Positive ion chemistry of SiH4/GeF4 gaseous misture studied by ion trap mass spectrometry and ab initio calculations.

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 ionized GeF4, resulted unreactive toward SiH4. All the primary ions SiHn+ (n = 0–3) react instead with GeF4 so to form SiF+ or SiH2F+. The latter species reacts in turn with SiH4 and GeF4 so 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.