Electron Spin Resonance of Alkali Metal Contact Ion Pairs of 2,6-di-tert-Butylbenzoquinone in Non Polar Solvent

Free radical and radical ion intermediates in the photochemical reactions of carbonyl compounds with organometals

“…of using crown ether has been demonstrated in the generation of ion pairs in non-polar solvents via thermal alkali metal reduction in the presence of crown ether[37,38]. Furthermore, by carefully choosing the crown ether, the contact ion pair of p_-quinone can be observed in benzene by photolyzing the solution of quinone in the presence of both alkali metal alkoxide and crown ether[39], as shown below. ) A limitation of this photochemical process becomes apparent when the ionic dissociation constants of the alkali metal salts of tetraphenylborates in a given solvent are compared.…”