Side chain engineering in π-stacked polybenzofulvene derivatives bearing electron-rich chromophores for OLED applications

In order to obtain new polymeric materials endowed with improved optoelectronic performances, suitable side chain engineering was designed to insert different chromophores showing electron donating ability [i.e. triphenylamine (TPA) and 9-methylcarbazole (MCBZ) residues] in two different key positions (i.e. 6 and 40) of the 3-phenylindene scaffold of the polybenzofulvene monomeric units. Among the four newly-synthesized polybenzofulvene derivatives, those bearing triphenylamine moieties were found to show higher emissive properties with respect to the corresponding carbazole derivatives. Moreover, the preliminary OLED devices prepared with the triphenylamine-based polymers showed promising features, but the role of the aggregation process in affecting the emission properties of poly-6-TPA-BF3k suggested that extensive device development studies are required in order to maximize polybenzofulvene performances in OLED applications.