Synthesis and characterization of achiral bent-core liquid crystalline molecules containing salicylaldimine-based with a wide temperature range of SmCP phase

Article abstract of DOI:10.1002/jccs.201000020

The design and synthesis of a series bent-core materials base on a 3,4'-biphenyldiol central core containing salicylaldimine-based and two terminal tetradecyloxy tails are reported. In addition, the effects of lateral substituents (R = F and Cl) at the biphenyl core into 3'-position are examined. These substituents have a strong influence in reducing the clearing temperatures and increasing temperature range of SmCP phase. Upon cooling process the isotropic liquid, compound SB-Cl exhibits the lowest clearing transition temperature of 180 oC and the widest SmCP phase range of 129 °C. The mesophase behaviour were investigated by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and electro-optical (EO) measurements in the mesophase temperature range.

Full text of DOI:10.1002/jccs.201000020

124
Journal of the Chinese Chemical Society, 2010, 57, 124-133
Synthesis and Characterization of Achiral Bent-Core Liquid Crystalline
Molecules Containing Salicylaldimine-Based with a Wide Temperature
Range of SmCP Phase
Chien-Tung Liao (
Nien-Chieh Wu (
Department of Polymer Engineering, National Taiwan University of Science and Technology,
), Jung-Yo Liu (
), Sing-Fang Zou (
),
), Zheng-Long Wu (
) and Jiunn-Yih Lee* (
)
Taipei, Taiwan, R.O.C.
The design and synthesis of a series bent-core materials base on a 3,4¢-biphenyldiol central core con-
taining salicylaldimine-based and two terminal tetradecyloxy tails are reported. In addition, the effects of
lateral substituents (R = F and Cl) at the biphenyl core into 3¢-position are examined. These substituents
have a strong influence in reducing the clearing temperatures and increasing temperature range of SmCP
phase. Upon cooling process the isotropic liquid, compound SB-Cl exhibits the lowest clearing transition
temperature of 180 oC and the widest SmCP phase range of 129 oC. The mesophase behaviour were inves-
tigated by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), X-ray diffrac-
tion (XRD), and electro-optical (EO) measurements in the mesophase temperature range.
Keywords: Bent-core liquid crystals; Salicylaldimine-based; Antiferroelectric switching process.
INTRODUCTION
Liquid crystals (LCs) are intermediate states between
base bent-core system have proven remarkably useful for
providing interesting polar smectics. Thus it is evident
from the literature that azoxybenzene,12,13 Schiff’s base,14,15
stibazole,16 and azobenzene17 mesogenic segments have
been connected covalently in the 3,4¢-positions of a diphe-
nol ring to obtain large range of mesogenic phase. Several
results on bent-core liquid crystals considered as new
supramolecular functional materials with potential for ap-
plications are reviewed.18-21 Various topics are discussed
where these materials present unique attributes with clear
advantages over conventional mesogens. In this particle, a
series of achiral bent-shaped liquid crystalline molecules
base on a 3,4¢-biphenyldiol central core containing salic-
ylaldimine-based and two terminal tetradecyloxy tails were
synthesized and characterized. Besides, we report the ef-
fect of lateral substituents (R = F and Cl) at the biphenyl
core into 3¢-position, leading to the influence of the meso-
morphic properties. We expected to obtain wider range and
lower temperature of SmCP phase.
crystal and isotropic liquid and emerging materials for
many useful applications. One of the more attractive appli-
cations of LCs is for display devices, due to the unique
electro-optical properties and the versatility in molecular
design of LCs. Rodlike or disclike molecules have been
considered as appropriate molecules for the formation of
liquid crystals. In 1929, Vorländer,1,2 who is a pioneer in the
field of liquid crystal synthesis,3,4 synthesized several bent-
core liquid crystals and reported their mesogenic proper-
ties. Matsunaga et al.5 reported for first time on a series of
bent core molecule, as 1,3-phenylene bis[4-(4-n-octyloxy-
phenyliminomethyl)benzoate] derivatives. In 1996 Niori et
al. reported on ferroelectricity in a smectic phase formed by
bent-shaped Schiff base derivatives in an achiral mesogen.6
One of the liquid crystalline phases, which was first desig-
nated as B2,7 revealed an antiferroelectric switching pro-
cess. In a structural evolution paralleling that of the ca-
lamitic SmC* LCs, most bent-core (bent-shaped, or bow-
shaped) mesogens8 exhibiting the remarkable SmCP anti-
ferroelectric9 and ferroelectric10 phases are Schiff bases.
