A crown ether decorated dibenzocoronene tetracarboxdiimide chromophore: Synthesis, sensing, and self-organization

Article abstract of DOI:10.1002/asia.201403037

A macrocyclic dibenzocoronene tetracarboxdiimide containing two benzo-21-crown-7 groups has been synthesized. It shows liquid-crystalline behavior and selectively binds Pb²⁺ or K⁺ to form 1:2 complexes in solution. The complexation l

Full text of DOI:10.1002/asia.201403037

COMMUNICATION
DOI: 10.1002/asia.201403037
A Crown Ether Decorated Dibenzocoronene Tetracarboxdiimide
Chromophore: Synthesis, Sensing, and Self-Organization
Yingjie Ma,[a] Tomasz Marszalek,[a] Zhongyi Yuan,[a] Rene Stangenberg,[a]
Wojciech Pisula,[a] Long Chen,*[a, b] and Klaus Mꢀllen*[a]
Abstract: A macrocyclic dibenzocoronene tetracarboxdii-
mide containing two benzo-21-crown-7 groups has been syn-
thesized. It shows liquid-crystalline behavior and selectively
binds Pb2+ or K+ to form 1:2 complexes in solution. The
complexation leads to a significant increase of fluorescence;
the surface organization of discotic columnar structures, in
the solid-state, can be controlled by selective ion binding.
Various rotaxanes[15b] and supramolecular polymers[15c–f]
have been constructed using B21C7 as an adaptive host mol-
ecule. In view of its unique binding properties, the introduc-
tion of B21C7 into PDIs will endow PDIs with efficient
binding groups that can selectively encapsulate metal ions.
Herein, we report a bay-extended PDI, namely, dibenzocor-
onene tetracarboxdiimide 1 (dibenzo-CDI 1), which bears
two B21C7 groups at the periphery. The incorporation of
flexible B21C7 groups not only controls the thermotropic
behavior but also imparts a high affinity to metal ions. The
non-covalent interaction between crown ether motifs and
metal ions readily tunes the optical properties as well as the
self-organization behavior of 1.
The synthetic route toward dibenzo-CDI 1 is shown in
Scheme 1. The bromo-B21C7 (5) was prepared according to
the typical cyclization method.[15a] 5 was then treated with
bis(pinacolato)diboron to obain the corresponding boronic
ester (4). The boronic ester 4 was further treated with
1,7(6)-dibromoperylenetetracarboxdiimide 3 through Suzuki
coupling to afford PDI derivative 2 in 90% yield. Although
dibromoperylenetetracarboxdiimide 3 usually contains 1,7-
and 1,6-isomers, which are hard to separate,[11] the resulting
PDI derivative 2 (mixture of 1,7- and 1,6-isomers) generated
the same product 1 upon cyclodehydrogenation. The crown
ether-substituted PDI 2 was further cyclodehydrogenated
with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in
dry dichloromethane at 08C,[11] affording the target dibenzo-
CDI 1, which was highly soluble in common organic solvents
such as dichloromethane, chloroform, toluene, and THF, but
hardly soluble in acetonitrile, acetone, and methanol. UV-
Vis and fluorescence spectra of dibenzo-CDI 1 were record-
ed in CHCl3 (see Figure S7 in the Supporting Information,
ESI). Dibenzo-CDI 1 displayed sharp absorption bands at
364, 499 and 549 nm. Upon excitation at 365 nm, it emitted
a bright yellow fluorescence with a maximum at 571 nm.
