Strongly Luminescent Tungsten Emitters with Emission Quantum Yields of up to 84 %: TADF and High‐Efficiency Molecular Tungsten OLEDs

Chan, Kaai‐Tung; Lam, Tsz‐Lung; Yu, Daohong; Du, Lili; Phillips, David Lee; Kwong, Chun‐Lam; Tong, Glenna So Ming; Cheng, Gang; Che, Chi‐Ming

doi:10.1002/anie.201906698

Cited by 53 publications

(29 citation statements)

References 24 publications

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“…The cavities between the octahedral columns are occupied by organic cations. So far, many AMnX 3 -type coordination polymers (30)(31)(32)(33) have been designed by selecting different kinds of organic cations, [35a,36,38,48,68,69,72-74] as shown in Scheme 6. The frequently used organic cations are organic ammonium and pyridinium salts.…”

Section: Manganese(ii) Complex-based Coordination Polymersmentioning

confidence: 99%

“…[ 4,23,24,28–31 ] Many kinds of non‐noble metal‐based PTMCs such as copper(I), tungsten(VI), and manganese(II) complexes have emerged rapidly. [ 4,23–25,28–31 ] Phosphorescent manganese(II) complexes show great potentials in many applications, due to their features including highly efficient phosphorescence, flexible design in molecular structure, ease of synthesis, and rich physical properties (e.g., triboluminescence, stimuli‐responsivity, etc.). [ 24,25a,32–36 ]…”

Section: Introductionmentioning

confidence: 99%

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Phosphorescent Manganese(II) Complexes and Their Emerging Applications

Tao

Liu

Wong

2020

Advanced Optical Materials

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light-emitting device (OLED) in 1998, [1] phosphorescent transition-metal complexes, especially for noble metal-based ones (e.g., iridium(III), platinum(II), etc.) as triplet emitters toward highly efficient organic electroluminescence, have aroused extensive attention. [15-21] Owing to strong spin-orbit coupling effect, these complexes may use both singlet and triplet excitons to greatly enhance the efficiency of OLED, breaking the upper limit of the conventional fluorescent device efficiency. Due to their unique properties of excited states, they also have extended their applications in other fields, for instance, catalysis, organic solar cells, organic memory devices, biological sensing and imaging, photodynamic therapy, information recording, and security protection, etc. [22-27] Although extensive works have been done to the design and preparation of phosphorescent materials based on noble metals, these noble metals usually have some disadvantages (such as high cost and low abundance in nature), thereby limiting their practical applications. The relatively abundant and cheap PTMCs of low toxicity have drawn considerable interests very recently. [4,23,24,28-31] Many kinds of non-noble metal-based PTMCs such as copper(I), tungsten(VI), and manganese(II) complexes have emerged rapidly. [4,23-25,28-31] Phosphorescent manganese(II) complexes show great potentials in many applications, due to their features including highly efficient phosphorescence, flexible design in molecular structure, ease of synthesis, and rich physical properties (e.g., triboluminescence, stimuli-responsivity, etc.). [24,25a,32-36] Compared with the noble metals, manganese element with an atomic number of 25 has abundant reserves, is environmentally friendly and inexpensive. Moreover, it has richer valence and coordination mode, which has been widely used in the fields of catalysis, ferroelectric, and magnetic materials. [37-39] Among the various valence states of manganese ion, the divalent manganese ion having a 3d 5 electron configuration has a 4 T 1 − 6 A 1 radiative transition closely related to the crystal field strength. The crystal field strength in the metal complex highly depends on the chemical structure of the ligand and the coordination number. These features make the manganese(II) complexes having rich photophysical properties. By regulating the ligand structure, the organic counterion and the coordination number of the manganese(II) complex, the green, yellow, orange, red, or even near-infrared phosphorescence can be achieved. [23-25,36,40] It Phosphorescent manganese(II) complexes are emerging as a new generation of phosphorescent materials showing great potentials in many applications, owing to their unique features including highly efficient phosphorescence, diverse structural/molecular design, and ease of synthesis, structural diversity, rich physical properties (e.g., triboluminescence, stimuli-responsivity, etc.), high abundance, and low cost. The research on phosphorescent manganese(II) complexes is just in its infancy...

