Combination of chiral and achiral triphenylene units in a novel unsymmetrical columnar twin

Article abstract of DOI:10.1002/1522-2675(20010516)84:5<1190::AID-HLCA1190>3.0.CO;2-4

The synthesis, characterization, and mesomorphic properties of a new type of liquid-crystalline twin bearing a pentadecyloxytriphenylene subunit tethered via a decyl spacer to a chiral pentakis(3,7-dimethyloctyloxy)-triphenylene are reported. The target compound displays a hexagonal columnar mesophase, which is metastable at room temperature.

Full text of DOI:10.1002/1522-2675(20010516)84:5<1190::AID-HLCA1190>3.0.CO;2-4

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Helvetica Chimica Acta ± Vol. 84 (2001)
Combination of Chiral and Achiral Triphenylene Units in a Novel
Unsymmetrical Columnar Twin
by David Hirsta), Siegmar Dieleb), Sabine Laschata)*, and Manfred Nimtzc)
a) Institut für Organische Chemie, Technische Universität Braunschweig, Hagenring 30, D-38106 Braunschweig
(Fax: ‡49-(0)531-3915388; e-mail: s.laschat@tu-bs.de)
b) Institut für Physikalische Chemie, Martin-Luther-Universität Halle-Wittenberg, Mühlpforte 1,
D-06108 Halle (Fax: ‡49-(0)345-5527156; e-mail: diele@chemie.uni-halle.de)
c) Gesellschaft für Biotechnologische Forschung, Mascheroder Weg 1, D-38124 Braunschweig
The synthesis, characterization, and mesomorphic properties of a new type of liquid-crystalline twin bearing
a pentadecyloxytriphenylene subunit tethered via a decyl spacer to a chiral pentakis(3,7-dimethyloctyloxy)-
triphenylene are reported. The target compound displays a hexagonal columnar mesophase, which is metastable
at room temperature.
Introduction. ± Among the two major classes of thermotropic liquid crystals, i.e.,
calamitic (rod-shaped) and discotic (disk-shaped) liquid crystals, the latter type, which
forms columnar short-range-ordered assemblies in the mesophase, has attracted many
researchers during the last decade [1][2]. The interest in discotic liquid crystals is
mainly due to their promising physical properties, such as electrical and photo-
conductivity, and high charge-carrier mobility along the columns [3]. From this work,
the so-called columnar twins or oligomers have emerged recently, constituting two or
more discotic subunits connected to each other by a flexible spacer [4]. 2,3,6,7,10,11-
Hexasubstituted triphenylenes are ideally suited building blocks for columar liquid
crystals, and many examples of both symmetrical and unsymmetrical twins based on
triphenylenes are known (for recent examples, see [5]). However, only few polymeric
liquid crystals and columnar twins containing chiral triphenylenes have been published
so far (for chiral polymeric triphenylenes, see [6]; for chiral monomeric triphenylenes,
see [7]). Particularly attractive to us seemed unsymmetrical twins bearing chiral and
achiral moieties of similar sizes, because these twins might be able to form different
chiral and achiral microdomains within a columnar mesophase. The presence of chiral
subunits might induce helical twisting of the columns, which is a prerequisite for
ferroelectricity [8]. Those unsymmetrical dimers may either retain the mesomorphic
properties of the subunits by columnar stacking of like subunits, or form supra-
molecular aggregates by columnar stacking of unlike subunits and thus display novel
mesomorphic properties. As shown in Fig. 1, four different orientations are conceiv-
able, i.e., a) formation of two-dimensional domains within one lattice sheet, b) an
intracolumnar regular ordered pattern, with the chiral and achiral subunits being
segregated in different columns, c) an intracolumnar regular mixed pattern, with chiral
and achiral subunits of neighboring twins stacked alternatively within the columns, and
d) an intracolumnar randomly mixed pattern [9]. The micro-segregation in a ± c should
lead to different mesomorphic properties, e.g., increased phase stability, as compared to

Helvetica Chimica Acta ± Vol. 84 (2001)
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Fig. 1. Possible arrangements of unsymmetrical twins in columnar mesophases. a) Formation of two-dimensional
domains within the hexagonal lattice; b) intracolumnar regularly ordered; c) intracolumnar regularly mixed;
and d) intracolumnar randomly mixed.
the properties of monomeric subunits. As a model system for such unsymmetrical twins,
compound 9, bearing (3R)-dihydrocitronellyloxy moieties [9] on one triphenylene and
decyloxy chains on the other achiral subunit, was chosen (Scheme).We report here the
synthesis and mesomorphic properties of 9.
