Optically active cyano-biphenyl compounds and liquid crystal materials containing them

• US 4,077,260 A
• Filed: 08/20/1976
• Issued: 03/07/1978
• Est. Priority Date: 09/03/1975
• Status: Expired due to Term

• Current Assignee: The secretary of state for defence in her Britannic Majesty's Government of the United Kingdom of Great Britain And Northern Ireland
• Original Assignee: The secretary of state for defence in her Britannic Majesty's Government of the United Kingdom of Great Britain And Northern Ireland
• Inventors: Gray, George William, McDonnell, Damien Gerard
• Primary Examiner(s): Schafer, Richard E.
• Assistant Examiner(s): Gron, T. S.
• Application Number:
  US05/716,300
• Time in Patent Office: 564 Days
• Field of Search: 252/299, 252/408, 350/154, 350/160 LC, 73/356, 260/465 C, 260/465 R
• US Class Current: 116/217
• CPC Class Codes: B41M 5/281 using liquid crystals only
• CPC Class Codes: C07C 17/12 in the ring of aromatic compounds
• CPC Class Codes: C07C 17/16 of hydroxyl groups
• CPC Class Codes: C07C 17/18 of oxygen atoms of carbonyl groups
• CPC Class Codes: C07C 17/35 by reactions not affecting the number of carbon or of halogen atoms in the reaction
• CPC Class Codes: C07C 19/075 containing bromine
• CPC Class Codes: C07C 25/18 Polycyclic aromatic halogenated hydrocarbons
• CPC Class Codes: C07C 49/813 polycyclic
• CPC Class Codes: C07C 51/15 by reaction of organic compounds with carbon dioxide, e.g. Kolbe-Schmitt synthesis
• CPC Class Codes: C07C 53/126 Acids containing more than four carbon atoms
• CPC Class Codes: C07F 3/02 Magnesium compounds
• CPC Class Codes: C09K 19/12 at least two benzene rings directly linked, e.g. biphenyls
• CPC Class Codes: C09K 19/126 Compounds containing at least one asymmetric carbon atom
• CPC Class Codes: G01K 11/165 of organic liquid crystals
• CPC Class Codes: G02F 1/13737 in liquid crystals doped with a pleochroic dye

Abstract

Liquid crystal compounds are disclosed having the formula ##STR1## where p is an integer having a value from 0 to 5 inclusive. These materials are optically active and cholesterogenic and may be used in an electro-optical display device either on their own or in admixture with nematogenic materials having a formula ##STR2## where i has a value from 0 to 5 inclusive and j is 0 or 1. These last mentioned mixtures may be thermochromic and employed in a temperature sensing device.

Claims

1. A liquid crystal material consisting essentially of an admixture of (1) one or more optically active biphenyl compounds having a positive optical rotation angle and having the formula:

##STR18## where p is an integer having a value of from 0 to 5 inclusive and (2) at least one optically active cholesterogenic compound different from (1) having a positive optical rotation angle and having the formula;

##STR19## where i is an integer having a value from 0 to 5 inclusive and j is 0 or 1.

2. A liquid crystal material as claimed in claim 1 wherein said cholesterogenic compound is a terphenyl wherein j is 1.

3. A liquid crystal material as claimed in claim 2 and wherein the cholesterogenic compound is

(+)-4-(3'"'"'"-methylpentyl)-4"-cyano-p-terphenyl.

4. A liquid crystal material as claimed in claim 2 and wherein the cholesterogenic compound is

(+)-4-(4'"'"'"-methylhexyl)-4"-cyano-p-terphenyl.

5. A liquid crystal material consisting essentially of a mixture of

(+)-4-(2"-methylbutyl)-4'"'"'-cyanobiphenyl and (+)-4-(3'"'"'"-methypentyl)-4"-cyano-p-terphenyl.

6. A liquid crystal material consisting essentially of a mixture of

(+)-4-(2"-methylbutyl)-4'"'"'-cyanobiphenyl and

(+)-4-(4'"'"'"-methylhexyl)-4"-cyano-p-terphenyl.

