U.S. patent application number 10/706286 was filed with the patent office on 2004-07-22 for acetylene polymers and their use as liquid crystals.
This patent application is currently assigned to The Hong Kong University of Science & Technology. Invention is credited to Kong, Xiangxing, Kwok, Hoi Sing, Lam, Wing Yip, Tang, Ben Zhong.
Application Number | 20040140449 10/706286 |
Document ID | / |
Family ID | 23386454 |
Filed Date | 2004-07-22 |
United States Patent
Application |
20040140449 |
Kind Code |
A1 |
Tang, Ben Zhong ; et
al. |
July 22, 2004 |
Acetylene polymers and their use as liquid crystals
Abstract
There is disclosed a liquid crystalline polyacetylene having a
repeat structure of the formula 1 where spa is a spacer group and
mes is a mesogenic substituent.
Inventors: |
Tang, Ben Zhong; (Kowloon,
HK) ; Lam, Wing Yip; (Kowloon, HK) ; Kong,
Xiangxing; (Kowloon, HK) ; Kwok, Hoi Sing;
(Kowloon, HK) |
Correspondence
Address: |
BURNS DOANE SWECKER & MATHIS L L P
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Assignee: |
The Hong Kong University of Science
& Technology
Hong Kong
HK
|
Family ID: |
23386454 |
Appl. No.: |
10/706286 |
Filed: |
November 13, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10706286 |
Nov 13, 2003 |
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10346360 |
Jan 17, 2003 |
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10346360 |
Jan 17, 2003 |
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09887660 |
Feb 20, 2001 |
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09887660 |
Feb 20, 2001 |
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09352778 |
Jul 14, 1999 |
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Current U.S.
Class: |
252/299.01 ;
252/299.66 |
Current CPC
Class: |
C09K 19/3838 20130101;
C09K 19/3833 20130101 |
Class at
Publication: |
252/299.01 ;
252/299.66 |
International
Class: |
C09K 019/38; C09K
019/52; C09K 019/12 |
Claims
1. A liquid crystalline polyacetylene having a repeat structure of
the formula 12where spa is a spacer group and mes is a mesogenic
substituent.
2. A polymer according to claim 1 in which the mesogenic
substituent comprises a substituted biphenyl group.
3. A polymer according to claim 1 in which the spacer group
comprises an alkyl chain.
4. A polymer according to claim 3 having a repeat structure of the
formula where: n is greater than 1; and A, B and C are polar
moieties.
5. A polymer according to claim 4 in which A is selected from the
group consisting of COO, OCO and O; B is selected from the group
consisting of COO, OCO and O; and C is selected from the group
consisting of CN, OH, CO.sub.2H, OR, CO.sub.2R or OCOR where R is
an alkyl group.
6. A polymer according to claim 5 in which A is COO, B is OCO and C
is O(CH.sub.2).sub.6CH.sub.3.
7.
Poly{4-({[6-(4'-heptyl)oxy-4-biphenylyl]carbonyl}oxy)hexyl]oxy}carbonyl-
)phenyl]acetylene}.
8.
[4-({[6-({[4'-(heptyl)oxy-4-biphenlyl]carbonyl}oxy)hexyl]oxy}carbonyl)p-
henyl]acetylene.
9. A substituted acetylene having the formula HC.dbd.C-spa1-mes,
where spa1 is a spacer group and mes is a mesogenic substituent
selected from the group consisting of: 13wherein A, B and D are
polar moieties, E is a polar moiety which is not cyano or methoxy,
spa2 is a spacer group, and R is H or an alkyl group.
10. An acetylene according to claim 9 in which spa1 and/or spa2
comprises an alkyl chain.
11. An acetylene according to claim 9 in which A and B are selected
from the group consisting of: OCO, COO and 0.
12. An acetylene according to claim 9 in which E is selected from
the group consisting of: OH, CO.sub.2H,
O(CH.sub.2).sub.m-1CH.sub.3, OCO(CH.sub.2).sup.m-1 CH.sub.3, and
CO.sub.2 (CH.sub.2).sub.m-1CH.sub.3 where m is greater than
one.
13. An acetylene according to claim 9 in which D is selected from
the group consisting of: CN, OH, CO.sub.2H, OR', COOR' and where R'
is an alkyl group.
14.
5-{[(4'-{[(undecyl)carbonyl]oxy}-biphenyl-4-yl)carbonyl]oxy}-1-pentyne-
.
15.
6-{[(4'-{[(undecyl)carbonyl]oxy}-biphenyl-4-yl)carbonyl]oxy}-1-hexyne.
16.
5-[(4'-{[(undecyl)carbonyl]oxy}-biphenyl-4-yl)oxy]-1-pentyne.
17.
4-{[({[(4'-[(nonyl)oxy]-biphenyl-4-yl)carbonyl]oxy}hexyl)oxy]carbonyl}-
-1-butyne.
18.
10-{[({[(4'-[(nonyl)oxy]-biphenyl-4-yl)carbonyl]oxy}hexyl)oxy]carbonyl-
}-1-decyne.
19.
5-[({[(4'-[(hexyl)oxy]-biphenyl-4-yl)oxy]hexyl}oxy)carbonyl]-1-pentyne-
.
20.
10-[({[(4'[(hexyl)oxy]-biphenyl-4-yl)oxy]hexyl}oxy)carbonyl]-1-decyne.
21.
5-({[(4-{[(hexyl)oxy]phenyl}oxy)carbonyl]phenyl}oxy)-1-pentyne.
22. A pplyacetylene polymer polymerised from a substituted
acetylene monomer according to claim 9.
23. A liquid crystalline polyacetylene polymerised from a
substituted acetylene monomer according to claim 9.
24. An acetylene according to claim 9 in liquid crystalline.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to novel classes of mesogen
containing acetylene polymers with particular, but by no means
exclusive, reference to their use as liquid crystals. The present
invention also relates to novel classes of mesogen containing
acetylene monomers, and to polymerisation methods for producing
said polymers from said monomers.
BACKGROUND OF THE INVENTION
[0002] Most industrially utilised plastics consist of polymers
having flexible chains. In contrast, polymers having relatively
rigid polymeric chains have proven far less useful in an industrial
context, primarily due to processing difficulties associated with
their low solubility and high melting temperature. This is despite
the fact that rigid polymers can exhibit some very interesting
properties.
[0003] For example, polyacetylene and associated derivatives
thereof can exhibit electrical conductivity (when doped), chemical
reactivity and complex forming ability. Another potential
application is chiral separation. However, polyacetylene is
completely intractable, insoluble and infusible, and has found few
practical applications.
[0004] Thus there is a long felt need in the art for rigid chain
polymers which possess some or all of the advantageous properties
usually associated with this class of material, but which also
possess desirable features, such as excellent tractability, which
are, traditionally, associated with polymers having flexible
backbones.
[0005] Liquid crystals are well known materials which are of
enormous importance in a number of applications, such as visual
display. Molecules which are disposed to form liquid crystalline
phases usually adopt either rigid, elongate or disc shaped
molecular structures. Molecular structures that form liquid
crystalline phases are called mesogens.
[0006] Ringsdorf et al (Macromol. Chem., 179 (1978) 2541) have
proposed that liquid crystals can be formed from a polymeric main
chain having a mesogenic side group attached thereto via a flexible
spacer (in order to decouple the motion of the main chain from the
mesogenic side group). To date, attention has focused almost
exclusively on the use of flexible polymeric main chains. Thus, the
standard molecular architecture of a side-chain liquid crystalline
polymer (SCLCP) is: flexible backbone+spacer+mesogenic group. Few
rigid chain SCLCPs have been developed, and often these rigid chain
SCLCPs are used as examples of the destructive role played by stiff
polymeric backbones. In general, rigid polymeric backbones are
regarded as defects which distort the packing arrangements of
pendant mesogenic groups in SCLCPs. Thus, the received wisdom in
the field teaches away from the use of rigid main polymeric chains
in SCLCPs.
[0007] Tang et al (Macromolecules 30 (1997) 5620) polymerised, with
difficulty, a phenylacetylene having a side chain comprising a
spacer group and a mesogenic group
(poly({4-[((n-((4'-cyano-4-biphenylyl)oxy)alk-
yl)oxy)carbonyl]phenyl}acetylene) shown below as Structure I).
2
[0008] Unfortunately, the polymer was not mesomorphic, i.e. did not
exhibit liquid crystalline behaviour. It was believed that the
nonmesomorphism of I is due to the high rigidity of the
polyphenylacetylene backbone, a conclusion which teaches against
the use of polyphenylacetylene backbones in SCLCPS.
[0009] Akagi and Shirakawa (Macromol. Symp., 104 (1996) 137) have
polymerised a group of mesomorphic acetylene monomers which contain
an ether functionality (such as
HC.ident.C(CH.sub.2).sub.3O-biph-C.sub.5H, .sub.1, where biph is
biphenyl) using a MoCl.sub.5-Ph.sub.4Sn catalyst. Tang et al
(Macromolecules 31 (1998) 2419) polymerised a number of mesomorphic
polyacetylenes, namely poly {n-[((4'-cyano-4-biphenylyl)oxy)c-
arbonyl]-1-alkynes}.
SUMMARY OF THE INVENTION
[0010] In brief, the present invention is directed to mesogen
containing acetylene polymers. The present invention has
particular, but, by no means exclusive, reference to their use as
liquid crystals. The polyacetylenes of the present invention
possess the SCLCP molecular "architecture" of
backbone+spacer+mesogenic group, but provide a rigid polymeric
backbone which can have numerous interesting and useful electronic
and mechanical properties, such as conductivity and molecular
orientability. An additional, and considerable, advantage is that
rigid chain polymers of the present invention are tractable, i.e.
soluble and fusable. Furthermore, and in contrast to many
polyacetylenes, polymers of the present invention exhibit excellent
thermal stabilities.
[0011] In one aspect, the present invention provides a novel class
of liquid crystalline polyphenylacetylene polymers having a repeat
structure II. 3
[0012] where spa is a spacer group and mes is a mesogenic
substituent. It is surprising that polymers having such rigid
backbones can exhibit liquid crystalline properties, particularly
in view of the conclusion of Tang et al, ibid. The present
invention also provides corresponding phenylacetylene monomers and
efficient polymerisation methods for polymerising such monomers to
produce polyphenylacetylenes in good yields.
[0013] In another aspect, the present invention provides novel
classes of polyacetylenes having a repeat structure III.
HCC-spa 1-mes III
[0014] where spa 1 is a spacer group and mes is a mesogenic
substituent selected from the group consisting of structures IV, V
and VI. 4
[0015] where A, B and D are polar moieties, E is a polar moiety
which is not cyano or methoxy, spa2 is a spacer group, and R is H
or an alkyl group.
[0016] The present invention is particularly concerned with the
liquid crystalline forms of these polyacetylenes. However,
non-mesomorphic phases may be of practical use: for example,
electrically conducting polyacetylenes might be produced by doping,
and such conducting polyacetylenes might have numerous
applications, for example as a sensing medium in an analyte
sensor.
