Synthesis and characterization of tris-methacrylated 3,4,5- tris[(alkoxy)benzyloxy]benzoate derivatives

Article abstract of DOI:10.1002/1521-3765(20000602)6:11<2016::AID-CHEM2016>3.0.CO;2-S

The synthesis of liquid crystalline 3,4,5-tris(11-methacryloylundecyl-1- oxybenzyloxy)benzoic acid, 2-methyl-(1,4,7,10,13-pentaoxacyclopentadecane)- 3,4,5-tris[4-(11-methacryloylundecyl-1-oxy)benzyloxy] benzoate and its 1:1 complex with sodium triflate is described. The observed mesophases were identified, by polarized optical microscopy and contact preparation techniques, to be of hexagonal columnar disordered structure. The amphiphiles form lyotropic columnar phases in concentrated methacrylate solvents, while at low solute contents supramolecular organogels emerge.

Full text of DOI:10.1002/1521-3765(20000602)6:11<2016::AID-CHEM2016>3.0.CO;2-S

FULL PAPER
Synthesis and Characterization of Tris-Methacrylated 3,4,5-Tris[(alkoxy)ben-
zyloxy]benzoate Derivatives
Uwe Beginn,* Gabriela Zipp, and Martin Möller[a]
Abstract: The synthesis of liquid crystalline 3,4,5-tris(11-methacryloylundecyl-1-
oxybenzyloxy)benzoic acid, 2-methyl-(1,4,7,10,13-pentaoxacyclopentadecane)-3,4,5-
tris[4-(11-methacryloylundecyl-1-oxy)benzyloxy] benzoate and its 1:1 complex with
Keywords: amphiphiles ´ benzoates
sodium triflate is described. The observed mesophases were identified, by polarized
´ crown compounds ´ mesophases ´
optical microscopy and contact preparation techniques, to be of hexagonal columnar
organogelators
disordered structure. The amphiphiles form lyotropic columnar phases in concen-
trated methacrylate solvents, while at low solute contents supramolecular organogels
emerge.
shaped molecules, which stack to form well-defined supra-
molecular columns.[4, 5] Each column represents a solid
Introduction
Although the present-day technical polymeric materials have
rather complicated microscopic superstructures, the molec-
ular-level structures remain much less complex than those of
biological functional units. Here specific transport units, such
as carrier molecules and ion pores or channels, are able to
aggregate consisting of regularly arranged, densely packed
molecular units (Figure 1). The molecules bear a receptor
recognize and selectively transport ions or molecules.[1]
A
major reason for this gap in development is that the structures
of synthetic macromolecules are polydisperse and their
intermolecular interactions are also for the most part not
directed or localized.[2] Yet, supramolecular chemistry that is
directed towards the formation of exactly defined assemblies
mostly works with rather small molecules. In addition, well-
defined supramolecular complexes are typically rather rigid
and have only limited abilities to undergo complex changes
depending on slight variations of the environment; this limits
their function as molecular devices, in contrast to the flexible
biomolecular assemblies. Hybrid materials composed of
supramolecular aggregates that are connected to macromo-
lecules may raise new opportunities to combine the specificity
of supramolecular recognition with the flexibility and long-
range effects of macromolecular systems.[3]
Figure 1. Schematic representation of the self-assembly of wedge-shaped
amphiphiles in monomeric solvents. The self-organization into networks of
solid supramolecular cylindrical aggregates causes the gelation of the
liquid. Subsequent polymerization yields a hybrid material containing
supramolecular channels, covalently anchored to the polymeric matrix
phase (ªmatrix-fixed supramolecular channelº) process.
We are interested in the preparation of functional mem-
branes containing self-organized transport channels based on
such supramolecular/macromolecular hybrids. Our synthetic
approach exploits the self-organization ability of wedge-
function at the tip of the wedge and have polymerizable
groups at the rim.[6] As they assemble to a solid supra-
molecular column, the receptor groups stack along the
cylinder axis, thus forming a potential transport channel.
Since the polymerizable groups are located at the outer rim of
the aggregates, each cylinder is surrounded by a coat of
monomer units. If the cylinders assemble in solution, a gel is
[a] Dr. U. Beginn, Dr. G. Zipp, Prof. Dr. M. Möller
Laboratory of Organic and Macromolecular Chemistry, OC-III
University of Ulm, Albert-Einstein-Allee 11
89069 Ulm (Germany)
Fax : (‡49)731-502-2883
E-mail: uwe.beginn@chemie.uni-ulm.de
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2016±2023
formed, at rather low concentrations.[7] When the solvent is a
monomer, possibly mixed with a cross-linker, which can be
photopolymerized, the cylinders can be embedded and
covalently linked in a polymer matrix. Corresponding thin
films may serve as a new type of membrane containing
ªmatrix-fixed supramolecular channelsº (Figure 1).
bled structures should be enhanced relative to the mono-
methacrylated B compound.[4, 5] In addition, the increased
number of polymerizable groups should improve the con-
nectivity between the supramolecular aggregates and the
surrounding cross-linked matrix.
In a first approach, we focussed on alkali-ion-selective
membranes. Crown ether compounds such as 1,4,7,10,13-
pentaoxacyclopentadecane (ª15-c-5º) selectively form com-
plexes with alkali metal cations, the stability of the complex
being ruled by the radius of the cation.[8] In earlier reports,
crown-ether-containing compounds such as 2-hydroxymethyl-
[1,4,7,10,13-pentaoxabenzocyclopentadecane]-3,4,5-tris[4-(n-
dodecyl-1-oxy)benzyloxy]benzoate (B) were shown to form a
Results and Discussion
The synthesis of 3,4,5-tris[4'-(11-methacryloylundecyl-1-oxy)-
benzyloxy]benzoic acid (7) was carried out as depicted in
Scheme 1. Methyl-4-hydroxybenzoate (1) was alkylated with
11-bromo-1-undecene to yield methyl-4-(10-undecenyl-1-
oxy)benzoate (2).
