- Synthesis of a highly phosphorescent emitting iridium(III) complex and its application in OLEDs
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A rigid ligand benzo[de]benzo[4,5]imidazo[2,1-α]isoquinolin-7-one (biio) was designed and conveniently synthesized, and the corresponding bis-cyclometalated iridium complex (biio)2Ir(acac) (acac = acetylacetone) was prepared. The light emitting and electrochemical properties of this complex were studied. The complex has the characters of simply synthetic procedure and strong phosphorescence. The electroluminescent device using this complex as dopant was fabricated. The device had the structure of ITO/NPB (40 nm)/Ir complex:CBP (7%, 30 nm)/BCP (15 nm)/Alq3 (30 nm)/LiF (1 nm)/Al (100 nm). The maximum emission of the device was at 496 nm. The maximum brightness of the device can reach 79640 cd m-2 with an external quantum efficiency of 12.1% and a maximum current efficiency of 31.7 cd A-1.
- Hu, Jiawei,Zhang, Guanghui,Shih, Hung-Hsin,Jiang, Xiaoqing,Sun, Peipei,Cheng, Chien-Hong
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- A new fluorogenic chemodosimetric system for mercury ion recognition
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A new probe system for fluorogenic sensing of mercury ions has been designed and synthesized. It is the first intermolecular reaction-based fluorogenic chemodosimetric probe system for Hg(II) ion recognition. High and low concentrations of mercury ions gave different fluorescence responses that could easily be distinguished by the naked eye. This unique system allows detection of the concentration and presence of the mercury ion.
- Ren, Wen Xiu,Bhuniya, Sankarprasad,Zhang, Jun Feng,Lee, Young Hoon,Lee, Suk Joong,Kim, Jong Seung
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- Naphthalene Benzimidazole Based Neutral Ir(III) Emitters for Deep Red Organic Light-Emitting Diodes
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Rigid naphthalene benzimidazole (NBI) based ligands (L1 and L2) are synthesized and utilized to make deep red phosphorescent cyclometalated iridium(III) complexes ([Ir(NBI)2(PyPzCF3)] (1) and [Ir(DPANBI)2(PyPzCF3)] (2)). Complexes 1 and 2 are prepared from the reaction of L1/L2 with the aid of ancillary ligands (PyPzCF3, 2-(3-(trifluoromethyl)-1H-pyrazol-5-yl)pyridine) in a two step method. The complexes are characterized by analytical and spectroscopic methods, as well as X-ray diffraction for 1. These complexes show a strong emission in the range of 635-700 nm that extends up to the near-infrared region (800 nm). The introduction of the diphenylamino (DPA) donor group on the naphthalene unit leads to a further red-shift in the emission. The complexes exhibit radiative quantum efficiency (φPL) of 0.27-0.29 in poly(methylmethacrylate) film and relatively short phosphorescence decay lifetimes (τ = 1.1-3.5 μs). The structural, electronic, and optical properties are investigated with the support of density functional theory (DFT) and time-dependent-DFT calculations. The calculation results indicate that the lowest-lying triplet (T1) excited state of 1 has a mixed metal-to-ligand charge transfer (3MLCT) and ligand-centered (3LC) character, while 2 shows a dominant 3LC character. Deep red-emitting organic light-emitting diodes fabricated using 1 as a dopant display a maximum external quantum efficiency of 10.9% with the CIE color coordinates of (0.690, 0.294), with an emission centered at 644 and 700 nm. Similarly, the emitter 2 also shows a maximum external quantum efficiency of 6.9% with emissions at 657 and 722 nm.
