Synthesis and structural studies of polyphilic mesogens with central or terminal perfluoroalkyl chains

Article abstract of DOI:10.1021/jp972613c

Benzyl 4-iodoperfluorobutanoate was synthesized by partial pyrolysis of perfluoroglutaryl chloride in the presence of potassium iodide followed by esterification. This compound gives access to mesogenic molecules with alkyl chain, perfluoroalkyl central bridge, and biphenyl moieties. Segregation of these chemical fragments depends on the molecular design. The molecule with a central alkyl chain forms smectic A layers (123-145°C) with interdigitation of aliphatic and aromatic parts. In contrast, the smectic E phase is observed between 60 and 87°C when the perfluoroalkyl chain is in the center of the molecule. In this case, X-ray diffraction data are consistent with the presence of three sublayers differing in their chemical nature.

Full text of DOI:10.1021/jp972613c

52
J. Phys. Chem. B 1998, 102, 52-60
Synthesis and Structural Studies of Polyphilic Mesogens with Central or Terminal
Perfluoroalkyl Chains
Sandrine Pensec, Franc¸ois-Gene`s Tournilhac,* Pierre Bassoul, and Claire Durliat
ESPCI (CNRS URA429) Chimie Inorganique et Mate´riaux Mole´culaires, 10 rue Vauquelin,
75231 Paris Cedex 05, France
ReceiVed: August 11, 1997; In Final Form: October 9, 1997X
Benzyl 4-iodoperfluorobutanoate was synthesized by partial pyrolysis of perfluoroglutaryl chloride in the
presence of potassium iodide followed by esterification. This compound gives access to mesogenic molecules
with alkyl chain, perfluoroalkyl central bridge, and biphenyl moieties. Segregation of these chemical fragments
depends on the molecular design. The molecule with a central alkyl chain forms smectic A layers (123-145
°C) with interdigitation of aliphatic and aromatic parts. In contrast, the smectic E phase is observed between
60 and 87 °C when the perfluoroalkyl chain is in the center of the molecule. In this case, X-ray diffraction
data are consistent with the presence of three sublayers differing in their chemical nature.
1. Introduction
The macroscopic properties of molecular materials are closely
related to the type of symmetry and organization existing in
the condensed phase considered. In this respect, any pertinent
factor permitting one to predict, to some extent the type of
structures that will be encountered with a given molecule is of
utmost interest.
The amphiphilic character, initially defined by Hartley1 for
explaining the organization properties of soaps, is now consid-
Figure 1. The three polyphilic compounds investigated.
ered to be relevant even for thermotropic liquid crystals.2
Lyotropic mesogens have two parts, one hydrophilic and one
alkyl and biphenyl moieties at the extremities form smectic
hydrophobic, and their segregation induces the formation of
cylinders, lamellae, etc. On the basis of structural similarities
between lyotropic and thermotropic liquid crystals, Skoulios and
layers composed of well-defined sublayers, exactly as expected
from polyphilic compounds. In contrast, compound 13 with
the alkyl chain in the middle of the sequence is only partially
segregated, the alkyl and biphenyl fragments being interdigi-
tated.
co-workers3 recognized that the very existence of smectic phases
was also related to amphiphilicity. The majority of smectogens
have a polarizable rigid core bearing one or several flexible
side chains. They can be considered as amphiphilic molecules
as soon as the two different chemical fragments segregate in
the smectic layers.
2. Synthesis
As a generalization of this concept, polyphilic compounds4
are made up of a sequence of (more than two) fragments
differing by their chemical nature. In the mesomorphic state,
unlike fragments have a tendency to form segregated sublayers.
Perfluoroalkyl chains have been widely used in the design
of polyphilic materials5-10 but always as end groups. Starting
from benzyl 4-iodoperfluorobutanoate, we have initiated the
synthesis of new polyphilic compounds incorporating a per-
fluoroalkyl section in the middle of the molecule.
Three typical molecules of different chemical architecture
(compounds 9, 13, and 15, Figure 1) were synthesized. The
X-ray study of their mesophase organization was used to
characterize the polyphilic behavior of these materials. We
found that the diblock biphenyl/perfluoroalkyl molecule, 15, and
the triblock one, 9, with a central perfluoroalkyl chain and the
Perfluoroalkyl iodides permit the formation of stable C-C
bonds by the Ullman reaction11 or by free-radical addition to
olefines followed by dehalogenation.12,13 These reactions are
commonly used in the design of highly fluorinated molecular
materials.14-17 Symmetric R,ω-diiodoperfluoroalkanes are avail-
able by several routes18-20 and their use in the design of
mesomorphic polymers was reported.21 However, to our
knowledge there is no efficient procedure for the synthesis of
a perfluoroalkyl chain bearing two different reactive groups in
the R and ω positions.
When reacting perfluoroglutaryl chloride with potassium
iodide at 200-400 °C (Scheme 1), McLoughlin noticed the
formation of some amount of 4-iodoperfluorobutyryl chloride,20
the latter was isolated in the form of the free acid.
When an excess of potassium iodide is used, both steps can
be regarded as first order. If the same reactivity is assumed
for the two acid chloride groups, the amounts n1, n2, n3 of the
three compounds can be written as a function of the quantity
* Author to whom correspondence should be addressed. E-mail:
fgt@cis.espci.fr.
X Abstract published in AdVance ACS Abstracts, December 1, 1997.
S1089-5647(97)02613-8 CCC: $15.00 © 1998 American Chemical Society
Published on Web 01/01/1998

Synthesis of Polyphilic Mesogens
J. Phys. Chem. B, Vol. 102, No. 1, 1998 53
SCHEME 1
SCHEME 3
SCHEME 2
of starting material, n0 and the degree of conversion ê:
n1 ) n0(1 - ê)2
(1)
(2)
n2 ) 2n0ê(1 - ê)
n3 ) n0ê2
(3)
SCHEME 4
The theoretical amount of 2 passes through the maximum n2
1
) /2n0 when ê ) 0.5. In the original work,20 relatively high
yields (50-60%) of 3 were obtained when using high temper-
atures and long reaction times. In our experiments,22 all
precautions were taken to stop the progression of the reaction
at the optimum time.
The starting material (hexafluoroglutaryl chloride) was vapor-
ized at 220 °C with a nitrogen flow and passed at 350 °C through
a glass tube packed with finely ground potassium iodide. The
reaction time was determined by the flow of nitrogen. The
products were trapped at -78 °C. The degree of conversion,
ê, was estimated by the relative intensities of the 1793 cm-1
(CdO stretching) and 1128 cm-1 (CF stretching) infrared bands;
it was optimized close to the ê ) 0.5 theoretical maximum by
changing the reaction time.