Results and Discussion. ± For the synthesis of 9, a convergent strategy was used, in
which the chiral triphenylene moiety 8 was attached to the tether carrying achiral
triphenylene 4c in the final step. Thus, decane-1,10-diol (2) was converted to the 3,4,5,6-
tetrahydro-2H-pyran-2-yl(Thp)-protected bromo derivative 3, which was further
coupled with achiral hydroxytriphenylene 1 [10] to give 4a in 90% yield. Deprotection
and bromination of the primary OH group yielded 4c. To obtain the required chiral
hydroxy triphenylene 8, a three-step sequence starting from 1,2-dialkyloxybenzene 5a
was elaborated. Compound 5a was first brominated to give 5b, which underwent
subsequent BuLi-mediated aryl coupling [11] to the biphenyl 6. FeCl3-Mediated
cyclization of 1,1'-biphenyl 6 and gujacol derivative 7 to 8 proceeded in 51% yield. With
regard to the yield, this coupling was found advantageous compared to the direct
coupling of 1,2-dialkyloxybenzene 5a with 7 [10]. Final condensation of the achiral
building block 4c with the chiral subunit 8 in the presence of K2CO3 provided the
desired twin 9 in 64% yield.
The mesomorphic behavior of compound 9 was studied by differential scanning
calorimetry (DSC). During the first heating cycle, two phase transitions, a melting
1
1
process at 348 (DH ˆ 21.4 kJ mol ), and a clearing process at 458 (DH ˆ 3.9 kJ mol )
were observed. However, during cooling (and subsequent heating) only the clearing
1
transition was detected (TM-I ˆ 418, DH ˆ 8.5 kJ mol
and TI-M ˆ 428, DH ˆ
1
9.5 kJ mol ). Even after prolonged cooling to 08, the mesophase did not crystallize.
Under the optical polarizing microscope, twin 9 displayed a fan-shaped texture at 448
(upon cooling) typical for columnar mesophases. Supercooling of the mesophase below
room temperature was observed (Fig. 2) and crystallization could be induced only by
scratching or shaking the supercooled sample, indicating that the columnar mesophase
of 9 is metastable. In comparison with the monomeric subunits hexadecyloxy-
triphenylene (C 588 CoIh 698 I) [12] and hexakis[(3'R)-3,7-dimethyloctyloxy]tri-

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Helvetica Chimica Acta ± Vol. 84 (2001)
Scheme. Synthesis of Columnar Twin 9.
a) Dihydropyran, TsOH ´ H2O, THF, 58, 2 d; 41%; Br4C, Ph3P, THF, r.t., 20 h; 32%. b) K2CO3; DMF, 808, 20 h;
90%. c) TsOH ´ H2O, MeOH, CH2Cl2, r.t., 18 h; 93%. d) Br4C, Ph3P, THF, r.t., 18 h; 24%. e) Br2, CHCl3, 08, 2 h;
r.t., 18 h; 65%. f) BuLi (0.5 equiv.), THF, 118, 0.5 h; r.t., 20 h; 43%. g) FeCl3 (10 equiv.), H2SO4, CH2Cl2, r.t.,
2 h; 51%. h) K2CO3, DMF, 808, 24 h; 64%.

Helvetica Chimica Acta ± Vol. 84 (2001)
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Fig. 2. Fan-shaped texture of the twin 9. The photomicroscopic image of the mesophase was obtained with a
polarizing microscope (Olympus BX 50 equipped with a Linkam LTS 50 hot stage) at 138 on cooling (0.28
min 1) from the isotropic liquid (crossed polarizers, magnification Â200).
phenylene (C 198 Colhd 368 I) [7k], twin 9 displays intermediate transition temper-
atures.
