Hydrogen bonded supramolecular liquid crystalline complex of 2,4,6-triarylamino-1,3,5-triazines with semiperfluorinated benzoic acids

Article abstract of DOI:10.1002/cjoc.201090326

Hydrogen bonded supramolecular complexes of 2,4,6-triarylamino-1,3,5-triazines (Tn) with semiperfluorinated benzoic acids have been prepared. The mesophase behaviors of such complexes were investigated with POM (polarized optical microscopy), DSC (differe

Full text of DOI:10.1002/cjoc.201090326

FULL PAPER
Hydrogen Bonded Supramolecular Liquid Crystalline Complex
of 2,4,6-Triarylamino-1,3,5-triazines with Semiperfluorinated
Benzoic Acids
Cheng, Xiaohong*(程晓红)
Jin, Jie(金杰)
Li, Quan(李全)
Dong, Xing(董星)
Key Laboratory of Medicinal Chemistry for Natural Resource, School of Chemistry and Material Engineering,
Yunnan University, Kunming, Yunnan 650091, China
Hydrogen bonded supramolecular complexes of 2,4,6-triarylamino-1,3,5-triazines (Tn) with semiperfluorinated
benzoic acids have been prepared. The mesophase behaviors of such complexes were investigated with POM (po-
larized optical microscopy), DSC (differential scanning calorimetry) and X-ray diffraction. Columnar mesophase
was found in the equimolar mixtures of the triazines with the semiperfluorinated benzoic acids. While the equimolar
mixture of triazines with the nonfluorinated three fold alkoxy-modified carboxylic acid was not mesogen. The
mesophase formation is analyzed as the hydrogen bonding between the Tn and benzoic acid which leads to discrete
dimeric supermolecule and enhances the polarity of the core region of the dimeric supermolecule; simultaneously,
an increased intramolecular polarity contrast upon replacing alkyl chains by semiperfluorinated chains, which fa-
vors a microsegregation, and leads to the fromation of the columnar phase.
Keywords hydrogenbonding, perfluorinated chains, liquid crystals
Introduction
the nonfluorinated three-chain benzoic acid AC3 were
also investigated. As far as we know, reports regarding
mesomorphic H-bonded complexes derived from two
complementary components and incorporating per-
fluorinated chains are restricted only to mixtures of
fluorinated acids and pyridine derivatives, as well as
mixtures of fluorinated acids and 2,4-diamino-6-
phenyl-1,3,5-triazines.4h,4i,
Hydrogen bonding and π-π interactions are fre-
quently employed as driving forces to give well-defined
supramolecular architectures. Melamine (2,4,6-triaryl-
amino-1,3,5-triazines) and its derivatives, which can
involve both types of interactions, have provided a vari-
ety of elegant approaches to design new types of soft
materials. Columnar mesophases formed by such com-
pounds have been found holding potential application
for electronic devices, such as (semi)conducting and
photoconducting materials and chemical sensors, due to
its high charge carrier mobility along the columnar axes.
Perfluorinated alkylchains are incompatibility with
polar, aliphatic and aromatic segments, they have larger
cross-sectional area in comparison to aliphatic chains,
and distinct conformational properties, it is possible to
use such fluorophobic effect to stabilize and even to
modify the smectic, columnar and cubic mesophases.
Considering the special roles of both the
2,4,6-triarylamino-1,3,5-triazines and perfluorinated
segment in supramolecular chemistry, we have decided
to investigate the mesogenic behaviors of hydrogen
bonded complex of alkoxy-substituted triarylmelamines
with complementary semifluorinated benzoic acids AF.
Additionally, to elucidate the influence of the fluori-
nated segments, mixtures of the triarylmelamines with
Results and discussion
Materials and methods
The alkoxy-substituted triarylmelamines (T12, T14
and T18) were prepared by the reaction of the corre-
sponding alkoxy-substituted anilines with cyanuric
chloride using potassium carbonate as the base in
2-butanone. The synthesis involved the preparation of
alkoxy-substituted anilines by reduction of the corre-
sponding nitro compounds with Fe-NH4Cl.
