Dynamics of Electrons in Ammonia Cages: The Discovery System of Solvation

✍ Scribed by I-Ren Lee; Wonchul Lee; Ahmed H. Zewail

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 520 KB
• Volume: 9
• Category: Article
• ISSN: 1439-4235
• DOI: 10.1002/cphc.200700562

✦ Synopsis

Abstract

Two centuries ago solvated electrons were discovered in liquid ammonia and a century later the concept of the solvent cage was introduced. Here, we report a real time study of the dynamics of size‐selected clusters, n=20 to 60, of electrons in ammonia, and, for comparison, that of electrons in water cages. Unlike the water case, the observed dynamics for ammonia indicates the formation, through a 100 fs temperature jump, of a solvent collective motion in a 500 fs relaxation process. The agreement of the experimental results—obtained for a well‐defined n, gated electron kinetic energy, and time delay—with molecular dynamics theory suggests the critical and different role of the kinetic energy and the librational motions involved in solvation.