Isosbestic Points Do Not Always Work as the Measure to Determine the Oneness of a Reaction as Exemplified by the Photoisomerization of Azobenzene Tethered to Polymer Chains
Even though two isosbestic points are generated in UV-induced changes in UV-vis absorption spectra of films of a polymethacrylate with azobenzene side chains, the corresponding fourth-order derivative spectra disclose the presence of H-aggregate so that the dual process comprised of UV-induced disaggregation and E/Z photoisomerization of non-aggregated species are involved.