- Kim, Hyung Suk,Kumar, Ajay,Lee, Min Hyung,Lee, Woochan,Rajakannu, Palanisamy,Yoo, Seunghyup
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- Design, synthesis and biological evaluation of naphthalenebenzimidizole platinum (II) complexes as potential antitumor agents
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A serial of naphthalenebenzimidizole-Pt complexes 1–6 were designed and synthesized as antitumor agents. In vitro antitumor assay results showed that complexes 1–6 exhibited moderate to high antiproliferative activity against Hela, HepG2, SKOV-3, NCI–H460, BEL-7404 and A549 cancer cell lines, while they displayed obvious sensitivity and selectivity against SMMC-7721 and U251 cell lines and low toxicity against normal HL-7702 cells, in comparison with cisplatin. In vivo antitumor assay results indicated that complex 1 and 5 exhibited important in vivo antiproliferative activity in the NCI-460 and SMMC-7721 models, in comparison with cisplatin, respectively. Complexes 1 and 5 exhibited better antiproliferative activity against A549CDDP and SKOV3CDDP cell lines than cisplatin, with IC50 values of 6.98 ± 0.47 μM, 5.62 ± 0.88 μM and 13.13 ± 2.11 μM, 5.30 ± 0.33 μM, respectively, while they displayed potential antiproliferation against A549 and SKOV3 cell lines, with IC50 values of 7.32 ± 0.51 μM, 5.19 ± 0.49 μM and 14.92 ± 0.11 μM, 12.19 ± 0.92 μM, indicating the introduction of naphthalenebenzimidizole into platinum-metal system may overcome the resistance. Mechanistic studies showed that the representative complexes 1 and 5 exerted the antitumor effect mainly by the obvious covalent binding with DNA and the upregulation of the expression level of intracellular topo I, showing different action mechanism from cisplatin.
- Liang, Gui-Bin,Yu, Yan-Cheng,Wei, Jian-Hua,Kuang, Wen-Bin,Chen, Zhen-Feng,Zhang, Ye
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- Efficient Phosphorescence from Naphthalenebenzimidizole-Coordinated Iridium(III) Chromophores
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The electronic structure and photophysical properties of two phosphorescent iridium(III) cyclometalated complexes are presented. The molecules were synthesized by cyclometalating the ligand 1,8-naphthalenebenzimidizole (NBI), to an iridium(III) metal center. Two NBI ligands were covalently attached along with a 1,10-phenanthroline (phen) ligand producing the [Ir(NBI)2(phen)](PF6) complex and three NBI ligands were used to prepare the corresponding tris-cyclometalate fac-Ir(NBI)3. The optical properties of these new IrIII molecules were investigated using DFT calculations, photoluminescence spectroscopy, and transient absorption spectroscopy. The molecules at the heart of this study were found to contain long-lived ligand-localized triplet excited states on the NBI species, featuring energies suitable for bimolecular photochemical reactions. Both iridium(III) chromophores possess excellent light absorptivity in the visible region of the spectrum with high photoluminescence quantum efficiencies approaching 30 %.
- Yarnell, James E.,De La Torre, Patricia,Castellano, Felix N.
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- Synthesis and photophysical characterizations of thermal -stable naphthalene benzimidazoles
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Microwave-assisted synthesis, photophysical and electrochemical properties of thermal-stable naphthalene benzimidazoles and naphthalimides are studied in this paper. Microwave-assisted synthesis of naphthalene benzimidazoles provide higher yields than the conventional thermal synthesis. Comparative photophysical properties of naphthalene benzimidazoles and naphthalimides are revealed that conjugation of electron-donating group onto naphthalimide moiety increases fluorescence quantum yields. Fluorophore-solvent interactions are also investigated using Lippert-Mataga equation for naphthalimides and naphthalene benzimidazoles. Thermal stabilities of naphthalene benzimidazoles are better than naphthalimides due to increased aromaticity. The experimental ELUMO levels of naphthalene benzimidazoles are found to be between 3.15 and 3.28 eV. Therefore, naphthalene benzimidazole derivatives consisting of anchoring groups are promising materials in organic dye sensitized solar cells. Springer Science+Business Media, LLC 2009.
- Erten-Ela, Sule,Ozcelik, Serdar,Eren, Esin
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- Electrochemical Activation of Diverse Conventional Photoredox Catalysts Induces Potent Photoreductant Activity**
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Herein, we disclose that electrochemical stimulation induces new photocatalytic activity from a range of structurally diverse conventional photocatalysts. These studies uncover a new electron-primed photoredox catalyst capable of promoting the reductive cleavage of strong C(sp2)?N and C(sp2)?O bonds. We illustrate several examples of the synthetic utility of these deeply reducing but otherwise safe and mild catalytic conditions. Finally, we employ electrochemical current measurements to perform a reaction progress kinetic analysis. This technique reveals that the improved activity of this new system is a consequence of an enhanced catalyst stability profile.
