Seven new triphenylene discogens with a phenylpropionyloxy or 3-phenylpropenoyloxy side chain, C₁₈H₆(OC_nH_2n＋1)₅OC(O)R' [R'＝C≡CC₆H₅, n＝4～9 (1a～1f); R'＝CH＝CHC₆H₅, n＝6 (1g)], were synthesized. Their structures were characterized by ¹H NMR, IR spectra and elemental analy-sis. Their mesomorphism was investigated with differential scanning calorimetry and polarizing optical mi-croscopy. The result showed that all these triphenylene derivatives exhibited enantiotropic hexagonal co-lumnar mesophases. DSC investigations showed that the clearing points of the triphenylenes containing phenylpropionyloxy 1a～1f gradually decreased with n from 4 to 9. The compound 1g containing phenylpropenoyloxy has almost the same clear point with, but lower melting point and crystallization point and wider columnar mesophase range than its counterpart compound 1c.

Key words: triphenylene, phenylpropiolate, phenylpropenoate, hexagonal columnar mesophase, discotic liquid crystal