An electron-transfer induced reaction path controlled by ion-pair formation: an ESR/ENDOR study of furan carbaldehydes and their reactivity

1995 ◽  
pp. 803 ◽  
Author(s):  
Markus Scholz ◽  
Georg Gescheidt ◽  
J. Daub
Keyword(s):  
Electron Transfer ◽  
Reaction Path ◽  
Ion Pair ◽  
Pair Formation ◽  
Ion Pair Formation ◽  
Induced Reaction

Elektronentransfer und Ionenpaar-Bildung, 48 [1] Titrationen von Tetraphenyl-p-benzochinon mit Natrium- und Kaliummetall in aprotischen Lösungen / Electron Transfer and Ion Pair Formation, 48 [ 1 ] Titrations of Tetraphenyl-p-benzoquinone with Sodium and Potassium Metals in Aprotic Solutions

1996 ◽  
Vol 51 (9) ◽  
pp. 1222-1228 ◽  
Author(s):  
Hans Bock ◽  
Markus Kleine
Keyword(s):  
Electron Transfer ◽  
Radical Anion ◽  
Esr Spectra ◽  
Electron Transfer Reaction ◽  
Ion Pair ◽  
Pair Formation ◽  
Reaction Products ◽  
Ion Pair Formation ◽  
Electron Reduction ◽  
Sodium And Potassium

UV/VIS and ESR spectra of electron transfer reaction products in aprotic (cH⊕ < 0,1 ppm) solution can be measured in an especially designed and sealed glass apparatus and provide information on unknown facets of the microscopic pathway through the network of interdependent equilibria. For tetraphenyl-p-benzoquinone in tetrahydrofuran, single-electron reduction by a sodium metal mirror produces a red solution and, unexpectedly, after addition of 2.2.2. cryptand, contact with a potassium metal mirror generates a green (!) one. For both, ESR/ENDOR spectra prove the presence of tetraphenyl-p-benzoquinone radical anion. UV/VIS measurements provide the clue: In the equilibrium revealed by repetetive spectra recording, M·⊖solv + Me⊕solv ⇄ [M·⊖···Me⊖]solv, the radical anion is green (vm = 16900 cm-1) and the contact ion pair red (vm=18900 cm-1 ). On ion pair formation, therefore, the excitation energy of the radical anion increases by 0.25 eV.

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.

scholarly journals Ion-Pair Formation in Neutral Potassium-Neutral Pyrimidine Collisions: Electron Transfer Experiments

2019 ◽  
Vol 7 ◽  
Author(s):  
Mónica Mendes ◽  
Beatriz Pamplona ◽  
Sarvesh Kumar ◽  
Filipe Ferreira da Silva ◽  
Antonio Aguilar ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Ion Pair ◽  
Pair Formation ◽  
Ion Pair Formation

Elektronentransfer und Ionenpaar-Bildung, 20 / Electron Transfer and Ion Pairing, 20

1991 ◽  
Vol 46 (8) ◽  
pp. 1091-1097 ◽  
Author(s):  
H. Bock ◽  
D. Jaculi
Keyword(s):  
Electron Transfer ◽  
Supporting Electrolyte ◽  
Ion Pairing ◽  
Ion Pair ◽  
Pair Formation ◽  
Ion Pair Formation ◽  
Reduction Potentials

Cyclovoltammetric measurements of solutions containing the rather basic tetra-(2′-pyridyl)pyrazine allow to detect even traces of water and thus can be used as a touchstone for aprotic (cH⊕ &lt; 1 ppm) conditions. On exchange of the “innocent” tetrabutylammonium R4N⊕ as supporting electrolyte cation by “interactive” ones such as Li⊕) or Na⊕, considerable changes in the reduction potentials are observed due to ion pair formation.

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