Columnar liquid crystalline assembly of a U-shaped molecular scaffold stabilized by covalent or noncovalent incorporation of aromatic molecules

Article abstract of DOI:10.1002/pola.29186

We report on our serendipitous finding of the anomalous behavior of a novel liquid crystalline (LC) molecule U_H/H, containing a U-shaped handle. While U_H/H itself shows a bicontinuous cubic (Cub_bi) phase, U_H/H i

Full text of DOI:10.1002/pola.29186

JOURNAL OF
POLYMER SCIENCE
WWW.POLYMERCHEMISTRY.ORG
ORIGINAL ARTICLE
Columnar Liquid Crystalline Assembly of a U-Shaped Molecular Scaffold
Stabilized by Covalent or Noncovalent Incorporation of Aromatic
Molecules
1,2
Yoshiki Shibuya,1 Yoshimitsu Itoh ,1 Takuzo Aida
1Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656,
Japan
2RIKEN Center for Emergent Matter Science, Hirosawa, Wako, Saitama 351-0198, Japan
Correspondence to: Y. Itoh (E-mail: itoh@macro.t.u-tokyo.ac.jp) or T. Aida (E-mail: aida@macro.t.u-tokyo.ac.jp)
Received 30 May 2018; Accepted 3 July 2018
DOI: 10.1002/pola.29186
ABSTRACT: We report on our serendipitous finding of the anoma-
lous behavior of a novel liquid crystalline (LC) molecule UH/H
incorporated in the LC system, the resultant material exhibited a
similar molecular assembly with a columnar geometry. This
finding is interesting because UH/H and pyrene molecules do not
seem to have specific interactions or shape complementarity to
form a columnar assembly, as in the case of UPy/Py. © 2018
Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018
,
containing a U-shaped handle. While UH/H itself shows a bicon-
tinuous cubic (Cubbi) phase, UH/H in the presence of pyrene mol-
ecules as an external guest forms a hexagonal columnar (Colh)
phase without phase separation. Interestingly, even when the
pyrene molecules were covalently attached to UH/H (UPy/Py), the
molecule exhibited a Colh phase, with a similar columnar geom-
etry to that of UH/H mixed with pyrene molecules (1–4 equiv.).
This result means that no matter how the pyrene moieties are
KEYWORDS: bicontinuous cubic phase, hexagonal columnar
phase, liquid crystal, luminescence, multi-component liquid
crystal, molecular tweezers, pyrene
Herein, we report a new type of multi-component liquid
crystals with a U-shaped handle8 that can exhibit a Colh LC
phase either by the external addition or the covalent
attachment of pyrene moieties. This work started from our
previous report on jumping behavior of a crystalline molec-
ular tweezers having two pyrenyl head groups in the
U-shaped handle (Compound 1, Sch. 1).9 As an extension of
our interest in the tweezers-like molecular scaffold8
toward novel functional materials, we designed UPy/Py
(Fig. 1) to confer LC nature to the scaffold by attaching a
large benzyl ether dendrons10 as a flexible side-chain to 1.
UPy/Py itself assembled in a Colh manner in its LC meso-
phase (Fig. 3). In the course of detailed investigations of
the columnar assembly of UPy/Py by comparing with LC
properties of UPy/H (one pyrene head group attached to a
U-shaped handle), UH/H (U-shaped core alone) (Fig. 1), and
their mixtures with pyrene molecules, we found that no
matter how pyrene moieties are incorporated in the liquid
crystals (i.e., covalently attached to U-shaped handle or
noncovalently mixed with UH/H), they all formed Colh
phase with a similar intercolumnar distances.
INTRODUCTION Columnar liquid crystals composed of multi-
ple small molecules, where individual component molecules
assemble anisotropically to form homogeneous liquid crystal-
line (LC) phases, have been attracting profound attention for
their potential to exhibit unprecedented functional proper-
ties.1 To provide such complex columnar LC materials, there
are mainly two general requirements: (1) specific intermole-
cular interactions between the components, such as hydrogen
bonding interactions,2 ionic interactions,3 and charge-transfer
interactions;4 and (2) complementary molecular shapes
between the component molecules through host–guest com-
plexation.5 For example, shape-persistent star mesogens6 with
pyridine pendants, developed by Lehmann et al., can accept
guest side-chain units with carboxylic acid moieties in their
void spaces via hydrogen bonding.6e Interestingly, the guest
side-chain unit without hydrogen bonding capability can also
fill the space to form a homogeneous hexagonal columnar
(Colh) phase7 with lower clearing temperature, owing to the
appropriate shape and size of the cavity.6e LC mixture sys-
tems, where the components in an LC phase do not mutually
satisfy both the requirements above, mostly lead to macro-
phase separation or the loss of the LC nature.
Additional supporting information may be found in the online version of this article.
This article is dedicated to Professor Mitsuo Sawamoto for his life-long outstanding achievements in polymer chemistry.
© 2018 Wiley Periodicals, Inc.
JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2018
1

JOURNAL OF
POLYMER SCIENCE
ORIGINAL ARTICLE
WWW.POLYMERCHEMISTRY.ORG
FIGURE 1 Chemical structures of the LC molecules in this report and the phase transition diagrams of those molecules (temperatures
in ꢀC; DSC at a scan rate of 10 ꢀC min−1). Colh, G, Cubbi, and Iso denote hexagonal columnar, glassy LC, bicontinuous cubic, and
isotropic phases, respectively. Mesophases are determined by XRD studies shown in Figure 3 and Supporting Information,
Figures S20–S23 and Tables S1–S4. [Color figure can be viewed at wileyonlinelibrary.com]
EXPERIMENTAL
as an excitation light source. Differential scanning calorimetry
(DSC) was performed on a Mettler–Toledo DSC 1 differential
scanning calorimeter. Polarized optical microscopy (POM) was
performed on an OLYMPUS model BX51 optical polarizing
microscope equipped with a Mettler FP-82HT hot stage. Pho-
tographs of the luminescence from the solids were taken by a
Keyence VHX-5000 digital microscope under 365 nm UV light.
The X-ray diffraction (XRD) experiments were carried out by
using a synchrotron radiation X-ray beam, with a wavelength
of λ = 1.08 Å on BL44B2 at the Super Photon Ring (SPring-8,
Hyogo, Japan). A large Debye–Scherrer camera was used in
conjunction with an imaging plate as a detector, and all the
diffraction patterns were obtained with a 0.01ꢀ step in 2θ.
During the measurements, all the samples placed into a
0.5-mm-thick glass capillary were rotated to obtain homoge-
neous diffraction patterns.