Bearing a large rigid benzocoronene core, dibenzo-CDI
1 tends to form aggregates in solution upon addition of poor
solvents. Due to the aggregation-caused quenching effect,
the fluorescence of 1 is expected to be severely decreased.[12]
For example, the dilute solution (10 mm) of dibenzo-CDI
1 in chloroform is highly luminescent. Upon addition of
a poor solvent (e.g. acetonitrile) to the chloroform solution,
a significant decrease of fluorescence intensity was observed
(Figure 1). Additionally, absorbance changes were observed,
including peak broadening, a decrease in intensity, and an
Perylenediimides (PDIs) and their core-expanded analogs
have found widespread applications,[1–10] as these fluorescent
dyes are readily accessible, strongly absorbing, and highly
photostable. However, owing to p–p stacking, they have
a great tendency to aggregate in solution. Suppressing the
aggregation is essential, considering the highly desirable ap-
plications of these dyes as fluorescent probes. Instead of in-
troducing bulky groups (e.g. large dendrons) in the “bay re-
gion”[13a,b] or at the diimide terminus by tedious synthesis,
control over non-covalent interactions by specific external
stimuli can not only provide a facile way to prevent dyes
from aggregating, but also create stimuli-responsive materi-
als.
Dibenzocoronene tetracarboxdiimide[11] (dibenzo-CDI),
representing a bay-extended PDI, easily forms aggregates in
solution due to its large aromatic p-system. It is a promising
candidate to create stimulus-responsive fluorescent materi-
als, because its aggregates can be reversibly changed to dis-
sociated molecules accompanied with enhanced fluores-
cence.[12] On the other hand, benzo-21-crown-7 (B21C7) has
been intensively investigated in supramolecular chemistry.
[a] Dr. Y. Ma, Dr. T. Marszalek, Dr. Z. Yuan, Dr. R. Stangenberg,
Dr. W. Pisula, Dr. L. Chen, Prof. Dr. K. Mꢀllen
Max Planck Institute for Polymer Research
Ackermannweg 10, 55128 Mainz (Germany)
Fax : (+49)6131-379-350
E-mail: muellen@mpip-mainz.mpg.de
[b] Dr. L. Chen
Department of Chemistry
School of Science, Tianjin University and
Collaborative Innovation Center of Chemical Science and Engineer-
ing
300072 Tianjin (Peopleꢁs Republic of China)
E-mail: long.chen@tju.edu.cn
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/asia.201404037.
1
&
&
Chem. Asian J. 2014, 00, 0 – 0
ꢂ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
These are not the final page numbers! ÞÞ

www.chemasianj.org
Klaus Mꢀllen et al.
The two B21C7 groups of di-
benzo-CDI 1 serve as a cation-
receptor. We initially investigat-
ed the fluorescence changes
after binding heavy metal ions
(Mn2+, Co2+, Ni2+, Cd2+, Hg2+
,
and Pb2+) in organic solution
(CHCl3/CH3CN=1:1, v/v). Ad-
dition of two equivalents of
Mn2+
, , , , or
Co2+ Ni2+ Cd2+
Hg2+, exerted only little effect
on the emission of dibenzo-CDI
1 (see Figure S8 in the Support-
ing Information). However, a re-
markable change was observed
upon addition of Pb2+, the fluo-
rescence intensity was signifi-
cantly increased.
We then further investigated
the fluorescence response of di-
benzo-CDI 1 by varying the
concentrations of Pb2+ (0–
120 mm) to obtain quantitative
information on the binding stoi-
chiometry (see Figure S9 in the
Supporting Information). Upon
addition of Pb2+, the fluores-
cence of dibenzo-CDI 1 gradual-
ly increased and saturated when
reaching two equivalents of
Pb2+. This indicates the forma-
tion of a 1:2 complex between
Scheme 1. Synthesis of dibenzocoronene tetracarboxdiimide (dibenzo-CDI 1).
dibenzo-CDI 1 and Pb2+. A mole ratio plot for the complex-
ation further confirmed a 1:2 stoichiometry (see Figure S10
in the Supporting Information). To obtain detailed informa-
tion on the association constant between dibenzo-CDI 1 and
Pb2+, isothermal titration calorimetry (ITC) was performed
(see Figure S14 in the Supporting Information). Titration of
Pb2+ into the solvent (CHCl3/CH3CN=1:1, v/v) was slightly
endothermic, however, addition of Pb2+ to a dibenzo-CDI
1 solution resulted in a strongly exothermic isotherm. An as-
sociation constant (Ka) value of 6.59 (Æ0.13)ꢃ104 mÀ1 for
the dibenzo-CDI 1 2ACTHNUTRGNEUNG
[Pb2+] complex was obtained through
fitting of the binding isotherm to a 1:2 complexation model.
