Smectic A liquid crystals from dihydrazide derivatives with lateral intermolecular hydrogen bonding

Article abstract of DOI:10.1016/j.tet.2005.04.004

Six dissymmetrical dihydrazide derivatives, N-(4-alkoxybenzoyl)-N′- (4′-nitrobenzoyl) hydrazine (Cn-NO₂) and N-(4-alkoxybenzoyl)- N′-(4′-biphenyl carbonyl) hydrazine (Cn-Ph), were synthesized and investigated by means of differential scanning c

Full text of DOI:10.1016/j.tet.2005.04.004

Tetrahedron 61 (2005) 6108–6114
Smectic A liquid crystals from dihydrazide derivatives with
lateral intermolecular hydrogen bonding*
*
Dongmei Pang, Haitao Wang and Min Li
Key Laboratory of Automobile Materials (Jilin University), Ministry of Education, Institute of Materials Science and Engineering,
Jilin University, Changchun 130012, People’s Republic of China
Received 24 December 2004; revised 29 March 2005; accepted 4 April 2005
Available online 17 May 2005
Abstract—Six dissymmetrical dihydrazide derivatives, N-(4-alkoxybenzoyl)-N0-(40-nitrobenzoyl) hydrazine (Cn–NO2) and N-(4-
alkoxybenzoyl)-N0-(40-biphenyl carbonyl) hydrazine (Cn–Ph), were synthesized and investigated by means of differential scanning
calorimetry, polarized optical microscopy and wide angle X-ray diffraction. The compounds exhibit smectic A1 phase. Based on the results of
1H NMR and variable temperature FT-IR spectroscopy, lateral intermolecular hydrogen bonding between –C]O and –N–H groups was
proposed and the effect of hydrogen bonding on the phase transitions was discussed. It was concluded that the combination of lateral
intermolecular hydrogen bonding and microphase segregation stabilized the smectic A phase.
q 2005 Elsevier Ltd. All rights reserved.
1. Introduction
Hydrogen bonding is crucial to mesophase formation and
stabilization.1–4,7 In the past decade, various types of rod-
like,2 discotic3 and network4 supramolecular liquid crystals
based on hydrogen bonding have been reported. However,
many efforts have been restricted in the generation of
calamitic mesophases with molecules bearing a donor or an
acceptor site at their terminals, in which hydrogen bonding
along the molecular long axis was utilized to form a new and
elongated mesogen to stabilize the mesophase, such as a
dimer of aromatic carboxyl acid5 or dimerization between
the carboxyl acid and pyridyl moieties.6 However, lateral
intermolecular hydrogen bonding has not been extensively
investigated, except a few reports which claimed that it can
Scheme 1. The molecular structures of 1-3, Cn–NO2, and Cn–Ph.
stabilize the smectic layer structure.7
decyloxy chain, for instance in compound 2, will decrease
the linearity of the calamatic molecule, preventing the
The linear N,N0-bis (40-decyloxybenzoyl) hydrazide8
1
formation of cubic phase and driving the smectic phase
metastable.10 Continuing to add terminal chains 3 will
further enlarge the volume fraction of flexible chains, which
gives rise to a more curvature of the aromatic–aliphatic
interface, leading to columnar phases.10 Beginn has
investigated the effect of the number of the terminal chains
and the structure of the hydrogen bonded rigid core on the
mesophases. He concluded that both the molecular shape
determined by the substituted chains and the intermolecular
hydrogen bonding dramatically affected the type and the
stability of the mesophases.10
(Scheme 1) exhibits the unusual phase sequence Cr/
Cubic/Sm C /Isotropic. Elongating the terminal alkoxy
chains, such as bisubstituted by the cetyloxy chains results
in exclusively cubic phase.9 The introduction of another
* CCDC 258072 contains the supplementary crystallographic data for this
paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk/
data_request/cif, or by emailing data_request@ccdc.cam.ac.uk, or by
contacting The Cambridge Crystallographic Data Centre, 12, Union
Road, Cambridge CB2 1EZ, UK; fax: C44 1223 336033.
Keywords: Lateral intermolecular hydrogen bonding; Liquid crystals;
Smectic A phase; Dihydrazide derivatives.
