Interactions of low-energy electrons with the FEBID precursor chromium hexacarbonyl (Cr(CO)6)

Abstract

Interactions of low-energy electrons with the FEBID precursor Cr(CO)6 have been investigated in a crossed electron–molecular beam setup coupled with a double focusing mass spectrometer with reverse geometry. Dissociative electron attachment leads to the formation of a series of anions by the loss of CO ligand units. The bare chromium anion is formed by electron capture at an electron energy of about 9 eV. Metastable decays of Cr(CO)5− into Cr(CO)4−, Cr(CO)4− into Cr(CO)3− and Cr(CO)3− into Cr(CO)2− are discussed. Electron-induced dissociation at 70 eV impact energy was found to be in agreement with previous studies. A series of Cr(CO)nC+ (0 ≤ n ≤ 3) cations formed by C–O cleavage is described for the first time. The metastable decay of Cr(CO)6+ into Cr(CO)5+ and collision-induced dissociation leading to bare Cr+, are discussed. In addition, doubly charged cations were identified and the ration between doubly and singly charged fragments was determined and compared with previous studies, showing considerable differences.

Keywords

• chromium hexacarbonyl Cr(CO)6
• dissociative electron attachment
• electron ionization
• FEBID
• metastable decay