Coassembly of a hexagonal columnar liquid crystalline superlattice from polymer(s) coated with a three-cylindrical bundle supramolecular dendrimer

Article abstract of DOI:10.1002/(SICI)1521-3765(19990301)5:3<1070::AID-CHEM1070>3.0.CO;2-9

The synthesis and structural analysis of a polymer containing twin- dendritic benzamide side-groups (i.e. poly{N-[3,4-bis(n-dodecan-1-yloxy)- 5(1-methacryloyl-η-undecan-1-yloxy)phenyl]-3,4,5-tris(n-dodecan-1- yloxy)benzamide}) (19) are described. The disc

Full text of DOI:10.1002/(SICI)1521-3765(19990301)5:3<1070::AID-CHEM1070>3.0.CO;2-9

FULL PAPER
Coassembly of a Hexagonal Columnar Liquid Crystalline Superlattice
from Polymer(s) Coated with a Three-Cylindrical Bundle Supramolecular
Dendrimer
Virgil Percec,*[a] Cheol-H. Ahn,[a] Tushar K. Bera,[a] Goran Ungar,[b]
and Duncan J. P. Yeardley[b]
Abstract: The synthesis and structural
analysis of a polymer containing twin-
dendritic benzamide side-groups (i.e.
poly{N-[3,4-bis(n-dodecan-1-yloxy)-5-
(1-methacryloyl-n-undecan-1-yloxy)-
phenyl]-3,4,5-tris(n-dodecan-1-yloxy)-
benzamide}) (19) are described. The
disc-like side groups of this polymer
self-assemble into supramolecular cylin-
drical dendrimers through hydrogen
bonding acting along the column long
axis, creating a novel architecture con-
sisting of a polymer chain(s) coated with
a three-cylindrical bundle supramolecu-
lar dendrimer. This polymer self-organ-
izes in a thermotropic nematic liquid
crystalline (LC) phase. The low molar
mass twin dendritic benzamide, 7-12/12,
which has a similar structure to that of
the polymer side groups, self-assembles
into supramolecular cylindrical den-
drimers, which self-organize on a two-
dimensional hexagonal columnar (Fh)
LC lattice. Coassembly of the polymer
19 with 7-12/12 produces a novel two-
dimensional Fh LC superlattice. The
mechanism responsible for this coassem-
bly provides access to libraries of func-
tional two-dimensionl Fh superlattices.
Keywords: dendrimers ´ liquid crys-
tals ´ superlattices ´ three-cylindri-
cal bundle
by polymerization up to a specific degree of polymerization,
yields spherical polymers. Above this degree of polymer-
ization, cylindrical supramolecules are produced.[5] Both the
cylindrical and spherical macromolecular dendrimers self-
organize in lattices similar to those of the corresponding
supramolecular objects created from their low molar mass
building blocks. Related cylindrical polymers which do not,
however, self-organize into lattices have been reported by
other laboratories.[6,7]
Herein we will demonstrate the synthetic capabilities of
mini-monodendrons as models or maquettes for the elabo-
ration of novel architectural motifs from larger generations of
dendritic building blocks.[8,9,10] The role of these mini-mono-
dendrons is analogous to that of simple peptides used in the
understanding of the molecular engineering involved in the
assembly of more complex proteins, or of maquettes used by
sculptors and architects to appreciate various aspects of full-
size objects.[11] The capability of mini-monodendrons is
illustrated by elaborating a new architectural motif. The
synthesis and characterization of the simplest examples of
twin-tapered dendritic benzamides and bisdendritic benz-
amides obtained from dissimilar monodendrons that self-
assemble into supramolecular cylindrical dendrimers that, in
turn, self-organize in a 2-D Fh LC lattice, will be described
first. The attachment of a polymerizable group to the
periphery of a twin-monodendritic benzamide selected from
Introduction
Previous publications from our laboratories reported the
design, synthesis, and structural analysis of flat tapered[1,2] and
conical[2,3] monodendrons that self-assemble into cylindrical
and spherical supramolecular dendrimers, respectively. Cylin-
drical dendrimers form two-dimensional (2-D) hexagonal
columnar (Fh) lattices, while the spherical dendrimers form
three-dimensional (3-D) cubic liquid-crystalline (LC) lattices.
The attachment of a polymerizable group to the core of the
flat tapered monodendrons followed by polymerization
produces, regardless of the degree of polymerization (DP),
cylindrical polymers with the polymer backbone penetrating
through their center.[4] Functionalization of the core of the
conical monodendrons with a polymerizable group, followed
[a] Prof. V. Percec, Dr. C. H. Ahn, Dr. T. K. Bera
The W. M. Keck Laboratories for Organic Synthesis
Department of Macromolecular Science
Case Western Reserve University
Cleveland, OH 44106 ± 7202 (USA)
Fax : (‡ 1)216-368-4202
E-mail : vxp5@po.cwru.edu
[b] Dr. G. Ungar, Dr. D. J. P. Yeardley
Department of Engineering Materials and Center for Molecular
Materials
University of Sheffield
Sheffield S1 3JD (UK)
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Chem. Eur. J. 1999, 5, No. 3

1070±1083
the first series of experiments followed by polymerization
produces a novel architecture consisting of polymer(s) coated
with a three-cylindrical bundle supramolecular dendrimer.
Coassembly of this new architecture with the low molar mass
twin-dendritic benzamide with the same structure as the
polymerꢁs side groups generates a novel Fh LC superlattice.
The new architecture described here provides a synthetic
concept that could become as powerful as that of the 3- and
4-helix bundle protein motifs used by Nature to create binding
and catalytic cavities,[12,13] even if the detailed self-assembly
mechanisms of these two systems are quite different.
of the resulting 4-n with KOH in refluxing EtOH (82 ± 97%
yield). Chlorination of 5-n with SOCl2 in the presence of a
catalytic amount of DMF was complete at 208C within 1 h and
produced the benzoyl chlorides 6-n in 100% yield. In the
subsequent step the benzoyl chlorides 6-n were used without
further purification. Amidation[20] of 3-m with 6-n in refluxing
pyridine yielded 7-m/n (72 ± 81% yield after recrystallization
from isopropanol). Compound 7-12/18 was methylated with
CH3I in anhydrous THF by using a suspension of NaH as base
and a catalytic amount of DMSO to yield 8-12/18 in 78% yield
after recrystallization from isopropyl alcohol.
The synthesis of monomethacrylate functionalized benza-
mide monomer 18 is shown in Scheme 2. 3,4-Isopropyliden-5-
hydroxy methylbenzoate (10) was synthesized[21] in 38% yield
from 3,4,5-trihydroxy methylbenzoate (9) with P2O5 in
acetone at 208C for 1 h. The hydroxy group of 3,4-isopropy-
liden-5-hydroxy methylbenzoate was etherified with 1-bro-
moundecanol in DMF at 608C using K2CO3 as base to yield
the yellow oily compound 11 in 83% yield. The isopropyli-
dene protective group was cleaved with HCl in refluxing
EtOH for 2 h to produce 12 in 93% yield after recrystalliza-
tion from CH2Cl2/hexane (1/1). During this step a partial
transesterification of the methyl ester 12 with ethanol took
place. The resulting mixture of 12 was etherified with
1-bromododecane in DMF at 608C using K2CO3 as base to
yield 13 in 72% yield after precipitation from THF solution
into MeOH. The ester group of 13 was hydrolyzed with KOH
in refluxing EtOH to yield the hydroxy acid 14 in 98% yield.
Esterification of 14 with methacryloyl chloride at 08C for 3 h
in dry CH2Cl2 in the presence of dry pyridine led to the mixed
ester anhydride 15. Compound 15 was heated for 10 min in a
mixture of pyridine (50 mL) and H2O (15 mL) to cleave the
mixed ester anhydride and maintain the methacryloyl ester
group. The reaction mixture was acidified with dilute HCl,
extracted with Et2O, washed with a solution of NaHCO3 and
Results and Discussion
Synthesis of benzamides 7-m/n and of monomer 18: Scheme 1
outlines the synthesis of N-[3,4,5-tris(n-alkan-1-yloxy)phen-
yl]-3,4,5-tris(n-alkan-1-yloxy)benzamides (7-m/n) and of the
N-methylated derivative of 7-12/18, that is, 8-12/18. In the first
step, 1,2,3-trihydroxybenzene was alkylated with 1-bromodo-
decane and 1-bromooctadecane, respectively, in DMF at 608C
using K2CO3 as a base to produce 3,4,5-tris(n-alkan-1-yloxy)-
benzene (1-m, mˆ 12, 18) in 75 and 79% yields after recrystal-
lization from acetone. Nitration of 1-m was carried out with
HNO3 supported on SiO2 at 208C for 15 min to produce 3,4,5-
tris(n-alkan-1-yloxy)-1-nitrobenzene (2-m) in 83% yield after
recrystallization from acetone. HNO3/SiO2
[14,15]
suppressed
oxidative demethylation of 1-m and nitrated selectively only
at the 1 position of 1-m. Reduction of 2-m with NH2NH2 ´ H2O
over graphite powder in ethanol produced 3,4,5-tris(n-alkan-
1-yloxy)-1-aminobenzene (3-m) in 93% yield.[16,17]
3,4,5-Tris(n-alkan-1-yloxy)benzoic acids (5-n) were synthe-
sized by the alkylation[18] of methyl-3,4,5-trihydroxybenzoate
(methyl gallate) with 1-bromoalkane (65 ± 72% yield after
recrystallization from acetone), followed by the hydrolysis[19]
Scheme 1. Synthesis of bis-dendritic benzamides 7-m/n and methyl benzamide 8-12/18.
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V. Percec et al.
FULL PAPER
Scheme 2. Synthesis and polymerization of bis-dendritic benzamide methacrylate, 19.
Figure 1. First heating (left), first cooling (center), and second heating (right) DSC traces of 7-12/18, 7-12/12, 7-12/10, 7-12/6, 8-12/8, and 19.
dried over anhydrous MgSO4. Et2O was distilled and the
remaining solid was recrystallized from MeOH/CHCl3 (1/2) to
yield 16 in 41.0% yield. Chlorination of 16 with SOCl2 in the
presence of a catalytic amount of DMF was complete at 208C
in 1 h and produced the benzoyl chloride 17 in 96% yield.
Amidation of 17 with 3-12 was carried out in pyridine at 608C
for 4 h to produce the monomethacrylate functionalized
benzamide 18 in 61% yield after purification by column
chromatography (SiO2, hexane/EtOAc; 10/1).
The resulting polymer was purified by column chromatog-
raphy (SiO2, hexane) to separate the unreacted monomer;
Mn ˆ 58800, Mw/Mn ˆ 2.16 (GPC with polystyrene standards).
When this polymerization was carried out in a less concen-
1
trated solution (4.36 Â 10-2 molL ), the reaction mixture was
homogeneous throughout the polymerization process. After
purification as above the resulting polymer had Mn ˆ 55095
and Mw/Mn ˆ 1.64 (GPC with polystyrene standards).
Thermal analysis of benzamides 7-m/n and of polymer 19: All
compounds were analyzed by a combination of techniques
consisting of differential scanning calorimetry (DSC), thermal
optical polarized microscopy (TOPM), and X-ray diffraction
(XRD) experiments. Transition temperatures were deter-
Polymerization of 18: Radical polymerization of 18 initiated
with AIBN was carried out in benzene at 608C. This
polymerization was very fast (89% conversion in 2 h, at
1
6.08 Â 10 2 molL monomer concentration), most probably
1
due to self-organization of the polymerizable groups in a
microreactor surrounded by three supramolecular columns. A
gel formed in the early stage of this polymerization. Although
kinetic analysis were needed to evaluate this process, it re-
sembled another related process that we recently reported.[5b]
mined by DSC with 10oCmin (see Experimental Section)
and the assignment of various phases was done by a
combination of XRD and TOPM.
