Synthesis and mesomorphic properties of mesogens containing (4-polyfluoroalkoxy-2,3,5,6-tetrafluorophenyl)ethynyl groups

Article abstract of DOI:10.1016/S0022-1139(01)00403-1

Due to the activation of fluorine atoms in aromatic rings by four other fluorine atoms and a 4-ethynyl bond, polyfluoroalkoxy chains can be introduced into aromatic rings by direct nucleophilic substitution reaction using potassium carbonate as base to pr

Full text of DOI:10.1016/S0022-1139(01)00403-1

Journal of Fluorine Chemistry 110 ꢀ2001) 37±42
Synthesis and mesomorphic properties of mesogens containing
ꢀ4-poly¯uoroalkoxy-2,3,5,6-tetra¯uorophenyl)ethynyl groups
Kan Wang, Baoquan Chen, Yonggang Yang, Hengfeng Li, Kegang Liu, Jianxun Wen*
Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, PR China
Received 25 January 2001; accepted 18 April 2001
Abstract
Due to the activation of ¯uorine atoms in aromatic rings by four other ¯uorine atoms and a 4-ethynyl bond, poly¯uoroalkoxy chains can
be introduced into aromatic rings by direct nucleophilic substitution reaction using potassium carbonate as base to prepare 4-
poly¯uoroalkoxy-2,3,5,6-tetra¯uorophenylacetylenes. Seven compounds containing ꢀ4-poly¯uoroalkoxy-2,3,5,6-tetra¯uorophenyl)ethynyl
groups have been prepared by catalytic reaction using bisꢀtriphenylphosphine)palladium dichloride and copperꢀI) iodide as catalysts.
Mesomorphic properties of target compounds were investigated by optical polarizing microscopy and differential scanning calorimetry
ꢀDSC). Mesophases were devalued by highly ¯uorinated alkoxy terminal chains compared with similar compounds whose terminal chains
were not highly ¯uorinated. # 2001 Elsevier Science B.V. All rights reserved.
Keywords: Mesogens; Highly ¯uorinated alkoxy tolane
1. Introduction
¯uoroalkoxylation was used in some reactions, which can be
carried out for activated aryl and heteroaryl halides [11±13].
Poly¯uorosubstituents and triple bonds were considered as
activating substituents in aromatic rings. So direct aromatic
nucleophilic ¯uoroalkoxylation can be carried out under
weakly basic conditions, such as with potassium carbonate.
Strong bases, such as sodium hydride or potassium hydro-
xide are so strong that they can attack other ¯uorine atoms
and produce by-products.
In this paper, we describe a convenient method to prepare
seven novel compounds containing ꢀ4-poly¯uoroalkoxy-
2,3,5,6-tetra¯uorophenyl)ethynyl groups and discuss the
mesomorphic properties of these compounds. The synthesis
of the target compounds is outlined in Scheme 2.
Fluorinated mesogens have been paid close attention in
the past decade due to their unique properties, such as low
viscosity, low conductivity and high chemical and thermal
stability. Laterally, ¯uorinated mesogens have been widely
studied, from their synthesis to their physical properties. The
2,3,5,6-tetra¯uorotolanes, which were reported ®rstly by our
group, possess high birefringence, low viscosity, low con-
ductivity and high photochemical stability [1±7], and are
valuable as components of mixtures for some electro-optical
applications, such as super twisted nematic ꢀSTN) and thin
®lm transistor ꢀTFT) liquid crystals displays ꢀLCD). At the
same time, mesogens containing highly ¯uorinated alkyl
terminal chains are advantageous to the formation of smectic
C phases [8,9] and are valuable as potential important
components of mixtures for ferroelectric liquid crystals
display ꢀFLCD). In order to meet the higher quality require-
ments for materials and observe the relationship between
structures and properties, the synthesis of mesogens contain-
ing a group that combines the two units mentioned above
was desired. The structures of the groups are shown in
Scheme 1.
