Generation of biaxiality in smectic A phases by introduction of intermolecular perfluoroarene-arene and C-H/F interactions, and the non-odd-even effect of the molecules in their transition temperatures and layer distances

Article abstract of DOI:10.1039/c1sm05887h

Compounds 1a-j, 4-alkoxy-4′-pentafluorobenzoyloxybiphenyls, were synthesized to investigate the biaxiality in the smectic A phases of rod-like molecules possessing both perfluorinated and non-fluorinated benzene rings. The phase behaviors of the compounds

Full text of DOI:10.1039/c1sm05887h

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PAPER
Generation of biaxiality in smectic A phases by introduction of intermolecular
perfluoroarene–arene and C–H/F interactions, and the non-odd–even effect of
the molecules in their transition temperatures and layer distances†
*
Keiki Kishikawa, Takahiro Inoue, Yoshiyuki Sasaki, Sumihiro Aikyo, Masahiro Takahashi
and Shigeo Kohmoto
Received 13th May 2011, Accepted 3rd June 2011
DOI: 10.1039/c1sm05887h
Compounds 1a–j, 4-alkoxy-40-pentafluorobenzoyloxybiphenyls, were synthesized to investigate the
biaxiality in the smectic A phases of rod-like molecules possessing both perfluorinated and non-
fluorinated benzene rings. The phase behaviors of the compounds and the molecular packing structures
of their smectic A phases were investigated by polarized optical microscopy (POM), differential
scanning colorimetry (DSC), and X-ray diffraction (XRD). As a result, it was found that the plot of the
transition temperatures against the number of carbon atoms in the terminal alkyl chains did not show
a clear odd–even effect, and an unique effect ‘‘tgg-effect’’ was observed in the plots of their layer
distances against the number of carbon atoms. In the detailed 1D- and 2D-XRD studies of the smectic
A phases, lateral directional orders in each layer were observed. It is assumed that these results originate
from the biaxiality of the smectic A phases and slow rotation of the molecules around their molecular
long axes.
assisted approach to realize laterally ordered smectic A phases of
Introduction
low molecular weight straight rod-like molecules by introducing
strong lateral intermolecular interactions. As a result, these
molecules showed local biaxiality in the smectic A phases and
unique phenomena in the transition temperatures and layer
distances depending on their alkyl chain lengths.
In rod-like molecules, smectic A phases are known as common
thermal liquid crystal phases and have layered superstructures.
In uniaxial smectic A phases, the molecular long axes are on
average parallel to the layer normal and the molecules have no
directional order in their lateral directions.1–3 On the other hand,
biaxial smectic A phases have a lateral directional order and the
phases have a possibility to realize new high-responsive LC
display devices.4 The study of biaxial smectic A phases is also
important to understand the mechanisms for generation of
biaxiality in nematic phases.5 However, realization of biaxial
smectic A phases is so difficult that the examples are still limited.
To generate the lateral directional order, laterally anisotropic
molecular shapes such as bent rods6,7 or boards8 have been used
for the molecular designs in most cases. Side-chain polymers with
laterally attached rod-like mesogenic units have also been used
for generation of biaxial smectic A phases.9 Those shape-assisted
and covalent bond-assisted approaches are thought to be
necessary for generation of biaxial smectic A phases, and it is still
difficult to realize them by using straight rod-like molecules with
low molecular weight. In this study, we indicate an interaction-
As shown in Fig. 1, we planned to introduce two different
kinds of benzene rings into one rod-like molecule. If both
intermolecular face-to-face (A) and edge-to-edge (B) interactions
simultaneously interact, a laterally ordered structure (C) is
generated by these two kinds of interactions. For this purpose,
Department of Applied Chemistry and Biotechnology, Faculty of
Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba,
263-8522, Japan. E-mail: kishikawa@faculty.chiba-u.jp; Fax: +81-43-
290-3422; Tel: +81-43-290-3238
† Electronic supplementary information (ESI) available: Layer distances
of 1a–j obtained by 1D-XRD. See DOI: 10.1039/c1sm05887h
Fig. 1 Concept for generation of a laterally ordered structure.
