Figure 5
The reversibility of the NDI/F− complexes.
(a,b) Schematic representation of the complex oxidation process using NOBF4 to produce trans-azo-NDI while this process do not proceed via heat or irradiation using light above wavelengths of 500 nm. (c) The UV-vis spectra change after irradiating the complex solution using visible light with 500 nm cut off for 120 min. (d) Is visual colour change of trans-azo-NDI at the native (i) radical ions (ii) and decolourisation to the original trans-azo-NDI native color (iii), shows the reverse system cis-to-trans after oxidation using NOBF4. (e) The 1H-NMR spectra of the initial trans-azo-NDI and NDI/F− complexes at 1:20 equiv. ratio of NDI:TBAF upon irradiation with UV light at 366 nm and the fully recovered trans-azo-NDI after oxidation using NOBF4. (f) The UV-vis spectra after oxidation using NOBF4 and the formation of trans-azo-NDI.
