CA1288093C - CHIRAL ESTERS OF .alpha.-SUBSTITUTED PHENYLALKANOIC ACIDS AND MESOGENIC HYDROXY COMPOUNDS, AND THEIR USE AS A DOPING SUBSTANCE IN LIQUID CRYSTAL PHASES - Google Patents
CHIRAL ESTERS OF .alpha.-SUBSTITUTED PHENYLALKANOIC ACIDS AND MESOGENIC HYDROXY COMPOUNDS, AND THEIR USE AS A DOPING SUBSTANCE IN LIQUID CRYSTAL PHASESInfo
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- C09K19/2028—Compounds containing at least one asymmetric carbon atom containing additionally a linking group other than -COO- or -OCO-, e.g. -CH2-CH2-, -CH=CH-, -C=C-; containing at least one additional carbon atom in the chain containing -COO- or -OCO- groups, e.g. -COO-CH*-CH3
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- C09K19/3441—Non-steroidal liquid crystal compounds containing at least one heterocyclic ring having nitrogen as hetero atom
- C09K19/345—Non-steroidal liquid crystal compounds containing at least one heterocyclic ring having nitrogen as hetero atom the heterocyclic ring being a six-membered aromatic ring containing two nitrogen atoms
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Abstract
ABSTRACT OF THE DISCLOSURE
The novel compounds are chiral esters of .alpha.-substituted phenylalkanoic acids and mesogenic hydroxy compounds, the symbols in the general formula (I) (I) being defined as follows:
MO = molecular radical of a mesogenic hydroxy compound MOH after removal of one H, the radical MO being expressed by the general formula (II) R2 - (A1)n1 - (B-)n2(A2)n3 - O (II) where R2 = straight-chain or branched (C1-C12)-alkyl, it being possible for one or two non-adjacent CH2 groups to be replaced by O and/or S
atoms, or, if n1 = 1, also F, Cl, Br, CN or CF3, A1, A2 = independently of one another 1,4-phenyl-ene, diazine-2,5-diyl, diazine-3,6-diyl, 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, 1,3-di-thiane-2,5-diyl or 1,4-bicyclo(2,2,2)octylene, it being possible for these groups also to be at least monosubstituted by F, Cl, Br, CN, CF3 and/or (C1-C12)-alkyl (one or two non-adjacent CH2 groups may be replaced by O
and/or S atoms), B = CO-O, O-CO, CH2-CH2, OCH2, CH2O, CH=N, N=CH, N=N, N(O)=N, n1, n2, n3 = independently of one another 0, 1 or 2, n1 and n3 not being 0 simultaneously, r = an electron-attracting substituent, Z = H or an electron-attracting substituent, but not identical with Y, and R1 = benzyl or phenyl, it being possible for these groups to be substituted in the aromatic moiety in the same way as A1 and A2, with the exception of the compounds with Z = H, r = F, Cl or Br, R2 = (C1-C11)-alkoxy, A1 and A2 = phenyl, n1, and n3 = 1 and n2 =0.
The compounds are preferably used in tilted smectic li-quid crystal phases, which are converted into ferroelec-tric liquid crystal phases by these compounds; they show high values of spontaneous polarization.
The novel compounds are chiral esters of .alpha.-substituted phenylalkanoic acids and mesogenic hydroxy compounds, the symbols in the general formula (I) (I) being defined as follows:
MO = molecular radical of a mesogenic hydroxy compound MOH after removal of one H, the radical MO being expressed by the general formula (II) R2 - (A1)n1 - (B-)n2(A2)n3 - O (II) where R2 = straight-chain or branched (C1-C12)-alkyl, it being possible for one or two non-adjacent CH2 groups to be replaced by O and/or S
atoms, or, if n1 = 1, also F, Cl, Br, CN or CF3, A1, A2 = independently of one another 1,4-phenyl-ene, diazine-2,5-diyl, diazine-3,6-diyl, 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, 1,3-di-thiane-2,5-diyl or 1,4-bicyclo(2,2,2)octylene, it being possible for these groups also to be at least monosubstituted by F, Cl, Br, CN, CF3 and/or (C1-C12)-alkyl (one or two non-adjacent CH2 groups may be replaced by O
and/or S atoms), B = CO-O, O-CO, CH2-CH2, OCH2, CH2O, CH=N, N=CH, N=N, N(O)=N, n1, n2, n3 = independently of one another 0, 1 or 2, n1 and n3 not being 0 simultaneously, r = an electron-attracting substituent, Z = H or an electron-attracting substituent, but not identical with Y, and R1 = benzyl or phenyl, it being possible for these groups to be substituted in the aromatic moiety in the same way as A1 and A2, with the exception of the compounds with Z = H, r = F, Cl or Br, R2 = (C1-C11)-alkoxy, A1 and A2 = phenyl, n1, and n3 = 1 and n2 =0.
The compounds are preferably used in tilted smectic li-quid crystal phases, which are converted into ferroelec-tric liquid crystal phases by these compounds; they show high values of spontaneous polarization.
