A crossover from rod-shaped to bent-shaped in symmetric isoflavone liquid crystal trimers exhibiting unusual mesomorphic behaviour

Article abstract of DOI:10.1039/c2jm30943b

A new series of symmetric isoflavone-based liquid crystalline trimers, 1,3-bis{[3-(4′-decyloxyphenyl)-4H-1-benzopyran-4-one-7-oxy]alkyloxy} benzenes with 3-12 methylene units in both lateral spacers have been synthesized and characterized by polarizing op

Full text of DOI:10.1039/c2jm30943b

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PAPER
A crossover from rod-shaped to bent-shaped in symmetric isoflavone liquid
crystal trimers exhibiting unusual mesomorphic behaviour
Tze-Nee Chan,a Guan-Yeow Yeap,a Wan-Sinn Yam,a Karolina Madrak,b Anna Zep,b Damian Pociechab
b
*
and Ewa Gorecka
Received 15th February 2012, Accepted 2nd April 2012
DOI: 10.1039/c2jm30943b
A new series of symmetric isoflavone-based liquid crystalline trimers, 1,3-bis{[3-(40-decyloxyphenyl)-
4H-1-benzopyran-4-one-7-oxy]alkyloxy}benzenes with 3–12 methylene units in both lateral spacers
have been synthesized and characterized by polarizing optical microscopy, differential scanning
calorimetry and X-ray diffraction. As expected, the phase transition temperatures strongly alternate as
the number of methylene units in the spacers changes. An unusual mesomorphic behaviour was
observed wherein short and long trimers exhibited smectic A (SmA) and/or smectic C (SmC) phase(s)
while homologues with intermediate spacer length were purely nematogenic (N) in a broad temperature
range. Formation and stabilization of the uniaxial nematic phase is caused by change of molecular
geometry from rod-shaped for short homologues to strongly bent-shaped for long homologues.
order to aid our understanding in how these homologues self-
Introduction
organize into the mesophase.
Liquid crystalline (LC) trimers, also referred to as trimesogens or
triplet liquid crystals, are supramolecular assemblies consisting of
molecules containing three mesogenic moieties connected via two
flexible spacers. Similar to liquid crystalline dimers, this class of
oligomers can be divided into symmetric and non-symmetric.1 In
symmetric LC trimers, the mesogenic moieties (two or all three)
and spacers are identical2,3 whilst non-symmetric trimers may
have different mesogenic units, spacers, terminal chains, substit-
uents, or have several structural combinations of these.4–6
Furthermore, there is an array of different molecular architectures
for these trimeric liquid crystals which include linear,7 cyclic,8 star-
shaped,9 U-, and l-shaped,10,11 as well as those comprising rod-
and disk-like units.12 However, the majority of the hitherto
reported and studied trimers are linear.13–20 Here, we report a new
series of liquid crystalline trimers, 1,3-bis{[3-(40-decyloxyphenyl)-
Experimental
All reagents were purchased from Acros Organics (Belgium),
Sigma Aldrich (USA) and Merck (Germany). They were used
without purification unless stated otherwise. The infrared (IR)
spectra for all compounds were recorded in the range 4000–400
cmꢀ1 using a Perkin Elmer 2000 FTIR spectrophotometer with
the samples embedded in KBr discs. The 1H-NMR and 13C-
NMR spectra were obtained using a Bruker 400 MHz Ultra-
Shieldꢀ spectrometer. CDCl3 and DMSO-d6 were used as
solvents and TMS as the internal standard. CHN microanalyses
were carried out on a Perkin Elmer 2400 LS Series CHNS/O
Analyzer. The liquid crystalline textures were observed under
a Carl Zeiss Axioskop 40 polarising microscope equipped with
a Linkam TMS94 temperature controller and a LTS350 hot
stage. The transition temperatures and enthalpy changes were
measured by a differential scanning calorimeter TA Q200 at
a rate of 5 K minꢀ1 for both heating and cooling cycles. Bruker
D8 Discover and GADDS systems were employed for X-ray
diffraction measurement.
