Poly fluorene copolymers

Campbell, A.J., et al. 2000. Transient and steady-state space-charge-limited currents in poly-fluorene copolymer diode structures with ohmic hole injecting contacts. Appl Phys Lett 76 1734— 1736. 

Whereas poly(9,9-dihexylfluorene) (PDHF, 195) is generally considered as amorphous, PF with longer octyl side chains, PFO 196, is crystalline material. Many PFs — dioctyl (PFO 196 [228,230,231]) or 2-ethyl hexyl) (197 [232]) as well as some fluorene copolymers [233] exhibit liquid crystalline behavior, opening a possibility to fabricate polarized LEDs [224,234,235] (Chart 2.45). 

Fang and Yamamoto [351] reported on postpolymerization functionalization of triarylamine-fluorene copolymer 253, resulting in copolymers 254a,b with stilbene pendant groups. Whereas in the solid-state absorption and PL maxima of both polymers are essentially the same, PL in solution is strongly influenced by solvent (from 433 nm in toluene to 466 nm in jY-methylpyrrolidone). Copolymer 254a showed d>PL in the solid state of 51%, comparable to that of poly(9,9-dialkylfluorenes) (Chart 2.66). 

An unusual synthetic approach to PF copolymers was demonstrated by Bunz and coworkers [370], who prepared poly(fluorene ethynylene) 281a-e by metathesis polymerization reaction (Scheme 2.44) [370], The aggregation of polymers 281 in concentrated solutions and in solid state is manifested in slight (up to 10-20 nm) red shift of the absorbance and emission peaks, although solutions and films emit pure blue light. 

S.-H. Jin, M.-Y. Kim, D.-S. Koo, and Y.-I. Kim, Synthesis and properties of poly(fluorene-a/t-cyanophenylene vinylenej-based alternating copolymers for light-emitting diodes, Chem. Mater., 16 3299-3307, 2004. 

Other common emissive conjugated polymers with aromatic ring backbones are poly(phenylene vinylenes) (PPVs), poly(fluorenes) (PFs) - usually formed as copolymers such as poly(fluorene-co-phenylene)s (PFPs), and, more rarely, poly (p-phenylene)s (PPPs). Hetero-aromatic based polymers and copolymers alternating... 

Light-emitting devices were fabricated by depositing a hole-transport layer of fluorene copolymer poly(9,9-dioctyl-C0-bis-/V,/V -(3-carboxyphenyl)-bis-/V,/V -... 

Rod—coil molecules containing structurally perfect conjugated rods were synthesized by using a-(phen-yl)-ft -(hydroxymethyl phenyl)-poly(fluoren-2,7-ylene) as macroinitiator (Scheme 8).98 Anionic polymerization of ethylene oxide by using the macroinitiator produced a corresponding rod—coil block copolymer (22). The absorption and emission measurements of... 

The first oxetane-functionalized emitter were pyrene derivatives (Fig. 9.19(b), [46]), however, with very limited performance in OLEDs. Later, a poly(pheny-lene-fluorene)-copolymer was reported, however, without any electroluminescence data (Fig. 9.19(c), [47]). The breakthrough came with a recent report on a crosslinkable class of state-of-the-art spirofluorenes (Fig. 9.19(a), [48, 49]). By incorporating a green- and red-emitting comonomer, it was possible to generate the three primary colors (RGB) necessary for color-display applications. More recent concepts use sterically hindered 9,9 -diarylfluorene blocks to link conjugated oligomers (Fig. 9.19(d), [50]). 

Fig. 9.19 Chemical structures of oxetane-functionalized emitters (a) low molecular weight pyrene-based emitter [46], (b) poly(fluorene-phenylene) copolymer [47], (c) spirobifluorene-cofluorene RGB emitter polymers [48], and (d) fluorene-bridged co-oligomers [50],...

Water Soluble Poly(fluorene) Homopolymers and Copolymers for Chemical and Biological Sensors... 

R. Verduzco, I. Botiz, D. L. Pickel, S. M. Kilbey, K. Hong, E. Dimasi, S. B. Darling, Polythiophene-BZocfc-Polyfluorene and Polythiophene-B/ocfc-Poly(Fluorene-co-Benzothiadiazole) Insights into the Self-Assembly of All-Conjugated Block Copolymers. Macromolecules 2011,44, 530-539. 

LeeSJ, Gallegos JR, KleinJ, CurtisMD, Kanicki J. Poly(fluorene-oxadiazole) copolymer-based light-emitting devices on a plastic substrate. Synth Met 2005 155(1) 1-10. 

Huang and coworkers [437] reported preparation of a series of well-defined amphiphilic block copolymers containing conjugated poly(fluorene) (PF) block and coil like poly(2-(dimethylamino) ethyl methacrylate) (PDMAEMA). The block copolymers were synthesized through ATRP. The reactions were initiated by a 2-bromoisobutyrate end-capped macroinitiator using CuCl/ 1,1,4,7,10,10-hexamethyltriethylenetetramine as the catalyst. 

Adapted from Table 1 and Figure 3 of A. Charasa, N. Barbagallo, J. Morgado and L. Alcacer, Synthesis and optical properties of poly(fluorene)-based alternating copolymers, Synth. Met., 122, 23-25 (2001), Copyright 2001, with permission from Elsevier. 

R. Yand, R. Tian, Q. Hou, Y. Zhang, Y. Li, W. Yang, C. Zhang, Y. Cao, Light-emitting copolymers based on fluorene and selenophene - comparative studies with its sulfur analogue poly(fluorene-ct>-thiophene), J. Polym. 

Three principal types of Suzuki polymerizations for polyfluorenes have been developed for homopolymers and copolymers by Dow, Cambridge Display Technology (CDT), and Covion, which was merged with Merck. Early detailed experimental procedures were reported in the patent literature (Scheme 5.5 and Table 5.2). These and other groups have used these polymerizations for numerous poly fluorene derivatives (Table 5.3). 

Some rigid-rod conjugated polymers also exhibit themotropic liquid crystallinity. Therefore, it is possible to align them from the liquid crystalline phase using an alignment layer. Improved mobility using this method was reported for a poly(fluorene bithiophene) copolymer. ... 

Fig. 4 (a) Rod-rod-rod PBLG-poly(fluorene)-PBLG triblock copolymers [50] and (b) rod-rod PBLG-poly(hexylthiophene) [44]... 

Other thiophene-based donor-acceptor-type copolymers that have shown efficiencies of over 4.2% include poly (fluorene-dicyclopentathiophene-a/t-benzothiadiazole) (65, Figure 25), poly(carbazole-dicyclopentathiophene-aft-benzothiadiazole) 66, and poly[9,9-dialkylfluorene-a/t-(bis-thienylene)benzothiadiazole] 67-69. Some other thiophene-based polymer designs, which have attracted... 

Verduzco, R. Botiz, I. Pickel, D. L. Kilbey II, S. M. Hong, K. Dimasi, E. and Darling, S. B., Polythiophene-block-polyfluorene and polythiophene-block-poly(fluorene-co-benzothiadiazole) Insights into the self-assembly of all-conjugated block copolymers. Macromolecules, 44,530-539 (2011) DOI 10.1021/ mal02728z. 

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