While SmCP mesogens without Schiff’s base units have
been reported,11 ariations on the theme of the bis-Schiff’s
RESULTS AND DISCUSSION
1. Synthesis
The general synthetic routes of intermediates and tar-
* Corresponding author. E-mail: jlee@mail.ntust.edu.tw

Achiral Bent-Core Liquid Crystalline Molecules
J. Chin. Chem. Soc., Vol. 57, No. 1, 2010 125
Scheme I Synthetic routes of intermediates and target bent-core molecules
Br
Br
OH
2
(ii)
R
5a: R = H
5b: R = F
5c: R = Cl
Br
OH
OTHP
OTHP
3
(ii)
(iii)
R
6a: R = H
6b: R = F
6c: R = Cl
Br
OTHP
(HO)2B
4
(iv)
7a: R = H
7b: R = F
7c: R = Cl
R
THPO
OTHP
(v)
8a: R = H
8b: R = F
8c: R = Cl
R
HO
OH
(vi)
O
R
O
O
O
9a: R = H
9b: R = F
9c: R = Cl
O
H
OH
O2N
(vii)
NO2
HO
HO
(i)
O
O
H
R
O
O
10a: R = H
10b: R = F
10c: R = Cl
OC14H29
H2N
O
1
NH2
(viii)
O
R
O
O
O
N
SB-H: R = H
SB-F: R = F
SB-Cl: R = Cl
C14H29
O
OH
N
HO
OC14H29
a Reagents and conditions: (i) C14H29Br, K2CO3, KI, acetone, reflux, 24 h; (ii) DHP, DPTS, DCM, r.t., 3 h; (iii) n-BuLi, THF, -78
°C, 1.5 h, B(OMe)3, r.t., 12 h, then 10% HCl; (iv) Pd(PPh3)4, K2CO3, Pd(PPh3)4, toluene/ethanol (3:1, v/v), 90 °C, 5 h; (v) PTSA,
DCM/methanol (3/1, v/v), 50 °C; (vi) 4-nitrobenzoic acid, DCC, DMAP, DCM, r.t., 12 h; (vii) 5% Pd-C, THF, H2, r.t., 6 h; (viii)
ethanol, acetic acid, reflux, 3 h.

126 J. Chin. Chem. Soc., Vol. 57, No. 1, 2010
Liao et al.
get bent-core molecules are outlined in Scheme I. Accord-
ing to Scheme I, compounds 2 and 5a–5c with a phenolic
hydroxyl group are protected with 3,4-dihydro-2H-pyran
(DHP) as a catalyst in the presence of 4-(dimethylamino)-
pyridinium p-toluenesulfonate (DPTS) in methylene chlo-
ride (DCM). Phenylboronic acid 4 was achieved from com-
pound 3 with the n-butyllithium (n-BuLi), followed by ad-
dition of trimethyl borate [B(OMe)3] in tetrahydrofuran
(THF) at -78 °C, and then was subjected to hydrolysis us-
ing 10% hydrochloric acid (HCl). Compounds 7a–7c was
prepared by means of Pd-catalyzed Suzuki coupling reac-
tion between compounds 4 and 6a–6c with tetrakis-(tri-
phenylphospine)palladium(0) [Pd(PPh3)4] as catalyst and
potassium carbonate as base in a toluene/ethanol (1/3, v/v)
solvent system, which was then deprotected with p-tolu-
enesulfonic acid (PTSA) monohydrate in the DCM/metha-
nol (3/1, v/v) to acquire 8a–8c. Compound 8a–8c was then
coupled to 4-nitrobenzoic acid in room temperature esteri-
fication procedure using N,N¢-dicyclohexylcarbodiimide
(DCC) as dehydrating agent and 4-(dimethylamino)pyri-
dine (DMAP) as catalyst to give 9a–9c. The nitro group of
compound 9a–9c was further reduced to a amino group of
compound 10a–10c with 5% Pd-C catalyst under a hydro-
gen atmosphere. 2,4-Dihydroxybenzaldehyde was reacted
with the suitable 1-bromotetradecane (C14H29Br) under
Williamson ether conditions to give the related 2-hy-
droxy-4-tetradecyloxybenzaldehyde (1). Finally, target
compounds were obtained by condensation reaction be-
tween compounds 1 and 10a–10c in ethanol and a few
traces of acetic acid. The purity and chemical structures of
the intermediates and target compounds can be easily veri-
fied by thin-layer chromatography, 1H NMR spectroscopy,
MS, FTIR, and elemental analysis. The target compounds
were further confirmed by 13C NMR spectroscopy.
