Formation of smectic and columnar liquid crystalline phases by cyclotriveratrylene (CTV) and cyclotetraveratrylene (CTTV) derivatives incorporating calamitic structural units

Article abstract of DOI:10.1039/a702034a

Novel liquid crystalline oligomesogens, which consist of five, six or eight calamitic 4-cyanobiphenyl, 2-alkyl-5-phenyl-1,3,4-thiadiazole or 5-octyl-2-phenylpyrimidine units covalently linked by spacers of different length with a cyclotribenzylene central

Full text of DOI:10.1039/a702034a

Formation of smectic and columnar liquid crystalline phases by cyclotriveratrylene
(CTV) and cyclotetraveratrylene (CTTV) derivatives incorporating calamitic
structural units
Ralph Lunkwitz,a Carsten Tschierske*a and Siegmar Dieleb
aInstitute of Organic Chemistry, Martin-L uther-University Halle, D-06120 Halle/Saale, Kurt-Mothes-Straße 2, Germany
E-mail: coqfx@mlucom.urz.uni-halle.de
bInstitute of Physical Chemistry, Martin-L uther-University Halle, D-06099 Halle/Saale, Muhlpforte 1, Germany
¨
Novel liquid crystalline oligomesogens, which consist of five, six or eight calamitic 4-cyanobiphenyl, 2-alkyl-5-phenyl-1,3,4-
thiadiazole or 5-octyl-2-phenylpyrimidine units covalently linked by spacers of different length with a cyclotribenzylene central
core (CTV derivatives, 2,3,7,8,12,13-hexa-substituted 10,15-dihydro-5H-tribenzo[a,d,g]cyclononenes) or a cyclotetrabenzylene
central core (CTTV derivatives, 2,3,6,7,10,11,14,15-octa-substituted 5,10,15,20-tetrahydrotetrabenzo[a,d,g,j]cyclododecenes) have
been synthesized. These compounds were investigated by polarizing microscopy, differential scanning calorimetry and some of
them were also studied by X-ray diffraction. Many of the CTV derivatives show liquid crystalline properties. The cyanobiphenyl
derivatives incorporating long spacer units have enantiotropic S phases which can easily be supercooled. The thiadiazole
derivatives and the pyrimidine derivatives have liquid crystalline phases only if the spacer units are rather short. Thiadiazole
A
derivatives with an odd number of connecting atoms between the CTV core and the calamitic mesogens form S phases, whereas
those with even-numbered spacers display columnar mesophases. We propose that the columnar mesophases observed for these
A
oligomesogens do not result from their ability to adopt a nearly disc-like shape. Instead, they represent ribbon phases which result
from a steric frustration caused by the different space filling of the central cone-like core and the rod-like mesogenic groups. A
chevron-like (banana-like) average shape of the molecules with even-numbered spacers is assumed to be responsible for the
formation of the ribbon phases.
Also a CTTV derivative with eight appended phenylthiadiazole mesogens displays a columnar mesophase. A nematic phase was
found for the corresponding cyanobiphenyl derivative, whereas the pyrimidine derivative is not liquid crystalline.
Liquid crystalline materials have become increasingly import-
ant for many applications.1 Besides their well-established appli-
cation in electrooptical display devices, they are also interesting
candidates for information storage, nonlinear optics2 and
photoconductivity.3
It is well known that thermotropic liquid crystalline phases
may be formed by rod-like as well as by disc-shaped molecules.
Thereby the molecular shape determines the kind of mesophase
observed. Rod-like molecules give rise to nematic and/or
lamellar liquid crystalline phases whereas flat discotic, on
average disc-shaped and also cone-shaped molecules can self
organize to give discotic nematic phases and/or columnar
mesophases.4
from the CTV-unit by spacers with a medium length (type B)
form smectic A phases, whereas long spacers cause the loss of
the mesogenic properties (type C). However, the materials
reported so far have not only differed in spacer length, but
also in the type of calamitic units incorporated and no system-
atic studies concerning the influence of the spacer length on
the mesomorphic properties have been carried out.
The investigation of the transition between layered (smectic)
and columnar liquid crystalline phases is a topic of current
interest. New materials and novel mesophases with interesting
properties (e.g. biaxial nematic5 and cubic phases6) can be
expected in this intermediate region. Initially, catenated mol-
ecules were designed to bridge the gap between these two
different types of mesophases.7 These molecules represent
hybrid molecules with a long rod-like rigid core ending in two
half-disc moieties and can exhibit nematic, lamellar and colum-
nar phases. The covalent linkage of differently shaped mol-
ecules via spacer units is an alternative way to create new
supramolecular structures.8 This was first realized by Ringsdorf
et al., who connected two disc-like triphenylene units with a
rigid core.9
We have recently reported the first cyclotriveratrylene (CTV)
derivatives connected with five or six calamitic units.10,11 We
found that, depending on the length of the spacers connecting
the central cone-shaped CTV-unit to the rod-like rigid cores,
either columnar or smectic phases can be formed. If the
calamitic unit was directly attached to the central unit via a
carboxy group, then broad columnar mesophases were found
(type A). Compounds in which the calamitic units are separated
Compounds with short spacers are of special interest because
they represent borderline cases between materials forming
lamellar and columnar phases.
J. Mater. Chem., 1997, 7(10), 2001–2011
2001

Three types of rod-like rigid cores have been chosen for our
investigations: 4-cyanobiphenyls, 2-phenylpyrimidines and 2-
phenylthiadiazoles. These rigid cores differ in the direction of
their dipole moments (along or perpendicular to the long
molecular axis) and in the kind of mesophases formed by their
simple alkyl derivatives (4-cyanobiphenyls: nematic, 2-phenyl-
pyrimidines and 2-phenylthiadiazoles: smectic A and C).
Scheme 1
Also, two different types of disc-like central units have been
used. The CTV unit is rigid but not strictly flat. Nevertheless,
derivatives with a sufficiently large number of aliphatic chains
connected to this cone-shaped central unit exhibit columnar
mesophases (bowlic liquid crystals).12,13 The possibility that
these achiral compounds can form mesophases with ferroelec-
tric properties is another interesting aspect which will not
however be discussed here.12,14 Cyclotetraveratrylene (CTTV)
derivatives in contrast are much more flexible and can be
regarded as being disc-shaped molecules on the average.15 We
hoped that the type of supermolecular arrangements could be
influenced by combining these different calamitic and disc-like
units. Here we report two homologous series of CTV deriva-
tives in which six calamitic phenylthiadiazole or cyanobiphenyl
rigid cores are fixed via flexible spacers of different length to
the macrocyclic cyclotribenzylene unit. Additionally, two phe-
nylpyrimidine derivatives have been prepared. Furthermore,
we have synthesized selected asymmetric cyclotribenzylene
derivatives carrying only five rigid cores and cyclotertraben-
zylene derivatives (CTTV derivatives), even with eight
appended rigid cores.
Fig. 1 Electrospray mass spectrum of compound 3e
octahydroxy-5,10,15,20-tetrahydrotetrabenzo[a,d,g,j]cyclodo-
decene)13,18 respectively with appropriate carboxylic acids
incorporating a 4∞-cyanobiphenyl, a 5-phenylthiadiazole or a
5-phenylpyrimidine rigid core. As an example, the synthesis of
the pyrimidine derivatives 5 and 9 is shown in Scheme 1.
Cyclotricatechylene and cyclotetracatechylene were obtained
according to standard procedures by cyclocondensation of
veratrole with formaldehyde, followed by cleavage of the
methyl ethers by means of boron tribromide.13,17,18 For the
synthesis of the asymmetric compounds a stepwise conden-
sation procedure was used to prepare 2-methyl-3,7,8,12,13-
pentahydroxy-10,15-dihydro-5H-tribenzo [a,d,g]cyclononene17
which was esterified as described above. The structure of all
final compounds was confirmed from their 1H NMR spectra
and combustion analysis. Furthermore electrospray–MS
investigations indicate the correct molecular mass. Peaks for
only partially acylated products were not detected (see for
example Fig. 1).
