Excited state chemistry of indigoid dyes. 5. The intermediacy of the triplet state in the direct photoisomerization and the effect of substituents

1977 ◽  
Vol 81 (5) ◽  
pp. 413-420 ◽  
Author(s):  
Andree D. Kirsch ◽  
George M. Wyman
Keyword(s):  
Excited State ◽  
Triplet State ◽  
Effect Of Substituents

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.

Excited State Dynamics of trisbipyridylruthenium(2+),Ru(bpy)32+, on Porous Vycor Glass. Intervention of a Ligand Localized Triplet State

1994 ◽  
Vol 116 (12) ◽  
pp. 5343-5351 ◽  
Author(s):  
Jianwei Fan ◽  
Steven Tysoe ◽  
Thomas C. Strekas ◽  
Harry D. Gafney ◽  
Nick Serpone ◽  
...  
Keyword(s):  
Excited State ◽  
Triplet State ◽  
Vycor Glass ◽  
Excited State Dynamics ◽  
Porous Vycor Glass

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.

scholarly journals Effect of substituents on the excited-state dynamics of the modified DNA bases 2,4-diaminopyrimidine and 2,6-diaminopurine

2010 ◽  
Vol 12 (20) ◽  
pp. 5375 ◽  
Author(s):  
Zsolt Gengeliczki ◽  
Michael P. Callahan ◽  
Nathan Svadlenak ◽  
Csaba István Pongor ◽  
Bálint Sztáray ◽  
...  
Keyword(s):  
Excited State ◽  
Dna Bases ◽  
Excited State Dynamics ◽  
Effect Of Substituents ◽  
Modified Dna

Extending Excited-state Lifetimes by Interchromophoric Triplet-state Equilibration in a Pyrene-Ru(II)diimine Dyad System

2003 ◽  
Vol 15 (7-8) ◽  
pp. 627-637 ◽  
Author(s):  
Stéphanie Leroy-lhez ◽  
Colette Belin ◽  
Anthony D'aleo ◽  
René M. Williams ◽  
Luisa De Cola ◽  
...  
Keyword(s):  
Excited State ◽  
Triplet State ◽  
Excited State Lifetimes

Photochemistry of Aryltert-Butyl Ethers in Methanol:  The Effect of Substituents on an Excited State Cleavage Reaction

2000 ◽  
Vol 65 (13) ◽  
pp. 4162-4168 ◽  
Author(s):  
D. P. DeCosta ◽  
A. Bennett ◽  
A. L. Pincock ◽  
J. A. Pincock ◽  
R. Stefanova
Keyword(s):  
Excited State ◽  
Cleavage Reaction ◽  
Effect Of Substituents

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.

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