2. Thermal Properties and Optical Textures
The phase behaviors of all compounds were investi-
gated by a combination polarizing optical microscopy
(POM) and differential scanning calorimetry (DSC). Phase
transition temperatures observed by POM match well with
the corresponding DSC thermograms. The mesomorphic
properties of the studied compounds SB-H, SB-F, and
SB-Cl, the phase sequence, phase transition temperatures
and enthalpy data are summarized in Table 1. Upon cooling
form the isotropic state, the compound SB-H displays a
characteristic schlieren texture and broken fan textures of
the mesophase at 153 °C (see Fig. 1a), indicating the for-
mation of the SmCP phase. The other compounds SB-F and
SB-Cl show similar optical texture at 130 °C and 100 °C,
respectively (see Fig. 1b and Fig. 1c), thus implying they
have the same mesophase. All of the compounds exhibit
enantiotropic mesomorphic behavior and only a meso
Table 1. Phase transition temperatures (oC) and enthalpies (kJ mol-1; in parentheses) for the
bent-core compounds as determined by DSC (scan rate = 5 °C min-1)a
O
O
O
N
O
R
C14H29
O
OH
N
HO
OC14H29
Second heating
first cooling
Second heating
first cooling
Compound
R
H
Cr
SmCP
I
DB-H
·
113.1 [67.8]
107.8 [68.6]
108.7 [32.7]
85.8 [33.0]
132.0 [29.5]
51.6 [26.7]
·
214.2 [25.1]
213.3 [25.2]
205.9 [26.6]
204.6 [25.7]
184.0 [20.8]
180.5 [21.0]
·
DB-F
F
·
·
·
·
·
·
DB-Cl
Cl
a Abbreviations: Cr = crystalline phase; SmCP = polar SmC phase (i.e. B2 phase); I = iso-
tropic phase. (· = phase exists)

Achiral Bent-Core Liquid Crystalline Molecules
J. Chin. Chem. Soc., Vol. 57, No. 1, 2010 127
phase. A typical DSC curve of compound SB-F is
shown in Fig. 2 that one mesophase can be obtained and
that there are no significant differences for different heat-
ing or cooling rates. In the DSC thermograms, the enthalpy
values obtained for the SmCP mesophase to isotropic phase
transition were in the range of about 20.6 to 26.6 kJ mol-1.
Comparison with the compound SB-H and SB-F
upon cooling from the isotropic liquid, the compound SB-
Cl is owing to the lowest clearing transition temperature of
180 oC and the widest SmCP phase range of 129 oC (see Ta-
ble 1). In this case, the chlorine atom has larger size atom
than the fluorine and hydrogen atom. As a result, when in-
troduction of the lateral substituent at the biphenyl core
into 3¢-position, the clearing temperature of the compound
was decreased and the temperature range of liquid crystal
was become widen. Thus, size effect of the lateral substi-
tuent has profound influence on their mesomorphic behav-
ior.
3. XRD Studies
To further identify the type of mesophases and the de-
termination of structural parameter have been further per-
formed by X-ray diffraction (XRD). The theoretical molec-
ular length of SB-F determined from molecular model esti-
mated using CS Chem3D Ultra 7.0 software gave molecu-
lar length of ca. 65.0 Å, where we supposes that the molec-
ular structure is coplanar and the alkyl chains are in the
fully extended all-trans conformation (see Fig 3a). XRD
pattern of compound SB-F is shown in Fig. 3b, as illustra-
tion example. The resulting XRD pattern of compound
SB-F at 110 °C exhibits three Bragg reflections in the
Fig. 1. Polarized optical microscopic textures obtained
schlieren with broken fan-shaped textures in
SmCP phase on cooling (1 °C/min) form the
isotropic state for (a) compound SB-H at 153
°C, (b) compound SB-F at 130 °C, and (c) com-
pound SB-Cl at 100 °C.
Fig. 2. DSC curves of compound SB-F obtained at a
rate of 5 °C min-1: (a) second heating scan and
(b) first cooling scan.

