Photo-optical and electrochemical behavior of novel heterocyclic copoly(naphthylimide-amide)s

This study is concerned with the synthesis and properties of new soluble quinoxaline-containing copoly(naphthylimide-amide)s having different flexible units such as ether, hexafluoroisopropylidene or diphenylsilane, in which the six-membered imide cycle is directly connected to the amide unit through a N-N bond. The polymers were successfully synthesized through the Yamazaki-Higashi polycondensation reaction of a mixture 1: 1 of naphthalene-N, N'-bis(imido-amine) and 4,4'-{1,4-phenylene-bis[(3-phenyl-2,7-quinoxalinediyl) oxy]} dianiline or 4,4'-{oxy-bis[4,1-phenylene(3-phenyl-2,7-quinoxalinediyl)oxy]} dianiline with 4,4'-hexafluoroisopropylidene-bis(benzoic) acid, 4,4'-diphenylsilane-bis(benzoic) acid or with 4,4'-oxy-bis(benzoic) acid. These poly(imide-amide) s exhibited good solubility in common aprotic solvents, and the resulting polymer solutions were processed into amorphous thin films with homogeneous and neat surfaces. Their thermal characterization indicated a moderate to high thermal stability and no glass transition. The photoluminescence study of polymers both in solution and film state showed their ability for blue light color emission. The HOMO and LUMO energy levels were calculated by using cyclic voltammetry and UV-vis spectroscopy data, showing good electron injection and transport characteristics.