Positive Ion Chemistry of SiH4/GeF4 Gaseous Mixtures Studied by Ion Trap Mass Spectrometry and Ab Initio Calculations

Abstract

The positive ion chemistry occurring in SiH4/GeF4 gaseous mixtures was investigated by ion trap mass spectrometry and ab initio theoretical calculations. The GeF3+ cation, the only fragment obtained from ionised GeF4, was unreactive towards SiH4. All the primary ions SiH n+ ( n = 0–3) react instead with GeF4 to form SiF+ or SiH2F+. The latter species reacts in turn with SiH4 and GeF4 to form SiH3+ and SiHF2+, respectively. The potential energy profiles conceivably involved in these reactions were investigated by ab initio calculations performed at the MP2 and coupled cluster [CCSD(T)] level of theory.