Wholly-rigid rod-rod amphiphiles: Synthesis, crystal structures, and self-assembling behavior in water

Article abstract of DOI:10.1016/j.tet.2014.02.029

A series of fully rigid rod-rod type amphiphilic molecules have been constructed by using 4,4′-bipyridin-1-ium or 4,4′-bipyridin-1, 1′-diium (viologen) as a hydrophilic segment and phenyl, biphenyl or para-tert-phenyl as a hydrophobic unit. The crystal st

Full text of DOI:10.1016/j.tet.2014.02.029

Tetrahedron 70 (2014) 2251e2256
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Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Wholly-rigid roderod amphiphiles: synthesis, crystal structures,
and self-assembling behavior in water
*
Feng Lin, Tian-You Zhou, Tian-Guang Zhan, Xin Zhao
Laboratory of Materials Science, 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
A series of fully rigid roderod type amphiphilic molecules have been constructed by using 4,40-bipyridin-
1-ium or 4,40-bipyridin-1,10-diium (viologen) as a hydrophilic segment and phenyl, biphenyl or para-tert-
phenyl as a hydrophobic unit. The crystal structures of four of the molecules have been elucidated. TEM,
SEM, AFM, and DLS experiments revealed that these stiff amphiphiles could self-assemble into diverse
architectures, including spherical micelles, ultra-long straight nanofibers (>1 mm), and nanotubes in
water, which depend on the hydrophilic/hydrophobic fraction ratios of the molecules.
Ó 2014 Elsevier Ltd. All rights reserved.
Article history:
Received 5 December 2013
Received in revised form 27 January 2014
Accepted 13 February 2014
Available online 18 February 2014
Keywords:
Roderod
Amphiphile
Self-assembly
Crystal structure
Viologen
1. Introduction
moiety (typically oligoglycol).8 For this type of amphiphiles, it was
reported that the stiff conformation of the rod moieties plays
Amphiphiles are a large family of molecules, which bear co-
valently connected hydrophilic and hydrophobic segments.1,2 The
self-assembling behavior of amphiphilic molecules is extremely
rich, with the objects assembled from them varying from micelles,
bilayers, lamellaes, ribbons, tubules to vesicles, depending on their
relative composition of hydrophilic and hydrophobic moieties, the
geometries of the molecules, and processing conditions. Currently
a myriad of amphiphiles have been created as building blocks to
fabricate ordered micro/nanoscale architectures with potential
applications ranging from drug and gene delivery3 to sustained-
release systems.4 Most of early reported amphiphiles are simple
molecules bearing a cationic or anionic head group and a hydro-
phobic tail, including lipids5 and surfactants,6 which are commonly
found and widely used in our daily life. In recent years, amphiphiles
with complicated structures, such as amphiphilic block copolymers
have been intensively investigated.7 Generally most of these am-
phiphiles can be classified as coilecoil type because the confor-
mations of both the hydrophilic and hydrophobic segments are
flexible. When one of the two flexible segments of a coil-coil
molecule is replaced by a rigid rod-like unit, a new amphiphilic
structure named ‘rodecoil’ is created. Such amphiphiles usually
contain a rigid hydrophobic segment and a flexible hydrophilic
a crucial role in dictating the orientational organization of the
molecules, which enable them to aggregate into ordered supra-
molecular structures even at very low molecular weights of each
block and can enhance aggregation stability greatly in comparison
with coilecoil systems.9 In this context, if the flexible coil part of
a rodecoil amphiphile can be further replaced by a rigid rod-like
segment, another type of amphiphiles, that is, roderod amphi-
phile should be generated. However, for this type of amphiphiles,
there only a few examples of block copolymers, which consist of
rigid backbones and whose hydrophilic head groups are linked to
the backbones by flexible alkyl chains, have been reported so far,10
These copolymers certainly still have some freedom to adjust their
conformations due to the flexible linkers. Several questions then
arise: (1) What will happen if an amphiphilic molecule is fully stiff?
