Broadband Visible Light-Harvesting Naphthalenediimide (NDI) Triad: Study of the Intra-/Intermolecular Energy/Electron Transfer and the Triplet Excited State

2015 ◽  
Vol 119 (20) ◽  
pp. 4787-4799 ◽  
Author(s):  
Shuang Wu ◽  
Fangfang Zhong ◽  
Jianzhang Zhao ◽  
Song Guo ◽  
Wenbo Yang ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Visible Light ◽  
Light Harvesting ◽  
Energy Electron ◽  
Triplet Excited State ◽  
Intermolecular Energy

scholarly journals Electron Transfer Initiated Reactions Photoinduced by Pterins

Pteridines ◽  
2011 ◽  
Vol 22 (1) ◽  
pp. 111-119 ◽  
Author(s):  
Carolina Lorente ◽  
Gabriela Petroselli ◽  
M. Laura Dántola ◽  
Esther Oliveros ◽  
Andrés H. Thomas
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Redox Reactions ◽  
Type I ◽  
Biological Processes ◽  
Type Ii ◽  
Triplet Excited State ◽  
Oxygen Production ◽  
Production Type ◽  
Transfer Mechanisms

Abstract Interest in the photochemistry and photophysics of pterins has increased since the participation of this family of compounds in different photobiological processes has been suggested or demonstrated in recent decades. Pterins participate in relevant biological processes, such as metabolic redox reactions, and can photoinduce the oxidation of biomolecules through both electron transfer mechanisms (Type I) and singlet oxygen production (Type II). This article describes recent findings on electron transfer-initiated reactions photoinduced by the triplet excited state of pterins and connects them in the context of photosensitized processes of biological relevance.

scholarly journals Light-driven deracemization enabled by excited-state electron transfer

Science ◽  
2019 ◽  
Vol 366 (6463) ◽  
pp. 364-369 ◽  
Author(s):  
Nick Y. Shin ◽  
Jonathan M. Ryss ◽  
Xin Zhang ◽  
Scott J. Miller ◽  
Robert R. Knowles
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Hydrogen Atom ◽  
Visible Light ◽  
Asymmetric Synthesis ◽  
Hydrogen Atom Transfer ◽  
Product Distributions ◽  
Reaction Proceeds ◽  
Molecular Catalysts ◽  
Distinct Approach

Deracemization is an attractive strategy for asymmetric synthesis, but intrinsic energetic challenges have limited its development. Here, we report a deracemization method in which amine derivatives undergo spontaneous optical enrichment upon exposure to visible light in the presence of three distinct molecular catalysts. Initiated by an excited-state iridium chromophore, this reaction proceeds through a sequence of favorable electron, proton, and hydrogen-atom transfer steps that serve to break and reform a stereogenic C–H bond. The enantioselectivity in these reactions is jointly determined by two independent stereoselective steps that occur in sequence within the catalytic cycle, giving rise to a composite selectivity that is higher than that of either step individually. These reactions represent a distinct approach to creating out-of-equilibrium product distributions between substrate enantiomers using excited-state redox events.

Exclusive triplet electron transfer leading to long-lived radical ion-pair formation in an electron rich platinum porphyrin covalently linked to fullerene dyad

2020 ◽  
Vol 56 (45) ◽  
pp. 6058-6061 ◽  
Author(s):  
Dili R. Subedi ◽  
Habtom B. Gobeze ◽  
Yuri E. Kandrashkin ◽  
Prashanth K. Poddutoori ◽  
Art van der Est ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Ion Pair ◽  
Pair Formation ◽  
Triplet Excited State ◽  
Ion Pair Formation ◽  
Donor Acceptor ◽  
Platinum Porphyrin ◽  
Covalently Linked ◽  
Pair Energy

Radical ion-pair energy as high as 1.48 eV with lifetime as much as ∼1 μs, exclusively from the triplet excited state of a photosensitizer, is established in a novel donor–acceptor conjugate.

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