The X-ray-diffraction data were obtained after heating the sample to 558 and
subsequent cooling to room temperature. As shown in Fig. 3, a distinct 10 reflection
p
(Vˆ 2.18, intensity 1100 cps) together with 11 reflection ( 3 reflection) indicates a
hexagonal columnar lattice (a ˆ 2.4 nm). In the wide-angle region (inset of Fig. 3),
three diffuse scatterings can be seen. The diffuse halo at ca. 108 corresponds to the
distance of the flexible alkyl side chains. The second scattering maximum at 138 can be
assigned to the columnar stacking of the aromatic cores. The third, very broad and weak
scattering maximum at ca. 78 hints at a sandwich-like packing of the two different
species (chiral and achiral) in the columns in a short-range order. Overall, the X-ray
data are consistent with a supramolecular array in which the different subunits of the
twin are positioned in neighboring columns. This observation is in good agreement with
2H-NMR experiments on symmetrical hexapentyloxytriphenylene-containing dimers
by Luz and co-workers, which also proved restricted planar reorientation in such twin
systems [5e]. To achieve optimum space-filling of the side chains in 9, a regularly
alternate stacking of chiral and achiral triphenylenes (Fig. 1,c) is conceivable.
In conclusion, a non-symmetrical columnar twin bearing chiral and achiral
triphenylene units of similar size has been prepared via a convergent route. No
evidence for a chiral mesophase has been found. However, the twin displays a
metastable hexagonal columnar mesophase at ambient temperature.

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Helvetica Chimica Acta ± Vol. 84 (2001)
Fig. 3. X-Ray diffractogram of the twin 9. The small-angle region is given in the inset.
Generous financial support by the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen
Industrie is gratefully acknowledged. D. H. thanks the European Community for an ERASMUS/SOKRATES
fellowship.
Experimental Part
General. NMR Spectra: Bruker AM-400 and AC-200 P; d in ppm and J in Hz. Differential scanning
calorimetry (DSC): Rheometric Scientific DSC SP, heating and cooling rate: 10 K min 1. Polarizing microscopy:
Olympus BX50 polarizing microscope combined with a Linkam LTS350 hot stage and Linkam TP 93 central
processor. (3R)-1,2-Bis(3,7-dimethyloctyloxy)benzene (5a) was prepared according to [13], (3R)-1-bromo-3,7-
dimethyloctane was prepared according to [14], and 2-hydroxy-3,6,7,10,11-pentakis(decyloxy)triphenylene (1)
was prepared according to [10].
1-Bromo-10-[(3,4,5,6-tetrahydro-2H-pyran-2-yl)oxy]decane (3). To a cooled soln. of decane-1,10-diol (2;
17.4 g, 0.10 mol) and 3,4-dihydro-2H-pyran (5.05 g, 0.06mol) in THF (500 ml) was added TsOH ´ H2O (0.95 g,
5.00 mmol) at 58. After stirring for 24 h at 58, the mixture was poured onto sat. NaHCO3 (500 ml), and the
aq. layer was extracted with Et2O (4 Â 100 ml). The combined org. layers were dried (MgSO4), evaporated, and
purified by flash chromatography (FC) (hexanes/AcOEt 10 :1) to yield 10-[(3,4,5,6-tetrahydropyran-2H-
yl)oxy]decan-1-ol as a white solid (6.40 g, 41%). To a vigorously stirred soln. of 10-[(3,4,5,6-tetrahydro-2H-
pyran(-2-yl)oxy]decan-1-ol (2.60 g, 10.0 mmol) in THF (150 ml) were added Ph3P (2.26 g, 10.0 mmol) and Br4C
(3.32 g, 10.0 mmol), and stirring was continued for 12 h at r.t. The precipitate was removed by filtration over
Celite, and the filtrate was concentrated. Purification by FC (hexanes/AcOEt 50 :1): 3 (1.02 g, 32%). Colorless
liquid. 1H-NMR (200 MHz, CDCl3): 1.30 ± 1.43, 1.50 ± 1.59, 1.71 ± 1.78, 1.82 ± 1.89 (m, 22 H); 3.32 ± 3.39 (m, 1 H);
3.41 (t, J ˆ 6.9, 2 H); 3.67 (m, 1 H); 3.71 ± 3.79 (m, 1 H); 3.82 ± 3.88 (m, 1 H); 4.58 (t, J ˆ 3.7, 1 H). 13C-NMR
(50 MHz, CDCl3): 19.7; 25.5; 26.2; 26.9; 28.2; 28.7; 29.3; 29.4; 29.7; 32.8; 34.0; 62.3; 67.7; 98.8. EI-MS: 321 (4,
‡
M ), 319 (3), 247 (2), 164 (2), 162 (2), 150 (5), 148 (5), 115 (3), 101 (6), 97 (7), 85 (100).
