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Developing solution-processable deep-blue emitters for organic light-emitting diodes (OLEDs) is still a challenging task. In this context, two new solution-processable deep-blue emitters, N,were successfully designed and synthesized by incorporating phenanthroimidazole (PI)/diphenylimidazole (BI)-triphenylamine (TPA), which is functional at the N1 position of the imidazole, with Ph-mCF 3 . The thermal, photophysical, and electrochemical properties of both fluorophores were systematically explored. These fluorophores showed a deep-blue emission in the solution as well as in the solid state. The highest occupied molecular orbital (HOMO)lowest unoccupied molecular orbital (LUMO) energy level of the fluorophores was calculated using electrochemical studies and compared with the theoretical calculation [the density functional theory (DFT)]. The asymmetrically twisted conformation of 4-PIMCFTPA between PI-TPA efficiently showed a high photoluminescence quantum yield. OLED (undoped and doped) devices were fabricated with the newly synthesized emitters, and 4-PIMCFTPA demonstrated better electroluminescence (EL) performance than the BI-based emitter. Thus, the OLED based on 4-PIMCFTPA (1 wt% in the CBP host) had the best EL performance, with a maximum external quantum efficiency 1.7% and CIE coordinates of (0.17, 0.06).

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Three fluorophores based on Imidazo[1,5-a]pyridine (ImPy) decorated with aromatic π-system (C3 position of ImPy is decorated with naphthalene, methoxy-naphthalene and pyrene) were designed and synthesized by one-pot synthesis method. The...

Three deep-blue emissive donor-acceptor (DÀ A) fluorophores, 2-(4'-(1-(4-(tert-butyl)phenyl)-1H-phenanthro [9,10-d] 10d]imidazol-1-yl)benzonitrile (m-CNPISN) based on benzothiazole with varying substituents at N1-position to tune the properties of the materials were designed and synthesized. The synthesized fluorophores were structurally confirmed by spectroscopic techniques. All the fluorophores exhibited good thermal properties with high thermal degradation temperatures. An optical study reveals that the fluorophores are capable of emitting in the blue spectral region in solution and solid. The quantum chemical investigations were also performed with the aim to understand the electronic structures of the fluorophores. Further, solution-processed OLED device was fabricated by using PTPISN as an emissive dopant and found that bright deep-blue electroluminescence with CIEy of (∼ 0.08). These results suggest that the introduction of benzothiazole moiety is a promising design strategy for obtaining new deep-blue emitters.