Formation and decay of negative ion states up to 11 eV above the ionization energy of the nanofabrication precursor HFeCo3(CO)12 † †Electronic supplementary information (ESI) available: Experimental and computational details. See DOI: 10.1039/c7sc01927k Click here for additional data file.

Experiments were conducted in a previously described crossed electron/molecular beam instrument1. In brief, an electron beam (~110 meV resolution) is generated with a trochoidal electron monochromator and crossed with an effusive beam of HFeCo3(CO)12 supplied through a capillary tube by sublimation at 348-353 K. The electron energy is scanned by ramping the acceleration voltage of the monochromatic electron beam, and the energy scale is calibrated using the SF6 signal from SF6 at 0 eV. Negative ions formed in the interaction zone are extracted by a weak electric field and analyzed with a quadrupole mass spectrometer in perpendicular arrangement to both the electron and molecular beams. The mass spectrometer is set to allow the transmission of the fixed m/z ratio for each negative ion and the electron acceleration voltage is scanned through the relevant energy range to record the respective ion yield curves. All experiments were carried out at a target pressure of about 4x10-7 mbar.