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Table 1 Phase transition behaviours of the 4-alkoxy-40-pentafluoro-
we selected the interactions between perfluorinated and non-
fluorinated benzene rings. It is known that perfluoroarene–arene
(PFA–A)10–15 and C–H/F16 interactions interact as face-to-face
and edge-to-edge manners, respectively. Based on this concept,
a pentafluorobenzoyloxy group was introduced at the 4-position
of a biphenyl moiety (Scheme 1).
benzoyloxybiphenylsa
Phase
transition/ꢀC (kcal/molꢁ1
)
Compound
n
1a
1b
1c
7
8
9
Further, to stabilize the liquid crystallinity, a flexible alkoxy
chain was introduced at the other terminal of the biphenyl
moiety.
Result and discussion
Synthesis and phase identification of liquid crystalline compounds
1a–j
1d
1e
1f
10
11
12
13
14
15
Compounds 1a–j were synthesized by condensation of penta-
fluorobenzoic acid and the corresponding 4-(4-alkoxyphenyl)
phenol. Their phase behaviors were identified by POM and DSC.
As shown in Table 1, all compounds in this study showed a stable
smectic A phase. The microphotograph of 1a is shown in Fig. 2.
It shows fan-like textures with dark lines parallel to the directions
of the crossed polarizers that were observed as the typical
textures of smectic A phases which indicated that the phases had
layer structures and the molecules were parallel to the layer
normal. These compounds also showed dark homeotropic
textures, indicative of the optically uniaxial phases.17 In Fig. 3,
the clearing and melting points are plotted against the number of
carbon atoms in the substituted normal alkyl chain. A distinctive
odd–even chain length effect18 is not observed in these
compounds. It is known that the odd–even effects on the clearing
points in rod-like liquid crystalline compounds originate from
the excluded volumes during rotation of the molecules around
the molecular long axes. Rapid rotational movements of mole-
cules around their long axes enhance the population of all-trans-
conformers to make their excluded volumes smaller, which
causes an odd–even effect.19 Accordingly, no odd–even effect for
these molecules strongly suggests that the rotation of the mole-
cules is highly suppressed by their strong intermolecular inter-
actions. The clearing point of 1d (n ¼ 10) is lower than those of
the homologues 1c (n ¼ 9) and 1e (n ¼ 11), while the melting
point of 1d is higher than those of 1c and 1e. It is difficult to
explain this discontinuity in the clearing and melting points. It is
assumed that the volume balance between the core and the chain
1g
1h
1i
1j
16
a
The transition temperatures (ꢀC) and transition enthalpies (kcal molꢁ1
)
were determined by DSC (5 ꢀC minꢁ1) and are given above and below the
arrows. Cr, SmA, Iso indicate crystal, smectic A, and isotropic liquid
phases, respectively.
parts is not appropriate for molecular packing in the liquid
crystalline state.
1D-XRD study of 1a–j
Fig. 4 shows the observed layer distances d(100) in the 1D-XRD
of 1a–j and their molecular lengths calculated as the all-trans
Fig. 2 Polarized light microphotograph of 1a (130 ꢀC, ꢂ300). The
directions of the crossed polarizers were indicated by the crossed arrows.
The scale bar is 100 mm.
Scheme 1 Molecular structures of 1a–j.
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Fig. 3 Plots of clearing and melting points of 1a–j (n ¼ 7–16) against n
(n: number of carbon atoms in the alkyl chain). The temperature rate is
5 ꢀC minꢁ1
.
Scheme 2 The most probable conformations of the alkyl chains of 1a,
1d, 1g, and 1j estimated from periodicity in the layer distance measured
by XRD in the series of 1a–j. The alkyl chains of 1a, 1d, 1g, and 1j have
tggtgg-, tggtggtgg-, tggtggtggtgg-, and tggtggtggtgg-forms (t: trans, g:
gauche) to attain the tight packing. The covalent bonds with trans- (t) and
gauche- (g) forms were indicated in red and black, respectively.
tggtgg-, tggtggtgg-, tggtggtggtgg-, and tggtggtggtgg-forms
(t: trans, g: gauche) as their averaged conformations to be packed
tightly in the layers, respectively.
