title: The structure of short-lived excited states of molecular complexes by time-resolved X-ray diffraction.
abstract: Experimental and computational methods for time-resolved (TR) diffraction now allow the determination of geometry changes on molecular excitation. The first results indicate significant changes in the interatomic distances and molecular shape on photo-excitation, but also a dependence of the induced changes on the molecular environment. Though the use of high-brightness synchrotron sources is essential, it limits the time resolution to the width of the synchrotron pulse which is currently 70-100 ps. The experiments discussed fall into two categories: (i) picosecond powder diffraction experiments on the molecular excitation to a singlet state, and (ii) microsecond experiments on the excited states of inorganic complexes. Both involve reversible processes for which a stroboscopic technique can be applied.
authors.affiliation: Department of Chemistry, State University of New York at Buffalo, NY 14260, USA.
authors.forename: Philip
authors.initials: P
authors.lastname: Coppens
authors.forename: Ivan I
authors.initials: II
authors.lastname: Vorontsov
authors.forename: Tim
authors.initials: T
authors.lastname: Graber
authors.forename: Milan
authors.initials: M
authors.lastname: Gembicky
authors.forename: Andrey Yu
authors.initials: AY
authors.lastname: Kovalevsky