Figure 1 presents the first heating, the second heating, and
first cooling DSC traces of benzamides 7-12/6, 7-12/10, 7-12/
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Liquid Crystalline Superlattices
1070±1083
12, and 7-12/18 and of the polymer 19 with Mn ˆ 55095 and
Mn/Mw ˆ 1.64. These benzamides exhibited an enantiotropic
columnar hexagonal (Fh) liquid crystalline (LC) phase. In all
cases, the Fh phase was confirmed by TOPM and XRD. A fan-
shaped focal conic texture representative of the Fh phase is
shown in Figure 2. Transition temperatures and the corre-
sponding enthalpy changes are summarized in Table 1. The
alkyl tails can easily self-assemble in a cylinder which self-
organizes in a hexagonal columnar LC lattice. The larger
degree of supercooling of 7-12/6 (17oC) is again in the range
of expected values[22b] and can be explained by its lower
1
enthalpy change (0.21 kcalmol ), which demonstrates a
higher difficulty for the self-assembly of this diamide to a
cylinder of sufficient perfection required for self-organization
in a hexagonal columnar LC lattice. This can easily be
understood if we consider that 7-12/4 does not form a
hexagonal columnar LC lattice at all (Table 1). Again, this
result is in line with reported data, that is, related diamides
with short alkyl tails form only crystalline phases.[22b] The
benzamides containing combinations of dissimilar long and
short alkyl chains, that is, 7-12/4, 7-18/4, 7-18/6, and 7-18/10, or
similar long alkyl chains, that is, 7-18/18, form only a
crystalline phase. The N-methylated benzamide 8-12/18 also
displays only crystalline melting at 328C. The crystals of its
precursor benzamide 7-12/18 melt into a Fh phase at 618C,
followed by isotropization at 958C. The behavior of the latter
demonstrates that hydrogen bonding is responsible for the
formation of the LC phase of 7-m/n.
On heating, the polymer 19 with Mn ˆ 55095 and Mn/Mw ˆ
1.64 exhibits a mesophase which undergoes isotropization at
95oC. This transition is not seen on cooling but it appears at
92oC on subsequent heating scans (Figure 1). A nematic
texture is observed for this mesophase. The polymer with a
broader molecular weight distribution does not show an
isotropization peak on heating or cooling by DSC unless the
sample is annealed at 55oC for 12 h. In this case, it showed an
isotropization peak only on heating at 69oC (DH ˆ
Figure 2. Optical polarized micrograph of the Fh mesophase of 7-12/12
1
observed at 113oC on cooling with 0.5oCmin from isotropic melt.
degree of supercooling of the isotropization temperature is
6oC for 7-12/12 and 7-12/18, 7oC for 7-12/10, and 17oC for 7-
12/6. A degree of supercooling of 6 and 7oC is in the expected
range[1,4b] even if the diamides 7-12/10 and 7-12/6 are
generated from two monodendrons with highly dissimilar
alkyl groups. The enthalpy changes associated with the
1
0.17 kcalmol ). However, both on heating and on cooling
1
isotropization of 7-12/10 (0.87 kcalmol ) and 7-12/18
an isotropization transition can be seen on TOPM. In this
case, mesophase formation is slow owing to the broad
polydispersity of the sample. In view of its birefringence and
1
1
(0.76 kcalmol ) are close to that of 7-12/12 (1.22 kcalmol ).
This demonstrates that even diamides with dissimilar but long
Table 1. Thermal characterization of 7-m/n, 8 ± 12/18, and 19 by DSC.
1
Phase transition [8C] and corresponding enthalpy changes [kcalmol
]
Compound
Heating[a]
Cooling
7 ± 12/4
k1 47 (6.32) k2 76 (10.26) i
k1 76 (10.55) i
i 28 ( 7.30) k1
7 ± 12/6
7 ± 12/10
7 ± 12/12
7 ± 12/18
8 ± 12/18
7 ± 18/4
7 ± 18/6
7 ± 18/10
7 ± 18/18
19
k1 43 (9.93) k2 53 (1.20) Fh 92 (0.21) i
k1 43 (9.60) Fh 91 (0.20) i
i 75 ( 0.17) Fh 27 ( 9.98) k1
i 115 ( 0.89) Fh 35 ( 10.31) k1
i 117 ( 1.16) Fh 45.5 ( 15.55) k1
i 89 ( 0.67) Fh 45 ( 19.98) k1
i 21 ( 21.47) k1
k1 47 (9.90) Fh 122 (0.97) i
k1 47 (10.46) Fh 122 (0.99) i
k1 74.5 (16.11) Fh 123 (1.22) i
k1 74 (16.10) Fh 122 (1.27) i
k1 65 (23.90) Fh 95 (0.76) i
k1 61 (20.06) Fh 95 (0.75) i
k1 35 (9.79) k2 47 (28.81) i
k1 32 (22.55) i
k1 63 (3.08) k 65 (1.76) k2 74 (22.98) i
k1 65 (8.62) k2 70 (12.26) k3 74 (2.28) i
k1 49 (11.89) k2 72 (18.06) i
k1 44 (0.84) k2 67 (19.88) i
k1 59 (0.74) k2 70 (21.64) i
k1 64 (5.31) k2 70 (15.66) i
k1 67 (32.38) k 70 (34.98) k2 95 (46.24) i
k1 67 (31.90) k 73 (45.24) k2 94 (53.47) i
k1 46 (5.22) n 95 (0.23) i
i 52 ( 20.73) k1
i 54 ( 20.36) k2 39 ( 0.41) k1
i 50 ( 20.92) k1
i 55 ( 37.23) k1
i 34 g
k1 47 (0.45) n 92 (0.22) i
[a] Data from the first heating and cooling scans are on the first line, and data from the second heating are on the second line; k ˆ crystalline, g ˆ glassy, n ˆ
nematic, i ˆ isotropic, Fh ˆ hexagonal columnar.
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V. Percec et al.
FULL PAPER
alkyl tails in the following or-
der: 22.5 Š (7-12/6), 24.5 Š (7-
12/10), 26.0 Š (7-12/12), and
28.3 Š (7-12/18). The difference
between the column diameter
obtained from fully extended
all-trans conformations of alkyl
tails and the experimental one
obtained by XRD is the result
of alkyl tail shrinkage. This
shrinkage is calculated as given
in expression 1, where Rext ˆ a-
verage measured radius for the
model based on fully extended
conformation (19.6 Š), Rexp
ˆ
radius determined by XRD
(13.0 Š), and Rcore ˆ radius of
rigid aromatic core including
methoxy
groups
(6.15 Š,
Scheme 3).
A
shrinkage of
48% of alkyl tails in their
melted state would be required.
Rext Rexp
%shrinkage ˆ
 100 (1)
Rext Rcore
In a previous publication[22b]
from our laboratories, we re-
ported that 1,2-bis[3,4,5-tris-
(dodecan-1-yloxy)benzamide]
ethanes (12-AG-DA) self-as-
semble into supramolecular cyl-
inders with
a diameter of
34.3 Š. These cylinders self-or-
ganize in a Fh LC phase. XRD
results combined with density
Scheme 3. Self-assembly of 7-12/12 into supramolecular cylindrical dendrimers that self-organize in a Fh lattice
and of 19 in a three-cylindrical bundle supramolecular dendrimer.
measurements demonstrated a
model in which two side-by-
lack of any Bragg-like X-ray diffraction (see Table 4), the
mesophase of 19 is nematic. Detailed characterization of
polymer 19 will be discussed later.
side 12-AG-DA molecules form a layer 4.60 Š in thickness.
An ABAB stacking of two adjacent pairs of side-by-side 12-
AG-DA molecules rotated by 908 around the column axis
produces a 9.2 Š quasi-repeat unit. Hydrogen bonding along
the column axis was demonstrated to be responsible for this
self-assembly process[22b] (see Figures 1 and 6 in ref. [22b]).
Compounds 7-12/6, 7-12/10, 7-12/12, and 7-12/18 produce a
Fh LC phase from supramolecular cylinders comprising only
one 7-m/n molecule per 4.6 Š column layer (Table 2). If we
compare the a parameter of the hexagonal lattice of 7-12/12
(26.0 Š), which has the same alkyl chain length as 12-AG-DA,
with the a parameter of the equivalent 12-AG-DA (a ˆ
34.3 Š) reported previously,[22b] we obtain a ratio of 1.35
Structural analysis of benzamides 7-m/n: Bragg diffraction
peaks corresponding to lattice spacing in a ratio of 1:1/
p p
3:1:/ 4 which are characteristic of a 2-D Fh lattice are
exhibited at small angles by the benzamides 7-12/6, 7-12/10,
7-12/12, and 7-12/18 in their LC phase. The diameter of the
supramolecular cylinders self-assembled from these benza-
mides (a, Š in Table 2) increases with increasing length of the
Table 2. Characterization of 7 ± 12/n by XRD.
p
p
which is fairly close to 2 (Scheme 4). This ratio should be
2
[a]
T
d100 d110 d200 < d100
>
a[b] R[b] S[b] 1[c]
[Š] [Š] [Š] [gcm
m[d]
if the intracolumnar repeat and the columnar structures are
the same in both cases, except that in 12-AG-DA there were
two adjacent molecules per column cross-section[22b] and only
one in the present benzamide 7-12/12. The cross-section areas
of these two columns should be in the ratio 2:1. Scheme 3
(middle-left and center) shows the side view (left) and top
view (center) of the hydrogen-bonded supramolecular col-
umn obtained from 7-12/12 containing only methoxy groups
3
Compound [8C] [Š] [Š] [Š] [Š]
]
7 ± 12/6
80 19.5 11.2 9.7 19.5
80 21.1 12.3 10.6 21.2
80 22.5 12.9 11.1 22.5
80 24.5 14.1 12.3 24.5
22.5 11.3 13.0 0.97
24.5 12.3 14.1 0.96
26.0 13.0 15.0 0.98
28.3 14.2 16.4 0.95
1.0
1.0
1.0
1.0
p
7 ± 12/10
7 ± 12/12
7 ± 12/18
p
p
p
p
[a] <d100 >ˆ (d100
‡
3d110
‡
4d200)/3. [b] aˆ 2d100 3, Rˆ d100
/
3, Sˆ 2R/ 3.
[c] Experimental density at 208C. [d] m ˆ Number of molecular units per 4.6 Š
stratum of the column.
1074
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Liquid Crystalline Superlattices
1070±1083
cores with the aromatic rings
rotated out of the plane of the
amide groups accounts for fill-
ing the core space and is sche-
matically illustrated on the bot-
tom-left part of Scheme 3. This
out-of-plane arrangement of
the benzene and amide groups
is in agreement with the near
60o dihedral angle of the two
benzene rings, that is well-es-
tablished for benzanilide and
related compounds.[23]
Structural analysis of binary
mixtures of benzamide 7-12/12
with polymer 19: Binary mix-
tures of 7-12/12 with polymer 19
Scheme 4. Comparison of the supramolecular columns generated by the self-assembly of 7-12/12 and of the 1,2-
bis[3,4,5-tris(dodecan-1-yloxy)benzamido]ethane 12-AG-DA (see ref. [22b] for details).
(Mn ˆ 55095,
Mw/Mn ˆ 1.64)
instead of dodecyloxy groups (for simplicity). The geometry
of the single molecule was first optimized by MOPAC
quantum mechanics program using the MNDO method.
Intermolecular stacking was then optimized by using the
CERIUS-2 Open Force Field and the periodic boundary
condition in the column direction. Molecules were initially
positioned with the projections of their long axes at right
angles to each other. The two types of molecules with
alternating orientations are shown lighter and darker for
clarity. Strong hydrogen bonds are shown by the model to
develop between amide hydrogen and oxygen in the column
direction, their length being 2.05 Š and 2.37 Š respectively.
The distance between similarly oriented molecules along the
column axis is 9 Š according to the model or an average
distance of 4.5 Š between molecules. This compares favour-
ably with the experimental value of 4.6 Š obtained by X-ray
structure analysis (Table 2). A circle of 12.3 Š diameter is
drawn in the top view of the model (Scheme 3) as a rough
indication of the extent of the rigid core of the column, which
includes methoxy groups. This criss-cross arrangement of
were prepared from CH2Cl2 solutions. Figure 3 presents the
DSC traces of the first and second heating and cooling scans
of 7-12/12, 19 and of their binary mixtures. The DSC heating
scan after annealing at 558C for 12 h was almost identical to
the first DSC heating scan and its results are summarized in
Table 2. A hexagonal columnar (Fh) liquid crystalline phase
was produced for mixtures containing more than 80 mol% of
7-12/12. The mixtures containing between 60 and 20 mol% of
7-12/12, exhibit a new phase. The mixture containing 60 to
80 mol% of 7-12/12 has a biphasic region. The results of the
thermal characterization are summarized in Table 3. The
range of the new phase is marked with dotted lines. Figure 4
presents the dependence of transition temperatures on com-
position for all mixtures. The range of the new phase is
marked with dotted lines. Table 4 presents the results of XRD.
The most intriguing feature of the X-ray diffractogram of the
new phase is the presence of a 45 Š reflection, that is, cor-
responding to twice the spacing of the strongest peak which, in
the case of ordinary Fh phase in pure 7-12/12, indexed as 10.
Further, there is the fact that pure polymer does not develop
Figure 3. DSC traces of the mixtures of 19 (Mn ˆ 55095, Mw/Mn ˆ 1.64) with 7-12/12 (mol/mol): first heating (left); first cooling (center); second heating (right)
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V. Percec et al.
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Table 3. Thermal characterization of 19/7 ‡ 12/12 mixtures by DSC.
