A series of polyaromatic hydrocarbons conjugated viologens: Synthesis, supramolecular structures in solid state, and electrochemical and photophysical properties

Article abstract of DOI:10.1016/j.tet.2014.12.054

Viologens have extensive applications in supramolecular chemistry and materials science. An efficient approach to tune the electrochemical and photophysical properties as well as supramolecular interactions of a viologen unit is to extend its conjugation

Full text of DOI:10.1016/j.tet.2014.12.054

Tetrahedron xxx (2015) 1e8
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A series of polyaromatic hydrocarbons conjugated viologens:
synthesis, supramolecular structures in solid state, and
electrochemical and photophysical properties
*
Feng Lin, Xin Zhao
Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules, Shanghai Institute of Organic Chemistry, Chinese Academy
of Sciences, 345 Lingling Lu, Shanghai 200032, China
a r t i c l e i n f o
a b s t r a c t
Article history:
Viologens have extensive applications in supramolecular chemistry and materials science. An efficient
approach to tune the electrochemical and photophysical properties as well as supramolecular in-
teractions of a viologen unit is to extend its conjugation extent. In this article, a series of conjugated
viologens have been designed and synthesized by incorporating polyaromatic hydrocarbons into 4,40-
bipyridyl unit. X-ray crystallographic analyses revealed that they assembled into various supramolecular
structures in solid state. Cyclic voltammetry, and UVevis and fluorescence spectroscopy studies indicated
that they displayed distinctive electrochemical and photophysical properties, which were different from
non-conjugated viologens. Furthermore, a correlation between reduction potentials and the dihedral
angles between bipyridyl unit and polyaromatic moieties was also revealed.
Received 3 November 2014
Received in revised form 9 December 2014
Accepted 15 December 2014
Available online xxx
Keywords:
Viologen
Conjugated
Supramolecular structure
Electrochemical and photophysical
properties
Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction
Moreover, extended conjugation of viologen unit could delocalize
its positive charger from bipyridyl unit into the conjugated sub-
Viologens, 1,10-disubstituted 4,40-bipyridylium salts, have been
widely utilized in supramolecular chemistry and materials science
over the last few decades because of their electron-deficient feature
and excellent electrochemical properties. Currently a myriad of
viologen-based systems including host-guest complexes,1 inter-
locked supermolecules,2 sensors,3 molecular machines,4 supra-
molecular polymers,5 solar cell prototype,6 and organic
electrochromic materials,7 have been well established. In addition,
novel structures consisting of multiple viologen units such as
viologen oligomers,8 dendrimers,9 and even polymers10 have also
been reported recently. However, as far as electrochemical and
optical properties are concerned, these compounds still exhibit
similar feature as the simplest viologen, namely paraquat or 1,10-
dimethyl-4,40-bipyridinium (DMBP) because the viologen units in
these molecules are isolated by unconjugated substituents, usually
alkyl or oligoglycol chains. In this context, tuning the electro-
chemical and optical properties of viologen is highly desired, es-
pecially for electronic materials. Incorporation of conjugated
segments into viologen unit should be an efficient approach to
change the electrochemical and optical properties of viologens.
stituents and therefore might result in distinctive supramolecular
interactions. However, examples for viologens with extended
conjugation are very few.11 The obtention of this type of viologens
and detailed investigation on their properties should be beneficial
not only to supramolecular chemistry but also to materials science.
In this article, we report a series of extendedly conjugated viol-
ogens, which were constructed by incorporating polyaromatic
moieties to 10- nitrogen of 1-methyl-4,40-bipyridin-1-ium (Scheme
1). The crystal structures of most of them and their precursors have
been resolved, which revealed that they adopted different supra-
molecular structures in the solid state. Furthermore, they were
found to exhibit different electrochemical and optical properties
from unconjugated viologens. A structure-reduction potential re-
lationship was also revealed.
2. Results and discussion
As an effective approach to synthesize 1,10-diarylsubstituted-
4,40-bipyridylium compounds, Zincke reaction was used to prepare
the target viologens.12 The synthesis of T1 and T2 was provided in
Scheme 2 as a representative. Refluxing Zincke salt 1 with 2-
aminonaphthalene generated compound T1, which was further
methylated by iodomethane to give compound T2 in almost
* Corresponding author. E-mail address: xzhao@mail.sioc.ac.cn (X. Zhao).
http://dx.doi.org/10.1016/j.tet.2014.12.054
0040-4020/Ó 2014 Elsevier Ltd. All rights reserved.
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BPI and the plane of naphthalene moiety is 0.35 nm, which is
a typical distance for aromatic stacking. Dictating by such stacking,
a one-dimensional (1D) extended packing of T1 along crystallo-
graphic a-axis generated (Fig. 1a). Interestingly, the methylated
product of T1, that is, compound T2, adopted different packing style
in solid state (Fig. 1b). T2 did not adopt the head-to-tail stacking
manner of T1. Instead, a zig-zag arrangement was observed. In this
way, only one pyridylium ring of the 4,40-bipyridin-1,10-diium
(BPD) unit was found to stack with naphthalene moiety with
a mean distance of 0.34 nm. Different from that of T1, the two
pyridylium rings of T2 were not coplanar anymore. They had
a torsion angle of 30.3ꢀ, which could be attributed to the electro-
static repulsion between them. Furthermore, the dihedral angle
between the plane of naphthalene moiety and its neighboring
pyridylium ring decreased to 43.0ꢀ (Fig. S2 in Supplementary data).
The difference between T3 and T1 is that in the former the
naphthalene moiety is 1-substituted whereas in the latter it is 2-
substituted. In the solid state of T3 (Fig. 2aeb), while the two
pyridine rings still kept almost coplanar as that of T1 (torsion angle
9.4ꢀ), its naphthalene moiety was perpendicular to the plane of BPI
(the dihedral angle being 89.4ꢀ, see Fig. S3 in Supplementary data),
which was almost twice of that in T1. It is reasonable because under
such conformation the steric hindrance between the a-H of pyr-
idylium and H2 and H8 of naphthalene moiety can be minimized.
