Synthesis and optical and electrochemical properties of a bispyrimidinium-dibenzothiophene-S,S-dioxide-based cationic conjugated polymer

A novel n-type cationic conjugated polymer ( PFSOmiCl ), consisting of bispyrimidinium-dibenzothiophene- S , S -dioxide and fluorene scaffolds, was developed from its polymeric precursor ( PFSOmi ) through an intramolecular cyclization reaction . In comparison with PFSOmi , PFSOmiCl exhibits significant bathochromical absorption and photoluminescence spectra in both solution and film form, as well as a more hydrophilic film surface. Cyclic voltammetry tests demonstrate that PFSOmiCl possesses a deep lowest unoccupied molecular orbital (LUMO) energy level of −4.18 eV, which is comparable to the LUMO energy levels of common fullerene derivatives. These unique properties endow PFSOmiCl with great utilization potential in organic optoelectronic devices. Moreover, this research offers a novel guideline for designing new conjugated polyelectrolytes .