(2) Does it still exhibit amphiphilic feature as traditional amphi-
philes? (3) Will it display unique behavior as a result of the pre-
organization of the wholly-rigid structure? Herein, we report the
construction of a series of wholly-rigid roderod amphiphilic mol-
ecules, i.e., T1eT6, and their self-assembling behavior in water.
These unique amphiphiles have been constructed by employing
4,40-bipyridin-1-ium or 4,40-bipyridin-1,10-diium (viologen) as hy-
drophilic segment and phenyl, biphenyl or para-tert-phenyl as
hydrophobic unit.11 They are stiff, fully conjugated, and thus shape-
persistent. We demonstrate that in water these rigid roderod
amphiphiles can self-assemble into discrete well-defined archi-
tectures including spherical micelles, ultra-long straight micro/
* Corresponding author. Tel.: þ86 21 54925023; e-mail addresses: xzhao@mail.
sioc.ac.cn, xinzhao72@yahoo.com (X. Zhao).
0040-4020/$ e see front matter Ó 2014 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.tet.2014.02.029

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F. Lin et al. / Tetrahedron 70 (2014) 2251e2256
nanofibers (>1 mm) or nanotubes, which sheds some light on the
self-assembling behavior of this unique type of amphiphilic
molecules.
compounds twist around each other, albeit to a small extent,
which leads to a nonplanar conformation for the whole backbone.
Furthermore, face-to-face stacking of the molecules in a head-to-
tail alignment, this is, biphenyl or para-tert-phenyl unit stacking
with 4,40-bipyridin-1-ium moiety, is observed. In the case of T5, it
adopts a similar torsional conformation as its precursor T2 but
a different packing manner. Although the adjacent molecules still
adopt the head-to-tail orientation, only the biphenylene unit and
the middle pyridinium unit stack in an offset way and thus the
terminal methylated pyridinium units stretch out at both ends.
This is reasonable because a strong electrostatic repulsion would
arise if two molecules of T5 adopted a justified head-to-tails
alignment. Compound T6 exhibits a packing pattern different
from that of its analogue T5. In this molecule, all the three phe-
nylene units of the para-tert-phenyl segment lie in nearly the
same plane while the two pyridiniums of 4,40-bipyridin-1,10-diium
unit are positioned in another plane, with the dihedral angle of the
two planes being 49.3ꢀ. In contrast to T2, T3, and T5, no aromatic
stacking was observed for the neighboring molecules. Instead,
2. Results and discussion
Compounds T1eT6 were synthesized via Zincke reaction12 and
the synthetic routes are provided in Scheme 1. Thus, the corre-
sponding amines were refluxed with Zincke salt 1 in ethanol to give
compounds T1eT3, respectively. These compounds further reacted
with iodomethane to generate compounds T4eT6, which have
been characterized by 1H and 13C NMR, and (HR) mass spectros-
copy. It should be noted that the counter anions of compounds
T4eT6 were iodide anions, not mixed salts with one iodide and one
chloride, which was confirmed by crystallographic analysis (vide
infra). It could be attributed to ion-exchange during the reaction
process.
they are held together by the CeH/
p interaction between two
adjacent para-tert-phenyl segments, with the 4,40-bipyridin-1,10-
diium units stretching out in the reverse direction. In all the cases
Table 1
Crystallographic data for T2, T3, T5, and T6
Compound
T2
T3
T5
T6
Formula
MW
Temp (K)
Crystal
system
Space
(C22H17ClN2)$(2CH3OH) C28H21ClN2 C23H20I2N2
C29H24I2N2
654.30
293(2)
408.91
140(2)
420.92
140(2)
578.21
293(2)
Orthorhombic
Monoclinic Orthorhombic Monoclinic
P212121
P21/n
Pbca
P21
group
ꢀ
a (A)
7.4179(10)
11.2220(15)
25.306(3)
90.00
90.00
90.00
7.681(3)
19.474(7) 13.9930(7)
16.273(6) 18.0866(10)
90.00
90.233(7) 90.00
90.00 90.00
2434.1(16) 4248.7(4)
16.7875(9)
5.8506(6)
7.8062(8)
27.658(3)
90.00
95.561(2)
90.00
ꢀ
b (A)
ꢀ
c (A)
a
b
g
(ꢀ)
(ꢀ)
(ꢀ)
90.00
°C
3
ꢀ
V (A )
Z
2106.6(5)
4
1257.2(2)
2
Scheme 1. The synthesis of compounds T1eT6.