1
19/7 ‡ 12/12
Phase transitions [8C] and corresponding enthalpy changes [kcalmol ]
(mol/mol)
Heating[a]
Heating after annealing[b]
Cooling
i 34 g
100/0
90/10
80/20
70/30
60/40
50/50
40/60
30/70
20/80
10/90
0/100
k1 46 (5.22) n 95 (0.23) i
k1 47 (0.45) n 92 (0.22) i
k1 45 (3.94) n 99 (0.31) i
g 6 g 30 n 98 (0.31) i
k1 47 n 92 (0.20) i
g 25 k1 42 (2.5) Fh 100(0.30) i
k1 39 (4.19) Fh 81 (0.18) i
i 66 ( 0.11) n 46 g 14 g
k1 42 (5.07) Fh 103 (0.32) i
k1 38 (2.07) Fh 103 (0.42) i
k1 46 (7.59) Fh 106 (0.43) i
k1 42 (3.23) Fh 107 (0.55) i
k1 47 (9.6) Fh108 (0.45) i
k1 45 (5.02) Fh 109 (0.59) i
k1 33 k2 61 (10.43), k3 75 (3.25) Fh107(0.64) i
k1 47 (6.58) Fh 108 (0.6) i
k1 43 k2 64 (13.69) k3 77 (3.2) Fh 110 (0.51) i
k1 50 (7.11) Fh 111 (0.57) i
k1 43 k2 67 k3 77 (46.3) Fh 115 (1.3) i
k1 54.03 (10.39) Fh 114.4 (0.86) i
k1 76 (39.15) Fh121 (0.75) i
k1 59 (13.04) Fh 120 (0.98) i
k1 76 (35.29) Fh 121 (0.75) i
k1 61 (6.07) 70 (8.39) Fh 121(0.89) i
k1 75 (16.11) Fh 123 (1.22) i
k1 74 (16.1) Fh 122 (1.27) i
i 79 ( 0.16) Fh 33 g
k1 49 (8.04) Fh 107 (0.55) i
k1 51 (9.86) Fh 108 (0.6) i
i 88 ( 0.31) Fh 28 ( 3.19) k1
i 93 ( 0.41) Fh 32 ( 4.2) k1
i 96 ( 0.46) Fh 35 ( 5.92) k1
i 111 ( 0.48) Fh 37 ( 6.89) k1
i 107 ( 0.67) Fh 40 ( 10.58) k1
i 112 ( 0.74) Fh 44 ( 12.55) k1
i 114 ( 0.84) Fh 46 ( 13.84) k1
i 116 ( 1.16) Fh 46 ( 15.55) k1
k1 50 (10.24) Fh 108 (0.6) i
k1 51 (6.24) Fh 111(0.58) i
k1 55 (11.58) Fh 114 (0.83) i
k1 67 (9.91), 74 (1.42), 79 (0.42) Fh 120 (1.14) i
k1 74 (19.69) Fh 122(0.95) i
[a] Data from the first and the second heating scans are on the first and the second line respectively. The cooling scan data are from the first cooling. [b]
Annealed at 558C for 12 h ; k ˆ crystalline, g ˆ glassy, n ˆ nematic, i ˆ isotropic, Fh ˆ hexagonal columnar.
Figure 4. Dependence of transition temperature on composition for the mixtures of 19 (Mn ˆ 55095, Mw/Mn ˆ 1.64) with 7-12/12: a) first heating; b) first
!
~
&
*
cooling; c) second heating. : Tk1±Fh; Tk1±n or Tk1±k2 and their reverse transitions; : Tk2±k3
;
: Tk3±Fh and their reverse transitions; : TFh±i or Tn±i and their
1
reverse transitions; d) enthalpy changes associated with the TFh±i transition. Tˆ termperature in 8C. E ˆ isotropisation enthalpy in kcalmru
.
Table 4. X-ray characterization of 19/7 ± 12/12 mixtures.
12/12 ˆ 2/8. When polymer 19
with Mn ˆ 58800 and Mw/Mn ˆ
2.16 was used to prepare binary
mixtures with 7-12/12, a similar
trend was observed except that
a biphasic region was observed
for the isotropization transitions.
These results can be ex-
plained by postulating a new
type of columnar liquid crystal
phase with a 2-D hexagonal
superlattice which is only
formed in the case of mixtures.
The structure of this superlat-
[a]
19/7 ± 12/12
T
Superlattice
d100
d110
[Š]
d200
[Š]
< d100
[Š]
>
a[b]
[Š]
(mol/mol)
[8C]
reflection [Š]
[Š]
100/0[c]
80/20[d]
60/40[e]
50/50[f]
30/70[f]
20/80[f]
10/90[f]
0/100[f]
60
65
60
66
85
85
85
90
43.0 d
44.8
45.0 w
46.0 wb
vvw
±
23.0 d
22.3
22. 2
22.2
22.9
22.9
22.9
22.5
12.8
22.3
22.2
22.2
22.9
22.9
22.9
22.5
25.7
25.6
25.6
26.4
26.1
26.1
26.0
±
±
12.9 vw
13.0
11.3
p
p
p
[a] < d100 >ˆ (d100
‡
3d110
‡
4d200)/3. [b] a ˆ 2 < d100 > / 3. [c] Annealed overnight at 608C. [d] Annealed 5 h
at 658C. [e] Cooled from isotropic state at 68Cmin 1. [f] As received. (vw ˆ very weak, vvw ˆ very very weak,
wb ˆ wide broad, w ˆ wide, d ˆ diffuse).
tice viewed along the columns is shown in Scheme 5. The
circles represent individual columns and the three-pointed
stars represent the PMA strands which contain one or several
backbones. The polymer backbones are situated on the nodes
of a regular hexagonal lattice (superlattice) whose unit cell
size is twice the size of the unit cell (subcell) of the sublattice
sharp diffraction peaks even after prolonged annealing.
Instead it shows two diffuse peaks (centered around 23 and
42 Š) indicating short-range order of the type found as long-
range order in the mixtures. Characteristically, the 43 Š dif-
fraction peak decreases in intensity as the proportion of
polymer decreases and it disappears around the ratio of 19 /7-
1076
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Chem. Eur. J. 1999, 5, No. 3

Liquid Crystalline Superlattices
1070±1083
appropriate for the above structure but a 4/1 mixture already
displays a well ordered superlattice, presumably with some
distortion. The mechanism of coassembly of this columnar
superlattice is shown schematically in Scheme 6.
Mechanism of self-assembly of the polymer(s) coated with a
three-cylindrical bundle supramolecular dendrimer: The self-
assembly of the bis- and twin-dendritic benzamides described
here relies on the ability of two successive molecules rotated
by 908 to form a disc-like shape and on the intermolecular
hydrogen bonding between building blocks along the long axis
of the supramolecular cylinder (Scheme 3). This molecular
wire type hydrogen bonding process has been demonstrated
and exploited in the construction of only a few other Fh LC
assemblies.[16b,22] More frequently, the stabilization of a Fh LC
assembly is accomplished through intermolecular hydrogen
bonding that occurs perpendicular to the column axis. Two
mechanisms are encountered in this case. In the first, hydro-
gen bonding between complementary building blocks gener-
ates discotic molecules that self-assemble in a column.[24] In
the second case, an intramolecular hydrogen bonding mech-
anism occurs that extends the rigidity of a discotic molecule
which generates the supramolecular column.[25] The main
difference between the axial versus transverse hydrogen
bonding mechanisms in the construction of these supra-
molecular columns is that the axial one generates a supra-
Scheme 5. Schematic representation of the supramolecular columnar
hexagonal liquid crystalline superlattice.
formed by individual columns. The true unit cell drawn with
thick solid lines has four times the area of the subcell drawn
with dashed lines and contains four supramolecular columns
of benzamides. In this way microphase separation between
the PMA backbone(s) and aliphatic chains is achieved, while
maintaining close proximity with three nearest neighbour
columns as required by molecular connectivity.
The reason that the pure polymer does not form an ordered
hexagonal columnar structure is explained by the fact that one
out of four columns in the
above unit cell (columns cross-
hatched in the Schemes 3
and 5) is not in direct contact
with the segregated polymer
backbones hence a hexagonal
columnar structure does not
satisfy the conflicting require-
ments for molecular connectiv-
ity, space filling and microphase
separation. A three-cylindrical
bundle like the one generated
from 19 can theoretically form a
oblique columnar lattice in-
stead. Nevertheless, no Bragg-
like diffraction was obtained
and therefore, as discussed in
the thermal characterization
section, polymer 19 forms only
a nematic phase. However, the
addition of free low molar mass
benzamide 7-12/12 allows the
formation of the columnar su-
perlattice as the added com-
pound is free to self-assemble
and fill the hatched columns. 7-
12/12 also can coassemble with
the polymer side groups and
enhance the perfection of the
three-cylinder bundle supramo-
lecular dendrimer. A polymer
19 to monomer 7-12/12 molar
ratio of 3/1 or less is most
Scheme 6. Coassembly of the hexagonal columnar liquid crystalline superlattice from 7-12/12 and 19.
Chem. Eur. J. 1999, 5, No. 3
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1077

V. Percec et al.
FULL PAPER
raphy (HPLC) using
a
Perkin-Elmer Series 10 high-pressure liquid
molecular polymer-backbone-like effect. This effect plays an
important role both during the self-assembly and during the
polymerization of the twin-dendritic benzamide monomer.
Since the shape of two molecules of 7-12/12 successively
rotated by 908 is disc-like, at the first sight the architecture of
polymer 19 should be almost identical to that of a polymer
with conventional disc-like mesogenic side groups except that
it contains two spacers from each disc-like side group. Side
chain liquid crystalline polymers with disc-like mesogenic side
groups have been always reported to exhibit a thermotropic
columnar mesophase.[26] However, in all these cases[26] the
single spacer connecting the disc-like mesogen to the polymer
backbone was at least twice as long as that of the alkyl
substituents attached to the disc-like side groups. This very
long spacer length was considered the main structural
requirement for the formation of a columnar lattice decou-
pled from the polymer backbone. Nevertheless, even in these
cases, when X-ray analysis of the side chain polymer with
discotic side groups was available, it indicated a rectangular
columnar rather than a hexagonal columnar lattice.[26c,d] In our
three-cylinder bundle supramolecular dendrimer the spacer
attaching the twin dendritic bisamide to the backbone is even
shorter than the alkyl groups of the diamide (i.e. eleven versus
twelve methylene groups). It is this shorter spacer length and
the two spacers to a disc-like side group that determine the
self-assembly of this new architectural supramolecular den-
drimer motif. A simple geometrical calculation shows that
most probably only one backbone in an almost all-trans
extended conformation penetrates between the three-column
bundle, although if the conformation is different, more than
one backbone is not excluded. In addition, the hydrogen
bonding along the cylinder axis is required to stabilize the
columnar and the very compact three-cylinder bundle supra-
molecular dendrimer assembly which coats the extended
backbone. This mechanism should be applicable to the
elaboration of functional libraries of hexagonal columnar
superlattices.
chromatograph equipped with an LC-100 column oven, Nelson Analyt-
ical 900 Series integrator data station, and two Perkin-Elmer PL gel
columns of 5  102 and 1  104 Š. THF was used as solvent. Detection was
by UV absorbance at 254 nm at 408C. Relative molecular weights were
determined by reference to polystyrene standards. Thermal transitions
were measured on a Perkin-Elmer DSC-7 differential scanning calorimeter
(DSC). In all cases, the heating and cooling rates were 108Cmin 1. The
transition temperatures were reported as the maxima and minima of their
endothermic and exothermic peaks. Indium was used as calibration
standard. An Olympus BX-40 optical polarized microscope (100 Â
magnification) equipped with a Mettler FP 82 hot stage and a Mettler FP
80 central processor was used to verify thermal transitions and characterize
anisotropic textures.
X-ray diffraction (XRD) patterns were recorded by using either a helium-
filled flat plate wide angle (WAXS) camera or a pinhole-collimated small
angle (SAXS) camera, and also by using an Image Plate area detector
(MAR Research) with a graphite-monochromatized pinhole-collimated
beam and a helium tent. The samples, in glass capillaries, were held in a
temperature-controlled cell (Æ0.18C). Ni-filtered CuKa radiation was used.
Densities (1) were determined by flotation in gradient columns. Elemen-
tary analysis was performed at MHW laboratories in Phoenix. Molecular
modeling was performed by using either CSC Chem3D from Cambridge
Scientific Computing Inc., MacroModel (Columbia University) on a
Silicon Graphics machine, or MOPAC programme using CERIUS 2 force
field on a Silicon Graphics machine.
