Ion/molecule reactions of silicon tetrafluoride.

An investigation of the ion/molecule of SiF4, examined by Fourier Transform Mass Spectrometry, is reported to provide a basis for analysis of its impurities. The reactions of ions derived from SiF4 with SiF4, N2, CH4, CHCl3, H2O, and C2H4 are reported. Three types of reactions were observed: 1) adduct formation where SiF3+ is bound to a neutral molecule, 2) halide abstraction where SiF3+ removes a halide anion from a neutral molecule, and 3) charge transfer where SiF4+ charge exchanges with a neutral molecule. The charge exchange was sometimes sufficiently exothermic to cause fragmentation. Rate constants for the major reaction pathways also determined.