128 J. Chin. Chem. Soc., Vol. 57, No. 1, 2010
Liao et al.
small-angle region at 2q = 1.44, 2.89, and 4.33° with the
d-spacing of 53.1, 26.4, and 17.6 Å, respectively, corre-
sponding to the reciprocal spacing in the rations 1, 2, and 3,
and to the indexation (hk) = (10), (20), and (30), that can be
implied the formation of a layered structure. On the other
hand, a diffuse scattering halo in the wide-angle region
centered at 2q around 16.64° with d-spacing of ca. 4.6 Å in-
dicates liquid-like arrangement of the molecules within the
layers. Therefore, the layer d-spacing value of 53.1 Å for
compound SB-F by XRD measurement is smaller than the
calculated theoretical molecular length of 65.0 Å, suggests
a tilted arrangement of smectic structure, i.e., smectic C
phase with tilt angle of 35.2° along the layer normal direc-
tion. Compounds SB-F and SB-Cl also revealed similar
diffraction pattern at temperatures within the respective
mesophase temperature range. As shown in Fig. 3c, the
temperature dependence of the layer d-spacing of com-
pound SB-F in the SmCP phase was recorded upon cooling
from the isotropic phase. This observation the values of the
layer d-spacing, is only slightly change within the tempera-
ture range of the SmCP phase.
To obtain more detailed on the structural information
of the molecular arrangement within the SmCP phase of
compound SB-F was achieved with surface aligned sample
on a glass plate treated with homeotropic agent, which usu-
ally used to induce an oriented alignment of the liquid crys-
tal chains perpendicular to the surface substrate. The 2D
XRD pattern of compound SB-F at 110 °C is shown in Fig.
4a. Three intense arcs in the small-angle region are located
on the meridian of the pattern, indicating the layer reflec-
tions lie at the meridian. The arrow indicates the direction
of the diffuse maxima at wide-angle region. This broad dif-
fuse scattering is situated out of the equator. The angular
profile at wide angles shows an angle of 113.2° between
maxima, corresponding to a tilted angle of 33.5° (see Fig.
4b). Therefore, such patterns are consistent with a fluid
smectic phase with tilted molecules.
4. Electro-Optical Studies
The switching behaviour has been observed in the
SmCP phase of the studied compound SB-H using the tri-
angular wave method. Two distinct sharp peaks per half pe-
riod of an applied triangular wave voltage are clearly seen
under a triangular wave field of about 300 Vpp at 60 Hz
(see in Fig. 5a). This is a strong indication of an antiferro-
electric switching process and spontaneous polarization
(Ps) is about 505 nC cm-2 at 130 °C. The temperature de-
Fig. 3. (a) Schematic representation of molecular
model, and (b) X-Ray diffraction intensity
against angle profile obtained in the SmCP
phase of compound SB-F at 110 °C and (c)
layer d-spacing as a function of the temperature
dependence (upon cooling from the isotropic
phase).

Achiral Bent-Core Liquid Crystalline Molecules
J. Chin. Chem. Soc., Vol. 57, No. 1, 2010 129
pendence of the magnitude of the Ps value for the com-
pound SB-H obtained by integrating the area under the two
peaks is shown in Fig. 5b. It can be seen that the Ps is de-
pendent of temperature for compound SB-H. Similar ten-
dency was also observed in the compounds SB-F and SB-
Cl. The abrupt increase of Ps around the isotropization
temperature indicates that the phase transformatioin from
the isotropic phase to the SmCP phase is a first order phase
transformation. The Ps value exhibits a maximum polariza-
tion of 615 nC cm-2 for compound SB-H at 115 °C, 550 nC
cm-2 for compound SB-F at 85 °C, and 606 nC cm-2 for
compound SB-Cl at 100 °C.
EXPERIMENTAL
1. Materials
All reagents and chemicals were purchased from
commercial sources (Alfa, TCI, and Fluka) and used as re-
ceived without further purification. Tetrahydrofuran (THF),
methylene chloride (DCM), and diethyl ether were distilled
to keep anhydrous before use. Thin-layer chromatography
was performed using aluminium-backed silica-gel plates
(Merck 60 F254), which were examined under UV light
and iodine vapor. Column chromatography was performed
using Merck 60-mesh silica gel.
Fig. 5. (a) Switching current response observed in the
SmCP phase of compound SB-H at 130 °C un-
der the applied triangular wave voltage (9 µm
antiparallel rubbed polyimide-coated ITO cell,
300 Vpp, 60 Hz) and (b) spontaneous polariza-
tion (Ps) as a function of the temperature.
Fig. 4. (a) 2D XRD pattern of a partially surface-
aligned sample of compound SB-F obtained in
the SmCP phase at 110 °C (upon cooling from
the isotropic phase) and (b) azimuthal scan of
small- and wide-angle reflection.

130 J. Chin. Chem. Soc., Vol. 57, No. 1, 2010
Liao et al.
2. Characterization Techniques
pic phase.
