1771775-13-3Relevant academic research and scientific papers
Comparative study of multi-functional luminogens with 1,3,5-triazine as the core and phenothiazine or phenoxy donors as the peripheral moieties for non-doped/doped fluorescent and red phosphorescent OLEDs
Tan, Xiao-Feng,Wang, Pei-Pei,Lu, Ling,Bezvikonnyi, Oleksandr,Volyniuk, Dmytro,Grazulevicius, Juozas Vidas,Zhao, Qing-Hua
, (2020)
A series of three-armed fluorescent emitters based on a 1,3,5-triazine acceptor as the central core and phenothiazine or phenoxy moieties as the different peripheral units, are designed and synthesized. All of them exhibit aggregation-induced emission enhancement and thermally activated delayed fluorescence. Photoluminescence quantum yields exceeded 37 and 67% for non-doped and doped solid-state samples respectively. The compounds were found to be capable of transporting both holes and electrons. The highest mobility values of more than 1 × 10?4 cm2V?1s?1 were obtained for the compound having three phenothiazine moieties at electric field of more than 1 × 106 Vcm?1. Additionally, three types of organic light emitting diodes based on these materials were fabricated. The device containing non-doped emission layer with the compound containing single phenothiazine moiety as the emitter gave maximum external quantum efficiency of 5.4%. The device with doped emission layer containing 5% solid solution of the compound having three phenothiazine moieties in an appropriate host gave maximum external quantum efficiency of 9.9%. The phosphorescent device hosted by the compound with single phenothiazine unit exhibited maximum external quantum efficiency of 10.3% and a low-efficiency roll-offs of 1% at 1000 cd/m2.
Phenothiazine Radical Cation Excited States as Super-oxidants for Energy-Demanding Reactions
Christensen, Joseph A.,Phelan, Brian T.,Chaudhuri, Subhajyoti,Acharya, Atanu,Batista, Victor S.,Wasielewski, Michael R.
, p. 5290 - 5299 (2018)
We demonstrate that the 10-phenyl-10H-phenothiazine radical cation (PTZ+?) has a manifold of excited doublet states accessible using visible and near-infrared light that can serve as super-photooxidants with excited-state potentials is excess of +2.1 V vs SCE to power energy demanding oxidation reactions. Photoexcitation of PTZ+? in CH3CN with a 517 nm laser pulse populates a Dn electronically excited doublet state that decays first to the unrelaxed lowest electronic excited state, D1′ (τ 1 (τ = 10.9 ± 0.4 ps), which finally decays to D0 (τ = 32.3 ± 0.8 ps). D1′ can also be populated directly using a lower energy 900 nm laser pulse, which results in a longer D1′→D1 relaxation time (τ = 19 ± 2 ps). To probe the oxidative power of PTZ+? photoexcited doublet states, PTZ+? was covalently linked to each of three hole acceptors, perylene (Per), 9,10-diphenylanthracene (DPA), and 10-phenyl-9-anthracenecarbonitrile (ACN), which have oxidation potentials of 1.04, 1.27, and 1.6 V vs SCE, respectively. In all three cases, photoexcitation wavelength dependent ultrafast hole transfer occurs from Dn, D1′, or D1 of PTZ+? to Per, DPA, and ACN. The ability to take advantage of the additional oxidative power provided by the upper excited doublet states of PTZ+? will enable applications using this chromophore as a super-oxidant for energy-demanding reactions.