2. Results and discussion
Although it is dif®cult to obtain 1H,1H-per¯uoroalkoxy-
benzene by the direct etheri®cation of the 1H,1H-per¯uoro-
alkanol, due to the activation of ¯uorine atoms in aromatic
ring by the other four ¯uorine atoms and 4-ethynyl bond,
but the ¯uoroalkoxylation can easily be carried out using
potassium carbonate as base.
Various methods have been developed to synthesize
¯uoroalkyl aryl ethers [10]. Direct aromatic nucleophilic
The transition behaviors of target compounds were sum-
marized in Table 1.
* Corresponding author. Tel.: ‡86-21-6416-3300.
E-mail address: wenjianxun@pub.sioc.ac.cn ꢀJ. Wen).
It was reported by our group that the compounds contain-
ing the structures in Scheme 3 are not mesogens [16]. There
0022-1139/01/$ ± see front matter # 2001 Elsevier Science B.V. All rights reserved.
PII: S 0 0 2 2 - 1 1 3 9 ꢀ 0 1 ) 0 0 4 0 3 - 1

38
K. Wang et al. / Journal of Fluorine Chemistry 110 -2001) 37±42
mesomorphic state at all. It seems that the second highly
¯uorinated alkyl chains in 2,3,5,6-tetra¯uorotolanes are
disadvantageous to the formation of mesophases in the
structures. This is considered to be caused by the effects
of self-assembly. These compounds can be divided into two
blocks, a ¯uorophilic block and a ¯uorophobic block [19].
There are almost no ¯uorophobic blocks in compounds a
and b, so it is dif®cult for them to arrange in an ordered way,
on the other side; the suitable layer arrangements can be
formed easily in compounds a0 and b0.
In conclusion, 4-poly¯uoroalkoxy-2,3,5,6-tetra¯uoro-
tolanes exhibit less good mesomorphic properties than
corresponding 4-alkoxy-2,3,5,6-tetra¯uorotolanes or 4-
alkoxytolanes. Higher quality mesogens were not obtained
in these structures. It is considered that highly ¯uorinated
alkyl terminal chains are advantageous to the formation of
smectic phases, not nematic phases, but a 2,3,5,6-tetra¯uoro-
phenyl is advantageous to the formation of a nematic phase
and can depress smectic phases. A combination of these two
contradictory characters damages all mesophases.
Scheme 1.
is a widely known conclusion that mesogens containing
highly ¯uorinated alkyl terminal chains are advantageous
to the formation of mesophases, especially of a tilted smectic
phases. So at ®rst, we wanted to obtain the ferroelectric
phases by introducing both the highly ¯uorinated alkyl
terminal chain and chiral center into the 2,3,5,6-tetra¯uor-
otolane mesomorphic cores; compound g was synthesized
based on this idea. But g did not exhibit mesophases. It was
considered that the short mesomorphic cores that include
only two aromatic rings, give it poor mesomorphic proper-
ties. For this reason, four chiral three-ring compounds ꢀc, d,
e, f) were prepared. The observed results prove that all these
four compounds are mesogens, but only c exhibits a narrow
chiral smectic C phase ꢀ7.68C), the other three compounds
do not exhibit ferroelectric phases. Compounds c and f
exhibit a narrow blue phase ꢀBP) between the cholesteric
phase and the isotropic liquid. For illustrating the in¯uence
of highly ¯uorinated alkyl terminal chains, phase transition
temperatures of compounds c0 and d0 [17] were compared
with c and d. The structures of c0 and d0 are seen in Scheme 4
and their phase transition properties are listed in Table 1. It is
clear that the range of mesophases were depressed by highly
¯uorinated alkyl chains, but that the smectic phase become
stable.
