Synthesis of novel sulfonyl-containing liquid-crystalline side-chain poly(vinyl ethers)

The synthesis of some new liquid-crystalline polymers with sulfonyl-containing mesogenic groups is described. 4-[(S)-(-)-2-MethylbutyIsulfonyl]-4′-[(11-vinyloxy)undecyloxy]biphenyl ( 10 -11), 4-[(S)-(-)-2-methylbutylsulfonyl]-4′-[8-(vinyloxy)octyloxy]biphenyl ( 10 -8), 4-[(S)-(-)-2- methylbutylsulfonyl]biphenyl 4-[11-(vinyloxy)undecyloxy]benzoate ( 12 -11), 4-[(S)-(-)-2-methylbutylsulfonyl]biphenyl 4-[8-(vinyloxy)octyloxy]benzoate ( 12 -8), 4-[(S)-(-)-2-methylbutyloxy]-4′- [11-(vinyloxy)undecylsulfonyl]biphenyl ( 18 -11) and 2-[11-(vinyloxy)undecyloxy]-6-{4-[(S)-(-)-2- methylbutylsulfonyl]phenyl}naphthalene ( 23 -11) were all synthesized, and polymerized with the initiating system CF₃SO₃H/S(CH₃)₂ in CH₃Cl₃ at 0°C. Monomers 10 -11, 10 -8, 18 -11 and 23 -11 are crystalline, while both 12 -11 and 12 -8 show an enantiotropic smectic A phase. All polymers exhibit the same thermotropic behaviour as their corresponding monomers, except poly( 23 -11) which exhibits an enantiotropic smectic A (s_A) and a monotropic chiral smectic C phase (S*_C).