Smectic-Ofilms

An optical study of the smectic-O films which float on the free surface of droplets of racemate MHTAC [1(methyl)-heptyl-terephtalidene-bis-amino cinnamate] in the isotropic phase, is presented. It allows us to elucidate the herringbone structure of the molecules in this original liquid-crystal phase, and to estimate the dipole moment (∼5×${10}^{\mathrm{-}3}$ D) that the molecules bear in the first smectic layer in contact with the air.