Description
~.2~38093 HOECHST AKTIENGESELLSCHAF~ HOE 86/F 135 Dr.BK/je Chiral esters of -substituted phenylalkanoic acids and mesogenic hydroxy compounds, and their use as a doping substance in liquid crystal phases The characteristics of the electro-optical effects used in liquid crystal displays change in general with the temperature. Especially in the case of driving in the multiplexing region, this causes difficulties which can lead to an undesired restriction in the working tempera-ture range. For various electro-optical effects, the temperature dependence of the electro-optical characteris-tics can be influenced advantageously by an addition of chiral compounds to the nematic liquid crystal, via the temperature function of the pitch of the cholesteric helix structure thus induced, for example for the choles-teric-nematic phase transition effect, the TN ttwisted nematic) cell and the recently introduced SaE (supertwis-ted birefringence effect) and STN (supertw;sted nemat;c) effects.
In addition to nematic and cholesteric liquid crystals, tilted smectic liquid crystal phases have also gained in the last few years an increasing importance for applica-tions in practice. If suitable doping substances, which sho~ a so-called spontaneous polarization (Ps)~ are added to such tilted smectic phases, in particular smectic C (Sc or SmC) phases, the said phases can be converted into a ferroelectric liquid crystal phase (designation of Ps in nC x cm 2); in this connection see, for example, Lagerwall et al. in the paper "Ferroelectric Liquid ~rystals for Dis-plays", SID Symposium, October meeting, 1985, San Diego (USA).
In EP-A 0,159,872, compounds of the general formula below are described, inter alia, which are said to be suitable as a component in liquid crystal systems and show high values of spontaneous polarization:
H
Ra ~ 4~--(~ O - CO - ~ - Rb ~;
-" ~L2`~3B~
where the substituents should have the following meanings:
Ra = (C1-C18)-aLkyl~ X = F, Cl or 8r and Rb = benzyl or phenyl.
S It is the object of the present invention to provide com-pounds which, at high values of the spontaneous polariza-tion Ps~ cnntain structural elements which also render them compatible (i.e. miscible) ~ith other components in li-quid crystal systems, since structural elements in the mesogenic part and/or chiral part of the molecules are frequently responsible for good compatibility with the other mixture components in liquid crystal systems.
The invention starts from the kno~n chiral esters of ~-substituted phenylalkanoic acids and mesogenic hydroxy compounds. The esters according to the invention are then defined by the symbols in the general formula (I) z MO - CO - ~ - R1 (I) having the follow;ng mean;ngs:
MO = molecular rad;cal of a mesogenic hydroxy compound MOH after removal of one H, the rad;cal MO being expressed by the general formula (II) R2 _ (A1 )n1 - (B-)n2(A2)n3 ~ (II) where R2 = straight-chain or branched (C1-C12)-alkyl, it being possible for one or t~o non-adjacent CH2 groups to be replaced by O and/or S atoms, or, if n1 = 1, also F, Cl, Br, CN or CF3, A1, A2 = ;ndependently of one another 1,4-phenylene, d;az;ne-2,5-d;yl, diazine-3,6-diyl, 1,4-cyclo-hexylene, 1,3-dioxane-2,5-diyl, 1,3-dithiane-2,5-diyl or 1,4-bicyclo~2,2,2)octylene, it be-ing possible for these groups also to be at least monosubstituted by F, Cl, Br, CN, CF3 and/or ~` ~ X~80~3 (C1-C12)-alkyl (one or two non-adjacent CH2 groups may be replaced by O and/or S
atoms), B = CO-O, O-CO, CH2-CH2, OCH2, CH20, ~H=N, N=CH, N=N, S N(O)=N, n1, n~, n3 = independently of one another 0, 1 or 2, n1 and n3 not being O simultaneously, Y = an electron-attracting substituent, Z = H or an eLectron-attracting substituent but not identical with Y, and R = benzyL or phenyl, it being possible for these groups to be substituted in the aromatic moiety in the same way as A1 and A2, with the exception of the compounds with Z = H, Y = F, Cl or Br, R2 = (C1-C11)-alkoxy, A1 and A2 = phenyl, n1 and n3 = 1 and n2 = O.
The electron-attracting substituents Y are meant especi-ally to include the CF3 and OCH3 group and also halo-2~ gens sùch as Cl or Br or the C~ group.
The said compounds are chiral ~-mono- or di-substituted phenylacetates or phenylpropionates (i.e. substituted in the 2-position of a chiral phenylalkanoic acid) of phen-ols (or comparable heterocyclic compounds) or cycloalka-nols.
The stated object is also achieved by a twistable liquid crystal phase containing at least one chiral compound which comprises, as the chiral compound, at least one compound of the general formula (I). The term "twistable liquid crystal phase" is to be understood as nematic, cholesteric or tilted smectic, in particular SmC, phases.