This conformation made T3 to adopt a totally different packing style
from T1. In this system, no stacking between BPI unit and naph-
thalene moiety was observed. In contrast, the BPI units stacked
each other in an offset face-to-face and head-to-tail manner (with
an average distance of 0.37 nm). The naphthalene moieties also
adopted an offset face-to-face stacking each other. Both the stack-
ings led to a linearly extended packing (Fig. 2a). As for T4, an almost
perpendicular arrangement of naphthalene moiety and BPD unit
(dihedral angle being 83.6ꢀ) also existed (Fig. S4 in Supplementary
data). Unexpectedly, in the assembling structure of T4 in solid, al-
though electrostatic repulsion might arise, weak aromatic stacking
with a distance of 0.39 nm was observed between the methylated
pyridylium units. Different from that of T2, only intermolecular
Scheme 1. Chemical structures of the conjugated viologens and their precursors
studied in this work.
quantitative yield. It should be noted that ion-exchange occurred
during the process of methylation, which led to full iodide salt of T2,
not mixed salt with one iodide and one chloride, as revealed by
crystallographic analyses (vide infra) and elemental analyses.
Compounds T3eT10 were prepared following the same procedure
but using corresponding amines, respectively.
CeH/p interaction was observed between a-H of its pyridylium
ring and the naphthalene moiety, and no aromatic stacking existed
between them (Fig. 2).
Scheme 2. Synthesis of compounds T1 and T2.
The single crystals of T1eT5, T7, T8, and T10 suitable for X-ray
crystallographic analysis were grown by slow evaporation of their
solutions in ethanol (for T7) or methanol (for the others) at room
temperature.13 Comparison of their crystal structures revealed that
they adopted different supramolecular structures in solid state,
which are illustrated as follows and the crystallographic data are
provided in Supplementary data.
As revealed by the crystal structure of T1, its two pyridine rings
are almost coplanar (torsion angle 2.0ꢀ) and the dihedral angle
between the pyridine ring and naphthalene moiety is 44.3ꢀ (Fig. S1
in Supplementary data). T1 adopted a head-to-tail packing in solid
state, in which the electron-deficient 4,40-bipyridin-1-ium (BPI)
units stacked with the relative electron-rich naphthalene moiety in
an offset face-to-face manner. The distance between the plane of
Compound T5 adopted quite similar conformation and packing
style as that of T1 (Fig. 3 and Fig. S5 in Supplementary data). Head-
to-tail stacking between BPI unit and anthracene moiety in an
offset manner was observed. Its two pyridine rings were almost
coplanar (torsion angle 3.1ꢀ) and the dihedral angle between it and
naphthalene moiety was 40.2ꢀ. Attempt to grow single crystals of
T6 suitable for crystallographic analysis was unsuccessful. It was
anticipated that its solid structure should be similar to that of T2
due to their similar chemical structures.
Similar to that of T3, in the crystals of compound T7 the steric
hindrance between the
a
-H of pyridine ring and H2 and H10 of
anthracene moiety resulted in a dihedral angle of 70.1ꢀ between the
plane of BPI and anthracene moiety (Fig. S6 in Supplementary
data). The head-to-tail stacking between BPI units and the face-
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F. Lin, X. Zhao / Tetrahedron xxx (2015) 1e8
3
Fig. 1. Packing patterns of (a) T1 and (b) T2 in solid state. Counterions and solvent molecules were omitted for clarity. It was found that anions were not involved in the stacking of
organic skeletons.
Fig. 2. Packing patterns of (a) T3 and (b) T4 in solid state. Counterions and solvent molecules were omitted for clarity. It was found that anions were not involved in the stacking of
organic skeletons.
by crystal packing force (Fig. 4, top). As for compound T8, the as-
sembly of the molecules were driven by both the stackings between
BPD units and anthracene moieties (d¼0.35 nm) as well as an-
thracene moieties themselves (d¼0.36 nm) (Fig. 4 bottom). Similar
to T4, in T8 anthracene moiety and BPD unit were almost perpen-
dicular. It adopted two conformations in solid state: one with a di-
hedral angle of 82.6ꢀ and the other having a dihedral angle of 87.7ꢀ
(Fig. S7 in Supplementary data).
While growing single crystals of T9 did not success in our hands,
we successfully obtained single crystals of T10 and resolved its
crystal structure. The two pyridine rings twisted each other with
a torsion angle of 23.6ꢀ. Meanwhile, the dihedral angle between
pyrene moiety and the neighboring pyridine ring was measured to
be 65.3ꢀ (Fig. S8 in Supplementary data). The incorporation of
Fig. 3. Packing pattern of T5 in solid state. Counterions and solvent molecules were
pyrene resulted in different packing style for this viologen salt from
omitted for clarity. It was found that anions were not involved in the stacking of or-
the above ones. No aromatic stacking was observed in the crystal
ganic skeletons.
structure. Instead, the aggregating of T10 molecules in solid state
was driven by weak intermolecular CeH/p interactions, which
existed between -H of the pyridylium ring and the pyrene moiety
a
to-face stacking between anthracene moieties led to the formation
of linearly extended structure. Interestingly, a pair of mirror-
symmetry structure was observed for T7 in solid state (Fig. 4,
top). This mirror-symmetry phenomenon was maintained even in
the 1D extension of the packed molecules, which should be driven
3
ꢀ
(with a distance of 2.76 A) and between H of pyrene and the
pyrene moiety of its neighboring molecule (with a distance of
ꢀ
2.78 A). Driven by such interactions, brush-like packing structure
generated (Fig. 5).
