| 摘要 |
Compounds of the formula: <IMAGE> I wherein R1 and R2 are independently straight-chain C1-C12-alkyl or when positioned on an aromatic ring R1 and R2 may also independently be straight-chain C1-C12-alkoxy, or one of R1 and R2 may also be a group of the formula: <IMAGE> II X1 and X2 are independently single covalent bonds or one of X1 and X2 may also be -CH2CH2-; rings A1 and A2 are independently 1,4-phenylene or, when X1 or X2 is -CH2CH2-, rings A1 and A2 may also independently be trans-1,4-cyclohexylene; and R3 is straight-chain C1-C12-alkyl or when positioned on an aromatic ring R3 may also be straight-chain C1-C12-alkoxy. Their manufacture and use in liquid crystalline mixtures are described.
|
