A probe of the Cl¿H2 van der Waals well and spin–orbit excited states

Photoelectron ~PE! spectra of ClH2 2 and ClD2 2 were measured at 299 nm ~4.154 eV!. Photodetachment of these anions accesses the prereactive van der Waals well on the ground state Cl1H2 potential energy surface, as well as the low-lying spin–orbit excited states resulting from the interaction of Cl and Cl* with H2 . The PE spectra are dominated by two relatively narrow peaks corresponding to transitions to the neutral Cl•H2 and Cl*•H2 complexes. The energetics and widths of these features are interpreted in terms of the properties of the anion and neutral potential energy surfaces. © 2002 American Institute of Physics. @DOI: 10.1063/1.1518998#