Polyfluorenes preparation

Poly(9-fluroenone) has also been prepared by the oxidation of polyfluorene using acetic acid and sodium dichromate, as described by Rauth-Berthelot [1] and Umemoto [2]. 

Methods for preparing poly(9-fluroenone) containing 35% polyfluorene content are described by the author in a subsequent investigation [3]. 

Uckert [5,6] prepared electroactive poly(fluorene-co-fluroenone), (II), and aliphatic and perfluoroaliphatic derivatives for use in as light-emitting diodes. Light-emitting devices consisting of polyfluorene alkoxy derivatives, (III), were prepared by Mizuno [7],... 

High-performance polyfluorene derivatives consisting of 9,9-bis(4-hydroxyphenyl)-fluorene and 4,4 -bis((4-chlorophenyl)sulfonyl)-l,l -biphenyl have been prepared using reagent ratios from 100 0 to 0 100. When poly(9,9-bis(4-hydroxyphenyl)-fluorene) was prepared it had a M of 58,000 daltons with a glass transistion temperature greater then 300°C. When copolymers of 9,9-bis(4-hydroxyphenyl)-fluorene and 4,4-hydroxybiphenyl were prepared, however, the glass transition temperature was lowered by up to 30°C. 

From the late 1970s onwards, efforts to synthesise conjugated polymers rapidly expanded and numerous new materials were prepared. Many of these still proved to be intractable substances that were difficult if not impossible to purify and characterise. The maximum levels of conductivity achieved on doping often fell well short of the metallic range. Such properties meant that the majority of these materials attracted little attention beyond the initial reports, and certainly no commercial interest. An example of the few polymers produced at this time that have been extensively studied subsequently is polythiophene (PTh), Fig. 9.2(h). Although this polymer was also reported in the nineteenth century (Meyer, 1883), the first reliable synthesis appeared in 1980, see McCullough (1998). Another example is polyfluorene, Fig. 9.2(i), which was prepared chemically and electrochemically in 1985, see Rault-Berthelot and Simonet (1986). Much subsequent synthesis has been directed to the inclusion of pendent groups to either enhance solubility,... 

Poly(9,10-dihydrophenanthren-2,7-diyl)s 74 (Scheme 33) which are analogous to polyfluorenes, but with ethane instead of methine bridges have been prepared by Yamamoto and co-workers [107]. The PL emission from 74... 

Hsu et al. [75,76] reported a new method for incorporating metal complexes into polyfluorenes to prepare phosphorescent polymers (polymer 47 and 48). A pyridine end-capped polyfluorene has been synthesized. The pyridine was used to form a polymer metal complex with 2,2-bipyridyl(tri-carbonyl)rhenium(I) chloride. Using the end-capping approach not only can control the molecular weight of polymer, but also avoid the interference of the metal complex and conjugated polymer in energy transfer. They can... 

Because polyfluorenes have undoubtedly emerged as a very attractive class of blue-emitting polymers, not surprisingly, a number of synthesis methods have been applied for the preparation of polyfluorenes and polyarylenes [20],... 

Kuo CC, Wang CT, Chen WC (2008) Highly-aligned electrospun luminescent nanofibers prepared from polyfluorene/PMMA blends fabrication, morphology, photophysical properties and sensory applications. Macromol Mater Eng 293( 12) 999—1008... 

The reductive coupling of arenes is one of the most important methods for preparing polyarenes. A number of methods have been used, but the most widely used is that developed by Yamamoto [92] using bis(cyclooctadiene)nickel(0) (Ni(COD)2) and 2,2 -bipyridyl as illustrated in Scheme 6.14 for the synthesis of a polyfluorene 73 [93],... 

In the section devoted to CNTs, some details concerning synthesis and purification methods, as well as separation techniques for metalfic and semiconducting nanotubes will be reviewed. Some aspects concerning the interactions of CNTs with reactants used in the synthesis of different composites based on conducting polymers, such as PANI, PPy, PEDOT, PBTh, PNVK, PPV, and polyfluorene (PF) will be discussed in the section devoted to the synthesis of the CP/CNT composites. Preparing a composite with the desired properties requires knowledge of the interaction between the host matrix and the guest carbon nanoparticles. 

Bolognesi, A., Galeotti, F., Giovanella, U., Bertini, F., Yunus, S. Nanophase separation in polystyrene-polyfluorene block copolymers thin films prepared through the breath figure procedure. Langmuir 25, 5333-5338 (2009)... 

Andersson and coworkers have prepared solar cells based on blends of poly(2,7-(9-(2 -ethylhexyl)-9-hexyl-fluorene)-fl/t-5,5-(4, 7 -di-2-thienyl-2, l, 3 -benzothiadiazole) (223) and PCBM [416]. The polymer shows a Amax (545 nm) with a broad optical absorption in the visible spectrum and an efficiency of 2.2% has been measured under simulated solar light. The same group has also reported the synthesis of low bandgap polymers 200 (1 = 1.25 eV) and 224 (1 = 1.46 eV) which have been blended with a soluble pyrazolino[70]fiillerene and PCBM, respectively, to form bulk heterojunction solar cells of PCE of 0.7% [417] and 0.9% [418]. Incorporation of an electron-delident silole moiety in a polyfluorene chain affords an alternating conjugated copolymer (225) with an optical bandgap of 2.08 eV. A solar cell based on a mixture 1 4 of 225 and PCBM exhibits 2.01% of PCE [419]. 

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