Speaker: Tomas Baer (Chemistry Department, University of North
Carolina, USA)
Title: Photoelectron photoion coincidence studies with electron
velocity focusing. The road to ± 0.1 kJ/mol thermochemistry
Time: Today, May 4, 10.15 to 11.00
Place: Fysisk Auditorium
Abstract:
Threshold photoelectron photoion coincidence (TPEPICO) is used to energy
select reactant ions in order to study the dissociation dynamics (rates,
branching ratios to various products, product energy distributions) of
polyatomic ions. Analysis of the ion time of flight distributions and
breakdown diagrams using the statistical theory of unimolecular
dissociation permits modeling multiple parallel and sequential
dissociation steps, and thus permits extracting quantitative onset
energies for higher energy dissociation channels. A recent
implementation
of this experiment at the Swiss Light Source (SLS) has improved the
electron resolution to ± 1 meV, which will lead to 0.1 kJ/mol
thermochemistry. Among the molecules investigated at the SLS are the
sequential dissociation of MCl4+ to M+ + 4Cl, (M = Sn and Ge). The
heat of
formation of the neutral MCl4 can be determined by using the final
products as an energy anchor.
Peter Staanum and Nicolai Nygaard
Coffee, tea and rundstykker will be served at 10.05.
N.B. There is also an AMO seminar Thursday this week by Guido Pupillo.