*
Corresponding author; e-mail: minli@mail.jlu.edu.cn
Dissymmetric dihydrazide derivatives, with one alkoxy
0040–4020/$ - see front matter q 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2005.04.004

D. Pang et al. / Tetrahedron 61 (2005) 6108–6114
6109
1
chain as terminal group, exhibit smectic and/or nematic
phases. Karamysheva and co-workers have reported the
phase transitional properties of the derivatives with different
substituents.11 In fact, the introduction of a hydarzide group
as linkage or part of the rigid unit to calamitic molecules, for
example the dissymmetric dihydrazide derivatives Cn–NO2
and Cn–Ph synthesized in our laboratory (Scheme 1), can
simplify the molecular model, providing an opportunity to
investigate the influence of lateral intermolecular hydrogen
bonding on the mesophase without the worry of steric effect,
as in the system of calamitic molecules with laterally
attached hydrophilic groups.7d Herein, we focused on the
hydrogen bonding motifs and the thermotropic liquid
crystalline properties of Cn–NO2 and Cn–Ph, to reveal the
role of the lateral intermolecular interactions in the
formation of the mesophases.
experiments were performed. In H NMR dilution studies,
the amide protons of Cn–NO2 and Cn–Ph showed strong
concentration dependence, for example, reducing the
concentration of C6–NO2 in CDCl3 from 15.6 to 0.2 mM
causes both NH-1 (near to nitro phenyl, DdZ0.57 ppm) and
NH-2 (near to alkoxy phenyl, DdZ0.19 ppm) to shift
upfield remarkably, as shown in Table 1. These results
strongly indicated that N–H groups were involved in
intermolecular hydrogen bonding.13 The variable-tempera-
ture measurements of amide protons further supported
above conclusion. Generally, internally hydrogen bonded
amides are expected to show a much smaller shift with
temperature (!3.0!10K3 ppm KK1) compared to those
directed externally and accessible for hydrogen bonding to a
polar solvent (O4.0!10K3 ppm KK1).14 However, both
NH-1 and NH-2 of C6–NO2 showed large shifts (5.85!
10K3 and 7.74!10K3 ppm KK1 respectively, as shown in
Fig. 2) with temperature in 20% DMSO-d6/CDCl3,
suggesting the primary involvement of N–H protons in
intermolecular hydrogen bonding. This may be due to a
more favorable geometry for the formation of the inter-
molecular hydrogen bonding than the intramolecular one, as
have been discussed in the crystal structure section.
2. Results and discussion
2.1. Crystal structure
The powder X-ray diffraction pattern of C3–NO2 was
recorded at ambient temperature on a Rigaku D/max 2500
PC X-ray diffractometer (reflection, Cu K-alpha1). The 2q
range was 2–358, measured in steps of 0.028. The crystal
structure determination from the powder diffraction data
was carried out using Materials Studio.† All the diffraction
peaks can be indexed as the monoclinic structure, and the
unit cell contains two molecules. It belongs to P121 space
Table 1. The chemical shifts of amide protons for C6–NO2 at different
concentrations in CDCl3 (NH-1: near to nitro phenyl, NH-2: near to alkoxy
phenyl)
Concentration/mM
NH-1 chemical shifts
/ppm
NH-2 chemical shifts
/ppm
15.6
7.8
3.9
2.6
0.2
9.85
9.64
9.44
9.40
9.28
9.19
9.09
9.02
9.01
9.00
˚
group and the lattice parameters are aZ17.179(5) A, bZ
˚
˚
3.319(2) A, cZ16.692(8) A and bZ92.533(8)8. The density
calculated was 1.20 g cmK3. The final Rietveld refinement
gave RwpZ7.38% and RpZ5.45% (110 reflections, 1627
data points). Figure 1 illustrated the molecules stacking of
C3–NO2 in the crystal. What can be observed directly was
that the intermolecular hydrogen bonding was more easily
accessible due to the higher linearity of the intermolecular
N–H/O bond.12 The angle of intermolecular hydrogen
bond of N–H/O (141.37 and 117.528) was larger than that
of intramolecular one (103.98 and 103.438).
(continued on next page)
Figure 2. The chemical shifts of NH-1 and NH-2 of C6–NO2 in 20%
DMSO-d6/CDCl3 versus temperature. NH-1: near to nitro phenyl, NH-2:
near to alkoxy phenyl.
Figure 1. The crystal structure of C3–NO2. The dashed line illustrated the
hydrogen bonding.
