Molecular rearrangements in intense laser fields

Abstract

Irradiation of molecules by strong optical fields readily leads to rupture of one or more molecular bonds. Such rupture is a consequence of field-induced multiple electron ejection from the molecule, leaving behind two or more ionic cores that experience strong Coulombic repulsion. The resulting Coulomb explosion occurs on ultrafast time scales. It now appears to be the case that bond formation processes can also occur on similar, ultrafast time scales. Ultrafast intramolecular rearrangements leading to bond formation upon intense field irradiation of a series of linear alcohols has been experimentally observed. The rearrangement process gives rise to an unusual ionic fragment, the hydrogen molecular ion, which is formed with substantial amount of kinetic energy. Results of polarization dependence measurements confirm that such rearrangement, leading to bond formation, occurs within the duration of a 100 fs-long laser pulse and that the unimolecular process is coaxed by the strong optical field. © 2008 Springer-Verlag.