Fig. 5 shows molecular models for a 1d molecule possessing
a decyl group with tggtggtgg-form which is suitable for the dense
Fig. 4 Plots of the observed layer distances (filled squares) and calcu-
lated molecular lengths20 with all-trans-forms (open triangles) against n in
1a–j (n ¼ 7–16, n: number of carbon atoms in the alkyl chains) at 130 ꢀC.
conformers.20 Their layer distances observed are significantly
shorter than the corresponding molecular lengths calculated. It
suggests that the alkyl chains also have gauche-forms. Further,
the layer distances against the number of carbon atoms (n) have
a periodicity. The layer distances of compounds 1a (n ¼ 7), 1d (n
¼ 10), 1g (n ¼ 13), and 1j (n ¼ 16) are particularly short
compared to their molecular lengths. It means that the ratios of
the layer distances to the calculated lengths become smaller for
every three carbon atoms added. To the best of our knowledge,
this phenomenon has not been reported. It is assumed that this
originated in the suppression of the rotational movements of the
rod-like molecules by the strong lateral intermolecular interac-
tions. It is not necessary that their alkyl chains have trans-forms
to make the excluded volumes small, because they are not
rotating rapidly. As shown in Scheme 2, there is a possibility that
the alkyl chains of 1a, 1d, 1g, and 1j in the smectic A phases have
Fig. 5 Molecular models (stick and space-fill models) of 1d with
a tggtggtgg-form.
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packing in the smectic layer structure. This ‘‘tgg-effect’’ explains
the periodicity in the plots of the layer distances against the n in
the alkyl chains.
In Fig. 6, the 1D-XRD profile of 1a is shown. In the small
angle region, it has a large sharp d(100) peak with small sharp d
(200) and d(300) peaks, which is indicative of a well-organized
layer structure. The magnified chart in the inset has the four
ꢀ
ꢀ
ꢀ
ꢀ
broad peaks b (¼ 7.8 A), c (¼ 5.6 A), d (¼ 4.5 A), and e (¼ 3.9 A).
It is assumed that the peaks b, c, and e indicate the repeat
distances in the lateral directions in each layer. The broad peak
d originates in the molten alkyl chains.
2D-XRD study of 1a
Compound 1a was sealed in a glass capillary of 1.5 mm diameter.
The sample was aligned by ꢀheating up to 170 ꢀC followed by
ꢀ
cooling slowly down to 120 C. The 2D-XRD profile at 120 C
Fig. 7 2D-XRD profile of 1a (120 ꢀC). The peaks of interlayer distances
(d(100) and d(200)) are pointed by arrows, and the areas of the lateral
repeat distances (a, b, c, d, and e) are indicated by oval and crescent moon
shapes drawn with black (a, b, c, and e) and yellow (d) broken lines,
respectively.
(smectic A phase) is shown in Fig. 7. The sets of d(100) and d(200)
peaks are observed clearly only on the equator, which means that
there is a well aligned layer structure, and some broad peaks are
shown on the meridian. It suggests that the rod-like molecules are
parallel to the layer normal and are also ordered laterally in each
layer.
was calculated by the DFT (B3LYP6-31G(d)) method.21 As
shown in Fig. 8, the p-faces of pentafluorophenyl and the ester
linked phenyl of biphenyl are almost in the same plane. The
torsion angle between the two benzene rings of the biphenyl
group was about 38ꢀ. The molecule has a board-like shape, and
the fluorine atoms at the 2, 3, 5, 6-positions of the penta-
fluorophenyl and all hydrogen atoms of the biphenyl moiety are
at the sides of the board-like molecule, which are suitable for the
intermolecular PFA–A and C–H/F interactions, respectively.
