摘要:
Methods, based on the Wittig-Horner reaction, are provided for the synthesis of compounds of formula (I) where m is from 5-150, X and Y are independently selected from: CN, H, OH, COCH3, CO2H, CO2H, CO2R1, where R1 is C1-12 alkyl, NCS, SCN, CF3, CH2X where X is F, Cl, Br, OH, CHF2 and formula (IB), where J for each X and Y group is independently selected from: CH2, single covalent bond, OOC, CO2, O, CH2O, OCH2, CH2CO2, CH2OOC; p=1-20; L for each X and Y group is independently selected from: O, CH2OCO, CO2, S, NH; (a) is defined by formula (IC), where rings A, B and C are independently selected from phenyl, cyclohexyl, pyridine and pyrimidine and may be independently of each other substituted with at least one of Cl or F; linking groups A and B may be selected from single bond, CO2, OOC, CH2O, OCH2, CH2CH2, C≡C; Z is selected from CN, F, Cl, NO2, R, OR, CO2R, CF3, OOCR, NCS, SCN, where R=straight chain or branched chain alkyl and may include from 1-16 carbon atoms and including where one or more non-adjacent CH2 groups may be substituted by CH(CN), CH(CF3), CH(Cl), CH(CH3) in chiral or non-chiral form; provided that at least one of X and Y is selected from (IB); the method polymerizing a compound of general formula (II), where X and Y are defined as formula (I).
摘要:
Compounds of formula ##STR1## are provided which may be used in a variety of devices including liquid crystal devices, piezoelectric devices, pyroelectric devices and in optical recording media, where m=at least 5; and R.sub.x, R.sub.y and R.sub.z are independently from formula (IA), ##STR2## where Y is selected from COO, OCO, O, S, CHOH, CHF, CH.sub.2 ; Q=(CH.sub.2).sub.n wherein one or more non-adjacent methylenes may be replaced by O and n=1-20; Z is selected from O, S, a single covalent bond, COO, a OCO; when Y is CH.sub.2 then n may also be 0; formula (IB) is ##STR3## and represents any mesogenic group; and R.sub.x, R.sub.y and R.sub.z are also independently selected from H, OH, OCOR.sup.1, COOH, CO.sub.2 R.sup.1 (CH.sub.2).sub.p OH, (CH.sub.2).sub.p CO.sub.2 H, --(CH.sub.2).sub.p OR.sup.1 or --(CH.sub.2).sub.p CO.sub.2 R.sup.1 and p=1-20, R.sup.1 =H or C.sub.1-16 alkyl, when R.sup.1 =C.sub.2-16 alkyl the terminal CH.sub.3 group may be replaced by Br or Cl; provided that at least one of and R.sub.x, R.sub.y and R.sub.z is selected from formula (IA).
摘要:
Laterally cyano-substituted terphenyls of formula (I), wherein R.sup.1 and R.sup.2 are independently selected from hydrogen or C.sub.1-15 alkyl, alkoxy, or alkyl or alkoxy in which one or more CH.sub.2 groups are replaced by O, COO, OOC, CHX, CX.sub.2, CH=CX, CX=CH, CX=CX, where X is fluorine or chlorine. CRCN where R is alkyl, or C.tbd.C or in which a terminal CH.sub.3 of the said alkyl or alkoxy chain is replaced by CF.sub.3, n is 0 or 1, and the CN and F (if present) substituent are independently located in any of the available substitution positions. Liquid crystal materials containing these terphenyls are also described.
摘要:
Compounds which may be used as a dopant or host in a ferroelectric chiral smectic liquid crystal mixture. The compounds are characterized in that they are derivates of an X-hydroxy carboxylic acid and contain the chiral unit (I), in which Ro may be alkyl, alkoxy, halogen, formula (II), where b may be 0 to 3 and the phenyl ring may be substituted, and a is 0 or 1. The chiral unit is combined with a range of mesogenic combinations of groups. Lactic acid derivatives are described in detail (i.e. Ro.dbd.methyl) together with various preparative routes, for example the compound formula (III), which has dopant properties in a range of hosts.
摘要:
A compound suitable for use in a ferroelectric smectic liquid crystal composition having a structure which contains two chiral centers derived from alpha hydroxy carboxylic acid groups and having the formula: ##STR1## wherein R.sub.1 is n-alkoxy containing 1-12 carbo atoms and R.sub.2 is n-alkyl containing 1-12 carbon atoms. Methods of preparation and details of liquid crystal mixtures containing these compounds are described.
摘要:
Novel derivatives of cyclic and acyclic terpenoid alcohols, having general formula (I) X--(CO).sub.n --O--T.sub.1, where n=O or l, T.sub.1 is a terpenoid group and X is a combination of cyclic groups, e.g. phenyl, cyclohexyl and pyrimidyl, X preferably contains up to three cyclic groups. Preferred derivatives are esters of cyclic terpenoid alcohols, e.g. menthol, borneol and isopineocampheol, e.g. formula (II) (-)-menthol. Ferroelectric smectic liquid crystal mixtures and devices containing these derivatives as chiral dopants in a tilted smectic host are also described. The properties of various other derivatives of terpenoid alcohols of formula (I) are also described, e.g. those of neomenthol, isolongifolol, fenchol, carveol, myrthenol, nopol, citronellol, perilla alcohol and dihydrocitronellol.
摘要:
The invention relates to the use of chiral and/or achiral compounds, containing at least one structural element from the group comprisingthiazole-2,4-diylthiazole-2,5-diyl1,2,4-thiadiazole-2,5-diyl1,2,4-thiadiazole-3,5-diylas components of media having a smectic liquid-crystalline phase.
摘要:
Compounds suitable for use as constituents of ferroelectric smectic liquid crystal compositions, which are esters of formula (I), where R.sub.2 and R.sub.3 together represent the residue of an alicyclic hydrocarbon ring system where .degree.C. is an asymmetric carbon atom and X is a chain of up to three linked aromatic or alicyclic six-membered organic cyclic groups, laterally and/or terminally substituted. Preferred compounds have a formula (II), where R.sub.1 is alkyl or alkoxy, A, B, and D are phenyl, fluoro or chloro substituted phenyl or cyclohexyl, n is 0 or 1, Y is a bond or CH.sub.2 CH.sub.2 if n is 0, or a bond CH.sub.2 CH.sub.2 COO or COO if n is 1. Preferred groups C(CN)R.sub.2 R.sub.3 are formula (III) and (IV).
摘要:
Amides having the following structure: ##STR1## used in ferroelectric smectic liquid crystal mixtures, especially as pitch compensators and liquid crystal compositions containing them.
摘要:
Novel lactic acid derivatives which may be used as a component of a ferroelectric smectic liquid crystal mixture, which derivatives have the general formula: ##STR1## in which R.sub.1 is alkyl or alkoxy and R.sub.2 is alkyl. Liquid crystalline compositions containing these compounds are also described.