Synthesis
The synthesis of the symmetric CTV and CTTV derivatives
was achieved by esterification10,11,16 of cyclotricatechylene
(2,3,7,8,12,13-hexahydroxy-10,15-dihydro-5H-tribenzo [a,d,g]
cyclononene)17 and cyclotetracatechylene (2,3,6,7,10,11,14,15-
2002
J. Mater. Chem., 1997, 7(10), 2001–2011

Results and Discussion
We have studied systematically the dependence of the meso-
morphic properties on spacer length. The transition tempera-
tures and the corresponding enthalpy values of the
cyclotribenzylene derivatives are summarized in Tables 1, 2
and 4.
4-Cyanobiphenyl derivatives
In the series of 4-cyanobiphenyl derivatives 1 the melting
points and the clearing temperatures decrease with increasing
chain length (Table 1). Thereby the decrease in the melting
temperatures is more pronounced than the decrease in the
clearing temperature. Owing to the high melting points of
the compounds with short spacers no mesophases could be
detected for compounds 1a and 1c and only monotropic phases
were found for 1b and 2a. The other cyanobiphenyl derivatives
with long chains (compounds 1d and 1e) display enantiotropic
liquid crystalline properties.
All mesophases of the cyanobiphenyl derivatives show the
same optical texture. On cooling, the appearance of a non-
specific birefringent texture and homeotropically aligned
regions were observed. On annealing these samples close to
the clearing temperature, the formation of a focal conic fan
texture could be observed.
The mesophase of compound 1b was investigated using a
Guinier goniometer. The typical diffraction pattern of a layered
structure without order within the layers was observed. The
layer thickness was calculated to be 3.03 nm. The length of the
molecule is estimated (CPK models) to be about 4.5 nm. From
this interdigitation of the cyanobiphenyl groups can be
deduced. From the textural observations and from the X-ray
pattern we conclude that a smectic A phase exists. Because the
optical textures are identical for all investigated compounds 1,
it is reasonable to assume that all mesomorphic cyanobiphenyl
Fig. 2 DSC heating and cooling traces of compound 1d (5 K min−1)
cyanobiphenyl mesogens to the cyclotribenzylene unit gives
rise to a significant mesophase stabilization and additionally
the nematic phase of the monomeric 4-cyanobiphenyl deriva-
tives is replaced by smectic A phases in the CTV derivatives 1.
This means that the cyclotribenzylene linking unit stabilizes a
layered arrangement of the individual calamitic molecules. The
clearing temperatures and also the melting points decrease by
elongation of the spacers. Because the melting temperatures
are more strongly influenced than the clearing temperatures,
compounds with short spacers have monotropic mesophases
and those with long spacers are enantiotropic liquid crystals.
In the cases of compounds 1a and 1c it was not possible to
supercool the samples to sufficiently low temperatures to allow
the observation of liquid crystalline phases. However, com-
pounds 1d and 1e with long spacer units form enantiotropic
S
phases which can easily be supercooled to −30 °C without
A
crystallization. Crystallization occurs only after prolonged
storage.† Sections of the DSC heating and cooling curves of
compound 1d are shown in Fig. 2.
derivatives 1 and 2 display S phases.
Comparison of these compounds with related monomeric 4-
A
cyanobiphenyl liquid crystals (e.g. C H OMC H MC H M
Replacing one of the rigid cores with a methyl group
(compounds 2) gives rise to a mesophase destabilization (cf.
compound 1b with six rigid cores and compound 2b with only
five rigid cores) and additionally, the melting points and the
crystallization tendency are decreased by this desymmetriz-
6
13
6
4
6 4
CN: Cr 57 °C N 75.5 °C I)19 indicates that appending the
Table 1 Phase transition temperaturesa and transition enthalpies
(lower lines) of the cyclotribenzylene derivatives 1 and 2
ation of the molecules.11 A monotropic S phase was observed
by cooling the cyclotribenzylene derivative 2a which is a
A
desymmetrized analogue of the non-liquid crystalline com-
pound 1a. Compound 2a with only five rigid cores, but with
the shortest spacer length, has the most stable mesophase of
all cyanobiphenyl derivatives investigated.
Thiadiazole derivatives
The phase behaviour of the thiadiazole derivatives 3 depends
on the spacer length and differs significantly from that of the
cyanobiphenyl compounds 1 (Table 2).
transition temperatures, T /°C
transition enthalpies, DH/kJ mol−1
R1
n
comp.
1a
Again, the clearing temperatures decrease on elongation of
the spacer units. However, the melting points of compounds 3
remain nearly constant. Therefore, in this series of compounds
mesomorphic properties are only observed for the short chain
derivatives and are lost on increasing the spacer length.
The optical textures of compounds 3a, 3c, 3i and 4b which
have three or five methylene groups in the spacers differ from
those of the compounds 3b, 3g, 3h and 4a with four methylene
groups in the spacer units. The next homologue with six
methylene units (compound 3d) is only a crystalline solid. The
liquid phase of 3d can be supercooled to 145 °C and at this
temperature no liquid crystalline phase is detected.
R
3
Cr 220
75.8
I
R
4
5
1b11
1c
Cr 165
76.6
(S 133)
6.6
I
A
R
Cr 159
83.9
Cr 65
18.8
Cr 95
58.3
I
R
6
1d
Cr 112
7.0
S
S
I
123 I
1
2
A
8.2
R
10
3
1e
116
21.3
A
CH
2a
Cr 163
40.4
(S 145)
I
3
A
CH
CH
4
10
2b11
2c
Cr 80
Cr 78
48.3
S
S
118
107
18.1
I
I
3
3
A
A
† Often, only part crystallization can be observed even after prolonged
storage. This explains the low melting enthalpy values found for some
compounds.
aAbbreviations: Cr=crystalline, S =smectic A-phase, I=isotropic
phase.
A
J. Mater. Chem., 1997, 7(10), 2001–2011
2003

Table 2 Phase transition temperaturesa and transition enthalpies
(lower lines) of the cyclotribenzylene derivatives 3 and 4 incorporating
a 2-phenylthiadiazole unit
of methylene groups (i.e. with an even total number of con-
necting atoms in each spacer) differ significantly from the
compounds discussed above. They form highly viscous meso-
phases and display spherulitic flower textures which are typical
of columnar mesophases (see Fig. 4).
The mesophases of compounds 3a and 3c were investigated
by X-ray diffraction using a Guinier film camera. Both com-
pounds have a diffuse scattering in the wide angle region.
Therefore a higher ordered smectic mesophase can be excluded.
Additionally, besides a strong scattering there are several
scatterings of low intensity in the small angle region. Table 3
displays the observed reflections of compound 3a, which have
been evaluated on the basis of an oblique cell. The resulting
lattice parameters are a=5.6, b=2.26 nm and b=48°.
To propose a model for the arrangement of the molecules
in this columnar phase, different molecular conformations have
to be considered. The CPK models of three possible confor-
mations of compound 3a are shown in Fig. 5. The star-shaped
conformation [Fig. 5(a)] cannot explain the observed lattice
parameters. If the averaged molecules exist in a stretched
double forked conformation with three calamitic units placed
side by side [Fig. 5(b)], then their total length in the most
transition temperatures, T /°C
transition enthalpies, DH/kJ mol−1
R1
m
n
comp.