2.2. Hydrogen-bonding motif
Position, intensity and shape of IR absorption bands are
known to be sensitive to conformations and intermolecular
interactions. So, in order to evaluate the effect of hydrogen
bonding on the phase transitional properties of the
compounds, temperature dependent FT-IR spectra of
C16–NO2 and C16–Ph were measured. Table 2 presented
the assignments of infrared frequencies for C16–NO2 and
In order to explore the hydrogen-bonding motif, tempera-
ture dependent FT-IR and 1H NMR spectroscopic
† The solution of the crystal structure from powder diffraction data was
performed on Materials Studio, and the modeling details will be
published elsewhere.

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D. Pang et al. / Tetrahedron 61 (2005) 6108–6114
Table 2. Assignments of infrared frequencies for C16–Ph and C16–NO2 at
room temperature
motif, in which N–H and C]O group were involved in
intermolecular hydrogen bonding. The direction of the
interaction is perpendicular to the molecular long axis, as
depicted in Figure 3a, in contrast to the intramolecular
hydrogen bonding pattern speculated by Karamysheva,
etc.11 as shown in Figure 3b.
Assignments
IR frequencies (cmK1
)
C16–Ph
C16–NO2
n (N–H)
n (Ar-H)
3247
3013
3203
3017
nas (CH3), nas (CH2)
ns (CH3), ns (CH2)
amide I, n C]O
nC]C of phenyl ring
2954, 2916
2849
2953, 2918
2871, 2850
1590, 1567
1608, 1578
Moreover, these conclusions were further supported by the
fact that the nN–H and amide I band became weaker and
shifted to higher frequencies upon heating. Figure 4 showed
the temperature dependence of nN–H of C16–Ph. We found a
sharp increase of nN–H wavenumbers on going from
crystalline to smectic A and from smectic A to isotropic
liquid. The typical wavenumbers of N–H vibration of C16–
Ph are at around 3250, 3295 and 3310 cmK1 in the
crystalline state, smectic A phase and isotropic phase,
respectively. The observed N–H stretching vibration
frequency at 3295 cmK1 in the smectic A phase and the
increase of N–H stretching vibration by ca. 15 cmK1 at the
isotropic transition strongly indicated that the presence of
the hydrogen bonding in the smectic A phase of C16–Ph.
Furthermore, this conclusion was also supported by the fact
that the blue-shift of C]O stretching vibration was
companied by an increase in intensity at around
1655 cmK1, while the absorption at 1690 cmK1 diffused
and decreased, as shown in Figure 5a. For C16–NO2, the
N–H vibrations shift from 3210 to 3295 cmK1 and the
amide I band from 1590, 1567 to 1654, 1688 cmK1, as
shown in Figure 5b and c, during the transition from
crystalline to smectic A phase. Due to the limitation of
infrared spectrometer range, FT-IR spectra of C16–NO2 in
its isotropic phase were not measured. However, based on
these observation, we have already been able to draw the
same conclusion that the intermolecular hydrogen bonding
exists in the smectic A phase, as that of the C16–Ph.
1684, 1650
1609, 1580
1506, 1485
1472, 1449
1529, 1297
—
1464
1255
1025
845
Amide II, III, nC–NCdN–H
nas, ns (NO2)
d (CH2)
n (Ar-O)
n (C–O)
d (Ar-H)o.o.p, para-
d (Ar-H)o.o.p, mono-
(CH2)n rocking, nR4
1493
1522, 1345
1466
1254
1026
844
741, 692
720
—
720
C16–Ph.15 At room temperature, apart from characteristic
bands of aromatic ring at 1609, 1580, 1506, 1485, 1472,
845, 741, and 692 cmK1, C16–Ph exhibits absorptions at
3247 cmK1 (n (N–H)), 1684, 1650 cmK1 (amide I, nC]O),
and 1529, 1297 cmK1 (amide II, III, nC–NCdN–H). The
absorption bands at 2954, 2916 cmK1 (nas (CH3, CH2)),
2872, 2849 cmK1 (ns (CH3, CH2)), 1465 cmK1 (d (CH2)),
and 720 cmK1 ((CH2)n rocking, nR4) were attributed to the
vibrations of alkoxy chains. The presence of N–H stretching
vibrations at 3247 cmK1 (the absence of free N–H, a
relatively sharp peak with the frequency higher than
3400 cmK1), intense absorption of amide I at 1650 cmK1
,
and relatively weak absorption at 1684 cmK1 clearly
indicated that almost all the N–H groups are associated
with C]O groups via N–H/O]C hydrogen bonding.16
For C16–NO2, the N–H stretching vibration located at
3202 cmK1, amide I at 1590, 1567 cmK1, and characteristic
absorption of nitro group at 1522 cmK1 (nas (NO2)) and
1345 cmK1 (ns (NO2)). The same conclusion can be drawn
for C16–NO2, in spite of the stronger hydrogen bonding
confirmed by the red-shift of the N–H and C]O stretching
vibrations in C16–NO2 with respect to C16–Ph. Thus, along
1
with the results of crystal structure, FT-IR, and H NMR
dilution experiments, we can get a clear hydrogen-bonding
Figure 4. The temperature dependent N–H stretching vibrations of C16–
Ph: Cr, Sm A and I indicates crystalline state, smectic A phase and isotropic
liquid, respectively.
