Minimization of free volume. Alignment of triptycenes in liquid crystals and stretched polymers.

Two triptycene derivs. were incorporated into a polyvinyl chloride (PVC) film or into the nematic phase of 4-(trans-4-pentylcyclohexyl)benzonitrile. The supramol. alignment taking place was visualized by polarized UV-vis and IR spectroscopy. The director axis of the nematic liq. crystal or the stretching direction of the polymer film are parallel to the the long axis of the guest mol. The degree of alignment for the 2 triptycene derivs. was detd. via the aspect ratio in comparison to anthracene. The alignment provided by the uniaxial PVC film was lower than that for the LC. A threading mechanism was proposed for the supramol. arrangement based on the minimization of the free vol. [on SciFinder(R)]