Self-assembly of coronene bisimides: Mechanistic insight and chiral amplification

Article abstract of DOI:10.1002/chem.201301251

The study of the organization of small π-conjugated molecules is imperative to understanding and controlling its properties for various applications. Coronene bisimides (CBIs) are potential candidates for novel liquid-crystalline materials and active n-type semiconductor molecules in organic electronics. To understand the self-assembly of this seldom-studied chromophore, we have designed two derivatives of CBIs bearing chiral and achiral 3,4,5-trialkoxyphenyl groups at the imide position, named as CBI-GCH and CBI-GACH, respectively. CBI-GCH self-assembles mainly through π-stacking and van der Waals interactions in nonpolar methylcyclohexane to result in long 1D fibrillar stacks. The mechanism of supramolecular polymerization was probed by using chiroptical studies, which showed an isodesmic pathway for CBI-GCH. The thermodynamic parameters that govern the self-assembly are detailed. CBI-GACH also shows similar self-assembly behavior as its chiral counterpart. X-ray diffraction studies of both molecules reveals a 2D hexagonal columnar arrangement. The coassembly of CBI-GCH and CBI-GACH shows chiral amplification (sergeant and soldiers experiment) with saturation at 30-50 % of the chiral derivative, which was further used to study the dynamics of the assembly. Thus, this study presents a rare report of chiral amplification in an isodesmic system. Copyright

Full text of DOI:10.1002/chem.201301251

DOI: 10.1002/chem.201301251
Self-Assembly of Coronene Bisimides: Mechanistic Insight and Chiral
Amplification
Chidambar Kulkarni,[a, b] Rajesh Munirathinam,[a] and Subi J. George*[a]
Abstract: The study of the organization
of small p-conjugated molecules is im-
perative to understanding and control-
ling its properties for various applica-
tions. Coronene bisimides (CBIs) are
potential candidates for novel liquid-
crystalline materials and active n-type
semiconductor molecules in organic
electronics. To understand the self-as-
sembly of this seldom-studied chromo-
phore, we have designed two deriva-
tives of CBIs bearing chiral and achiral
3,4,5-trialkoxyphenyl groups at the
imide position, named as CBI-GCH
and CBI-GACH, respectively. CBI-
GCH self-assembles mainly through p-
stacking and van der Waals interactions
in nonpolar methylcyclohexane to
result in long 1D fibrillar stacks. The
mechanism of supramolecular polymer-
ization was probed by using chiroptical
studies, which showed an isodesmic
pathway for CBI-GCH. The thermody-
namic parameters that govern the self-
assembly are detailed. CBI-GACH also
shows similar self-assembly behavior as
its chiral counterpart. X-ray diffraction
studies of both molecules reveals a 2D
hexagonal columnar arrangement. The
coassembly of CBI-GCH and CBI-
GACH shows chiral amplification (ser-
geant and soldiers experiment) with
saturation at 30–50% of the chiral de-
rivative, which was further used to
study the dynamics of the assembly.
Thus, this study presents a rare report
of chiral amplification in an isodesmic
system.
Keywords: chirality · coronene bisi-
mides · isodesmic systems · liquid
crystals · organic electronics · self-
assembly
Introduction
six-membered rings have been synthesized from a twofold
benzogenic Diels–Alder reaction that starts from perylene.[9]
CBIs were mainly studied for liquid-crystalline properties.[10]
A recent report has used dithienocoronene bisimide as ac-
ceptors with thiophenes as donors to form copolymers, thus
showing promising thin-film-transistor properties.[11] Howev-
er, the self-assembly of coronene imide derivatives in solu-
tion has seldom been reported.[12]
The self-assembly of p-conjugated molecules, through vari-
ous noncovalent interactions, such as hydrogen bonding, p-
stacking, and van der Waals interactions to achieve function-
al 1D nanostructures has been an active area of research.[1]
The immense interest in this field is due to the tunability of
noncovalent interactions that enable better control over the
resulting nanostructure, thereby improving their optoelec-
tronic functionality.[2] Varied classes of both n- and p-type
chromophores, such as triphenylenes,[3] perylene bisimides,[4]
naphthalene bisimides,[5] oligo(para-phenylenevinylenes),[6]
porphyrins,[7] and so forth, have been extensively studied for
self-assembly and potential applications. Coronene bisimides
(CBIs) bearing six-membered imide rings are another class
of n-type chromophore, and they can be obtained by the
core expansion of perylene bisimides.[8] Another class of
CBI that possesses five-membered imide rings instead of
The study of the self-assembly of p-conjugated systems to
obtain a deeper understanding of the mechanism can be
useful to control its material properties. The two main cate-
gories of mechanism used to describe 1D supramolecular
polymerization are isodesmic and cooperative, as classified
by de Greef et al.[13] In an isodesmic mechanism, monomer
addition to a growing assembly is characterized by a con-
stant equilibrium constant (or a constant change in free
energy), which is independent of the degree of polymeriza-
tion. However, the cooperative-nucleated supramolecular
polymerization is similar to a nucleation-elongation process,
which involves two distinct stages. In the first stage, a few
monomers group together to form a less-stable assembly
called the nucleus. The second step involves the further
growth of a supramolecular polymer by the addition of mon-
omers to the formed nuclei. The formation of the nucleus is
less stable than the formation of the subsequent elongated
structures (i.e., the equilibrium constant for nucleation Kn is
smaller than the equilibrium constant for elongation Ke).
These mechanisms have been reviewed in great detail by
Meijer and co-workers, who have provided thermodynamic
classification and examples for each type.[13] However, the
[a] C. Kulkarni, R. Munirathinam, Dr. S. J. George
Supramolecular Chemistry Laboratory, New Chemistry Unit
Jawaharlal Nehru Centre for Advanced Scientific Research
ACHTUNGTRENNUNG(JNCASR), Jakkur P.O., Bangalore 560064 (India)
Fax : (+91)80-2208-2627
E-mail: george@jncasr.ac.in
[b] C. Kulkarni
Chemistry and Physics of Materials Unit (CPMU)
Jawaharlal Nehru Centre for Advanced Scientific Research
ACHTUNGTRENNUNG(JNCASR), Bangalore-64 (India)
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/chem.201301251.
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FULL PAPER
molecular features that govern the mechanism of supramo-
lecular polymerization continues to be a matter of study.[14]
Chiral amplification has been studied quite extensively in
both macromolecular (polymer) and supramolecular assem-
blies by using the principles of “sergeant and soldiers” and
“majority rules”.[15] In the sergeant-and-soldiers experiment,
a small amount of a chiral derivative dictates the handed-
ness of a pool of achiral derivatives;[16] however, in majority
rules, a slight excess of one enantiomer guides the chirality
of the complete assembly toward itself.[16] In synthetic supra-
molecular polymers, these two modes of chiral amplification
are observed for systems mainly following a cooperative
mechanism.[17] An exception to the above is benzene-1,3,5-
tricarboxamide (BTA) substituted with 3,3’-diamino-2,2’-bi-
pyridine groups, which self-assembles in an isodesmic
manner and exhibits the principle of sergeant and soldiers.[18]
Also these BTA derivatives have been shown to display the
phenomenon of majority rules.[17b] The compounds studied
herein belong to a rare class of molecule that follows an iso-
desmic mechanism while still
Figure 1. Coronene bisimide molecules CBI-GCH and CBI-GACH under
study.
ing 3,4,5-tris[(S)-3,7-dimethyloctyloxy]phenyl and 3,4,5-tris(-
dodecyloxy)phenyl groups, respectively; Scheme 1). Both
the molecules were completely characterized by 1H and
13C NMR spectroscopic, matrix-assisted laser desorption/ion-
exhibiting chiral amplification.