hexagonal columnar mesophase,[9] in which the stacked crown
ether moieties form potential ion channels parallel to the
column axis. In fact, it was reported that B exhibits ionic
conductivity in the mesophase.[9]
In an earlier report, we described derivatives of B with one
alkyloxybenzyloxy group replaced by an 11-methacryloylun-
decyl-1-oxy unit.[4] Here we describe the synthesis of tris-
methacrylate-functionalized B analogues. Because of the
symmetrical substitution pattern, the stability of self-assem-
Abstract in German: Die Synthese der flüssigkristallinen
Verbindungen 3,4,5-Tris(11-methacryloyl-undeceyl-1-oxyben-
zyloxy)benzoesäure, 2-Methyl-(1,4,7,10,13-pentaoxacyclopen-
tadecan)-3,4,5-tris[4-(11-methacryloyl-undecyl-1-oxy)benzyl-
oxy]benzoats und seines 1: 1 Komplexes mit Natriumtrifluor-
sulfonat wird beschrieben. Die beobachteten Mesophasen
wurden mittels Polarisationsmikroskopie und Kontaktpräpa-
raten charakterisiert. Die Amphiphile bilden sowohl in bulk,
als auch aus konzentrierten Lösungen in Methacrylat-Solven-
tien hexagonal columnare Phasen aus, während verdünnte
Lösungen unter Ausbildung supramolekularer Organogele
thermoreversibel gelieren.
Scheme 1. Synthesis of 3,4,5-tris(4-(11-methacryloylundecyl-1-oxy)benzy-
loxy)benzoic acid (7).
After reduction of the ester with lithium aluminum hydride,
the resulting benzyl alcohol 3 was converted to 4-(10-
undecenyl-1-oxy)benzyl chloride (4). On alkylating ethyl-
gallate with 4, ethyl-3,4,5-tris[4-(10-undecenyl-1-oxy)benzyl-
oxy]benzoate (5) was obtained. By hydroboration/oxidation
of the terminal alkene groups of 5 with 9-borabicyclo[1.3.3]-
nonane and an alkaline hydrogen peroxide solution, three
hydroxy functions were introduced in the anti-Markovnikov
position; the ester group was simultaneously saponified to
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U. Beginn et al.
FULL PAPER
yield 6. Finally, the tris-methacrylated acid 7 was synthesized
from 6 and methacryloyl chloride.
compound melted at 258C into a liquid crystalline phase
which transformed into the isotropic melt at 62.58C (see DSC
trace of 7 in Figure 2). The highly viscous, optically aniso-
As shown in Scheme 2, 2-methyl-(1,4,7,10,13-pentaoxacy-
clopentadecane)-3,4,5-tris(4-(11-methacryloylundecyl-1-oxy)-
benzyloxy)benzoate (8) was obtained simply by DPTS-
catalyzed, DCC-activated reaction of 7 with (2-hydroxy-
methyl)benzo-15-crown-5.
Figure 2. Representative DSC trace of the non-methacrylated acid A and
7. Heating rate: 10Kmin À1, second heating run.
tropic phase observed by thermo-optical analysis between 23
and 62.58C confirmed the occurrence of a mesophase. From
the broken fan-shaped texture (seen in the optical micrograph
in Figure 3) and the large melt viscosity, the presence of a
columnar mesophase was concluded.
Scheme 2. Synthesis of 2-methyl-(1,4,7,10,13-pentaoxacyclopentadecane)-
3,4,5-tris(4-(11-methacryloyl-undecyl-1-oxy)benzyloxy)benzoate (8) and
its 1:1 NaSO3CF3 complex (8a).
Stoichiometric amounts of 8 and NaSO3CF3 were mixed in
THF, to convert the crown ether derivative 8 into the 1:1
sodium complex 8a. After slow evaporation of the solvent, the
complex was dried in vacuum until the weight remained
constant. Table 1 summarizes the phase behavior of 7 and 8 as
obtained by DSC measurements.
The pure compound 7 was a waxy white material with a
glass transition temperature at À338C and a softening/
recrystallization transition at À68C. On further heating, the
Table 1. Transition temperatures of compounds 7, 8 and 8a.[b]
TC!M [8C]
DHC!M [kJmolÀ1
]
TM!I [8C]
DHM!I [kJmolÀ1
]
7
8
8a
25.029.0
17.042.7
25.5
62.7 .5
0
28.0
[b]
0.9[b]
14.35.046.0
[a] C ˆ crystalline phase, M ˆ mesophase, I ˆ isotropic phase; DSC meas-
urements, heating rate ˆ 108CminÀ1Ðfirst heating only. [b] Heating rate ˆ
Figure 3. Representative optical micrograph of the fan-shaped texture of
the tris-functionalized acid compound 7 at 558C (top) and the non-
methacrylated acid A at 1208C (bottom).
58CminÀ1
.
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Supramolecular Organogels
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Figure 2 also shows a representative DSC trace of the non-
methacrylated 3,4,5-tris(4-dodecyl-1-oxy-benzyloxy)benzoic
acid (A). The attachment of the methacrylate groups to the
acid resulted in a decrease in the melting temperature, from
608C to 258C, while the isotropization temperatures reduced
from 1328C to 638C.
finally into the pure amphiphile 7. Even the thermodynami-
cally required two-phase region, separating the isotropic melt
from the mesophase, was distinguished (see Figure 4).
When the crown ether compound 8 was heated, two broad,
partially overlapping endothermic signals appeared in the
DSC trace (Figure 5); the two signals could be separated by a
According to the Arnold ± Sackmann miscibility rule, two
mesogens exhibit identical mesophases if the bordering
regions of the two phases are connected by a continuous
series of (liquid) mixed crystals.[10] The binary phase diagrams
of 7 and A were investigated by means of Koflerꢁs contact
preparation technique.[11] Small drops of the molten com-
pounds were brought in contact and were observed between
crossed polarizers. In the contact zone, the two compounds
diffused into one another, creating a region in which all
possible compositions of binary mixtures were realized. At a
given temperature, the interdiffusion area represents the
complete isothermal section of the phase diagram.
