Quinoxaline compound, liquid crystal composition containing the compound, liquid crystal device using the composition, display apparatus and display method

A quinoxaline compound represented by the following formula (I):

• R.sub.1 --A.sub.1 --X.sub.1 --A.sub.2 --X.sub.2 --A.sub.3 --R.sub.2(I),
• wherein
• R.sub.1 and R.sub.2 independently denote halogen or a linear or branched alkyl group having 2-18 carbon atoms capable of including one or non-neighboring two or more --CH.sub.2 -groups which can be replaced with --O--, --S--, --CO--, --CO--O--, --O--CO--, --CH.dbd.CH-- or --C.ident.C--;
• said linear or branched alkyl group being capable of including hydrogen which can be replaced with fluorine;
• X.sub.1 and X.sub.1 independently denote a single bond, --CO--O--, --O--CO--, --CH.sub.2 CH.sub.2 -- OR --C.ident.C--;
• A.sub.1, A.sub.2 and A.sub.3 independently denote a single bond, 1,4-phenylene, 1-4-phenylene having one or two substituents comprising F, Cl, Br, CH.sub.3, CF.sub.3 or CN;
• 1,4-cyclohexylene, pyrimidine-2,5-diyl, pyridine-2,5-diyl, thiophene-2,5-diyl, 2,6-naphthylene, thiazole-2,5-diyl, thiadiazole-2,5-diyl, pyrazine-2,5-diyl, pyridazine-3,6-diyl, benzothiazole-2,6-diyl, benzoxazole-2,5-diyl, indan-2,5-diyl, 2-alkylindan-2,5-diyl having a linear or branched alkyl group having 1-18 carbon atoms, coumaran-2,5-diyl, 2-alkylcoumaran-2,5-diyl having a linear or branched alkyl group having 1-18 carbon atoms, guinoxaline-2,6-diyl or quinoxaline-2,7-diyl;
• with the proviso that:
• at least one group of A.sub.1, A.sub.2 and A.sub.3 is quinoxaline-2,6-diyl or quinoxaline-2,7-diyl and the remaining two groups of A.sub.1, A.sub.2 and A.sub.3 cannot be a single bond simultaneously;
• and when A.sub.1 or A.sub.3 is quinoxaline-2,6-diyl and A.sub.2 is 1,4-phenylene, then the remaining A.sub.1 or A.sub.3 cannot be 1,4-phenylene.