Seminar Series

Watching Chemistry in Action: Molecular Motions in Space and Time

Speaker

Professor Peter Weber

Institute

Department of Chemistry Brown University, Providence USA

Time & Place

Wed, 01 Mar 2017 12:00:00 NZDT in

All are welcome

Abstract

Molecules can display a fascinatingly complex array of dynamical motions, giving rise to a multitude of chemical reactions and functional properties. Two new highly time-resolved methods have been developed to track molecules as they perform their intricate structural motions: a gasphase x-ray diffraction experiment uses the ultrashort x-ray pulses from SLAC’s Linac Coherent Light Source (LCLS) to record time-dependent scattering signals that can be analyzed to yield the time-dependent molecular structures, i.e. a ‘molecular movie’. And time-resolved photoionization through Rydberg states provides a structural-spectroscopic view that is complementary to the scattering picture. The methods are used to explore and illustrate different types of molecular reaction dynamics phenomena: direct dissociations along repulsive surfaces; photochemically induced electrocyclic ring opening reactions; conformeric motions in tertiary amines; charge delocalization phenomena; and coherent motions and dephasing of wavepackets in polyatomic systems.