- Chernowsky, Colleen P.,Chmiel, Alyah F.,Wickens, Zachary K.
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supporting information
p. 21418 - 21425
(2021/08/25)
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- ARYL HYDROCARBON RECEPTOR ACTIVATORS
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Small molecule AhR ligands are disclosed. The ligands can induce the differentiation of Tr1 cells to suppress pathogenic immune responses without inducing nonspecific immune suppression. Methods of treatment of autoimmune diseases using the AhR ligands are also disclosed.
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Page/Page column 38-39
(2021/02/05)
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- Understanding the influence of geometric and electronic structure on the excited state dynamical and photoredox properties of perinone chromophores
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In this work, a series of eight similarly structured perinone chromophores were synthesized and photophysically characterized to elucidate the electronic and structural tunability of their excited state properties, including excited state redox potentials and fluorescence lifetimes/quantum yields. Despite their similar structure, these chromophores exhibited a broad range of visible absorption properties, quantum yields, and excited state lifetimes. In conjunction with static and time-resolved spectroscopies from the ultrafast to nanosecond time regimes, time-dependent computational modeling was used to correlate this behavior to the relationship between non-radiative decay and the energy-gap law. Additionally, the ground and excited state redox potentials were calculated and found to be tunable over a range of 1 V depending on the diamine or anhydride used in their synthesis (Ered* = 0.45-1.55 V;Eox* = ?0.88 to ?1.67 V), which is difficult to achieve with typical photoredox-active transition metal complexes. These diverse chromophores can be easily prepared, and with their range of photophysical tunability, will be valuable for future use in photofunctional applications.
- Castellano, Felix N.,Chakraborty, Arnab,Favale, Joseph M.,Garakyaraghi, Sofia,Palmer, Jonathan R.,Pemberton, Barry C.,Valchar, Mary Katharine,Wells, Kaylee A.,Yarnell, James E.
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p. 24200 - 24210
(2021/11/16)
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- Visible-Light-Mediated Organocatalyzed Thiol-Ene Reaction Initiated by a Proton-Coupled Electron Transfer
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A convenient method for performing a thiol-ene reaction is described. The reaction is performed under blue-light irradiation and catalyzed by photoactive Lewis basic molecules such as acridine orange or naphthalene-fused N-acylbenzimidazole. It is believed that the process is initiated by a proton-coupled electron transfer process within the complex between the thiol and the Lewis basic catalyst.
- Levin, Vitalij V.,Dilman, Alexander D.
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p. 8337 - 8343
(2019/06/27)
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- Benzimidazole-1,8-naphthalimide-platinum complex as well as preparation method and application thereof
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The invention discloses a benzimidazole-1,8-naphthalimide-platinum complex as well as a preparation method and application thereof. The preparation method of the complex mainly comprises the followingsteps; taking a compound shown as a formula (II) and a compound shown as a formula (III), putting the compounds into an organic solvent and carrying out coordination reaction under the condition of heating or not heating to obtain a target product. The inhibitory activity of the complex to certain cancer cells is higher than the activity of a common antitumor drug cis-platinum; the complex has lower toxicity to human liver normal cell HL-7702. The structure of the complex disclosed by the invention is shown as a formula (I); the structural formulas of the compound shown as the raw material formula (II) and the compound shown as the formula (III) involved in preparation of the complex are shown in the description.
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Paragraph 0029
(2018/11/22)
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- NOVEL COLOR CONVERTER
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Color converter comprising at least one polymer and at least one organic fluorescent dye comprising at least one structural unit of the formula (I) where the structural unit may be mono- or polysubstituted by identical or different substituents and where one or more CH groups of the six-membered ring of the benzimidazole structure shown may be replaced by nitrogen.