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F. Lin, X. Zhao / Tetrahedron xxx (2015) 1e8
In addition to the 1D extension of the viologens driven by aro-
matic stacking or CHꢁ interaction, closer crystallographic analy-
p
ses also revealed the existence of higher-ordered supramolecular
architectures driven by CeH/anion or CeH/N hydrogen bonding.
For example, the formation of two dimensional (2D) network
driven by the CeH/Iꢁ hydrogen bonds between iodide ions and
hydrogen atoms of pyridylium ring and naphthalene units was
observed for T2 in solid state (Fig. 6, top). 2D network could also be
constructed in solid state through the formation of CeH/N hy-
drogen bonds. As demonstrated by Fig. 6, the formation of three-
centered CeH/N hydrogen bonds between pyridine nitrogen
atoms and b-Hs of BPI unit resulted in well-ordered 2D assembly.
The electrochemical properties of these viologen derivatives
with extended conjugation were investigated by cyclic voltamme-
try (CV) in CH3CN at ambient temperature and Bu4NPF6 (0.1 M) was
used as supporting electrolyte. As can be seen in Fig. 7, they exhibit
two reversible reduction waves, which are corresponding to the
first and second reducing processes of the divalent cations. Com-
pared to DMBP, the introduction of polyaromatic moieties into
viologen increase its reduction potentials considerably. Their first
reduction potentials were shifted from ꢁ0.47 V of DMBP to around
ꢁ0.36 V for the conjugated viologens while their second reduction
waves appeared in the range of ꢁ0.76 to ꢁ0.70 V, which is
0.13e0.19 V more positive than that of DMBP (ꢁ0.89 V) (Table 1).
Such large positive shifts of reduction potentials should be attrib-
uted to the extended conjugation between BPD unit and the pol-
yaromatic moieties. The positive shifts of the reduction potentials
suggest that these viologens are easier to be reduced and should be
better electron acceptors than their unconjugated counterparts.
Moreover, this result also suggests that they can work under lower
driving voltage if they could be further exploited as organic elec-
trochromic materials. Although the structures or substituted posi-
tion of the polyaromatic moieties are different, the first reduction
potentials of these viologens are almost same. However, their
second reduction waves exhibited different values and a tendency
in an order of T6>T2>T10>T4¼T8 was observed. The differences in
their second reduction potentials could be related to the extent of
the conjugation between the BPD unit and the polyaromatic moi-
eties in these viologens, because it was found that such order was
well consistent with the extent of the conjugation estimating from
the dihedral angles between the BPD and the polyaromatic moie-
ties of the viologens obtained from their crystallographic data. The
smaller of the dihedral angle, the more conjugation between BPD
and polyaromatic moiety should be. This result also suggests that
the extent of conjugation plays more important role than the
structure of conjugated substituent. The CV profiles of 4,40-bipyr-
idin-1-ium salts (T1, T3, T5, T7 and T9) were also recorded. Positive
shifts (0.16e0.22 V) of their reduction potentials and a correlation
with the dihedral angles between the BPI units and the poly-
aromatic units of the monocationic salts was also observed (Fig. S10
in Supplementary data).
Fig. 4. Packing patterns of T7 (top) and T8 (bottom) in solid state. Counterions and
solvent molecules were omitted for clarity. It was found that anions were not involved
in the stacking of organic skeletons.
The photophysical properties of the viologens were investigated
by UV-visible and fluorescence spectroscopies in acetonitrile. The
absorption of BPD unit was overlapped with the maximum ab-
sorptions of polyaromatic moieties around 250 nm. In addition to
the absorptions in UV region, broad peaks were also observed in the
range of 400e500 nm for all the viologens investigated (Fig. 8),
which could also be revealed by the pale yellow color of their so-
lutions in CH3CN (Fig. S11 in Supplementary data). These peaks
were assigned to charge transfer (CT) absorptions, which resulted
from the charge transfers between the electron-deficient BPD unit
and relatively electron-rich polyaromatic moieties. The CT was
further proved to be an intramolecular process by control experi-
ments: No CT absorption could be observed for the mixtures of
DMBP and the corresponding polyaromatic hydrocarbons (Figs.
S12eS14 in Supplementary data). As to fluorescence
Fig. 5. Packing structure of T10 in the single crystal. Counterions and solvent mole-
cules were omitted for clarity. It was found that anions were not involved in the
stacking of organic skeletons.
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F. Lin, X. Zhao / Tetrahedron xxx (2015) 1e8
5
Fig. 6. The formation of 2D supramolecular structures from T2 (top) and T5 (bottom) in solid state.
T2
T4
T6
T8
T10
DMBP
T2
T4
T6
T8
20
15
10
5
0.8
0.6
0.4
0.2
0.0
T10
0
-5
-10
0.0
-0.2
-0.4
-0.6
-0.8
-1.0
-1.2
200
300
400
500
600
Potential(V)
wavelength (nm)
Fig. 7. Cyclic voltammograms for the reductions of the conjugated viologens in CH3CN.
The concentration was 1.0ꢂ10ꢁ3 M and a saturated calomel electrode (SCE) was used
as reference.
Fig. 8. UVevis spectra of the conjugated viologens recorded in acetonitrile. The con-
centration was 1.0ꢂ10ꢁ5 M. Inset: enlargement of the range of 340e550 nm.
unit in excited state, which quenched the fluorescence emission of
the polyaromatics.
