We have developed a system of dimesogens containing azobenzene linked with cholesterol which have unique properties including as liquid crystals with the capacity for photo-control of alignment and order. Photo-control of the order of the medium comes from the trans-cis photoisomerization of the azobenzene moiety. By changing the electron donating or withdrawing character of the functional group on the azobenzene moiety and/or the bridging linker between the azobenzene and cholesterol (an ester or a diester with a varying alkyl chain length), it is possible to adjust the photoisomerization wavelength, half-life of the cis-azobenzene state, transition temperatures, and structure of this system. These properties have been studied with various characterization methods, including DSC, optical microscope, UV-Visible absorbance, kinetics studies, and NMR. The resulting azobenzene-cholesterol system has an increased level of order compared with isotropic liquids and can be applied as a structured, adaptable, photo-controllable medium for compatible reactions.

Tuning properties of a family of azo-cholesterol liquid crystals for application as photo-controllable reaction media

256th National Meeting (2018)

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