Because of their chemical similarity to the substances under
investigation, the non-methacrylated compounds A and B
were chosen as standard mesogens for the miscibility experi-
ments.
Figure 4 depicts the contact zone of 7 and A at different
temperatures. A miscibility gap would create a black border
separating the two mesogens; this phenomenon was not
observed. Instead, when the temperature was decreased from
1358C, a columnar texture formation was found that started
from pure A, gradually moved into the diffusion zone, and
Figure 5. Representative DSC trace of 8 and 8a (solid lines: first heating
run, dashed lines: first cooling run, heating rate: 10Kmin À1).
reduction in the heating rate. Polarized optical investigations
confirmed that 8 also has a crystalline phase (m.p. 178C) and a
mesophase (Ti ˆ 288C), see Table 1.
Since it is known that the addition of alkali metal triflate to
B destabilizes its crystalline phase and favors the hexagonal
columnar mesophase,[9] the sodium triflate complex of com-
pound 8 was prepared (8a).
From the DSC traces (Figure 5), compound 8a was found to
have a recrystallization transition at 138C. Further heating
caused the compound to melt at 25.58C into a liquid-
crystalline phase, which transformed into an isotropic melt
at 468C. Thus, the addition of sodium triflate (NaSO3CF3) to 8
caused the clearing temperature to increase by 138C above
that of uncomplexed 8.
Miscibility experiments demonstrated that 8 and 8a formed
the same type of mesophase. Compounds 8 and 8a can be
mixed in all proportions without any miscibility gap forming
in the mesophase region; the same was found to be true for 8a
and the B:NaCF3SO3 complex. Since this complex exhibits a
hexagonal columnar disordered mesophase,[9] according to
the Arnold ± Sackmann rule, both the synthesized amphi-
philes formed this mesophase (Scheme 3).
Scheme 3. The contact preparation technique[11] proves that the structure
of the thermotropic mesophase of 7, 8 and 8a is hexagonal columnar
disordered (Colhd).
As the most stable thermotropic mesophase was observed
with complex 8a, this substance was chosen for the first
investigation of lyotropic mesomorphism. In previous stud-
Figure 4. Schematic binary phase diagram of 7 and A and the correspond-
ing polarized optical micrographs of the contact preparation.
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U. Beginn et al.
FULL PAPER
ies,[5, 12] ªLowicryl HM20ºÐa methacrylate mixture that
undergoes low volume shrinkage on polymerizationÐwas found
to be a good solvent for the presented class of compounds.
Figure 6 depicts the pseudo-binary phase diagram of the
system 8a/HM20. The solid ± solid transition, the melting and
the isotropisation transition of 8a were detected for mixtures
Figure 6. Pseudo-binary phase diagram of the system 8a/HM20, obtained
from DSC measurements. Heating rate: 10Kmin À1, isotropisation temper-
~
&
*
ature ( ), melting temperature ( ), low temperature peak ( ). C ˆ crys-
talline phase, Col ˆ columnar mesophase, L ˆ lyotropic phase, I ˆ isotropic
phase.
that contained as little as 10wt% of the solute. Gelation of
the 8a/HM20mixtures was observed when the samples, which
contained at least 10wt% 8a, were cooled for several hours
below 158C or annealed for 20minutes at À188C. The gels
were all clear and transparent. Details on the gel formation
and the gel morphologies will be reported elsewhere.[13]
The presence of a mesophase was observed over the whole
concentration range. From 0wt% to 10wt% solvent content,
the isotropization temperatures of 8a/HM20decreased con-
siderably (ca. 0.68C/wt%). In this region, polarized microscopy
showed the whole sample to have a uniform texture (Figure 7).
This was attributed to a lyotropic columnar mesophase. In
mixtures with larger solvent concentrations, this texture was
found in single islands, surrounded by an isotropic liquid (see
Figure 7 bottom). The fraction of the isotropic phase in-
creased with higher dilution of the mesogen. When a solvent
content of about 10wt% was exceeded, the melting temper-
atures became constant and the isotropization temperature
varied more slowly (ca. 0.098C/wt%) with concentration.
It was deduced that the columnar mesophase of 8a can
include up to approximately 10wt% of the solvent. At higher
solvent content, phase separation into the lyotropic columnar
phase and an isotropic methacrylate phase occurred. Below
178C, the mixtures are solid gels that consist of coexisting
solids and a liquid phase. Between 20and 32 8C, the crystalline
phase melted into the mesophase and the gels decomposed
due to macroscopic phase separation.
Figure 7. Optical micrographs of 8a/HM20mixtures between crossed
polarizers. Top: 8a at 288C. Bottom: 8a/HM20 ˆ 15 wt%/85 wt% at 218C.
mesomorphism. We thus demonstrated the formations of
novel supramolecular tectons with a functional core envel-
oped by a coat of polymerizable groups. Methacrylation
caused the transition temperatures to decrease relative to that
of the nonfunctionalized substances. Miscibility experiments
proved that all the functionalized amphiphiles formed a
hexagonal columnar disordered (Colhd) mesophase.
In a parallel approach, Gin et al. recently reported the
synthesis and self-assembly of 3,4,5-tris(acryloylalkyloxy)ben-
zoates.[14, 15]
Unusual aspects of the compounds described here are the
stacking of a receptor group in the center of the columns and
the lyotropic-ordering reported above. This class of supra-
molecular assembly can provide new opportunities for the
synthesis of supramolecular gels and the preparation of
functional membranes that contain self-organized transport
channels. The latter will be the subject of forthcoming reports.
Experimental Section
General: Infrared spectra were were run on a BRUKER IFS 113V
spectrophotometer. The samples were placed in KBr pellets for the
measurements which were performed in transmission mode. GC chromato-
grams were recorded with a Perkin ± Elmer Autosystem gas chromatograph
with a 25 m Optima 5 column (95% PDMS, 4% PDPhS, 1% PDVS, film
thickness 0.5 mm, ID 0.32 mm). Helium was used as carrier gas at a flow rate
Conclusion
The tris-methacrylated wedge-like molecules 7 and 8 and
complex 8a exhibited columnar thermotropic and lyotropic
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Supramolecular Organogels
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of about 2 mLminÀ1
.
