Photoelectron Imaging Spectroscopy of AuC₃H^– Anions: Four Isomers

Laser ablation generated AuC₃H^– anions were skimmed into a time-of-flight mass spectrometer (TOF-MS) and selected with a mass gate. Photoelectron spectra of AuC₃H^– were recorded using the velocity map imaging technique at several photon energies. The experimental spectra, quantum chemistry calculations, and Franck–Condon simulations suggest that the AuC₃H^– cluster has four structure isomers, including one unexpected structure of [CCC–Au–H]⁻. When AuC₃H^– is compared with C₃H₂^–, introduction of gold into the hydrocarbon system results in the much lower isomerization barriers