SCHEME 5
Compound 2 is highly sensitive to moisture, is undetectable
by thin-layer or gas chromatography, and can hardly be
distinguished from a mixture of compounds 1 and 3. Due to
these difficulties, we decided to form a versatile derivative of
2 which may be purified and characterized. For this purpose,
the benzyl moiety has the double advantage of being easily
removable23 and light absorbing in the 254 nm region.
The products 1 + 2 + 3 were immediately treated with benzyl
alcohol in toluene in the presence of pyridine, and benzyl
4-iodoperfluorobutanoate 4 was isolated by liquid chromatog-
raphy (Scheme 2). Compound 4 was characterized by NMR,
IR, GC-MS, and elemental analysis. The overall yield did not
exceed 16% but was reproducible when all the above precautions
were taken. In our opinion, this result is perfectible: Ankudinov
et al.24 obtained good yields by reacting 4-(carboxymethyl)-
perfluorobutyryl chloride with sodium or potassium iodide at
200 °C; the electrochemical reduction of perfluoroglutaryl
chloride is also an alternative way to a mixture of compounds
2 and 3.25 Regardless of the method chosen, the key step in
each is to achieve a single substitution onto a bifunctional
molecule.
Compound 9 was synthesized in five steps starting from
benzyl 4-iodo-perfluorobutanoate, 4 (Scheme 3). The homolytic
cleavage of the carbon-iodine bond was induced by the thermal
decomposition of AIBN12,13 hence initiating the 1,2 addition of
4 on 1-decene. The iodine atom in the R position of the
perfluoroalkyl fragment in compound 5 was removed by Zn/
H+ reduction13 and benzyl 2,2,3,3,4,4-hexafluorotetradecanoate,
6, was obtained. The latter was reduced to 2,2,3,3,4,4-
hexafluoro-1-tetradecanol, 7, with the aid of lithium aluminum
hydride. The nonaflate activation26 of 7 proved to be efficient
TABLE 1: Transition Temperatures (°C) of Compounds 9,
13, and 15 Detected by DSCa
compd
K
M
SE
SA
I
9
13
15
b
60 (28.0)
123 (40.8)
72 (14.4)
b
87 (14.4)
b
b
b
b
b
b
145 (9.4)
168 (10.4)
b
b
138 (7.8)
a The transition enthalpies (kJ/mol) are indicated in parentheses.
for initiating the SN2 reaction despite the inductive effect of
vicinal fluorine atoms. In these conditions, 8 reacted with a
phenate in dimethylformamide (DMF) giving rise to the
polyphilic compound 9.
Polyphilic compound 13 with the perfluoroalkyl chain at the
extremity was prepared in four steps using standard procedures5
(Scheme 4): The semifluorinated alcohol 11 was obtained by
1,2 addition of perfluoroalkyl iodide on 9-decen-1-ol followed
by reduction; it was then converted to the bromide 12 and
reacted with 4-methoxy-4′-hydroxybiphenyl giving 13. Com-
pound 15 was prepared similarly from 1H,1H-perfluorooctanol
through nonaflate activation (Scheme 5).
3. Mesomorphic Properties
Investigation of the polymorphism of compound 15 has been
reported;27 this material forms smectic E and A phases (Table
1). The mesomorphic properties of compounds 9 and 13 have
been investigated by differential scanning calorimetry (DSC),

54 J. Phys. Chem. B, Vol. 102, No. 1, 1998
Pensec et al.
Figure 3. The lancet texture of compound 9 in the SE phase, 80 °C,
crossed polarizers, full width ) 1 mm.
Figure 4. The focal conics texture of compound 13 in the SA phase,
130 °C, same conditions as in Figure 3.
Figure 2. DSC thermogram ((5 °C/ min) of compounds 9 (a) and 13
(b).
transition to an ordered smectic mesophase M exhibiting
paramorphotic focal conic textures was observed. At room
temperature, the X-ray diffraction figure of the latter phase
displays several maxima in the vicinity of q ) 1.2-1.5 Å-1
which cannot be indexed in the hexagonal or orthorhombic
systems hence excluding the identification as smectic B or E
phase. The structure of the “M” phase will not be discussed
here.
optical microscopy, and X-ray diffraction. DSC thermograms
were recorded at (5 °C per minute using a Perkin-Elmer DSC
7 apparatus; the transition temperatures and enthalpies are
collected in Table 1. On heating, the polymorphism of 9 was
evidenced by a broad endotherm between 57 and 70 °C and a
well-defined transition at 87 °C (Figure 2a). On cooling, this
transition was detected by an exotherm at 86 °C. The phase
existing below this temperature was then overcooled to 15-20
°C, the temperature at which the compound slowly recrystallizes.
Optical microscopy was carried out using a Leitz Orthoplan
polarizing microscope equipped with a Mettler FP52 hot stage.
On cooling from the isotropic phase, the growth of birefringent
lancets like domains is observed below 87 °C (Figure 3). This
texture characterizes a smectic E phase growing directly from
the isotropic liquid.28 The “lancet texture” was stable down to
room temperature whereupon the recrystallization takes place.
The transitions occurring between 57 and 70 °C correspond to
crystal-crystal transitions and have not been investigated in
details.
4. X-ray Diffraction Experiments.
4.1 Methods. Due to its biaxial symmetry, the smectic E
phase cannot form single domains on application of a magnetic
field or by surface treatements. X-ray spacings and intensities
were determined from powder samples for all compounds, using
the Cu KR radiation. Relative intensities of 00l reflections were
estimated by scanning the films obtained with a Debye-Scherrer
camera and analyzed using the classical formula:30
1
q200l
2
I(q00l)
|F(q00l)| exp(-σ2 q020l)
(4)
The DSC thermogram of compound 13 (Figure 2b) shows
two sharp peaks at 123 and 145 °C with a few degrees of
supercooling for the latter. On cooling from the isotropic phase,
the birefringence of 13 was detected at 145 °C by the growth
of baˆtonnets;29 on further cooling, the characteristic focal conics
texture can be recognized (Figure 4). The mesophase was
identified as smectic A since homeotropic domains were also
present in some portions of the specimens. The smectic A phase
can be overcooled to about 114 °C. On further cooling, a
1/q200l is the relevant Lorentz correction factor at small diffrac-
tion angles, F(q00l) is the structure factor, and σ is the Debye-
Waller coefficient that accounts for positional fluctuations. For
liquid crystals, similar expressions have been established.31 In
the case of rodlike mesogens, the electronic density is supposed
to be uniform within the layers and equal to zero in the interlayer
2
gaps. In the limit case of infinitely thin interfaces, all |F(q00l)|
are equal to unity. This approach cannot explain the nonmono-

Synthesis of Polyphilic Mesogens
J. Phys. Chem. B, Vol. 102, No. 1, 1998 55
Figure 5. Herringbone packing of biaryl cores. Drawn from the data
of ref 37.
tonic decay of the intensities I(q00l) observed in our case: due
to the presence of heavy fluorine atoms in one part of the
molecules, the electronic density can no longer be considered
1
as uniform in the layers. We calculated D structure factors
along the layer normal by considering for each molecular
fragment the number of electrons and the dimensions given by
molecular models and by geometrical considerations. To reduce
the number of adjustable parameters, the width of the interlayer
gap, z, was taken equal to the value previously determined for
compound 1527 (z ) 1.1 Å).
