Vibrational Radiationless Transition from Triplet States of Chromophores at Room Temperature

2021 ◽  
Vol 125 (3) ◽  
pp. 885-894
Author(s):  
Shuzo Hirata ◽  
Indranil Bhattacharjee
Keyword(s):  
Room Temperature ◽  
Triplet States ◽  
Radiationless Transition

scholarly journals Thermochromic AIE Dual Phosphorescence via Temperature-Dependent sp3-Linked Donor-Acceptor Electronic Coupling

2020 ◽  
Author(s):  
Tao Wang ◽  
Zhubin Hu ◽  
Xiancheng Nie ◽  
Linkun Huang ◽  
Hui Miao ◽  
...  
Keyword(s):  
Excited State ◽  
Room Temperature ◽  
Electronic Coupling ◽  
Triplet States ◽  
Molecular Motions ◽  
Temperature Dependent ◽  
Molecular Systems ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
And Control

<p>Aggregation-induced emission (AIE) has proven to be a viable strategy to achieve highly efficient RTP in bulk by restricting molecular motions. Here we show that by utilizing triphenylamine (TPA) as an electronic donor which connects to an acceptor via an sp3 linker, six TPA-based AIE-active RTP luminophores were obtained. Both the TPA AIE-gen and the <i>sp</i><sup>3</sup>-linkage can suppress aggregation-caused quenching. Consequently, dual phosphorescence bands emitting from localized donor and acceptor triplet states, respectively, could be recorded at lowered temperatures; at room temperature, only a single RTP band corresponding to the lowest triplet state is present, presumably due to thermally assisted electronic coupling between the two states. The reported molecular construct serves as an “intermediary case” between a fully conjugated donor-acceptor system and a do-nor/acceptor binary mix, which may provide important clues on the design and control of molecular systems with complex excited-state dynamics.<br></p>

Tunable broad-band white light emission in the two-dimensional (110)-oriented lead bromide perovskite (C3H8N6)[PbBr4]: Structural characterization, Optical and Luminescence properties.

2021 ◽  
Author(s):  
Rawia Msalmi ◽  
Slim Elleuch ◽  
Besma Hamdi ◽  
Eros Radicchi ◽  
Anowar Tozri ◽  
...  
Keyword(s):  
Energy Transfer ◽  
White Light ◽  
Room Temperature ◽  
Light Emission ◽  
Broad Band ◽  
Organic Cations ◽  
Triplet States ◽  
Two Dimensional ◽  
Room Temperature Phosphorescence ◽  
Lead Bromide

Newly, room temperature phosphorescence (RTP) in 2D hybrid perovskites has been proved due to the energy transfer from inorganic sheets to the conjugated organic cations harnessing the triplet states. So...

Relaxation und optische Kernspinpolarisation der Protonen in optisch angeregten Anthracen-Kristallen

1968 ◽  
Vol 23 (7) ◽  
pp. 1068-1076 ◽  
Author(s):  
G. Maier ◽  
H. C. Wolf
Keyword(s):  
Room Temperature ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Triplet States ◽  
Spin Lattice ◽  
Low Field ◽  
New Type ◽  
Spin Polarisation ◽  
Triplet Excitons

The influence of optically excited metastable triplet states on the spin lattice relaxation time T1 of protons in anthracene is investigated at room temperature. From the H0-field dependence of T1 in the presence of excited triplets we calculate the hopping time of triplet excitons τc=(5±1) · 10–12 sec. Especially in the low field region a new type of dynamic nuclear polarisation is observed. Triplet excitons, which are excited using unpolarized light produce via optical exciton spin polarisation an optical nuclear spin polarisation. Polarisation factors of more than 1000 are observed. Preliminary experiments with anthracene-tetracene mixed crystals are able to separate relaxation and polarisation effects due to mobile excitons from effects, which don’t need the mobility of excitons.

scholarly journals Activating Room-Temperature Phosphorescence of Organic Luminophores via External Heavy-Atom Effect and Rigidity of Ionic Polymer Matrix

2021 ◽  
Author(s):  
Xiang Ma ◽  
Zi-Ang Yan ◽  
Xiaohan Lin ◽  
Siyu Sun ◽  
He Tian
Keyword(s):  
Polymer Matrix ◽  
Room Temperature ◽  
Fluorescent Dyes ◽  
Amorphous Polymer ◽  
Heavy Atom ◽  
General Strategy ◽  
Triplet States ◽  
Room Temperature Phosphorescence ◽  
Heavy Atom Effect ◽  
Atom Effect

Pure organic room-temperature phosphorescence (RTP) materials have attracted wide attention for their easy preparation, low toxicity and applications in professional fields such as bioimaging and anti-counterfeiting. Developing phosphorescent systems with more universality and less difficulty in synthesis has long been the pursuit of materials scientists. By employing polymeric quaternary ammonium salt with an ionic bonding matrix and heavy atoms, commercial fluorescent dyes are directly endowed with phosphorescence emission. In a single amorphous polymer, the external heavy-atom effect generates excited triplet states, which are further stabilized by the rigid polymer matrix. This study proposed a new general strategy to design and develop pure organic RTP materials starting from the vast library of organic dyes without complicated chemical synthesis.

The Missing Link Between Molecular Triplets and Spin-Polarized Free Radicals: Room Temperature Triplet States of Nanocrystalline Radical Pairs

2010 ◽  
Vol 132 (1) ◽  
pp. 82-84 ◽  
Author(s):  
Natalia V. Lebedeva ◽  
Valery F. Tarasov ◽  
Marino J. E. Resendiz ◽  
Miguel A. Garcia-Garibay ◽  
Ryan C. White ◽  
...  
Keyword(s):  
Free Radicals ◽  
Room Temperature ◽  
Triplet States ◽  
Radical Pairs ◽  
Missing Link ◽  
Spin Polarized
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