Patent ID: 7429411

Claim:
A compound represented by formula (1): wherein Ra and Rb independently are hydrogen, alkyl having 1 to 20 carbons, halogen, —CN, —C≡C—CN, —NCO, or —NCS, any —CH 2 — in the alkyl may be replaced with —O—, —S—, —CO— or —SiH 2 —, any —(CH 2 ) 2 — may be replaced by —CH═CH— or —C≡C—, and any of hydrogen may be replaced by halogen; rings A 1 , A 2 , A 3 , A 4 , A 5 and A 6 independently are 1,4-cyclohexylene, 1,4-phenylene, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, or naphthalene-2,6-diyl and, any —CH 2 — in these rings may be replaced by —O—, —S—, —CO— or —SiH 2 —, any —(CH 2 ) 2 — may be replaced by —CH═CH—, any —CH═ in 1,4-phenylene may be replaced by —N═, and any hydrogen in these rings may be replaced by halogen, —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , —OCHF 2 , or —OCH 2 F; Z 11 , Z 12 , Z 13 , Z 14 , Z 15 and Z 16 independently are a single bond or alkylene having 1 to 4 carbons and, any —CH 2 — in the alkylene may be replaced by —O—, —S—, —CO—, or —SiH 2 —, any —(CH 2 ) 2 — may be replaced by —CH═CH— or —C≡C—, and any hydrogen may be replaced by halogen; Y 1 and Y 2 independently are hydrogen, halogen, —CN, —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , —OCHF 2 , or —OCH 2 F, and Y 1 and Y 2 are not hydrogen at the same time; k, l, m, n, p and q independently are 0 or 1, and the sum of k, l, m, n, p and q is 1, 2 or 3; with the proviso that at least one of Z 11 , Z 12 , Z 13 , Z 14 , Z 15 and Z 16 is a group (q1), (q2) or (q3), in the case that Y 1 is fluorine, chlorine, —CF 3 , —CHF 2 , —OCF 3 or —OCHF 2 and Y 2 is fluorine, chlorine, —CF 3 , —CHF 2 , —OCF 3 or —OCHF 2 at the same time,