Synthesis and characterization of spirobifluorene-based polymers for organic light-emitting diode applications

The following series of blue EL polymers was synthesized using the Suzuki polymerization method: poly(3',6'-bis(3,7-dimethyloctyloxy)-9,9'-spirobifluorene-2,7-diyl) poly[(OC10)2-spirobifluorene], poly {3',6'-bis(3,7-dimethyloctyloxy)-9,9'-2,7-diyl-co-4-(3,7-dimethyloctyloxy) phenyl-diphenylamine-4',4 -diyl} poly[(OC10)(2)-spiro bifluorene-TPA] (5:1, 9:1) and poly {3',6'-bis(3,7-dimethyloctyloxy)-9,9'-spirobifluorene-2,7-diyl-co-4-(6-((3-methyloxetan-3-yl)methoxy)hexyloxyphenyl-bisphenylamine-4',4'-diyl) poly[(OC10)(2)-spirobifluorene-TPA-oxetane]. The weight average molecular weight (Mw) and polydispersity of the resulting polymers ranged from 1.6x10(4)- 1.5 x 10(5) and 1.77-2.31, respectively. The resulting polymers were completely soluble in common organic solvents and were easily spin-coated onto an indium tin oxide (ITO) substrate. The polymers exhibited strong blue emission peaking at 450 nm. The maximum brightness and luminance efficiency were 9,960 cd/m(2) and 1.2 cd/A, respectively.