3. Experimental details
3.1. General techniques
The structures of the ®nal products and intermediates
were elucidated by a variety of spectral methods. IR spectra
were recorded on a PE-983G spectrophotometer, using KBr
1
pellets of solids or ®lms of liquids. H NMR spectra with
tetramethylsilane ꢀTMS) as internal standard and 19F NMR
spectra with tri¯uoroacetic acid ꢀTFA) as external standard
were recorded on a Bruker 300 spectrometer ꢀ300 MHz), a
Varian EM360L spectrometer ꢀ60 MHz) or a FX-90Q spec-
trometer ꢀ90 MHz). For 19F NMR spectra high ®eld
was positive. MS spectra were measured with a Finnigan-
4021 spectrometer using electrical ionization. The phase
transition temperatures of the target compounds were mea-
sured visually by optical microscopy using a polarizing
microscope ꢀOlympus PM-6) ®tted with a heating stage
Compounds a and b have two highly ¯uorinated alkyl
chains at both terminal sides, so they are strongly hydro-
phobic molecules. When they were compared with corre-
sponding compounds ꢀa0 and b0, their structures are in
Scheme 5 and their phase transition properties are listed
in Table 1 [18]), which contain no ¯uorosubstituent on the
tolane side, it can be concluded that their mesormorphic
properties have been damaged by their second highly ¯uori-
nated alkyl chain, and especially b does not exhibit a
Table 1
The phase transition temperatures of the target compounds on heating and subsequent coolinga
Compounds
Transition temperatures ꢀ8C)
a
Cr 122.29 SmA 162.76 I 159.47 SmA 96.71 Recr
b
c
Cr 110.68 I 89.00 Recr
Cr 126.7 SmCÃ 134.3 SmA 159.1 Ch 163.2 ꢀBP) I ꢀBP) 161.5 Ch 156.9 SmA 132.0 SmCÃ 103.6 Recr
Cr 96.0 SmA 121.7 Ch 133.7 I 132.2 Ch 120.3 SmA 65.7 Recr
Cr 65.6 I 56.7 SmA 42.5 Recr
d
e
f
Cr 119.9 SmA 135.7 Ch 148.8 ꢀBP) I ꢀBP) 147.2 Ch 127.5 SmA 102.8 Recr
Cr 80.6 I 63.7 Recr
g
a0
b0
c0
d0
Cr 130.36 SmA 222.20 I 220.08 SmA 112.02 Recr
Cr 84.7 SmB 87.4 SmA 157.5 I 154.6 SmA 85.8 SmB 68.4 CrE
Cr 89.5 SmCÃ 90.0 SmA 124.7 Ch 153.1 I 152.9 Ch 124.2 SmA 89.7 SmCÃ 70.6 Recr
Cr 93.8 Ch 141.1 I 139.9 Ch 53.4 Recr
a Cr: crystal; CrE: crystal E phase; SmA: smectic A phase; SmC: smectic C phase; Ch: cholesteric phase; SmCÃ: chiral smectic C phase; I: isotropic
liquid; N: nematic phase; BP: blue phase; Recr: recrystallization.

K. Wang et al. / Journal of Fluorine Chemistry 110 -2001) 37±42
39
Scheme 2. Synthesis route.

40
K. Wang et al. / Journal of Fluorine Chemistry 110 -2001) 37±42
was trimethylsilylethynyl-2,3,4,5,6-penta¯uorobenzene
ꢀcompound 2). The ¯uorosubstituent on the para-position
of compound 2 was substituted by a 2,2,3,3,4,4,5,5-octa-
¯uoropentoxy group under basic conditions, at the same
time, the trimethylsilyl protected group was removed and
4-ꢀ2,2,3,3,4,4,5,5-octo¯uoropentoxy)-2,3,5,6-tetra¯uoro-
phenylacetylene ꢀcompound 3) was obtained. Target com-
pounds were prepared by cross-coupling reaction between
compound 3 and corresponding reagents ꢀ4-I-C6H4-X) using
bisꢀtriphenylphosphine)palladium dichloride and copperꢀI)
iodide as catalyst.
Scheme 3.