4.2. Structure of the Smectic E Layers of Compound 15.
The geometrical analysis and form factor calculations have
demonstrated that the SE phase of this material is composed of
well-segregated sublayers as expected from the amphiphilic
constitution of the molecule.27 Recent structural investigations
of polyfluoroalkyl-(4-phenylbenzylidene) imines have demon-
strated that the same conclusions are also valid for other
perfluoroalkyl/biphenyl amphiphiles.32 In the biphenyl sublayer,
the long axis of the rigid stems are parallel to the layer normal;
in the layer plane, the elliptic shapes of the aromatic rings form
2
a rectangular arrangement with the p2gg D symmetry. This
herringbone packing which is schematically represented in
Figure 5 is a quite frequent situation for parasubstituted
biphenyls, as a matter of fact, the a and b parameters recorded
in the smectic E phase of fluorinated27,32 and nonfluorinated33,34
smectic E materials are all very close to those reported for poly
paraphenylenes in their monoclinic form.35-37 Perfluoroalkyl
chains, in a liquidlike conformation are located on either side
of the crystalline sublayer.
Figure 6. X-ray diffraction patterns of a: mesogen 9, SE phase at 72
°C; (b) mesogen 13, SA phase, 134 °C (densitometric profile of the
photographic film).
TABLE 2: Experimental Values of the Intensities of the 00l
Reflections in the SE Phase of 9 and the Calculated Values
from the Model of Figure 7
4.3. Structure of the Smectic E Layers of Compound 9.
Diffraction diagrams of the smectic E phase were recorded at
72 °C (Figure 6a, Table 2). They contain three 00l reflections
at small angles corresponding to an interlayer distance of c )
34.5 Å. At larger angles three hk0 reflections were indexed
001
002
003
004
expt
calc
100
100
6.5
5
0.6
0.3
2
0.05
with a D rectangular unit cell of parameters a ) 7.9 Å and b
) 5.6 Å. A broad scattering signal with a maximum at q ) 4π
sin(θ)/λ ) 1.20 Å-1 was recorded (Figure 6a) hence indicating
that a liquidlike order with an average molecular distance of r
) 1.15 × 2π/q ) 6.0 Å is also present within the layers. (For
estimation of this distance, we consider that the local order is
close to a hexagonal packing: r ) (2/x3)(2π/q).) The rectan-
gular cell (a ) 7.9, b ) 5.6 Å) is almost identical to that of
unsubstituted biphenyl (a ) 8.12, b ) 5.63 Å), hence indicating
that the packing is again of the herringbone type (Figure 5). In
this structure, the area available per each biphenyl core in the
ab plane is 22.1 Å.2 The perfluoroalkyl fragments, with a typical
cross section of 27-31 Å2, must be alternated on either side of
the aromatic sublayer (Figure 7). However, in this arrangement,
a surface of 44.2 Å2 is available in the ab plane for each
perfluoroalkyl and alkyl chain. They have to take disordered
conformations which can be related to the presence of a halo
in the diffraction figure. According to this model, the biphenyl
units and their oxymethylene groups are overlapped by a length
of about 12.8 Å. Hence, the volume available for each side
chain (perfluoroalkyl + alkyl) is 480 Å3. A typical volume of
410 Å3, slightly inferior than the previous value, is found from
the molar volumes of alkanes38 and perfluoroalkanes39 at room
temperature. Thus, as already encountered with compound 15,27
the smectic E phase is characterized by the coexistence of
crystallized biphenyl cores and liquidlike flexible chains. Such
an arrangement is schematically represented in Figure 7.
This model should be tested by considering the relative
intensities of the X-ray reflections. The three different molec-

56 J. Phys. Chem. B, Vol. 102, No. 1, 1998
Pensec et al.
TABLE 3: Experimental and Calculated Values of the
Intensities of the 00l Reflections in the SA Phase of 13
001
002
003
004
expt
calc
100
100
1.3
1.4
1.7
1.6
To optimize the packing, it may be hypothesized that the
perfluoroalkyl and alkyl fragments adopt a disordered confor-
mation (Figure 8b), consistent with the presence of a double
halo in the diffraction figure. In that model, the length covered
by the overlapped biphenyl rings with their oxymethylene groups
is 12.5 Å, as noted previously. Hence, each alkyl/perfluoroalkyl
side chain should be curled up as to be accommodated into a
total distance of 14.4 Å. In such a conformation, these
fragments will occupy approximately the same volume as in
the liquid state. If we perform the calculation as above, we
expect a molecular volume of 565 Å3 for the F(CF2)7 (CH2)10-
fragment which corresponds to a cross section of 39 Å2. This
area does not match the cross section of 44 Å2 which is
characteristic of overlapped biphenyl rings, on the other hand,
the herringbone ordering of biphenyl stems would likely induce
the appearance of the smectic B or smectic E phase at lower
temperature, which is not observed. This model is also
unsatisfactory from the standpoint of structure factor analysis:
in the situation of Figure 8b, the electron density profile displays
two maxima corresponding to the perfluoroalkyl chains at the
layer boundaries and one secondary maximum related to the
biphenyl rings in the middle of the layer. Such distribution
would magnify the second harmonic rather than any other, in
contradiction with experimental data (Table 3).
Figure 7. Model for the repartition of molecular cores and chains in
the smectic E layer of compound 9. The corresponding mean electron
density profile perpendicular to the layers taken to calculate the X-ray
intensities is shown.