1H NMR (200 MHz) and 13C NMR (50.4 MHz)
0.116 mol) in absolute THF (250 mL) was dropped slowly into the refluxing
suspension, and the resulting reaction mixture was subsequently heated
overnight. At ambient temperature, the excess hydride was destroyed by
careful addition of moist THF, and the resulting slurry was acidified with
10wt% dilute hydrochloric acid. After rotary evaporation of the THF/
water mixture, the residue was taken up in diethyl ether and, after the
solution was dried over sodium sulfate, the solvent was removed again. The
raw product was purified by crystallization from hexane. Yield: 29.8 g
(92.9%) white plate-like crystals; m.p. 49.5 ± 50.58C; TLC (silica gel 60,
spectra were recorded at 258C on a BRUKER AC200 spectrometer, with
tetramethylsilane as internal standard. DSC measurements were obtained
with samples of about 4 ± 6 mg on a Perkin ± Elmer DSC 7 equipped with a
TAS 7 data processor. The samples were heated by 108CminÀ1, after being
cooled from room temperature by 108CminÀ1. Transition temperatures
were taken as the onset of the endotherm during the second heating scan.
Water, gallium, indium, cyclopentane, and cyclohexane were used as
calibration standards. A Zeiss Axioskop equipped with a Mettler Hotstage
FP 82 and a Zeiss MC 80photoautomat was used for the thermo-optical
analyses. GC/MS analyses were performed with a Finnigan MATSSQ700
mass spectrometer coupled to a Varian 3400 gas chromatograph. The GC-
column (DB5 MS from J&W Scientific) had a length of 30m, an internal
diameter of 0.25 mm, and a film thickness of 0.25 mm. Helium was used as
carrier gas at a flow rate of ca. 1 mLminÀ1. Abbreviations: s ˆ singlet, d ˆ
doublet, t ˆ triplet, qui ˆ quintet, m ˆ multiplet, tRet ˆ retention time, RF ˆ
retention factor.
CH2Cl2): Rf ˆ 0.3, GC(tRet ˆ 10.68 min): purity > 99.5%; GC-MS: m/z: 959
‡
[M ] (>99%); 1H NMR (CDCl3): d ˆ 1.31 (m, 12H; CH2 CH-
ˆ
3
À
À
À
CH2(CH2)6 ), 1.78 (qui, J(H,H) ˆ 6.9 Hz, 2H; (CH2)6CH2CH2O ), 2.06
3
3
ˆ
À
(qui, J(H,H) ˆ 6.1 Hz, 2H; CH2 CHCH2 ), 3.96 (t, J(H,H) ˆ 5.8 Hz, 2H;
À
À
À
ˆ
À
CH2OPh ), 4.63 (s, 2H; CH2OH), 4.96 (m, 2H; CH2 CH ), 5.82 (m,
3
ˆ
À
1H; CH2 CH ), 6.91 (d, J(H,H) ˆ 7.7 Hz, 2 H ; Haromatic, ortho to O), 7.27
(d, 3J(H,H) ˆ 7.6 Hz, 2H; Haromatic, ortho to CH2 group); 13C NMR (CDCl3):
À
À
À
d ˆ 26.07 ± 33.84 (Calkyl), 65.07 ( CH2OH), 68.08 ( CH2OPh ), 114.09
ˆ
À
(CH2 CH ), 114.50(C aromatic, ortho to alkyloxy chain), 128.65 (Caromatic
,
Materials: 9-Borabicyclo[3.3.1]nonane (0.5m in THF, Aldrich), dicyclohex-
ylcarbodiimide (99 ‡ %, Aldrich), N,N-dimethylaminopyridine (99%,
Aldrich), 2-methyl-1,2-diphenylethanone (photoinitiator, 99 ‡ %, Al-
drich), lithium aluminium hydride (99%, Fluka), methyl-4-hydroxyben-
zoate (99 ‡ %, Aldrich), methyl-3,4,5-trihydroxybenzoate (98% Aldrich),
methacryloyl chloride (98% Aldrich), potassium carbonate (Merck, 99%),
phosphorus tribromide (95%, Aldrich), pyridine (p.a. grade, Merck),
ruthenium trichloride dihydrate (90%, Aldrich), sodium hypochlorite
(10wt% solution, Janssen Chimica), thionyl chloride (99 ‡ %, Aldrich),
and 10-undecen-1-ol (95% Aldrich) were used as received. Acetone,
cyclohexane, dichloromethane, N,N-dimethylformamide (DMF), ethyl
acetate, hexane, hydrogen peroxide (30wt% in water), sodium sulfate,
sodium hydrogen carbonate, sodium hydroxide, tetrahydrofuran (THF),
and 2-propanol were gifts from the ªFonds der Chemischen Industrieº. The
solvents were purified by standard procedures. 2-Methyl-[1,4,7,10,13-
pentaoxabenzocyclopentadecane] was synthesized according to a literature
method. The methacrylate resin was selected to exhibit low shrinkage upon
polymerization and consisted of 80mol% 2-ethylhexylmethacrylate,
13 mol% n-hexylmethacrylate and 7 mol% triethylene glycol dimethacry-
late (HM20, Low GmbH).
À
ortho to CH2OH group), 132.953 (Caromatic, a to CH2OH group), 139.254
ˆ
À
(CH2 CH ), 158.803 (Caromatic, a to alkoxy chain); IR (KBr): nÄ ˆ 3324,
3220, 2936, 2920, 2850, 1643, 1613, 1583, 1512, 1475, 1470, 1424, 1395, 1367,
1337, 1319, 1256, 1208, 1198, 1169, 1112, 1049, 1038, 1016, 960, 911, 849, 837,
816, 773, 748, 719, 634, 590, 526, 510 cmÀ1; elemental analysis calcd (%) for
C18H28O2: C 78.21, H 10.21; found C 78.06, H 10.16.
10-Undecenyl-1-oxybenzyl chloride (4): At room temperature, thionyl
chloride (10.24 g, 0.86 mol) was dropped slowly into a solution of 3 (17 g,
0.615 mol) and dry DMF (5 mL) in absolute dichloromethane (200 mL).