3.2.1. Preparation of 4--2,2,3,3,4,4,5,5-octafluoropen
toxy)-2,3,5,6-tetrafluorophenylacetylene -compound 3)
Trimethylsilylethynyl-2,3,4,5,6-penta¯uorobenzene
ꢀcompound 2) ꢀ2.00 g, 7.58 mmol), potassium carbonate
ꢀ1.27 g, 9.20 mmol), 2,2,3,3,4,4,5,5-octa¯uoropentanol
ꢀ2.54 g, 10.95 mmol) and anhydrous N,N-dimethylforma-
mide ꢀ30 ml) were added into a 100 ml ¯ask, then stirred at
room temperature. 19F NMR monitored the reaction solution
until the reagent 2 was disappeared. Diethyl ether ꢀ50 ml)
and water ꢀ20 ml) were added into the ¯ask, the solution was
extracted with diethyl ether. The ether extracts were washed
neutral with brine and dried over anhydrous magnesium
sulfate. Solvent was removed in vacuo and the residue was
puri®ed by column chromatography on silica gel using
petroleum ether ꢀbp 60±908C) as the eluent to give com-
Scheme 4.
ꢀMETTER FP-80) and a control unit ꢀFP-82), and by
differential scanning calorimetry ꢀDSC, Shimadzu DSC-
50 calorimeter with a data system, heating and cooling rate
58C minÀ1). The transition temperatures reported in this
paper were the peak values of the transition on DSC traces.
Phase identi®cation was made by comparing the observed
texture with those in the literature [14,15].
1
pound 3 as a colorless liquid 1.92 g, yield 63%. H NMR
ꢀCDCl3/TMS, 90 MHz) dH ꢀppm): 3.46 ꢀs, 1H, BC±H), 4.62
ꢀt, 2H, J ˆ 13 Hz, CF2CH2O), 5.95 ꢀtt, 1H, J1 ˆ 52 Hz,
J2 ˆ 6 Hz, CF2H). 19F NMR ꢀCDCl3/TFA, 56.4 MHz) dF
ꢀppm): 44.4 ꢀt, 2F, J ˆ 13 Hz, CF2CH2), 48.7 ꢀm, 2F, CF2),
53.6 ꢀm, 2F, CF2), 59.5±61.7 ꢀm, 4F, CF2H and ArF), 79.5 ꢀd,
2F, J ˆ 24 Hz, ArF).
3.2. Synthesis route
The synthesis of the target compounds is outlined in
Scheme 2. The preparation of intermediate 2 was reported
previously [16]. References to the preparation of the
reagents noted 4-I-C6H4-X in Scheme 2 used to synthesis
target compounds a±g are given in [18,20±22].
3.2.2. Synthesis of target compounds
3.2.2.1. Preparation of 4--6-chloro-3,3,4,4,5,5,6,6-octa-
fluorohexoxycarbonyl)phenyl 4-[4--2,2,3,3,4,4,5,5-octa-
fluoropentoxy-2,3,5,6-tetrafluorophenyl)ethynyl]benzoate
-a).Typicalprocedure:Compound3ꢀ250 mg,0.496 mmol),4-
ꢀ6-chloro-3,3,4,4,5,5,6,6-octofluorohexoxycarbonyl)phenyl
4-iodobenzoate ꢀ192 mg, 0.40 mmol), bisꢀtriphenylphos-
phine)palladium dichloride ꢀ30 mg), copperꢀI) iodide
ꢀ50 mg), triphenylphosphine ꢀ80 mg), anhydrous triethyl-
amine ꢀ15 ml) were added into a 25 ml flask. The resulting
mixture was stirred at 608C for 48 h under a nitrogen
atmosphere. After the reaction was completed, the pre-
cipitate formed was filtered off and washed with water, then
dried over anhydrous magnesium sulfate. The solvent was
removed in vacuo and the residue was purified by column
chromatography on silica gel using petroleum ether ꢀbp
60±908C) ethyl acetate ꢀ12:1) as the eluent. This gave
pale yellow crystals, which were recrystallized from
methanol to yield white flaky crystals of compound ꢀa)
Penta¯uorochlorobenzene was reacted with magnesium
®lings in anhydrous tetrahydrofuran solution at À108C, then
iodine was added into the obtained Grignard reagent to get
penta¯uoroiodobenzene ꢀcompound 1). Compound 1 was
coupled with trimethylsilylacetylene using bisꢀtriphenyl-
phosphine)palladium dichloride and copperꢀI) iodide as
catalyst in anhydrous triethylamine solution; the product
‡
408 mg, yield 90%. MS ꢀm/z, %): 906 ꢀM , 0.11), 507
Scheme 5.

