title: Nuclear flux densities during a model pericyclic reaction with energies well above and below the potential barrier.
abstract: Pericyclic reactions with energies E well above the potential energy barrier B (case E>B) proceed with quantum nuclear flux densities 〈j〉 which are essentially proportional to the nuclear densities ρ in the femtosecond time domain. This corresponds to the definition of classical (cl) mechanics, j(cl)=υ(cl) ρ(cl), with almost constant velocity v(cl). For the other case E<B, however, that is, in the domain of coherent tunneling, we discover the opposite trend, that is, 〈j〉 has maximum value close to the barrier where ρ is a minimum (in fact where ρ is close to zero). The general conclusion is that quantum mechanical nuclear flux densities may be at variance from traditional expectations based on classical trajectories. This prediction calls for experimental demonstration. The counter-intuitive proof-of-principle is demonstrated for a simple, one-dimensional model of the Cope rearrangement of semibullvalene.
authors: Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin (Germany). bredt@chemie.fu-berlin.de.
authors: Timm
authors: T
authors: Bredtmann
authors: Hirohiko
authors: H
authors: Kono
authors: Jörn
authors: J
authors: Manz
authors: Kosuke
authors: K
authors: Nakamura
authors: Christian
authors: C
authors: Stemmle