After the reaction mixture was stirred for two hours, the liquids were
removed by vacuum distillation and the residue was dried at 208C/0.01 torr.
Yield: 18.1 g (100%) pale yellow oil; TLC (silica gel 60, CH2Cl2): Rf ˆ 0.9;
GC (tRet ˆ 10.5 min): purity >99.5%; 1H NMR (CDCl3): d ˆ 1.31 (m, 12H;
CH2 CHCH2(CH2)6 ), 1.78 (qui, 3J(H,H) ˆ 6.8 Hz, 2H;
(CH2)6-
ˆ
À
À
3
À
ˆ
À
CH2CH2O ), 2.06 (qui, J(H,H) ˆ 6.1 Hz, 2H; CH2 CHCH2 ), 3.96 (t,
3
À
À
À
J(H,H) ˆ 5.6 Hz, 2H; CH2OPh ), 4.63 (s, 2H; CH2Cl), 4.96 (m, 2H;
CH2 CH ), 5.82 (m, 1H; CH2 CH ), 6.91 (d, 3J(H,H) ˆ 7.8 Hz, 2H;
ˆ
À
ˆ
À
3
Haromatic, ortho to O), 7.27 (d, J(H,H) ˆ 7.7 Hz, 2H; Haromatic, ortho to CH2
group); 13C NMR (CDCl3): d ˆ 26.07 ± 33.49 (Calkyl), 46.011 ( CH2Cl),
À
À
À
ˆ
À
11-Bromo-1-undecene (1): The reaction between 11-undecen-1-ol (130mL,
0.645 mol) and phosphorus tribromide was performed in diethyl ether,
according to a literature procedure,[16] to yield 117.62 g, 78.4%, of a clear
yellowish liquid. B.p. 68 ± 708C (0.07 torr); purity >99% according to GC
67.685 ( CH2OPh ), 113.804 (CH2 CH ), 114.320(C aromatic, ortho to OCH2
group), 129.731 (Caromatic, ortho to CH2OH group), 130.029 (Caromatic, a to
ˆ
À
À
CH2Cl group), 139.286 (CH2 CH ), 159.358 (Caromatic, a to OCH2 group);
IR (KBr): nÄ ˆ 2926, 2854, 1640, 1612, 1584, 1514, 1467, 1391, 1302, 1247,
(tRet ˆ 5.91 min); GC-MS: m/z: 418 [M ]; 1H NMR (CDCl3): d ˆ 1.31 (m,
1175, 1110, 1028, 995, 910, 830, 733, 671, 665, 634 cmÀ1
.
‡
3
ˆ
À
12H; CH2 CHCH2(CH2)6 ), 1.78 (qui, J(H,H) ˆ 6.9 Hz, 2H; (CH2)6CH2-
3,4,5-Tris(10-undecenyl-1-oxybenzoyl)methylbenzoate (5): A well-stirred
mixture of 3,4,5-tris-hydroxyethylbenzoate (3.96 g, 20mmol), potassium
carbonate (24 g, 180mmol) and dry DMF (100mL) was flushed with argon
for 30min. After the mixture was heated to 60 8C, benzyl chloride 4 (18.2 g,
61 mmol) was slowly added and left to react for 16 h. The reaction mixture
was cooled to 208C and poured into well-stirred ice-water (1000 mL). The
organic layer was separated and the aqueous phase was extracted with
diethyl ether (3 Â 200 mL). The combined organic phases were subse-
quently washed with diluted hydrochloric acid and water. The organic
phase was dried over sodium sulfate, and after rotary distillation of the
solvent, the resulting brown oil was recrystallized twice from 2-propanol.
Yield: 9.73 g (50%) white powder; TLC: (silica gel 60, CH 2Cl2: Rf ˆ 0.6;
GC (tRet ˆ 9.7 min) purity >99.5%; 1H NMR (CDCl3): d ˆ 1.31 (m, 12H;
3
3
ˆ
À
CH2-), 2.03 (qui, J(H,H) ˆ 6.3 Hz, 2H; CH2 CHCH2 ), 3.44 (t, J(H,H) ˆ
6.7 Hz, 2H; CH2Br), 5.00 (m, 2H; CH2 CH ), 5.81 (m, 3J(Ha,Hb) ˆ
ˆ
À
10.3 Hz, 3J(Ha,Hc) ˆ 35 Hz, 3J(Hb,Hc) ˆ 16.9 Hz, 1H; CH H CH );
13C NMR (CDCl3): d ˆ 33.72 (C(C-Br)), 28.11 ± 33.65 (C2 ± C9), 111.05
b
c
a
ˆ
ˆ
À
ˆ
(C(CH2 CH )), 138.9 (C(CH2 CH)); elemental analysis calcd (%) for
C11H21Br: C 77.14, H 10.0; found C 77.98, H 10.16.