[0017] The present invention also provides corresponding acetylene
monomers and efficient polymerisation methods for polymerising such
monomers to produce polyacetylenes in good yields. Many of the
monomers exhibit liquid crystal behaviour.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 shows a reaction scheme for the synthesis of
[4-({[6-({[4'-(heptyl)oxy-4-biphenylyl]carbony}oxy)hexyl]oxy}carbonyl)phe-
nyl]acetylene;
[0019] FIG. 2 shows a reaction scheme for the synthesis of
5-[(4'-{[(undecyl)carbonyl]oxy}-biphenyl-4-yl)oxy]-1-pentyne;
[0020] FIG. 3 shows a reaction scheme for the synthesis of
n-{[4'-{[(undecyl)carbonyl]oxy}-biphenyl-4-yl)carbonyl]oxy}-1-alkynes;
[0021] FIG. 4 shows a reaction scheme for the synthesis of
n-{[({[4'-[(nonyl)oxy]-biphenyl-4-yl)carbonyl]oxy}hexyl)oxy]carbonyl}-1-a-
lkynes;
[0022] FIG. 5 shows a reaction scheme for the synthesis of
n-[({[(4'-[(hexyl)oxy]-biphenyl-4-yl)oxy]hexyl}oxy)carbonyl]-1-alkynes;
and
[0023] FIG. 6 shows a reaction scheme for the synthesis of polymer
XIII.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present invention provides liquid crystal
polyphenylacetylenes having a repeat structure II, wherein spa is a
spacer group and mes is a mesogenic substituent.
[0025] A preferred mesogenic substituent is a substituted biphenyl
group, although other mesogenic substituents, such as, for example,
Ph-X-ph-Y (where X and Y ares respectively, a linking group and a
terminal group, and are preferably polar, and Ph is a phenyl group)
may be used instead.
[0026] Suitable spacer groups spa would suggest themselves to those
skilled in the art. Alkyl chains are well suited: primary alkyl
chains are preferred, although other alkyl chains might be utilised
provided that they are not so bulky as to inhibit packing in the
mesophase. In general, the longer the alkyl chain, the more
flexible the spacer group.
[0027] Preferred embodiments of polyphenylacetylenes of the present
invention have a repeat structure VII 5
[0028] where n is greater than 1, and A, B and C are polar
moieties. Typically n is in the range 1 to 12, although the use of
longer alkyl chains is also feasible. A and B can be COO, OCO or 0.
C can be CN, OH, CO.sub.2H, OR, CO.sub.2R or OCOR where R is a
substituent such as an alkyl group.
[0029] The present invention also provides polyacetylene polymers
having a repeat structure III, in which the mesogenic substituent
mes can be a structure IV, V or VI. Referring to structures IV, V
and VI, A, B and D are polar moieties, E is a polar moiety which is
not cyano or methoxy, and R is H or an alkyl group. In preferred
embodiments, A and B can be OCO, COO or 0, and E can be OH,
CO.sub.2H, O(CH.sub.2).sub.m-1CH.sub.3,
OCO(CH.sub.2).sub.m-1CH.sub.3 or CO.sub.2 (CH.sub.2).sub.m-1
CH.sub.3 where m is greater than one.
[0030] The polyacetylenes of the present invention can be prepared
using molybdenum, tungsten and rhodium catalysts such as
MoCl.sub.5, MoCl.sub.5-Ph.sub.4Sn, WCl.sub.6, WCl.sub.6-Ph.sub.4Sn,
W(mes)(CO).sub.3, Mo (nbd) (CO).sub.4, [Rh (nbd) Cl].sub.2, [Rh
(cod) Ci].sub.2, Rh (cod) (bbpmt), Rh(cod)(pip) Cl, Rh(cod)(NH3)Cl,
Rh(cod)(t-BuNH.sub.3)Cl, Rh(cod)(mid)Cl,
[RH(cod)(mid).sub.2]PF.sub.6, [Rh(cod)Cl].sub.2(pda),
Rh(nbd)(tos)(H.sub.2O) and Rh(cod) (tos)(H.sub.2O), where
mes=mesitylene, nbd=2,5-norbornadiene, cod=1,5 cyclooctadiene,
bbpmt=bis(4-t-butyl)-2-pyr- idylmethylthiolate, pip=piperidine,
mid=N-methylimidazole, pda=O-phenylenediamine,
tos=p-toluenesulphonate.
[0031] Rh based catalysts are preferred for the polymerisation of
phenylacetylenes. W based catalysts are preferred for the
polymerisation of alkyl acetylenes.
[0032] Materials
[0033] Dioxane (Aldrich), THF (Lab-Scan), and toluene (BDH) were
predried over 4 .ANG. molecular sieves and distilled from sodium
benzophenone ketyl immediately prior to use. Triethylamine
(Aldrich) was also predried but purified from calcium hydride by
simple distillation. 4'-Hydroxy-4-biphenyl-carboxylic acid,
1,3-dicyclohexylcarbodiimide (DCC), 4-(dimethylamino) pyridine
(DMAP), and p-toluenesulfonic acid (TsOH) were all purchased from
Aldrich. The rhodium complexes [Rh(nbd)Cl].sub.2,
Rh(nbd)(tos)(H.sub.2O), [Rh(nbd)(PMe.sub.3).sub.3)]PF.- sub.6,
[Rh(cod)Cl].sub.2, Rh(cod)(tos)(H.sub.2O), Rh(cod)NH.sub.3)l.sub.2,
and Rh(cod)-(pip)C1 were synthesised according to procedures well
known in the art. All other commercial reagents including the metal
halide catalysts were purchased from Aldrich and used as received
without further purification. Technical grade acetone was used to
precipitate the polymeric products.
[0034] Instrumentation
[0035] Infrared (IR) spectra were recorded on a Perkin-Elmer 16 PC
FT-IR spectrophotometer. .sup.1H and .sup.13C NMR spectra were
measured on a Bruker ARX 300 NMR spectrometer using chloroform-d or
dichloromethane-d.sub.2 as solvent. Tetramethylsilane (.delta.=0),
chloroform (.delta.=7.26), and/or dichloromethane (.delta.=5.38)
were used as internal references for the NMR analysis. UV-vis
spectra were recorded on a Milton Roy Spectronic 3000 array
spectrophotometer, and molar absorptivity (.epsilon.) was
calculated on the basis of the repeat units of the polymers. Mass
spectra (MS) were recorded on a Finnigan TSQ 7000 triple quadrupole
mass spectrometer operating in a chemical ionization (CI) mode
using methane as carrier gas. Elemental analysis was performed by a
commercial analytical company, M-H--W Laboratories. Molecular
weights of the polymers were estimated by a Waters Associates gel
permeation chromatography (GPC) using 12 monodisperse polystyrenes
(molecular weight range 102'107) as calibration standards.
Differential scanning calorimetry (DSC) analysis was carried out on
a Setaram DSC 92 under nitrogen at a scanning rate of 10.degree.
C./min. An Olympus BX 60 polarised optical microscope (POM)
equipped with a Linkam TMS 92 hot stage was used in cross-polarised
mode for the visual observation of mesomorphic textures. X-ray
diffraction (XRD) patterns were recorded on a Philips PW 1830
powder diffractometer at room temperature using a monchromatised
X-ray beam from nickel-filtered Cu K.alpha. radiation with a
wavelength of 1.5406 .ANG. (scan rate 0.010/s; scan range 2-300).
The samples for the XRD experiments were prepared by quickly
quenching by liquid nitrogen the polymers annealed at their liquid
crystalline states.
EXAMPLE 1
[0036]
Poly{[4-({[6-({[4'-(heptyl)oxy-4-biphenylyl]carbonyl}oxy)hexyl]oxy}-
carbonyl)phenyl]acetylene} (VIII) 6
[0037] Monomer Synthesis
[0038] The phenylacetylene derivative 1 was synthesised by the
multiple-step reactions shown in FIG. 1. Detailed experimental
procedures and characterisation data are given below.
[0039] 4'-(Heptyl)oxy-4-biphenylylcarboxylic Acid (1b). In a 1000
mL round-bottom flask equipped with a condenser, 10 g (46.7 mmol)
of 1a, 5.23 g of KOH (93.5 mmol), and a catalytic amount of KI were
dissolved in 500 mL of ethanol/water mixture (6:1 by volume) under
gentle heating and stirring. To the solution was added 12 g (67
mmol) of 1-bromoheptane, and the resulting mixture was refluxed for
30 h. The reaction mixture was poured into 300 mL of water
acidified with 20 mL of 37% hydrochloric acid. The solid was
collected by suction filtration. Recrystallisation in glacial
acetic acid gave 9 g of white crystalline product (yield 61.7%). IR
(KBr), .nu.(cm.sup.-1): 3200-2300 (br. CO.sub.2H), 1684 (s, C--O).
.sup.1H NMR (300 M[z, DMSO-d.sub.6) .delta. (ppm): 12.95 (s,
CO.sub.2H), 8.09 (d, 2H, Ar--H ortho to CO.sub.2H), 7.83 (m, 4H,
Ar--H), 7.14 (d, 2H, Ar--H ortho to OC.sub.7H.sub.15), 4.11 (t, 2H,
OCH.sub.2), 1.83 (m, 2H, OCH.sub.2CH.sub.3), 1.48 .mu.m, 8H,
(CH.sub.2).sub.4], 0.97 (t, 3H, CH.sub.3). .sup.13C NMR (75 MHz,
DMSO-d.sub.6). .delta.(ppm): 167.41 (C-0), 159.20 (aromatic carbon
linked with OC.sub.7H.sub.15), 144.15 (aromatic carbon para to
CO.sub.2H), 131.28 (aromatic carbon para to OC.sub.7H.sub.15),
130.15 (aromatic carbons ortho to CO.sub.2H), 128.91 (aromatic
carbon linked with CO.sub.2H), 128.32 (aromatic carbons meta to
CO.sub.2H), 126.28 (aromatic carbons meta to OC.sub.7H.sub.15),
115.21 (aromatic carbons ortho to OC.sub.7H.sub.15), 67.77
(OCH.sub.2), 31.45 (CH.sub.2C.sub.3H.sub.7), 28.87
(CH.sub.2C.sub.2H.sub.5), 28.64 (OCH.sub.2CH.sub.2), 25.68
(OC.sub.2H.sub.4CH.sub.2), 22.26 (CH.sub.2CH.sub.3). 14.16
(CH.sub.3).
[0040] 6-Hydroxy-1-hexyl[4-(heptyl)oxy-4-biphenyl]carboxylate (1c).
