Thiophene compound, liquid-crystalline medium and liquid-crystal display comprising the same

Liquid-crystalline medium characterized in that it comprises one or more compounds of formula T

• in which
• one of
• which is present, denotes
• and the other
• if present, denotes
• wherein the respective rings optionally may each be substituted by one or two alkyl groups,
• n denotes 1 or 2,
• RS denotes alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy preferably having 1 to 7 C atoms, wherein one —CH2— group may be replaced by cyclopropylene, 1,3-cyclobutylene, 1,3-cyclopentylene, 1,3-cyclo-pentenylene, alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl preferably having 2 to 7 C atoms, wherein one —CH2— group may be replaced by cyclopropylene, 1,3-cyclobutylene, 1,3-cyclopentylene, 1,3-cyclo-pentenylene, and
• XS denotes F, Cl, CN, NCS fluorinated alkyl, fluorinated alkenyl, fluorinated alkoxy or fluorinated alkenyloxy, the latter four groups preferably having 1 to 4 C atoms, preferably F, CF3 or OCF3.