Synthesis of 4-Alkyl-2″, 3″ difluoro terphenyl nitrile using coupling reactions

Article abstract of DOI:10.1016/j.molliq.2012.08.012

Study of chirality in liquid crystals is one of the most interesting areas of liquid crystal science. Liquid crystalline terphenyls with two lateral fluoro substituent and alkyl substituent in the 4- have been synthesised. Convergent approach was applied which involved the use of arylboronic acids and aryl halides in palladium-catalysed cross-coupling reactions. All the diifluoroterphenyls generate the smectic C phase. Mixture of 4-Alkyl-2″, 3difluoro terphenyl nitrile in achiral host mixture HM1 generates ferroelectric liquid crystal properties. Ferroelectric properties were found to be highly dependent upon the relative lengths of the alkyl chain attached to chiral dopant. The compounds were studied using optical polarisation microscopy, differential scanning calorimetric, nuclear magnetic resonance, and Instec elecro-optical device to find ferroelectric liquid crystal properties.

Full text of DOI:10.1016/j.molliq.2012.08.012

Journal of Molecular Liquids 175 (2012) 72–84
Contents lists available at SciVerse ScienceDirect
Journal of Molecular Liquids
journal homepage: www.elsevier.com/locate/molliq
Synthesis of 4-Alkyl-2′′, 3′′ difluoro terphenyl nitrile using coupling reactions
c
b
Zohra N. Kayani a, , Robert A. Lewis , Shahzad Naseem
⁎
a
Lahore College for Women University, Lahore, Pakistan
b
Centre for Solid State Physics, University of the Punjab, Lahore-54590, Pakistan
Department of Chemistry, University of Hull, Hull, HU6 7RX, UK
c
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 21 April 2012
Received in revised form 21 June 2012
Accepted 12 August 2012
Available online 6 September 2012
Study of chirality in liquid crystals is one of the most interesting areas of liquid crystal science. Liquid crystalline
terphenyls with two lateral fluoro substituent and alkyl substituent in the 4- have been synthesised. Convergent
approach was applied which involved the use of arylboronic acids and aryl halides in palladium-catalysed
cross-coupling reactions. All the diifluoroterphenyls generate the smectic C phase. Mixture of 4-Alkyl-2′′,
3difluoro terphenyl nitrile in achiral host mixture HM1 generates ferroelectric liquid crystal properties.
Ferroelectric properties were found to be highly dependent upon the relative lengths of the alkyl chain
attached to chiral dopant. The compounds were studied using optical polarisation microscopy, differential
scanning calorimetric, nuclear magnetic resonance, and Instec elecro-optical device to find ferroelectric liquid
crystal properties.
Keywords:
Terphenyls
Convergent approach
Host mixture
Chiral dopant
Ferroelectric liquid crystal
© 2012 Elsevier B.V. All rights reserved.
1. Introduction
A phase and then to chiral Smectic C phase. The FLC is enclosed in cell to
measure its ferroelectric properties. For ideal FLC the N* pitch length
Dopants ferroelectric properties could be increased by using a
terphenyl structure [1,2] and ferroelectric properties can be improved
by increasing the length of the chain attached to nitrile [3]. The in-
creased chain length increases the spontaneous polarisation Ps, viscos-
ity by making them bulky and decreases the pitch length. The decrease
in pitch length results from the restricted rotation produced by length-
ening the chain. Position of fluorine on terphenyl plays important role
in chiral dopant ferroelectric properties [4]. The SmC1 phase behaviour
is higher when the difluoro unit is located on the end ring.
The chiral ‘dopant’ needs not be mesogenic but it should not cause a
large reduction of the SmC phase stability or to raise the melting point.
FLC2 is not a single compound but mixture of many components i.e.
mixture of chiral dopant and achiral host mixture. Major component
is achiral host mixture which has SmC phase at room temperature,
low viscosity and excellent stability. Small percentage of achiral host
mixture is doped with chiral dopant. The resulting FLC3 should have
an I3–N4*–SmA5*–SmC* cooling phase sequence. Isotropic phase is liq-
uid phase when temperature is lowered its phase changes to chital ne-
matic phase. Further cooling transforms chiral nematic to chiral smectic
should be>4× the cell gap. The SmC* pitch length should be greater
than the cell gap. Spontaneous polarisation Ps should be moderately
large, around 15–30 nC cm−2 and ideally, the tilt angle would remain
constant over the operating temperature of the device at 22.5 °.
Two achiral host mixtures are used in this research work. One of
them is HM1 which is mixture of three components.
50%
F
F
C5H11
C7H15
4-pentyl-4′′-heptyl-2′, 3′-difluoroterphenyl
25 %
F
F
C5H11
C7H15
4-pentyl-4′′-heptyl-2, 3-difluoroterphenyl
25%
F
F
C5H11
C7H15
⁎
Corresponding author. Tel.: +92 3224042222; fax: +92 42 9923 1139.
E-mail address: zohrakayani@yahoo.com (Z.N. Kayani).
Smectic C.
Ferroelectric Liquid Crystal.
Isotropic.
Nematic.
1
4-pentyl-4′′-heptyl-2′′, 3′′-difluoroterphenyl
2
3
4
5
Another achiral host mixture is LM3 which is also consisted of
three components.
SmecticA.
0167-7322/$ – see front matter © 2012 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.molliq.2012.08.012

