Journal of Chemical Physics, Vol.105, No.20, 9115-9120, 1996
2-Pulse Laser Control of Bond-Selective Fragmentation
We elaborate on a two-pulse (pump-pump) laser control scheme for selective bond-breaking in molecules [Amstrup and Henriksen, J. Chem. Phys. 97, 8285 (1992)]. We show, in particular, that with this scheme one can overcome the obstacle of intramolecular vibrational relaxation. As an example, we consider an ozone molecule with isotopic substitution, that is, (OOO)-O-16-O-16-O-18. It is shown that asymmetric bond stretching can be created in simple (intense) laser fields. We predict that an alternating high selectivity between the channels O-16+(OO)-O-16-O-18 and (OO)-O-16-O-16+ O-18 can be obtained when such a non-stationary vibrating ozone molecule is photodissociated with short laser pulses (similar to 10-15 fs) with a time delay corresponding to half a vibrational period (similar to 17 fs).
Keywords:INFRARED MULTIPHOTON EXCITATION;QUANTUM-MECHANICAL CALCULATIONS;HOD PHOTODISSOCIATION DYNAMICS;SEQUENCE INDUCED CONTROL;1ST ABSORPTION-BAND;SCHRODINGER-EQUATION;ANALYTICAL POTENTIALS;TRIATOMIC-MOLECULES;COHERENT CONTROL;HARTLEY BAND