R
7
3
3a
Cr
152 Col 182
I
10.7
117
151 Col 155
54.0
159
R
R
7
7
4
5
3b11 Cr
S
I
I
A
3c
3d
3e
Cr
Cr
Cr
30.6
156
144.9
158
65.8
R
R
7
7
6
7
I
I
135.6
142
152
102 Cr
87.1
R
R
R
7
9
15
10
4
4
3f11 Cr
3g11 Cr
I
S
160
143
0.9
I
S
A
3h
Cr
155 I
142 I
1
2
A
R
CH
CH
9
9
9
5
4
5
3i
Cr
80
<20 S
62
Col 162
126
Col 148
I
4a11 Cr
4b Cr
S
I
3
3
x
A
aAbbreviations: S =unknown smectic phase, Col=columnar
mesophase.
x
Fig. 3 Model of the S phase of compound 3b, 3g and 3h
A
Smectic phases of thiadiazole derivatives. The above men-
tioned compounds with an even number of methylene groups
(i.e. with an odd total number of connecting atoms in each
spacer, because of the ether oxygen and the carboxy group)
show small focal conic fan-textures, which can be homeotrop-
ically aligned on shearing the samples to give optically isotropic
regions. These textural features are typical for S phases. The
X-ray patterns of compounds 3b and 4a have been discussed
A
in a recent paper11 and confirm a smectic layer structure
without order in the layers. The layer period in the S phase
of compound 3g is 5.3 nm. The molecules can be considered
Fig. 4 Optical textures of the thiadiazole derivative 3a as obtained by
cooling from the isotropic melt (crossed polarizers): (a) transition I–Col
at 182 °C; (b) Col phase at 170 °C
A
as oligomesogens consisting of rod-like rigid cores appended
to the CTV central unit with an average double forked
conformation. Assuming this conformation, the molecular
length in the most extended form (CPK models) is 6.3 nm.
With respect to the calamitic phenylthiadiazole mesogens,
these smectic phases can be regarded as bilayer structures
which are formed by the segregation of the central CTV units
from the terminal aliphatic chains (Fig. 3).
Table 3 Lattice parameter of the mesophase of compound 3a at
T =170 °C
no.
H
hk
exp
1
2
3
4
5
1.05
2.07
2.61
3.11
3.69
10
11
01
30
32
Columnar mesophases of thiadiazole derivatives. The thiadia-
zole derivatives 3a, 3c, 3i and 4b which have an odd number
2004
J. Mater. Chem., 1997, 7(10), 2001–2011

Fig. 6 Structure of the CTV central unit (right-hand side) and possible
packing model of the molecules of compound 3a in the ribbon phase
(left-hand side)
sional arrangement of ribbons which are extended in the third
dimension (ribbon-phase).
According to this structure, the lattice parameter a should
be equal to twice the length of the mesogenic units (2.4 nm)
plus the diameter of the CTV unit (1.0 nm).‡ The observed
lattice parameter a=5.6 nm is in excellent agreement with this
molecular parameter. The angle b=48° of the oblique lattice
is provided by the angle w=47 2° between the planes of the
benzene rings of the CTV unit and the C -axis of the CTV
3
unit,20 which is orientated parallel to b. Assuming two mol-
ecules per unit cell and considering the tilt of the molecular
moieties, then the value of the parameter b can also be well
understood. Considering the mesogenic groups as structural
units, which are linked via the CTV moieties, then the ribbons
can be regarded as one-dimensionally extended fragments of a
smectic bilayer.
Such a ribbon arrangement, which partly destroys the
natural segregation between the aromatic CTV units and the
alkane chains must be favoured for geometric reasons. The
different space filling of the CTV unit and the spacers on the
one hand and the calamitic mesogens with their appended
alkyl chains on the other are likely responsible for the destabil-
ization of the layer-like organization of the molecules and give
rise to the formation of ribbons. This model of the columnar
mesophase is related to other two-dimensional modulated
phases.21–30 Modulated phases were also detected for terminally
connected dimesogens.31–33§ In this case an alternation of the
mesomorphic behaviour with the parity of the spacer length
was found. When the total number of atoms in the spacer is
even, the molecules adopt a rod-like shape and form smectic
phases. When this number is odd, the dimesogens have a bent
average conformation. The formation of antiferroelectrically
ordered and modulated phases is then favoured.
Fig. 5 Structure of compound 3a: (a) fully stretched (star-shaped)
conformation; (b) double-forked structure showing aligned rigid cores
(side view and top view); (c) chevron-shaped conformation (side view)
An alternation of the mesomorphic properties with the
parity of the spacer length is also found for the CTV derivatives
synthesized by us (see above).¶ In our case however, spacers
with an odd total number of connecting atoms can partly
compensate for the bent structure of the CTV unit and give
rise to a more rod-like total shape [see Fig. 5(b)] which favours
smectic phases. The chevron-like molecular shape provided by
extended conformation is ca. 5.7 nm, which agrees well with
the lattice parameter a=5.6 nm. However, in order to realize
this conformation the cone-like shape of the CTV unit must
be compensated for by a bend in the spacer units. In the third
conformation [Fig. 5(c)] a chevron-like molecular shape is
proposed. It should be provided by the cone-like shape of the
CTV unit and is transferred to the total shape of the molecules
by the even-numbered spacers. Interestingly, the angle b=48°
of the oblique lattice of the columnar phase of 3a corresponds
‡ This roughly corresponds to the molecular length in the biforked
conformation [Fig. 5(b)].
§ In this respect some unusual features of nematic and smectic phases
of terminally connected oligomesogens, such as cyclotriphosphaz-
enes,38 oligosiloxanes39 and cyclohexane 1,3,5-tricarboxylates40 are
under discussion.
¶ Because only three homologues are liquid crystalline, the question
remains open as to whether this odd–even parity is also valid for the
higher homologues.
exactly to the angle w=47 2° between the C -axis and the
3
planes of the benzene rings of the CTV unit (see Fig. 6).20
A possible model of the columnar phase based on a chevron-
like average conformation of compound 3a is sketched in
Fig. 6. This columnar phase can be regarded as a two-dimen-
J. Mater. Chem., 1997, 7(10), 2001–2011
2005

the even-numbered spacers favours the formation of ribbon
phases. Thus the cone-like shape of the CTV linking unit
provides an inverted odd–even parity in comparison to
dimesogens.
Pyrimidine derivatives
Three 2-phenylpyrimidine derivatives have been synthesized.
Compound 5a exhibits liquid crystalline properties in the
temperature range between 143 and 177 °C, whereas the next
homologue 5b is only a crystalline solid (Table 4).
It seems that the dependence of the mesophase stability on
the spacer length is analogous to that of the thiadiazole
derivatives, i.e. decreasing mesophase stability is observed on
elongation of the spacers. However, in the case of the pyrim-
idine derivatives the melting temperatures are significantly
higher and therefore the mesogenic properties are lost in the
tetramethylene derivative 5b. Even desymmetrization of the
molecule by replacing one mesogenic unit by a methyl group
(compound 6) cannot give rise to liquid crystalline properties.
The mesophase behaviour of compound 5a is rather interes-
ting because a phase transition occurs within the mesomorphic
range at a temperature of 170 °C. The high temperature
mesophase shows a spherulitic flower texture [Fig. 7(a)], which
is similar to the texture observed for the columnar mesophases
of the thiadiazole derivatives (see Fig. 4). However the X-ray
pattern displays only a layer reflection with a periodicity of
2.9 nm and a diffuse halo in the wide angle region. It is
remarkable that the observed periodicity corresponds only to
half the total molecular length [L =5.9 nm, CPK model in the
most extended conformation similar to Fig. 5(b)], which
supports a smectic ‘monolayer’ structure.
At the transition to the low temperature mesophase the
texture becomes broken and nonspecific as shown in Fig. 7(b).
Here the X-ray studies suggest an oblique cell with a=5.82,
b=2.27 nm, b=47.4°. The diffuse halo in the wide angle region
is maintained. The parameter a corresponds to the molecular
length, whereas the parameters b and b are nearly identical to
the corresponding parameters of the thiadiazole derivative 3a.
Therefore, the same ribbon model as for compound 3a can be
discussed for the low temperature mesophase of the pyrimidine
derivative 5a.
A possible model for the high temperature phase is based
on the assumption that increasing the temperature can lower
the steric frustration between terminal chains and CTV units
and therefore give rise to a partial segregation of the CTV
units from the alkyl chains. The aggregation of the CTV units
Fig. 7 Optical textures (crossed polarizers) of the 2-phenylpyrimidine
derivative 5a as obtained by cooling from the isotropic melt:
(a) transition I–M at 177 °C; (b) transition M–Col at 170 °C
can lead to an enlarged and non-uniform diameter of the
ribbons (more than one molecule is found in the diameter of
the ribbons). The well-defined oblique lattice is lost and only
a layer-like scattering corresponding to approximately half the
molecular length remains. If this is valid, the M phase should
also be a ribbon phase; only a layer reflection can be seen in
the X-ray diffraction pattern, however, suggesting a smectic
layer structure.