To shed more light on the complexation, the 1H NMR
spectra of dibenzo-CDI 1 were analyzed both in the absence
and presence of Pb2+ (Figure 2). After addition of Pb2+ to
dibenzo-CDI 1 in a (CDCl3/CD3CN=1:1, v/v) mixture, the
resonance of protons Ha–Hh shifted downfield due to com-
plexation. In addition, the signals of protons Hc–Hg on the
two crown ether rings broadened. Evidently, the crown
ether rings of dibenzo-CDI 1 bind Pb2+ in organic solution
to form a 1:2 complex. Upon complexation with Pb2+, the
steric hindrance between Pb2+ resulted in disaggregation of
dibenzo-CDI 1. The disaggregation led to a downfield shift
of proton signals of 1 and a fluorescence enhancement of
Figure 1. Fluorescence emission spectra of dibenzo-CDI 1 in chloroform
and MeCN, lex =365 nm, [dibenzo-CDI 1]=1.00ꢃ10À5 m. The inset shows
a photograph of dibenzo-CDI 1 in chloroform and MeCN under UV-
light irradiation.
overall hypsochromic shift (Figure S8, Supporting Informa-
tion). These changes indicated the overlapping of benzocor-
onene chromophores to form J-type aggregates.
&
&
2
Chem. Asian J. 2014, 00, 0 – 0
ꢂ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ÝÝ These are not the final page numbers!

www.chemasianj.org
Klaus Mꢀllen et al.
host of 18-crown-6, which has a higher affinity for K+ com-
pared with that of B21C7.[11c] When two equivalents of 18-
crown-6 were added to a solution of 1 (100 mm) and K+
(200 mm) in CHCl3/CH3CN (1:1), the original emission of di-
benzo-CDI 1 was fully recovered (Figure 3, the blue and
black curves fully overlapped), thus indicating the dissocia-
tion of the dibenzo-CDI 1 2 [K+] complex.
Apart from the aggregation/disaggregation studies in solu-
tion, the thermotropic behavior and solid-state self-organiza-
tion of dibenzo-CDI 1 were investigated as well. In the first
step, the thermotropic behavior of dibenzo-CDI 1 was stud-
ied by differential scanning calorimetry (DSC) and polarized
optical microscopy (POM) (see Figure S19 in the Supporting
Information and Figure 4a,b). The DSC curves of dibenzo-
CDI 1 showed two endothermic peaks upon heating, thus in-
dicating a mesophase above 748C and an isotropic melt
from 2498C. The formation of the liquid crystalline phase
was monitored by POM on an open film of dibenzo-CDI 1,
which was prepared by drop-casting from a 3 mgmLÀ1
chloroform solution. Slow cooling resulted in a dendritic
texture, which is characteristic for a discotic columnar
phase.[16] Apart from defect structures, the dendritic micro-
structure remains dark being in agreement with a homeo-
tropic alignment of the columnar stacks towards the surface
(Figure 4a,b). Addition of K+ or Pb2+ did not cause phase
transitions. Interestingly, after complexation with K+ or
Pb2+, these two complexes did not even melt within the in-
vestigated temperature range from 308C to 3408C. This phe-
nomenon is attributed to the immobilization of the crown
ether subsitutents during metal ion binding.