In Fig. 9a (molecular model of 1) and Fig. 9b (the top view of
the layer), the lateral repeat distances in 1D- and 2D-XRD
In comparison with the result of the 1D-XRD of 1a, the broad
ꢀ
ꢀ
ꢀ
ꢀ
peaks b (¼ 7.8 A), c (¼ 5.6 A), d (¼ 4.5 A), and e (¼ 3.9 A)
observed in 1D-XRD were depicted on the 2D-XRD profile, and
the broad peaks in the 1D-XRD profile almost agree with those
on the meridian in the 2D-XRD profile. In addition, the most
ꢀ
intensive broad peak a z 11 A was observed in the 2D-XRD,
which is difficult to distinguish from d(200) in the 1D-XRD
profile.
Estimation of the packing structure in the smectic A phase. To
estimate the most stable conformation of 1, the conformation of
the homologue, 4-methoxy-40-pentafluorobenzoyloxy-biphenyl,
ꢀ
profiles, ca. 11, 7.8, 5.6, and 3.9 A, are indicated as a, b, c, and e.
The two different benzene rings alternately stack and this
packing structure generates the repeat distances e and b corre-
ꢀ
sponding to once and twice the stacking distance of 3.9 A which
ꢀ
is close to the value 3.7 A reported as the inter-centroid distance
in co-crystals of hexafluorobenzene and benzene.11 The mole-
cules aligned laterally in each layer generate the repeat distances
a and c. The alkyl chains are interdigitated between the adjacent
two layers (Fig. 9c), and they are tightly packed not to make
leave space by having both trans- and gauche-conformations.
The p-faces of the molecules direct one direction in each of the
layers, and the long axes of the rod-like cores are perpendicular
to the layer normal. The rotation of the rod-like molecules
around the molecular long axes is strongly suppressed by the
Fig. 6 XRD profile of 1a at 120 ꢀC. The d(100) and d(200) are indicated
at the top of the peaks. The magnified profile is shown in the inset, and
the d(200), d(300), and broad peaks (a, b, c, d, and e) are indicated by the
arrows.
Fig.
8
Most
stable
conformation
of
4-methoxy-40-penta-
fluorobenzoyloxybiphenyl calculated by the DFT (B3LYP6-31G(d))
method.21 The fluorine, carbon, oxygen, and hydrogen atoms are color-
ized yellow, gray, red, and white, respectively.
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2a–j were 74.5, 65.3, 25.5, 50.9, 58.4, 48.4, 64.6, 26.3, 29.1, and
33.4%, respectively.
2a: Rf ¼ 0.7 (hexane : ethyl acetate ¼ 1 : 1); 1H NMR (300.22
MHz, CDCl3): 0.91 (t, J ¼ 7.0 Hz, 3H), 1.26–1.52 (m, 8H), 1.80
(quint, J ¼ 7.0 Hz, 2H), 3.99 (t, J ¼ 6.4 Hz, 2H), 4.77 (s, 1H), 6.88
(d, J ¼ 2.7 Hz, 2H), 6.94 (d, J ¼ 2.9 Hz, 2H), 7.43 (m, 4H).
2b: Rf ¼ 0.7 (hexane : ethyl acetate ¼ 1 : 1); 1H NMR (300.22
MHz, CDCl3): 0.89 (t, J ¼ 6.8 Hz, 3H), 1.31–1.56 (m, 10H), 1.80
(quint, J ¼ 7.0 Hz, 2H), 3.98 (t, J ¼ 6.6 Hz, 2H), 4.70 (s, 1H), 6.91
(m, 4H), 7.44 (m, 4H).
2c: Rf ¼ 0.7 (hexane : ethyl acetate ¼ 1 : 1); 1H NMR (300.22
MHz, CDCl3): 0.89 (t, J ¼ 6.8 Hz, 3H), 1.28–1.55 (m, 12H), 1.80
(quint, J ¼ 7.0 Hz, 2H), 3.98 (t, J ¼ 6.6 Hz, 2H), 4.80 (s, 1H), 6.88
(d, J ¼ 8.6 Hz, 2H), 6.94 (d, J ¼ 8.7 Hz, 2H), 7.43 (m, 4H).
