Liquid crystal compounds having bis(trifluoromethyl) phenyl rings, liquid crystal compositions and liquid crystal display devices
申请人:——
公开号:US20030077405A1
公开(公告)日:2003-04-24
The compound (1) having 2,3-bis(trifluoromethyl)-1,4-phenylene is stable chemically and has excellent miscibility with other liquid crystal compounds, large and negative dielectric anisotropy and proper optical anisotropy. A liquid crystal composition comprising the compound has large specific resistance and a large voltage holding ratio, and that the composition is useful for a liquid crystal display element. The compound (1) is represented by formula (1):
Ra&Parenopenst;A
1
—Z
1
&Parenclosest;
m
&Parenopenst;A
2
—Z
2
&Parenclosest;
n
—A
3
—Z
3
—A
4
—Rb (1)
wherein Ra and Rb independently are alkyl having 1 to 20 carbons, any —CH
2
— in the alkyl may be replaced by —O—, —S—, —CH═CH—, or —C≡C—, and any hydrogen may be replaced by halogen; A
1
, A
2
, A
3
, and A
4
independently are 1,4-cyclohexylene, 1,4-cyclohexenyleene, 1,3-dioxane-2,5-diyl, 1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, pyridazine-3,6-diyl, or 2,3-bis(trifluoromethyl)-1,4-phenylene, any hydrogen in these rings may be replaced by halogen, and at least one of A
1
, A
2
, A
3
, and A
4
is 2,3-bis(trifluoromethyl)-1,4-phenylene; Z
1
, Z
2
and Z
3
independently are a single bond, —(CH
2
)
2
—, —(CF
2
)
2
—, —COO—, —OCO—, —CH
2
O—, —OCH
2
—, —CF
2
O—, —OCF
2
—, —CH═CH—, —CF═CF—, —C≡C—, —(CH
2
)
4
—, —(CH
2
)
3
O—, or —Q(CH
2
)
3
—; m and n independently are 0 or 1.
化合物(1)具有2,3-双三氟甲基-1,4-苯基,具有良好的化学稳定性和与其他液晶化合物的优异溶解性,具有大且负的介电各向异性和适当的光学各向异性。包括该化合物的液晶组合物具有大的特定电阻和大的电压保持比,适用于液晶显示元件。该化合物(1)由式(1)表示:Ra&Parenopenst;A1—Z1&Parenclosest;m&Parenopenst;A2—Z2&Parenclosest;n—A3—Z3—A4—Rb (1),其中Ra和Rb分别是具有1至20个碳的烷基,烷基中的任何-CH2-都可以被- O-,-S-,- CH═ CH-或-C≡C-替换,并且任何氢可以被卤素替换; A1,A2,A3和A4独立地是1,4-环己烯,1,4-环己烯基,1,3-二氧杂环戊烷-2,5-二基,1,4-苯基,吡啶-2,5-二基,嘧啶-2,5-二基,吡嗪-3,6-二基或2,3-双三氟甲基-1,4-苯基,这些环中的任何氢均可以被卤素替换,并且A1,A2,A3和A4中至少有一个是2,3-双三氟甲基-1,4-苯基; Z1,Z2和Z3独立地是单键,-(CH2)2-,-(CF2)2-,-COO-,-OCO-,-CH2O-,-OCH2-,-CF2O-,-OCF2-,-CH═ CH-,-CF═ CF-,-C≡C-,-(CH2)4-,-(CH2)3O-或-Q(CH2)3-; m和n独立地为0或1。