Synthesis
3,4,5-tris(n-dodecan-1-yloxy)benzene (1-12): To a round-bottom flask
equipped with a N2 inlet ± outlet containing a stirring mixture of 1,2,3-
trihydroxybenzene (31.5 g, 0.25 mol) and K2CO3 (249.0 g, 1.20 mol) in
DMF (400 mL) at 608C, 1-bromododecane (176.5 g, 0.60 mol) was added in
small portions over 10 min. After 4 h at 608C, the reaction mixture was
poured into vigorously stirring ice/H2O (2 L). The creamy, granular solid
was filtered and washed with H2O. After recrystallization from acetone,
94.8 g (75.1%) of white crystals were obtained. Purity (HPLC), 99‡%;
m.p. 39 ± 408C (ref. [16]: 39.5 ± 40.58C); TLC (20/1 hexane/EtOAc): Rf ˆ
0.68; 1H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 0.88 (t, 9H, CH3, J ˆ
6.6 Hz), 1.26 (overlapped peaks, 48H, CH3(CH2)8), 1.47 (m, 6 H,
CH2(CH2)2O), 1.78 (m, 6H, CH2CH2O), 3.90 (overlapped t, 6H, CH2O,
J ˆ 6.3 Hz), 6.55 (d, 2H, 4,6 position, J ˆ 8.1 Hz), 6.90 (d, 1H, 5 position,
J ˆ 8.4 Hz); 13C NMR (50 MHz, CDCl3, 208C, TMS): d ˆ 14.1 (CH3), 22.7
(CH3CH2), 26.1 (CH2CH2CH2O), 29.4 (CH3CH2CH2CH2), 29.5
(CH3CH2CH2CH2(CH2)5), 29.9 (CH2CH2O, 1,3 position), 30.3 (CH2CH2O,
2 position), 31.9 (CH3CH2CH2), 69.0 (CH2O, 1,3 position), 73.3 (CH2O,
2 position), 106.7 (4,6 position), 123.1 (5 position), 138.4 (2 position), 153.4
(1,3 position); elemental analysis calcd (%): C 79.93, H 12.46; found: C
79.73, H 12.63.
Experimental Section
3,4,5-Tris(n-octadecan-1-yloxy)benzene (1-18): Compound 1-18 was syn-
thesized by the same general procedure described for the synthesis of 1-12.
From 1,2,3-trihydroxybenzene (5.0 g, 0.04 mol), K2CO3 (33.2 g, 0.24 mol),
and 1-bromooctadecane (46.7 g, 0.14 mol) in DMF (140 mL) at 608C, 27.9 g
(79.3%) of white crystals were obtained after recrystallization from
acetone. Purity (HPLC), 99‡%; m.p. 64 ± 658C; TLC (20/1 hexane/
EtOAc): Rf ˆ 0.70. 1H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 0.89 (t,
9H, CH3, J ˆ 6.1 Hz), 1.25 (overlapped peaks, 90H, CH3(CH2)15), 1.79 (m,
6H, CH2CH2O), 4.08 (overlapped t, 6H, CH2O, J ˆ 6.2 Hz), 6.64 (d, 2H,
4,6 position, J ˆ 8.0 Hz), 7.00 (d, 1H, 5 position, J ˆ 8.3 Hz); 13C NMR
(50 MHz, CDCl3, 208C, TMS): d ˆ 13.9 (CH3), 22.5 (CH3CH2), 26.8
(CH2CH2CH2O), 29.1 (CH3CH2CH2CH2), 29.7 (CH3CH2CH2CH2(CH2)11),
30.1 (CH2CH2O), 31.9 (CH3CH2CH2), 69.2 (CH2O, 1,3 position), 73.5
(CH2O, 2 position), 106.7 (4,6 position), 123.4 (5 position), 138.7 (2 posi-
tion), 153.7 (1,3 position).
Materials: 1-Bromobutane (97%), 1-bromohexane (97%), 1-bromodecane
(98%), 1-bromododecane (98%), 1-bromooctadecane (97%), methyl
3,4,5-trihydroxybenzoate (98%), SOCl2 (97%), hydrazine monohydrate
(98%) (all from Aldrich), 1,2,3-trihydroxybenzene (99%), DMF (99.9%),
pyridine (99.9%), graphite powder (Grade No.38), P2O5 (99.1%), CH3I
(99%), NaH (80% dispersion in oil) (all from Fisher), 1-bromoundecanol
(99%), and methacryloyl chloride (97%) (both from Fluka) were used as
received. The nitrating agent (25% HNO3 on silica gel by titration with 1n
NaOH using phenolphthalein as an indicator) was prepared according to a
literature procedure[14] and was used after drying in air for seven days.
Benzene (thiophene-free, Fisher Scientific) used for the free radical
polymerizations was washed three times with concentrated H2SO4 and
dried over MgSO4. CH2Cl2 (ACS reagent grade, Fisher Scientific) used for
the preparation of blends was refluxed over CaH2 and freshly distilled
before use. Pyridine was dried over KOH, distilled and stored over KOH.
All other chemicals were commercially available and were used as
received.
3,4,5-Tris(n-dodecan-1-yloxy)-1-nitrobenzene (2-12): Compound 2-12 was
synthesized by the nitration of 1-12 with SiO2 ´ HNO3 according to a
literature procedure.[14±16] To a stirred suspension of HNO3 (63.0 g,
0.25 mol, 25% on SiO2) in CH2Cl2 (400 mL) was rapidly added 1-12
(31.6 g, 0.05 mol) in CH2Cl2 (100 mL). The resulting red solution was
stirred at room temperature for 15 min, after which time the SiO2 was
filtered and washed several times with CH2Cl2. The solvent was evaporated
on a rotary evaporator and the resultant orange oil was dissolved in
Techniques: 1H NMR (200 MHz) spectra were recorded on a Varian
Gemini 200 MHz spectrometer. The purity of the products was determined
by a combination of thin-layer chromatography (TLC) on silica gel plates
(Kodak) with fluorescent indicator and high pressure liquid chromatog-
1078
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Liquid Crystalline Superlattices
1070±1083
hexanes (50 mL). Upon addition of MeOH (600 mL) with vigorous
shaking, the product separated as a yellow solid. The solid was filtered,
washed with cold MeOH, and dried in air. Recrystallization from acetone
yielded 28.0 g (82.8%) of white crystals. Purity (HPLC), 99‡%; m.p. 54.5 ±
55.58C (ref. [27]: 58 ± 598C); TLC (20/1 hexane/EtOAc): Rf ˆ 0.49;
1H NMR (200 MHz, CDCl3 , 208C, TMS): d ˆ 0.88 (t, 9H, CH3 , J ˆ
5.9 Hz), 1.26 (overlapped peaks, 48H, CH3(CH2)8), 1.47 (m, 6 H,
CH2(CH2)2O), 1.78 (m, 6H, CH2CH2O), 4.04 (overlapped t, 6H, CH2O,
J ˆ 6.3 Hz), 7.47 (s, 2H, ArH); 13C NMR (50 MHz, CDCl3, 208C, TMS):
d ˆ 14.1 (CH3), 22.7 (CH3CH2), 26.1 (CH2CH2CH2O), 29.4
(CH3CH2CH2CH2), 29.5 (CH3CH2CH2CH2(CH2)5), 29.9 (CH2CH2O,
3,5 position), 30.3 (CH2CH2O, 4 position), 31.9 (CH3CH2CH2), 69.3
(CH2O, 3,5 position), 73.7 (CH2O, 4 position), 101.9 (ortho to NO2), 143.0
(ipso to NO2), 144.0 (para to NO2), 152.6 (meta to NO2); elemental analysis
calcd (%): C 74.61, H 11.48, N 2.07; found: C 74.24, H 11.88, N 2.02.
three-neck flask containing a Teflon-coated magnetic stirrer was charged
with methyl 3,4,5-trihydroxybenzoate (11.1 g, 0.06 mol), K2CO3 (51.0 g,
0.36 mol), and DMF (300 mL). The mixture was purged with N2, then
1-bromobutane (32.9 g, 0.24 mol) was added dropwise. The reaction
mixture was heated at 608C for 8 h with stirring under N2, then it was
cooled to room temperature. The reaction mixture was dissolved in Et2O
(400 mL) and transferred to a separatory funnel. The mixture was washed
four times with H2O (700 mL), once with dilute HCl (500 mL), and once
with H2O (500 mL). The organic phase was separated and dried over
MgSO4. The solvent was evaporated and the crude product was passed
through a short column of basic Al2O3 using CH2Cl2 as eluent to yield 15.2 g
(69.0%) of a liquid. Purity (HPLC), 99‡%; TLC (10/1 hexane/EtOAc):
1
Rf ˆ 0.54; H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 0.89 (t, 9H, CH3,
J ˆ 6.3 Hz), 1.29 (m, 6H, CH2(CH2)2OPh), 1.75 (m, 6H, CH2CH2OPh), 3.90
(s, 3H, CO2CH3), 4.00 (m, 6H, CH2OPh, J ˆ 6.3 Hz), 7.24 (s, 2H, ArH);
13C NMR (50 MHz, CDCl3, 208C, TMS): d ˆ 14.1 (CH3), 20.7 (CH2CH3),
32.9 (CH2CH2OPh), 73.4 (CH2OPh), 107.7 (ortho to CO2CH3), 124.6 (ipso
to CO2CH3), 142.3 (para to CO2CH3), 152.8 (meta to CO2CH3), 166.9
(PhCO2CH3).
3,4,5-Tris(n-octadecan-1-yloxy)-1-nitrobenzene (2-18): Compound 2-18
was synthesized by the same general procedure described for the synthesis
of 2-12. Over a stirred suspension of HNO3 (39.2 g, 0.11 mol, 25% on SiO2)
in CH2Cl2 (300 mL) was rapidly added 1-18 (20.0 g, 0.023 mol) in CH2Cl2
(70 mL). Recrystallization from acetone yielded 17.5 g (83.1%) of white
crystals. Purity (HPLC), 99‡%; m.p. 76.5 ± 77.58C; TLC (20/1 hexane/
EtOAc): Rf ˆ 0.50; 1H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 0.89 (t,
9H, CH3, J ˆ 6.2 Hz), 1.30 (overlapped peaks, 90H, CH3(CH2)15), 1.81 (m,
6H, CH2CH2O), 4.03 (overlapped t, 6H, CH2O, J ˆ 6.3 Hz), 7.47 (s, 2H,
ArH); 13C NMR (50 MHz, CDCl3, 208C, TMS): d ˆ 14.0 (CH3), 22.8
(CH3CH2), 26.0 (CH2CH2CH2O), 29.2 (CH3CH2CH2CH2), 29.7
(CH3CH2CH2CH2(CH2)11), 30.0 (CH2CH2O, 3,5 position), 30.3 (CH2CH2O,
4 position), 31.9 (CH3CH2CH2), 69.3 (CH2O, 3,5 position), 73.7 (CH2O,
4 position), 101.8 (ortho to NO2), 143.1 (ipso to NO2), 144.2 (para to NO2),
152.6 (meta to NO2).
Methyl 3,4,5-tris(n-hexan-1-yloxy)benzoate (4-6): Compound 4-6 was
synthesized by the same general procedure described for the synthesis of
4-4. From methyl 3,4,5-trihydroxybenzoate (11.1 g, 0.06 mol), K2CO3
(51.0 g, 0.36 mol) and 1-bromohexane (39.6 g, 0.24 mol) in DMF
(300 mL) at 608C, 19.7 g (72.6%) of a liquid was obtained. Purity (HPLC),
99‡%; TLC (10/1 hexane/EtOAc): Rf ˆ 0.54; 1H NMR (200 MHz, CDCl3,
208C, TMS): d ˆ 0.89 (t, 9H, CH3, J ˆ 6.2 Hz), 1.27 (overlapped m, 18H,
CH3(CH2)3), 1.75 (m, 6H, CH2CH2OPh), 3.91 (s, 3H, CO2CH3), 4.02 (m,
6H, CH2OPh, J ˆ 6.3 Hz), 7.24 (s, 2H, ArH); 13C NMR (50 MHz, CDCl3,
208C, TMS): d ˆ 14.0 (CH3), 22.7 (CH2CH3), 26.2 ± 30.1 ((CH2)2), 31.9
(CH2CH2CH3), 52.0 (CO2CH3), 69.1 (CH2OPh, meta to CO2CH3), 73.4
(CH2OPh, para to CO2CH3), 107.7 (ortho to CO2CH3), 124.6 (ipso to
CO2CH3), 142.3 (para to CO2CH3), 152.8 (meta to CO2CH3), 166.9
(PhCO2CH3).