7. A liquid crystal material consisting essentially of a mixture of

(+)-4-(3"-methylpentyl)-4'"'"'-cyanobiphenyl and

(+)-4-(3'"'"'"-methylpentyl)-4"-cyano-p-terphenyl.

8. A liquid crystal material consisting essentially of a mixture of

(+)-4-(3"-methylpentyl)-4'"'"'-cyanobiphenyl and

(+)-4-(4'"'"'"-methylhexyl)-4"-cyano-p-terphenyl.

9. A liquid crystal material consisting essentially of a mixture of

(+)-4-(4"-methylhexyl)-4'"'"'-cyanobiphenyl and

(+)-4(3'"'"'"methylpentyl)-4"-cyano-p-terphenyl.

10. A liquid crystal material consisting essentially of a mixture of

(+)-4-(4"-methylhexyl)-4'"'"'-cyanobiphenyl and

(+)-4(4'"'"'"-methylhexyl)-4"-cyano-p-terphenyl.

11. A liquid crystal material consisting essentially of a mixture of

(+)-4-(2"-methylbutyl)-4"-cyanobiphenyl,

(+)-4-(4"-methylhexyl)-4'"'"'-cyanobiphenyl and

(+)-4-(3'"'"'"-methylpentyl)-4"-cyano-p-terphenyl.

12. A liquid crystal material consisting essentially of a mixture of

(+)-4-(2"-methylbutyl)-4'"'"'-cyanobiphenyl,

(+)-4-(4"-methyl hexyl)-4'"'"'-cyanobiphenyl and

(+)-4-(4'"'"'"-methyl hexyl)-4"-cyano-p-terphenyl.

13. A liquid crystal material consisting essentially of a mixture of

(+)-4-(3"-methylpentyl)-4'"'"'-cyanobiphenyl,

(+)-4(4"-methylhexyl)-4'"'"'-cyanobiphenyl and

(+)-4-(3'"'"'"-methylpentyl)-4"-cyano-p-terphenyl.

14. A liquid crystal material consisting essentially of a mixture of

(+)-4-(4"-methylhexyl)-4'"'"'-cyanobiphenyl,

(+)-4-(3"-methylpentyl)-4'"'"'-cyanobiphenyl and

(+)-4-(3'"'"'"-methylpentyl)-4"-cyano-p-terphenyl.

15. A liquid crystal material consisting essentially of a mixture of

(+)-4-(3"-methylpentyl)-4'"'"'-cyanobiphenyl,

(+)-4-(2"-methylbutyl)-4'"'"'-cyanobiphenyl,

(+)-4-(4"-methylhexyl)-4'"'"'-cyanobiphenyl and

(+)-4-(4'"'"'"-methylhexyl)-4"-cyano-p-terphenyl.

16. A temperature sensing device containing a cholesteric liquid crystal material consisting essentially of in admixture (1) one or more optically active biphenyl compounds having a positive optical rotation angle and having the formula:

##STR20## wherein p is an integer having a value from 0 to 5 inclusive and (2) at least one optically active cholesterogenic compound different from (1) having a positive optical rotation angle and having the formula;

##STR21## wherein i is an integer having a value from 0 to 5 inclusive and j is 0 or 1,

said liquid crystal material being sandwiched, in its Grandjean plane texture, between the inner surface area of two transparent slides.

17. A temperature sensing device as claimed in claim 16 and wherein the liquid crystal material consists of the following mixture

(+)-4-(3'"'"'"-methylpentyl)-4"-cyano-p-terphenyl -- 14% by weight

(+)-4-(3"-methylpentyl)-4'"'"'-cyanobiphenyl -- 86% by weight.

18. A temperature sensing device as claimed in claim 16 and wherein the liquid crystal material consists of the following mixture

(+)-4-(2"-methylbutyl)-4'"'"'-cyanobiphenyl -- 14% by weight

(+)-4-(4"-methylexyl)-4'"'"'-cyanobiphenyl -- 74% by weight

(+)-4-(4'"'"'"-methylhexyl)-4"-cyano-p-terphenyl -- 12% by weight.