Our group has previously
studied the self-assembly of an
amphiphilic derivative of a CBI
containing
a
five-membered
imide ring and hydrogen-
bonded monoimide chromo-
phores.[12] In continuation of
our effort to study the self-as-
sembly of this chromophore, we
present herein a detailed inves-
tigation of the self-assembly,
Scheme 1. Synthetic routes to obtain CBI-GCH and CBI-GACH.
polymerization
mechanisms,
and the morphology of two
novel CBI derivatives substituted with 3,4,5-trialkoxy gallic
wedges. The analogous perylene bisimide (PBI) derivatives
have been extensively studied by Wꢁrthner and co-work-
ers.[4d,19] Chiroptical probing and microscopic studies of
these CBI derivatives revealed that they self-assemble into
1D nanostructures in an isodesmic manner. Furthermore, we
show the presence of chiral amplification through the princi-
ple of sergeant and soldiers in the coassemblies of these two
derivatives.
ization mass-spectrometric (MALDI), high-resolution mass-
spectrometric (HRMS), and thermogravimeteric analysis
(TGA; see the Supporting Information for details).
Self-assembly of CBI-GCH: UV/Vis spectra of CBI-GCH in
chloroform (c=1ꢂ10ꢀ5 m) show characteristic absorption
features of the CBI chromophore (Figure 2a) with the maxi-
mum at lmax =346 nm (e=1.0ꢂ105 Lmolꢀ1 cmꢀ1), accompa-
nied by three vibronic features between l=425 and 500 nm.
These spectral features indicate a molecularly dissolved
state in chloroform.[12a] On the other hand, CBI-GCH in
methylcyclohexane (MCH) shows a broad hypsochromically
shifted absorption maximum at lmax =325 nm, along with the
loss of vibronic features and the emergence of a new broad
band between l=500 and 520 nm. These features indicate
the presence of p stacking in MCH; thus, leading to H-type
excitonically coupled aggregates. Although fluorescence
spectroscopy can also offer valuable insight into the type of
aggregate, the CBI derivatives under study are nonfluores-
cent, even in their molecularly dissolved state in chloroform,
probably due to the presence of phenoxy groups in the
imide region. Similar effects were observed for perylene bi-
simides containing phenoxy wedges and were attributed to
Results and Discussion
The molecules under study contain 3,4,5-trialkoxyphenyl
wedges attached at the imide positions of CBI, with the fol-
lowing alkyl chains: dodecyl and (S)-(ꢀ)-3,7-dimethyloctyl
in CBI-GACH and CBI-GCH; respectively (Figure 1).
Coronene dianhydride (1),[9] 3,4,5-tris[(S)-3,7-dimethyloc-
tyloxy]-1-aminobenzene (2),[20] and 3,4,5-tris(dodecyloxy)-1-
aminobenzene (3)[20] were synthesized following reported
procedures. These aminobenzenes were further treated with
coronene dianhydride in freshly distilled quinoline to obtain
the corresponding CBIs CBI-GCH and CBI-GACH (bear-
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S. J. George et al.
The molar ellipticity De or
magnitude of CD effect (mdeg)
decreases with an increase in
temperature and almost vanish-
es at temperatures above 958C,
thus indicating the absence of
excitonically coupled helical ag-
gregates at high temperatures
(Figure 2c).
Correspondingly,
the molar extinction coefficient
e increases, and the absorption
maxima red-shifts with the ap-
pearance of vibronic features as
the temperature is increased
(Figure 2d). These absorption
changes reiterate that the mole-
cules exist in their monomeric
form at high temperature. Al-
though the molecularly dis-
solved state is observed in
chloroform at room tempera-
ture and in MCH at high tem-
peratures, the absorption spec-
tra in these two states are not
identical (lmax =346 and 331 nm
in CHCl3 at 208C and MCH at
958C, respectively). This dis-
Figure 2. Self-assembly of CBI-GCH. a) Normalized UV/Vis spectra in two different solvents at 208C. b) Top
view of the optimized geometry of the CBI dimer (with 3,4,5-triethoxyphenyl groups) by using DFT-based cal-
culations. Carbon: gray, hydrogen: white, oxygen and nitrogen: black (see Figure S19 in the Supporting Infor-
mation for a colored version of the figure). Temperature-dependent c) CD and d) UV/Vis spectra (c=5ꢂ
10ꢀ5 m in MCH, 1 cm cuvette). The arrows indicate the spectral changes with a decrease in temperature.
the electron transfer from the phenoxy groups to the pery-
lene bisimide core.[19a,21] Because CBI-GCH assembles in an
H-type aggregate, the angle between the transition dipole
moments of two consecutive monomers should be greater
than 54.78.[19c,22,23] To understand the possible packing in the
aggregates, computational studies were carried out. This re-
veals a rotational angle of approximately 648 (without much
translation) in the dimer (Figure 2b), thus ascertaining the
formation of H-type aggregates.
The presence of chiral centers on the phenoxy wedge aids
the organization of the 1D assemblies into a preferred heli-
cal direction. This helical bias in molecular organization can
be monitored by means of circular dichroism (CD) spectro-
scopy. The CD spectra (Figure 2c) of CBI-GCH in MCH
(c=5ꢂ10ꢀ5 m) shows four clear zero crossings at l=476,
465, 327, and 307 nm with bisignated exciton coupling in
both the vibronic and p–p* regions (l=425–500 and 300–
375 nm, respectively). The CD spectra show a positive fol-
lowed by negative Cotton effect in both the regions when
viewed from the region of higher wavelength to the lower
wavelength. Also, the wavelength that corresponds to two
major zero crossings in the CD spectra match well with the
absorption maxima (lmax =327 and 476 nm), thus indicating
that the type of excitonic coupling observed by using both
spectroscopic techniques (i.e., UV/Vis and CD) is similar.
Thus, we can conclude that the molecular chirality present
in the peripheral side chains of CBI-GCH has been transfer-
red to the supramolecular level when self-assembled in
MCH.[24]
tinction is due to the difference in the polarity of the two
solvents (er =2.02 and 4.81 for MCH and CHCl3, respective-
ly), or in other words solvatochromism.
Having studied the aggregation behavior of CBI-GCH;
we examined the mechanism of self-assembly. The mecha-
nism of the supramolecular polymerization is important to
study because knowing it helps control the degree of poly-
merization and consequently the properties of the poly-
mer.[13] Recently, Smulders et al. have shown that the use of
temperature-dependent measurements to monitor the frac-
tion of aggregates a is more reliable than concentration-de-
pendent experiments to assign the mechanisms of supramo-
lecular polymerization.[25] Thus, we employed temperature-
dependent studies to elucidate the mechanism of the supra-
molecular polymerization. Solutions of CBI-GCH in MCH
at various concentrations were heated to 371 K to obtain a
molecularly dissolved state and then were slowly cooled
(2 Kminꢀ1) to form a supramolecular polymer, while moni-
toring the CD effect at l=322 nm. No hysteresis in the CD
effect was observed between the heating and cooling cycles
(c=3ꢂ10ꢀ5 m) with a temperature gradient of 2 Kminꢀ1.