4H-1-benzopyran-4-one-7-oxy]alkyloxy}benzenes
containing
resorcinol as the central unit. Resorcinol or1,3-dihydroxybenzene
is one of the most utilized central units for banana (bent-core)
LCs. Due to their geometry, the molecular symmetry of the
banana molecule is reduced and in turn leads to the generation of
complex liquid crystalline structures.13 The aforementioned units,
however, are rarely being utilized as a building block in oligomeric
LCs. We observed interesting and unusual mesomorphic behav-
iour for homologues of the presently reported series. A correlation
between the formation of the mesophase and a crossover of
molecular geometry from rod- to bent-shaped is established in
Synthesis
The syntheses of all intermediates, 1–12 and related trimers,
referred to using the acronyms RS-n-I were carried out using the
experimental procedures illustrated in Scheme 1.
aLiquid Crystal Research Laboratory, School of Chemical Sciences,
Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia
bDepartment of Chemistry, Warsaw University, Al.Zwirki I Wigury 101,
02-089 Warsaw, Poland. E-mail: gorecka@chem.uw.edu.pl
Synthesis of 4-decyloxyphenylacetic acid, 1. Potassium
hydroxide (7.84 g, 0.14 mol) in 25.0 ml of methanol was added
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The product was then recrystallized from methanol. Yield: 46%.
IR (KBr) n/cmꢀ1: 3226 (OH), 2929–2851 (C–H alkyl), 1633 (C]
O), 1616 (C]C), 1241 (C–O). 1H-NMR (CDCl3) d/ppm: 10.8 (s,
1H, OH), 8.33 (s, 1H, Ar–H), 7.98 (d, 1H, J ¼ 8.8 Hz, Ar–H),
7.49 (d, 2H, J ¼ 8.8 Hz, Ar–H), 6.98–6.95 (m, 3H, Ar–H), 6.87
(d, 1H, J ¼ 2.2 Hz, Ar–H), 3.98 (t, 2H, OCH2), 1.75–1.68 (m, 2H,
OCH2CH2), 1.41–1.26 (m, 14H, alkyl-H), 0.86 (t, 3H, CH3).
Syntheses of 7-(n-bromoalkyloxy)-3-(40-decyloxyphenyl)-4H-1-
benzopyran-4-ones, 3–12.
A reaction mixture containing
compound 2 (2.00 g, 5.08 mmol) in acetone (50 ml), respective
dibromoalkanes (5 equiv.), and potassium carbonate anhydrous
(2.76 g, 0.02 mol) was refluxed for 6 h. The reaction mixture was
then cooled to room temperature and the solvent was removed
via evaporation. Subsequently, water (50 ml) was added and the
resulting precipitate filtered and dried. The crude product was
recrystallized from chloroform and ethanol mixture (1 : 1, v/v). 3
Yield: 80%. IR (KBr) n/cmꢀ1: 2917–2851 (C–H alkyl), 1634 (C]
O), 1604 (C]C), 1250 (C–O). 1H-NMR (CDCl3) d/ppm: 8.22 (d,
1H, J ¼ 9 Hz, Ar–H), 7.93 (s, 1H, Ar–H), 7.49 (d, 2H, J ¼ 9 Hz,
Ar–H), 7.01–6.95 (m, 3H, Ar–H), 6.88 (d, 1H, J ¼ 2.3 Hz, Ar–H),
4.22 (t, 2H, OCH2), 3.99 (t, 2H, OCH2), 3.64 (t, 2H, BrCH2),
2.41–2.37 (m, 2H, OCH2CH2), 1.82–1.77 (m, 2H, OCH2CH2),
1.48–1.27 (m, 14H, alkyl-H), 0.89 (t, 3H, CH3).
Syntheses of 1,3-bis{[3-(40-decyloxyphenyl)-4H-1-benzopyran-
4-one-7-oxy]alkyloxy}benzenes, RS-n-I. Resorcinol (0.10 g, 0.91
mmol) and 1.8 equivalents of the corresponding intermediate 3–
12 were dissolved in acetone. Three equivalents of potassium
carbonate anhydrous together with a catalytic amount of
potassium iodide were then added to the solution. The reaction
mixture was refluxed for 12 h. The reaction mixture was cooled to
room temperature and excess solvent was removed via evapo-
ration. Water was then added to the mixture and the resulting
precipitate filtered, washed using acetone and recrystallized from
a chloroform and ethanol mixture (1 : 1, v/v). RS-3-I Yield: 62%.