The twistable liquid crystal phases compr;se 2 to 20 and preferably 2 to 15 components, including at least one of the chiral compounds claimed according to the inven-tion. The other constituents are preferably selected from the known compounds showing nemat;c, cholester;c ~ ~88093 . . ~
and/or tilted smectic phases; these include, for example, Schiff bases, biphenyls, terphenyls, phenylcyclohexanes, cyclohexylbiphenyls, pyrimidines, cinnamates, cholester-ol esters and variously bridged, terminal-polar polynu-clear esters of p-alkylbenzoic acids. In general, the commercially available liquid crystal phases, even be-fore the addition of the chiral compound(s), are mixtures of the most diverse components, of ~hich at least one is mesogenic, i.e. a compound which, in a derivatized form or as a mixture with certain cocomponents, shows a li-quid crystal phase [= formation of at least one enantio-tropic (clear point > melting point) or monotropic (clear point ~ melting point) mesophase].
Amongst the compounds of the general formula (I), those are preferred in which the symbols have the following meanings:
R2 = straight-chain (C4-C10)-alkyl, it being possible for one CH2 group to be replaced by an O or S atom, A1 and A2 = ;ndependently of one ~nother unsubstituted 1,4-phenylene, 1,4-cyclohexylene or pyrimidine-2,5-diyl, B = CO-O or O-CO, n1 = 1, n2 = 0 or 1 and n3 = 1 or 2, Y = CF3 and Z = OCH3, or Y = OCH3 and Z = H, and R1 =
unsubstituted phenyl.
The compounds according to the invention are advantage-ously prepared by reacting mesogenic compounds of the formula (III) or (III') MOH (III) (MO)mMe (III') ~herein MO is as defined above, Me is an alkaline earth metal or preferably an alkali metal and m = 1 (Me =
alkali metal) or m = 2 (Me = alkaline earth metal), ~ith compounds of the formula (IV) z X -CO-b-R1 ( IV) y ~ '~880~3 in which xf is an OH group or halogen, preferably chlo-rine, and Z and Y are as defined above.
Preferably, mesogenic hydroxy compounds (III) and acid chlorides (IV; xf = Cl) are used for preparing the com-pounds, the reaction taking place in the presence ofacid acceptors such as amines, for example pyridine or triethylamine, or of alkaLi metal or alkaline earth metal (hydrogen) carbonates, in general at temperatures be-tween -40C and +70C. It is also possible, however, to react the mesogenic hydroxy compound (III) with the car-boxylic acid (IV, xf = OH) itself, namely in the presenc~
of Bro'nstedt or Lewis acids, if appropriate in the pre-sence of dehydrating agents, or with the aid of condens-ing reagents such as N,N'-carbonyldiimidazole, dicyclo-hexylcarbodiimide or azodicarboxylate/triphenylphosphine.
Finally, compounds (I) are also obtained by reactingalkali metal or alkaline earth metal salts of the meso-genic hydroxy compound (III') with the carboxylic acid halide (IV, xf = halogen).
The crude product (I) obtained can be purified in a rnan-ner known per se, for example by recrystallization or column chromatography.
The liquid crystal phases contain in general 0.0~ to 7D%
by weight, especially 0.05 to 50% by weight, of the com-pound or compounds according to the invention.
The compounds according to the invention are suitable especially as doping substances for tilted smectic li-quid crystal phases, since they convert the latter into ferroelectric liquid crystal phases.
Examples 1 to 4 The phenol or cycloalkanol component is d;ssolved in pyridine, and an equimolar quantity of (-)-2-methoxy-2-trifluoromethyl-2-phenyl-ethanoyl chloride is added drop-WisQ. ~hile excluding moisture, the mixture is then heated for 60 minutes to 65C and then stirred for 12 hours at room temperature. Subsequently, the mixture is poured into ice water, acidified with concentrated hydro-chloric acid and extracted with ether several times, and the combined ether phases are washed with aqueous NaHC03 solution. After drying of the ether phases over MgS04, concentrating to a smaller volume and supersaturating the phases with petroleum ether, the following products crystallize out in a refrigerator:
(1 ) C7H15 ~ OCH3 ( 2, CgH 1 9 ~N~ OCH~
In addition to nematic and cholesteric liquid crystals, tilted smectic liquid crystal phases have also gained in the last few years an increasing importance for applica-tions in practice. If suitable doping substances, which sho~ a so-called spontaneous polarization (Ps)~ are added to such tilted smectic phases, in particular smectic C (Sc or SmC) phases, the said phases can be converted into a ferroelectric liquid crystal phase (designation of Ps in nC x cm 2); in this connection see, for example, Lagerwall et al. in the paper "Ferroelectric Liquid ~rystals for Dis-plays", SID Symposium, October meeting, 1985, San Diego (USA).