Z.N. Kayani et al. / Journal of Molecular Liquids 175 (2012) 72–84
73
N
N
Yield ( 40.11 g, 84.98%): M.P. 133.3 [5]; δH(400 MHz;CDCl3) 2.64
(3H,s,CH3),8.03 (2H, d, J 8.25),7.64 (2H,d,J 8.61), 7.59 (2H,d,J 8.80),
7.49 (2H, d, J 8.43); δC (100.5;CDCl3)26.67 (CHMe),127.03, 128.81,
129.01, 132.09, 136.12, 138.76, 144.49, 197.62 (CO);
C8H17
OC8H17
5-octyl-2-(4-(octyloxy)phenyl)pyrimidine
1
4-bromo-biphenyl carboxylic acid
N
C8H17
OC10H21
HO
Br2,NaOH
N
CHBr3
2-(4-(decyloxy)phenyl)-5-octylpyrimidine
Br
Br
HCl
O
O
2
Quantities and procedure:
A solution of sodium hypobromite prepared at 0 °C (by keeping flask
N
C8H17O
OC8H17
N
in ice) by dissolving bromine (79.6 g, 497.5 mmol, 160 g/mol) in a solu-
tion of sodium hydroxide (71.4 g, 1785 mmol, 40 g/mol) in a 350 ml
water, was added with stirring to a solution of the 4- bromo-4′′-
acetylbiphenyl (20 g, 72.73 mmol, 275 g/mol) in dioxan (300 ml). The
oil bath was used and the temperature was maintained at 35–40 °C
throughout the addition and for 15 minutes afterwards. The suspension
was treated with enough aqueous sodium thiosulfate pentahydrate to
remove the excess of hypobromite till solution was white. Water
(500 ml) was added and liquid was distilled off. The residual suspension
or solution was acidified with concentrated hydrochloric acid and
cooled. The free acid was filtered off and crystallised from propanol
and ethanol. It was then filtered off and left in 60 °C oven overnight.
Yield (15.81 g, 78.18%); M.P.306 °C [6] m/z 278 (M+, 100%), 261,
230, 196, 152, 76; δH(400 MHz;CDCl3) 7.53 (2H, d, J 8.43),7.6 (2H,d,J
8.61),7.65 (2H,d,J 8.06),8.09 (2H,d,J 8.25); ;δC(100.5;CDCl3) 122.22,
126.64, 128.8, 130.28, 131.93, 138.88, 143.66, 168.05 (CO);
5-(octyloxy)-2-(4-(octyloxy)phenyl)pyrimidine
3
Ternary host mixture was prepared in weight ratios of 1:1:1. The
actual measured percentage of compound 1, 2 and 3 were 33.1%,
33.7% and 33.12% respectively. This mixture melts below the room
temperature. Mixture has thermally stable SmC phase with a transi-
tion of 66.5 °C to the SmA phase. This achiral host mixture is called
LM3.
2. Synthesis of 4-Alkyl-2′′, 3′′ difluoro terphenyl nitrile
Ortho difluoro substituted materials were synthesised that possess a
central terphenyl core and to incorporate chiral centre in the terminal
chain. Two fluorine rings were attached to terminal ring. Length of
alkyl chain was changed from pentyl-heptyl-nonyl. Synthesis routes of
these chiral dopants can be found in some other paper [3].
Research paper Cyanoalkyl difluoro-terphenyl-carboxylate chiral
dopants Z. N. Kayani. et.al [3] provides synthesis details of biphenyl cy-
anohydrin ester which is initial compound for synthesis of 4-Alkyl-2′′,
3′′ difluoro terphenyl nitrile. Same research paper [3] provides
Synthesis steps of 4-(pentyl, heptyl)-2′′, 3′′ difluoro terphenyl nitrile
using coupling reactions [1]. Biphenyl cynohydrin ester is used as starting
material in this synthesis. [3] Shows synthesis steps of 4-nonyl-2′′, 3′′
difluoro terphenyl nitrile using coupling reactions. For this chiral dopant
synthesis route described for 4-(pentyl, heptyl)-2′′, 3′′ difluoro terphenyl
nitrile were not adopted.
Bromobiphenyl carbonyl chloride
O
O
Oxalyl chloride
Br
Br
CH2Cl2,Cat DMF
Cl
OH
Quantities and procedure:
4- Bromobiphenyl carboxylic acid (3 g, 10.79 mmol, 278 g/mol)
was put in a 100 ml round bottom flask with (30 ml, 36.5 g/mol)
DCM, placed it on a mechanical stirrer. A nitrogen bubbler was at-
tached to it. Syringed out (1.12 ml, 12.95 mmol, 126 g/mol) of oxalyl
chloride and few drops of DMF. After adding few drops of DMF
switched off the Nitrogen. Bubbles will be coming out. Left it to stir
for the time bubbles stopped coming off. The solvent was removed
in vacuo.
2.1. Synthesis details of all intermediates and final products
bromobiphenyl carbonyl amide
Synthesis of Biphenyl cynohydrin ester
4-bromo-4′-acetyl biphenyl
O
O
O
(s)-Lactamide,pyridine
tetrahydrofuran
Br
Br
CONH2
Cl
O
AlCl3
Br
Quantities and procedure:
The s-(-)-lactamide (0.19 g, 10.25 mmol, 89 g/mol) was dissolved
Br
O
DCM
Cl
in (8.94 ml) pyridine with magnetic stirrer. The bromobiphenyl car-
bonyl chloride (3.19 g, 10.79 mmol, 296 g/mol) in 15 ml ether and
15 ml THF was added to the above solution drop wise with the help
of dropping funnel while stirring. It was left stirring for ten hours.
Ice was put in 40 ml of diluted HCl solution; over it suspension in
round bottom flask was poured. It was filtered and dry product,
re-crystallised through hexane and toluene.
Yield (1.51 g, 40%); M.P. 171.1 °C (from hexane and toluene).
Elemental analysis: calc. for (Found: C, 55.49; H, 3.94 ; N, 3.86
.C16H14BrNO3 requires C, 55.19; H, 4.05; N, 4.02%). m/z 349 (M+),
276, 261 (100%), 230, 152, 76; IR(KBr)υmax/cm−1 3419 and 3199
(CONH2), 1716 vs, (CO), 1636, 1608, 1481, 1393, 1294, 1276, 1119,
1076, 1003, 817, 767; δH(400 MHz;CDCl3) 1.65 (3H,t, J6.78), 5.52
(1H,q, J6.96, CHMe), 5.59 and 6.15 (1H, brs, NH),7.50 (2H,d,J
8.80),7.61 (2H,d,J 8.61), 7.66 (2H,d,J 8.61), 8.14 (2H,d,J 8.61); δC (100.5;
CDCl3) 17.7, 53.42, 122.85, 127.09, 128.89, 130.41, 132.16, 138.59,
145.17, 164.97 (CO), 172.41 (CONH2);
Quantities and procedure:
Dichloromethane (500 ml) was added to Aluminium chloride
(26.66 g, 199.7 mmol, 133.5 g/mol). The mixture was stirred and
cooled to
a 5 °C in a salt/ice bath. Acetyl chloride (26.83 g,
343.97 mmol, 78 g/mol) was quickly added through a dropping funnel
and cooled to −3 °C to give a transparent yellow solution. Solid
4-bromobiphenyl (40 g, 171.67 mmol, 233 g/mol) was added in small
amounts and stirred, wait for ½ an hour then add more. The mixture
was left stirring for ten hours with the temperature rising to 15 °C.
The mixture was poured into bucket of ice /37% HCl to destroy the alu-
minium chloride, then transferred to a separatory funnel and extracted
into DCM. Then the mixture was washed twice with 200 ml of water to
destroy HCl. Again it was washed with 10% NaOH and 200 ml of water.
The collected DCM layer was dried over Magnesium Sulfate, the most of
it filtered by gravity. The solvent was removed in vacuo and residue was
re-crystallised through ethanol.

