New pyridinium type thermotropic ionic liquid crystal materials having
a 1,3-oxathiane ring in the central core, N-ethyl-4-( 5-alkyl-1,3-oxa
thian-2-yl) pyridinium bromides 8, were synthesized. These compounds e
xhibited a smectic A phase over a very wide range including room tempe
rature (for example 8c: G - 30 S-A 21 I).