Anion-yield spectroscopy using x rays is shown to be a selective probe of molecular core-level processes, providing unique experimental verification of shape resonances. For CO, partial anion and cation yields are presented for photon energies near the C K edge. The O- yield exhibits features above threshold related only to doubly excited states, in contrast to cation yields which also exhibit pronounced structure due to the well-known σ* shape resonance. Because the shape resonance is completely suppressed for O-, anion spectroscopy thus constitutes a highly selective probe, yielding information unobtainable with absorption or electron spectroscopy.
Atomic, Molecular and Optical Physics | Physical Chemistry
Copyright American Physical Society. Used with permission.
Stolte, W. C.,
Hansen, D. L.,
Piancastelli, M. N.,
Schlachter, A. S.,
Lubell, M. S.,
Lindle, D. W.
Anionic Photofragmentation of CO: A Selective Probe of Core-Level Resonances.
Physical review letters, 86(20),