An optically active compound of the following general formula (1),
1
wherein A is —C≡C— or —COO—, each of R
1
and R
2
is independently C
n
H
2n+1
—, (C
2
H
5
)
2
CHCH
2
C*H(CH
3
)OOC—, C
m
H
2m+1
C*H(CH
3
)OOC— or C
6
H
5
C*H(CH
3
)OOC— in which n is an integer of 2 to 5, m is an integer of 5 to 9, C
6
H
5
— is phenyl group, and C* is an asymmetric carbon, provided that there is no case where R
1
and R
2
are together C
n
H
2n+1
— or C
6
H
5
C*H(CH
3
)OOC— and that when both R
1
and R
2
are C
m
H
2m+1
C*H(CH
3
)OOC—, m in C
m
H
2m+1
C*H(CH
3
)OOC— represented by R
1
and m in C
m
H
2m+1
C*H(CH
3
)OOC— represented by R
2
may be different integers.
The optically active compound of the present invention is excellently valuable as a chiral dopant since it has properties that its helical twisting power (HTP) is at least 9, that a helical pitch induced decreases with an increase in temperature and further that its birefringence (&Dgr;n) is large.
以下是通用公式(1)的一个光学活性化合物,其中A为—C≡C—或—COO—,R1和R2中的每一个独立地为CnH2n+1—,(
C2H5)2CHCH2C*H(
CH3)OOC—,CmH2m+1C*H( )OOC—或 C*H( )OOC—,其中n为2至5的整数,m为5至9的整数,
C6H5—为
苯基,C*为不对称
碳,前提是不存在R1和R2同时为CnH2n+1—或 C*H( )OOC—的情况,当R1和R2均为CmH2m+1C*H( )OOC—时,CmH2m+1C*H( )OOC—中的m由R1表示,CmH2m+1C*H( )OOC—中的m由R2表示,可能是不同的整数。本发明的光学活性化合物非常有价值,因为它作为手性掺杂剂具有以下特性:其螺旋扭转功率(HTP)至少为9,随着温度升高,诱导的螺距减小,而且其双折射(Δn)很大。