74
Z.N. Kayani et al. / Journal of Molecular Liquids 175 (2012) 72–84
(S)-1-cynoethyl 4′-bromobiphenyl -4-carboxylate
−78 °C for 1 hour, poured on to mixture of dry ice and dry ether and
allowed to warm at room temperature. 50 ml of diluted hydrochloric
acid was added. The THF was evaporated through rotary evaporator
till 50 ml solution was left. It was cooled by ice and after an hour filtered
by pressure. It was washed by water several times to remove excess
acid. It was re-crystallised through isopropanol. The dry product was
placed in oven overnight.
O
O
O
O
POCl3,DMF
Br
CN
Br
CONH2
Quantities and procedure:
Dry DMF (40 ml) was cooled to 0 °C. POCl3 (1.85 ml) was added slow-
ly by syringe under nitrogen keeping the temperature below 5 °C .It was
stirred for 20 minutes and turned coloured. Bromobiphenyl amide
(1.39 g, 3.98 mmol, 349 g/mol) was added in portion and stirred for
twenty hours at room temperature. Solution was poured in ice and
water mixture. Swirled around and was placed to settle down. A precipi-
tate was obtained. It was filtered and washed with water. The dry product
was re-crystallised through toluene.
Yield (1.39 g, 100%); M.P. 167 °C (from toluene). Elemental
analysis: (Found: C, 58.45; H, 3.57; N, 4.11. C16H12BrNO2 requires
C, 58.2; H, 3.66; N, 4.24%); IR (KBr) υmax/cm−1 1718 s(CO),1653,
1605, 1585, 1558, 1478, 1388, 1277, 1253, 1203, 1178, 1077, 997, 816,
757, 685; δH(400 MHz;CDCl3) 1.80 (3H, d, J 6.96, Me), 5.68 (1H, q, J
6.96, CHMe), 7.50 (2H, d, J 8.80), 7.61 (2H, d, J 8.61), 7.66 (2H, d, J
8.61), 8.12 (2H, d, J 8.61), δC (100.5;CDCl3) 18.99, 57.80, 117.54 (CN),
123.02, 127.51, 128.86, 130.63, 132.16, 138.53, 145.42, 164.41 (CO);
Synthesis of 4-(pentyl, heptyl)-2′′, 3′′ difluoro terphenyl nitrile
4-pentyl-2′′, 3′′-difluoro terphenyl
Yield (6.40 g, 85.46%). M.P. 270 °C (from isopropanol); Elemental
analysis: (Found: C, 77.94; H, 5.83. calc. for C47H44F4O2: C, 75.77; H,
5.83%); m/z 380 (M+).336, 323 (100%), 310, 277, 165, 153; IR(KBr)
υ
max/cm−1 2925 (CH),1700 (COvs), 1653, 1623, 1507, 1464, 1419,
1399, 1303, 1220, 1105, 809, 781, 765; δH(400 MHz;CDCl3) 0.90 (3H,t, J
7.0, CH3CH2),1.28–1.39 (4H,m),1.63 (2H, quint, J 7.7, ArCH2CH2), 2.64
(2H,t, J 7.9, ArCH2), 7.34 (2H,d,J 8.2), 7.53 (1H, ddd, J 7, 6.8, 1.6), 7.68
(2 H, d, J 8.2), 7.73 (2 H, dd, J 8.4, 1.5), 7.77 (1 H, ddd, J 7.0, 6.8,
1.6),7.84 (2H,d,J 8.6),; δF(376 MHz;CDCl3), −135.16 (1F, dd, JF,F 20.81,
JF,H 6.9), −142.43 (1F, dd, JF,F 18.5, JF,H 6.9); δC(100.5;CDCl3) 13.93,
21.97, 30.69, 30.91, 34.70, 120.43 (dd, JC,F 3.8, 2.3), 124.68 (dd, JC,F 3.8,
2.3),125.35.126.41 (d, JC,F 3.8), 126.61, 126.85, 128.99, 129.37 (d, JC,F
3.1), 131.92, 133.35, 133.44, 136.59, 140.65, 142.23, 164.04 (dd, JC,F 3.1,
2.3, CO);
* 4-pentyl-2′′, 3′′-difluoro terphenyl carbonyl chloride
F
F
F
F
O
O
Oxalyl Chloride
DCM,Cat DMF
C5H11
C5H11
OH
Cl
F
F
F
F
DME,2M Na2CO3
Br
(HO)2B
C5H11
C5H11
Quantities and procedure:
pd(pph3)4
4- pentyl-2′′,3′′-difluoro terphenyl carboxylic acid (3 g, 7.89 mmol,
380 g/mol), DCM (30 ml, 36.5 g/mol), oxalyl chloride (1.1 ml,
12.98 mmol, 126 g/mol) and few drops of DMF.
The experimental procedure was as described for the preparation
of compound Bromobiphenyl carbonyl chloride.
Quantities and procedure:
1, 2-dimethoxyethene (150 ml) and sodium carbonate (2 M,
150 ml) were added to diflouroboronic acid (4.79 g, 30.33 mmol,
158 g/mol) and 4-bromo-4′′pentylbiphenyl (7.07 g, 23.33 mmol,
303 g/mol) under dry nitrogen with continuous stirring. Tetrakis
(triphenylphosphine) palladium (0) (0.1348 g, 0.11 mmol, 1156 g/mol)
was added. The stirred mixture was heated under reflux (ca. 120 °C) for
2 h (i.e., until g. L .c/ t. l. c. analysis revealed a complete reaction). Reaction
mixture was cooled to room temperature and 100 ml water was added.
The product was extracted into 200 ml ether (twice) and the combined
ethereal extracts were washed with brine and dried (MgSO4), the most
of it filtered off by pressure. The solvent was removed in vacuo. The dry
product was purified by addition to a packed chromatography column
of silica gel [silica gel, Hexane] to yield white product. Product was
re-crystallised through ethanol. It was put in the desiccators overnight.
Yield (6.47 g, 82.53%).M.P. 97.5 °C (from EtOH). Elemental analysis:
(Found: C, 82.40; H, 6.74 .Calc. for C23H22F2: C, 82.11; H, 6.59%);m/z 336
(M+), 292, 279 (100%),165, 151; transitions / °C K 95.8 (25.79 J/g) SmA
108.8 (18.98 J/g) I;IR (KBr) υmax/cm−1 2927 (CH), 1473, 1398, 1264,
1216, 1100, 897, 817, 785, 721; δH(400 MHz;CDCl3) 0.80 (3H,t,J 7,
CH3CH2), 1.19–.27 (8H, m), 1.57 (2H, quint, J7.7, ArCH2CH2), 2.57 (2H,
t, J7.9, ArCH2), 7.02 (1H, ddd, J 6.8, 6.6, 1.5, 20H), 7.16 (1H, ddd, J 6.8,
6.4, 1.6, 19H),7.47 (2H,d,J 8.1), 7.52 (2H, dd, J 8.2, 1.5), 7.59 (2H, d,
J8.2),;(δF(376; CDCl3)) −143.30 (1F, dd, JF,F20.81, JF,H6.9), −143.88
(1F, dd, JF,F18.5, JF,H6.9);δC(100.5;CDCl3) 14.10, 22.68, 29.20, 29.34,
31.50, 31.82, 35.64, 116.0 (d, J 16.9), 124.08 (dd, JC,F 5.4, 4.6), 125.20
(dd, JC,F 3.8, 1.5), 126.93, 127.11, 128.92, 129.27 (d JC,F 3.1), 130.83,
131.00, 133.26 (d, JC,F 4.6), 137.75, 141.00, 142.51;
# 4-pentyl-2′′, 3′′-difluoro terphenyl carbonyl amide
F
F
O
Lactamide,pyridine
tetrahydrofuran
C5H11
Cl
F
F
O
C5H11
CONH2
O
Quantities and Procedure:
4-pentyl-2″, 3″-difluoro terphenyl carbonyl chloride (3 g, 7.54 mmol,
398 g/mol), s-(-)-lactamide 0.86 g, 9.66 mmol, 89 g/mol, pyridine
(8.4 ml, 106.33 mmol, 79 g/mol) and dry THF (60 ml). The experimental
procedure was as described for the preparation of compound
bromobiphenyl carbonyl amide.
Yield (1.3 g, 37.25%); M.P.193.4 °C (from ethyl acetate); Elemental
analysis: calc. for (Found: C, 71.93; H,6.25; N, 3.14 . C27H27F2NO3 re-
quires C, 71.82; H, 6.03; N, 3.10%); m/z 451 (M+), 394, 379, 363, 335,
322, 278, 165, 153, 44 (100%); transitions/°C K 177.8 (79.86 J/g)SmA*
206.4 (20.11 J/g)I; IR (KBr) υmax/cm−1 3391 (CONH2), 2925 (CH),
1723 vs (CO), 1652 vs(CONH2), 1559, 1506, 1458, 1419, 1300, 1165,
1105800, 779; δH (400 MHz;CDCl3) 0.91 (3H,t,J 6.9, CH3CH2), 1.34–
1.38 (4H,m), 1.63 (3H, d, J 7, Me), 1.82 (2H, quint, J 7.9, ArCH2CH2),
2.66 (2H,t, J 7.9, ArCH2), 5.4 (1H, q, J 6.78, CHMe), 6, 8 and 6.92 (1H,
brs, NH), 7.3 (2H,d,J 8.2), 7.39 (1H, ddd, J 6. 8,6.6, 1.5), 7.58 (2H, d,
J 8.4),7.66 (2H, dd, J 7, 1.5), 7.73 (2H, d, J 8.4), 7.85 (1H, ddd, J 6.6,
6.4, 1.8); δF (376 MHz;CDCl3), −134.55 (1F, dd, JF,F 20.81, JF,H 6.9),
−142.26 (1F, dd, JF,F 20.81, JF,H 6.9); δC(100.5;CDCl3) 13.99, 17.79,
22.36, 30.99, 31.35, 35.37, 71.18 (CHMe), 121.5, 124.4, 126.46, 126.73,
127.04, 128.94, 129.21, 135.09, 137.05, 142.59, 146.58, 160.07, 172.41;
Quantities, procedure, yield and elemental analysis of 4-pentyl-2″,
3″-difluoro terphenyl carbonyl nitrile can be found in some other
paper [3].
4-pentyl-2′′, 3′′-difluoro terphenyl carboxylic acid
F
F
F
F
O
2.5 M BuLi,THF
CO2,HCl
C5H11
C5H11
OH
Quantities and procedure:
A solution of n-butylithium (8.27 ml, 22.39 mmol in hexanes) was
added drop wise to a stirred, cooled (−78 °C) solution of 4-pentyl-2′′,
3′′-difluoro terphenyl (6.27 g, 18.66 mmol, 336 g/mol) in( 150 ml)
THF under dry nitrogen..The reaction mixture was maintained at

