Monitoring laser driven hydrogen atom motion by transient infrared spectroscopy

Laser control of a hydrogen transfer reaction in a small model system embed ded in a condensed phase environment is investigated. The two-dimensional m odel comprises those features of the multi-dimensional potential energy sur face of thioacetylacetone which are most relevant for the isomerization rea ction from the enol to the enethiol configuration. The influence of the rem aining intramolecular coordinates as well as of a possible environment is d escribed by a spectral density within the reduced density matrix approach. Different forms of the driving infrared laser pulse are explored placing em phasis on their capability for competing successfully with relaxation proce sses. The reaction dynamics is characterized by calculating the nonlinear o ptical response nonperturbatively in the driving held. (C) 2000 Elsevier Sc ience B.V. All rights reserved.