3,4,5-Tris(n-dodecan-1-yloxy)-1-aminobenzene (3-12): Compound 3-12
was synthesized by the reduction of 2-12 with NH2NH2 ´ H2O over graphite
powder.[16,17] Compound 2-12 (40.6 g, 0.60 mol), NH2NH2 ´ H2O (15.0 g,
0.20 mol), and graphite (30.0 g) were heated in reluxing EtOH (400 mL)
for 24 h under an Ar atmosphere. The cooled mixture was diluted with
CH2Cl2 (400 mL). Graphite was filtered and washed several times with
CH2Cl2. The colorless solution was concentrated in a rotary evaporator and
the resultant white solid was dissolved in CH2Cl2 (300 mL). After
precipitation in MeOH (2 L), the obtained white solid was collected by
filtration and washed with cold MeOH. After drying under vacuum over
P2O5, 36.0 g (92.8%) of a white powder was obtained. Purity (HPLC),
99‡%; m.p. 71.5 ± 72.58C (ref. [16]: 758C); TLC (10/1 hexane/EtOAc):
Methyl 3,4,5-tris(n-decan-1-yloxy)benzoate (4-10): A 500 mL 3-neck flask
containing a Teflon-coated magnetic stirrer was charged with methyl 3,4,5-
trihydroxybenzoate (5.5 g, 0.03 mol), K2CO3 (25.5 g, 0.18 mol) and DMF
(170 mL). The mixture was sparged with N2, then 1-bromodecane (26.5 g,
0.12 mol) was added dropwise. The reaction mixture was heated at 608C for
8 h with stirring under N2 atmosphere, then it was cooled to RTand poured
into ice/H2O (1 L). The precipitate was filtered and the crude product was
passed through a short column of basic Al2O3 using CH2Cl2 as an eluent.
The product was recrystallized from acetone to yield 11.8 g (65.0%) of
white crystals. Purity (HPLC), 99‡%; m.p. 29 ± 308C (ref. [28]: 298C); TLC
(10/1 hexane/EtOAc): Rf ˆ 0.56; 1H NMR (200 MHz, CDCl3, 208C, TMS):
d ˆ 0.88 (t, 9H, CH3, J ˆ 6.7 Hz), 1.27 (overlapped m, 42H, (CH2)7), 1.78
(m, 6H, CH2CH2OPh), 3.89 (s, 3H, CO2CH3), 4.01 (t, 6H, CH2OPh, J ˆ
6.2 Hz), 7.25 (s, 2H, ArH); 13C NMR (50 MHz, CDCl3, 208C, TMS): d ˆ
14.0 (CH3), 22.6 (CH2CH3), 26.0 ± 30.3 [(CH2)6], 31.9 (CH2CH2CH3), 52.1
(CO2CH3), 69.1 (CH2OPh, meta to CO2CH3), 73.4 (CH2OPh, para to
CO2CH3), 107.9 (ortho to CO2CH3), 124.6 (ipso to CO2CH3), 142.3 (para to
CO2CH3), 152.7 (meta to CO2CH3), 166.8 (PhCO2CH3).
1
Rf ˆ 0.25; H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 0.88 (t, 9H, CH3,
J ˆ 6.3 Hz), 1.26 (overlapped m, 54 H, CH3(CH2)9), 1.46 (m, 6 H,
CH2(CH2)2O), 1.76 (m, 6H, CH2CH2O), 3.46 (bs, 2H, NH2), 3.84 (t, 2H,
CH2O on 4 position, J ˆ 6.4 Hz), 3.91 (t, 4H, CH2O on 3,5 position, J ˆ
6.3 Hz), 5.91 (s, 2H, ortho to NH2); 13C NMR (50 MHz, CDCl3, 208C,
TMS): d ˆ 14.1 (CH3), 22.7 (CH3CH2), 26.1 (CH2CH2CH2O), 29.4
(CH3CH2CH2CH2), 29.5 (CH3CH2CH2CH2(CH2)5), 29.9 (CH2CH2O,
3,5 position), 30.3 (CH2CH2O, 4 position), 31.9 (CH3CH2CH2), 68.8
(CH2O, 3,5 position), 73.5 (CH2O, 4 position), 94.3 (ortho to NH2), 130.2
(para to NH2), 142.3 (ipso to NH2), 153.6 (meta to NH2); elemental analysis
calcd (%): C 78.07, H 12.33, N 2.17; found: C 78.28, H 12.67, N 2.12.
Methyl 3,4,5-tris(n-dodecan-1-yloxy)benzoate (4-12): Compound 4-12 was
synthesized by the same general procedure described for the synthesis of 4-
10. From methyl 3,4,5-trihydroxybenzoate (11.1 g, 0.06 mol), K2CO3
(51.0 g, 0.36 mol), and 1-bromododecane (60.3 g, 0.24 mol) in DMF
(300 mL) at 608C, 30.3 g (73.3%) of white crystals were obtained. Purity
(HPLC), 99‡%; m.p. 438C (ref. [19]: 39 ± 42.58C) ; TLC (10/1 hexane/
EtOAc): Rf ˆ 0.56; 1H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 0.88 (t,
9H, CH3, J ˆ 6.3), 1.27 (overlapped m, 54H, (CH2)9), 1.78 (m, 6H,
CH2CH2OPh), 3.89 (s, 3H, CO2CH3), 4.01 (m, 6H, CH2OPh, J ˆ 6.3), 7.25
(s, 2H, ArH); 13C NMR (50 MHz, CDCl3, 208C, TMS): d ˆ 14.1 (CH3), 22.7
(CH2CH3), 26.1 ± 30.2 ((CH2)7), 31.9 (CH2CH2CH3), 52.1 (CO2CH3), 69.1
(CH2CH2OPh), 73.4 (CH2OPh), 107.7 (ortho to CO2CH3), 124.6 (ipso to
CO2CH3), 142.3 (para to CO2CH3), 152.8 (meta to CO2CH3), 166.9
(PhCO2CH3).
3,4,5-Tris(n-dodecan-1-yloxy)-1-aminobenzene (3-18): Compound 3-18
was synthesized by the same general procedure described for the synthesis
of 3-12. Compound 2-18 (12.0 g, 0.013 mol), NH2NH2 ´ H2O (3.92 g,
0.078 mol), and graphite (11.1 g) were heated in reluxing EtOH (170 mL)
for 24 h under an Ar atmosphere. After recrystalization from a CHCl3/
MeOH (1/1), 10.8 g (93.2%) of a white powder was obtained. Purity
(HPLC), 99‡%; m.p. 74 ± 758C; TLC (10/1 hexane/EtOAc): Rf ˆ 0.27;
1H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 0.88 (t, 9H, CH3, J ˆ 6.3 Hz),
1.26 (overlapped m, 90H), 1.76 (m, 6H, CH2CH2O), 3.43 (bs, 2H, NH2),
3.86 (t, 2H, CH2O on 4 position, J ˆ 6.3 Hz), 3.91 (t, 4H, CH2O on
3,5 position, J ˆ 6.3 Hz), 5.91 (s, 2H, ortho to NH2); 13C NMR (50 MHz,
CDCl3, 208C, TMS): d ˆ 14.1 (CH3), 22.7 (CH3CH2), 26.1 (CH2CH2CH2O),
29.4 (CH3CH2CH2CH2), 29.5 (CH3CH2CH2CH2(CH2)11), 29.9 (CH2CH2O,
3,5 position), 30.3 (CH2CH2O, 4 position), 31.9 (CH3CH2CH2), 68.8 (CH2O,
3,5 position), 73.5 (CH2O, 4 position), 94.3 (ortho to NH2), 130.2 (para to
NH2), 142.3 (ipso to NH2), 153.6 (meta to NH2).
Methyl 3,4,5-tris(n-octadecan-1-yloxy)benzoate (4-18): Compound 4-18
was synthesized by the same procedure described for the preparation of 4-
10. From methyl 3,4,5-trihydroxybenzoate (7.4 g, 0.04 mol), K2CO3 (33.2 g,
0.24 mol), and 1-bromooctadecane (46.6 g, 0.14 mol) in DMF (250 mL) at
608C, 27.1 g (72.1%) of white crystals were obtained. Purity (HPLC),
99‡%; m.p. 61 ± 628C; TLC (10/1 hexane/EtOAc): Rf ˆ 0.56; 1H NMR
Methyl 3,4,5-tris(n-butan-1-yloxy)benzoate (4-4): The synthesis of 4-4 was
performed using a modification of a literature procedure.[18] A 500 mL
Chem. Eur. J. 1999, 5, No. 3
ꢀ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1999
0947-6539/99/0503-1079 $ 17.50+.50/0
1079

V. Percec et al.
FULL PAPER
(200 MHz, CDCl3, 208C, TMS): d ˆ 0.88 (t, 9H, CH3, J ˆ 5.8 Hz), 1.26
(overlapped m, 90H, (CH2)15), 1.80 (q, 6H, CH2CH2OPh), 3.89 (s, 3H,
CO2CH3), 4.01 (t, 6H, CH2OPh J ˆ 6.2 Hz), 7.25 (s, 2H, ArH); 13C NMR
(50 MHz, CDCl3, 208C, TMS): d ˆ 14.0 (CH3), 22.6 (CH2CH3), 26.1 ± 30.5
((CH2)13), 31.9 (CH2CH2CH3), 52.2 (CO2CH3), 69.0 (CH2CH2OPh), 73.1
(CH2OPh), 107.7 (ortho to CO2CH3), 124.6 (ipso to CO2CH3), 142.3 (para
to CO2CH3), 152.8 (meta to CO2CH3), 167.0 (PhCO2CH3).
(1.0 equiv), CH2Cl2, and a catalytic amount of DMF. The reaction flask was
flushed with N2, sealed with a rubber septum, and cooled in an ice bath.
SOCl2 (1.1 equiv) was added dropwise to the cooled reaction mixture. The
ice bath was removed and the reaction mixture was stirred for 1 h. The
solvent was evaporated and the resulting compound was dried under
vacuum. The product was used for the next step without further
purification.
N-[3,4,5-tris(n-butan-1-yloxy) phenyl]-3,4,5-tris (n-dodecan-1-yloxy)benz-
amide (7-12/4): A solution of 3-12 (2.6 g, 4.0 mmol) and 6-4 (1.6 g,
4.0 mmol) in pyridine (80 mL) were refluxed for 2 h. The pale brown
mixture was poured onto ice/H2O, extracted with Et2O, and washed several
times with 5% and concentrated HCl. The crude product was recrystallized
twice from isopropanol to yield 3.2 g (80.3%) of light brown crystals. Purity
(HPLC), 99‡%; m.p. 768C; TLC (10/1 hexane/EtOAc): Rf ˆ 0.17; 1H NMR
(200 MHz, CDCl3, 208C, TMS): d ˆ 0.88 (t, 18H, CH3, J ˆ 6.1 Hz), 1.26
(overlapped m, 60 H, CH3(CH2)9 and CH3CH2), 1.79 (m, 12 H,
PhOCH2CH2), 3.91 (m, 12H, PhOCH2), 6.90 (s, 2H, ortho to NHCO),
7.03 (s, 2H, ortho to COHN), 7.72 (s, 1H, NH); 13C NMR (50 MHz, CDCl3,
208C, TMS): d ˆ 14.0 (CH3), 20.9, 22.7 (CH2CH3), 26.1 (CH2CH2CH2OPh),
29.4 ± 32.9 (CH2CH2OPh and (CH2)7CH2CH3), 69.0, 69.3 (CH2OPh), 99.2
(ortho to NHCO), 105.9 (ortho to CONH), 124.7 (ipso to CONH), 133.8,
134.9 (para to CONH and NHCO), 141.4 (ipso to NHCO), 153.1, 153.3
(meta to CONH and NHCO), 166.1 (CONH).
3,4,5-Tris(n-butan-1-yloxy)benzoic acid (5-4): The synthesis of 5-4 was
performed by using a modification of a literature procedure.[18] In a 125 mL
Erlenmeyer flask containing a Teflon-coated magnetic stir bar was placed
4-4 (14.0 g, 0.038 mol), 95% EtOH (140 mL), and KOH (14.9 g, 0.27 mol).
The mixture was refluxed for 2 h with stirring. The extent of reaction was
followed by TLC. The reaction mixture was cooled to RT and the solution
was acidified with dilute HCl to pH 1. The solution was poured into H2O
(1 L) to precipitate 12.9 g (96.2%) of a white solid. Purity (HPLC), 99‡%;
m.p. 62 ± 638C (ref. [22b]: 65 ± 678C); TLC (10/1 hexane/EtOAc): Rf ˆ 0.
1H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 0.93 (t, 9H, CH3, J ˆ 6.7 Hz),
1.52 (m, 6H, CH3CH2), 1.79 (m, 6H, CH2CH2OPh), 4.04 (m, 6H, CH2OPh),
7.34 (s, 2H, ArH); 13C NMR (50 MHz, CDCl3, 208C, TMS): d ˆ 14.0 (CH3),
20.9 (CH2CH3), 32.9 (CH2CH2OPh), 73.2 (CH2OPh), 107.9 (ortho to
CO2H), 124.7 (ipso to CO2H), 142.5 (para to CO2H), 152.8 (meta to CO2H),
167.0 (PhCO2H).
