Polyquinoxalines preparation

Polyquinoxalines are prepared by the solution polymerisation of aromatic bis((9-diamines) such as 3,3, 4,4 -tetraminobiphenyl and aromatic bis(glyoxal hydrates) such as 4,4 -oxybis(phenylglyoxalhydrate) ... 

The synthesis of polyether quinoxaline by nucleophilic displacement discussed in Section 5.4.2.2 has also been used for the preparation of hyperbranched polyquinoxaline based on AB2 or A2B monomers. In the AB2 monomer the focal point is a single fluoro group (Fig. 5.42)172 in the A2B the focal point is a single... 

T. Yamamoto, K. Sugiyama, T. Kushida, T. Inoue, and T. Kanbara, Preparation of new electron-accepting Tr-conjugated polyquinoxalines. Chemical and electrochemical reduction, electrically conducting properties, and use in light-emitting diodes, J. Am. Chem. Soc., 118 3930-3937, 1996. 

The condensation between a carbonyl and an amine leads to the rather fragile imine link. However, its stability is greatly increased when it is included in a heterocycle. This may be used to prepare ladder molecules such as polyquinoxalines. 

Other tetraketones have also been used in the preparation of PQs. The PQs have proven to be one of the better high temperature polymers with respect to both stability and potential application. The PQs are also one of the three most highly developed systems—the others being benzimidazoles and oxadiazoles. The interest in the PQs increased considerably after the development in 1967 of the soluble phenylated polyquinoxaline (PPQ). PQs are stable to 550°C and are used for high-temperature composites and adhesives. 

High molecular weight polyquinoxaline polymers were prepared from 3,3, 4,4 -tetraamino-biphenyl that was reacted with aromatic bis(a-diketones) and/or ethynyl-substituted aromatic bis(a-diketones). The polymers contain 0, 5, 10, 30, and 100% pendant groups. Also, ethynyl-substituted diketones were synthesized by the following procedure ... 

Different ladder polyquinoxalines were prepared as well. One example is shown below ... 

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