9.9- Dioctylfluorene

Polymer 163 (and similar alternating copolymers of 9,9-dioctylfluorene and oxadiazole <2002MM3474>) with blue-light-emitting activity were synthesized by the Suzuki coupling reaction and studied by GPC, MALDI-TOF MS, LJV spectroscopy, and several other techniques <2002ANC6252>. 

FIGURE 2.9 Typical absorption and emission spectra of polyfluorene in thin films (shown for poly(9,9-dioctylfluorene) 196). (From Gong, X., Iyer, P.K., Moses, D., Bazan, G.C., Heeger, A.J., and Xiao, S.S., Adv. Fund. Mater., 13, 325, 2003. With permission.)... 

Star-like PFs 236 with a silsesquioxane core have been prepared by Ni-mediated copolymerization of 2,7-dibromo-9,9-dioctylfluorene with octa(2-(4-bromophenyl)ethyl)octasilses-quioxane [333]. The polymer is thermally stable up to 424°C (TGA). In both chloroform solution and films, its absorption and PL spectra are very close to that for PFO 196, although a somewhat higher PL efficiency is observed in films (64 and 55%, respectively). The polymer 236, however, demonstrates a better PL color stability during thermal annealing. An ITO/PEDOT/236/Ca/Ag device can be turned on at 6.0 V, and shows a brightness of 5430 cd/m2 (at 8.8 V) with F] =0.44%, almost twice as high as that for the corresponding PFO device (Chart 2.60). 

Dibromo-9,9-dioctylfluorene 624 was obtained as described above procedure and after the column chromatography was additionally recrystallized from ethanol yielding pure product in 78% yield. H NMR (400 MHz, CDC13) 8 7.52 (2H, dd, J3 4 = 8.0 Hz,... 

M. Grell, D.D.C. Bradley, X. Long, T. Chamberlain, M. Inbasekaran, E.P. Woo, and M. Soliman, Chain geometry, solution aggregation and enhanced dichroism in the liquid-crystalline conjugated polymer poly(9,9-dioctylfluorene), Acta Polym., 49 439-444, 1998. 

M. Misaki, Y. Ueda, S. Nagamatsu, Y. Yoshida, N. Tanigaki, and K. Yase, Formation of singlecrystal-like poly(9,9-dioctylfluorene) thin films by the friction-transfer technique with subsequent thermal treatments, Macromolecules, 37 6926-6931, 2004. 

M. Ariu, D.G. Lidzey, M. Sims, A.J. Cadby, P.A. Lane, and D.D.C. Bradley, The effect of morphology on the temperature-dependent photoluminescence quantum efficiency of the conjugated polymer poly(9,9-dioctylfluorene), J. Phys. Condens. Matter, 14 9975-9986, 2002. 

D. Poplavsky, J. Nelson, and D.D.C. Bradley, Ohmic hole injection in poly(9,9-dioctylfluorene) polymer light-emitting diodes, Appl. Phys. Lett., 83 707-709, 2003. 

M. Sims, D.D.C. Bradley, M. Ariu, M. Koeberg, A. Asimakis, M. Grell, and D.G. Lidzey, Understanding of the origin of the 535 nm emission band in oxidized poly(9,9-dioctylfluorene) the essential role of inter-chain/inter-segment interactions, Adv. Fund. Mater., 14 765-781, 2004. 

KS Whitehead, M Grell, DDC Bradley, M Jandke, and P Strohriegl, Highly polarized blue electroluminescence from homogeneously aligned films of poly(9,9-dioctylfluorene), Appl. Phys. Lett., 76 2946-2948, 2000. 

Y.H. Niu, Q. Hou, and Y. Cao, High efficiency polymer light-emitting diodes with stable saturated red emission based on blends of dioctylfluorene-benzothiadiazole-dithienylbenzothiadiazole terpolymers and poly[2-methoxy,5-(2-ethylhexoxy)-l,4-phenylene vinylene], Appl. Phys. Lett., 82 2163-2165, 2003. 

A.J. Campbell, D.D.C. Bradley, and H. Antoniadis, Quantifying the efficiency of electrodes for positive carrier injection into poly(9,9-dioctylfluorene) and representative copolymers, J. Appl. Phys., 89 3343-3351, 2001. 

Kreouzis T, Poplavskyy D, Tuladhar 8M, Campoy-Quiles M, Nelson J, Campbell AJ, Bradley DDC (2006) Temperature and field dependence of hole mobility in poly (9,9-dioctylfluorene). Phys Rev B 73 235201... 

Blue electroluminescent polymers and electroluminescent device were prepared by Sohn et al. (5) using poly(dioctylfluorene-co-indolocarbazole), (V). 

High and low molecular weight electroactive polymers containing pendant 2-(7-benzothiazolyl-9,9 -dioctylfluorene) units have been prepared. These materials display electroluminescent properties that are useful in electronic devices. 

Butyl lithium (0.116 mol) was added dropwise to a solution of 2,7-dibromo-9,9 -dioctylfluorene (0.0918 mol) in 200 ml of THF at —78°C over 45 minutes and then stirred for an additional 30 minutes. The mixture was treated with dimethylformamide (0.1539 mol) at —78°C, warmed to ambient temperature over 4 hours, and concentrated. The yellow residue was dissolved in 130 ml of hexanes/xylenes, 10 3, respectively, and then quenched with 5 ml 20% hydrochloric acid. After separating from the aqueous fraction, the organic layer was neutralized with NaHCOs, filtered, dried over MgS04, and decolorized with activated carbon (10 g). The final solution was filtered and concentrated, yielding a colorless solid with a faint greenish hue. The light greenish color was removed by suspension in methanol, and the product was isolated in 83% yield as a colorless microcrystalline solid with MP = 48-50°C. 

Poly(styrene-co-2-vinyl-7-benzothiazolyl-9,9 -dioctylfluorene) was also prepared. 

TABLE 1. Summary of electroactive properties of poly(2-vinyl-7-benzothiazolyl-9, 9 -dioctylfluorene) and poly(styrene-co-2-vinyl-7-benzothiazoly-9,9 -dioctyl-fluorene). 

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