Figure 2. 1H NMR spectra (CDCl3/CD3CN 1:1, 293 K, 250 MHz) of
(a) 4.00 mm dibenzo-CDI 1+8.00 mm Pb2+; (b) 4.00 mm dibenzo-CDI 1.
about 37%. Therefore, dibenzo-CDI 1 can work as a “turn-
on” probe for Pb2+
.
As expected, dibenzo-CDI 1 also binds K+ owing to the
high affinity of B21C7 for K+.[15a] The 1:2 stoichiometry was
confirmed by the mole ratio plot, based on fluorescence
data (see Figures S11–S12 in the Supporting Information).
The Ka of the complex dibenzo-
CDI 1 2[K+] was determined by
ITC to be 2.28 (Æ0.36)ꢃ104 mÀ1
(see Figure S15 in the Support-
ing Information). Binding K+
also enhances the fluorescence
of dibenzo-CDI 1 and makes
the resonances of correspond-
ing protons on dibenzo-CDI
1
shift downfield (see Fig-
ure S17 in the Supporting Infor-
mation). When two equivalents
of K+ were added to dibenzo-
CDI 1 in CHCl3/CH3CN (1:1,
v:v), the fluorescence intensity
of 1 increased by 31%, which
was smaller than that of adding
Pb2+ under identical conditions
(see Figure S16 in the Support-
ing Information). This result is
consistent with the smaller
binding constant of K+ com-
pared with that of Pb2+. Fur-
thermore, K+ can be excluded
from the crown ether binding
Figure 3. The inter-conversion of aggregation and disaggregation by external stimuli: fluorescence (100 mm in
CHCl3/CH3CN (1:1 v:v)) of (a) dibenzo-CDI 1 (100 mm); (b) dibenzo-CDI 1 (100 mm)+K+ (200 mm); (c) diben-
site of 1 by adding a competitive zo-CDI 1 (100 mm)+K+ (200 mm)+18-crown-6 (200 mm).
3
&
&
Chem. Asian J. 2014, 00, 0 – 0
ꢂ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
These are not the final page numbers! ÞÞ

www.chemasianj.org
Klaus Mꢀllen et al.
Figure 5. GIWAXS of dibenzo-CDI 1 film with a) K+ and b) Pb2+ after
solution depostion (white arrow indicates the p-stacking peak).
1+Pb2+ organized face-on with a slightly decreased p-stack-
ing distance of 3.7 ꢄ, due to the smaller size of the lead ion
(Figure 6). The enlarged packing space is related to the
steric hindrance of the K+ ions. Moreover, the structural
Figure 4. POM of dibenzo-CDI 1 film prepared by drop casting after
cooling from the isotropic phase: a) with cross-polarizers (white arrows)
and b) almost parallel polarizers (scale bar corresponds to 50 mm).
GIWAXS of the dibenzo-CDI 1 film recorded at 308C: c) before and
d) after annealing in the isotropic melt (insets illustrate the correspond-
ing surface arrangement of 1. The intercolumnar lattice is negleted).
Next, grazing-incidence wide-angle X-ray scattering
(GIWAXS) was used to understand the impact of metal ions
on molecular organization on the surface. After solution
deposition, dibenzo-CDI 1 organized in an edge-on fashion,
whereby the columns were lying parallel to the surface. The
p-stacking reflection was therefore located on the equatorial
plane[17] of the GIWAXS pattern at qx,y =1.80 ꢄÀ1 corre-
sponding to a real spacing of 3.5 ꢄ (Figure 4c). In the
stacks, the molecular discs were packed in an orthogonal
manner, which is typical for a liquid crystalline columnar or-
ganization. Annealing of the isotropic melt resulted in
a drastic reorganization of a face-on alignment as a conse-
quence of the position change of the p-stacking reflection to
the meridional plane of the pattern,[18] whereby the intraco-
lumnar distance remained unchanged (Figure 4d). This ho-
meotropic orientation, as determined by GIWAXS, is in
agreement with the non-birefringent dendritic textures in
the POM images of dibenzo-CDI 1 (Figure 4a,b). Addition-
ally, the scattering intensities in the small-angle region imply
a modification of the intercolumnar organization after an-
nealing (see Figure S18a,b in the Supporting Information)
from a rectangular unit cell with a=27.2 ꢄ and b=35.3 ꢄ
to an oblique one with a=30.5 ꢄ, b=25.8 ꢄ and a=658.
