Steric Control of Complex Chemical Reactions - II

The aim of this project is to understand and ultimately to stereo-control the reactive outcome of complex systems by vibrational excitations of reactants. The most exciting result during this period is the paper published in Nature Chemistry 4, 636-641 2012. In that work, we reported the complete three-dimensional characterization of the sterics of a benchmark polyatomic reaction by measuring the dependence of the product state-resolved angular distributions on the spatial alignment of the reactive bond in a crossed molecular beam experiment. This is for the first time that a true three-dimensional view of the steric effects has been realized experimentally for any chemical reaction in the half century history of chemical dynamics. The results prove the existence of two distinct microscopic reaction mechanisms in the reaction of Cl CHD3v11 8594 HClv0, 1 CD300. Detailed analysis further reveals the origin of the stereodynamics in the HClv0 CD300 product channel can be captured by a textbook line-of-centres model. In contrast, a time-delay pathway, most likely mediated by reactive resonances, appears to be operative in forming the excited HClv1 CD300 product pair. The work received immediate attention upon publication, as highlighted by Science Editors Choice under the title Angle of Attack, in Science 337, 779 2012.