Elemental analysis: found, C 76.15, H 7.68%; calculated
(C62H74O10), C 76.04, H 7.62%. IR (KBr) n/cmꢀ1: 2921–2852
(C–H alkyl), 1636 (C]O benzopyran), 1605 (C]C), 1288, 1249
Scheme 1 Syntheses of intermediates 1–12 and compounds of series RS-
n-I. Reactions and reagents: (a) KOH (2 equiv.), 1-bromodecane (1.2
equiv.), refluxing in methanol, 18 h, yield: 72%; (b) resorcinol (1.1 equiv.)
in BF3/Et2O, N2, 70–75 ꢁC, 4 h; DMF, 50 ꢁC, 1 h, then in MeSO2Cl (3
equiv.), 75–80 ꢁC, 1.5 h, yield: 46%; (c) dibromoalkane, BrCnH2nBr (5
equiv.) (n ¼ 3–12), K2CO3 (4 equiv.), refluxing in acetone, 6 h, yield: 70–
80%; (d) resorcinol (0.56 equiv.), K2CO3 (3 equiv.), KI, refluxing in
acetone, 12 h, yield: 56–70%.
into a cold solution containing 4-hydroxyphenylacetic acid
(10.00 g, 0.07 mol) in 25.0 ml of methanol. The ice bath was then
removed and 1-bromodecane (17.40 g, 0.08 mol) was added and
the reaction mixture was heated under reflux for 18 h. The
solvent was subsequently removed and the mixture was
neutralized with 10% of aqueous hydrochloric acid. The solid
was filtered off, washed thoroughly with water and recrystallized
from methanol. Yield: 75%. IR (KBr) n/cmꢀ1: 2932–2851 (C–H
1
(C–O). H-NMR (CDCl3) d/ppm, 8.22 (d, 2H, J ¼ 8.9 Hz, Ar–
H), 7.93 (s, 2H, Ar–H), 7.50 (d, 4H, J ¼ 8.7 Hz, Ar–H), 7.20 (t,
1H, Ar–H), 7.01 (d, 4H, J ¼ 2.3 Hz, Ar–H), 6.97 (dd, 2H, Ar–H),
6.88 (d, 2H, J ¼ 2.3 Hz, Ar–H), 6.56 (dd, 2H, Ar–H), 6.53 (t, 1H,
Ar–H), 4.28 (t, 4H, OCH2), 4.19 (t, 4H, OCH2), 4.00 (t, 4H,
OCH2), 2.36–2.30 (m, 4H, OCH2CH2), 1.85–1.74 (m, 4H,
OCH2CH2), 1.51–1.30 (m, 28H, alkyl-H), 0.91 (t, 6H, CH3). 13C-
NMR (CDCl3) d/ppm, 175.80 (C]O), 163.35, 160.14, 159.13,
157.97, 152.07, 130.12, 129.95, 127.77, 124.85, 123.88, 118.34,
114.56, 114.34, 106.67, 101.55, 100.65 (Carom), 68.23, 68.07, 67.44
(OCH2), 31.54, 29.43, 29.33, 29.21, 29.26, 26.04, 25.83, 25.81,
22.77 (CH2), 14.23 (CH3).
1
aliphatic), 1701 (C]O), 1617 (C]C), 1251 (C–O). H-NMR
(CDCl3) d/ppm: 12.23 (s, 1H, COOH), 7.15 (d, 2H, J ¼ 8.7 Hz,
Ar–H), 6.85 (d, 2H, J ¼ 8.7 Hz, Ar–H), 3.92 (t, 2H, OCH2), 3.47
(s, 2H, CH2), 1.72–1.65 (m, 2H, OCH2CH2), 1.41–1.26 (m, 14H,
alkyl-H), 0.86 (t, 3H, CH3).