Alternatively, the interlayer distance which is only 20% larger
than the molecular length may be interpreted by the formation
of a more completely interdigitated arrangement. In Figure 8c,
the alkyl and biphenyl fragments, which have approximately
the same length, are covering each other whereas the perfluo-
roalkyl chains form separated sublayers on either side of the
hydrocarbon region. Such an arrangement has been already
encountered in the crystal phase of certain polyphilic com-
pounds;9 the mixture of the alkyl and aryl moieties in the center
of the layer may also explain the absence of the herringbone
arrangement. In that case, the double diffraction halo can be
interpreted as follows: the first peak at 2π/q ) 5.4 Å is due to
the perfluoroalkyl chains in a disordered conformation, and the
second one at 2π/q ) 4.8 Å is to be attributed to the random
distribution in the alkyl/aryl sublayer with an average intermo-
lecular distance of r ) 1.15 × 2π/q ) 5.54 Å. (The local order
was considered to be close to a hexagonal packing: r ) (2/
x3)(2π/q).) (Figure 9). In the model of Figure 8c, the electron
density modulation has the shape of a square signal: Electron-
poor hydrocarbons cover one-half of the layer period whereas
the perfluoroalkyl chains with a higher electron density fill the
remaining space. In our structure factor calculations, the length
of the overlap, a and the Debye-Waller coefficient, σ, were
used as adjustable parameters; the results of the best fit are
summarized in Table 3. Such a distribution enhances the third
harmonic intensity as observed experimentally. The value of
a ) 23 Å indicates that the biphenyl and alkyl fragments are
completely overlapped. The value σ ) 3.4 Å gives an estimate
of the thermal fluctuations amplitude. This value is larger than
in the smectic E phase of compound 9 and 15, also consistent
with more disordered and less segregated molecules.
Figure 8. Structural hypothetic models for the SA phase of compound
13 with corresponding electron density profiles: (a) with stretched
chains and interdigitated cores, (b) with disordered alkyl chains and
interdigitated cores, (c) with overlap of the alkyl and aryl parts.
ular fragments are characterized by their electronic density
distribution along a direction perpendicular to the smectic layer.
We used the density profile shown in Figure 7 to calculate the
00l reflections intensities. Formula 1 was applied with σ as
adjustable parameter. The results of the best fit are collected
in Table 2. The value σ ) 1.3 Å indicates well-defined surfaces
between consecutive layers. The above analysis affords the
picture of a smectic layer made up of well-segregated sublayers
as expected from the polyphilic constitution of the molecule.
4.4. Structure of the Smectic A Layers of Compound 13.
Compound 13 was investigated in its smectic A phase at 134
°C. At small angles, three 00l reflections were recorded
corresponding to an interlayer distance of 41.3 Å. At larger
angles, a double halo is detected, indicating that two different
characteric distances may be recognized in the in-plane ar-
rangement of the molecules. In the smectic A phase, the
interlayer distance is 41.3 Å, which is significantly larger than
the end-to-end molecular length in the fully extended conforma-
tion (34.5 Å); a bimolecular packing with a partial overlap of
the molecules should therefore be postulated.
Let us first assume that we are still dealing with a fully
segregated arrangement, with interdigitation of the biaryl cores.
The picture of Figure 8a, with stretched perfluoroalkyl and alkyl
moieties, leads to an interlayer distance of 56.5 Å which is
greater than observed. On the other hand, the model does not
satisfy the close packing principle since it leaves a lot of empty
space in the region of the side chains.
5. Conclusion
In compounds 15 and 9, the geometrical characteristics of
the whole arrangement in the SE phase are influenced by the

Synthesis of Polyphilic Mesogens
J. Phys. Chem. B, Vol. 102, No. 1, 1998 57
of finely ground potassium iodide, and heated at 350 °C for 2
h under a stream of nitrogen. 3.62 g (13 mmol) of hexafluo-
roglutaryl dichloride (1) was vaporized at 220 °C from a 50
mL two-necked flask and driven by the nitrogen flow into the
reaction tube. The reaction began at the contact with potassium
iodide which turned to a pink coloration. The temperature and
the flow of nitrogen (140 mL/h) were monitored throughout
the process. The vapors that issued from the reaction tube were
trapped at -78 °C. After consumption of the starting material,
potassium iodide turned colorless and the process was stopped.
The reaction mixture was immediately diluted with 5 mL of
toluene and added dropwise at 0 °C to 13 mmol of freshly
distillated benzyl alcohol. Two drops of pyridine were added
as a catalyst. The reaction occurred immediately. The product
was purified by liquid chromatography on silica [63-200 µm]
with a cyclohexanes-ether (98:2) mixture as eluent and
collected as a liquid. The purity was checked by gas chroma-
tography (GC-MS). (Yield: 17% (relative to perfluoroglutaryl
chloride).) Anal. Found: C, 32.18; H, 1.76; I, 30.89. Calcd:
C, 32.06; H, 1.71; I, 30.80. IR (KBr, cm-1): 1778.9 [CdO],
1190.1, 1145.0 [C-F], 770 [δ C-H arom out-of-plane]. MS
(electron impact, m/z): 412 [M]+, 277, 227, 177, 127 [M -
Figure 9. Random repartition of interdigitated alkyl and biphenyl
groups in the hydrocarbon sublayer giving rise to the diffuse reflection
at 2π/q ) 4.8 Å.
herringbone packing of biphenyl cores close to the crystal
structure of unsubstituted biphenyl. The flexible chains in a
liquidlike conformation are located up and down alternatively.
As a comparison, polyphilic compounds with perfluoroalkyl side
chains at both extremities were not shown to form herringbone
structures,40 but in this case, the bulkiness of terminal groups
prevents the biphenyls from approaching each other. In
compounds 9 and 15, the perfluoroakyl fragment, nearly globular
in shape, located on a single side of the aromatic core, limits
the molecular motions across the layer, favoring a well-
segregated arrangement. Despite important disparities in cross
sections the various fragments may be accommodated in the
same area thanks to the flexibility of the side chains. Molecular
modeling of compound 15 using the esff force-field simulation
demonstrates that the perfluoroalkyl-methyloxy chain in its all-
trans conformation forms an angle of about 30° with respect to
the biphenyl axis. In the mesophase, additional gauche bonds
distributed along the flexible chains enable them to deviate even
more from the layers normal direction. In compound 9, the
alkyl fragment with a basic cross section of 20-22 Å2 is able
to swell itself as to fill the 44 Å2 available; most likely such a
swelling would be unrealizable if both extremities were fasten
in a predetermined position as in 13. Compound 13, with the
alkyl chain in the middle, displays a quite different behavior.
