Dissociative electron attachment to c-C₄F₈ molecules and clusters

The electron attachment and dissociative electron attachment to gas phase octafluorocyclobutane (c-C4F8) and to its clusters have been measured. The majority of the gas phase products were already reported earlier and have been successfully confirmed in this work. In addition, two new fragments c-C4F7- and C2F5- have been detected at electron energies similar to 3.6 eV and 3.1 eV respectively. The parent molecular ion c-C4F8 - has been detected not only at the expected similar to 0 eV energy, but also with a weak resonance at similar to 0.66 eV as well. Contrary to gas phase measurements, the electron attachment to c-C4F8 molecular clusters has been measured for the first time. The dominant ionic products at electron energies similar to 0 eV are the monomer, dimer and trimer of ((c-C4F8) (n=0,1,2)center dot c-C4F8)(-), ((c-C4F8) (n=0,1,2)center dot c-C4F7)(-) and ((c-C4F8) (n=0,1,2)center dot F)(-). The higher energy resonances at similar to 4 eV have been associated with the metastable c-C4F8- ion as well as with possible electron scavenging processes in clusters. Finally, above 8 eV the core-excited electron attachment has been observed.