Dynamics of electrons in ammonia cages: the discovery system of solvation.
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.
Lee
I-Ren
IR
Physical Biology Center for Ultrafast Science and Technology, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, CA 91125, USA.
Lee
Wonchul
W
Zewail
Ahmed H
AH
D000641:Ammonia / Q000737:chemistry*; D002627:Chemistry, Physical / Q000295:instrumentation / Q000379:methods*; D004583:Electrons; D007700:Kinetics; D046032:Microscopy, Energy-Filtering Transmission Electron / Q000379:methods*; D008956:Models, Chemical; D008968:Molecular Conformation; D011789:Quantum Theory; D012997:Solvents / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
D012997:Solvents; D014867:Water; D000641:Ammonia