scholarly journals Singlet Fission and Electron Injection from the Triplet Excited State in Diphenylisobenzofuran–Semiconductor Assemblies: Effects of Solvent Polarity and Driving Force

2020 ◽  
Vol 124 (38) ◽  
pp. 20794-20805
Author(s):  
Elin Sundin ◽  
Rasmus Ringström ◽  
Fredrik Johansson ◽  
Betül Küçüköz ◽  
Andreas Ekebergh ◽  
...  
Keyword(s):  
Excited State ◽  
Driving Force ◽  
Solvent Polarity ◽  
Electron Injection ◽  
Triplet Excited State ◽  
Singlet Fission

Long-lived charge-separated states of simple electron donor-acceptor dyads using porphyrins and phthalocyanines

2008 ◽  
Vol 12 (09) ◽  
pp. 993-1004 ◽  
Author(s):  
Kei Ohkubo ◽  
Shunichi Fukuzumi
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Electron Donor ◽  
Driving Force ◽  
Reorganization Energy ◽  
Charge Recombination ◽  
Zinc Phthalocyanine ◽  
Intramolecular Electron Transfer ◽  
Triplet Excited State ◽  
Donor Acceptor

Control of electron-transfer processes is described for a number of electron donor-acceptor dyads containing porphyrins or phthalocyanines as models for the photosynthetic reaction center. The rates for intramolecular electron transfer in the dyads are controlled by the driving force and reorganization energy of electron transfer. The small reorganization energy of electron transfer reactions and large driving force of charge recombination are required to form long-lived charge-separated states. A directly linked zinc chlorin-fullerene dyad, especially, has the longest lifetime of charge-separated state at 120 s at -150 °C, which is a much longer lifetime and higher energy than those of natural photosynthetic reaction centers. On the other hand, the charge-separated states of the phthalocyanine-based donor-acceptor dyads (silicon phthalocyanine-fullerene, and zinc phthalocyanine-perylenebisimide) are short-lived since charge recombination forms the low-lying triplet excited state of the chromophore. The energy of the charge-separated state of a zinc phthalocyanine-perylenebisimide dyad is decreased by binding of metal ions to the radical anion moiety in order to be lower than the triplet excited state. This results in formation of a long-lived charge-separated state. The mechanistic viability of formation of long-lived charge-separated states is demonstrated by a variety of examples based on the Marcus theory of electron transfer.

Interligand Electron Transfer Determines Triplet Excited State Electron Injection in RuN3−Sensitized TiO2Films

2004 ◽  
Vol 108 (9) ◽  
pp. 2862-2867 ◽  
Author(s):  
Gábor Benkö ◽  
Jani Kallioinen ◽  
Pasi Myllyperkiö ◽  
Florentina Trif ◽  
Jouko E. I. Korppi-Tommola ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Electron Injection ◽  
Triplet Excited State ◽  
State Electron

Influence of solvent polarity on the dual fluorescence of p-N,N-dimethylaminobenzonitrile: An AM1 theoretical study

1990 ◽  
Vol 55 (8) ◽  
pp. 1891-1895 ◽  
Author(s):  
Peter Ertl
Keyword(s):  
Excited State ◽  
Theoretical Study ◽  
Solvent Polarity ◽  
Semiempirical Method ◽  
Dual Fluorescence ◽  
Long Wavelength ◽  
Polar Media ◽  
Wavelength Emission ◽  
Ground State Geometry ◽  
Influence Of Solvent

Twisting of the NMe2 group in p-N,N-dimethylaminobenzonitrile (DMABN) was investigated using AM1 semiempirical method with configuration interaction. Effect of polar media was considered by placing + and - charge centers ("sparkles") at appropriate places opposite the molecule. Optimized ground state geometry of DMABN is slightly twisted with the lowest vertical excited state of 1B character. As the polarity of media increases and/or the - NMe2 group twists, the symmetric 1A excited state having considerable charge separation becomes energetically favorable. Anomalous long-wavelength emission of DMABN comes from this state.

scholarly journals Ultra long‐lived triplet excited state in water at room temperature: Insights on the molecular design of tridecafullerenes

2021 ◽  
Author(s):  
Javier Ramos-Soriano ◽  
Alfonso Pérez-Sánchez ◽  
Sergio Ramírez-Barroso ◽  
Beatriz M. Illescas ◽  
Khalid Azmani ◽  
...  
Keyword(s):  
Excited State ◽  
Room Temperature ◽  
Molecular Design ◽  
Triplet Excited State

The role of conformational heterogeneity in the excited state dynamics of linked diketopyrrolopyrrole dimers

2021 ◽  
Author(s):  
Siobhan Bradley ◽  
Ming Chi ◽  
Jonathan White ◽  
Christopher R. Hall ◽  
Lars Goerigk ◽  
...  
Keyword(s):  
Excited State ◽  
Conformational Heterogeneity ◽  
Singlet Fission ◽  
Excited State Dynamics

Diketopyrrolopyrrole (DPP) derivatives have been proposed for both singlet fission and energy upconversion as they meet the energetic requirements and exhibit superior photostability compared to many other chromophores. In this...

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.

Investigation of the triplet excited state and application of cationic meso-tetra(cisplatin)porphyrins in antimicrobial photodynamic therapy

2021 ◽  
pp. 102459
Author(s):  
Dariane Clerici Jornada ◽  
Rafael de Queiroz Garcia ◽  
Carolina Hahn da Silveira ◽  
Lino Misoguti ◽  
Cleber Renato Mendonça ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Excited State ◽  
Antimicrobial Photodynamic Therapy ◽  
Triplet Excited State
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