2.3. Phase behaviors
The phase behaviors of Cn–NO2 and Cn–Ph were studied by
polarized optical microscopy, differential scanning calori-
metry and wide angle X-ray diffraction. Their transitional
temperatures and associated enthalpies were summarized in
Table 3. The molecules of Cn–NO2 and Cn–Ph exhibited
enantiotropic smectic A behavior with a fan-shaped texture
Figure 3. Schematic hydrogen bonding motifs. The dashed line illustrated
the hydrogen bonding.

D. Pang et al. / Tetrahedron 61 (2005) 6108–6114
6111
Figure 6. The fan-shaped texture (!400) of C3–NO2 at 193 8C in the
cooling run.
high as 268 8C) and large isotropic transition enthalpy
(O6 kJ/mol). The high stability of the smectic A phase may
be ascribed to the combination of lateral intermolecular
hydrogen bonding and microphase segregation. Firstly, the
large transitional enthalpies implied that strong attractive
force still existed in the smectic A phase. This might be due
to the lateral hydrogen bonding, as have been confirmed by
the temperature dependent FT-IR spectroscopic study. The
presence of intermolecular cohesive forces within the layer
may have stabilized the parallel alignment of the smetogen
in the layer structures.7 Secondly, the clearing points rise,
the transition enthalpies increase, and the mesophase ranges
broaden with the elongating terminal chain. This may be
explained as the elongation of the terminal chains increased
the microphase segregation effect by enhancing the
incompatibility between the hydrogen bonded rigid
aromatic rings and flexible alkoxy chains. Such micro-
segregation effect was considered to be the driving force for
the formation of smectic phase.17 Moreover, the hydrogen
bonding and the strong dipole substitute were considered to
enhance the incompatibility. Therefore Cn–NO2 has higher
thermal stability than Cn–Ph. Additionally, the clearing
point increased while the melting temperature decreased
with the elongation of alkoxy chain (see Table 3), which
suggested that the terminal chains have bigger impact on the
melting process than that on the isotropic transition. The
elongating alkoxyl chain may be favorable to the formation
of the mesophase by decreasing the melting point, whereas
the stability of the mesophase must be ascribed to the
Figure 5. The temperature dependent FT-IR spectra at the interval of 15 8C.
(a) C16–Ph at the range of 1450–1750 cmK1, (b) C16–NO2 at the range of
3000–3600 cmK1, (c) C16–NO2 at the range of 1450–1750 cmK1
.
(as shown in Figure 6). In the thermodynamic studies, it
should be noticed that remarkably stable smectic A phase
was obtained, which was characterized by wide mesophase
ranges (even broader than 110 8C), high clearing points (as
Table 3. Transition temperatures and enthalpies of Cn–NO2 and Cn–Ph
Compound
C3–NO2
Transitiona
T/8C heating (DH/kJ molK1
)
T/8C cooling (DH/kJ molK1
)
Cr–Sm A
Sm A–I
Cr–Sm A
Sm A–I
Cr–Sm A
Sm A–I
Cr–Sm A
Sm A–I
Cr–Sm A
Sm A–I
Cr–Sm A
Sm A–I
208.2(19.86)
232.8(6.54)
172.2(19.17)
259.5(9.07)
144.2(14.90)
262.5(13.90)
146.3(8.86)
260.6(12.14)
147.7(36.53)
208.6(4.76)
145.2(57.37)
210.9(7.48)
184.0(21.12)
230.3(6.32)
158.2(18.84)
257.82(8.16)
139.3(11.04)
263.1(8.21)
141.2(11.30)
258.8(8.87)
117.2(9.90)b
204.0(4.39)
113.3(66.09)
208.6(7.22)
C6–NO2
C12–NO2
C16–NO2
C12–Ph
C16–Ph
a Cr, Sm A and I indicate crystalline state, Smectic A phase and isotropic liquid, respectively.
b The small enthalpy was due to another phase transition observed below the melting process.