4'-(Heptyl)oxy-4-biphenylylcarboxylic acid (1.7 g, 5.44 mmol),
1,6-hexanediol (1.3 g, 11 mmol), TsOH (0.2 g, 1.16 mmol), and DMAP
(0.1 g, 0.82 mmol) were dissolved in 400 mL of dry CH.sub.2Cl.sub.2
in a 500 mL two-necked flask under nitrogen. The solution was
cooled to 0-5.degree. C. with an ice bath, to which 1.8 g of DCC
(7.5 mmol) in 50 mL of dichloromethane was added under stirring via
a dropping funnel with a pressure-equalisation arm. The mixture was
stirred at room temperature overnight. After filtering out the
formed insoluble urea crystals, the filtrate was concentrated by a
rotary evaporator. The crude product was purified by a silica gel
column using CHCl.sub.3/acetone mixture (10:1 by volume) as eluent.
After recrystallisation from ethanol/water (3:1 by volume), 1.6 g
of white crystalline product was obtained (yield 71.3%). IR (KBr),
v (cm.sup.-1): 3316 (br, OH), 1714 (s, C.dbd.O). .sup.1H NMR (300
MHz, CDCl.sub.3), 6 (ppm): 8.35 (d, 2H, Ar--H ortho to CO.sub.2R),
7.58 (m, 4H, Ar--H), 7.00 (d, 2H, Ar--H ortho to OC.sub.7H.sub.15),
4.34 (t, 2H, CH.sub.2OCO), 4.00 (t, 2H, OCH.sub.2), 3.67 (t, 2H,
HOCH.sub.2), 1.81 (m, 4H CH.sub.2CH.sub.2OCO, OCH.sub.2CH.sub.2),
1.61-1.35 [m, 14H, (CH.sub.2).sub.7], 0.90 (t, 3H.sub.2CH.sub.3).
.sup.13C NMR (75 MHz, CDCl.sub.3, 8 (ppm): 166.64 (C.dbd.O), 159.45
(aromatic carbon linked with OC.sub.7H.sub.15), 145.24 (aromatic
carbon para to CO.sub.2R), 131.91 (aromatic carbon para to
OC.sub.7H.sub.15), 130.03 (aromatic carbons ortho to CO.sub.2R),
128.51 (aromatic carbon linked with CO.sub.2--R), 128.29 (aromatic
carbons meta to OC.sub.7H.sub.15), 126.40 (aromatic carbons meta to
CO.sub.2R), 114.96 (aromatic carbons ortho to OC.sub.7H.sub.15),
68.17 (PhOCH.sub.2), 64.85 (CH.sub.2OCOPh), 62.88 (HOCH.sub.2),
32.64 (HOCH.sub.2--CH.sub.2), 31.77 (CH.sub.2C.sub.3H.sub.7- ),
29.26 (CH.sub.2CH.sub.2OCOPh), 29.04 (CH.sub.2C.sub.2H.sub.5),
28.94 (PhOCH.sub.2CH.sub.2 (26.00[HO(CH.sub.2).sub.2CH.sub.2],
25.87 [HO(CH.sub.2).sub.3CH.sub.2], 25.43
(PhOC.sub.2H.sub.4CH.sub.2), 22.59 (CH.sub.2CH.sub.3), 14.05
(CH.sub.3).
[0041]
[4-({[6-({[4'-(Heptyl)oxy-4-biphenylyl]carbonyl}oxy)-hexyl]oxy}carb-
onyl)phenyl]acetylene (1d). Into a 50 mL two-necked round-bottom
flask were added 0.8 g (5.5 mmol) of 4-ethynylbenzoic acid, 2 mL of
thionyl chloride, and 15 mL of THF. After refluxing for 2 h, the
solvent and excess SOC 12 were distilled off under reduced
pressure. The solid left in the flask was dissolved in 15 mL of THF
and cooled to 0-5.degree. C. using an ice bath. A solution of 1c
(2.2 g, 5;3 mmol) and pyridine (0.6 mL) in 25 mL of TBF was
injected into the flask, and the mixture was slowly warmed to room
temperature and stirred overnight. THF was evaporated using a
rotary evaporator. The solid residue in the flask was dissolved in
50 mL of chloroform, and the solution was washed with water and
dried over anhydrous magnesium sulfate. The crude product was
purified on a silica gel column using dichloromethane as eluent.
Recrystallisation from absolute ethanol gave 1.2 g of white
crystalline product (yield 45%). IR (KBr), v (cm.sup.-1): 3312 (s,
HC.ident.), 1714 (s, C.dbd.O), 648 (s, --C--H). .sup.1H NMR (300
MHz, CDCl.sub.3), .delta. (ppm): 8.06 (d, 2H, Biph-H;
Biph=biphenyl), 8.00 (d, 2H Ph-H meta to HC.dbd.C), 7.57 (m, 6H,
Ph-H ortho to HC.dbd.C), 7.00 (d, 2H, Biph-H ortho to
OC.sub.7H.sub.15), 4.35 (m, 4H, CH.sub.3OCO, CO.sub.2CH.sub.2),
4.00 (t, 2H, OCH.sub.2), 3.22 (s, 1H, HC.ident.), 1.81 (m, 6H,
CH.sub.2CH.sub.2OCO, CO.sub.2CH.sub.2CH.sub.2, OCH.sub.2CH.sub.2),
1.55-1.29 [m, 12H, (CH.sub.2).sub.6], 0.90 (t, 3H, CH.sub.3).
.sup.13C NMR (75 MHz, CDCl.sub.3), 6 (ppm): 166.60 (C.dbd.O),
165.90. (C.dbd.O), 159.40 (aromatic carbon linked with
OC.sub.7H.sub.15), 145.20 (aromatic carbon linked with
PhOC.sub.7H.sub.15), 132.20 (aromatic carbons ortho to HC.ident.C),
132.00 (aromatic carbon para to OC.sub.7H.sub.15), 130.40 (aromatic
carbons meta to HC.ident.C), 130.00 (aromatic carbon para to
HC.ident.C), 129.40 (aromatic carbons meta to PhOC.sub.7H.sub.15).
128.40 (aromatic carbon para to PhOC.sub.7H.sub.5), 128.30
(aromatic carbons ortho to PhOC.sub.7H.sub.15), 126.70
(aromaticcabon linked with HC.ident.C); 126.40 (aomatic carbons, to
OC.sub.7H.sub.15), 114.90 (aromatic carbons ortho to
OC.sub.7H.sub.15), 82.80 (.ident.C), 79.90 (HC.ident.), 68.10
(PhOCH.sub.2), 65.10 (.ident.CPhCO.sub.2CH.sub.2), 64.80
(CH.sub.2OCOBiph), 31.80 (CH.sub.2C.sub.3H.sub.7), 29.20
(CH.sub.2CH.sub.2OCOBiph), 29.00
(.ident.CPhCO.sub.2CH.sub.2CH.sub.2), 28.70
(CH.sub.2C.sub.2H.sub.5), 28.60 (OCH.sub.2CH.sub.2), 26.00
(.ident.CPh CO.sub.2 C.sub.2H.sub.4CH.sub.2) 25.79
(CH.sub.2C.sub.2H.sub.4OCOBiph), 25.77
[BiphO(CH.sub.2).sub.2CH.sub.2], 22.60 (CH.sub.2CH.sub.3), 14.00
(CH.sub.3). MS (CI; CH.sub.4): m/e 540.7 [M.sup.+. calcd 540.3].
Anal. Calcd for C.sub.35H.sub.40O.sub.5: C, 77.78; H, 7.41. Found:
C, 75.35; H 7.39.
[0042] Polymerisation
[0043] All the polymerisation reactions and manipulations were
carried out under a nitrogen gas atmosphere using an
inert-atmosphere glovebox (Vacuum Atmospheres) or Schlenk
techniques in a vacuum line system, except for the purification of
the polymers, which was done in an open atmosphere. A typical
procedure for the polymerisation of 1d catalysed by
[Rh(nbd)Cl].sub.2 is given below. Into a baked 20 mL Schlenk tube
with a three-way stopcock on the sidearm was added 227.0 mg of 1d.
The tube was evacuated under vacuum and then flushed with dry
nitrogen three times through the sidearm. One millilitre of
THF/ET.sub.3N mixture (4:1 by volume) was injected into the tube to
dissolve the monomer. The catalyst solution was prepared in another
tube by dissolving 9 mg of [Rh(nbd)Cl].sub.2 in 1 mL of THF/EtaN
mixture (4:1 by volume). The monomer solution was then transferred
to the catalyst solution using a hypodermic syringe. The
polymerisation mixture was stirred under nitrogen at room
temperature for 24 h. The mixture was then diluted with 5 mL of THF
and added dropwise to 500 mL of acetone under stirring through a
cotton filter. The precipitate was allowed to stand overnight,
which was then filtered by a Gooch crucible, washed with acetone,
and dried in a vacuum oven to a constant weight. A yellow powdery
polymer was obtained in 93.0% yield. M.sub.w.ident.637 500
M.sub.w/M.sub.n.ident.5.23 (GPC, polystyrene calibration). IR
(KBr), .nu.(cm.sup.-1); 3036 (w, .dbd.C--H), 1716 (s, C.dbd.O).
.sup.1H NMR (300 MHz, CD.sub.2Cl.sub.2), .delta. (ppm): 7.91
(Biph-H); 7.58 (Ph-H meta to backbone), 7.45 (Biph-H), 6.84 (Ph-H
meta to backbone), 6.68 (Ar--H), 5.76 (cis .dbd.C--H), 4.16
(CH.sub.2OCO), 3.86 (OCH.sub.2), 1.68 (OCH.sub.2CH.sub.2)
1.38-1.25[O(CH.sub.2).sub.2(CH.sub.2).sub.2,
(CH.sub.2).sub.4CH.sub.3], 0.84 (CH.sub.3). .sup.13CNMR (75 MHz,
CD.sub.3Cl.sub.2), .delta. (ppm): 166.52 (C.dbd.O), 165.97
(C.dbd.O), 159.85 (aromatic carbon linked with OC.sub.7H.sub.15),
146.45 (.ident.C--), 145.23 (aromatic carbon linked with
PhOC.sub.7H.sub.15), 139.57 (aromatic carbon linked with backbone),
132.18 (aromatic carbon para to OC.sub.7H.sub.15), 130.28 (aromatic
carbon meta to PhOC.sub.7H.sub.15), 129.70 (H-CE, aromatic carbons
meta and para to backbone), 128.92 (aromatic carbon para to
PhOC.sub.7H.sub.15), 128.51 (aromatic carbon ortho to
PhOC.sub.7H.sub.15), 127.66 (aromatic carbon ortho to backbone),
126.54 (aromatic carbon meta to OC.sub.7H.sub.15), 115.17 (aromatic
carbons ortho to OC.sub.7H,s), 68.46 (PhOCH.sub.3), 65.14
(.ident.CPhCO.sub.3CH.s- ub.2. CH.sub.2OCOBiph), 32.19
(CH.sub.2C.sub.8H.sub.7), 29.67 (CH.sub.2CH.sub.2OCOBiph), 29.48
(.ident.CPhCO.sub.2CH.sub.2CH.sub.2) 29.04
(CH.sub.2C.sub.2H.sub.5), 26.37 (CH.sub.2C.sub.2H.sub.4OCOBiph),
26.08 [PhO(CH.sub.2).sub.2--CH.sub.2], 23.01 (CH.sub.2CH.sub.3),
14.25 (CH.sub.3). LWV (THF, 8.52.times.10.sup.-5 mol/L),
.lambda..sub.max (nm)/.epsilon..sub.max(mol.sup.-1 L cm.sup.-1):
295/29.times.10.sup.3, 426/3.1.times.10.sup.3 (sh).
