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.
具有2,3-双(三氟甲基)-1,4-苯基的化合物(1)在化学上是稳定的,与其他液晶化合物具有出色的相容性,具有较大且负向的介电各向异性以及适当的光学各向异性。包含该化合物的液晶组合物具有较大的比电阻和较大的电压保持比,该组合物适用于液晶显示元件。该化合物(1)由以下式表示:Ra&Parenopenst;A1—Z1&Parenclosest;m&Parenopenst;A2—Z2&Parenclosest;n—A3—Z3—A4—Rb (1)其中Ra和Rb独立地是具有1至20个碳的烷基,烷基中的任何—CH2—可被—O—、—S—、—CH═CH—或—C≡C—替代,任何氢可被卤素替代;A1、A2、A3和A4独立地是1,4-环己烯基、1,4-环己烯基、1,3-二氧杂环己烷-2,5-二基、1,4-苯基、吡啶-2,5-二基、嘧啶-2,5-二基、吡啶嗪-3,6-二基或2,3-双(三氟甲基)-1,4-苯基,这些环中的任何氢可被卤素替代,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。