Fig. 2. (a) Chemical structures of PAzo-l-3 and PAzo-l-2. (b) CD and UV-vis spectra of PAzo-l-2 in mixed solvents with different volume ratios of DCE/MCH. (c) Schematic presentation of the corresponding Cotton effects and odd–even effects for polymers PAzo-l-3 and PAzo-l-2 in different states.