Liquid crystalline compounds which have a wide temperature range of liquid crystal phase, low viscosity, and improved threshold voltage; liquid crystal compositions; and liquid crystal display devices comprising the composition can be provided; and the liquid crystalline compounds are expressed by the general formula (1)
Ra-A1-Z1-A2-Z2-A3-(Z3-A4)m-Rb (1)
wherein Ra represents an alkyl group having 1 to 20 carbon atoms one or more -CH2- in which alkyl group may be replaced by -O- or the like, and one or more hydrogen atoms in which alkyl group may be replaced by a halogen atom; Rb represents Ra, a halogen atom, or cyano group; A1, A2, A3, and A4 independently represent a divalent ring group; Z1, Z2, and Z3 independently represent an alkenylene group having 2 to 4 carbon atoms, -COO-, a covalent bond, or the like provided that at least one of Z1 to Z3 represents an alkenylene group having 2 to 4 carbon atoms, and at least one of Z1 to Z3 represents -COO- or -OCO-; and m is 0 or 1.
可提供液晶相温度范围宽、粘度低、阈值电压更高的液晶化合物、液晶组合物以及包含该组合物的液晶显示设备,液晶化合物由通式(1)表示
Ra-A1-Z1-A2-Z2-A3-(Z3-A4)m-Rb (1)
其中,Ra 代表具有 1 至 20 个碳原子的烷基,其中一个或多个-
CH2- 可以被-O- 或类似物取代,以及一个或多个氢原子,其中烷基可以被卤素原子取代;Rb 代表 Ra、卤素原子或
氰基;A1、A2、A3 和 A4 独立地代表二价环基;Z1、Z2 和 Z3 独立地代表具有 2 至 4 个碳原子的烯基、-COO-、共价键或类似物,条件是 Z1 至 Z3 中至少有一个代表具有 2 至 4 个碳原子的烯基,且 Z1 至 Z3 中至少有一个代表 -COO- 或 -OCO-;以及 m 为 0 或 1。