CTTV derivatives
Table 4 Phase transition temperaturesa and transition enthalpies
(lower lines) of the pyrimidine derivatives 5 and 6
The mesomorphic properties of the synthesized CTTV deriva-
tives 7–9 are summarized in Table 5. In contrast to the CTV
derivatives 1, which have S phases, the cyanobiphenyl deriva-
tive 7 is a nematic liquid crystal as is obvious from the typical
nematic schlieren texture.
A
A spherulitic texture was observed for the thiadiazole deriva-
tive 8 on cooling from the isotropic melt (Fig. 8). From this
texture we can conclude that an S phase is absent. This
A
mesophase could possibly be a columnar phase (ribbon phase).
However, the high melting temperature and the onset of
decomposition at temperatures above 200 °C does not allow
the X-ray investigations of this mesophase and therefore no
confirmation of the phase structure was possible.
The pyrimidine derivative 9 is a crystalline solid with no
mesophase.
Interestingly, in the case of the CTTV derivatives, columnar
mesophases can be observed for compounds with an odd
number of connecting atoms in the spacers. Because the CTTV
unit adopts an averaged disc-like shape rather than a bowl-
like shape, this observation is in accordance with the proposed
model. The odd–even parity is possibly inverted for the CTTV
transition temperatures, T /°C
transition enthalpies, DH/kJ mol−1
R1
n
3
4
4
comp.
5a
R
Cr 143
7.4
Col 170
32.4
M
177 I
22.2
R
5b
Cr 168
84.6
Cr 126
I
CH
6
Cr 138
70.3
I
3
1
2
20.6
aAbbreviations: M=unknown liquid crystalline phase.
2006 J. Mater. Chem., 1997, 7(10), 2001–2011

Table 5 Phase transition temperaturesa and transition enthalpies
(lower lines) of the CTTV derivatives 7–9
mesogens are not the result of the ability to adopt a disc-like
shape. Rather, they represent ribbon phases which arise from
the steric frustration caused by the different space filling of the
central cone-like core and the attached rod-like mesogens. A
chevron-like average shape of the molecules with even-num-
bered spacers is assumed to facilitate this steric frustration and
be responsible for the formation of the ribbon phases. Odd-
numbered spacers can partly compensate for the bent structure
of the CTV unit and give rise to S phases.
A nematic phase was only found in the case of a CTTV
A
derivative with appended cyanobiphenyl mesogens. Thus, the
covalent fixation of calamitic mesogens to central connecting
units can not only stabilize smectic mesophases but also
provide the possibility to change the phase structure of cala-
mitic mesogens from smectic to columnar with only minor
adjustments of the chemical structure. The ability of these
transition temperatures, T /°C
comp. transition enthalpies, DH/kJ mol−1
R
7
Cr 174
53.8
Cr 222 (N 220) I
63.6
1
2
molecules to adopt
a chevron-shaped (banana-shaped)
geometry is of special interest with respect to potential ferro-
electric properties.34 Furthermore, the special kind of meso-
phases found in the so-called banana-shaped molecules34 could
be related to the ribbon-phases described here.
8
Cr 142
70.3
Cr 204
10.6
M
222 I
44.5
1
2
9
Cr 241
I
Experimental
aAbbreviations: N=nematic phase.
Methods
Confirmation of the structures of intermediates and products
was obtained by 1H and 13C NMR spectroscopy (Bruker WP
200 spectrometer and a Varian Unity 500; coupling constants J
are given in Hz), infrared spectroscopy (Specord 71 IR) and
mass spectrometry (Intectra GmbH, AMD 402, electron
impact, 70 eV; electrospray–MS, VG Bio-Q Fisons
Instruments). Microanalyses were performed using an Carlo-
Erba 1102 or a Leco CHNS-932 elemental analyser. Transition
temperatures were measured using a Mettler FP 82 HT hot
stage and control unit in conjunction with a Nikon Optiphot
2 polarizing microscope and these were confirmed using
differential scanning calorimetry (Perkin-Elmer DSC-7). X-
Ray studies were performed using a Guinier goniometer
(Fa. Huber).
Materials
Fig. 8 Optical photomicrograph of the mesophases of the CTTV
derivative 8 (crossed polarizers) as obtained by cooling from the
isotropic melt at 222 °C
4-(5-Alkyl-1,3,4-thiadiazol-2-yl)phenols35 and 4-(5-octylpyrim-
idin-2-yl)phenol,36 3,7,8,12,13-hexahydroxy-10,15-dihydro-5H-
tribenzo[a,d,g]cyclononene,17
3,7,8,12,13-pentahydroxy-2-
methyl-10,15-dihydro-5H-tribenzo[a,d,g]cyclononene11 and
2,3,6,7,10,11,14,15-octahydroxy-5,10,15,20-tetrahydrotetrabenzo-
[a,d,g,j]cyclododecene18 were synthesized according to litera-
ture procedures. 4-(4-Cyanophenyl)phenol and 11-bromo-
undecanoic acid were obtained from Merck. The methyl and
ethyl v-bromoalkanoates (Aldrich) were used as obtained.
Methyl 7-bromoheptanoate was synthesized from 6-bromo-
hexanoic acid via chain elongation with diazomethane.37
derivatives. Unfortunately no liquid crystalline CTTV deriva-
tives with even numbered spacer units have been obtained.
Summary
In conclusion, we have prepared liquid crystalline oligomeso-
gens which consists of five, six and even eight calamitic 4-
cyanobiphenyl, 2-alkyl-5-phenyl-1,3,4-thiadiazole or 5-octyl-2-
phenylpyrimidine units covalently linked by spacers of different
lengths with cyclotribenzylene or cyclotetrabenzylene central
cores. The cyanobiphenyl derivatives incorporating the CTV
Alkyl v-[4-(4-cyanophenyl)phenoxy]alkanoates 10, alkyl v-
[4-(5-alkyl-1,3,4-thiadiazol-2-yl)phenoxy]alkanoates 12 and
ethyl v-[4-(5-octylpyrimidin-2-yl)-phenoxy]alkanoates 14. 4-
(4-Cyanophenyl)phenol, 4-(5-alkyl-1,3,4-thiadiazol-2-yl)phenol
or 4-(5-octylpyrimidin-2-yl)phenol (20 mmol) was dissolved
in dry butan-2-one (200 ml), the appropriate alkyl v-
bromoalkanoate (40 mmol), K CO (8.3 g, 60 mmol) and tetra-
unit have broad S phases which can easily be supercooled if
the spacer units are long. The thiadiazole derivatives and the
A
pyrimidine derivatives have liquid crystalline phases only if
the spacer units are rather short. Phenylthiadiazole substituted
CTV derivatives with an odd number of connecting atoms
2
3
form S phases. With respect to the calamitic phenylthiadiazole
mesogens, these smectic phases can be regarded as bilayer
butylammonium iodide (50 mg) were added and the resulting
mixture was stirred at reflux temperature until the phenol
could not be detected by TLC (1–10 h). After cooling, the
solvent was evaporated and the residue was dissolved in water
(50 ml) and dichloromethane (100 ml). The organic phase was
washed with sodium hydrogen carbonate (50 ml), hydrochloric
acid (10%, 50 ml) and water (50 ml) successively. Afterwards
the solution was dried with Na SO and the solvent was
A
structures which are formed by the segregation of the central
CTV units from the terminal aliphatic chains.
Columnar mesophases were found for those compounds
in which phenylthiadiazoles and phenylpyrimidines were
appended via even numbered spacers to a CTV unit and for
phenylthiadiazole derivatives grafted to CTTV units. We pro-
pose that the columnar mesophases observed for these oligo-
2
4
removed in vacuo. The 4-cyanobiphenyl derivatives 10 and the
J. Mater. Chem., 1997, 7(10), 2001–2011 2007

Table 8 Phase transition temperatures of the v-[-4-(5-octylpyrimidin-
2-yl)phenoxy]alkanoic acids 15 and their ethyl esters 14
thiadiazole derivatives 12 were crystallized twice from light
petroleum (bp 60–85 °C)–ethyl acetate. The pyrimidine deriva-
tives 14 were crystallized from ethanol. The transition tempera-
tures of the compounds 10, 12 and 14 are summarized in
Tables 6–8. Analytical data of the compounds 10a, 12a and
14a are given as representative examples.
