Tuning the Triplet Excited State of Bis(dipyrrin) Zinc(II) Complexes: Symmetry Breaking Charge Transfer Architecture with Exceptionally Long Lived Triplet State for Upconversion

2020 ◽  
Vol 26 (65) ◽  
pp. 14912-14918
Author(s):  
Zafar Mahmood ◽  
Noreen Rehmat ◽  
Shaomin Ji ◽  
Jianzhang Zhao ◽  
Shanshan Sun ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Symmetry Breaking ◽  
Triplet State ◽  
Triplet Excited State

scholarly journals Triplet energies and excimer formation in meta - and para -linked carbazolebiphenyl matrix materials

2015 ◽  
Vol 373 (2044) ◽  
pp. 20140446 ◽  
Author(s):  
Sergey A. Bagnich ◽  
Alexander Rudnick ◽  
Pamela Schroegel ◽  
Peter Strohriegl ◽  
Anna Köhler
Keyword(s):  
Excited State ◽  
Triplet State ◽  
Spectroscopic Investigation ◽  
Triplet Excited State ◽  
Conjugation Length ◽  
Triplet Energy ◽  
Excimer Formation

We present a spectroscopic investigation on the effect of changing the position where carbazole is attached to biphenyl in carbazolebiphenyl (CBP) on the triplet state energies and the propensity to excimer formation. For this, two CBP derivatives have been prepared with the carbazole moieties attached at the ( para ) 4- and 4 ′ -positions ( p CBP) and at the ( meta ) 3- and 3 ′ -positions ( m CBP) of the biphenyls. These compounds are compared to analogous m CDBP and p CDBP, i.e. two highly twisted carbazoledimethylbiphenyls, which have a high triplet energy at about 3.0 eV and tend to form triplet excimers in a neat film. This torsion in the structure is associated with localization of the excited state onto the carbazole moieties. We find that in m CBP and p CBP, excimer formation is prevented by localization of the triplet excited state onto the central moiety. As conjugation can continue from the central biphenyls into the nitrogen of the carbazole in the para -connected p CBP, emission involves mainly the benzidine. By contrast, the meta -linkage in m CBP limits conjugation to the central biphenyl. The associated shorter conjugation length is the reason for the higher triplet energy of 2.8 eV in m CBP compared with the 2.65 eV in p CBP.

Symmetry-breaking intramolecular charge transfer in the excited state of meso-linked BODIPY dyads

2012 ◽  
Vol 48 (2) ◽  
pp. 284-286 ◽  
Author(s):  
Matthew T. Whited ◽  
Niral M. Patel ◽  
Sean T. Roberts ◽  
Kathryn Allen ◽  
Peter I. Djurovich ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Symmetry Breaking ◽  
Intramolecular Charge Transfer

Detection and chemistry of the triplet state of thymine

1970 ◽  
Vol 48 (4) ◽  
pp. 694-696 ◽  
Author(s):  
A. G. Szabo ◽  
W. D. Rlddell ◽  
R. W. Yip
Keyword(s):  
Excited State ◽  
Triplet State ◽  
Rate Constant ◽  
Triplet Excited State

The transient produced on flash excitation of degassed solutions of thymine in acetonitrile has been characterized as the triplet excited state of thymine. This triplet state has a lifetime of 14 ± 1 μs and the associated dimerization rate was found to be 5.3 ± 0.3 × 108 M−1 s−1. The triplet state of thymine could be quenched by 2,4-hexadien-1-ol with a rate constant of 8.1 ± 0.6 × 109 M−1 s−1.

Ultralong organic luminogens with color-tunability via intermolecular through-space charge-transfer characters

2020 ◽  
Vol 8 (33) ◽  
pp. 11603-11609
Author(s):  
Yanju Luo ◽  
Zhenguo Pang ◽  
Chuan Li ◽  
Kuan Chen ◽  
Xujun Zheng ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Space Charge ◽  
Triplet Excited State ◽  
Initial State ◽  
Color Tunable ◽  
Color Tunability

A feasible constructive strategy for color-tunable UOL materials is demonstrated by utilizing triplet excited state with an intermolecular through-space charge-transfer character as the initial state.