2d: Rf ¼ 0.7 (hexane : ethyl acetate ¼ 1 : 1); 1H NMR (300.22
MHz, CDCl3): 0.91 (t, J ¼ 6.9 Hz, 3H), 1.30–1.55 (m, 14H), 1.80
(quint, J ¼ 7.0 Hz, 2H), 3.99 (t, J ¼ 6.4 Hz, 2H), 4.77 (s, 1H), 6.91
(m, 4H), 7.43 (m, 4H).
2e: Rf ¼ 0.7 (hexane : ethyl acetate ¼ 1 : 1); 1H NMR (300.22
MHz, CDCl3): 0.88 (t, J ¼ 6.6 Hz, 3H), 1.26–1.47 (m, 16H), 1.79
(quint, J ¼ 7.0 Hz, 2H), 3.98 (t, J ¼ 6.6 Hz, 2H), 4.74 (s, 1H), 6.91
(m, 4H), 7.43 (m, 4H).
Fig. 9 Schematic representations of (a) the molecular model of 1
(L: molecular length), (b) the top view of a part of the layer (the alkyl
chains are omitted for clarity, the four repeat distances a, b, c, and e are
indicated), and (c) the layer structure of 1 in the smectic A phase (d(100):
layer distance observed in XRD).
2f: Rf ¼ 0.7 (hexane : ethyl acetate ¼ 1 : 1); 1H NMR (300.22
MHz, CDCl3): 0.88 (t, J ¼ 6.8 Hz, 3H), 1.26–1.46 (m, 18H), 1.80
(quint, J ¼ 7.3 Hz, 2H), 3.98 (t, J ¼ 6.6 Hz, 2H), 4.70 (s, 1H), 6.90
(m, 4H), 7.43 (m, 4H).
2g: Rf ¼ 0.7 (hexane : ethyl acetate ¼ 1 : 1); 1H NMR (300.22
MHz, CDCl3): 0.88 (t, J ¼ 6.8 Hz, 3H), 1.36 (m, 20H), 1.80
(quint, J ¼ 7.0 Hz, 2H), 3.98 (t, J ¼ 6.6 Hz, 2H), 4.78 (s, 1H), 6.91
(m, 4H), 7.43 (m, 4H).
PFA–A and C–H/F interactions. It is assumed that these smectic
A phases are locally biaxial in each layer, they have no macro-
scopic biaxiality from the observation of the POM in the smectic
A phase which gave dark homeotropic textures.
Conclusion
2h: Rf ¼ 0.7 (hexane : ethyl acetate ¼ 1 : 1); 1H NMR (300.22
MHz, CDCl3): 0.88 (t, J ¼ 6.6 Hz, 3H), 1.26–1.56 (m, 22H), 1.80
(quint, J ¼ 6.9 Hz, 2H), 3.98 (t, J ¼ 6.6 Hz, 2H), 4.69 (s, 1H), 6.91
(m, 4H), 7.44 (m, 4H).
We demonstrated an interaction assisted approach for realiza-
tion of biaxiality in smectic A phases, and indicated the effec-
tiveness of the PFA–A and CH/F interactions as the
intermolecular interactions. The 1D- and 2D-XRD studies
indicated that the molecules in the smectic A phases have lateral
directional order in each layer, and it is assumed to originate
from the local biaxiality of the smectic A phases. Further, the
slow rotation of the molecules showed unique phenomena such
as no clear odd–even effect in their clearing and melting points,
and a ‘‘tgg-effect’’ in the plots of their layer distances against the
number of carbon atoms in the terminal alkyl chains.
1
2i: Rf ¼ 0.7 (hexane : ethyl acetate ¼ 1 : 1); H NMR (300.22
MHz, CDCl3): 0.91 (t, J ¼ 6.9 Hz, 3H), 1.25–1.55 (m, 24H), 1.80
(quint, J ¼ 7.0 Hz, 2H), 3.99 (t, J ¼ 6.4 Hz, 2H), 4.77 (s, 1H), 6.88
(d, J ¼ 2.7 Hz, 2H), 6.94 (d, J ¼ 0.29 Hz, 2H), 7.43 (m, 4H).