Methyl (10-undecenyl-1-oxy)benzoate (2): In analogy to
a literature
method,[17] 11-bromo-1-undecene (67.5 g, 0.289 mol), methyl 4-hydroxy-
benzoate (1) (41.9 g, 0.275 mol), potassium carbonate (114.0 g, 0.825 mol)
and acetone (600 mL) were converted into 2, which was recrystallized from
hexane. Yield: 79.5 g (94.9%) white plate-like crystals; m.p. 57 ± 598C
(DSC measurement 108CminÀ1); TLC (silica gel 60/CH2Cl2): Rf ˆ 0.8; GC
(tRet ˆ 11.15 min): purity >99.5%; 1H NMR (CDCl3): d ˆ 1.31 (m, 12H;
CH2 CHCH2(CH2)6 ), 1.78 (qui, 3J(H,H) ˆ 6.6 Hz, 2H;
(CH2)6-
ˆ
À
À
CH2 CHCH2(CH2)6 ), 1.78 (qui, 3J(H,H) ˆ 6.8 Hz, 2H;
(CH2)6-
3
ˆ
À
À
À
ˆ
À
CH2CH2O ), 2.06 (qui, J(H,H) ˆ 6.3 Hz, 2H; CH2 CHCH2 ), 3.76 (t,
3
À
ˆ
À
3J(H,H) ˆ 6.66 Hz, 3H; OCH2CH3), 3.95 (m, 6H; CH2OPh ), 4.35
CH2CH2O ), 2.04 (qui, J(H,H) ˆ 6.2 Hz, 2H; CH2 CHCH2 ), 3.88 (s,
À
À
À
3
À
À
3H; COOCH3), 3.96 (t, J(H,H) ˆ 6.5 Hz, 2H; CH2OPh ), 4.96 (m, 2H;
À
ˆ
À
À
(quartet, 2H; OCH2CH3), 5.02 (m, 12H; CH2 CH , PhCH2O ), 5.83 (m,
CH2 CH ), 5.82 (m, 3J(Hb,Ha) ˆ 10.3 Hz, 3J(Ha,Hc) ˆ 35 Hz, 3J(Hb,Hc) ˆ
3
ˆ
À
ˆ
À
1H; CH2 CH ), 6.76 (d, J(H,H) ˆ 8.65 Hz, 2H; Haromatic, ortho to Ointernal),
b
c
a
3
ˆ
16.9 Hz, 1H; CH H CH ), 6.91 (d, J(H,H) ˆ 8.7 Hz, 2H; Haromatic, ortho
3
6.91 (d, J(H,H) ˆ 8.6 Hz, 4H; Haromatic, ortho to Oexternal), 7.35 (mbroad, 8H;
to O), 7.27 (d, 3J(H,H) ˆ 8.4 Hz, 2H; Haromatic, ortho to CH2 group);
Haromatic, ortho to CH2 group and ortho to CO group); 13C NMR (CDCl3):
À
13C NMR (CDCl3): d ˆ 25.87 ± 33.695 (Calkyl), 51.66 ( COOCH3), 68.04
À
À
d ˆ 14.319 ( COOCH2CH3), 24.309 ± 29.464 (Calkyl), 33.747 (CH2OPh-
À
À
ˆ
( CH2OPh ), 113.92 (CH2 CH), 114.037 (Caromatic, ortho to alkoxy chain),
À
À
À
À
CH2O ), 60.957 ( PhCH2OPh ), 71.026 ( COOCH2CH3), 109.107
À
À
122.8 (Caromatic, a to COOCH3 group), 130.7 (Caromatic, ortho to COOCH3
group), 139.009 (CH2 CH ), 162.833 (Caromatic, a to alkyloxy chain), 166.72
( COOCH3)); elemental analysis calcd (%) for C19H28O3: C 74.96, H 9.27;
found C 74.34, H 9.17.
À
ˆ
À
(Caromatic, ortho to COOCH2CH3 group), 114.075 (CH2 CH ), 114.375
(Caromatic, carbon in side unit, ortho to alkyloxy chain), 125.283 (Caromatic, a to
COOC2H5 group), 128.5 (Caromatic, carbon in side unit, ortho to CH2OPh
group), 129.26 (Caromatic, carbon in side unit, a to CH2OPh group), 139.254
ˆ
À
À
ˆ
À
10-Undecenyl-1-oxybenzyl alcohol (3): Under an argon atmosphere,
LiAlH4 (7.75 g, 0.204 mol) was suspended in absolute THF (50 mL), with
vigorous stirring. A solution of methyl 10-undecenyl-1-oxybenzoate (35.5 g,
(CH2 CH ), 142.294 (Caromatic, 4' and para to COOC2H5 group), 152.53
(Caromatic, 3' and 5' to COOC2H5), 166.171 (COOC2H5); elemental analysis
calcd (%) for C62H86O8: C 77.62, H 9.04; found C 77.63, H 9.13.
Chem. Eur. J. 2000, 6, No. 11
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2021

U. Beginn et al.
FULL PAPER
3,4,5-Tris(11-hydroxyundecyl-1-oxybenzyloxy)benzoic acid (6): Under an
argon atmosphere, 5 (1 g, 1 mmol) dissolved in absolute THF (5 mL), was
slowly added to a solution of 9-BBN in absolute THF (9 mL, 0.5m,
4.5 mmol); the mixture was kept at 668C for one hour. After the complete
conversion of 5 was shown by TLC, the mixture was cooled to 208C, and
ethanol (5 mL) was added carefully to it. Subsequently, sodium hydroxide
(10mL, 6 n) and hydrogen peroxide (20mL, 30%) were slowly added, and
the solution was refluxed for another hour. During the whole operation, the
reaction apparatus was flushed with argon. The solvent was removed by
rotary evaporation, the residue was dissolved in water, and this solution was
acidified with diluted hydrochloric acid and extracted four times with
dichloromethane. After the organic phases were dried over sodium sulfate,
the solvent was evaporated, and the waxy raw material was taken up in a
small amount of THF. It was purified by precipitation from 50mL hexane.
Yield: 0.8 g (78.4%) white powder; m.p. 70 ± 718C; TLC (silica gel 60,
CH2Cl2): Rf ˆ 0 ; GC (tRet ˆ 8.5 min) purity >99.5%; 1H NMR (CDCl3): d ˆ
sized following the procedure described in ref. [9]. Compound 7 (1.178 g,
0.98 mmol) and 4-hydroxybenzo 15-crown-5 (0.292 g; 0.98 mmol) were
dissolved in dry dichloromethane (5 mL) in a round-bottomed flask
equipped with a magnetic stirrer. 4-Dimethylaminopyridinium toluene-p-
sulfonate (DPTS) (57.7 mg, 2 mmol, 20mol%) and 1,3-dicyclohexylcarbo-
diimide (DCC; 222 mg, 0.11 mmol) were added to this solution. The
reaction mixture was stirred for 12 h at room temperature. Then the
reaction was filtered and the filtrate was added to methanol to precipitate
the product, which was collected by vacuum filtration and was purified by
column chromatography (silical gel 60, cyclohexane/ethyl acetate 1:1).