Synthesis of 7-hydroxy-3-(40-decyloxyphenyl)-4H-1-benzo-
pyran-4-one, 2. A mixture containing 4-decyloxyphenylacetic
acid (12.00 g, 0.04 mol) and resorcinol (5.18 g, 0.05 mol) in 80 ml
BF3$Et2O was heated for 4 h at 70–75 ꢁC under nitrogen
atmosphere. The mixture was then cooled to room temperature
and dry DMF (20 ml) was added. The mixture was again heated
to 50 ꢁC for 1 h and a solution of methanesulfonyl chloride
(12 ml) in dry DMF (20 ml) was added slowly. After heating the
reaction mixture at 75–80 ꢁC for 1.5 h, it was poured into a rapid
stirring of ice-water bath upon which a solid was formed.
Results
The phase transition temperatures and associated enthalpies for
RS-n-I trimers, determined by DSC studies, are collected in
Table 1 and illustrated in Fig. 1. An archetypal behaviour of LC
dimers, the odd–even effect found in mesophase–isotropic tran-
sition temperatures was also observed for the trimeric
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Table 1 Phase transition temperatures (ꢁC) and enthalpy change values (kJ molꢀ1) for RS-n-I trimers recorded in a heating scan at 5 K minꢀ1
n
Cry
SmC
SmCanti
SmCsyn
SmA
N
Iso
3
4
5
6
7
8
9
10
11
12
*
*
*
*
*
*
*
*
*
*
142.5(45.53)
146.7(61.04)
119.1(59.53)
118.1(51.15)
119.4(68.54)
117.7(58.10)
136.0(67.17)b
126.1(7.52)
*
*
143.9(5.19)
154.1(4.63)
*
*
*
*
*
*
*
*
*
*
*
*
[113.9]c(4.24)
[134]a
*
*
*
*
133.1(2.59)
144.2(2.02)
133.2(2.95)
133.0(2.46)
*
*
*
*
138
*
[109.5](0.02)
*
135a
136.9(11.80)
129.0(6.58)
121.8
114.8(71.80)
121.2(61.39)b
*
*
[112]a
[100]a
a
b
Temperatures determined via polarizing optical microscopy or X-ray measurements. Total enthalpy change value due to total heating effect
(indicated by inseparable peaks in DSC thermograms). c [ ] Monotropic phase.
Fig. 2 The growth of parallel lines over the domains of the SmCsyn phase
(yellow birefringence color) indicating the transition to the SmCanti phase
(gray birefringence color), homologue RS-10-I.
Fig. 1 Phase diagram for RS-n-I trimers.
homologues presented here. The transition temperatures of the
homologues with short to moderate lengths (n ¼ 3–7) were found
to alternate strongly as the number of methylene units in the
spacers changes. Homologues with even-parity spacers have
significantly higher phase transition temperatures than homo-
logues with odd-parity spacers. The odd–even effect attenuates
for longer homologues (n ¼ 8–12). Contrary to such an expected
behaviour, the phase sequence in the studied homologue series is
highly unusual, despite the fact that only simple mesophases,
nematic, SmA and SmC, are observed with second order phase
transition between smectics. Smectic phases are observed for
short (n ¼ 3–5) and long (n ¼ 10–12) homologues whilst those
with intermediate spacer length (n ¼ 6–9) exhibit only the
Fig. 3 Schlieren texture of (a) SmCanti and (b) SmCsyn phases of
nematic phase. The compound RS-10-I exhibits additionally the
homologue RS-10-I. Two-brush defects with s ¼ 1/2 (marked with
synclinic–anticlinic SmC phase transition; for this homologue the
phase sequence is Iso–SmA–SmCsyn–SmCanti. When observing
the optical texture in the planar cell, the phase transition to the
SmCanti was signified by lowering birefringence and appearance
of characteristic stripes that wriggled through the broken focal
conic domains of SmCsyn and gradually took over all of the
SmCsyn area (Fig. 2). When observing the schlieren texture in
a hometropic cell (Fig. 3), in SmCsyn exclusively four brush
defects, s ¼ 1, were detected while in SmCanti also two
brush defects, s ¼ 1/2, could be found. The existence of two brush
defects in the tilted smectic phase unambiguously confirms the
a circle) are present only in the anticlinic phase. Arrangement of mole-
cules in synclinic and anticlinic smectic is shown schematically.
anticlinic tilt structure in consecutive layers.21 The SmCsyn
–
SmCanti phase transition is also proven by X-ray measurements,
ꢀ
in which a small layer spacing jump (ꢂ0.1 A) is observed at the
phase transition temperature (Fig. 4). There is no change in the
broadness of the high angle X-ray signal (corresponding to
ꢀ
4.5 A), showing that both tilted smectic phases have short range
positional order inside the layers.
