Newer aspects of electron transfer in electrophilic Aromatic Nitration. Radical pairs as reactive intermediates by time-resolved spectroscopy

1994 ◽  
Vol 7 (7) ◽  
pp. 325-351 ◽  
Author(s):  
T. Michael Bockman ◽  
Jay K. Kochi
Keyword(s):  
Electron Transfer ◽  
Reactive Intermediates ◽  
Radical Pairs ◽  
Time Resolved ◽  
Time Resolved Spectroscopy ◽  
Aromatic Nitration

Time-Resolved Spectroscopy of Photoinduced Electron Transfer in Dinuclear and Tetranuclear Fe/Co Prussian Blue Analogues

2020 ◽  
Vol 60 (1) ◽  
pp. 449-459
Author(s):  
Jennifer Zimara ◽  
Hendrik Stevens ◽  
Rainer Oswald ◽  
Serhiy Demeshko ◽  
Sebastian Dechert ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Prussian Blue ◽  
Photoinduced Electron Transfer ◽  
Time Resolved ◽  
Time Resolved Spectroscopy ◽  
Prussian Blue Analogues

Effective Quenching and Excited-State Relaxation of a Cu(I) Photosensitizer Addressed by Time-Resolved Spectroscopy and TDDFT Calculations

2018 ◽  
Author(s):  
Aleksej Friedrich ◽  
Olga S. Bokareva ◽  
Shu-Ping Luo ◽  
Henrik Junge ◽  
Matthias Beller ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Copper Complex ◽  
Hydrogen Generation ◽  
Iron Catalyst ◽  
Time Resolved ◽  
Solar Hydrogen ◽  
Time Resolved Spectroscopy ◽  
Oxidative Pathway ◽  
The Individual ◽  
Mlct State

<p>Homogenous photocatalytic systems based on copper photosensitizers are promising candidates for noble metal free approaches in solar hydrogen generation. To improve their performance a detailed understanding of the individual steps is needed. Here, we study the interaction of a heteroleptic copper (I) photosensitizer with an iron catalyst by time-resolved spectroscopy and ab-initio calculations. The catalyst leads to rather efficient quenching of the <sup>3</sup>MLCT state of the copper complex, with a bimolecular rate being about three times smaller than the collision rate. Using control experiments with methyl viologen an appearing absorption band is assigned to the oxidized copper complex demonstrating that electron transfer from the sensitizer to the iron catalyst occurs and the system reacts along an oxidative pathway. However, only about 30% of the quenching events result in an electron transfer while the other 70% experience deactivation indicating that the photocatalytic performance could be improved by optimizing the intermolecular interaction.</p><p><br></p>

Effective Quenching and Excited-State Relaxation of a Cu(I) Photosensitizer Addressed by Time-Resolved Spectroscopy and TDDFT Calculations

2018 ◽  
Author(s):  
Aleksej Friedrich ◽  
Olga S. Bokareva ◽  
Shu-Ping Luo ◽  
Henrik Junge ◽  
Matthias Beller ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Copper Complex ◽  
Hydrogen Generation ◽  
Iron Catalyst ◽  
Time Resolved ◽  
Solar Hydrogen ◽  
Time Resolved Spectroscopy ◽  
Oxidative Pathway ◽  
The Individual ◽  
Mlct State

<p>Homogenous photocatalytic systems based on copper photosensitizers are promising candidates for noble metal free approaches in solar hydrogen generation. To improve their performance a detailed understanding of the individual steps is needed. Here, we study the interaction of a heteroleptic copper (I) photosensitizer with an iron catalyst by time-resolved spectroscopy and ab-initio calculations. The catalyst leads to rather efficient quenching of the <sup>3</sup>MLCT state of the copper complex, with a bimolecular rate being about three times smaller than the collision rate. Using control experiments with methyl viologen an appearing absorption band is assigned to the oxidized copper complex demonstrating that electron transfer from the sensitizer to the iron catalyst occurs and the system reacts along an oxidative pathway. However, only about 60% of the quenching events result in an electron transfer while the other 40% experience deactivation indicating that the photocatalytic performance could be improved by optimizing the intermolecular interaction.</p>

Roles of adsorption sites in electron transfer from CdS quantum dots to molecular catalyst cobaloxime studied by time-resolved spectroscopy

2016 ◽  
Vol 18 (26) ◽  
pp. 17389-17397 ◽  
Author(s):  
Yun Ye ◽  
Yuxing Xu ◽  
Lei Huang ◽  
Dayong Fan ◽  
Zhaochi Feng ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electron Transfer ◽  
Absorption Spectroscopy ◽  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Cds Quantum Dots ◽  
Time Resolved ◽  
Time Resolved Spectroscopy ◽  
Molecular Catalyst ◽  
Adsorption Sites

Electron transfer from CdS quantum dots (QDs) to cobaloxime (Co(dmgH)2pyCl) is demonstrated by transient absorption spectroscopy (TAS), and further confirmed using photoluminescence (PL) techniques.

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