K. Wang et al. / Journal of Fluorine Chemistry 110 -2001) 37±42
41
‡
ꢀp-HꢀCF2)4CH2O±C6F4BC6H4±CO , 100.00), 691 ꢀꢀM±
‡
calc. C 54.24, H 3.23, F 33.21%, found C 54.35, H 2.93, F
1
‡
HꢀCF2)4CH2) , 0.51), 292 ꢀO±C6F4BC6H4±CO , 5.66).
Anal. for C33H15ClF20O5 calc. C 43.71, H 1.67, F 41.90%,
33.30%. H NMR ꢀCDCl3/TMS, 90 MHz) dH ꢀppm): 0.90±
2.08 ꢀm, 9H, RH), 3.90 ꢀd, 2H, J ˆ 6 Hz, OCH2), 4.72 ꢀt, 2H,
J ˆ 12 Hz, OCH2CF2), 6.05 ꢀtt, 1H, J1 ˆ 60 Hz, J2 ˆ 6 Hz,
CF2H), 6.95 ꢀd, 2H, J ˆ 9 Hz, ArH), 7.24 ꢀd, 2H, J ˆ 9 Hz,
ArH),7.64ꢀd,2H,J ˆ 9 Hz,ArH),8.14ꢀd,2H,J ˆ 9 Hz,ArH).
19F NMR ꢀCDCl3/TFA, 56.4 MHz) dF ꢀppm): 43.9 ꢀt, 2F,
J ˆ 12 Hz, CH2CF2), 48.2 ꢀm, 2F, CF2), 52.9 ꢀt, 2F,
J ˆ 52 Hz, CF2), 59.1 ꢀm, 2F, ArF), 60.1 ꢀd, 2F, J ˆ 52 Hz,
CF2H), 79.2 ꢀm, 2F, ArF). IR ꢀKBr, umax, cmÀ1): 1731, 1605,
1516, 1493, 1264, 1203, 1170, 991, 536.
1
found C 43.78, H 1.78, F 41.99%. H NMR ꢀCDCl3/TMS,
90 MHz) dH ꢀppm):2.70 ꢀm, 2H, CH2CF2), 4.50±5.20ꢀm, 4H,
OCH2), 6.20 ꢀtt, 1H, J1 ˆ 52 Hz, J2 ˆ 6 Hz, CF2H), 7.45 ꢀd,
2H, J ˆ 9 Hz, ArH), 7.83 ꢀd, 2H, J ˆ 9 Hz, ArH), 8.10±8.40
ꢀm, 4H, ArH). 19F NMR ꢀCDCl3/TFA, 56.4 MHz) dF ꢀppm):
À9.4ꢀm,2F, CF2Cl), 36.2ꢀm,2F, CF2),42.4ꢀm,2F,CF2),43.5
ꢀm, 2F, CF2), 45.5 ꢀm, 2F, CF2), 47.7 ꢀm, 2F, CF2), 53.4 ꢀm, 2F,
CF2), 58.4±60.7 ꢀm, 4F, CF2H and ArF), 78.7 ꢀm, 2F, ArF). IR
ꢀKBr, umax, cmÀ1): 1739, 1603, 1490, 1443, 1406, 1346, 1260,
1168, 1133, 1067, 992, 764, 700, 544, 504.