In that case, the molecular fragments are only partially
segregated. As a consequence, the herringbone packing is not
observed, and the thin alkyl fragment freely permeates the biaryl
region. Compound 13 may be regarded as an amphiphilic
molecule in which only two segregating parts are recognized:
the perfluoroalkyl chain on one side; the full hydrocarbon part
(alkyl + aryl) on the other side.
1
(CF2)nCO2CH2C6H5]+, 91 [C7H7]+. NMR H (CDCl3, TMS,
300 MHz, δ ppm): 7.43 (s, 5H, cycle), 5.4 (s, 2H, CH2). NMR
13C (CDCl3, 75 MHz, δ ppm): 158.45 (t, J ) 29.9 Hz,
CF2COOR), 133.23 (s, arom), 129.11 (s, arom), 128.73 (s,
arom), 128.48 (s, arom), 108.45 (m, J ) 265.5 Hz, J ) 31.75
Hz, CF2CF2CF2COOR), 106.94 (m, J ) 267.95 Hz, J ) 33.6
Hz, CF2CF2COOR), 93.39 (m, J ) 319.8, J ) 41.5, ICF2CF2-
CF2), 69.75 (s COCH2). NMR 19F (CDCl3, 235 MHz, δ ppm):
-59.5 (m, 2F, I CF2), -114.7 (m, 2F, CF2CF2CF2), -117.7 (t,
J ) 11.2 Hz, 2F, CF2COOR).
Benzyl 2,2,3,3,4,4-Hexafluoro-6-iodo-1-tetradecanoate (5).
In a 50 mL three-necked flask fitted with a reflux condenser
and a nitrogen inlet, 344 mg (835 µmol) of benzyl 4-iodoper-
fluorobutanoate (4), 5 mL of heptane, and 142 mg (1 mmol) of
1-decene (Aldrich) were heated at 90 °C with stirring. AIBN
(R,R′-azobisisobutyronitrile, Fluka) was added by small portions
every 15 min, whereupon the pinkish solution turned colorless.
After three AIBN additions and the 1.5 h reaction at 90 °C, the
solvent was evaporated and the crude product was purified by
liquid chromatography on silica (eluant: 2% ether in cyclo-
hexane). Compound 5 was obtained as a pale yellow liquid
(yield: 74%). The product rapidly decomposes and must be
used without delay in the next step. Anal. Found: C, 47.51;
H, 5.27. Calcd: C, 45.67; H, 4.92. IR (KBr cm-1): 2926.3
[C-H asym], 2855.8 [C-H sym], 1780 [CdO], 1179.6, 1178.3
[C-F], 1138.5 [CF]. MS (electron impact, m/z): 425 [M -
1
I]+, 91 [C7H7]+. NMR H (CDCl3, TMS, 300 MHz, δ ppm):
7.40 (s, 5H, cycle), 5.37 (s, 2H, CH2-C6H5), 4.30 (m, 1H, CHI),
2.82 (m, 2H, CHI-CH2-CF2), 1.78 (m, 2H, CH2-CH2-CHI),
1.44 (alkyl), 0.89 (t, CH3). NMR 13C (CDCl3, 75 MHz, δ
ppm): 159.01 [t, J ) 29.9 Hz, CF2-COO], 133.42 [s, arom],
129.11 [s, arom], 128.77 [s, arom], 128.56 [s, arom], 117.78
[m, J ) 256.3 Hz, J ) 31.1 Hz, CH2-CF2-CF2], 110.39 [m,
CF2-CF2-CF2], 108.22 [m, CF2-CF2-COO], 69.63 [s, CH2-
C6H5], 41.64 [t, J ) 21 Hz, CH2-CF2-CF2], 40.32 [s, CH2-
CHI], 31.95 [s, H3C-CH2-CH2], 29.69-28.53 [CH2], 22.71
[s, H3C-CH2], 21.16 [s, CHI], 14.11 [s, CH3].
Benzyl 2,2,3,3,4,4-Hexafluoro-1-tetradecanoate (6). In a
250 mL two-necked flask fitted with a gas inlet and a reflux
condenser, 988 mg (1.85 mmol) of benzyl 2,2,3,3,4,4-hexafluoro-
6-iodotetradecanoate (5) was diluted in a mixture of 20 mL
isooctane and 15 mL acetic acid. This solution was heated at
6. Experimental Section
Hexafluoroglutaryl Dichloride (1). In a 25 mL Claisen flask
bearing a 5 cm long Vigreux column, 4 g of hexafluoroglutaric
acid (16.7 mmol) (Fluorochem), 123 mg of potassium chloride
(1.6 mmol), and 6.7 mL of oxalyl dichloride (78 mmol) (Fluka)
were stirred together at 30 °C with the help of an ultrasonic
stage. After 2 h, the mixture was carefully fractionated. The
excess of oxalyl chloride distillates at 63-64 °C. Hexafluo-
roglutaryl dichloride was collected in the fraction boiling at 111
°C (yield: 78%). IR (KBr, cm-1): 1805.5 [CdO], 1190 [C-F].
Benzyl 4-Iodo-2,2,3,3,4,4-hexafluorobutanoate (4). The
reaction tube of length 80 mm and diameter 20 mm fitted with
an electrical heating belt (38 × 24 mm) was packed with 45 g

58 J. Phys. Chem. B, Vol. 102, No. 1, 1998
Pensec et al.
100 °C in an oil bath. 1.21 g (18 mmol) of zinc powder was
added with vigorous stirring. Gaseous HCl was admitted into
the solution, and the reaction began. After consumption of the
Zn powder (3 h), the mixture was cooled to room temperature
and filtered, and the precipitate was washed with water and dried
over magnesium sulfate. The liquid phase was concentrated
under vacuum and benzyl 2,2,3,3,4,4-hexafluorotetradecanoate
was obtained as a liquid after Kugelrohr distillation (yield:
80%). Anal. Found: C, 59.15; H, 6.62. Calcd: C, 58.80; H,
6.35. IR (KBr cm-1): 2926.2 [C-H asym], 2856.5 [C-H sym],
1781.2 [CdO], 1178, 1138 [C-F]. MS (electron impact,
m/z): 426 [M]+ 293, 133, 91 [C7H7]+. NMR 1H (CDCl3, TMS,
300 MHz, δ ppm): 7.4 (s, 5H, C6H5), 5.36 (s, 2H, CH2-C6H5),
2.05 (m, 2H, CH2-CF2), 1.57 (m, 2H, CH2-CH2-CF2), 1.46-
1.29 (alkyl.), 0.92 (t, CH3). NMR 13C (CDCl3, 75 MHz, δ
ppm): 159.34 [t, J ) 29.9 Hz, CF2-COO], 133.52 [s, arom],
129.02 [s, arom], 128.74 [s, arom], 128.49 [s, arom], 118.39
[m, J ) 252.6 Hz, J ) 30.5 Hz, CH2-CF2-CF2], 110.87 [m,
J ) 265 Hz, J ) 34.5 Hz, CF2-CF2-CF2], 108.38 [m, J )
265 Hz, J ) 31.1 Hz, CF2-CF2-COO], 69.49 [s, CH2-C6H5],
30.77 [t, J ) 23.2 Hz, CH2-CF2-CF2], 31.9 [s, H3C-CH2-
CH2], 29.7-29.1 [CH2], 22.68 [s, H3C-CH2], 20.07 [s, CH2-
CH2-CF2], 14.10 [s, CH3].