General
Unless otherwise noted, all the commercial reagents were
used as received. Recycling preparative high-performance liq-
uid chromatography (HPLC) was performed at room tempera-
ture using a 20 mm × 250 mm silica gel column (JAIGEL SIL
SH043–10) on a Japan Analytical Industry Model LC-9201
HPLC system, equipped with a variable-wavelength UV–Vis
detector. 1H and 13C NMR spectra were recorded on a JEOL
model JNM-ECA500II spectrometer, operating at 500 and
126 MHz for 1H and 13C NMR, respectively, where chemical
shifts were determined with respect to tetramethylsilane (δ
1
0.00 ppm) for H NMR spectroscopy and CDCl3 (δ 77.0 ppm)
for 13C NMR spectroscopy as internal standards. Matrix-
assisted laser desorption/ionization time-of-flight (MALDI-
TOF) mass spectrometry was performed on a Bruker Dal-
tonics Autoflex™ speed spectrometer with dithranol as a
matrix. The electronic absorption spectra were recorded on a
JASCO V-670 UV/VIS/NIR spectrometer. The fluorescence
spectra were recorded on a Jobin Yvon Horiba Spex Fluorolog
3 spectrometer. The absolute fluorescence quantum yields
were recorded on a Hamamatsu C9920–02 absolute PL quan-
tum yield measurement system. The fluorescence lifetimes
were recorded by means of a typical time-correlated single-
Synthesis of UPy/Py
To a CH2Cl2 solution (900 mL) of 19 (428 mg, 0.542 mmol)
was added BBr3 (10.8 mL of 1 M solution in CH2Cl2,
10.8 mmol) at −5 ꢀC under Ar. After warming to 25 ꢀC, the
reaction mixture was stirred for 12 h. Then, saturated NaHCO3
aq. was added to the mixture, and the mixture was succes-
sively acidified with 10% aq. HCl. The resulting mixture was
then extracted with CH2Cl2, and the lower phase separated
was collected. The organic extract was washed with brine,
dried over anhydrous Na2SO4, filtered, and evaporated to
photon counting (TCSPC) method using
Quantaurus-Tau C11367–02 fluorescence lifetime measure-
ment system, where an internal LED (λ = 340 nm) was used
a Hamamatsu
2
JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2018

JOURNAL OF
POLYMER SCIENCE
WWW.POLYMERCHEMISTRY.ORG
ORIGINAL ARTICLE
dryness, resulting in the phenol precursor as a yellow powder
(384 mg), which was used for the next step without further
purification.
resulting in 4 as a white powder in 16% yield (41.9 mg,
1
ꢀ
0.0627 mmol). H NMR (500 MHz, CDCl3, 25 C, ppm): δ 9.06
(d, J = 2.0 Hz, 1H), 8.72 (d, J = 2.5 Hz, 1H), 8.58 (s, 2H), 8.20
(d, J = 7.5 Hz, 2H), 8.20 (d, J = 9.0 Hz, 2H), 8.13 (d, J = 9.5 Hz,
2H), 8.00–8.03 (m, 1H), 7.86 (dd, J = 2.0 Hz, 7.8 Hz, 1H),
7.41–7.43 (m, 2H), 7.17 (d, J = 9.0 Hz, 2H), 7.09 (d, J = 8.0 Hz,
1H), 7.06 (d, J = 9.0 Hz, 2H), 3.91 (s, 3H), 2.92–2.95 (m, 2H),
2.76–2.82 ꢀ(m, 4H), 2.69–2.72 (m, 2H); 13C NMR (126 MHz,
CDCl3, 25 C, ppm): δ 159.1, 150.3, 148.9, 147.5, 140.4, 139.0,
137.3, 137.2, 136.6, 135.7, 131.6, 131.4, 131.1, 130.1, 129.9,
129.6, 129.5, 129.1, 128.4, 128.3, 128.2, 127.7, 127.7, 125.8,
125.0, 124.7, 124.6, 123.9, 123.8, 121.0, 114.0, 55.3, 27.9,
27.7, 26.0, 25.7; MALDI-TOF-MS m/z calcd. For C44H31BrNO
[M + H]+ 668.16, found 668.64.
A DMF solution (37.6 mL) of the crude phenol precursor
obtained above (101 mg, 0.130 mmol), dendron 210 (541 mg,
0.260 mmol), K2CO3 (56.4 mg, 0.408 mmol), and 18-crown-6
ꢀ
(4.10 mg, 0.0155 mmol) was stirred for 21 h at 80 C under
Ar. Then, the reaction mixture was poured into 150 mL of an
ice/water mixture. The resulting mixture was extracted with
CH2Cl2, and the lower separated phase was collected. The
organic extract was washed with brine, dried over with
Na2SO4, filtered, and evaporated to dryness. The residue was
chromatographed on silica gel with hexane/CH2Cl2 (2/3) as
the eluent, where the main fraction was collected and evapo-
rated to dryness. The residue was subjected to recycling pre-
parative HPLC (JAIGEL-SIL) with hexane/CH2Cl2 (2/3) as the
eluent, at a flow rate of 9.9 mL min−1, where the main fraction
was collected and evaporated to dryness, resulting in UPy/Py
as a white paste in 46% yield (2 steps, 185 mg, 0.0656 mmol).
Synthesis of 5
To a THF solution (15.0 mL) of 4 (41.0 mg, 0.0613 mmol)
was added nBuLi (70.0 μL of 2.66 M solution in hexane,
0.184 mmol) at −78 ꢀC under Ar. After the reaction mixture
ꢀ
was stirred for 1 h at −78 C, MeOH (18 μL) was added. After
1
ꢀ
ꢀ
H NMR (500 MHz, CDCl3, 25 C, ppm): δ 9.22 (d, J = 2.0 Hz,
2H), 8.53 (s, 4H), 8.11 (d, J = 7.5 Hz, 4H), 7.98–8.01 (m, 2H),
7.92 (d, J = 9.0 Hz, 4H), 7.86 (dd, J = 1.5 Hz, 7.5 Hz, 2H), 7.79
(d, J = 9.0 Hz, 4H), 7.40 (d, J = 7.5 Hz, 2H), 7.32 (d, J = 9.0 Hz,
8H), 7.28 (d, J = 8.5 Hz, 4H), 7.17 (d, J = 8.0 Hz, 2H), 7.12
(d, J = 9.0 Hz, 2H), 6.87 (d, J = 9.0 Hz, 8H), 6.75–6.77
(m, 10H), 6.61 (t, J = 2.0 Hz, 1H), 5.11 (s, 2H), 5.03 (s, 8H),
4.97 (s, 4H), 4.94 (s, 4H), 3.90–3.95 (m, 12H), 2.92–2.95
(m, 4H), 2.77–2.79 (m, 4H), 1.73–1.79 (m, 12H), 1.40–1.47
(m, 12H), 1.25–1.33 (m, 96H), 0.85–0.89 (m, 18H); 13C NMR
(126 MHz, CDCl3, 25 ꢀC, ppm): δ 160.2, 158.9, 158.9, 158.0,
153.2, 149.7, 140.0, 139.4, 138.9, 138.4, 137.0, 135.8, 132.0,
131.3, 131.0, 130.2, 130.1, 129.8, 129.2, 129.1, 128.9, 128.1,
128.0, 127.6, 127.4, 125.6, 125.0, 124.8, 124.5, 123.6, 114.7,
114.6, 114.4, 114.1, 107.4, 106.6, 106.5, 101.5, 74.8, 71.2,
70.4, 70.0, 68.0, 67.9, 31.9, 29.7, 29.6, 29.6, 29.4, 29.3, 29.3,
27.7, 26.1, 25.7, 22.7, 14.1; MALDI-TOF-MS m/z calcd. For
warming to 25 C, the reaction mixture was stirred fꢀor 15 h.
