Solvent-Vapor Annealing of Conjugated Oligomers

Morphologically stable GLCs have been constructed with cyclohexane, benzene, bicyclooctene, adamantane, cubane, and the extended cores derived therefrom to which mesogenic and chiral groups are linked via ethylene or propylene spacers. A Tg and Tc close to 130 and 350 °C, respectively, have been achieved while remaining glassy liquid crystalline at room temperature for over one year in most cases. 

In view of the unique roles of cholesteric GLCs in material synthesis and device application, the commonly practiced statistical synthesis and the continuing effort in deterministic synthesis are highlighted. All factors considered, a hybrid chiral-nematic precursor is much preferred over separate chiral and nematic precursors in terms of synthesis and subsequent product separation and purification. 

Cholesteric and nematic GLC films following the core-pendant strategy are promising for circular polarizers, optical notch filters and reflectors with spectral position and bandwidth adjustable by chemical and photochemical means circularly polarized fluorescence from a doped light-emitter photonic switching and optical memory with cholesteric and nematic GLC films comprising a dithienylethene core. 

Rochester by the U.S. National Science Foundation, Department of Defense, Department of Energy, New York State Eneigy Research and Development Authority, the Japanese Ministry of International Trade and Industry, and Eastman Kodak Company. Additional funding was provided by the U.S. Department of Energy Office of Inertial Confinement Fusion under cooperative agreements with Laboratory for Laser Energetics at the University of Rochester. The support of DOE does not constitute an endorsement by DOE of the views expressed herein. 

Dibenedetti, F.H. Stillinger, Supercooled liquids and the glass transition. Nature 410, 259 267 (2001) 

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