4
8
Dcalcd
1.289
1.149
1.808
1.728
(g cmꢁ3)
m
(mmꢁ1
)
0.204
0.173
2.971
2.521
The single crystals of T2, T3, T5, and T6 suitable for the X-ray
analysis were grown by slow evaporation of their solutions in
methanol at room temperature. Their crystal structures are shown
in Fig. 1 and the crystal data summarized in Table 1. It can be found
that the conformation and packing style of monocationic com-
pounds T2 and T3 are quite similar. The aromatic rings of both
GOF
Rint
Final R1
wR2 [I>2
CCDC ref.
code
1.033
0.0406
0.0452
0.982
1.041
1.012
0.1108
0.0863
0.2312
942631
0.0439
0.0284
0.0734
942630
0.0295
0.0456
0.1182
942632
s
(I)] 0.1188
942629
Fig. 1. The crystal structures of (a) T2, (b) T3, (c) T5, and (d) T6. Counterions and solvent molecules are omitted for clarity.

F. Lin et al. / Tetrahedron 70 (2014) 2251e2256
2253
above, it was found that the counterions had very little influence
on the stacking of the molecules. These results suggest that aro-
matic stacking should play a crucial role in driving the self-
assembly of these amphiphiles. However, it should be noted that
the structures of aggregates in solution state might not be fully
same as that in the bulk crystals.
inside because a clear contrast between the wall and the inner part
was observed (Fig. 2f), which supported the formation of nano-
tubes. The wall thickness was estimated to be 1.8 nm from the TEM
image. This value was very close to the length (2.08 nm) of T3
measured from its crystal structure, suggesting that the wall of
nanotubes was generated by the monolayered packing of T3.
Compared to T1eT3, the hydrophilic segments of amphiphiles
T4eT6 are more polar. DLS also confirmed that they existed as
aggregates in aqueous media (Fig. S2, SD). Similar to its precursor
T1, T4 also self-assembled into spherical micelles (Fig. 3a). How-
ever, the diameters of the micelles generated from T4 were only
30e40 nm, quite smaller than those from T1, (Fig. 3b). It might be
attributed to the higher charge density of T4, which kept a small
size to reduce electrostatic repulsion. In contrast, compound T5
gave rise to ultra-long nanofibers (Fig. 3c). The solid feature of these
fibers was revealed by TEM (Fig. 3e). As shown in Fig. 3c, the fibers
were quite straight and the lengths of these fibers were estimated
to be >1.0 mm because no ends of the fibers could be observed in
the scope of the SEM image. AFM was further used to characterize
the morphology of the self-assembled structures of T5, which also
revealed the formation of nanofibers (Fig. S3, SD). From the SEM
image of higher resolution, the widths of the fibers were estimated
to be less than 500 nm (Fig. 3d). Since viologens have been widely
used in optoelectronic materials,13 these ultra-long nanofibers
might be further exploited as optoelectronic devices. In contrast to
T4 and T5, T6 gave rise to ill-defined aggregates. This result might
be attributed to its different packing style from the other amphi-
philes and its unmeet hydrophilic/hydrophobic ratio.
Similar to conventional flexible amphiphiles, these wholly-rigid
roderod amphiphilic molecules also possess critical micelle con-
centrations (CMCs). Their CMCs were determined by the specific
conductivity method in water (Fig. S1, SD) and the results provided
in Table 2. For comparison, the CMCs of rodecoil type amphiphiles
T7eT12, which were constructed from the same hydrophilic unit
but flexible alkyl chains of comparable lengths as hydrophobic
segments, were also measured. Specific conductivityeconcentra-
tion plots of solutions of compounds T7eT9 did not show a de-
tectable inflection point, suggesting that their amphiphilic feature
is not obvious. In contrast, compounds T10eT12 exhibited CMCs
and the values are higher than those of T1eT6, indicating the ag-
gregating tendency of the roderod type amphiphiles is higher than
the rodecoil type amphiphiles. This result might be attributed to
the more orientational organization of the stiff roderod structures.
