Thermally Activated Delayed Fluorescence from Ag(I) Complexes: A Route to 100% Quantum Yield at Unprecedentedly Short Decay Time

2017 ◽  
Vol 56 (21) ◽  
pp. 13274-13285 ◽  
Author(s):  
Marsel Z. Shafikov ◽  
Alfiya F. Suleymanova ◽  
Rafał Czerwieniec ◽  
Hartmut Yersin
Keyword(s):  
Quantum Yield ◽  
Decay Time ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated

scholarly journals Hinged and Wide: A New P^P Ligand for Emissive [Cu(P^P)(N^N)][PF6] Complexes

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3934 ◽  
Author(s):  
Sarah Keller ◽  
Matthias Bantle ◽  
Alessandro Prescimone ◽  
Edwin C. Constable ◽  
Catherine E. Housecroft
Keyword(s):  
Mass Spectrometry ◽  
Excited State ◽  
Quantum Yield ◽  
Delayed Fluorescence ◽  
Ionization Mass ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Single Crystal Structures ◽  
Photoluminescence Quantum Yield ◽  
Deaerated Solution

Heteroleptic [Cu(BIPHEP)(N^N)][PF6] complexes (BIPHEP = 1,1′-biphenyl-2,2′-diylbis(diphenylphosphane)), in which N^N is 2,2′-bipyridine (bpy), 6-methyl-2,2′-bipyridine (6-Mebpy), 6-ethyl-2,2′-bipyridine (6-Etbpy), or 5,5′-dimethyl-2,2′-bipyridine (5,5′-Me2bpy), have been synthesized and characterized using multinuclear NMR spectroscopies and electrospray ionization mass spectrometry. The single crystal structures of [Cu(BIPHEP)(bpy)][PF6]∙CH2Cl2, [Cu(BIPHEP)(5,5′-Me2bpy)][PF6]∙CH2Cl2, [Cu(BIPHEP)(6-Mebpy)][PF6]∙Et2O∙0.5H2O and [Cu(BIPHEP)(6-Etbpy)][PF6] confirm distorted tetrahedral {Cu(P^P)(N^N)} coordination environments. Each compound shows a quasi-reversible Cu+/Cu2+ process. In deaerated solution, the compounds are weak emitters. Powdered samples are yellow emitters (λemmax in the range 558–583 nm) and [Cu(BIPHEP)(5,5′-Me2bpy)][PF6] exhibits the highest photoluminescence quantum yield (PLQY = 14%). On cooling to 77 K (frozen 2-methyloxolane), the emission maxima are red-shifted and the excited state lifetimes increase from τ1/2 < 8 μs, to τ1/2 values of up to 53 μs, consistent with the compounds with N^N = 6-Mebpy, 6-Etbpy and 5,5′-Me2bpy exhibiting thermally activated delayed fluorescence (TADF).

scholarly journals Modulation of Charge Transfer by N-Alkylation to Control Photoluminescence Energy and Quantum Yield

2020 ◽  
Author(s):  
Andrew T. Turley ◽  
Andrew Danos ◽  
Antonio Prlj ◽  
Andrew P. Monkman ◽  
Basile F.E. Curchod ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Quantum Yield ◽  
Delayed Fluorescence ◽  
Basic Site ◽  
Synthetic Control ◽  
Photophysical Process ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Stable Species ◽  
Emission Quenching

Charge transfer in organic fluorophores is a fundamental photophysical process that can be either beneficial, e.g., facilitating thermally activated delayed fluorescence, or detrimetnal, e.g., mediating emission quenching. <i>N</i>-Alkylation is shown to provide straightforward synthetic control of the charge transfer, emission energy and quantum yield of amine chromophores. We demonstrate this concept using quinine as a model. <i>N</i>-Alkylation causes changes in its emission that mirror those caused by changes in pH (i.e., protonation). Unlike protonation, however, alkylation of quinine’s two N sites is performed in a stepwise manner to give kinetically stable species. This kinetic stability allows us to isolate and characterize an <i>N</i>-alkylated analog of an ‘unnatural’ protonation state that is quaternized selectively at the less basic site, which is inaccessible using acid. These materials expose (i) the through-space charge-transfer excited state of quinine and (ii) the associated loss pathway, while (iii) developing a simple salt that outperforms quinine sulfate as a quantum yield standard. This <i>N</i>-alkylation approach can be applied broadly in the discovery of emissive materials by tuning charge-transfer states.