Table 1
Electrochemical data and dihedral angles of T2, T4, T6, T8, and T10
Compound
DMBP
T2
T4
T6
T8
T10
redꢁ1
redꢁ2
3. Conclusions
E
E
(V)
(V)
ꢁ0.47
ꢁ0.89
/
ꢁ0.36
ꢁ0.73
43.0ꢀ
ꢁ0.37
ꢁ0.76
83.6ꢀ
ꢁ0.35
ꢁ0.70
ꢁ0.36
ꢁ0.35
ꢁ0.75
65.3ꢀ
ꢁ0.76
a
b
Dihedral angle
39.5ꢀ
82.6ꢀ/87.7ꢀ
A series of polyaromatics conjugated viologens have been syn-
thesized. They adopted different supramolecular structures in solid
state driven by a variety of noncovalent interactions such as aro-
a
Calculated value from Hartree-Fock/3e21G method (Fig. S9 in Supplementary
data).
b
Two conformations coexisted in the crystal structure of T8.
matic stacking, hydrogen bonding or CeH/p interaction. Com-
pared to non-conjugated viologens, these conjugated viologens
exhibited distinctive electrochemical and photophysical properties
as a result of their extended conjugation with the polyaromatic
moieties. Their lower reduction potentials make them better elec-
tron acceptors than non-conjugated viologens and might find
spectroscopy, although the polyaromatic hydrocarbons are excel-
lent fluorescent chromophores, it was found that these conjugated
viologens were fluorescence silent. It could be attributed to the
charge transfers from the polyaromatic moieties to the viologen
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F. Lin, X. Zhao / Tetrahedron xxx (2015) 1e8
further applications in photoelectric materials. This research shed
some light on the properties of viologens with extended conjuga-
tion, which should be helpful for the design of novel viologen-
based supramolecular systems and functional materials.
4.5. Compound T3
This compound was prepared in 53% yield as a pale green
powder from the reaction of Zincke salt 1 and 1-aminonaphthalene
according to a procedure similar to that described for compound
4. Experimental section
4.1. General methods
T1: mp 314.7 ꢀC; 1H NMR (400 MHz, DMSO-d6)
d
9.56 (d, J¼6.9 Hz,
2H), 8.94 (d, J¼6.1 Hz, 2H), 8.89 (d, J¼6.9 Hz, 2H), 8.38 (d, J¼8.4 Hz,
1H), 8.25 (d, J¼8.1 Hz, 1H), 8.20 (d, J¼6.1 Hz, 2H), 8.06 (d, J¼6.7 Hz,
1H), 7.85 (t, J¼7.9 Hz,1H), 7.77 (t, J¼7.2 Hz,1H), 7.71 (t, J¼7.6 Hz,1H),
All reactions were carried out under a dry nitrogen atmosphere.
All solvents were dried before use following the standard pro-
cedures. Unless otherwise indicated, all starting materials were
obtained from commercial suppliers and were used without further
purification. The 1H and 13C NMR spectra were recorded on a Varian
Mercury 400 MHz spectrometer in the indicated solvents. Chemical
7.51 (d, J¼8.3 Hz, 1H). 13C NMR (100 MHz, methanol-d4)
d 156.74,
151.96, 148.44, 143.54, 140.10, 135.75, 133.54, 130.49, 130.01, 129.15,
128.46, 127.38, 126.48, 125.56, 123.78, 121.43. MS (ESI) m/z 283.0
[MꢁCl]þ. HRMS (MALDI-TOF) Calcd for C20H15N2: 283.1230. Found:
283.1233.
shifts are expressed in parts per million (
d) using residual solvent
4.6. Compound T4
protons as internal standards. The melting points were determined
by differential scanning calorimetry (DSC).
This compound was prepared in 97% yield as a red powder from
the reaction of compounds T3 and methyl iodide according to
a procedure similar to that described for compound T2: mp
4.2. Zincke salt 1
274.6 ꢀC; 1H NMR (400 MHz, DMSO-d6)
d
9.72 (d, J¼6.7 Hz, 2H), 9.37
4,40-Bipyridine (3.5 g, 22.5 mmol) and 2,4-dinitrochlorobenzene
(3.0 g, 15 mmol) were dissolved in acetone (25 mL). The solution
was refluxed for 13 h, during which time a pale grey precipitate
formed. The precipitate was collected by filtration and washed
several times with dichloromethane. The product was dried in
vacuo to yield Zincke salt 1 as a grey powder (3.57 g, 74%). 1H NMR
(d, J¼6.5 Hz, 2H), 9.06 (d, J¼6.7 Hz, 2H), 8.92 (d, J¼6.5 Hz, 2H), 8.41
(d, J¼8.3 Hz,1H), 8.27 (d, J¼8.0 Hz,1H), 8.10 (d, J¼7.2 Hz,1H), 7.87 (t,
J¼7.8 Hz, 1H), 7.79 (t, J¼7.3 Hz, 1H), 7.72 (t, J¼7.3 Hz, 0H), 7.54 (d,
J¼8.3 Hz, 1H), 4.50 (s, 3H). 13C NMR (100 MHz, DMSO-d6)
d 150.14,
147.99, 147.62, 146.75, 138.45, 133.51, 131.88, 128.92, 128.60, 127.82,
126.90, 126.83, 126.29, 125.48, 124.70, 120.92, 48.18. MS (ESI) m/z
298.0 [Mꢁ2I]þ, 149.1 [Mꢁ2I]2þ. HRMS (MALDI-TOF) Calcd for
(400 MHz, D2O)
d
9.41 (d, J¼2.5 Hz, 1H), 9.25 (d, J¼7.0 Hz, 2H), 8.94
(dd, J¼8.7, 2.5 Hz, 1H), 8.85 (dd, J¼4.6, 1.7 Hz, 2H), 8.69 (d, J¼7.0 Hz,
2H), 8.28 (d, J¼8.7 Hz, 1H), 8.04 (dd, J¼4.6, 1.7 Hz, 2H). MS (ESI) m/z
323.0 [MꢁCl]þ.
C21H18N2: 298.1465. Found: 298.1462. Anal. Calcd for C21H18I2N2: C,
45.68; H, 3.29; I, 45.96; N, 5.07. Found: C, 45.57; H, 3.26; I, 45.55; N,
5.16.
