| 摘要 |
<p>Liquid-crystal compounds combining an extremely large negative value of permittivity anisotropy with a small value of optical anisotropy; a liquid-crystal composition containing the same; and a liquid-crystal display element formed from the liquid-crystal composition. The compounds are novel liquid-crystal compounds represented by general formula (1) having a 2,3-difluorophenyl moiety and the liquid-crystal composition contains any of the novel liquid-crystal compounds, while the liquid-crystal display element is formed from this liquid-crystal composition; wherein Ra and Rb each represents linear or branched C1-20 alkyl in which any methylene group may have been replaced with -O-, -CH=CH-, or -C C-, provided that each -O- does not neighbor another -O-; ring A1 represents cyclohexane-1,4-diyl in which any methylene group may have been replaced with -O-; ring A2 represents 2,3-difluoro-1,4-phenylene in which the hydrogen atoms at the 5- and 6-positions each may have been replaced with methyl or a fluorine atom; Z1 and Z2 each represents a single bond or -CH2CH2-; and Xa, Xb, Xc, and Xd each represents a hydrogen, fluorine, or chlorine atom, provided that at least one of them is a fluorine or chlorine atom.</p> |