3,4,5-Tris(n-hexan-1-yloxy)benzoic acid (5-6): Compound 5-6 was synthe-
sized by the same procedure described for the preparation of 5-4. From 4-6
(17.2 g, 0.038 mol) and KOH (14.9 g, 0.27 mol) in 95% EtOH (160 mL),
16.2 g (97.3%) of a white solid was obtained. Purity (HPLC), 99‡%;
m.p. 38 ± 398C (ref. [22b]: 38 ± 408C); TLC (10/1 hexane/EtOAc): Rf ˆ 0;
1H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 0.86 (t, 9H, CH3, J ˆ 6.8 Hz),
1.26 (m, 18H, CH3(CH2)3), 1.75 (m, 6H, CH2CH2OPh), 3.99 (m, 6H,
CH2OPh), 7.33 (s, 2H, ArH); 13C NMR (50 MHz, CDCl3, 208C, TMS): d ˆ
14.1 (CH3), 22.7 (CH2CH3), 26.1 ± 30.3 ((CH2)2), 31.6 (CH2CH2CH3), 69.5
(CH2CH2OPh, meta to CO2H), 73.5 (CH2OPh, para to CO2H), 107.9 (ortho
to CO2H), 124.7 (ipso to CO2H), 142.5 (para to CO2H), 152.8 (meta to
CO2H), 167.0 (PhCO2H).
N-[3,4,5-tris(n-hexan-1-yloxy)phenyl]-3,4,5-tris(n-dodecan-1-yloxy)benz-
amide (7-12/6): Compound 7-12/6 was synthesized by the same procedure
described for the preparation of 7-12/4. From 3-12 (2.6 g, 4.0 mmol) and 6-6
(2.2 g, 4.0 mmol) in pyridine (80 mL), 3.2 g (76.3%) of light brown crystals
were obtained. Purity (HPLC), 99‡%; thermal transitions and corre-
sponding enthalpy changes are summarized in Table 1; TLC (10/1 hexane/
EtOAc): Rf ˆ 0.17; 1H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 0.88 (t,
18H, CH3, J ˆ 5.9 Hz), 1.26 (overlapped m, 72H, CH3(CH2)9 and
CH3(CH2)3), 1.80 (m, 12H, PhOCH2CH2), 3.90 (m, 12H, PhOCH2), 6.90
(s, 2H, ortho to NHCO), 7.03 (s, 2H, ortho to COHN), 7.72 (s, 1H, NH);
13C NMR (50 MHz, CDCl3, 208C, TMS): d ˆ 14.1 (CH3), 22.7 (CH2CH3),
26.1 (CH2CH2CH2OPh), 28.9 ± 32.6 (CH2CH2CH3 and (CH2)7CH2CH3),
69.2, 69.6 (CH2OPh), 99.8 (ortho to NHCO), 106.4 (ortho to CONH), 125.1
(ipso to CONH), 133.8, 134.9 (para to CONH and NHCO), 142.4 (ipso to
NHCO), 153.1, 153.3 (meta to CONH and NHCO), 166.8 (CONH);
elemental analysis calcd (%): C 76.62, H 11.55, N 1.32; found: C 76.54, H
11.49, N 1.22.
3,4,5-Tris(n-decan-1-yloxy)benzoic acid (5-10): Compound 5-10 was syn-
thesized by the same procedure described for the preparation of 5-4. From
4-10 (11.8 g, 19.5 mmol) and KOH (7.7 g, 0.14 mol) in 95% EtOH
(110 mL), 9.49 g (82.3%) of a white solid was obtained. Purity (HPLC),
99‡%; m.p.51 ± 528C (ref. [22b]: 53 ± 548C); TLC (10/1 hexane/EtOAc):
Rf ˆ 0; 1H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 0.88 (t, 9H, CH3, J ˆ
6.9 Hz) 1.27 (overlapped m, 36H, (CH2)6), 1.47 (m, 6H, CH2CH2CH2OPh),
1.79 (m, 6H, CH2CH2OPh), 4.02 (m, 6H, CH2OPh), 7.32 (s, 2H, ArH);
13C NMR (50 MHz, CDCl3, 208C, TMS): d ˆ 14.1 (CH3), 22.7 (CH2CH3),
26.1 ± 30.3 ((CH2)7), 31.9 (CH2CH2CH3), 69.1 (CH2CH2OPh, meta to
CO2H), 73.5 (CH2OPh, para to CO2H), 108.6 (ortho to CO2H), 123.7 (ipso
to CO2H), 143.1 (para to CO2H), 152.8 (meta to CO2H), 172.2 (PhCO2H).
N-[3,4,5-tris(n-decan-1-yloxy)phenyl]-3,4,5-tris(n-dodecan-1-yloxy)benz-
amide (7-12/10): Compound 7-12/10 was synthesized by the same proce-
dure described for the preparation of 7-12/4. From 3-12 (2.6 g, 4.0 mmol)
and 6-10 (2.5 g, 4.0 mmol) in pyridine (80 mL), 3.9 g (79.8%) of light brown
crystals were obtained. Purity (HPLC), 99‡%; thermal transitions and
corresponding enthalpy changes are summarized in Table 1; TLC (10/1
hexane/EtOAc): Rf ˆ 0.19; 1H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ
0.88 (t, 18H, CH3, J ˆ 6.0 Hz), 1.27 (overlapped m, 96H, CH3(CH2)9 and
CH3(CH2)7), 1.82 (m, 12H, PhOCH2CH2), 3.91 (m, 12H, PhOCH2), 6.91 (s,
2H, ortho to NHCO), 7.03 (s, 2H, ortho to COHN), 7.74 (s, 1H, NH);
13C NMR (50 MHz, CDCl3, 208C, TMS): d ˆ 14.1 (CH3), 22.7 (CH2CH3),
26.0 (CH2CH2CH2OPh), 28.9 ± 32.6 ((CH2)5CH2CH3 and (CH2)7CH2CH3),
69.2, 69.6 (CH2OPh), 99.8 (ortho to NHCO), 106.4 (ortho to CONH), 125.1
(ipso to CONH), 133.8, 134.9 (para to CONH and NHCO), 142.4 (ipso to
NHCO), 153.1, 153.3 (meta to CONH and NHCO), 166.8 (CONH);
elemental analysis calcd (%): C 77.91, H 11.93, N 1.17; found: C 78.03, H
11.71, N 1.06.
3,4,5-Tris(n-dodecan-1-yloxy)benzoic acid (5-12): Compound 5-12 was
synthesized by the same procedure described for the preparation of 5-4.
From 4-12 (5.1 g, 7.3 mmol) and KOH (2.9 g, 51.1 mmol) in 95% EtOH
(40 mL), 4.7 g (95.3%) of a white solid was obtained. Purity (HPLC),
99‡%; m.p. 60 ± 618C (ref. [16]: 608C); TLC (10/1 hexane/EtOAc): Rf ˆ 0.
1H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 0.88 (t, 9H, CH3, J ˆ 6.7 Hz),
1.26 (overlapped m, 54H, (CH2)9), 1.79 (m, 6H, CH2CH2OPh), 4.02 (m, 6H,
CH2OPh), 7.32 (s, 2H, ArH); 13C NMR (50 MHz, CDCl3, 208C, TMS): d ˆ
14.1 (CH3), 22.7 (CH2CH3), 26.1 ± 30.2 ((CH2)7), 31.9 (CH2CH2CH3), 69.2
(CH2CH2OPh), 73.6 (CH2OPh), 108.5 (ortho to CO2H), 123.7 (ipso to
CO2H), 143.1 (para to CO2H), 152.9 (meta to CO2H), 172.2 (PhCO2H).
N-[3,4,5-tris(n-dodecan-1-yloxy)phenyl]-3,4,5-tris(n-dodecan-1-yloxy)benz-
amide (7-12/12): Compound 7-12/12 was synthesized by the same
procedure described for the preparation of 7-12/4. From 3-12 (2.6 g,
4.0 mmol) and 6-12 (2.8 g, 4.0 mmol) in pyridine (80 mL), 4.2 g (80.1%) of
light brown crystals were obtained. Purity (HPLC), 99‡%; thermal
transitions and corresponding enthalpy changes are summarized in Table 1;
TLC (10/1 hexane/EtOAc): Rf ˆ 0.19; 1H NMR (200 MHz, CDCl3, 208C,
TMS): d ˆ 0.88 (t, 18H, CH3, J ˆ 5.6 Hz), 1.26 (m, 108H, CH3(CH2)9), 1.79
(m, 12H, PhOCH2CH2), 3.91 (m, 12H, PhOCH2), 6.90 (s, 2H, ortho to
NHCO), 7.03 (s, 2H, ortho to COHN), 7.72 (s, 1H, NH); 13C NMR
(50 MHz, CDCl3, 208C, TMS): d ˆ 14.1 (CH3), 22.8 (CH2CH3), 26.2
(CH2CH2CH2OPh), 28.4 ± 32.6 ((CH2)7CH2CH3), 69.3, 69.6 (CH2OPh),
99.8 (ortho to NHCO), 106.5 (ortho to CONH), 125.1 (ipso to CONH),
133.5, 134.9 (para to CONH and NHCO), 142.4 (ipso to NHCO), 153.0,
3,4,5-Tris (n-octadecan-1-yloxy)benzoic acid (5-18): Compound 5-18 was
synthesized by the same procedure described for the preparation of 5-4.
From 4-18 (25.1 g, 0.026 mol) and KOH (11.7 g, 0.21 mol) in 95% EtOH
(250 mL), 24.2 g (95.3%) of a white solid was obtained. Purity (HPLC),
99‡%; m.p. 83 ± 848C; TLC (10/1 hexane/EtOAc): Rf ˆ 0; 1H NMR
(200 MHz, CDCl3, 208C, TMS): d ˆ 0.88 (t,9H, CH3, J ˆ 5.6 Hz), 1.26 (m,
90H, CH3(CH2)15), 1.79 (q, 6H, ArOCH2CH2), 4.02 (t, 6H, ArOCH2, J ˆ
6.2 Hz), 7.31 (s, 2H, ArH); 13C NMR (50 MHz, CDCl3, 208C, TMS): d ˆ
14.0 (CH3), 22.6 (CH2CH3), 26.1 ± 30.5 ((CH2)13), 31.9 (CH2CH2CH3), 69.0
(CH2CH2OPh), 73.1 (CH2OPh), 107.7 (ortho to CO2H), 124.6 (ipso to
CO2H), 142.3 (para to CO2H), 152.8 (meta to CO2H), 172.0 (PhCO2H).
3,4,5-Tris(n-alkan-1-yloxy)benzoyl chloride (6-n): A two-neck round-
bottom flask with a Teflon-coated magnetic stirrer was charged with 5-n
1080
ꢀ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1999
0947-6539/99/0503-1080 $ 17.50+.50/0
Chem. Eur. J. 1999, 5, No. 3

Liquid Crystalline Superlattices
1070±1083
153.3 (meta to CONH and NHCO), 167.0 (CONH); elemental analysis
calcd (%): C 78.43, H 12.13, N 1.10; found: C 78.28, H 12.07, N 1.12.
NHCO), 7.03 (s, 2H, ortho to COHN), 7.58 (s, 1H, NH); 13C NMR
(50 MHz, CDCl3, 208C, TMS): d ˆ 14.1 (CH3), 22.8 (CH2CH3), 26.2
(CH2CH2CH2OPh), 28.4 ± 32.6 ((CH2)13CH2CH3), 69.6 (CH2OPh), 99.8
(ortho to NHCO), 106.5 (ortho to CONH), 125.1 (ipso to CONH), 134.5
(para to CONH and NHCO), 142.4 (ipso to NHCO), 153.2 (meta to CONH
and NHCO), 167.0 (CONH).