Ethyl 4-[4-(4-cyanophenyl) phenoxy]butanoate 10a. Elemen-
tal analysis (%): found (calc. for C H NO ): C, 73.46 (73.77);
phase transition
temperatures T /°C
n
R
comp.
R
comp.
mp T /°C
19 19
3
H, 5.96 (6.19); N, 4.52 (4.53). d (CDCl ) 1.26 (m, 6H, CH ),
2.15 (m, 2H, CH ), 2.54 (t, 2H, J 7.2, CH COO), 4.05 (t, 2H,
H
3
3
3
4
C H
14a
14b
Cr 51 (S 44) I
A
H
H
15a
15b
137
117
2
C H
2
5
5
2
2
2
3
Cr 41 N 43 I
J 6.1, OCH CH ), 4.15 (q, 2H, OCH CH ), 6.99 (d, 2H, J 8.8,
Ar-H), 7.52 (d, 2H, J 8.8, Ar-H), 7.62–7.75 (m, 4H, Ar-H).
2
2
Ethyl 4-[4-(5-heptyl-1,3,4-thiadiazol-2-yl)phenoxy]butanoate
12a. Elemental analysis (%): found (calc. for C H N O S):
filtered off, washed with water and crystallized twice from light
petroleum (bp 60–85 °C)–ethyl acetate. The transition tem-
peratures of the compounds 11, 13 and 15 are summarized in
the Tables 6–8. Analytical data of the compounds 11a, 13a
and 15a are given as representative examples.
21 30
2 3
C, 64.79 (64.59); H, 7.75 (7.74); N, 7.25 (7.17); S, 8.27 (8.21).
(CDCl ) 0.86 (m, 6H, CH ), 1.23–1.8 (m, 10H, CH ), 2.12
(m, 2H, CH ), 2.5 (t, 2H, J 7.3, CH COO), 3.08 (t, 2H, J 7.7,
d
H
3
3
2
2
2
2
ArCH ), 4.05 (t, 2H, J 6.1, OCH CH ), 4.13 (q, 2H J 7.1,
OCH CH ), 6.93 (d, 2H, J 8.85, Ar-H), 7.83 (d, 2H, J 8.85,
Ar-H).
2
2
2
4-[4-(4-Cyanophenyl)phenoxy]butanoic acid 11a. Elemental
analysis (%): found (calc. for C H NO ): C, 72.30 (72.58);
3
17 15
H
3
H, 5.61 (5.37); N, 4.74 (4.98). d (CDCl ) 2.15 (m, 2H, CH ),
2.60 (t, 2H, J 7.2, CH COO), 4.07 (t, 2H, J 5.9, OCH CH ),
3
2
2
Ethyl 4-[4-(5-octylpyrimidin-2-yl)phenoxy]butanoate 14a. d
(CDCl ) 0.86 (m, 6H, CH ), 1.15–2.11 (m, 14H, CH ), 2.52 (t,
H
2
2
6.97 (d, 2H, J 8.8, Ar-H), 7.50 (d, 2H, J 8.8, Ar-H), 7.61 (d,
2H, J 8.55, Ar-H), 7.67 (d, 2H, J 8.55, Ar-H). MS m/z (relative
intensity, %): 281 (26, M+), 228 (15), 195 (100), 166 (18), 151
(5), 140 (12), 101 (11), 87 (8).
3
3
2
2H, J 7.2, CH COO), 2.58 (t, 2H, ArCH , J 7.7), 4.07 (t, 2H,
J 6.1, OCH CH ), 4.14 (q, 2H, J 7.2, CH CH ), 6.95 (d, 2H, J
8.9, Ar-H), 8.32 (d, 2H, J 8.9, Ar-H), 8.55 (s, 2H, Ar-H).
2
2
2
2
2
3
v-[4-(4-Cyanophenyl)phenoxy]alkanoic acids 11, v-[4-(5-
alkyl-1,3,4-thiadiazol-2-yl)phenoxy]alkanoic acids 13, and v-
[4-(5-octylpyrimidin-2-yl)phenoxy]alkanoic acids 15. The com-
pounds 10, 12 or 14 (10 mmol) were dissolved in methanol
(150 ml) and heated to reflux. A solution of potassium hydrox-
ide (1.7 g, 30 mmol) in water (20 ml) was added under stirring
and the solution was refluxed for 2 h in the cases of 12 and 14
and only for 5 min in the case of compound 10. After cooling,
the mixture was poured on crushed ice. The precipitate which
formed on acidification with dilute hydrochloric acid was
4-[4-(5-Heptyl-1,3,4-thiadiazol-2-yl)phenoxy]butanoic acid
13a. Elemental analysis (%): found (calc. for C H N O S):
19 26
2 3
C, 63.01 (62.96) H, 7.27 (7.23); N, 7.72 (7.73); S, 8.91 (8.84).
(CDCl ): 0.86 (t, 3H, J 7, CH ), 1.23–1.8 (m, 10H, CH ),
2.12 (m, 2H, CH ), 2.59 (t, 2H, J 7.2, CH COO), 3.09 (t, 2H,
d
H
3
3
2
2
2
J 7.6, ArCH ), 4.07 (t, 2H, J 6.1, OCH CH ), 6.94 (d, 2H, J
8.7, Ar-H), 7.84 (d, 2H, J 8.7, Ar-H). d (CDCl ) 178, 169.8,
2
2
C
2
3
168.2, 161, 129.4, 123.2, 115, 66.8, 31.6, 30.3, 30.2, 30.1, 28.9,
28.8, 24.3, 22.6, 14. MS m/z (relative intensity, %): 362 (84,
M+), 347 (8, M+−CH ), 333 (34), 319 (32), 305 (12), 291
137 (8).
3
(92), 278 (100), 247 (8), 233 (6), 219 (4), 205 (18), 192 (55),
Table 6 Phase transition temperatures of the v-[4-(4-cyanophenyl)-
phenoxy]alkanoic acids 11 and their alkyl esters 10
4-[4-(5-Octylpyrimidin-2-yl)phenoxy]butanoic acid 15a. d
(CDCl ) 0.85 (t, 3H, J 6.4, CH ), 1.2–1.7 (m, 14H, CH ),
H
3
3
2
2.52–2.67 (m, 4H, CH ), 4.08 (t, 2H, J 6.05, OCH CH ), 6.95
(d, 2H, J 8.3, Ar-H), 8.31 (d, 2H, J 8.8, Ar-H), 8.56 (s, 2H, Ar-
H). d (CDCl ): 177.8, 162.4, 160.7, 156.9, 132.2, 130.4, 129.5,
114.5, 66.7, 31.8, 30.8, 30.4, 30.2, 29.3, 29.2, 29.1, 24.5, 22.6,
14.1. MS m/z (relative intensity, %): 370 (38, M+), 284 (100),
241 (5), 227 (10), 213 (6), 199 (31), 185 (74), 158 (11), 119 (4).
2
2
2
C
3
phase transition
temperatures T /°C
n
R
comp.
mp T /°C
R
comp.
3
5
6
C H
10a
10b
10c
10d
76
89–90
103
H
H
H
H
11a
11b
11c
11d
Cr 200 (N 192) I
Cr 173 (N 170) I
Cr 123 (N 118) I
Cr 129 (N 122) I
2
C H
2
5
5
Esterification of the polyphenols. 2,3,7,8,12,13-Hexahydroxy-
10,15-dihydro-5H-tribenzo[a,d,g]cyclononene, 3,7,8,12,13-
pentahydroxy-2-methyl-10,15-dihydro 5H-tribenzo[a,d,g]-
CH
3
10 CH
104
3
Table 7 Phase transition temperatures of the v–4-(5-alkyl-1,3,4-thiadiazol-2-yl)phenoxy]alkanoic acids 13 and their alkyl esters 12
phase transition
temperatures T /°C
m
n
R
comp.
