| abstract |
A tetracyclic compound expressed by the following general formula (1)wherein H1 to H12 represent hydrogen atom at least one of which is replaced by a halogen atom, when either H6 or H8 is replaced by a halogen atom, at least one of the remaining hydrogen atoms is replaced by a halogen atom; R1 and Y1 independently represent an alkyl group, alkoxy group, or alkoxyalkyl group having 1 to 20 carbon atoms, or an alkenyl group having 2 to 20 carbon atoms, one or more methylene group in R1 and Y1 may be replaced by oxygen atom, sulfur atom, dihydrosilylene group, dimethylsilylene group, -CH=CH-, or -C=C-; and X1, X2, and X3 independently represent a covalent bond, 1,2-ethylene group, or 1,4-butylene group; and a novel liquid crystal composition comprising the tetracyclic compound and having, at the same time, a wide temperature range of a nematic phase, high optical anisotropy, and high chemical stability. |