N-[3,4,5-tris(n-octadecan-1-yloxy)phenyl]-3,4,5-tris(n-dodecan-1-yloxy)-
benzamide (7-12/18): Compound 7-12/18 was synthesized by the same
procedure described for the preparation of 7-12/4. From 3-12 (2.6 g,
4.0 mmol) and 6-18 (3.8 g, 4.0 mmol) in pyridine (80 mL), 4.5 g (72.1%) of
light brown crystals were obtained. Purity (HPLC), 99‡%; thermal
transitions and corresponding enthalpy changes are summarized in Table 1;
TLC (10/1 hexane/EtOAc): Rf ˆ 0.20; 1H NMR (200 MHz, CDCl3, 208C,
TMS): d ˆ 0.88 (t, 18H, CH3, J ˆ 5.6 Hz), 1.26 (m, 144H, CH3(CH2)9 and
CH3(CH2)15), 1.79 (m, 12H, ArOCH2CH2), 3.99 (m, 12H, ArOCH2), 6.90
(s, 2H, ortho to NHCO), 7.03 (s, 2H, ortho to COHN), 7.58 (s, 1H, NH);
13C NMR (50 MHz, CDCl3, 208C, TMS): d ˆ 14.1 (CH3), 22.8 (CH2CH3),
26.2 (CH2CH2CH2OPh), 28.4 ± 32.6 ((CH2)7CH2CH3 and (CH2)13CH2CH3),
69.6 (CH2OPh), 99.8 (ortho to NHCO), 106.5 (ortho to CONH), 125.1 (ipso
to CONH), 134.5 (para to CONH and NHCO), 142.4 (ipso to NHCO),
153.2 (meta to CONH and NHCO), 167.0 (CONH); elemental analysis
calcd (%): C 79.51, H 12.43, N 0.93; found: C 79.28, H 12.67, N 1.12.
Methyl N-[3,4,5-tris(n-octadecan-1-yloxy)phenyl]-3,4,5-tris(n-dodecan-1-
yloxy)benzamide (8-12/18): A flame-dried apparatus consisting of a round
bottom flask equipped with an additional funnel, N2 inlet ± outlet and
magnetic stirrer was cooled under a flow of N2. The apparatus was charged
with anhydrous THF (15 mL) suspension of NaH, 80% in mineral oil
(15.6 mg, 0.65 mmol) and a catalytic amount of DMSO. 7-12/18 (1.0 g,
0.65 mmol) in anhydrous THF (15 mL) was added dropwise. After 3 h,
CH3I (0.11 g, 0.78 mmol) was added dropwise. During the reaction, aliquots
were removed for 1H NMR analysis (d 7.58 (CONH) disappears, d 3.43
(CONH3) appears). After 3 h, the reaction was complete. The reaction
mixture was added dropwise into H2O (50 mL) and stirred for 30 min. The
precipitate was filtered, washed 3 times with dilute HCl and recrystallized
from isopropanol to yield 0.78 g (77.7%) of light brown crystals. Purity
(HPLC), 99‡%; m.p. 328C; TLC (10/1 hexane/EtOAc): Rf ˆ 0.25;
1H NMR (200 MHz, CDCl3 , 208C, TMS): d ˆ 0.88 (t, 18H, CH3, J ˆ
5.6 Hz), 1.26 (m, 144H, CH3(CH2)9 and CH3(CH2)15), 1.79 (m, 12H,
ArOCH2CH2), 3.43 (s, 3H, CONCH3), 3.99 (m, 12H, ArOCH2), 6.90 (s,
2H, ortho to NHCO), 7.03 (s, 2H, ortho to COHN); 13C NMR (50 MHz,
CDCl3 , 20 8C, TMS): d ˆ 14.1 (CH3), 22.8 (CH2CH3), 26.2
(CH2CH2CH2OPh), 28.4 ± 32.6 ((CH2)7CH2CH3 and (CH2)13CH2CH3),
34.7 (CONCH3), 69.6 (CH2OPh), 99.8 (ortho to N(CH3)CO), 106.5 (ortho
to CONCH3), 125.1 (ipso to CONCH3), 134.5 (para to CONCH3 and
N(CH3)CO), 142.4 (ipso to N(CH3)CO), 153.2 (meta to CONCH3 and
N(CH3)CO), 164.0 (CONCH3).
N-[3,4,5-tris(n-butan-1-yloxy)phenyl]-3,4,5-tris(n-octadecan-1-yloxy)benz-
amide (7-18/4): Compound 7-18/4 was synthesized by the same procedure
described for the preparation of 7-12/4. From 3-18 (3.6 g, 4.0 mmol) and 6-4
(1.6 g, 4.0 mmol) in pyridine (80 mL), 3.7 g (74.1%) of light brown crystals
were obtained. Purity (HPLC), 99‡%; m.p. 748C; TLC (10/1 hexane/
EtOAc): Rf ˆ 0.17; 1H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 0.88 (t,
18H, CH3, J ˆ 6.1 Hz), 1.26 (overlapped m, 96H, CH3(CH2)15 and
CH3CH2), 1.79 (m, 12H, PhOCH2CH2), 3.91 (m, 12H, PhOCH2), 6.90 (s,
2H, ortho to NHCO), 7.03 (s, 2H, ortho to COHN), 7.72 (s, 1H, NH);
13C NMR (50 MHz, CDCl3, 208C, TMS): d ˆ 14.0 (CH3), 20.9, 22.7
(CH2CH3), 26.1 (CH2CH2CH2OPh), 29.4 ± 32.9 (CH2CH2OPh and
(CH2)13CH2CH3), 69.0, 69.3 (CH2OPh), 99.2 (ortho to NHCO), 105.9
(ortho to CONH), 124.7 (ipso to CONH), 133.8, 134.9 (para to CONH and
NHCO), 141.4 (ipso to NHCO), 153.1, 153.3 (meta to CONH and NHCO),
166.1 (CONH).
3,4-Isopropyliden-5-hydroxymethylbenzoate (10): Compound, 10 was syn-
thesized according to a literature procedure.[21] From 3,4,5-trihydroxy
methylbenzoate (36.8 g, 0.2 mol) and P2O5 (42.6 g, 0.3 mol) in acetone was
obtained 17.1 g (38.2%) of a white powder. Purity (HPLC), 99‡%;
m.p. 114 ± 1158C (ref. [21]: 114 ± 1168C) ; TLC (20/1 hexane/EtOAc): Rf ˆ
N-[3,4,5-tris(n-hexan-1-yloxy)phenyl]-3,4,5-tris(n-octadecan-1-yloxy)benz-
amide (7-18/6): Compound 7-18/6 was synthesized by the same procedure
described for the preparation of 7-12/4. From 3-18 (3.6 g, 4.0 mmol) and 6-6
(2.2 g, 4.0 mmol) in pyridine (80 mL), 4.7 g (79.3%) of light brown crystals
were obtained. Purity (HPLC), 99‡%; m.p. 678C; TLC (10/1 hexane/
EtOAc): Rf ˆ 0.18; 1H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 0.88 (t,
18H, CH3, J ˆ 5.9 Hz), 1.26 (overlapped m, 108H, CH3(CH2)15 and
CH3(CH2)3), 1.80 (m, 12H, PhOCH2CH2), 3.90 (m, 12H, PhOCH2), 6.90
(s, 2H, ortho to NHCO), 7.03 (s, 2H, ortho to COHN), 7.72 (s, 1H, NH);
13C NMR (50 MHz, CDCl3, 208C, TMS): d ˆ 14.1 (CH3), 22.7 (CH2CH3),
26.1 (CH2CH2CH2OPh), 28.9 ± 32.6 (CH2CH2CH3and (CH2)13CH2CH3),
69.2, 69.6 (CH2OPh), 99.8 (ortho to NHCO), 106.4 (ortho to CONH), 125.1
(ipso to CONH), 133.8, 134.9 (para to CONH and NHCO), 142.4 (ipso to
NHCO), 153.1, 153.3 (meta to CONH and NHCO), 166.8 (CONH).
1
0.26; H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 1.71 (s, 6H, C(CH3)2),
3.87 (s, 3H, CO2CH3), 5.37 (s, 1H, OH), 7.01 (d, 1H, 2-position, J ˆ 1.5 Hz),
7.31 (d, 1H, 6-position, J ˆ 1.6 Hz).
3,4-Isopropyliden-5-(1-hydroxyundecan)methylbenzoate (11): Compound
11 was synthesized by the etherification of 10 with 1-bromoundecanol. To a
round-bottom flask equipped with a N2 inlet ± outlet containing a mixture
of 10 (5.0 g, 22 mmol) and anhydrous K2CO3 (6.9 g, 50 mmol) in DMF
(90 mL) at 608C, 1-bromoundecanol (6.2 g, 26 mmol) was added in small
portions. After 4 h, the reaction mixture was poured into ice/H2O (1 L),
followed by acidification with concentrated HCl to pH 2. The yellow, oily
compound was filtered and vacuum-dried for 6 h to give 7.0 g (83.4%) of a
yellow waxy compound. Purity (HPLC), 98.5%; TLC (10/1 hexane/
1
EtOAc): Rf ˆ 0.47; H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 1.29 (m,
N-[3,4,5-tris(n-decan-1-yloxy)phenyl]-3,4,5-tris(n-octadecan-1-yloxy)benz-
amide (7-18/10): Compound 7-18/10 was synthesized by the same
procedure described for the preparation of 7-12/4. From 3-18 (3.6 g,
4.0 mmol) and 6-10 (2.5 g, 4.0 mmol) in pyridine (80 mL), 4.8 g (81.1%) of
light brown crystals were obtained. Purity (HPLC), 99‡%; m.p. 708C;
TLC (10/1 hexane/EtOAc): Rf ˆ 0.19; 1H NMR (200 MHz, CDCl3, 208C,
TMS): d ˆ 0.88 (t, 18H, CH3, J ˆ 6.0 Hz), 1.27 (overlapped m, 132H,
CH3(CH2)15 and CH3(CH2)7), 1.82 (m, 12H, PhOCH2CH2), 3.91 (m, 12H,
PhOCH2), 6.91 (s, 2H, ortho to NHCO), 7.03 (s, 2H, ortho to COHN), 7.74
(s, 1H, NH); 13C NMR (50 MHz, CDCl3, 208C, TMS): d ˆ 14.1 (CH3), 22.7
(CH2CH3), 26.0 (CH2CH2CH2OPh), 28.9 ± 32.6 ((CH2)5CH2CH3 and
(CH2)13CH2CH3), 69.2, 69.6 (CH2OPh), 99.8 (ortho to NHCO), 106.4
(ortho to CONH), 125.1 (ipso to CONH), 133.8, 134.9 (para to CONH and
NHCO), 142.4 (ipso to NHCO), 153.1, 153.3 (meta to CONH and NHCO),
166.8 (CONH).
14H, PhOCH2CH2(CH2)7), 1.56 (q, 2H, HOCH2CH2, J ˆ 6.5 Hz), 1.71 (s,
6H, C(CH3)2), 1.80 (q, 2H, PhOCH2CH2), 3.63 (t, 2H, HOCH2, J ˆ 6.6 Hz),
3.86 (s, 3H, CO2CH3), 4.07 (t, 2H, PhOCH2, J ˆ 6.8 Hz), 7.10 (d, 1H,
2-position, J ˆ 1.4 Hz), 7.27 (d, 1H, 6-position, J ˆ 1.5 Hz).
3,4-Dihydroxy-5-(1-hydroxyundecan)alkylbenzoate (12): Over a mixture
of 11 (6.0 g, 15 mmol) and pure EtOH (90 mL), 12n HCl (15 mL) was
added. The mixture was refluxed for 2 h and poured onto ice/H2O
(800 mL). The resulting white solid was filtered and recrystallized from
CH2Cl2 and hexane to yield 5.0 g (93.2%) of a mixture containing 4%
methylbenzoate and 96% ethylbenzoate. Purity (HPLC), 99‡%; m.p. 91 ±
928C. 1H NMR (200 MHz, CDCl3 , 208C, TMS): d ˆ 1.22 (m, 14H,
PhOCH2CH2(CH2)7), 1.48 (q, 2H, HOCH2CH2, J ˆ 6.6 Hz), 1.74 (q, 2H,
PhOCH2CH2, J ˆ 7.2 Hz), 3.54 (t, 2H, HOCH2, J ˆ 6.6 Hz), 3.79 (s, 3H,
CO2CH3), 3.99 (t, 2H, PhOCH2, J ˆ 6.7 Hz), 4.23 (q, 2H, CO2CH2CH3, J ˆ
7.1 Hz), 7.09 (d, 1H, 2-position, J ˆ 1.8 Hz), 7.23 (d, 1H, 6-position, J ˆ
1.9 Hz).
N-[3,4,5-tris(n-octadecan-1-yloxy)phenyl]-3,4,5-tris(n-octadecan-1-yloxy)-
benzamide (7-18/18): Compound 7-18/18 was synthesized by the same
procedure described for the preparation of 7-12/4. From 3-18 (3.6 g,
4.0 mmol) and 6-18 (3.8 g, 4.0 mmol) in pyridine (80 mL), 5.5 g (75.1%) of
light brown crystals were obtained. Purity (HPLC), 99‡%; m.p. 948C;
TLC (10/1 hexane/EtOAc): Rf ˆ 0.19; 1H NMR (200 MHz, CDCl3, 208C,
TMS): d ˆ 0.88 (t, 18H, CH3, J ˆ 5.6 Hz), 1.26 (m, 180H, CH3(CH2)15), 1.79
(m, 12H, ArOCH2CH2), 3.99 (m, 12H, ArOCH2), 6.90 (s, 2H, ortho to
3,4-Didodecyloxy-5-(1-hydroxyundecan)alkylbenzoate (13): To a round-
bottom flask equipped with a N2 inlet ± outlet containing a mixture of 12
(4.5 g, 13 mmol) and K2CO3 (7.6 g, 55 mmol) in DMF (70 mL) at 608C,
1-bromododecane (6.8 g, 27 mmol) was added. After 4 h, the reaction
mixture was poured onto ice/H2O (1 L). The resulting light brown solid was
filtered and purified by precipitation from THF solution into MeOH to
Chem. Eur. J. 1999, 5, No. 3
ꢀ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1999
0947-6539/99/0503-1081 $ 17.50+.50/0
1081

V. Percec et al.
FULL PAPER
ˆ
yield 6.3 g (72.8%) of a white waxy compound. Purity (HPLC), 99‡%;
1H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 0.87 (m, 6H, CH3), 1.26 (m,
50H, PhOCH2CH2(CH2)7), 1.46 (m, 2H, HOCH2CH2), 1.77 (m, 6H,
PhOCH2CH2), 3.63 (t, 2H, HOCH2, J ˆ 6.6 Hz), 3.97 (s, 3H, COOCH3),
4.01 (t, 6H, PhOCH2, J ˆ 6.5 Hz), 4.33 (q, 2H, COOCH2CH3, J ˆ 7.1 Hz),
7.25 (s, 2H, ortho to CO2).