R
comp.
mp T /°C
7
7
7
7
15
3
5
6
7
4
C H
12a
12b
12c
12d
12e
Cr 67 (S 63) I
Cr 64 I
H
H
H
H
H
13a
13b
13c
13d
13e
123
113
99
107
116
2
C H
2
5
A
5
CH
3
Cr 58 I
Cr 59 I
Cr 78 I
CH
3
C H
2
5
2008
J. Mater. Chem., 1997, 7(10), 2001–2011

cyclononene or 2,3,6,7,10,11,14,15-octahydroxy-5,10,15,20-
octahydrotetrabenzo[a,d,g,j]cyclododecene (0.2 mmol) and
N-cyclohexyl-N∞-[2-(N-methylmorpholinio)ethyl]carbodiimide
toluene-p-sulfonate (1.5 equiv. per OH group) were dissolved
in 50 ml of dry chloroform. After 5 min the appropriate substi-
tuted alkanoic acids 11, 13 or 15 (1.3 equiv. per OH group)
was added followed by addition of 4-(dimethylamino)pyridine
(40 mg). The resulting mixture was stirred at room temp. for
20 h. After the reaction was complete, water (50 ml) was added
to the mixture, and the phases were separated. The aqueous
3, 7, 8, 12, 13-Pentakis{11-[4-(4-cyanophenyl)phenoxy]unde-
canoyloxy}-2-methyl-10,15-dihydro-5H-tribenzo[a,d,g]cyclo-
nonene 2c. Yield: 52%, phase transitions (°C): Cr 78 S 107 I.
A
Elemental analysis (%): found (calc. for C
142 155
C, 78.55 (78.52); H, 6.99 (7.29); N, 3.09 (3.23). d (CDCl )
H
N O ):
5
15
H
3
1.2–1.86 (m, 70H, CH ), 2.05 (s, 3H, CH ), 2.1–2.2 (m, 10H,
CH ), 2.6–2.8 (m, 10H, CH COO), 3.67 (d, 3H, ArCH Ar, H ),
3.95–4.15 (m, 10H, OCH CH ), 4.7–4.85 (m, 3H, ArCH Ar,
H ), 6.9–7.73 (m, 46H, Ar-H).
2
3
2
2
2
e
2
2
2
a
phase was extracted with CHCl (30 ml). The combined
organic phase was washed successively with saturated aqueous
2, 3, 7, 8, 12, 13-Hexakis{4-[4-(5-heptyl-1,3,4-thiadiazol-2-yl)
phenoxy]butanoyloxy}-10,15-dihydro-5H-tribenzo[a,d,g]cyclo-
nonene 3a. Yield: 56%, phase transitions (°C): Cr 152 Col 182
3
sodium hydrogen carbonate (30 ml), brine (30 ml), and water
(30 ml). Afterwards, the solution was dried (Na SO ) and the
I. Elemental analysis (%): found (calc. for C
H
N O S ):
135 162 12 18 6
C, 66.23 (66.64); H, 6.82 (6.71); N, 6.84 (6.91); S, 8.02 (7.91).
2
4
solvent was removed in vacuo. The products were purified by
column chromatography using chloroform–methanol (2551)
followed by crystallization from nitromethane.
d
2.12 (m, 12H, CH ), 2.66 (t, 12H, J 7, CH COO), 3.06 (t, 12H,
(CDCl ) 0.86 (t, 18H, J 6.9, CH ), 1.24–1.8 (m, 60H, CH ),
H
3
3
2
2
2
2
J 7.7, ArCH ), 3.69 (d, 3H, J 14.1, ArCH Ar, H ), 4.0 (t, 12H,
J 6.1, OCH CH ), 4.76 (d, 3H, J 13.7, ArCH Ar, H ), 6.89 (d,
2
2
e
2, 3, 7, 8, 12, 13-Hexakis{4-[4-(4-cyanophenyl)phenoxy]buta-
noyloxy}-10,15-dihydro-5H-tribenzo[a,d,g]cyclononene 1a. Yield:
73%, mp 220 °C. Elemental analysis (%): found (calc. for
2
2
a
12H, J 9, Ar-H), 7.14 (s, 6H, Ar-H), 7.79 (d, 12H, J 9, Ar-H).
d (CDCl ) 170.3, 169.6, 167.9, 160.8, 140.7, 137.2, 129.4, 124.7,
123.4, 114.9, 66.6, 36.3, 31.6, 30.4, 30.2, 30.0, 29, 28.9, 24.4, 22.6,
C
3
C
H N O ): C, 75.56 (75.91); H, 5.05 (4.97); N, 3.94 (4.32).
123 96 18
(CDCl ) 1.32–2.12 (m, 12H, CH ), 2.66 (t, 12H, J 6.95,
6
3
14. Electrospray–MS: found (calc. for C
2431.72 0.22 (2431.04).
H
N O S ): M+
d
204 264 16 24 8
H
2
CH COO), 3.69 (d, 3H, J 14.2, ArCH Ar, H ), 4.0 (t, 12H, J
5.9, OCH CH ), 4.76 (d, 3H, J 13.55, ArCH Ar, H ), 6.91 (d,
2
2
e
2
2
2
a
2, 3, 7, 8, 12, 13-Hexakis{6-[4-(5-heptyl-1,3,4-thiadiazol-2-yl)
phenoxy]hexanoyloxy}-10,15-dihydro-5H-tribenzo[a,d,g]cyclo-
nonene 3c. Yield: 59%, phase transitions (°C): Cr 151 Col 155
12H, J 8.8, Ar-H), 7.14 (s, 6H, Ar-H), 7.45 (d, 12H, J 8.75, Ar-
H), 7.56 (d, 12H, J 8.4, Ar-H), 7.64 (d, 12H, J 8.4, Ar-H).
I. Elemental analysis (%): found (calc. for C
H
N O S ):
147 186 12 18 6
C, 68.13 (67.87); H, 7.38 (7.21); N, 6.42 (6.46); S, 7.21 (7.39).
2, 3, 7, 8, 12, 13-Hexakis{6-[4-(4-cyanophenyl)phenoxy]hexa-
noyloxy}-10,15-dihydro-5H-tribenzo[a,d,g]cyclononene
Yield: 85%, mp 159 °C. Elemental analysis (%): found (calc.
for C N O ): C, 76.43 (76.69); H, 5.64 (5.72); N, 4.21
1c.
d
(t, 12H, J 7.05, CH COO), 3.08 (t, 12H, J 7.6, ArCH ), 3.67
(CDCl ) (t, 18H, J 6.9, CH ), 1.2–1.8 (m, 96H, CH ), 2.51
H
3
3
2
H
2
2
2
135 120 18
6
(d, 3H, J 14.2, ArCH Ar, H ), 3.96 (t, 12H, J 6.3, OCH CH ),
4.75 (d, 3H, J 13.6, ArCH Ar, H ), 6.9 (d, 12H, J 8.4, Ar-H),
(3.97). d (CDCl ) 1.53–1.86 (m, 36H, CH ), 2.57 (t, 12H, J
6.6, CH COO), 3.74 (d, 3H, J 13.4, ArCH Ar, H ), 4.01 (t,
12H, J 5.9, OCH CH ), 4.81 (d, 3H, J 13.45, ArCH Ar, H ),
2
e
2
H
2
3
2
2
a
2
e
7.13 (s, 6H, Ar-H), 7.81 (d, 12H, J 8.4, Ar-H). Electrospray–MS:
found (calc. for
(2599.23).
2
2
2
a
C
H
N O S ): M+ 2600.5 1.66
6.99 (d, 12H, J 8.6, Ar-H), 7.19 (s, 6H, Ar-H), 7.53 (d, 12H, J
8.55, Ar-H), 7.64 (d, 12H, J 8.35, Ar-H), 7.69 (d, 12H, J 8.2,
Ar-H).