[0044] It is known that metathesis catalysts such as WCl.sub.6 and
MoCl.sub.5 can polymerise substituted acetylenes. An attempt was
made to polymerise 1d using the WCl.sub.6 and MoCi.sub.5 based
catalysts. It is found, however, that the tungsten and molybdenum
halides are ineffective or poor catalysts for the polymerisation of
1d (Table 1, nos. 1-4). In contrast, Rh-nbd complexes work well for
the polymerisation of 1d. For example, when [Rh(nbd)Cl].sub.2 is
used to initiate the polymerisation of 1d in a mixture of THF and
triethylamine, an orange polymer is obtained in high yield (93.0%)
after 24 h polymerisation (Table 1, no. 5). The polymer has a high
molecular weight. (Mn=1.22.times.10.sup.5) and possesses high
stereoregularity (cis content 92%).
1TABLE 1 Polymerisation of [4-({[6-({[4'-(Heptyl)ox-
y-4-biphenylyl]carbonyl}oxy)hexyl]
oxy}carbonyl)phenyl]acetylene.su- p.a No. catalyst.sup.b solvent
yield % M.sub.n.sup.c M.sub.w/M.sub.n.sup.c cis %.sup.d 1
WCl.sub.6--Ph.sub.4Sn dioxane 0 2 WCl.sub.6--Ph.sub.4Sn toluene 7.2
28 200 2.04 3 MoCl.sub.5--Ph.sub.4Sn dioxane 0 4
MoCl.sub.5--Ph.sub.4Sn toluene 10.2 14 200 2.33 5 [Rh(nbd)Cl].sub.2
Et.sub.3N/THF.sup.e 93.0 122 000 5.23 92 6 Rh(nbd)(tos)(H.sub.2O)
THF 0 7 [Rh(nbd)(PMe.sub.3).sub.3]PF.sub.6 THF 5.7 79 200 9.64 78 8
[Rh(cod)Cl].sub.2 Et.sub.3N/THF.sup.e 85.7 83 800 4.60 91 9
Rh(cod)(tos)(H.sub.2O) THF 73.5 26 800 3.93 85 10
Rh(cod)(NH.sub.3)Cl THF 93.1 62 600 6.38 92 11 Rh(cod)(pip)Cl THF
92.8 72 400 5.33 91 .sup.aAt room temperature under nitrogen for 24
h: [M].sub.0 = 0.2 M, [cat.] = ([cocat.] = 10 mM.
.sup.bAbbreviation: nbd = 2,5-norbordiene, tos =
p-toleuenesulfonate, cod = 1.5-cyclooetadiene, pip = piperidine.
.sup.cDetermined by GPC in THF on the basis of a polystyrene
calibration .sup.dDetermined by .sup.1H NMR spectra. .sup.eVolume
ratio of Et.sub.3N to THF: 1:4.
[0045] Liquid Crystal Behaviour
[0046] POM microphotographs taken after a melted sample of VIII was
cooled to and annealed at 33.6.degree. C. reveal many small btonnet
structures. Closer inspection revealed the existence of tiny bands,
the directors of which are prependicular to the longitudinal axes
of the btonnets, suggesting that the mesophase of VIII is smectic A
in nature. XRD measurments on samples of VIII quenched by liquid
nitrogen from 140.degree. C. confirm the smecticity of the
mesophase.
EXAMPLE 2
[0047]
Poly{5-[(4'-{[(undecyl)carbonyl]oxy}biphenyl-4-yl)oxy]-1-pentyne}
(1.times.) 7
[0048] Monomer Synthesis
[0049] The acetylene derivative was synthesised by the multiple
step reactions shown in FIG. 2. Detailed experimental procedures
and characterisation data are given below.
[0050] (4-Hydroxy-biphenyl-4-yl)oxy-1-pentyne (2c)
[0051] In a 1000-mL Erlenmeyer flask equipped with a condenser, 10
g (53.7 mmol) of 4-4' biphenol and 3.3 g of KOH (58.8 mmol) were
dissolved in 400 mL of acetone/DMSO mixture (v/v: 10:1) under
gentle heating and stirring. To the homogeneous solution were added
5.5 g (53.6 mmol) of 5-chloro-1-pentyne and a catalytic amount of
potassium iodide. The resulting mixture was then refluxed for 30 h.
The solution was poured into 300 mL of water, acidified with 15 mL
of 37% concentrated hydrochloric acid. The solid was collected by
suction filtration, washed with water and dried in vacuum oven. The
crude product was purified on a silica-gel column using chloroform
first as eluent, then chloroform-acetone mixture (v/v: 10:1).
Recrystallization from toluene gave 5 g of product. White crystals;
yield: 33%
[0052] IR (KBr), v(cm.sup.-1): 3375 (br, OH), 3304 (HC.ident.),
1250 (--C--H overtone), 636 (--C--H)
[0053] .sup.1H NMR (300 MHz, DMSO-d.sub.6), .delta.(ppm): 9.57 (s,
OH), 7.52 (m, 4H, Ar--H), 7.05 (d, 2H, Ar--H ortho to
OC.sub.5H.sub.7), 6.92 (d, 2H, Ar--H ortho to OH), 4.14 (t, 2H,
OCH.sub.2), 2.92 (t, 1H, HC.ident.), 2.44 (td, 2H,
.dbd.C--CH.sub.2), 1.99 (m, 2H, OCH.sub.2CH.sub.2)
[0054] .sup.13C NMR (75 MHz; DMSO-d.sub.6), .delta. (ppm): 157.6
(aromatic carbon attached to OC.sub.5H.sub.7), 156.7 (aromatic
carbon attached to OH), 131.0 (aromatic carbon para to OH), 130.9
(aromatic carbon para to OC.sub.5H.sub.7), 127.4 (aromatic carbons
meta to OH), 127.2 (aromatic carbons meta to OC.sub.5H.sub.7),
115.9 (aromatic carbons ortho to OH), 115.0 (aromatic carbons ortho
to OC.sub.5H.sub.7), 83.9 (.ident.C), 71.9 (OCH.sub.2), 66.1 (HC_),
28.0 (.ident.C--CH.sub.2CH.sub.2), 14.7 (.ident.C--CH.sub.2)
[0055] 5-[(4'-{[(Undecyl)carbonyl]oxy}-biphenyl-4-yl)oxy]-1-pentyne
(2d)
[0056] Lauric acid (2.9 g, 14.5 mmol),
5-[4'-(hydroxy-biphenyl-4-yl)oxy]-1- -pentyne (3.6 g, 14.3 mmol),
TsOH (0.6 g, 3.5 mmol) and DMAP (0.4 g, 3.3 mmol) were dissolved in
250 mL of dry THF in a 500 mL two-necked flask under nitrogen. The
solution was cooled down to 0-5.degree. C. with an ice-water bath,
to which 4.6 g of DCC (22.3 mmol) dissolved in 50 mL of THF was
added with stirring via a dropping funnel with a
pressure-equalization arm. The reaction mixture was stirred
overnight. After filtering out the formed urea solid, the solution
was concentrated by rotary evaporator. The product was purified by
column chromatography using chloroform as eluent. Recrystallization
from absolute ethanol gave 5 g of product. White crystals; yield:
87%
[0057] IR (KBr), v(cm.sup.-1): 3300 (s, HC.dbd.), 1748 (s,
C.dbd.O), 630 (.dbd.C--H bending)
[0058] .sup.1H NMR (300 MHz, CDCl.sub.3), .delta. (ppm): 7.52 (m,
4H, Ar--H), 7.12 (d, 2H, Ar--H ortho to OCOC.sub.11H.sub.25), 6.97
(d, 2H, Ar--H ortho to OC.sub.5H.sub.7), 4.12 (t, 2H, OCH.sub.2),
2.57 (t, 2H, OCOCH.sub.2), 2.43 (td, 2H, .ident.C--CH.sub.2), 2.01
(m, 3H, .dbd.C--H and OCH.sub.2CH.sub.2), 1.77 (m, 2H,
OCOCH.sub.2CH.sub.2), 1.43-1.28 [m, 16H, (CH).sub.2], 0.89 (t, 3H,
CH.sub.3)
[0059] .sup.13C NMR (75 MHz, CDCl.sub.3), 6 (ppm): 172.4 (C.dbd.O),
158.4 (aromatic carbon attached to OC.sub.5H.sub.7), 149.6
(aromatic carbon attached to OCOC.sub.11H.sub.25), 138.4 (aromatic
carbon para to OCOC.sub.11H.sub.25), 132.9 (aromatic carbon para to
OC.sub.5H.sub.7), 128.0 (aromatic carbons meta to
OCOC.sub.11H.sub.25), 127.6 (aromatic carbons meta to
OC.sub.5H.sub.7), 121.7 (aromatic carbons ortho to
OCOC.sub.11H.sub.25), 114.7 (aromatic carbons ortho to
OC.sub.5H.sub.7), 83.3 (--C), 68.9 (OCH.sub.2), 66.1 (HC.ident.),
34.5 (OCOCH.sub.2), 31.9 (CH.sub.2CH.sub.2CH.sub.3), 29.6, 29.4,
29.3, 29.2, 29.1, 28.1, 24.9, 22.7, 22.6, 15.1 (.dbd.C--CH.sub.2),
14.1 (CH.sub.3)
[0060] MS (Cl): m/e: 435.3 [(M+1)+calcd 435.3)]
[0061] Anal calcd for C.sub.29H.sub.38O.sub.3: C; 80.13, H; 8.82.
Found: C, 80.00, H; 8.49.
[0062] Polymerisation
[0063] Typical experimental procedures for polymerizing 2d using a
WCl.sub.6-Ph.sub.4Sn catalyst is given below. Into a baked 20 mL
Schlenk tube side arm was added 375.0 mg (0.8 mmol) of monomer. The
tube was evacuated under vacuum and then flushed with dry nitrogen
three times through the side arm. 2 mL of 1,4-dioxane was injected
into the tube to dissolve the monomer. The catalyst solution was
prepared in another tube by dissolving 16.0 mg of tungsten (VI)
chloride and 17.0 mg of tetraphenyltin in 2 mL of 1,4-dioxane.