6112
D. Pang et al. / Tetrahedron 61 (2005) 6108–6114
presence of attractive force or the combination of the two.
Thus, based on these analyses, we can conclude that
combination of the lateral intermolecular hydrogen bonding
and microphase segregation played an important role in
generating the stable smectic phase.
lengths (l). These d/l ratios were from 1.10 to 1.14, while the
layer spacings of Cn–Ph were almost equal to the molecular
lengths. These results indicated that the molecules of Cn–
NO2 and Cn–Ph kept a Semectic A1 arrangement in their
liquid crystalline phases.18
2.4. Mesophase structure
3. Conclusion
X-ray diffraction measurements have been performed on the
mesophases of Cn–NO2 and Cn–Ph. Characteristic patterns
of smectic A phase with sharp peaks at lower angle region
and a broad halo at higher angle region (about 208) were
observed, as shown in Fig. 7. The layer spacing values (d)
collected in the Table 4, were almost independent to the
temperature. The d-spacings of Cn–NO2 in their meso-
Lateral intermolecular hydrogen bonding was considered
undesirable for the calamitic mesogenic materials, because
it could lead to a high melting temperature. However, high
stable smectic A phase was generated from these dis-
symmetric dihydrazide derivatives. Based on our investi-
gations, the presence of intermolecular attractive force in
the semectic A phase may enhance the parallel alignment
and the combination of lateral intermolecular interaction
and microphase segregation effect may be the leading
contribution to the stable smectic phase. In fact, lateral
hydrogen bonding has been applied to main chain liquid
crystal polymers to obtain high mechanical strength, and to
LB films to stabilize the layer structure. In conclusion we
hope that more attention will be paid to exploit the potential
use of the lateral hydrogen bonding in materials science.
Now the investigations using Cn–Ph and Cn–NO2 as
organogelators are in progress.
˚
phases were 2–5 A longer than the calculated molecular
4. Experimental
4.1. Synthesis
Cn–NO2 and Cn–Ph were synthesized according to the route
shown in Scheme 2. 4-Nitrobenzoyl chloride or 4-biphenyl
carbonyl chloride was reacted with 4-alkoxyl-benzoyl-
hydrazine in THF at room temperature for 8 h, yielding
the products of Cn–NO2 and Cn–Ph. All the compounds
were purified by a recrystallization from methanol or
alcohol for further NMR, FT-IR, measurements and
elemental analysis.
Figure 7. X-ray diffraction patterns of dissymmetric dihydrazide
derivatives: (a) C6–NO2 at 190 8C, (b) C16–Ph at 170 8C.
Table 4. Summary of X-ray diffraction results of Cn–NO2 and Cn–Ph
Compound
Molecular
lengtha
T/8C
Layer
spacing
d/l
˚
(l)/A
˚
(d)/A
C3–NO2
C6–NO2
C12–NO2
C16–NO2
C12–Ph
19.5
22.5
30.0
34.6
32.6
37.4
225
190
160
200
190
170
21.4, 10.9
25.4
33.5
39.4, 19.7
32.7
36.2, 18.1
1.10
1.13
1.12
1.14
1.00
0.97
C16–Ph
a Molecular length was calculated by MM2.
Scheme 2. The synthesis of Cn–NO2 and Cn–Ph.

D. Pang et al. / Tetrahedron 61 (2005) 6108–6114
6113
4.1.1. N-(4-Propyloxybenzoyl)-N0-(40-nitrobenzoyl)
hydrazine (C3–NO2). 1H NMR (500 MHz, DMSO),
(ppm, from TMS): 10.83 (s, 1H); 10.50 (s, 1H); 8.39 (d,
2H, JZ7.9 Hz); 8.15 (d, 2H, JZ7.7 Hz); 7.90 (d, 2H, JZ
8.1 Hz); 7.06 (d, 2H, JZ7.9 Hz); 4.02 (t, 2H, JZ5.7 Hz);
1.78–1.74 (m, 2H); 0.99 (t, 3H, JZ6.9 Hz). FT-IR (KBr
disc, cmK1): 3205, 2964, 2937, 2879, 2855, 1609, 1593,
1566, 1527, 1495, 1465, 1416, 1393, 1345, 1317, 1255,
1175, 1111, 1066, 1011, 977, 866, 842, 819, 758, 724, 714,
702, 684, 657, 639, 622. Anal. calcd for C17H17N3O5: C,
59.47; H, 4.99; N, 12.24. Found C, 59.57; H, 4.78; N, 12.18.