1H NMR spectra were recorded with a Bruker Avance-
500 spectrometer (500 MHz), using CDCl3 as a solvent. El-
emental analyses for C and H were carried out on a Heraeus
VarioEL-III elemental analyzer. The electron impact (EI)
mass spectra were obtained on a Finnigan TSQ 700 spec-
trometer. The optical textures of mesophases were charac-
terized by polarizing optical microscopy (POM, model:
Olympus BH5) equipped with a hot stage (Mettler Toledo
FP82HT) and a programmable temperature controller
(Mettler Toledo FP90 central processor). Temperatures and
enthalpies of transitions were determined by differential
scanning calorimetry (DSC, model: Perkin Elmer Dia-
mond). Powder samples of ca 5.0 mg were examined at
heating and cooling rates of 5 oC min-1 under a nitrogen at-
mosphere.
3. Synthesis
The synthetic route the bent-core liquid crystalline
materials of this study are shown in the Scheme I. The syn-
thetic procedures and chemical analyses of each product
are described sequentially below.
2-Hydroxy-4-tetradecyloxy-benzaldehyde (1)
1
Yield 81%, as a white solid, H NMR (300 MHz,
CDCl3) d: 0.95 (t, J = 6.3 Hz, 3H), 1.21-1.62 (m, 24H), 1.87
(m, 2H), 4.01 (t, J = 6.6 Hz, 2H), 6.41 (d, J = 2.1 Hz, 1H),
6.52-6.58 (dd, J1 = 8.7 Hz, J2 = 2.4 Hz, 1H), 7.42-7.46 (ds,
1H), 9.70 (s, 1H); HRMS (ESI), m/z, 334.2508; Anal. Calc.
for C21H34O3: C 75.41; H 10.25. Found: C 75.39; H 10.34.
2-(3-Bromo-phenoxy)-tetrahydro-pyran (3)
1
Yield 90%, as a colorless oil, H NMR (300 MHz,
CDCl3) d: 1.51-1.72 (m, 3H), 1.81 (m, 2H), 2.02 (m, 1H),
3.63 (m, 1H), 3.91 (m, 1H), 5.42 (m, 1H), 6.95 (m, 1H),
7.10 (m, 2H), 7.22 (m, 1H); HRMS (ESI), m/z, 256.0099;
Anal. Calc. for C11H13BrO2: C 51.38; H 5.10. Found: C
51.34; H 5.21.
Synchrotron powder X-ray diffraction (XRD) mea-
surements were performed in transmission geometry with
synchrotron radiation at beamline BL17A of the National
Synchrotron Radiation Research Center (NSRRC), Tai-
wan, where the X-ray wavelength was 1.33366 Å. The
XRD data were collected using Mar345 image plate detec-
tor mounted orthogonal to the beam with sample-to-detec-
tor distance of 220 mm. The diffraction signals were accu-
mulated for 10 seconds. The powder samples were packed
into a capillary tube and heated by a heat gun, where the
temperature controller is programmable by a PC with a PID
feed back system. The scattering angle theta was calibrated
by a mixture of silver behenate and silicon. For the 2D
XRD patterns, the surface aligned samples of the meso-
phases were obtained by very slow cooling (1 oC min-1) of a
small droplet of the compound from the isotropic melt on a
glass plate treated with commercially available homeo-
tropic agent.
2-Tetrahydropyranyloxy-4-phenylboronic acid (4)
1
Yield 65%, as a white solid, H NMR (300 MHz,
CDCl3) d: 1.61-2.22 (m, 8H), 3.63 (m, 1H), 3.82 (m, 1H),
5.61 (s, 1H), 7.23-7.41 (m, 3H), 7.91 (d, J = 6.9 Hz, 1H);
HRMS (ESI), m/z, 222.1063; Anal. Calc. for C11H15BO4: C
59.50; H 6.81. Found: C 59.39; H 6.79.
2-(4-Bromo-phenoxy)-tetrahydro-pyran (6a)
1
Yield 80%, as a white solid, H NMR (300 MHz,
CDCl3) d: 1.50-1.75 (m, 3H), 1.85 (m, 2H), 2.12 (m, 1H),
3.51 (m, 1H), 3.83 (m, 1H), 5.58 (m, 1H), 6.92 (m, 2H),
7.43 (m, 2H); HRMS (ESI), m/z, 256.0099; Anal. Calc. for
C11H13BrO2: C 51.38; H 5.10. Found: C 51.32; H 5.20.