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Paragraph 0286; 0287
(2016/10/17)
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- Synthesis and photophysical properties of three ladder-type chromophores with large and rigid conjugation structures
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Three novel ladder-conjugated chromophores indicated as LT1–LT3 were synthesized and characterized. Further studies on linear, nonlinear optics and electrochemical properties demonstrated their photophysical features respectively. Compound LT1 shows good two-photon absorption cross-section (δ) up to?～1200?GM at 810?nm in tetrahydrofuran, which is attributed to intramolecular charge transfer effect, as supported by density functional theory theoretical calculations. Compound LT2 and LT3 show considerable molar extinction coefficients, which are more than 105, and higher quantum yields. Structure–function relationship is further discussed, suggesting a rational strategy to develop ladder-conjugated small molecules.
- Zhang, Kaichen,Dai, Yong,Zhang, Xinfu,Xiao, Yi
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- A versatile synthesis of bicyclic lactams from 1,8-naphthalaldehydic acid: An extension of Meyers' method
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A new and versatile approach to prepare bicyclic lactams in moderate to high yield is reported herein. This approach, based on an extension of Meyers' method, provides 6,5-, 6,6-and 6,7-fused bicyclic lactams 6a-j from reaction of 1,8-naphthalaldehydic acid 7 with several aminoalcohols including L-serine, diamines and ethanethiol, in the absence of any catalyst. The reaction of 7 with (R)-phenylglycinol gave the 6,5-fused bicyclic lactam 6j in excellent diastereoselectivity (>98:2). ARKAT-USA, Inc.
- Claudio-Catalan, Miguel Angel,Reyes-Gonzalez, Miguel Angel,Ordonez, Mario
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p. 413 - 423
(2014/01/23)
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- Green synthesis of polycyclic benzimidazole derivatives and organic semiconductors
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Polycyclic benzimidazole derivatives, an important class of compounds in organic electronics and photovoltaics, were prepared using a solvent-free "green" process based on heating carboxylic acid anhydrides and arylene diamines in the presence of zinc acetate in the solid state. Products were isolated and purified directly by train sublimation of the crude reaction mixtures. The reaction conditions were optimized using various carboxylic acid anhydrides. Optical and electrochemical properties of these materials are also described.
- Mamada, Masashi,Perez-Bolivar, Cesar,Anzenbacher, Pavel
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scheme or table
p. 4882 - 4885
(2011/12/05)
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- Selective preparation of fluorescent 1,8-naphthalimides using acidic alumina under microwave irradiation
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7H-benzimidazo[2,1-a]benz[de]isoquinolin-7-one compounds were prepared in a selective manner by reaction between o-phenylenediamines and appropriate 1,8-naphthalenedicarboxylic anhydrides using acidic alumina under microwave irradiation.
- Pourjavadi, Ali,Marandi, Gholam Bagheri
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p. 485 - 487
(2007/10/03)
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- A "green" route to perylene dyes: Direct coupling reactions of 1,8-naphthalimide and related compounds under mild conditions using a "new" base complex reagent, t-BuOK/DBN
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The direct coupling reactions of 1,8-naphthalimide compounds efficiently occurred at 130 or 170 °C without the intervention of the leuco form dyes in the presence of base complex reagent, t-BuOK/1,5-diazabicyclo[4.3.0]non-5-ene (DBN), to give the corresponding perylene dyes in good yields with >95% purities. A possible mechanistic speculation for these oxidative coupling reactions is briefly discussed.
- Sakamoto,Pac
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- NOVEL HETEROCYCLIC COMPOUNDS VIA AZA- AND BIS-AZA-WITTIG REACTIONS
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Two quinoxaline derivatives, 1 and 2, were prepared via a bis-aza-Wittig reaction when the suitable aromatic diamine was treated with (MeO)3PBr2/Et3N followed by the addition of benzil.Also, two additional novel heterocyclic compounds, 4 and 6 were prepared via an intramolecular aza-Wittig reaction. Key words: Quinoxaline; bis-aza-Wittig; heterocycles.
- Alkhathlan, Hamad Z.,Al-Lohedan, Hamad A.
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p. 301 - 305
(2007/10/02)
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