Z.N. Kayani et al. / Journal of Molecular Liquids 175 (2012) 72–84
75
4-heptyl-2′′, 3′′-difluoro terphenyl
4-heptyl-2′′,3′′-difluoro terphenyl carbonyl amide
F
F
F
F
F
F
O
Lactamide,pyridine
tetrahydrofuran
DME,2M Na2CO3
(HO)2B
C7H15
C7H15
Br
C7H15
pd(pph3
)
4
Cl
F
F
O
C7H15
Quantities and procedure:
4-bromo-4′′-heptyl biphenyl (7.07 g, 21.36 mmol, 331 g/mol),
diflouroboronic acid (5.69 g, 27.77 mmol, 158 g/mol) Tetrakis
(triphenylphosphine) palladium (0)(.2 g, 0.11 mmol, 1156 g/mol),1,
2-dimethoxyethene (150 ml) and sodium carbonate (2 M, 150 ml).
The experimental procedure was as described for the preparation
of compound 4-pentyl-2′′, 3′′-difluoro terphenyl except that reaction
completed in 23 h.
CONH2
O
,
Quantities and procedure:
4-heptyl-2″, 3″-difluoro terphenyl carbonyl chloride (2 g, 4.69 mmol,
426 g/mol), s-(-)-lactamide 0.57 g, 6.4 mmol, 89 g/mol, pyridine (5.6 ml,
79.89 mmol, 79 g/mol) and dry THF (40 ml).
The experimental procedure was as described for the preparation
of compound bromobiphenyl carbonyl amide.
Yield (0.9 g, 40.9%); M.P. 195.9 °C (from ethyl acetate); Elemental
analysis: calc. for (Found: C, 72.68; H, 6.81 ; N, 2.85 . C29H31F2NO3 re-
quires C, 72.63; H,6.52; N,2.92%);m/z 479 (M+, 100%),407, 391, 380,
323, 307, 278, 165, 153; transitions/°C K 174.5 (65.57 J/g) SmA* 198.6
(98.26 J/g) I; IR (KBr) υmax/cm−1 3392 (CONH2), 2924 (CH), 1723 vs
Yield (6.5 g, 83.55%); M.P. 47.6 °C (from EtOH). Elemental analysis:
( Found: C, 82.56; H, 7.47. calc. for C25H26F2: C, 82.38; H ,7.19%);m/z 364
(M+), 292, 279 (100%),165, 151; transitions/°C K 34.5 (11.67 J/g) cryst
E 61.1 (6.15 J/g) SmB 73.7 (1.3 J/g) SmA 104.6 (18.81 J/g) I ; IR (KBr)
υ
max/cm−1 2925 (CH),1472, 1398, 1265, 1216, 1099, 896, 816, 701,
718; δH(400 MHz; CDCl3) 0.80 (3H,t,J7.1,CH3CH2),1.19–.27 (8H, m),1.57
(2H, quint, J 7.7, ArCH2CH2), 2.57 (2H, t, J 7.9, ArCH2), 7.02 (1H, ddd, J
6.8, 6.6, 1.5, 20H),7.16 (1H, ddd, J 6.8, 6.4, 1.6, 19H),7.47 (2H, d, J 8.1),
7.52 (2H, dd, J 8.2, 1.5),7.59 (2H,d,J 8.2); (δF(376; CDCl3)) −143.30(1F,
dd, JF,F 20.81, JF,H 6.9), −143.88 (1F, dd, JF,F 18.5, JF,H 6.9); δC (100.5;
CDCl3) 14.10, 22.68, 29.20, 29.34, 31.50, 31.82, 35.64, 115.91, 116.08,
124.06 (dd, JC,F 5.4, 3.5), 125.20 (dd, JC,F 3.8, 3.5), 126.93, 127.11, 128.92,
129.27 (d, JC,F 3.1), 130.90, 131.00, 133.26 (d, JC,F 4.6), 137.75, 141.00,
142.51;
Table 1
Transition temperatures (°C) and enthalpy change taken by optical polarising micro-
scope and differential scanning calorimeter for the 4-alkyl-2′′, 3′′-difluoro terphenyl
nitrile and their intermediate compounds.
Structure
Mesomorphic behaviour
F
F
F
F
F
F
Melting point: 97.5°C
4-heptyl-2′′, 3′′-difluoro terphenyl carboxylic acid
Transitions/°C K 95.8 (25.79J/g)
SmA 108.8 (18.98J/g) I
C5H11
F
F
F
F
O
Melting point: 191.45°C
2.5 M BuLi,THF
CO2,HCl
C7H15
C7H15
O
O
transitions/° C K 177.8 (79.86J/g)
SmA* 206.4 (20.11J/g) I
OH
CONH2
C5H11
Quantities and procedure:
4-heptyl-2′′, 3′′-difluoro terphenyl (6.25 g, 17.17 mmol, 364 g/mol),
n-butylithium (8.24 ml, 20.60 mmol in hexanes) and THF.
Melting point: 103.2°C
O
Transitions/°C SmC* 102.8
(15.85J/g)SmA* 164.9 (16.45J/g)
I[3]
CN
C5H11
O
The experimental procedure was as described for the preparation
of compound 4-pentyl-2″, 3″-difluoro terphenyl carboxylic acid.
Yield (4.13 g, 61.4%); M.P. 247.7 °C (from isopropanol); Elemental
analysis: ( Found: C, 76.22; H, 6.21. calc. for C26H26F2O2: C, 76.45; H,
6.42%);m/z 408 (M+), 364, 336, 323 (100%),310, 279, 165, 153;
IR(KBr)υmax/cm−1 2924 (CH), 1684 (COvs), 1623, 1506, 1465, 1419,
1306, 1103, 956, 894, 806, 777; δH(400 MHz;CDCl3) 0.89 (3H,t,J 7.0,
CH3CH2), 1.24–1.39 (9H, m),1.65 (2H, quint, J 7.7, ArCH2CH2), 2.65
(2H,t, J 7.9, ArCH2), 7.29 (2H,d,J 8.2), 7.35 (1H, ddd, J 6.8, 6.6, 1.6),
7.57 (2H,d,J 8.1),7.65 (2H, dd, J 7, 1.5), 7.72 (2H,d,J 8.6),7.78(1H, ddd,
J 6.8, 6.6, 1.6); (δF(376; CDCl3)) −135.8 (1F, dd, JF,F 18.5, JF,H 6.9),
−143.111 (1F, dd, JF,F 20.8, JF,H 6.9);δC(100.5;CDCl3) 14.06, 22.5, 29.00,
29.11, 31.34, 31.64, 35.44, 119.82 (dd, JC,F 3.8, 3.1), 124.09 (d, JC,F 3.8),
126.44 (d, JC,F 4.6), 126.73, 127.00, 128.93, 129.22 (d, JC,F 3.1), 132, 28,
134.15, 134.24 (d, JC,F2.3), 137.17, 141.36, 142.57, 146.93, 164.86 (dd,
Melting point: 47.61°C
F
F
F
F
Transitions/°C K 34.5 (11.67J/g)
cryst E 61.1 (6.15J/g) SmB 73.7
(1.3J/g) SmA 104.6 (18.81J/g) I
C7H15
Melting point: 195.93°C
O
O
transitions/°C K 174.5 (65.57J/g)
SmA* 198.6 (98.26J/g) I
CONH2
C7H15
Melting point: 95.78°C
F
F
F
F
O
transitions/°C SmC* 95.2
(14.61 J/g )SmA* 145.5 (14.85J/g)
I I[3]
CN
C7H15
O
Melting point: 66.66°C
JC,F 3.8, 3.1),
Transitions temperature/°C K
52.4 (28.58 J/g ) Cryst E 61.6
(4.4 J/g) SmB 71.6 (64.26 J/g)
SmA 103.1 (18.97 J/g) I;
4-heptyl-2′′, 3′′-difluoro terphenyl carbonyl chloride
C9H19
F
F
F
F
O
O
Oxalyl Chloride
DCM,Cat DMF
C7H15
Melting point:193.60 ° C (97.52
F
F
C7H15
OH
Cl
O
O
J/g) Transitions/°C K 182.9
(94.19 J/g) SmA 190.3 (97.52 J/g)
CONH2
C9H19
Quantities and procedure:
4-heptyl-2′′, 3′′-difluoro terphenyl carboxylic acid (2 g, 4.9 mmol,
408 g/mol), DCM (20 ml, 36.5 g/mol), oxalyl chloride (0.75 ml,
8.65 mmol, 126 g/mol) and few drops of DMF.
The experimental procedure was as described for the preparation
of compound Bromobiphenyl carbonyl chloride.
Melting point: 85.43°C (13.93
F
F
O
J/g) Transition/°C K 82.9
(13.93 2 J/g) SmY 94.9 (0.40 J/g)
SmX 100.99 ( 0.44 J/g) SmA
131.6 (11.42 J/g) I[3]
CN
C9H19
O