Furthermore, the CMCs of compounds T4eT6 are slightly lower
than their corresponding precursors T1eT3, suggesting T4eT6
exhibit more ‘amphiphilic feature’ due to their dicationic hydro-
philic segment.
Table 2
Critical micelle concentrations of T1eT5 and T10eT12 in water at 25 ꢀC
For comparison, the self-assembling behavior of control com-
pounds T10eT12 in water were also investigated using TEM. It was
found that these compounds all assembled into sphere-like mi-
celles, which was independent on the length of their hydrophobic
tail (Fig. S4, SD). This result clearly demonstrated the difference of
the self-assembling property of the roderod and rodecoil amphi-
philes, even though they share same hydrophilic segments. The
morphology should be dictated by the different hydrophilic/hy-
drophobic ratios of these amphiphiles. Compared to the rodecoil
ones, the roderod amphiphiles were more sensitive to the subtle
change of the hydrophilic/hydrophobic ratio. This feature could be
attributed to the stiffness of the wholly-rigid molecules, which
were hard to alter their conformations during the self-assembling
process. In contrast, the rodecoil structures were semi-rigid and
thus the hydrophilic/hydrophobic ratio might be adjusted by the
change of their conformation.
Compound
CMC/mM
Compound
CMC/mM
Compound
CMC/mM
T1
T2
T3
0.08
0.10
0.081
T4
T5
T6
0.073
0.088
0.076
T10
T11
T12
0.136
0.107
0.092
The self-assembling behavior of T1eT3 in water was then in-
vestigated. Dynamic light scattering (DLS) experiment revealed
that they all aggregated into large species in aqueous media (Fig. 2a
and Fig. S2, SD). The average hydrodynamic diameter (Dh) of the
aggregates formed by T1 in the aqueous solution was estimated to
be 190 nm (Fig. 2a). Transmission electron microscopy (TEM)
revealed that T1 gave rise to spherical micelles and the diameters of
the micelles were estimated from the TEM image to be in a range of
100e200 nm (Fig. 2a), which is consistent with the value obtained
from DLS. Under the similar conditions, T2 self-assembled into one-
dimensional (1D) fibrous morphology with the diameter being ca.
2 microns (ca. 350 nm at lower concentration, see the TEM below),
as demonstrated by scanning electron microscopy (SEM) (Fig. 2c).
The SEM image also clearly revealed that the microfibers were solid
inside from the visible cylindrical section of the end of one fiber
(Fig. 2c, inset). The fibrous morphology was also revealed by atomic
force microscopy (AFM) image (Fig. S3, SD). This solid feature was
further evidenced by the TEM image, which displayed no contrast
between the inner part and the peripheral part (Fig. 2d). It was
found that T3 also self-assembled into 1D structures, with their
lengths being several hundred microns and widths being hundreds
nanometers (Fig. 2e). However, different from those fabricated from
T2, TEM revealed that the fibers assembled from T3 were hollow
3. Conclusion
In summary, a series of wholly-rigid roderod amphiphiles have
been constructed and their self-assembling properties have been
investigated. Generally these new compounds exhibit the typical
amphiphilic feature possessed by conventional flexible amphi-
philes and thus can self-assemble into diverse well-defined archi-
tectures of different morphologies, depending on the hydrophilic/
hydrophobic fraction ratio of the molecule. However, the new rigid
amphiphiles also exhibit their own feature by displaying a higher
assembly tendency and a preferred tendency of forming 1D struc-
tures with high stiffness. The behavior exhibited by these novel
amphiphiles is different from the previously reported roderod
block copolymers, which prefer to self-assemble into low-curvature
vesicular or lamellar structures and the morphologies assembled
from them are independent on the specific chemical structure and
composition of the copolymers.14 We believe systematic studies on
more roderod amphiphilic structures will uncover more intriguing
properties of this new family member of amphiphiles. Further
study is pointing to the roderod bolaamphiphiles and gemini
amphiphiles.