3,6,7,10,11-Pentakis(decyloxy)-2-{10-[(3,4,5,6-tetrahydro-2H-pyran-2-yl)oxy]decyloxy}triphenylene (4a). A
mixture of 1 (150 mg, 0.15 mmol), 3 (48 mg, 0.15 mmol), and K2CO3 (100 mg, 0.73 mmol) in DMF (2 ml) was
heated at 808 for 20 h. Then, the mixture was poured onto ice, and the resulting precipitate was filtered over
Celite, redissolved in CH2Cl2 (10 ml), dried (MgSO4), and evaporated. Purification by FC (hexanes/CH2Cl2
10 :3) yielded 0.17 g (0.134 mmol, 89.5%) of 4a (170 mg, 90%). Purple amorphous solid. 1H-NMR (200 MHz,
CDCl3): 0.85 ± 0.91 (t, J ˆ 6.5, 15 H); 1.28 ± 1.70 (m, 90 H); 1.87 ± 1.97 (m, 14 H); 3.22 ± 3.40 (m, 1 H); 3.44 ± 3.52

Helvetica Chimica Acta ± Vol. 84 (2001)
1195
(m, 1 H); 3.68 ± 3.76 (m, 1 H); 3.79 ± 3.87 (m, 1 H); 4.23 (t, J ˆ 6.5, 12 H); 4.58 (t, J ˆ 4.4, 1 H); 7.83 (s, 6 H).
13C-NMR (50 MHz, CDCl3): 14.1; 19.7; 22.7; 25.5; 26.2; 29.4; 29.5; 29.5; 29.6; 29.7; 30.8; 31.9; 62.3; 67.6; 69.9;
‡
107.4; 123.6; 149.0. EI-MS: 1265 (65, M ), 1182 (4), 312 (9), 186 (10), 95 (10), 85 (100). Anal. calc. for
C83H140O8: C 78.74, H 11.15; found: C 78.81, H 11.10.
10-[3,6,7,10,11-Pentakis(decyloxy)triphenylen-2-yl]decan-1-ol (4b). To a soln. of 4a (130 mg, 0.10 mmol) in
MeOH (5 ml) and CH2Cl2 (0.5 ml) was added TsOH ´ H2O (2 mg, 0.01 mmol), and the mixture was stirred for
18 h at r.t. Then, the mixture was poured onto sat. NaHCO3 (10 ml). The aq. layer was extracted with CH2Cl2
(3 Â 10 ml) and the combined org. extracts were dried (MgSO4), evaporated, and purified by FC (hexanes/
AcOEt 10 :1) to give 4b (110 mg, 93%). Amorphous purple solid. 1H-NMR (200 MHz, CDCl3): 1.20 ± 1.70
(m, 84 H); 1.80 ± 2.10 (m, 12 H); 3.63 (t, J ˆ 6.7, 2 H); 4.21 (t, J ˆ 6.5, 12 H); 7.83 (s, 6 H). 13C-NMR (50 MHz,
‡
CDCl3): 14.1; 22.7; 26.0; 29.2; 29.3; 29.4; 29.5; 31.9; 62.0; 67.0; 107.0; 123.2; 149.0. EI-MS: 1181 (100, M ), 1154
(5), 1041 (5), 1025 (3), 900 (4), 744 (2), 603 (5), 463 (4), 390 (14), 323 (8), 295 (6), 148 (3), 83 (6). Anal. calc.
for C78H132O7: C 79.27, H 11.26; found: C 79.26, H 11.31.