2-(4-Bromo-2-fluoro-phenoxy)-tetrahydro-pyran (6b)
1
Yield 85%, as a white solid, H NMR (300 MHz,
Electro-optical investigations were carried out using
commercially available liquid crystal cells with indium tin
oxide (ITO) electrodes coated with antiparallel rubbed
polyimide (from Mesostate Corp., cell gap = 9 µm for ac-
tive area = 1 cm2). The sample was filled into the cell in the
isotropic phase. A digital oscilloscope (Yokogawa Elect.,
DL1640) was used in these measurements, and a high
power amplifier was connected to an arbitrary function
generator (Tektronix AWG2005). For the switching polar-
ization experiment was measured using triangular wave-
form voltage method under slowly cooling from the isotro-
CDCl3) d: 1.45-1.65 (m, 3H), 1.75 (m, 2H), 1.95 (m, 1H),
3.43 (m, 1H), 3.75 (m, 1H), 5.40 (m, 1H), 6.62 (m, 1H),
7.02 (m, 1H), 7.13 (m, 1H); HRMS (ESI), m/z, 274.0006;
Anal. Calc. for C11H12BrFO2: C 48.02; H 4.40. Found: C
48.10; H 4.35.
2-(4-Bromo-2-chloro-phenoxy)-tetrahydro-pyran (6c)
1
Yield 75%, as a white solid, H NMR (300 MHz,
CDCl3) d: 1.41-1.55 (m, 3H), 1.65 (m, 2H), 1.95 (m, 1H),
3.55 (m, 1H), 3.85 (m, 1H), 5.35 (m, 1H), 6.82 (m, 1H),
7.15 (m, 1H), 7.25 (m, 1H); HRMS (ESI), m/z, 289.9707;
Anal. Calc. for C11H12BrClO2: C 45.31; H 4.15. Found: C

Achiral Bent-Core Liquid Crystalline Molecules
J. Chin. Chem. Soc., Vol. 57, No. 1, 2010 131
45.14; H 4.30.
3,4¢-Bis(4-nitrobenzoyloxy)-biphenyl (9a)
2-(Biphenyl-3-yloxy)-bis-tetrahydro-pyran (7a)
1
Yield 95%, as a yellowish solid, 1H NMR (300 MHz,
CDCl3) d: 7.26 (m, 1H), 7.34 (m, 2H), 7.47 (m, 1H), 7.55
(m, 2H), 7.70 (m, 2H), 8.40 (m, 8H); HRMS (ESI), m/z,
484.0906; Anal. Calc. for C26H16N2O8: C 64.47; H 3.33; N
5.78. Found: C 64.70; H 3.42; N 5.73.
Yield 78%, as a white solid, H NMR (300 MHz,
CDCl3) d: 1.62-1.81 (m, 6H), 1.93-2.13 (m, 6H), 3.62 (m,
2H), 4.02 (m, 2H), 5.51 (m, 2H), 7.03 (m, 1H), 7.12 (m,
2H), 7.15 (m, 1H), 7.25 (m, 1H), 7.35 (m, 1H), 7.52 (m,
1H); HRMS (ESI), m/z, 354.1831; Anal. Calc. for
C22H26O4: C 74.55; H 7.39. Found: C 74.37; H 7.50.
2-(3¢-Fluoro-biphenyl-3-yloxy)-bis-tetrahydro-pyran
(7b)
3,4¢-Bis(4-nitrobenzoyloxy)-3¢-fluoro-biphenyl (9b)
Yield 90%, as a yellowish solid, 1H NMR (300 MHz,
CDCl3) d: 7.28 (m, 1H), 7.40 (m, 1H), 7.47 (m, 1H), 7.50-
7.6 (m, 3H), 7.75 (m, 1H), 8.43 (m, 8H); HRMS (ESI), m/z,
502.0812; Anal. Calc. for C26H15FN2O8: C 62.16; H 3.01;
N 5.58. Found: C 62.29; H 3.34; N 5.71.
1
Yield 69%, as a white solid, H NMR (300 MHz,
CDCl3) d: 1.55-1.77 (m, 6H), 1.87-2.08 (m, 6H), 3.55 (m,
2H), 3.95 (m, 2H), 5.45 (m, 2H), 6.95 (m, 1H), 7.01 (m,
1H), 7.12 (m, 1H), 7.15 (m, 1H), 7.25 (m, 1H), 7.35 (m,
1H), 7.45 (m, 1H), 7.55 (m, 1H); HRMS (ESI), m/z,
372.1737; Anal. Calc. for C22H25FO4: C 70.95; H 6.77.
Found: C 71.30; H 6.66.