In EP-A 0,159,872, compounds of the general formula below are described, inter alia, which are said to be suitable as a component in liquid crystal systems and show high values of spontaneous polarization:
H
Ra ~ 4~--(~ O - CO - ~ - Rb ~;
-" ~L2`~3B~
where the substituents should have the following meanings:
Ra = (C1-C18)-aLkyl~ X = F, Cl or 8r and Rb = benzyl or phenyl.
S It is the object of the present invention to provide com-pounds which, at high values of the spontaneous polariza-tion Ps~ cnntain structural elements which also render them compatible (i.e. miscible) ~ith other components in li-quid crystal systems, since structural elements in the mesogenic part and/or chiral part of the molecules are frequently responsible for good compatibility with the other mixture components in liquid crystal systems.
The invention starts from the kno~n chiral esters of ~-substituted phenylalkanoic acids and mesogenic hydroxy compounds. The esters according to the invention are then defined by the symbols in the general formula (I) z MO - CO - ~ - R1 (I) having the follow;ng mean;ngs:
MO = molecular rad;cal of a mesogenic hydroxy compound MOH after removal of one H, the rad;cal MO being expressed by the general formula (II) R2 _ (A1 )n1 - (B-)n2(A2)n3 ~ (II) where R2 = straight-chain or branched (C1-C12)-alkyl, it being possible for one or t~o non-adjacent CH2 groups to be replaced by O and/or S atoms, or, if n1 = 1, also F, Cl, Br, CN or CF3, A1, A2 = ;ndependently of one another 1,4-phenylene, d;az;ne-2,5-d;yl, diazine-3,6-diyl, 1,4-cyclo-hexylene, 1,3-dioxane-2,5-diyl, 1,3-dithiane-2,5-diyl or 1,4-bicyclo~2,2,2)octylene, it be-ing possible for these groups also to be at least monosubstituted by F, Cl, Br, CN, CF3 and/or ~` ~ X~80~3 (C1-C12)-alkyl (one or two non-adjacent CH2 groups may be replaced by O and/or S
atoms), B = CO-O, O-CO, CH2-CH2, OCH2, CH20, ~H=N, N=CH, N=N, S N(O)=N, n1, n~, n3 = independently of one another 0, 1 or 2, n1 and n3 not being O simultaneously, Y = an electron-attracting substituent, Z = H or an eLectron-attracting substituent but not identical with Y, and R = benzyL or phenyl, it being possible for these groups to be substituted in the aromatic moiety in the same way as A1 and A2, with the exception of the compounds with Z = H, Y = F, Cl or Br, R2 = (C1-C11)-alkoxy, A1 and A2 = phenyl, n1 and n3 = 1 and n2 = O.
The electron-attracting substituents Y are meant especi-ally to include the CF3 and OCH3 group and also halo-2~ gens sùch as Cl or Br or the C~ group.
The said compounds are chiral ~-mono- or di-substituted phenylacetates or phenylpropionates (i.e. substituted in the 2-position of a chiral phenylalkanoic acid) of phen-ols (or comparable heterocyclic compounds) or cycloalka-nols.
The stated object is also achieved by a twistable liquid crystal phase containing at least one chiral compound which comprises, as the chiral compound, at least one compound of the general formula (I). The term "twistable liquid crystal phase" is to be understood as nematic, cholesteric or tilted smectic, in particular SmC, phases.
The twistable liquid crystal phases compr;se 2 to 20 and preferably 2 to 15 components, including at least one of the chiral compounds claimed according to the inven-tion. The other constituents are preferably selected from the known compounds showing nemat;c, cholester;c ~ ~88093 . . ~
and/or tilted smectic phases; these include, for example, Schiff bases, biphenyls, terphenyls, phenylcyclohexanes, cyclohexylbiphenyls, pyrimidines, cinnamates, cholester-ol esters and variously bridged, terminal-polar polynu-clear esters of p-alkylbenzoic acids. In general, the commercially available liquid crystal phases, even be-fore the addition of the chiral compound(s), are mixtures of the most diverse components, of ~hich at least one is mesogenic, i.e. a compound which, in a derivatized form or as a mixture with certain cocomponents, shows a li-quid crystal phase [= formation of at least one enantio-tropic (clear point > melting point) or monotropic (clear point ~ melting point) mesophase].
Amongst the compounds of the general formula (I), those are preferred in which the symbols have the following meanings:
R2 = straight-chain (C4-C10)-alkyl, it being possible for one CH2 group to be replaced by an O or S atom, A1 and A2 = ;ndependently of one ~nother unsubstituted 1,4-phenylene, 1,4-cyclohexylene or pyrimidine-2,5-diyl, B = CO-O or O-CO, n1 = 1, n2 = 0 or 1 and n3 = 1 or 2, Y = CF3 and Z = OCH3, or Y = OCH3 and Z = H, and R1 =
unsubstituted phenyl.
