Electroluminescent polymers groups

T. Ahn, S. Song, and H. Shim, Highly photoluminescent and blue-green electroluminescent polymers new silyl- and alkoxy-substituted poly(p-phenylene vinylene) related copolymers containing carbazole or fluorene groups, Macromolecules, 33 6764-6771, 2000. 

Note 1 Electroluminescent polymers are often made by incorporating luminescent groups or dyes into conducting polymers. 

Poly(arylene vinyene)s (PAVs) represent the most widely studied group of electroluminescent polymers. The parent compound poly(para-phenylene vinylene) (PPV, 1, Fig. 6.1) [5] is insoluble and so must be processed as a precursor polymer but derivatives such as MEH-PPV (2) [6] with solubilizing alkyl, aryl, silyl, or al-koxy chains show good solubility in organic solvents and so can be readily processed by techniques such as spin casting. By appropriate choice of substituents... 

Electroluminescent conjugated polymers can be synthesized by incorporating high electronegative heterocyclic groups, such as 1,3,4-oxadiazole, 1,3,4-thiadiazole and 1,2,4-triazole moieties. These electroluminescent polymers are obtained by polymerization of a bis-(halomethyl) aromatic monomer modified with a heterocyclic group. ... 

FIGURE 7.11 Chemical structures of electroluminescent polymers (copolymers) with ion-transporting side groups. 

The most studied of the PPV compounds are those containing at least one solubilizing alkoxy group (271-273) poly[(2-methoxy-5-(2-ethylhexyl)oxy-l,4-phenylenejvinylene (MEH-PPV) is most commonly used (274). The ability to fine-tune the color to produce red, green, and blue PLEDs has been demonstrated by appropriate functionalization of polymers (275-279), copolymerization (280-282), and blending (283-285). Several representative electroluminescent polymers covering the visible spectrum are shown in Table 3 (286-290). 

Polysilanes are cr-conjugated polymers composed of Si-Si skeletons and organic pendant groups. They are insulators with filled intramolecular valence bands and empty intramolecular conduction bands. However, because of strong cr conjugation, they have rather narrow band gaps of less than 4 eV [24,25] and are converted to conductors by photoexcitation or by doping electron donors or acceptors. Recently they have attracted much attention because of their potential utility as one-dimensional conductors, nonlinear optical materials, and electroluminescent materials [26-28]. 

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