Then, drops of water were added to the solution at 0 C. After
the organic solvents were evaporated, CH2Cl2 and water were
added to the resultant solid. The resulting mixture was
extracted with CH2Cl2, and the lower phase separated was col-
lected. The organic extract was washed with brine, dried over
anhydrous Na2SO4, filtered, and evaporated to dryness under
reduced pressure. The residue was subjected to column chro-
matography on silica gel using hexane/CH2Cl2 (2/1) as eluent,
where the main fraction was collected and evaporated to dry-
ness under reduced pressure. The residue was reprecipitated
from CHCl3/MeOH, resulting in 5 as a white solid in 74% yield
(26.7 mg, 0.0452 mmol). 1H NMR (500 MHz, CDCl3, 25 ꢀC,
ppm): δ 9.07 (d, J = 2.5 Hz, 1H), 8.60 (dd, J = 1.0 Hz, 7.5 Hz,
1H), 8.55 (s, 2H), 8.18–8.22 (m, 4H), 8.13 (d, J = 9.5 Hz, 2H),
8.00–8.03 (m, 1H), 7.83 (dd, J = 1.8 Hz, 7.3 Hz, 1H), 7.39–7.42
(m, 2H), 7.31 (td, J = 1.5 Hz, 7.3 Hz, 1H), 7.22 (d, J = 7.0 Hz,
1H), 7.18 (d, J = 9.0 Hz, 2H), 7.06 (d, J = 8.5 Hz, 2H), 3.91
(s, 3H), 2.93–2.96 (m, 2H), 2.85–2.87 (m, 2H), 2.76–2.79
(m,ꢀ 2H), 2.70–2.73 (m, 2H); 13C NMR (126 MHz, CDCl3,
25 C, ppm): δ 159.0, 150.2, 150.0, 147.3, 140.4, 139.3, 137.9,
137.2, 136.0, 135.3, 131.5, 131.1, 129.9, 129.9, 129.5, 129.4,
128.7, 128.3, 128.2, 127.7, 127.7, 127.4, 127.1, 125.8, 125.4,
125.0, 124.8, 124.6, 123.9, 123.8, 114.0, 55.3, 28.2, 28.0, 25.9,
25.9; MALDI-TOF-MS m/z calcd. For C44H32NO [M + H]+ 590.25,
found 590.66.
C
194H236NO15 [M + H]+ 2819.77, found 2820.08; Anal. Calcd.
for C194H235NO15: C, 82.60; H, 8.40; N, 0.50. Found: C,
82.36; H, 8.33; N, 0.41.
Synthesis of 4
To a toluene solution (25.0 mL) of 39 (221 mg, 0.404 mmol),
after being degassed by Ar bubbling for 30 min, were added
4,4,5,5-tetramethyl-2-pyren-2-yl-[1,3,2]dioxaborolane
(2-(Bpin)pyrene)11 (128 mg, 0.390 mmol), 1.0 mM K2CO3
aq. (2.50 mL, 2.50 mmol), 2-dicyclohexylphosphino-20,60-
dimethoxybiphenyl (SPhos) (35.5 mg, 0.0865 mmol), and
tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) (45.4 mg,
0.0393 mmol) under a geꢀntle flow of Ar, and the resulting
mixture was stirred at 80 C for 28 h. After the mixture was
allowed to cool to 25 ꢀC, saturated aq. NaHCO3 was added.
The resulting mixture was extracted with toluene, and the
upper separated phase was collected. The organic extract was
washed with brine, dried over anhydrous Na2SO4, filtered, and
evaporated to dryness. The residue was chromatographed on
silica gel with hexane/CH2Cl2 (2/1) as the eluent, where the
main fraction was collected and evaporated to dryness,
Synthesis of UPy/H
To a CH2Cl2 solution (10 mL) of 5 (26.0 mg, 0.0440 mmol) was
addꢀed BBr3 (150 μL of 1 M solution inꢀCH2Cl2, 0.150 mmol) at
−5 C under Ar. After warming to 25 C, the reaction mixture
was stirred for 7 h. Saturated aq. NaHCO3 was added to the
mixture, and the mixture was acidified with 10% HCl aq. The
resulting mixture was then extracted with CH2Cl2, and the
lower phase was separated and collected. The organic extract
was washed with brine, dried over anhydrous Na2SO4, filtered,
and evaporated to dryness under reduced pressure. The resi-
due was subjected to column chromatography on silica gel
JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2018
3

JOURNAL OF
POLYMER SCIENCE
ORIGINAL ARTICLE
WWW.POLYMERCHEMISTRY.ORG
SCHEME 1 Synthesis of LC molecules containing a U-shaped handle (UPy/Py, UPy/H, UH/H, and UPh/Ph) and their precursors (5, 6, and 7).
using hexane/CH2Cl2 (1/5) as the eluent, where the main frac-
tion was collected and evaporated to dryness under reduced
pressure, resulting in the phenol precursor as a white powder
(20.0 mg), which was used for the next step without further
purification.
extract was washed with brine, dried over with Na2SO4, fil-
tered, and evaporated to dryness. The residue was chromato-
graphed on silica gel with hexane/CH2Cl2 (2/5) as the eluent,
where the main fraction was collected and evaporated to dry-
ness, resulting in UPy/H as a white paste in 15% yield (2 steps,
11.4 mg, 0.00435 mmol). 1H NMR (500 MHz, CDCl3, 25 ꢀC,
ppm): δ 9.07 (d, J = 2.5 Hz, 1H), 8.60 (dd, J = 1.0 Hz, 8.0 Hz,
1H), 8.55 (s, 2H), 8.18–8.22 (m, 4H), 8.13 (d, J = 9.0 Hz, 2H),
8.00–8.03 (m, 1H), 7.83 (dd, J = 1.8 Hz, 7.8 Hz, 1H), 7.38–7.41
(m, 2H), 7.32 (d, J = 8.5 Hz, 8H), 7.28 (d, J = 8.5 Hz, 4H), 7.20
(d, J = 7.0 Hz, 1H), 7.17 (d, J = 8.5 Hz, 2H), 7.11 (d, J = 8.5 Hz,
2H), 6.87 (d, J = 8.5 Hz, 8H), 6.75–6.77 (m, 10H), 6.60
(t, J = 2.3 Hz, 1H), 5.10 (s, 2H), 5.03 (s, 8H), 4.96 (s, 4H), 4.94
A DMF solution (8.00 mL) containing the crude phenol pre-
cursor obtained above (20.0 mg, 0.0347 mmol), dendron 210
(183 mg, 0.0879 mmol), K2CO3 (17.6 mg, 0.127 mmol), and
18-crown-6 (1.20 mg, 0.00588 mmol) was stirred for 54 h at
ꢀ
80 C under Ar. The reaction mixture was poured into 40 mL
of ice/water. The resulting mixture was extracted with CH2Cl2,
and the lower phase separated was collected. The organic
4
JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2018

JOURNAL OF
POLYMER SCIENCE
WWW.POLYMERCHEMISTRY.ORG
ORIGINAL ARTICLE
0.496 mmol). 1H NMR (500 MHz, CDCl3, 25 ꢀC, ppm): δ 8.57
(dd, J = 1.5 Hz, 7.3 Hz, 2H), 7.40 (t, J = 7.5 Hz, 2H), 7.30
(td, J = 1.2 Hz, 7.4 Hz, 2H), 7.20 (d, J = 7.5 Hz, 2H), 7.12
(d, J = 8.5 Hz, 2H), 7.02 (d, J = 8.5 Hz, 2H), 3.89 (s, 3H),
2.81–2.84 (m, 2H), 2.66–2.69 (m, 2H); 13C NMR (126 MHz,
ꢀ
CDCl3, 25 C, ppm): δ 159.0, 150.0, 147.2, 137.8, 135.4, 129.9,
129.9, 129.2, 128.6, 127.4, 127.0, 125.3, 113.9, 55.3, 28.2, 25.8;
MALDI-TOF-MS m/z calcd. For C28H24NO [M + H]+ 390.19,
found 390.45.
