Synthesis of novel ester series and study of its mesomorphism dependence on terminal end group with lateral-OCH3 group

Article abstract of DOI:10.1080/15421406.2015.1044158

Novel liquid crystal (LC) materials of ester derivatives were synthesized and studied with a view to understanding and establishing the effects of molecular structure on LC properties. The novel molecules consist of two phenyl rings bonded through-COO-central group and a laterally substituted methoxy group with-OC_nH2_n+1 as well as-COOCH₃ terminal end groups, and yielded 12 homologous members of an ester series. The C₁ to C₃ members are nonmesomorphic, the C₄ to C₁₂ members are enantiotropic nematic only, and the C₁₄ to C₁₆ members are enantiotropically smectogenic in addition to nematogenic. Transition temperatures and the textures of LC state were observed through an optical polarizing microscope (POM) equipped with a heating stage. The textures of nematic phase are threaded or Schlieren, and that of smectic phase are focal conic of the type A or C. Transition curves of a phase diagram behave in normal manner with the exhibition of an odd-even effect (only N-I). Analytical and spectral data support the molecular structures of the novel ester derivatives. The LC properties of the present series are compared with structurally similar other known series. The average thermal stability of the series is 93°C for smectic and 120.88°C for nematic and the mesogenic phase length ranges between 2°C and 46°C.

Full text of DOI:10.1080/15421406.2015.1044158

Molecular Crystals and Liquid Crystals
ISSN: 1542-1406 (Print) 1563-5287 (Online) Journal homepage: http://www.tandfonline.com/loi/gmcl20
Synthesis of novel ester series and study of its
mesomorphism dependence on terminal end
group with lateral –OCH3 group
M. S. Vadodaria, K. D. Ladva, A. V. Doshi & J. J. Travadi
To cite this article: M. S. Vadodaria, K. D. Ladva, A. V. Doshi & J. J. Travadi (2016) Synthesis
of novel ester series and study of its mesomorphism dependence on terminal end group
with lateral –OCH3 group, Molecular Crystals and Liquid Crystals, 624:1, 59-68, DOI:
10.1080/15421406.2015.1044158
To link to this article: http://dx.doi.org/10.1080/15421406.2015.1044158
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Date: 22 April 2016, At: 20:44

MOL. CRYST. LIQ. CRYST.
, VOL. , NO. , –
http://dx.doi.org/./..
Synthesis of novel ester series and study of its mesomorphism
dependence on terminal end group with lateral –OCH group
M. S. Vadodariaa, K. D. Ladvaa, A. V. Doshib, and J. J. Travadic
aDepartment of Chemistry, Shree M. N. Virani Science College, Rajkot, Gujarat, India; bMatushri Virbaima Mahila
Science and Home Science College, Rajkot, Gujarat, India; cDepartment of Chemistry, Kamani Science College
and Prataprai Arts College, Amreli, Gujarat, India
ABSTRACT
KEYWORDS
Enantiotropy; liquid crystal;
mesomorphism; nematic;
smectic
Novel liquid crystal (LC) materials of ester derivatives were synthesized
and studied with a view to understanding and establishing the effects
of molecular structure on LC properties. The novel molecules consist of
two phenyl rings bonded through –COO– central group and a laterally
substituted methoxy group with –OCnH2n+1 as well as –COOCH3 termi-
nal end groups, and yielded 12 homologous members of an ester series.
The C1 to C3 members are nonmesomorphic, the C4 to C12 members are
enantiotropic nematic only, and the C14 to C16 members are enantiotrop-
ically smectogenic in addition to nematogenic. Transition temperatures
and the textures of LC state were observed through an optical polar-
izing microscope (POM) equipped with a heating stage. The textures
of nematic phase are threaded or Schlieren, and that of smectic phase
are focal conic of the type A or C. Transition curves of a phase diagram
behave in normal manner with the exhibition of an odd-even effect
(only N-I). Analytical and spectral data support the molecular structures
of the novel ester derivatives. The LC properties of the present series are
compared with structurallysimilar other known series. Theaveragether-
malstabilityoftheseriesis93°Cforsmecticand120.88°Cfornematicand
the mesogenic phase length ranges between 2°C and 46°C.
Introduction
Liquid crystalline (LC) state of a substance is well known for its importance in various fields
of applications due to its dual character as to flow as liquid and to possess optical properties
of crystals, and was first recognized as a special state of matter in 1888 [1]. A critical survey
of literature indicated that many researchers have synthesized novel LC substances through
homologous series and binary systems [2–6]. We, being chemists, decided to synthesize novel
LC substances and to correlate effects of molecular structure on liquid crystal properties of
a substance by varying molecular aromaticity, central groups, terminal groups, positions of
same or different functional groups on phenyl ring or rings, geometrical shape, size, polarity
and polarizability, etc. Such novel substances may be useful to the researchers who are work-
ing with different aims in varying disciplines for the study of biological and pharmaceutical
activity as well as in the manufacture of electronic display (LCD) devices like television screen
CONTACT J. J. Travadi
j.travadi@gmail.com
College, Amreli, Gujarat , India.
Department of Chemistry, Kamani Science College and Prataprai Arts
©  Taylor & Francis Group, LLC