2254
F. Lin et al. / Tetrahedron 70 (2014) 2251e2256
Fig. 2. (a) TEM image and (b) DLS profile of T1. (c) SEM and (d) TEM images of T2. (e) SEM and (f) TEM images of T3. The samples were prepared from their solutions in water. The
concentration was 0.1 mg mLꢁ1 except the SEM of T2 whose concentration was 0.5 mg mLꢁ1. SEM image of this sample, instead of the sample of 0.1 mg mLꢁ1, was provided here
because the section of fibers was observed for this sample.
Fig. 3. (a) TEM image and (b) DLS profile of T4. (c, d) SEM and (e) TEM images of T5. The samples were prepared from their solutions (0.1 mg mLꢁ1) in water.
4. Experimental section
4.1. General methods
electron microscope. TEM was performed on a Philips CM 200/FEG
transmission electron microscope. DLS was performed using
a Zetasizer NanoZS instrument. Specific conductivity measure-
ments were conducted on an INESA DDSJ-308A conductivity
meter.
All solvents were dried before use following the standard
procedures. Unless otherwise indicated, all starting materials were
obtained from commercial suppliers and were used without fur-
ther purification. The 1H and 13C NMR spectra were recorded on
a 400 MHz spectrometer in the indicated solvents. Chemical shifts
4.1.1. Zincke salt 1.16 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 gray 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 gray powder
are expressed in parts per million (d) using residual solvent pro-
tons as internal standards. Compounds T7eT12 were prepared
following the procedure reported in the previous literature.15 SEM
was carried out using a JEOL JSM-6390-LV microscope scanning
(3.57 g, 74%). 1H NMR (400 MHz, D2O)
d
9.41 (d, J¼2.5 Hz, 1H), 9.25

F. Lin et al. / Tetrahedron 70 (2014) 2251e2256
2255
(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.
(ESI): m/z 162.1 [Mꢁ2I]2þ. HRMS (MALDI): calcd for C23H20N2
:324.1621. Found: 324.1619.
4.1.7. Compound T6. This compound was prepared in 83% yield as
a red powder from the reaction of compounds T3 and methyl iodide
according to a procedure similar to that described for compound
4.1.2. Compound T1. Zincke salt 1 (1.23 g, 3.44 mmol) was dis-
solved with aniline (0.4 g, 4.3 mmol) in ethanol (10 mL) under ni-
trogen atmosphere. The resulting solution was refluxed for 24 h and
the formed precipitate was filtered and discarded. The filtrate was
evaporated in vacuo and the crude product was refluxed with ac-
etone (300 mL) for 2 h, filtered, and dried in vacuo to yield T1 as
a very pale green powder (0.63 g, 55%). 1H NMR (400 MHz, meth-
T4. 1H NMR (400 MHz, DMSO-d6)
d
9.74 (d, J¼6.8 Hz, 2H), 9.33 (d,
J¼6.8 Hz, 2H), 8.97 (d, J¼6.9 Hz, 2H), 8.89 (d, J¼6.8 Hz, 2H), 8.18 (d,
J¼8.8 Hz, 2H), 8.08 (d, J¼8.7 Hz, 2H), 7.95 (d, J¼8.3 Hz, 2H), 7.87 (d,
J¼8.4 Hz, 2H), 7.77 (d, J¼7.4 Hz, 2H), 7.52 (t, J¼7.6 Hz, 2H), 7.43 (t,
J¼7.3 Hz, 1H), 4.47 (s, 3H). 13C NMR (100 MHz, DMSO-d6)
d 149.10,
anol-d4)
d
9.37 (d, J¼6.8 Hz, 2H), 8.88 (d, J¼6.1 Hz, 2H), 8.69 (d,
147.70, 146.69, 145.70, 142.54, 141.31, 140.29, 139.27, 136.94, 129.08,
128.10, 127.83, 127.67, 127.46, 126.69, 126.47, 126.26, 125.45, 48.13.
