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.
Physical Biology Center for Ultrafast Science and Technology, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, CA 91125, USA.
I-Ren
IR
Lee
Wonchul
W
Lee
Ahmed H
AH
Zewail
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