High-Resolution Electron Spectroscopy of Gas-Phase Metal-Aromatic Complexes

High-resolution electron spectroscopy combines pulsed ionization zero-electron kinetic energy (ZEKE) detection with in situ laser-assisted synthesis and supersonic expansion. The technique offers sub-meV spectral resolution for the electron spectra of metal complexes and is a powerful tool to study their bonding and structures. This Perspective presents recent progress in single-photon ZEKE spectroscopy of metal-aromatic complexes and on the determination of the electron spin multiplicities, metal binding sites and modes, rotational conformers, and conformational changes of these critical species in organometallic chemistry.