Mesomorphic compound, liquid crystal composition and liquid crystal device

A mesomorphic compound represented by the following formula (I):

• ##STR33## wherein R.sub.1 and R.sub.3 denote methyl or a mesomorphic residual group represented by the following formula (II):
• B.paren open-st.Y.paren close-st..sub.P --A.paren open-st.X.paren close-st..sub.Q --C-- (II),
• wherein A is a mesogen group comprising at least two cyclic groups;
• B is a terminal flexible group;
• C is a spacer flexible group;
• and X and Y each is independently selected from the group consisting of --OCO--, --COO--, --CH.sub.2 O--, --OCH.sub.2 -- and --O--;
• and P and Q are independently 0 or 1, at least one of R.sub.1 and R.sub.3 being the mesomorphic residual group containing the terminal flexible group B having an optically active group of the formula:
• ##STR34## wherein R.sub.4 is an alkyl group having 1-12 carbon atoms.

A liquid crystal composition, comprising:

• at least one species of a mesomorphic compound represented by the following formula (I):
• ##STR36## wherein R.sub.1 and R.sub.3 denote methyl and R.sub.2 denotes a mesomorphic residual group represented by the following formula (II):
• B--(Y).sub.p --A--(X).sub.Q --C-- (II),
• wherein A is a mesogen group comprising at least two cyclic groups;
• B is a terminal flexible group;
• C is a spacer flexible group;
• X is selected from the group consisting of --OCO--, --COO--, --CH.sub.2 O--, --OCH.sub.2 -- and --O--;
• Y is selected from the group consisting of --OCO--, --COO--, --CH.sub.2 O--, --OCH.sub.2 -- and --O--;
• and P and Q are independently 0 or 1, the terminal flexible group B having an optically active group of the formula:
• ##STR37## wherein R.sub.4 is an alkyl group having 1-12 carbon atoms;
• n is an integer of 1-5;
• m is an integer of 1-10;
• and L is an integer of 1-100;
• and
• said mesomorphic compound has a number-average molecular weight of 500-1,000,000.

A liquid crystal composition, comprising:

• at least one species of a mesomorphic compound represented by the following formula (I):
• ##STR38## wherein R.sub.1 and R.sub.3 independently denote methyl or a mesomorphic residual group represented by the following formula (II):
• B--Y--.sub.P --A--X--.sub.Q C-- (II),
• wherein A is a mesogen group comprising at least two cyclic groups;
• B is a terminal flexible group;
• C is a spacer flexible group;
• and X and Y each is independently a bonding group selected from the group consisting of --OCO--, --COO--, --CH.sub.2 O--, --OCH.sub.2 -- and --O--;
• and P and Q are independently 0 or 1, at least one of R.sub.1 and R.sub.3 being the terminal flexible group B having an optically active group of the formula:
• ##STR39## wherein R.sub.4 is an alkyl group having 1-12 carbon atoms.