nyl (prepared according to ref 41), 198 mg (1.43 mmol) of K2-
CO3, and 5 mL of dry DMF were stirred under nitrogen. 434
mg (718 µmol) of 2,2,3,3,4,4-hexafluoro-1-tetradecyl nonafluo-
robutane-sulfonate were added, and the mixture was heated at
90 °C for 2.5 h. The reaction mixture was poured into 20 mL
of a saturated NaCl aqueous solution, and the organic layer was
extracted using 40 mL of CH2Cl2. The organic layer was
washed with 400 mL water, dried over MgSO4, and purified
by liquid chromatography on Kieselgel 60 (Merck) with a
mixture of cyclohexane/ethyl acetate (90:10) as eluent. The
product was recrystallized from acetonitrile (mp: 88.5 °C,
yield: 27%). IR (KBr cm-1): 2918.7 [C-H asym], 2850.5
[C-H sym], 1610.1 [arom CdC], 1275.9 [C-O], 1252.7,
1187.7, 1150.5 [C-F], 808.6 [δ C-Η out-of-plane]. MS
(electron impact, m/z): 504 [M]+, 489 [M-CH3]+, 199 [CH3O-
(C6H4)2-O]+. Anal. Found: C: 64.58, H: 6.51. Calcd: C,
1
64.27; H, 6.78. NMR H (CDCl3, TMS, 300 MHz, δ ppm):
7.52 (2H), 7.50 (2H), 7.03 (2H), 6.99 (2H) (aa′bb′ patterns, J
) 8.82 Hz arom), 4.50 (t, 2H, J ) 14.7 Hz, CF2-CH2-O),
3.86 (s, 3H, O-CH3), 2.12 (m, 2H, CH2-CH2-CF2), 1.64 (m,
2H, J ) 6.99 Hz, CH2-CH2-CF2), 1.31 (CH2), 0.93 (t, 3H, J
) 6.63 Hz, CH2-CH3). NMR 13C (CDCl3, 75 MHz, δ ppm):
158.93 (s, C-O-CH3), 156.88 (s, C-O-CH2), 135.11 and
133.01 (s, C6H4-C), 127.86, 127.80, 115.25 and 114.18 (s, arom
CH), 65.63 (t, J ) 25.6 Hz, CF2-CH2-O), 55.27 (s, OCH3),
31.00 (t, J ) 22.6 Hz, C9H19-CH2-CF2), 31.88 (s, H3C-CH2-
CH2), 29.52-29.16 (CH2), 22.67 (s, H3C-CH2), 20.17 (s, CH2-
CH2-CF2), 14.08 (s, CH3).
2,2,3,3,4,4-Hexafluoro-1-tetradecanol (7). 60 mg (1.6
mmol) of LiAlH4 was stirred with 30 mL of anhydrous ether in
a 250 mL three-necked flask fitted with a nitrogen inlet and
reflux condenser. 498 mg (1.16 mmol) of benzyl 2,2,3,3,4,4-
hexafluoro-1-tetradecanoate (6), diluted in 3 mL of ether, was
added after 15 min using a separatory funnel. The mixture was
refluxed for 15 min and cooled to room temperature. 36 mL
water were added carefully, and the mixture was poured into
30 mL of 10% (w/w) aqueous sulfuric acid. The ether phase
was separated and dried over magnesium sulfate. After
evaporation of the solvent, the excess of benzyl alcohol was
removed by azeotropic evaporation with 2 mL of water (yield:
9-Iodo-11,11,12,12,13,13,14,14,15,15,16,16,17,17,17-penta-
decafluoroheptadecan-1-ol (10). 887 mg (5.67 mmol) of
9-decen-1-ol and 2.5 g (5.04 mmol) of perfluoroheptyl iodide
were stirred under reflux in 5 mL of dry heptane. Azobisisobu-
tyronitrile was added every 5 min by portions of about 20 mg
during 30 min. The reaction mixture was kept one hour under
reflux for 1 h after AIBN addition, and the solvent was
evaporated. The oily residue was crystallized from methyl ethyl
ketone at -15 °C. Recrystallization from acetone (-15 °C)
afforded 1.77 g (54%) of 10 mp 28.9 °C. Anal. Found: C,
31.31; H, 2.55. Calcd: C, 31.31; H, 3.09. IR (KBr cm-1):
3393.2 (OH), 2931.2 (C-H asym), 2931.2 (C-H sym), 1240.0,
1
64%). NMR H (CDCl3, TMS, 300 MHz, δ ppm): 4.02 (t,
2H, J ) 14.7 Hz, CF2-CH2-OH), 3.07 (s, 1H, CH2OH, 2.04
(m, 2H, CH2-CF2), 1.58 (m, 2H, J ) 7.35 Hz, CH2-CH2-
CF2), 1.28 (s, 7H, CH2), 0.89 (t, 3H, J ) 6.6 Hz, CH3).
2,2,3,3,4,4-Hexafluoro-1-tetradecyl Nonafluorobutylsul-
fonate (8). 355 µL (2 mmol) of perfluorobutane sulfonyl
fluoride (Fluorochem) was dissolved in 20 mL of dichlo-
romethane previously dried over neutral aluminum oxide (Merck
90, activity I) and cooled to -40 °C under nitrogen in a 250
mL three necked flask. 581 mg (1.8 mmol) of 2,2,3,3,4,4-
hexafluoro-1-tetradecanol and 277 µL (2 mmol) of triethylamine
dissolved in 5 mL CH2Cl2 were added at -40 °C after 15 min.
