Liquid-crystalline, 2,5-disubstituted, 1,3,4-thiadiazoles with extended smectic C phases

US4952699A · kind A · utility

Assignee

• VEB Werk fuer Fernsehelektronik im VEB Kombinat Mikroelektronik · DE

Inventors

• Bak G Yong · Halle, BE
• Dietrich Demus · Halle, BE
• Horst Kresse · Halle, BE
• Annelore Madicke · Halle, BE
• Gerhard Pelzl · Halle (Saale), DE
• Wolfgang Schafer · Potsdam, DE
• Carsten Tschierske · Bodenwerder, DE
• Horst Zaschke · Halle, BE

Key dates

• Filing date: Jun 20, 1988
• Grant date: Aug 28, 1990
• Expiry date: Jun 20, 2008

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09K19/3497
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

2,5-substituted 1,3,4-thiadiazoles of the general formula ##STR1## The aforementioned compounds are used in amounts of 0.1 to 80 mole percent in mixtures for electrooptical arrangements for the modulation of transmitted and reflected light, as well as for the colored or black-and-white display of numerals, symbols and moving or still pictures. The compounds endow the liquid-crystalline mixtures with an extended phase field of the smectic C phase, negative dielectric anisotropy and the property of forming optically active C phases upon admixture with optically active compounds.