The role of molecular orientation and light polarization on the control of bond dissociation. Time-dependent simulations for CH2BrCl

Abstract

The role of orientation on the bond selective dissociation of CH2BrCl into CH2Br + Cl or CH2Cl + Br has been investigated employing two-dimensional time-dependent wave packet propagations. Both channels are reactive when CH2BrCl is photoexcited to the lowest excited singlet states of A′ symmetry, which are nonadiabatically coupled. The branching ratio between both channels can be controlled using a driving few-cycle IR laser pulse followed by a control UV pulse. It is shown that the molecular orientation has a very important effect on the branching ratio. If the constraint of orientation is lifted and the system is only aligned, control is possible when using perpendicularly polarized IR and UV pulses.