1
2j: Rf ¼ 0.7 (hexane : ethyl acetate ¼ 1 : 1); H NMR (300.22
MHz, CDCl3) 0.88 (t, J ¼ 6.2 Hz, 3H), 1.24–1.55 (m, 26H), 1.79
(quint, J ¼ 6.9 Hz, 2H), 3.98 (t, J ¼ 6.2 Hz, 2H), 4.68 (s, 1H), 6.91
(m, 4H), 7.43 (m, 4H).
Experimental
Synthesis of compound 1
Synthesis of 4-(4-alkoxyphenyl)phenol (synthesis of 2)
Compound 2 (3.99 mmol), pentafluorobenzoic acid (0.85 g,
4.0 mmol), and dry THF (20 mL) were placed in a 200 mL three-
necked flask equipped with a CaCl2 tube. The solution was
stirred at 0 ꢀC, and DIPC (0.74 mL, 4.8 mmol) and DMAP (0.05
g, 0.4 mmol) were added and stirred at room temperature for 24
h. The solution was concentrated in vacuo, and chloroform (100
mL) was added. The solution was washed with water (100 mL ꢂ
3), and dried over anhydrous MgSO4. The solution was filtered
and the filtrate was concentrated. The product was purified by
silica gel column chromatography eluting with chloroform, and
then the product was purified by recrystallization from chloro-
form–hexane to give 1 as a white crystal. Compounds 1a–j were
obtained by the same procedure. The yields of 1a–j were 47.3,
49.2, 42.4, 37.2, 38.0, 44.7, 34.2, 30.8, 24.0, and 26.8%.
To 4,40-biphenol (1.00 g, 5.37 mmol), K2CO3 (0.740 g, 5.37
mmol), and potassium iodide (0.090 g, 0.54 mmol) in a 200 mL
three necked round bottom flask equipped with a Dimroth
condenser and a CaCl2 tube was added acetone (30 mL). The
solution was refluxed with stirring and 1-bromoalkane (5.37
mmol) was added dropwise. The solution was refluxed for 24 h
with stirring. After cooling, ethyl acetate (100 mL) was added
and the solution was washed with water (100 mL ꢂ 3). The
organic solution was dried over anhydrous MgSO4, filtered with
suction, and concentrated in vacuo. The product was purified by
recrystallization from hexane–ethyl acetate to give 4-(4-alkox-
yphenyl)phenol 2 as a white powder crystal. Compounds 2a–j
were prepared by the abovementioned procedure. The yields of
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1a: Rf ¼ 0.27 (hexane : chloroform ¼ 1 : 1); IR (KBr) 2914,
2770, 1748, 1653, 1497, 1216, 1010 cmꢁ1; 1H NMR (300.22 MHz,
CDCl3): 0.91 (t, J ¼ 6.8 Hz, 3H), 1.26–1.48 (m, 8H), 1.80 (m,
2H), 4.00 (t, J ¼ 6.3 Hz, 2H), 6.96 (m, 2H), 7.30 (m, 2H), 7.49 (m,
2H), 7.64 (m, 2H); 13C NMR (75.48 MHz, CDCl3): 14.55, 23.07,
26.48, 29.53, 29.73, 32.25, 68.57, 109.87, 115.30, 121.86, 128.33,
128.58, 132.75, 135.02, 137.82, 148.96, 149.12, 149.30, 159.41,
166.59; HRMS (FAB) calcd for C26H23F5O3Na [(M + Na)+]
501.1443, found 501.1460.
Hz, 2H), 7.30 (d, J ¼ 8.5 Hz, 2H), 7.50 (d, J ¼ 8.6 Hz, 2H), 7.60
(d, J ¼ 8.7 Hz, 2H); 13C NMR (75.48 MHz, CDCl3): 14.57, 23.15,
26.51, 29.72, 29.81, 29.86, 30.05, 30.09, 30.12, 32.37, 68.57,
111.17, 115.30, 121.86, 128.33, 128.58, 132.74, 136.19, 139.74,
147.39, 149.28, 150.04, 159.41, 162.78; HRMS (FAB) calcd for
C32H35F5O3 [M+] 562.2497, found 562.2501.