60
M. S. VADODARIA ET AL.
and related articles [7–13]. The present investigation is planned to synthesize and character-
ize novel LC ester substances with two phenyl rings, and aimed to understand and establish
the correlation between molecular structure and LC behavior or LC properties of novel sub-
stances [14,15] as a consequence of molecular rigidity and flexibility [16–20].
Experimental
Synthesis
4-Hydroxybenzoic acid was alkylated by suitable alkylating agent (R-X) to convert it into
dimeric 4-n-alkoxy benzoic acid by the modified method of Dave and Vora [21].
4-Hydroxy 3-methoxy cinnamic acid (m.p. 64°C yield 67%) was esterified by methanol by
using conc. H2SO4 by a usual established method [22]. The solid ester was crystallized from
distilled n-hexane. The melting point is 62–63°C. The yield was 75.6%. Dimeric 4-n-alkoxy
benzoic acids were individually condensed with 4-hydroxy, 3-methoxy methyl cinnamate in
dry cold pyridine through corresponding acid chlorides [23, 24]. Final products were individ-
ually decomposed, filtered, washed, dried, and purified until constant transition temperatures
were obtained.
The synthetic route to the series is shown in Scheme 1.
The chemicals required were 4-hydroxy benzoic acid, MeOH, KOH, alkyl halide (R-X),
thionyl chloride, 4-hydroxy,3-methoxy, cinnamic acid (ferulic acid), conc. H2SO4, pyridine,
1:1 HCl, NaHCO3, NaOH, anhydrous CaCl2, silicagel, petrolium ether, methyl acetate, and
n-hexane, and were used as received except solvents that were dried and purified prior to use.
Scheme . Synthetic route to the series. R = –CnHn+ where, n = ,,,,,,,,,,,.