Synthesis of UH/H
To a DMF solution (20 mL) of 6 (40.4 mg, 0.104 mmol) was
added NaSEt (24ꢀ0 mg, 2.86 mmol) at 25 ꢀC under Ar. After
warming to 140 C, the reaction mixture was stirred for 1 h.
Then, the reaction mixture was poured into saturated
aq. NaHCO3, and the mixture was acidified with 10% HCl
aq. The resulting mixture was extracted with CH2Cl2, and the
lower phase was collected. The organic extract was washed
with brine, dried over anhydrous Na2SO4, filtered, and evapo-
rated to dryness under reduced pressure. The residue was
subjected to column chromatography on silica gel using hex-
ane/AcOEt (3/1) as eluent, where the main fraction was col-
lected and evaporated to dryness under reduced pressure,
resulting in phenol precursor as a white powder (39.6 mg),
which was used for the next step without further purification.
FIGURE 2 Schematic illustration of the stacking of U-shaped
handles observed in both Colh and Cubbi LC assemblies of the
LC molecules in this report. [Color figure can be viewed at
wileyonlinelibrary.com]
A DMF solution (13.0 mL) of the crude phenol precursor
obtained above (20.6 mg, 0.0549 mmol), dendron 210
(173 mg, 0.0831 mmol), K2CO3 (22.0 mg, 0.159 mmol), and
18-crown-6 (2.30 mg, 0.0113 mmol) was stirred for 22 h at
(s, 4H), 3.90–3.96 (m, 12H), 2.90–2.93 (m, 2H), 2.82–2.85
(m, 2H), 2.74–2.77 (m, 2H), 2.69–2.72 (m, 2H), 1.73–1.80
(m, 12H), 1.41–1.47 (m, 12H), 1.25–1.34 (m, 96H), 0.86–0.89
(m, 18H); 13C NMR (126 MHz, CDCl3, 25 ꢀC, ppm): δ 160.2,
158.9, 158.9, 158.2, 153.2, 140.4, 139.3, 139.2, 138.4, 137.8,
137.7, 137.2, 136.0, 135.3, 132.0, 131.5, 131.1, 130.2, 130.0,
129.8, 129.4, 129.4 129.2, 128.9, 128.7, 128.3, 128.2, 127.7,
127.4, 125.8, 125.4, 125.0, 125.0, 124.7, 124.6, 123.9, 123.8,
114.9, 114.6, 114.4, 114.1, 107.4, 106.5, 106.5, 101.5, 74.8,
71.2, 70.4, 70.1, 68.0, 68.0, 31.9, 29.7, 29.6, 29.6, 29.6, 29.4,
29.3, 29.3, 27.7, 29.4, 29.3, 29.3, 26.0, 26.0, 22.7, 14.1; MALDI-
TOF-HRMS m/z calcd. For C178H228NO15 [M + H]+ 2619.7031,
found 2619.7041.
ꢀ
80 C under Ar. The reaction mixture was poured into 60 mL
of ice/water. The resulting mixture was extracted with CH2Cl2,
and the lower phase was collected. The organic extract was
washed with brine, dried over with Na2SO4, filtered, and evap-
orated to dryness. The residue was chromatographed on silica
gel with hexane/AcOEt (5/1) as the eluent, where the main
fraction was collected and evaporated to dryness. The residue
was further chromatographed on silica gel with hexane/
CH2Cl2 (1/2) as the eluent, where the main fraction was col-
lected and evaporated to dryness, resulting in UH/H as a white
1
paste in 26% yield (2ꢀsteps, 34.6 mg, 0.0143 mmol). H NMR
(500 MHz, CDCl3, 25 C, ppm): δ 8.57 (dd, J = 1.0 Hz, 7.5 Hz,
2H), 7.40 (t, J = 7.5 Hz, 2H), 7.27–7.32 (m, 14H), 7.19
(d, J = 7.5 Hz, 2H), 7.12 (d, J = 8.5 Hz, 2H), 7.08 (d, J = 8.5 Hz,
2H), 6.87 (d, J = 8.5 Hz, 8H), 6.74–6.77 (m, 10H), 6.59
(t, J = 2.0 Hz, 1H), 5.07 (s, 2H), 5.02 (s, 8H), 4.95 (s, 4H), 4.93
(s, 4H), 3.90–3.95 (m, 12H), 2.79–2.82 (m, 4H), 2.65–2.68
(m, 4H), 1.74–1.80 (m, 12H), 1.41–1.47 (m, 12H), 1.26–1.34
(m,ꢀ 96H), 0.86–0.89 (m, 18H); 13C NMR (126 MHz, CDCl3,
25 C, ppm): δ 160.2, 158.9, 158.9, 158.2, 153.2, 150.0, 147.1,
139.3, 138.4, 137.8, 135.4, 132.0, 130.3, 130.2, 130.0, 129.8,
129.2, 129.1, 128.9, 128.6, 127.4, 127.0, 125.3, 114.8, 114.4,
114.1, 107.4, 106.5, 101.5, 74.8, 71.2, 70.4, 70.0, 68.0, 68.0,
31.9, 29.7, 29.6, 29.4, 29.3, 29.3, 28.1, 26.1, 25.8, 22.7, 14.1;
MALDI-TOF-MS m/z calcd. For C162H220NO15 [M + H]+ 2419.65,
found 2419.51; Anal. Calcd. for C162H219NO15: C, 80.39; H,
9.12; N, 0.58. Found: C, 80.42; H, 9.20; N, 0.63.
Synthesis of 6
To a THF solution (16.0 mL) of 39 (300 mg, 0.548 mmol) was
added nBuLi (1.30 mL of 2.66
M solution in hexane,
3.46 mmol) at −78 ꢀC under Ar. After the reaction mixture
was stirred for 1 h at −78 ꢀC, MeOH (270 μL) was added. After
ꢀ
warming to 25 C, the reaction mixture was stirred fꢀor 18 h.
Then, drops of water were added to the solution at 0 C. After
the organic solvents were evaporated, CH2Cl2 and water were
added to the resultant solid, and the resulting mixture was
extracted with CH2Cl2. The lower phase was collected. The
organic extract was washed with brine, dried over anhydrous
Na2SO4, filtered, and evaporated to dryness under reduced
pressure. The residue was recrystallized from CHCl3/MeOH,
resulting in 6 as white prisms in 91% yield (193 mg,
JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2018
5

JOURNAL OF
POLYMER SCIENCE
ORIGINAL ARTICLE
WWW.POLYMERCHEMISTRY.ORG
FIGURE 3 A series of characterization data for UPy/Py, UPy/H, UPh/Ph, and UH/H in the LC phase. Each column contains a phase
transition diagram (temperature in ꢀC; DSC at a scan rate of 10 ꢀC min−1), a POM image, and an XRD pattern. Colh, G, Cubbi, and Iso
denote hexagonal columnar, glassy LC, bicontinuous cubic, and isotropic phases, respectively. The numbers in parentheses in XRD
patterns are Miller indexes assigned to each diffraction peak. The XRD patterns were taken at 110 ꢀC (for UPy/Py), 87 ꢀC (for UPy/H),
99 ꢀC (for the Colh phase of UPh/Ph), 70 ꢀC (for the Cubbi phase of UPh/Ph), and 60 ꢀC (for UH/H). [Color figure can be viewed at
wileyonlinelibrary.com]
Synthesis of 7
under reduced pressure, resulting in the phenol precursor as
a white powder (34.8 mg), which was used for the next step
without further purification.