The compounds according to the invention are advantage-ously prepared by reacting mesogenic compounds of the formula (III) or (III') MOH (III) (MO)mMe (III') ~herein MO is as defined above, Me is an alkaline earth metal or preferably an alkali metal and m = 1 (Me =
alkali metal) or m = 2 (Me = alkaline earth metal), ~ith compounds of the formula (IV) z X -CO-b-R1 ( IV) y ~ '~880~3 in which xf is an OH group or halogen, preferably chlo-rine, and Z and Y are as defined above.
Preferably, mesogenic hydroxy compounds (III) and acid chlorides (IV; xf = Cl) are used for preparing the com-pounds, the reaction taking place in the presence ofacid acceptors such as amines, for example pyridine or triethylamine, or of alkaLi metal or alkaline earth metal (hydrogen) carbonates, in general at temperatures be-tween -40C and +70C. It is also possible, however, to react the mesogenic hydroxy compound (III) with the car-boxylic acid (IV, xf = OH) itself, namely in the presenc~
of Bro'nstedt or Lewis acids, if appropriate in the pre-sence of dehydrating agents, or with the aid of condens-ing reagents such as N,N'-carbonyldiimidazole, dicyclo-hexylcarbodiimide or azodicarboxylate/triphenylphosphine.
Finally, compounds (I) are also obtained by reactingalkali metal or alkaline earth metal salts of the meso-genic hydroxy compound (III') with the carboxylic acid halide (IV, xf = halogen).
The crude product (I) obtained can be purified in a rnan-ner known per se, for example by recrystallization or column chromatography.
The liquid crystal phases contain in general 0.0~ to 7D%
by weight, especially 0.05 to 50% by weight, of the com-pound or compounds according to the invention.
The compounds according to the invention are suitable especially as doping substances for tilted smectic li-quid crystal phases, since they convert the latter into ferroelectric liquid crystal phases.
Examples 1 to 4 The phenol or cycloalkanol component is d;ssolved in pyridine, and an equimolar quantity of (-)-2-methoxy-2-trifluoromethyl-2-phenyl-ethanoyl chloride is added drop-WisQ. ~hile excluding moisture, the mixture is then heated for 60 minutes to 65C and then stirred for 12 hours at room temperature. Subsequently, the mixture is poured into ice water, acidified with concentrated hydro-chloric acid and extracted with ether several times, and the combined ether phases are washed with aqueous NaHC03 solution. After drying of the ether phases over MgS04, concentrating to a smaller volume and supersaturating the phases with petroleum ether, the following products crystallize out in a refrigerator:
(1 ) C7H15 ~ OCH3 ( 2, CgH 1 9 ~N~ OCH~
(3) CgH19~0 ~- O - C - C -~
( 4 ) C7H 1 5-~ C-O~C - C~) Examples 5 and 6 -R-(-)-2-Methoxy-2-phenyl-ethanoic acid in benzene is heated with SOCl2 for 1 hour under reflux and then con-centrated in vacuo, and the residue is taken up in abso-lute benzene. A solution of the phenol or cycloalkanol component in benzene is added and the reaction m;xture is treated with pyridine. It ;s then st;rred for 12 hours, poured into water and extracted with ether by shaking, and the organic phase is treated successively with aqueous K2C03 solution, aqueous saturated NaCl solution, aqueous 3N HCl solution and aqueous saturated NaCl solution. It is then dried (over MgS04) and concentrated, and the reac-tion product is purified by column chromatography onsilica gel with methylene chloride as the mobile phase.
(5) C7H15 ~ ~ ~ _ O - C - C
O H
(6 ) C9H19 _ o ~_ o _ C - C
Example Melting point ~a]D in Ps (C) CHCl3 (nC x cm 2)/
at C
1 51 ~55 Z 40.5 +54 5.6t75 3 42 - 9.6/76 4 39 - 6.6/70 6 68 -70 14.0/70 The spontaneous polarization (Ps) is determined in the SmC phase of the commercially available compound "HEPTOA~"
~manufacturer, for example, Frinton - USA) having the characteristic data "C 74.4 SmC 95.4 N 124.2 1", 10 mol%
of the particular doping substance being added.
HEPTOAP 7H15 0 ~ -N=N ~ 7 15 Example 7 The compounds according to the invention are also very suitable for inducing a cholesteric helix structure in ~.~88~)9~3 a nematic liquid crysta~ phase, in order to exert a posi-tive influence, for example as described at the outset, on the temperature dependence of the electro-optical characteristic of liquid crystal displays.
To determine the twisting capacity, compound (III) was added to a commercially available nematic wide-range mix-ture - "R0-TN 404" from Hoffmann-La Roche Aktiengesell-schaft (~asel/Switzerland) - having a clear point of 104C.
