scholarly journals Control of triplet state generation in heavy atom-free BODIPY–anthracene dyads by media polarity and structural factors

2018 ◽  
Vol 20 (12) ◽  
pp. 8016-8031 ◽  
Author(s):  
Mikhail A. Filatov ◽  
Safakath Karuthedath ◽  
Pavel M. Polestshuk ◽  
Susan Callaghan ◽  
Keith J. Flanagan ◽  
...  
Keyword(s):  
Excited State ◽  
Triplet State ◽  
State Formation ◽  
Heavy Atom ◽  
Molecular Rotation ◽  
Structural Factors ◽  
Triplet Excited State ◽  
State Generation

Heavy atom-free BODIPY–anthracene dyads show triplet excited state formation via PeT, controlled by molecular rotation and environmental polarity.

Photoreduction and light-induced triplet-state formation in a single-site fluoroalkylated zinc phthalocyanine

2014 ◽  
Vol 43 (40) ◽  
pp. 14942-14948 ◽  
Author(s):  
Hans Moons ◽  
Andrei Loas ◽  
Sergiu M. Gorun ◽  
Sabine Van Doorslaer
Keyword(s):  
Excited State ◽  
Low Power ◽  
Triplet State ◽  
State Formation ◽  
Red Light ◽  
Single Site ◽  
Zinc Phthalocyanine ◽  
Light Illumination ◽  
Triplet Excited State ◽  
Uv Illumination

Anaerobic red-light illumination leads to reduction of perfluoroisopropyl-substituted zinc(ii) phthalocyanine in ethanol, while low power UV illumination favours the formation of a triplet excited state.

A fullerene-rhodamine B photosensitizer with pH-activated visible-light absorbance/fluorescence/photodynamic therapy

2018 ◽  
Vol 6 (18) ◽  
pp. 2778-2784 ◽  
Author(s):  
Qianyun Tang ◽  
Wanyue Xiao ◽  
Jiewei Li ◽  
Dapeng Chen ◽  
Yewei Zhang ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Excited State ◽  
Visible Light ◽  
Rhodamine B ◽  
Heavy Atom ◽  
Triplet Excited State ◽  
Turn On ◽  
State Generation ◽  
Fluorescence Turn On ◽  
Light Absorbance

A heavy-atom-free photosensitizer (C60-RB) with pH-activable visible-light absorbance enhancement, fluorescence turn-on and triplet excited state generation was designed for tumor bioimaging and photodynamic therapy.

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.

Triplet state quantum yields for some arom atic hydrocarbons and xanthene dyes in dilute solution

1967 ◽  
Vol 299 (1458) ◽  
pp. 348-353 ◽  
Keyword(s):  
Triplet State ◽  
State Formation ◽  
Heavy Atom ◽  
Quantum Yields ◽  
Triplet States ◽  
Dilute Solution ◽  
Perturbation Techniques ◽  
Excited Singlet ◽  
Xanthene Dyes ◽  
Extinction Coefficients

Quantum yields of triplet state formation and extinction coefficients of the triplet states have been determined by direct depletion methods for solutions of anthracene, phenanthrene, 1,2,5,6-dibenzanthracene, fluorescein, dibromofluorescein, eosin and erythrosin. The values obtained for the hydrocarbons are in reasonable agreement with those obtained by other workers using energy transfer and heavy atom perturbation techniques. In all cases which we have studied, the sum of the quantum yields of fluorescence and triplet state formation is equal to unity within the limits of experimental error, showing that radiationless transfer from the excited singlet to the ground state is negligible.

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.

Efficient intersystem crossing using singly halogenated carbomethoxyphenyl porphyrins measured using delayed fluorescence, chemical quenching, and singlet oxygen emission

2015 ◽  
Vol 17 (43) ◽  
pp. 29090-29096 ◽  
Author(s):  
Dawn M. Marin ◽  
Sonia Payerpaj ◽  
Graham S. Collier ◽  
Angy L. Ortiz ◽  
Gaurav Singh ◽  
...  
Keyword(s):  
Excited State ◽  
Singlet Oxygen ◽  
State Formation ◽  
Delayed Fluorescence ◽  
Intersystem Crossing ◽  
Fluorescence Lifetimes ◽  
Triplet Excited State

Singly halogenated carbomethoxyphenylporphyrins show decreased singlet fluorescence lifetimes and increased rates of triplet excited state formation.

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.

Morphology dependence of the triplet excited state formation and absorption in polyfluorene

2005 ◽  
Vol 71 (24) ◽  
Author(s):  
Anna Hayer ◽  
Amena L. T. Khan ◽  
Richard H. Friend ◽  
Anna Köhler
Keyword(s):  
Excited State ◽  
State Formation ◽  
Triplet Excited State
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