Thermal and light control of the sol-gel phase transition in cholesterol-based organic gels. Novel helical aggregation modes As detected by circular dichroism and electron microscopic observation

Article abstract of DOI:10.1021/ja00094a023

Nineteen cholesterol derivatives containing a variety of azobenzene moieties coupled to C-3 of a steroidal moiety through an ester linkage were synthesized. We employed two different esterification methods by which cholesterol derivatives with the natural