Furthermore, this curve also exactly matches the cooling
curve obtained at a slower rate of cooling of 1 Kminꢀ1 (see
Figure S1 in the Supporting Information). This outcome
confirms that the assembly process is under thermodynamic
control when cooled at a rate of 2 Kminꢀ1. The normalized
cooling curves and the corresponding fits to the tempera-
ture-dependent isodesmic model [see Equation (4) in the
Supporting Information] proposed by Smulders et al.[25] are
shown in Figure 3. This model described the cooling curves
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Self-Assembly of Coronene Bisimides To Form 1D Fibers
FULL PAPER
ꢀ62.6 kJmolꢀ1, DS=ꢀ104.4 JKꢀ1 molꢀ1, and Ke =5.4ꢂ
104 mꢀ1, respectively.
To obtain insight into the morphology of the CBI-GCH
assembly in MCH (c=5ꢂ10ꢀ5 m), field-emission SEM
(FESEM), atomic force microscopy (AFM), TEM, dynamic
light scattering (DLS), and XRD studies were performed.
FESEM images recorded on a glass substrate (Figure 4a)
show the presence of 1D fibers of several microns in length.
AFM imaging was performed by drop casting a solution of
CBI-GCH in MCH on a freshly cleaved mica surface to
obtain a more quantitative picture of the aggregates, which
also showed uniform distribution of the fibers (Figure 4b).
A detailed height-profile analysis of the fibers showed an
average height of 14 nm. The height of an isolated individual
fiber was around 5 nm (inset of Figure 4c), which matches
well with the calculated dimension of CBI-GCH (i.e.,
4.4 nm; see Figure S4 in the Supporting Information), thus
indicating that these fibers consist of p-stacks of individual
molecules. These individual fibers further come together to
form larger aggregates, which is evident from the increase in
the height of the larger bundles. The height analysis of the
fibers in four or five independent images gives a histogram
that indicates that the fibers are present throughout the
sample and provides a better representation of the fiber
heights (Figure 4d). TEM micrographs recorded on a dried
carbon-coated grid with 1% aqueous uranyl acetate staining
show that the width of the fibers is 5–10 nm (see Figure S5
in the Supporting Information), which is in agreement with
other microscopic analysis.
Although CBI-GCH follows an isodesmic mechanism of
supramolecular polymerization, long fibers were observed in
morphological studies, which could be partly due to the
drying effect of the substrate. DLS experiments were per-
formed to study the formation of aggregates in solution.
DLS (c=5ꢂ10ꢀ5 m) shows an apparent hydrodynamic radii
of 100–200 nm (see Figure S6 in the Supporting Informa-
tion), which suggests that the aggregates are indeed present
in the solution state as well. Thus, CBI-GCH forms individu-
al p-stacked aggregates that lead to fibers, which further ag-
gregate through van der Waals interactions of the side
chains to form fiber bundles in solution.
Figure 3. Mechanism of self-assembly of CBI-GCH. Fraction of aggrega-
tion a monitored at l=322 nm versus temperature at four different con-
centrations in MCH, with a cooling rate of 2 Kminꢀ1. The solid line for
each curve shows the fit to the temperature-dependent isodesmic model
[see Equation (4) in the Supporting Information]. Each curve is displaced
vertically by 0.20 from each other for clarity.
fairly accurately. Thus, the mechanism of self-assembly of
CBI-GCH follows an isodesmic pathway.
Recently, it has been argued that the lack of long-range
interactions leads to an isodesmic mechanism.[14a] Because
the molecule under consideration has mainly a central p-sur-
face and van der Waals interactions of the peripheral side
chains, there does not seem to be any moiety that can pro-
duce long-range interactions. One possibility is the interac-
tion between the phenoxy wedges through weak hydrogen
bonds, but because the molecules are rotated by more than
54.78 in the dimer because of H-type aggregation, this inter-
action seems improbable (as seen from Figure 2b). CBI-
GCH thus provides an example of a system of self-assembly
through mainly p-stacking and van der Waals interactions,
thus resulting in an isodesmic mechanism of self-assembly.
By using the temperature-dependent isodesmic model, we
have obtained various thermodynamic parameters that
govern supramolecular polymerization (as summarized in
Table 1). The number-averaged degree of polymerization as
Table 1. Thermodynamic parameters for the self-assembly of CBI-GCH in
MCH.
Concentration
[m]
Melting
temperature
Tm [K]
Enthalpy of
Number-average
degree of
polymerization
DH [kJmolꢀ1
]
polymerization[a]
DPN
X-ray diffraction studies of the films obtained by drop
casting solutions of CBI-GCH in MCH on a glass substrate
showed the presence of low-angle reflections (Figure 4e,f).
1ꢂ10ꢀ5
3ꢂ10ꢀ5
5ꢂ10ꢀ5
7ꢂ10ꢀ5
303.35
310.55
313.65
320.55
ꢀ63.20
ꢀ61.84
ꢀ62.50
ꢀ62.85
1.54
1.90
2.00
2.16
p
p
The ratio of the d spacing was 1:1/ 3:1/2:1/ 7 for the first
four reflections (see Table S1 in the Supporting Informa-
tion). Also a broad reflection was observed between 20 and
308 (2q). This ratio of d spacing and the broad reflection at
higher 2q is characteristic of a 2D hexagonal columnar lat-
tice (inset of Figure 4e).[26] The higher 2q peaks correspond
to the alkyl-chain interaction and core–core distance within
the columns. The lattice parameter (a) for CBI-GCH was
29.04 ꢄ.
[a] At 298.05 K.
a function of temperature at various concentrations was ob-
tained (see Figure S2 in the Supporting Information). The
equilibrium constant was also calculated for the temperature
298.05 K. The vanꢃt Hoff plot (ln(Ke) vs. 1/T) at various con-
centrations were obtained, and the entropy of polymeriza-
tion was calculated (see Figure S3 in the Supporting Infor-
mation). The average values for the enthalpy, entropy, and
the equilibrium constant of polymerization are DH=
Self-assembly of CBI-GACH: Having studied the chiral
CBI derivative, we further explored the self-assembly of the
achiral analogue CBI-GACH bearing a dodecyl group on
the phenoxy wedges. This molecule was also molecularly
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S. J. George et al.
325 nm, with the loss of vibron-
ic features (Figure 5a). With an
increase in temperature, a red-
shifted absorption maximum at
lmax =331 nm and vibronic fea-
tures is observed, thus indicat-
ing a lesser degree of aggrega-
tion (see Figure S7 in the Sup-
porting Information). Because
of the achiral nature of the mol-
ecule, CD spectroscopy could
not be used to monitor the self-
assembly. Also, this CBI deriva-
tive is nonfluorescent in the
monomeric state for the same
reasons as for the chiral ana-
logue.
Temperature-dependent UV/
Vis spectroscopy was used to
understand the mechanism of
self-assembly of CBI-GACH.