MS (ESI): m/z 200.1 [Mꢁ2I]2þ. HRMS (MALDI): calcd for C29H24N2
:400.1934. Found: 400.1925.
J¼6.7 Hz, 2H), 8.08 (d, J¼6.1 Hz, 2H), 7.93e7.86 (m, 2H), 7.82e7.75
(m, 3H). MS (ESI): m/z 233.1 [MꢁCl]þ. HRMS (MALDI): calcd for
C
16H13N2 :233.1073. Found: 233.1074.
4.1.3. Compound T2. This compound was prepared in 61% yield as
a pale green powder from the reaction of Zincke salt 1 and 4-
aminobiphenyl according to a procedure similar to that described
Acknowledgements
We thank Professor Zhan-Ting Li (Fudan University) for his
helpful advices and the National Science Foundation of China
(91127007 and 21172249) for the financial support.
for compound T1. 1H NMR (400 MHz, DMSO-d6)
d
9.56 (d, J¼6.7 Hz,
2H), 8.92 (d, J¼5.9 Hz, 2H), 8.81 (d, J¼6.7 Hz, 2H), 8.17 (d, J¼6.0 Hz,
2H), 8.08 (d, J¼8.7 Hz, 2H), 8.03 (d, J¼8.6 Hz, 2H), 7.82 (d, J¼7.4 Hz,
2H), 7.56 (t, J¼7.5 Hz, 2H), 7.48 (t, J¼7.5 Hz, 1H). 13C NMR (100 MHz,
Supplementary data
DMSO-d6)
d 153.06, 151.10, 145.31, 142.89, 141.39, 140.56, 138.16,
129.22, 128.56, 128.20, 127.08, 125.32, 122.08. MS (ESI): m/z 309.0
[MꢁCl]þ. HRMS (MALDI): calcd for C22H17N2: 309.1386. Found:
309.1383.
Supplementary data include conductivityeconcentration plots,
additional TEM images, DLS profiles, and copies of 1H NMR and 13
C
NMR spectra of compounds T1eT6. Supplementary data related to
this article can be found at http://dx.doi.org/10.1016/
j.tet.2014.02.029.
4.1.4. Compound T3. Zincke salt 1 (0.28 g, 0.77 mmol) and 4-
amino-p-terphenyl (0.2 g, 0.82 mmol) was dissolved in ethanol
(5 mL) under nitrogen atmosphere. The resulting solution was
refluxed for 48 h and the formed precipitate was filtered and dis-
carded. The filtrate was evaporated in vacuo and the crude product
was refluxed with acetone (100 mL) for 2 h and then filtered. Pu-
rification was carried out via column chromatography (SiO2, chlo-
roform/methanol 5:1) and then compound T3 was obtained as
a pale yellow powder (0.13 g, 38%). 1H NMR (400 MHz, DMSO-d6)
References and notes
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d
9.57 (d, J¼6.9 Hz, 2H), 8.93 (d, J¼6.1 Hz, 2H), 8.82 (d, J¼6.8 Hz, 2H),
8.17 (dd, J¼10.4, 5.7 Hz, 4H), 8.05 (d, J¼8.5 Hz, 2H), 7.94 (d, J¼8.3 Hz,
2H), 7.86 (d, J¼8.5 Hz, 2H), 7.77 (d, J¼7.0 Hz, 2H), 7.52 (t, J¼7.5 Hz,
2H), 7.42 (t, J¼7.3 Hz, 1H). 13C NMR (100 MHz, DMSO-d6)
d 153.09,
151.14, 145.31, 142.31, 141.43, 140.59, 140.27, 139.34, 137.07, 129.10,
128.09, 127.85, 127.66, 127.48, 126.72, 125.39, 125.34, 122.11. MS
(ESI): m/z 385.1 [MꢁCl]þ. HRMS (MALDI): calcd for C28H21N2
:385.1699. Found: 385.1693.