The values of the twisting capacity in the nematic liquid crystal phase in ~m.% by weight (= p.c) are:
Measuring temperature tC~ 10 20 30 40 50 60 p . c ~m.% by weight~ -12.3 -12.3 -12~4 -12.5 -12.5 -12.6
( 4 ) C7H 1 5-~ C-O~C - C~) Examples 5 and 6 -R-(-)-2-Methoxy-2-phenyl-ethanoic acid in benzene is heated with SOCl2 for 1 hour under reflux and then con-centrated in vacuo, and the residue is taken up in abso-lute benzene. A solution of the phenol or cycloalkanol component in benzene is added and the reaction m;xture is treated with pyridine. It ;s then st;rred for 12 hours, poured into water and extracted with ether by shaking, and the organic phase is treated successively with aqueous K2C03 solution, aqueous saturated NaCl solution, aqueous 3N HCl solution and aqueous saturated NaCl solution. It is then dried (over MgS04) and concentrated, and the reac-tion product is purified by column chromatography onsilica gel with methylene chloride as the mobile phase.
(5) C7H15 ~ ~ ~ _ O - C - C
O H
(6 ) C9H19 _ o ~_ o _ C - C
Example Melting point ~a]D in Ps (C) CHCl3 (nC x cm 2)/
at C
1 51 ~55 Z 40.5 +54 5.6t75 3 42 - 9.6/76 4 39 - 6.6/70 6 68 -70 14.0/70 The spontaneous polarization (Ps) is determined in the SmC phase of the commercially available compound "HEPTOA~"
~manufacturer, for example, Frinton - USA) having the characteristic data "C 74.4 SmC 95.4 N 124.2 1", 10 mol%
of the particular doping substance being added.
HEPTOAP 7H15 0 ~ -N=N ~ 7 15 Example 7 The compounds according to the invention are also very suitable for inducing a cholesteric helix structure in ~.~88~)9~3 a nematic liquid crysta~ phase, in order to exert a posi-tive influence, for example as described at the outset, on the temperature dependence of the electro-optical characteristic of liquid crystal displays.
To determine the twisting capacity, compound (III) was added to a commercially available nematic wide-range mix-ture - "R0-TN 404" from Hoffmann-La Roche Aktiengesell-schaft (~asel/Switzerland) - having a clear point of 104C.
The values of the twisting capacity in the nematic liquid crystal phase in ~m.% by weight (= p.c) are:
Measuring temperature tC~ 10 20 30 40 50 60 p . c ~m.% by weight~ -12.3 -12.3 -12~4 -12.5 -12.5 -12.6
Claims (6)
1. A chiral ester of an .alpha.-substituted phenylalkanoic acid and a mesogenic hydroxy compound, wherein, in the formu-la I
(I) the symbols are defined as follows:
MO = molecular radical of a mesogenic hydroxy compound MOH after removal of one H, the radical MO being expressed by the formula (II) R - (A1)n1 - (B-)n2(A2)n3 - O (II) where R2 = straight-chain or branched (C1-C12)-alkyl, it being possible for one or two non-adjacent CH2 groups to be replaced by O and/or S
atoms, or, if n1 = 1, also F, Cl, Br, CN or CF3, A1, A2 = independently of one another 1,4-phenyl-ene, diazine-2,5-diyl, diazine-3,6-diyl, 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, 1,3-di-thiane-2,5-diyl or 1,4-bicyclo(2,2,2)octylene, it being possible for these groups also to be at least monosubstituted by F, Cl, Br, CN, CF3 and/or (C1-C12)-alkyl (one or two non-adjacent CH2 groups may be replaced by O
and/or S atoms), B = CO-O, O-CO, CH2-CH2, OCH2, CH2O, CH-N, N=CH, N=N, N(O)=N, n1, n2, n3 = independently of one another 0, 1 or 2, n1 and n3 not being 0 simultaneously, Y = an electron-attracting substituent, Z = H or an electron-attracting substituent, but not identical with Y, and R1 = benzyl or phenyl, it being possible for these groups to be substituted in the aromatic moiety in the same way as A1 and A2, with the exception of the compounds with Z = H, Y = F, Cl or Br, R2 = (C1-C11)-alkoxy, A1 and A2 = phenyl, n1 and n3 = 1 and n2 = 0.
(I) the symbols are defined as follows:
MO = molecular radical of a mesogenic hydroxy compound MOH after removal of one H, the radical MO being expressed by the formula (II) R - (A1)n1 - (B-)n2(A2)n3 - O (II) where R2 = straight-chain or branched (C1-C12)-alkyl, it being possible for one or two non-adjacent CH2 groups to be replaced by O and/or S
atoms, or, if n1 = 1, also F, Cl, Br, CN or CF3, A1, A2 = independently of one another 1,4-phenyl-ene, diazine-2,5-diyl, diazine-3,6-diyl, 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, 1,3-di-thiane-2,5-diyl or 1,4-bicyclo(2,2,2)octylene, it being possible for these groups also to be at least monosubstituted by F, Cl, Br, CN, CF3 and/or (C1-C12)-alkyl (one or two non-adjacent CH2 groups may be replaced by O
and/or S atoms), B = CO-O, O-CO, CH2-CH2, OCH2, CH2O, CH-N, N=CH, N=N, N(O)=N, n1, n2, n3 = independently of one another 0, 1 or 2, n1 and n3 not being 0 simultaneously, Y = an electron-attracting substituent, Z = H or an electron-attracting substituent, but not identical with Y, and R1 = benzyl or phenyl, it being possible for these groups to be substituted in the aromatic moiety in the same way as A1 and A2, with the exception of the compounds with Z = H, Y = F, Cl or Br, R2 = (C1-C11)-alkoxy, A1 and A2 = phenyl, n1 and n3 = 1 and n2 = 0.
