Compounds capable of shortening the response time of liquid crystal display elements have the formula:
wherein
X is a hydrogen or halogen atom or a cyano or methyl group;
Ar is a group -COO- or CH₂O-;
R² is a C₁-C₁₈ alkyl, C₂-C₁₈ alkanoyl, C₃-C₁₈ alkoxycarbonyl or C₄-C₁₈ 2-alkoxy-propanoyl group;
and the carbon atoms having a symbol * thereon is an asymmetric carbon atom;
provided that when R² is a linear alkyl group and A is a group -COO-, Ar is not a 1,4-phenylene group.
能够缩短液晶显示元件响应时间的化合物具有以下式子:
其中
X 是氢原子或卤素原子或
氰基或甲基;
Ar 是基团 -COO- 或 CH₂O-;
R² 是 C₁-C₁₈ 烷基、C₂-C₁₈ 烷酰基、C₃-C₁₈ 烷氧羰基或 C₄-C₁₈ 2- 烷氧基丙酰基;
其中符号 * 的碳原子为不对称碳原子;
但当 R² 为直链烷基且 A 为基团-COO-时,Ar 不是 1,4-亚苯基基团。