The cooling curves obtained at
two different concentrations by
monitoring the absorbance at
l=472 nm in UV/Vis spectra
shows a sigmoidal nature and
fits to the temperature-depend-
ent isodesmic model (see Fig-
ure S8 in the Supporting Infor-
mation). A higher-temperature
region (greater than 350 K) of
the cooling curves shows a devi-
ation from the fitted curve
probably due to the contribu-
tion from monomer absorption
at the monitored temperature.
Thus, we defer to perform any
thermodynamic analysis from
the obtained cooling curves.
Figure 4. Morphological studies of CBI-GCH (c=5ꢂ10ꢀ5 m in MCH). a) FESEM image of the film recorded
on a glass substrate in the low-vacuum mode. b) AFM height image of a film obtained by drop-casting a solu-
tion of CBI-GCH in MCH on a freshly cleaved mica surface. c) Cross-sectional analysis along the lines shown
in (b). The inset shows the presence of individual fibers with a typical height of 4 nm. d) Histogram of fiber
heights obtained from the analysis of four or five independent images with areas of 20ꢂ20 mm and 10ꢂ10 mm.
e) XRD pattern of CBI-GCH on a glass substrate. The inset shows the hexagonal columnar arrangement with
lattice parameter (a). f) Low-angle reflections of the XRD pattern that show the peak indexing and d spacing.
FESEM and AFM were used
to understand the morphology
of aggregates of CBI-GACH
dissolved in chloroform at
dilute concentration (c=1ꢂ
10ꢀ5 m), which is evident from
the characteristic CBI spectral
features such as the absorption
maxima at lmax =346 nm (e=
1.3ꢂ105 Lmolꢀ1 cmꢀ1) with vi-
bronic features between l=425
and 500 nm. This molecule
forms H-type aggregates in
MCH (c=5ꢂ10ꢀ5 m), indicated
Figure 5. Self-assembly of CBI-GACH. a) Normalized UV/Vis spectra in chloroform and MCH in a 1 cm cuv-
ette. b) FESEM image of a film obtained by drop-casting a solution (c=5ꢂ10ꢀ5 m in MCH) on a glass sub-
by the hypsochromic shift of
the absorption maxima to l= strate.
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Self-Assembly of Coronene Bisimides To Form 1D Fibers
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Figure 6. Coassembly of CBI-GCH and CBI-GACH and resultant chiral amplification. All the experiments were done in MCH (c=2.5ꢂ10ꢀ5 m). a) CD
spectra of the coassembly at different percentages of CBI-GCH in a 1 cm cuvette at 208C. The arrow indicates the spectral change with an increase in
the percentage of the sergeant. b) Anisotropy value or g value monitored at l=320 nm as a function of the percentage of CBI-GCH. The dashed line
that connects the fraction of CBI-GCH indicates the linear variation of the g value in the absence of any chiral amplification. c) The kinetics of the as-
sembly seen by monitoring the time taken to reach the CD effect at l=320 nm when preassembled CBI-GCH (35%) was added to CBI-GACH at a con-
stant concentration. d) FESEM and e) AFM images of a film obtained by drop-casting a solution containing 40% CBI-GCH on glass and freshly cleaved
mica surface, respectively. f) AFM cross-sectional analysis of fibers in (e) along the line 1–1’ showing the presence of individual fibers.
(c=5ꢂ10ꢀ5 m) on glass and mica substrates, respectively.
The FESEM images showed the formation of long fibrillar
networks (Figure 5b). The AFM images show the presence
of a fibrous network with an average height of 11 nm (see
Figure S9 in the Supporting Information). Detailed height
analysis showed a bimodal distribution in the heights of the
fibers (see Figure S9c in the Supporting Information). A sig-
nificant amount of isolated fibers showed an average height
of 5–7 nm (see the inset of Figure S9b in the Supporting In-
formation), which is very close to the calculated molecular
dimension of 5.4 nm (see Figure S10 in the Supporting Infor-
mation). Furthermore, these isolated fibers interdigitate
through van der Waals interactions to form larger aggre-
gates with heights of 15–25 nm. DLS experiments (c=1ꢂ
10ꢀ5 m) showed an apparent hydrodynamic radii of 200–
300 nm (see Figure S11 in the Supporting Information),
which confirms the presence of aggregates in the solution
state. The XRD pattern of CBI-GACH also showed a simi-
lar 2D hexagonal columnar arrangement with a lattice pa-
rameter of 29.63 ꢄ (see Figure S12 and Table S2 in the Sup-
porting Information).
coassembled with CBI-GACH (c=2.5ꢂ10ꢀ5 m), and their
chiroptical properties were probed. Even with a small
amount (3%) of the chiral derivative (CBI-GCH) or ser-
geant, the CD spectra of the coassembly shows a bisignated
Cotton effect (Figure 6a) with very little change in the ab-
sorption spectra (see Figure S13 in the Supporting Informa-
tion).[27] Also the X-ray diffraction studies of a mixture of
CBI-GCH and CBI-GACH shows a similar 2D hexagonal
columnar arrangement with a slight change in the basal
(100) reflection and lattice parameter (a=30.11 ꢄ), thus
suggesting a coassembly (see Figure S14 and Table S3 in the
Supporting Information). The anisotropy factor or g value
De/e monitored at l=320 nm shows nonlinear behavior
(Figure 6b), which reaches the corresponding value of the
pure chiral assembly at around 50% of the sergeant. This
outcome suggests a rather weak chiral amplification in this
system. We further used chiral amplification to probe the
dynamics of the molecules in the CBI stacks. An aliquot of
35% of the sergeant solution in its assembled state was
added to the solution of preassembled CBI-GACH in MCH
at the same concentration, and the evolution of the CD
effect was monitored at l=320 nm as a function of time.
The CD effect saturates to its equilibrium value within 3–
4 minutes (Figure 6c). Thus, the rapid attainment of an equi-
librium CD effect indicates that the coassembly and aggre-
gates are dynamic.
CBI coassembly: sergeant-and-soldiers experiment: We per-
formed the sergeant-and-soldiers experiment to understand
chiral amplification in the coassemblies of CBI-GCH and
CBI-GACH in MCH. Different amounts of CBI-GCH were
Chem. Eur. J. 2013, 19, 11270 – 11278
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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S. J. George et al.
Computational details: Geometry optimization of monomers of CBI-
GCH and CBI-GACH was carried out at the B3LYP-6–31G level of
theory with the Gaussian 09 package.[29] The molecules were visualized
by using visual molecular dynamics.[30] The geometry optimization of the
dimer in the gas phase was carried out by using periodic DFT calcula-
tions, as implemented in CP2K by means of the QUICKSTEP module.[31]
BLYP exchange-correlation functional[29a,b] was used along with double
zet-valence polarized basis set and the Grimme D2[32] dispersion correc-
tion. An energy cut-off of 280 Ry for electron density, Goedecker-Teter-
Hutter (GTH) pseudopotential,[33] wavelet Poisson solver, and L-BFGS
optimizer were used. A cubical box of dimension 36 ꢄ was used. Jmol
software was employed to visualize the dimer geometry.[34] The initial ge-
ometry for optimization of the dimer was decided based on the mini-
mum-energy configuration obtained in a scan run at different angles be-
tween the two molecules (see Figure S18 in the Supporting Information).