After direct solution deposition, dibenzo-CDI 1+K+ re-
vealed slight differences in ordering as compared to the
compound without metal ions (Figure 5a). The position of
the p-stacking reflection on the equatorial plane proves an
edge-on arrangement of the molecules, while the intermo-
lecular distance within the stacks increased to 3.8 ꢄ. The
columnar organization changed as compared to the unmodi-
fied dibenzo-CDI 1 (see Figure S18c in the Supporting In-
formation). In contrast to the addition of K+, dibenzo-CDI
Figure 6. Illustration of the molecular packing of dibenzo-CDI 1 a) with-
out and b) with metal ions.
data offer the possibility of controlling the surface organiza-
tion of dibenzo-CDI 1 by annealing the isotropic phase or
by applying metal ions of a defined size. Larger ions hinder
the molecular interactions and lead to an edge-on arrange-
ment in solution-processed films, while stronger aggregation
provokes a face-on organization. A similar explanation can
be applied to the change in the surface arrangement for
parent dibenzo-CDI 1. The molecular interactions are
weaker in solution than in the isotropic melt because of the
shorter molecular distances in the latter case.
In summary, we have presented the synthesis of the mac-
rocyclic dibenzo-CDI 1 with two B21C7 moieties as a novel
derivative of bay-extended PDIs. The introduction of B21C7
groups and alkyl swallow-tail substituents facilitates thermo-
tropic liquid crystalline behavior. We demonstrated a facile
host-guest supramolecular interaction to prevent the diben-
zo-CDI 1 dye from aggregation in solution by forming
a strong 1:2 complex with Pb2+ or K+. Such a disaggregation
process results in significant enhancement (37% for Pb2+
and 31% for K+) of the fluorescence intensity. Thus diben-
zo-CDI 1 can be used as a “turn-on” probe for Pb2+ or K+.
Furthermore, the size of the metal ions had a strong impact
on the molecular packing and their surface organization, al-
lowing a control between face-on and edge-on arrangement.
This work will stimulate further research on covalently “dec-
orating” flexible molecular recognition motifs onto rigid
disc-shape molecules to build up new functional supramolec-
ular p-conjugated systems.
&
&
4
Chem. Asian J. 2014, 00, 0 – 0
ꢂ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ÝÝ These are not the final page numbers!

www.chemasianj.org
Klaus Mꢀllen et al.
Org. Lett. 2014, 16, 3180–3183; c) P. G. A. Janssen, P. Jonkheijm, P.
Thordarson, J. C. Gielen, P. C. M. Christianen, J. L. J. Van Dongen,
E. W. Meijer, A. P. H. J. Schenning, J. Mater. Chem. 2007, 17, 2654–
2660.
Experimental Section
Synthetic procedures, material characterizations, and full details about
the instrumentation can be found in the Supporting Information.
[13] a) S. Rehm, V. Stepanenko, X. Zhang, T. H. Rehm, F. Wꢀrthner,
Chem. Eur. J. 2010, 16, 3372–3382; b) C. Kohl, T. Weil, J. Qu, K.
Mꢀllen, Chem. Eur. J. 2004, 10, 5297–5310; c) B. Gao, H. Li, H. Liu,
L. Zhang, Q. Bai, X. Ba, Chem. Commun. 2011, 47, 3894–3896.
[14] F. Biedermann, E. Elmalem, I. Ghosh, W. M. Nau, O. A. Scherman,
Angew. Chem. Int. Ed. 2012, 51, 7739–7743; Angew. Chem. 2012,
124, 7859–7863.