Synthesis of (perfluoro)alkoxy benzoic acids
Synthesis of (perfluoro)alkoxy benzoic acids has
been described in detail previously.4h,9 The binary
mixed systems were prepared as follows: the solvent of
the solution of equimolar amount of triazine (T12, T14
or T16) and benzoic acids (A3, AF2, AF3 or AC3) in
*
E-mail: xhcheng@ynu.edu.cn
Received October 12, 2009; revised March 2, 2010; accepted May 26, 2010.
Project supported by the National Natural Science Foundation of China (Nos. 20972133, 20472070), Ph.D. Program Foundation of Education Min-
istry of China (No. 2007067300) and Yunnan Science Foundation (No. 2005E008M).
Chin. J. Chem. 2010, 28, 1957— 1962
© 2010 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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Cheng et al.
FULL PAPER
THF was evaporated and the material was heated to the
isotropic state, then a dimeric complex consisting of
both species linked through H-bonding was obtained.
All the mixtures gave rise to homogeneous materials,
providing evidence for the formation of a complex.
The formation of the mixed complex is readily de-
duced from infrared spectra. The infrared spectra of the
separate components (triazine and acid), and that of the
corresponding mixture were recorded from KBr pellets.
As a representative example, the infrared spectra of T14,
AF2 and their complex T14/AF2 (1/1) are shown in
Figure 1. A clear change in the characteristic carbonyl
bands is observed among the pure components and the
mixture. Two C＝O stretching bands appear in the acid
－
1
and they correspond to the dimeric form (1650 cm )
Figure 1 FTIR spectra of the pure triazine (T14), equimolar
mixture (T14/AF2) and acid AF2.
－
1
and to the nonassociated form (1705 cm ) of acid re-
spectively. After H-bonding association with the triaz-
ine, however, these bands merge to give a single peak at
Table 1 Mesophase, phase transition temperature and enthalpy
change (in bracket) of pure compounds Tn and equimolar com-
positions of Tn with the benzoic acids A
－
1
1668 cm , which corresponds to the associated triaz-
ine-carboxylic acid. Changes in the region from 3400 to
2400 cm－ are also significant. T14 shows sharp bands
1
－
1
Transition temperature (T/℃) and enthalpy
within the region between 3500 to 3000 cm , which
gives a much simple broad bond corresponding to the
H-bonded N stretching band in the mixture, and the
Sample
change [∆H/(J•g－ 1)]
T12
Cr 114 SmA 121 Isoa
－
1
broad COOH bond (3400—2400 cm ) in the acid dis-
appeared in the mixture. All these indicate the formation
of the hydrogen bonded complex. The chemical struc-
T14
Cr 121 SmA 126 Isoa
T18
Cr 116 SmA 127 Isoa
1
T12/AC3
T12/AF2
T12/AF3
T14/AC3
T14/AF2
T14/AF3
T18/AC3.
T18/AF2
T18/AF3
Cr 81 Isoa
ture of the complex T14/AF2 is also confirmed by H
NMR (see experimental section).
Cr 48 (17.3) Col 110 (0.5) Isob
Cr 55 (0.9) Col 144 (2.8) Isob
Cr193 (21.2) Cr2104 (32.9) Isob
Cr 47 (4.5) Col 117 (0.7)Col 131 (0.1) Isob
Cr 54 (6.2) Col 139 (3.6) Isob
Cr 114 Isoa
Scheme 1 Chemical structures of the 2,4,6-triarylamino-1,3,5-
triazines and the complementary semiperfluorinated benzoic ac-
ids
Cr 67 (13.3)Cr 102 (33.0) Col 134 (6.5) Isob
Cr 43 (12.9) Cr 63 (5.6) Col 117 (1.8) Isob
a Transition temperature was determined by POM; b Transition
temperature and enthalpy changes were determined by DSC
(peak temperature, first cooling scan, 5 ℃•min－ 1).