Because the chiral-amplification experiment was per-
formed at a temperature (293 K) close to the Tm (ca. 308 K)
of CBI-GCH (c=2.5ꢂ10ꢀ5 m), the extent of chiral amplifica-
tion could be low. To investigate this outcome further, we
performed the sergeant-and-soldiers experiments at a higher
concentration (1ꢂ10ꢀ4 m) in MCH; and we indeed observed
that the amount of sergeant required for complete chiral
bias is around 30% (see Figure S15 in the Supporting Infor-
mation). This finding indicates that the extent of amplifica-
tion increases at higher concentration. These results concur
with a recent theoretical treatment of the effect of tempera-
ture on the principle of sergeant and soldiers,[28] which
shows that at higher temperatures the extent of the chiral
amplification or CD effect decreases.
Morphological details of the mixed stacks or coassembly
were studied by FESEM and AFM. The FESEM images
(40% sergeant) obtained on a glass substrate showed the
presence of 1D fibers (Figure 6d). AFM images obtained by
drop-casting a solution of 40% sergeant on a freshly cleaved
mica surface shows the presence of fibers with an average
height of the isolated fibers of 4 nm (Figure 6e,f; also see
Figure S16 in the Supporting Information). Thus, the coas-
sembly also forms fibers as well as the individual compo-
nents.
Synthesis of CBI-GCH: Freshly distilled quinoline (25 mL) was added to
1 (150 mg, 0.34 mmol), 2 (457 mg, 0.81 mmol), and zinc acetate (75 mg,
0.4 mmol) in a 100 mL three-necked round-bottom flask connected to a
reflux condenser. The reaction mixture was heated at 1708C with con-
stant stirring for 5 h under argon and then allowed to cool to room tem-
perature. An orange precipitate settled at the bottom of the flask. Metha-
nol (50 mL) was added to ensure complete precipitation of the product
followed by filtration under suction to obtain an orange crude product.
This product was purified by repeated column chromatography (CHCl3/
hexane 95:5) and size-exclusion chromatography (Biobeads, S-X3; CHCl3
as the solvent) to obtain a pure dark-orange solid (120 mg, 23%). Rf =
1
0.48 (CHCl3); H NMR (400 MHz, CDCl3): d=9.50 (br, 4H; Arcoro), 8.38
(br, 4H; Arcoro), 7.20 (s, 4H; HPh), 4.13–4.21 (m, 12H; -OCH2), 1.99, 1.85,
1.68, 1.54, 1.38, 1.20 (six multiplets, 60H), 1.06 (d, J=6.4 Hz, 6H;
-CHCH3), 0.97 (d, J=6.4 Hz, 12H; -CHCH3), 0.95 (d, J=6.8 Hz, 12H;
(CH3)2); 13C NMR
-CHACTHNUTGRENNGU(CH3)2), 0.87 ppm (d, J=6.4 Hz, 24H; -CHACHTUNGTRENNUGN
(100 MHz, CDCl3): d=168.4 (CC O), 153.8, 138.4, 128.1, 126.6, 123.6,
122.6, 120.7, 106.6, 71.9, 67.8, 39.7, 39.6, 37.9, 37.8, 36.6, 30.2, 30.0, 29.8,
29.5, 28.26, 28.20, 25.0, 24.9, 22.9, 22.88, 22.86, 19.8, 19.5 ppm; IR (KBr):
=
Conclusion
Two novel CBI (CBI-GCH and CBI-GACH) derivatives
have been synthesized, and their self-assembly behavior in
nonpolar solvents has been investigated in detail by using
various spectroscopic and microscopic tools. Both the deriv-
atives form 1D fibers, with a molecular width, that consist of
p-stacked columns of CBI chromophores in which the chro-
mophores are organized in H-type or face-to-face fashions.
Temperature-dependent chrioptical probing revealed that
CBI-GCH follows an isodesmic mechanism of self-assembly
with an association constant of 5.4ꢂ104 mꢀ1 in MCH. Both
derivatives form a 2D hexagonal columnar arrangement, as
evidenced from XRD studies. Coassemblies of chiral and
achiral CBI derivatives (sergeant-and-soldiers experiment)
exhibited chiral amplification, as seen by the saturation of
the anisotropy factor (i.e., g value) of approximately 30–
50% of the chiral sergeant. Thus, more work on different
types of system is necessary to establish a relation between
the mechanism of supramolecular polymerization and chiral
amplification.
ꢀ
n˜ =3108 (aromatic C H stretching), 2954, 2927, 2897, 2869, 2843 (aliphat-
ꢀ
ic C H stretching), 1764, 1708 (imide C=O stretching), 1597, 1506, 1468,
1438, 1416, 1382, 1339, 1300, 1240, 1119, 851, 795, 751, 702, 573 cmꢀ1
;
MALDI-TOF (DCTB): m/z calcd for C100H138N2O10: 1527.03515 [M]+;
found: 1527.04 and 1550.03 [M+Na]+; HRMS (APCI): m/z calcd for
1528.0424 [M+H]+; found: 1528.0467. APCI=atmospheric pressure
chemical ionization, DCTB=trans-2-[3-(4-tert-Butylphenyl)-2-methyl-2-
propenylidene]malononitrile.
Synthesis of CBI-GACH: Freshly distilled quinoline (20 mL) was added
to
1 (150 mg, 0.34 mmol), 3 (660 mg, 1.02 mmol), and zinc acetate
(63 mg, 0.34 mmol) in a 50 mL three-necked round-bottom flask connect-
ed to a reflux condenser. The reaction mixture was heated at 1908C with
constant stirring for 5 h under argon and then was allowed to cool to
room temperature. The reaction mixture was transferred to a 250 mL
beaker and 1m HCl (150 mL) was added to obtain the precipitate. The
precipitate was collected by filtration under suction and washed thor-
oughly with water followed by methanol. The obtained product was dis-
solved in a minimum amount of chloroform and reprecipitated with an
excess of methanol. The formed precipitate was collected by filtration.
The crude product was purified by a combination of column chromatog-
raphy (CHCl3/hexane 95:5) and size-exclusion chromatography (Bio-
beads, S-X3; CHCl3) to obtain a pure dark-orange solid (130 mg, 22%).
Rf =0.40 (CHCl3); 1H NMR (400 MHz, CDCl3): d=9.16 (br, 4H; Arcoro),
7.97 (br, 4H; Arcoro), 7.19 (s, 4H; HPh), 4.15 (t, J=6.2 Hz, 6H; -OCH2),
4.08 (m, 8H; -OCH2), 1.86–1.94 (m, 12H; -OCH2CH2), 1.20–1.70 (m,
108H; n-CH2 of alkyl chains), 0.93 (t, J=6.2 Hz, 6H; n-CH2CH3),
0.83 ppm (t, J=6.4 Hz, 12H; n-CH2CH3); 13C NMR (100 MHz, CDCl3):
Experimental Section
d=168.4 (CC O), 153.7, 138.3, 128.1, 126.5, 123.6, 122.6, 120.7, 106.7, 73.7,
69.4, 32.19, 32.13, 30.8, 30.1, 30.09, 30.00, 29.9, 29.8, 29.7, 29.67, 29.64,
General: All the solvents and reagents were used as purchased without
further purification unless mentioned. All the moisture-sensitive reac-
tions were carried out under an argon atmosphere. Quinoline was distil-
led under reduced pressure and stored in the dark to avoid degradation
(this compound becomes dark brown on exposure to light). Analytical
TLC was performed on plates of silica gel (60 F254 Merck) and column
chromatography was carried out using silica gel (100–200 mesh).