1h: Rf ¼ 0.25 (hexane : chloroform ¼ 1 : 1); IR (KBr) 2917,
1
2850, 1750, 1653, 1607, 1490, 1234, 989 cmꢁ1; H NMR (300.22
MHz, CDCl3): 0.88 (t, J ¼ 6.6 Hz, 3H), 1.26–1.47 (m, 22H), 1.81
(quint, J ¼ 7.0 Hz, 2H), 4.00 (t, J ¼ 6.4 Hz, 2H), 6.97 (d, J ¼ 8.7
Hz, 2H), 7.29 (d, J ¼ 8.7 Hz, 2H), 7.50 (d, J ¼ 8.6 Hz, 2H),7.60
(d, J ¼ 8.7 Hz, 2H); 13C NMR (75.48 MHz, CDCl3): 14.57, 23.15,
26.51, 29.72, 29.81, 29.86, 30.00, 30.04, 30.06, 30.11, 32.38, 68.57,
109.88, 115.30, 121.86, 128.33, 128.58, 132.75, 134.36, 137.98,
146.94, 147.46, 149.30, 159.41, 164.97; HRMS (FAB) calcd for
C33H37F5O3 [M+] 576.2656, found 576.2657.
1b: Rf ¼ 0.27 (hexane : chloroform ¼ 1 : 1); IR (KBr) 2921,
1
2769, 1750, 1652, 1607, 1505, 1275, 996 cmꢁ1; H NMR (300.22
MHz, CDCl3): 0.89 (t, J ¼ 6.8 Hz, 3H), 1.29–1.47 (m, 10H), 1.80
(m, 2H), 3.99 (t, J ¼ 6.3 Hz, 2H), 6.93 (m, 2H), 7.30 (m, 2H), 7.47
(m, 2H), 7.64 (m, 2H); 13C NMR (75.48 MHz, CDCl3): 14.57,
23.12, 26.51, 29.72, 29.87, 32.33, 68.57, 109.97, 115.29, 121.87,
128.08, 128.33, 132.76, 134.34, 139.23, 147.81, 148.02, 149.30,
158.64, 165.34; HRMS (FAB) calcd for C27H25F5O3 [M+]
492.1688, found 492.1718.
1i: Rf ¼ 0.25 (hexane : chloroform ¼ 1 :1); IR (KBr) 2917,
1
2849, 1750, 1652, 1607, 1490, 1235, 989 cmꢁ1; H NMR (300.22
1c: Rf ¼ 0.27 (hexane : chloroform ¼ 1 : 1); IR (KBr) 2933,
MHz, CDCl3) 0.88 (t, J ¼ 6.8 Hz, 3H), 1.26–1.47 (m, 24H), 1.80
(quint, J ¼ 7.0 Hz, 2H), 4.00 (t, J ¼ 6.6 Hz, 2H), 6.97 (d, J ¼ 8.6
Hz, 2H), 7.29 (d, J ¼ 8.7 Hz, 2H), 7.50 (d, J ¼ 8.7 Hz, 2H), 7.61
(d, J ¼ 8.7 Hz, 2H); 13C NMR (75.48 MHz, CDCl3): 14.56, 23.14,
26.51, 29.72, 29.83, 29.86, 30.04, 30.06, 30.12, 32.37, 68.57,
109.37, 115.30, 121.86, 128.33, 128.57, 132.74, 134.33, 140.12,
145.91, 148.47, 149.30, 159.40, 165.52; HRMS (FAB) calcd for
C34H39F5O3 [M+] 590.2811, found 590.2814.
1
2851, 1750, 1652, 1607, 1503, 1229, 989 cmꢁ1; H NMR (300.22
MHz, CDCl3): 0.89 (t, J ¼ 6.6 Hz, 3H), 1.28–1.47 (m, 12H), 1.80
(m, 2H), 3.99 (t, J ¼ 6.3 Hz, 2H), 6.95 (m, 2H), 7.29 (m, 2H), 7.50
(m, 2H), 7.62 (m, 2H); 13C NMR (75.48 MHz, CDCl3): 14.57,
23.13, 26.52, 29.72, 29.87, 30.00, 32.33, 68.57, 110.12, 115.30,
121.86, 128.08, 128.33, 132.75, 135.87, 139.90, 145.90, 149.26,
149.83, 157.56, 165.28; HRMS (FAB) calcd for C28H28F5O3Na
[(M + H + Na)+] 530.1805, found 530.1851.