After the tubes were aged at room temperature for 15 minutes, the
monomer solution was transferred to the catalyst solution by
hypodermic syringe. The reaction mixture was stirred at room
temperature under nitrogen for 24 hours. The mixture was then
diluted with 5 mT. of Chloroform and added dropwise to 500 mL of
acetone under stirring. The precipitate was allowed to stay
overnight, which was then filtered off by a Gooch crucible, washed
with acetone, and dried in vacuum oven to a constant weight. Red
powdery solid; yield: 68.9% M.sub.w: 18600, M.sub.w/M.sub.n: 2.48
(GPC, polystyrene calibration)
[0064] IR (KBr), v(cm.sup.-1): 1756 (C.dbd.O)
[0065] .sup.1H NMR (300 MHz, CDCl.sub.3) 8 (ppm): 7.35, 7.00, 6.82
(Ar--H and trans .dbd.C--H), 6.15 (cis=C--H), 3.87 (OCH.sub.2),
2.56 (CO.sub.2CH.sub.2), 2.1 (.dbd.C--CH.sub.2), 1.81
(CO.sub.2CH.sub.2CH.sub.- 2), 1.35 [(CH.sub.2).sub.9], 0.96
(CH.sub.3).
[0066] .sup.13C NMR (75 MHz, CDCl3), .delta. (ppm): 172.1
(C.dbd.O), 158.5, 149.7, 138.0, 132.5 127.9, 127.4, 121.8, 114.7,
(aromatic carbons) 67.4, (OCH.sub.2), 34.4, 31.9, 29.7, 29.6, 29.4,
29.2, 25.0, 22.7, 14.1.
[0067] UV (CHCl.sub.3, 1.13.times.10.sup.-4 mol/L):
.lambda..sub.max/.epsilon..sub.max 265 nm/2.23.times.10.sup.4
mol.sup.-1L cm.sup.-1, 360 (sh) nm 1.33.times.10.sup.3 mol.sup.-1 L
cm.sup.-1.
[0068] Liquid Crystal Behaviour
[0069] Monomer 2d exhibited liquid crystal behaviour. Upon cooling
from the isotropic liquid, POM microphotographs reveal a mosaic
texture corresponding to a smetic B mesophase, followed, very
quickly, by concentric arcs running across the backs of the mosaic
platelets. The areas remain until the monomer 2d crystallized at
47.0.degree. C., suggesting that a smectic E mesophase is formed
over a long temperature range. Liquid crystal textures were
observed both on heating and cooling cycles, suggesting that
monomer 2d is an enantiotropic liquid crystal.
[0070] DSC analysis of polymer IX gave a sharp peak at
137.7.degree. C. followed by a diffuse peak extending to
180.degree. C. in the heating cycle. A sharp peak with a diffuse
peak was similarly observed at 121.6.degree. C. during the cooling
cycle. POM observations indicate that the polymer IX melts at
142.0.degree. C. and an isotropic liquid is formed at 175.0.degree.
C. Therefore, it appears that the sharp peak corresponds to a
transition from the solid state to a smectic A mesophase (or vice
versa). The diffuse peak may correspond to the smetic A mesophase
to isotropic liquid state transition (or vice versa).
EXAMPLE 3
[0071] Poly(n-{[4'-{[(undecyl)carbonyl]oxy}
biphenyl-4-yl)carbonyl]oxy}-1-- alkyne), n=5, 6 (X) 8
[0072] Monomer Synthesis
[0073] The acetylene derivative were synthesised by the multiple
step reactions shown in FIG. 3. Detailed experimental procedures
and characterisation data are given below.
[0074] (((Undecyl)carbonyl)oxy)-4-biphenylcarboxylic acid (3c)
[0075] In a 100-mL, two-necked, round bottomed flask were added 4.0
g (20 mmol) of lauric acid, 3 mL of thionyl chloride and 20 mL of
THF. After refluxing for 2 hours, the excess thionyl chloride was
distilled off under reduced pressure. The solid left in the flask
was dissolved in 20 mL of THF and cooled down using an ice bath. A
solution of 4'-hydroxy-4-biphenylcarboxylic acid (4.5 g, 21 mmol)
and pyridine (2 mL) in 30 mL of THF was injected into the flask and
the mixture was slowly warmed up to room temperature and stirred
overnight. The was then distilled off using a rotary evaporator.
Recrystallization of the solid residue from absolute ethanol gave
5.6 g of product. White crystals; yield: 69.6%.,
[0076] IR (KBr), .nu.(cm.sup.-1): 1746 (CO.sub.2Ar), 1684
(CO.sub.2H)
[0077] .sup.1H NMR (300 MHz, DMSO-d.sub.6), .delta.(ppm): 13.01 (s,
1H, CO.sub.2), 8.13 (d, 2H, Ar--H ortho to CO.sub.2H), 7.80 (m, 4H,
Ar--H), 7.30 (d, 2H, Ar--H ortho to CO.sub.2 (C.sub.11H.sub.23),
2.70 (t, 2H, CO.sub.2CH.sub.2), 1.80 (m, 2H,
CO.sub.2CH.sub.2CH.sub.2), 1.40 .mu.m, 16H, (CH.sub.2).sub.8], 1.00
(t, 3H, CH.sub.3) .sup.13C NMR (75 MHz DMSO-d.sub.6), .delta.
(ppm): 171.8 (CO.sub.2C.sub.11H.sub.23), 170.2 (CO.sub.2H), 150.3
(aromatic carbon connected to CO.sub.2C.sub.11H.sub.23- ), 143.5
(aromatic carbon para to CO.sub.2H), 136.6 (aromatic carbon para to
CO.sub.2C.sub.11H.sub.23), 123.0 (aromatic carbons to CO.sub.2H),
129.8 (aromatic carbon connected to CO.sub.2H). 128.2 (aromatic
carbons meta to CO.sub.2H), 126.8 (aromatic carbons meta to OCOR),
122.5 (aromatic carbons ortho to OCOR), 33.6 (CH.sub.2CO.sub.2Ar),
31.3 (CH.sub.2CH.sub.2CH.sub.3), 29.1, 29.0, 28.8, 28.5, 24.5
(CH.sub.2CH.sub.2CO.sub.2Ar), 22.2 (CH.sub.2CH.sub.3), 14.0
(CH.sub.3).
[0078] n-{[(4'
{[(Undecyl)carbonyl]oxy}-biphenyl-4-yl)carbonyl]oxy}-1-alky- nes
(3d; n=5,6)
[0079] Typical procedure for the syntheseis of 3d (n=3) is shown
below: 4'-(((Undecyl)carbonyl)oxy)-4-biphenylcarboxylic acid (1.25
g, 3.2 mmol), 4-pentyn-1-ol (0.32 g, 3.8 mmol), TsOH (0.12 g 0.70
mmol) and DMAP (0.08 g, 0.65 mmol) were dissolved in 250 mL of dry
dichloromethane in a 500-mL two-necked flask under nitrogen. The
solution was cooled down to 0-5.degree. C. with an ice-water bath,
to which 0.98 g of DCC (4.75 mmol) in 50 mL of dichloromethanie was
added with stirring via a dropping funnel with a pressure
equilization arm. The reaction mixture was stirred overnight. After
filtering out the formed urea solid, the solution was concentrated
by a rotary evaporator. The product was purified by silica-gel
column using dichloromethane as eluent. After recrystallization
from absolute ethanol, 1.09 g of product was obtained. Monomer 3d
((n=6) was synthesized in a similar procedure. Characterization for
3d (n=5): White crystals; yield: 64.6%
[0080] IR (KBr), .nu. (cm.sup.-1): 3288 (.dbd.C--H), 1746
(CO.sub.2C.sub.11H.sub.23), 1714 (C.sub.5H.sub.7CO.sub.2), 654 (m,
.ident.C--H) .sup.1H NMR (300 MHz, CDCl.sub.3), 8 (Ppm): 8.1 (m,
2H, Ar--H ortho to CO.sub.2C.sub.5H.sub.7), 7.6 (d, 4H, Ar--H), 7.2
(d, 2H, Ar--H ortho to CO.sub.2C.sub.11H.sub.23), 4.5 (t, 2H,
CH.sub.2OCO), 2.8 (t, 2H, OCOCH.sub.2), 2.4 (td, 2H,
.ident.CCH.sub.2), 2.0 (m, 3H, CH.sub.2CH.sub.2C.ident. and
HC.ident.), 1.8 (m. 2H, CH.sub.2CH.sub.2C.sub.9H.sub.19), 1.6-1.4
.mu.m, 16H, (CH.sub.2).sub.8], 0.9 (t, 3H, CH.sub.3).
[0081] .sup.13C NMR (75 MHz, CDCl.sub.3), .delta. (ppm): 172.1
(CO.sub.2C.sub.11H.sub.23), 169.3 (C.sub.5H.sub.7CO.sub.2), 150.9
(aromatic carbon attached to CO.sub.2C.sub.11H.sub.23), 144.8
(aromatic carbon para to C.sub.5H.sub.7CO.sub.2), 137.5 (aromatic
carbon para to CO.sub.2C.sub.11H.sub.23), 130.1 (aromatic carbon
ortho to C.sub.5H.sub.7CO.sub.2), 129.0 (aromatic carbon attached
to C.sub.5H.sub.7CO.sub.2), 128.3 (aromatic carbons meta to
C.sub.5H.sub.7CO.sub.2), 127.0 (aromatic carbons meta to CO.sub.2C,
1H.sub.23), 122.1 (aromatic carbons ortho to
CO.sub.2C.sub.11H.sub.23), 83.0 (.ident.C). 69.1 (HC.ident.), 63.5
(CH.sub.2OCO), 34.4 (OCOCH.sub.2), 31.9 (CH.sub.2CH.sub.2CH.sub.3),
29.6, 29.4, 29.3, 29.2, 29.1, 27.7 (.ident.C--CH.sub.2CH.sub.2),
24.9 (OCOCH.sub.2CH.sub.2), 22.6 (CH.sub.2CH.sub.3), 15.4
(CH.sub.2C.ident.), 14.0 (CH.sub.3).
[0082] MS (CI): m/e 463.3 [(M+1).sup.+, calcd 463.3]
[0083] Anal. Calcd for C.sub.30H.sub.38O.sub.4: C, 77.88; H, 8.28.
Found C, 77.53; H, 7.85.
[0084] Polymerisation
[0085] The polymer was synthesized by a similar process to that
described in Example 2, except that the polymerization process was
conducted at 60.degree. C. instead of room temperature.
Characterisation for polymer X (n=5): Yellow powdery solid; yield:
84.05%. Mw: 37740, M.sub.n: 1.9 (GPC polystyrene calibration).
[0086] IR (KBr), .nu.(cm.sup.-1): 1758 (C.sub.5H.sub.7CO.sub.2),
1716 (CO.sub.2C.sub.11H.sub.23).