3.2.2.5. [4--2,2,3,3,4,4,5,5-octafluoropentoxy-2,3,5,6-
tetrafluorophenyl)ethynyl]phenyl -R)--4-oct-2-oxy)-
benzoate -e). ‰a2D4Š ˆ À0:128 ꢀC ˆ 5:45 mg/1.2 ml). MS
3.2.2.2. -S)-4-[1--30,30,40,40,50,50,60,60,70,70,80,80-dodeca-
fluorooctoxycarbonyl)ethoxy]phenyl 4-[4--2,2,3,3,4,4,5,
5-octafluoropentoxy-2,3,5,6-tetrafluorophenyl)ethynyl]-
benzoate -b). ‰a2D4Š ˆ À1:837ꢀ ꢀC ˆ 5:743 mg/1.2 ml). MS
‡
‡
ꢀm/z, %): 729 ꢀꢀM ‡ 1), 0.15), 121 ꢀO±C6H4±CO ,
‡
100.00), 233 ꢀ4-C6H13CHꢀCH3)O±C6H4±CO , 59.42).
Anal. for C34H28F12O4 calc. C 56.05, H 3.87, F 31.29%,
found C 56.15, H 3.71, F 31.20%. H NMR ꢀCDCl3/TMS,
‡
1
ꢀm/z, %): 1016 ꢀM , 0.82), 507 ꢀp-HꢀCF2)4CH2O±
‡
‡
C6F4BC6H4±CO , 100.00), 643 ꢀꢀM±COOC2H4ꢀCF2)6H) ,
2.97). Anal. for C37H20F24O6 cacl. C 43.72, H 1.98, F
44.85%, found C 43.68, H 2.03, F 45.00%. 1H NMR
ꢀCDCl3/TMS, 90 MHz) dH ꢀppm): 1.78 ꢀd, 3H,
J ˆ 6:8 Hz, CH3), 2.62 ꢀm, 2H, CH2CF2), 4.55±5.05 ꢀm,
5H, 2OCH2 and OCH), 5.50±6.90 ꢀm, 2H, 2CF2H), 7.05 ꢀd,
2H, J ˆ 9 Hz, ArH), 7.30 ꢀd, 2H, J ˆ 9 Hz, ArH), 7.83 ꢀd,
2H, J ˆ 9 Hz, ArH), 8.33 ꢀd, 2H, J ˆ 9 Hz, ArH). 19F NMR
ꢀCDCl3/TFA, 56.4 MHz) dF ꢀppm): 36.8 ꢀm, 2F, CF2), 44.0±
49.0 ꢀm, 10F, 5CF2), 53.0 ꢀm, 2F, CF2), 59.0±61.5 ꢀm, 6F,
2CF2H and ArF), 79.0 ꢀm, 2F, ArF). IR ꢀKBr, umax, cmÀ1):
1753, 1727, 1605, 1491, 1406, 1444, 1272, 1250, 1202,
1140, 1078, 990, 860, 765, 693, 541.
90 MHz) dH ꢀppm): 0.82±1.82 ꢀm, 16H, RH), 4.52 ꢀt, 1H,
J ˆ 7 Hz, OCH), 4.77 ꢀt, 2H, J ˆ 12 Hz, OCH2CF2), 6.15
ꢀtt, 1H, J1 ˆ 60 Hz, J2 ˆ 6 Hz, CF2H), 7.03 ꢀd, 2H,
J ˆ 9 Hz, ArH), 7.30 ꢀd, 2H, J ˆ 9 Hz, ArH), 7.70 ꢀd, 2H,
J ˆ 9 Hz, ArH), 8.18 ꢀd, 2H, J ˆ 8 Hz, ArH). 19F NMR
ꢀCDCl3/TFA, 56.4 MHz) dF ꢀppm): 44.0 ꢀt, 2F, J ˆ 12 Hz,
CH2CF2), 48.2 ꢀm, 2F, CF2), 53.0 ꢀt, 2F, J ˆ 52 Hz, CF2),
59.7 ꢀm, 2F, ArF), 60.2 ꢀdt, 2F, J1 ˆ 52 Hz, J2 ˆ 5:2 Hz,
CF2H), 79.2 ꢀm, 2F, ArF). IR ꢀKBr, umax, cmÀ1): 2925, 2857,
1683, 1604, 1528, 1496, 1433, 1295, 1257, 1204, 1132,
1003, 894, 861, 838, 777, 723, 553.