The mixture was kept at this temperature for 45 min after the
end of addition. The reaction mixture was heated to 10 °C and
washed with 20 mL of HCl (5% in H2O), 20 mL of NaOH (5%
in H2O) and 80 mL of water. The organic phase was separated,
dried over MgSO4, and evaporated (yield 93%). MS (electron
impact, m/z): 533 [M - (CH2)4CH3]+, 219 [C4F9]+. NMR 1H
(CDCl3, TMS, 300 MHz, δ ppm): 4.81 (t, 2H, J ) 12.8 Hz,
CF2-CH2-OS), 2.04 (m, 2H, CH2-CF2), 1.58 (m, 2H, J )
12.8 Hz, CH2-CH2-CF2), 1.27 (CH2), 0.87 (t, 3H, J ) 6.6
Hz, CH3). NMR 13C (CDCl3, 75 MHz, δ ppm): 118.67, 110.8,
109.72 (CF2), 69.43 (t, J ) 25 Hz, CF2-CH2-O), 30.65 (t, J
) 22 Hz, C9H19-CH2-CF2), 31.8 (s, H3C-CH2-CH2), 29.5-
29.1 (CH2), 22.65 (s, H3C-CH2), 20.01 (s, CH2-CH2-CF2),
13.92 (s, CH3).
1
1209.9, 1149.3 (C-F). NMR H (CCl4, TMS, 90 MHz, δ
ppm): 1.27-1.43 (br. CH2), 1.55 (s, OH), 1.75 (br., OCH2CH2),
1.1-2 (integral: 15 H), 2.6, 3.1 (m, 2H, CH2CHI), 3.53 (t, J )
5.7 Hz, 2H, OCH2), 4.3 (qt., J ) 6.5 Hz, 1H, CHI).
11,11,12,12,13,13,14,14,15,15,16,16,17,17,17-Pentadeca-
fluoroheptadecan-1-ol (11). 2.3 g of 9-iodo-11,11,12,12,13,-
13,14,14,15,15,16,16,17,17,17-pentadecafluoroheptadecan-
1-ol (10) were dissolved in a mixture of n-propanol (30 mL)
and isooctane (50 mL) and heated at 100 °C. 0.5 g of Zn
powder was added, and HCl gas was injected into the mixture
until complete dissolution of the metal. Then, the reaction
mixture was filtered through paper and evaporated. 20 mL of
water was added, and the product crystallized. The solid was
collected onto a glass filter, thoroughly washed with water, and
dried over P2O5 in vacuum. The product was recrystallized three
times in 20 mL of acetonitrile (yield: 58%). Anal. Found:
N, 0.00; C, 38.84; H, 3.49. Calcd: N, 0.00; C, 38.79; H, 4.02.
IR (KBr cm-1): 3422.1 [O-H], 2934.3 [C-H asym], 2855.2
[C-H sym], 1240.9, 1210.3, 1168.1, 1148.1 [C-F]. MS
(electron impact, m/z): 55 [C4F7]+, 57 [C4H9]+, 69 [CF3]+, 83
[C6H11]+, 97 [C7H15]+, 119 [C2F5]+, 131 [C3F5]+, 169 [C3F7]+,
181 [C4F7]+, 391 [C7F14]+ and [C3F5]+, 424, 438, 452, 466,
480 [M-CnH2n + H2O]+, 508 [M-H2O]+. NMR 13C (CDCl3,
75 MHz, δ ppm): 62.90 (CH2OH), 32.63 (CH2CH2OH), 30.86
4-Methoxy-4′-(2,2,3,3,4,4-hexafluoro-1-tetradecyloxy)diphe-
nyl (9). In a 50 mL two-necked flask fitted with a reflux
condenser, 143 mg (718 µmol) of 4′-methoxy-4-hydroxybiphe-

Synthesis of Polyphilic Mesogens
J. Phys. Chem. B, Vol. 102, No. 1, 1998 59
(t, J ) 22 Hz, CF2CH2), 29.46, 29.35, 29.27, 29.17, 29.06 (CH2),
25.56 (CH2CH2CH2OH), 19.93 (CF2CH2CH2). NMR 1H (CDCl3,
TMS, 300 MHz, δ ppm): 1.32 (br., 12H, CH2), 1.53-1.68 (m,
5H, CH2CH2CF2 + CH2CH2OH + OH), 2.07 (m, 2H, CH2-
CF2), 3.66 (t, J ) 6.61 Hz, CH2OH).
2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-Pentadecafluorooctyl Nonafluo-
robutanesulfonate (14). A solution of 2.15 mL (12 mmol) of
nonafluorobutanesulfonyl fluoride (fluorochem) in 60 mL of
dry dichloromethane was cooled to -40 °C under nitrogen. A
solution of 4.4 g (11.5 mmol) of 1H,1H-perfluorooctanol
(Aldrich) in 2 mL of triethylamine was added with the help of
a separatory funnel. The reaction mixture was brought back to
-15 °C. The white precipitate was collected and recrystallized
1-Bromo-11,11,12,12,13,13,14,14,15,15,16,16,17,17,17-Pen-
tadecafluoroheptadecane (12). 560 mg (1.06 mmol) of 11,-
11,12,12,13,13,14,14,15,15,16,16,17,17,17-pentadecafluorohep-
tadecan-1-ol (11) were placed in the bottom of a 25 mL Pyrex
tube and carefully melted with the aid of an oil bath. A mixture
of 1 g sulfuric acid and 3 g fuming hydrobromic acid (37% in
water) and a piece of carborundum were added. The tube was
fitted with a reflux condenser and heated at 130 °C for 2 h.
After cooling, 10 mL of water and 10 mL CH2Cl2 were added
with stirring. The organic layer was separated and dried over
MgSO4. The solvent was then evaporated and the product
purified by liquid chromatography on silica with a mixture of
cyclohexane/dichloromethane (90:10) as eluent (yield: 80%;
mp ) 38-39 °C). IR (KBr cm-1): 2920.8, 2853.5, 1471.1,
1371.7, 1325.1, 1241.0, 1215.9, 1204.4, 1168.2, 1150.0, 1131.2,
1096.0, 1048.0, 1030.8, 1002.1, 978.1, 948.1, 777.9, 722.6,
699.5, 657.3, 570.6, 542.3, 532.0, 477.7. MS (electron impact,
m/z): 467 [M-C3H6Br]+, 453 [M-C4H8Br]+, 439 [M-C5H10-
Br]+, 425 [M-C6H12]+, 181 [C4F7]+, 163-165 [C6H12Br]+,
149-151 [C5H10Br]+, 135-137 [C4H8Br]+, 121-123 [C3H6-
Br]+, 119 [C2F5]+, 107-109 [C2H4Br]+, 69 [CF3]+ and [C5H9]+,
57 [C4H9]+, 55 [C4H7]+. Anal. Found: C, 35.00; H, 3.56.