[0087] .sup.1H NMR (300 MHz, CDCl.sub.3), .delta.(ppm): 7.97, 7.42,
7.01 (Ar--H and trans HC.ident.C), 6.00 (cis .ident.C--H), 4.36
(CH.sub.2OCOAr), 2.63 (CH.sub.2CO.sub.2), 2.1 (.ident.CCH.sub.2),
1.84 (CH.sub.2CH.sub.2CO.sub.2, .ident.CCH.sub.2CH.sub.2), 1.40
[(CH.sub.2).sub.8], 1.00 (CH.sub.3)
[0088] .sup.13C NMR (75 MHz, CDCl.sub.3), .delta.(ppm): 171.8
(CO.sub.2C.sub.11H.sub.23), 165.9 (C.sub.5H.sub.7CO.sub.2), 150.5
(aromatic carbon attached to CO.sub.2C.sub.11H.sub.23), 144.0
(aromatic carbon para to C.sub.5H.sub.7CO.sub.2), 137.1 (aromatic
carbon para to CO.sub.2C.sub.11H.sub.23), 129.9 (aromatic carbons
ortho to C.sub.5H.sub.7CO.sub.2), 128.8 (aromatic carbon attached
to C.sub.5H.sub.7CO.sub.2), 128.0 (aromatic carbons meta to
C.sub.5H.sub.7CO.sub.2), 126.8 (aromatic carbons meta to
CO.sub.2C.sub.11H.sub.23), 121.8 (aromatic carbons ortho to
CO.sub.2C.sub.11H.sub.23), 64.3 (CH.sub.2OCO), 34.3
(CH.sub.2CO.sub.2), 31.8 (CH.sub.2CH.sub.2CH.sub.3), 29.6, 29.5,
29.3, 29.1, 24.8, 22.6 (CH.sub.2CH.sub.3), 14.0 (CH.sub.3).
[0089] UV (CHCl.sub.3, 9.00.times.10.sup.-5 mol/L,
.lambda..sub.max(nm)/.e- psilon..sub.max(mol.sup.-1L cm.sup.-1):
277/2.56.times.10.sup.4.
[0090] Liquid Crystal Behaviour
[0091] Of the monomers, 3d (n=5) exhibited a short temperature
range (ca. 2.degree. C.) monotropic smectic B mesophase. On cooling
from the isotropic liquid, texture in the form of pseudo
n-disclinations was observed with simultaneous crystallization. 3d
(n=6) forms enantriotropic smectic A and smectic B mesophases upon
cooling from the isotropic liquid. The temperature range of the
mesophase is wide. DSC, POM and XRD analysis indicates that
polymers X (n=5,6) form interdigitiated smectic A mesophases. Glass
transition temperatures Tg of ca. 1100.degree. C. were found.
EXAMPLE 4
[0092]
Poly(n-{[({[4'-[(nonyl)oxy]-biphenyl-4-yl)carbonyl]oxy}hexyl)oxy]ca-
rbonyl}-1-alkyne), n=4,10 (XI) 9
[0093] Monomer Synthesis
[0094] The acetylene derivatives were synthesised by the multiple
step reactions shown in FIG. 4. Detailed experimental procedures
and characterisation data are given below.
[0095] 4'-(Nonyl)oxy-4-biphenylcarboxylic acid (4a)
[0096] In a 500-mL Erlenmeyer flask equipped with a condenser, 3 g
(14 mmol) of 4'-hydroxy-4-biphenylcarboxylic acid and 2 g of KOH
(28 mmol) were dissolved in 300 mL of ethanol/water mixture (v/v:
6:1) under gentle heating and stirring. To the homogeneous solution
was added 3 g of 1-bromononane (15 mmol) and a catalytic amount of
KI and the resulting mixture was then refluxed for 30 h. The
mixture was poured into 200 mL of water, acidified with 20 mL of
37% concentrated hydrochloric acid. The solid was collected by
suction filtration and recrystallization in glacial acetic acid
gave 3 g of product. White crystals; yield: 62%.
[0097] IR (KB4), .nu.(cm.sup.-1): 3250-2500 (br, COOH), 1686
(C.dbd.O).
[0098] .sup.1H NMR (300 MHz, DMSO-d.sub.6), .delta. (ppm): 13.00
(s, 1H, COOH), 8.00 (d, 2H, Ar--H), 7.9 (m, 4H, Ar--H), 7.2 (d, 2H,
Ar--H), 4.13 (5, 2H, OCH.sub.2), 1.9 (m, 2H, OCH.sub.2CH.sub.2),
1.36 .mu.m, 12H, (CH.sub.2).sub.6], 1.00 t, 3H, CH.sub.3)
[0099] .sup.13C NMR (75 MHz, DMSO-d.sub.6), .delta. (ppm): 167.3
(COOH), 160.2 (aromatic carbon attached to OC.sub.9H.sub.19), 144.1
(aromatic carbon para to CO.sub.2H), 131.2 (aromatic carbon para to
OC.sub.9H.sub.19), 130.1 (aromatic carbons meta to CO.sub.2H),
128.9 (aromatic carbon attached to CO.sub.2H), 128.2 (aromatic
carbons ortho to --CO.sub.2H), 126.2 (aromatic carbons meta to
OC.sub.9H.sub.19), 115.2 (aromatic carbons ortho to
OC.sub.9H.sub.19), 67.7 (OCH.sub.2), 31.3
(CH.sub.2CH.sub.2CH.sub.3), 29.1, 28.9, 28.8, 25.6, 22.2
(CH.sub.2CH.sub.3), 14.1 (CH.sub.3).
[0100] 6-Hydroxy-1-hexyl[4'-(Heptyl)oxy-4-biphenyl]carboxylate
(4b)
[0101] 4'-((Nonyl)oxy)-4-biphenylcarboxylic acid (0.9 g, 2.6 mmol),
1,6-hexanediol (0.6 g, 5.4 mmol), TsOH (0.1 g, 0.5 mmol) and DMAP
(0.07 g, 0.5 mmol) were dissolved in 200 mL of dry CH.sub.2Cl.sub.2
in a 500 mL two-necked flask under nitrogen. The solution was
cooled down to 0-5.degree. C. with an ice-water bath, to which 0.8
g (3.9 mmol) of DCC in 50 mL of CH.sub.2Cl.sub.2 was added with
stirring via a dropping funnel with a pressure-equalization arm.
The solution mixture was stirred overnight. After filtering out the
formed urea solid, the solution was concentrated by a rotary
evaporator. The product was purified by column chromatography using
chloroform/acetone mixture (v/v: 10:1) as eluent followed by
recrystallization from 70% aqueous ethanol solution. White solid;
yield: 77.7%
[0102] IR (Kbr), .nu.(cm.sub.-1): 3346 (br,OH), 1718 (C.dbd.O)
[0103] .sup.1H NMR (300 MHz, CDCl.sub.3), .delta.(ppm): 8.08 (d,
2H, Ar--H) 7.56 (m, 4H, Ar--H), 6.98 (d, 2H, Ar--H), 4.34 (t, 2H
CH.sub.2OCOAr), 4.00 (t, 2H OCH.sub.2), 3.66 (t, 2H, HOCH.sub.2),
1.80 (m, 4H, CH.sub.2CH.sub.2OCOAr and OCH.sub.2CH.sub.2),
1.64-1.25 .mu.m, 18H, (CH.sub.2).sub.9], 0.89 (t, 3H, CH.sub.3)
.sup.13C NMR (75 MHz, CDCl.sub.3), .delta.(ppm): 166.6 (CO.sub.2R),
159.5 (aromatic carbon attached to OC.sub.9H.sub.19), 145.3
(aromatic carbon para to CO.sub.2R), 132.2 (aromatic carbon para to
OC.sub.9H.sub.19), 130.1 (aromatic carbons meta to CO.sub.2R),
128.5 aromatic carbon attached to CO.sub.2R), 128.3 (aromatic
carbons ortho to CO.sub.2R), 126.4 (aromatic carbons meta to
OC.sub.9H.sub.19), 115.0 (aromatic carbons ortho to
OC.sub.9H.sub.19), 68.2 (OCH.sub.2), 64.9 (CH.sub.2OCOAr), 62.9
(HOCH.sub.2), 32.7 (HOCH.sub.2CH.sub.2, 31.9
(CH.sub.2CH.sub.2CH.sub.3), 29.5, 29.4, 29.3, 29.2, 28.8, 26.0
[HO(CH.sub.2).sub.3CH.sub.2], 25.9[O(CH.sub.2).sub.2CH.s- ub.2],
25.4 [HO(CH.sub.2).sub.2CH.sub.2], 22.7 (CH.sub.2CH.sub.3), 14.1
(CH.sub.3).
[0104]
n-{[({[4'-[(Nonyl)oxy]-biphenyl-4-yl)carbonyl]oxy}hexyl)oxy]carbony-
l}-1-alkyne (4c; n=4, 10)
[0105] Typical procedure for the synthesis of 4c (n=4) is shown
below: Into a 500 mL flask, 6-hydroxy-1-hexyl
[4'-((Heptyl)oxy)-4-biphenyl]carbo- xylate (2 g, 4.5 mmol),
5-pentynoic acid (0.6 g, 4.5 mmol), DCC (1.9 g, 6.5 mmol), TsOH
(0.2 g, 1 mmol) and DMAP (0.16 g, 1 mmol) were dissolved in 200 mL
of CH.sub.2Cl.sub.2. After the solution was stirred for 24 h, the
formed urea was filtered out and the solvent was removed by a
rotary evaporator. The residue was separated by silica-gel column
using chloroform as eluent. After recrystallization in absolute
ethanol, 1.6 g of product was obtained. Monomer 4c (n=10) was
synthesized by a similar process.
[0106] Characterisation for 4c (n=4): White solid, yield:
67.5%.
[0107] IR (KBr), .nu. (cm.sup.-1): 3282 (s, .ident.C--H), 1734
(C.sub.5H, CO.sub.2) and 1712 (CO.sub.2Ar), 630 (.ident.C--H)
.sup.1H NMR (300 MHz, CDCl.sub.3), .delta. (rpm) 8.08 (d, 2H,
Ar--H); 7.57 (m; 4H, Ar--H), 6.98 (d, 2H, Ar--H), 4.34 (t, 2H,
CH.sub.2OCO), 4.13 (t, 2H, OCH.sub.2), 4.00 (t, 2H, ROCOCH.sub.2),
2.52 (m, 4H, .ident.C--CH.sub.2CH.sub.2 and .ident.C--CH.sub.2),
1.97 (t, 1H, HC_), 1.82 (m, 4H, CO.sub.2CH.sub.2CH.sub.2 and
CH.sub.2CH.sub.2OCO), 1.71 (m, 2H, OCH.sub.2CH.sub.2), 1.49-1.29
.mu.m, 16H, (CH.sub.2).sub.8], 0.89 (t, 3H, CH.sub.3). .sup.13C NMR
(75 MHz, CDCl.sub.3), .delta. (ppm): 171.8 (RCO.sub.2R), 166.6
(RCO.sub.2Ar), 159.4 (aromatic carbon attached to
OC.sub.9H.sub.19), 145.2 (aromatic carbon para to CO.sub.2R), 132.2
(aromatic carbon para to OC.sub.9H.sub.19), 130.0 (aromatic carbons
ortho to CO.sub.2R), 128.4 (aromatic carbon attached to CO.sub.2R),
128.3 (aromatic carbons meta to OC.sub.9H.sub.19), 126.4 (aromatic
carbons meta to CO.sub.2R), 114.9 (aromatic carbons ortho to
OC.sub.9H.sub.19), 82.5 (--C), 69.0 (HC--), 68.1 (OCH.sub.2), 64.8
(CH.sub.2OCOAr), 64.7 (ROCOCH.sub.2), 33.4 (EC-CH.sub.2CH.sub.2),
31.9 (CH.sub.2CH.sub.2CH.sub.- 2), 29.5 (OCH.sub.2CH.sub.2), 29.4
[O(CH.sub.2).sub.4CH.sub.2], 29.3 [O(CH.sub.2).sub.3CH.sub.2], 28.7
[O(CH.sub.2).sub.5CH.sub.2], 28.5 [O(CH.sub.2).sub.2CH.sub.2],
26.03, 25.74, 25.73, 25.7 (CH.sub.2CH.sub.3), 14.4
(.dbd.C--CH.sub.2), 14.1 (CH.sub.3).