3.2.2.6. -1S,2S)--1-chloro-2-methyl-butylcarbony-
loxy)phenyl 4-[4--2,2,3,3,4,4,5,5-octafluoropentoxy-
2,3,5,6-tetrafluorophenyl)ethynyl]benzoate -f). ‰a2D4Šˆ1:458
ꢀC ˆ 3:57 mg/1.2 ml). MS ꢀm/z, %): 507 ꢀHꢀCF2)4CH2O±
3.2.2.3. -S)--2-methyl-butoxycarbonyl)phenyl 4-[4--2,2,
3,3,4,4,5,5-octafluoropentoxy-2,3,5,6-tetrafluorophenyl)-
ethynyl]benzoate -c). ‰a2D4Š ˆ 1:4508 ꢀC ˆ 3:57 mg/1.2 ml).
‡
C6F4BC6H4±CO ), 109 ꢀ100.00), 135 ꢀ7.11). Anal. for
‡
MS ꢀm/z, %): 714 ꢀM ), 507 ꢀp-HꢀCF2)4CH2O±C6F4BC6H4±
C32H21ClF12O5 calc. C 51.32, H 2.83, F 31.95%, found C
51.46, H 2.60, F31.54%. 1H NMRꢀCDCl3/TMS, 90 MHz) dH
ꢀppm): 0.90±2.60 ꢀm, 9H, RH), 4.37 ꢀt, 1H, J ˆ 7 Hz, OCH),
4.73 ꢀt, 2H, J ˆ 13 Hz, OCH2CF2), 6.06 ꢀtt, 1H, J1 ˆ 52 Hz,
J2 ˆ 6 Hz, CF2H), 7.15±7.45 ꢀm, 4H, ArH), 7.72 ꢀd, 2H,
J ˆ 9 Hz, ArH), 8.23 ꢀd, 2H, J ˆ 9 Hz, ArH). 19F NMR
ꢀCDCl3/TFA, 56.4 MHz) dF ꢀppm): 43.9 ꢀt, 2F, J ˆ 13 Hz,
CH2CF2), 48.2ꢀm, 2F, CF2), 53.0ꢀt, 2F, J ˆ 52 Hz, CF2), 59.1
ꢀm, 2F, ArF), 60.1 ꢀdt, 2F, J1 ˆ 52 Hz, J2 ˆ 5:2 Hz, CF2H),
79.2 ꢀm, 2F, ArF). IR ꢀKBr, umax, cmÀ1): 2971, 1726, 1605,
1493,1446,1406, 1273,1178, 1080,1019,990, 860, 767, 694,
524.
‡
CO , 100.00). Anal. for C32H22F12O5 calc. C 53.79, H 3.07,
1
F 31.90%, found C 53.66, H 2.63, F 32.00%. H NMR
ꢀCDCl3/TMS, 90 MHz) dH ꢀppm): 0.95±1.04 ꢀm, 6H,
2CH3), 1.25±1.57 ꢀm, 2H, CH2), 1.85±1.89 ꢀm, 1H, CH),
Ã
4.18 ꢀd, 2H, J ˆ 7 Hz, OCH2), 4.72 ꢀt, 2H, J ˆ 12 Hz,
OCH2CF2), 6.09 ꢀtt, 1H, J1 ˆ 52 Hz, J2 ˆ 6 Hz, CF2H),
7.31 ꢀd, 2H, J ˆ 9 Hz, ArH), 7.71 ꢀd, 2H, J ˆ 9 Hz, ArH),
8.14 ꢀd, 2H, J ˆ 9 Hz, ArH), 8.21 ꢀd, 2H, J ˆ 9 Hz, ArH).