All alkoxy substituted triarylmelamines Tn show
smectic A phase, which is characterized by texture,
consisting of both focal-conic and pseudo isotropic re-
gions (Figure 2a). The occurrence of focal-conic fans
suggests a layered structure, whereas the pseudo iso-
tropic region indicates an on average orthogonal or-
ganization of the molecules with respect to the layer
planes. With the elongation of the alkoxy chains, an
increase of both the melting and clear temperatures is
observed. The formation of the smectic A phase can be
explained with the model shown in Figure 2d. The tri-
azines are suspected to form H-bonding dimmers, in
which the six periperial alkoxy chains are located in
both side of the rigid core consisted by the N—H…N
hydrogen bonded aromatic cores, to form layer structure.
Mesophase behavior
The liquid crystalline properties of separate compo-
nents and the mixtures were investigated by POM and
DSC, and X-ray investigation were made for selected
samples. Their mesophase behaviors are summarized in
Table 1.
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Hydrogen Bonded Supramolecular Liquid Crystalline Complex of 2,4,6-Triarylamino-1,3,5-triazines
Figure 2 (a) Smectic A phase of compound T14 at 121 ℃ under POM; (b) columnar phase of binary mixture of T14/AF2 at 117 ℃
under POM; (c) columnar phase of binary mixture of T14/AF3 at 139 ℃ under POM; (d) model showing the organization of the mole-
cules in the smectic A phase of compound T14; (e) model showing the organization of the molecules in the columnar phase of binary
mixture of T14/AF2; (f) model showing the organization of the molecules in the columnar phase of binary mixture of T14/AF3.
H-Bonded complexes tiazine (Tn)/benzonic acid
mixture of triazine T14 with semifluorinated benzoic
acids AF2 and AF3, respectively. Unfortunately for
both samples, there is only one reflex together with a
weak second order reflex and it was not possible to ob-
tain aligned samples. We have tentatively indexed it to
square or hexagonal (Figure 3, Table 2) columnar phase.
The texture appears to be uniaxial and therefore a
rectangular or oblique lattice is unlikely. Simultaneously
the texture clearly indicates a columnar phase (Figures
2b and 2c), hence smectic phase can be excluded. As the
hexagonal phase is found more frequently than square
phase, columnar hexagonal phase appears to be the most
likely phase for T14/AF2 and T14/AF3.
(AF2, AF3 or A3) (1/1)
Each investigation of binary 1∶1 mixture of the tri-
azines Tn with the semiperfluorinated benzoic acids
(AF2 or AF3) exhibits columnar mesophase, as shown
by their typical spherulitic textures with homotropic
aligned regions containing birefringent filamens under
POM (Figures 2b, 2c).
The binary 1∶1 mixture of Tn with the three fold
semifluorinated chain substituted benzoic acids (AF3) is
much border than the corresponding binary 1∶1 mix-
ture of benzoic acid with two semiflurinated chains
(AF2). This means, with increasing degree of fluorina-
tion, the fluorophobic effect and the intramolecular con-
trast increased and thus forces micro-segregation, which
can efficiently be used to dramatically stabilize the
mesophases.
On the contrary, all the equimolar mixtures of Tn
with the nonfluorinated three fold alkoxy-modified car-
boxylic acid AC3 show a single melting transition.
However, no mesomorphic properties can be found in
the mixed system Tn/AC3.
We have made the X-ray investigation on the binary
Chin. J. Chem. 2010, 28, 1957— 1962
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FULL PAPER
Figure 3 WAXS (wide angle X-ray scattering) diffraction patterns of Colhex/p6mm (or Colsqu/p4mm) phase of binary mixture of
T14/AF2 at 90 ℃ (a) and 140 ℃ (b).
