Liquid crystal compound having chroman ring, liquid crystal composition comprising the compound and liquid crystal display device comprising the composition

Abstract

The present invention relates to a compound having a chroman ring, which has good thermal and optical stability, adequate optical anisotropy, adequate dielectric anisotropy and superior compatibility with other liquid crystal compounds, a liquid crystal composition comprising the compound, and a liquid crystal device comprising the composition. A compound represented by formula (1) below is provided: where Ris hydrogen or C-Calkyl; Ris halogen, —CN, alkyl (at least one hydrogen of which is replaced by halogen), alkenyl (at least one hydrogen of which may be replaced by halogen), or alkoxy (at least one hydrogen of which may be replaced by halogen); each of A, A, Aand Ais independently 1,4-cyclohexylene, 1,4-cyclohexenylene or 1,4-phenylene, in which any —CH— may be replaced by —O— or —S—, any —CH═ may be replaced by —N═ and any hydrogen may be replaced by halogen, methyl or —CF; each of Z, Z, Zand Zis independently a single bond or C-Calkylene; each of h, k, m and n is independently 0, 1 or 2, the sum of h, k, m and n being 1, 2 or 3; and Q is one of the group represented by formulas (q1), (q2) and (q3) below: where Xis hydrogen, halogen, methyl, ethyl, methoxy, ethoxy, —CF, —CFH, —CFH, —OCF, —OCFH, or —OCFH; and each of Y, Y, Y, Yand Yis independently hydrogen, halogen or methyl.