Cholesterol Decorated Diazocine Gelator with Photo- and Thermo-Responsive Properties for Smart Window

Abstract

A new gelator (BAzo-Chol) comprising a diazocine core and two cholesterol units linked via carbamate groups has been designed and synthesized. Its gelation ability in several kinds of organic solvents is identified. Investigations with scanning electron microscopy (SEM), transmission electron microscopy (TEM), rheological measurements, and UV-vis absorption and ¹H NMR spectroscopy reveal that BAzo-Chol can self-assemble into elastically interpenetrating one-dimensional nanostructures in organogels through a cooperative effect of the π-π interactions, hydrogen-bonding, and van der Waals forces. Moreover, the unconventional Z/E conformational transitions of these organogels, due to the inclusion of diazocine, endow the BAzo-Chol gels with excellent photo-responsive gel-sol transition and remarkable visible light-induced chromic properties. Lastly, due to its sensitive response to visible light accompanied by distinct changes in both colour and transparency of the gel-sol transitions, the potential application of the current gelator in smart windows is signified.