Table 2 X-ray data of binary mixtures of T14/AF2 and T14/AF3
Sample
T/℃ Phase group
2θobs/(°)
2.7550
5.4570
3.0500
17.2440
dobs/nm
3.2068
1.6194
2.8967
0.5142
hk
10
20
10
11
Parameter/nm
ahex＝3.7 (or asqu＝3.2)
T14/AF2
90 Colhex/p6mm (or Colsqu/p4mm)
ahex＝3.45 (or asqu＝2.9)
140 Colhex/p6mm (or Colsqu/p4mm)
T14/AF3
The hydrogen bonding between the triazines Tn and
benzoic acids predominantly leads to discrete dimeric
supermolecules (Figures 2e, 2f). The hydrogen bonding
enhances the polarity of the core region of the dimeric
supermolecules. Simultaneously, the nonpolar nature of
molecular periphery is enhanced by introducing the
non-polar alkyl (or semifluorinated) chains of the acid
components. The nonappearance of mesomorphic be-
havior for the mixtures Tn/AC3 very distinctly illus-
trated the enhanced mesophase structure formation ten-
dencies obtained by replacing the alkyl groups of the
benzoic acid components by semifluorinated chains.
were conducted under argon and the glassware was
oven-dried (140 ℃). Commercially available chemicals
1
were used as received. H NMR and 13C NMR spectra
were recorded on a Bruker-DRX-500 spectrometer.
Mass spectra were recorded on a Finnigan MAT 90
spectrometer at an ionization potential of 70 eV. Mi-
croanalysis was performed using a Leco CHNS-932
elemental analyzer. IR (KBr) spectra were recorded on a
Nicolet AVATAR 360 infrared spectrophotometer.
Column chromatography was performed with silica gel
60 (230—400 mesh) from Merck. Transition tempera-
tures were measured by means of a Nikon Optiphot po-
larizing microscope with Linkam LTS 350 hotstage and
control unit and confirmed using differential scanning
calorimetry (Perkin Elmer DSC-7). X-ray investigations
were carried out with a Guinier-Goniometer (Huber).
Conclusion
A new family of hydrogen bonded supramolecular
liquid crystalline complex of melamine (2,4,6-triaryl-
amino-1,3,5-triazines) with semiperfluorinated benzoic
acids has been obtained. Columnar mesophases are
found in these binary 1∶1 mixtures of the triazine Tn
with the semiperfluorinated benzoic acids AF2 or AF3.
While the equimolar mixtures of Tn with the non-
fluorinated three fold alkoxy-modified carboxylic acid
AC3 are non mesogens. The mesophase formation is
essentially due to an increased intramolecular polarity
contrast upon replacing alkyl chains by semiperfluori-
nated chains, which favors a microsegregation.
Preparation
3,4,5-Tris-dodecyloxy-benzoic acid was prepared
according to literature, m.p. 59 ℃ (Lit.9 60 ℃). Per-
fluoroalkoxy benzoic acids were synthesized according
to reference.4h
3,4-Bis(1H,1H,2H,2H,3H,3H,4H,4H-perfluoro-
decyl-1-oxy)benzoic acid (9-H4F6)
Transitional
temperature: Cr 57 Col 82 Iso; IR (KBr) ν: 3300 (OH),
2915, 2853 (CH2, CH3), 1705, 1650 (C＝O), 1596, 1416,
1336 (C＝C), 1272, 1224, 1128, 1048 (C—O—C), 877,
－
1
824, 748 (＝CH, ArH) cm .
Experimental
3,4,5-Tris(1H,1H,2H,2H,3H,3H,4H,4H-perfluoro-
octyl-1-oxy)benzoic acid (10-H4F4) Cr 43 (Col 34)
Iso.
Apparatus and materials
Reactions require an inert gas atmosphere, so they
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Hydrogen Bonded Supramolecular Liquid Crystalline Complex of 2,4,6-Triarylamino-1,3,5-triazines
General procedure for etherification
60H, 30CH2), 3.94 (t, J＝6.5 Hz, 6H, 3OCH2), 6.85 (d,
J＝8.5 Hz, 6H, ArH), 7.42 (d, J＝8.8 Hz, 6H, ArH); IR
(KBr) ν: 3351, 3253 (NH), 2918, 2850 (CH2, CH3),
1616 (C＝N), 1596, 1516, 1416 (C＝C), 1225, 1228,
Under an argon atmosphere, a mixture of nitrophe-
nol (8 mmol), K2CO3 (24 mmol) and n-bromoakane (12
mmol) in acetone (50 mL) was heated under reflux
overnight. Ethyl acetate (50 mL) and water (50 mL)
were added, the organic layer was separated, dried over
MgSO4, and the solvent was evaporated in vacuo. The
rude product was purified by column chromatography
(eluent: petroleum ether/ethyl acetate, V∶V＝10∶1).
