Surface-sensitive and polarization-dependent near-edge X-ray absorption fine structure (NEXAFS) measurements clearly reveal a preferred in-plane and out-of-plane orientation of phenyl and CO groups at the surface of rubbed polyimide films. The unidirectional molecular alignment at the surface is argued to provide the template for liquid crystal (LC) alignment of the films. Both the LC orientation along the rubbing direction as well as the direction of the out-of-plane LC pretilt are explained in a simple model. In this model the LC direction follows the preferential orientation of the phenyl rings at the surface. The preferred phenyl orientation is explained in terms of preferential chain segment alignment through a pulling action of the rubbing cloth fibers. The proposed LC alignment model is based on the existence of a statistically significant unidirectional bond asymmetry at the polymer surface, and it does not require the existence of crystalline order.

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Ordering transitions are observed in azo-dendrimer-dissolved nematic liquid crystal (NLC) droplets dispersed in a glycerol matrix. The dendrimer molecules are spontaneously attached at the interface between NLC and glycerol, so that the nematic directors orient perpendicular to the interface, in the radial confi guration. Photoisomerization makes the directors be tangential to the interface, in a photoinduced ordering transition from radial to bipolar structure. Similar experiments are conducted both in cholesteric (Ch) and smectic-A (SmA) LC droplets. Complicated photoinduced ordering transitions are also observed in Ch and SmA droplets, and the associated molecular orientation changes are discussed. Photoisomerizable azo-dendrimer molecules provide a possible way to control orientation, even in microdroplet systems in which the interface cannot be treated by conventional surface agents.

The enantiocontrolled total synthesis of (-)-haouamine B pentaacetate was accomplished via an optically active indane-fused β-lactam, which was prepared by a newly developed Friedel-Crafts reaction. Subsequent cleavage of the β-lactam and an intramolecular McMurry coupling reaction provided the core indane-fused tetrahydropyridine, which led to the elucidation of the structure, as proposed by Trauner and Zubía.

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