Liquid crystal compound, liquid crystal composition and liquid crystal display device

A compound represented by formula (1):

• wherein, in formula (1),
• R1 is alkyl having 1 to 15 carbons, in the alkyl, at least one of —CH2— may be replaced by —O— or —S—, at least one of —(CH2)2— may be replaced by —CH═CH—, and in the groups, at least one of hydrogen may be replaced by halogen;
• ring A1, ring A2, ring A3 and ring A4 are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, 2,6,7-trioxabicyclo[2.2.2]octane-1,4-diyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl, chroman-2,6-diyl, 2,3-dihydro-1H-indene-2,5-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, and at least one of hydrogen directly bonded with the above rings may be replaced by halogen;
• W1 is a group represented by formula (1a) or formula (1b);
• wherein, in formula (1a) and formula (1b),
• Y1 and Y2 are independently fluorine or chlorine, Y3, Y4 and Y5 are independently hydrogen, fluorine or chlorine, and at least two of Y3, Y4 and Y5 is fluorine or chlorine;
• and
• in formula (1),
• W2 is a group represented by formula (1c) or formula (1d);
• wherein, in formula (1c) and formula (1d),
• L1, L2, L3, L4 and L5 are independently hydrogen, fluorine or chlorine;
• and
• in formula (1),
• when W1 is represented by formula (1a) and W2 is represented by formula (1c), at least one of ring A1, ring A2, ring A3 and ring A4 is naphthalene-2,6-diyl in which at least one of hydrogen may be replaced by halogen;
• X1 is fluorine, —C≡N, —N═C═S or alkyl having 1 to 10 carbons in which at least one of hydrogen is replaced by fluorine, alkenyl having 2 to 10 carbons in which at least one of hydrogen is replaced by fluorine, alkoxy having 1 to 9 carbons in which at least one of hydrogen was replaced by fluorine, or alkenyloxy having 2 to 9 carbons in which at least one of hydrogen is replaced by fluorine;
• a, b, c and d are independently 0 or 1, and a sum of a, b, c and d is 0, 1, 2 or 3;
• Z1, Z2, Z3, Z4 and Z5 are independently a single bond or alkylene having 1-6 carbons, in the alkylene, at least one of —CH2— may be replaced by —O—, —S—, —CO— or —SiH2—, one or two of —CH2CH2— may be replaced by —CH═CH— or —C≡C—, and in the divalent groups, at least one of hydrogen may be replaced by fluorine or chlorine;
• and
• at least one of Z1 in the case where a is 1, Z2 in the case where b is 1, Z3 in the case where c is 1, Z4 in the case where d is 1, and Z5 is —CF2O—.