An electrochemically prepared sky-blue light emitting ether functionalized polyfluorene as chemosensor for metal ions

Abstract

Synthesis and electrochemical polymerization of 9,9-bis(2-(2-(2-methoxy ethoxy)ethoxy)ethyl)-fluorene (EO-F) into poly[9,9-bis(2-(2-(2-methoxy ethoxy)ethoxy)ethyl)-fluorene] (EO-PF) films are reported. The boron trifluoride diethyl etherate electrolyte enables facile preparation of EO-PF films at lower potential compared to LiClO4/MeCN and the electrochemical polymerizations are discussed. The EO-PF shows good electrochemical behavior and can be dissolved in solvents such as DMSO and THF. The solubility of EO-PF in THF is 2 mg·mL−1 and the number average molecular weight is 35300 with a polydispersity index of 1.65. The side chains on C9 position of the monomer maintain unchanged after electrooxidation into corresponding polymer. The EO-PF dissolved in THF under 365 nm ultraviolet light is sky blue light emitting with the Commission Internationale de L’Eclairage-CIE coordinates of (0.19, 0.15). The electropolymerized EO-PF is used for the first time in chemosensing metal ions, demonstrating fluorescence quenching for Mn2+ and Fe3+ while fluorescence enhancement for Cr6+ ions.