High-efficiency near-infrared fluorescent organic light-emitting diodes with small efficiency roll-off based on AIE-active phenanthro[9,10-d]imidazole derivatives
Du, Chunya,Gao, Lei,Jin, Haixu,Liu, Futong,Liu, Hui,Lu, Ping,Min, Jiarui,Tan, Yongbo,Tang, Xiangyang
, p. 6883 - 6890 (2020)
The simultaneous realization of high-efficiency and low-cost in fluorescent organic light-emitting diodes (OLEDs) is still a formidable challenge in the deep-red (DR)/near-infrared (NIR) region because of the intrinsic limitation of the energy-gap law and fluorescence quenching effect. Herein, three novel donor-acceptor-donor' (D-A-D') fluorophores,PIBz-10-PTZ,PIBz-10P-PTZandPIBz-3-PTZ, by utilizing phenanthro[9,10-d]imidazole and phenothiazine as the donor and benzothiadiazole as the acceptor are synthesized. Owing to the unilateral steric hindrance between adjacent hydrogen atoms along the horizontal axis,PIBz-3-PTZpossesses a completely planar conformation and fully conjugated structure.PIBz-3-PTZexhibits a strong DR emission and aggregation induced emission (AIE) property with a high photoluminescence quantum yield of 35% in neat thin films. The nondoped OLEDs achieved a maximum external quantum efficiency (EQE) of 2.02% with an emission peak at 672 nm and a brightness of up to 3403 cd m-2. In addition, the device was able to maintain an EQE of 1.69% at a high luminance of 100 cd m-2, with a low efficiency roll-off of 16%, suggesting that the nondoped device can keep a relatively high efficiency at very high brightness.
Cavity-promotion by pillar[5]arenes expedites organic photoredox-catalysed reductive dehalogenations
Schmidt, Maximilian,Esser, Birgit
, p. 9582 - 9585 (2021/09/28)
The efficiency of the photo-induced electron transfer in photoredox catalysis is limited by the diffusional collision of the excited catalyst and the substrate. We herein present cavity-bound photoredox catalysts, which preassociate the substrates, leading to significantly shortened reaction times. A pillar[5]arene serves as the cavity and phenothiazine as a catalyst in the reductive dehalogenation of aliphatic bromides as a proof of concept reaction.
Luminescent solar concentrators with outstanding optical properties by employment of D-A-D quinoxaline fluorophores
Battisti, Antonella,Calamante, Massimo,Charaf, Rima,Coppola, Carmen,De Jong, Bastiaan,Di Donato, Mariangela,Foggi, Paolo,Mordini, Alessandro,Papucci, Costanza,Pucci, Andrea,Reginato, Gianna,Sinicropi, Adalgisa,Taddei, Maria,Zani, Lorenzo
supporting information, p. 15608 - 15621 (2021/11/30)
Luminescent solar concentrators (LSCs) are devices designed to efficiently collect both direct and diffuse solar radiation and concentrate it on photovoltaic cells to foster their use in building-integrated photovoltaics (BIPV). The optimization of LSC performances involves the adjustment of both the fluorophore and the guest polymer matrix. On this account, we investigated a series of high quantum yield, donor-acceptor-donor (D-A-D) photostable fluorophores (DQ1-5), presenting a central quinoxalinic acceptor core, not previously employed in LSCs, and triarylamines or phenothiazine as donor groups. The molecules were also decorated with alkyl chains on the central core and/or the donor groups, to explore their compatibility with the poly(methyl methacrylate) (PMMA) and poly(cyclohexyl methacrylate) (PCMA) matrices utilized in this study. The PMMA and PCMA films (25 μm thick), containing 0.2-2.2 wt% of DQ1-5, absorbed in the 370-550 nm range and presented emission maxima at 550-600 nm, with fluorescence quantum yields higher than 40% even at the highest doping contents. Notably, the DQ1/PMMA thin-films showed enhanced phase compatibility and excellent quantum yields, i.e., >95%. Accordingly, they were designed to obtain 25 cm2 area LSCs with remarkable internal (ηint) and external (ηext) photon efficiencies of 42.9% and 6.2%, respectively, higher than those observed from state-of-the-art devices based on the Lumogen Red 305 (LR305) as the reference fluorophore. Overall, these were the best results ever achieved in our laboratory for thin-film LSCs built with organic fluorescent emitters.
Thermally activated delayed fluorescence material for locking triphenylphosphine oxide receptor based on ether bond conformation
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, (2020/03/05)
The invention discloses a thermally activated delayed fluorescence material for locking a triphenylphosphine oxide receptor based on ether bond conformation. The material has a structure as shown in aformula which is described in the specification. The thermally activated delayed fluorescence material has very good blue light or green light color purity, very high luminous quantum efficiency andcharge injection/transmission performance, and is applicable as a luminescent material for preparation of a high-performance organic electroluminescent device; in addition, the blue light-emitting material also has a very high excited state energy level, and can be used as a host material for preparing a high-performance organic light-emitting device.