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Section: Manganese(ii) Complex-based Coordination Polymersmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Phosphorescent Manganese(II) Complexes and Their Emerging Applications

Tao

Liu

Wong

2020

Advanced Optical Materials

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“…While for singlet harvesting, the molecules have to show efficient thermally activated delayed fluorescence (TADF) at ambient temperature. Examples are found among Cu(I), Ag(I), Au(III), W(VI) and Zn(II) complexes [ 7 , 9 , 10 , 11 , 12 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 ] or specifically designed organic molecules [ 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 ,…”

Section: Introductionmentioning

confidence: 99%

P∩N Bridged Cu(I) Dimers Featuring Both TADF and Phosphorescence. From Overview towards Detailed Case Study of the Excited Singlet and Triplet States

et al. 2021

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We present an overview over eight brightly luminescent Cu(I) dimers of the type Cu2X2(P∩N)3 with X = Cl, Br, I and P∩N = 2-diphenylphosphino-pyridine (Ph2Ppy), 2-diphenylphosphino-pyrimidine (Ph2Ppym), 1-diphenylphosphino-isoquinoline (Ph2Piqn) including three new crystal structures (Cu2Br2(Ph2Ppy)3 1-Br, Cu2I2(Ph2Ppym)3 2-I and Cu2I2(Ph2Piqn)3 3-I). However, we mainly focus on their photo-luminescence properties. All compounds exhibit combined thermally activated delayed fluorescence (TADF) and phosphorescence at ambient temperature. Emission color, decay time and quantum yield vary over large ranges. For deeper characterization, we select Cu2I2(Ph2Ppy)3, 1-I, showing a quantum yield of 81%. DFT and SOC-TDDFT calculations provide insight into the electronic structures of the singlet S1 and triplet T1 states. Both stem from metal+iodide-to-ligand charge transfer transitions. Evaluation of the emission decay dynamics, measured from 1.2 ≤ T ≤ 300 K, gives ∆E(S1-T1) = 380 cm−1 (47 meV), a transition rate of k(S1→S0) = 2.25 × 106 s−1 (445 ns), T1 zero-field splittings, transition rates from the triplet substates and spin-lattice relaxation times. We also discuss the interplay of S1-TADF and T1-phosphorescence. The combined emission paths shorten the overall decay time. For OLED applications, utilization of both singlet and triplet harvesting can be highly favorable for improvement of the device performance.

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“…After focusing onto the flowing sample solution gently with these two beams, the Raman light was detected through a spectrometer whose grating dispersed the light onto a CCD detector with liquid nitrogen cooling. The known MeCN solvent’s Raman bands (5 cm −1 accuracy) were used to calibrate all the obtained Raman spectra, and the target sample solutions were determined by UV absorption value at 266 nm to be 1 in a 1 mm path-length cuvette [28]. The corresponding IRF for the ns-TR 3 is around 5 ns.…”

Section: Methodsmentioning

confidence: 99%

Time-Resolved Spectroscopic Study of N,N–Di(4–bromo)nitrenium Ions in Acidic Aqueous Solution

Yan

Bai

et al. 2019

IJMS

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Nitrenium ions are common reactive intermediates with high activities towards some biological nucleophiles. In this paper, we employed femtosecond transient absorption (fs-TA) and nanosecond transient absorption (ns-TA) as well as nanosecond time-resolved resonance Raman (ns-TR3) spectroscopy and density function theory (DFT) calculations to study the spectroscopic properties of the N(4,4′–dibromodiphenylamino)–2,4,6–trimethylpyridinium BF4− salt (1) in an acidic aqueous solution. Efficient cleavage of the N–N bond (4 ps) to form the N,N–di(4–bromophenyl)nitrenium ion (DN) was also observed in the acidic aqueous solution. As a result, the dication intermediate 4 appears more likely to be produced after abstracting a proton for the nitrenium ion DN in the acid solution first, followed by an electron abstraction to form the radical cation intermediate 3. These new and more extensive time-resolved spectroscopic data will be useful to help to develop an improved understanding of the identity, nature, and properties of nitrenium ions involved in reactions under acidic aqueous conditions.

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Strongly Luminescent Tungsten Emitters with Emission Quantum Yields of up to 84 %: TADF and High‐Efficiency Molecular Tungsten OLEDs

Cited by 53 publications

References 24 publications

Phosphorescent Manganese(II) Complexes and Their Emerging Applications

Phosphorescent Manganese(II) Complexes and Their Emerging Applications

P∩N Bridged Cu(I) Dimers Featuring Both TADF and Phosphorescence. From Overview towards Detailed Case Study of the Excited Singlet and Triplet States

Time-Resolved Spectroscopic Study of N,N–Di(4–bromo)nitrenium Ions in Acidic Aqueous Solution

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