Matrix effect on the electrochromism of spirochromics

The reduction of six spirocompounds in the absence and presence of polymethylmethacrylate (PMMA) matrix was investigated by in situ spectrochemical measurements. The effect of polymer concentration and chemical structure of spirocompounds on the electrochromism in solution was investigated and an advantage of the presence of the PMMA matrix for two spirooxazine compounds in the bleaching process was reported. The vertical ionization potentials obtained with semiempirical quantum mechanical calculations and those obtained from λ_max of the sample solutions in PMMA proved to be consistent with oxidation potentials obtained from cyclic voltammetry experiments. This correlation can be explained by the stability of compounds in the PMMA matrix.