2-(10-Bromodecyloxy)-3,6,7,10,11-pentakis(decyloxy)triphenylene (4c). To
a soln. of 4b (118 mg,
0.10 mmol) in THF (5 ml) were sequentially added Ph3P (26 mg, 0.10 mmol) and Br4C (33 mg, 0.10 mmol),
and the resulting mixture was stirred overnight. The precipitate was removed by filtration, and the filtrate was
dissolved in CH2Cl2 (25 ml), washed with H2O (2 Â 20 ml), dried (MgSO4), and evaporated. Purification by FC
1
(hexanes/AcOEt 20 :1) yielded 4c (30 mg, 24%). Purple amorphous solid. H-NMR (400 MHz, CDCl3): 0.88
(t, J ˆ 7.0, 15 H); 1.28 ± 1.48, 150 ± 1.62 (m, 82 H); 1.83 ± 1.93, 1.93 ± 2.03 (m, 14 H); 3.40 (t, J ˆ 7.0, 2 H); 4.23
(t, J ˆ 6.6, 12 H); 7.84 (s, 6 H). 13C-NMR (100 MHz, CDCl3): 14.1; 22.6; 26.2; 28.1; 29.3; 29.4; 29.5; 29.6; 29.7;
‡
31.9; 32.8; 33.9; 69.7; 107.4; 123.6; 149.0. EI-MS: 1244 (100, M ), 1164 (16), 1105 (18), 1025 (14), 964 (14), 885
(13), 744 (10), 603 (33), 463 (22), 323 (37), 296 (13), 97 (5).
(3R)-1-Bromo-3,4-bis[(3R)-3,7-dimethyloctyloxy]benzene (5b). To a cooled soln. of (1,2-bis[(3R)-3,7-
dimethyloctyl)oxy]benzene (5a; 3.90 g, 0.01 mol) in CHCl3 (25 ml) was added dropwise over 2 h at 08 a soln. of
Br2 (0.51 ml, 0.01 mmol) in CHCl3 (15 ml). The cooling bath was removed, and the soln. was stirred at r.t.
overnight and then poured into 10% aq. NaHSO3 (20 ml). The org. layer was washed with 2n NaOH (10 ml),
H2O (10 ml), dried (MgSO4), and evaporated. Purification by FC (hexanes/AcOEt 80 :1) yielded 5b (3.03 g,
65%). Yellow oil. [a]2D0 ˆ ‡2.4 (c ˆ 1.00; CHCl3). 1H-NMR (400 MHz, CDCl3): 0.87 (d, J ˆ 6.6, 12 H); 0.94
(d, J ˆ 6.4, 6 H); 1.10 ± 1.23, 1.24 ± 1.37, 1.40 ± 1.45, 1.45 ± 1.72, 1.82 ± 1.92 (m, 20 H); 3.98 (m, 4 H); 6.74 (d, J ˆ 9.1,
1 H); 6.90 (m, 2 H). 13C-NMR (100 MHz, CDCl3): 19.7; 22.7; 22.8; 24.8; 28.0; 29.9; 36.2; 37.4; 39.3; 67.8; 112.8;
‡
115.1; 116.9; 123.4; 148.4; 150.0. EI-MS: 470 (12, M ), 328 (10), 188 (88), 99 (11), 85 (68),71 (79), 57 (100).
(3,3',4,4')-Tetrakis[(3R)-3,7-dimethyloctyloxy-1,1'-biphenyl (6). Treatment of 5b according to the proce-
dure described [11] and subsequent purification by FC (hexanes/CH2Cl2 5 :1) gave 6 (0.71 g, 0.91 mmol, 43%).