3,4¢-Bis(4-nitrobenzoyloxy)-3¢-chloro-biphenyl (9c)
Yield 92%, as a yellowish solid, 1H NMR (300 MHz,
CDCl3) d: 7.29 (m, 1H), 7.49 (m, 1H), 7.51 (m, 1H), 7.60-
7.70 (m, 3H), 7.82 (m, 1H), 8.41 (m, 8H); HRMS (ESI),
m/z, 518.0517; Anal. Calc. for C26H15ClN2O8: C 60.19; H
2.91; N 5.40. Found: C 60.15; H 2.79; N 5.60.
2-(3¢-Chloro-biphenyl-3-yloxy)-bis-tetrahydro-pyran
(7c)
3,4¢-Bis(4-aminibenzoyloxy)-biphenyl (10a)
1
Yield 69%, as a colorless viscous liquid, H NMR
Yield 97%, as a yellow powder, IR (KBr) v/cm-1
3475, 3365, 3221, 3064, 2924, 2852, 2674, 1915, 1700,
1624, 1597, 1516, 1481, 1445, 1395, 1319, 1270, 1212,
1167, 1069, and 1010; 1H NMR (300 MHz, CDCl3) d: 6.21
(s, 4H), 6.42 (m, 4H), 7.18-7.30 (m, 3H), 7.49-7.60 (m,
3H), 7.73-7.83 (m, 6H); HRMS (ESI), m/z, 424.1423;
Anal. Calc. for C26H20N2O4: C 73.57; H 4.75; N 6.60.
Found: C 73.45; H 4.89; N 6.45.
(300 MHz, CDCl3) d: 1.62-1.81 (m, 6H), 1.91-2.12 (m,
6H), 3.62 (m, 2H), 4.01 (m, 2H), 5.52 (m, 2H), 7.02 (m,
1H), 7.05 (m, 1H), 7.11 (m, 1H), 7.15 (m, 1H), 7.18 (m,
1H), 7.23 (m, 1H), 7.38 (m, 1H), 7.47 (m, 1H), 7.61 (m,
1H); HRMS (ESI), m/z, 388.1441; Anal. Calc. for
C22H25ClO4: C 67.95; H 6.48. Found: C 68.03; H 6.49.
Biphenyl-3,4¢-diol (8a)
1
Yield 90%, as a white solid, H NMR (300 MHz,
3,4¢-Bis(4-aminibenzoyloxy)-3¢-fluoro-biphenyl (10b)
Yield 98%, as a yellow powder, IR (KBr) v/cm-1
3884, 3473, 3362, 3237, 2979, 2943, 2872, 2683, 2522,
2336, 2120, 2010, 1991, 1703, 1610, 1596, 1506, 1460,
1443, 1392, 1316, 1261, 1221, 1167, 1051, and 1012; 1H
NMR (300 MHz, CDCl3) d: 6.17 (s, 2H), 6.24 (s, 2H), 6.47
(m, 4H), 7.25 (m, 1H), 7.43-7.60 (m, 4H), 7.70-7.83 (m,
5H), 7.93 (m, 1H); HRMS (ESI), m/z, 442.1329; Anal.
Calc. for C26H19FN2O4: C 70.58; H 4.33; N 6.33. Found: C
70.19; H 4.52; N 6.41.
CDCl3) d: 6.72 (m, 1H), 6.82 (m, 2H), 6.95 (m, 2H), 7.22
(m, 1H), 7.42 (m, 2H), 9.41 (s, 1H), 9.52 (s, 1H); HRMS
(ESI), m/z, 186.0681; Anal. Calc. for C12H10O2: C 77.40; H
5.41. Found: C 77.09; H 5.50.
3¢-Fluoro-biphenyl-3,4¢-diol (8b)
1
Yield 83%, as a white solid, H NMR (300 MHz,
CDCl3) d: 6.71 (m, 1H), 6.81 (m, 1H), 6.85 (m, 1H), 6.95
(m, 1H), 7.05 (m, 1H), 7.15 (m, 1H), 7.21 (m, 1H), 9.41 (s,
1H), 9.52 (s, 1H); HRMS (ESI), m/z, 204.0586; Anal. Calc.
for C12H9FO2: C 70.58; H 4.44. Found: C 70.33; H 4.52.
