New platinum(II) one-armed Schiff base complexes for blue and orange PHOLEDs applications

Zhang, Jie; Zhu, Xunjin; Zhong, Aiguo; Jia, Wenping; Wu, Fengshou; Li, Dan; Tong, Hongbo; Wu, Chenglin; Tang, Wenyuan; Zhang, Ping; Wang, Lei; Han, Deman

doi:10.1016/j.orgel.2016.12.024

Cited by 42 publications

(23 citation statements)

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“…Basic research of photophysical and chemical properties of organo-transition-metal compounds was strongly activated by their potential commercial use. This became particularly apparent for classes of compounds that may be applied as emitters in organicl ight emitting diodes (OLEDs) [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] or in light emitting electrochemical cells (LEEC). [7,[20][21][22][23][24][25][26][27][28] These scientific investigations led to am uch deeper understanding of photophysical principles and of the compound's properties resultingi nt he development of an enormousn umber of new materials in part with drastically improved properties for OLED applications.…”

Section: Introductionmentioning

confidence: 99%

TADF Material Design: Photophysical Background and Case Studies Focusing on Cu^Iand Ag^IComplexes

et al. 2017

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The development of organic light emitting diodes (OLEDs) and the use of emitting molecules have strongly stimulated scientific research of emitting compounds. In particular, for OLEDs it is required to harvest all singlet and triplet excitons that are generated in the emission layer. This can be achieved using the so-called triplet harvesting mechanism. However, the materials to be applied are based on high-cost rare metals and therefore, it has been proposed already more than one decade ago by our group to use the effect of thermally activated delayed fluorescence (TADF) to harvest all generated excitons in the lowest excited singlet state S . In this situation, the resulting emission is an S →S fluorescence, though a delayed one. Hence, this mechanism represents the singlet harvesting mechanism. Using this effect, high-cost and strong SOC-carrying rare metals are not required. This mechanism can very effectively be realized by use of Cu or Ag complexes and even by purely organic molecules. In this investigation, we focus on photoluminescence properties and on crucial requirements for designing Cu and Ag materials that exhibit short TADF decay times at high emission quantum yields. The decay times should be as short as possible to minimize non-radiative quenching and, in particular, chemical reactions that frequently occur in the excited state. Thus, a short TADF decay time can strongly increase the material's long-term stability. Here, we study crucial parameters and analyze their impact on the TADF decay time. For example, the energy separation ΔE(S -T ) between the lowest excited singlet state S and the triplet state T should be small. Accordingly, we present detailed photophysical properties of two case-study materials designed to exhibit a large ΔE(S -T ) value of 1000 cm (120 meV) and, for comparison, a small one of 370 cm (46 meV). From these studies-extended by investigations of many other Cu TADF compounds-we can conclude that just small ΔE(S -T ) is not a sufficient requirement for short TADF decay times. High allowedness of the transition from the emitting S state to the electronic ground state S , expressed by the radiative rate k (S →S ) or the oscillator strength f(S →S ), is also very important. However, mostly small ΔE(S -T ) is related to small k (S →S ). This relation results from an experimental investigation of a large number of Cu complexes and basic quantum mechanical considerations. As a consequence, a reduction of τ(TADF) to below a few μs might be problematic. However, new materials can be designed for which this disadvantage is not prevailing. A new TADF compound, Ag(dbp)(P -nCB) (with dbp=2,9-di-n-butyl-1,10-phenanthroline and P -nCB=bis-(diphenylphosphine)-nido-carborane) seems to represent such an example. Accordingly, this material shows TADF record properties, such as short TADF decay time at high emission quantum yield. These properties are based (i) on geometry optimizations of the Ag complex for a fast radiative S →S rate and (ii) on restricting the extent of geometry reorganiza...