1
Yellow amorphous solid. [a]2D0 ˆ ‡3.7 (c ˆ 1.00, CHCl3). H-NMR (400 MHz, CDCl3): 0.86 (d, J ˆ 6.6, 12 H);
0.87 (d, J ˆ 6.6, 12 H); 0.95 (d, J ˆ 6.6, 12 H); 1.11 ± 1.22, 1.23 ± 1.38, 1.46 ± 1.57, 1.58 ± 1.76, 1.83 ± 1.95 (m, 20 H);
4.07 (m, 8 H); 6.93 (d, J ˆ 8.3, 2 H); 7.51 (m, 4 H). 13C-NMR (100 MHz, CDCl3): 19.8; 22.7; 22.8; 24.8; 28.0;
‡
30.0; 36.4; 37.4; 39.3; 67.8; 113.1; 114.1; 119.3; 134.3; 148.5; 149.3. EI-MS: 779 (100, M ), 639 (4), 497 (2), 357
(5), 218 (6). Anal. calc. for C52H90O4: C 80.15, H 11.64; found: C 80.12, H 11.69.
2-[(3R)-3,7-Dimethyloctyloxy]phenol (7). A mixture of benzene-1,2-diol (1.10 g, 10.0 mmol), (3R)-1-
bromo-3,7-dimethyloctane (1.11 g, 5.00 mmol) and K2CO3 (3.01 g, 21.5 mmol) in EtOH (25 ml) was refluxed for
48 h. After evaporation of the solvent, the residue was redissolved in MeOH (4.5 ml) and H2O (6.0 ml), and the
aq. layer was washed with brine (20 ml) and H2O (20 ml), dried (MgSO4), and evaporated. Purification by FC
(hexanes/AcOEt 50 :1) yielded 7 (0.54 g, 43%). White amorphous solid. [a]2D0 ˆ ‡1.6 (c ˆ 1.00, CHCl3).
1H-NMR (400 MHz, CDCl3): 0.87 (d, J ˆ 6.8, 6 H); 0.95 (d, J ˆ 6.6, 3 H); 1.15 ± 1.24, 1.25 ± 1.42, 1.50 ± 1.59, 1.60 ±
1.75, 1.83 ± 1.93 (m, 10 H); 4.07 (m, 2 H); 5.63 (s, 1 H); 6.84 (m, 3 H); 6.93 (dd, J ˆ 7.7, 1.9, 1 H). 13C-NMR
(100 MHz, CDCl3): 19.7; 22.6; 22.7; 24.7; 28.0; 30.0; 36.3; 37.3; 39.3; 67.2; 111.6; 114.4; 120.1; 121.3; 145.8; 146.0.
‡
EI-MS: 250 (27, M ), 198 (4), 183 (10), 121 (4), 110 (100), 95 (6), 85 (16), 71 (19). Anal. calc. for C16H26O2:
C 76.75, H 10.47; found: C 76.83, H 10.71.
3,6,7,10,11-Pentakis[(3R)-3,7-dimethyloctyloxy]triphenylen-2-ol (8). To a soln. of 6 (0.77 g, 0.99 mmol) and
7 (0.74 g, 2.96 mmol) in CH2Cl2 (15 ml) were carefully added conc. H2SO4 (0.15 ml) and anh. FeCl3 (2.24 g,
14.0 mmol), and the mixture was stirred for 2 h at r.t. The mixture was poured into MeOH (40 ml), the resulting
soln. was washed with hexanes (4 Â 40 ml). The combined hexane layers were dried (MgSO4), evaporated, and
purified by FC (hexanes/AcOEt 80 :1) to yield 8 (0.52 g, 51%). Yellow oil. [a]2D0 ˆ ‡3.4 (c ˆ 1.00, CHCl3).
1H-NMR (400 MHz, CDCl3): 0.85 ± 0.91 (m, 30 H); 1.00 ± 1.06 (m, 15 H); 1.10 ± 1.27, 1.28 ± 1.44, 1.47 ± 1.62, 1.67 ±
1.86, 1.93 ± 2.05 (m, 50 H); 4.19 ± 4.39 (m, 10 H, 5 CH2O); 5.89 (s, 1 H); 7.79, 7.83, 7.84 (s, 5 H). 13C-NMR
(100 MHz, CDCl3): 19.6; 22.4; 22.5; 24.5; 24.6; 26.7; 27.8; 29.8; 36.1; 36.2; 37.1; 37.2; 37.3; 39.0; 39.1; 67.4; 67.8;

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Helvetica Chimica Acta ± Vol. 84 (2001)
68.2; 103.4; 104.3; 106.4; 107.1; 107.3; 107.5; 122.9; 123.2; 123.5; 123.6; 123.7; 123.9; 145.2; 145.8; 148.7; 148.9;
‡
149.2. EI-MS: 1025 (100, M ), 885 (8), 745 (4), 603 (12), 463 (7), 324 (6), 295 (4). Anal. calc. for C68H112O6:
C 79.63, H 11.01; found: C 79.48, H 11.05.