76
Z.N. Kayani et al. / Journal of Molecular Liquids 175 (2012) 72–84
(CO), 1663.1652 (CONH2),1635, 1558, 1507, 1464, 1300, 1232, 1166,
1105804, 780; δH(400 MHz;CDCl3) 0.89 (3H, t, J7.0, CH3CH2), 1.24–
1.42 (8H, m),1.65(3H, d, J 6.8, Me), 1.69 (2H, quint, J 7.3, ArCH2CH2),
2.56–2.74 (8H, m), 5.45 (1H, q, J 6.8, CHMe), 6.49 and 6.73(1H, brs,
NH), 7.29 (2H,d,J 8.1) 7.38 (1H, ddd, J 7, 6.6, 1.3), 7.57 (2H, d, J
8.1),7.65 (2H, dd, J 7.1, 1.0), 7.72 (2H,d,J 8.4), 7.84 (1H, ddd, J 7, 6.6,
1.6); (δF(376; CDCl3)) −139.92 (1F, dd, JF,F 20.81, JF,H 6.9), −142.69
(1F, dd, JF,F 20.81, JF,H 4.6); δC (100.5;CDCl3) 14.01, 17.71, 22.38.28.92
(d, J10), 31.23, 31.52, 35.2971.02, 118.37, 124.32, 126.44, 126.63,
126.93, 128.90, 129.20 (d, JC,F 3.1), 131.90, 136.92, 141.37, 142.5,
144.09, 161.87, 172.22;
Synthesis of 4-nonyl-2′′, 3′′difluoro terphenyl nitrile
4-nonanoyl-4′-bromo biphenyl
O
AlCl3
DCM
Br
+
Cl
O
Br
Quantities and procedure:
Quantities, procedure, yield and elemental analysis of 4-heptyl-2″,
3″-difluoro terphenyl carbonyl nitrile can be found in some other
paper [3].
4′-bromobiphenyl (50 g, 214.59 mmol, 233 g/mol), aluminium
chloride (33.36 g, 249.91 mmol, 133.5 g/mol), nonanoyl chloride
(52.23 ml, 277.9 mmol, 176.69 g/mol) and DCM (650 ml , 36.5 g/mol).
a
b
c
d
e
f
Fig. 1. (a) Mixture of 7% D9R in HM1, Isotropic phase to nematic phase transition; shearing induces homogeneous alignment and produces birefrigent, (b) Mixture of 14% D5R in
HM1; fingerprint texture of chiral nematic phase, (c) Mixture of 7% D9R in HM1; focal conic texture of SmA* phase and (d) Mixture of 7% D9R in HM1; the scheliring texture of SmC*
phase (e). The scheliring texture of nematic phase of 3% D5R in pyrimidine (LM3) mixture, (f) The scheliring texture of SmC* phase of 3% D5R in pyrimidine (LM3) mixture.

Z.N. Kayani et al. / Journal of Molecular Liquids 175 (2012) 72–84
77
The experimental procedure was as described for the preparation
4- nonyl-4′-bromo biphenyl
of compound 4-bromo-4′-acetyl biphenyl.
O
Yield (68.23 g ,85.24%); M.P. 106.7 °C (from ethanol, ethyl acetate);
H (400 MHz;CDCl3) 0.88 (3H,t,J7.1,CH3CH2), 1.23–1.43 (10H, m), 1.75
NH2NH2.H2O
KOH,DEG
δ
C9H19
Br
Br
(2H, quint, J7.5, ArCH2CH2), 2.98 (2H, t, J 7.5), 7.49 (2H,d,J 8.8), 7.59
(2H, d, J 8.8), 7.64 (2H, d, J 8.6), 8.03 (2H, d, J 8.8); δC(100.5;CDCl3)
14.11, 22.67, 24.45, 29.18, 29.43 (d, J 5.4), 31.85, 38.73, 122.59, 127.02,
128.79 ( d, J 3.8), 132.09, 136.09, 138.85, 144.24, 200.13; m/z 374
(M+), 276, 261, 152 (100%);
Quantities and procedure:
4- onanoyl-4′-bromo biphenyl (50 g, 139.16 mmol, 359.30 g/mol)
and potassium hydroxide ( 23.38 g, 147.48 mmol, 56 g/mol)were
a
^e n d o
z k 2 7 3 % in K C H M 2 1 1 h e a t & c o o l 1 8 . 0 5 . 2 0 0 7 0 8 : 1 9 : 0 9
normalized
Onset
3.01 Jg^-1
121.55 °C
122.12 °C
Peak
zk27 3%inKCHM211 heat &cool
Integral
normalized
Onset
6.07 mJ
1.38 Jg^-1
104.57 °C
105.81 °C
Peak
]1[3%zk27inKCHM211
3%zk27inKCHM211, 4.3900 mg
2
mW
Integral
normalized
Onset
-76.81e-03 mJ
-17.50e-03 Jg^-1
80.37 °C
Integral
-6.08 mJ
Peak
79.57 °C
normalized
Onset
-1.38 Jg^-1
105.76 °C
104.46 °C
]2[3%zk27inKCHM211
3%zk27inKCHM211, 4.3900 mg
Peak
Integral
-13.79 mJ
-3.14 Jg^-1
121.26 °C
120.78 °C
normalized
Onset
Peak
0
10
20
30
40
50
60
70
80
90
100
110
120
130
°C
Hull Liquid Crystal Group: dapreut
S T A R e S W 8 . 1 0
b
^e n d o
z k 2 7 7 % in K C H M 2 1 1 h e a t & c o o l
1 1 .0 5 .2 0 0 7 1 3 :5 7 :4 9
normalized 2.64 Jg^-1
Onset
Peak
121.79 °C
122.44 °C
zk27 7% in KCHM211 heat & cool
Integral
7.49 mJ
normalized 2.01 Jg^-1
Onset
Peak
109.77 °C
111.44 °C
_]3[zk 27 7% in KCHM211
zk 27 7% in KCHM211, 3.7300 mg
2
mW
Integral
-2.02e-03 mJ
]4[zk 27 7% in KCHM211
normalized -540.61e-06 Jg^-1
zk 27 7% in KCHM211, 3.7300 mg
Onset
Peak
70.42 °C
69.46 °C
Integral
-6.65 mJ
normalized -1.78 Jg^-1
Onset
Peak
111.25 °C
109.70 °C
Integral
normalized -3.01 Jg^-1
-11.24 mJ
Onset
Peak
121.63 °C
121.13 °C
-20
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
°C
S T A R e S W 8 . 1 0
Hull Liquid Crystal Group: dapreut
Fig. 2. Heating and cooling of 3%, 7% and 14% 4-pentyl-2′′, 3′′-difluoroterphenyl nitrile and 3%, 7% 4-(heptyl, nonyl)-2′′, 3′′-difluoroterphenyl nitrile in achiral host mixture HM1
showing SmC* phase, SmA* phase, nematic phase and isotropic phase. 14 % 4-pentyl-2′′, 3′′-difluoroterphenyl nitrile in HM1 does not possess ferroelectroic properties as sown in
curve c.

