Known compounds showing negative dielectric anisotropy show negative dielectric anisotropy of relatively large values but are not satisfactory in view of the balance of the physical property as the liquid crystal material such as having low clearing point and showing high viscosity. The present invention intends to provide a liquid crystalline compound showing a negative dielectric anisotropy, as well as having excellent balance for physical property such as having relatively high clearing point, relatively low viscosity, appropriate optical anisotropy, and excellent compatibility with other liquid crystalline compounds.
The compound of the invention is a compound represented by Formula (1) or Formula (2). In the formulae, Ra and Rb each independently is hydrogen or alkyl of 1 to 20 carbon atoms, A1, A11, A12, A2, A21 and A22 each independently is a cyclic group, Y, W, Z11, Z12, Z2, Z21 and Z22 each independently is a bonding group, and j, k, m, n, p and q each independently is 0 or 1 and the sum of them is 1, 2 or 3;
已知的表现出负介电各向异性的化合物虽然具有相对较大的负介电各向异性值,但在物理性质方面的平衡方面并不令人满意,例如具有低清晰点和高粘度等液晶材料的物理性质。本发明旨在提供一种具有负介电各向异性的液晶化合物,以及具有相对较高的清晰点、相对较低的粘度、适当的光学各向异性和与其他液晶化合物具有良好的相容性等物理性质的卓越平衡的液晶化合物。本发明的化合物是由公式(1)或公式(2)表示的化合物。在公式中,Ra和Rb各自独立地是氢或1至20个碳原子的烷基,A1、A11、
A12、A2、A21和A22各自独立地是环状基团,Y、W、Z11、Z12、Z2、Z21和Z22各自独立地是连接基团,j、k、m、n、p和q各自独立地为0或1,它们的总和为1、2或3;