Combinatorial donor engineering for highly efficient blue thermally activated delayed fluorescence emitters with low efficiency roll-off

2021 ◽  
Author(s):  
Dong Jin Shin ◽  
Jun Seop Lim ◽  
Jun Yeob Lee
Keyword(s):  
Quantum Yield ◽  
Delayed Fluorescence ◽  
Intersystem Crossing ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Highly Efficient ◽  
Photoluminescence Quantum Yield ◽  
Low Efficiency

A thermally activated delayed fluorescence (TADF) molecule with high reverse intersystem crossing rate accompanied by high photoluminescence quantum yield was developed by combinatorial donor engineering of bicarbazole and 12H-benzofuro[3,2-a]carbazole. The...

Bright bluish-green emitting Cu(i) complexes exhibiting efficient thermally activated delayed fluorescence

2021 ◽  
Vol 50 (15) ◽  
pp. 5171-5176
Author(s):  
Chun-Hua Huang ◽  
Mingxue Yang ◽  
Xu-Lin Chen ◽  
Can-Zhong Lu
Keyword(s):  
Solid State ◽  
Quantum Yield ◽  
Delayed Fluorescence ◽  
High Quantum Yield ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
High Quantum ◽  
Bluish Green

Three strongly emissive Cu(i) complexes exhibiting bright bluish-green thermally activated delayed fluorescence in the solid state with high quantum yield up to 91% were synthesized and characterized.

A unique tetranuclear Ag(i) complex emitting efficient thermally activated delayed fluorescence with a remarkably short decay time

2018 ◽  
Vol 47 (17) ◽  
pp. 5956-5960 ◽  
Author(s):  
Xue-Min Gan ◽  
Rongmin Yu ◽  
Xu-Lin Chen ◽  
MingXue Yang ◽  
Ling Lin ◽  
...  
Keyword(s):  
Decay Time ◽  
Delayed Fluorescence ◽  
Frontier Orbitals ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Highly Efficient ◽  
Metal Orbital

A novel emissive tetranuclear Ag(i) complex with highly efficient thermally activated delayed fluorescence (TADF) was successfully prepared and characterized. The significant participation of a metal orbital in the occupied frontier orbitals leads to dominant MLCT emission.

A strongly greenish-blue-emitting Cu4Cl4 cluster with an efficient spin–orbit coupling (SOC): fast phosphorescence versus thermally activated delayed fluorescence

2016 ◽  
Vol 52 (37) ◽  
pp. 6288-6291 ◽  
Author(s):  
Xu-Lin Chen ◽  
Rongmin Yu ◽  
Xiao-Yuan Wu ◽  
Dong Liang ◽  
Ji-Hui Jia ◽  
...  
Keyword(s):  
Decay Time ◽  
Delayed Fluorescence ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Greenish Blue

A novel greenish-blue-emitting Cu(i) complex with high PLQY of 90% and short decay time of 9.9 μs is reported. The emission at 293 K consists of approximately equivalent fast phosphorescence and TADF.

scholarly journals Modulation of Charge Transfer by N-Alkylation to Control Photoluminescence Energy and Quantum Yield

2020 ◽  
Author(s):  
Andrew T. Turley ◽  
Andrew Danos ◽  
Antonio Prlj ◽  
Andrew P. Monkman ◽  
Basile F.E. Curchod ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Quantum Yield ◽  
Delayed Fluorescence ◽  
Basic Site ◽  
Synthetic Control ◽  
Photophysical Process ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Stable Species ◽  
Emission Quenching

Charge transfer in organic fluorophores is a fundamental photophysical process that can be either beneficial, e.g., facilitating thermally activated delayed fluorescence, or detrimetnal, e.g., mediating emission quenching. <i>N</i>-Alkylation is shown to provide straightforward synthetic control of the charge transfer, emission energy and quantum yield of amine chromophores. We demonstrate this concept using quinine as a model. <i>N</i>-Alkylation causes changes in its emission that mirror those caused by changes in pH (i.e., protonation). Unlike protonation, however, alkylation of quinine’s two N sites is performed in a stepwise manner to give kinetically stable species. This kinetic stability allows us to isolate and characterize an <i>N</i>-alkylated analog of an ‘unnatural’ protonation state that is quaternized selectively at the less basic site, which is inaccessible using acid. These materials expose (i) the through-space charge-transfer excited state of quinine and (ii) the associated loss pathway, while (iii) developing a simple salt that outperforms quinine sulfate as a quantum yield standard. This <i>N</i>-alkylation approach can be applied broadly in the discovery of emissive materials by tuning charge-transfer states.

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