4.3. Compound T1
4.7. Compound T5
A mixture of Zincke salt
1
(1.19 g, 3.33 mmol) and 2-
This compound was prepared in 35% yield as a orange powder
from the reaction of Zincke salt 1 and 2-aminoanthracene accord-
ing to a procedure similar to that described for compound T1: mp
aminonaphthalene (0.5 g, 3.49 mmol) was dissolved in ethanol
(10 mL) under nitrogen atmosphere. The resulting solution was
refluxed for 12 h and then evaporated in vacuo. The crude product
was refluxed with acetone (200 mL) for 2 h, filtered, and dried in
vacuo to yield T1 as a pale green powder (0.71 g, 67%): mp 223.3 ꢀC;
301.5 ꢀC; 1H NMR (400 MHz, DMSO-d6)
d
9.69 (d, J¼6.9 Hz, 2H), 8.94
(dd, J¼4.6, 1.4 Hz, 2H), 8.86 (dd, J¼10.4, 5.2 Hz, 4H), 8.76 (d,
J¼1.7 Hz, 1H), 8.50 (d, J¼9.2 Hz, 1H), 8.23 (ddd, J¼10.5, 7.7, 3.3 Hz,
4H), 8.00 (dd, J¼9.1, 2.2 Hz, 1H), 7.75e7.59 (m, 2H). 13C NMR
1H NMR (400 MHz, DMSO-d6)
d
9.64 (d, J¼6.9 Hz, 2H), 8.93 (dd,
J¼4.5, 1.6 Hz, 2H), 8.85 (d, J¼6.9 Hz, 2H), 8.58 (d, J¼2.1 Hz, 1H), 8.34
(d, J¼8.9 Hz, 1H), 8.18 (ddd, J¼9.9, 6.1, 3.4 Hz, 2H), 8.03 (dd, J¼8.8,
2.3 Hz, 1H), 7.82e7.71 (m, 1H). 13C NMR (100 MHz, methanol-d4)
(100 MHz, methanol-d4) d 155.76, 151.94, 146.58, 143.42, 140.70,
134.72, 134.28, 133.02, 132.39, 131.50, 129.47, 129.35, 128.24, 128.21,
128.04, 127.11, 125.91, 123.65, 121.10. MS (ESI) m/z 333.0 [MꢁCl].
HRMS (MALDI-TOF) Calcd for C24H17N2: 333.1386. Found: 333.1384.
d
155.78, 151.82, 146.76, 143.58, 141.28, 135.45, 134.41, 132.24,
129.99, 129.49, 129.22, 127.16, 125.24, 123.73, 121.92, 111.42. MS
(ESI) m/z 283.0 [MꢁCl]þ. HRMS (MALDI-TOF) Calcd for C20H15N2:
283.1230. Found: 283.1227.
4.8. Compound T6
This compound was prepared in 99% yield as a red powder from
the reaction of compounds T5 and methyl iodide according to
a procedure similar to that described for compound T2: mp
4.4. Compound T2
Compound T1 (0.3 g, 0.94 mmol) and methyl iodide (1.8 mL,
28 mmol) was dissolved with dry acetonitrile (3 mL) in a sealed
tube, and then heated at 90 ꢀC for two days. The resulting red
precipitate was filtered and washed with dichloromethane and
dried in vacuo to yield T2 as a red powder (0.43 g, 98%): mp
291.2 ꢀC; 1H NMR (400 MHz, DMSO-d6)
d
9.86 (d, J¼6.9 Hz, 2H), 9.35
(d, J¼6.7 Hz, 2H), 9.03 (d, J¼7.0 Hz, 2H), 8.93 (d, J¼6.8 Hz, 2H), 8.88
(d, J¼8.9 Hz, 2H), 8.79 (s, 1H), 8.53 (d, J¼9.2 Hz, 1H), 8.31e8.15 (m,
2H), 8.02 (dd, J¼9.1, 2.2 Hz, 1H), 7.74e7.57 (m, 2H), 4.48 (s, 3H). 13
C
NMR (100 MHz, DMSO-d6)
d 149.16, 147.74, 146.72, 146.01, 139.10,
268.2 ꢀC; 1H NMR (400 MHz, DMSO-d6)
d
9.81 (d, J¼6.7 Hz, 2H),
132.56, 132.12, 131.02, 130.55, 129.60, 128.29, 128.19, 127.15, 126.91,
126.88, 126.46, 126.28, 125.11, 121.15, 48.13. MS (ESI) m/z 348.0
[Mꢁ2I]þ, 173.9[Mꢁ2I]2þ. HRMS (MALDI-TOF) Calcd for C25H20N2:
348.1621. Found: 348.1625. Anal. Calcd for C25H20I2N2: C, 49.86; H,
3.35; I, 42.14; N, 4.65. Found: C, 49.67; H, 3.29; I, 41.89; N, 4.76.
9.34 (d, J¼6.5 Hz, 2H), 8.96 (d, J¼6.6 Hz, 2H), 8.92 (d, J¼6.6 Hz, 2H),
8.62 (d, J¼1.4 Hz, 1H), 8.37 (d, J¼8.9 Hz, 1H), 8.19 (d, J¼6.6 Hz, 2H),
8.05 (dd, J¼8.8, 2.0 Hz, 1H), 7.86e7.72 (m, 2H), 4.48 (s, 3H). 13C NMR
(100 MHz, DMSO-d6) d 149.17, 147.70, 146.67, 146.03, 139.51, 133.40,
132.21, 130.32, 128.78, 128.71, 128.16, 127.99, 126.45, 126.28, 124.43,
121.65, 51.35. MS (ESI) m/z 298.0 [Mꢁ2I]þ, 149.1 [Mꢁ2I]2þ. HRMS
(MALDI-TOF) Calcd for C21H18N2: 298.1465. Found: 298.1468. Anal.