MOL. CRYST. LIQ. CRYST.
61
Characterization
Representative homologues of the series were characterized by elemental analysis, IR spectra,
and 1H NMR spectra. Microanalysis was performed on Perkin-Elmer PE CHN analyzer. IR
1
spectra were recorded on Perkin-Elmer spectrum GX and H NMR spectra were recorded
on Bruker using CDCl3 solvent. Mesomorphic properties were investigated using hot stage
polarizing microscope. Thermodynamic quantity enthalpy (ꢀH) and entropy (ꢀS = ꢀH/T)
were discussed qualitatively instead of DSC scan.
Analytical data
Elemental Analysis for Hexyloxy, Octyloxy, Decyloxy, and Dodecyloxy Derivative
IR Spectra in cm− for Propyloxy and Pentyloxy Homologoue Derivatives
Propyloxy. The IR spectrum of the compound showed 677.33 cm−1polymethylene of –C6H13
group; 873.34 cm−1 and 828.46 cm−1 as p-sub. benzene ring; 1152.50 cm−1 as –CO– of alkoxy
group; 1240 cm−1, 1508 cm−1, 1600 cm−1, and 1701.78 cm−1 confirms –COO– of ester group;
−1
971.58 cm−1 confirms trans –CH CH– group; and 3065.2 cm confirms alkyl group IR sup-
ports the structure.
=
Pentyloxy. The IR spectrum of the compound showed 689.26 cm−1polymethylene of –C6H13
group; 842.91 cm−1 as p-sub. benzene ring; 1156.90 cm−1 as –CO– of alkoxy group;
1250.22 cm−1, 1604.22 cm−1, 1703.28 cm−1, and 1736.76 cm−1 conforms –COO– of ester group;
977.27 cm−1 confirms trans –CH CH– group; and 3192.95 cm−1 confirms alkyl group IR sup-
ports the structure.
=
H NMR Spectra in ppm for Hexyloxy and Octyloxy Derivatives
Hexyloxy. H1 NMR data in δ ppm (n-octyloxy derivative, 400 MHz, CDCl3, standard TMS):
–0.828 (–CH3 of –C6H13), 1.288 and 1.18 (–CH2 of – C6H13), 1.7365 (–OCH2–CH2 of –C6H13),
=
3.7755 and 3.8569 (–O–CH3), 3.9518 (–O–CH2– of –C6H13), 6.91–7.19 (–O–C6H4–CH CH–
CO–), 7.96–8.08 (p-sub. benzene ring)
The data supports the molecular structure.
Octyloxy. H1 NMR data in δ ppm (n-octyloxy derivative, 400 MHz, CDCl3, standard TMS):
–0.817 (–CH3 of –C8H17), 1.255 (–CH2 of –C8H17), 1.753 (–OCH2–CH2 of –C8H17), 3.749 and
=
3.798(–O–CH3), 3.965 (–O–CH2– of –C8H17), 6.36 and 7.189 (–O–C6H4–CH CH–CO–), 6.88
and 8.05 (p-sub. benzene ring)
The data supports the molecular structure.
Textures by Miscibility Method.
➤ C4 ——→ Threaded nematic
➤ C7 ——→ Schlieren nematic
➤ C16 ——→ Smectic–C
Result and discussion
4-Hydroxy-3 methoxy methyl cinnamate is a nonliquid crystal substance. However, on link-
ing it with dimerized 4-n-alkoxy benzoic acids yielded C4 to C16 derivatives as mesomor-
phic and C1 to C3 nonmesomorphic. C4 to C12 homologues are only enantiotropic nematic

62
M. S. VADODARIA ET AL.
Table . Elemental analysis for hexyloxy, octyloxy, decyloxy and dodecyloxy derivatives.
Molecular
Molecular formula
Mol.% of C experimental
(theoretical)
Mol.% of H experimental
(theoretical)
Compound no.
C
C
C
C
CHO
CHO
. (.)
. (.)
. (.)
. (.)
. (.)
. (.)
. (.)
. (.)
C 
H
O
O
C 
H
Table . Transition temperatures in °C.
Compound no.
n-Alkyl group R = -CnHn+
Sm
N
Isotropic









C
C
C
C
C
C
C
C
C
C
C
C
—
—
—
—
—
—
—
—
—
—
—
—
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.



