Liquid crystalline thio-benzoic acid derivs. for dielectrics - esp. phenyl thio-benzoates, biphenyl thio-carboxylic acid esters and diphenylyl thio-benzoates

摘要

New thiobenzoates have formula (I):- (where R1 and R2 are 1-12C alkyl, alkoxy or alkyl mercapto, 2-12C alkanoyl, alkanoyloxy or alkoxycarbonyloxy, or one of these gps. is also -CN or -NO2. Nos. m and n are 1 or 2, provided n + m =3). (I) are either S-phenyl thiobenzoates, (Ia), biphenyl thiocarboxylic acid esters (Ib) or S-biphenylyl thiobenzoates (Ic): (I) are used as mixing components of liquid crystalline dielectrics for electro-optical indicator elements, working in twisted nematic cells or by dynamic scattering or phase deformation. (I) form, either along or with other mesomorphs, liquid-crystalline phases having m.pts. up to room temp. and clarifying points at higher temps. than known comparable mixts. An example describes prepn. of 4-n-heptyl-thiobenzoic acid-S-4-n-pentyl-phenyl ester from 4-n-heptyl benzoyl chloride and 4-n-pentyl-thiophenol.