Nearly pure blue photoluminescent poly{2,7-[9-{3,5-bis[3,5-bis(benzyloxy)benzyloxy]benzyl}-9 -(3,6-dioxaoctyl)]fluorene} in filmElectronic supplementary information (ESI) available: characterization data for 2, 3, and 4, and measurement details of the quantum yield in THF solution. See http://www.rsc.org/suppdata/cc/b1/b108097k/

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.