摘要:
An intermediate useful in the production of liquid crystal esters has a molecular structure ##STR1## in which of the groups R' and R" one is fluorine and the other is hydrogen, and in which R is an alkyl group having more than one carbon atom, an aryl substituted alkyl group or a cyclohexyl substituted alkyl group.These compounds may be prepared from the corresponding alkoxy compounds ##STR2## where R'" is a protective alkyl group such as methyl. These compounds may be used in the production of liquid crystal esters by a conventional esterification with carboxylic acids, or acid derivative, eg chloride, eg containing the radical ##STR3## where X is an alkyl group and ##STR4## is a benzene or cyclohexane ring.
摘要:
A liquid crystal ester has a structure: ##STR1## where X and Y are fluorine or hydrogen at least one being hydrogen, and Z is either:(a) ##STR2## where R.sub.2 is alkyl, alkoxy, alkylcarbonyloxy or alkoxycarbonyloxy(b) ##STR3## where R.sub.3 is an alkyl group. The ester may be prepared by a conventional esterification from the corresponding phenol ##STR4## and the corresponding acid chloride Z--COCl. The ester may be used in mixtures with other liquid crystal compounds for use in known electro-optic devices.
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:
The invention comprises liquid crystalline polyesters suited to be used as a medium for optical data storage, especially reversible (or erasable) optical data storage. The polyesters comprise the polycondensation product of an aliphatic dicarboxylic acid or a derivative thereof and propane diol which on its center carbon bears a mesogenic substituent comprising two rings, either alicyclic or aromatic. Preferably also the dicarboxylic acid or derivative thereof is mesogenically substituted. The invention further comprises a medium for optical data storage containing polyesters of the above type.
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.