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Organic–Inorganic Semiconductor Heterojunctions for Hybrid Light-Emitting Diodes
Published in Ye Zhou, Optoelectronic Organic–Inorganic Semiconductor Heterojunctions, 2021
The 4,4-difluoro-4-borata-3a-azonia-4a-aza-s-indacene unit, or BODIPY as it is commonly known, is an organic fluorescent dye and part of the difluoro-boraindacene family. Advantages of BODIPY are its thermal and photochemical stability, high fluorescence quantum yields, large absorption and emission profiles and good solubility in various organic solvents, such as acetone and toluene [66]. Due to its properties, it has found applications in biological labelling [67], luminescence [68], dye-sensitized solar cells [69] and as sensors for pH and ions [70,71]. Its tunable emission in the yellow spectral region makes it attractive for organic light-emitting devices [66]. BODIPY has a strong, but narrow absorption peak, which is confined to around 500 nm. Therefore, another absorbing partner unit in the UV or blue spectral region is needed for color conversion when combined with an inorganic LED.
State-of-the-Art Active Materials for Organic Lasers
Published in Marco Anni, Sandro Lattante, Organic Lasers, 2018
Discovered by Treibs and Kreuzer [20], 4,4-difluoro-4-bora-3a,4a-diaza-s-indacenes (Fig. 3.3), commercially known as BODIPYs (BOron DIPYrromethenes), are considered today as one of the most useful and versatile organic chromophores [21,22]. The interest in BODIPY dyes originates from their outstanding photophysical properties, such as high absorption coefficient, high fluorescence quantum yield, high photostability, and low sensitivity to medium effects. Currently, the development of new fluorescent BODIPYs has become a booming area of research due to their potential applications in biosciences and photonics, including lasers.
Self-assembly as a key player for materials nanoarchitectonics
Published in Science and Technology of Advanced Materials, 2019
Katsuhiko Ariga, Michihiro Nishikawa, Taizo Mori, Jun Takeya, Lok Kumar Shrestha, Jonathan P. Hill
Because of high selection capability of the component molecules/materials and inclusion of functional groups, materials nanoarchitectonics with self-assembly strategy would be a powerful approach to create functional nanostructures. Ajayaghosh and co-workers have investigated π-conjugated nanostructured materials including specific functional groups such as borondipyrromethene (Bodipy) dyes [111]. Hard tasks for synthesis of the Bodipy derivatives as structural units for their self-assembly are not usually required, giving materials with promising photo-properties including high molar absorptivity, fluorescence quantum yield, and excellent photo-stability. Materials synthesized through their self-assembly are expected to be applied for energy transfer cassettes, liquid crystalline materials, and for bioimaging/labelling usages.
Novel near-infrared fluorescent liquid crystal: Bodipy bearing multiple alkyl chains with columnar mesophase
Published in Liquid Crystals, 2019
Jianchao Cheng, Sining Zheng, Liangbin Lin, Hongyu Guo, Fafu Yang
It had been reported that the condensation on methyl groups of Bodipy produced larger conjugated effect, resulting in the near-infrared emission usually [12]. On the other hand, the symmetric structure with an aromatic core and 3–6 alkyl chain on peripheral is favourable for columnar liquid crystal [1]. Thus, the synthetic routes for near-infrared fluorescent liquid crystal with Bodipy core bearing 3 and 6 alkyl chains were designed as Scheme 1. Firstly, the benzaldehyde derivatives 1 and 4 with one alkyl chain or two alkyl chains were prepared according to the literature [31]. Furthermore, the Bodipy derivatives 2 and 5 with one or two alkyl chains were synthesised by treating compound 1 or 4 with 2,4-dimethylpyrrole via sequential condensation, oxidation and complexation reactions according to the typical procedure for preparation of Bodipy skeleton [18]. The yields were moderate ones of 30%. Finally, by Knoevenagel condensation reaction of compounds 2 and 5 with compound 1 or 4 in the presence of piperidine and glacial acetic acid, target compounds 3 and 6 were obtained after columnar chromatography in yields of 28% and 25%, respectively.
Novel fluorescent liquid crystals: synthesis, mesomorphism and fluorescence of triphenylene-Bodipy derivatives based on 1,3,5-triazine core
Published in Liquid Crystals, 2018
Huiyi Feng, Xiaotong Geng, Jianrong Lin, Hongyu Guo, Fafu Yang
In the past decades, columnar discotic liquid crystals bearing the unique core with π-π stacking structures, have attracted much research attentions due to their various potential applications such as organic field-effect transistors, organic light-emitting diodes, gas sensors and organic photovoltaic cells [1–4]. Recently, the columnar liquid crystals with high fluorescence had been paid considerable attention because of the effective combination of intrinsic luminescent capability and supramolecular self-assembly characteristic within a mesophase [5,6]. On the other hand, it was well known that BODIPY (full name as 4,4-Difluoro-4-borata-3a,4a-diaza-s-indacene) is a kind of luminescent dye with high fluorescence, photochemical stability, and energy/electron-transfer capabilities [7–12]. The investigation on BODIPY liquid crystals was also carried out to study novel fluorescent liquid crystalline materials [13–20]. However, due to the asymmetric structure for BODIPY skeleton and the difficulty of introducing multiple symmetric alkyl chains, the columnar BODIPY liquid crystals were difficult to obtain in most cases.