147 186 12 18 6
2,3,7,8,12,13-Hexakis{7-[4-(5-heptyl-1,3,4-thiadiazol-2-yl)
phenoxy]heptanoyloxy}-10,15-dihydro-5H-tribenzo[a,d,g]cyclo-
nonene 3d. Yield: 87%, mp 156 °C. Elemental analysis (%):
2, 3, 7, 8, 12, 13-Hexakis{7-[4-(4-cyanophenyl)phenoxy]hep-
tanoyloxy}-10,15-dihydro-5H-tribenzo[a,d,g]cyclononene 1d.
Yield: 40%, phase transitions (°C): Cr 65 Cr 112 S 123 I.
found (calc. for C
H
N O S ): C, 68.63 (68.43); H, 7.48
153 198 12 18 6
(7.43); N, 6.32 (6.26). d (CDCl ) 0.92 (t, 18H, CH , J 6.8),
1
2
A
H
3
3
Elemental analysis (%): found (calc. for C
141 132
C, 76.93 (77.03); H, 6.14 (6.05); N, 3.73 (3.82). d (CDCl )
H
N O ):
1.2–1.8 (m, 108H), 2.56 (t, 12H, J 7.2, CH COO), 3.13 (t, 12H,
J 7.5, ArCH ), 3.72 (d, 3H, J 14.3 ArCH Ar, H ), 4.01 (t, 12H,
6
18
2
H
3
2
2
2
e
1.3–1.84 (m, 48H, CH ), 2.49 (t, 12H, J 7.35, CH COO), 3.67
(d, 3H, J 14.1, ArCH Ar, H ), 3.95 (t, 12H, J 6.35, OCH CH ),
4.73 (d, 3H, J 13.3, ArCH Ar, H ), 6.92 (d, 12H, J 8.9, Ar-H),
7.12 (s, 6H, Ar-H), 7.47 (d, 12H, J 8.8, Ar-H), 7.6–7.7 (m, 24H,
Ar-H).
J 6.4, OCH CH ), 4.79 (d, 3H, J 13.8, ArCH Ar, H ), 6.95 (d,
12H, J 8.6, Ar-H), 7.18 (s, 6H, Ar-H), 7.87 (d, 12H, J 8.6, Ar-
2
2
2
2
a
2
e
2
2
H); Electrospray–MS: found (calc. for C
2683.70 0.24 (2683.32).
H
N O S ): M+
2
a
153 198 12 18 6
2,3,7,8,12,13-Hexakis{8-[4-(5-heptyl-1,3,4-thiadiazol-2-yl)
phenoxy]octanoyloxy}-10,15-dihydro-5H-tribenzo[a,d,g]cyclo-
nonene 3e. Yield: 54%, mp 158 °C. Elemental analysis (%):
2, 3, 7,8, 12,13-Hexakis{11-[4-(4-cyanophenyl)phenoxy]unde-
canoyloxy}-10,15-dihydro-5H-tribenzo[a,d,g]cyclononene 1e.
Yield: 45%, phase transitions (°C): Cr 95 S 116 I. Elemental
found (calc. for C
H
N O S ): C, 69.16 (68.95); H, 7.64
159 210 12 18 6
(7.64); N, 5.96 (6.07). d (CDCl ) 0.86 (t, 18H, J 6.95, CH ),
A
6 18
analysis (%): found (calc. for C
H, 7.23 (7.16); N, 3.21 (3.31). d (CDCl ) 1.2–1.84 (m, 96H,
H
N O ): C, 78.50 (78.17);
165 180
H
3
3
1.23–1.82 (m, 120H, CH ), 2.48 (t, 12H, J 7.5, CH COO), 3.07
(t, 12H, J 7.7, ArCH ), 3.66 (d, 3H, J 14.4, ArCH Ar, H ), 3.96
H
3
2
2
CH ), 2.45 (t, 12H, J 7.4, CH COO), 3.65 (d, 3H, J 14.1,
ArCH Ar, H ), 3.96 (t, 12H, J 6.51, OCH CH ), 4.72 (d, 3H,
J 14.3, ArCH Ar, H ), 6.94 (d, 12H, J 8.8, Ar-H), 7.1 (s, 6H,
Ar-H), 7.49 (d, 12H, J 8.8, Ar-H), 7.58 (d, 12H, J 8.8, Ar-H),
7.65 (d, 12H, J 8.67, Ar-H).
2
2
2
2
2
e
(t, 12H, J 6.4, OCH CH ), 4.73 (d, 3H, J 13.4, ArCH Ar, H ),
6.9 (d, 12H, J 8.65, Ar-H), 7.12 (s, 6H, Ar-H), 7.81 (d, 12H, J
8.85, Ar-H). d (CHCl ) 170.8, 169.7, 168.2, 161.3, 140.7, 137.0,
2
e
2
2
2
2
a
2
a
C
3
129.4, 124.6, 122.5, 120.0, 144.9, 68.0, 34.0, 31.6, 30.9, 30.1, 30.0,
29.1, 29.0, 28.9, 28.85, 25.8, 25.75, 22.6, 14.1. Electrospray–MS:
3,7,8,12,13-Pentakis{4-[4-(4-cyanophenyl)phenoxy]butanoy-
loxy}-2-methyl-10,15-dihydro-5H-tribenzo[a,d,g]cyclononene 2a.
found (calc. for
(2767.42).
C
H
N O S ): M+ 2768.67 1.07
159 210 12 18 6
Yield: 55%, phase transitions (°C): Cr 163 (S 145) I. Elemental
analysis (%): found (calc. for C H N O ): C, 76.55 (76.45);
A
5 15
2, 3, 7, 8, 12, 13-Hexakis{5-[4-(5-pentadecyl-1,3,4-thiadiazol-
2-yl)phenoxy]pentanoyloxy}-10,15-dihydro-5H-tribenzo[a,d,g]
107 85
H, 5.08 (5.10); N, 4.09 (4.17). d (CDCl ) 2.05 (s, 3H, CH ),
2.1–2.27 (m, 10H, CH ), 2.6–2.8 (m, 10H, CH COO), 3.67 (d,
H
3
3
cyclononene 3h. Yield: 53%, phase transitions (°C): Cr 102
Cr 135 S 158 I. Elemental analysis (%): found (calc. for
2
2
2
1
3H, ArCH Ar, H ), 3.95–4.15 (m, 10H, OCH CH ), 4.7–4.85
(m, 3H, ArCH Ar, H ), 6.9–7.73 (m, 46H, Ar-H).
2
e
2
2
A
C
H
N O S ): C, 71.23 (71.15); H, 8.8 (8.53); N, 5.3
2
a
189 270 12 18 6
J. Mater. Chem., 1997, 7(10), 2001–2011
2009

(5.27). d (CDCl ) 0.86 (t, 18H, J 7, CH ), 1.2–1.86 (m, 180H,
CH ), 2.57 (t, 12H, J 5.45, CH COO), 3.06 (t, 12H, J 7.85,
2,3,6,7,10,11,14,15-Octakis{6-[4-(4-cyanophenyl)phenoxy]
hexanoyloxy}-5,10,15,20-tetrahydrotetrabenzo[a,d,g,j]cyclodo-
decene 7. Yield: 55%, phase transitions (°C): Cr 174 Cr 222
H
3
3
2
2
ArCH ), 3.67 (d, 3H, J 13.6, ArCH Ar, H ), 3.98 (t, 12H, J
5.65, OCH CH ), 4.74 (d, 3H, J 13.7, ArCH Ar, H ), 6.89 (d,
2
2
e
1
2
(N 220) I. Elemental analysis (%): found (calc. for
2
2
2
a
12H, J 9, Ar-H), 7.14 (s, 6H, Ar-H), 7.80 (d, 12H, J 8.85, Ar-
N O S ): M+
C
H
N O ): C, 76.78 (76.67); H, 5.94 (5.72); N, 3.78 (3.98).
24
(CDCl ) 1.43–1.81 (m, 48H, CH ), 2.57 (m, br, 16H,
180 160
8
3
H). Electrospray–MS: found (calc. for C
3189.17 0.87 (3187.89).