PhOCH2CH2), 1.94 (m, 3H, CH3C CH2), 3.98 (m, 12H, PhOCH2), 4.13
ˆ
(t, 2H, COOCH2, J ˆ 6.6 Hz), 5.54 (s, 1H, C CH2,trans), 6.09 (s, 1H,
ˆ
C CH2, cis), 6.90 (s, 2H, ortho to NHCO), 7.03 (s, 2H, ortho to COHN),
7.61 (s, 1H, NHCO); 13C NMR (50 MHz, CDCl3, 208C, TMS): d ˆ 14.1
ˆ
(CH3), 18.2 (CH2 C(CH3)CO), 22.8 (CH2CH3), 26.2 (CH2CH2CH2OPh),
28.4 ± 32.6 ((CH2)7CH2CH3), 65.9 (CO2CH2), 69.3, 69.6 (CH2OPh), 99.8
ˆ
(ortho to NHCO), 106.5 (ortho to CONH), 122.2 (CH2 C(CH3)CO), 125.1
3,4-Didodecyloxy-5-(1-hydroxyundecan)benzoic acid (14): A solution of
KOH (3.4 g, 60 mmol) in H2O (6 mL) was added to a mixture of 13 (6.0 g,
8.7 mmol) in EtOH (54 mL). The mixture was refluxed for 3 h, then
acidified with concentrated HCl. After refluxing for 15 min, the reaction
mixture was poured onto ice/H2O (1 L). The product was filtered and
recrystallized from hexane/CH2Cl2 (10/1) to yield 5.8 g (98.2%) of white
crystals. Purity (HPLC), 99‡%; m.p. 52 ± 538C; TLC (10/1 hexane/
EtOAc): Rf ˆ 0; 1H NMR (200 MHz, CDCl3, 208C, TMS): d ˆ 0.88 (m,
6H, CH3), 1.29 (m, 50H, PhOCH2CH2(CH2)7), 1.47 (m, 2H, HOCH2CH2),
1.77 (m, 6H, PhOCH2CH2), 3.61 (t, 2H, HOCH2, J ˆ 6.4 Hz), 4.01 (m, 6H,
PhOCH2), 7.33 (s, 2H, ortho to CO2).
(para to CONH), 129.9 (ipso to CONH), 133.5 (para to NHCO), 138.0
(CH2 ˆ C(CH3)CO), 140.5 (ipso to NHCO), 153.2, 153.4 (meta to CONH
ˆ
and NHCO), 165.0 (CH2 C(CH3)CO), 165.5 (CONH); elemental analysis
calcd (%): C 77.03, H 11.51, N 1.03; found: C 76.95, H 11.38, N 1.12.
Free radical polymerization of 18
Method A: Compound 18 (1.8 g, 1.31 mmol), AIBN (18 mg, 1 wt%), and
dry benzene (3.0 mL) were introduced in a Schlenk tube. The solution was
degassed by four freeze-pump-thaw cycles and the polymerization mixture
was heated at 608C under N2. After 18 h, the resulting polymer was diluted
with hexanes and purified from unconverted monomer by column
chromatography (SiO2, hexanes). Finally, the purified polymer 19 was
dissolved in CH2Cl2 and was precipitated in cold MeOH to yield 1.56 g
(87%) of a light yellow solid; Mn ˆ 55095 and Mw/Mn ˆ 1.64 (GPC with
polystyrene standards).
3,4-Didodecyloxy-5-(1-methacryloyloxyundecanyloxy)benzoic acid (16):
To a 100 mL flask, 14 (5.0 g, 7.4 mmol), dry CH2Cl2 (30 mL), and dry
pyridine (0.9 mL, 73.8 mmol) were added. Methacryloyl chloride (1.3 g,
12.6 mmol) was added dropwise at 08C and the reaction was stirred at room
temperature for 3 h. To the reaction mixture, H2O was added, and the
product was extracted with CH2Cl2. The solution was dried over MgSO4
and the solvent was distilled in a rotary evaporator. The resulting product
was heated for 10 min in pyridine (50 mL) and H2O (15 mL) to cleave the
mixed ester anhydride 15. After acidification with dilute HCl, the mixture
was extracted by Et2O. The organic layer was washed with a solution of
NaHCO3 and dried over anhydrous MgSO4. The solvent was distilled in a
rotary evaporator and the product was recrystallized from MeOH/CHCl3
(1/2) to give 2.3 g (41.0%) of white crystals. Purity (HPLC), 99‡%;
m.p. 49 ± 508C; TLC (10/1 hexane/EtOAc): Rf ˆ 0. 1H NMR (200 MHz,
CDCl3 , 20 8C, TMS): d ˆ 0.88 (m, 6 H, CH3), 1.26 (m, 50 H,
PhOCH2CH2(CH2)7), 1.53 (m, 2 H, CO2CH2CH2), 1.70 (m, 6 H,
Method B: Compound 18 (1.0 g, 0.73 mmol), AIBN (10 mg, 1 wt%), and
dry benzene (1.2 mL) were introduced in a Schlenk tube. The solution was
degassed by four freeze-pump-thaw cycles and the polymerization mixture
was heated at 608C under N2. After 2 h, the increase in the viscosity of the
reaction mixture made stirring impossible. The resulting polymer was
dissolved in CHCl3 and was precipitated into methanol. The polymer 19
was purified from unconverted monomer by column chromatography
(SiO2, hexanes) to yield 0.9 g (89.3%) of a light yellow solid; Mn ˆ 58800
and Mw/Mn ˆ 2.16 (GPC with polystyrene standards).
Preparation of the binary mixtures of 7-12/12 with 19: Mixtures of 7-12/12
and 19 were prepared by weighing the individual components in glass vials,
then adding dry CH2Cl2 to give an equal final volume of a homogeneous
solution. Then solvent was removed under a gentle stream of dry N2 and the
vials were placed under vacuum for 12 h at 208C before thermal analysis.
Annealed samples were prepared under vacuum at 558C for 12 h before
thermal analysis.
ˆ
PhOCH2CH2), 1.94 (m, 3H, CH3C CH2), 3.96 (m, 6H, PhOCH2), 4.13 (t,
ˆ
ˆ
2H, CO2CH2, J ˆ 6.7 Hz), 5.54 (s, 1H, C CH2,trans), 6.10 (s, 1H, C CH2,
cis), 7.29 (s, 2H, ortho to CO2); 13C NMR (50 MHz, CDCl3, 208C, TMS):
ˆ
d ˆ 14.1 (CH3), 18.3 (CH2 C(CH3)), 22.7 (CH2CH3), 26.1 ± 30.2 ((CH2)7),
31.9 (CH2CH2CH3), 66.1 (CO2CH2), 69.3 (CH2CH2OPh), 73.7 (CH2OPh),
ˆ
110.0 (ortho to CO2H), 122.7 (CH2 C(CH3)), 127.3 (ipso to CO2H), 138.1
ˆ
(CH2 C(CH3)), 144.7 (para to CO2H), 152.9 (meta to CO2H), 172.2
Acknowledgment
(CO2H).
3,4-Didodecyloxy-5-(1-methacryloxyundecan)benzoyl chloride (17): Into a
round-bottom flask equipped with magnetic stirrer, compound 16 (2.0 g,
2.7 mmol) was dissolved in dry CH2Cl2 (11 mL). Dry DMF (two drops) was
added and the solution was stirred for 5 min. SOCl2 (1.0 mL, 5.4 mmol) was
slowly added to the reaction mixture over several min. An aliquot was
analysized by 13C NMR spectroscopy (d ˆ 172.2 (PhCO2H) disappears, d ˆ
167.7 (PhCOCl) appears), indicating complete conversion at the end of the
addition. The solvent was removed on a rotary evaporator at room
temperature and the residual SOCl2 was removed under vacuum for 4 h at
room temperature to yield 2.0 g (96.3%) of a light yellow solid. Compound
17 was used immediately in the next step without further purification.
Purity (HPLC), 99‡%; m.p. 40 ± 428C. 1H NMR (200 MHz, CDCl3, 208C,
TMS): d ˆ 0.88 (m, 6H, CH3), 1.26 (m, 50H, PhOCH2CH2(CH2)7), 1.47 (m,
Financial support by the ARO-MURI, the National Science Foundation
(DMR-97 ± 08581), ONR, and the Engineering and Physical Science
Research Council (UK) is gratefully acknowledged.
[1] V. Percec, G. Johansson, G. Ungar, J. Zhou, J. Am. Chem. Soc. 1996,
118, 9855, and references therein.
[2] S. D. Hudson, H. T. Jung, V. Percec, W. D. Cho, G. Johansson, G.
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[4] a) V. Percec, D. Schlueter, Macromolecules 1997, 30, 5783; b) V.
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ˆ
2H, CO2CH2CH2), 1.70 (m, 6H, PhOCH2CH2), 1.94 (m, 3H, CH3C CH2),
3.99 (m, 6H, PhOCH2), 4.14 (t, 2H, CO2CH2, J ˆ 6.7 Hz), 5.54 (s, 1H,
ˆ
ˆ
C CH2,trans), 6.10 (s, 1H, C CH2, cis), 7.33 (s, 2H, ortho to CO2);
13C NMR (50 MHz, CDCl3 , 20 8C, TMS): d ˆ 14.1 (CH3), 18.3
ˆ
(CH2 C(CH3)), 22.7 (CH2CH3), 26.1 ± 30.2 ((CH2)7), 31.9 (CH2CH2CH3),
66.1 (CO2CH2), 69.3 (CH2CH2OPh), 73.7 (CH2OPh), 110.0 (ortho to
[6] a) D. A. Tomalia, P. M. Kirchoff, U. S. Patent 4,694,064, 1987; b) R.
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2678.
ˆ
COCl), 122.7 (CH2 C(CH3)), 127.3 (ipso to COCl), 138.1 (CH2 ˆ C(CH3)),
144.7 (para to COCl), 152.9 (meta to COCl), 167.7 (COCl).
N-[3,4-Didodecyloxy-5-(1-methacryloxyundecan)phenyl]3,4,5-tris(n-do-
decan-1-yloxy)benzamide (18): Compound 18 was synthesized according to
the general procedure described for 7 ± 2/12 at 608C for 4 h, starting from 3-
12 (1.3 g, 2.0 mmol), 17 (1.5 g, 2.0 mmol), and pyridine (30 mL). The
resulting brown solid was purified by column chromatography (SiO2,
hexane/EtOAc 10/1) to yield 1.7 g (60.9%) of a white solid. Purity (HPLC),
99‡%; m.p. 73 ± 748C; TLC (10/1 hexane/EtOAc): Rf ˆ 0.33; 1H NMR
(200 MHz, CDCl3, 208C, TMS): d ˆ 0.88 (m, 15H, CH3), 1.26 (m, 104H,
PhOCH2CH2(CH2)7), 1.58 (m, 2 H, CO2CH2CH2), 1.78 (m, 12 H,
[7] B. Karakaya, W. Claussen, K. Gessler, W. Saenger, A. D. Schlüter, J.
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Â
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1082
ꢀ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1999
0947-6539/99/0503-1082 $ 17.50+.50/0
Chem. Eur. J. 1999, 5, No. 3

Liquid Crystalline Superlattices
1070±1083
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Received: May 5, 1998
Revised version: October 26, 1998 [F1136]
Chem. Eur. J. 1999, 5, No. 3
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