Calcd for C21H18I2N2: C, 45.68; H, 3.29; I, 45.96; N, 5.07. Found: C,
45.30; H, 3.45; I, 45.58; N, 5.01.
4.9. Compound T7
This compound was prepared in 84% yield as a orange powder
from the reaction of Zincke salt
1 and 1-aminoanthracene
Please cite this article in press as: Lin, F.; Zhao, X., Tetrahedron (2015), http://dx.doi.org/10.1016/j.tet.2014.12.054

F. Lin, X. Zhao / Tetrahedron xxx (2015) 1e8
7
according to a procedure similar to that described for compound
T1: mp 310.9 ꢀC; 1H NMR (400 MHz, methanol-d4)
9.46 (d,
Supplementary data
d
J¼6.9 Hz, 2H), 8.94 (dd, J¼4.5, 1.7 Hz, 2H), 8.85e8.80 (m, 3H), 8.50
(d, J¼8.7 Hz,1H), 8.17 (dt, J¼16.3,10.3 Hz, 4H), 8.02 (d, J¼8.4 Hz,1H),
7.95 (d, J¼6.5 Hz,1H), 7.76 (dd, J¼8.6, 7.2 Hz, 1H), 7.67e7.55 (m, 2H).
Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.tet.2014.12.054.
13C NMR (100 MHz, methanol-d4)
d 156.85, 152.00, 151.96, 148.55,
References and notes
143.64, 140.18, 134.53, 134.08, 134.01, 133.15, 129.42, 129.34, 129.12,
128.41, 128.27, 127.49, 126.75, 125.57, 124.97, 123.80, 123.75, 120.64.
MS (MALDI-TOF) m/z 332.5 [MꢁCl]þ. HRMS (MALDI-TOF) Calcd for
1. (a) Su, Y. S.; Chen, C.-F. Org. Lett. 2010, 12, 1888; (b) Cao, J.; Lu, H.-Y.; Xiang, J.-F.;
Chen, C.-F. Chem. Commun. 2010, 3586; (c) Andersen, S. S.; Jensen, M.; Sørensen,
A.; Miyazaki, E.; Takimiya, K.; Laursen, B. W.; Flood, A. H.; Jeppesen, J. O. Chem.
Commun. 2012, 5157; (d) Yonemoto, E. H.; Saupe, G. B.; Schmehl, R. H.; Hubig, S.
M.; Riley, R. L.; Iverson, B. L.; Mallouk, T. E. J. Am. Chem. Soc. 1994, 116, 4786; (e)
C
24H17N2: 333.1386. Found: 333.1381.
4.10. Compound T8
€
Balzani, V.; Bandmann, H.; Ceroni, P.; Giansante, C.; Hahn, U.; Klarner, F.-G.;
€
€
€
Muller, U.; Muller, W. M.; Verhaelen, C.; Vicinelli, V.; Vogtle, F. J. Am. Chem. Soc.
2005, 128, 637; (f) Ogoshi, T.; Kanai, S.; Fujinami, S.; Yamagishi, T.-a.; Nakamoto,
Y. J. Am. Chem. Soc. 2008, 130, 5022; (g) Wang, K.; Guo, D.-S.; Wang, X.; Liu, Y.
ACS Nano 2011, 5, 2880; (h) Ong, W.; Grindstaff, J.; Sobransingh, D.; Toba, R.;
Quintela, J. M.; Peinador, C.; Kaifer, A. E. J. Am. Chem. Soc. 2005, 127, 3353; (i) Yu,
G.; Zhou, X.; Zhang, Z.; Han, C.; Mao, Z.; Gao, C.; Huang, F. J. Am. Chem. Soc. 2012,
134, 19489.
This compound was prepared in 88% yield as a red powder from
the reaction of compounds T7 and methyl iodide according to
a procedure similar to that described for compound T2: mp
332.1 ꢀC; 1H NMR (400 MHz, methanol-d4)
d
9.62 (d, J¼6.9 Hz, 2H),
9.30 (d, J¼6.7 Hz, 2H), 8.97 (d, J¼6.9 Hz, 2H), 8.85 (d, J¼6.9 Hz, 3H),
8.51 (d, J¼8.7 Hz, 1H), 8.22 (s, 1H), 8.19 (d, J¼8.2 Hz, 1H), 8.10 (d,
J¼8.4 Hz, 1H), 8.01 (d, J¼7.1 Hz, 1H), 7.77 (dd, J¼8.6, 7.2 Hz, 1H),
2. (a) Stoddart, J. F. Acc. Chem. Soc. 1997, 30, 393; (b) Cao, D.; Amelia, M.; Klivansky,
L. M.; Koshkakaryan, G.; Khan, S. I.; Semeraro, M.; Silvi, S.; Venturi, M.; Credi, A.;
Liu, Y. J. Am. Chem. Soc. 2010, 121, 1110; (c) Zhao, X.; Jiang, X.-K.; Shi, M.; Yu, Y.-
H.; Xia, W.; Li, Z.-T. J. Org. Chem. 2001, 66, 7035; (d) Chen, L.; Zhao, X.; Chen, Y.;
Zhao, C.-X.; Jiang, X.-K.; Li, Z.-T. J. Org. Chem. 2003, 68, 2704; (e) Feng, D.-J.; Li,
X.-Q.; Wang, X.-Z.; Jiang, X.-K.; Li, Z.-T. Tetrahedron 2004, 60, 6137; (f) Zhang,
W.-X.; Fan, C.-Q.; Tu, B.; Zhao, X.; Jiang, X.-K.; Li, Z.-T. Chin. J. Chem. 2003, 21,
739; (g) Liu, M.; Li, S.; Hu, M.; Wang, F.; Huang, F. Org. Lett. 2010, 12, 760; (h) Li,
S.; Liu, M.; Zheng, B.; Zhu, K.; Wang, F.; Li, N.; Zhao, X.-L.; Huang, F. Org. Lett.