=
ꢀ
26.5, 26.4, 22.9, 22.8, 14.3, 14.2 ppm; IR (KBr): n˜ =3103 (aromatic C H
ꢀ
stretching), 2954, 2922, 2871, 2851 (aliphatic C H stretching), 1762, 1707
(imide C=O stretching), 1596, 1507, 1467, 1437, 1414, 1392, 1338, 1300,
1261, 1240, 1120, 1011, 852, 796, 767, 750, 721, 702, 624, 572, 542 cmꢀ1
;
MALDI-TOF (DCTB): m/z calcd for C112H162N2O10: 1695.2229 [M]+;
11276
www.chemeurj.org
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2013, 19, 11270 – 11278

Self-Assembly of Coronene Bisimides To Form 1D Fibers
FULL PAPER
found 1695.33; HRMS (APCI): m/z calcd for C112H162N2O10: 1696.2302
[M+H]+; found: 1696.2310.
129, 9819–9828; c) V. K. Praveen, S. J. George, R. Varghese, C. Vi-
jayakumar, A. Ajayaghosh, J. Am. Chem. Soc. 2006, 128, 7542–
7550; d) S. Yagai, S. Kubota, H. Saꢈto, K. Unoike, T. Karatsu, A. Ki-
tamura, A. Ajayaghosh, M. Kanesato, Y. Kikkawa, J. Am. Chem.
Soc. 2009, 131, 5408–5410; e) A. Ajayaghosh, V. K. Praveen, Acc.
Chem. Res. 2007, 40, 644; f) A. Ajayaghosh, S. J. George, J. Am.
Chem. Soc. 2001, 123, 5148–5149.
Acknowledgements
[7] a) F. Helmich, M. M. J. Smulders, C. C. Lee, A. P. H. J. Schenning,
E. W. Meijer, J. Am. Chem. Soc. 2011, 133, 12238–12246; b) F. Hel-
mich, C. C. Lee, M. M. L. Nieuwenhuizen, J. C. Gielen, P. C. M.
Christianen, A. Larsen, G. Fytas, P. E. L. G. Leclꢇre, A. P. H. J.
Schenning, E. W. Meijer, Angew. Chem. 2010, 122, 4031–4034;
Angew. Chem. Int. Ed. 2010, 49, 3939–3942; c) T. Ishizuka, M.
Sankar, Y. Yamada, S. Fukuzumi, T. Kojima, Chem. Commun. 2012,
48, 6481–6483; d) B. Nieto-Ortega, F. J. Ramꢉrez, D. Amabilino, M.
Linares, D. Beljonne, J. T. L. Navarrete, J. Casado, Chem. Commun.
2012, 48, 9147–9149; e) H. Engelkamp, S. Middelbeek, R. J. M.
Nolte, Science 1999, 284, 785–788; f) R. van Hameren, P. Schçn,
A. M. van Buul, J. Hoogboom, S. V. Lazarenko, J. W. Gerritsen, H.
Engelkamp, P. C. M. Christianen, H. A. Heus, J. C. Mann, T. Rasing,
S. Speller, A. E. Rowan, J. A. A. W. Elemans, R. J. M. Nolte, Science
2006, 314, 1433–1436; g) Y. Kataoka, Y. Shibata, H. Tamiaki,
Bioorg. Med. Chem. Lett. 2012, 22, 5218–5221; h) A. Jesorka, A. R.
Holzwarth, A. Eichhçfer, C. M. Reddy, Y. Kinoshita, H. Tamiaki,
M. Katterle, J.-V. Naubron, T. S. Balaban, Photochem. Photobiol.
Sci. 2012, 11, 1069–1080; i) Y. Hizume, K. Tashiro, R. Charvet, Y.
Yamamoto, A. Saeki, S. Seki, T. Aida, J. Am. Chem. Soc. 2010, 132,
6628–6629; j) R. Charvet, D.-L. Jiang, T. Aida, Chem. Commun.
2004, 2664–2665; k) J. Aimi, Y. Nagamine, A. Tsuda, A. Muranaka,
M. Uchiyama, T. Aida, Angew. Chem. 2008, 120, 5231–5234;
Angew. Chem. Int. Ed. 2008, 47, 5153–5156.
The authors thank Prof. C. N. R. Rao for his support and guidance. We
thank Prof. S. Balasubramanian for use of the computational facilities
and fruitful discussions on the manuscript. We thank Mr. Venkata Rao
for guidance during the synthetic work. We thank Peter Korevaar and
Ralf Bovee from Technical University Eindhoven for the MALDI-TOF
analysis and JNCASR for financial support. We also thank Agilent tech-
nologies, Dr. Basavaraj, Ms N. R. Selvi, Mr. Amrit, Mr. Swamynathan
and Ms Usha for the HRMS, AFM, FESEM, DLS, XRD and TEM
measurements, respectively.
[1] a) L. Zang, Y. Che, J. S. Moore, Acc. Chem. Res. 2008, 41, 1596–
1608; b) M. R. Wasielewski, Acc. Chem. Res. 2009, 42, 1910–1921;
c) F. S. Kim, G. Ren, S. A. Jenekhe, Chem. Mater. 2011, 23, 682–
732; d) F. J. M. Hoeben, P. Jonkheijm, E. W. Meijer, A. P. H. J.
Schenning, Chem. Rev. 2005, 105, 1491–1546; e) D. G. Rodrꢅguez,
A. P. H. J. Schenning, Chem. Mater. 2011, 23, 310–325; f) X. Y. Ling,
D. N. Reinhoudt, J. Huskens, Pure Appl. Chem. 2009, 81, 2225–
2233; g) B. Rybtchinski, ACS Nano 2011, 5, 6791–6818; h) F. Wꢁrth-
ner, K. Meerholz, Chem. Eur. J. 2010, 16, 9366–9373; i) A. W.
Bosman, R. P. Sijbesma, E. W. Meijer, Mater. Today 2004, 7, 34–39;
j) T. Aida, E. W. Meijer, S. I. Stupp, Science 2012, 335, 813–817;
k) S. S. Babu, S. Prasanthkumar, A. Ajayaghosh, Angew. Chem.
2012, 124, 1800–1810; Angew. Chem. Int. Ed. 2012, 51, 1766–1776;
l) B.-K. An, J. Gierschner, S. Y. Park, Acc. Chem. Res. 2012, 45,
544–554.
[2] a) X. Yan, F. Wang, B. Zheng, F. Huang, Chem. Soc. Rev. 2012, 41,
6042–6065; b) M. M. Safont-Sempere, G. Fernꢆndez, F. Wꢁrthner,
Chem. Rev. 2011, 111, 5784–5814.
[3] a) X. Kong, Z. He, Y. Zhang, L. Mu, C. Liang, B. Chen, X. Jing, A.
Cammidge, Org. Lett. 2011, 13, 764–767; b) G. Koshkakaryan, P.
Jiang, V. Altoe, D. Cao, L. M. Klivansky, Y. Zhang, S. Chung, A.