78
Z.N. Kayani et al. / Journal of Molecular Liquids 175 (2012) 72–84
c
^ e n d o
z k 2 7 1 4 % i n K C H M 2 1 1 h e a t & c o o l 1 8 . 0 5 . 2 0 0 7 1 1 : 5 4 : 5 4
Integral33.45 mJ
normalized9.59 Jg^-1
Onset120.73 °C
Peak123.24 °C
zk27 14% in KCHM211 heat & cool
__]1[14%zk27inKCHM211
14%zk27inKCHM211, 3.4900 mg
2
mW
]2[14%zk27inKCHM211
14%zk27inKCHM211, 3.4900 mg
Integral-36.76 mJ
normalized-10.53 Jg^-1
Onset123.38 °C
Peak122.02 °C
°C
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
115
120
125
130
S T A R e S W 8 . 1 0
Hull Liquid Crystal Group: dapreut
d
^en do
z k1 9 ,3% in HM1
01 .06 .20 07 09 :13 :43
Integral10.02 mJ
normalized2.99 Jg^-1
Onset121.49 °C
Peak122.06 °C
zk19 3% inHM1
Integral4.87 mJ
normalized1.45 Jg^-1
Onset104.87 °C
Peak106.09 °C
Integral67.52e-03 mJ
normalized20.15e-03 Jg^-1
Onset80.29 °C
Peak81.76 °C
[]]1[$3%zk19 inHM1
3%zk19 inHM1, 3.3500 mg
2
mW
Integral-61.54e-03 mJ
normalized-18.37e-03 Jg^-1
Onset80.95 °C
Peak80.19 °C
]2[$3%zk19 inHM1
3%zk19 inHM1, 3.3500 mg
Integral-4.23 mJ
normalized-1.26 Jg^-1
Onset105.97 °C
Peak104.79 °C
Integral-10.55 mJ
normalized-3.15 Jg^-1
Onset121.12 °C
Peak120.65 °C
-20
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
°C
S T AR e S W 8.10
Hull Liquid Crystal Group: chsjah
Fig. 2 (continued).
added to a 1 litre three necked flask. Diethylene glycol was added and
the mixture heated to 80 °C, then hydrazine monohydrate (23 ml,
416.7 mmol, 50 g/mol) was added slowly. Then the mixture was heat-
ed at 130–140 °C for 3 hours continuous stirring under reflux to give a
light brown liquid, before distilling off the hydrozone monohydrate and
some vapours at 120 °C. The mixture was heated to 180–190 °C for
3 hours to give a dark brown liquid that was then cooled to 80 °C and
poured into ice/37% HCl to remove KOH. The crude was extracted
through DCM (250 ml).The organic extracts was then washed with
water, dried over MgSO4 and then solvent removed in vacuo. It was
re-crystallised through ethanol. It still has impurity. So the crude was
purified by addition to a packed chromatography column of silica gel
[silica gel, Hexane] to yield white product.
Yield (24.15 g, 48.3%); M.P. 87.6 °C (from ethanol); δH (400 MHz;
CDCl3) 0.88 (3H, t, J 7.1, CH3CH2), 1.23–1.41 (13H, m), 1.64 (2H, quint,
J7.7, ArCH2CH2),2.63(2H, t, J 7.9),7.23 (2H, d, J 8.2),7.44 (2H, d, J 8.8),
7.46, (2H, d, J 8.6), 7.54 (2H, d, J 8.6); δC(100.5; CDCl3) 14.11, 22.68,
29.34 (d, J 2.3), 29.54 (d, J 3.1), 31.48, 31.9, 35.61, 121.15, 126.76,
128.57, 128.96, 131.79, 137.28, 140.10, 142.62; m/z 360 (M+), 247
(100%), 178, 165, 152, 41

Z.N. Kayani et al. / Journal of Molecular Liquids 175 (2012) 72–84
79
e
^en do
z k1 9,7 % in H M1
01 .06 .20 07 09 :29 :53
Integral10.14 mJ
normalized2.26 Jg^-1
Onset121.65 °C
Peak122.29 °C
zk19,7% inHM1
Integral8.32 mJ
normalized1.86 Jg^-1
Onset110.92 °C
Peak112.59 °C
Integral74.63e-03 mJ
normalized16.66e-03 Jg^-1
Onset68.58 °C
_[]]1[$7%zk19 inHM1
7%zk19 inHM1, 4.4800 mg
Peak70.12 °C
2
mW
]2[$7%zk19 inHM1
7%zk19 inHM1, 4.4800 mg
Integral-72.47e-03 mJ
normalized-16.18e-03 Jg^-1
Onset68.96 °C
Peak68.05 °C
Integral-6.82 mJ
normalized-1.52 Jg^-1
Onset112.24 °C
Peak110.62 °C
Integral-11.97 mJ
normalized-2.67 Jg^-1
Onset121.19 °C
Peak120.62 °C
-20
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
°C
Hull Liquid Crystal Group: chsjah
S T AR e S W 8. 10
}
f
^en do
z k5 2 , 3 % in H M1 H e at & c ool
23 .06 .20 07 18 :48 :10
Integral12.08 mJ
normalized3.04 Jg^-1
Onset121.02 °C
Peak121.55 °C
zk52 ,3 % in HM1 Heat & cool
Integral4.94 mJ
normalized1.24 Jg^-1
Onset104.66 °C
Peak105.94 °C
_]1[zk 52 ,3% in HM1
zk 52 ,3% in HM1, 3.9700 mg
2
mW
Integral-4.68 mJ
normalized-1.18 Jg^-1
Onset106.05 °C
Peak104.82 °C
]2[zk 52 ,3% in HM1
zk 52 ,3% in HM1, 3.9700 mg
Integral-12.88 mJ
normalized-3.24 Jg^-1
Onset120.86 °C
Peak120.40 °C
-20
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
°C
Hull Liquid Crystal Group: dapreut
S T AR e S W 8 . 10
Fig. 2 (continued).
4- nonyl-2′, 3′ difluoroterphenyl
The experimental procedure was as described for the preparation
of compound 4-(pentyl, heptyl)-2′′, 3′′-difluoro terphenyl.
F
F
F
F
Yield (7.54 g, 69.17%); M. P. 66.66 °C Transitions temperature / °C K
52.4 (28.58 J/g) Cryst E 61.6 (4.4 J/g) SmB 71.6 (64.26 J/g) SmA 103.1
(18.97 J/g) I; Elemental analysis: calc. for (Found: C; H; N. C27H30F2 re-
quires C, 82.62; H, 7.7; N%);δH(400 MHz;CDCl3) 0.88 (3H, t, J7,
CH3CH2),1.23–1.41 (13H, m), 1.66 (2H, quint, J7.9, ArCH2CH2), 2.66
(2H, t, J 7.9, ArCH2), 7.02 (1H, ddd, J 6.8, 6.6, 1.5, 20H), 7.16 (1H, ddd,
J 6.8, 6.4, 1.6, 19H), 7.56 (2H, d, J8.2), 7.61 (2H, dd, J8.6, 1.6), 7.6
8(2H, d, J8.6); (δF (376; CDCl3)) −143.30(1F, dd, JF,F 20.81, JF,H 6.9),
−143.88(1F, dd, JF,F 18.5, JF,H 6.9); δC (100.5;CDCl3) 14.13, 22.7,
DME,2M Na2CO3
pd(pph3)4
(HO)2B
C9H19
Br
C9H19
Quantities and procedure:
4- nonyl-4′-bromo biphenyl (10 g, 27.8 mmol, 359 g/mol), difluoro-
boronic acid (7.03 g, 36.21 mmol, 158 g/mol), dimethoxyethane
(220 ml), 2 M sodium carbonate (220 ml) and tetrakis (triphenyl-
phosphine) palladium(0)(.241 g, 0.208 mmol, 1156 g/mol).