To a toluene solution (1.00 mL) of 39 (30.2 mg, 0.0552 mmol),
after being degassed by Ar bubbling for 30 min, were added
phenylboronic acid (17.1 mg, 0.140 mmol), K3PO4 (231 mg,
1.09 mmol), 2-dicyclohexylphosphino-20,60-dimethoxybiphenyl
(SPhos) (5.30 mg, 0.0129 mmol), and palladium acetate (Pd
(OAc)2) (2.0 mg, 0.00891 mmol) under a gentle flow of Ar,
and the resulting mixture was stirred at 80 ꢀC for 8 h. After
A DMF solution (13.0 mL) of the crude phenol precursor
obtained above (23.1 mg, 0.0438 mmol), dendron 210
(144 mg, 0.0692 mmol), K2CO3 (19.8 mg, 0.143 mmol), and
18-crown-6 (1.90 mg, 0.00931 mmol) was stirred for 23 h at
ꢀ
ꢀ
the mixture was allowed to cool to 25 C, it was filtered with
80 C under Ar. The reaction mixture was poured into 60 mL
Celite and a pad of silica. The filtrate was evaporated to dry-
ness under reduced pressure. The residue was recrystallized
from CHCl3/MeOH, resulting in 7 as a white powder in 84%
yield (25.0 mg, 0.0462 mmol). 1H NMR (500 MHz, CDCl3,
25 ꢀC, ppm): δ 8.86 (d, J = 2.0 Hz, 1H), 7.76 (d, J = 6.5 Hz, 4H),
7.57 (dd, J = 2.3 Hz, 7.8 Hz, 2H), 7.47 (t, J = 7.8 Hz, 4H),
7.35–7.38 (m, 2H), 7.29 (d, J = 8.0 Hz, 2H), 7.16 (d, J = 8.5 Hz,
2H), 7.04 (d, J = 8.5 Hz, 2H), 3.90 (s, 3H), 2.87–2.90 (m, 4H),
2.71–2.74 (m, 4H); C NMR (126 MHz, CDCl3, 25 C, ppm): δ
159.0, 150.0, 147.3, 141.3, 139.8, 137.0, 135.7, 129.9, 129.9,
129.4, 128.7, 127.9, 127.2, 127.1, 123.9, 114.0, 55.3, 27.9,
25.9; MALDI-TOF-MS m/z calcd. For C40H32NO [M + H]+
542.25, found 542.64.
of ice/water. The resulting mixture was extracted with CH2Cl2,
and the lower phase was collected. The organic extract was
washed with brine, dried over Na2SO4, filtered, and evapo-
rated to dryness. The residue was chromatographed on silica
gel with hexane/AcOEt (5/1) as the eluent, where the main
fraction was collected and evaporated to dryness. The residue
was further chromatographed on silica gel with hexane/
CH2Cl2 (1/2) as the eluent, where the main fraction was col-
lected and evaporated to dryness, resulting in UPh/Ph as a
13
ꢀ
1
white paste in 48% yield (2 steps, 49.8 mg, 0.0194 mmol). H
ꢀ
NMR (500 MHz, CDCl3, 25 C, ppm): δ 8.86 (d, J = 2.5 Hz, 2H),
7.76 (d, J = 7.0 Hz, 4H), 7.56 (dd, J = 2.3 Hz, 7.8 Hz, 2H), 7.47
(t, J = 7.8 Hz, 4H), 7.35–7.38 (m, 2H), 7.31 (d, J = 8.5 Hz, 8H),
7.26–7.29 (m, 6H), 7.15 (d, J = 9.5 Hz, 2H), 7.10 (d, J = 8.5 Hz,
2H), 6.87 (d, J = 8.5 Hz, 8H), 6.74–6.77 (m, 10H), 6.60
(t, J = 2.0 Hz, 1H), 5.09 (s, 2H), 5.02 (s, 8H), 4.95 (s, 4H), 4.93
(s, 4H), 3.90–3.95 (m, 12H), 2.84–2.87 (m, 4H), 2.70–2.73
(m, 4H), 1.73–1.80 (m, 12H), 1.41–1.47 (m, 12H), 1.26–1.35
(m,ꢀ 96H), 0.86–0.89 (m, 18H); 13C NMR (126 MHz, CDCl3,
25 C, ppm): δ 160.2, 158.9, 158.9, 158.2, 153.2, 150.0, 147.2,
141.3, 139.8, 139.3, 138.4, 136.9, 135.7, 132.0, 130.3, 130.2,
130.0, 129.8, 129.4, 128.9, 128.7, 127.9, 127.2, 127.0, 114.9,
114.4, 114.1, 107.4, 106.5, 101.5, 74.8, 71.2, 70.4, 70.1, 68.0,
Synthesis of UPh/Ph
To a DMF solution (15 mL) of 7 (33.0 mg, 0.0610 mmol) was
added NaSEt (15ꢀ9 mg, 1.89 mmol) at 25 ꢀC under Ar. After
warming to 140 C, the reaction mixture was stirred for 1 h.
The reaction mixture was poured into saturated aq. NaHCO3,
and the mixture was acidified with 10% HCl aq. The resulting
mixture was extracted with CH2Cl2, and the lower phase was
collected. The organic extract was washed with brine, dried
over anhydrous Na2SO4, filtered, and evaporated to dryness
6
JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2018

JOURNAL OF
POLYMER SCIENCE
WWW.POLYMERCHEMISTRY.ORG
ORIGINAL ARTICLE
FIGURE 4 A series of characterization data for the binary mixtures of UPy/H/Pyr = 1/1, UH/H/Pyr = 1/0.5, UH/H/Pyr = 1/1, and UH/H
/
Pyr = 1/2 (molar ratio) in LC phase. Each column contains a phase transition diagram (temperature in ꢀC; DSC at a scan rate of
10 ꢀC min−1), a POM image, and an XRD pattern. Colh, Cubbi, and Iso denote hexagonal columnar, bicontinuous cubic, and isotropic
phases, respectively. The numbers in parentheses in XRD patterns are Miller indexes assigned to each diffraction peak. The XRD
patterns were taken at 75 ꢀC (for UPy/H/Pyr = 1/1), 45 ꢀC (for the Cubbi phase of UH/H/Pyr = 1/0.5), 58 ꢀC (for the Colh phase of UH/H
Pyr = 1/0.5), 58 ꢀC (for UH/H/Pyr = 1/1), and 50 ꢀC (for UH/H/Pyr = 1/2). [Color figure can be viewed at wileyonlinelibrary.com]
/
ꢀ
68.0, 31.9, 29.7, 29.6, 29.4, 29.3, 29.3, 27.8, 26.1, 25.9, 22.7,
14.1; MALDI-TOF-MS m/z calcd. For C174H228NO15 [M + H]+
2571.71, found 2571.87; Anal. Calcd. for C174H227NO15: C,
81.23; H, 8.89; N, 0.54. Found: C, 80.88; H, 9.16; N, 0.54.
exhibited a Colh phase below 91 C on cooling (DSC, Support-
ing Information, Fig. S11). Its intercolumnar distance of
40.4 Å (Fig. 3 and Supporting Information, Fig. S21 and
Table S2) calculated from the XRD pattern at 87 ꢀC was
ꢀ
slightly shorter than that of UPy/Py at 110 C (42.5 Å, Fig. 3).
