Pendant-decorated polytriphenylamine derivative: potential blue-emitting and hole-transporting material

Using Suzuki coupling reaction, we successfully synthesized a conjugated polymer with alternating fluorene and triphenylamine as the main chain and bearing bulky (2,3,4,5-tetraphenyl) phenyl pendants: poly(9,9-dioctyl)-2,7-fluorene-co-N-4-(2,3,4,5-tetraphenyl)diphenyl-4,4′-diphenylamine (PFT-TPP). This polymer is readily soluble in common organic solvents, has good thermal stability, and readily forms thin film by solution processing. It has an optical bandgap of ca. 2.90 eV, as indicated by the UV–vis investigation. The PL emission of PFT-TPP peaks at 447 nm in dilute THF solution and at 444 nm in a solid film. PFT-TPP shows relatively high HOMO (−5.30 eV) and LUMO levels (−2.40 eV) by cyclic voltammetry, due to the high content of electron-donating triphenylamine segments in the polymer backbone.