Extending the scope of the carbonyl facilitated triplet excited state towards visible light excitation

2018 ◽  
Vol 20 (28) ◽  
pp. 19120-19128 ◽  
Author(s):  
Shinaj K. Rajagopal ◽  
Nagaraj K. ◽  
Somadrita Deb ◽  
Vinayak Bhat ◽  
Devika Sasikumar ◽  
...  
Keyword(s):  
Excited State ◽  
Visible Light ◽  
Triplet State ◽  
Lewis Acid ◽  
Triplet Excited State ◽  
Light Excitation ◽  
Acid Catalyzed

A series of extended π-conjugated benzophenone analogs was synthesized through a facile Lewis-acid catalyzed Friedel–Crafts reaction in order to exploit the integral triplet state properties of benzophenone.

Symmetry-breaking charge transfer in the excited state of directly linked push–pull porphyrin arrays

2017 ◽  
Vol 19 (21) ◽  
pp. 13970-13977 ◽  
Author(s):  
Taeyeon Kim ◽  
Jinseok Kim ◽  
Hirotaka Mori ◽  
Seongchul Park ◽  
Manho Lim ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Steady State ◽  
Symmetry Breaking ◽  
Time Resolved ◽  
Spectroscopic Measurements

We revealed a symmetry-breaking charge transfer (SBCT) process in the excited state of a directly linked push–pull porphyrin dyad (AD) and triad (ADA) via both steady-state and time-resolved spectroscopic measurements.

Electron-Phonon Coupling and CT-Character in the lowest Triplet Excited State of Anthracene EDA-Complex Crystals

1987 ◽  
Vol 42 (11) ◽  
pp. 1261-1265 ◽  
Author(s):  
S. Maier ◽  
H. Port
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Spectral Resolution ◽  
High Spectral Resolution ◽  
Phonon Coupling ◽  
Triplet Excited State ◽  
Electron Phonon Coupling ◽  
Donor Acceptor ◽  
Eda Complex ◽  
Complex Crystals

Photoexcitation spectra of triplet (T1← S0) zero-phonon lines and phonon sidebands in different anthracene electron donor-acceptor (EDA) complex crystals (A-PMDA, A-TCNB, A-TCPA) have been analyzed between 1.3 K and 50 K at high spectral resolution. From the electron-phonon coupling strength at T = 0 K values of the charge-transfer (CT) character in the range between 6% and 10% are calculated. The differences in these values are found to be correlated with the energetic positions of the triplet state, which are explained within the framework of the Mulliken theory.

The unquenched triplet excited state of the fluorescent OFF/ON Bodipy-derived molecular probe based on photo-induced electron transfer

2016 ◽  
Vol 15 (11) ◽  
pp. 1358-1365 ◽  
Author(s):  
Zafar Mahmood ◽  
Jianzhang Zhao
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Triplet State ◽  
Molecular Probe ◽  
Singlet Excited State ◽  
Triplet Excited State ◽  
Photo Induced Electron Transfer

Different from the singlet excited state (fluorescence), the triplet state of the probes is not quenched by photo-induced electron transfer.

scholarly journals Guidelines for Tuning the Excited State Hückel-Baird Hybrid Aromatic Character of Pro-Aromatic Quinoidal Compounds

2020 ◽  
Author(s):  
Sílvia Escayola ◽  
Claire Tonnelé ◽  
Eduard Matito ◽  
Albert Poater ◽  
Henrik Ottosson ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Organic Compounds ◽  
Intramolecular Charge Transfer ◽  
Triplet Excited State ◽  
Computational Tools ◽  
Future Studies ◽  
Aromatic Character ◽  
Wide Range ◽  
New Energy

<p>The present study aims to provide a solid ground for the identification, characterization and controlled design of pro-aromatic quinoidal organic compounds holding conjugated rings with Hückel and/or Baird (singlet and triplet) excited state aromatic character, and expects to become a reference work for future studies on Baird-aromaticity. Concretely, we explore a wide range of compounds with a central conjugated ring of different sizes and symmetric exocyclic substitutions. We employ a combination of different computational tools and we also introduce a new energy-based approach for the quantification of the Baird-aromatic character. </p> <p> </p> The key findings of this study indicate that Baird aromaticity is achieved in pro-aromatic quinoidal compounds having small anionic rings or in electron deficient rings with the proper exocyclic substitution. Low-lying states of these systems show very strong hole/electron overlaps, implying that their aromaticity cannot be related to intramolecular charge transfer.

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