2009, 11, 3350.
7.67e7.55 (m, 2H). 13C NMR (100 MHz, DMSO-d6)
d 150.11, 148.00,
147.82, 146.86, 138.53, 132.38, 132.35, 131.81, 131.14, 128.18, 128.13,
127.54, 127.18, 127.07, 127.04, 126.29, 125.25, 124.77, 124.25, 120.01,
48.21. MS (MALDI-TOF): m/z 347.5 [Mꢁ2I]þ. HRMS (MALDI-TOF)
Calcd for C25H20N2: 348.1621. Found: 348.1615. Anal. Calcd for
C
25H20I2N2: C, 49.86; H, 3.35; I, 42.14; N, 4.65. Found: C, 49.68; H,
3. (a) Li, H.; Chen, D. X.; Sun, Y. L.; Zheng, Y. B.; Tan, L. L.; Weiss, P. S.; Yang, Y. W. J.
Am. Chem. Soc. 2013, 135, 1570; (b) Zayats, M.; Pogorelova, S. P.; Kharitonov, A.
B.; Lioubashevski, O.; Katz, E.; Willner, I. Chem.dEur. J. 2003, 9, 6108; (c)
3.38; I, 41.94; N, 4.71.
€
Strehlitz, B.; Grundig, B.; Schumacher, W.; Kroneck, P. M. H.; Vorlop, K.-D.;
Kotte, H. Anal. Chem. 1996, 68, 807.
4.11. Compound T9
4. (a) Jeon, W. S.; Kim, E.; Ko, Y. H.; Hwang, I.; Lee, J. W.; Kim, S.-Y.; Kim, H.-J.; Kim,
K. Angew. Chem., Int. Ed. 2005, 44, 87; (b) Balzani, V.; Credi, A.; Venturi, M.
Chem. Soc. Rev. 2009, 38, 1542; (c) Green, J. E.; Choi, J. W.; Boukai, A.; Buni-
movich, Y.; Johnston-Halperin, E.; DeIonno, E.; Luo, Y.; Sheriff, B. A.; Xu, K.; Shik
Shin, Y.; Tseng, H.-R.; Stoddart, J. F.; Heath, J. R. Nature 2007, 445, 414; (d)
Andersen, S. S.; Share, A. I.; Poulsen, B. L. C.; Kørner, M.; Duedal, T.; Benson, C.
R.; Hansen, S. W.; Jeppesen, J. O.; Flood, A. H. J. Am. Chem. Soc. 2014, 136, 6373;
This compound was prepared in 70% yield as a orange powder
from the reaction of Zincke salt 1 and 1-aminopyrene according to
a procedure similar to that described for compound T1: mp
315.3 ꢀC; 1H NMR (400 MHz, DMSO-d6)
d
9.69 (d, J¼6.7 Hz, 2H), 8.97
(d, J¼6.2 Hz, 4H), 8.64 (d, J¼8.2 Hz, 1H), 8.60e8.40 (m, 6H),
ꢁ
(e) Badjic, J. D.; Balzani, V.; Credi, A.; Silvi, S.; Stoddar, S. F. Science 2004, 303,
8.32e8.20 (m, 3H), 7.81 (d, J¼9.2 Hz, 1H). 13C NMR (100 MHz,
1845; (f) Zhu, L.; Yan, H.; Wang, X.-J.; Zhao, Y. J. Org. Chem. 2012, 77, 10168.
5. (a) Wang, F.; Han, C.; He, C.; Zhou, Q.; Zhang, J.; Wang, C.; Li, N.; Huang, F. J. Am.
Chem. Soc. 2008, 130, 11254; (b) Wang, K.-P.; Guo, D.-S.; Zhao, H.-X.; Liu, Y.
Chem.dEur. J. 2014, 20, 4023; (c) Stoffelen, C.; Voskuhl, J.; Jonkheijm, P.;
Huskens, J. Angew. Chem., Int. Ed. 2014, 53, 3400; (d) Ji, Z.; Liu, J.; Chen, G.; Jiang,
M. Polym. Chem. 2014, 5, 2709; (e) Zhou, C.; Tian, J.; Wang, J.-L.; Zhang, D.-W.;
Zhao, X.; Liu, Y.; Li, Z.-T. Polym. Chem. 2014, 5, 341; (f) Appel, E. A.; Biedermann,
F.; Rauwald, U.; Jones, S. T.; Zayed, J. M.; Scherman, O. A. J. Am. Chem. Soc. 2010,
132, 14251; (g) Lin, F.; Zhan, T.-G.; Zhou, T.-Y.; Zhang, K.-D.; Li, G.-Y.; Wu, J.;
Zhao, X. Chem. Commun. 2014, 7982; (h) Wang, F.; Zhang, J.; Ding, X.; Dong, S.;
Liu, M.; Zheng, B.; Li, S.; Wu, L.; Yu, Y.; Gibson, H. W.; Huang, F. Angew. Chem.,
Int. Ed. 2010, 49, 1090; (i) Ji, X.; Dong, S.; Wei, P.; Xia, D.; Huang, F. Adv. Mater.
2013, 25, 5725.
6. (a) Zahavy, S.; Seiler, M.; Marx-Tibbon, S.; Joselevich, E.; Willner, I.; Durr, H.;
O’Connor, D.; Harriman, A. Angew. Chem., Int. Ed. 1995, 34, 1005; (b) Nishikitani,
Y.; Uchida, S.; Asano, T.; Minami, M.; Oshima, S.; Ikai, K.; Kubo, T. J. Phys. Chem.
