Spectroscopy of reactive potential energy surfaces

This perspective reviews experiments in which spectroscopy rather than scattering is used to probe reactive potential energy surfaces. The application of negative ion photodetachment to the transition state spectroscopy of benchmark reactions is described, followed by a brief description of recent transition state spectroscopy experiment starting from clustered precursor anions that probe the effects of solvation on transition state spectroscopy and dynamics. Experiments on the spectroscopy of open-shell “pre-reactive” complexes are also discussed.