Acknowledgements
This work was supported by the Volkswagen foundation (AZ. 85101–
85103).
[15] a) C. Zhang, S. Li, J. Zhang, K. Zhu, N. Li, F. Huang, Org. Lett.
2007, 9, 5553–5556; b) C.-C. Hsu, N.-C. Chen, C.-C. Lai, Y.-H. Liu,
S.-M. Peng, S. Chiu, Angew. Chem. Int. Ed. 2008, 47, 7475–7478;
Angew. Chem. 2008, 120, 7585–7588; c) X. Yan, D. Xu, X. Chi, J.
Chen, S. Dong, X. Ding, Y. Yu, F. Huang, Adv. Mater. 2012, 24,
362–369; d) X. Yan, M. Zhou, J. Chen, X. Chi, S. Dong, M. Zhang,
X. Ding, Y. Yu, S. Shao, F. Huang, Chem. Commun. 2011, 47, 7086–
7088; e) J. Chen, X. Yan, X. Chi, X. Wu, M. Zhang, C. Han, B. Hu,
Y. Yu, F. Huang, Polym. Chem. 2012, 3, 3175–3179; f) S. Dong, B.
Zheng, F. Wang, F. Huang, Acc. Chem. Res. 2014, 47, 1982–1994;
g) X. Yan, B. Jiang, T. R. Cook, Y. Zhang, J. Li, Y. Yu, F. Huang,
H.-B. Yang, P. J. Stang, J. Am. Chem. Soc. 2013, 135, 16813–16816;
h) B. Zheng, M. Zhang, S. Dong, J. Liu, F. Huang, Org. Lett., 2012,
14, 306–309.
[16] a) E. Pouzet, V. De Cupere, C. Heintz, J. W. Andreasen, D. W.
Breiby, M. M. Nielsen, P. Viville, R. Lazzaroni, G. Gbabode, Y. H.
Geerts, J. Phys. Chem. C 2009, 113, 14398–14406; b) W. Pisula, M.
Kastler, B. El Hamaoui, M.-C. Garcꢆa-Gutiꢇrrez, R. J. Davies, C.
Riekel, K. Mꢀllen, ChemPhysChem 2007, 8, 1025–1028; c) E.
Grelet, H. Bock, Europhys. Lett. 2006, 73, 712–718; d) G. Schweich-
er, G. Gbabode, F. Quist, O. Debever, N. Dumont, S. Sergeyev,
Y. H. Geerts, Chem. Mater. 2009, 21, 5867–5874; e) O. Thiebaut, H.
Bock, E. Grelet, J. Am. Chem. Soc. 2010, 132, 6886–6887; f) K. Ban,
K. Nishizawa, K. Ohta, A. M. van de Craats, J. M. Warman, I. Yama-
motoa, H. Shirai, J. Mater. Chem. 2001, 11, 321–331.
Keywords: crown ether · dyes · sensors · supramolecular
chemistry · surface organization
[1] R. Schmidt, M. M. Ling, J. H. Oh, M. Winkler, M. Kçnemann, Z.
Bao, F. Wꢀrthner, Adv. Mater. 2007, 19, 3692–3695.
[2] M. K. R. Fischer, T. E. Kaiser, F. Wꢀrthner, P. Bꢅuerle, J. Mater.
Chem. 2009, 19, 1129–1141.
[3] A. C. Grimsdale, K. Mꢀllen, Angew. Chem. Int. Ed. 2005, 44, 5592–
5629; Angew. Chem. 2005, 117, 5732–5772.
[4] a) G. Horowitz, Adv. Mater. 1998, 10, 365–377; b) E. Katz, Z. Bao,
S. L. Gilat, Acc. Chem. Res. 2001, 34, 359–369; c) Z. Chen, M. G.
Debije, T. Debaerdemaeker, P. Osswald, F. Wꢀrthner, ChemPhys-
Chem 2004, 5, 137–140.