—
.
.
.
.
Note: Sm = Smectic; N = Nematic.
Figure . Phase behavior of the series.
and remaining two mesomorphic derivatives are enantiotropically smectogenic in addition
to nematogenic. Dimerization of aromatic acids disappears on esterification of process. Tran-
sition temperatures of homologues (Table 2) are plotted versus the number of carbon atoms
present in n-alkyl chain of left n-alkoxy terminal end group. Transition curves showing phase
behaviors are obtained by linking like or related transition points. Thus, a phase diagram is
constructed (Fig. 1) to depict the phase behavior of the novel series. Cr-I or Cr-M transition

MOL. CRYST. LIQ. CRYST.
63
curve adopt a zigzag path of rising and falling as series is ascended with overall falling ten-
dency. Sm-N transition curve shows rising tendency in usual manner. However Sm-N tran-
sition curve is extrapolated [25–27] toward left side of a curve to predict and determine the
latent ability of nonsmectogenic homologues C10 and C12 keeping in view of the trend of Sm-N
transition curve. The predicted latent transition temperatures (LTT) for C10 and C12 are hypo-
thetically 72.5°C and 82.0°C to exhibit smectogenic character. However, these values are not
realizable, due to their high crystallizing tendency. N-I transition curve initially rises and then
descends as series is ascended with exhibition of odd-even effect. N-I transition curve for odd
members occupies relatively at lower position than the position of a N-I transition curve for
even members of series. Thus, all the transition curves of a phase diagram behaved in normal
manner with negligible abnormality (N-I) at C14 and C16 homologues. N-I transition curve
for odd members below even membered curve do not merge into each other but the effect
discontinued from and beyond heptyloxy (C7) derivative and then, single transition curve for
higher homologues prolonged. Variations in mesomorphic behavior and LC properties from
homologue to homologue in present series appear by sequential addition of methylene unit
or units. Thermal stability as related to enthalpy change (ꢀH) in average for a series is 93.0°C
for smectic and 120.88°C for nematic mesophase. The mesogenic phase length ranges from
2.0°C to 46.0°C.
Thus, a novel ester series under discussion is predominantly nematogenic and partly smec-
togenic with middle-ordered melting type.
The dimerization of n-alkoxy aromatic acids disappears by breaking of hydrogen bond-
ing between two acid molecules by esterification process. The molecular length, polarizabil-
ity, aromaticity, etc. undergo variations in suitable or unsuitable magnitudes of anisotropic
forces of intermolecular cohesion on linking acid chlorides of 4-n-alkoxy benzoic acid with
4-hydroxy-3-methoxy methyl cinnamate. The homologues C1 to C3 molecules are nonliq-
uid crystals, because their unsuitability in magnitudes of anisotropic forces of intermolecu-
lar attractions as a consequence of molecular rigidity and flexibility arising due to their per-
manent dipole moment across the long molecular axis, dipole–dipole interaction, dispersion
forces, etc., which are insufficient and unsuitable to resist, exposed thermal vibrations. Thus,
their crystal lattices are abruptly breaking and sharply transform directly into isotropic liquid
without passing through an intermediate state (LC state) of physical existence. At this stage
molecules of C1 to C3 homologues are randomly oriented in all possible directions without
any ordered arrangement to acquire LC state.
Exhibition of mesogenic behaviors of C4 to C16 members of a series is attributed to the
disalignment of molecules at an angle 90° or less than 90° with the floating surface, depend-
ing upon the suitable magnitudes of inter-molecular cohesive forces and closeness and its
resistivity against the intensity of exposed thermal vibrations for some degree of temperature
difference to cause either only nematic or only smectic or smectic and nematic mesophase for-
mation. The molecules of C4 to C12 homologue derivatives are floated on the surface under the
influence of exposed thermal vibrations with only statistically parallel orientational order of
molecules, which exhibited only nematogenic mesophase formation prior to isotropic tem-
perature in reversible manner. However, the homologue derivatives C14 and C16 are floated
on the surface with higher-ordered sliding layered arrangement of molecules for some tem-
perature difference prior to less-ordered statistically parallel orientational order of molecules
for another some degree of temperature difference in reversible manner till isotropic tem-
perature. Thus, C14 and C16 derivatives exhibited smectogenic mesophase formation prior to
nematogenic mesophase formation with reversible manner, i.e., the molecules of C14 and C16
as well as C4 to C12 are randomly oriented in all possible directions from and beyond isotropic