2-(10-{[3,6,7,10,11-Pentakis(decyloxy)triphenylen-2-yl]oxy}decyloxy)-3,6,7,10,11-pentakis{[(3R)-3,7-di-
methyloctyl]oxy}triphenylene (9). A mixture of 4c (70 mg, 0.056 mmol), 8 (58 mg, 0.056 mmol), and K2CO3
(34.5 mg, 0.23 mmol) in DMF (2 ml) was heated at 808 for 24 h. Then, the mixture was poured onto ice and the
aq. layer was washed with CH2Cl2 (3 Â 10 ml). The combined org. extracts were dried (MgSO4), filtered and
evaporated. Purification by FC (hexanes/Et2O 30 :1) yielded 9 (78 mg, 64%). Purple solid product. [a]2D0 ˆ ‡1.4
(c ˆ 1.00, CHCl3). 1H-NMR (400 MHz, CDCl3): 0.86 (d, J ˆ 6.7, 15 H); 0.87 (d, J ˆ 6.7, 30 H); 1.02 (d, J ˆ 6.7,
15 H); 1.10 ± 1.47, 1.48 ± 1.64, 1.68 ± 1.85, 1.87 ± 2.05 (m, 146 H); 4.22 (t, J ˆ 6.7, 12 H); 4.23 ± 4.31 (m, 12 H); 7.83
(s, 6 H); 7.84 (s, 6 H). 13C-NMR (100 MHz, CDCl3): 13.9; 19.6; 22.4; 22.5; 22.7; 24.8; 26.2; 26.3; 27.8; 29.4; 29.5;
29.6; 29.6; 29.7; 29.7; 29.8; 31.9; 36.4; 37.5; 39.3; 68.0; 69.7; 107.4; 123.5; 123.6; 149.0. MALDI-TOF-MS: 2188.6
‡
(M ). Anal. calc. for C146H242O12: C 80.09, H 11.14; found: C 79.96, H 11.16.
REFERENCES
[1] S. Chandrasekhar, Liq. Cryst. 1993, 14, 3.
[2] a) A. N. Cammidge, R. J. Bushby, in ꢀ Handbook of Liquid Crystalsꢁ, Eds. D. Demus, J. Goodby, G. W. Gray,
H.-W. Spiess, V. Vill, Wiley-VCH, Weinheim, 1998, Vol. 2 B, p. 693; b) S. Chandrasekhar, in ꢀ Handbook of
Liquid Crystalsꢁ, Eds. D. Demus, J. Goodby, G. W. Gray, H.-W. Spiess, Wiley-VCH, Weinheim, 1998,
Vol. 2 B, p. 749.
[3] a) N. Boden, B. Movaghar, in ꢀ Handbook of Liquid Crystalsꢁ, Eds. D. Demus, J. Goodby, G. W. Gray, H.-W.
Spiess, Wiley-VCH, Weinheim, 1998, Vol. 2 B, p. 781; b) J. Kopitzke, J. H. Wendorff, Chemie in unserer Zeit
2000, 34, 4; c) C. F. van Nostrum, Adv. Mater. 1996, 8, 1027.
[4] C. T. Imrie, G. R. Luckhurst, in ꢀ Handbook of Liquid Crystalsꢁ, Eds. D. Demus, J. Goodby, G. W. Gray, H.-
W. Spiess, Wiley-VCH, Weinheim, 1998, Vol. 2 B, p. 801.
[5] a) W. Kranig, C. Boeffel, H.-W. Spiess, O. Karthaus, H. Ringsdorf, R. Wüstefeld, Liq. Cryst. 1990, 8, 375;
b) W. Kranig, B. Hüser, H.-W. Spiess, W. Kreuder, H. Ringsdorf, H. Zimmermann, Adv. Mater. 1990, 2, 36;
c) M. Möller, V. Tsukruk, J. H. Wendorff, H. Bengs, H. Ringsdorf, Liq. Cryst. 1992, 12, 17; d) D. Markovitsi,
H. Bengs, H. Ringsdorf, J. Chem. Soc., Faraday Trans. 1992, 88, 1275; e) S. Zamir, R. Poupko, Z. Luz, B.
Huser, C. Boeffel, H. Zimmermann, J. Am. Chem. Soc. 1994, 116, 1973; f) I. Voigt-Martin, M.