Colorless crystal (yield 82%—85%).
－
1
1049 (C—O—C), 816 (＝CH, ArH) cm ; MS (70 eV)
m/z (%): 907.7 (M ＋ 1, 100). Anal. calcd for
C57N90N6O3: C 75.45, H 10.00, N 9.26; found C 75.05,
H 9.78, N 9.58.
N2,N4,N6-Tris(4-(tetradecyloxy)phenyl)-1,3,5-tri-
azine-2,4,6-triamine (T14) 1H NMR (CDCl3, 500
MHz) δ: 0.88 (t, J＝6.9 Hz, 9H, 3CH3), 1.26—1.79 (m,
72H, 36CH2), 3.94 (t, J＝6.5 Hz, 6H, OCH2), 6.85 (d,
J＝8.5 Hz, 6H, ArH), 7.42 (d, J＝8.8 Hz, 6H, ArH); IR
(KBr) ν: 3349, 3250 (NH), 2916, 2852 (CH2, CH3),
1614 (C＝N), 1596, 1516, 1416 (C＝C), 1224, 1228,
1-(Dodecyloxy)-4-nitrobenzene m.p. 54 ℃ (Lit.10
1
55 ℃); H NMR (CDCl3, 500 MHz) δ: 0.88 (t, J＝6.8
Hz, 3H, CH3), 1.27—1.85 (m, 20H, 10CH2), 4.05 (t, J＝
6.5 Hz, 2H, OCH2), 6.94 (d, J＝9.2 Hz, 2H, ArH), 8.20
(d, J＝9.2 Hz, 2H, ArH).
－
1
1048 (C—O—C), 814 (＝CH, ArH) cm ; MS (70 eV)
m/z (%): 991.8 (M ＋ 1, 100). Anal. calcd for
C63N102N6O3: C 76.31, H10.37, N 8.48; found C 76.71,
H 10.14, N 8.65.
1-Nitro-4-(tetradecyloxy)benzene
(Lit.11 57—60 ℃).
m.p. 59 ℃
m.p. 71 ℃
1-Nitro-4-(octadecyloxy)benzene
(Lit.12 71—72 ℃).
N2,N4,N6-Tris(4-(octadecyloxy)phenyl)-1,3,5-tri-
azine-2,4,6-triamine (T18) 1H NMR (CDCl3, 500
MHz) δ: 0.88 (t, J＝6.9 Hz, 9H, 3CH3), 1.26—1.79 (m,
96H, 48CH2), 3.94 (t, J＝6.5 Hz, 6H, OCH2), 6.85 (d,
J＝8.5 Hz, 6H, ArH), 7.42 (d, J＝8.8 Hz, 6H, ArH); IR
(KBr) ν: 3350, 3249 (NH), 2919, 2852 (CH2, CH3),
1613 (C＝N), 1595, 1514, 1417 (C＝C), 1227, 1229,
Synthesis of the alkoxysubstituted anilines 3/n
A mixture of ammonium chloride (0.8 mmol) and
iron powder (6 mmol) in water (10 mL) was heated un-
der reflux for 5 min. Then the corresponding nitro com-
pound was added and the solution was refluxed for 3 h.
Afterwards, saturated aqueous Na2CO3 solution was
added, the mixture was stirred for 30 min at 40 ℃ and
extracted with CHCl3. The combined organic extracts
were dried over MgSO4, and the solvent was evaporated
in vacuo. The rude product was purified by column
chromatography (eluent: petroleum ether/ethyl acetate,
V∶V＝5∶1). Yields of 3/12, 3/14 and 3/18 were 68%,
70% and 68%, respectively.
－
1
1050 (C—O—C), 818 (＝CH, ArH) cm ; MS (70 eV)
m/z (%): 1160.0 (M ＋ 1, 100). Anal. calcd for
C75N126N6O3: C 77.67, H 10.95, N 7.25; found C 77.93,
H 10.74, N 7.03.