64
M. S. VADODARIA ET AL.
Figure . Structurally similar series.
temperature, but on cooling the same from and below isotropic temperature exhibit respec-
tive mesophase (smectic and/or nematic) formation at their respective transition tempera-
tures. The magnitudes of intermolecular attractions as a consequence of molecular rigidity
and flexibility (in present series) depended upon intermolecular distance, i.e., intermolecu-
lar attractions decreases by increasing intermolecular width by laterally substituted –OCH3
group. But at the same time increasing molecular width by –OCH3 increases intermolecular
attractions due to increase into molecular polarizability. Thus, two opposing forces of inter-
molecular attraction causes two opposite effect operated at a same time for the same reason.
The extrapolation of Sm-N transition curve for C10 and C12 homologues, whose missing of
smectogenic character is attributed to their high crystallizing tendency, hinders lamellar pack-
ing of molecules in their crystal lattices. The suitable magnitudes of intermolecular cohesive
forces occurred in C14 and C16 homologue molecules by their permanent dipole moment
across the long molecular axes, dipole–dipole interactions, dispersion forces, etc. as a conse-
quence of favorable molecular rigidity and flexibility, which causes the formation of lamel-
lar packing of molecules in their crystal lattices to build up three-dimensional network in
their crystalline state and occupy sliding layered arrangement of molecular network of two-
dimensional molecular order, under floating condition to facilitate smectic mesophase for-
mation under the influence of thermal vibrations for some degree temperature difference.
The exhibition of odd–even effect in N-I transition curve is attributed to the sequentially and
progressively added methylene unit to the n-alkoxy terminal end group that varies LC prop-
erty from homologue to homologue in present novel series, keeping rest of the molecular
part unchanged for all the homologue molecules of a series. Thus, variations in mesomorphic
properties of a substance depend upon the molecular structure of respective molecules.
Some mesomorphic properties of presently investigated series-1 are compared with the
structurally similar other known series-X [28] and Y [29] as shown in Fig. 2.
Homologous series-1 of present investigation and series-X and Y chosen for comparison
are similar with respect to two phenyl rings, –COO– central bridge and varying flexible –
OCnH2n+1 end group for the same homologue from series to series. However they differ with
=
respect to terminal end groups –CH CH–COOCH3, including and excluding laterally sub-
stituted –OCH3 group respectively and –COOCH3. Homologous series-1 and X are identical
with respect to two phenyl rings, central bridge –COO–, and both terminal end groups, but
they differ with respect to the presence of laterally substituted –OCH3 group that replaces –
H from second phenyl ring in series-1 and it is absent in series-X. Homologous series-1 and