H
d
189 270 12 18 6
H
2
CH COO), 3.7 (m, br, 8H, ArCH Ar), 3.96 (t, 16H, J 6.2,
OCH CH ), 6.6–6.9 (s, br, 8H), 6.93 (d, 16H, J 8.7, Ar-H),
2
2
2
2
7.46 (d, 16H, J 8.9, Ar-H), 7.57 (d, 16H, J 8.7, Ar-H), 7.63 (d,
16H, J 8.5, Ar-H).
2,3,7,8,12,13-Hexakis{6-[4-(5-nonyl-1,3,4-thiadiazol-2-yl)
phenoxy]hexanoyloxy}-10,15-dihydro-5H-tribenzo[a,d,g]cyclo-
nonene 3i. Yield: 41%, phase transitions (°C): Cr 80 Col 162 I.
2,3,6,7,10,11,14,15-Octakis{5-[4-(5-nonyl-1,3,4-thiadiazol-2-
yl)phenoxy]pentanoyloxy} - 5, 10, 15, 20 - tetrahydrotetrabenzo
[a,d,g,j]cyclododecene 8. Yield: 20%, phase transitions (°C):
Cr 142 Cr 204 Col 222 I. Elemental analysis (%): found (calc.
Elemental analysis (%): found (calc. for C
159 210 12 18 6
C, 69.08 (68.95); H, 7.80 (7.64); N, 5.85 (6.07). d (CDCl ) 0.86
H
N O S ):
H
3
(t, 18H, J 6.9, CH ), 1.2–1.8 (m, 120H, CH ), 2.51 (t, 12H, J
7.05, CH COO), 3.08 (t, 12H, J 6.5, Ar-CH ), 3.67 (d, br, 3H,
3
2
2
1
2
2
for C
H
N O S ): C, 68.22 (68.43); H, 7.52 (7.43); N, 6.14
204 264 16 24 8
(6.26). d (CDCl ) 0.86 (t, 24H, J 7, CH ), 1.2–1.9 (m, 160H,
J 14.2, ArCH Ar, H ), 3.98 (t, 12H, J 6.25, OCH CH ), 4.75
(d, br, 3H, J 13.6, ArCH Ar, H ), 6.92 (d, 12H, J 9, Ar-H),
7.16 (s, 6H, Ar-H), 7.83 (d, 12H, J 9, Ar-H).
2
e
2
2
H
3
3
2
a
CH ), 2.6 (m, 16H, CH COO), 3.08 (t, 16H, J 7.5 ArCH ), 3.7
(m, br, 8H, ArCH Ar), 3.99 (m, 16H, O-CH -CH ), 6.6–6.9 (m,
br, 8H, Ar-H), 6.89 (d, 16H, J 8.2, Ar-H), 7.81 (d, 16H, J 8.2,
Ar-H). Electrospray–MS: found (calc. for C
M+ 3579.91 0.86. (3580.91).
2
2
2
2
2
2
3, 7, 8, 12, 13 - Pentakis{6 - [4 - (5-nonyl-1, 3, 4 - thiadiazol-2-yl)
phenoxy]hexanoyloxy} - 2-methyl - 10, 15-dihydro - 5H - tribenzo
[a,d,g]cyclononene 4b. Yield: 45% phase transitions (°C): Cr
62 Col 148 I. Elemental analysis (%): found (calc. for
H
N O S ):
204 264 16 24 8
2,3,6,7,10,11,14,15-Octakis{5-[4-(5-octylpyrimidin-2-yl)-
phenoxy]pentanoyloxy} - 5, 10, 15, 20 - tetrahydrotetrabenzo
[a,d,g,j]cyclododecene 9. Yield: 10%, mp 241 °C. d (CDCl )
C
H
N O S ): C, 69.55 (69.51); H, 7.87 (7.66); N, 5.77
137 180 10 15 5
(5.92). d (CDCl ) 0.85 (t, 15H, J 6.4, CH ), 1.24–1.55 (m,
H
3
3
H
3
60H, CH ), 1.71–1.92 (m, 40H, CH ), 2.06 (s, 3H, ArCH ),
2.57–2.62 (m, 10H, CH COO), 3.06 (t, 10H, J 7.6, ArCH ),
3.65 (d, br, 3H, J 13.9, ArCH Ar, H ), 3.94–4.05 (m, 10H,
CH O), 4.75–4.85 (m, 3H, ArCH Ar, H ), 6.89–6.95 (m, 10H,
Ar-H), 7.13–7.25 (m, 6H, Ar-H), 7.80–7.87 (m, 10H, Ar-H).
0.85 (t, 24H, CH ), 1.15–1.95 (m, 128H, CH ), 2.5–2.57 (m,
2
2
3
2
3
2
32H, ArCH and CH COO), 3.7 (m, br, 8H, ArCH Ar), 3.98
(t, 16H, OCH CH ), 6.6–6.9 (m, br, 8H, Ar-H), 6.92 (d, 16H,
J 8.7, Ar-H), 8.31 (d, 16H, J 8.9, Ar-H), 8.53 (s, 16H, Ar-H).
2
2
2
2
2
e
2
2
2
2
a
This work was supported by the BMBF and the Fonds der
Chemischen Industrie.
2,3,7,8,12,13-Hexakis{4-[4-(5-octylpyrimidin-2-yl)phenoxy]
butanoyloxy} - 10,15 - dihydro - 5H - tribenzo[a,d,g]cyclononene
5a. Yield: 37%, phase transitions (°C): Cr 143 Col 170 M 177
References
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153 186 12 18
C, 74.39 (74.06); H, 7.74 (7.56); N, 6.54 (6.77). d (CDCl ) 0.86
H
N O ):
1
2
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2
2
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2
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H
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5b. Yield: 45%, mp 168 °C. Elemental analysis (%): found (calc.
8
9
for C
H
N O ): C, 74.22 (74.44); H, 7.91 (7.78); N, 6.48
159 198 12 18
(6.55). d (CDCl ) 0.86 (t, 18H, J 6.95, CH ), 1.15–1.95 (m,
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H
3
3
96H, CH ), 2.40 (t, 12H, J 7.1, CH COO), 2.57 (m, 12H,
ArCH ), 3.66 (d, 3H, J 13.9, ArCH Ar, H ), 3.99 (t, 12H, J 5.5,
OCH CH ), 4.73 (d, 3H, J 13.7, ArCH Ar, H ), 6.93 (d, 12H,
J 8.8, Ar-H), 7.13 (s, 6H, Ar-H), 8.33 (d, 12H, J 8.8, Ar-H),
2
2
2
2
e
2
2
2
a
8.55 (s, 12H, Ar-H). Electrospray–MS; found (calc. for
C
H
N O ): M+ 2564.19 0.73 (2563.49).
159 198 12 18
3,7,8,12,13-Pentakis{5-[4-(5-octylpyrimidin-2-yl)phenoxy]
pentanoyloxy}-2-methyl-10,15-dihydro-5H-tribenzo[a,d,g]-cyclo-
nonene 6. Yield: 35%, phase transitions Cr 125 Cr 138 I.
1
2
Elemental analysis (%): found (calc. for C
H
N O ):
137 170 10 15
C, 75.19 (74.90); H, 8.1 (7.8); N, 6.09 (6.38). d (CDCl ) 0.86
H
3
(m, 15H, J 6.5, CH ), 2.08 (s, 3H, CH ), 1.15–2.12 (m, 60H,
CH ), 2.5–2.7 (m, 20H, ArCH and CH COO), 3.6–3.7 (m, 3H,
3
3
2
2
2
ArCH Ar, H ), 3.95–4.1 (m, 10H, OCH CH ), 4.62–4.80 (m,
3H, ArCH Ar, H ), 6.91–8.38 (m, br, 26H, Ar-H), 8.57 (s, 10H,
Ar-H).
2
e
2
2
2
a
2010
J. Mater. Chem., 1997, 7(10), 2001–2011

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Paper 7/02034A; Received 24th March, 1997
J. Mater. Chem., 1997, 7(10), 2001–2011
2011