2. A chiral ester as claimed in claim 1, wherein, in the formula (I), the symbols are defined as follows: R2 =
straight-chain (C4-C10)-alkyl, it being possible for one CH2 group to be replaced by an O or S atom, A1 and A2 = independently of one another unsubstituted 1,4-phenyl-ene, 1,4-cyclohexylene or pyrimidine-2,5-diyl, B = CO-O
or O-CO, n1 = 1, n2 = 0 or 1 and n3 = 1 or 2, Y = CF3 and Z = OCH3 or Y = OCH3 and Z = H, and R1 = unsub-stituted phenyl.
straight-chain (C4-C10)-alkyl, it being possible for one CH2 group to be replaced by an O or S atom, A1 and A2 = independently of one another unsubstituted 1,4-phenyl-ene, 1,4-cyclohexylene or pyrimidine-2,5-diyl, B = CO-O
or O-CO, n1 = 1, n2 = 0 or 1 and n3 = 1 or 2, Y = CF3 and Z = OCH3 or Y = OCH3 and Z = H, and R1 = unsub-stituted phenyl.
3. A twistable liquid crystal phase containing at least one chiral compound, which comprises at least one chiral compound of the formula (I) as claimed in claim 1.
4. A liquid crystal display element, containing a liquid crystal phase as claimed in claim 3.
5. The use of a chiral compound of the formula (I) as claim-ed in claim 1, for converting a tilted smectic liquid crystal phase into a ferroelectric liquid crystal phase.
6. A process for converting a tilted smectic liquid crystal phase into a ferroelectric liquid crystal phase by add-ing at least one chiral compound, which comprises adding at least one compound of the formula (I) as claimed in claim 1 to the liquid crystal phase.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3620049.2 | 1986-06-14 | ||
| DE19863620049 DE3620049A1 (en) | 1986-06-14 | 1986-06-14 | CHIRAL ESTERS MADE FROM (ALPHA) SUBSTITUTED PHENYL ALKANIC ACIDS AND MESOGENIC HYDROXYL COMPOUNDS AND THEIR USE AS A DOPER IN LIQUID CRYSTAL PHASES |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1288093C true CA1288093C (en) | 1991-08-27 |
Family
ID=6303004
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000539575A Expired - Fee Related CA1288093C (en) | 1986-06-14 | 1987-06-12 | CHIRAL ESTERS OF .alpha.-SUBSTITUTED PHENYLALKANOIC ACIDS AND MESOGENIC HYDROXY COMPOUNDS, AND THEIR USE AS A DOPING SUBSTANCE IN LIQUID CRYSTAL PHASES |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4874545A (en) |
| EP (1) | EP0250961B1 (en) |
| JP (1) | JP2593875B2 (en) |
| AT (1) | ATE78472T1 (en) |
| CA (1) | CA1288093C (en) |
| DE (2) | DE3620049A1 (en) |
| ES (1) | ES2044869T3 (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3627964C2 (en) * | 1985-08-26 | 2000-11-02 | Samsung Electronic Devices | Ferroelectric crystalline-liquid derivatives of branched acyclic chiral alpha-chlorocarboxylic acids, processes for their preparation and their use in mixtures for fast-switching displays in optoelectronics |
| GB8623582D0 (en) * | 1986-10-01 | 1986-11-05 | Secr Defence | Mandelic acid derivatives |
| JPH07116131B2 (en) * | 1987-06-15 | 1995-12-13 | チッソ株式会社 | Thioether compound and liquid crystal composition |
| US5536442A (en) * | 1987-09-25 | 1996-07-16 | Merck Patent Gesellschaft Mit Beschrankter Haftung | Fluorinated liquid crystal compounds and liquid crystal medium containing same |
| DE3909802A1 (en) * | 1988-07-27 | 1990-04-05 | Merck Patent Gmbh | DIFLUORMETHYLVERBINDUNGEN |
| US5324449A (en) * | 1987-09-25 | 1994-06-28 | Merck Patent Gesellschaft Mit Beschrankter Haftung | Substituted phenyl trifluoromethyl ethers |
| JPH0830023B2 (en) * | 1988-05-19 | 1996-03-27 | 株式会社ジャパンエナジー | Novel biphenyl compound, liquid crystal composition containing the same, and optical switching device |
| US5211879A (en) * | 1989-11-07 | 1993-05-18 | Nippon Mining Co., Ltd. | Ester compounds and liquid crystal compositions containing the same |
