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

Quantum dynamical simulations within the Schrodinger wave-function formalis m have been performed for a three-dimensional (3-D) model of HONO2 in the g round electronic state excited by linearly polarized shaped infrared (IR) l aser pulses of picosecond (ps) and subpicosecond duration. The OH and the O N single bond stretches are explicitly treated together with the bending an gle between them on the basis of the respective, ab initio defined, 3-D pot ential-energy surface and dipole function. Selective breaking of the ON sin gle 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, w ith the respective branching ratio ranging from about 2.35 to 7.04. It is a lso demonstrated that optimally designed strong and short IR laser pulses c an compete against intramolecular vibrational-enegry redistribution (IVR) a nd prepare a desirable molecular state. (C) 1999 Elsevier Science B.V. All rights reserved.