Synthesis of a fluoresceine-derivatized fluorene and its electrogenerated copolymers with fluorene: New pH indicators

The synthesis of a fluorene derivative bearing a fluorescein moiety is described together with its anodic electropolymerization in presence of various amount of fluorene. Both polymers and monomers can be used as pH indicators in water and other medium. The fluorescence and absorption properties in function of the pH are presented and compared with those of fluorescein. In the excited state, the Fluorescein–fluorene monomer appears to be a stronger acid than fluorescein.