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Fig. 6 The low angle X-ray patterns for the nematic phase in RS-5-I (a)
and RS-8-I (b).
Fig. 4 Layer thickness vs. temperature in the smectic phase for RS-n-I
trimers. In the inset is shown the characteristic length corresponding to
the X-ray signal position in the SmA phase (black squares) or nematic
phase (open circles).
possibility is more probable since for homologue n ¼ 10 the
SmCsyn–SmCanti phase transition is observed. The formation of
an anticlinic structure for strongly intercalated trimeric mole-
cules would involve abrupt change in molecular conformation at
phase transition, from mesogenic cores being in ‘trans’ to
mesogenic cores being in ‘cis’ conformation, such a change would
lead to a large jump in layer spacing at the SmCsyn–SmCanti
phase transition, contrary to what is observed experimentally.
It should be stressed that molecular conformation can be
considered as statistical, and particularly for intermediate
homologues both conformers, rod, preferred for short homo-
logues, and kinked, preferred for long homologues, have to co-
exist. The co-existence leads to frustration in the system. As
a result, compounds with intermediate spacer length, n ¼ 5–8,
form a nematic phase. The crossover of the molecular structure
from rod-like to kink-like can be followed also by X-ray
measurements in the nematic phase. For RS-5-I and RS-6-I
compounds two diffused signals (Fig. 6a) are observed in the low
angle region of the X-ray pattern. The position of lower angle
signal fits to the extrapolated position of the ‘monolayer’ smectic
layer thickness and the position of higher angle signal fits to the
extrapolated ‘half layer’ smectic layer thickness (inset in Fig. 5).
This reflects coexistence of two types of short range positional
orders with average longitudinal distance between molecules ꢂl1
and ꢂl2. The range of positional order correlation, as deduced
from the signal’s width, for both types of fluctuations is similar
In order to understand the complex phase behaviour, we must
take into account the molecular arrangements within the smectic
layer. Hence, detailed X-ray studies have been performed to
investigate the structure of these phases. The layer spacing, d, for
the SmA phase was compared with the estimated all-trans
molecular length, l. According to the X-ray measurements
(Fig. 4), short homologues with n ¼ 3–5 in the spacers, form
layers with d/l1 z 0.75–0.80, where l1 is the molecular length of
the most extended rod-like conformer. This is indicative of the
formation of the smectic phase in which parts of terminal chains
(up to few carbon atoms) intercalate into neighbouring layers.
Such significant interdigitation of terminal chains is a conse-
quence of the molecular shape; rotation of the trimer molecule
around its long axis makes its middle cross-section broader as
compared to that of the alkyl terminal chains; the terminal chains
have to intercalate between layers in order to fill the space effi-
ciently. Intercalation of terminal chains is a known factor
favouring the synclinic structure of the SmC phase, such a phase
is indeed found in homologue n ¼ 5. However, upon increasing
the spacer length, n $ 9, the layer thickness in the SmA phase is
found to be approximately l1/2 or alternatively l2, where l2 is the
molecular length of the strongly kinked conformer with both
isoflavone moieties placed at the same side of the central unit
(Fig. 5). Thus either molecules increase intercalation to nearly
half of their molecular length or smectic layers are made from
molecules adopting a strongly bent conformation. The latter
ꢀ
(around 5 A). For longer homologues, RS-7-I and RS-8-I, only
one X-ray signal at d z l2 is observed (Fig. 6b) in the nematic
phase, suggesting that the kink conformation becomes
dominating.
