par Jung, Céline Gisèle ;Peeters, Fabienne ;Castillo, José ;Boué, Stéphane ;Fontana, André
Référence Journal of the Chemical Society. Faraday transactions (Print), 91, 21, page (3809-3812)
Publication Publié, 1995
Article révisé par les pairs
Résumé : Solvated electrons, e s -, have been generated in hexamethylphosphoric triamide (HMPA) by chemical and electrochemical means. When Na metal was used to release e s -, two distinct bands, already reported in the literature, appeared in the absorption spectrum of the solution, which rapidly turned red-brown and decomposed according to irreproducible complex kinetics which could not be analysed. When Li was used instead of sodium, a single broad band extending into the IR region developed and later decayed obeying consistently first-order kinetics in absorbance. Kinetic rate constants are reported and half-lives at ambient temperature were about 1 h duration. A systematic study of the disappearance of solvated electrons in HMPA was carried out at several temperatures (from 7 to 27 °C) and an activation energy (85-89 kJ mol -1) is estimated both in the absence and in the presence of lithium perchlorate. However, the overall reaction rate is markedly increased in the presence of Li +; a mechanism is proposed to account for this lithium salt effect.