Katan, F. Martin, M. Salmeron, B. Ma, S. Aloni, Y. Liu, Chem.
Commun. 2010, 46, 8579–8581; c) J. Miao, L. Zhu, Chem. Mater.
2010, 22, 197–206.
[4] a) T. E. Kaiser, H. Wang, V. Stepanenko, F. Wꢁrthner, Angew.
Chem. 2007, 119, 5637–5640; Angew. Chem. Int. Ed. 2007, 46, 5541–
5544; b) S. Yagai, M. Usui, T. Seki, H. Murayama, Y. Kikkawa, S.
Uemura, T. Karatsu, A. Kitamura, A. Asano, S. Seki, J. Am. Chem.
Soc. 2012, 134, 7983–7994; c) F. Wꢁrthner, Chem. Commun. 2004,
1564–1579; d) V. Dehm, Z. Chen, U. Baumeister, P. Prins, L. D. A.
Siebbeles, F. Wꢁrthner, Org. Lett. 2007, 9, 1085–1088; e) T. Weil, T.
Vosch, J. Hofkens, K. Peneva, K. Mꢁllen, Angew. Chem. 2010, 122,
9252–9278; Angew. Chem. Int. Ed. 2010, 49, 9068–9093; f) C.
Huang, S. Barlow, S. R. Marder, J. Org. Chem. 2011, 76, 2386–2407.
[5] a) G. D. Pantos, P. Pengo, J. K. M. Sanders, Angew. Chem. 2007, 119,
198–201; Angew. Chem. Int. Ed. 2007, 46, 194–197; b) H. Shao, T.
Nguyen, N. C. Romano, D. A. Modarelli, J. R. Parquette, J. Am.
Chem. Soc. 2009, 131, 16374–16376; c) M. R. Molla, S. Ghosh,
Chem. Eur. J. 2012, 18, 9860–9869; d) M. Kumar, S. J. George,
Chem. Eur. J. 2011, 17, 11102–11106; e) N. Sakai, M. Lista, O. Kel,
S.-I. Sakurai, D. Emery, J. Mareda, E. Vauthey, S. Matile, J. Am.
Chem. Soc. 2011, 133, 15224–15227; f) F. Wꢁrthner, M. Stolte,
Chem. Commun. 2011, 47, 5109–5115; g) S. V. Bhosale, C. H. Jani,
S. J. Langford, Chem. Soc. Rev. 2008, 37, 331–342; h) S. V. Bhosale,
S. V. Bhosale, S. K. Bhargava, Org. Biomol. Chem. 2012, 10, 6455–
6468.
[8] a) C. L. Eversloh, C. Li, K. Mꢁllen, Org. Lett. 2011, 13, 4148–4150;
b) Q. Yan, K. Cai, C. Zhang, D. Zhao, Org. Lett. 2012, 14, 4654–
4657; c) S. Mꢁller, K. Mꢁllen, Chem. Commun. 2005, 4045–4046;
d) F. Nolde, W. Pisula, S. Mꢁller, C. Kohl, K. Mꢁllen, Chem. Mater.
2006, 18, 3715–3725; e) L. hao, W. Jiang, Z. Wang, Tetrahedron
2012, 68, 9234–9239; f) Y. Zhang, Z. Zhao, X. Huang, Y. Xie, C.
Liu, J. Li, X. Guan, K. Zhang, C. Cheng, Y. Xiao, RSC Adv. 2012, 2,
12644–12647.
[9] S. Alibert-Fouet, I. Seguy, J.-F. Bobo, P. Destruel, H. Bock, Chem.
Eur. J. 2007, 13, 1746–1753.
[10] a) U. Rohr, C. Kohl, K. Mꢁllen, A. van de Craats, J. Warman, J.
Mater. Chem. 2001, 11, 1789–1799; b) Z. An, J. Yu, B. Domercq,
S. C. Jones, S. Barlow, B. Kippelen, S. R. Marder, J. Mater. Chem.
2009, 19, 6688–6698; c) U. Rohr, P. Schlichting, A. Bçhm, M. Gross,
K. Meerholz, C. Brꢊuchle, K. Mꢁllen, Angew. Chem. 1998, 110,
1463–1467; Angew. Chem. Int. Ed. 1998, 37, 1434–1437.
[11] H. Usta, C. Newman, Z. Chen, A. Facchetti, Adv. Mater. 2012, 24,
3678–3684.
[12] a) K. V. Rao, S. J. George, Org. Lett. 2010, 12, 2656–2659; b) A.
Jain, K. V. Rao, C. Kulkarni, A. George, S. J. George, Chem.
Commun. 2012, 48, 1467–1469.
[13] T. F. A. de Greef, M. M. J. Smulders, M. Wolffs, A. P. H. J. Schen-
ning, R. P. Sijbesma, E. W. Meijer, Chem. Rev. 2009, 109, 5687–
5754.
[14] a) C. Kulkarni, S. Balasubramanian, S. J. George, ChemPhysChem
2013, 14, 661–673; b) C. Kulkarni, S. K. Reddy, S. J. George, S. Bala-
subramanian, Chem. Phys. Lett. 2011, 515, 226–230; c) I. A. W.
Filot, A. R. A. Palmans, P. A. J. Hilbers, R. A. van Santen, E. A.
Pidko, T. F. A. de Greef, J. Phys. Chem. B 2010, 114, 13667–13674;
d) R. Q. Albuquerque, A. Timme, R. Kress, J. Senker, H.-W.
Schmidt, Chem. Eur. J. 2013, 19, 1647–1657; e) M. J. Mayoral, C.
Rest, V. Stephanenko, J. Schellheimer, R. Q. Albuqerque, G.
Fernꢆndez, J. Am. Chem. Soc. 2013, 135, 2148–2151.
[15] a) A. R. A. Palmans, E. W. Meijer, Angew. Chem. 2007, 119, 9106–
9126; Angew. Chem. Int. Ed. 2007, 46, 8948–8968; b) E. Yashima,
K. Maeda, T. Nishimura, Chem. Eur. J. 2004, 10, 42–51; c) M. M.
Green, J.-W. Park, T. Sato, A. Teramoto, S. Lifson, R. L. B. Selinger,
[6] a) P. Jonkheijm, A. Miura, M. Zdanowska, F. J. M. Hoeben, S. de
Feyter, A. P. H. J. Schenning, F. C. de Schryver, E. W. Meijer,
Angew. Chem. 2004, 116, 76–80; Angew. Chem. Int. Ed. 2004, 43,
74–78; b) F. J. M. Hoeben, M. Wolffs, J. Zhang, S. de Feyter, P. Le-
clꢇre, A. P. H. J. Schenning, E. W. Meijer, J. Am. Chem. Soc. 2007,
Chem. Eur. J. 2013, 19, 11270 – 11278
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
11277

S. J. George et al.
J. V. Selinger, Angew. Chem. 1999, 111, 3328–3345; Angew. Chem.
Int. Ed. 1999, 38, 3138–3154.
[16] a) B. M. W. Langeveld-Voss, R. J. M. Waterval, R. A. J. Janssen,
E. W. Meijer, Macromolecules 1999, 32, 227–230; b) M. M. J. Smuld-
ers, A. P. H. J. Schenning, E. W. Meijer, J. Am. Chem. Soc. 2008, 130,
606–611.