| US5128061A (en) * | 1990-08-14 | 1992-07-07 | Optical Shields, Inc. | Phenyl-pyrimidine liquid crystal materials |
| JP3081024B2 (en) * | 1991-07-11 | 2000-08-28 | 株式会社リコー | Optically active azo compound and liquid crystal composition containing the same |
| US5547605A (en) * | 1993-12-15 | 1996-08-20 | Hoechst Aktiengesellschaft | 2-Aryloxytetrafluoropropionic esters, process for their preparation, and their use in liquid-crystalline mixtures |
Family Cites Families (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4613209A (en) * | 1982-03-23 | 1986-09-23 | At&T Bell Laboratories | Smectic liquid crystals |
| DE3377219D1 (en) * | 1982-11-26 | 1988-08-04 | Hitachi Ltd | Smectic liquid crystal compounds and liquid crystal compositions |
| DE3333677A1 (en) * | 1983-09-17 | 1985-04-04 | Merck Patent Gmbh, 6100 Darmstadt | LIQUID CRYSTAL PHASE |
| US4686305A (en) * | 1984-03-07 | 1987-08-11 | Chisso Corporation | 4'-substituted-phenyl α-methyl-β-(4-substituted-phenyl) propionates |
| JPS60218358A (en) * | 1984-04-13 | 1985-11-01 | Ajinomoto Co Inc | Liquid crystal |
| DE3577211D1 (en) * | 1984-06-07 | 1990-05-23 | Seiko Instr Inc | LIQUID CRYSTAL CONNECTION. |
| JPS6117541A (en) * | 1984-07-03 | 1986-01-25 | Seiko Instr & Electronics Ltd | Liquid crystal compound |
| EP0168043B1 (en) * | 1984-07-11 | 1990-11-07 | MERCK PATENT GmbH | Liquid crystal phase |
| EP0174816B1 (en) * | 1984-09-10 | 1990-05-23 | Ajinomoto Co., Inc. | Biphenyl-based diester compounds and liquid crystal compositions containing same |
| JPH0717904B2 (en) * | 1985-01-29 | 1995-03-01 | 旭硝子株式会社 | Ferroelectric liquid crystal composition |
| DE3683062D1 (en) * | 1985-02-08 | 1992-02-06 | Ajinomoto Kk | POLYPHENYL-BASED ESTER COMPOUNDS AND LIQUID CRYSTALLINE COMPOSITIONS CONTAINING THEM. |
| DE3534778A1 (en) * | 1985-09-30 | 1987-04-02 | Hoechst Ag | CHIRAL ESTER OF MESOGENIC CARBONIC ACIDS, A METHOD FOR THE PRODUCTION THEREOF AND THEIR USE AS A DOPER IN LIQUID CRYSTAL PHASES |
| JPS62111950A (en) * | 1985-11-08 | 1987-05-22 | Ajinomoto Co Inc | Liquid crystal |
| DE3689329T2 (en) * | 1985-12-04 | 1994-07-07 | Ajinomoto Kk | Compounds based on the phenylpyrimidines and liquid-crystalline compositions containing them. |
| JPS62142131A (en) * | 1985-12-13 | 1987-06-25 | Ajinomoto Co Inc | Liquid crystal intermediate |
| DE3618213A1 (en) * | 1986-05-30 | 1987-12-10 | Hoechst Ag | Chiral esters of alpha -substituted carboxylic acids with mesogenic hydroxyl compounds, and their use as doping substance in liquid-crystalline phases |
| GB8623582D0 (en) * | 1986-10-01 | 1986-11-05 | Secr Defence | Mandelic acid derivatives |
-
1986
- 1986-06-14 DE DE19863620049 patent/DE3620049A1/en not_active Withdrawn
-
1987
- 1987-06-10 ES ES87108377T patent/ES2044869T3/en not_active Expired - Lifetime
- 1987-06-10 EP EP87108377A patent/EP0250961B1/en not_active Expired - Lifetime
- 1987-06-10 DE DE8787108377T patent/DE3780523D1/en not_active Expired - Fee Related
- 1987-06-10 AT AT87108377T patent/ATE78472T1/en not_active IP Right Cessation
- 1987-06-12 US US07/062,062 patent/US4874545A/en not_active Expired - Fee Related
- 1987-06-12 CA CA000539575A patent/CA1288093C/en not_active Expired - Fee Related
- 1987-06-12 JP JP62145423A patent/JP2593875B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| EP0250961B1 (en) | 1992-07-22 |
| EP0250961A2 (en) | 1988-01-07 |
| US4874545A (en) | 1989-10-17 |
| DE3620049A1 (en) | 1987-12-17 |
| DE3780523D1 (en) | 1992-08-27 |
| ES2044869T3 (en) | 1994-01-16 |
| ATE78472T1 (en) | 1992-08-15 |
| EP0250961A3 (en) | 1988-09-28 |
| JP2593875B2 (en) | 1997-03-26 |
| JPS632953A (en) | 1988-01-07 |
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