3¢-Chloro-biphenyl-3,4¢-diol (8c)
3,4¢-Bis(4-aminibenzoyloxy)-3¢-chloro-biphenyl (10c)
Yield 96%, as a yellow powder, IR (KBr) v/cm-1
3874, 3475, 3364, 3239, 2969, 2933, 2875, 2680, 2525,
2338, 2122, 2011, 1993, 1701, 1617, 1601, 1512, 1468,
1446, 1390, 1318, 1263, 1223, 1168, 1052, and 1002; 1H
NMR (300 MHz, CDCl3) d: 6.19 (s, 2H), 6.23 (s, 2H), 6.53
(m, 4H), 7.23 (m, 1H), 7.42-7.63 (m, 4H), 7.72-7.95 (m,
6H); HRMS (ESI), m/z, 458.1033; Anal. Calc. for
1
Yield 87%, as a white solid, H NMR (300 MHz,
CDCl3) d: 6.75 (m, 1H), 6.83 (m, 1H), 6.87 (m, 1H), 6.97
(m, 1H), 7.03 (m, 1H), 7.25 (m, 1H), 7.35 (m, 1H), 9.41 (s,
1H), 9.52 (s, 1H); HRMS (ESI), m/z, 220.0291; Anal.
Calc. for C12H9ClO2: C 65.32; H 4.11. Found: C 65.42; H
4.09.

132 J. Chin. Chem. Soc., Vol. 57, No. 1, 2010
Liao et al.
C26H19ClN2O4: C 68.05; H 4.17; N 6.10. Found: C 67.95; H
4.15; N 6.04.
164.09; MS (FAB), m/z, 1090.5; Anal. Calc. for
C68H83ClN2O8: C 74.80; H 7.66; N 2.57. Found: C 74.72; H
7.78; N 2.51.
3,4¢-Biphenylene bis[N-(2-hydroxy-4-tetradecyloxy-
benzylidene)-4¢-aminobenzoate]s (SB-H)
Yield 68%, as a yellow solid, IR (KBr) v/cm-1: 2921,
2848, 1733, 1637, 1599, 1517, 1465, 1388, 1278, 1168,
1072, and 1010; 1H NMR (300 MHz, CDCl3) d: 0.88 (t, J =
6.3 Hz, 6H), 1.20-1.49 (m, 44H), 1.76 (m, 4H), 4.02 (t, J =
6.6 Hz, 4H), 6.52 (m, 4H), 7.22 (m, 1H), 7.28-7.38 (m, 8H),
7.47-7.53 (m, 3H), 7.68 (m, 2H), 8.27 (dd, J1 = 8.4 Hz, J2 =
3.0 Hz, 4H), 8.58 (s, 2H), 13.38 (s, 2H); 13C NMR (300
MHz, CDCl3) d: 14.11, 22.68, 25.97, 29.03, 29.58 29.67,
31.92, 76.57, 101.54, 108.10, 112.76, 120.46, 122.08,
124.65, 126.99, 128.30, 129.86, 130.81, 131.71, 133.99,
137.98, 151.38, 153.29, 158.02, 163.07, 164.09, 164.28;
MS (FAB), m/z, 1056.6; Anal. Calc. for C68H84N2O8: C
77.24; H 8.01; N 2.65. Found: C 76.99; H 8.15; N 2.63.
3¢-Fluoro-3,4¢-biphenylene bis[N-(2-hydroxy-4-tetra-
decyloxybenzylidene)-4¢-aminobenzoate]s (SB-F)
Yield 68%, as a yellow solid, IR (KBr) v/cm-1 2922,
2849, 1734, 1640, 1594, 1519, 1468, 1402, 1262, 1202,
1164, 1076, and 1006; 1H NMR (300 MHz, CDCl3) d: 0.89
(t, J = 6.3 Hz, 6H), 1.20-1.55 (m, 44H), 1.81 (m, 4H), 4.02
(t, J = 6.6 Hz, 4H), 6.53 (m, 4H), 7.25-7.28 (m, 3H),
7.31-7.56 (m, 11H), 8.28 (d, J = 8.4 Hz, 4H), 8.57 (s, 2H),
13.36 (s, 2H); 13C NMR (300 MHz, CDCl3) d: 14.11, 22.67,
25.96, 29.03, 29.55, 29.64, 31.91, 76.57, 101.53, 108.11,
112.74, 115.39, 120.46, 121.25, 123.12, 124.18, 124.56,
129.37, 130.00, 131.71, 131.92, 134.02, 137.82, 139.63,
153.53, 155.99, 158.66, 163.09, 163.72, 164.09; MS
(FAB), m/z, 1074.6; Anal. Calc. for C68H83FN2O8: C 75.95;
H 7.78; N 2.60. Found: C 76.02; H 8.00; N 2.49.
ACKNOWLEDGEMENT
We would like to thank Dr. Jey-Jau Lee for help with
the XRD experiments at National Synchrotron Radiation
Research Center (NSRRC, for the beamline BL17A), in
Taiwan. The financial support from the National Science
Council of Taiwan (ROC) through 98-2221-E-011-004 is
gratefully acknowledged for this project.
Received November 11, 2009.
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