[17] a) M. M. Green, B. A. Garetz, B. Munoz, H. Chang, J. Am. Chem.
Soc. 1995, 117, 4181–4182; b) J. van Gestel, A. R. A. Palmans, B.
Titulaer, J. A. J. M. Vekemans, E. W. Meijer, J. Am. Chem. Soc.
2005, 127, 5490–5494; c) M. M. J. Smulders, I. A. W. Filot, J. M. A.
Leenders, P. van der Schoot, A. R. A. Palmans, A. P. H. J. Schenning,
E. W. Meijer, J. Am. Chem. Soc. 2010, 132, 611–619; d) F. Garcꢉa,
P. M. Viruela, E. Matesanz, E. Ortꢉ, L. Sꢆnchez, Chem. Eur. J. 2011,
17, 7755–7759; e) F. Garcꢉa, L. Sꢆnchez, J. Am. Chem. Soc. 2012,
134, 734–742.
[18] a) L. Brunsveld, B. G. G. Lohmeijer, J. A. J. M. Vekemans, E. W.
Meijer, Chem. Commun. 2000, 2305–2306; b) A. R. A. Palmans,
J. A. J. M. Vekemans, E. E. Havinga, E. W. Meijer, Angew. Chem.
1997, 109, 2763–2765; Angew. Chem. Int. Ed. Engl. 1997, 36, 2648–
2651.
[19] a) F. Wꢁrthner, C. Thalacker, S. Diele, C. Tschierske, Chem. Eur. J.
2001, 7, 2245–2253; b) J. van Herrikhuyen, F. Wꢁrthner, Z. Chen, V.
Dehm, V. Stepanenko, Chem. Commun. 2006, 1180–1190; c) Z.
Chen, V. Stepanenko, V. Dehm, P. Prins, L. D. A. Siebbeles, J. Seibt,
P. Marquetand, V. Engel, F. Wꢁrthner, Chem. Eur. J. 2007, 13, 436–
449.
[20] K. Pieterse, Thesis: Electron deficient materials based on azahetero-
cycles, Eindhoven University of Technology, Eindhoven (The Neth-
erlands), 2001; Chapter 4 in the above mentioned thesis describes
the synthesis of 2 and 3.
[21] A. Syamakumari, A. P. H. J. Schenning, E. W. Meijer, J. Am. Chem.
Soc. 2004, 126, 10021–10027.
[22] a) F. Wꢁrthner, T. E. Kaiser, C. R. Saha-Mçller, Angew. Chem. 2011,
123, 3436–3473; Angew. Chem. Int. Ed. 2011, 50, 3376–3410; b) M.
Kasha, H. R. Rawls, M. A. El-Bayoumi, Pure Appl. Chem. 1965, 11,
371–392.
[25] M. M. J. Smulders, M. K. L. Nieuwenhuizen, T. F. A. de Greef, P. van
der Schoot, A. P. H. J. Schenning, E. W. Meijer, Chem. Eur. J. 2010,
16, 362–367.
[26] a) S. Laschat, A. Baro, N. Steinke, F. Giesselmann, C. Hꢊgele, G.
Scalia, R. Judele, E. Kapatsina, S. Sauer, A. Schreivogel, M. Tosoni,
Angew. Chem. 2007, 119, 4916–4973; Angew. Chem. Int. Ed. 2007,
46, 4832–4887; b) M. Yoshio, T. Kagata, K. Hoshino, T. Mukai, H.
Ohno, T. Kato, J. Am. Chem. Soc. 2006, 128, 5570–5577.
[27] Further evidence of coassembly comes from a subtle change in the
CD spectra; that is, the CD effect at l=332 nm is higher with an in-
creasing amount of sergeant than the pure sergeant; this change in
the CD spectra indicates that the packing in the aggregates is al-
tered, thus suggesting a coassembly between the sergeant and sol-
dier.
[28] A. J. Markvoort, H. M. M. ten Eikelder, P. A. J. Hilbers, T. A. F. de
Greef, E. W. Meijer, Nat. Commun. 2011, 2, 509.
[29] a) A. D. Becke, J. Chem. Phys. 1993, 98, 5648–5652; b) C. Lee, W.
Yang, R. G. Parr, Phys. Rev. B 1988, 37, 785–789; c) M. J. Frisch,
G. W. Trucks, H. B. Schlegel, G. E. Scuseria, M. A. Robb, J. R.
Cheeseman, G. Scalmani, V. Barone, B. Mennucci, G. A. Petersson,
H. Nakatsuji, M. Caricato, X. Li, H. P. Hratchian, A. F. Izmaylov, J.
Bloino, G. Zheng, J. L. Sonnenberg, M. Hada, M. Ehara, K. Toyota,
R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda, O.
Kitao, N.Nakai, T. Vreven, J. A. Montgomery, Jr. J. E. Peralta, F.
Ogliaro, M. Bearpark, J. J. Heyd, E. Brothers, K. N. Kudin, V. N.
Staroverov, T. Keith, R. Kobayashi, J. Normand, K. Raghavachari,
A. Rendell, J. C. Burant, S. S. Iyengar, J. Tomasi, M. Cossi, N. Rega,
J. M. Millam, M. Klene, J. E. Knox, J. B. Cross, V. Bakken, C.
Adamo, J. Jaramillo, R. Gomperts, R. E. Stratmann, O. Yazyev, A. J.
Austin, R. Cammi, C. Pomelli, J. W. Ochterski, R. L. Martin, K. Mo-
rokuma, V. G. Zakrzewski, G. A. Voth, P. Salvador, J. J. Dannen-
berg, S. Dapprich, A. D. Daniels, O. Farkas, J. B. Foresman, J. V.
Ortiz, J. Cioslowski, and D. J. Fox, Gaussian 09, Revision B.01,
Gaussian, Inc„ Wallingford CT, 2010.
[30] W. Humphrey, A. Dalke, K. Schulten, J. Mol. Graphics 1996, 14,
33–38.
[31] J. VandeVondele, M. Krack, F. Mohamed, M. Parrinello, T. Chassa-
ing, J. Hutter, J. Comput. Phys. Commun. 2005, 167, 103–128.
[32] S. Grimme, J. Comput. Chem. 2006, 27, 1787–1799.
[33] C. Hartwigsen, S. Goedecker, J. Hutter, Phys. Rev. B 1998, 58,
3641–3662.
[34] a) “Jmol: An open-source Java viewer for chemical structures in
3D” to be found under http://www.jmol.org; b) B. McMahon, R. M.
Hanson, J. Appl. Crystallogr. 2008, 41, 811–814.
[23] J. Seibt, P. Marquetand, V. Engel, Z. Chen, V. Dhem, F. Wꢁrthner,
Chem. Phys. 2006, 328, 354–362; as noted herein and referen-
ce [19c], perylene bisimides with 3,4,5-trialkylphenyl groups at the
imide positions form H-type aggregates, which are rotated with re-
spect to each other by 558 in the dimer; thus, because of the geomet-
rical similarity in the structure of the coronene and perylene bisi-
mides, we expect a very similar arrangement of molecules in the ag-
gregates.
Received: April 3, 2013
Published online: June 28, 2013
[24] No artifacts that arose from linear dichroism were observed.
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