Conclusion
For the studied homologue series it was found that the molecular
geometry is strongly affected by the length of the spacers of
trimeric molecules; the cross-over from rod-like to kink-shaped
geometry is observed with elongation of the spacers. The kink-
like structure is apparently produced by strong core–core inter-
actions between the isoflavone moieties. The change in the
molecular shape leads to unusual mesomorphic behavior within
the homologue series. Short and long homologues exhibited
smectic phases with the layer spacing corresponding roughly to
the molecular length and half molecular length, respectively,
while intermediate homologues exhibit the nematic phase. The
types of smectic fluctuations in the nematic phase are also
determined by the spacer length and thus molecular
Fig. 5 Structures of smectic phases formed by (a) intercalated molecules
in rod-like conformation and (b) molecules in kink-like conformation.
Note that both structures show the same layer spacing.
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7 P. A. Handerson and C. T. Imrie, Liq. Cryst., 2005, 32, 673.
8 V. Percec and M. Kawasumi, Liq. Cryst., 1993, 13, 83.
9 K. Zab, D. Joachimi, E. Novotna, S. Diele and C. Tschierske, Liq.
Cryst., 1995, 18, 631.
conformations. For one of the homologues SmCsyn to SmCanti
phase transition is observed.
10 A. Yoshizawa and A. Yamaguchi, Chem. Commun., 2002, 2060.
11 A. Yamaguchi, I. Nishiyama, J. Yamamoto, H. Yokoyama and
A. Yoshizawa, J. Mater. Chem., 2005, 15, 280.
12 S. Mahlstedt, D. Janietz, A. Stracke and J. H. Wendorff, Chem.
Commun., 2000, 15–16.
13 N. V. Tsvetkov, V. V. Zuev and V. N. Tsvetkov, Liq. Cryst., 1997, 22,
245.
14 N. Tamaoki, H. Matsuda and A. Takahashi, Liq. Cryst., 2001, 28,
1823.
Acknowledgements
The authors would like to thank Universiti Sains Malaysia for
funding the project through RU Research Grant (account no.
1001/PKIMIA/811127 and 1001/PKIMIA/811140) and USM
Fellowship Scheme. The Polish group wishes to acknowledge the
TEAM program from FNP (Project TEAM/2010-5/4).
15 P. A. Henderson, A. G. Cook and C. T. Imrie, Liq. Cryst., 2004, 31,
1427.
16 C. T. Imrie, P. A. Henderson and J. M. Seddon, J. Mater. Chem.,
2004, 14, 2486.
17 G. Y. Yeap, T. C. Hng, W. A. K. Mahmood, E. Gorecka,
D. Takeuchi and K. Osakada, Mol. Cryst. Liq. Cryst., 2009, 506, 109.
18 G. Y. Yeap, T. C. Hng, M. M. Ito, W. A. K. Mahmood, D. Takeuchi
and K. Osakada, Mol. Cryst. Liq. Cryst., 2009, 515, 215.
19 A. C. Sentman and D. L. Gin, Adv. Mater., 2001, 13(18), 1398.
20 A. Yoshizawa, H. Kinbara, T. Narumi, A. Yamaguchi and H. Dewa,
Liq. Cryst., 2005, 32, 1175.
Notes and references
1 C. T. Imrie and P. A. Henderson, Chem. Soc. Rev., 2007, 36, 2096.
2 C. T. Imrie and G. R. Luckhurst, J. Mater. Chem., 1998, 8(6), 1339.
3 I. Nishiyama, J. Yamamoto, J. W. Goodby and H. Yokoyama, J.
Mater. Chem., 2003, 13, 2429.
4 C. V. Yelamaggad, U. S. Hiremath, D. S. Shanker Rao and
S. Krishna Prasad, Chem. Commun., 2000, 57.
5 S. Mahlstedt, D. Janietz, C. Schmidt, A. Stracke and J. H. Wendorff,
Liq. Cryst., 1999, 26, 1359.
6 C. V. Yelamaggad, S. Anitha Nagamani, U. S. Hiremath,
D. S. Shankar Rao and S. Krishna Prasad, Liq. Cryst., 2001, 28, 1581.
21 Y. Takanishi, H. Takezoe, A. Fukuda and J. Watanabe, Phys. Rev. B:
Condens. Matter Mater. Phys., 1992, 45, 7684.
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