Polyfluorenes

Polyfluorenes (PFs), the simplest regular stepladder-type polyphenylenes, in which only every second ring is bridged, have been much studied in recent years due to their large PL quantiun efficiencies and excellent chemical and thermal stability, as evidenced by the number of recent reviews [162-164]. A further attractive feature of poly(9,9-dialkylfluorene)s (PDAFs) is the synthetic accessibility of the monomers, as alkylation and halogenation of fluorene proceed smoothly and in high yields. 

Polyfluorenes (PFs), the simplest regular stepladder-type polyphenylenes, in which only every second ring is bridged, have been much studied in recent years due to their large PL quantum efficiencies and excellent chemical and 

Fluorene (FI) is a polycyclic aromatic compound, which received its name due to strong violet fluorescence arising from its highly conjugated planar n-electron system (Chart 2.44). 

Hydrogan Bonding at Dapratodolion at Low F Concentration High F-Concemratloa 

P(MMA-co-NBDAE)-f -PF-b-P(MMA o-NBDAE) deprotonation in acetone solutions, triblock copolymers, (b) Diagram Reproduced with permission 

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One of the first examples was that reported by Yoshino et al. [12] concerning the synthesis of polyfluorenes via oxidative coupling of fluorene derivatives as decribed above. 

Kietzke, T, Neher, D., Kumke, M., Montenegro, R., Landfester, K. and Scherf, U. (2004) A nanoparticle approach to control the phase separation in polyfluorene photovoltaic devices. Macromolcculcs, 37, 4882 890. 

M Radler, Progress in Dow Polyfluorenes for Light Emitting Diodes, 23rd Internaional Display Research Conference, September 15-18, 2003, Pointe South Mountain Resort, Phoenix, Arizona. 

M Svensson, F Zhang, SC Veenstra, WJH Verhees, JC Hummelen, JM Kroon, O Inganas, and MR Andersson, High-performance polymer solar cells of an alternating polyfluorene copolymer and a fullerene derivative, Adv. Mater., 15 988-991, 2003. 

The 2,5-dicyanophenylene unit has also been used by Jen and coworkers [164] in the synthesis of a series of polyfluorene (PF) PPV copolymers 129-131 through Suzuki-coupling... 

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.)... 

The Problem of Pure Blue Emission in Polyfluorenes Excimer and Aggregate Formation or Fluorenone Defects ... 

FIGURE 2.20 Schematic illustration of a disorder in polyfluorene introduced by carbazole-3,6-diyl unit in the main chain. (From Xia, C. and Advincula, R.C., Macromolecules, 34, 5854, 2001. With permission.)... 

J. Rault-Berthelot, Polyfluorenes, a family of versatile conjugated polymers. Anodic synthesis, physicochemical properties, electrochemical behaviour and application fields, Recent Res. Dev. Macromol. Res., 3 425-437, 1998. 

M. Leclerc, Polyfluorenes twenty years of progress, J. Polym. Sci., Part A Polym. Chem., 39 2867-2873, 2001. 

D. Neher, Polyfluorene homopolymers conjugated liquid-crystalline polymers for bright emission and polarized elecroluminescence, Macromol. Rapid Commun., 22 1365-1385,2001. 

U. Scherf and E.J.W. List, Semiconducting polyfluorenes — towards reliable structure-property... 

G. Fytas, H.G. Nothofer, U. Scherf, D. Vlassopoulus, and G. Meier, Structure and dynamics of nondilute polyfluorene solutions, Macromolecules, 35 481-488, 2002. 

M. Grell, W. Knoll, D. Lupo, A. Miesel, T. Miteva, D. Neher, H.-G. Nothofer, U. Scherf, and A. Yasuda, Blue polarized electroluminescence from a liquid crystalline polyfluorene, Adv. Mater., 11 671-675, 1999. 

M. Grell, D.D.C. Bradley, G. Ungar, J. Hill, and K.S. Whitehead, Interplay of physical structure and photophysics for a liquid crystalline polyfluorene, Macromolecules, 32 5810-5817, 1999. 

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