[0108] MS (CI): m/e 520.9 (M+calcd 520.3).
[0109] Anal. Calcd for C.sub.33H.sub.44O.sub.5: C; 76.15, H; 8.46.
Found: C; 77.29, H; 8.60.
[0110] Polymerisation
[0111] Polymerisation was performed using a WCH/Ph.sub.4Sn system
substantially as described in Example 2.
[0112] Characterisation data for Polymer XI (n=4): Pale yellow
powdery solid; yield: 53.1% M.sub.w: 40070, M.sub.w/M.sub.n: 1.84
(GPC, polystyrene calibration).
[0113] IR (KBr), v (cm.sup.-1): 1716 (CO.sub.2R)
[0114] .sup.1H NMR (300 MHz, CDCl.sub.3), .delta. (ppm): 8.02,
7.57, 6.92 (Ar--H and trans .dbd.C--H), 5.8 (cis .dbd.C--H), 4.29
(CH.sub.2OCOAr), 4.07 (OCH.sub.2), 3.98 (RCO.sub.2CH.sub.2), 2.60
(.dbd.C--CH.sub.2CH.sub.- 2), 2.60 (.dbd.C--CH.sub.2), 1.78
(OCH.sub.2CH.sub.2), 1.45-1.31 (CH.sub.2).sub.8, 0.92
(CH.sub.3).
[0115] .sup.13CNMR(75 MHz, CDCl.sub.3), .delta. (ppm): 172.7
(C.sub.4H.sub.5CO.sub.2), 166.3 (ArCO.sub.2), 159.4 (aromatic
carbon attached to OC.sub.9H.sub.19), 145.0 (aromatic carbon para
to C.sub.4H.sub.5CO.sub.2), 132.1 (aromatic carbon para to
OC.sub.9H.sub.19), 131.6 (.dbd.C) 130.0 (aromatic carbon ortho to
C.sub.4H.sub.5CO.sub.2), 128.4 (aromatic carbon attached to
C.sub.4H.sub.5CO.sub.2), 128.3 (aromatic carbons meta to
OC.sub.9H.sub.19), 126.2 (aromatic carbons meta to
C.sub.4H.sub.5CO.sub.2), 114.9 (aromatic carbons ortho to
OC.sub.9H.sub.19), 68.1 (OCH.sub.2), 64.8 (CH.sub.2OCOAr), 64.3
(RCO.sub.2CH.sub.2), 31.9, 29.5, 29.4, 29.3, 29.2, 28.7, 26.0,
25.7, 22.7 (CH.sub.2CH.sub.3), 14.1 (CH.sub.3).
[0116] UV (CHCl.sub.3, 8.85.times.10.sup.-5 mol/L),
.lambda..sub.max (nm)/.epsilon..sub.ma (mol.sup.-1 Lcm.sup.-1):
296/2.40.times.10.sup.4.
[0117] Liquid Crystal Behaviour
[0118] Polymers XI (n=4,10) exhibit a DSC peak corresponding to a
transition from isotropic liquid to smectic A mesophase, and a
further peak relating to a transition to a crystal state. POM
micrographs reveal focal-conic texture in polymer XI (n=4) and
Schlieren like texture in polymer XI (n=10).
EXAMPLE 5
[0119]
Poly{n-[({[(4'-[(hexyl)oxy]-biphenyl-4-yl)oxy]hexy}oxy)carbonyl]-1--
alkyne}, n=5,10 (XII) 10
[0120] Monomer Synthesis
[0121] The acetylene derivatives were synthesised according to the
scheme shown in FIG. 5.
[0122] 4'-Hydroxy-4-biphenylyl hexyl ether (5a)
[0123] Into a 500-mL Erlenmeyer flask equipped with a condenser,
4.1 g (22 mmol) of 4-4'-biphenol and 1.2 g (22 mmol) of KOH were
dissolved in 250 mL acetone/DMSO mixture (v/v: 10:1). To the
homogeneous solution were added 1.8 g (11 mmol) of 1-bromohexane
and a catalytic amount of potassium iodide. The resulting mixture
was refluxed for 24 h and the solution was poured into 150 mL of
water, acidified with 15 mL of 37% concentrated hydrochloric acid.
The precipitate was collected by suction filtration, washed with
water and dried in vacuum oven. The crude product was purified on a
silica-gel column using chloroform as eluent first, then a
chloroform/acetone mixture (v/v: 10:1). Recrystallization from
ethanol/water mixture (v/v: 3:1) gave 1.4 g of product. White
crystals; yield: 42.9%.
[0124] IR (KBr), .nu.(cm.sup.-1): 3298 (br, OH)
[0125] .sup.1H NMR (300 MHz, CDCl.sub.3), .delta. (ppm): 7.44 (m,
4H, Ar--H), 6.91 (m, 4H, Ar--H), 4.69 (s, OH), 3.99 (t, 2H,
OCH.sub.2), 1.80 (t, 2H, OCH.sub.2CH.sub.2), 1.52-1.29 .mu.m, 6H,
(CH.sub.2).sub.3], 0.92 (t, 3H, CH.sub.3).
[0126] .sup.13C NMR (300 MHz, CDCl.sub.3), .delta. (ppm): 158.3
(aromatic carbon attached to OC.sub.6H.sub.13), 154.6 (aromatic
carbon attached to OH), 133.8, 133.2 (aromatic carbon para to
OC.sub.6H.sub.13), 127.9, 127.7 (aromatic carbons meta to
OC.sub.6H.sub.13), 115.6, 114.8 (aromatic carbons ortho to
OC.sub.6H.sub.13), 68.1 (OCH.sub.2), 31.6
(CH.sub.2CH.sub.2CH.sub.3), 29.3, 25.7, 22.6 (CH.sub.2CH.sub.3),
14.0 (CH.sub.3)
[0127] 6-((4'-((Hexyl)oxy)-4-biphenylyl)oxy)-1-hexanol (5b)
[0128] Into a 500-mL Erlenmeyer flask equipped with a condenser,
3.6 g of 4'-hydroxy-4-biphenylyl hexyl ether (13.3 mmol), 2.4 g
(13.3 mmol) of 6-bromo-hexan-1-ol, 0.8 g of KOH (13 mmol) and a
catalytic amount of potassium iodide were dissolved in 250 mL of
acetone/DMSO mixture (v/v: 1-0:1). The resulting mixture was
refluxed for 24 h. The mixture was poured into 150 mL of water,
acidified with 15 mL of 37% of concentrated hydrochloric acid. The
precipitate was collected by suction filtration and dried in a
vacuum oven.
[0129] Recrystallization from absolute ethanol gave 4.0 g of
product. White solid; yield: 80.7%
[0130] IR (KBr), .nu. (cm.sup.-1): 3300 (br, OH)
[0131] .sup.1H NMR (300 MHz, CDCl.sub.3), .delta. (ppm): 7.46 (m,
4H, Ar--H), 6.94 (m, 4H, Ar--H), 4.00 (m, 4H, OCH.sub.2), 3.67 (m,
2H, HOCH.sub.2), 1.81 (m, 4H, OCH.sub.2CH.sub.2), 1.67-1.24 .mu.m,
12H, (CH.sub.2).sub.6], 0.92 (t, 3H, CH.sub.3)
[0132] .sup.13C NMR (75 MHz, CDCl.sub.3), 6 (ppm): 158.24 (aromatic
carbon attached to OC.sub.6H.sub.13), 158.16, 133.4 (aromatic
carbon para to C.sub.6H.sub.13O), 133.2, 127.7, 127.6 (aromatic
carbon meta to OC.sub.6H.sub.13), 114.9, 114.8 (aromatic carbons
ortho to OC.sub.6H.sub.13), 68.1, 67.9, (OCH.sub.2C.sub.5H.sub.1),
62.9 (HOCH.sub.2), 32.7 (HOCH.sub.2CH.sub.2), 31.6
(CH.sub.2CH.sub.2CH.sub.3), 29.3 (OCH.sub.2CH.sub.2), 25.9, 25.7,
25.6, 22.6 (CH.sub.2CH.sub.3), 14.0 (CH.sub.3)
[0133]
n-[(([(4'-[(Hexyl)oxy]-biphenyl-4-yl)oxy]hexyl}oxy)carbonyl]-1-alky-
ne (5c; n=5, 10)
[0134] A general procedure for the synthesis of 5c (n=5) is given
below: Into a 250-mL flask,
6-((4'-((hexyl)oxy)-4-biphenylyl)oxy)-1-hexanol (2.6 g, 7 mmol),
5-hexynoic acid (0.8 g, 7 mmol), DCC (2.1 g, 10 mmol), TsOH (0.3 g,
1.2 mmol) and DMAP (0.2 g, 1.2 mmol) were dissolved in 200 mL of
CH.sub.2Cl.sub.2. After the solution was stirred at room
temperature for 24 h, the formed urea was filtered out and the
solvent was removed by rotary evaporator. The crude product was
separated on a silica-gel column using CHCl.sub.3 as eluent.
Recrystallization from absolute ethanol gave 2.7 g of product.