Yield: 1.1 g (90%) yellowish oily-waxy material; TLC (silica gel 60,
cyclohexane/ethyl acetate 1:1): one spot, Rf ˆ 0.87; 1H NMR (CDCl3):
ˆ
À
À
d ˆ 1.31 (m, 52H; CH2 C(CH3)COOCH2(CH2)6 ), 1.56 (m, 6H; (CH2)6-
À
ˆ
À
CH2CH2O ), 1.78 (m, 6H; CH2 C(CH3)COOCH2CH2 ), 1.96 (s, 9H;
ˆ
À
À
À
CH2 C(CH3)COO ), 3.76 (s, 8H; OCH2CH2O ), 3.94 (m, 2H;
CH2OPh internal), 3.97 (t, 3J(H,H) ˆ 7.0Hz, 4H; CH2OPh external),
À
À
À
ˆ
À
À
À
À
À
À
1.31 (m, 52H; CH2 CH CH2 (CH2)6 ), 1.57 (m, 6H; (CH2)6CH2CH2O ),
4.11 ( m, 4H; C6H4OCH2CH2O ), 4.99 (s, 2H; OC6H4CH2OC6H2CO2 of
À
À
À
À
À
À
1.77 (m, 6H; HOCH2CH2 ), 3.64 (t, 3J(H,H) ˆ 6.6 Hz, 6H; HOCH2 ), 3.97
4' position) 5.02 (s, 2H; ArCH2O internal), 5.05 (s, 4H; ArCH2O
external), 5.24 (s, 2H; C6H4CO2CH2C6H2 ), 5.5 (s, CH2 C(CH3)COO
À
À
À
À
À
À
ˆ
À
(m, 6H; CH2OPh ), 4.58 (s, 1H; OH), 4.95 (s, 1H; OH), 5.02 (s, 2H;
ArCH2O internal), 5.05 (s, 4H; ArCH2O external), 6.78 (d, 3J(H,H) ˆ
8.6 Hz, 2H; Haromatic, ortho to Ointernal), 6.93 (d, 3J(H,H) ˆ 8.5 Hz, 4H;
Haromatic, ortho to Oexternal), 7.23 ± 7.37 (m, 8H; Haromatic, ortho to CH2 group
and ortho to CO group); 13C NMR (CDCl3): d ˆ 25.601 ± 32.637 (Calkyl),
3
ˆ
À
internal), 6.13 (s, CH2 C(CH3)COO external), 6.78 (d, J(H,H) ˆ 8.6 Hz,
2H; Haromatic, ortho to Ointernal), 6.93 (d, 3J(H,H) ˆ 8.5 Hz, 4H; Haromatic
,
ortho to Oexternal), 6.90± 6.93 (overlapping peaks, 3H; aromatic crown
protons), 7.26 (d, 3J(H,H) ˆ 8.6 Hz, 2H; H aromatic, meta to O of internal
benzyl ring), 7.30(d, 3J(H,H) ˆ 8.7 Hz, 4H; meta to O of external benzyl
ring), 7.38 (s, 2H; ortho to CO2); 13C NMR (CDCl3): d ˆ 18.31
À
À
À
À
36.183 ( CH2OPhCH2O ), 52.06 (PhCH2OPh ), 62.875 (HOCH2 ), 67.897
À
(HOCH2 ), 109.014 (Caromatic
,
ortho to COOH group), 113.941
ˆ
ˆ
(C(CH2 CH-)), 114.317 (Caromatic, in side unit, ortho to alkyloxy chain),
124.846 (Caromatic, a to COOH group), 128.984 (Caromatic, in side unit, ortho to
CH2OPh group), 130.121 (Caromatic, in side unit, a to CH2OPh group),
142.284 (Caromatic, 4' and para to COOH group), 152.48 (Caromatic, 3' and 5' to
COOC2H5), 166.625 (COOH); elemental analysis calcd (%) for C61H90O11:
C 73.31, H 9.04; found C 76.44, H 9.41.
(CCH2 CCH3), 25.95 ± 30.287 (Calkyl), 52.06 (CH2OPhCH2Oexternal), 64.80
(CH2OPhCH2Ointernal), 67.997 (CH2OPhexternal), 74.64 (CH2OPhinternal),
109.153 (Caromatic, ortho to COOH group), 114.317 (Caromatic, in side unit,
ortho to alkyloxy chain), 124.846 (Caromatic
, a to COOH), 125.489
ˆ
(CCH2 C(CH3), 3' ,5'), 128.984 (Caromatic, in side unit, ortho to CH2OPh),
ˆ
129.42 (CCH2 C(CH3), 4' position), 130.224 (Caromatic, in side unit, a to
ˆ
CH2OPh), 136.514 (CCH2 C(CH3)), 142.284 (Caromatic, in 4' and para
3,4,5-Tris(11-methacryloylundecyl-1-oxybenzyloxy)benzoic acid (7): Un-
der a nitrogen atmosphere, a solution of 6 (0.78 g, 0.78 mmol), triethyl-
amine (0.47 g, 3.4 mL), DMAP (95.34 mg, 0.78 mmol) and 2,6-di-tert-butyl-
4-methylphenol (0.86 mg, 0.007 mmol) in dichloromethane (5 mL) was
cooled to 08C. After slow addition of methacryloyl chloride (0.49 g,
4 mmol), the solution was allowed to warm to room temperature and was
stirred for 48 h. On complete conversion of the acid chloride (TLC
control), the mixture was filtered and the solvent was removed by rotary
evaporation. The reaction product was refluxed with a solution of water
(10mL) in pyridine (30mL) for 10min; the resultant mixture was then
cooled to 208C and acidified with diluted hydrochloric acid. Subsequently,
the aqueous phase was extracted four times with diethyl ether, and the
combined organic layers were washed with aqueous NaHCO3 solutions
(10%) and were then dried over anhydrous sodium sulfate. The diethyl
ether was removed and the remaining raw product was purified by column
chromatography (silica gel 60, cyclohexane/ethylacetate 1:1). Yield: 0.8 g
(81%) oily to waxy material; TLC (silica gel 60, cyclohexane/ethylacetate
1:1): one spot, Rf ˆ 0.63; 1H NMR (CDCl3): d ˆ 1.31 (m, 52H;
position to COOH), 152.60(C aromatic, in 3' and 5' position to COOH),
166.625 (CCOOCH2), 166.71 (CCOOH); IR (KBr): nÄ ˆ 3512, 3405, 3074,
3075, 2976, 2926, 2854, 1716, 1640, 1613, 1586, 1514, 1467, 1446, 1431, 1392,
1368, 1331, 1302, 1248, 1102, 1057, 1030, 994, 963, 910, 864, 823, 768, 723,
637, 593, 518 cmÀ1; elemental analysis calcd (%) for C88H122O19: C 71.23, H
8.29; found C 70.80, H 8.01.