MOL. CRYST. LIQ. CRYST.
65
Table . Average thermal stability in °C.
Series:→

X
Y
Smectic-isotropic or
Smectic-nematic
Commencement of Smectic
phase
Nematic-isotropic
Commencement of nematic
phase
. (C-C)
C
—
—
. (C-C)
C
.(C-C)
C
. (C-C)
C
—
—
Mesophase length range in
°C(Sm +N)
.–.
.–.
.°C to .°C
Y are identical in all respect except terminal end group at the other end of second phenyl
=
ring, i.e., –CH CH–COOCH3 is replaced by –COOCH3 with absence of lateral substituted
–OCH3 group in series-Y.
Therefore, the liquid crystal properties or behavior and the degree of liquid crystallinity will
depend upon the differing molecular part as a consequence of differing magnitudes of molec-
ular rigidity, flexibility, and the magnitudes of thermal resistivity toward externally exposed
thermal vibrations.
Following Table 3 represents some LC properties of presently investigated homologous
series-1 and the series-X and Y selected for comparative study.
Table 3 indicates that:
r
Homologous series-1 of present investigation is smectogenic in addition to nematogenic
in character, whereas series-X and Y chosen for comparison are only nematogenic and
only smectogenic, respectively.
Smectic and nematic mesophases commences from C14 and C4 homologue in series-1
whereas the same commences (nematic only) from C2 homologue in series-X and from
C5 homologue as smectic only in case of series-Y.
Average thermal stability of series-X and Y are 105.0 (N) and 111.75 (Sm), whereas that
of series-1 are 93.0 and 120.88 for smectic and nematic, respectively.
Smectic thermal stability of present series-1 is lower than a smectogenic series-Y, while
nematic thermal stability of present series-1 is higher than a nematogenic series-X.
r
r
r
r
Total mesophase length of present series-1 is the highest and that of series-X is the lowest
among the series under comparative study.
Homologous series-X and Y under comparison with series-1 do not contain any functional
group at lateral position on any phenyl ring. Homologous series-1 bears mesogenic ortho-
substituted highly polar functional group –OCH3, which is substituted on lateral position to
=
central group –COO– on second phenyl ring to which –CH CH–COOCH3 terminal end
group is substituted. Laterally substituted –OCH3 functional group increases intermolecu-
lar width as compared to series-X and Y. Therefore, two opposing effects are operated at a
time as: (i) increase in the intermolecular distance reduces suitable magnitudes of anisotropic
forces of intermolecular attractions, which induce or affect mesomorphism; and (ii) presence
of lateral –OCH3 group increases molecular polarizability, which can enhance intermolecu-
lar anisotropic forces of attractions to induce and affect mesomorphism. Thus, two oppos-
ing forces or effects are operated at a time for the same reason. Therefore, the resultant net
effect of intermolecular end-to-end and lateral attractions depends upon the predominancy
of the effects (i) or (ii) as mentioned above. Second effect (ii) due to polarizability is relatively
less operative in case of series-X and Y as compared to series-1 as a consequence of effec-
tive molecular rigidity and flexibility inducing LC property in the homologue substances.

66
M. S. VADODARIA ET AL.
The smectic thermal stability of present series-1 is lower (93.0) than a smectogenic series-
Y (111.75), because homologous series-Y contain terminal and central group –COO–, i.e.,
smectogenic –COO– functional groups, whereas a homologous series-1 of present investi-
=
gation (and series-X) contain terminal nematogenic –CH CH–COO– group that involve
conjugated double bond affecting molecular rigidity, flexibility, and end-to-end attractions.
Therefore, such effect hinders more the lamellar packing of molecules in series-1 (and X) and
favors the lamellar packing of molecules in crystal lattices of series-Y. The suitable magnitudes
of anisotropic forces of intermolecular end-to-end attractions are disturbed for a series-Y and
favored for series-1 and X to induce nematogenic character with accordingly more or less
degree of mesomorphism and early commencement of mesophase formation. Absence of lat-
=
eral substitution –OCH3 group and presence of vinyl carboxy group –CH CH–COOCH3
hinders lamellar packing of molecules in the crystal lattices of homologue substances belong-
ing to series-X and leads to float molecules on floating surface with only statistically paral-
lel orientational two-dimensional order, till isotropic temperature of mesogenic homologues
giving rise to exhibit only nematic mesophase formation, neglecting exhibition of smectic
character. Homologous series-1, X, and Y contain –COO– central group as common identi-
=
cal part, but difference in lateral substitution and end groups viz. –CH CH–COO– (series-1
and X) and –COO– (series-Y) causes difference in the magnitudes of molecular flexibility
and rigidity for the same homologue from series to series. Thus, in all other respect except
=
the end groups, which is –CH CH–COO–CH3 in case of homologous series-1 and X and car-
boxylate –COOCH3 in case of series-Y under comparative study, these three series are closely
similar to each other. Both these end groups are comfortable, though the vinyl carboxylate
=
–CH CH–COO– has greater length and causes more noncoplanarity due to a twist obtained
as the oxygen atoms of the vinyl carboxy group bump into the nonbonded adjacent hydrogen
atoms of the methyl group and a phenyl ring. On account of these differences, the smectic ther-
mal stability of series-1 is though lower than a series-Y but nematic thermal stability is higher
than the series-X and Y. The difference of the extent of molecular noncoplanarity induces
smectic character in C14 and C16 homologues of series-1, whereas it induces smectic charac-
ter earlier from C5 homologue to C16 homologue of series-Y at the cost of nematic mesophase
formation. Similarly, nematic mesophase commences earlier from C2 homologue (to C16) in
series-X at the cost of smectic mesophase formation as compared to series-1, in which nematic
mesophase commences late from C4 homologue (to C16). Thus, mesomorphic properties and
the degree of mesomorphism for the same homologue from series to series and homologue to
homologue in the same series depend upon molecular structure as a consequence of molecu-
lar rigidity and flexibility as emerged from permanent dipole moment across the long molec-
ular axis, dipole–dipole interactions, dispersion forces, electron–electron interaction, etc.
Conclusions
r
Novel homologous ester series consisting of two phenyl rings of 12 homologues is pre-
dominantly nematogenic (C4 to C16) and partly (C14 to C16) smectogenic with three
homologues (C1 to C3) as nonliquid crystals.
Transition temperatures of mesomorphic homologues range between 70°C and 145°C.
The group efficiency order derived for smectic and nematic mesophase formation on the
basis of (i) thermal stability, (ii) early commencement of mesophase, and (iii) mesophase
length are as under.
r
r