4.1.6. N-(4-Cetyloxybenzoyl)-N0-(40-biphenyl carbonyl)
hydrazine (C16–Ph). 1H NMR: (500 MHz, DMSO) (ppm,
from TMS): 10.46 (s, 1H); 10.33 (s, 1H); 8.01 (d, 2H, JZ
8.4 Hz); 7.89 (d, 2H, JZ8.8 Hz); 7.82 (d, 2H, JZ8.4 Hz);
7.75 (d, 2H, JZ7.4 Hz); 7.50 (t, 2H, JZ7.6 Hz); 7.41 (t, 1H,
JZ7.3 Hz); 7.02 (d, 2H, JZ8.8 Hz); 4.03 (t, 2H, JZ
6.5 Hz); 1.73–1.70 (m, 2H); 1.42–1.39 (m, 2H); 1.31–1.23
(m, 24H); 0.84 (t, 3H, JZ6.9 Hz). FT-IR (KBr disc, cmK1):
3247, 3013, 2964, 2916, 2849, 1684, 1650, 1609, 1580,
1529, 1506, 1485, 1472, 1464, 1449, 1396, 1297, 1255,
1181, 1109, 1025, 1006, 924, 895, 845, 741, 720, 685. Anal.
calcd for C36H48N2O3: C, 77.66; H, 8.69; N, 5.03. Found C,
77.63; H, 8.81; N, 5.02.
4.1.2.
N-(4-Hexyloxybenzoyl)-N0-(40-nitrobenzoyl)
hydrazine (C6–NO2). 1H NMR: (500 MHz, DMSO),
(ppm, from TMS): 10.79 (s, 1H); 10.47 (s, 1H); 8.38 (d,
2H, JZ8.6 Hz); 8.14 (d, 2H, JZ8.4 Hz); 7.90 (d, 2H, JZ
8.5 Hz); 7.05 (d, 2H, JZ8.6 Hz); 4.05 (t, 2H, JZ6.2 Hz);
1.75–1.71 (m, 2H); 1.43–1.40 (m, 2H), 1.34–1.32 (m, 4H),
0.86 (t, 3H, JZ6.4 Hz). FT-IR (KBr disc, cmK1): 3196,
2932, 2857, 1609, 1592, 1568, 1525, 1495, 1467, 1396,
1344, 1317, 1253, 1175, 1110, 1030, 866, 846, 759, 723,
702, 661, 623. Anal. calcd for C20H23N3O5: C, 62.33; H,
6.02; N, 10.90. Found C, 62.56; H, 5.71; N, 10.68.
4.2. Characterization
1H NMR spectra were recorded with a Bruker Avance
500 MHz spectrometer, using chloroform-d or DMSO-d6 as
solvent and tetramethylsilane (TMS) as an internal standard.
FT-IR spectra were recorded with a Perkin–Elmer
spectrometer (Spectrum One B). The sample was pressed
tablet with KBr. Phase transitional properties were
investigated by a Mettler Star DSC 821e. Texture observ-
ation was conducted on a Leica DMLP polarized optical
microscope equipped with a Leitz 350 microscope heating
stage. X-ray diffraction was carried out with a Rigaku
D/max 2500 PC X-ray diffractometer.
4.1.3. N-(4-Dodecyloxybenzoyl)-N0-(40-nitrobenzoyl)
hydrazine (C12–NO2). 1H NMR (500 MHz, DMSO),
(ppm, from TMS): 10.79 (s, 1H); 10.47 (s, 1H); 8.38 (d,
2H, JZ8.4 Hz); 8.15 (d, 2H, JZ8.5 Hz); 7.90 (d, 2H, JZ
8.5 Hz); 7.04 (d, 2H, JZ8.4 Hz); 4.04 (t, 2H, JZ6.2 Hz);
1.74–1.70 (m, 2H); 1.42–1.40 (m, 2H); 1.33–1.25 (m, 16H);
0.86 (t, 3H, JZ6.4 Hz). FT-IR (KBr disc, cmK1): 3202,
2920, 2851, 1609, 1591, 1567, 1523, 1494, 1466, 1395,
1345, 1318, 1254, 1172, 1109, 1028, 1010, 871, 844, 810,
759, 721, 699, 682, 658, 638, 623. Anal. calcd for
C26H35N3O5: C, 66.50; H, 7.51; N, 8.95. Found C, 66.70;
H, 7.71; N, 9.07.