[0135] Characterization for 5c (n=5): White solid; yield: 83.9%
[0136] IR (KBr), v (cm.sup.-1): 3288 (s, HC.ident.), 1736
(C.dbd.O), 640 (.dbd.C--H)
[0137] .sup.1H NMR (300 MHz, CDCl.sub.3), 5 (ppm): 7.47 (d, 4H,
Ar--H), 6.95 (m, 4H, Ar--H), 4.12 (t, 2H, CH.sub.2OCOR), 4.00 (t,
4H, OCH.sub.2), 2.47 (t, 2H, CH.sub.2CO.sub.2), 2.27 (td, 2H,
EC-CH.sub.2), 1.98 (t, 1H, HCl), 1.90-1.34 .mu.m, 12H,
(CH.sub.2).sub.6], 0.93 (t, 3H, CH.sub.3)
[0138] .sup.13C NMR (300 MHz, CDCl.sub.3), 6 (ppm): 173.10
(C.dbd.O), 158.20 (aromatic carbon attached to OC.sub.6H.sub.13),
158.10 (aromatic carbon attached to OC.sub.6H.sub.13R), 133.40
(aromatic carbon para to OC.sub.6H.sub.12R), 133.20 (aromatic
carbon para to OC.sub.6H.sub.13), 127.62 (aromatic carbons meta to
OC.sub.6H.sub.12R), 127.61 (aromatic carbons meta to
OC.sub.6H.sub.13), 114.71 (aromatic carbons ortho to
OC.sub.6H.sub.12R), 114.69 (aromatic carbons ortho to
OC.sub.6H.sub.13), 83.30 (--C), 69.10 (OCH.sub.2), 68.00
(HC.ident.), 67.80 (CH.sub.2OAr), 64.40 (CO.sub.2CH.sub.2), 32.90
(CH.sub.2CO.sub.2R), 31.60 (CH.sub.2CH.sub.2CH.sub.3), 29.30
(OCH.sub.2CH.sub.2), 29.20, 28.60, 25.80, 25.73, 25.70, 23.60,
22.60 (CH.sub.2CH.sub.3), 17.80 (EC-CH.sub.2), 14.00 (CH.sub.3) MS
(CI): m/e 465.2 [(M+1).sup.+ calcd 465.2]
[0139] Polymerisation
[0140] Polymerisation was performed using a WCl.sub.6/Ph.sub.4Sn
system substantially as described in Example 2. The polymerisation
of 5c (n=5) was performed at 60.degree. C. owing to limited
solubility in dioxane at room temperature.
[0141] Polymer XII (n=10) Characterisation data: Pale green powdery
solid; yield: 86.3%.
[0142] M.sub.w: 40860, M.sup.w/M.sub.n: 2.13
[0143] IR (Kr), .nu. (cm.sup.-1): 1734 (C.dbd.O)
[0144] .sup.1H NMR (300 MHz, CDCl.sub.3), .delta. (ppm): 7.45, 6.94
(Ar--H and trans .dbd.C--H), 5.91 (cis .dbd.C--H), 4.11
(CH.sub.2OCOR), 4.00 (OCH.sub.2), 2.57 (.dbd.C--H), 2.32
(CH.sub.2CO.sub.2), 1.81-1.35 [(CH.sub.2).sub.14], 0.94
(CH.sub.3).
[0145] .sup.13CNMR (75 MHz, CDCl.sub.3, 8 (ppm): 173.6 (C.dbd.O),
158.2, 158.1, 133.2, 127.53, 127.50, 114.6, 68.0, 67.72, 64.1,
34.2, 31.5, 29.2, 28.5, 25.70, 25.69, 24.9, 22.6, 14.0 UV (THF,
8.43.times.10.sup.-5 mol/L): 268 nm/2.06.times.10.sup.4 mol.sup.-1
L cm.sup.-1
[0146] Liquid Crystal Behaviour
[0147] Polymers XII (n=5, 10) exhibit a DSC peak corresponding to a
transition from isotropic liquid to a smectic A mesophase, and a
further peak relating a transition to a crystal state.
EXAMPLE 6
[0148]
Poly[5-({[(4-{[(hexyl)oxy]phenyl}oxy)carbonyl]phenyl}oxy)-1-pentyne
(XIII) 11
[0149] Polymer XIII was synthesised according to the scheme shown
in FIG. 6.
[0150] Monomer Synthesis
[0151] 4-((5-Pentyn-1-yl)oxy)benzoic acid (6a)
[0152] In a 500 mL Erlenmeyer flask equipped with a condenser, 8.8
g (63.7 mmol) of 4-hydroxybenzoic acid and 7.2 g (128.3 mmol) of
KOH were dissolved in 360 mL ethanol/water mixture (v/v: .delta.:
1) under gentle heating and stirring. To the homogeneous solution
were added 6.5 g (63.4 mmol) of 5-chloro-1-pentyne and a catalytic
amount of potassium iodide, and the resulting mixture was then
refluxed for 24 h. The mixture was poured into water, acidified
with 20 mL of 37% hydrochloric acid. The solid was collected by
suction filtration and washed with water. Recrystallization from
absolute ethanol gave 4.5 g of product (yield: 34.8%).
[0153] IR (KBr), .nu. (cm.sup.-1): 3300 (s, .ident.C--H), 3200-2400
(br, CO.sub.2H), 1688 (s, C.dbd.O).
[0154] .sup.1H NMR (300 MHz, DMSO-d.sub.6), .delta. (ppm): 12.71
(s, 1H, CO.sub.2H), 7.99 (d, 2H, Ar--H ortho to CO.sub.2H), 7.13
(d, 2H, Ar--H ortho to OC.sub.5H.sub.7), 4.20 (t, 2H, OCH.sub.2),
2.91 (t, 1H, HC-=), 2.44 (td, 2H, .ident.C--CH.sub.2), 2.00 (m, 2H,
CH.sub.2CH.sub.2CH.sub.2)- .
[0155] .sup.13C NMR (75 MHz, DMSO-d.sub.6), 6 (ppm): 167.6
(CO.sub.2H), 162.6 (aromatic carbon attached to C.sub.5H.sub.7),
131.9 (aromatic carbons ortho to CO.sub.2H), 123.4 (aromatic carbon
attached to CO.sub.2H), 114.8 (aromatic carbons ortho to
OC.sub.5H.sub.7), 84.0 (.ident.C), 71.9 (OCH.sub.2), 65.5
(HC.ident.), 27.8 (.dbd.C--CH.sub.2CH.sub.2), 14.7
(.ident.C--CH.sub.2)
[0156]
5-{[({4-{[(Hexyl)oxy]phenyl]oxy}carbonyl)phenyl]oxy}-1-pentyne
(6b)
[0157] 4-((5-pentyn-1-yl)oxy)benzoic acid (4.4 g, 21.5 mmol),
4-hexyloxyphenol (4.6 g, 23.7 mmol), TsOH (0.9 g, 5.2 mmol) and
DMAP (0.5 g, 4.1 mmol) were dissolved in 300 mL of dry
dichloromethane in a 500-mL two-necked flask under nitrogen. The
solution was cooled down to 0-5.degree. C. with an ice-water bath,
to which 6.7 g of DCC (27.9 mmol) in 70 mL of dichloromethane was
added with stirring via a dropping funnel with a
pressure-equalization arm. The reaction mixture was stirred
overnight. After filtering out the formed urea solid, the solution
was concentrated by a rotary evaporator. The product was purified
by column chromatography using chloroform as eluent, followed by
recrystallization from absolute ethanol. 7.0 g of product was
obtained. White crystals; yield: 85.6%.
[0158] IR (KBr), .nu. (cm.sup.-1): 3312 (s, .ident.C--H), 1726
(C.dbd.O), 632 (s, .ident.C--H)
[0159] .sup.1H NMR (300 MHz, CDCl.sub.3), .delta. (ppm): 8.13 (d,
2H, Ar--H ortho to CO.sub.2Ph), 7.09 (d, 2H, ArH ortho to
ArCO.sub.2), 6.95 (m, 4H, Ar--H) 4.16 (t, 2H, CH.sub.2OAr); 3.96
(t, 2H, PhOCH.sub.2), 2.44 (td, 2H, .ident.C--CH.sub.2), 2.01 (m,
3H, --C--H and .ident.CH.sub.2CH.sub.2), 1.76 (m, 2H,
OCH.sub.2CH.sub.2), 1.49-1.31 .mu.m, 6H, (CH.sub.2).sub.3], 0.93
(t, 2H, CH.sub.3)
[0160] .sup.13C NMR (75 MHz. CDCl.sub.3), .delta. (ppm): 165.2
(C.dbd.O)) 163.1 (aromatic carbon attached to OC.sub.5H.sub.7),
156.7 (aromatic carbon attached to OC.sub.6H.sub.13), 144.3
(aromatic carbon attached to ArCO.sub.2), 132.2 (aromatic carbons
ortho to CO.sub.2Ph), 122.4 (aromatic carbons ortho to PhCO.sub.2),
121.9 (aromatic carbon attached to CO.sub.2Ph), 115.0 (aromatic
carbons ortho to OC.sub.5H.sub.7), 114.2 (aromatic carbons ortho to
OC.sub.6H.sub.13), 31.5, 29.2 (OCH.sub.2CH.sub.2), 27.9
(.ident.C--CH.sub.2CH.sub.2), 25.7, 22.5 (CH.sub.2CH.sub.3), 15.0
(.ident.C--CH.sub.2), 14.0 (CH.sub.3).
[0161] MS(CI): m/e 381.2 [(M+1).sup.+, calcd 381.2]
[0162] Anal. Calcd for C.sub.24H.sub.28O.sub.4: C; 75.19, H; 7.36.
Found: C; 74.19, H; 7.75
[0163] Polymerisation
[0164] 310.0 mg of monomer 6b was polymerised using a
WCl.sub.6/Ph.sub.4Sn system substantially as described in Example
2, and gave a red powdery solid; yield: 64.5%. M.sub.w: 118300,
M.sub.w/M.sub.n: 2.33 (GPC, polystyrene calibration).
[0165] IR (KBr), .nu. (cm.sup.-1): 1734 (C.dbd.O)
[0166] .sup.1H NMR (300 MHz, CDCl.sub.3), .delta. (ppm): 8.04,
7.03, 6.86 (Ar--H and trans .dbd.C--H), 6.08 (cis .dbd.C--H), 3.92
(OCH.sub.2), 2.54 (.dbd.C--CH.sub.2), 1.81
(.dbd.C--CH.sub.2CH.sub.2), 1.41 [(CH.sub.2).sub.4], 0.99
(CH.sub.3).
[0167] .sup.13C NMR (75 MHz, CDCl.sub.3), 6 (ppm): 164.8 (C.dbd.O),
162.8, 156.8, 144.1, 132.1, 122.3, 114.8, 114.0 (aromatic carbons),
68.2, 67.5, 31.6, 29.2, 25.7, 22.5, 14.0
[0168] UV (THF, 8.95.times.10.sup.-5 mol/L), .lambda..sub.max
(nm)/.epsilon..sub.max (mol.sup.-1 L cm.sup.-1):
261/2.33.times.10.sup.4, 360 (sh), 1.34.times.10.sup.3.
[0169] Liquid Crystal Behaviour
[0170] Monomer 6b exhibits an enantiotropic nematic mesophase; DSC
reveals transition temperatures on cooling of 75.2 and 59.7.degree.
C. for isotropic to nematic and nematic to crystalline transitions,
respectively (corresponding temperatures on heating are 77.4 and
65.2.degree. C., respectively).
[0171] Polymer XIII forms an enantiotropic interdigitated smectic A
mesophase with weak side chain interactions. Typical focal conic
texture is observed on cooling from the isotropic liquid. DSC
reveals broad peaks at 209.0.degree. C. during second heating and
198.7.degree. C. during first cooling. These peaks correspond to
the transitions from the smectic A mesophase to the isotropic
liquid and vice versa.
* * * * *