Elektronentransfer und Ionenpaare, 15 [ 1– 3] Radikalanion und Radikal-Kontakt-Ionenpaare von Dimesityl-tetraketon / Electron Transfer and Ion Pairing, 15 [1-3] Radical Anion and Radical Ion Pairs of Dimesityl Tetraketone

1990 ◽  
Vol 45 (8) ◽  
pp. 1197-1204 ◽  
Author(s):  
H. Bock ◽  
P. Hänel ◽  
H.-F. Herrmann
Keyword(s):  
Electron Transfer ◽  
Radical Anion ◽  
Ion Pairs ◽  
Ion Pairing ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Temperature Dependent ◽  
Contact Ion Pairs

The radical anion of dimesityltetraketone (ERed, I = -0.40 V) is easily generated in THF by potassium mirror/[2.2.2]-cryptand reduction. Its contact ion pairs with Na⊕, Cs⊕ and Ba⊕⊕ counter cations, prepared in THF solution by single electron transfer from the respective metals, are characterized by their ESR/ENDOR spectra, which exhibit temperature-dependent metal couplings of aNa⊕ = 0.061 mT (190 K), aCs⊕ = 0.021 mT (190 K), and aBa⊕⊕ = 0.145 mT (295 K).

Elektronentransfer und Ionenpaar-Bildung, 7 [1, 2] Kontakt-Ionenpaare Schwefel enthaltender Radikalanionen / Electron Transfer and Ion Pairing, 7 [1, 2] Contact Ion Pairs of Sulfur-Containing Radical Anions

1988 ◽  
Vol 43 (10) ◽  
pp. 1240-1246 ◽  
Author(s):  
Hans Bock ◽  
Peter Hänel ◽  
H.-F Herrmann ◽  
Heindirk torn Dieck
Keyword(s):  
Electron Transfer ◽  
Ion Pairs ◽  
Ion Pairing ◽  
Radical Anions ◽  
Contact Ion Pairs ◽  
Sulfur Containing

The structurally different radical anions M⊖ of peralkylated 1-sila-2,5-diazacyclopentane-3,4-dithione and of tetrakis(isopropylthio)-p-benzoquinone are generated by reduction with potassium/2.2.2-cryptand under aprotic conditions in THF solution. On addition of Li⊕B(C6H5)4⊖, both form hitherto elusive sulfur-containing contact ion pairs, which are characterized by their ESR/ENDOR spectra.

Formation of Carbanions from Carboxylate Ions Bearing Electron-Withdrawing Groups via Photoinduced Decarboxylation: Addition of Generated Carbanions to Benzaldehyde

2015 ◽  
Vol 68 (11) ◽  
pp. 1668 ◽  
Author(s):  
Yuta Kumagai ◽  
Takashi Naoe ◽  
Keisuke Nishikawa ◽  
Kazuyuki Osaka ◽  
Toshio Morita ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Electron Acceptor ◽  
Radical Anion ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Mild Conditions ◽  
Efficient Generation ◽  
Photochemical Method

The photoinduced decarboxylation of carboxylate ions bearing electron-withdrawing groups using biphenyl and 1,4-dicyanonaphthalene leads to the efficient generation of carbanions under mild conditions. The efficiency of the carbanion generation is strongly dependent on the single-electron transfer from the photogenerated radical anion of the electron-acceptor to the radical. In particular, the cyanomethyl anion formed using this photochemical method can be added to benzaldehydes to give the corresponding adducts.

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