Acknowledgements
The authors are grateful to the National Science Foundation
Committee of China (Project No. 29974013, 50373016) and
the Excellent Young Teachers Program of MOE, China for
their financial support of this work.
4.1.4.
N-(4-Cetyloxybenzoyl)-N0-(40-nitrobenzoyl)
hydrazine (C16–NO2). 1H NMR (500 MHz, DMSO),
(ppm, from TMS): 10.81 (s, 1H); 10.49 (s, 1H); 8.38 (d,
2H, JZ8.6 Hz); 8.15 (d, 2H, JZ8.6 Hz); 7.90 (d, 2H, JZ
8.6 Hz); 7.04 (d, 2H, JZ8.7 Hz); 4.04 (t, 2H, JZ6.4 Hz);
1.74–1.71 (m, 2H); 1.41–1.40 (m, 2H); 1.32–1.24 (m, 24H);
0.85 (t, 3H, JZ6.7 Hz). FT-IR (KBr disc, cmK1): 3203,
2919, 2850, 1608, 1591, 1567, 1523, 1493, 1466, 1394,
1346, 1318, 1254, 1172, 1109, 1027, 872, 844, 810, 758,
720, 698, 658, 637, 622. Anal. calcd for C30H43N3O5: C,
68.54; H, 8.24; N, 7.99. Found C, 68.76; H, 8.41; N, 8.05.
References and notes
1. (a) Kato, T. Struct. Bond. 2000, 96, 95–146. (b) Paleos, C. M.;
Tsiourvas, D. Liq. Cryst. 2001, 28, 1127–1161. (c) Beginn, U.
Prog. Polym. Sci. 2003, 28, 1049–1105.
2. (a) Kato, T.; Frechet, J. M. J. J. Am. Chem. Soc. 1989, 111,
8533–8534. (b) Price, D. J.; Willis, K.; Richardson, T.; Ungar,
G.; Bruce, D. W. J. Mater. Chem. 1997, 7, 883–891. (c) Price,
D. J.; Adams, H.; Bruce, D. W. Mol. Cryst. Liq. Cryst. 1999,
289, 127. (d) Sideratou, Z.; Tsiourvas, D.; Paleos, C. M.;
Skoulios, A. Liq. Cryst. 1997, 22, 51–64. (e) Wallage, M. J.;
Imrie, C. T. J. Mater. Chem. 1997, 7, 1163–1167. (f) Kato, T.;
Frechet, J. M. J.; Wilson, P. G.; Saito, T.; Uryu, T.; Fujishima,
A.; Jin, C.; Kaneuchi, F. Chem. Mater. 1993, 5, 1094–1100.
3. (a) Brienne, M. J.; Gabard, J.; Lehn, J. M.; Stibor, J. J. Chem.
Soc., Chem. Comm. 1989, 1868–1870. (b) Kleppinger, R.;
Lillya, C. P.; Yang, C. Angew. Chem., Int., Ed. Engl. 1995, 34,
1637–1638. (c) Kleppinger, R.; Lillya, C. P.; Yang, C. J. Am.
Chem. Soc. 1997, 119, 4097–4102. (d) Suarez, M.; Lehn, J. M.;
Zimmermann, S. C.; Skoulios, A.; Heinrich, B. J. Am. Chem.
Soc. 1998, 120, 9526–9532. (e) Goldmann, D.; Janietz, R. D.;
Festag, R. H.; Schmidt, C.; Wendorff, J. H. Liq. Cryst. 1996,
21, 619. (f) Kraft, A.; Reichert, A.; Kleppinger, R. Chem.
Comm. 2000, 1015–1016. (g) Lee, C. J.; Lee, S. J.; Chang, J. Y.
4.1.5. N-(4-Dodecyloxybenzoyl)-N0-(40-biphenyl carbonyl)
hydrazine (C12–Ph). H NMR: (500 MHz, DMSO) (ppm,
1
from TMS): 10.53 (s, 1H); 10.40 (s, 1H); 8.02 (d, 2H, JZ
8.1 Hz); 7.91 (d, 2H, JZ8.6 Hz); 7.84 (d, 2H, JZ8.1 Hz);
7.77 (d, 2H, JZ7.5 Hz); 7.52 (t, 2H, JZ7.5 Hz); 7.43 (t, 1H,
JZ7.3 Hz); 7.05 (d, 2H, JZ8.6 Hz); 4.04 (t, 2H, JZ
6.3 Hz); 1.75–1.72 (m, 2H); 1.42–1.41 (m, 2H); 1.32–1.25
(m, 16H); 0.86 (t, 3H, JZ6.5 Hz). FT-IR (KBr disc, cmK1):
3233, 3053, 2954, 2936, 2858, 1678, 1643, 1609, 1579,
1535, 1507, 1485, 1448, 1393, 1296, 1253, 1181, 1111,
1076, 1038, 1013, 898, 846, 742, 696. Anal. calcd for
C32H40N2O3: C, 76.77; H, 8.05; N, 5.60. Found C, 76.73; H,
8.30; N, 5.65.