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X.-K.; Li, Z.-T. Langmuir 2012, 28, 14839; (c) Schaefer, J. J.; Ma, C.; Harris, J. M.
4.1.5. Compound T4. Compound T1 (0.2 g, 0.74 mmol) and methyl
iodide (0.93 mL, 14.9 mmol) was dissolved with dry acetonitrile
(3 mL) in a sealed tube, and heated at 90 ꢀC for two days. The
resulting red precipitate was filtered and washed by dichloro-
methane, and dried in vacuo to yield T4 as a red powder (0.30 g,
ꢁ
€
Anal. Chem. 2012, 84, 9505; (d) Begu, S.; Aubert-Pouessel, A.; Polexe, R.; Leit-
manova, E.; Lerner, D. A.; Devoisselle, J.-M.; Tichit, D. Chem. Mater. 2009, 21,
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80% yield). 1H NMR (400 MHz, DMSO-d6)
d
9.68 (d, J¼6.9 Hz, 2H),
9.32 (d, J¼6.7 Hz, 2H), 8.95 (d, J¼6.9 Hz, 2H), 8.88 (d, J¼6.8 Hz, 2H),
5. (a) Hawthorne, J. N.; Ansell, G. B. Phospholipids; Elsevier: Amsterdam, The
Netherlands, 1982; (b) Menger, F. M.; Gabrielson, K. D. Angew. Chem., Int. Ed.
Engl. 1995, 34, 2091; (c) Sugiura, S.; Kuroiwa, T.; Kagota, T.; Nakajima, M.; Sato,
S.; Mukataka, S.; Walde, P.; Ichikawa, S. Langmuir 2008, 24, 4581.
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Stache, H. W. Anionic Surfactants; Dekker: New York, NY, 1996; (d) Jungermann,
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7.96 (dd, J¼6.8, 2.7 Hz, 2H), 7.88e7.68 (m, 3H), 4.46 (s, 3H). MS
(ESI): m/z 124.1 [Mꢁ2I]2þ
.
HRMS (MALDI): calcd for
C
17H16N2:248.1308. Found: 248.1307.
4.1.6. Compound T5. This compound was prepared in 77% yield as
a red powder from the reaction of compounds T2 and methyl iodide
according to a procedure similar to that described for compound
ꢁ
7. (a) Checot, F.; Lecommandoux, S.; Gnanou, Y.; Klok, H.-A. Angew. Chem., Int. Ed.
T4. 1H NMR (400 MHz, DMSO-d6)
d
9.72 (d, J¼6.9 Hz, 2H), 9.33 (d,
2002, 41, 1339; (b) Kuang, H.; Wu, S.; Xie, Z.; Meng, F.; Jing, X.; Huang, Y. Bio-
ꢁ
ꢁ
molecules 2012, 13, 3004; (c) Leon, A. S. D.; Campo, A. D.; Fernandez-Garcia, M.;
J¼6.7 Hz, 2H), 8.97 (d, J¼7.0 Hz, 2H), 8.89 (d, J¼6.8 Hz, 2H), 8.11 (d,
J¼8.7 Hz, 2H), 8.06 (d, J¼8.8 Hz, 2H), 7.83 (d, J¼7.3 Hz, 2H), 7.57 (t,
J¼7.5 Hz, 2H), 7.49 (t, J¼7.3 Hz, 1H), 4.47 (s, 3H). 13C NMR (100 MHz,
ꢁ
~
Rodriguez-Hernandez, J.; Munoz-Bonilla, A. Langmuir 2012, 28, 9778.
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W.-C.; Chen, W.-C.; Jen, A. K.-Y. Macromolecules 2010, 43, 282.
DMSO-d6)
d 149.02, 147.63, 146.65, 145.67, 143.06, 141.25, 138.01,
129.21, 128.60, 128.20, 127.08, 126.46, 126.22, 125.38, 48.15. MS
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Baumann, K. L; Theiste, D. A. U.S. Patent 5998617, 1999.
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