[5] L. Schmidt-Mende, A. Fechtenkçtter, K. Mꢀllen, E. Moons, R. H.
Friend, J. D. MacKenzie, Science 2001, 293, 1119–1122.
[6] a) M. P. O’Neil, M. P. Niemczyk, W. A. Svec, D. Gosztda, G. L.
Gaines, M. R. Wasielewski, Science 1992, 257, 63–65; b) M. J.
Tauber, R. F. Kelley, J. M. Giaimo, B. Rybtchinski, M. R. Wasielew-
ski, J. Am. Chem. Soc. 2006, 128, 1782–1783.
[7] M. A. Angadi, D. Cosztola, M. R. Wasielewski, Mater. Sci. Eng. B
1999, 63, 191–194.
[17] a) E. Grelet, S. Dardel, H. Bock, M. Goldmann, E. Lacaze, F.
Nallet, Eur. Phys. J. E: Soft Matter Biol. Phys. 2010, 31, 343–349;
b) H. H. Dam, K. Sun, E. Hanssen, J. M. White, T. Marszalek, W.
Pisula, J. Czolk, J. Ludwig, A. Colsmann, M. Pfaff, D. Gerthsen,
W. W. H. Wong, D. J. Jones, ACS Appl. Mater. Interfaces 2014, 6,
8824–8835.
[8] N. G. Pschirer, C. Kohl, F. Nolde, J. Qu, K. Mꢀllen, Angew. Chem.
Int. Ed. 2006, 45, 1401–1404; Angew. Chem. 2006, 118, 1429–1432.
[9] A. Wicklein, A. Lang, M. Muth, M. Thelakkat, J. Am. Chem. Soc.
2009, 131, 14442–14453.
[10] a) S. Mꢀller, K. Mꢀllen, Chem. Commun. 2005, 4045–4046; b) W.
Jiang, Y. Li, W. Yue, Y. Zhen, J. Qu, Z. Wang, Org. Lett. 2010, 12,
228–231; c) C. L. Eversloh, C. Li, K. Mꢀllen, Org. Lett. 2011, 13,
4148–4150.
[18] J. Eccher, G. C. Faria, H. Bock, H. von Seggern, I. H. Bechtold, ACS
Appl. Mater. Interfaces 2013, 5, 11935–11943.
[11] T. Yang, J. Pu, J. Zhang, W. Wang, J. Org. Chem. 2013, 78, 4857–
4866.
[12] a) D. Zhai, W. Xu, L. Zhang, Y. T. Chang, Chem. Soc. Rev. 2014, 43,
2402–2411; b) Y.-J. Tian, E.-T. Shi, Y.-K. Tian, R.-S. Yao, F. Wang,
Received: September 4, 2014
Published online: && &&, 0000
5
&
&
Chem. Asian J. 2014, 00, 0 – 0
ꢂ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
These are not the final page numbers! ÞÞ

COMMUNICATION
Supramolecular Sensors
Yingjie Ma, Tomasz Marszalek,
Zhongyi Yuan, Rene Stangenberg,
Wojciech Pisula, Long Chen,*
Klaus Mꢀllen*
&&&& — &&&&
A Crown Ether Decorated Dibenzo-
coronene Tetracarboxdiimide Chromo-
phore: Synthesis, Sensing, and Self-
Organization
Sensing Sensibility: A macrocyclic
dibenzocoronene tetracarboxdiimide
containing two benzo-21-crown-7
groups has been synthesized. It shows
liquid-crystalline behavior and selec-
tively binds Pb2+ or K+ to form 1:2
complexes in solution. The complexa-
tion leads to a significant increase in
fluorescence. The surface organization
of discotic columnar structures, in the
solid-state, can be controlled by selec-
tive ion binding.
&
&
6
Chem. Asian J. 2014, 00, 0 – 0
ꢂ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ÝÝ These are not the final page numbers!