Preparation of the 1:1 sodium triflate complex 8a: Complex 8a was
prepared by mixing a solution of 8 (100 mg) in dry THF (5 mL) with an
appropriate volume of dry THF that contained NaSO3CF3 (0.05m). After
slow evaporation of the solvent under reduced pressure at 208C, the solid
was dried in vacuo at 408C until the weight remained constant.
Acknowledgements
The authors gratefully acknowledge V. Percec for valuable suggestions and
discussions. The work was funded by the German research ministry (BMBF
project ªGel template leachingº, no 03D0047 5).
ˆ
À
À
À
CH2 C(CH3)COOCH2(CH2)6 ), 1.56 (m, 6H; (CH2)6CH2CH2O ), 1.78
ˆ
À
ˆ
À
(m, 6H; CH2 C(CH3)COOCH2CH2 ), 1.96 (s, 9H; CH2 C(CH3)COO ),
3.94 (m, 2H; CH2OPh internal), 3.97 (t, 3J(H,H) ˆ 7.0Hz, 4H; -C H2OPh
À
À
external), 5.02 (s, 2H; ArCH2O internal), 5.05 (s, 4H; ArCH2O
ˆ
ˆ
external), 5.5 (s, CH2 C(CH3)COO internal), 6.13 (s, CH2 C(CH3)COO
external), 6.78 (d, 3J(H,H) ˆ 8.6 Hz, 2H; Haromatic, ortho to Ointernal), 6.93 (d,
3J(H,H) ˆ 8.5 Hz, 4H; Haromatic, ortho to Oexternal), 7.23 ± 7.37 (m, 8H;
Haromatic, ortho to CH2 and ortho to CO); 13C NMR (CDCl3): d ˆ 18.31
[1] B. Alberts, D. Bray, J. Lewis, M. Raff, K. Roberts, J. D. Watson, The
Molecular Biology of the Cell, 3rd ed, Garland, New York, 1994.
[2] P.-G. deGennes, Scaling Concepts in Polymer Physics, Cornell
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[3] V. Percec, C.-H. Ahn, W.-D. Cho, A. M. Jamieson, J. Kim, T. Leman,
M. Schmidt, M. Gerle, M. Möller, S. A. Prokhorova, S. S. Sheiko,
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2839.
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[7] a) J. Boissonade, J. Phys. A 1983, 16, 2777; b) M. Sinclair, K. C. Lim,
A. J. Heeger, Phys. Rev. Lett. 1983, 51, 1768; c) A. L. R. Bug, S. A.
Safran, I. Webman, Phys. Rev. B 1986, 33, 4716.
ˆ
(CH2 CCH3), 25.95 ± 30.287 (Calkyl), 52.06 (CH2OPhCH2Oexternal), 64.80
(CH2OPhCH2Ointernal), 67.997 (CH2OPhexternal), 74.64 (CH2OPhinternal), 109.153
(Caromatic, ortho to COOH group), 114.317 (Caromatic, in side unit, ortho to
alkyloxy chain), 124.846 (Caromatic, a to COOH group), 125.489 (CH2
ˆ
C(CH3) of 3',5' position), 128.984 (Caromatic, in side unit, ortho to CH2OPh),
ˆ
129.42 (CH2 C(CH3), the 4' position), 130.224 (Caromatic, in side unit, a to
ˆ
CH2OPh), 136.514 (CCH2 C(CH3)), 142.284 (Caromatic, in 4' and para
position to COOH group), 152.60(C aromatic, in 3' and 5' position to COOH
group), 166.625 (CCOOCH2), 166.71 (CCOOH); IR (KBr): nÄ ˆ 2926, 2854,
1719, 1638, 1614, 1594, 1515, 1466, 1435, 1419, 1384, 1338, 1298, 1247, 1173,
1131, 1072, 1072, 939, 913, 862, 817, 764, 722, 657, 593, 514 cmÀ1; elemental
analysis calcd (%) for C73H102O14: C 72.85, H 8.54; found C 72.40, H 8.21.
2-Methyl-(1,4,7,10,13-pentaoxacyclopentadecane)-3,4,5-tris[4-(11-meth-
acryloyl-undecyl-1-oxy)benzyloxy]benzoate (8): Compound 8 was synthe-
2022
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0947-6539/00/0611-2022 $ 17.50+.50/0
Chem. Eur. J. 2000, 6, No. 11

Supramolecular Organogels
2016±2023
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[14] E. Juang, K. B. Schwartz, H. Deng, J. A. Reimer, D. L. Gin, Polym.
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Perkin Trans. 1, 1993, 1411.
[10] H. Sackmann, D. Demus, Z. Phys. Chem. 1963, 222, 143.
[11] L. Kofler, A. Kofler, M. Brandstätter, Thermo-Mikro-Methoden,
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[15] H. Deng, D. L. Gin, R. C. Smith, J. Am. Chem. Soc. 1998, 120, 3522.
[16] A. Roedig, Methoden Org. Chem. (Houben-Weyl) 4th ed., Vol. V/4,
p. 389.
[17] M. Kelly, R. Buchecker, Helv. Chim. Acta 1988, 71, 461.
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2379.
Received: September 15, 1999 [F2035]
Chem. Eur. J. 2000, 6, No. 11
ꢀ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000
0947-6539/00/0611-2023 $ 17.50+.50/0
2023