19F NMR ꢀCDCl3/TFA, 56.4 MHz) dF ꢀppm): 43.9 ꢀt, 2F,
J ˆ 12 Hz, CH2CF2), 48.2 ꢀm, 2F, CF2), 52.9 ꢀt, 2F,
J ˆ 52 Hz, CF2), 59.1 ꢀm, 2F, ArF), 60.1 ꢀd, 2F,
J ˆ 52 Hz, CF2H), 79.2 ꢀm, 2F, ArF). IR ꢀKBr, umax
,
cmÀ1): 1730, 1708, 1492, 1269, 1206, 1170, 1132, 991, 768.
3.2.2.7. -S)-2-methyl-butyl 4-[4--2,2,3,3,4,4,5,5-octa-
fluoropentoxy-2,3,5,6-tetrafluorophenyl)ethynyl]benzoate
-g). ‰a2D4Š ˆ 0:278 ꢀC ˆ 11:79 mg/1.2 ml). MS ꢀm/z, %): 594
3.2.2.4. [4--2,2,3,3,4,4,5,5-octafluoropentoxy-2,3,5,6-
tetrafluorophenyl)ethynyl]phenyl -S)-4--2-methylbutoxy)-
benzoate -d). ‰a2D4Š ˆ 1:6268 ꢀC ˆ 2:14 mg/1.2 ml). MS ꢀm/
‡
‡
ꢀM , 14.80), 507 ꢀHꢀCF2)4CH2O±C6F4BC6H4±CO ,
100.00). Anal. for C25H18F12O3 calc. C 50.52, H 3.05, F
38.35%, found C 50.73, H 2.79, F 38.57%. 1H NMR
ꢀCDCl3/TMS, 90 MHz) dH ꢀppm): 0.95±1.04 ꢀm, 6H,
‡
‡
z, %): 686 ꢀM ), 191 ꢀp-C2H5CHꢀCH3)CH2O±C6H4±CO ,
‡
100.00), 121 ꢀO±C6H4±CO , 82.81). Anal. for C31H22F12O4

42
K. Wang et al. / Journal of Fluorine Chemistry 110 -2001) 37±42
Ã
[5] J. Wen, M. Tian, H. Yu, Z. Guo, Q. Chen, J. Mater. Chem. 4 ꢀ2)
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2CH3), 1.25±1.57 ꢀm, 2H, CH2), 1.85±1.89 ꢀm, 1H, CH),
4.18 ꢀd, 2H, J ˆ 7 Hz, OCH2), 4.70 ꢀt, 2H, J ˆ 13 Hz,
OCH2CF2), 6.06 ꢀtt, 1H, J1 ˆ 60 Hz, J2 ˆ 6 Hz, CF2H),
7.61 ꢀd, 2H, J ˆ 9 Hz, ArH), 8.03 ꢀd, 2H, J ˆ 9 Hz, ArH).
19F NMR ꢀCDCl3/TFA, 56.4 MHz) dF ꢀppm): 44.0 ꢀt, 2F,
J ˆ 12 Hz, CH2CF2), 48.2 ꢀm, 2F, CF2), 53.0 ꢀt, 2F,
J ˆ 52 Hz, CF2), 59.7 ꢀm, 2F, ArF), 60.2 ꢀdt, 2F,
J1 ˆ 52 Hz, J2 ˆ 5:2 Hz, CF2H), 79.2 ꢀm, 2F, ArF). IR
ꢀKBr, umax, cmÀ1): 2969, 1707, 1606, 1493, 1446, 1408,
1391, 1279, 1248, 1180, 1132, 1060, 1022, 990, 897, 864,
817, 775, 698, 626, 531.
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The authors gratefully acknowledge the National Natural
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29974038).
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