Multilayer thin films by layer-by-layer assembly of hole- and electron-transport polyelectrolytes: optical and electrochemical properties was written by Choi, Kyungsun;Zentel, Rudolf. And the article was included in Macromolecular Chemistry and Physics in 2006.Electric Literature of C12H8N4O This article mentions the following:
A series of p-type and n-type semiconducting polyelectrolytes with triarylamine, oxadiazole, thiadiazole, and triazine moieties were prepared by radical polymerization of triarylamine monomers with maleic anhydride, followed by ring opening of the anhydride and formation of amide bonds. The synthesized polymeric hole and electron transport materials were examined optically and electrochem. using UV/Vis spectroscopy, photoluminescence (PL) spectroscopy and CV (cyclic voltammetry). Based on the optical and electrochem. data, each of the energy levels were calculated and values suggest that the polyelectrolytes are promising hole- (p-type) or electron-transport (n-type) materials for devices. The synthesized ionic polymers were suitable for LBL (layer-by-layer) thin film deposition from dilute polymer solutions and the multilayers were fully characterized by UV/Vis, PL spectroscopy and CV. In the experiment, the researchers used many compounds, for example, 2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7Electric Literature of C12H8N4O).
2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds. Many analogues of pyridine are known where N is replaced by other heteroatoms . Substitution of one C–H in pyridine with a second N gives rise to the diazine heterocycles (C4H4N2), with the names pyridazine, pyrimidine, and pyrazine.Electric Literature of C12H8N4O