Abstract
An organosoluble phthalocyanine substituted by four silylated tetraethyleneglycol chains was designed. This phthalocyanine become water-soluble after acid-promoted removal of the TBDMS moieties (which does not occur in acetonitrile), and is therefore a naked-eye observation system of acid aqueous media. Fluoride anion sensitivity based on the same principle proved unfortunately unsuccessful.