6114
D. Pang et al. / Tetrahedron 61 (2005) 6108–6114
Tetrahedron Lett. 2002, 43, 3863–3866. (h) Lee, H. K.; Lee,
H.; Ko, Y. H.; Chang, Y. J.; Oh, N. K.; Zin, W. C.; Kim, K.
Angew. Chem. 2001, 113, 2741–2743.
9. Tang, B. C. Dissertation Thesis, Jilin University, China, 2003.
10. (a) Beginn, U. Dissertation Thesis, Bayreuth, Germany,
1994.(b) Beginn, U. Prog. Polym. Sci. 2003, 28, 1049–1105.
11. Karamysheva, L. A.; Agafonova, I. F. Mol. Cryst. Liq. Cryst.
1999, 2527–2536.
4. (a) Kihara, H.; Kato, T.; Uryu, T.; Frechet, J. M. J. Chem.
Mater. 1996, 8, 961–968. (b) Kihara, H.; Kato, T.; Uryu, T.;
Frechet, J. M. J. Liq. Cryst. 1998, 24, 413–418. (c) Wilson,
L. M. Liq. Cryst. 1995, 18, 381. (d) Malthete, J.; Levelut,
A. M.; Liebert, L. Adv. Mater. 1992, 4, 37.
12. Steiner, T. Angew. Chem., Int., Ed. 2002, 41, 48–76.
13. Zhao, X.; Wang, X.; Jiang, X.; Chen, Y.; Li, Z.; Chen, G.
J. Am. Chem. Soc. 2003, 125, 15128–15139.
5. Gray, G. W. Molecular Structure and the Properties of Liquid
Crystals; Academic: New York, NY, 1962; p 163.
14. Hamuro, Y.; Geib, S. J.; Hamilton, A. D. J. Am. Chem. Soc.
1996, 118, 7529–7541.
6. Kato, T.; Frechet, J. M. J. J. Am. Chem. Soc. 1989, 111,
8533–8534.
15. The assignments of IR absorption bands were based on Refs.,
(a) Gunzler, H.; Gremlich, H. IR Spectroscopy; Wiley-VCH:
New York, 2002. (b) Bellamy, L. J., 3rd ed. In The Infra-Red
Spectra of Complex Molecules, Vol. 1; Chapman and Hall:
London, 1975.
7. (a) Mori, A.; Katahira, K.; Kida, K.; Takeshita, H. Chem. Lett.
1992, 1767–1770. (b) Mori, A.; Nimura, R.; Isobe, M.;
Takeshita, H. Chem. Lett. 1992, 859–862. (c) Mori, A.;
Nimura, R.; Takeshita, H. Chem. Lett. 1991, 77–80. (d)
Plehnert, R.; Schroter, J. A.; Tschierske, C. J. Mater. Chem.
1998, 8, 2611–2626. (e) Kajitani, T.; Kohmoto, S.; Yamamoto,
M.; Kishikawa, K. Chem. Mater. 2004, 16, 2329–2331.
8. (a) Demus, D.; Gloza, A.; Hauser, H.; Rapthel, I.; Wiegeleben,
A. Cryst. Res. Technol. 1981, 16, 1445. (b) Kutsumizu, S.
Curr. Opin. Solid State 2002, 6, 537.
16. Xue, C.; Jin, S.; Weng, X.; Ge, J. J.; Shen, Z.; et al. Chem.
Mater. 2004, 16, 1014–1025 and references cited therein.
17. (a) Tschierske, C. J. Mater. Chem. 1998, 8, 1485–1508. (b)
Tschierske, C. J. Mater. Chem. 2001, 11, 2647–2671 and
references cited there in.
18. Tasaka, T.; Okamoto, H.; Morita, Y.; Kasatani, K.; Takenaka,
S. Liq. Cryst. 2003, 961–977.