fig3
Figure 3. Phase transition of isomers and energy storage properties. First row: DSC plots of trans (top black curve)- and cis (bottom red curve)-isomers upon heating and cooling with Azo-Cl (A) as a representative example of halogen-grafted Azos and Azo-OEt (B) as a representative example of alkoxy-grafted Azos. Tm, Tc, and Tcc represent the melting, crystallization, and cold-crystallization temperatures, respectively. Second row: 1H NMR spectra of Azo-Cl (C) and Azo-OEt (D) isomers for DSC test. Third row: DSC curves of typical cis-liquid Azos for Azo-Cl (E) as a representative example of halogen-grafted Azos and Azo-OEt (F) as a representative example of alkoxy-grafted Azos. Fourth row: time-evolved UV-Vis absorption spectra of the cis-liquid form of Azo-Cl (G) and Azo-OEt (H) reversion in darkness (the spectra were normalized with respect to their corresponding isosbestic point). The arrows indicate the test order.