80
Z.N. Kayani et al. / Journal of Molecular Liquids 175 (2012) 72–84
g
^endo
zk52,7% in HM1 Heat & cool
23.06.2007 19:04:47
Integral
normalized
Onset
11.65 mJ
2.43 Jg^-1
121.42 °C
121.96 °C
zk52,7% in HM1 heat & cool
Peak
Integral
normalized
Onset
8.92 mJ
1.86 Jg^-1
110.52 °C
112.21 °C
Peak
_]1[zk 52 ,7% in HM1
zk 52 ,7% in HM1, 4.8000 mg
2
mW
Integral
-8.17 mJ
]2[zk 52 ,7% in HM1
zk 52 ,7% in HM1, 4.8000 mg
normalized
-1.70 Jg^-1
112.35 °C
110.53 °C
Onset
Peak
Integral
normalized
Onset
-13.25 mJ
-2.76 Jg^-1
121.20 °C
120.71 °C
Peak
-20
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
°C
STAR e S W 8.10
Hull Liquid Crystal Group: dapreut
Fig. 2 (continued).
29.37 (d, J 4.6), 29.56 (d, J 2.3), 31.51, 31.91, 35.65, 116.02 (d, J 16.9),
124.09(dd, JC,F 5.8, 4.6), 125.21 (dd, JC,F 3.1, 2.3), 126.95, 127.12,
128.94, 129.29 (d JC,F 3.1), 130.92, 131.02, 133.29 (d, JC,F
2.3),137.77, 141.02, 142.53; m/z 392 (M+), 292, 279 (100%), 165;
4- nonyl-2′, 3′-difluoroterphenyl carboxylic acid
Quantities and procedure:
4-nonyl-2′-3′-difluoroterphenyl carboxylic acid (3 g, 6.86 mmol,
437 g/mol), oxyl chloride (1.05 ml, 12.18 mmol, 126 g/mol), DCM
(30 ml) and catalyst DMF (one drop).The experimental procedure as
described by compound 4-(pentyl, heptyl)-2″, 3″-difluoro terphenyl
carbonyl chloride.
F
F
F
F
4-nonyl-2′-3′-difluoroterphenyl carbonyl amide
O
2.5 M BuLi,THF
CO2,HCl
C9H19
C9H19
OH
F
F
O
Lactamide,pyridine
tetrahydrofuran
Quantities and procedure:
C9H19
4- nonyl-2′, 3′-difluoroterphenylphenyl (6.25 g, 15.94 mmol,
392 g/mol), n-butylithium (7.65 ml, 19.13 mmol in hexanes) and
THF (150 ml).
Cl
F
F
O
The experimental procedure was as described for the preparation
of compound 4-(pentyl, heptyl)-2″, 3″-difluoro terphenyl carboxylic
acid.
C9H19
CONH2
O
Quantities and procedure:
Yield (6.2 g, 89.08%),M.P. 255 °C(Dec); Elemental analysis: calc.
for (Found: C, H, N, C28H30F2O2 requires C,77.04; H, 6.93%); δH
(400 MHz; CDCl3) 0.88 (3H, t, J 7.1, CH3CH2),1.24–1.34 (6H, m),
1.65 (2H, quint, J 7.5, ArCH2CH2), 2.66(2H, t, J 7.9, ArCH2), 7.29 (2H,
d, J 8.1),7.32(1H, ddd, J 8.2, 6.6, 1.8), 7.57 (2H, d, J 8.2),7.65(2H, dd,
J 7.7, 1.5),7.71 (2H,d,J 8.6), 7.79 (1H, ddd, J 8.4, 6.6, 1.8); (δF(376;
CDCl3)) −135.4(1F, dd, JF,F 18.5, JF,H 6.9), −142.66 (1F, dd, JF,F
20.81, JF,H 6.9); δC (100.5; CDCl3) 14.09, 22.57, 29.23 (d, J 2.3), 29.43
(d, J 3.1), 31.41, 31.79, 35.53, 119.81 (d, J7.7), 124.08 (dd, JC,F 4.6,
2.3), 126.4 4(dd, JC,F 4.6, 3.1), 126.82, 127.09, 128.95, 129.23 (d JC,F
3.1), 132.35, 137.33, 141.5, 142.64, 165.05; m/z 436 (M+), 392, 323
(100%), 279, 44;
4-nonyl-2′-3′-difluoroterphenyl carbonyl chloride (3 g, 6.59 mmol,
455 g/mol), S-(-)-lactamide (0.8 g, 8.99 mmol, 89 g/mol), pyridine
(8.4 ml, 106.33 mmol, 79 g/mol) and dry THF (60 ml).The experimen-
tal procedure as described by compound 4-(pentyl, heptyl) -2″,
3″-difluoro terphenyl carbonyl amide.
Yield (3.15 g, 94%); M. P 193.60 °C (85.43 J/g) (from ethyl
acetate); Transitions temperature /°C K 182.9 (94.19 J/g) SmX 190.3
(97.52 J/g) I; Elemental analysis: calc. for (Found: C; H; N.
C
31H35F2NO3 requires C, 73.35; H, 6.95; N, 2.76%); δH(400 MHz;
CDCl3) 0.87 (3H,t,J 7.1,CH3CH2), 1.24–1.34 (13H, m), 1.65 (2H,
quint, J 8.1, ArCH2CH2), 2.63 (2H, t, J 8.1, ArCH2), 5.19 (1H, q, J 6.8),
7.29 (2H, d, J 8.2),7.32(1H, ddd, J 8.2, 6.6, 1.8), 7.62 (2H, d, J8.2), 7.7
(2H, dd, J 8.2, 1.3), 7.79 (2H, d, J8.6), 7.86 (1H, ddd, J 8.5, 6.8, 1.8);
(δF(376; CDCl3)) −136.03(1F, dd, JF,F20.81, JF,H6.9), −143.52(1F, dd,
JF,F 25.43, JF,H 4.6); δC (100.5; CDCl3) 13.78, 17.40, 22.01, 28.61,
28.84 (d, J6.9), 30.88, 31.19, 34.10, 78.87, 116.85 (d, J6.9), 117.17,
124.50 (dd, JC,F 4.6, 2.3),126.36 (dd, JC,F 4.6, 3.1), 126.94, 127.30,
4-nonyl-2′-3′-difluoroterphenyl carbonyl chloride
F
F
F
F
O
O
Oxalyl Chloride
DCM,Cat DMF
C9H19
C9H19
OH
Cl

Z.N. Kayani et al. / Journal of Molecular Liquids 175 (2012) 72–84
81
Fig. 3. Variation of polarisation and viscosity with Tc–T °C of mixture of 4-(pentyl, heptyl, nonyl)-2′′, 3′′ difluoro terphenyl nitrile in HM1.