Meanwhile, UH/H exhibited a bicontinuous cubic (Cubbi) phase
with Ia3d space group12 below 64 ꢀC on cooling (DSC, Sup-
porting Information, Fig. S12), with a lattice constant of
91.9 Å at 60 ꢀC (XRD, Fig. 3 and Supporting Information,
Fig. S22 and Table S3). UPh/Ph, with two phenyl head groups,
exhibited a Colh LC mesophase between 105 and 42 ꢀC on
cooling (DSC, Supporting Information, Fig. S13) with an inter-
RESULTS AND DISCUSSION
UPy/Py was synthesized from the methoxy-substituted precur-
sor 19 (Sch. 1). Subsequent deprotection of the methoxy unit
followed by a Williamson etherification reaction with a benzyl
chloride-terminated Percec-type dendron10 gave UPy/Py. This
molecule was unambiguously characterized by 1H and 13C
NMR spectroscopy (Supporting Information, Figs. S1 and S2)
and MALDI-TOF-MS. The differential scanning calorimetry
(DSC) profile of UPy/Py showed a phase transition at 112 and
114 ꢀC for the cooling and heating processes, respectively
(Supporting Information, Fig. S10). Polarized optical micros-
copy (POM) of UPy/Py on cooling from its isotropic melt dis-
ꢀ
columnar distance of 41.1 Å (99 C, XRD, Fig. 3) and a Cubbi
LC mesophase (Ia3d) between 45 and 77 ꢀC on heating
(Supporting Information, Fig. S23 and Table S4). These char-
acterizations of the LC molecules demonstrated that the geom-
etries of an LC assembly are determined by the size of the
head groups; the larger head groups (pyrenyl) formed a Colh
assembly, and the smaller head groups (hydrogen) formed a
Cubbi assembly (Fig. 2).
ꢀ
played a fan texture at 111 C (Fig. 3), which is characteristic
of a Colh LC mesophase. Synchrotron radiation X-ray diffrac-
tion (XRD) analysis of UPy/Py at 110 ꢀC showed diffraction
peaks, with d spacings of 36.8, 21.2, and 18.4 Å (Supporting
Information, Fig. S20 and Table S1), which were indexed as
(100), (110), and (200) diffractions of a Colh assembly, with
an intercolumnar distance of 42.5 Å (Fig. 3).
Interestingly, the addition of one or two equivalents of pyrene
molecules as a guest to Cubbi liquid crystal of UH/H formed a
homogeneous Colh LC assembly. Mixtures of UH/H with one
equivalent of pyrene (UH/H/Pyr = 1/1) and two equivalents
of pyrene (UH/H/Pyr = 1/2) were prepared by the slow-
evaporation of CHCl3 solutions, and their LC properties were
investigated (DSC: Supporting Information, Figs. S16 and S17;
POM: Fig. 4; XRD: Fig. 4 and Supporting Information, Figs. S26
and S27 and Tables S7 and S8). Both the mixtures exhibited
Colh LC mesophases, with intercolumnar distances of 40.0 Å
(58 ꢀC for UH/H/Pyr = 1/1 in Fig. 4) and 40.2 Å (50 ꢀC for
For the detailed understanding of the columnar assembly of
U
Py/Py, the LC properties of UPy/H, UH/H, and UPh/Ph (Fig. 1)
were investigated. These molecules were synthesized from
the corresponding methoxy-substituted precursors (5, 6, and
7 in Sch. 1) in the same way as the synthesis of UPy/Py. Analo-
gous to UPy/Py, UPy/H with one pyrenyl head group also
JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2018
7

JOURNAL OF
POLYMER SCIENCE
ORIGINAL ARTICLE
WWW.POLYMERCHEMISTRY.ORG
times of 3.4 Å14) and the density of the LC molecule is
1.0 g cm−3, as reported in a reference using the same benzyl-
ether dendron,10c the number of molecules used for making
one disk can be calculated to be 3.4, 3.3, and 3.5 for UPy/Py
Py/H, and UPh/Ph, respectively. These results also support the
model (Fig. 2).
,
U
Interestingly, both UPy/Py and UPy/H in their Colh LC states
displayed a deep blue luminescence.15 In CHCl3, UPy/Py and
UPy/H in electronic absorption spectroscopy showed fine
vibronic absorption bands assignable to the absorption of pyr-
ene (Supporting Information, Figs. S32 and S33).16 The lumi-
nescence spectra of UPy/Py and UPy/H in CHCl3 upon excitation
at 340 nm likewise displayed a fine vibronic structure, with
three emission maxima (Supporting Information, Figs. S34
and S35).15 The film samples of UPy/Py and UPy/H, upon exci-
tation at 340 nm, explicitly displayed luminescence peaks at
425 nm and 421 nm, respectively [Fig. 5(a,b)], without any
obvious excimer peaks, and showed deep blue-color emissions
[Fig. 5(a,b), insets].15 We monitored the luminescence decay
profiles (Supporting Information, Figs. S36 and S37) of UPy/Py
and UPy/H at six different emission wavelengths, 400, 420,
440, 460, 480, and 500 nm, upon excitation at 340 nm
(Supporting Information, Tables S11 and S12). For UPy/Py, the
luminescence decay profiles at 400 nm and 420 nm, which
are at around the peak of the luminescence spectrum [425 nm,
Fig. 5(a)], could be fit by one or two components without rise
time (Supporting Information, Table S11 and Fig. S36), indicat-
ing that the luminescence profile was dominated by the emis-
sion from nonstacked pyrenyl head groups.15 This was also the
case in the luminescence decay profiles of UPy/H (Supporting
Information, Table S12 and Fig. S37), where the decay profiles
at 400, 420, and 440 nm could be fit by one component with-
out rise time. These spectral features indicate that the pyrenyl
moieties most likely exist as a monomeric species. Notably,
none of the previously reported pyrene-containing LC mate-
rials17 displayed deep blue-color emissions (λem,max = 425 nm
for UPy/Py and 421 nm for UPy/H) in bulk. Therefore, the lumi-
nescence behaviors of UPy/Py and UPy/H were quite distinctive.
FIGURE 5 Luminescence spectra (λex = 340 nm) of film samples
of (a) UPy/Py, (b) UPy/H, (c) UPy/H/Pyr = 1/1, (d) UH/H, (e) UH/H
/
Pyr = 1/1, and (f ) UH/H/Pyr = 1/2. The insets in (a) and (b) show
photographs of emission from film samples of (a) UPy/Py and
(b) UPy/H under 365 nm UV light. ΦF denotes absolute luminescence
quantum yield. The film samples were prepared by sandwiching
the LC molecules by two quartz flats and cooled from its isotropic
melt to 25 ꢀC at a rate of 5 ꢀC min−1. [Color figure can be viewed at
wileyonlinelibrary.com]
UH/H/Pyr = 1/2 in Fig. 4). These intercolumnar distances are
close to those of UPy/Py (42.5 Å, Fig. 3), UPy/H (40.4 Å, Fig. 3),
and UPh/Ph (41.1 Å, Fig. 3) in their Colh LC mesophases. Similarly,
UPy/H incorporated with one equivalent of pyrene molecule as a
guest (UPy/H/Pyr = 1/1) exhibited a Colh phase, with an interco-
lumnar distance of 40.8 Å (75 ꢀC, Fig. 4). The series of investiga-
tions above clarified that the intercolumnar distances of a Colh
phase are independent of how the pyrene moieties are incorpo-
rated in the LC system. From these observations, we propose in
Figure 2 and Figure S38 in the Supporting Information a model
of columnar assembly of UPy/Py based on the stacking of the
U-shaped handle, where one column stratum consists of three
molecules.13 In this model, the center of disk is the U-shaped
handle, and the pyrene head groups overhang from the center.