T14/AF2 The solvent of the solution of equimolar
amounts of triazine (T12, T14 or T16) (0.05 mmol) and
benzoic acids (A3, AF2 or AF3) (0.05 mmol) was
evaporated and the material heated to the isotropic state,
a dimeric complex consisting of both species linked
through H-bonding was obtained. All the mixtures gave
rise to homogeneous materials, providing evidence for
the formation of a complex.
4-(Dodecyloxy)benzenamine (3/12) m.p. 51 ℃
1
(Lit.13 51 ℃); H NMR (CDCl3, 500 MHz) δ: 0.88 (t,
J＝6.6 Hz, 3H, CH3), 1.26—1.75 (m, 20H, 10CH2),
3.88 (t, J＝6.5 Hz, 2H, OCH2), 6.64 (d, J＝8.7 Hz, 2H,
ArH), 6.74 (d, J＝8.6 Hz, 2H, ArH).
As an example, the NMR date of complex T14/AF2:
1H NMR (CDCl3, 500 MHz) δ: 0.88 (t, J＝6.8 Hz, 9H,
3CH3), 1.26—2.22 (m, 84H, 42CH2), 3.94 (t, J＝6.6 Hz,
6H, 3OCH2), 4.10 (t, J＝5.3 Hz, 4H, 2OCH2), 6.86 (d,
J＝8.4 Hz, 6H, ArH), 6.89 (d, J＝8.6 Hz, 1H, ArH),
7.44 (d, J＝8.8 Hz, 6H, ArH), 7.59 (s, 1H, ArH), 7.74 (d,
J＝8.4 Hz, 1H, ArH); IR (KBr) ν: 3320 (NH…O＝C—
OH), 2915, 2853 (CH2, CH3), 1668 (C＝O), 1613 (C＝
N), 1596, 1416 (C＝C), 1224, 1128, 1048 (C—O—C),
4-(Tetradecyloxy)benzenamine (3/14) m.p. 66 ℃
(Lit.14 65—68 ℃).
4-(Octadecyloxy)benzenamine (3/18) m.p. 64 ℃
(Lit.12 64 ℃).
General procedure for the preparation of
alkoxy-substituted triarylmelamine Tn
Under an argon atmosphere, a mixture of cyanuric
chloride (0.5 mmol), K2CO3 (2 mmol) and appropriate
alkoxysubstituted anilines (3/12, 3/14, 3/18) (2 mmol)
in 2-butanone (20 mL) was heated under reflux for 3 d.
Chloroform and water were added, the organic layer
was separated, dried over MgSO4, and the solvent was
evaporated in vacuo. The crude product was purified by
column chromatography (eluent: petroleum ether/ethyl
acetate, V∶V＝10∶1). Yields of T12, T14 and T18
were 71%, 68% and 64%, respectively.
－
1
878, 814,749 (＝CH, ArH) cm .
References
1
(a) Beginn, U. Prog. Polym. Sci. 2003, 28, 1049.
(b) Kato, T.; Mizoshita, N.; Kanie, K. Macromol. Rapid
Commun. 2001, 22, 797.
(c) Paleos, C. M.; Tsiourvas, D. Angew. Chem., Int. Ed.
Engl. 1995, 34, 1696.
N2,N4,N6-Tris(4-(dodecyloxy)phenyl)-1,3,5-tri-
azine-2,4,6-triamine (T12) 1H NMR (CDCl3, 500
MHz) δ: 0.88 (t, J＝6.5 Hz, 9H, 3CH3), 1.26—1.79 (m,
2
(a) Goldmann, D.; Dietel, R.; Janietz, D.; Schmidt, C.;
Wendorff, J. H. Liq. Cryst. 1998, 24, 407.
Chin. J. Chem. 2010, 28, 1957— 1962
© 2010 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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Cheng et al.
FULL PAPER
(b) Goldmann, D.; Janietz, D.; Schmidt, C.; Wendorff, J. H.
Mol. Cryst. Liq. Cryst. 1999, 332, 141.
