Nearly pure blue photoluminescent poly(2,7-[9-)3,5-bis[3,5- bis(benzyloxy)benzyloxy]benzyl)-9-(3,6-dioxaoctyl)]fluorene) in film.

The first unsymmetrically substituted polyfluorene bearing a bulky poly(benzyl ether) dendron and less bulky 3,6-dioxaoctyl groups in the 9-position was designed and synthesized, which gives almost a pure bluish photoluminescence with negligible weak greenish excimer emission around 520 nm even in a thermally annealed thin solid film.