Even in the mixture systems, such as UH/H/Pyr = 1/1, UH/H
/
FIGURE 6 Phase diagram of the mixtures of UH/H with guest
pyrene molecules (UH/H/Pyr = 1/x) with x = 0, 0.5, 1, 2, 3, and
4 (phase transition temperatures (in ꢀC; DSC on cooling at a scan
rate of 10 ꢀC min−1) versus molar equivalent of guest pyrene
molecules). UH/H/Pyr = 1/0 means UH/H alone without any guest
molecules. Colh, Cubbi, Cr, and Iso denote hexagonal columnar,
bicontinuous cubic, crystal, and isotropic phases, respectively.
[Color figure can be viewed at wileyonlinelibrary.com]
Pyr = 1/2, and UPy/H/Pyr = 1/1, the guest pyrene molecules
resided around the center, resulting in similar Colh geometries to
UPy/Py (Fig. 2). This model is consistent with a previous report
that the benzyl-ether dendron employed in this study forms a
disk with three molecules for the construction of a columnar
structure.10c If we suppose that the average height of the column
stratum is three times of the average π-stacking distance (three
8
JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2018

JOURNAL OF
POLYMER SCIENCE
WWW.POLYMERCHEMISTRY.ORG
ORIGINAL ARTICLE
ACKNOWLEDGMENTS
Luminescence spectroscopy for the film samples of mixtures,
Py/H/Pyr = 1/1, UH/H/Pyr = 1/1, and UH/H/Pyr = 1/2, pro-
vided information about how guest pyrene disks are incorpo-
rated in the parent LC molecules. In the case of UPy/H
U
The authors thank Dr Takashi Kajitani for his fruitful discussion.
The authors also thank Mr Hideki Waragai for the measurements
of the absolute photoluminescence quantum yield in the solid
state. This work was financially supported by JSPS KAKENHI,
Grant-in-Aid for Specially Promoted Research (25000005) on
“Physically Perturbed Assembly for Tailoring High-Performance
Soft Materials with Controlled Macroscopic Structural Anisotropy”
for T. A. and Y. I. Synchrotron radiation experiments were per-
formed at the BL44B2 beamline of SPring-8 with the approval of
the RIKEN SPring-8 Center (proposal 20140045, 20160024). Y. S.
thanks JSPS for a Young Scientist Fellowship and the Program for
Leading Graduate Schools (MERIT).
/
Pyr = 1/1, the luminescence spectrum [Fig. 5(c)] was similar
to that of UPy/H [Fig. 5(b)], without the distinctive broad lumi-
nescence peak at ~470 nm. This result indicated that pyrene
molecules and pyrenyl head groups do not form excimers.15
The mixtures UH/H/Pyr = 1/1 and UH/H/Pyr = 1/2 both
showed broad luminescence peaks at ~470 nm [Fig. 5(e,f )],
which were not observed in luminescence spectra of UPy/Py
and UPy/H [Fig. 5(a,b)]. These broad peaks could be due to an
excimer emission from the guest pyrene molecules, indicating
that the guest molecules in the LC medium have positional
freedom to form an excimer.
REFERENCES
The summary of phase transition behaviors of the mixtures of
UH/H and pyrene molecules at different molar ratios is shown
in Figure 6. DSC traces, POM images, and XRD patterns of
these mixtures are shown in Figure 4 and the Supporting
Information (DSC: Supporting Information, Figs. S15–S19;
POM: Supporting Information, Figs. S30 and S31; XRD: Sup-
porting Information, Figs. S25–S29 and Tables S6–S10). First,
1 (a) T. Kato, N. Mizoshita, K. Kishimoto, Angew. Chem. Int. Ed.
2006, 45, 38. (b) T. Kato, J. Uchida, T. Ichikawa, T. Sakamoto,
Angew. Chem. Int. Ed. 2018, 57, 4355.
2 (a) T. Kato, Y. Kamikawa, Handbook of Liquid Crystals. In , 2nd
edn, Chapter 10 ed., J. W. Goodby, P. J. Collings, T. Kato,
C. Tschierske, H. Gleeson, P. Raynes Eds., Wiley-VCH,
Weinheim, Germany, 2014; Vol. 5, p. 513. (b) T. Kato,
J. M. J. Fréchet, J. Am. Chem. Soc. 1989, 111, 8533.
a mixture of UH/H with 0.5 equivalent of pyrene (UH/H
/
3 (a) V. Percec, G. Johansson, G. Ungar, J. Zhou, J. Am. Chem.
Soc. 1996, 118, 9855. (b) T. Kato, T. Matsuoka, M. Nishii,
Y. Kamikawa, K. Kanie, T. Nishimura, E. Yashima, S. Ujiie,
Angew. Chem. Int. Ed. 2004, 43, 1969.
Pyr = 1/0.5) was prepared. Interestingly, this mixture exhib-
ited a Cubbi LC mesophase below 54 ꢀC (DSC, Supporting
Information, Fig. S15), with a lattice constant of 93.1 Å at
45 ꢀC (Fig. 4 and Supporting Information, Fig. S25 and
Table S6) together with a Colh LC mesophase with a lattice
constant of 40.0 Å at 58 ꢀC (Fig. 4 and Supporting Informa-
tion, Fig. S25 and Table S6) in a very narrow temperature
4
(a) V. Percec, M. Glodde, T. K. Bera, Y. Miura,
I. Shiyanovskaya, K. D. Singer, V. S. K. Balagurusamy,
P. A. Heiney, I. Schnell, A. Rapp, H.-W. Spiess, S. D. Hudson,
ꢀ
H. Duan, Nature 2002, 419, 384. (b) M. Stępien, B. Donnio,
ꢀ
J. L. Sessler, Angew. Chem. Int. Ed. 2007, 46, 1431.
range between 64 and 54 C on cooling. This result indicates
5 (a) B. Xu, T. M. Swager, J. Am. Chem. Soc. 1995, 117, 5011.
(b) D. Felder, B. Heinrich, D. Guillon, J.-F. Nicoud,
J.-F. Nierengarten, Chem. Eur. J. 2000, 6, 3501.
that at least one equivalent of guest pyrene is required to con-
vert the original Cubbi LC mesophase of UH/H completely to a
Colh LC mesophase. Interestingly, upon further addition of the
guest pyrene molecules (UH/H/Pyr = 1/2, 1/3, and 1/4), POM
images of the samples showed homogeneous fan textures
(Fig. 4 and Supporting Information, Figs. S30 and S31). The
XRD patterns of the sample were consistent with Colh assem-
blies (Supporting Information, Tables S8–S10), without any
peaks assignable to crystalline guest pyrene (Supporting
Information, Figs. S27–S29). This observation indicates that
6 (a) M. Lehmann, B. Schartel, M. Hennecke, H. Meier, Tetrahe-
dron 1999, 55, 13377. (b) M. Lehmann, M. Hügel, Angew. Chem.
