Sol-Gel Phase Transition of Switch-Functionalized Cholesterols as Detected by Circular Dichroism

Abstract

Abstract Cholesterol derivatives containing an azobenzene moiety coupled to C3 of a steroidal moiety showed the reversible sol-gel phase transition in certain organic solvents. Strong ICD spectra appeared in the gel phase, but the ICD disappeared in the sol phase. The sol-gel phase transition which accompanies the drastic ICD spectral change was synchronously induced by light-mediated cis-trans isomerism of the azobenzene moiety.