Phenylcyclohexanes and a liquid-crystalline medium

Abstract

Novel phenylcyclohexanes of the formula I in which n is 0 to 7, Q 1 and Q 2 are H, or one of these radicals is alternatively CH 3 , r is 0, 1, 2, 3, 4 or 5, A is trans-1,4-cyclohexylene, 1,4-phenylene, 3-fluoro-1,4-phenylene or a single bond, X is F, Cl, —CF 3 , —CN, —OCF 3 or —OCHF 2 , and Y and Z are each, independently of one another, H or F, with the proviso that, in the case where A is a single bond, Q 1 =Q 2 =H and simultaneously X=CN, Y and/or Z are F.

1 . Phenylcyclohexanes of the formula I  
       
         
           
           
               
               
           
         
       
       in which n is 0 to 7, Q 1  and Q 2  are H, or one of these radicals is alternatively CH 3 , r is 0, 1, 2, 3, 4 or 5, A is trans-1,4-cyclohexylene, 1,4-phenylene, 3-fluoro-1,4-phenylene or a single bond, X is F, Cl, —CF 3 , —CN, —OCF 3  or —OCHF 2 , and Y and Z are each, independently of one another, H or F, with the proviso that, in the case where A is a single bond, Q 1 =Q 2 =H and simultaneously X=CN, Y and/or Z are F:  
     
     
         2 . Phenylcyclohexanes according to  claim 1 , characterized in that X is F, Cl, —CF 3  or —OCF 3 .  
     
     
         3 . Phenylcyclohexanes according to at least one of  claims 1  to  2 , characterized in that Y=Z=H.  
     
     
         4 . Phenylcyclohexanes according to at least one of  claims 1  to  2 , characterized in that Y=F and Z=H or F.  
     
     
         5 . Phenylcyclohexanes according to  claim 1 , characterized in that X=CN, Y=F and Z=H or F.  
     
     
         6 . Use of the phenylcyclohexanes of the formula I according to  claim 1  as components of liquid-crystalline media for electrooptical displays.  
     
     
         7 . Liquid-crystalline medium for electrooptical displays having at least two liquid-crystalline components, characterized in that at least one component is a phenylcyclohexane of the formula I according to  claim 1 .  
     
     
         8 . Electrooptical display based on a liquid-crystal cell, wherein the liquid-crystal cell contains a medium according to  claim 7.