Violet-blue- or pure-blue-emitting triphenylamine derivatives: synthesis and properties

We report the synthesis and optoelectronic properties of a series of nine triphenylamine derivatives. They were synthesized by Suzuki cross-coupling reactions and characterized by elemental analysis, nuclear magnetic resonance, ultraviolet visible absorption spectra, fluorescence spectra, and cyclic voltammetry. All compounds exhibit reversibly electrochemical behavior. In solid state, compounds 5 and 9 emit near violet blue and compounds 1, 2,4,6, 7, and 8 emit deep blue or pure blue and compound 3 emits green. Of all of these compounds, compounds 1, 3, 4, and 8 exhibit high fluorescence quantum yields (44%-68%) with the best coplanarity. Compared with them, compounds 5 and 9 have the lowest fluorescence quantum yields due to the least coplanarity. With the similarity in structure with those reported in literature, these compounds can be potentially useful for blue-emitting, host, and up-converting materials. Key words: triphenylamine, violet blue, blue-emitting, quantum yield, electrochemistry. On presente la synthese et les proprietes optoelectroniques d'une serie de neuf derives de la triphenylamine. Ces derives ont ete synthetises par des reactions de couplage de Suzuki et caracterises en se basant sur l'analyse elementaire, la resonance magnetique nucleaire, les spectres d'absorption ultraviolet-visible, les spectres de fluorescence et la voltammetrie cyclique. Tous les composes presentent un comportement electrochimique reversible. A l'etat solide, les composes 5 et 9 emettent dans le bleu tirant sur le violet, les composes 1, 2,4, 6, 7 et 8 emettent dans le bleu fonce ou le bleu pur, et le compose 3 emet dans le vert. Les composes 1,3,4 et 8 presentent un rendement quantique de fluorescence eleve (44%-68%) et la meilleure coplanarite. Comparativement, les composes 5 et 9, qui possedent le moins de coplanarite, donnent le rendement quantique de fluorescence le plus faible. En raison de la similarite entre leur structure et celle des composes decrits dans la litterature, ces composes pourraient etre utiles a titre de materiaux emettant dans le bleu, de materiaux hotes et de materiaux convertisseurs elevateurs de frequence. [Traduit par la Redaction] Mots-cles: triphenylamine, bleu-violet, emettant dans le bleu, rendement quantique, electrochimie.
Introduction Organic light-emitting diodes (OLEDs) have been widely recognized as the next-generation technology for flat panel displays and white lighting. (1-5) In recent years, there has been considerable interest in [...]