C. 2008, 112, 4372; (c) Perera, A. S.; Subbaiyan, N. K.; Kalita, M.; Wendel, S. O.;
Samarakoon, T. N.; D’Souza, F.; Bossmann, S. H. J. Am. Chem. Soc. 2013, 135, 6842.
7. (a) Chidichimo, G.; Benedittis, M. D.; Lanzo, J.; Simone, B. C. D.; Imbardelli, D.;
Gabriele, B.; Veltri, L.; Salerno, G. Chem. Mater. 2007, 19, 353; (b) Mortimer, R. J.
Annu. Rev. Mater. Res. 2011, 41, 241; (c) Choi, S. Y.; Mamak, M.; Coombs, N.;
Chopra, N.; Ozin, G. A. Nano. Lett. 2004, 4, 1231.
methanol-d4)
d 156.65, 152.00, 148.93, 143.60, 136.63, 135.04,
132.64, 132.60, 131.90, 131.29, 128.70, 128.12, 128.06, 127.37, 126.60,
126.39, 126.00, 124.92, 124.47, 123.80, 119.82. MS (ESI) m/z 357.0
[MꢁCl]þ. HRMS (MALDI-TOF) Calcd for C26H17N2: 357.1386. Found:
357.1393.
4.12. Compound T10
This compound was prepared in 98% yield as a red powder from
the reaction of compounds T9 and methyl iodide according to
a procedure similar to that described for compound T2: mp
288.7 ꢀC; 1H NMR (400 MHz, DMSO-d6)
d
9.86 (d, J¼6.8 Hz, 2H),
9.38 (d, J¼6.8 Hz, 2H), 9.12 (d, J¼6.9 Hz, 2H), 8.94 (d, J¼6.8 Hz, 2H),
8.66 (d, J¼8.3 Hz, 1H), 8.60e8.40 (m, 6H), 8.28 (t, J¼7.7 Hz, 1H), 7.81
(d, J¼9.2 Hz, 1H), 4.50 (s, 3H). 13C NMR (100 MHz, DMSO-d6)
d
150.07, 148.09, 146.83, 135.32, 132.81, 130.79, 130.60, 130.02,
8. Gothard, C. M.; Bruns, C. J.; Gothard, N. A.; Grzybowski, B. A.; Stoddart, J. F. Org.
Lett. 2012, 14, 5066.
129.85, 127.59, 127.42, 126.99, 126.94, 126.84, 126.33,125.16, 124.92,
124.02, 123.76, 122.95, 119.64, 48.21. MS (ESI) m/z 372.0 [Mꢁ2I]þ,
185.9 [Mꢁ2I]2þ. HRMS (MALDI-TOF) Calcd for C27H20N2: 372.1621.
Found: 372.1631. Anal. Calcd for C27H20I2N2: C, 51.78; H, 3.22; I,
40.53; N, 4.47. Found: C, 51.33; H, 3.12; I, 40.01; N, 4.61.
9. (a) Kathiresan, M.; Walder, L. Macromolecules 2011, 44, 8563; (b) Katir, N.;
Majoral, J. P.; Kadib, A. E.; Caminade, A. M.; Bousmina, M. Eur. J. Org. Chem. 2012,
269; (c) Ciepluch, K.; Katir, N.; Kadib, A. E.; Felczak, A.; Zawadzka, K.; Weber,
M.; Klajnert, B.; Lisowska, K.; Caminade, A.-M.; Bousmina, M.; Bryszewska, M.;
Majoral, J. P. Mol. Pharmaceutics 2012, 9, 448; (d) Asaftei, S.; Clercq, E. D. J. Med.
Chem. 2010, 53, 3480; (e) Ronconi, C. M.; Stoddart, J. F.; Balzani, V.; Baroncini,
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Marchioni, F.; Venturi, M.; Credi, A.; Balzani, V.; Belohradsky, M.; Elizarov, A.
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Acknowledgements
€
10. (a) Lieder, M.; Schlapfer, C. W. J. Appl. Electrochem. 1997, 27, 235; (b) Choi, S.; Lee,
The authors are grateful for the financial support provided by
the National Science Foundation of China (Nos 21172249 and
91127007).
J. W.; Ko, Y. H.; Kim, K. Macromolecules 2002, 35, 3526; (c) Belitsky, J. M.;
Nelson, A.; Stoddart, J. F. Org. Biomol. Chem. 2006, 4, 250; (d) Hoyle, R.; Will, G.;
Fitzmaurice, D. J. Mater. Chem. 1998, 8, 2033.
Please cite this article in press as: Lin, F.; Zhao, X., Tetrahedron (2015), http://dx.doi.org/10.1016/j.tet.2014.12.054

8
F. Lin, X. Zhao / Tetrahedron xxx (2015) 1e8
11. (a) Nanasawa, M.; Miwa, M.; Hirai, M.; Kuwabara, T. J. Org. Chem. 2000, 65, 593;
(b) Matsushita, M. M.; Tachikawa, T.; Suzuki, T.; Kawai, T.; Iyoda, T. Mol. Cryst.
12. Christl, M. Angew. Chem., Int. Ed. 2007, 46, 9152.
13. The crystal structures have been deposited at the Cambridge Crystallographic
Data Center and assigned the deposition numbers as CCDC 1021798e1021805
(see Supplementary data for details).
€
Liq. Cryst. 1999, 334, 149; (c) Bongard, D.; Moller, M.; Rao, S. N.; Coor, D.; Walder,
L. Helv. Chim. Acta 2005, 88, 3200; (d) Lin, F.; Zhou, T.-Y.; Zhan, T.-G.; Zhao, X.
Tetrahedron 2014, 70, 2251.
Please cite this article in press as: Lin, F.; Zhao, X., Tetrahedron (2015), http://dx.doi.org/10.1016/j.tet.2014.12.054