PII: S0301-0104(99)00319-5
Copyright © 1999 Elsevier Science B.V. All rights reserved

Picosecond laser control of bond-selective dissociation and clockwise and anticlockwise rotation of the dissociation fragments: applications to a three-dimensional model of HONO₂ in the ground electronic state

M. Oppel and G. K. Paramonov¹

Institut für Chemie, Physikalische und Theoretische Chemie, Freie Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany

Received 31 May 1999. Available online 6 January 2000.

Abstract

Quantum dynamical simulations within the Schrödinger wave-function formalism have been performed for a three-dimensional (3-D) model of HONO₂ in the ground electronic state excited by linearly polarized shaped infrared (IR) laser pulses of picosecond (ps) and subpicosecond duration. The OH and the ON single bond stretches are explicitly treated together with the bending angle between them on the basis of the respective, ab initio defined, 3-D potential-energy surface and dipole function. Selective breaking of the ON single bond by optimally shaped IR laser pulses with more than 97% probability is demonstrated. Selective preparation of the clockwise and anticlockwise rotating OH fragments after the breakage of the ON single bond in HONO₂ by optimally designed subpicosecond IR laser pulses is demonstrated as well, with the respective branching ratio ranging from about 2.35 to 7.04. It is also demonstrated that optimally designed strong and short IR laser pulses can compete against intramolecular vibrational-enegry redistribution (IVR) and prepare a desirable molecular state.

¹On leave from National Academy of Sciences of Belarus, Institute of Physics, Skaryna ave. 70, 220602 Minsk, Republic of Belarus.