Competitive local laser control of photodissociation reaction HCo(CO)(4)->HCo(CO)(3)+CO in electronic ground state

The performance of locally generated driving fields in the case of strong m ode competition in two-dimensional models of the title reaction is investig ated. The simulations are based on an all-Cartesian reaction surface Hamilt onian derived from ab initio quantum chemistry data. Here the one-dimension al reaction coordinate is defined by the Co-CO distance and motions of the HCo(CO)(3) fragment are described in the harmonic approximation. The influe nce of two substrate normal modes is investigated in detail. First, we cons ider the high-frequency H-Co stretching vibration, whose presence is shown to give no problem for driving the reaction coordinate. Second, we focus on a low-frequency umbrella-type mode involving the equatorial carbonyls. Thi s mode provides a challenge to the method because of resonance and dipole g radient effects.