Int. Ed. 2015, 54, 4110. (c) M. Lehmann, P. Maier, Angew. Chem.
Int. Ed. 2015, 54, 9710. (d) M. Lehmann, P. Maier, M. Grüne,
M. Hügel, Chem. Eur. J. 2017, 23, 1018. (e) P. Maier, M. Grüne,
M. Lehmann, Chem. Eur. J. 2017, 23, 1060.
7 (a) S. Laschat, A. Baro, N. Steinke, F. Giesselmann, C. Hägele,
G. Scalia, R. Judele, E. Kapatsina, S. Sauer, A. Schreivogel,
M. Tosoni, Angew. Chem. Int. Ed. 2007, 46, 4832. (b) T. Wöhrle,
I. Wurzbach, J. Kirres, A. Kostidou, N. Kapernaum, J. Litterscheidt,
J. C. Haenle, P. Staffeld, A. Baro, F. Giesselmann, S. Laschat, Chem.
Rev. 2016, 116, 1139.
U
H/H has a large capability to incorporate guest molecules.
8 (a) S. C. Zimmerman, C. M. VanZyl, J. Am. Chem. Soc. 1987,
109, 7894. (b) S. C. Zimmerman, C. M. VanZyl, G. S. Hamilton,
J. Am. Chem. Soc. 1989, 111, 1373. (c) S. C. Zimmerman,
M. Mrksich, M. Baloga, J. Am. Chem. Soc. 1989, 111, 8528.
(d) S. C. Zimmerman, K. W. Saionz, Z. Zeng, Proc. Natl. Acad.
Sci. U. S. A. 1993, 90, 1190. (e) S. C. Zimmerman, K. W. Saionz,
J. Am. Chem. Soc. 1995, 117, 1175.
CONCLUSIONS
In conclusion, we developed a novel LC molecule UH/H, bear-
ing a U-shaped handle, that exhibited a Cubbi phase. In the
presence of pyrene molecules as an external guest, UH/H
formed the Colh phase without phase separation. Columnar
assemblies with similar intercolumnar distances were
observed in the LC molecules UPy/Py and UPy/H, where pyrene
moieties were covalently attached to the U-shaped handle.
This study demonstrates a potential use of guest molecules to
form multi-component liquid crystals to control the LC assem-
bly. Incorporation of other functional guest molecules to UH/H
is now under investigation in our research group.
9 Y. Shibuya, Y. Itoh, T. Aida, Chem. Asian J. 2017, 12, 811.
10 (a) B. M. Rosen, C. J. Wilson, D. A. Wilson, M. Peterca,
M. R. Imam, V. Percec, Chem. Rev. 2009, 109, 6275.
(b) V. Percec, C.-H. Ahn, W.-D. Cho, A. M. Jamieson, J. Kim,
T. Leman, M. Schmidt, M. Gerle, M. Moller, S. A. Prokhorova,
S. S. Sheiko, S. Z. D. Cheng, A. Zhang, G. Ungar,
D. J. P. Yeardley, J. Am. Chem. Soc. 1998, 120, 8619.
JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2018
9

JOURNAL OF
POLYMER SCIENCE
ORIGINAL ARTICLE
WWW.POLYMERCHEMISTRY.ORG
(c) V. Percec, W.-D. Cho, G. Ungar, D. J. P. Yeardley, J. Am.
Chem. Soc. 2001, 123, 1302. (d) M. R. Imam, M. Peterca,
U. Edlund, V. S. K. Balagurusamy, V. Percec, J. Polym. Sci. Part
A: Polym. Chem. 2009, 47, 4165.
16 A. G. Crawford, A. D. Dwyer, Z. Liu, A. Steffen, A. Beeby,
L.-O. Pålsson, D. J. Tozer, T. B. Marder, J. Am. Chem. Soc. 2011,
133, 13349.
17 (a) S. A. Benning, T. Hassheider, S. Keuker-Baumann,
H. Bock, F. Della Sala, T. Frauenheim, H.-S. Kitzerow, Liq.
Cryst. 2001, 28, 1105. (b) T. Hassheider, S. A. Benning,
H.-S. Kitzerow, M.-F. Achard, H. Bock, Angew. Chem. Int. Ed.
2001, 40, 2060. (c) A. Hayer, V. de Halleux, A. Kohler,
A. El-Garoughy, E. W. Meijer, J. Barberá, J. Tant, J. Levin,
M. Lehmann, J. Gierschner, J. Cornil, Y. H. Geerts, J. Phys.
Chem. B 2006, 110, 7653. (d) Y. H. Kim, D. K. Yoon, E. H. Lee,
Y. K. Koan, H.-T. Jung, J. Phys. Chem. B 2006, 110, 20836.
(e) Y. Sagara, T. Kato, Angew. Chem. Int. Ed. 2008, 47, 5175. (f )
S. Diring, F. Camerel, B. Donnio, T. Dinrzer, S. Toffanin,
R. Capelli, M. Muccini, R. Ziessel, J. Am. Chem. Soc. 2009, 131,
18177. (g) Y. Sagara, T. Komatsu, T. Ueno, K. Hanaoka, T. Kato,
T. Nagano, Adv. Funct. Mater. 2013, 23, 5277. (h) M. Bucos¸,
T. Sierra, A. Golemme, R. Termine, J. Barberá, R. Giménez,
J. L. Serrano, P. Romero, M. Marcos, Chem. Eur. J. 2014, 20,
10027. (i) K. P. Gan, M. Yoshio, T. Kato, J. Mater. Chem. C
2016, 4, 5073. (j) Y. Sagara, C. Weder, N. Tamaoki, Chem.
Mater. 2017, 29, 6145. (k) Y. Sagara, N. Tamaoki, RSC Adv.
2017, 7, 47056.
11 D. N. Coventry, A. S. Batsanov, A. E. Goeta, J. A. K. Howard,
T. B. Marder, R. N. Perutz, Chem. Commun. 2005, 2172.
12 (a) S. Kutsumizu, Isr. J. Chem. 2012, 52, 844.
(b) C. Tschierske, Angew. Chem. Int. Ed. 2013, 52, 8828.
(c) M. A. Alam, J. Motoyanagi, Y. Yamamoto, T. Fukushima,
J. Kim, K. Kato, M. Takata, A. Saeki, S. Seki, S. Tagawa, T. Aida,
J. Am. Chem. Soc. 2009, 131, 17722. (d) T. Ichikawa, M. Yoshio,
A. Hamasaki, S. Taguchi, F. Liu, X.-b. Zeng, G. Ungar, H. Ohno,
T. Kato, J. Am. Chem. Soc. 2012, 134, 2634.
13 Note that a model comprising a dimeric core (length = ~
29 Å), as reported in ref. 9, exceeds the size of the column diam-
eter (~40 Å) obtained in this study. See Fig. S38 for details.
14 XRD pattern did not show a diffraction assignable to the value of
3.4 Å, probably due to weak and disordered stacking between the
mesogenic U-shaped core. Therefore, we employed the value for a
standard π-stacking distance. See,L. M. Salonen, M. Ellermann,
F. Diederich, Angew. Chem. Int. Ed. 2011, 50, 4808.
15 F. M. Winnik, Chem. Rev. 1993, 93, 587.
10
JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2018