Spiro-xanthene fluorene-cored compound and application thereof to organic electroluminescent devices
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Paragraph 0106; 0107; 0108, (2019/04/17)
The invention discloses a spiro-xanthene fluorene-cored compound and application thereof to organic electroluminescent devices. Containing a s spiro-xanthene fluorene structure, the spiro-xanthene fluorene-cored compound is high in rigidity, and after bei
Compound with spirodimethyl anthracene fluorene as core and application thereof in organic light emission diode device
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Paragraph 0116-0124, (2019/04/17)
The invention relates to a compound with spirodimethyl anthracene fluorene as a core and an application thereof in organic light emission diode device. A structure of the compound is shown as the following formula. The compound provided by the invention u
Asymmetric thermally activated delayed fluorescence (TADF) emitters with 5,9-dioxa-13: B -boranaphtho[3,2,1- de] anthracene (OBA) as the acceptor and highly efficient blue-emitting OLEDs
Song, Dongdong,Yu, Yue,Yue, Ling,Zhong, Daokun,Zhang, Yindi,Yang, Xiaolong,Sun, Yuanhui,Zhou, Guijiang,Wu, Zhaoxin
, p. 11953 - 11963 (2019/10/16)
A series of new organic emitters was prepared by introducing various donors (Ds) to the meta-position of the boron atom in the central phenyl ring in the acceptor (A) of 5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene (OBA). Moreover, their thermal, photophysical, electrochemical and electroluminescent (EL) properties were characterized in detail. The photophysical results revealed that these OBA-based molecules adopted a D-A configuration and exhibited efficient thermally activated delayed fluorescence (TADF) properties with a reverse inter-system crossing constant (kRISC) in the order of 105 s-1. It has been shown that introducing the -Br group to the OBA acceptor could increase kRISC by 2 to 3 times. Importantly, the deep-blue TADF emitter OBA-O showed a high photoluminescent quantum yield (PLQY) of 0.84, while its blue analog OBA-BrO with the -Br group exhibited an even higher PLQY of 0.92 in the doped film state. Benefitting from their high PLQYs as blue-emitting TADF emitters, the doped organic light-emitting diodes (OLEDs) based on these OBA-based TADF emitters exhibited attractive electroluminescent (EL) performances. The blue-emitting OLEDs with CIE (0.17, 0.17) showed the maximum external quantum efficiency (ηext) of 17.8%, current efficiency (ηL) of 33.2 cd A-1 and power efficiency (ηP) of 34.2 lm W-1, while that for the bluish-green device were 22.5%, 49.2 cd A-1 and 56.9 lm W-1, respectively. Thus, the great potential of these TADF emitter-based OBA acceptors was clearly demonstrated by their EL data. In addition, these asymmetric OBA-based molecules will enrich the structural diversity of this type of TADF emitter.
Organic micromolecule material based on 2,6-dimethyl-4-cyanophenyl receptor unit, preparation and application
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Paragraph 0082; 0086; 0087; 0090; 0092; 0095; 0096, (2018/10/19)
The invention belongs to the technical field of organic photoelectric materials, and discloses an organic micromolecule material based on a 2,6-dimethyl-4-cyanophenyl receptor unit, preparation and application. The organic micromolecule material has a structural formula as shown in formula (I), and Ar in the formula shows a phenyl aromatic amine heterocycle or phenyl aromatic amine donor unit. Thematerial has a weak intramolecular charge transfer state, and thus, fluorescence emission of a zone from dark blue to ultraviolet can be realized. Meanwhile, because the molecules have quite short effective conjugated length, the material has high triplet state energy level. In the application of an organic electroluminescent device, the problem of unbalanced charge carriers of a unipolar organicphotoelectric material can be solved effectively, therefore, the structure of the device is simplified, and the performance of the device is improved.
