Matrix effect on the electrochromism of spirochromics

The reduction of six spirocompounds in the absence and presence of polymeth ylmethacrylate (PMMA) matrix was investigated by in situ spectrochemical me asurements. The effect of polymer concentration and chemical structure of s pirocompounds on the electrochromism in solution was investigated and an ad vantage of the presence of the PMMA matrix for two spirooxazine compounds i n the bleaching process was reported. The vertical ionization potentials ob tained with semiempirical quantum mechanical calculations and those obtaine d from lambda(max) of the sample solutions in PMMA proved to be consistent with oxidation potentials obtained from cyclic voltametry experiments. This correlation can be explained by the stability of compounds br the PMMA mat rix. Copyright (C) 1999 John Wiley & Sons, Ltd.