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Section: Introductionmentioning

confidence: 99%

TADF Material Design: Photophysical Background and Case Studies Focusing on Cu^Iand Ag^IComplexes

et al. 2017

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“…6,8,9 Indeed, cyclometallated Pt(II) and Ir(III) complexes are often employed as emitters in phosphorescent OLEDs (PhOLEDs). 7,[10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] Apart from a high emission quantum yield, it is desirable that an OLED emitter shows a high radiative rate (short radiative decay time) in order to utilize more excitons per unit of time.…”

Section: Introductionmentioning

confidence: 99%

Unusually Fast Phosphorescence from Ir(III) Complexes via Dinuclear Molecular Design

Shafikov

Daniels

Kozhevnikov

2019

J. Phys. Chem. Lett.

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“…Synthesized compounds were screen for their cytotoxicity using the protocol of Meyer et al . This cytotoxic process is inexpensive, less time consuming and consistent. LC 50 value is calculated from the plot of the log concentration of compounds vs LC 50 values.…”

Section: Resultsmentioning

confidence: 99%

Design, synthesis, pharmacological evaluation and DNA interaction studies of binuclear Pt(II) complexes with pyrazolo[1,5‐a]pyrimidine scaffold

Lunagariya

Thakor

Waghela

et al. 2018

Applied Organom Chemis

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Substituted pyrazolo[1,5-a]pyrimidine ligands were synthesized by cyclization, using 3-(thiophen-2-yl)-1H-pyrazol-5-amine with substituted enones (3-phenyl-1-(pyridin-2-yl)prop-2-en-1-one) in presence of KOH and DMF as solvent to form cyclic aromatic compounds. The substituted pyrazolo[1,5-a] pyrimidine based binuclear Pt II complexes containing neutral tetradentated ligands have general formula [Pt 2 (5a-5f)Cl 4 ], (where, (5a -5f) = pyrazolo[1,5-a] pyrimidine ligand). This compounds were characterized by physicochemical and spectroscopic method like elemental analyses, UV-Visible, FT-IR, EDX, TGA, molar conductivity, magnetic susceptibility measurements, mass spectroscopy, 1 H and 13 C NMR method. The square planar geometry was predicted by electronic spectral study. All Pt II compounds were evaluated by antimicrobial assay, in vitro brine shrimp assay, in vivo cellular level bioassay using S. Pombe cells and anti-tuberculosis study. LC 50 (50% lethal concentration) values of compounds are observed between 6.450 -102.07 μg/mL. UV-vis absorption titration, competitive displacement assay, molecular docking and viscosity measurement were carried out to examine the binding type and binding strength of complexes. The binding studies suggest partial intercalative binding mode of the complexes and the observed binding constant (K b ) values are found in the order of 6d > 6b > 6c > 6a > 6e > 6 f. The anti-proliferative cytotoxicity of the synthesized Pt II complexes (6a-6f) were tested against the HCT-116 (Human Colorectal Carcinoma) cancer cell line.

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New platinum(II) one-armed Schiff base complexes for blue and orange PHOLEDs applications

Cited by 42 publications

References 51 publications

TADF Material Design: Photophysical Background and Case Studies Focusing on Cu^Iand Ag^IComplexes

TADF Material Design: Photophysical Background and Case Studies Focusing on Cu^Iand Ag^IComplexes

Unusually Fast Phosphorescence from Ir(III) Complexes via Dinuclear Molecular Design

Design, synthesis, pharmacological evaluation and DNA interaction studies of binuclear Pt(II) complexes with pyrazolo[1,5‐a]pyrimidine scaffold

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New platinum(II) one-armed Schiff base complexes for blue and orange PHOLEDs applications

Cited by 42 publications

References 51 publications

TADF Material Design: Photophysical Background and Case Studies Focusing on CuIand AgIComplexes

TADF Material Design: Photophysical Background and Case Studies Focusing on CuIand AgIComplexes

Unusually Fast Phosphorescence from Ir(III) Complexes via Dinuclear Molecular Design

Design, synthesis, pharmacological evaluation and DNA interaction studies of binuclear Pt(II) complexes with pyrazolo[1,5‐a]pyrimidine scaffold

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Product

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TADF Material Design: Photophysical Background and Case Studies Focusing on Cu^Iand Ag^IComplexes

TADF Material Design: Photophysical Background and Case Studies Focusing on Cu^Iand Ag^IComplexes