We report on the synthesis and the characterization of a new class of segmented polyethers POC containing the oxadiazole and carbazole units. The polymers exhibit a high thermal stability, high glass transition temperatures, and good solubility in common organic solvents, despite the extended aromatic portion in the main polymer chain. The synthetic procedures are simple, and no acid side-products are obtained. According to previous reports on oxadiazole/carbazole-containing materials, POCs show high photoluminescence activity in the blue region of the visible spectra. The good solubility in chlorinate solvents allows the preparation of films with homogeneous thickness by spin coating. Glass transition temperature in the range 115– ensures good stability of film morphology at room temperature. The only exception is POC(6), which shows a poor solubility and higher ( ), due to its shorter aliphatic chain portion. For these features, polymers POC are potential candidate materials for fabricating blue light-emitting devices. 1. Introduction Phosphorescent polymer light-emitting diodes (PLEDs) have attracted considerable attention for their convenient preparation from solution by spin coating or inkjet printing methods. In order to have a balanced carrier recombination in the emitting layer, the polymer should possess good carrier transport properties, as well as energy level matching with electrodes for effective charge injection [1–13]. To improve the electron transfer in PLEDs, researchers usually spin a p-type polymer on an n-type polymer with electron transport properties. But this kind of multilayer system may suffer difficulties in spinning a polymer solution on an organic film, which can easily dissolve. To deal with this issue, polymers containing both hole- and electron-transporting moieties have been prepared. Recently, polymers with either electron-withdrawing (such as oxadiazole, diphenylquinoline, etc.) or electron-donating groups (such as triphenylamine, carbazole, etc.) have been prepared [14–17]. Oxadiazole/carbazole derivatives having good solubility, high quality film formation, and a strong blue emission can play a very important role in organic/polymeric optoelectronic materials, and they can be used as single-layer materials for OLEDs. In this work we report on the synthesis and characterization of a series of oxadiazole/carbazole-containing polymers (POCs), having the formula mentioned in Scheme 1, where is 12 or 6 for the two homopolymers and 12 and 6 or 8 and 4 for the two copolymers. The synthetic procedures are based on the
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