57229-05-7Relevant academic research and scientific papers
SYNTHESIS AND LIQUID CRYSTAL PROPERTIES OF SOME URETHANS.
Verbit,Lorenzo
, p. 87 - 99,90,98 (1975)
The urethan (carbamate) linkage ( - NHCOO - ) has been investigated as a central group in liquid crystal systems. Cholesteryl N-para-substituted-phenylcarbamates exhibit cholesteric mesophases with mesophase stability roughly parallel to increasing molecular polarizability. A smectic, in addition to a cholesteric mesophase was found in the case of cholesteryl N-n-hexadecylcarbamate. The n-octyl analog has a monotropic cholesteric mesophase, while the n-butyl analog is not mesogenic. The N-para-methoxyphenylcarbamates of cholesterol, cholestanol, stigmasterol, alpha -sitosterol, campesterol, and 5-androstene-3 beta -ol-17-one, with the exception of the latter which was not mesogenic, exhibit enantiotropic mesophases. Twenty-five other nonsteroidal urethans having a wide variety of structures, as well as several urea derivatives, were prepared but none was mesogenic.