5
(a) Nishikawa, E.; Yamamoto, J. Mol. Cryst. Liq. Cryst.
2004, 411, 139.
3
4
Adam, D.; Schuhmacher, P.; Simmerer, J.; Häussling, L.;
Siemensmeyer, K.; Etzbach, K. H.; Ringsdorf, H.; Haarer, D.
Nature 1994, 371, 141.
(a) Nguyen, H. T.; Sigaud, G.; Achard, M. F.; Hardouin, F.;
Twieg, R. J.; Betterton, K. Liq. Cryst. 1991, 10, 389.
(b) Doi, T.; Sakurai, Y.; Tamatani, A.; Takenaka, S.;
Kusabayashi, S.; Nishihata, Y.; Terauchi, H. J. Mater.
Chem. 1991, 1, 169.
(b) Pensec, S.; Tournilhac, F.-G.; Bassoul, P. J. Phys. II
1996, 6, 1597.
(c) Johansson, G.; Percec, V.; Ungar, G.; Zhou, J. P.
Macromolecules 1996, 29, 646.
(d) Percec, V.; Johansson, G.; Ungar, G.; Zhou, J. J. Am.
Chem. Soc. 1996, 118, 9855.
(e) Percec, V.; Schlueter, D.; Kwon, Y. K.; Blackwell, J.;
Moller, M.; Slangen, P. J. Macromolecules 1995, 28, 8807.
(f) Cheng, X. H.; Diele, S.; Tschierske, C. Angew. Chem.,
Int. Ed. 2000, 39, 592.
(b) Nishikawa, E.; Yamamoto, J.; Yokoyama, H. Chem. Lett.
2001, 454.
(c) Nishikawa, E.; Yamamoto, J.; Yokoyama, H. Chem. Lett.
2001, 94.
(d) Bernhardt, H.; Weissflog, W.; Kresse, H. Chem. Lett.
1997, 151.
Kohlmeier, A.; Janietz, D. Chem. Mater. 2006, 18, 1483.
Goldmann, D.; Janietz, D.; Festag, R.; Schmidt, C.;
Wendorff, J. H. Liq. Cryst. 1996, 21, 619.
Dierking, I. Texture of Liquid Crystals, Wiley-VCH, Wein-
heim, 2003.
6
7
8
9
Percec, V.; Cho, W.-D.; Ungar, G.; Yeardley, D. J. P. J. Am.
Chem. Soc. 2001, 123, 1302.
10 Kuhn, R.; Jerchel, D. Chem. Ber. 1940, 73, 1100.
11 Wissner, A.; Carroll, M. L.; Johnson, B. D.; Kerwar, S. S.;
Pickett, W. C. J. Med. Chem. 1992, 35, 4779.
12 Arnaud-Neu, F.; Boehmer, V.; Dozol, J. F.; Gruettner, C.;
Jakobi, R. A.; Kraft, D.; Mauprivez, O.; Rouquette, H.;
Schwing-Weill, M. J.; Simon, N.; Vogt, W. J. Chem. Soc.,
Perkin Trans. 2: Phys. Org. Chem. 1996, 6, 1175.
(g) Pegenau, A.; Cheng, X. H.; Tschierske, C.; Goring, P.;
Diele, S. New J. Chem. 1999, 23, 465.
(h) Cheng, X.; Das, M. K.; Diele, S.; Tschierske, C.
Langmuir 2002, 18, 6521.
13 Kimura, T.; Takeuchi, M.; Hamachi, I.; Shinkai, S. Israel J.
Chem. 1996, 36, 379.
(i) Cheng, X.; Prehm, M.; Das, M. K.; Kain, J.; Baumeister,
U.; Diele, S.; Leine, D.; Blume, A.; Tschierske, C. J. Am.
Chem. Soc. 2003, 125, 10977.
14 Wissner, A.; Carroll, M. L.; Johnson, B. D.; Kerwar, S. S.;
Pickett, W. C.; Schaub, R. E.; Torley, L. W.; Trova, M. P.;
Kohler, C. A. J. Med. Chem. 1992, 35, 4779.
(E0910123 Zhao, C.)
1962
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