Schuhmacher, M. Honig, P. Simon, R. Garbella, Mol. Cryst. Liq. Cryst. Sci. Technol., Sect. A 1994, 254, 299;
g) S. Disch, H. Finkelmann, H. Ringsdorf, P. Schuhmacher, Macromol. Chem. 1995, 28, 2424; h) N. Boden,
R. J. Bushby, A. N. Cammidge, J. Am. Chem. Soc. 1995, 117, 924; i) D. Adam, P. Schuhmacher, J. Simmerer,
L. Häussling, W. Paulus, K. Siemensmeyer, K. H. Etzbach, H. Ringsdorf, D. Haarer, Adv. Mater. 1995, 7,
276; j) S. Kumar, P. Schuhmacher, P. Henderson, J. Rego, H. Ringsdorf, Mol. Cryst. Liq. Cryst. 1996, 288,
211; k) S. Mahlstedt, D. Janietz, A. Stracke, J. H. Wendorff, Chem. Commun. 2000, 15.
[6] M. M. Green, H. Ringsdorf, J. Wagner, R. Wüstefeld, Angew. Chem., Int. Ed. 1990, 29, 1478.
[7] a) C. Destrade, T. H. Nguyen, J. Malthete, J. Jacques, Phys. Lett. A 1980, 79, 189; b) J. Malthete, C.
Destrade, N. H. Tinh, Mol. Cryst. Liq. Cryst. 1981, 64, 233; c) J. Malthete, J. Jacques, N. H. Tinh, C.
Destrade, Nature 1982, 298, 46; d) M. Werth, S. U. Vallerien, H.-W. Spiess, Liq. Cryst. 1991, 10, 759; e) H.
Bock, W. Helfrich, G. Heppke, EP 529439, 1992; Chem. Abstr. 1992, 119, 170902; f) J. P. Gallivan, G. B.
Schuster, J. Org. Chem. 1995, 60, 2423; g) G. Heppke, D. Krüerke, M. Müller, H. Bock, Ferroelectrics 1996,
179, 203; h) N. Boden, R. G. Bushby, A. N. Cammidge, S. Duckworth, G. Headdock, J. Mater. Chem. 1997, 7,
604; i) K. Praefcke, A. Eckert, D. Blunck, Liq. Cryst. 1997, 22, 113; j) C. V. Yelamaggad, V. Prasad, M.
Manickam, S. Kumar, Mol. Cryst. Liq. Cryst. 1998, 325, 33; k) M. Weck, A. R. Dunn, K. Matsumoto, G. W.
Coates, E. B. Lobkovsky, R. H. Grubbs, Angew. Chem., Int. Ed. 1999, 38, 2741.
[8] P. J. Collings, M. Hird, ꢀIntroduction to Liquid Crystalsꢁ, Taylor & Francis Ltd., London, 1997, p. 111.
[9] C. Tschierske, J. Mater. Chem. 1998, 8, 1485.
[10] J. L. Schulte, S. Laschat, V. Vill, E. Nishikawa, H. Finkelmann, M. Nimtz, Eur. J. Org. Chem. 1998, 2499.
[11] J. L. Schulte, S. Laschat, Synthesis 1999, 475.
[12] H. Naarmann, M. Hanack, R. Mattmer, Synthesis 1994, 477.
[13] P. G. Schouten, J. F. van der Pol, J. W. Zwikker, W. Drenth, S. J. Picken, Mol. Cryst. Liq. Cryst. 1991, 195, 291.
[14] R. Schmid, S. Antolas, A. Rüttimann, M. Schmid, M. Vecchi, H. Weiser, Helv. Chim. Acta 1990, 73, 1276.
Received February 12, 2001