MOL. CRYST. LIQ. CRYST.
67
(i) Smectic:
=
=
–COOCH3 > –CH CH–COOCH3 > –CH CH–COOCH3
With lateral –OCH3 group without lateral –OCH3 group
Nematic:
=
=
–CH CH–COOCH3 > –CH CH–COOCH3 > –COOCH3
With lateral –OCH3 group without lateral –OCH3 group
Smectic:
=
–COOCH3 > –CH CH–COOCH3 with and without –OCH3 group
(ii) Nematic:
=
=
–CH CH–COOCH3 > –CH CH–COOCH3 > –COOCH3
Without –OCH3 group with –OCH3 group
(iii) Mesophase (Sm N):
=
=
–CH CH–COOCH3 > –COOCH3 > –CH CH–COOCH3
With –OCH3 group without –OCH3 group
r
Phenomena of mesomorphism is very sensitive and susceptible to molecular structure
of a substance.
Present investigation supports the views and conclusions drawn earlier.
r
Acknowledgments
The authors are especially thankful to the management, principal, and HOD, Chemistry, of Shree M.
N. Virani Science College, Rajkot, and Kamani Science College and Prataprai Arts College, Amreli, for
their valuable cooperation to facilitate the present research work, and IR spectra. The authors are also
thankful to the authorities of Saurashtra University for analytical services.
References
[1] Reinitzer, F. (1888). Monatsh, 9, 421.
[2] Demus, D. (1988). Mol. Cryst. Liq. Cryst., 165, 45.
[3] Demus, D. (1989). Liq. Cryst., 5, 75.
[4] Doshi et al. (i) Suthar, D. M., & Doshi, A. V. (2013). Mol. Cryst. Liq. Cryst., 575, 76. (ii) Chauhan,
H. N., & Doshi, A. V. (2013). Mol. Cryst. Liq. Cryst., 570, 92. (iii) Chaudhari, R. P., Chauhan, M.
L., & Doshi, A. V. (2013). Mol. Cryst. Liq. Cryst., 575, 88. (iv) Bhoya, U. C., Vyas, N. N., & Doshi,
A. V. (2012). Mol. Cryst. Liq. Cryst., 552, 104.
[5] Imrie, C. T., & Luckhrust, G. R. (1998). In: Hand Book of Liquid Crystals: Low Molecular Weight
Liquid Crystals, Vol. 624, Demus, D., Goodby, J. W., Gray, G. W., Spiess, H. W., & Vill, V. (Eds.),
pp. 801–833, Willey, VCH: Weinheim.
[6] Vora, R. A., Prajapati, A. K., Kevat, J. B., & Rao, K. K. (2001). Liq. Cryst., 28, 983.
[7] (a) Naemura, S. (2001). Displays, 22, 1. (b) Tadwee, I., Shahi, S., Ramteke, V., & Syed, I. (2012).
IJPRAS, 1, 6.
[8] (a) Kim, W. S., Elston, S. J., & Raynes, F. P. (2008). Display, 29, 458. (b) Stewart, G. T. (1974). In:
Liquid Crystals and Plastic Crystals, Vol. 624, Gray, G. W. & Winsor, P. A. (Eds.), pp. 308–326,
Ellis Horwood: Chichester.
[9] Cauiste, C. A. et al. (2001). Anti Cancer. Res., 21, 3949.
[10] Jahng, Y. et al. (2004). Bioorg. Med. Chem. Lett., 14, 2559.
[11] Modzelewska, A. et al. (2006). Bioorg. Med. Chem., 14, 3491.
[12] Rajesh, G. et al. (2008). Chem. Pharm. Bull., 56, 897.
[13] Lee, Y. S. et al. (2006). Biol. Pharm. Bull., 29, 1028.

