title: Photoelectron-photoion momentum spectroscopy as a clock for chemical rearrangements: isomerization of the di-cation of acetylene to the vinylidene configuration.
abstract: We have used complete correlated momentum mapping of the photoelectron and heavy ion products from the dissociation of the di-cation of acetylene, induced by photoionizing the carbon K shell of one of the atoms, to map out the angular correlation between the electron and the axis of the target molecule. The (quasi-) symmetric decay is found to proceed through both acetylene and vinylidene configurations. By using the strongly peaked photoelectron emission to "start a clock," an upper limit of 60 fs is placed on the isomerization time from the acetylene to the vinylidene configuration.
authors.affiliation: J. R. Macdonald Laboratory, Physics Department, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: T
authors.initials: T
authors.lastname: Osipov
authors.forename: C L
authors.initials: CL
authors.lastname: Cocke
authors.forename: M H
authors.initials: MH
authors.lastname: Prior
authors.forename: A
authors.initials: A
authors.lastname: Landers
authors.forename: Th
authors.initials: T
authors.lastname: Weber
authors.forename: O
authors.initials: O
authors.lastname: Jagutzki
authors.forename: L
authors.initials: L
authors.lastname: Schmidt
authors.forename: H
authors.initials: H
authors.lastname: Schmidt-Böcking
authors.forename: R
authors.initials: R
authors.lastname: Dörner