1j: Rf ¼ 0.25 (hexane : chloroform ¼ 1 : 1); IR (KBr) 2917,
1
1d: Rf ¼ 0.27 (hexane : chloroform ¼ 1 : 1); IR (KBr) 2919,
2849, 1750, 1653, 1607, 1490, 1234, 990 cmꢁ1; H NMR (300.22
1
2851, 1751, 1652, 1607, 1491, 1234, 990 cmꢁ1; H NMR (300.22
MHz, CDCl3) 0.88 (t, J ¼ 6.6 Hz, 3H), 1.26–1.49 (m, 26H), 1.81
(quint, J ¼ 7.3 Hz, 2H), 4.00 (t, J ¼ 7.3 Hz, 2H), 6.98 (d, J ¼ 8.7
MHz, CDCl3): 0.89 (t, J ¼ 6.6 Hz, 3H), 1.28–1.47 (m, 14H), 1.80
(m, 2H), 3.99 (t, J ¼ 6.3 Hz, 2H), 6.95 (m, 2H), 7.32 (m, 2H), 7.48
(m, 2H), 7.63 (m, 2H); 13C NMR (75.48 MHz, CDCl3): 14.58,
23.14, 26.52, 29.73, 29.78, 29.87, 30.02, 30.05, 32.36, 68.57,
110.03, 115.29, 122.15, 128.08, 128.92, 132.75, 133.74, 139.24,
146.77, 147.84, 148.46, 158.63, 165.25; HRMS (FAB) calcd for
C29H28F5O3 [(MꢁH)+] 519.1959, found 519.1953.
Hz, 2H), 7.29 (m, 2H), 7.50 (d, J ¼ 8.6 Hz, 2H), 7.61 (m, 2H); 13
C
NMR (75.48 MHz, CDCl3) 14.57, 23.15, 26.51, 29.72, 29.82,
29.86, 30.04, 30.06, 30.12, 30.14, 32.38, 68.57, 109.69, 115.29,
121.86, 128.33, 128.58, 132.74, 136.36, 140.11, 145.47, 147.21,
149.30, 159.40, 164.37; HRMS (FAB) calcd for C35H41F5O3 [M+]
604.2965, found 604.2970.
1e: Rf ¼ 0.25 (hexane : chloroform ¼ 1 : 1); IR (KBr) 2918,
1
2850, 1750, 1653, 1607, 1490, 1234, 990 cmꢁ1; H NMR (300.22
Acknowledgements
MHz, CDCl3): 0.88 (t, J ¼ 6.6 Hz, 3H), 1.27–1.47 (m, 16H), 1.79
(m, 2H), 3.99 (t, J ¼ 6.3 Hz, 2H), 6.96 (m, 2H), 7.31 (m, 2H), 7.49
(m, 2H), 7.62 (m, 2H); 13C NMR (75.48 MHz, CDCl3): 14.56,
23.12, 26.49, 29.70, 29.74, 29.79, 29.85, 30.02, 30.05, 32.34, 68.55,
107.84, 115.27, 121.85, 128.06, 128.57, 132.78, 134.23, 140.16,
147.75, 149.27, 150.66, 159.38, 167.13; HRMS (FAB) calcd for
C30H31F5O3 [M+] 534.2182, found 534.2188.
We are grateful to the Futaba Electronics Memorial Foundation,
and we thank Grant-in-Aid for Scientific Research (B) 19350090.
Notes and references
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1f: Rf ¼ 0.25 (hexane : chloroform ¼ 1 : 1); IR (KBr) 2917,
1
2850, 1750, 1653, 1607, 1489, 1235, 989 cmꢁ1; H NMR (300.22
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1
2849, 1750, 1653, 1607, 1490, 1234, 989 cmꢁ1; H NMR (300.22
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7538 | Soft Matter, 2011, 7, 7532–7538
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