82
Z.N. Kayani et al. / Journal of Molecular Liquids 175 (2012) 72–84
128.98, 129.27 (d JC,F3.1), 131.92, 136.13, 136.24, 137.38, 142.09,
142.85, 152.78, 161.67, 171.45;
4-pentyl-2′′, 3′′-difluoroterphenyl nitrile were mixed with pyrimidine
achiral host mixture (LM3).
Quantities, procedure, yield and elemental analysis of 4-nonyl-2′-
3′-difluoroterphenyl carbonyl nitrile can be found in some other
paper [3].
Phase Transitions of 4-pentyl-2′′, 3′′-difluoroterphenyl nitrile in
Host Mixture LM3:-
F
F
O
CN
C5H11
O
3. Results and discussions
Transition temperatures of helical phases of 4-Alkyl-2′′, 3′′difluoro
terphenyl nitrile and all intermediates (which has liquid crystalline
properties) were studied by optical polarising microscope and further
confirmed by Differential Scanning Calorimeter. This mesomorphic
behaviour is illustrated in Table 1.
From Table 1 it is clear that as the length of the alkyl chain to the
nitriles increases, the melting point decreases. Increase in alkyl chain
length makes nitrile unstable. All nitriles are smectic materials exhibiting
SmC*phase at high temperature. 4- nonyl-2′′, 3′′ difluoro terphenyl
nitrile has shown some unknown smectic phases when it was cooled
from isotropic phase to smectic phases.
Liquid crystal phases were viewed through optical polarising micro-
scope and the results are given in Fig. 1 (a–d). Fig. 1(a) shows Isotropic
phase to nematic phase transition of 3% 4- heptyl-2′′, 3′′ difluoro
terphenyl nitrile in achiral host mixture HM1 in which shearing
induces homogeneous alignment and produces birefringent, Fig. 1(b)
shows 14% D5R in HM1 unwinding of the helical texture of the N*
phase. In the dark areas, the homeotropic texture of the nematic
phase predominates whereas in the birefringent fingerprint region,
remnants of the N* phase remain, Fig. 1(c) shows focal-conic texture
of SmA* phase of 7% D9R in HM1. Fig. 1 (d) exhibit schlieren texture
of the SmC* phase of mixture of 7% D9R in HM1. The scheliring texture
of nematic phase and Smectic phase of 3% D5R in pyrimidine (LM3)
mixture is visible in Fig. 1(e) and 1(f) respectively.
3% chiral dopant Melting point:- 11.68 (47.16 J/g) SmC 60.8
(.444 J/g) SmA 77 N 79.8 (13.07 J/g)
4% chiral dopant Melting point: - 10.54 (49.53 J/g) SmC 48.8
(301.26×10−9 J/g) SmA 80.2 N 81.3 (14.64 J/g)
After creating achiral host mixture, the chiral dopant D5R was added
in small quantities (3%, 7%) to the achiral host mixture in order to gen-
erate ferroelectric formulations. The transition temperatures/°C of the
formulations and spontaneous polarisation (Ps 7.9 nC/cm−2), viscosity
(η 18.3 mpa-section), tilt angles (° 21) and dielectric constant (5.5)
were measured as a function of temperature. In pyrimidine mixture
LM3 pure and mixture with dopant (3% and 7% of D5R), the SmC*
phase has transition of 2nd order. The nematic phase and the SmA
phase lie very close to each other especially in the 7% mixture of D5R
and HM1. From the isotropic liquid the nematic phase appears in drop-
lets which coalance into fingerprint texture in 3% mixture of D5R while
in 7% mixture of D5R the nematic droplets goes directly to the
focal-conic texture of SmA. In SmA* phase both D5R mixture have
focal-conic and homeo-tropic texture but in 3% mixture, the
homeotropic texture dominates the focal-conic texture. In SmC* phase
the 3% D5R in LM3 and 7% D5R in LM3 have schlieren texture and tran-
sition to SmC* is of 2nd order.
The Instec automatic liquid crystal tester was used to measure the
ferroelectric liquid crystal properties of various mixtures prepared
during this study. 3% and 7% of 4- Alkyl-2′′, 3′′ difluoro terphenyl
nitrile was mixed with achiral host mixture HM1. Initially 14% of
4- pentyl-2′′, 3′′ difluoro terphenyl nitrile were mixed in HM1 but
mixture did not possess ferroelectric properties. So no more 14% chiral
dopants were mixed with HM1. Fig. 3 shows spontaneous polarisation
and viscosity versus reduced temperature of various ferroelectric
mixtures which contain 3% or 7% 4- Alkyl-2′′, 3′′ difluoro terphenyl
nitrile in achiral host mixture HM1. The spontaneous polarisation
increases as the alkyl chain length attached to the chiral dopant
increases. At the same time the spontaneous polarisation increases
with the increase of the percentage of the chiral dopant. Viscosity also
shows same trend.
Differential scanning calorimetry (DSC) is a complementary tool
to optical microscopy and reveals liquid crystal phase by detecting
the enthalpy change associated with phase transition.
Liquid crystal, whose phase transition is to be evaluated, heated
and cooled four times i.e., first heating, first cooling, second heating,
and second cooling. This is to ensure liquid crystal phase transition
temperatures. Figs. 2 shows some DSC curves obtained for mixtures
prepared from 3% and 7% 4-Alkyl-2′′, 3′′-difluoroterphenyl nitrile in
HM1 and one curve for 14% 4-pentyl-2′′, 3′′-difluoroterphenyl nitrile.
3.1. LM3 achiral host mixture
Fig. 4 shows variation of dielectric constant with the reduced tem-
perature of the FLC mixture. It shows linear behaviour. Increase in the
alkyl chain length also increases dielectric constant.
So far achiral host mixture HM1 was mixed with 4-Alkyl-2′′, 3′′-
difluoroterphenyl nitrile but to study effect of host mixture 3% and 7% of
Fig. 4. Variation of Dielectric constant with Tc-T °C of mixture of 4-(pentyl, heptyl, nonyl)-2′′, 3′′ difluoro terphenyl nitrile in HM1.

Z.N. Kayani et al. / Journal of Molecular Liquids 175 (2012) 72–84
83
Fig. 5. Switching state of 4-Alkyl-2′′, 3′′-difluoroterphenyl nitrile in HM1.
In mixture of achiral host material doped with 3% and 7% chiral
dopant switching between two states can be produced. These mix-
tures are used in devices operating in the τVmin switching mode.
Fig. 5 shows photo micrographs of switched states of D5R and D9R
in HM1 in a cell of spacing 5 μm with an applied electric field 10 V,
25 V and 30 V.
Fig. 6. Comparison of spontaneous polarisation and viscosity of D5R in HM1 and LM3.

84
Z.N. Kayani et al. / Journal of Molecular Liquids 175 (2012) 72–84
Fig. 6 shows comparison of ferroelectric properties of D5R in achi-
Acknowledgements
ral host mixture HM1 and LM3. It is evident that mixture in LM3 has
greater value of spontaneous polarisation, viscosity and dielectric
constant than HM1. It means change in achiral host mixtures has tre-
mendous effect on the FLC properties of materials even same chiral
dopant is used.
The paper is extracted from Ph.D thesis of Dr. Zohra Nazir Kayani.
The author wants to thank The University of the Hull, United Kingdom
for providing laboratory facilities, Higher Education Commission
Pakistan for funding and Kingston Chemicals Limited UK for providing
materials.
4. Conclusions
4-Alkyl-2′′, 3′′ difluoro terphenyl nitrile are successfully syn-
thesised. Melting point of dopants decreased as the length of alkyl
chain to dopant increased. The spontaneous polarisation and viscosity
increase as the alkyl chain length attached to the chiral dopant in-
creases and % of chiral dopant in HM1 increases. Change in achiral
host mixture can tremendously change FLC properties of material [7].
References
[1] G.W. Gray, M. Hird, D. Lacey, K.J. Toyne, Journal of the Chemical Society, Perkin
Transactions 2 (1989) 2041–2053.
[2] M. Hird, K.J. Toyne, A.J. Slaney, J.W. Goodby, Journal of Materials Chemistry 5
(1995) 423–430.
[3] Z.N. Kayani, R.A. Lewis, S. Naseem, Journal of Molecular Liquids 170 C (2012)
11–19.
[4] M. Hird, K.J. Toyne, Journal of Materials Chemistry 5 (12) (1995) 2239–2245.
[5] T. Carpenter, Journal of the Chemical Society (1934) 869–872.
[6] G.W. Gray, Molecular Crystals and Liquid Crystals 1 (1966) 333–349.
[7] Z. N. Kayani, PhD Thesis, University of the Punjab, Lahore, Pakistan, 2009.
Abbreviations
D5R
4-pentyl-2′′, 3′′ difluoro terphenyl nitrile
4-heptyl-2′′, 3′′ difluoro terphenyl nitrile
4-nonyl-2′′, 3′′ difluoro terphenyl nitrile
1, 2-dimethoxyethane.
D 7R
D 9R
DME
DMF
THF
N, N-Dimethylformamide.
Tetra hydrofuran.
DCM
Dichloromethane.