Calcd: C, 34.65; H, 3.42. NMR 1H (CDCl3, TMS, 300 MHz,
δ ppm): 1.31 (br., 12H, CH2), 1.61 (m, 2H, CH2CH2CF2), 1.87
(m, 2H, CH2CH2Br), 2.06 (m, 2H, CH2CF2), 3.42 (t, J ) 6.79
Hz, CH2Br). NMR 13C (CDCl3, 75 MHz, δ ppm): 19.93 (br.,
CH2CH2CF2), 27.98 (CH2CH2CH2Br), 28.56, 28.92, 29.02,
29.09, 29.17 (CH2), 30.73 (t, J ) 22.2 Hz, CH2CF2), 32.65 (CH2-
CH2Br), 32.81 (CH2Br). NMR 19F (CDCl3, 235 MHz, δ ppm):
-81.3 (t, J ) 9.6 Hz, CF3), -114.9 (m, CF2CH2), -122.3,
-122.6, -123.3, -124.0, -125.3 (CF2), -126.7 (CF3CF2).
4-(11,11,12,12,13,13,14,14,15,15,16,16,17,17,17-Pentadeca-
fluoroheptadecyl oxy)-4′-methoxybiphenyl (13). 45 mg (320
µmol) K2CO3, 38 mg (190 µmol) of 4′-methoxy-biphenyl-4-
ol,41 and 8 mL DMF were placed in a 50 mL two-necked flask
fitted with reflux condenser, nitrogen inlet, and calcium chloride
tube. The mixture was heated at 90 °C with strirring. After
complete dissolution, 112 mg (190 µmol) of 1-bromo-11,11,-
12,12,13,13,14,14,15,15,16,16,17,17,17-pentadecafluoro hepta-
decane (12) were added. After 2 h of reaction, the mixture was
cooled, and the jelly-like solid was separated from the solvent
by filtration and dried over P2O5. The product was purified by
liquid chromatography on silica at 50 °C (cyclohexane 85%:
ethyl acetate 15%) and recrystallization from cyclohexane
(yield: 67%). IR (KBr cm-1): 2935.9 [C-H asym], 2852.1
[C-H sym], 1608.3 [arom CdC], 1274.5 [C-O], 1247.6,
1217.9, 1145.5 [C-F], 824.8 [δ C-Η out-of-plane]. MS
(electron impact, m/z): 708 [M]+. Anal. Found: C, 50.82; H,
4.33. Calcd: C, 50.86; H, 4.41. NMR 1H (CDCl3, TMS, 300
MHz, δ ppm): 7.49 (2H), 7.47 (2H), 6.97 (2H), 6.95 (2H)
(aa′bb′ patterns, J ) 8.8 Hz arom), 4.01 (t, 2H, J ) 6.6 Hz,
CH2-CH2-O), 3.85 (s, 3H, O-CH3), 2.06 (m, 2H, CH2-CH2-
CF2), 1.81 (m, 2H, J ) 6.6 Hz, CH2-CH2-O), 1.61-1.34
(CH2). NMR 13C (CDCl3, 75 MHz, δ ppm): 158.65 (s, C-O-
CH3), 158.24 (s, C-O-CH2), 135.53 and 132.27 (s, C6H4-
C), 127.8, 114.73 and 114.13 (s, arom CH), 68.04 (CH2-O-
C6H4), 55.33 (CH3-O-C6H4), 30.87 (t, J ) 23.2 Hz, CF2-
CH2), 29.42-20.08 (CH2).
1
from dichloromethane (yield: 49%; mp ) 46 °C). NMR H
(CDCl3, TMS, 300 MHz, δ ppm): 4.86 (t, J ) 12.6 Hz,
CF2CH2). IR (KBr cm-1): 1202.7, 1144.8 [C-F], 1042.7
[CdO], 1010.1 [SdO]. MS (electron impact, m/z): 683 [M]+,
463 [M-C4F9]+, 447 [M-OC4F9]+, 219 [C4F9]+, 169 [C3F7]+,
131 [C3F5]+, 119 [C2F5]+, 69 [CF3]+. Anal. Found: C, 20.76;
H, 0.30; S, 5.04. Calcd: C, 21.12; H, 0.29; S, 4.69.
4-(2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-Pentadecafluorooctyloxy)-4′-
methoxybiphenyl (15). 404 mg (2.34 mmol) of potassium
carbonate, 234 mg (1.17 mmol) of 4′-methoxy-biphenyl-4-ol,41
and 10 mL of DMF were stirred at 90 °C under nitrogen. 800
mg (1.7 mmol) of 2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluo-
rooctyl nonafluorobutanesulfonate (compound 14) was added.
After 2.5 h at 90 °C, the reaction mixture was cooled and poured
into 10 mL of water. The precipitate was collected onto a glass
filter, thoroughly washed with water, and dried over P2O5 under
vacuum. The solid was purified by liquid chromatography at
50 °C on silica (eluent: cyclohenane + ethyl acetate 85:15)
and recrystallization from cyclohexane (yield: 74%; mp ) 168
°C). IR (KBr cm-1): 1610.3, 1505.8 [arom CdC], 1243.6
[C-O], 1209.3, 1149.8 [C-F], 820.9 [δ C-H out-of-plane].
MS (electron impact, m/z): 582 [M]+,567 [M-CH3]+, 199
[CH3O(C6H4)2O]+, 313, 363, 413, 463 [CH3O(C6H4)2OCH2-
(CF2)n]+. Anal. Found: C, 43.17; H, 2.09. Calcd: C, 43.31;
H, 2.24. NMR 1H (CDCl3, TMS, 300 MHz, δ ppm): 7.52 (d,
J ) 9 Hz, 2H, arom), 7.49 (d, J ) 8.8 Hz, 2H, arom), 7.01 (d,
J ) 8.8 Hz, 2H, J ) 9 Hz, arom), 6.98 (d, J ) 9 Hz, 2H, arom),
4.51 (t, J ) 13.2 Hz, OCH2CF2), 3.86 (s, 3H, H3CO). NMR
13C (CDCl3, 75 MHz, δ ppm): 158.87 (s, C-O-CH3), 156.41
(s, C-O-CH2), 135.36 and 132.8 (s, C6H4-C), 127.8, 127.7,
115.12 and 114.1 (s, arom CH), 65.37 (t, J ) 29.9 Hz, CH2-
O-C6H4), 55.19 (CH3-O-C6H4).
Acknowledgment. Robert Corte`s is thanked for his help in
X-ray diffraction experiments.
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