Spectrally resolved luminescence lifetime detection for measuring the energy splitting of the long-lived excited states

Abstract Thermally activated delayed fluorescence (TADF) was achieved when electron-rich triphenylene (Tpl) donors (D) were confined to a cage-based porous MOF host (NKU-111) composed of electron-deficient 2,4,6-tri(pyridin-4-yl)-1,3,5-triazine (Tpt) acceptor (A) as the ligand. The spatially-separated D and A molecules in a face-to-face stacking pattern generated strong through-space charge transfer (CT) interactions with a small singlet-triplet excited states energy splitting (∼0.1 eV), which enabled TADF. The resulting Tpl@NKU-111 exhibited an uncommon enhanced emission intensity as the temperature increased. Extensive steady-state and time-resolved spectroscopic measurements and first-principles simulations revealed the chemical and electronic structure of this compound in both the ground and low-lying excited states. A double-channel (T1, T2) intersystem crossing mechanism with S1 was found and explained as single-directional CT from the degenerate HOMO-1/HOMO of the guest donor to the LUMO + 1 of one of the nearest acceptors. The rigid skeleton of the compound and effective through-space CT enhanced the photoluminescence quantum yield (PLQY). A maximum PLQY of 57.36% was achieved by optimizing the Tpl loading ratio in the host framework. These results indicate the potential of the MOFs for the targeted construction and optimization of TADF materials.

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Auto-phase-locked Time-gated Luminescence Detection System for Spectrally Resolved Luminescence Lifetime Detection

Frontiers in Optics / Laser Science ◽

10.1364/fio.2020.jtu1a.2 ◽

2020 ◽

Author(s):

Qisheng Deng ◽

Zece Zhu ◽

Xuewen Shu

Keyword(s):

Detection System ◽

Luminescence Lifetime ◽

Luminescence Detection ◽

Spectrally Resolved

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Molecular-energy splitting of highly excited states in the two-Coulomb-center problem

Physical Review A ◽

10.1103/physreva.26.116 ◽

1982 ◽

Vol 26 (1) ◽

pp. 116-124 ◽

Cited By ~ 5

Author(s):

R. K. Janev ◽

C. J. Joachain ◽

N. N. Nedeljkovic

Keyword(s):

Excited States ◽

Energy Splitting ◽

Center Problem ◽

Coulomb Center

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Nuclear dynamics in electronic ground and excited states probed by spectrally resolved four wave mixing

The Journal of Chemical Physics ◽

10.1063/1.1479345 ◽

2002 ◽

Vol 116 (24) ◽

pp. 10801-10808 ◽

Cited By ~ 13

Author(s):

June-Sik Park ◽

Taiha Joo

Keyword(s):

Excited States ◽

Four Wave Mixing ◽

Wave Mixing ◽

Nuclear Dynamics ◽

Spectrally Resolved ◽

Electronic Ground

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Vuv Spectra Y to Mo

International Astronomical Union Colloquium ◽

10.1017/s0252921100107808 ◽

1988 ◽

Vol 102 ◽

pp. 239

Author(s):

M.S.Z. Chaghtai

Keyword(s):

Excited States ◽

Spectral Analyses ◽

Vuv Spectra

Using R.D. Cowan’s computations (1979) and parametric calculations of Meinders et al (1982), old analyses are thoroughly revised and extended at Aligarh, of Zr III by Khan et al (1981), of Nb IV by Shujauddin et Chaghtai (1985), of Mo V by Tauheed at al (1985). Cabeza et al (1986) confirmed the last one largely.Extensive studies have been reported of the 1–e spectra, Zr IV (Rahimullah et al 1980; Acquista and Reader 1980), Nb V (Shujauddin et al 1982; Kagan et al 1981) and Mo VI (Edlén et al 1985). Some interacting 4p54d2levels of these spectra have been reported from our laboratory, also.Detailed spectral analyses of transitions between excited states have furnished complete energy values for J ≠ 1 levels of these spectra during 1970s and 80s. Shujauddin et al (1982) have worked out Nb VI and Tauheed et al (1984) Mo VII from our lab, while Khan et al (1981) share the work on Zr V with Reader and Acquista (1979).

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