68
M. S. VADODARIA ET AL.
[14] (a) Gray, G. W. (1974). In: Liquid Crystals and Plastic Crystals, Vol. 624, Gray, G. W. & Winsor, P.
A. (Eds.), pp. 103–153, Ellis Horwood: Chichester. (b) Gray, G. W. (1962). Molecular Structure
and Properties of Liquid Crystals, Academic Press: London.
[15] Imrie, C. T. (1999). Liq. Cryst. Dimmers. Struct. Bond, 95, 149.
[16] Hird, M., Toynel, K. J., Gray, G. W., Day, S. E., & Mc. Donnell, D. G. (1993). Liq. Cryst., 15, 123.
[17] Collings, P. J., & Hird, M. (1998). Introduction to Liquid Crystals: Chemistry and Physics, Taylor &
Francis: London.
[18] Marcos, M., Omenat, A., Serrono, J. L., & Ezcurra, A. (1992). Adv. Mater., 4, 285.
[19] Hird, M., Toyen, K. J., & Gray, G. W. (1993). Liq. Cryst., 14, 741.
[20] Hertz, E., Lavorel, B., & Faucher, O. (2011). Nat. Photon, 5, 78.
[21] Dave, J. S., & Vora, R. A. (1970). In: Liquid Crystals and Ordered Fluids, Johnson, J. F. & Porter,
R. S. (Eds.), Plenum Press: New York, p. 477.
[22] Vogel, A. I. (1989). In: Text Book of Practical Organic Chemistry, 5th ed., ELBS and Longman:
London, p. 1077.
[23] Bhoya, U. C., Vyas, N. N., & Doshi, A. V. (2012). Mol. Cryst. Liq. Cryst., 552, 104.
[24] Suthar, D. M., Doshi, A. A., & Doshi, A. V. (2013). Mol. Cryst. Liq. Cryst., 577, 51.
[25] Lohar, J. M., & Doshi, A. V. (1993). Proc. Ind. Acad. Sci. Bangalore, 105, 209.
[26] Ganatra, K. J., & Doshi, A. V. (2000). J. Ind. Chem. Soc., 77, 322.
[27] Doshi, A. V., Bhoya, U. C., & Travadi, J. J. (2012). Mol. Cryst. Liq. Cryst., 552, 10.
[28] Chauhan, M. L., & Doshi, A. V. (2011). Mol. Cryst. Liq. Cryst., 548, 228.
[29] Lohar, J. M., & Doshi, A. V. (1992). Acta Ciencia Indica, XVIII C(3), 245.