ed. 2005, 44, 6763; d) T. Kimoto, K.
Tanaka, Y. Sakai, A. Ohno, K. Yoza, K. Kobayashi, Org. Lett. 2009,
11, 3658; e) R. Ozawa, K. Yoza, K. Kobayashi, Chem. Lett. 2011, 40,
941; f) A. G. Crawford, Z. Liu, I. A. I. Mkhalid, M.-H. Thibault, N.
Schwarz, G. Alcaraz, A. Steffen, J. C. Collings, A. S. Batsanov,
J. A. K. Howard, T. B. Marder, Chem. Eur. J. 2012, 18, 5022; g) S.
Hitosugi, Y. Nakamura, T. Matsuno, W. Nakanishi, H. Isobe, Tetra-
hedron Lett. 2012, 53, 1180.
Acknowledgements
This work was supported by Grants-in-Aid for Scientific Research (Nos.
22750036 and 23108705 “pi-Space”) from MEXT, Japan. H.S. also ac-
knowledges Daiko Foundation for financial support. The work at Yonsei
University was supported by the Midcareer Researcher Program (2010-
0029668), an AFSOR/APARD grant (no. FA2386-09-1-4092) and World
Class University (R32-2010-000-10217) Programs of the Ministry of Edu-
cation, Science, and Technology (MEST) of Korea.
[14] Crystallographic data for 3b: C80H60O2Cl6, Mw =1265.98, Monoclin-
ic, Space Group=P21/n a=8.099(4) ꢂ, b=22.002(11) ꢂ, c=
35.641(18) ꢂ, b=92.477(10)8, Z=4, R=0.0704 (I>2.0s(I)), Rw =
0.2471 (all data), GOF=1.050. CCDC 894808 contains the supple-
mentary crystallographic data for this paper. These data can be ob-
tained free of charge from The Cambridge Crystallographic Data
Centre via www.ccdc.cam.ac.uk/data_request/cif..
[15] X. Feng, J. Wu, V. Enkelmann, K. Mꢀllen, Org. Lett. 2006, 8, 1145.
[16] a) G. Battagliarin, Y. Zhao, C. Li, K. Mꢀllen, Org. Lett. 2011, 13,
3399; b) G. Battagliarin, C. Li, V. Enkelmann, K. Mꢀllen, Org. Lett.
2011, 13, 3012; c) J. M. Murphy, X. Liao, J. F. Hartwig, J. Am. Chem.
Soc. 2007, 129, 15434.
[17] D. S. Surry, S. L. Buchwald, Chem. Sci. 2011, 2, 27.
[18] a) K. Takagi, Y. Sakakibara, Chem. Lett. 1989, 1957; b) R. Chidam-
baram, Tetrahedron Lett. 2004, 45, 1441.
[19] M. Kastler, J. Schmidt, W. Pisula, D. Sebastiani, K. Mꢀllen, J. Am.
Chem. Soc. 2006, 128, 9526.
[20] a) A. D. Becke, Phys. Rev. A 1988, 38, 3098; b) C. Lee, W. Yang,
R. G. Parr, Phys. Rev. B 1988, 37, 785.
[1] a) Carbon-Rich Compounds (Eds.: M. M. Haley, R. R. Tykwinski),
Wiley-VCH, Weinheim, 2006; b) R. G. Harvey, Polycyclic Aromatic
Hydrocarbons, Wiley-VCH, Weinheim, 1997; c) Functional Organic
Materials (Eds.: T. J. J. Mꢀller, U. H. F. Bunz), Wiley-VCH, Wein-
heim, 2007.
[2] a) J. E. Anthony, Angew. Chem. 2008, 120, 460; Angew. Chem. Int.
Ed. 2008, 47, 452; b) T. M. Figueira-Duarte, K. Mꢀllen, Chem. Rev.
2011, 111, 7260; c) F. Wꢀrthner, Chem. Commun. 2004, 1564; d) X.
Feng, W. Pisula, K. Mꢀllen, Pure. Appl. Chem. 2009, 81, 2203.
[3] Recent achievements of polycyclic aromatic hydrocarbons, see:
a) L. T. Scott, E. A. Jackson, Q. Zhang, B. D. Steinberg, M. Bancu,
B. Li, J. Am. Chem. Soc. 2012, 134, 107; b) A. Konishi, Y. Hirao, M.
Nakano, A. Shimizu, E. Botek, B. Champagne, D. Shiomi, K. Sato,
T. Takui, K. Matsumoto, H. Kurata, T. Kubo, J. Am. Chem. Soc.
2010, 132, 11021; c) L. Dçssel, L. Gherghel, X. Feng, K. Mꢀllen,
Angew. Chem. 2011, 123, 2588; Angew. Chem. Int. Ed. 2011, 50,
2540; d) S. Hitosugi, W. Nakanishi, T. Yamasaki, H. Isobe, Nat.
Commun. 2011, 2, 492; e) M. Watanabe, Y. J. Chang, S.-W. Liu, T.-
H. Chao, K. Goto, M. M. Islam, C.-H. Yuan, Y.-T. Tao, Y. Shinmyo-
zu, T. J. Chow, Nat. Chem. 2012, 4, 574; f) B. Purushothaman, M.
Chem. Asian J. 2013, 8, 178 – 190
189
ꢁ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemasianj.org
Hiroshi Shinokubo, Dongho Kim et al.
[21] A. G. Crawford, A. D. Dwyer, Z. Liu, A. Steffen, A. Beeby, L.-O.
Pꢆlsson, D. J. Tozer, T. B. Marder, J. Am. Chem. Soc. 2011, 133,
13349.
[22] Z. Zeng, Z. Guan, Q.-H. Xu, J. Wu, Chem. Eur. J. 2011, 17, 3837.
Received: August 7, 2012
Published online: October 24, 2012
Chem. Asian J. 2013, 8, 178 – 190
190
ꢁ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim